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authorFelipe Balbi <balbi@ti.com>2012-09-12 12:58:01 +0200
committerWolfram Sang <w.sang@pengutronix.de>2012-09-12 15:02:28 +0200
commit4151e74177b68c40079d8fe98f2fda4b9792a998 (patch)
treed8848fe19d195f8fcb0f5a543d8e98cecbae0f25 /drivers/i2c
parenti2c: omap: split out [XR]DR and [XR]RDY (diff)
downloadlinux-4151e74177b68c40079d8fe98f2fda4b9792a998.tar.xz
linux-4151e74177b68c40079d8fe98f2fda4b9792a998.zip
i2c: omap: improve i462 errata handling
Make it not depend on ISR's local variables in order to make it easier to re-factor the transmit data loop. Also since we are waiting for XUDF(Transmitter underflow) just before writing data lets not flag the underflow. This is anyways going to go once we write the data. Signed-off-by: Felipe Balbi <balbi@ti.com> Signed-off-by: Shubhrajyoti D <shubhrajyoti@ti.com> Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Diffstat (limited to 'drivers/i2c')
-rw-r--r--drivers/i2c/busses/i2c-omap.c43
1 files changed, 30 insertions, 13 deletions
diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
index 815577b1c89f..fb5722186d95 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -725,27 +725,30 @@ omap_i2c_omap1_isr(int this_irq, void *dev_id)
* data to DATA_REG. Otherwise some data bytes can be lost while transferring
* them from the memory to the I2C interface.
*/
-static int errata_omap3_i462(struct omap_i2c_dev *dev, u16 *stat, int *err)
+static int errata_omap3_i462(struct omap_i2c_dev *dev)
{
unsigned long timeout = 10000;
+ u16 stat;
- while (--timeout && !(*stat & OMAP_I2C_STAT_XUDF)) {
- if (*stat & (OMAP_I2C_STAT_NACK | OMAP_I2C_STAT_AL)) {
+ do {
+ stat = omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG);
+ if (stat & OMAP_I2C_STAT_XUDF)
+ break;
+
+ if (stat & (OMAP_I2C_STAT_NACK | OMAP_I2C_STAT_AL)) {
omap_i2c_ack_stat(dev, (OMAP_I2C_STAT_XRDY |
OMAP_I2C_STAT_XDR));
- return -ETIMEDOUT;
+ return -EIO;
}
cpu_relax();
- *stat = omap_i2c_read_reg(dev, OMAP_I2C_STAT_REG);
- }
+ } while (--timeout);
if (!timeout) {
dev_err(dev->dev, "timeout waiting on XUDF bit\n");
return 0;
}
- *err |= OMAP_I2C_STAT_XUDF;
return 0;
}
@@ -903,9 +906,16 @@ complete:
}
}
- if ((dev->errata & I2C_OMAP_ERRATA_I462) &&
- errata_omap3_i462(dev, &stat, &err))
- goto complete;
+ if (dev->errata & I2C_OMAP_ERRATA_I462) {
+ int ret;
+
+ ret = errata_omap3_i462(dev);
+ stat = omap_i2c_read_reg(dev,
+ OMAP_I2C_STAT_REG);
+
+ if (ret < 0)
+ goto complete;
+ }
omap_i2c_write_reg(dev, OMAP_I2C_DATA_REG, w);
}
@@ -943,9 +953,16 @@ complete:
}
}
- if ((dev->errata & I2C_OMAP_ERRATA_I462) &&
- errata_omap3_i462(dev, &stat, &err))
- goto complete;
+ if (dev->errata & I2C_OMAP_ERRATA_I462) {
+ int ret;
+
+ ret = errata_omap3_i462(dev);
+ stat = omap_i2c_read_reg(dev,
+ OMAP_I2C_STAT_REG);
+
+ if (ret < 0)
+ goto complete;
+ }
omap_i2c_write_reg(dev, OMAP_I2C_DATA_REG, w);
}