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i2c: omap: add notes related to i2c multimaster mode 

No functional changes.

Signed-off-by: Alexander Kochetkov <al.kochet@gmail.com>
Reviewed-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
This commit is contained in:
Alexander Kochetkov 2014-11-22 23:47:14 +04:00 committed by Wolfram Sang
parent b76911d2fe
commit 4f734a3a04
1 changed files with 11 additions and 1 deletions
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12
drivers/i2c/busses/i2c-omap.c
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@ -299,6 +299,12 @@ static void __omap_i2c_init(struct omap_i2c_dev *dev)
/* Take the I2C module out of reset: */
omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN);
/*
* NOTE: right after setting CON_EN, STAT_BB could be 0 while the
* bus is busy. It will be changed to 1 on the next IP FCLK clock.
* udelay(1) will be enough to fix that.
*/
/*
* Don't write to this register if the IE state is 0 as it can
* cause deadlock.
@ -660,7 +666,11 @@ static int omap_i2c_xfer_msg(struct i2c_adapter *adap,
if (!dev->b_hw && stop)
w |= OMAP_I2C_CON_STP;
/*
* NOTE: STAT_BB bit could became 1 here if another master occupy
* the bus. IP successfully complete transfer when the bus will be
* free again (BB reset to 0).
*/
omap_i2c_write_reg(dev, OMAP_I2C_CON_REG, w);
/*