Re: [PATCHv2 1/9] v4l2-common: create v4l2_g/s_parm_cap helpers

[Mauro Carvalho Chehab <mchehab@s-opensource.com>]

Em Mon, 22 Jan 2018 13:31:17 +0100
Hans Verkuil <hverkuil@xs4all.nl> escreveu:

> From: Hans Verkuil <hans.verkuil@cisco.com>
> 
> Create helpers to handle VIDIOC_G/S_PARM by querying the
> g/s_frame_interval v4l2_subdev ops.
> 
> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
> ---
>  drivers/media/v4l2-core/v4l2-common.c | 48 +++++++++++++++++++++++++++++++++++
>  include/media/v4l2-common.h           | 26 +++++++++++++++++++
>  2 files changed, 74 insertions(+)
> 
> diff --git a/drivers/media/v4l2-core/v4l2-common.c b/drivers/media/v4l2-core/v4l2-common.c
> index 8650ad92b64d..96c1b31de9e3 100644
> --- a/drivers/media/v4l2-core/v4l2-common.c
> +++ b/drivers/media/v4l2-core/v4l2-common.c
> @@ -392,3 +392,51 @@ void v4l2_get_timestamp(struct timeval *tv)
>  	tv->tv_usec = ts.tv_nsec / NSEC_PER_USEC;
>  }
>  EXPORT_SYMBOL_GPL(v4l2_get_timestamp);
> +
> +int v4l2_g_parm_cap(struct video_device *vdev,
> +		    struct v4l2_subdev *sd, struct v4l2_streamparm *a)
> +{
> +	struct v4l2_subdev_frame_interval ival = { 0 };
> +	int ret;
> +
> +	if (a->type != V4L2_BUF_TYPE_VIDEO_CAPTURE &&
> +	    a->type != V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE)
> +		return -EINVAL;
> +
> +	if (vdev->device_caps & V4L2_CAP_READWRITE)
> +		a->parm.capture.readbuffers = 2;

Hmm... why don't you also initialize readbuffers otherwise?

> +	if (v4l2_subdev_has_op(sd, video, g_frame_interval))
> +		a->parm.capture.capability = V4L2_CAP_TIMEPERFRAME;
> +	ret = v4l2_subdev_call(sd, video, g_frame_interval, &ival);
> +	if (!ret)
> +		a->parm.capture.timeperframe = ival.interval;
> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(v4l2_g_parm_cap);
> +
> +int v4l2_s_parm_cap(struct video_device *vdev,
> +		    struct v4l2_subdev *sd, struct v4l2_streamparm *a)
> +{
> +	struct v4l2_subdev_frame_interval ival = {
> +		.interval = a->parm.capture.timeperframe
> +	};
> +	int ret;
> +
> +	if (a->type != V4L2_BUF_TYPE_VIDEO_CAPTURE &&
> +	    a->type != V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE)
> +		return -EINVAL;
> +
> +	memset(&a->parm, 0, sizeof(a->parm));
> +	if (vdev->device_caps & V4L2_CAP_READWRITE)
> +		a->parm.capture.readbuffers = 2;
> +	else
> +		a->parm.capture.readbuffers = 0;
> +
> +	if (v4l2_subdev_has_op(sd, video, g_frame_interval))
> +		a->parm.capture.capability = V4L2_CAP_TIMEPERFRAME;
> +	ret = v4l2_subdev_call(sd, video, s_frame_interval, &ival);
> +	if (!ret)
> +		a->parm.capture.timeperframe = ival.interval;
> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(v4l2_s_parm_cap);
> diff --git a/include/media/v4l2-common.h b/include/media/v4l2-common.h
> index e0d95a7c5d48..f3aa1d728c0b 100644
> --- a/include/media/v4l2-common.h
> +++ b/include/media/v4l2-common.h
> @@ -341,4 +341,30 @@ v4l2_find_nearest_format(const struct v4l2_frmsize_discrete *sizes,
>   */
>  void v4l2_get_timestamp(struct timeval *tv);
>  
> +/**
> + * v4l2_g_parm_cap - helper routine for vidioc_g_parm to fill this in by
> + *      calling the g_frame_interval op of the given subdev. It only works
> + *      for V4L2_BUF_TYPE_VIDEO_CAPTURE(_MPLANE), hence the _cap in the
> + *      function name.
> + *
> + * @vdev: the struct video_device pointer. Used to determine the device caps.
> + * @sd: the sub-device pointer.
> + * @a: the VIDIOC_G_PARM argument.
> + */
> +int v4l2_g_parm_cap(struct video_device *vdev,
> +		    struct v4l2_subdev *sd, struct v4l2_streamparm *a);
> +
> +/**
> + * v4l2_s_parm_cap - helper routine for vidioc_s_parm to fill this in by
> + *      calling the s_frame_interval op of the given subdev. It only works
> + *      for V4L2_BUF_TYPE_VIDEO_CAPTURE(_MPLANE), hence the _cap in the
> + *      function name.
> + *
> + * @vdev: the struct video_device pointer. Used to determine the device caps.
> + * @sd: the sub-device pointer.
> + * @a: the VIDIOC_S_PARM argument.
> + */
> +int v4l2_s_parm_cap(struct video_device *vdev,
> +		    struct v4l2_subdev *sd, struct v4l2_streamparm *a);
> +
>  #endif /* V4L2_COMMON_H_ */



Thanks,
Mauro