linux/drivers/base/soc.c

258 lines
6.2 KiB

base: soc: Introduce soc_device_match() interface We keep running into cases where device drivers want to know the exact version of the a SoC they are currently running on. In the past, this has usually been done through a vendor specific API that can be called by a driver, or by directly accessing some kind of version register that is not part of the device itself but that belongs to a global register area of the chip. Common reasons for doing this include: - A machine is not using devicetree or similar for passing data about on-chip devices, but just announces their presence using boot-time platform devices, and the machine code itself does not care about the revision. - There is existing firmware or boot loaders with existing DT binaries with generic compatible strings that do not identify the particular revision of each device, but the driver knows which SoC revisions include which part. - A prerelease version of a chip has some quirks and we are using the same version of the bootloader and the DT blob on both the prerelease and the final version. An update of the DT binding seems inappropriate because that would involve maintaining multiple copies of the dts and/or bootloader. This patch introduces the soc_device_match() interface that is meant to work like of_match_node() but instead of identifying the version of a device, it identifies the SoC itself using a vendor-agnostic interface. Unlike of_match_node(), we do not do an exact string compare but instead use glob_match() to allow wildcards in strings. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-21 14:57:19 +08:00
base: soc: Allow early registration of a single SoC device Commit 1da1b3628df34a2a ("base: soc: Early register bus when needed") added support for early registration of SoC devices from a core_initcall(). However, some drivers need to check the SoC revision from an early_initcall(), which is even earlier. A specific example is the Renesas R-Car SYSC driver, which manages PM Domains and thus needs to be initialized from an early_initcall. Preproduction versions of the R-Car H3 SoC have an additional power area, which no longer exists on H3 ES2.0, so the R-Car SYSC driver needs to check the exact SoC revision before instantiating a PM Domain for that power area. While registering the SoC bus and device, and using soc_device_match(), from an early_initcall() do work, the "soc" directory and the "soc0" file end up wrongly in the sysfs root, as the "bus" resp. "devices" directories haven't been created yet. To fix this, allow to register a single SoC device early on. As long as the SoC bus isn't registered, soc_device_match() just matches against this early device. When the SoC bus is registered later, the early device is registered for real. Note that soc_device_register() returns NULL (no error, but also not a valid pointer) when registering an early device. Hence platform devices cannot be instantiated as children of the "soc0" node representing an early SoC device. This should not be an issue, as that practice has been deprecated for new platforms. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Acked-by: Arnd Bergmann <arnd@arndb.de>
2017-03-09 14:17:50 +01:00
base: soc: Allow early registration of a single SoC device Commit 1da1b3628df34a2a ("base: soc: Early register bus when needed") added support for early registration of SoC devices from a core_initcall(). However, some drivers need to check the SoC revision from an early_initcall(), which is even earlier. A specific example is the Renesas R-Car SYSC driver, which manages PM Domains and thus needs to be initialized from an early_initcall. Preproduction versions of the R-Car H3 SoC have an additional power area, which no longer exists on H3 ES2.0, so the R-Car SYSC driver needs to check the exact SoC revision before instantiating a PM Domain for that power area. While registering the SoC bus and device, and using soc_device_match(), from an early_initcall() do work, the "soc" directory and the "soc0" file end up wrongly in the sysfs root, as the "bus" resp. "devices" directories haven't been created yet. To fix this, allow to register a single SoC device early on. As long as the SoC bus isn't registered, soc_device_match() just matches against this early device. When the SoC bus is registered later, the early device is registered for real. Note that soc_device_register() returns NULL (no error, but also not a valid pointer) when registering an early device. Hence platform devices cannot be instantiated as children of the "soc0" node representing an early SoC device. This should not be an issue, as that practice has been deprecated for new platforms. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Acked-by: Arnd Bergmann <arnd@arndb.de>
2017-03-09 14:17:50 +01:00
base: soc: Allow early registration of a single SoC device Commit 1da1b3628df34a2a ("base: soc: Early register bus when needed") added support for early registration of SoC devices from a core_initcall(). However, some drivers need to check the SoC revision from an early_initcall(), which is even earlier. A specific example is the Renesas R-Car SYSC driver, which manages PM Domains and thus needs to be initialized from an early_initcall. Preproduction versions of the R-Car H3 SoC have an additional power area, which no longer exists on H3 ES2.0, so the R-Car SYSC driver needs to check the exact SoC revision before instantiating a PM Domain for that power area. While registering the SoC bus and device, and using soc_device_match(), from an early_initcall() do work, the "soc" directory and the "soc0" file end up wrongly in the sysfs root, as the "bus" resp. "devices" directories haven't been created yet. To fix this, allow to register a single SoC device early on. As long as the SoC bus isn't registered, soc_device_match() just matches against this early device. When the SoC bus is registered later, the early device is registered for real. Note that soc_device_register() returns NULL (no error, but also not a valid pointer) when registering an early device. Hence platform devices cannot be instantiated as children of the "soc0" node representing an early SoC device. This should not be an issue, as that practice has been deprecated for new platforms. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Acked-by: Arnd Bergmann <arnd@arndb.de>
2017-03-09 14:17:50 +01:00
base: soc: Allow early registration of a single SoC device Commit 1da1b3628df34a2a ("base: soc: Early register bus when needed") added support for early registration of SoC devices from a core_initcall(). However, some drivers need to check the SoC revision from an early_initcall(), which is even earlier. A specific example is the Renesas R-Car SYSC driver, which manages PM Domains and thus needs to be initialized from an early_initcall. Preproduction versions of the R-Car H3 SoC have an additional power area, which no longer exists on H3 ES2.0, so the R-Car SYSC driver needs to check the exact SoC revision before instantiating a PM Domain for that power area. While registering the SoC bus and device, and using soc_device_match(), from an early_initcall() do work, the "soc" directory and the "soc0" file end up wrongly in the sysfs root, as the "bus" resp. "devices" directories haven't been created yet. To fix this, allow to register a single SoC device early on. As long as the SoC bus isn't registered, soc_device_match() just matches against this early device. When the SoC bus is registered later, the early device is registered for real. Note that soc_device_register() returns NULL (no error, but also not a valid pointer) when registering an early device. Hence platform devices cannot be instantiated as children of the "soc0" node representing an early SoC device. This should not be an issue, as that practice has been deprecated for new platforms. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Acked-by: Arnd Bergmann <arnd@arndb.de>
2017-03-09 14:17:50 +01:00
base: soc: Allow early registration of a single SoC device Commit 1da1b3628df34a2a ("base: soc: Early register bus when needed") added support for early registration of SoC devices from a core_initcall(). However, some drivers need to check the SoC revision from an early_initcall(), which is even earlier. A specific example is the Renesas R-Car SYSC driver, which manages PM Domains and thus needs to be initialized from an early_initcall. Preproduction versions of the R-Car H3 SoC have an additional power area, which no longer exists on H3 ES2.0, so the R-Car SYSC driver needs to check the exact SoC revision before instantiating a PM Domain for that power area. While registering the SoC bus and device, and using soc_device_match(), from an early_initcall() do work, the "soc" directory and the "soc0" file end up wrongly in the sysfs root, as the "bus" resp. "devices" directories haven't been created yet. To fix this, allow to register a single SoC device early on. As long as the SoC bus isn't registered, soc_device_match() just matches against this early device. When the SoC bus is registered later, the early device is registered for real. Note that soc_device_register() returns NULL (no error, but also not a valid pointer) when registering an early device. Hence platform devices cannot be instantiated as children of the "soc0" node representing an early SoC device. This should not be an issue, as that practice has been deprecated for new platforms. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Acked-by: Arnd Bergmann <arnd@arndb.de>
2017-03-09 14:17:50 +01:00
base: soc: Introduce soc_device_match() interface We keep running into cases where device drivers want to know the exact version of the a SoC they are currently running on. In the past, this has usually been done through a vendor specific API that can be called by a driver, or by directly accessing some kind of version register that is not part of the device itself but that belongs to a global register area of the chip. Common reasons for doing this include: - A machine is not using devicetree or similar for passing data about on-chip devices, but just announces their presence using boot-time platform devices, and the machine code itself does not care about the revision. - There is existing firmware or boot loaders with existing DT binaries with generic compatible strings that do not identify the particular revision of each device, but the driver knows which SoC revisions include which part. - A prerelease version of a chip has some quirks and we are using the same version of the bootloader and the DT blob on both the prerelease and the final version. An update of the DT binding seems inappropriate because that would involve maintaining multiple copies of the dts and/or bootloader. This patch introduces the soc_device_match() interface that is meant to work like of_match_node() but instead of identifying the version of a device, it identifies the SoC itself using a vendor-agnostic interface. Unlike of_match_node(), we do not do an exact string compare but instead use glob_match() to allow wildcards in strings. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-21 14:57:19 +08:00
base: soc: Allow early registration of a single SoC device Commit 1da1b3628df34a2a ("base: soc: Early register bus when needed") added support for early registration of SoC devices from a core_initcall(). However, some drivers need to check the SoC revision from an early_initcall(), which is even earlier. A specific example is the Renesas R-Car SYSC driver, which manages PM Domains and thus needs to be initialized from an early_initcall. Preproduction versions of the R-Car H3 SoC have an additional power area, which no longer exists on H3 ES2.0, so the R-Car SYSC driver needs to check the exact SoC revision before instantiating a PM Domain for that power area. While registering the SoC bus and device, and using soc_device_match(), from an early_initcall() do work, the "soc" directory and the "soc0" file end up wrongly in the sysfs root, as the "bus" resp. "devices" directories haven't been created yet. To fix this, allow to register a single SoC device early on. As long as the SoC bus isn't registered, soc_device_match() just matches against this early device. When the SoC bus is registered later, the early device is registered for real. Note that soc_device_register() returns NULL (no error, but also not a valid pointer) when registering an early device. Hence platform devices cannot be instantiated as children of the "soc0" node representing an early SoC device. This should not be an issue, as that practice has been deprecated for new platforms. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Acked-by: Arnd Bergmann <arnd@arndb.de>
2017-03-09 14:17:50 +01:00
base: soc: Introduce soc_device_match() interface We keep running into cases where device drivers want to know the exact version of the a SoC they are currently running on. In the past, this has usually been done through a vendor specific API that can be called by a driver, or by directly accessing some kind of version register that is not part of the device itself but that belongs to a global register area of the chip. Common reasons for doing this include: - A machine is not using devicetree or similar for passing data about on-chip devices, but just announces their presence using boot-time platform devices, and the machine code itself does not care about the revision. - There is existing firmware or boot loaders with existing DT binaries with generic compatible strings that do not identify the particular revision of each device, but the driver knows which SoC revisions include which part. - A prerelease version of a chip has some quirks and we are using the same version of the bootloader and the DT blob on both the prerelease and the final version. An update of the DT binding seems inappropriate because that would involve maintaining multiple copies of the dts and/or bootloader. This patch introduces the soc_device_match() interface that is meant to work like of_match_node() but instead of identifying the version of a device, it identifies the SoC itself using a vendor-agnostic interface. Unlike of_match_node(), we do not do an exact string compare but instead use glob_match() to allow wildcards in strings. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-21 14:57:19 +08:00
base: soc: Allow early registration of a single SoC device Commit 1da1b3628df34a2a ("base: soc: Early register bus when needed") added support for early registration of SoC devices from a core_initcall(). However, some drivers need to check the SoC revision from an early_initcall(), which is even earlier. A specific example is the Renesas R-Car SYSC driver, which manages PM Domains and thus needs to be initialized from an early_initcall. Preproduction versions of the R-Car H3 SoC have an additional power area, which no longer exists on H3 ES2.0, so the R-Car SYSC driver needs to check the exact SoC revision before instantiating a PM Domain for that power area. While registering the SoC bus and device, and using soc_device_match(), from an early_initcall() do work, the "soc" directory and the "soc0" file end up wrongly in the sysfs root, as the "bus" resp. "devices" directories haven't been created yet. To fix this, allow to register a single SoC device early on. As long as the SoC bus isn't registered, soc_device_match() just matches against this early device. When the SoC bus is registered later, the early device is registered for real. Note that soc_device_register() returns NULL (no error, but also not a valid pointer) when registering an early device. Hence platform devices cannot be instantiated as children of the "soc0" node representing an early SoC device. This should not be an issue, as that practice has been deprecated for new platforms. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Acked-by: Arnd Bergmann <arnd@arndb.de>
2017-03-09 14:17:50 +01:00
base: soc: Introduce soc_device_match() interface We keep running into cases where device drivers want to know the exact version of the a SoC they are currently running on. In the past, this has usually been done through a vendor specific API that can be called by a driver, or by directly accessing some kind of version register that is not part of the device itself but that belongs to a global register area of the chip. Common reasons for doing this include: - A machine is not using devicetree or similar for passing data about on-chip devices, but just announces their presence using boot-time platform devices, and the machine code itself does not care about the revision. - There is existing firmware or boot loaders with existing DT binaries with generic compatible strings that do not identify the particular revision of each device, but the driver knows which SoC revisions include which part. - A prerelease version of a chip has some quirks and we are using the same version of the bootloader and the DT blob on both the prerelease and the final version. An update of the DT binding seems inappropriate because that would involve maintaining multiple copies of the dts and/or bootloader. This patch introduces the soc_device_match() interface that is meant to work like of_match_node() but instead of identifying the version of a device, it identifies the SoC itself using a vendor-agnostic interface. Unlike of_match_node(), we do not do an exact string compare but instead use glob_match() to allow wildcards in strings. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-21 14:57:19 +08:00
base: soc: Allow early registration of a single SoC device Commit 1da1b3628df34a2a ("base: soc: Early register bus when needed") added support for early registration of SoC devices from a core_initcall(). However, some drivers need to check the SoC revision from an early_initcall(), which is even earlier. A specific example is the Renesas R-Car SYSC driver, which manages PM Domains and thus needs to be initialized from an early_initcall. Preproduction versions of the R-Car H3 SoC have an additional power area, which no longer exists on H3 ES2.0, so the R-Car SYSC driver needs to check the exact SoC revision before instantiating a PM Domain for that power area. While registering the SoC bus and device, and using soc_device_match(), from an early_initcall() do work, the "soc" directory and the "soc0" file end up wrongly in the sysfs root, as the "bus" resp. "devices" directories haven't been created yet. To fix this, allow to register a single SoC device early on. As long as the SoC bus isn't registered, soc_device_match() just matches against this early device. When the SoC bus is registered later, the early device is registered for real. Note that soc_device_register() returns NULL (no error, but also not a valid pointer) when registering an early device. Hence platform devices cannot be instantiated as children of the "soc0" node representing an early SoC device. This should not be an issue, as that practice has been deprecated for new platforms. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Acked-by: Arnd Bergmann <arnd@arndb.de>
2017-03-09 14:17:50 +01:00
base: soc: Introduce soc_device_match() interface We keep running into cases where device drivers want to know the exact version of the a SoC they are currently running on. In the past, this has usually been done through a vendor specific API that can be called by a driver, or by directly accessing some kind of version register that is not part of the device itself but that belongs to a global register area of the chip. Common reasons for doing this include: - A machine is not using devicetree or similar for passing data about on-chip devices, but just announces their presence using boot-time platform devices, and the machine code itself does not care about the revision. - There is existing firmware or boot loaders with existing DT binaries with generic compatible strings that do not identify the particular revision of each device, but the driver knows which SoC revisions include which part. - A prerelease version of a chip has some quirks and we are using the same version of the bootloader and the DT blob on both the prerelease and the final version. An update of the DT binding seems inappropriate because that would involve maintaining multiple copies of the dts and/or bootloader. This patch introduces the soc_device_match() interface that is meant to work like of_match_node() but instead of identifying the version of a device, it identifies the SoC itself using a vendor-agnostic interface. Unlike of_match_node(), we do not do an exact string compare but instead use glob_match() to allow wildcards in strings. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-21 14:57:19 +08:00
base: soc: Allow early registration of a single SoC device Commit 1da1b3628df34a2a ("base: soc: Early register bus when needed") added support for early registration of SoC devices from a core_initcall(). However, some drivers need to check the SoC revision from an early_initcall(), which is even earlier. A specific example is the Renesas R-Car SYSC driver, which manages PM Domains and thus needs to be initialized from an early_initcall. Preproduction versions of the R-Car H3 SoC have an additional power area, which no longer exists on H3 ES2.0, so the R-Car SYSC driver needs to check the exact SoC revision before instantiating a PM Domain for that power area. While registering the SoC bus and device, and using soc_device_match(), from an early_initcall() do work, the "soc" directory and the "soc0" file end up wrongly in the sysfs root, as the "bus" resp. "devices" directories haven't been created yet. To fix this, allow to register a single SoC device early on. As long as the SoC bus isn't registered, soc_device_match() just matches against this early device. When the SoC bus is registered later, the early device is registered for real. Note that soc_device_register() returns NULL (no error, but also not a valid pointer) when registering an early device. Hence platform devices cannot be instantiated as children of the "soc0" node representing an early SoC device. This should not be an issue, as that practice has been deprecated for new platforms. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Acked-by: Arnd Bergmann <arnd@arndb.de>
2017-03-09 14:17:50 +01:00
base: soc: Introduce soc_device_match() interface We keep running into cases where device drivers want to know the exact version of the a SoC they are currently running on. In the past, this has usually been done through a vendor specific API that can be called by a driver, or by directly accessing some kind of version register that is not part of the device itself but that belongs to a global register area of the chip. Common reasons for doing this include: - A machine is not using devicetree or similar for passing data about on-chip devices, but just announces their presence using boot-time platform devices, and the machine code itself does not care about the revision. - There is existing firmware or boot loaders with existing DT binaries with generic compatible strings that do not identify the particular revision of each device, but the driver knows which SoC revisions include which part. - A prerelease version of a chip has some quirks and we are using the same version of the bootloader and the DT blob on both the prerelease and the final version. An update of the DT binding seems inappropriate because that would involve maintaining multiple copies of the dts and/or bootloader. This patch introduces the soc_device_match() interface that is meant to work like of_match_node() but instead of identifying the version of a device, it identifies the SoC itself using a vendor-agnostic interface. Unlike of_match_node(), we do not do an exact string compare but instead use glob_match() to allow wildcards in strings. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-21 14:57:19 +08:00
base: soc: Allow early registration of a single SoC device Commit 1da1b3628df34a2a ("base: soc: Early register bus when needed") added support for early registration of SoC devices from a core_initcall(). However, some drivers need to check the SoC revision from an early_initcall(), which is even earlier. A specific example is the Renesas R-Car SYSC driver, which manages PM Domains and thus needs to be initialized from an early_initcall. Preproduction versions of the R-Car H3 SoC have an additional power area, which no longer exists on H3 ES2.0, so the R-Car SYSC driver needs to check the exact SoC revision before instantiating a PM Domain for that power area. While registering the SoC bus and device, and using soc_device_match(), from an early_initcall() do work, the "soc" directory and the "soc0" file end up wrongly in the sysfs root, as the "bus" resp. "devices" directories haven't been created yet. To fix this, allow to register a single SoC device early on. As long as the SoC bus isn't registered, soc_device_match() just matches against this early device. When the SoC bus is registered later, the early device is registered for real. Note that soc_device_register() returns NULL (no error, but also not a valid pointer) when registering an early device. Hence platform devices cannot be instantiated as children of the "soc0" node representing an early SoC device. This should not be an issue, as that practice has been deprecated for new platforms. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Acked-by: Arnd Bergmann <arnd@arndb.de>
2017-03-09 14:17:50 +01:00
base: soc: Introduce soc_device_match() interface We keep running into cases where device drivers want to know the exact version of the a SoC they are currently running on. In the past, this has usually been done through a vendor specific API that can be called by a driver, or by directly accessing some kind of version register that is not part of the device itself but that belongs to a global register area of the chip. Common reasons for doing this include: - A machine is not using devicetree or similar for passing data about on-chip devices, but just announces their presence using boot-time platform devices, and the machine code itself does not care about the revision. - There is existing firmware or boot loaders with existing DT binaries with generic compatible strings that do not identify the particular revision of each device, but the driver knows which SoC revisions include which part. - A prerelease version of a chip has some quirks and we are using the same version of the bootloader and the DT blob on both the prerelease and the final version. An update of the DT binding seems inappropriate because that would involve maintaining multiple copies of the dts and/or bootloader. This patch introduces the soc_device_match() interface that is meant to work like of_match_node() but instead of identifying the version of a device, it identifies the SoC itself using a vendor-agnostic interface. Unlike of_match_node(), we do not do an exact string compare but instead use glob_match() to allow wildcards in strings. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-21 14:57:19 +08:00
base: soc: Allow early registration of a single SoC device Commit 1da1b3628df34a2a ("base: soc: Early register bus when needed") added support for early registration of SoC devices from a core_initcall(). However, some drivers need to check the SoC revision from an early_initcall(), which is even earlier. A specific example is the Renesas R-Car SYSC driver, which manages PM Domains and thus needs to be initialized from an early_initcall. Preproduction versions of the R-Car H3 SoC have an additional power area, which no longer exists on H3 ES2.0, so the R-Car SYSC driver needs to check the exact SoC revision before instantiating a PM Domain for that power area. While registering the SoC bus and device, and using soc_device_match(), from an early_initcall() do work, the "soc" directory and the "soc0" file end up wrongly in the sysfs root, as the "bus" resp. "devices" directories haven't been created yet. To fix this, allow to register a single SoC device early on. As long as the SoC bus isn't registered, soc_device_match() just matches against this early device. When the SoC bus is registered later, the early device is registered for real. Note that soc_device_register() returns NULL (no error, but also not a valid pointer) when registering an early device. Hence platform devices cannot be instantiated as children of the "soc0" node representing an early SoC device. This should not be an issue, as that practice has been deprecated for new platforms. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Acked-by: Arnd Bergmann <arnd@arndb.de>
2017-03-09 14:17:50 +01:00
base: soc: Introduce soc_device_match() interface We keep running into cases where device drivers want to know the exact version of the a SoC they are currently running on. In the past, this has usually been done through a vendor specific API that can be called by a driver, or by directly accessing some kind of version register that is not part of the device itself but that belongs to a global register area of the chip. Common reasons for doing this include: - A machine is not using devicetree or similar for passing data about on-chip devices, but just announces their presence using boot-time platform devices, and the machine code itself does not care about the revision. - There is existing firmware or boot loaders with existing DT binaries with generic compatible strings that do not identify the particular revision of each device, but the driver knows which SoC revisions include which part. - A prerelease version of a chip has some quirks and we are using the same version of the bootloader and the DT blob on both the prerelease and the final version. An update of the DT binding seems inappropriate because that would involve maintaining multiple copies of the dts and/or bootloader. This patch introduces the soc_device_match() interface that is meant to work like of_match_node() but instead of identifying the version of a device, it identifies the SoC itself using a vendor-agnostic interface. Unlike of_match_node(), we do not do an exact string compare but instead use glob_match() to allow wildcards in strings. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-21 14:57:19 +08:00
base: soc: Allow early registration of a single SoC device Commit 1da1b3628df34a2a ("base: soc: Early register bus when needed") added support for early registration of SoC devices from a core_initcall(). However, some drivers need to check the SoC revision from an early_initcall(), which is even earlier. A specific example is the Renesas R-Car SYSC driver, which manages PM Domains and thus needs to be initialized from an early_initcall. Preproduction versions of the R-Car H3 SoC have an additional power area, which no longer exists on H3 ES2.0, so the R-Car SYSC driver needs to check the exact SoC revision before instantiating a PM Domain for that power area. While registering the SoC bus and device, and using soc_device_match(), from an early_initcall() do work, the "soc" directory and the "soc0" file end up wrongly in the sysfs root, as the "bus" resp. "devices" directories haven't been created yet. To fix this, allow to register a single SoC device early on. As long as the SoC bus isn't registered, soc_device_match() just matches against this early device. When the SoC bus is registered later, the early device is registered for real. Note that soc_device_register() returns NULL (no error, but also not a valid pointer) when registering an early device. Hence platform devices cannot be instantiated as children of the "soc0" node representing an early SoC device. This should not be an issue, as that practice has been deprecated for new platforms. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Acked-by: Arnd Bergmann <arnd@arndb.de>
2017-03-09 14:17:50 +01:00
base: soc: Introduce soc_device_match() interface We keep running into cases where device drivers want to know the exact version of the a SoC they are currently running on. In the past, this has usually been done through a vendor specific API that can be called by a driver, or by directly accessing some kind of version register that is not part of the device itself but that belongs to a global register area of the chip. Common reasons for doing this include: - A machine is not using devicetree or similar for passing data about on-chip devices, but just announces their presence using boot-time platform devices, and the machine code itself does not care about the revision. - There is existing firmware or boot loaders with existing DT binaries with generic compatible strings that do not identify the particular revision of each device, but the driver knows which SoC revisions include which part. - A prerelease version of a chip has some quirks and we are using the same version of the bootloader and the DT blob on both the prerelease and the final version. An update of the DT binding seems inappropriate because that would involve maintaining multiple copies of the dts and/or bootloader. This patch introduces the soc_device_match() interface that is meant to work like of_match_node() but instead of identifying the version of a device, it identifies the SoC itself using a vendor-agnostic interface. Unlike of_match_node(), we do not do an exact string compare but instead use glob_match() to allow wildcards in strings. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Yangbo Lu <yangbo.lu@nxp.com> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-09-21 14:57:19 +08:00