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>
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 @@
*
*****************************************************************************
*/
+
+/* 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 @@
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 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 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)