Re: [PATCH 1/2] media: imx274: improve v4l2-compliance

[Sakari Ailus <sakari.ailus@iki.fi>]

Hi Bob,

Thanks for the patch.

On Sat, Apr 24, 2021 at 01:14:58PM +0200, Bob Veringa wrote:
> 1) Fix incorrect return of get_fmt when fmt->which is set
> to V4L2_SUBDEV_FORMAT_TRY. get_fmt always returns the active format,
> but should return the pad configuration when V4L2_SUBDEV_FORMAT_TRY
> is requested.
> 
> 2) Fix set_fmt not functioning correctly when fmt->which is set to
> V4L2_SUBDEV_FORMAT_TRY. When a trying a format the driver assumes that
> try_crop is already set. If this is not the case it causes
> unexpected behavior. Add a default value if crop value is not set.
> 
> 3) Add support for enumerating media bus formats
> via VIDIOC_SUBDEV_ENUM_MBUS_CODE.
> 
> 4) Add  support for enumerating frame sizes
> via VIDIOC_SUBDEV_ENUM_FRAME_SIZE.
> 
> 5) Fix v4l2-compliance error 'VIDIOC_(UN)SUBSCRIBE_EVENT/DQEVENT: FAIL'
> by implementing v4l2_subdev_core_ops struct with default functions.
> 
> Signed-off-by: Bob Veringa <bob.veringa@topic.nl>
> Acked-by: Mike Looijmans <mike.looijmans@topic.nl>
> ---
>  drivers/media/i2c/imx274.c | 72 +++++++++++++++++++++++++++++++++++---
>  1 file changed, 68 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/media/i2c/imx274.c b/drivers/media/i2c/imx274.c
> index d9849d34f39f..942407ed931b 100644
> --- a/drivers/media/i2c/imx274.c
> +++ b/drivers/media/i2c/imx274.c
> @@ -28,6 +28,7 @@
>  #include <media/v4l2-ctrls.h>
>  #include <media/v4l2-device.h>
>  #include <media/v4l2-subdev.h>
> +#include <media/v4l2-event.h>
>  
>  /*
>   * See "SHR, SVR Setting" in datasheet
> @@ -72,6 +73,7 @@
>  #define IMX274_MAX_FRAME_RATE			(120)
>  #define IMX274_MIN_FRAME_RATE			(5)
>  #define IMX274_DEF_FRAME_RATE			(60)
> +#define IMX274_DEFAULT_MEDIA_FORMAT		MEDIA_BUS_FMT_SRGGB10_1X10
>  
>  /*
>   * register SHR is limited to (SVR value + 1) x VMAX value - 4
> @@ -1011,7 +1013,7 @@ static int __imx274_change_compose(struct stimx274 *imx274,
>  				   u32 flags)
>  {
>  	struct device *dev = &imx274->client->dev;
> -	const struct v4l2_rect *cur_crop;
> +	struct v4l2_rect *cur_crop;
>  	struct v4l2_mbus_framefmt *tgt_fmt;
>  	unsigned int i;
>  	const struct imx274_mode *best_mode = &imx274_modes[0];
> @@ -1025,6 +1027,11 @@ static int __imx274_change_compose(struct stimx274 *imx274,
>  		tgt_fmt = &imx274->format;
>  	}
>  
> +	if (cur_crop->height == 0 || cur_crop->width == 0) {
> +		cur_crop->height = IMX274_MAX_HEIGHT;
> +		cur_crop->width = IMX274_MAX_WIDTH;

Shouldn't this be done in probe / init_cfg (to be added to subdev ops),
unconditionally?

The try format should also be initialised there. Both should be device
defaults, i.e. the same as those set in probe.

> +	}
> +
>  	for (i = 0; i < ARRAY_SIZE(imx274_modes); i++) {
>  		u8 wratio = imx274_modes[i].wbin_ratio;
>  		u8 hratio = imx274_modes[i].hbin_ratio;
> @@ -1072,11 +1079,24 @@ static int imx274_get_fmt(struct v4l2_subdev *sd,
>  			  struct v4l2_subdev_format *fmt)
>  {
>  	struct stimx274 *imx274 = to_imx274(sd);
> +	int ret = 0;
>  
>  	mutex_lock(&imx274->lock);
> -	fmt->format = imx274->format;
> +
> +	switch (fmt->which) {
> +	case V4L2_SUBDEV_FORMAT_TRY:
> +		fmt->format = *v4l2_subdev_get_try_format(sd, cfg, fmt->pad);
> +		break;
> +	case V4L2_SUBDEV_FORMAT_ACTIVE:
> +		fmt->format = imx274->format;
> +		break;
> +	default:
> +		ret = -EINVAL;
> +		break;
> +	}
> +
>  	mutex_unlock(&imx274->lock);
> -	return 0;
> +	return ret;
>  }
>  
>  /**
> @@ -1274,6 +1294,41 @@ static int imx274_set_selection(struct v4l2_subdev *sd,
>  	return -EINVAL;
>  }
>  
> +static int imx274_enum_frame_size(struct v4l2_subdev *sd,
> +				  struct v4l2_subdev_pad_config *cfg,
> +				  struct v4l2_subdev_frame_size_enum *fse)
> +{
> +	__u32 width, height;

u32, please. __u32 is for the user space facing headers.

> +
> +	if (fse->index >= ARRAY_SIZE(imx274_modes))
> +		return -EINVAL;
> +
> +	width = IMX274_MAX_WIDTH / imx274_modes[fse->index].wbin_ratio;
> +	height = IMX274_MAX_HEIGHT / imx274_modes[fse->index].hbin_ratio;
> +
> +	fse->code = IMX274_DEFAULT_MEDIA_FORMAT;
> +	fse->min_width = width;
> +	fse->max_width = width;
> +	fse->min_height = height;
> +	fse->max_height = height;
> +	return 0;
> +}
> +
> +static int imx274_enum_mbus_code(struct v4l2_subdev *sd,
> +				 struct v4l2_subdev_pad_config *cfg,
> +				 struct v4l2_subdev_mbus_code_enum *code)
> +{
> +	if (code->index > 0)
> +		return -EINVAL;
> +
> +	if (code->pad != 0)
> +		return -EINVAL;

The caller has checked the pad field is valid, and with a single pad in the
entity no additional check is necessary.

> +
> +	code->code = IMX274_DEFAULT_MEDIA_FORMAT;
> +
> +	return 0;
> +}
> +
>  static int imx274_apply_trimming(struct stimx274 *imx274)
>  {
>  	u32 h_start;
> @@ -1903,11 +1958,19 @@ static int imx274_set_frame_interval(struct stimx274 *priv,
>  	return err;
>  }
>  
> +static const struct v4l2_subdev_core_ops imx274_core_ops = {
> +	.log_status = v4l2_ctrl_subdev_log_status,
> +	.subscribe_event = v4l2_ctrl_subdev_subscribe_event,
> +	.unsubscribe_event = v4l2_event_subdev_unsubscribe,
> +};
> +
>  static const struct v4l2_subdev_pad_ops imx274_pad_ops = {
>  	.get_fmt = imx274_get_fmt,
>  	.set_fmt = imx274_set_fmt,
>  	.get_selection = imx274_get_selection,
>  	.set_selection = imx274_set_selection,
> +	.enum_mbus_code = imx274_enum_mbus_code,
> +	.enum_frame_size = imx274_enum_frame_size,
>  };
>  
>  static const struct v4l2_subdev_video_ops imx274_video_ops = {
> @@ -1917,6 +1980,7 @@ static const struct v4l2_subdev_video_ops imx274_video_ops = {
>  };
>  
>  static const struct v4l2_subdev_ops imx274_subdev_ops = {
> +	.core = &imx274_core_ops,
>  	.pad = &imx274_pad_ops,
>  	.video = &imx274_video_ops,
>  };
> @@ -1968,7 +2032,7 @@ static int imx274_probe(struct i2c_client *client)
>  	imx274->format.width = imx274->crop.width / imx274->mode->wbin_ratio;
>  	imx274->format.height = imx274->crop.height / imx274->mode->hbin_ratio;
>  	imx274->format.field = V4L2_FIELD_NONE;
> -	imx274->format.code = MEDIA_BUS_FMT_SRGGB10_1X10;
> +	imx274->format.code = IMX274_DEFAULT_MEDIA_FORMAT;
>  	imx274->format.colorspace = V4L2_COLORSPACE_SRGB;
>  	imx274->frame_interval.numerator = 1;
>  	imx274->frame_interval.denominator = IMX274_DEF_FRAME_RATE;

-- 
Kind regards,

Sakari Ailus