Re: [media-ctl PATCH 1/1] libv4l2subdev: Add v4l2_subdev_enum_mbus_code()

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Sakari,

Thanks for the patch.

On Tuesday 31 July 2012 01:16:00 Sakari Ailus wrote:
> v4l2_subdev_enum_mbus_code() enumerates over supported media bus formats on
> a pad.
> 
> Signed-off-by: Sakari Ailus <sakari.ailus@iki.fi>
> ---
>  src/v4l2subdev.c |   23 +++++++++++++++++++++++
>  src/v4l2subdev.h |   14 ++++++++++++++
>  2 files changed, 37 insertions(+), 0 deletions(-)
> 
> diff --git a/src/v4l2subdev.c b/src/v4l2subdev.c
> index d60bd7e..6b6df0a 100644
> --- a/src/v4l2subdev.c
> +++ b/src/v4l2subdev.c
> @@ -58,6 +58,29 @@ void v4l2_subdev_close(struct media_entity *entity)
>  	entity->fd = -1;
>  }
> 
> +int v4l2_subdev_enum_mbus_code(struct media_entity *entity,
> +			       uint32_t *code, uint32_t pad, uint32_t index)

I would use unsigned int for the pad and index arguments to match the other 
functions. We could then fix all of them in one go to use stdint types to 
match the kernel API types.

> +{
> +	struct v4l2_subdev_mbus_code_enum c;
> +	int ret;
> +
> +	ret = v4l2_subdev_open(entity);
> +	if (ret < 0)
> +		return ret;
> +
> +	memset(&c, 0, sizeof(c));
> +	c.pad = pad;
> +	c.index = index;
> +
> +	ret = ioctl(entity->fd, VIDIOC_SUBDEV_ENUM_MBUS_CODE, &c);
> +	if (ret < 0)
> +		return -errno;
> +
> +	*code = c.code;
> +
> +	return 0;
> +}

What about a higher-level API that would enumerate all formats and return a 
list/array ?

> +
>  int v4l2_subdev_get_format(struct media_entity *entity,
>  	struct v4l2_mbus_framefmt *format, unsigned int pad,
>  	enum v4l2_subdev_format_whence which)
> diff --git a/src/v4l2subdev.h b/src/v4l2subdev.h
> index 5d55482..1cca7b9 100644
> --- a/src/v4l2subdev.h
> +++ b/src/v4l2subdev.h
> @@ -22,6 +22,7 @@
>  #ifndef __SUBDEV_H__
>  #define __SUBDEV_H__
> 
> +#include <stdint.h>
>  #include <linux/v4l2-subdev.h>
> 
>  struct media_entity;
> @@ -47,6 +48,19 @@ int v4l2_subdev_open(struct media_entity *entity);
>  void v4l2_subdev_close(struct media_entity *entity);
> 
>  /**
> + * @brief Enumerate mbus pixel codes.
> + * @param entity - subdev-device media entity.
> + * @param code - mbus pixel code
> + *
> + * Enumerate media bus pixel codes. This is just a wrapper for
> + * VIDIOC_SUBDEV_ENUM_MBUS_CODE IOCTL.
> + *
> + * @return 0 on success, or a negative error code on failure.
> + */
> +int v4l2_subdev_enum_mbus_code(struct media_entity *entity,
> +			       uint32_t *code, uint32_t pad, uint32_t index);
> +
> +/**
>   * @brief Retrieve the format on a pad.
>   * @param entity - subdev-device media entity.
>   * @param format - format to be filled.

-- 
Regards,

Laurent Pinchart