Re: [PATCH 1/3] properly report a single frame rate of 60 FPS

[Hans Verkuil <hverkuil@xs4all.nl>]

On 05/14/2016 12:19 AM, Florian Echtler wrote:
> The device hardware is always running at 60 FPS, so report this both via
> PARM_IOCTL and ENUM_FRAMEINTERVALS.
> 
> Signed-off-by: Martin Kaltenbrunner <modin@yuri.at>
> Signed-off-by: Florian Echtler <floe@butterbrot.org>
> ---
>  drivers/input/touchscreen/sur40.c | 17 +++++++++++++++--
>  1 file changed, 15 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/input/touchscreen/sur40.c b/drivers/input/touchscreen/sur40.c
> index 880c40b..fcc5934 100644
> --- a/drivers/input/touchscreen/sur40.c
> +++ b/drivers/input/touchscreen/sur40.c
> @@ -788,6 +788,16 @@ static int sur40_vidioc_fmt(struct file *file, void *priv,
>  	return 0;
>  }
>  
> +static int sur40_ioctl_parm(struct file *file, void *priv,
> +			    struct v4l2_streamparm *p)
> +{
> +	if (p->type == V4L2_BUF_TYPE_VIDEO_CAPTURE) {
> +		p->parm.capture.timeperframe.numerator = 1;
> +		p->parm.capture.timeperframe.denominator = 60;
> +	}

It should return -EINVAL if it is not of type VIDEO_CAPTURE. You should also set the
V4L2_CAP_TIMEPERFRAME capability for this to work. The readbuffers field should also
be set (typically to the minimum required number of buffers).

Please check with v4l2-compliance! It would have warned about these issues.

> +	return 0;
> +}
> +
>  static int sur40_vidioc_enum_fmt(struct file *file, void *priv,
>  				 struct v4l2_fmtdesc *f)
>  {
> @@ -814,13 +824,13 @@ static int sur40_vidioc_enum_framesizes(struct file *file, void *priv,
>  static int sur40_vidioc_enum_frameintervals(struct file *file, void *priv,
>  					    struct v4l2_frmivalenum *f)
>  {
> -	if ((f->index > 1) || (f->pixel_format != V4L2_PIX_FMT_GREY)
> +	if ((f->index > 0) || (f->pixel_format != V4L2_PIX_FMT_GREY)
>  		|| (f->width  != sur40_video_format.width)
>  		|| (f->height != sur40_video_format.height))
>  			return -EINVAL;
>  
>  	f->type = V4L2_FRMIVAL_TYPE_DISCRETE;
> -	f->discrete.denominator  = 60/(f->index+1);
> +	f->discrete.denominator  = 60;
>  	f->discrete.numerator = 1;
>  	return 0;
>  }
> @@ -880,6 +890,9 @@ static const struct v4l2_ioctl_ops sur40_video_ioctl_ops = {
>  	.vidioc_enum_framesizes = sur40_vidioc_enum_framesizes,
>  	.vidioc_enum_frameintervals = sur40_vidioc_enum_frameintervals,
>  
> +	.vidioc_g_parm = sur40_ioctl_parm,
> +	.vidioc_s_parm = sur40_ioctl_parm,
> +
>  	.vidioc_enum_input	= sur40_vidioc_enum_input,
>  	.vidioc_g_input		= sur40_vidioc_g_input,
>  	.vidioc_s_input		= sur40_vidioc_s_input,
> 

Regards,

	Hans