[PATCH v6 4/4] media: i2c: ov5675: add .get_selection support

[Quentin Schulz <foss+kernel@0leil.net>]

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:
+	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