linux/drivers/i3c/master.c

4051 lines
105 KiB

i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: master: Reconcile dynamic addresses after DAA After Dynamic Address Assignment (DAA), there may be cases where devices have been assigned dynamic addresses on the bus, but are not successfully registered in the device model. This can happen, for example, if errors occur during device addition, leaving the bus state and software state inconsistent. Introduce a reconciliation step to resolve such inconsistencies. Scan all address slots marked as I3C devices by the bus, and compare them against the set of devices currently registered. For any dynamic address that is marked occupied but has no corresponding i3c_dev_desc, probe for device presence using a GETSTATUS CCC. Retry the probe (with exponential backoff delay) to handle transient NACK conditions. If a device responds, register it via i3c_master_add_i3c_dev_locked(). Otherwise, free the address slot so it may be reused in future DAA operations. Note, i3c_master_add_i3c_dev_locked() may fail (again), in which case the dynamic address remains marked as occupied. A future DAA will try again. This also handles a corner case where a device is assigned a dynamic address but not successfully added, and subsequently loses that address (e.g. due to power management). If DAA is run again, the device may receive a new dynamic address while the old one remains marked as occupied. Repeated occurrences of this scenario could eventually exhaust the dynamic address space. The reconciliation step ensures that stale addresses are detected and freed, preventing address leakage. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Reviewed-by: Frank Li <Frank.Li@nxp.com> Link: https://patch.msgid.link/20260612080107.11606-8-adrian.hunter@intel.com Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2026-06-12 11:01:07 +03:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: master: Reconcile dynamic addresses after DAA After Dynamic Address Assignment (DAA), there may be cases where devices have been assigned dynamic addresses on the bus, but are not successfully registered in the device model. This can happen, for example, if errors occur during device addition, leaving the bus state and software state inconsistent. Introduce a reconciliation step to resolve such inconsistencies. Scan all address slots marked as I3C devices by the bus, and compare them against the set of devices currently registered. For any dynamic address that is marked occupied but has no corresponding i3c_dev_desc, probe for device presence using a GETSTATUS CCC. Retry the probe (with exponential backoff delay) to handle transient NACK conditions. If a device responds, register it via i3c_master_add_i3c_dev_locked(). Otherwise, free the address slot so it may be reused in future DAA operations. Note, i3c_master_add_i3c_dev_locked() may fail (again), in which case the dynamic address remains marked as occupied. A future DAA will try again. This also handles a corner case where a device is assigned a dynamic address but not successfully added, and subsequently loses that address (e.g. due to power management). If DAA is run again, the device may receive a new dynamic address while the old one remains marked as occupied. Repeated occurrences of this scenario could eventually exhaust the dynamic address space. The reconciliation step ensures that stale addresses are detected and freed, preventing address leakage. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Reviewed-by: Frank Li <Frank.Li@nxp.com> Link: https://patch.msgid.link/20260612080107.11606-8-adrian.hunter@intel.com Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2026-06-12 11:01:07 +03:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
driver core: make struct device_type.uevent() take a const * The uevent() callback in struct device_type should not be modifying the device that is passed into it, so mark it as a const * and propagate the function signature changes out into all relevant subsystems that use this callback. Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Andreas Noever <andreas.noever@gmail.com> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Bard Liao <yung-chuan.liao@linux.intel.com> Cc: Chaitanya Kulkarni <kch@nvidia.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: Frank Rowand <frowand.list@gmail.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jens Axboe <axboe@kernel.dk> Cc: Jilin Yuan <yuanjilin@cdjrlc.com> Cc: Jiri Slaby <jirislaby@kernel.org> Cc: Len Brown <lenb@kernel.org> Cc: Mark Gross <markgross@kernel.org> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org> Cc: Maximilian Luz <luzmaximilian@gmail.com> Cc: Michael Jamet <michael.jamet@intel.com> Cc: Ming Lei <ming.lei@redhat.com> Cc: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> Cc: Rob Herring <robh+dt@kernel.org> Cc: Sakari Ailus <sakari.ailus@linux.intel.com> Cc: Sanyog Kale <sanyog.r.kale@intel.com> Cc: Sean Young <sean@mess.org> Cc: Stefan Richter <stefanr@s5r6.in-berlin.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Won Chung <wonchung@google.com> Cc: Yehezkel Bernat <YehezkelShB@gmail.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com> # for Thunderbolt Acked-by: Mauro Carvalho Chehab <mchehab@kernel.org> Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Acked-by: Wolfram Sang <wsa@kernel.org> Acked-by: Vinod Koul <vkoul@kernel.org> Acked-by: Hans de Goede <hdegoede@redhat.com> Link: https://lore.kernel.org/r/20230111113018.459199-6-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-11 12:30:07 +01:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
driver core: make struct device_type.uevent() take a const * The uevent() callback in struct device_type should not be modifying the device that is passed into it, so mark it as a const * and propagate the function signature changes out into all relevant subsystems that use this callback. Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Andreas Noever <andreas.noever@gmail.com> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Bard Liao <yung-chuan.liao@linux.intel.com> Cc: Chaitanya Kulkarni <kch@nvidia.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com> Cc: Frank Rowand <frowand.list@gmail.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jens Axboe <axboe@kernel.dk> Cc: Jilin Yuan <yuanjilin@cdjrlc.com> Cc: Jiri Slaby <jirislaby@kernel.org> Cc: Len Brown <lenb@kernel.org> Cc: Mark Gross <markgross@kernel.org> Cc: "Martin K. Petersen" <martin.petersen@oracle.com> Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org> Cc: Maximilian Luz <luzmaximilian@gmail.com> Cc: Michael Jamet <michael.jamet@intel.com> Cc: Ming Lei <ming.lei@redhat.com> Cc: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com> Cc: Rob Herring <robh+dt@kernel.org> Cc: Sakari Ailus <sakari.ailus@linux.intel.com> Cc: Sanyog Kale <sanyog.r.kale@intel.com> Cc: Sean Young <sean@mess.org> Cc: Stefan Richter <stefanr@s5r6.in-berlin.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Won Chung <wonchung@google.com> Cc: Yehezkel Bernat <YehezkelShB@gmail.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com> # for Thunderbolt Acked-by: Mauro Carvalho Chehab <mchehab@kernel.org> Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Acked-by: Wolfram Sang <wsa@kernel.org> Acked-by: Vinod Koul <vkoul@kernel.org> Acked-by: Hans de Goede <hdegoede@redhat.com> Link: https://lore.kernel.org/r/20230111113018.459199-6-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-11 12:30:07 +01:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
2026-08-07 17:56:30 +03:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
bus: Make remove callback return void The driver core ignores the return value of this callback because there is only little it can do when a device disappears. This is the final bit of a long lasting cleanup quest where several buses were converted to also return void from their remove callback. Additionally some resource leaks were fixed that were caused by drivers returning an error code in the expectation that the driver won't go away. With struct bus_type::remove returning void it's prevented that newly implemented buses return an ignored error code and so don't anticipate wrong expectations for driver authors. Reviewed-by: Tom Rix <trix@redhat.com> (For fpga) Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org> Reviewed-by: Cornelia Huck <cohuck@redhat.com> (For drivers/s390 and drivers/vfio) Acked-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> (For ARM, Amba and related parts) Acked-by: Mark Brown <broonie@kernel.org> Acked-by: Chen-Yu Tsai <wens@csie.org> (for sunxi-rsb) Acked-by: Pali Rohár <pali@kernel.org> Acked-by: Mauro Carvalho Chehab <mchehab@kernel.org> (for media) Acked-by: Hans de Goede <hdegoede@redhat.com> (For drivers/platform) Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Acked-By: Vinod Koul <vkoul@kernel.org> Acked-by: Juergen Gross <jgross@suse.com> (For xen) Acked-by: Lee Jones <lee.jones@linaro.org> (For mfd) Acked-by: Johannes Thumshirn <jth@kernel.org> (For mcb) Acked-by: Johan Hovold <johan@kernel.org> Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> (For slimbus) Acked-by: Kirti Wankhede <kwankhede@nvidia.com> (For vfio) Acked-by: Maximilian Luz <luzmaximilian@gmail.com> Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> (For ulpi and typec) Acked-by: Samuel Iglesias Gonsálvez <siglesias@igalia.com> (For ipack) Acked-by: Geoff Levand <geoff@infradead.org> (For ps3) Acked-by: Yehezkel Bernat <YehezkelShB@gmail.com> (For thunderbolt) Acked-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> (For intel_th) Acked-by: Dominik Brodowski <linux@dominikbrodowski.net> (For pcmcia) Acked-by: Rafael J. Wysocki <rafael@kernel.org> (For ACPI) Acked-by: Bjorn Andersson <bjorn.andersson@linaro.org> (rpmsg and apr) Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> (For intel-ish-hid) Acked-by: Dan Williams <dan.j.williams@intel.com> (For CXL, DAX, and NVDIMM) Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com> (For isa) Acked-by: Stefan Richter <stefanr@s5r6.in-berlin.de> (For firewire) Acked-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> (For hid) Acked-by: Thorsten Scherer <t.scherer@eckelmann.de> (For siox) Acked-by: Sven Van Asbroeck <TheSven73@gmail.com> (For anybuss) Acked-by: Ulf Hansson <ulf.hansson@linaro.org> (For MMC) Acked-by: Wolfram Sang <wsa@kernel.org> # for I2C Acked-by: Sudeep Holla <sudeep.holla@arm.com> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Acked-by: Finn Thain <fthain@linux-m68k.org> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Link: https://lore.kernel.org/r/20210713193522.1770306-6-u.kleine-koenig@pengutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-07-13 21:35:22 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: master: Extend address status bit to 4 and add I3C_ADDR_SLOT_EXT_DESIRED Extend the address status bit to 4 and introduce the I3C_ADDR_SLOT_EXT_DESIRED macro to indicate that a device prefers a specific address. This is generally set by the 'assigned-address' in the device tree source (dts) file. ┌────┬─────────────┬───┬─────────┬───┐ │S/Sr│ 7'h7E RnW=0 │ACK│ ENTDAA │ T ├────┐ └────┴─────────────┴───┴─────────┴───┘ │ ┌─────────────────────────────────────────┘ │ ┌──┬─────────────┬───┬─────────────────┬────────────────┬───┬─────────┐ └─►│Sr│7'h7E RnW=1 │ACK│48bit UID BCR DCR│Assign 7bit Addr│PAR│ ACK/NACK│ └──┴─────────────┴───┴─────────────────┴────────────────┴───┴─────────┘ Some master controllers (such as HCI) need to prepare the entire above transaction before sending it out to the I3C bus. This means that a 7-bit dynamic address needs to be allocated before knowing the target device's UID information. However, some I3C targets may request specific addresses (called as "init_dyn_addr"), which is typically specified by the DT-'s assigned-address property. Lower addresses having higher IBI priority. If it is available, i3c_bus_get_free_addr() preferably return a free address that is not in the list of desired addresses (called as "init_dyn_addr"). This allows the device with the "init_dyn_addr" to switch to its "init_dyn_addr" when it hot-joins the I3C bus. Otherwise, if the "init_dyn_addr" is already in use by another I3C device, the target device will not be able to switch to its desired address. If the previous step fails, fallback returning one of the remaining unassigned address, regardless of its state in the desired list. Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com> Signed-off-by: Frank Li <Frank.Li@nxp.com> Link: https://lore.kernel.org/r/20241021-i3c_dts_assign-v8-2-4098b8bde01e@nxp.com Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2024-10-21 11:45:07 -04:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: master: Extend address status bit to 4 and add I3C_ADDR_SLOT_EXT_DESIRED Extend the address status bit to 4 and introduce the I3C_ADDR_SLOT_EXT_DESIRED macro to indicate that a device prefers a specific address. This is generally set by the 'assigned-address' in the device tree source (dts) file. ┌────┬─────────────┬───┬─────────┬───┐ │S/Sr│ 7'h7E RnW=0 │ACK│ ENTDAA │ T ├────┐ └────┴─────────────┴───┴─────────┴───┘ │ ┌─────────────────────────────────────────┘ │ ┌──┬─────────────┬───┬─────────────────┬────────────────┬───┬─────────┐ └─►│Sr│7'h7E RnW=1 │ACK│48bit UID BCR DCR│Assign 7bit Addr│PAR│ ACK/NACK│ └──┴─────────────┴───┴─────────────────┴────────────────┴───┴─────────┘ Some master controllers (such as HCI) need to prepare the entire above transaction before sending it out to the I3C bus. This means that a 7-bit dynamic address needs to be allocated before knowing the target device's UID information. However, some I3C targets may request specific addresses (called as "init_dyn_addr"), which is typically specified by the DT-'s assigned-address property. Lower addresses having higher IBI priority. If it is available, i3c_bus_get_free_addr() preferably return a free address that is not in the list of desired addresses (called as "init_dyn_addr"). This allows the device with the "init_dyn_addr" to switch to its "init_dyn_addr" when it hot-joins the I3C bus. Otherwise, if the "init_dyn_addr" is already in use by another I3C device, the target device will not be able to switch to its desired address. If the previous step fails, fallback returning one of the remaining unassigned address, regardless of its state in the desired list. Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com> Signed-off-by: Frank Li <Frank.Li@nxp.com> Link: https://lore.kernel.org/r/20241021-i3c_dts_assign-v8-2-4098b8bde01e@nxp.com Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2024-10-21 11:45:07 -04:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: master: Extend address status bit to 4 and add I3C_ADDR_SLOT_EXT_DESIRED Extend the address status bit to 4 and introduce the I3C_ADDR_SLOT_EXT_DESIRED macro to indicate that a device prefers a specific address. This is generally set by the 'assigned-address' in the device tree source (dts) file. ┌────┬─────────────┬───┬─────────┬───┐ │S/Sr│ 7'h7E RnW=0 │ACK│ ENTDAA │ T ├────┐ └────┴─────────────┴───┴─────────┴───┘ │ ┌─────────────────────────────────────────┘ │ ┌──┬─────────────┬───┬─────────────────┬────────────────┬───┬─────────┐ └─►│Sr│7'h7E RnW=1 │ACK│48bit UID BCR DCR│Assign 7bit Addr│PAR│ ACK/NACK│ └──┴─────────────┴───┴─────────────────┴────────────────┴───┴─────────┘ Some master controllers (such as HCI) need to prepare the entire above transaction before sending it out to the I3C bus. This means that a 7-bit dynamic address needs to be allocated before knowing the target device's UID information. However, some I3C targets may request specific addresses (called as "init_dyn_addr"), which is typically specified by the DT-'s assigned-address property. Lower addresses having higher IBI priority. If it is available, i3c_bus_get_free_addr() preferably return a free address that is not in the list of desired addresses (called as "init_dyn_addr"). This allows the device with the "init_dyn_addr" to switch to its "init_dyn_addr" when it hot-joins the I3C bus. Otherwise, if the "init_dyn_addr" is already in use by another I3C device, the target device will not be able to switch to its desired address. If the previous step fails, fallback returning one of the remaining unassigned address, regardless of its state in the desired list. Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com> Signed-off-by: Frank Li <Frank.Li@nxp.com> Link: https://lore.kernel.org/r/20241021-i3c_dts_assign-v8-2-4098b8bde01e@nxp.com Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2024-10-21 11:45:07 -04:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: master: Extend address status bit to 4 and add I3C_ADDR_SLOT_EXT_DESIRED Extend the address status bit to 4 and introduce the I3C_ADDR_SLOT_EXT_DESIRED macro to indicate that a device prefers a specific address. This is generally set by the 'assigned-address' in the device tree source (dts) file. ┌────┬─────────────┬───┬─────────┬───┐ │S/Sr│ 7'h7E RnW=0 │ACK│ ENTDAA │ T ├────┐ └────┴─────────────┴───┴─────────┴───┘ │ ┌─────────────────────────────────────────┘ │ ┌──┬─────────────┬───┬─────────────────┬────────────────┬───┬─────────┐ └─►│Sr│7'h7E RnW=1 │ACK│48bit UID BCR DCR│Assign 7bit Addr│PAR│ ACK/NACK│ └──┴─────────────┴───┴─────────────────┴────────────────┴───┴─────────┘ Some master controllers (such as HCI) need to prepare the entire above transaction before sending it out to the I3C bus. This means that a 7-bit dynamic address needs to be allocated before knowing the target device's UID information. However, some I3C targets may request specific addresses (called as "init_dyn_addr"), which is typically specified by the DT-'s assigned-address property. Lower addresses having higher IBI priority. If it is available, i3c_bus_get_free_addr() preferably return a free address that is not in the list of desired addresses (called as "init_dyn_addr"). This allows the device with the "init_dyn_addr" to switch to its "init_dyn_addr" when it hot-joins the I3C bus. Otherwise, if the "init_dyn_addr" is already in use by another I3C device, the target device will not be able to switch to its desired address. If the previous step fails, fallback returning one of the remaining unassigned address, regardless of its state in the desired list. Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com> Signed-off-by: Frank Li <Frank.Li@nxp.com> Link: https://lore.kernel.org/r/20241021-i3c_dts_assign-v8-2-4098b8bde01e@nxp.com Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2024-10-21 11:45:07 -04:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: master: Extend address status bit to 4 and add I3C_ADDR_SLOT_EXT_DESIRED Extend the address status bit to 4 and introduce the I3C_ADDR_SLOT_EXT_DESIRED macro to indicate that a device prefers a specific address. This is generally set by the 'assigned-address' in the device tree source (dts) file. ┌────┬─────────────┬───┬─────────┬───┐ │S/Sr│ 7'h7E RnW=0 │ACK│ ENTDAA │ T ├────┐ └────┴─────────────┴───┴─────────┴───┘ │ ┌─────────────────────────────────────────┘ │ ┌──┬─────────────┬───┬─────────────────┬────────────────┬───┬─────────┐ └─►│Sr│7'h7E RnW=1 │ACK│48bit UID BCR DCR│Assign 7bit Addr│PAR│ ACK/NACK│ └──┴─────────────┴───┴─────────────────┴────────────────┴───┴─────────┘ Some master controllers (such as HCI) need to prepare the entire above transaction before sending it out to the I3C bus. This means that a 7-bit dynamic address needs to be allocated before knowing the target device's UID information. However, some I3C targets may request specific addresses (called as "init_dyn_addr"), which is typically specified by the DT-'s assigned-address property. Lower addresses having higher IBI priority. If it is available, i3c_bus_get_free_addr() preferably return a free address that is not in the list of desired addresses (called as "init_dyn_addr"). This allows the device with the "init_dyn_addr" to switch to its "init_dyn_addr" when it hot-joins the I3C bus. Otherwise, if the "init_dyn_addr" is already in use by another I3C device, the target device will not be able to switch to its desired address. If the previous step fails, fallback returning one of the remaining unassigned address, regardless of its state in the desired list. Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com> Signed-off-by: Frank Li <Frank.Li@nxp.com> Link: https://lore.kernel.org/r/20241021-i3c_dts_assign-v8-2-4098b8bde01e@nxp.com Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2024-10-21 11:45:07 -04:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: master: Extend address status bit to 4 and add I3C_ADDR_SLOT_EXT_DESIRED Extend the address status bit to 4 and introduce the I3C_ADDR_SLOT_EXT_DESIRED macro to indicate that a device prefers a specific address. This is generally set by the 'assigned-address' in the device tree source (dts) file. ┌────┬─────────────┬───┬─────────┬───┐ │S/Sr│ 7'h7E RnW=0 │ACK│ ENTDAA │ T ├────┐ └────┴─────────────┴───┴─────────┴───┘ │ ┌─────────────────────────────────────────┘ │ ┌──┬─────────────┬───┬─────────────────┬────────────────┬───┬─────────┐ └─►│Sr│7'h7E RnW=1 │ACK│48bit UID BCR DCR│Assign 7bit Addr│PAR│ ACK/NACK│ └──┴─────────────┴───┴─────────────────┴────────────────┴───┴─────────┘ Some master controllers (such as HCI) need to prepare the entire above transaction before sending it out to the I3C bus. This means that a 7-bit dynamic address needs to be allocated before knowing the target device's UID information. However, some I3C targets may request specific addresses (called as "init_dyn_addr"), which is typically specified by the DT-'s assigned-address property. Lower addresses having higher IBI priority. If it is available, i3c_bus_get_free_addr() preferably return a free address that is not in the list of desired addresses (called as "init_dyn_addr"). This allows the device with the "init_dyn_addr" to switch to its "init_dyn_addr" when it hot-joins the I3C bus. Otherwise, if the "init_dyn_addr" is already in use by another I3C device, the target device will not be able to switch to its desired address. If the previous step fails, fallback returning one of the remaining unassigned address, regardless of its state in the desired list. Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com> Signed-off-by: Frank Li <Frank.Li@nxp.com> Link: https://lore.kernel.org/r/20241021-i3c_dts_assign-v8-2-4098b8bde01e@nxp.com Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2024-10-21 11:45:07 -04:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: master: Consolidate Hot-Join DAA work in the core Three master drivers (dw-i3c-master, i3c-master-cdns, svc-i3c-master) each carry an essentially identical Hot-Join handler: a struct work_struct embedded in their private state, a work function that just calls i3c_master_do_daa() on the embedded i3c_master_controller, plus matching INIT_WORK()/cancel_work_sync() boilerplate in probe/remove (and shutdown for dw-i3c). The IBI/ISR paths then queue that work onto master->wq, which already lives in the core. Move this pattern into the I3C core: - Add struct work_struct hj_work to struct i3c_master_controller and initialise it in i3c_master_register() with a core-provided handler i3c_master_hj_work_fn() that performs i3c_master_do_daa(). - Cancel the work in i3c_master_unregister() so all controllers get correct teardown ordering against the workqueue for free. - Export i3c_master_queue_hotjoin() as the single entry point drivers call from their Hot-Join IBI handler. Convert the three existing users to the new API: drop their private hj_work fields, work functions, INIT_WORK() and cancel_work_sync() calls, and replace the queue_work(master->wq, &drv->hj_work) call sites with i3c_master_queue_hotjoin(&drv->base). The dw-i3c shutdown path still needs to flush pending Hot-Join work before tearing down the hardware, so it is updated to cancel master->base.hj_work directly. No functional change intended: the work is still queued on the same master->wq, runs the same i3c_master_do_daa(), and is cancelled at controller teardown. Future Hot-Join improvements now only need to be made in one place. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Reviewed-by: Frank Li <Frank.Li@nxp.com> Link: https://patch.msgid.link/20260608054312.10604-4-adrian.hunter@intel.com Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2026-06-08 08:43:07 +03:00
i3c: master: Ensure Hot-Join operations are stopped on shutdown System shutdown invokes each device's bus shutdown callback to quiesce hardware, but the I3C bus type does not currently implement one. As a result, on shutdown the controller's Hot-Join work and any in-flight i3c_master_do_daa() can keep running (or be newly triggered) while the rest of the system is being torn down. A similar window exists at i3c_master_unregister() time: cancel_work_sync() on hj_work prevents queued work from completing, but does not stop a fresh Hot-Join IBI from re-queueing the worker, nor a concurrent sysfs writer from toggling Hot-Join via i3c_set_hotjoin(). Introduce a single "shutting down" gate in the I3C core, set under the bus maintenance lock so it is observed by any in-progress DAA path before pending work is cancelled. Install an i3c_bus_type shutdown callback that engages this gate for master devices during system shutdown, and use the same gate in i3c_master_unregister() so both paths get identical guarantees. Once the gate is engaged, the Hot-Join worker, i3c_master_do_daa_ext() and i3c_set_hotjoin() all bail out cleanly, so Hot-Join IBIs that race with shutdown become no-ops, direct DAA callers see -ENODEV, and sysfs writers can no longer re-enable Hot-Join through ops->enable_hotjoin() while the controller is going away. No functional change for the steady-state runtime path; the new checks only take effect once the controller has been marked as shutting down. Note, this patch depends on patch "i3c: master: Consolidate Hot-Join DAA work in the core". Fixes: 3a379bbcea0af ("i3c: Add core I3C infrastructure") Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Reviewed-by: Frank Li <Frank.Li@nxp.com> Link: https://patch.msgid.link/20260608054312.10604-5-adrian.hunter@intel.com Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2026-06-08 08:43:08 +03:00
i3c: master: Consolidate Hot-Join DAA work in the core Three master drivers (dw-i3c-master, i3c-master-cdns, svc-i3c-master) each carry an essentially identical Hot-Join handler: a struct work_struct embedded in their private state, a work function that just calls i3c_master_do_daa() on the embedded i3c_master_controller, plus matching INIT_WORK()/cancel_work_sync() boilerplate in probe/remove (and shutdown for dw-i3c). The IBI/ISR paths then queue that work onto master->wq, which already lives in the core. Move this pattern into the I3C core: - Add struct work_struct hj_work to struct i3c_master_controller and initialise it in i3c_master_register() with a core-provided handler i3c_master_hj_work_fn() that performs i3c_master_do_daa(). - Cancel the work in i3c_master_unregister() so all controllers get correct teardown ordering against the workqueue for free. - Export i3c_master_queue_hotjoin() as the single entry point drivers call from their Hot-Join IBI handler. Convert the three existing users to the new API: drop their private hj_work fields, work functions, INIT_WORK() and cancel_work_sync() calls, and replace the queue_work(master->wq, &drv->hj_work) call sites with i3c_master_queue_hotjoin(&drv->base). The dw-i3c shutdown path still needs to flush pending Hot-Join work before tearing down the hardware, so it is updated to cancel master->base.hj_work directly. No functional change intended: the work is still queued on the same master->wq, runs the same i3c_master_do_daa(), and is cancelled at controller teardown. Future Hot-Join improvements now only need to be made in one place. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Reviewed-by: Frank Li <Frank.Li@nxp.com> Link: https://patch.msgid.link/20260608054312.10604-4-adrian.hunter@intel.com Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2026-06-08 08:43:07 +03:00
i3c: master: Ensure Hot-Join operations are stopped on shutdown System shutdown invokes each device's bus shutdown callback to quiesce hardware, but the I3C bus type does not currently implement one. As a result, on shutdown the controller's Hot-Join work and any in-flight i3c_master_do_daa() can keep running (or be newly triggered) while the rest of the system is being torn down. A similar window exists at i3c_master_unregister() time: cancel_work_sync() on hj_work prevents queued work from completing, but does not stop a fresh Hot-Join IBI from re-queueing the worker, nor a concurrent sysfs writer from toggling Hot-Join via i3c_set_hotjoin(). Introduce a single "shutting down" gate in the I3C core, set under the bus maintenance lock so it is observed by any in-progress DAA path before pending work is cancelled. Install an i3c_bus_type shutdown callback that engages this gate for master devices during system shutdown, and use the same gate in i3c_master_unregister() so both paths get identical guarantees. Once the gate is engaged, the Hot-Join worker, i3c_master_do_daa_ext() and i3c_set_hotjoin() all bail out cleanly, so Hot-Join IBIs that race with shutdown become no-ops, direct DAA callers see -ENODEV, and sysfs writers can no longer re-enable Hot-Join through ops->enable_hotjoin() while the controller is going away. No functional change for the steady-state runtime path; the new checks only take effect once the controller has been marked as shutting down. Note, this patch depends on patch "i3c: master: Consolidate Hot-Join DAA work in the core". Fixes: 3a379bbcea0af ("i3c: Add core I3C infrastructure") Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Reviewed-by: Frank Li <Frank.Li@nxp.com> Link: https://patch.msgid.link/20260608054312.10604-5-adrian.hunter@intel.com Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2026-06-08 08:43:08 +03:00
i3c: master: Consolidate Hot-Join DAA work in the core Three master drivers (dw-i3c-master, i3c-master-cdns, svc-i3c-master) each carry an essentially identical Hot-Join handler: a struct work_struct embedded in their private state, a work function that just calls i3c_master_do_daa() on the embedded i3c_master_controller, plus matching INIT_WORK()/cancel_work_sync() boilerplate in probe/remove (and shutdown for dw-i3c). The IBI/ISR paths then queue that work onto master->wq, which already lives in the core. Move this pattern into the I3C core: - Add struct work_struct hj_work to struct i3c_master_controller and initialise it in i3c_master_register() with a core-provided handler i3c_master_hj_work_fn() that performs i3c_master_do_daa(). - Cancel the work in i3c_master_unregister() so all controllers get correct teardown ordering against the workqueue for free. - Export i3c_master_queue_hotjoin() as the single entry point drivers call from their Hot-Join IBI handler. Convert the three existing users to the new API: drop their private hj_work fields, work functions, INIT_WORK() and cancel_work_sync() calls, and replace the queue_work(master->wq, &drv->hj_work) call sites with i3c_master_queue_hotjoin(&drv->base). The dw-i3c shutdown path still needs to flush pending Hot-Join work before tearing down the hardware, so it is updated to cancel master->base.hj_work directly. No functional change intended: the work is still queued on the same master->wq, runs the same i3c_master_do_daa(), and is cancelled at controller teardown. Future Hot-Join improvements now only need to be made in one place. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Reviewed-by: Frank Li <Frank.Li@nxp.com> Link: https://patch.msgid.link/20260608054312.10604-4-adrian.hunter@intel.com Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2026-06-08 08:43:07 +03:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: master: Ensure Hot-Join operations are stopped on shutdown System shutdown invokes each device's bus shutdown callback to quiesce hardware, but the I3C bus type does not currently implement one. As a result, on shutdown the controller's Hot-Join work and any in-flight i3c_master_do_daa() can keep running (or be newly triggered) while the rest of the system is being torn down. A similar window exists at i3c_master_unregister() time: cancel_work_sync() on hj_work prevents queued work from completing, but does not stop a fresh Hot-Join IBI from re-queueing the worker, nor a concurrent sysfs writer from toggling Hot-Join via i3c_set_hotjoin(). Introduce a single "shutting down" gate in the I3C core, set under the bus maintenance lock so it is observed by any in-progress DAA path before pending work is cancelled. Install an i3c_bus_type shutdown callback that engages this gate for master devices during system shutdown, and use the same gate in i3c_master_unregister() so both paths get identical guarantees. Once the gate is engaged, the Hot-Join worker, i3c_master_do_daa_ext() and i3c_set_hotjoin() all bail out cleanly, so Hot-Join IBIs that race with shutdown become no-ops, direct DAA callers see -ENODEV, and sysfs writers can no longer re-enable Hot-Join through ops->enable_hotjoin() while the controller is going away. No functional change for the steady-state runtime path; the new checks only take effect once the controller has been marked as shutting down. Note, this patch depends on patch "i3c: master: Consolidate Hot-Join DAA work in the core". Fixes: 3a379bbcea0af ("i3c: Add core I3C infrastructure") Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Reviewed-by: Frank Li <Frank.Li@nxp.com> Link: https://patch.msgid.link/20260608054312.10604-5-adrian.hunter@intel.com Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2026-06-08 08:43:08 +03:00
i3c: master: Defer new-device registration out of DAA caller context Master drivers may invoke i3c_master_do_daa_ext() during resume to re-run Dynamic Address Assignment. As well as assigning addresses to any newly arrived devices, this restores the dynamic address of devices that lost it across system suspend, so it has to run as part of the controller's resume path. A side effect of i3c_master_do_daa_ext() today is that it also registers any newly discovered I3C devices with the driver model inline, via i3c_master_register_new_i3c_devs(). Doing that from the resume path is problematic: a hot-join-capable device may join the bus during this same DAA, and registering it immediately would push driver model work (probing, sysfs, etc.) into the controller's resume context, where the rest of the system is not yet fully resumed and the controller driver is still partway through its own resume sequence. Decouple discovery from registration: add a reg_work work item to struct i3c_master_controller and have i3c_master_do_daa_ext() queue it on master->wq (the freezable workqueue) instead of calling i3c_master_register_new_i3c_devs() directly. The worker performs the registration only when the controller is not shutting_down, and is cancelled alongside hj_work in i3c_master_shutdown(). Because wq is freezable, any newly observed devices end up being registered after the system has finished resuming. i3c_master_register() also routes its initial post-bus-init registration through reg_work, using flush_work() to keep probe-time behavior synchronous. This keeps a single registration code path and ensures the worker is the only writer of desc->dev. Fixes: 3a379bbcea0af ("i3c: Add core I3C infrastructure") Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Reviewed-by: Frank Li <Frank.Li@nxp.com> Link: https://patch.msgid.link/20260608054312.10604-7-adrian.hunter@intel.com Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2026-06-08 08:43:10 +03:00
i3c: master: Ensure Hot-Join operations are stopped on shutdown System shutdown invokes each device's bus shutdown callback to quiesce hardware, but the I3C bus type does not currently implement one. As a result, on shutdown the controller's Hot-Join work and any in-flight i3c_master_do_daa() can keep running (or be newly triggered) while the rest of the system is being torn down. A similar window exists at i3c_master_unregister() time: cancel_work_sync() on hj_work prevents queued work from completing, but does not stop a fresh Hot-Join IBI from re-queueing the worker, nor a concurrent sysfs writer from toggling Hot-Join via i3c_set_hotjoin(). Introduce a single "shutting down" gate in the I3C core, set under the bus maintenance lock so it is observed by any in-progress DAA path before pending work is cancelled. Install an i3c_bus_type shutdown callback that engages this gate for master devices during system shutdown, and use the same gate in i3c_master_unregister() so both paths get identical guarantees. Once the gate is engaged, the Hot-Join worker, i3c_master_do_daa_ext() and i3c_set_hotjoin() all bail out cleanly, so Hot-Join IBIs that race with shutdown become no-ops, direct DAA callers see -ENODEV, and sysfs writers can no longer re-enable Hot-Join through ops->enable_hotjoin() while the controller is going away. No functional change for the steady-state runtime path; the new checks only take effect once the controller has been marked as shutting down. Note, this patch depends on patch "i3c: master: Consolidate Hot-Join DAA work in the core". Fixes: 3a379bbcea0af ("i3c: Add core I3C infrastructure") Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Reviewed-by: Frank Li <Frank.Li@nxp.com> Link: https://patch.msgid.link/20260608054312.10604-5-adrian.hunter@intel.com Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2026-06-08 08:43:08 +03:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: master: Reconcile dynamic addresses after DAA After Dynamic Address Assignment (DAA), there may be cases where devices have been assigned dynamic addresses on the bus, but are not successfully registered in the device model. This can happen, for example, if errors occur during device addition, leaving the bus state and software state inconsistent. Introduce a reconciliation step to resolve such inconsistencies. Scan all address slots marked as I3C devices by the bus, and compare them against the set of devices currently registered. For any dynamic address that is marked occupied but has no corresponding i3c_dev_desc, probe for device presence using a GETSTATUS CCC. Retry the probe (with exponential backoff delay) to handle transient NACK conditions. If a device responds, register it via i3c_master_add_i3c_dev_locked(). Otherwise, free the address slot so it may be reused in future DAA operations. Note, i3c_master_add_i3c_dev_locked() may fail (again), in which case the dynamic address remains marked as occupied. A future DAA will try again. This also handles a corner case where a device is assigned a dynamic address but not successfully added, and subsequently loses that address (e.g. due to power management). If DAA is run again, the device may receive a new dynamic address while the old one remains marked as occupied. Repeated occurrences of this scenario could eventually exhaust the dynamic address space. The reconciliation step ensures that stale addresses are detected and freed, preventing address leakage. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Reviewed-by: Frank Li <Frank.Li@nxp.com> Link: https://patch.msgid.link/20260612080107.11606-8-adrian.hunter@intel.com Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2026-06-12 11:01:07 +03:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: master: Fix dynamic address leak when 'assigned-address' is present If the DTS contains 'assigned-address', a dynamic address leak occurs during hotjoin events. Assume a device have assigned-address 0xb. - Device issue Hotjoin - Call i3c_master_do_daa() - Call driver xxx_do_daa() - Call i3c_master_get_free_addr() to get dynamic address 0x9 - i3c_master_add_i3c_dev_locked(0x9) - expected_dyn_addr = newdev->boardinfo->init_dyn_addr (0xb); - i3c_master_reattach_i3c_dev(newdev(0xb), old_dyn_addr(0x9)); - if (dev->info.dyn_addr != old_dyn_addr && ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 0xb != 0x9 -> TRUE (!dev->boardinfo || ^^^^^^^^^^^^^^^ -> FALSE dev->info.dyn_addr != dev->boardinfo->init_dyn_addr)) { ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 0xb != 0xb -> FALSE ... i3c_bus_set_addr_slot_status(&master->bus, old_dyn_addr, I3C_ADDR_SLOT_FREE); ^^^ This will be skipped. So old_dyn_addr never free } - i3c_master_get_free_addr() will return increased sequence number. Remove dev->info.dyn_addr != dev->boardinfo->init_dyn_addr condition check. dev->info.dyn_addr should be checked before calling this function because i3c_master_setnewda_locked() has already been called and the target device has already accepted dyn_addr. It is too late to check if dyn_addr is free in i3c_master_reattach_i3c_dev(). Add check to ensure expected_dyn_addr is free before i3c_master_setnewda_locked(). Fixes: cc3a392d69b6 ("i3c: master: fix for SETDASA and DAA process") Cc: stable@kernel.org Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com> Signed-off-by: Frank Li <Frank.Li@nxp.com> Link: https://lore.kernel.org/r/20241021-i3c_dts_assign-v8-3-4098b8bde01e@nxp.com Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2024-10-21 11:45:08 -04:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: master: Fix recursive locking during device registration i3c_master_register_new_i3c_devs() registers newly discovered devices while holding i3c_bus_normaluse_lock(), a down_read(). device_register() can immediately probe the device, and probe callbacks typically invoke I3C helpers that take i3c_bus_normaluse_lock() again, leading to a recursive acquisition of the same rwsem. rwsems do not support recursive read locking and can deadlock when a writer is waiting. See the "Recursive read locks" section of Documentation/locking/lockdep-design.rst. For example, with Intel LPSS I3C, LOCKDEP generates a WARNING like: # echo intel-lpss-i3c.0 > /sys/bus/platform/drivers/mipi-i3c-hci/unbind # echo intel-lpss-i3c.0 > /sys/bus/platform/drivers/mipi-i3c-hci/bind WARNING: possible recursive locking detected kworker/5:1/94 is trying to acquire lock: ffff88811c810d78 (&i3cbus->lock){++++}-{4:4}, at: i3c_device_match_id+0x45/0x370 but task is already holding lock: ffff88811c810d78 (&i3cbus->lock){++++}-{4:4}, at: i3c_master_reg_work_fn+0x21/0x5f0 Fix this by separating device creation from device registration. Populate desc->dev under the maintenance lock, collect the devices that still need registration into a local list, then release the lock before calling device_register(). Finally retake the lock and clean up any devices that failed to register. Use the maintenance lock rather than the normal-use lock while adding device objects. A write-side maintenance lock prevents readers from observing a partially initialized desc->dev during initial device population, or desc->dev disappearing if registration fails. The local list requires a list node, so add a list node member to struct i3c_device. Fixes: 3a379bbcea0a ("i3c: Add core I3C infrastructure") Cc: stable@vger.kernel.org Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Reviewed-by: Frank Li <Frank.Li@nxp.com> Link: https://patch.msgid.link/20260807145638.168865-2-adrian.hunter@intel.com Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2026-08-07 17:56:25 +03:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: master: Fix recursive locking during device registration i3c_master_register_new_i3c_devs() registers newly discovered devices while holding i3c_bus_normaluse_lock(), a down_read(). device_register() can immediately probe the device, and probe callbacks typically invoke I3C helpers that take i3c_bus_normaluse_lock() again, leading to a recursive acquisition of the same rwsem. rwsems do not support recursive read locking and can deadlock when a writer is waiting. See the "Recursive read locks" section of Documentation/locking/lockdep-design.rst. For example, with Intel LPSS I3C, LOCKDEP generates a WARNING like: # echo intel-lpss-i3c.0 > /sys/bus/platform/drivers/mipi-i3c-hci/unbind # echo intel-lpss-i3c.0 > /sys/bus/platform/drivers/mipi-i3c-hci/bind WARNING: possible recursive locking detected kworker/5:1/94 is trying to acquire lock: ffff88811c810d78 (&i3cbus->lock){++++}-{4:4}, at: i3c_device_match_id+0x45/0x370 but task is already holding lock: ffff88811c810d78 (&i3cbus->lock){++++}-{4:4}, at: i3c_master_reg_work_fn+0x21/0x5f0 Fix this by separating device creation from device registration. Populate desc->dev under the maintenance lock, collect the devices that still need registration into a local list, then release the lock before calling device_register(). Finally retake the lock and clean up any devices that failed to register. Use the maintenance lock rather than the normal-use lock while adding device objects. A write-side maintenance lock prevents readers from observing a partially initialized desc->dev during initial device population, or desc->dev disappearing if registration fails. The local list requires a list node, so add a list node member to struct i3c_device. Fixes: 3a379bbcea0a ("i3c: Add core I3C infrastructure") Cc: stable@vger.kernel.org Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Reviewed-by: Frank Li <Frank.Li@nxp.com> Link: https://patch.msgid.link/20260807145638.168865-2-adrian.hunter@intel.com Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2026-08-07 17:56:25 +03:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: master: Fix recursive locking during device registration i3c_master_register_new_i3c_devs() registers newly discovered devices while holding i3c_bus_normaluse_lock(), a down_read(). device_register() can immediately probe the device, and probe callbacks typically invoke I3C helpers that take i3c_bus_normaluse_lock() again, leading to a recursive acquisition of the same rwsem. rwsems do not support recursive read locking and can deadlock when a writer is waiting. See the "Recursive read locks" section of Documentation/locking/lockdep-design.rst. For example, with Intel LPSS I3C, LOCKDEP generates a WARNING like: # echo intel-lpss-i3c.0 > /sys/bus/platform/drivers/mipi-i3c-hci/unbind # echo intel-lpss-i3c.0 > /sys/bus/platform/drivers/mipi-i3c-hci/bind WARNING: possible recursive locking detected kworker/5:1/94 is trying to acquire lock: ffff88811c810d78 (&i3cbus->lock){++++}-{4:4}, at: i3c_device_match_id+0x45/0x370 but task is already holding lock: ffff88811c810d78 (&i3cbus->lock){++++}-{4:4}, at: i3c_master_reg_work_fn+0x21/0x5f0 Fix this by separating device creation from device registration. Populate desc->dev under the maintenance lock, collect the devices that still need registration into a local list, then release the lock before calling device_register(). Finally retake the lock and clean up any devices that failed to register. Use the maintenance lock rather than the normal-use lock while adding device objects. A write-side maintenance lock prevents readers from observing a partially initialized desc->dev during initial device population, or desc->dev disappearing if registration fails. The local list requires a list node, so add a list node member to struct i3c_device. Fixes: 3a379bbcea0a ("i3c: Add core I3C infrastructure") Cc: stable@vger.kernel.org Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Reviewed-by: Frank Li <Frank.Li@nxp.com> Link: https://patch.msgid.link/20260807145638.168865-2-adrian.hunter@intel.com Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2026-08-07 17:56:25 +03:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: master: Fix recursive locking during device registration i3c_master_register_new_i3c_devs() registers newly discovered devices while holding i3c_bus_normaluse_lock(), a down_read(). device_register() can immediately probe the device, and probe callbacks typically invoke I3C helpers that take i3c_bus_normaluse_lock() again, leading to a recursive acquisition of the same rwsem. rwsems do not support recursive read locking and can deadlock when a writer is waiting. See the "Recursive read locks" section of Documentation/locking/lockdep-design.rst. For example, with Intel LPSS I3C, LOCKDEP generates a WARNING like: # echo intel-lpss-i3c.0 > /sys/bus/platform/drivers/mipi-i3c-hci/unbind # echo intel-lpss-i3c.0 > /sys/bus/platform/drivers/mipi-i3c-hci/bind WARNING: possible recursive locking detected kworker/5:1/94 is trying to acquire lock: ffff88811c810d78 (&i3cbus->lock){++++}-{4:4}, at: i3c_device_match_id+0x45/0x370 but task is already holding lock: ffff88811c810d78 (&i3cbus->lock){++++}-{4:4}, at: i3c_master_reg_work_fn+0x21/0x5f0 Fix this by separating device creation from device registration. Populate desc->dev under the maintenance lock, collect the devices that still need registration into a local list, then release the lock before calling device_register(). Finally retake the lock and clean up any devices that failed to register. Use the maintenance lock rather than the normal-use lock while adding device objects. A write-side maintenance lock prevents readers from observing a partially initialized desc->dev during initial device population, or desc->dev disappearing if registration fails. The local list requires a list node, so add a list node member to struct i3c_device. Fixes: 3a379bbcea0a ("i3c: Add core I3C infrastructure") Cc: stable@vger.kernel.org Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Reviewed-by: Frank Li <Frank.Li@nxp.com> Link: https://patch.msgid.link/20260807145638.168865-2-adrian.hunter@intel.com Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2026-08-07 17:56:25 +03:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: master: Fix recursive locking during device registration i3c_master_register_new_i3c_devs() registers newly discovered devices while holding i3c_bus_normaluse_lock(), a down_read(). device_register() can immediately probe the device, and probe callbacks typically invoke I3C helpers that take i3c_bus_normaluse_lock() again, leading to a recursive acquisition of the same rwsem. rwsems do not support recursive read locking and can deadlock when a writer is waiting. See the "Recursive read locks" section of Documentation/locking/lockdep-design.rst. For example, with Intel LPSS I3C, LOCKDEP generates a WARNING like: # echo intel-lpss-i3c.0 > /sys/bus/platform/drivers/mipi-i3c-hci/unbind # echo intel-lpss-i3c.0 > /sys/bus/platform/drivers/mipi-i3c-hci/bind WARNING: possible recursive locking detected kworker/5:1/94 is trying to acquire lock: ffff88811c810d78 (&i3cbus->lock){++++}-{4:4}, at: i3c_device_match_id+0x45/0x370 but task is already holding lock: ffff88811c810d78 (&i3cbus->lock){++++}-{4:4}, at: i3c_master_reg_work_fn+0x21/0x5f0 Fix this by separating device creation from device registration. Populate desc->dev under the maintenance lock, collect the devices that still need registration into a local list, then release the lock before calling device_register(). Finally retake the lock and clean up any devices that failed to register. Use the maintenance lock rather than the normal-use lock while adding device objects. A write-side maintenance lock prevents readers from observing a partially initialized desc->dev during initial device population, or desc->dev disappearing if registration fails. The local list requires a list node, so add a list node member to struct i3c_device. Fixes: 3a379bbcea0a ("i3c: Add core I3C infrastructure") Cc: stable@vger.kernel.org Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Reviewed-by: Frank Li <Frank.Li@nxp.com> Link: https://patch.msgid.link/20260807145638.168865-2-adrian.hunter@intel.com Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2026-08-07 17:56:25 +03:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: master: Defer new-device registration out of DAA caller context Master drivers may invoke i3c_master_do_daa_ext() during resume to re-run Dynamic Address Assignment. As well as assigning addresses to any newly arrived devices, this restores the dynamic address of devices that lost it across system suspend, so it has to run as part of the controller's resume path. A side effect of i3c_master_do_daa_ext() today is that it also registers any newly discovered I3C devices with the driver model inline, via i3c_master_register_new_i3c_devs(). Doing that from the resume path is problematic: a hot-join-capable device may join the bus during this same DAA, and registering it immediately would push driver model work (probing, sysfs, etc.) into the controller's resume context, where the rest of the system is not yet fully resumed and the controller driver is still partway through its own resume sequence. Decouple discovery from registration: add a reg_work work item to struct i3c_master_controller and have i3c_master_do_daa_ext() queue it on master->wq (the freezable workqueue) instead of calling i3c_master_register_new_i3c_devs() directly. The worker performs the registration only when the controller is not shutting_down, and is cancelled alongside hj_work in i3c_master_shutdown(). Because wq is freezable, any newly observed devices end up being registered after the system has finished resuming. i3c_master_register() also routes its initial post-bus-init registration through reg_work, using flush_work() to keep probe-time behavior synchronous. This keeps a single registration code path and ensures the worker is the only writer of desc->dev. Fixes: 3a379bbcea0af ("i3c: Add core I3C infrastructure") Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Reviewed-by: Frank Li <Frank.Li@nxp.com> Link: https://patch.msgid.link/20260608054312.10604-7-adrian.hunter@intel.com Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2026-06-08 08:43:10 +03:00
i3c: master: Fix recursive locking during device registration i3c_master_register_new_i3c_devs() registers newly discovered devices while holding i3c_bus_normaluse_lock(), a down_read(). device_register() can immediately probe the device, and probe callbacks typically invoke I3C helpers that take i3c_bus_normaluse_lock() again, leading to a recursive acquisition of the same rwsem. rwsems do not support recursive read locking and can deadlock when a writer is waiting. See the "Recursive read locks" section of Documentation/locking/lockdep-design.rst. For example, with Intel LPSS I3C, LOCKDEP generates a WARNING like: # echo intel-lpss-i3c.0 > /sys/bus/platform/drivers/mipi-i3c-hci/unbind # echo intel-lpss-i3c.0 > /sys/bus/platform/drivers/mipi-i3c-hci/bind WARNING: possible recursive locking detected kworker/5:1/94 is trying to acquire lock: ffff88811c810d78 (&i3cbus->lock){++++}-{4:4}, at: i3c_device_match_id+0x45/0x370 but task is already holding lock: ffff88811c810d78 (&i3cbus->lock){++++}-{4:4}, at: i3c_master_reg_work_fn+0x21/0x5f0 Fix this by separating device creation from device registration. Populate desc->dev under the maintenance lock, collect the devices that still need registration into a local list, then release the lock before calling device_register(). Finally retake the lock and clean up any devices that failed to register. Use the maintenance lock rather than the normal-use lock while adding device objects. A write-side maintenance lock prevents readers from observing a partially initialized desc->dev during initial device population, or desc->dev disappearing if registration fails. The local list requires a list node, so add a list node member to struct i3c_device. Fixes: 3a379bbcea0a ("i3c: Add core I3C infrastructure") Cc: stable@vger.kernel.org Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Reviewed-by: Frank Li <Frank.Li@nxp.com> Link: https://patch.msgid.link/20260807145638.168865-2-adrian.hunter@intel.com Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2026-08-07 17:56:25 +03:00
i3c: master: Defer new-device registration out of DAA caller context Master drivers may invoke i3c_master_do_daa_ext() during resume to re-run Dynamic Address Assignment. As well as assigning addresses to any newly arrived devices, this restores the dynamic address of devices that lost it across system suspend, so it has to run as part of the controller's resume path. A side effect of i3c_master_do_daa_ext() today is that it also registers any newly discovered I3C devices with the driver model inline, via i3c_master_register_new_i3c_devs(). Doing that from the resume path is problematic: a hot-join-capable device may join the bus during this same DAA, and registering it immediately would push driver model work (probing, sysfs, etc.) into the controller's resume context, where the rest of the system is not yet fully resumed and the controller driver is still partway through its own resume sequence. Decouple discovery from registration: add a reg_work work item to struct i3c_master_controller and have i3c_master_do_daa_ext() queue it on master->wq (the freezable workqueue) instead of calling i3c_master_register_new_i3c_devs() directly. The worker performs the registration only when the controller is not shutting_down, and is cancelled alongside hj_work in i3c_master_shutdown(). Because wq is freezable, any newly observed devices end up being registered after the system has finished resuming. i3c_master_register() also routes its initial post-bus-init registration through reg_work, using flush_work() to keep probe-time behavior synchronous. This keeps a single registration code path and ensures the worker is the only writer of desc->dev. Fixes: 3a379bbcea0af ("i3c: Add core I3C infrastructure") Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Reviewed-by: Frank Li <Frank.Li@nxp.com> Link: https://patch.msgid.link/20260608054312.10604-7-adrian.hunter@intel.com Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2026-06-08 08:43:10 +03:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: master: Fix dynamic address leak when 'assigned-address' is present If the DTS contains 'assigned-address', a dynamic address leak occurs during hotjoin events. Assume a device have assigned-address 0xb. - Device issue Hotjoin - Call i3c_master_do_daa() - Call driver xxx_do_daa() - Call i3c_master_get_free_addr() to get dynamic address 0x9 - i3c_master_add_i3c_dev_locked(0x9) - expected_dyn_addr = newdev->boardinfo->init_dyn_addr (0xb); - i3c_master_reattach_i3c_dev(newdev(0xb), old_dyn_addr(0x9)); - if (dev->info.dyn_addr != old_dyn_addr && ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 0xb != 0x9 -> TRUE (!dev->boardinfo || ^^^^^^^^^^^^^^^ -> FALSE dev->info.dyn_addr != dev->boardinfo->init_dyn_addr)) { ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 0xb != 0xb -> FALSE ... i3c_bus_set_addr_slot_status(&master->bus, old_dyn_addr, I3C_ADDR_SLOT_FREE); ^^^ This will be skipped. So old_dyn_addr never free } - i3c_master_get_free_addr() will return increased sequence number. Remove dev->info.dyn_addr != dev->boardinfo->init_dyn_addr condition check. dev->info.dyn_addr should be checked before calling this function because i3c_master_setnewda_locked() has already been called and the target device has already accepted dyn_addr. It is too late to check if dyn_addr is free in i3c_master_reattach_i3c_dev(). Add check to ensure expected_dyn_addr is free before i3c_master_setnewda_locked(). Fixes: cc3a392d69b6 ("i3c: master: fix for SETDASA and DAA process") Cc: stable@kernel.org Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com> Signed-off-by: Frank Li <Frank.Li@nxp.com> Link: https://lore.kernel.org/r/20241021-i3c_dts_assign-v8-3-4098b8bde01e@nxp.com Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2024-10-21 11:45:08 -04:00
i3c: master: Extend address status bit to 4 and add I3C_ADDR_SLOT_EXT_DESIRED Extend the address status bit to 4 and introduce the I3C_ADDR_SLOT_EXT_DESIRED macro to indicate that a device prefers a specific address. This is generally set by the 'assigned-address' in the device tree source (dts) file. ┌────┬─────────────┬───┬─────────┬───┐ │S/Sr│ 7'h7E RnW=0 │ACK│ ENTDAA │ T ├────┐ └────┴─────────────┴───┴─────────┴───┘ │ ┌─────────────────────────────────────────┘ │ ┌──┬─────────────┬───┬─────────────────┬────────────────┬───┬─────────┐ └─►│Sr│7'h7E RnW=1 │ACK│48bit UID BCR DCR│Assign 7bit Addr│PAR│ ACK/NACK│ └──┴─────────────┴───┴─────────────────┴────────────────┴───┴─────────┘ Some master controllers (such as HCI) need to prepare the entire above transaction before sending it out to the I3C bus. This means that a 7-bit dynamic address needs to be allocated before knowing the target device's UID information. However, some I3C targets may request specific addresses (called as "init_dyn_addr"), which is typically specified by the DT-'s assigned-address property. Lower addresses having higher IBI priority. If it is available, i3c_bus_get_free_addr() preferably return a free address that is not in the list of desired addresses (called as "init_dyn_addr"). This allows the device with the "init_dyn_addr" to switch to its "init_dyn_addr" when it hot-joins the I3C bus. Otherwise, if the "init_dyn_addr" is already in use by another I3C device, the target device will not be able to switch to its desired address. If the previous step fails, fallback returning one of the remaining unassigned address, regardless of its state in the desired list. Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com> Signed-off-by: Frank Li <Frank.Li@nxp.com> Link: https://lore.kernel.org/r/20241021-i3c_dts_assign-v8-2-4098b8bde01e@nxp.com Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2024-10-21 11:45:07 -04:00
i3c: master: Fix dynamic address leak when 'assigned-address' is present If the DTS contains 'assigned-address', a dynamic address leak occurs during hotjoin events. Assume a device have assigned-address 0xb. - Device issue Hotjoin - Call i3c_master_do_daa() - Call driver xxx_do_daa() - Call i3c_master_get_free_addr() to get dynamic address 0x9 - i3c_master_add_i3c_dev_locked(0x9) - expected_dyn_addr = newdev->boardinfo->init_dyn_addr (0xb); - i3c_master_reattach_i3c_dev(newdev(0xb), old_dyn_addr(0x9)); - if (dev->info.dyn_addr != old_dyn_addr && ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 0xb != 0x9 -> TRUE (!dev->boardinfo || ^^^^^^^^^^^^^^^ -> FALSE dev->info.dyn_addr != dev->boardinfo->init_dyn_addr)) { ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 0xb != 0xb -> FALSE ... i3c_bus_set_addr_slot_status(&master->bus, old_dyn_addr, I3C_ADDR_SLOT_FREE); ^^^ This will be skipped. So old_dyn_addr never free } - i3c_master_get_free_addr() will return increased sequence number. Remove dev->info.dyn_addr != dev->boardinfo->init_dyn_addr condition check. dev->info.dyn_addr should be checked before calling this function because i3c_master_setnewda_locked() has already been called and the target device has already accepted dyn_addr. It is too late to check if dyn_addr is free in i3c_master_reattach_i3c_dev(). Add check to ensure expected_dyn_addr is free before i3c_master_setnewda_locked(). Fixes: cc3a392d69b6 ("i3c: master: fix for SETDASA and DAA process") Cc: stable@kernel.org Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com> Signed-off-by: Frank Li <Frank.Li@nxp.com> Link: https://lore.kernel.org/r/20241021-i3c_dts_assign-v8-3-4098b8bde01e@nxp.com Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2024-10-21 11:45:08 -04:00
i3c: master: Extend address status bit to 4 and add I3C_ADDR_SLOT_EXT_DESIRED Extend the address status bit to 4 and introduce the I3C_ADDR_SLOT_EXT_DESIRED macro to indicate that a device prefers a specific address. This is generally set by the 'assigned-address' in the device tree source (dts) file. ┌────┬─────────────┬───┬─────────┬───┐ │S/Sr│ 7'h7E RnW=0 │ACK│ ENTDAA │ T ├────┐ └────┴─────────────┴───┴─────────┴───┘ │ ┌─────────────────────────────────────────┘ │ ┌──┬─────────────┬───┬─────────────────┬────────────────┬───┬─────────┐ └─►│Sr│7'h7E RnW=1 │ACK│48bit UID BCR DCR│Assign 7bit Addr│PAR│ ACK/NACK│ └──┴─────────────┴───┴─────────────────┴────────────────┴───┴─────────┘ Some master controllers (such as HCI) need to prepare the entire above transaction before sending it out to the I3C bus. This means that a 7-bit dynamic address needs to be allocated before knowing the target device's UID information. However, some I3C targets may request specific addresses (called as "init_dyn_addr"), which is typically specified by the DT-'s assigned-address property. Lower addresses having higher IBI priority. If it is available, i3c_bus_get_free_addr() preferably return a free address that is not in the list of desired addresses (called as "init_dyn_addr"). This allows the device with the "init_dyn_addr" to switch to its "init_dyn_addr" when it hot-joins the I3C bus. Otherwise, if the "init_dyn_addr" is already in use by another I3C device, the target device will not be able to switch to its desired address. If the previous step fails, fallback returning one of the remaining unassigned address, regardless of its state in the desired list. Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com> Signed-off-by: Frank Li <Frank.Li@nxp.com> Link: https://lore.kernel.org/r/20241021-i3c_dts_assign-v8-2-4098b8bde01e@nxp.com Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2024-10-21 11:45:07 -04:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: master: Reconcile dynamic addresses after DAA After Dynamic Address Assignment (DAA), there may be cases where devices have been assigned dynamic addresses on the bus, but are not successfully registered in the device model. This can happen, for example, if errors occur during device addition, leaving the bus state and software state inconsistent. Introduce a reconciliation step to resolve such inconsistencies. Scan all address slots marked as I3C devices by the bus, and compare them against the set of devices currently registered. For any dynamic address that is marked occupied but has no corresponding i3c_dev_desc, probe for device presence using a GETSTATUS CCC. Retry the probe (with exponential backoff delay) to handle transient NACK conditions. If a device responds, register it via i3c_master_add_i3c_dev_locked(). Otherwise, free the address slot so it may be reused in future DAA operations. Note, i3c_master_add_i3c_dev_locked() may fail (again), in which case the dynamic address remains marked as occupied. A future DAA will try again. This also handles a corner case where a device is assigned a dynamic address but not successfully added, and subsequently loses that address (e.g. due to power management). If DAA is run again, the device may receive a new dynamic address while the old one remains marked as occupied. Repeated occurrences of this scenario could eventually exhaust the dynamic address space. The reconciliation step ensures that stale addresses are detected and freed, preventing address leakage. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Reviewed-by: Frank Li <Frank.Li@nxp.com> Link: https://patch.msgid.link/20260612080107.11606-8-adrian.hunter@intel.com Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2026-06-12 11:01:07 +03:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: master: Reconcile dynamic addresses after DAA After Dynamic Address Assignment (DAA), there may be cases where devices have been assigned dynamic addresses on the bus, but are not successfully registered in the device model. This can happen, for example, if errors occur during device addition, leaving the bus state and software state inconsistent. Introduce a reconciliation step to resolve such inconsistencies. Scan all address slots marked as I3C devices by the bus, and compare them against the set of devices currently registered. For any dynamic address that is marked occupied but has no corresponding i3c_dev_desc, probe for device presence using a GETSTATUS CCC. Retry the probe (with exponential backoff delay) to handle transient NACK conditions. If a device responds, register it via i3c_master_add_i3c_dev_locked(). Otherwise, free the address slot so it may be reused in future DAA operations. Note, i3c_master_add_i3c_dev_locked() may fail (again), in which case the dynamic address remains marked as occupied. A future DAA will try again. This also handles a corner case where a device is assigned a dynamic address but not successfully added, and subsequently loses that address (e.g. due to power management). If DAA is run again, the device may receive a new dynamic address while the old one remains marked as occupied. Repeated occurrences of this scenario could eventually exhaust the dynamic address space. The reconciliation step ensures that stale addresses are detected and freed, preventing address leakage. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Reviewed-by: Frank Li <Frank.Li@nxp.com> Link: https://patch.msgid.link/20260612080107.11606-8-adrian.hunter@intel.com Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2026-06-12 11:01:07 +03:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: master: Reconcile dynamic addresses after DAA After Dynamic Address Assignment (DAA), there may be cases where devices have been assigned dynamic addresses on the bus, but are not successfully registered in the device model. This can happen, for example, if errors occur during device addition, leaving the bus state and software state inconsistent. Introduce a reconciliation step to resolve such inconsistencies. Scan all address slots marked as I3C devices by the bus, and compare them against the set of devices currently registered. For any dynamic address that is marked occupied but has no corresponding i3c_dev_desc, probe for device presence using a GETSTATUS CCC. Retry the probe (with exponential backoff delay) to handle transient NACK conditions. If a device responds, register it via i3c_master_add_i3c_dev_locked(). Otherwise, free the address slot so it may be reused in future DAA operations. Note, i3c_master_add_i3c_dev_locked() may fail (again), in which case the dynamic address remains marked as occupied. A future DAA will try again. This also handles a corner case where a device is assigned a dynamic address but not successfully added, and subsequently loses that address (e.g. due to power management). If DAA is run again, the device may receive a new dynamic address while the old one remains marked as occupied. Repeated occurrences of this scenario could eventually exhaust the dynamic address space. The reconciliation step ensures that stale addresses are detected and freed, preventing address leakage. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Reviewed-by: Frank Li <Frank.Li@nxp.com> Link: https://patch.msgid.link/20260612080107.11606-8-adrian.hunter@intel.com Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2026-06-12 11:01:07 +03:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: master: Reconcile dynamic addresses after DAA After Dynamic Address Assignment (DAA), there may be cases where devices have been assigned dynamic addresses on the bus, but are not successfully registered in the device model. This can happen, for example, if errors occur during device addition, leaving the bus state and software state inconsistent. Introduce a reconciliation step to resolve such inconsistencies. Scan all address slots marked as I3C devices by the bus, and compare them against the set of devices currently registered. For any dynamic address that is marked occupied but has no corresponding i3c_dev_desc, probe for device presence using a GETSTATUS CCC. Retry the probe (with exponential backoff delay) to handle transient NACK conditions. If a device responds, register it via i3c_master_add_i3c_dev_locked(). Otherwise, free the address slot so it may be reused in future DAA operations. Note, i3c_master_add_i3c_dev_locked() may fail (again), in which case the dynamic address remains marked as occupied. A future DAA will try again. This also handles a corner case where a device is assigned a dynamic address but not successfully added, and subsequently loses that address (e.g. due to power management). If DAA is run again, the device may receive a new dynamic address while the old one remains marked as occupied. Repeated occurrences of this scenario could eventually exhaust the dynamic address space. The reconciliation step ensures that stale addresses are detected and freed, preventing address leakage. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Reviewed-by: Frank Li <Frank.Li@nxp.com> Link: https://patch.msgid.link/20260612080107.11606-8-adrian.hunter@intel.com Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2026-06-12 11:01:07 +03:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: master: Reconcile dynamic addresses after DAA After Dynamic Address Assignment (DAA), there may be cases where devices have been assigned dynamic addresses on the bus, but are not successfully registered in the device model. This can happen, for example, if errors occur during device addition, leaving the bus state and software state inconsistent. Introduce a reconciliation step to resolve such inconsistencies. Scan all address slots marked as I3C devices by the bus, and compare them against the set of devices currently registered. For any dynamic address that is marked occupied but has no corresponding i3c_dev_desc, probe for device presence using a GETSTATUS CCC. Retry the probe (with exponential backoff delay) to handle transient NACK conditions. If a device responds, register it via i3c_master_add_i3c_dev_locked(). Otherwise, free the address slot so it may be reused in future DAA operations. Note, i3c_master_add_i3c_dev_locked() may fail (again), in which case the dynamic address remains marked as occupied. A future DAA will try again. This also handles a corner case where a device is assigned a dynamic address but not successfully added, and subsequently loses that address (e.g. due to power management). If DAA is run again, the device may receive a new dynamic address while the old one remains marked as occupied. Repeated occurrences of this scenario could eventually exhaust the dynamic address space. The reconciliation step ensures that stale addresses are detected and freed, preventing address leakage. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Reviewed-by: Frank Li <Frank.Li@nxp.com> Link: https://patch.msgid.link/20260612080107.11606-8-adrian.hunter@intel.com Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2026-06-12 11:01:07 +03:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: master: Remove i3c_dev_disable_ibi_locked(olddev) on device hotjoin When a new device hotjoins, a new dynamic address is assigned. i3c_master_add_i3c_dev_locked() identifies that the device was previously attached to the bus and locates the olddev. i3c_master_add_i3c_dev_locked() { ... olddev = i3c_master_search_i3c_dev_duplicate(newdev); ... if (olddev) { ... i3c_dev_disable_ibi_locked(olddev); ^^^^^^ The olddev should not receive any commands on the i3c bus as it does not exist and has been assigned a new address. This will result in NACK or timeout. So remove it. } i3c_dev_free_ibi_locked(olddev); ^^^^^^^^ This function internally calls i3c_dev_disable_ibi_locked() function causing to send DISEC command with old Address. The olddev should not receive any commands on the i3c bus as it does not exist and has been assigned a new address. This will result in NACK or timeout. So, update the olddev->ibi->enabled flag to false to avoid DISEC with OldAddr. } Include part of Ravindra Yashvant Shinde's work: https://lore.kernel.org/linux-i3c/20240820151917.3904956-1-ravindra.yashvant.shinde@nxp.com/T/#u Fixes: 317bacf960a4 ("i3c: master: add enable(disable) hot join in sys entry") Co-developed-by: Ravindra Yashvant Shinde <ravindra.yashvant.shinde@nxp.com> Signed-off-by: Ravindra Yashvant Shinde <ravindra.yashvant.shinde@nxp.com> Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com> Signed-off-by: Frank Li <Frank.Li@nxp.com> Link: https://lore.kernel.org/r/20241001162232.223724-1-Frank.Li@nxp.com Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2024-10-01 12:22:32 -04:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: master: Remove i3c_dev_disable_ibi_locked(olddev) on device hotjoin When a new device hotjoins, a new dynamic address is assigned. i3c_master_add_i3c_dev_locked() identifies that the device was previously attached to the bus and locates the olddev. i3c_master_add_i3c_dev_locked() { ... olddev = i3c_master_search_i3c_dev_duplicate(newdev); ... if (olddev) { ... i3c_dev_disable_ibi_locked(olddev); ^^^^^^ The olddev should not receive any commands on the i3c bus as it does not exist and has been assigned a new address. This will result in NACK or timeout. So remove it. } i3c_dev_free_ibi_locked(olddev); ^^^^^^^^ This function internally calls i3c_dev_disable_ibi_locked() function causing to send DISEC command with old Address. The olddev should not receive any commands on the i3c bus as it does not exist and has been assigned a new address. This will result in NACK or timeout. So, update the olddev->ibi->enabled flag to false to avoid DISEC with OldAddr. } Include part of Ravindra Yashvant Shinde's work: https://lore.kernel.org/linux-i3c/20240820151917.3904956-1-ravindra.yashvant.shinde@nxp.com/T/#u Fixes: 317bacf960a4 ("i3c: master: add enable(disable) hot join in sys entry") Co-developed-by: Ravindra Yashvant Shinde <ravindra.yashvant.shinde@nxp.com> Signed-off-by: Ravindra Yashvant Shinde <ravindra.yashvant.shinde@nxp.com> Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com> Signed-off-by: Frank Li <Frank.Li@nxp.com> Link: https://lore.kernel.org/r/20241001162232.223724-1-Frank.Li@nxp.com Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2024-10-01 12:22:32 -04:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: master: Fix dynamic address leak when 'assigned-address' is present If the DTS contains 'assigned-address', a dynamic address leak occurs during hotjoin events. Assume a device have assigned-address 0xb. - Device issue Hotjoin - Call i3c_master_do_daa() - Call driver xxx_do_daa() - Call i3c_master_get_free_addr() to get dynamic address 0x9 - i3c_master_add_i3c_dev_locked(0x9) - expected_dyn_addr = newdev->boardinfo->init_dyn_addr (0xb); - i3c_master_reattach_i3c_dev(newdev(0xb), old_dyn_addr(0x9)); - if (dev->info.dyn_addr != old_dyn_addr && ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 0xb != 0x9 -> TRUE (!dev->boardinfo || ^^^^^^^^^^^^^^^ -> FALSE dev->info.dyn_addr != dev->boardinfo->init_dyn_addr)) { ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ 0xb != 0xb -> FALSE ... i3c_bus_set_addr_slot_status(&master->bus, old_dyn_addr, I3C_ADDR_SLOT_FREE); ^^^ This will be skipped. So old_dyn_addr never free } - i3c_master_get_free_addr() will return increased sequence number. Remove dev->info.dyn_addr != dev->boardinfo->init_dyn_addr condition check. dev->info.dyn_addr should be checked before calling this function because i3c_master_setnewda_locked() has already been called and the target device has already accepted dyn_addr. It is too late to check if dyn_addr is free in i3c_master_reattach_i3c_dev(). Add check to ensure expected_dyn_addr is free before i3c_master_setnewda_locked(). Fixes: cc3a392d69b6 ("i3c: master: fix for SETDASA and DAA process") Cc: stable@kernel.org Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com> Signed-off-by: Frank Li <Frank.Li@nxp.com> Link: https://lore.kernel.org/r/20241021-i3c_dts_assign-v8-3-4098b8bde01e@nxp.com Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2024-10-21 11:45:08 -04:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: master: Reconcile dynamic addresses after DAA After Dynamic Address Assignment (DAA), there may be cases where devices have been assigned dynamic addresses on the bus, but are not successfully registered in the device model. This can happen, for example, if errors occur during device addition, leaving the bus state and software state inconsistent. Introduce a reconciliation step to resolve such inconsistencies. Scan all address slots marked as I3C devices by the bus, and compare them against the set of devices currently registered. For any dynamic address that is marked occupied but has no corresponding i3c_dev_desc, probe for device presence using a GETSTATUS CCC. Retry the probe (with exponential backoff delay) to handle transient NACK conditions. If a device responds, register it via i3c_master_add_i3c_dev_locked(). Otherwise, free the address slot so it may be reused in future DAA operations. Note, i3c_master_add_i3c_dev_locked() may fail (again), in which case the dynamic address remains marked as occupied. A future DAA will try again. This also handles a corner case where a device is assigned a dynamic address but not successfully added, and subsequently loses that address (e.g. due to power management). If DAA is run again, the device may receive a new dynamic address while the old one remains marked as occupied. Repeated occurrences of this scenario could eventually exhaust the dynamic address space. The reconciliation step ensures that stale addresses are detected and freed, preventing address leakage. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Reviewed-by: Frank Li <Frank.Li@nxp.com> Link: https://patch.msgid.link/20260612080107.11606-8-adrian.hunter@intel.com Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2026-06-12 11:01:07 +03:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: master: Reconcile dynamic addresses after DAA After Dynamic Address Assignment (DAA), there may be cases where devices have been assigned dynamic addresses on the bus, but are not successfully registered in the device model. This can happen, for example, if errors occur during device addition, leaving the bus state and software state inconsistent. Introduce a reconciliation step to resolve such inconsistencies. Scan all address slots marked as I3C devices by the bus, and compare them against the set of devices currently registered. For any dynamic address that is marked occupied but has no corresponding i3c_dev_desc, probe for device presence using a GETSTATUS CCC. Retry the probe (with exponential backoff delay) to handle transient NACK conditions. If a device responds, register it via i3c_master_add_i3c_dev_locked(). Otherwise, free the address slot so it may be reused in future DAA operations. Note, i3c_master_add_i3c_dev_locked() may fail (again), in which case the dynamic address remains marked as occupied. A future DAA will try again. This also handles a corner case where a device is assigned a dynamic address but not successfully added, and subsequently loses that address (e.g. due to power management). If DAA is run again, the device may receive a new dynamic address while the old one remains marked as occupied. Repeated occurrences of this scenario could eventually exhaust the dynamic address space. The reconciliation step ensures that stale addresses are detected and freed, preventing address leakage. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Reviewed-by: Frank Li <Frank.Li@nxp.com> Link: https://patch.msgid.link/20260612080107.11606-8-adrian.hunter@intel.com Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2026-06-12 11:01:07 +03:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: master: Reconcile dynamic addresses after DAA After Dynamic Address Assignment (DAA), there may be cases where devices have been assigned dynamic addresses on the bus, but are not successfully registered in the device model. This can happen, for example, if errors occur during device addition, leaving the bus state and software state inconsistent. Introduce a reconciliation step to resolve such inconsistencies. Scan all address slots marked as I3C devices by the bus, and compare them against the set of devices currently registered. For any dynamic address that is marked occupied but has no corresponding i3c_dev_desc, probe for device presence using a GETSTATUS CCC. Retry the probe (with exponential backoff delay) to handle transient NACK conditions. If a device responds, register it via i3c_master_add_i3c_dev_locked(). Otherwise, free the address slot so it may be reused in future DAA operations. Note, i3c_master_add_i3c_dev_locked() may fail (again), in which case the dynamic address remains marked as occupied. A future DAA will try again. This also handles a corner case where a device is assigned a dynamic address but not successfully added, and subsequently loses that address (e.g. due to power management). If DAA is run again, the device may receive a new dynamic address while the old one remains marked as occupied. Repeated occurrences of this scenario could eventually exhaust the dynamic address space. The reconciliation step ensures that stale addresses are detected and freed, preventing address leakage. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Reviewed-by: Frank Li <Frank.Li@nxp.com> Link: https://patch.msgid.link/20260612080107.11606-8-adrian.hunter@intel.com Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2026-06-12 11:01:07 +03:00
i3c: master: Reconcile dynamic addresses after DAA After Dynamic Address Assignment (DAA), there may be cases where devices have been assigned dynamic addresses on the bus, but are not successfully registered in the device model. This can happen, for example, if errors occur during device addition, leaving the bus state and software state inconsistent. Introduce a reconciliation step to resolve such inconsistencies. Scan all address slots marked as I3C devices by the bus, and compare them against the set of devices currently registered. For any dynamic address that is marked occupied but has no corresponding i3c_dev_desc, probe for device presence using a GETSTATUS CCC. Retry the probe (with exponential backoff delay) to handle transient NACK conditions. If a device responds, register it via i3c_master_add_i3c_dev_locked(). Otherwise, free the address slot so it may be reused in future DAA operations. Note, i3c_master_add_i3c_dev_locked() may fail (again), in which case the dynamic address remains marked as occupied. A future DAA will try again. This also handles a corner case where a device is assigned a dynamic address but not successfully added, and subsequently loses that address (e.g. due to power management). If DAA is run again, the device may receive a new dynamic address while the old one remains marked as occupied. Repeated occurrences of this scenario could eventually exhaust the dynamic address space. The reconciliation step ensures that stale addresses are detected and freed, preventing address leakage. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Reviewed-by: Frank Li <Frank.Li@nxp.com> Link: https://patch.msgid.link/20260612080107.11606-8-adrian.hunter@intel.com Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2026-06-12 11:01:07 +03:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
2023-09-21 03:51:04 +00:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: master: Fix info leak and UAF in device unregister path i3c_master_unregister_i3c_devs() clears i3cdev->dev->desc before calling device_unregister(). During device_unregister(), device_del() emits a KOBJ_REMOVE uevent and unbinds the driver while the device descriptor is still expected to be valid. As a result, i3c_device_uevent() and a racing modalias_show() can observe a NULL desc and fall back to an uninitialized stack struct i3c_device_info, leaking kernel stack contents in the generated modalias. Driver .remove() callbacks may also encounter an unexpected NULL desc during unbind. Keep desc valid until device_unregister() has completed. Since device_unregister() drops the device reference and may free the device, take an extra reference with get_device() before unregistering. Clear desc afterwards and release the extra reference with put_device(). This preserves the release-time invariant that desc must be NULL while avoiding both the information leak and a potential use-after-free from writing desc after the device has been released. Reported-by: sashiko-bot@kernel.org Link: https://lore.kernel.org/linux-i3c/20260702190003.8BF741F000E9@smtp.kernel.org/ Fixes: 3a379bbcea0a ("i3c: Add core I3C infrastructure") Cc: stable@vger.kernel.org Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Reviewed-by: Frank Li <Frank.Li@nxp.com> Link: https://patch.msgid.link/20260723075747.34049-1-adrian.hunter@intel.com Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2026-07-23 10:57:47 +03:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: master: Fix info leak and UAF in device unregister path i3c_master_unregister_i3c_devs() clears i3cdev->dev->desc before calling device_unregister(). During device_unregister(), device_del() emits a KOBJ_REMOVE uevent and unbinds the driver while the device descriptor is still expected to be valid. As a result, i3c_device_uevent() and a racing modalias_show() can observe a NULL desc and fall back to an uninitialized stack struct i3c_device_info, leaking kernel stack contents in the generated modalias. Driver .remove() callbacks may also encounter an unexpected NULL desc during unbind. Keep desc valid until device_unregister() has completed. Since device_unregister() drops the device reference and may free the device, take an extra reference with get_device() before unregistering. Clear desc afterwards and release the extra reference with put_device(). This preserves the release-time invariant that desc must be NULL while avoiding both the information leak and a potential use-after-free from writing desc after the device has been released. Reported-by: sashiko-bot@kernel.org Link: https://lore.kernel.org/linux-i3c/20260702190003.8BF741F000E9@smtp.kernel.org/ Fixes: 3a379bbcea0a ("i3c: Add core I3C infrastructure") Cc: stable@vger.kernel.org Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Reviewed-by: Frank Li <Frank.Li@nxp.com> Link: https://patch.msgid.link/20260723075747.34049-1-adrian.hunter@intel.com Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2026-07-23 10:57:47 +03:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
2026-06-08 08:43:05 +03:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: master: Consolidate Hot-Join DAA work in the core Three master drivers (dw-i3c-master, i3c-master-cdns, svc-i3c-master) each carry an essentially identical Hot-Join handler: a struct work_struct embedded in their private state, a work function that just calls i3c_master_do_daa() on the embedded i3c_master_controller, plus matching INIT_WORK()/cancel_work_sync() boilerplate in probe/remove (and shutdown for dw-i3c). The IBI/ISR paths then queue that work onto master->wq, which already lives in the core. Move this pattern into the I3C core: - Add struct work_struct hj_work to struct i3c_master_controller and initialise it in i3c_master_register() with a core-provided handler i3c_master_hj_work_fn() that performs i3c_master_do_daa(). - Cancel the work in i3c_master_unregister() so all controllers get correct teardown ordering against the workqueue for free. - Export i3c_master_queue_hotjoin() as the single entry point drivers call from their Hot-Join IBI handler. Convert the three existing users to the new API: drop their private hj_work fields, work functions, INIT_WORK() and cancel_work_sync() calls, and replace the queue_work(master->wq, &drv->hj_work) call sites with i3c_master_queue_hotjoin(&drv->base). The dw-i3c shutdown path still needs to flush pending Hot-Join work before tearing down the hardware, so it is updated to cancel master->base.hj_work directly. No functional change intended: the work is still queued on the same master->wq, runs the same i3c_master_do_daa(), and is cancelled at controller teardown. Future Hot-Join improvements now only need to be made in one place. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Reviewed-by: Frank Li <Frank.Li@nxp.com> Link: https://patch.msgid.link/20260608054312.10604-4-adrian.hunter@intel.com Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2026-06-08 08:43:07 +03:00
i3c: master: Defer new-device registration out of DAA caller context Master drivers may invoke i3c_master_do_daa_ext() during resume to re-run Dynamic Address Assignment. As well as assigning addresses to any newly arrived devices, this restores the dynamic address of devices that lost it across system suspend, so it has to run as part of the controller's resume path. A side effect of i3c_master_do_daa_ext() today is that it also registers any newly discovered I3C devices with the driver model inline, via i3c_master_register_new_i3c_devs(). Doing that from the resume path is problematic: a hot-join-capable device may join the bus during this same DAA, and registering it immediately would push driver model work (probing, sysfs, etc.) into the controller's resume context, where the rest of the system is not yet fully resumed and the controller driver is still partway through its own resume sequence. Decouple discovery from registration: add a reg_work work item to struct i3c_master_controller and have i3c_master_do_daa_ext() queue it on master->wq (the freezable workqueue) instead of calling i3c_master_register_new_i3c_devs() directly. The worker performs the registration only when the controller is not shutting_down, and is cancelled alongside hj_work in i3c_master_shutdown(). Because wq is freezable, any newly observed devices end up being registered after the system has finished resuming. i3c_master_register() also routes its initial post-bus-init registration through reg_work, using flush_work() to keep probe-time behavior synchronous. This keeps a single registration code path and ensures the worker is the only writer of desc->dev. Fixes: 3a379bbcea0af ("i3c: Add core I3C infrastructure") Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Reviewed-by: Frank Li <Frank.Li@nxp.com> Link: https://patch.msgid.link/20260608054312.10604-7-adrian.hunter@intel.com Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2026-06-08 08:43:10 +03:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
Revert "i3c master: fix missing destroy_workqueue() on error in i3c_master_register" Adding the destroy_workqueue call in i3c_master_register introduced below kernel warning because it makes duplicate destroy_workqueue calls when i3c_master_register fails after allocating the workqueue. The workqueue will be destroyed by i3c_masterdev_release which is called by put_device at the end of the i3c_master_register function eventually in failure cases so the workqueue doesn't need to be destroyed in i3c_master_register. [ 6.972952] WARNING: CPU: 1 PID: 1 at lib/list_debug.c:48 __list_del_entry_valid+0x9c/0xf4 [ 6.982205] list_del corruption, 8fe03c08->prev is LIST_POISON2 (00000122) [ 6.989910] CPU: 1 PID: 1 Comm: swapper/0 Tainted: G W 5.10.23-c12838a-dirty-31dc772 #1 [ 7.000295] Hardware name: Generic DT based system [ 7.005638] Backtrace: [ 7.008369] [<809133f0>] (dump_backtrace) from [<80913644>] (show_stack+0x20/0x24) [ 7.016819] r7:00000030 r6:60000013 r5:00000000 r4:813b5d40 [ 7.023137] [<80913624>] (show_stack) from [<8091e1a0>] (dump_stack+0x9c/0xb0) [ 7.031201] [<8091e104>] (dump_stack) from [<8011fa30>] (__warn+0xf8/0x154) [ 7.038972] r7:00000030 r6:00000009 r5:804fa1c8 r4:80b6eca4 [ 7.045289] [<8011f938>] (__warn) from [<80913d14>] (warn_slowpath_fmt+0x8c/0xc0) [ 7.053641] r7:00000030 r6:80b6eca4 r5:80b6ed74 r4:818cc000 [ 7.059960] [<80913c8c>] (warn_slowpath_fmt) from [<804fa1c8>] (__list_del_entry_valid+0x9c/0xf4) [ 7.069866] r9:96becf8c r8:818cc000 r7:8fe03c10 r6:8fe03c00 r5:8fe03ba0 r4:ff7ead4c [ 7.078513] [<804fa12c>] (__list_del_entry_valid) from [<8013f0b4>] (destroy_workqueue+0x1c4/0x23c) [ 7.088615] [<8013eef0>] (destroy_workqueue) from [<806aa124>] (i3c_masterdev_release+0x40/0xb0) [ 7.098421] r7:00000000 r6:81a43b80 r5:8fe65360 r4:8fe65048 [ 7.104740] [<806aa0e4>] (i3c_masterdev_release) from [<805f3f04>] (device_release+0x40/0xb0) [ 7.114254] r5:00000000 r4:8fe65048 [ 7.118245] [<805f3ec4>] (device_release) from [<808fe754>] (kobject_put+0xc8/0x204) [ 7.126885] r5:813978dc r4:8fe65048 [ 7.130877] [<808fe68c>] (kobject_put) from [<805f5fbc>] (put_device+0x20/0x24) [ 7.139037] r7:8fe65358 r6:8fe65368 r5:8fe65358 r4:8fe65048 [ 7.145355] [<805f5f9c>] (put_device) from [<806abac4>] (i3c_master_register+0x338/0xb00) [ 7.154487] [<806ab78c>] (i3c_master_register) from [<806ae084>] (dw_i3c_probe+0x224/0x24c) [ 7.163811] r10:00000000 r9:8fe7a100 r8:00000032 r7:819fa810 r6:819fa800 r5:8fe65040 [ 7.172547] r4:00000000 [ 7.175376] [<806ade60>] (dw_i3c_probe) from [<805fdc14>] (platform_drv_probe+0x44/0x80) [ 7.184409] r9:813a25c0 r8:00000000 r7:815ec114 r6:00000000 r5:813a25c0 r4:819fa810 [ 7.193053] [<805fdbd0>] (platform_drv_probe) from [<805fb83c>] (really_probe+0x108/0x50c) [ 7.202275] r5:815ec004 r4:819fa810 [ 7.206265] [<805fb734>] (really_probe) from [<805fc180>] (driver_probe_device+0xb4/0x190) [ 7.215492] r10:813dc000 r9:80c4385c r8:000000d9 r7:813a25c0 r6:819fa810 r5:00000000 [ 7.224228] r4:813a25c0 [ 7.227055] [<805fc0cc>] (driver_probe_device) from [<805fc5cc>] (device_driver_attach+0xb8/0xc0) [ 7.236959] r9:80c4385c r8:000000d9 r7:813a25c0 r6:819fa854 r4:819fa810 [ 7.244439] [<805fc514>] (device_driver_attach) from [<805fc65c>] (__driver_attach+0x88/0x16c) [ 7.254051] r7:00000000 r6:819fa810 r5:00000000 r4:813a25c0 [ 7.260369] [<805fc5d4>] (__driver_attach) from [<805f954c>] (bus_for_each_dev+0x88/0xc8) [ 7.269489] r7:00000000 r6:818cc000 r5:805fc5d4 r4:813a25c0 [ 7.275806] [<805f94c4>] (bus_for_each_dev) from [<805fc76c>] (driver_attach+0x2c/0x30) [ 7.284739] r7:81397c98 r6:00000000 r5:8fe7db80 r4:813a25c0 [ 7.291057] [<805fc740>] (driver_attach) from [<805f9eec>] (bus_add_driver+0x120/0x200) [ 7.299984] [<805f9dcc>] (bus_add_driver) from [<805fce44>] (driver_register+0x98/0x128) [ 7.309005] r7:80c4383c r6:00000000 r5:00000000 r4:813a25c0 [ 7.315323] [<805fcdac>] (driver_register) from [<805fedb4>] (__platform_driver_register+0x50/0x58) [ 7.325410] r5:818cc000 r4:81397c98 [ 7.329404] [<805fed64>] (__platform_driver_register) from [<80c23398>] (dw_i3c_driver_init+0x24/0x28) [ 7.339790] r5:818cc000 r4:80c23374 [ 7.343784] [<80c23374>] (dw_i3c_driver_init) from [<80c01300>] (do_one_initcall+0xac/0x1d0) [ 7.353206] [<80c01254>] (do_one_initcall) from [<80c01630>] (kernel_init_freeable+0x1a8/0x204) [ 7.362916] r8:000000d9 r7:80c4383c r6:00000007 r5:819ca2c0 r4:80c67680 [ 7.370398] [<80c01488>] (kernel_init_freeable) from [<8091eb18>] (kernel_init+0x18/0x12c) [ 7.379616] r10:00000000 r9:00000000 r8:00000000 r7:00000000 r6:00000000 r5:8091eb00 [ 7.388343] r4:00000000 [ 7.391170] [<8091eb00>] (kernel_init) from [<80100148>] (ret_from_fork+0x14/0x2c) [ 7.399607] Exception stack(0x818cdfb0 to 0x818cdff8) [ 7.405243] dfa0: 00000000 00000000 00000000 00000000 [ 7.414371] dfc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 [ 7.423499] dfe0: 00000000 00000000 00000000 00000000 00000013 00000000 [ 7.430879] r5:8091eb00 r4:00000000 This reverts commit 59165d16c699182b86b5c65181013f1fd88feb62. Fixes: 59165d16c699 ("i3c master: fix missing destroy_workqueue() on error in i3c_master_register") Signed-off-by: Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com> Link: https://lore.kernel.org/r/20210408172803.24599-1-jae.hyun.yoo@linux.intel.com
2021-04-08 10:28:03 -07:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: master: Defer new-device registration out of DAA caller context Master drivers may invoke i3c_master_do_daa_ext() during resume to re-run Dynamic Address Assignment. As well as assigning addresses to any newly arrived devices, this restores the dynamic address of devices that lost it across system suspend, so it has to run as part of the controller's resume path. A side effect of i3c_master_do_daa_ext() today is that it also registers any newly discovered I3C devices with the driver model inline, via i3c_master_register_new_i3c_devs(). Doing that from the resume path is problematic: a hot-join-capable device may join the bus during this same DAA, and registering it immediately would push driver model work (probing, sysfs, etc.) into the controller's resume context, where the rest of the system is not yet fully resumed and the controller driver is still partway through its own resume sequence. Decouple discovery from registration: add a reg_work work item to struct i3c_master_controller and have i3c_master_do_daa_ext() queue it on master->wq (the freezable workqueue) instead of calling i3c_master_register_new_i3c_devs() directly. The worker performs the registration only when the controller is not shutting_down, and is cancelled alongside hj_work in i3c_master_shutdown(). Because wq is freezable, any newly observed devices end up being registered after the system has finished resuming. i3c_master_register() also routes its initial post-bus-init registration through reg_work, using flush_work() to keep probe-time behavior synchronous. This keeps a single registration code path and ensures the worker is the only writer of desc->dev. Fixes: 3a379bbcea0af ("i3c: Add core I3C infrastructure") Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Reviewed-by: Frank Li <Frank.Li@nxp.com> Link: https://patch.msgid.link/20260608054312.10604-7-adrian.hunter@intel.com Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2026-06-08 08:43:10 +03:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: master: Defer new-device registration out of DAA caller context Master drivers may invoke i3c_master_do_daa_ext() during resume to re-run Dynamic Address Assignment. As well as assigning addresses to any newly arrived devices, this restores the dynamic address of devices that lost it across system suspend, so it has to run as part of the controller's resume path. A side effect of i3c_master_do_daa_ext() today is that it also registers any newly discovered I3C devices with the driver model inline, via i3c_master_register_new_i3c_devs(). Doing that from the resume path is problematic: a hot-join-capable device may join the bus during this same DAA, and registering it immediately would push driver model work (probing, sysfs, etc.) into the controller's resume context, where the rest of the system is not yet fully resumed and the controller driver is still partway through its own resume sequence. Decouple discovery from registration: add a reg_work work item to struct i3c_master_controller and have i3c_master_do_daa_ext() queue it on master->wq (the freezable workqueue) instead of calling i3c_master_register_new_i3c_devs() directly. The worker performs the registration only when the controller is not shutting_down, and is cancelled alongside hj_work in i3c_master_shutdown(). Because wq is freezable, any newly observed devices end up being registered after the system has finished resuming. i3c_master_register() also routes its initial post-bus-init registration through reg_work, using flush_work() to keep probe-time behavior synchronous. This keeps a single registration code path and ensures the worker is the only writer of desc->dev. Fixes: 3a379bbcea0af ("i3c: Add core I3C infrastructure") Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Reviewed-by: Frank Li <Frank.Li@nxp.com> Link: https://patch.msgid.link/20260608054312.10604-7-adrian.hunter@intel.com Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2026-06-08 08:43:10 +03:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: master: Ensure Hot-Join operations are stopped on shutdown System shutdown invokes each device's bus shutdown callback to quiesce hardware, but the I3C bus type does not currently implement one. As a result, on shutdown the controller's Hot-Join work and any in-flight i3c_master_do_daa() can keep running (or be newly triggered) while the rest of the system is being torn down. A similar window exists at i3c_master_unregister() time: cancel_work_sync() on hj_work prevents queued work from completing, but does not stop a fresh Hot-Join IBI from re-queueing the worker, nor a concurrent sysfs writer from toggling Hot-Join via i3c_set_hotjoin(). Introduce a single "shutting down" gate in the I3C core, set under the bus maintenance lock so it is observed by any in-progress DAA path before pending work is cancelled. Install an i3c_bus_type shutdown callback that engages this gate for master devices during system shutdown, and use the same gate in i3c_master_unregister() so both paths get identical guarantees. Once the gate is engaged, the Hot-Join worker, i3c_master_do_daa_ext() and i3c_set_hotjoin() all bail out cleanly, so Hot-Join IBIs that race with shutdown become no-ops, direct DAA callers see -ENODEV, and sysfs writers can no longer re-enable Hot-Join through ops->enable_hotjoin() while the controller is going away. No functional change for the steady-state runtime path; the new checks only take effect once the controller has been marked as shutting down. Note, this patch depends on patch "i3c: master: Consolidate Hot-Join DAA work in the core". Fixes: 3a379bbcea0af ("i3c: Add core I3C infrastructure") Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Reviewed-by: Frank Li <Frank.Li@nxp.com> Link: https://patch.msgid.link/20260608054312.10604-5-adrian.hunter@intel.com Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
2026-06-08 08:43:08 +03:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00
i3c: Add core I3C infrastructure Add core infrastructure to support I3C in Linux and document it. This infrastructure adds basic I3C support. Advanced features will be added afterwards. There are a few design choices that are worth mentioning because they impact the way I3C device drivers can interact with their devices: - all functions used to send I3C/I2C frames must be called in non-atomic context. Mainly done this way to ease implementation, but this is not set in stone, and if anyone needs async support, new functions can be added later on. - the bus element is a separate object, but it's tightly coupled with the master object. We thus have a 1:1 relationship between i3c_bus and i3c_master_controller objects, and if 2 master controllers are connected to the same bus and both exposed to the same Linux instance they will appear as two distinct busses, and devices on this bus will be exposed twice. - I2C backward compatibility has been designed to be transparent to I2C drivers and the I2C subsystem. The I3C master just registers an I2C adapter which creates a new I2C bus. I'd say that, from a representation PoV it's not ideal because what should appear as a single I3C bus exposing I3C and I2C devices here appears as 2 different buses connected to each other through the parenting (the I3C master is the parent of the I2C and I3C busses). On the other hand, I don't see a better solution if we want something that is not invasive. Missing features: - I3C HDR modes are not supported - no support for multi-master and the associated concepts (mastership handover, support for secondary masters, ...) - I2C devices can only be described using DT because this is the only use case I have. However, the framework can easily be extended with ACPI and board info support - I3C slave framework. This has been completely omitted, but shouldn't have a huge impact on the I3C framework because I3C slaves don't see the whole bus, it's only about handling master requests and generating IBIs. Some of the struct, constant and enum definitions could be shared, but most of the I3C slave framework logic will be different Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-19 11:52:29 +02:00