Re: [PATCH v4 6/6] media: max9286: Implement get_frame_desc()

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

Hi Jacopo,

Thank you for the patch.

On Thu, Dec 16, 2021 at 06:47:46PM +0100, Jacopo Mondi wrote:
> Implement the get_frame_desc pad operation to allow retrieving the
> stream configuration of the max9286 subdevice.
> 
> Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
> ---
>  drivers/media/i2c/max9286.c | 53 +++++++++++++++++++++++++++++++++++++
>  1 file changed, 53 insertions(+)
> 
> diff --git a/drivers/media/i2c/max9286.c b/drivers/media/i2c/max9286.c
> index aa7cb7c10fc0..78988f2bdf91 100644
> --- a/drivers/media/i2c/max9286.c
> +++ b/drivers/media/i2c/max9286.c
> @@ -876,6 +876,58 @@ static int max9286_set_fmt(struct v4l2_subdev *sd,
>  	return ret;
>  }
>  
> +static int max9286_get_frame_desc(struct v4l2_subdev *sd, unsigned int pad,
> +				  struct v4l2_mbus_frame_desc *fd)
> +{
> +	struct v4l2_subdev_route *route;
> +	struct v4l2_subdev_state *state;
> +	int ret = 0;
> +
> +	if (pad != MAX9286_SRC_PAD)
> +		return -EINVAL;
> +
> +	state = v4l2_subdev_lock_active_state(sd);
> +
> +	memset(fd, 0, sizeof(*fd));
> +
> +	/* One stream entry per each connected route. */
> +	for_each_active_route(&state->routing, route) {
> +		struct v4l2_mbus_frame_desc_entry *entry =
> +						&fd->entry[fd->num_entries];
> +		struct v4l2_mbus_framefmt *fmt;

This can be const.

> +
> +		fmt = v4l2_state_get_stream_format(state, pad,
> +						   route->source_stream);
> +		if (!fmt) {
> +			ret = -EINVAL;
> +			goto out;
> +		}
> +
> +		/*
> +		 * Assume a YUYV format (0x1e DT) and 16 bpp: we only support
> +		 * these formats at the moment.
> +		 */
> +		entry->stream = fd->num_entries++;
> +		entry->flags = V4L2_MBUS_FRAME_DESC_FL_LEN_MAX;
> +		entry->length = fmt->width * fmt->height * 16 / 8;
> +		entry->pixelcode = fmt->code;
> +
> +		/*
> +		 * The source stream id corresponds to the virtual channel a
> +		 * stream is output on.
> +		 */
> +		entry->bus.csi2.vc = route->source_stream;
> +		entry->bus.csi2.dt = 0x1e;

A header file for the CSI-2 data types could be useful (out of scope for
this series, unless you insist :-)).

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

> +	}
> +
> +	fd->type = V4L2_MBUS_FRAME_DESC_TYPE_CSI2;
> +
> +out:
> +	v4l2_subdev_unlock_state(state);
> +
> +	return ret;
> +}
> +
>  static int max9286_routing_validate(struct max9286_priv *priv,
>  				    struct v4l2_subdev_krouting *routing)
>  {
> @@ -1025,6 +1077,7 @@ static const struct v4l2_subdev_pad_ops max9286_pad_ops = {
>  	.enum_mbus_code = max9286_enum_mbus_code,
>  	.get_fmt	= v4l2_subdev_get_fmt,
>  	.set_fmt	= max9286_set_fmt,
> +	.get_frame_desc = max9286_get_frame_desc,
>  	.set_routing	= max9286_set_routing,
>  };
>  

-- 
Regards,

Laurent Pinchart