Hi Quentin
On Wed, May 25, 2022 at 04:58:33PM +0200, Quentin Schulz wrote:
> From: Quentin Schulz <quentin.schulz@xxxxxxxxxxxxxxxxxxxxx>
>
> The sensor has 2592*1944 active pixels, surrounded by 16 active dummy
> pixels and there are an additional 24 black rows "at the bottom".
>
> [2624]
> +-----+------------------+-----+
> | | 16 dummy | |
> +-----+------------------+-----+
> | | | |
> | | [2592] | |
> | | | |
> |16 | valid | 16 |[2000]
> |dummy| |dummy|
> | | [1944]| |
> | | | |
> +-----+------------------+-----+
> | | 16 dummy | |
> +-----+------------------+-----+
> | | 24 black lines | |
> +-----+------------------+-----+
>
> The top-left coordinate is gotten from the registers specified in the
> modes which are identical for both currently supported modes.
>
> Signed-off-by: Quentin Schulz <quentin.schulz@xxxxxxxxxxxxxxxxxxxxx>
> ---
>
> v4:
> - explicit a bit more the commit log,
> - added drawing in the commit log,
> - fixed reporting for V4L2_SEL_TGT_CROP_* thanks to Jacopo's help,
>
> added in v3
>
> drivers/media/i2c/ov5675.c | 33 +++++++++++++++++++++++++++++++++
> 1 file changed, 33 insertions(+)
>
> diff --git a/drivers/media/i2c/ov5675.c b/drivers/media/i2c/ov5675.c
> index c1f3c387afde0..384a9ea2372c3 100644
> --- a/drivers/media/i2c/ov5675.c
> +++ b/drivers/media/i2c/ov5675.c
> @@ -1121,6 +1121,38 @@ static int ov5675_get_format(struct v4l2_subdev *sd,
> return 0;
> }
>
> +static int ov5675_get_selection(struct v4l2_subdev *sd,
> + struct v4l2_subdev_state *state,
> + struct v4l2_subdev_selection *sel)
> +{
> + struct ov5675 *ov5675 = to_ov5675(sd);
> +
> + if (sel->which != V4L2_SUBDEV_FORMAT_ACTIVE)
> + return -EINVAL;
> +
> + switch (sel->target) {
> + case V4L2_SEL_TGT_CROP_BOUNDS:
> + sel->r.top = 0;
> + sel->r.left = 0;
> + sel->r.width = 2624;
> + sel->r.height = 2000;
> + return 0;
> + case V4L2_SEL_TGT_CROP:
> + sel->r.top = 16;
> + sel->r.left = 16;
> + sel->r.width = ov5675->cur_mode->width;
> + sel->r.height = ov5675->cur_mode->height;
> + return 0;
I'm afraid this doesn't match exactly my understanding of the
discussion we had.
The driver defines the following modes
/*
* OV5670 sensor supports following resolutions with full FOV:
* 4:3 ==> {2592x1944, 1296x972, 648x486}
* 16:9 ==> {2560x1440, 1280x720, 640x360}
*/
static const struct ov5670_mode supported_modes[] = {
{
.width = 2592,
.height = 1944,
},
{
.width = 1296,
.height = 972,
},
{
.width = 648,
.height = 486,
},
{
.width = 2560,
.height = 1440,
},
{
.width = 1280,
.height = 720,
},
{
.width = 640,
.height = 360,
}
};
The comment says all modes retain the "full FOV", which I assume it
implies they are obtained by sub-sampling and not cropping.
The first three modes (4:3) are indeed obtained by subsampling the
full active pixel array:
(2592,1944) / 2 = (1296,972) / 2 = (648,486)
The last three are obtained by subsampling a slightly cropped portion
of the pixel array
(2560,1440) / 2 = (1280,720) / 2 = (640,360)
If you set CROP = cur_mode->[width/height] you will instead report the
visible width/height, which as said it's obtained by subsampling (of a
slightly cropped portion of the pixel array for the last three ones)
The CROP rectangle is then (2592, 1944) for the first three and (2560,
1440) for the last three.
I would add a v4l2_rect to struct ov5670_mode where to record that and
report it here.
> + case V4L2_SEL_TGT_CROP_DEFAULT:
> + sel->r.top = 16;
> + sel->r.left = 16;
> + sel->r.width = supported_modes[0].width;
> + sel->r.height = supported_modes[0].height;
> + return 0;
You could also define these values instead of fishing in the
supported_modes array, to protect against future changes to the array
itself. Up to you.
> + }
> + return -EINVAL;
> +}
> +
> static int ov5675_enum_mbus_code(struct v4l2_subdev *sd,
> struct v4l2_subdev_state *sd_state,
> struct v4l2_subdev_mbus_code_enum *code)
> @@ -1170,6 +1202,7 @@ static const struct v4l2_subdev_video_ops ov5675_video_ops = {
> static const struct v4l2_subdev_pad_ops ov5675_pad_ops = {
> .set_fmt = ov5675_set_format,
> .get_fmt = ov5675_get_format,
> + .get_selection = ov5675_get_selection,
> .enum_mbus_code = ov5675_enum_mbus_code,
> .enum_frame_size = ov5675_enum_frame_size,
> };
> --
> 2.36.1
>
