android_kernel_xiaomi_sm8450/drivers/i2c
Edgar Cherkasov e058e7a4bc i2c: i2c-scmi: add a MS HID
Description of the problem:
 - i2c-scmi driver contains only two identifiers "SMBUS01" and "SMBUSIBM";
 - the fist HID (SMBUS01) is clearly defined in "SMBus Control Method
   Interface Specification, version 1.0": "Each device must specify
   'SMBUS01' as its _HID and use a unique _UID value";
 - unfortunately, BIOS vendors (like AMI) seem to ignore this requirement
   and implement "SMB0001" HID instead of "SMBUS01";
 - I speculate that they do this because only "SMB0001" is hard coded in
   Windows SMBus driver produced by Microsoft.

This leads to following situation:
 - SMBus works out of box in Windows but not in Linux;
 - board vendors are forced to add correct "SMBUS01" HID to BIOS to make
   SMBus work in Linux. Moreover the same board vendors complain that
   tools (3-rd party ASL compiler) do not like the "SMBUS01" identifier
   and produce errors.  So they need to constantly patch the compiler for
   each new version of BIOS.

As it is very unlikely that BIOS vendors implement a correct HID in
future, I would propose to consider whether it is possible to work around
the problem by adding MS HID to the Linux i2c-scmi driver.

v2: move the definition of the new HID to the driver itself.

Signed-off-by: Edgar Cherkasov <echerkasov@dev.rtsoft.ru>
Signed-off-by: Michael Brunner <Michael.Brunner@kontron.com>
Acked-by: Viktor Krasnov <vkrasnov@dev.rtsoft.ru>
Reviewed-by: Jean Delvare <jdelvare@suse.de>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2017-04-16 21:48:06 +02:00
..
algos i2c: algo-bit: declare i2c_bit_quirk_no_clk_stretch as static 2016-05-11 17:16:30 +02:00
busses i2c: i2c-scmi: add a MS HID 2017-04-16 21:48:06 +02:00
muxes i2c: mux: ltc4306: LTC4306 and LTC4305 I2C multiplexer/switch 2017-04-12 17:10:31 +02:00
i2c-boardinfo.c Revert "i2c: copy device properties when using i2c_register_board_info()" 2017-03-09 16:41:48 +01:00
i2c-core.c Merge branch 'i2c/for-4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux 2017-02-25 14:21:18 -08:00
i2c-core.h i2c: remove FSF address 2014-11-07 18:35:33 +01:00
i2c-dev.c i2c: fix kernel memory disclosure in dev interface 2017-01-12 20:06:10 +01:00
i2c-mux.c i2c: mux: provide more info on failure in i2c_mux_add_adapter 2017-04-03 14:07:31 +02:00
i2c-slave-eeprom.c i2c: Drop owner assignment from i2c_driver 2015-08-10 08:37:35 +02:00
i2c-smbus.c i2c: use an IRQ to report Host Notify events, not alert 2016-11-24 16:22:06 +01:00
i2c-stub.c i2c: i2c-stub: sort includes 2016-02-20 23:33:39 +01:00
Kconfig Merge branch 'i2c/for-4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux 2016-12-15 12:56:35 -08:00
Makefile i2c: slave-eeprom: add eeprom simulator driver 2014-12-11 22:25:54 +01:00