Re: [PATCH 18/19] media: rcar-csi2: Implement set_routing

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

Hi Jacopo,

Thank you for the patch.

On Tue, Apr 30, 2024 at 12:39:54PM +0200, Jacopo Mondi wrote:
> Add the set_routing() subdev operation to allow userspace to activate
> routes on the R-Car CSI-2 receiver.
> 
> Routing for this device is fixed. Validate that the provided route
> respects it.
> 
> Signed-off-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
> ---
>  drivers/media/platform/renesas/rcar-csi2.c | 48 +++++++++++++++++++++-
>  1 file changed, 47 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/media/platform/renesas/rcar-csi2.c b/drivers/media/platform/renesas/rcar-csi2.c
> index ed818a6fa655..47cb12f077e5 100644
> --- a/drivers/media/platform/renesas/rcar-csi2.c
> +++ b/drivers/media/platform/renesas/rcar-csi2.c
> @@ -1287,6 +1287,51 @@ static int rcsi2_set_pad_format(struct v4l2_subdev *sd,
>  	return 0;
>  }
>  
> +static int rcsi2_apply_routing(struct v4l2_subdev *sd,
> +			       struct v4l2_subdev_state *state,
> +			       struct v4l2_subdev_krouting *routing)
> +{
> +	int ret;
> +
> +	ret = v4l2_subdev_routing_validate(sd, routing,
> +					   V4L2_SUBDEV_ROUTING_ONLY_1_TO_1);
> +	if (ret)
> +		return ret;
> +
> +	/*
> +	 * Routing is fixed for this device.
> +	 *
> +	 * Only routes in the form of CSI2:0/x->CSI2:x+1/0 are allowed.
> +	 *
> +	 * We have anyway to implement set_routing to mark the route as active.

Then it's not fixed :-)

> +	 */
> +	for (unsigned int i = 0; i < routing->num_routes; ++i) {
> +		const struct v4l2_subdev_route *route = &routing->routes[i];
> +		unsigned int pad = route->sink_stream + 1;
> +
> +		if (route->sink_pad != 0)
> +			return -EINVAL;

I don't think this can happen, the core should check the validity of
pads for you.

> +
> +		if (route->source_pad != pad || route->source_stream != 0)
> +			return -EINVAL;

You should adjust invalid routes, not return an error.

> +	}
> +
> +	return v4l2_subdev_set_routing(sd, state, routing);
> +}
> +
> +static int rcsi2_set_routing(struct v4l2_subdev *sd,
> +			     struct v4l2_subdev_state *state,
> +			     enum v4l2_subdev_format_whence which,
> +			     struct v4l2_subdev_krouting *routing)
> +{
> +	struct rcar_csi2 *priv = sd_to_csi2(sd);
> +
> +	if (which == V4L2_SUBDEV_FORMAT_ACTIVE && priv->stream_count)
> +		return -EBUSY;
> +
> +	return rcsi2_apply_routing(sd, state, routing);
> +}
> +
>  static const struct v4l2_subdev_video_ops rcar_csi2_video_ops = {
>  	.s_stream = rcsi2_s_stream,
>  };
> @@ -1294,6 +1339,7 @@ static const struct v4l2_subdev_video_ops rcar_csi2_video_ops = {
>  static const struct v4l2_subdev_pad_ops rcar_csi2_pad_ops = {
>  	.set_fmt = rcsi2_set_pad_format,
>  	.get_fmt = v4l2_subdev_get_fmt,
> +	.set_routing = rcsi2_set_routing,
>  };
>  
>  static const struct v4l2_subdev_ops rcar_csi2_subdev_ops = {
> @@ -1353,7 +1399,7 @@ static int rcsi2_init_state(struct v4l2_subdev *sd,
>  		.routes = routes,
>  	};
>  
> -	return v4l2_subdev_set_routing(sd, state, &routing);
> +	return rcsi2_apply_routing(sd, state, &routing);
>  }
>  
>  static const struct v4l2_subdev_internal_ops rcar_csi2_internal_ops = {

-- 
Regards,

Laurent Pinchart