OpenCloudOS-Kernel/drivers/i2c
Valentin Longchamp d49019a069 i2c: mpc: insert DR read in i2c_fixup()
The mpc_i2c_fixup function is called when the bus is not released by a
slave. The function generates 9 pulses that should lead the slave
to release the bus.

The sequence that generates the pulses disables/enables the I2C module
that controls the blocked bus. We have found out on the P2041 SoC that
this could cause the CPU to hang (for a short delay).

To avoid this, this patch introduces a read to the I2CDR register
between the re-enablement of the I2C module in master mode and its
returning to the slave mode instead of the delay (the final delay,
between the pulses is kept), as proposed in procedure from the P2041
reference manual (16.6.2.3), and the other manuals from the mpc83xx and
mpc85xx families.

Signed-off-by: Rainer Boschung <rainer.boschung@keymile.com>
Signed-off-by: Valentin Longchamp <valentin.longchamp@keymile.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-06-03 14:24:16 +02:00
..
algos Merge branch 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux 2014-01-29 19:56:20 -08:00
busses i2c: mpc: insert DR read in i2c_fixup() 2014-06-03 14:24:16 +02:00
muxes Merge branch 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux 2014-01-29 19:56:20 -08:00
Kconfig Remove GENERIC_HARDIRQ config option 2013-09-13 15:09:52 +02:00
Makefile i2c-stub: Move to drivers/i2c 2012-10-28 21:37:00 +01:00
i2c-boardinfo.c i2c: Update the FSF address 2012-03-26 21:47:19 +02:00
i2c-core.c i2c: Add message transfer tracepoints for SMBUS [ver #2] 2014-03-13 22:15:07 +01:00
i2c-core.h i2c: Update the FSF address 2012-03-26 21:47:19 +02:00
i2c-dev.c i2c: i2c-dev: Create 'name' attribute automatically 2013-09-30 06:02:31 +02:00
i2c-mux.c i2c: mux: Inherit retry count and timeout from parent for muxed bus 2013-12-12 22:39:28 +01:00
i2c-smbus.c Update Jean Delvare's e-mail address 2014-01-29 20:40:08 +01:00
i2c-stub.c Update Jean Delvare's e-mail address 2014-01-29 20:40:08 +01:00