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authorFelipe Balbi <balbi@ti.com>2012-09-12 16:28:01 +0530
committerWolfram Sang <w.sang@pengutronix.de>2012-09-12 15:02:28 +0200
commit4151e74177b68c40079d8fe98f2fda4b9792a998 (patch)
treed8848fe19d195f8fcb0f5a543d8e98cecbae0f25 /drivers/i2c
parent6d9939f651419a63e091105663821f9c7d3fec37 (diff)
downloadlinux-4151e74177b68c40079d8fe98f2fda4b9792a998.tar.gz
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);
 			}