[PATCH 3/6] media: synopsys: implement .get_frame_desc() callback

[Sakari Ailus]

Hi Frank,

On Tue, Feb 10, 2026 at 12:11:10PM -0500, Frank Li wrote:
> Implement the .get_frame_desc() callback to fetch information from the
> remote endpoint.
> 
> Signed-off-by: Frank Li <Frank.Li at nxp.com>
> ---
>  drivers/media/platform/synopsys/dw-mipi-csi2rx.c | 25 ++++++++++++++++++++++++
>  1 file changed, 25 insertions(+)
> 
> diff --git a/drivers/media/platform/synopsys/dw-mipi-csi2rx.c b/drivers/media/platform/synopsys/dw-mipi-csi2rx.c
> index 61cd7f491b3d5b8a37707b23ca03ce709b40a79f..4ad4e3b23448affeeaa932a706653818ba4019ba 100644
> --- a/drivers/media/platform/synopsys/dw-mipi-csi2rx.c
> +++ b/drivers/media/platform/synopsys/dw-mipi-csi2rx.c
> @@ -70,6 +70,8 @@ struct dw_mipi_csi2rx_device {
>  	struct v4l2_async_notifier notifier;
>  	struct v4l2_subdev sd;
>  
> +	struct v4l2_subdev *remote_source;
> +
>  	enum v4l2_mbus_type bus_type;
>  	u32 lanes_num;
>  };
> @@ -431,10 +433,31 @@ static int dw_mipi_csi2rx_disable_streams(struct v4l2_subdev *sd,
>  	return ret;
>  }
>  
> +static int
> +dw_mipi_csi2rx_get_frame_desc(struct v4l2_subdev *sd, unsigned int pad,
> +			      struct v4l2_mbus_frame_desc *fd)
> +{
> +	struct dw_mipi_csi2rx_device *csi2 = to_csi2(sd);
> +	struct media_pad *remote_pad;
> +
> +	if (!csi2->remote_source)
> +		return -ENODEV;
> +
> +	remote_pad = media_pad_remote_pad_unique(&csi2->pads[DW_MIPI_CSI2RX_PAD_SINK]);
> +	if (IS_ERR(remote_pad)) {
> +		dev_err(csi2->dev, "can't get source pad of %s (%pe)\n",
> +			csi2->remote_source->name, remote_pad);
> +		return PTR_ERR(remote_pad);
> +	}
> +	return v4l2_subdev_call(csi2->remote_source, pad, get_frame_desc,
> +				remote_pad->index, fd);
> +}

Can you use v4l2_subdev_get_frame_desc_passthrough()?

> +
>  static const struct v4l2_subdev_pad_ops dw_mipi_csi2rx_pad_ops = {
>  	.enum_mbus_code = dw_mipi_csi2rx_enum_mbus_code,
>  	.get_fmt = v4l2_subdev_get_fmt,
>  	.set_fmt = dw_mipi_csi2rx_set_fmt,
> +	.get_frame_desc = dw_mipi_csi2rx_get_frame_desc,
>  	.set_routing = dw_mipi_csi2rx_set_routing,
>  	.enable_streams = dw_mipi_csi2rx_enable_streams,
>  	.disable_streams = dw_mipi_csi2rx_disable_streams,
> @@ -487,6 +510,8 @@ static int dw_mipi_csi2rx_notifier_bound(struct v4l2_async_notifier *notifier,
>  		return ret;
>  	}
>  
> +	csi2->remote_source = sd;
> +
>  	return 0;
>  }
>  
> 

-- 
Regards,

Sakari Ailus