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authorDale Farnsworth <dale@farnsworth.org>2007-08-14 18:37:14 +0200
committerJean Delvare <khali@hyperion.delvare>2007-08-14 18:37:14 +0200
commita07ad1cc0300931bfd76bfcd2da3ddad743f4a89 (patch)
treed8b7eb634571649f9401d351801e5de87cc5c91d
parent5af0e07f87e7d9be2a9db514af1e338341240f6d (diff)
i2c-mv64xxx: Reinitialize hw and driver on I2C bus hang
Under certain conditions, the mv64xxx I2C bus can hang preventing further operation. To make the driver more robust, we now reset the I2C hardware and the driver state machine when such hangs are detected. Signed-off-by: Dale Farnsworth <dale@farnsworth.org> Acked-by: Mark A. Greer <mgreer@mvista.com> Signed-off-by: Jean Delvare <khali@linux-fr.org>
-rw-r--r--drivers/i2c/busses/i2c-mv64xxx.c31
1 files changed, 17 insertions, 14 deletions
diff --git a/drivers/i2c/busses/i2c-mv64xxx.c b/drivers/i2c/busses/i2c-mv64xxx.c
index 251154ae5d9..bb7bf68a7fb 100644
--- a/drivers/i2c/busses/i2c-mv64xxx.c
+++ b/drivers/i2c/busses/i2c-mv64xxx.c
@@ -107,6 +107,21 @@ struct mv64xxx_i2c_data {
*
*****************************************************************************
*/
+
+/* Reset hardware and initialize FSM */
+static void
+mv64xxx_i2c_hw_init(struct mv64xxx_i2c_data *drv_data)
+{
+ writel(0, drv_data->reg_base + MV64XXX_I2C_REG_SOFT_RESET);
+ writel((((drv_data->freq_m & 0xf) << 3) | (drv_data->freq_n & 0x7)),
+ drv_data->reg_base + MV64XXX_I2C_REG_BAUD);
+ writel(0, drv_data->reg_base + MV64XXX_I2C_REG_SLAVE_ADDR);
+ writel(0, drv_data->reg_base + MV64XXX_I2C_REG_EXT_SLAVE_ADDR);
+ writel(MV64XXX_I2C_REG_CONTROL_TWSIEN | MV64XXX_I2C_REG_CONTROL_STOP,
+ drv_data->reg_base + MV64XXX_I2C_REG_CONTROL);
+ drv_data->state = MV64XXX_I2C_STATE_IDLE;
+}
+
static void
mv64xxx_i2c_fsm(struct mv64xxx_i2c_data *drv_data, u32 status)
{
@@ -203,7 +218,7 @@ mv64xxx_i2c_fsm(struct mv64xxx_i2c_data *drv_data, u32 status)
drv_data->state, status, drv_data->msg->addr,
drv_data->msg->flags);
drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP;
- drv_data->state = MV64XXX_I2C_STATE_IDLE;
+ mv64xxx_i2c_hw_init(drv_data);
drv_data->rc = -EIO;
}
}
@@ -367,6 +382,7 @@ mv64xxx_i2c_wait_for_completion(struct mv64xxx_i2c_data *drv_data)
"mv64xxx: I2C bus locked, block: %d, "
"time_left: %d\n", drv_data->block,
(int)time_left);
+ mv64xxx_i2c_hw_init(drv_data);
}
} else
spin_unlock_irqrestore(&drv_data->lock, flags);
@@ -443,19 +459,6 @@ static const struct i2c_algorithm mv64xxx_i2c_algo = {
*
*****************************************************************************
*/
-static void __devinit
-mv64xxx_i2c_hw_init(struct mv64xxx_i2c_data *drv_data)
-{
- writel(0, drv_data->reg_base + MV64XXX_I2C_REG_SOFT_RESET);
- writel((((drv_data->freq_m & 0xf) << 3) | (drv_data->freq_n & 0x7)),
- drv_data->reg_base + MV64XXX_I2C_REG_BAUD);
- writel(0, drv_data->reg_base + MV64XXX_I2C_REG_SLAVE_ADDR);
- writel(0, drv_data->reg_base + MV64XXX_I2C_REG_EXT_SLAVE_ADDR);
- writel(MV64XXX_I2C_REG_CONTROL_TWSIEN | MV64XXX_I2C_REG_CONTROL_STOP,
- drv_data->reg_base + MV64XXX_I2C_REG_CONTROL);
- drv_data->state = MV64XXX_I2C_STATE_IDLE;
-}
-
static int __devinit
mv64xxx_i2c_map_regs(struct platform_device *pd,
struct mv64xxx_i2c_data *drv_data)