[PATCH] i2c-imx: sync with kernel's driver

[Marc Reilly]

On Thursday, January 13, 2011 02:21:37 am Eric Bénard wrote:
> strange behaviour was observed with actual driver : bus lock, probe of
> absent adresses, wrong data read.
> This patch sync the driver with linux's one and after a few tests, we
> don't see anymore strange behaviour (tested on i.MX27).
> 
> Signed-off-by: Eric Bénard <eric at eukrea.com>

FWIW, This patch doesn't seem to break anything for me, but I also wasn't 
seeing any problems (that I was aware of!).

Cheers,
Marc

> ---
>  drivers/i2c/busses/i2c-imx.c |   35 ++++++++---------------------------
>  1 files changed, 8 insertions(+), 27 deletions(-)
> 
> diff --git a/drivers/i2c/busses/i2c-imx.c b/drivers/i2c/busses/i2c-imx.c
> index 266cb52..93e978e 100644
> --- a/drivers/i2c/busses/i2c-imx.c
> +++ b/drivers/i2c/busses/i2c-imx.c
> @@ -151,7 +151,7 @@ static int i2c_imx_bus_busy(struct i2c_adapter
> *adapter, int for_busy) break;
>  		if (!for_busy && !(temp & I2SR_IBB))
>  			break;
> -		if (is_timeout(start, MSECOND)) {
> +		if (is_timeout(start, 500 * MSECOND)) {
>  			dev_err(adapter->dev,
>  				 "<%s> timeout waiting for I2C bus %s\n",
>  				 __func__,for_busy ? "busy" : "not busy");
> @@ -170,34 +170,15 @@ static int i2c_imx_trx_complete(struct i2c_adapter
> *adapter) start = get_time_ns();
>  	while (1) {
>  		unsigned int reg = readb(base + IMX_I2C_I2SR);
> -		if (reg & I2SR_ICF)
> -			break;
> -
> -		if (is_timeout(start, 100 * MSECOND)) {
> -			dev_err(adapter->dev, "<%s> TXR timeout\n", __func__);
> -			return -EIO;
> -		}
> -	}
> -
> -	return 0;
> -}
> -
> -static int i2c_imx_wait_iif(struct i2c_adapter *adapter)
> -{
> -	unsigned long base = adapter->dev->map_base;
> -	uint64_t start;
> -
> -	start = get_time_ns();
> -	while (1) {
> -		unsigned int reg = readb(base + IMX_I2C_I2SR);
>  		if (reg & I2SR_IIF)
>  			break;
> 
>  		if (is_timeout(start, 100 * MSECOND)) {
> -			dev_err(adapter->dev, "<%s> IIF timeout\n", __func__);
> +			dev_err(adapter->dev, "<%s> TXR timeout\n", __func__);
>  			return -EIO;
>  		}
>  	}
> +	writeb(0, base + IMX_I2C_I2SR);
> 
>  	return 0;
>  }
> @@ -277,9 +258,13 @@ static void i2c_imx_stop(struct i2c_adapter *adapter)
>  		udelay(i2c_imx->disable_delay);
>  	}
> 
> +	if (!i2c_imx->stopped) {
> +		i2c_imx_bus_busy(adapter, 0);
> +		i2c_imx->stopped = 1;
> +	}
> +
>  	/* Disable I2C controller, and force our state to stopped */
>  	writeb(0, base + IMX_I2C_I2CR);
> -	i2c_imx->stopped = 1;
>  }
> 
>  static void i2c_imx_set_clk(struct imx_i2c_struct *i2c_imx,
> @@ -379,10 +364,6 @@ static int i2c_imx_read(struct i2c_adapter *adapter,
> struct i2c_msg *msgs) if (result)
>  		return result;
> 
> -	result = i2c_imx_wait_iif(adapter);
> -	if (result)
> -		return result;
> -
>  	/* setup bus to read data */
>  	temp = readb(base + IMX_I2C_I2CR);
>  	temp &= ~I2CR_MTX;