Re: [PATCH v6 09/11] media: rcar-csi2: Call get_frame_desc to find out VC & DT (Gen3)

["Niklas Söderlund" <niklas.soderlund@ragnatech.se>]

Hi Tomi,

Thanks for your work.

On 2026-06-17 14:55:02 +0300, Tomi Valkeinen wrote:
> Call get_frame_desc to find out VC & DT, for Gen3 platforms, instead of
> hardcoding the VC routing and deducing the DT based on the mbus format.
> 
> If the source subdevice doesn't implement .get_frame_desc, we use a
> fallback case where we assume there's a single stream with VC = 0 and DT
> based on the mbus format.
> 
> Signed-off-by: Tomi Valkeinen <tomi.valkeinen+renesas@ideasonboard.com>

Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>

> ---
>  drivers/media/platform/renesas/rcar-csi2.c | 111 ++++++++++++++++++-----------
>  1 file changed, 71 insertions(+), 40 deletions(-)
> 
> diff --git a/drivers/media/platform/renesas/rcar-csi2.c b/drivers/media/platform/renesas/rcar-csi2.c
> index 0d9e730fa677..8cd38b4cbc7f 100644
> --- a/drivers/media/platform/renesas/rcar-csi2.c
> +++ b/drivers/media/platform/renesas/rcar-csi2.c
> @@ -1069,62 +1069,93 @@ 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;
> +	u32 phycnt, vcdt = 0, vcdt2 = 0;
> +	u32 fld = FLD_DET_SEL(1);
> +	struct v4l2_mbus_frame_desc source_fd;
> +	struct v4l2_subdev_route *route;
>  	unsigned int lanes;
> -	unsigned int i;
>  	int mbps, ret;
> +	u8 ch = 0;
>  
> -	/* Use the format on the sink pad to compute the receiver config. */
> +	ret = v4l2_subdev_call(priv->remote, pad, get_frame_desc,
> +			       priv->remote_pad, &source_fd);
> +	if (ret && ret != -ENOIOCTLCMD)
> +		return ret;
>  
> -	if (state->routing.num_routes != 1)
> -		return -EINVAL;
> +	if (ret == -ENOIOCTLCMD) {
> +		/* Create a fallback source_fd */
> +		struct v4l2_mbus_frame_desc *fd = &source_fd;
> +		const struct v4l2_subdev_route *route;
> +		const struct rcar_csi2_format *format;
> +		struct v4l2_mbus_framefmt *fmt;
>  
> -	route = &state->routing.routes[0];
> +		if (state->routing.num_routes != 1)
> +			return -EINVAL;
>  
> -	fmt = v4l2_subdev_state_get_format(state, route->sink_pad,
> -					   route->sink_stream);
> -	if (!fmt)
> -		return -EINVAL;
> +		route = &state->routing.routes[0];
>  
> -	dev_dbg(priv->dev, "Input size (%ux%u%c)\n",
> -		fmt->width, fmt->height,
> -		fmt->field == V4L2_FIELD_NONE ? 'p' : 'i');
> +		fmt = v4l2_subdev_state_get_format(state, route->sink_pad,
> +						   route->sink_stream);
> +		if (!fmt)
> +			return -EINVAL;
>  
> -	/* Code is validated in set_fmt. */
> -	format = rcsi2_code_to_fmt(fmt->code);
> -	if (!format)
> -		return -EINVAL;
> +		format = rcsi2_code_to_fmt(fmt->code);
> +		if (!format)
> +			return -EINVAL;
>  
> -	/*
> -	 * Enable all supported CSI-2 channels with virtual channel and
> -	 * data type matching.
> -	 *
> -	 * NOTE: It's not possible to get individual datatype for each
> -	 *       source virtual channel. Once this is possible in V4L2
> -	 *       it should be used here.
> -	 */
> -	for (i = 0; i < priv->info->num_channels; i++) {
> +		memset(fd, 0, sizeof(*fd));
> +
> +		fd->num_entries = 1;
> +		fd->type = V4L2_MBUS_FRAME_DESC_TYPE_CSI2;
> +		fd->entry[0].stream = 0;
> +		fd->entry[0].pixelcode = fmt->code;
> +		fd->entry[0].bus.csi2.vc = 0;
> +		fd->entry[0].bus.csi2.dt = format->datatype;
> +	}
> +
> +	for_each_active_route(&state->routing, route) {
> +		const struct v4l2_mbus_frame_desc_entry *source_entry = NULL;
> +		const struct v4l2_mbus_framefmt *fmt;
> +		unsigned int i;
>  		u32 vcdt_part;
>  
> -		if (priv->channel_vc[i] < 0)
> -			continue;
> +		for (i = 0; i < source_fd.num_entries; i++) {
> +			if (source_fd.entry[i].stream == route->sink_stream) {
> +				source_entry = &source_fd.entry[i];
> +				break;
> +			}
> +		}
>  
> -		vcdt_part = VCDT_SEL_VC(priv->channel_vc[i]) | VCDT_VCDTN_EN |
> -			VCDT_SEL_DTN_ON | VCDT_SEL_DT(format->datatype);
> +		if (!source_entry) {
> +			dev_err(priv->dev,
> +				"Failed to find stream from source frame desc\n");
> +			return -EPIPE;
> +		}
> +
> +		vcdt_part = VCDT_SEL_VC(source_entry->bus.csi2.vc) |
> +			    VCDT_VCDTN_EN | VCDT_SEL_DTN_ON |
> +			    VCDT_SEL_DT(source_entry->bus.csi2.dt);
>  
>  		/* Store in correct reg and offset. */
> -		if (i < 2)
> -			vcdt |= vcdt_part << ((i % 2) * 16);
> +		if (ch < 2)
> +			vcdt |= vcdt_part << ((ch % 2) * 16);
>  		else
> -			vcdt2 |= vcdt_part << ((i % 2) * 16);
> -	}
> +			vcdt2 |= vcdt_part << ((ch % 2) * 16);
> +
> +		fmt = v4l2_subdev_state_get_format(state, RCAR_CSI2_SINK,
> +						   route->sink_stream);
> +		if (!fmt)
> +			return -EINVAL;
> +
> +		dev_dbg(priv->dev, "Input size (%ux%u%c)\n",
> +			fmt->width, fmt->height,
> +			fmt->field == V4L2_FIELD_NONE ? 'p' : 'i');
>  
> -	if (fmt->field == V4L2_FIELD_ALTERNATE)
> -		fld = FLD_DET_SEL(1) | FLD_FLD_EN(3) | FLD_FLD_EN(2) |
> -		      FLD_FLD_EN(1) | FLD_FLD_EN(0);
> +		if (fmt->field == V4L2_FIELD_ALTERNATE)
> +			fld |= FLD_FLD_EN(ch);
> +
> +		ch++;
> +	}
>  
>  	/*
>  	 * Get the number of active data lanes inspecting the remote mbus
> 
> -- 
> 2.43.0
> 

-- 
Kind Regards,
Niklas Söderlund