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i2c: cadence: Check for errata condition involving master receive
authorHarini Katakam <harinik@xilinx.com>
Tue, 13 Jan 2015 18:34:59 +0000 (00:04 +0530)
committerWolfram Sang <wsa@the-dreams.de>
Wed, 14 Jan 2015 10:36:58 +0000 (11:36 +0100)
commit8a86c3aee0cfec09b35159da9d925157f3e4f2cc
tree5c9612020efa6cb0d27c744291a0135451013d1d
parentef2829144dc995d8263dbec3b057a29541e789b4
i2c: cadence: Check for errata condition involving master receive

Cadence I2C controller has the following bugs:
- completion indication is not given to the driver at the end of
a read/receive transfer with HOLD bit set.
- Invalid read transaction are generated on the bus when HW timeout
condition occurs with HOLD bit set.

As a result of the above, if a set of messages to be transferred with
repeated start includes any message following a read message,
completion is never indicated and timeout occurs.
Hence a check is implemented to return -EOPNOTSUPP for such sequences.

Signed-off-by: Harini Katakam <harinik@xilinx.com>
Signed-off-by: Vishnu Motghare <vishnum@xilinx.com>
[wsa: fixed some whitespaces]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
drivers/i2c/busses/i2c-cadence.c