kernel_optimize_test/drivers/i2c
Enrik Berkhan 2196d1cf4a i2c-algo-pca: Let PCA9564 recover from unacked data byte (state 0x30)
Currently, the i2c-algo-pca driver does nothing if the chip enters state
0x30 (Data byte in I2CDAT has been transmitted; NOT ACK has been
received).  Thus, the i2c bus connected to the controller gets stuck
afterwards.

I have seen this kind of error on a custom board in certain load
situations most probably caused by interference or noise.

A possible reaction is to let the controller generate a STOP condition.
This is documented in the PCA9564 data sheet (2006-09-01) and the same
is done for other NACK states as well.

Further, state 0x38 isn't handled completely, either. Try to do another
START in this case like the data sheet says. As this couldn't be tested,
I've added a comment to try to reset the chip if the START doesn't help
as suggested by Wolfram Sang.

Signed-off-by: Enrik Berkhan <Enrik.Berkhan@ge.com>
Reviewed-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2009-05-05 08:39:25 +02:00
..
algos i2c-algo-pca: Let PCA9564 recover from unacked data byte (state 0x30) 2009-05-05 08:39:25 +02:00
busses i2c: Timeouts off by 1 2009-05-05 08:39:24 +02:00
chips Move the pcf8591 driver to hwmon 2009-03-30 21:46:43 +02:00
i2c-boardinfo.c i2c: Add i2c_board_info and i2c_new_device() 2007-05-01 23:26:31 +02:00
i2c-core.c i2c: Let new-style drivers implement attach_adapter 2009-04-13 17:02:14 +02:00
i2c-core.h i2c: Add i2c_board_info and i2c_new_device() 2007-05-01 23:26:31 +02:00
i2c-dev.c i2c-dev: Clarify the unit of ioctl I2C_TIMEOUT 2009-02-24 19:19:49 +01:00
Kconfig i2c: Let users select algorithm drivers manually again 2008-08-10 22:56:15 +02:00
Makefile i2c: Add i2c_board_info and i2c_new_device() 2007-05-01 23:26:31 +02:00