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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 /drivers/i2c
parent5af0e07f87e7d9be2a9db514af1e338341240f6d (diff)
downloadop-kernel-dev-a07ad1cc0300931bfd76bfcd2da3ddad743f4a89.zip
op-kernel-dev-a07ad1cc0300931bfd76bfcd2da3ddad743f4a89.tar.gz
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>
Diffstat (limited to 'drivers/i2c')
-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 251154a..bb7bf68 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)
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