Hi Sascha,

something, that skipped both of us:

On Thu, 12 Mar 2009, Sascha Hauer wrote:

> Some Phytec cameras have a I2C GPIO expander which allows it to
> switch between different sensor bus widths. This was previously
> handled in the camera driver. Since handling of this switch
> varies on several boards the cameras are used on, the board
> support seems a better place to handle the switch
> 
> Signed-off-by: Sascha Hauer <s.ha...@pengutronix.de>
> ---
>  arch/arm/mach-pxa/pcm990-baseboard.c |   53 
> ++++++++++++++++++++++++++++------
>  1 files changed, 44 insertions(+), 9 deletions(-)
> 
> diff --git a/arch/arm/mach-pxa/pcm990-baseboard.c 
> b/arch/arm/mach-pxa/pcm990-baseboard.c
> index 34841c7..fd8f786 100644
> --- a/arch/arm/mach-pxa/pcm990-baseboard.c
> +++ b/arch/arm/mach-pxa/pcm990-baseboard.c
> @@ -381,14 +381,49 @@ static struct pca953x_platform_data pca9536_data = {
>       .gpio_base      = NR_BUILTIN_GPIO + 1,
>  };
>  
> -static struct soc_camera_link iclink[] = {
> -     {
> -             .bus_id = 0, /* Must match with the camera ID above */
> -             .gpio   = NR_BUILTIN_GPIO + 1,
> -     }, {
> -             .bus_id = 0, /* Must match with the camera ID above */
> -             .gpio   = -ENXIO,
> +static int gpio_bus_switch;
> +
> +static int pcm990_camera_set_bus_param(struct soc_camera_link *link,
> +             unsigned long flags)
> +{
> +     if (gpio_bus_switch <= 0) {
> +             if (flags == SOCAM_DATAWIDTH_10)
> +                     return 0;
> +             else
> +                     return -EINVAL;
> +     }
> +
> +     if (flags & SOCAM_DATAWIDTH_8)
> +             gpio_set_value(gpio_bus_switch, 1);
> +     else
> +             gpio_set_value(gpio_bus_switch, 0);
> +
> +     return 0;
> +}
> +
> +static unsigned long pcm990_camera_query_bus_param(struct soc_camera_link 
> *link)
> +{
> +     int ret;
> +
> +     if (!gpio_bus_switch) {
> +             ret = gpio_request(NR_BUILTIN_GPIO + 1, "camera");

There's no gpio_free() now... So, for example, you cannot unload the 
extender driver any more, unloading i2c adapter driver (i2c-pxa) produces 
ugly stuff like

pca953x 0-0041: gpiochip_remove() failed, -16

So, we either have to request and free the GPIO in each query / set, or we 
need an explicit .free_bus() call in soc_camera_link. None of the two 
really pleases me, but maybe the latter is slightly less ugly, what do you 
think?

Thanks
Guennadi

> +             if (!ret) {
> +                     gpio_bus_switch = NR_BUILTIN_GPIO + 1;
> +                     gpio_direction_output(gpio_bus_switch, 0);
> +             } else
> +                     gpio_bus_switch = -EINVAL;
>       }
> +
> +     if (gpio_bus_switch > 0)
> +             return SOCAM_DATAWIDTH_8 | SOCAM_DATAWIDTH_10;
> +     else
> +             return SOCAM_DATAWIDTH_10;
> +}
> +
> +static struct soc_camera_link iclink = {
> +     .bus_id = 0, /* Must match with the camera ID above */
> +     .query_bus_param = pcm990_camera_query_bus_param,
> +     .set_bus_param = pcm990_camera_set_bus_param,
>  };
>  
>  /* Board I2C devices. */
> @@ -399,10 +434,10 @@ static struct i2c_board_info __initdata 
> pcm990_i2c_devices[] = {
>               .platform_data = &pca9536_data,
>       }, {
>               I2C_BOARD_INFO("mt9v022", 0x48),
> -             .platform_data = &iclink[0], /* With extender */
> +             .platform_data = &iclink, /* With extender */
>       }, {
>               I2C_BOARD_INFO("mt9m001", 0x5d),
> -             .platform_data = &iclink[0], /* With extender */
> +             .platform_data = &iclink, /* With extender */
>       },
>  };
>  #endif /* CONFIG_VIDEO_PXA27x ||CONFIG_VIDEO_PXA27x_MODULE */
> -- 
> 1.5.6.5
> 
> -- 
> Pengutronix e.K.                           |                             |
> Industrial Linux Solutions                 | http://www.pengutronix.de/  |
> Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0    |
> Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |
> 

---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer
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