Re: [PATCH 08/20] media: soc_camera pad-aware driver initialisation

[Hans Verkuil <hverkuil@xs4all.nl>]

On 05/20/2015 06:39 PM, William Towle wrote:
> Add detection of source pad number for drivers aware of the media
> controller API, so that soc_camera/rcar_vin can create device nodes
> to support a driver such as adv7604.c (for HDMI on Lager) underneath.
> 
> Signed-off-by: William Towle <william.towle@codethink.co.uk>
> Reviewed-by: Rob Taylor <rob.taylor@codethink.co.uk>
> ---
>  drivers/media/platform/soc_camera/rcar_vin.c   |    4 ++++
>  drivers/media/platform/soc_camera/soc_camera.c |   27 +++++++++++++++++++++++-
>  include/media/soc_camera.h                     |    1 +
>  3 files changed, 31 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/media/platform/soc_camera/rcar_vin.c b/drivers/media/platform/soc_camera/rcar_vin.c
> index 0f67646..b4e9b43 100644
> --- a/drivers/media/platform/soc_camera/rcar_vin.c
> +++ b/drivers/media/platform/soc_camera/rcar_vin.c
> @@ -1364,8 +1364,12 @@ static int rcar_vin_get_formats(struct soc_camera_device *icd, unsigned int idx,
>  		struct v4l2_mbus_framefmt *mf = &fmt.format;
>  		struct v4l2_rect rect;
>  		struct device *dev = icd->parent;
> +		struct media_pad *remote_pad;
>  		int shift;
>  
> +		remote_pad = media_entity_remote_pad(
> +					&icd->vdev->entity.pads[0]);
> +		fmt.pad = remote_pad->index;

This won't work if CONFIG_MEDIA_CONTROLLER isn't defined. All these media calls would all
have to be under #ifdef CONFIG_MEDIA_CONTROLLER.

Unfortunately, if it is not defined, then you still have no way of finding the source pad.

Laurent, do you think if it would make sense to add a new subdev core op that will return
the default source pad (I'm saying 'default' in case there are more) of a subdev? That way
it can be used in non-MC drivers. We never needed the source pad before, but now we do,
and this op only needs to be implemented if the default source pad != 0.

Regards,

	Hans


>  		ret = v4l2_subdev_call(sd, pad, get_fmt, NULL, &fmt);
>  		if (ret < 0)
>  			return ret;
> diff --git a/drivers/media/platform/soc_camera/soc_camera.c b/drivers/media/platform/soc_camera/soc_camera.c
> index d708df4..126d645 100644
> --- a/drivers/media/platform/soc_camera/soc_camera.c
> +++ b/drivers/media/platform/soc_camera/soc_camera.c
> @@ -1293,6 +1293,7 @@ static int soc_camera_probe_finish(struct soc_camera_device *icd)
>  		.which = V4L2_SUBDEV_FORMAT_ACTIVE,
>  	};
>  	struct v4l2_mbus_framefmt *mf = &fmt.format;
> +	int src_pad_idx = -1;
>  	int ret;
>  
>  	sd->grp_id = soc_camera_grp_id(icd);
> @@ -1311,7 +1312,25 @@ static int soc_camera_probe_finish(struct soc_camera_device *icd)
>  	}
>  
>  	/* At this point client .probe() should have run already */
> -	ret = soc_camera_init_user_formats(icd);
> +	ret = media_entity_init(&icd->vdev->entity, 1, &icd->pad, 0);
> +	if (!ret) {
> +		for (src_pad_idx = 0; src_pad_idx < sd->entity.num_pads;
> +				src_pad_idx++)
> +			if (sd->entity.pads[src_pad_idx].flags
> +						== MEDIA_PAD_FL_SOURCE)
> +				break;
> +
> +		if (src_pad_idx < sd->entity.num_pads) {
> +			if (!media_entity_create_link(
> +				&icd->vdev->entity, 0,
> +				&sd->entity, src_pad_idx,
> +				MEDIA_LNK_FL_IMMUTABLE |
> +				MEDIA_LNK_FL_ENABLED)) {
> +				ret = soc_camera_init_user_formats(icd);
> +			}
> +		}
> +	}
> +
>  	if (ret < 0)
>  		goto eusrfmt;
>  
> @@ -1322,6 +1341,7 @@ static int soc_camera_probe_finish(struct soc_camera_device *icd)
>  		goto evidstart;
>  
>  	/* Try to improve our guess of a reasonable window format */
> +	fmt.pad = src_pad_idx;
>  	if (!v4l2_subdev_call(sd, pad, get_fmt, NULL, &fmt)) {
>  		icd->user_width		= mf->width;
>  		icd->user_height	= mf->height;
> @@ -1335,6 +1355,7 @@ static int soc_camera_probe_finish(struct soc_camera_device *icd)
>  evidstart:
>  	soc_camera_free_user_formats(icd);
>  eusrfmt:
> +	media_entity_cleanup(&icd->vdev->entity);
>  	soc_camera_remove_device(icd);
>  
>  	return ret;
> @@ -1856,6 +1877,10 @@ static int soc_camera_remove(struct soc_camera_device *icd)
>  	if (icd->num_user_formats)
>  		soc_camera_free_user_formats(icd);
>  
> +	if (icd->vdev->entity.num_pads) {
> +		media_entity_cleanup(&icd->vdev->entity);
> +	}
> +
>  	if (icd->clk) {
>  		/* For the synchronous case */
>  		v4l2_clk_unregister(icd->clk);
> diff --git a/include/media/soc_camera.h b/include/media/soc_camera.h
> index 2f6261f..f0c5238 100644
> --- a/include/media/soc_camera.h
> +++ b/include/media/soc_camera.h
> @@ -42,6 +42,7 @@ struct soc_camera_device {
>  	unsigned char devnum;		/* Device number per host */
>  	struct soc_camera_sense *sense;	/* See comment in struct definition */
>  	struct video_device *vdev;
> +	struct media_pad pad;
>  	struct v4l2_ctrl_handler ctrl_handler;
>  	const struct soc_camera_format_xlate *current_fmt;
>  	struct soc_camera_format_xlate *user_formats;
>