[i2c] [patch 1/2] I2C: S3C2410: Pass the I2C bus number via drivers platform data

[Jean Delvare]

Hi Ben,

On Wed, 09 Jul 2008 13:51:48 +0100, Ben Dooks wrote:
> Allow the platform data to specify the bus bumber that the
> new I2C bus will be given. This is to allow the use of the
> board registration mechanism to specify the new style of
> I2C device registration which allows boards to provide a
> list of attached devices.
> 
> Note, as discussed on the mailing list, we have dropped
> backwards compatibility of adding an dynamic bus number
> as it should not affect most boards to have the bus pinned
> to 0 if they have either not specified platform data for

either?

> driver. Any board supplying platform data will automatically
> have the bus_num field set to 0, and anyone who needs the
> driver on a different bus number can supply platform data
> to set bus_num.

Sounds OK to me.

> 
> Signed-off-by: Ben Dooks <ben-linux at fluff.org>
> 
> Index: linux-2.6.26-rc4-quilt3/drivers/i2c/busses/i2c-s3c2410.c
> ===================================================================
> --- linux-2.6.26-rc4-quilt3.orig/drivers/i2c/busses/i2c-s3c2410.c	2008-06-02 22:55:20.000000000 +0100
> +++ linux-2.6.26-rc4-quilt3/drivers/i2c/busses/i2c-s3c2410.c	2008-06-02 22:55:29.000000000 +0100
> @@ -752,9 +752,12 @@ static int s3c24xx_i2c_init(struct s3c24
>  static int s3c24xx_i2c_probe(struct platform_device *pdev)
>  {
>  	struct s3c24xx_i2c *i2c = &s3c24xx_i2c;
> +	struct s3c2410_platform_i2c *pdata;
>  	struct resource *res;
>  	int ret;
>  
> +	pdata = s3c24xx_i2c_get_platformdata(&pdev->dev);
> +
>  	/* find the clock and enable it */
>  
>  	i2c->dev = &pdev->dev;
> @@ -832,7 +835,15 @@ static int s3c24xx_i2c_probe(struct plat
>  	dev_dbg(&pdev->dev, "irq resource %p (%lu)\n", res,
>  		(unsigned long)res->start);
>  
> -	ret = i2c_add_adapter(&i2c->adap);
> +	/* Note, previous versions of the driver used i2c_add_adapter()
> +	 * to add an bus at any number. We now pass the bus number via

"an bus" doesn't look correct.

> +	 * the platform data, so if unset it will now default to always
> +	 * being bus 0.
> +	 */
> +
> +	i2c->adap.nr = pdata->bus_num;
> +	ret = i2c_add_numbered_adapter(&i2c->adap);
> +
>  	if (ret < 0) {

Best practice is to not have a blank line between a function call and
the test of its return value.

>  		dev_err(&pdev->dev, "failed to add bus to i2c core\n");
>  		goto err_irq;
> Index: linux-2.6.26-rc4-quilt3/include/asm-arm/plat-s3c/iic.h
> ===================================================================
> --- linux-2.6.26-rc4-quilt3.orig/include/asm-arm/plat-s3c/iic.h	2008-06-02 20:12:47.000000000 +0100
> +++ linux-2.6.26-rc4-quilt3/include/asm-arm/plat-s3c/iic.h	2008-06-02 22:55:29.000000000 +0100
> @@ -21,6 +21,7 @@
>  */
>  
>  struct s3c2410_platform_i2c {
> +	int		bus_num;	/* bus number to use */
>  	unsigned int	flags;
>  	unsigned int	slave_addr;	/* slave address for controller */
>  	unsigned long	bus_freq;	/* standard bus frequency */
> 

Other than these details, the patch looks OK to me.

-- 
Jean Delvare