Re: [PATCH v7 04/15] media: i2c: imx219: Report streams using frame descriptors

[Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>]

On 25/03/2024 00:08, Laurent Pinchart wrote:
> Implement the .get_frame_desc() subdev operation to report information
> about streams to the connected CSI-2 receiver. This is required to let
> the CSI-2 receiver driver know about virtual channels and data types for
> each stream.
> 
> Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> Reviewed-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
> ---
> Changes since v6:
> 
> - Replace v4l2_subdev_state_get_stream_format() with
>    v4l2_subdev_state_get_format()
> - Make imx219_format_bpp() return an unsigned int
> ---
>   drivers/media/i2c/imx219.c | 67 ++++++++++++++++++++++++++++----------
>   1 file changed, 50 insertions(+), 17 deletions(-)
> 
> diff --git a/drivers/media/i2c/imx219.c b/drivers/media/i2c/imx219.c
> index 6602250834be..fa64bc402c9a 100644
> --- a/drivers/media/i2c/imx219.c
> +++ b/drivers/media/i2c/imx219.c
> @@ -23,6 +23,7 @@
>   #include <linux/pm_runtime.h>
>   #include <linux/regulator/consumer.h>
>   
> +#include <media/mipi-csi2.h>
>   #include <media/v4l2-cci.h>
>   #include <media/v4l2-ctrls.h>
>   #include <media/v4l2-device.h>
> @@ -591,6 +592,24 @@ static void imx219_free_controls(struct imx219 *imx219)
>    * Subdev operations
>    */
>   
> +static unsigned int imx219_format_bpp(u32 code)
> +{
> +	switch (code) {
> +	case MEDIA_BUS_FMT_SRGGB8_1X8:
> +	case MEDIA_BUS_FMT_SGRBG8_1X8:
> +	case MEDIA_BUS_FMT_SGBRG8_1X8:
> +	case MEDIA_BUS_FMT_SBGGR8_1X8:
> +		return 8;
> +
> +	case MEDIA_BUS_FMT_SRGGB10_1X10:
> +	case MEDIA_BUS_FMT_SGRBG10_1X10:
> +	case MEDIA_BUS_FMT_SGBRG10_1X10:
> +	case MEDIA_BUS_FMT_SBGGR10_1X10:
> +	default:
> +		return 10;
> +	}
> +}
> +
>   static int imx219_set_framefmt(struct imx219 *imx219,
>   			       struct v4l2_subdev_state *state)
>   {
> @@ -602,23 +621,7 @@ static int imx219_set_framefmt(struct imx219 *imx219,
>   
>   	format = v4l2_subdev_state_get_format(state, IMX219_PAD_SOURCE);
>   	crop = v4l2_subdev_state_get_crop(state, IMX219_PAD_IMAGE);
> -
> -	switch (format->code) {
> -	case MEDIA_BUS_FMT_SRGGB8_1X8:
> -	case MEDIA_BUS_FMT_SGRBG8_1X8:
> -	case MEDIA_BUS_FMT_SGBRG8_1X8:
> -	case MEDIA_BUS_FMT_SBGGR8_1X8:
> -		bpp = 8;
> -		break;
> -
> -	case MEDIA_BUS_FMT_SRGGB10_1X10:
> -	case MEDIA_BUS_FMT_SGRBG10_1X10:
> -	case MEDIA_BUS_FMT_SGBRG10_1X10:
> -	case MEDIA_BUS_FMT_SBGGR10_1X10:
> -	default:
> -		bpp = 10;
> -		break;
> -	}
> +	bpp = imx219_format_bpp(format->code);
>   
>   	cci_write(imx219->regmap, IMX219_REG_X_ADD_STA_A,
>   		  crop->left - IMX219_PIXEL_ARRAY_LEFT, &ret);
> @@ -1029,6 +1032,35 @@ static int imx219_init_state(struct v4l2_subdev *sd,
>   	return 0;
>   }
>   
> +static int imx219_get_frame_desc(struct v4l2_subdev *sd, unsigned int pad,
> +				 struct v4l2_mbus_frame_desc *fd)
> +{
> +	const struct v4l2_mbus_framefmt *fmt;
> +	struct v4l2_subdev_state *state;
> +	u32 code;
> +
> +	if (pad != IMX219_PAD_SOURCE)
> +		return -EINVAL;
> +
> +	state = v4l2_subdev_lock_and_get_active_state(sd);
> +	fmt = v4l2_subdev_state_get_format(state, IMX219_PAD_SOURCE, 0);

I was going to say change 0 to IMX219_STREAM_IMAGE, but you only add it 
in the next patch. Perhaps a pointless reshuffling, but you could 
introduce IMX219_STREAM_IMAGE in patch 3, or maybe as a separate patch, 
so that in patch 5 (embedded data) you don't need to convert the lines 
related to the image stream.

> +	code = fmt->code;
> +	v4l2_subdev_unlock_state(state);
> +
> +	fd->type = V4L2_MBUS_FRAME_DESC_TYPE_CSI2;
> +	fd->num_entries = 1;
> +
> +	memset(fd->entry, 0, sizeof(fd->entry));

The whole fd has been already cleared in call_get_frame_desc().

> +
> +	fd->entry[0].pixelcode = code;
> +	fd->entry[0].stream = 0;
> +	fd->entry[0].bus.csi2.vc = 0;
> +	fd->entry[0].bus.csi2.dt = imx219_format_bpp(code) == 8
> +				 ? MIPI_CSI2_DT_RAW8 : MIPI_CSI2_DT_RAW10;
> +
> +	return 0;
> +}
> +
>   static const struct v4l2_subdev_core_ops imx219_core_ops = {
>   	.subscribe_event = v4l2_ctrl_subdev_subscribe_event,
>   	.unsubscribe_event = v4l2_event_subdev_unsubscribe,
> @@ -1044,6 +1076,7 @@ static const struct v4l2_subdev_pad_ops imx219_pad_ops = {
>   	.set_fmt = imx219_set_pad_format,
>   	.get_selection = imx219_get_selection,
>   	.enum_frame_size = imx219_enum_frame_size,
> +	.get_frame_desc = imx219_get_frame_desc,
>   };
>   
>   static const struct v4l2_subdev_ops imx219_subdev_ops = {

  Tomi