Hi Steve,

On Sun, Nov 24, 2019 at 11:06:46AM -0800, Steve Longerbeam wrote:
> If the given endpoint fwnode passed to the .get_fwnode_pad() op is
> the adv748x-csi2 TXA/TXB source endpoint, return the associated media
> pad index ADV748X_CSI2_SOURCE. The adv748x-csi2 has no other media pads
> that are associated with fwnode endpoints.
>
> Signed-off-by: Steve Longerbeam <slongerbeam@gmail.com>
> ---
>  drivers/media/i2c/adv748x/adv748x-csi2.c | 21 +++++++++++++++++++++
>  1 file changed, 21 insertions(+)
>
> diff --git a/drivers/media/i2c/adv748x/adv748x-csi2.c b/drivers/media/i2c/adv748x/adv748x-csi2.c
> index 2091cda50935..810085a1f2f0 100644
> --- a/drivers/media/i2c/adv748x/adv748x-csi2.c
> +++ b/drivers/media/i2c/adv748x/adv748x-csi2.c
> @@ -228,6 +228,24 @@ static const struct v4l2_subdev_ops adv748x_csi2_ops = {
>  	.pad = &adv748x_csi2_pad_ops,
>  };
>
> +/* -----------------------------------------------------------------------------
> + * media_entity_operations
> + */
> +
> +static int adv748x_csi2_get_fwnode_pad(struct media_entity *entity,
> +				       struct fwnode_endpoint *endpoint)
> +{
> +	struct v4l2_subdev *sd = media_entity_to_v4l2_subdev(entity);
> +	struct adv748x_csi2 *tx = adv748x_sd_to_csi2(sd);
> +
> +	return endpoint->local_fwnode == tx->sd.fwnode ?
> +		ADV748X_CSI2_SOURCE : -ENXIO;

Couldn't you check if the endpoint port is either 10 or 11, as those
are the only port numbers that provide a CSI-2 source pad ?

In that case you could drop extending get_fwnode_pad() with th entity
argument, as it is only used here (this one is actually the first user
in the whole code base of this operation)

> +}
> +
> +static const struct media_entity_operations adv748x_csi2_entity_ops = {
> +	.get_fwnode_pad = adv748x_csi2_get_fwnode_pad,
> +};
> +
>  /* -----------------------------------------------------------------------------
>   * Subdev module and controls
>   */
> @@ -295,6 +313,9 @@ int adv748x_csi2_init(struct adv748x_state *state, struct adv748x_csi2 *tx)
>  	/* Register internal ops for incremental subdev registration */
>  	tx->sd.internal_ops = &adv748x_csi2_internal_ops;
>
> +	/* Register media_entity ops */
> +	tx->sd.entity.ops = &adv748x_csi2_entity_ops;
> +
>  	tx->pads[ADV748X_CSI2_SINK].flags = MEDIA_PAD_FL_SINK;
>  	tx->pads[ADV748X_CSI2_SOURCE].flags = MEDIA_PAD_FL_SOURCE;
>
> --
> 2.17.1
>