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Parker Newman 3fbde70274 misc: eeprom: eeprom_93cx6: Add quirk for extra read clock cycle 
[ Upstream commit 7738a7ab9d ]

Add a quirk similar to eeprom_93xx46 to add an extra clock cycle before
reading data from the EEPROM.

The 93Cx6 family of EEPROMs output a "dummy 0 bit" between the writing
of the op-code/address from the host to the EEPROM and the reading of
the actual data from the EEPROM.

More info can be found on page 6 of the AT93C46 datasheet (linked below).
Similar notes are found in other 93xx6 datasheets.

In summary the read operation for a 93Cx6 EEPROM is:
Write to EEPROM:	110[A5-A0]	(9 bits)
Read from EEPROM:	0[D15-D0]	(17 bits)

Where:
	110 is the start bit and READ OpCode
	[A5-A0] is the address to read from
	0 is a "dummy bit" preceding the actual data
	[D15-D0] is the actual data.

Looking at the READ timing diagrams in the 93Cx6 datasheets the dummy
bit should be clocked out on the last address bit clock cycle meaning it
should be discarded naturally.

However, depending on the hardware configuration sometimes this dummy
bit is not discarded. This is the case with Exar PCI UARTs which require
an extra clock cycle between sending the address and reading the data.

Datasheet: https://ww1.microchip.com/downloads/en/DeviceDoc/Atmel-5193-SEEPROM-AT93C46D-Datasheet.pdf
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Parker Newman <pnewman@connecttech.com>
Link: https://lore.kernel.org/r/0f23973efefccd2544705a0480b4ad4c2353e407.1727880931.git.pnewman@connecttech.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
History 2024-12-14 20:00:16 +01:00
..
altera-stapl misc: add HAS_IOPORT dependencies 2023-05-29 15:05:00 +01:00
bcm-vk Char/Misc driver changes for 6.6-rc1 2023-09-01 09:53:54 -07:00
c2port driver core: class: remove module * from class_create() 2023-03-17 15:16:33 +01:00
cardreader misc: rtsx: Fix some platforms can not boot and move the l1ss judgment to probe 2023-09-25 10:48:19 +02:00
cb710 cb710: avoid NULL pointer subtraction 2021-10-05 15:50:05 +02:00
cxl Char/Misc driver changes for 6.6-rc1 2023-09-01 09:53:54 -07:00
echo char: Replace HTTP links with HTTPS ones 2020-07-23 09:44:15 +02:00
eeprom misc: eeprom: eeprom_93cx6: Add quirk for extra read clock cycle 2024-12-14 20:00:16 +01:00
genwqe misc: genwqe: make class_genwqe a static const structure 2023-08-11 21:41:33 +02:00
ibmasm ibm: convert to ctime accessor functions 2023-07-13 10:28:02 +02:00
lis3lv02d misc: lis3lv02d_i2c: Fix regulators getting en-/dis-abled twice on suspend/resume 2024-04-03 15:28:43 +02:00
lkdtm Compiler Attributes: disable __counted_by for clang < 19.1.3 2024-12-09 10:32:46 +01:00
mchp_pci1xxxx misc: microchip: pci1xxxx: add support for NVMEM_DEVID_AUTO for OTP device 2024-10-22 15:46:33 +02:00
mei mei: use kvmalloc for read buffer 2024-11-08 16:28:26 +01:00
ocxl mmu_notifiers: rename invalidate_range notifier 2023-08-18 10:12:41 -07:00
pvpanic misc/pvpanic-pci: register attributes via pci_driver 2024-06-12 11:12:35 +02:00
sgi-gru misc: sgi-gru: Don't disable preemption in GRU driver 2024-11-08 16:28:21 +01:00
sgi-xp sgi-xp: simplify sysctl registration 2023-03-09 17:32:13 +01:00
ti-st misc: st_core: Do not call kfree_skb() under spin_lock_irqsave() 2023-11-20 11:59:26 +01:00
uacce uacce: vma_close clears q->qfrs when freeing qfrs 2023-05-31 19:00:26 +01:00
vmw_vmci VMCI: Fix use-after-free when removing resource in vmci_resource_remove() 2024-09-12 11:11:41 +02:00
ad525x_dpot-i2c.c misc: Switch i2c drivers back to use .probe() 2023-05-29 15:04:52 +01:00
ad525x_dpot-spi.c spi: make remove callback a void function 2022-02-09 13:00:45 +00:00
ad525x_dpot.c misc: ad525x_dpot: Make ad_dpot_remove() return void 2021-10-13 14:35:37 +02:00
ad525x_dpot.h misc: ad525x_dpot: Make ad_dpot_remove() return void 2021-10-13 14:35:37 +02:00
apds990x.c misc: apds990x: Fix missing pm_runtime_disable() 2024-12-09 10:32:37 +01:00
apds9802als.c misc: Switch i2c drivers back to use .probe() 2023-05-29 15:04:52 +01:00
atmel-ssc.c misc: atmel-ssc: Use devm_platform_get_and_ioremap_resource() 2023-08-04 15:38:45 +02:00
bh1770glc.c misc: Switch i2c drivers back to use .probe() 2023-05-29 15:04:52 +01:00
cs5535-mfgpt.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 206 2019-05-30 11:29:53 -07:00
ds1682.c misc: Switch i2c drivers back to use .probe() 2023-05-29 15:04:52 +01:00
dummy-irq.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 2019-06-19 17:09:55 +02:00
dw-xdata-pcie.c misc: Add Synopsys DesignWare xData IP driver 2021-04-05 13:15:52 +02:00
enclosure.c drivers: remove struct module * setting from struct class 2023-03-17 15:16:27 +01:00
fastrpc.c misc: fastrpc: Fix double free of 'buf' in error path 2024-09-12 11:11:41 +02:00
gehc-achc.c misc: gehc: Add SPI ID table 2021-10-05 15:47:18 +02:00
hi6421v600-irq.c misc: hi6421-spmi-pmic: Remove redundant dev_err() 2023-08-04 15:39:10 +02:00
hisi_hikey_usb.c misc: hisi_hikey_usb: change the DT schema 2021-09-14 10:57:31 +02:00
hmc6352.c misc: Switch i2c drivers back to use .probe() 2023-05-29 15:04:52 +01:00
hpilo.c misc: hpilo: make ilo_class a static const structure 2023-08-11 21:41:36 +02:00
hpilo.h misc: hpilo: map iLO shared memory by PCI revision id 2021-06-04 15:28:23 +02:00
ibmvmc.c ibm: convert to ctime accessor functions 2023-07-13 10:28:02 +02:00
ibmvmc.h misc: Use the correct style for SPDX License Identifier 2019-10-10 15:34:40 +02:00
ics932s401.c misc: Switch i2c drivers back to use .probe() 2023-05-29 15:04:52 +01:00
isl29003.c misc: Switch i2c drivers back to use .probe() 2023-05-29 15:04:52 +01:00
isl29020.c misc: Switch i2c drivers back to use .probe() 2023-05-29 15:04:52 +01:00
Kconfig misc: open-dice: make OPEN_DICE depend on HAS_IOMEM 2023-08-04 15:39:42 +02:00
kgdbts.c kgdbts: fix return value of __setup handler 2022-03-18 14:17:56 +01:00
lattice-ecp3-config.c spi: make remove callback a void function 2022-02-09 13:00:45 +00:00
Makefile misc: tps6594-pfsm: Add driver for TI TPS6594 PFSM 2023-06-15 13:41:53 +02:00
open-dice.c misc: open-dice: Fix spurious lockdep warning 2024-03-01 13:34:51 +01:00
pch_phub.c misc: pch_phub: Remove superfluous descriptions to non-existent args 'offset_address' 2020-07-01 15:05:37 +02:00
pci_endpoint_test.c misc: pci_endpoint_test: Add Device ID for R-Car S4-8 PCIe controller 2023-11-28 17:19:44 +00:00
phantom.c driver core: class: remove module * from class_create() 2023-03-17 15:16:33 +01:00
qcom-coincell.c misc: Explicitly include correct DT includes 2023-08-04 15:39:04 +02:00
smpro-errmon.c misc: smpro-errmon: Remove the unneeded include <linux/i2c.h> 2023-05-31 19:00:10 +01:00
smpro-misc.c misc: smpro-misc: Add Ampere's Altra SMpro misc driver 2022-11-10 19:03:03 +01:00
sram-exec.c mm: Introduce set_memory_rox() 2022-12-15 10:37:26 -08:00
sram.c misc: Explicitly include correct DT includes 2023-08-04 15:39:04 +02:00
sram.h misc: sram: Improve and simplify clk handling 2023-03-09 17:31:53 +01:00
tifm_7xx1.c misc: tifm: fix possible memory leak in tifm_7xx1_switch_media() 2022-11-23 19:55:26 +01:00
tifm_core.c driver core: make struct bus_type.uevent() take a const * 2023-01-27 13:45:52 +01:00
tps6594-esm.c Merge 6.5-rc6 into char-misc-next 2023-08-13 22:14:51 +02:00
tps6594-pfsm.c misc: tps6594: Remove redundant dev_err_probe() for platform_get_irq_byname() 2023-08-12 12:58:40 +02:00
tsl2550.c misc: Switch i2c drivers back to use .probe() 2023-05-29 15:04:52 +01:00
vcpu_stall_detector.c misc: Explicitly include correct DT includes 2023-08-04 15:39:04 +02:00
vmw_balloon.c misc: vmw_balloon: fix memory leak with using debugfs_lookup() 2023-02-08 13:24:22 +01:00
xilinx_sdfec.c misc: Explicitly include correct DT includes 2023-08-04 15:39:04 +02:00
xilinx_tmr_inject.c misc: Explicitly include correct DT includes 2023-08-04 15:39:04 +02:00
xilinx_tmr_manager.c misc: Explicitly include correct DT includes 2023-08-04 15:39:04 +02:00