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 <[email protected]>
> ---
> arch/arm/mach-pxa/pcm990-baseboard.c | 49 +++++++++++++++++++++++++++------
> 1 files changed, 40 insertions(+), 9 deletions(-)
>
> diff --git a/arch/arm/mach-pxa/pcm990-baseboard.c
> b/arch/arm/mach-pxa/pcm990-baseboard.c
> index 34841c7..8b01565 100644
> --- a/arch/arm/mach-pxa/pcm990-baseboard.c
> +++ b/arch/arm/mach-pxa/pcm990-baseboard.c
> @@ -381,14 +381,45 @@ 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)
> + return 0;
Are you really sure you don't want to return an error here? In
query_bus_param() below, if you fail to get the GPIO, you set
gpio_bus_switch to -EINVAL and return only 10 bit. Now if a buggy host
driver still requests 8 bits, mt9m001 will call ->set_bus_param and you
will happily return 0...
> +
> + 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");
> + 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 +430,10 @@ 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
>
Thanks
Guennadi
---
Guennadi Liakhovetski, Ph.D.
Freelance Open-Source Software Developer
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