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| author | Sachin Surendran <sachin.surendran@alliedtelesis.co.nz> | 2012-11-26 11:20:01 +1300 |
|---|---|---|
| committer | Scott Wood <scottwood@freescale.com> | 2013-06-25 16:53:26 -0500 |
| commit | a16d8aa4726a944ffc1616689ae34ff6a902faba (patch) | |
| tree | 383c8a010d1dc8a2a6a6bda0467f52507b91d9d7 /drivers/i2c | |
| parent | 98c7355fb373d7c29e5c45d0a423810ad2476b34 (diff) | |
| download | blackbird-obmc-linux-a16d8aa4726a944ffc1616689ae34ff6a902faba.tar.gz blackbird-obmc-linux-a16d8aa4726a944ffc1616689ae34ff6a902faba.zip | |
i2c-cpm: Fix to takeback i2c bus master-ship after a collision
In case of collision on i2c bus the controller which lost bus mastership
stays as a slave for all subsequent transfers. This results in the i2c
controller never writing to the bus for future transactions, resulting
in i2c transfer timeouts.
This fix checks for a collision on last I2C transaction and sets the
I2COM_MASTER bit for the new transaction.
Signed-off-by: Sachin Surendran <sachin.surendran@alliedtelesis.co.nz>
Signed-off-by: Scott Wood <scottwood@freescale.com>
Diffstat (limited to 'drivers/i2c')
| -rw-r--r-- | drivers/i2c/busses/i2c-cpm.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-cpm.c b/drivers/i2c/busses/i2c-cpm.c index 3823623baa48..9e6002108720 100644 --- a/drivers/i2c/busses/i2c-cpm.c +++ b/drivers/i2c/busses/i2c-cpm.c @@ -338,6 +338,14 @@ static int cpm_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num) tptr = 0; rptr = 0; + /* + * If there was a collision in the last i2c transaction, + * Set I2COM_MASTER as it was cleared during collision. + */ + if (in_be16(&tbdf->cbd_sc) & BD_SC_CL) { + out_8(&cpm->i2c_reg->i2com, I2COM_MASTER); + } + while (tptr < num) { pmsg = &msgs[tptr]; dev_dbg(&adap->dev, "R: %d T: %d\n", rptr, tptr); |
