[PATCH 2/2] drivers: i2c-omap: Add support for shorten I2C timeout

From: Samu Onkalo
Date: Wed Oct 13 2010 - 09:45:52 EST


Use short I2C timeout if requested by i2c-message flag.
This is for cases where the it is known that target chip causes timeout.

Signed-off-by: Samu Onkalo <samu.p.onkalo@xxxxxxxxx>
---
drivers/i2c/busses/i2c-omap.c | 9 ++++++++-
1 files changed, 8 insertions(+), 1 deletions(-)

diff --git a/drivers/i2c/busses/i2c-omap.c b/drivers/i2c/busses/i2c-omap.c
index b33c785..d7ed7ca 100644
--- a/drivers/i2c/busses/i2c-omap.c
+++ b/drivers/i2c/busses/i2c-omap.c
@@ -50,6 +50,7 @@

/* timeout waiting for the controller to respond */
#define OMAP_I2C_TIMEOUT (msecs_to_jiffies(1000))
+#define OMAP_I2C_SHORT_TIMEOUT (msecs_to_jiffies(50))

/* For OMAP3 I2C_IV has changed to I2C_WE (wakeup enable) */
enum {
@@ -548,6 +549,7 @@ static int omap_i2c_xfer_msg(struct i2c_adapter *adap,
struct i2c_msg *msg, int stop)
{
struct omap_i2c_dev *dev = i2c_get_adapdata(adap);
+ unsigned long timeout;
int r;
u16 w;

@@ -618,8 +620,13 @@ static int omap_i2c_xfer_msg(struct i2c_adapter *adap,
*/
if (dev->set_mpu_wkup_lat != NULL)
dev->set_mpu_wkup_lat(dev->dev, dev->latency);
+ if (unlikely((msg->flags & I2C_M_SHORT_TIMEOUT)))
+ timeout = OMAP_I2C_SHORT_TIMEOUT;
+ else
+ timeout = OMAP_I2C_TIMEOUT;
+
r = wait_for_completion_timeout(&dev->cmd_complete,
- OMAP_I2C_TIMEOUT);
+ timeout);
if (dev->set_mpu_wkup_lat != NULL)
dev->set_mpu_wkup_lat(dev->dev, -1);
dev->buf_len = 0;
--
1.6.0.4

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