[ Upstream commit 0a355aeb24081e4538d4d424cd189f16c0bbd983 ]
If something goes wrong (such as the SCL being stuck low) then we need
to reset the PCA chip. The issue with this is that on reset we lose all
config settings and the chip ends up in a disabled state which results
in a lock up/high CPU usage. We need to re-apply any configuration that
had previously been set and re-enable the chip.
Signed-off-by: Evan Nimmo <evan.nimmo@alliedtelesis.co.nz>
Reviewed-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit cd217f2300793a106b49c7dfcbfb26e348bc7593 ]
The PCA9665 datasheet says that I2CSTA = 78h indicates that SCL is stuck
low, this differs to the PCA9564 which uses 90h for this indication.
Treat either 0x78 or 0x90 as an indication that the SCL line is stuck.
Based on looking through the PCA9564 and PCA9665 datasheets this should
be safe for both chips. The PCA9564 should not return 0x78 for any valid
state and the PCA9665 should not return 0x90.
Fixes: eff9ec95efaa ("i2c-algo-pca: Add PCA9665 support")
Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Evan Nimmo