Re: [RFCv2 PATCH 05/21] videodev2.h: add struct v4l2_query_ext_ctrl and VIDIOC_QUERY_EXT_CTRL.

[Sylwester Nawrocki <sylvester.nawrocki@gmail.com>]

On 01/20/2014 01:45 PM, Hans Verkuil wrote:
> From: Hans Verkuil<hans.verkuil@cisco.com>
>
> Add a new struct and ioctl to extend the amount of information you can
> get for a control.
>
> It gives back a unit string, the range is now a s64 type, and the matrix
> and element size can be reported through cols/rows/elem_size.
>
> Signed-off-by: Hans Verkuil<hans.verkuil@cisco.com>
> ---
>   include/uapi/linux/videodev2.h | 30 ++++++++++++++++++++++++++++++
>   1 file changed, 30 insertions(+)
>
> diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
> index 4d7782a..9e5b7d4 100644
> --- a/include/uapi/linux/videodev2.h
> +++ b/include/uapi/linux/videodev2.h
> @@ -1272,6 +1272,34 @@ struct v4l2_queryctrl {
>   	__u32		     reserved[2];
>   };
>
> +/*  Used in the VIDIOC_QUERY_EXT_CTRL ioctl for querying extended controls */
> +struct v4l2_query_ext_ctrl {
> +	__u32		     id;
> +	__u32		     type;
> +	char		     name[32];
> +	char		     unit[32];

> +	union {
> +		__s64 val;
> +		__u32 reserved[4];
> +	} min;
> +	union {
> +		__s64 val;
> +		__u32 reserved[4];
> +	} max;
> +	union {
> +		__u64 val;
> +		__u32 reserved[4];
> +	} step;
> +	union {
> +		__s64 val;
> +		__u32 reserved[4];
> +	} def;

Are these reserved[] arrays of any use ?

> +	__u32                flags;
> +	__u32                cols, rows;

nit: I would put them on separate lines and use full words.

> +	__u32                elem_size;
> +	__u32		     reserved[17];
> +};
> +
>   /*  Used in the VIDIOC_QUERYMENU ioctl for querying menu items */
>   struct v4l2_querymenu {
>   	__u32		id;
> @@ -1965,6 +1993,8 @@ struct v4l2_create_buffers {
>      Never use these in applications! */
>   #define VIDIOC_DBG_G_CHIP_INFO  _IOWR('V', 102, struct v4l2_dbg_chip_info)
>
> +#define VIDIOC_QUERY_EXT_CTRL	_IOWR('V', 103, struct v4l2_query_ext_ctrl)
> +
>   /* Reminder: when adding new ioctls please add support for them to
>      drivers/media/video/v4l2-compat-ioctl32.c as well! */

--
Regards,
Sylwester