I've seen i2c recovery reporting long loops of:
[ 1035.887818] i2c i2c-4: SCL is stuck low, exit recovery
[ 1037.999748] i2c i2c-4: SCL is stuck low, exit recovery
[ 1040.111694] i2c i2c-4: SCL is stuck low, exit recovery
...
Add a TWSI software reset which clears the status and
STA,STP,IFLG in SW_TWSI_EOP_TWSI_CTL.
With this the recovery works fine and above message is not seen.
Signed-off-by: Jan Glauber <jglauber@cavium.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Do not infinitely retry register readq and writeq operations
in order to not lock up the CPU in case the TWSI gets stuck.
Return -ETIMEDOUT in case of a failed data read. For all other
cases just return so subsequent operations will fail.
Signed-off-by: Jan Glauber <jglauber@cavium.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
In case the high-level controller (HLC) is used the status code is
reported at a different location. Check that location after HLC
write operations if the ready bit is not set and return an appropriate
error code instead of always returning -EAGAIN.
Signed-off-by: Jan Glauber <jglauber@cavium.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Due to a bug in the ThunderX I2C hardware sending STOP during
a recovery attempt could lock up the hardware. To work around
this problem do not send STOP at the beginning of the recovery
but use the override registers to bring the TWSI including
the high-level controller out of the bad state.
Signed-off-by: Dmitry Bazhenov <dmitry.bazhenov@auriga.com>
Signed-off-by: Jan Glauber <jglauber@cavium.com>
[Changed commit message]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
The set SCL recovery function unconditionally pulls the SCL line low.
Only pull SCL line low according to val parameter.
Signed-off-by: Dmitry Bazhenov <dmitry.bazhenov@auriga.com>
Signed-off-by: Jan Glauber <jglauber@cavium.com>
[Changed commit message]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
The register offsets are different between Octeon and ThunderX so move
them into the algorithm struct and get rid of the define.
Signed-off-by: Jan Glauber <jglauber@cavium.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Move common functionality into a separate file in preparation of the
re-use from the ThunderX i2c driver.
Functions are slightly re-ordered but no other changes are included.
Signed-off-by: Jan Glauber <jglauber@cavium.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Jan Glauber