Purpose: Its purpose is to introduce i2c slave capability to the imx i2c bus controller driver. This patch was tested on i.MX6q sabresd, sabreai and UDOO boards. It is a continuation of the work started in the following thread https://www.spinics.net/lists/linux-i2c/msg27340.html The current version is version 7 and is a continuation of the discussion in https://www.spinics.net/lists/linux-i2c/msg30208.html and https://marc.info/?l=linux-i2c&m=154202241501928&w=2 v7 change summary: 1. rebased patchset on i2c/for-next dcd4072a2e0be81b31f94c97183e938b051d24f7 "Merge branch 'i2c/for-5.3' into i2c/for-next" 2. reduced #ifdef usage for i2c-slave and replaced with __maybe_unused 3. re-ordered i2c-slave functions to remove prototyping 4. refactored white space in commenting 5. removed scheduler priority adjustment code 6. updated added function names to use i2c_imx_ prefixing 7. grouped slave related members together in imx_i2c_struct 8. removed v6 changes due to different co-author and not being able to comment on the changes (cc'd co-author in v7) 9. removed cosmetic changes v6 change summary: 1. rebased patchset on i2c/for-next 2. Add STOP signal process in slave receive mode. 3. Add CONFIG_PPC_55xx support v5 change summary: 1. rebased patchset on i2c/for-next 5ff37d1a67e2fed0cae537ad682abb7f6647cca4 "Merge branch 'i2c/for-4.13' into i2c/for-next" v4 change summary: 1. preserved Maxim's authorship, added rework note with signoff 2. re-arranged #include ordering 3. fixed check-patch warnings 4. redefined MAX_EVENTS to an integer 5. removed introduction of error codes 6. changed last_error (atomic_t) to type int 7. removed white lines 8. fixed multiple parenthesis alignment issues 9. removed explicit casting 10. replace udelay with usleep_range 11. removed multiple excess spacing issues 12. check for return of wait_event_interruptible_timeout 13. simplified conditional statements 14. removed dubious pinctrl handling 15. updated commit message Testing: (validated locally with 3 different imx6q devices) For the purpose of this test, any 2 imx6 boards were hooked together to form a multimaster bus. In this configuration, slave and multimaster configurations can alternatively be stress tested. It is rebased and tested on the i2c/for-next branch. 1. enable CONFIG_I2C_SLAVE=y 2. enable CONFIG_I2C_SLAVE_EEPROM=y[m] 3. enable CONFIG_I2C_CHARDEV=y[m] 4. build the kernel 5. install the kernel/drivers on 2 imx devices 6. wire the i2c busses of both devices together 7. load kernel modules if needed 8. instantiate a slave eeprom on device 1 with address A on whatever bus it corresponds to (e.g. `echo slave-24c02 0x1066 > /sys/bus/i2c/devices/i2c-0/new_device`) 9. instantiate a slave eeprom on device 2 with address B on whatever bus it corresponds to (e.g. `echo slave-24c02 0x1064 > /sys/bus/i2c/devices/i2c-2/new_device`) 10. using i2cget/set on the appropriate bus, randomly read/write on device 1 from/to address B. (e.g. `i2cget -y 0 0x64` OR `i2cset -y 0 0x64 0x01 5`) 11. using i2cget/set on the appropriate bus, randomly read/write on device 2 from/to address A. (e.g. `i2cget -y 2 0x66` OR `i2cset -y 2 0x66 0x02 7`) 12. confirm operation between devices by observing the input and output of the i2cget/set functions as well as dumping the contents of the eeprom via the sysfs entry (/sys/bus/i2c/devices/i2c-<BUS #>/new_device) Any constructive comments would be greatly appreciated. Thank you Maxim Syrchin (1): i2c: imx: add slave support drivers/i2c/busses/i2c-imx.c | 753 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++----------- 1 file changed, 708 insertions(+), 45 deletions(-) -- 2.5.5
