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Date:   Tue, 7 Jun 2022 18:51:36 +0200
From:   Jacopo Mondi <jacopo@jmondi.org>
To:     Quentin Schulz <foss+kernel@0leil.net>
Cc:     shawnx.tu@intel.com, mchehab@kernel.org, robh+dt@kernel.org,
        krzysztof.kozlowski+dt@linaro.org, linux-media@vger.kernel.org,
        devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
        Quentin Schulz <quentin.schulz@theobroma-systems.com>
Subject: Re: [PATCH v6 4/4] media: i2c: ov5675: add .get_selection support
Message-ID: <20220607165136.bmriu2n7yorc7fx6@uno.localdomain>
References: <20220607153335.875956-1-foss+kernel@0leil.net>
 <20220607153335.875956-4-foss+kernel@0leil.net>
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In-Reply-To: <20220607153335.875956-4-foss+kernel@0leil.net>
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Hi Quentin,

On Tue, Jun 07, 2022 at 05:33:35PM +0200, Quentin Schulz wrote:
> From: Quentin Schulz <quentin.schulz@theobroma-systems.com>
>
> 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.
>
> There are currently two modes supported by this driver: 2592*1944 and
> 1296*972. The second mode is obtained thanks to subsampling while
> keeping the same field of view (FoV). No cropping involved, hence the
> harcoded values.
>
> Signed-off-by: Quentin Schulz <quentin.schulz@theobroma-systems.com>
> ---
>
> v6:
>  - explicit a bit more the commit log around subsampling for lower
>  resolution modes,
>  - (again) fixed reporting for V4L2_SEL_TGT_CROP_* thanks to Jacopo's help,
>
> 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 | 21 +++++++++++++++++++++
>  1 file changed, 21 insertions(+)
>
> diff --git a/drivers/media/i2c/ov5675.c b/drivers/media/i2c/ov5675.c
> index 80840ad7bbb0..2230ff47ef49 100644
> --- a/drivers/media/i2c/ov5675.c
> +++ b/drivers/media/i2c/ov5675.c
> @@ -1121,6 +1121,26 @@ 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)
> +{
> +	if (sel->which != V4L2_SUBDEV_FORMAT_ACTIVE)
> +		return -EINVAL;
> +
> +	switch (sel->target) {
> +	case V4L2_SEL_TGT_CROP:
> +	case V4L2_SEL_TGT_CROP_BOUNDS:

Seem like we have trouble understanding each other, or better, I have
troubles explaining myself most probably :)

If the dummy/black area is readable, this should just be (0, 0, 2624,
2000) like it was in your previous version. What has changed that I
have missed ?

Thanks
  j


> +	case V4L2_SEL_TGT_CROP_DEFAULT:
> +		sel->r.top = 16;
> +		sel->r.left = 16;
> +		sel->r.width = 2592;
> +		sel->r.height = 1944;
> +		return 0;
> +	}
> +	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 +1190,7 @@ 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
>