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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>
This commit is contained in:
Dale Farnsworth 2007-08-14 18:37:14 +02:00 committed by Jean Delvare
parent 5af0e07f87
commit a07ad1cc03
1 changed files with 17 additions and 14 deletions
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31
drivers/i2c/busses/i2c-mv64xxx.c
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@ -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)