diff options
| author | Dinh Nguyen <r00091@freescale.com> | 2009-09-01 11:12:12 -0500 |
|---|---|---|
| committer | Dinh Nguyen <r00091@freescale.com> | 2009-09-01 11:30:17 -0500 |
| commit | 27f1b60875b736e73e6f7a8db305368995051de7 (patch) | |
| tree | d2b63e4da50439ce56998b86466678bf3f8e3685 /drivers | |
| parent | c7c619b467c410721535d377fef02776031e5659 (diff) | |
ENGR00116103 Need to poll I2C Busy bit after a repeat-start signal
Errors on the I2C lines when the Busy bit was not being polled during
a repeat-start transaction.
Signed-off-by: Dinh Nguyen <Dinh.Nguyen@freescale.com>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/i2c/busses/mxc_i2c.c | 16 |
1 files changed, 13 insertions, 3 deletions
diff --git a/drivers/i2c/busses/mxc_i2c.c b/drivers/i2c/busses/mxc_i2c.c index 54dd0f1dec65..689ed1ec0c1d 100644 --- a/drivers/i2c/busses/mxc_i2c.c +++ b/drivers/i2c/busses/mxc_i2c.c @@ -235,10 +235,11 @@ static int mxc_i2c_start(mxc_i2c_device *dev, struct i2c_msg *msg) * @param *msg pointer to a message structure that contains the slave * address */ -static void mxc_i2c_repstart(mxc_i2c_device * dev, struct i2c_msg *msg) +static void mxc_i2c_repstart(mxc_i2c_device *dev, struct i2c_msg *msg) { - volatile unsigned int cr; + volatile unsigned int cr, sr; unsigned int addr_trans; + int retry = 16; /* * Set the slave address and the requested transfer mode @@ -251,7 +252,16 @@ static void mxc_i2c_repstart(mxc_i2c_device * dev, struct i2c_msg *msg) cr = readw(dev->membase + MXC_I2CR); cr |= MXC_I2CR_RSTA; writew(cr, dev->membase + MXC_I2CR); - udelay(3); + /* Wait till the Bus Busy bit is set */ + sr = readw(dev->membase + MXC_I2SR); + while (retry-- && (!(sr & MXC_I2SR_IBB))) { + udelay(3); + sr = readw(dev->membase + MXC_I2SR); + } + if (retry <= 0) { + dev_err(&dev->adap.dev, "Could not grab Bus ownership\n"); + return -EBUSY; + } writew(addr_trans, dev->membase + MXC_I2DR); } |