Re: [PATCH v2 05/11] media: adv748x-csi2: Implement enum_mbus_codes

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

Hi Jacopo,

Thank you for the patch.

On Mon, May 06, 2024 at 06:49:33PM +0200, Jacopo Mondi wrote:
> Define a list of supported mbus codes for the TXA and TXB CSI-2
> transmitters and implement the enum_mbus_code operation.
> 
> The TXB transmitter only support YUV422 while the TXA one supports
> multiple formats as reported by the chip's manual in section 9.7.
> 
> Signed-off-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
> ---
>  drivers/media/i2c/adv748x/adv748x-csi2.c | 35 ++++++++++++++++++++++++
>  1 file changed, 35 insertions(+)
> 
> diff --git a/drivers/media/i2c/adv748x/adv748x-csi2.c b/drivers/media/i2c/adv748x/adv748x-csi2.c
> index 5b265b722394..4fd6d3a681d5 100644
> --- a/drivers/media/i2c/adv748x/adv748x-csi2.c
> +++ b/drivers/media/i2c/adv748x/adv748x-csi2.c
> @@ -14,6 +14,18 @@
>  
>  #include "adv748x.h"
>  
> +static const unsigned int adv748x_csi2_txa_fmts[] = {
> +	MEDIA_BUS_FMT_UYVY8_1X16,
> +	MEDIA_BUS_FMT_UYVY10_1X20,
> +	MEDIA_BUS_FMT_RGB565_1X16,
> +	MEDIA_BUS_FMT_RGB666_1X18,
> +	MEDIA_BUS_FMT_RGB888_1X24,
> +};
> +
> +static const unsigned int adv748x_csi2_txb_fmts[] = {
> +	MEDIA_BUS_FMT_UYVY8_1X16,
> +};
> +
>  int adv748x_csi2_set_virtual_channel(struct adv748x_csi2 *tx, unsigned int vc)
>  {
>  	return tx_write(tx, ADV748X_CSI_VC_REF, vc << ADV748X_CSI_VC_REF_SHIFT);
> @@ -139,6 +151,28 @@ static const struct v4l2_subdev_video_ops adv748x_csi2_video_ops = {
>   * But we must support setting the pad formats for format propagation.
>   */
>  
> +static int adv748x_csi2_enum_mbus_code(struct v4l2_subdev *sd,
> +				       struct v4l2_subdev_state *sd_state,
> +				       struct v4l2_subdev_mbus_code_enum *code)
> +{
> +	struct adv748x_csi2 *tx = adv748x_sd_to_csi2(sd);
> +	const unsigned int *codes = is_txa(tx) ?
> +				    adv748x_csi2_txa_fmts :
> +				    adv748x_csi2_txb_fmts;
> +	size_t num_fmts = is_txa(tx) ? ARRAY_SIZE(adv748x_csi2_txa_fmts)
> +				     : ARRAY_SIZE(adv748x_csi2_txb_fmts);
> +
> +	if (code->pad != ADV748X_CSI2_SOURCE)
> +		return -EINVAL;

Any reason to not support enumeration of formats on the sink pad ?

Is the CSI-2 TX pass-through regarding media bus formats ? That is, does
it modify the format between the sink and source pads ? If not, I think
this function should be implemented as

	if (code->pad == ADV748X_CSI2_SINK) {
		if (code->index >= num_fmts)
			return -EINVAL;

		code->code = codes[code->index];
	} else {
		const struct v4l2_msbu_framefmt *fmt;

		if (code->index > 0)
			return -EINVAL;

		/*
		 * The device doesn't modify formats, the same media bus code is
		 * used on the sink and source.
		 */
		fmt = v4l2_subdev_state_get_format(sd_state, ADV748X_CSI2_SINK);
		code->code = fmt->code;
	}

> +
> +	if (code->index >= num_fmts)
> +		return -EINVAL;
> +
> +	code->code = codes[code->index];
> +
> +	return 0;
> +}
> +
>  static struct v4l2_mbus_framefmt *
>  adv748x_csi2_get_pad_format(struct v4l2_subdev *sd,
>  			    struct v4l2_subdev_state *sd_state,
> @@ -228,6 +262,7 @@ static int adv748x_csi2_get_mbus_config(struct v4l2_subdev *sd, unsigned int pad
>  }
>  
>  static const struct v4l2_subdev_pad_ops adv748x_csi2_pad_ops = {
> +	.enum_mbus_code = adv748x_csi2_enum_mbus_code,
>  	.get_fmt = adv748x_csi2_get_format,
>  	.set_fmt = adv748x_csi2_set_format,
>  	.get_mbus_config = adv748x_csi2_get_mbus_config,

-- 
Regards,

Laurent Pinchart