Re: [PATCH v5 04/10] media: rcar-csi2: Switch to Streams API

[Laurent Pinchart]

On Wed, Mar 11, 2026 at 03:53:17PM +0200, Tomi Valkeinen wrote:
> Switch to Streams API with a single hardcoded route.
> 
> For single-stream use case there should be no change in behavior.
> 
> Signed-off-by: Tomi Valkeinen <tomi.valkeinen+renesas@xxxxxxxxxxxxxxxx>
> ---
>  drivers/media/platform/renesas/rcar-csi2.c | 64 +++++++++++++++++++++++-------
>  1 file changed, 50 insertions(+), 14 deletions(-)
> 
> diff --git a/drivers/media/platform/renesas/rcar-csi2.c b/drivers/media/platform/renesas/rcar-csi2.c
> index 158fa447e668..ad62c95c8f9a 100644
> --- a/drivers/media/platform/renesas/rcar-csi2.c
> +++ b/drivers/media/platform/renesas/rcar-csi2.c
> @@ -1023,17 +1023,24 @@ static int rcsi2_calc_mbps(struct rcar_csi2 *priv,
>  	 */
>  	freq = v4l2_get_link_freq(remote_pad, 0, 0);
>  	if (freq < 0) {
> +		const struct v4l2_subdev_route *route;
>  		const struct rcar_csi2_format *format;
>  		const struct v4l2_mbus_framefmt *fmt;
>  		unsigned int lanes;
>  		unsigned int bpp;
>  		int ret;
>  
> +		if (state->routing.num_routes != 1)
> +			return -EINVAL;
> +
>  		ret = rcsi2_get_active_lanes(priv, &lanes);
>  		if (ret)
>  			return ret;
>  
> -		fmt = v4l2_subdev_state_get_format(state, RCAR_CSI2_SINK);
> +		route = &state->routing.routes[0];
> +
> +		fmt = v4l2_subdev_state_get_format(state, route->sink_pad,
> +						   route->sink_stream);
>  		if (!fmt)
>  			return -EINVAL;
>  
> @@ -1062,6 +1069,7 @@ static int rcsi2_calc_mbps(struct rcar_csi2 *priv,
>  static int rcsi2_start_receiver_gen3(struct rcar_csi2 *priv,
>  				     struct v4l2_subdev_state *state)
>  {
> +	const struct v4l2_subdev_route *route;
>  	const struct rcar_csi2_format *format;
>  	u32 phycnt, vcdt = 0, vcdt2 = 0, fld = 0;
>  	const struct v4l2_mbus_framefmt *fmt;
> @@ -1070,7 +1078,16 @@ static int rcsi2_start_receiver_gen3(struct rcar_csi2 *priv,
>  	int mbps, ret;
>  
>  	/* Use the format on the sink pad to compute the receiver config. */
> -	fmt = v4l2_subdev_state_get_format(state, RCAR_CSI2_SINK);
> +
> +	if (state->routing.num_routes != 1)
> +		return -EINVAL;
> +
> +	route = &state->routing.routes[0];
> +
> +	fmt = v4l2_subdev_state_get_format(state, route->sink_pad,
> +					   route->sink_stream);
> +	if (!fmt)
> +		return -EINVAL;
>  
>  	dev_dbg(priv->dev, "Input size (%ux%u%c)\n",
>  		fmt->width, fmt->height,
> @@ -1892,8 +1909,7 @@ static int rcsi2_set_pad_format(struct v4l2_subdev *sd,
>  				struct v4l2_subdev_state *state,
>  				struct v4l2_subdev_format *format)
>  {
> -	struct rcar_csi2 *priv = sd_to_csi2(sd);
> -	unsigned int num_pads = rcsi2_num_pads(priv);
> +	struct v4l2_mbus_framefmt *fmt;
>  
>  	if (format->pad > RCAR_CSI2_SINK)
>  		return v4l2_subdev_get_fmt(sd, state, format);
> @@ -1901,11 +1917,20 @@ static int rcsi2_set_pad_format(struct v4l2_subdev *sd,
>  	if (!rcsi2_code_to_fmt(format->format.code))
>  		format->format.code = rcar_csi2_formats[0].code;
>  
> -	*v4l2_subdev_state_get_format(state, format->pad) = format->format;
> +	/* Set sink format. */
> +	fmt = v4l2_subdev_state_get_format(state, format->pad, format->stream);
> +	if (!fmt)
> +		return -EINVAL;

Can the call return NULL, isn't it checked by the subdev core already ?

> +
> +	*fmt = format->format;
> +
> +	/* Propagate the format to the source pad. */
> +	fmt = v4l2_subdev_state_get_opposite_stream_format(state, format->pad,
> +							   format->stream);
> +	if (!fmt)
> +		return -EINVAL;

I wonder if this error check could be omitted too. If there's a format
for the sink stream, it means there's a route, so the opposite stream
format should be guaranteed to exist. Or maybe it's too late and I
should go to bed :-)

Looking at what other drivers do, they all check the return value of the
function, so let's keep it as-is for now.

Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>

>  
> -	/* Propagate the format to the source pads. */
> -	for (unsigned int i = RCAR_CSI2_SOURCE_VC0; i < num_pads; i++)
> -		*v4l2_subdev_state_get_format(state, i) = format->format;
> +	*fmt = format->format;
>  
>  	return 0;
>  }
> @@ -1925,8 +1950,15 @@ static const struct v4l2_subdev_ops rcar_csi2_subdev_ops = {
>  static int rcsi2_init_state(struct v4l2_subdev *sd,
>  			    struct v4l2_subdev_state *state)
>  {
> -	struct rcar_csi2 *priv = sd_to_csi2(sd);
> -	unsigned int num_pads = rcsi2_num_pads(priv);
> +	static struct v4l2_subdev_route routes[] = {
> +		{
> +			.sink_pad = RCAR_CSI2_SINK,
> +			.sink_stream = 0,
> +			.source_pad = RCAR_CSI2_SOURCE_VC0,
> +			.source_stream = 0,
> +			.flags = V4L2_SUBDEV_ROUTE_FL_ACTIVE,
> +		},
> +	};
>  
>  	static const struct v4l2_mbus_framefmt rcar_csi2_default_fmt = {
>  		.width		= 1920,
> @@ -1939,10 +1971,13 @@ static int rcsi2_init_state(struct v4l2_subdev *sd,
>  		.xfer_func	= V4L2_XFER_FUNC_DEFAULT,
>  	};
>  
> -	for (unsigned int i = RCAR_CSI2_SINK; i < num_pads; i++)
> -		*v4l2_subdev_state_get_format(state, i) = rcar_csi2_default_fmt;
> +	static const struct v4l2_subdev_krouting routing = {
> +		.num_routes = ARRAY_SIZE(routes),
> +		.routes = routes,
> +	};
>  
> -	return 0;
> +	return v4l2_subdev_set_routing_with_fmt(sd, state, &routing,
> +						&rcar_csi2_default_fmt);
>  }
>  
>  static const struct v4l2_subdev_internal_ops rcar_csi2_internal_ops = {
> @@ -2599,7 +2634,8 @@ static int rcsi2_probe(struct platform_device *pdev)
>  	v4l2_set_subdevdata(&priv->subdev, &pdev->dev);
>  	snprintf(priv->subdev.name, sizeof(priv->subdev.name), "%s %s",
>  		 KBUILD_MODNAME, dev_name(&pdev->dev));
> -	priv->subdev.flags = V4L2_SUBDEV_FL_HAS_DEVNODE;
> +	priv->subdev.flags = V4L2_SUBDEV_FL_HAS_DEVNODE |
> +			     V4L2_SUBDEV_FL_STREAMS;
>  
>  	priv->subdev.entity.function = MEDIA_ENT_F_PROC_VIDEO_PIXEL_FORMATTER;
>  	priv->subdev.entity.ops = &rcar_csi2_entity_ops;
> 

-- 
Regards,

Laurent Pinchart