[PATCH v3] media: i2c: imx471: return 0 from get_selection after filling crop

libcamera issues VIDIOC_SUBDEV_G_SELECTION with target CROP (rectangle
0) during CameraSensorLegacy bring-up. imx471_get_selection filled the
rectangle then fell out of the switch and returned -EINVAL.

Fill every supported target, break, and return 0 after the switch
(default: -EINVAL), as Kate Hsuan suggested.

Compute analog crop in set_pad_format: 2x binning, centered in the
native array, same idea as imx219. IMX471 2x2-binned 1928x1088 then
reports CROP as 3856x2176 centered in 4672x3512.

Rebased onto media-committers next (4900cad020c0). v2 was against the
Fedora tree and did not apply here.

Tested on ThinkPad X9-15 Gen 1 (SONY471A / IPU7), Fedora 44
kernel 7.1.8-200.fc44.

Link: https://bugzilla.redhat.com/show_bug.cgi?id=2454119
Signed-off-by: John Cronin <[email protected]>
---
 drivers/media/i2c/imx471.c | 24 +++++++++++++++++++++---
 1 file changed, 21 insertions(+), 3 deletions(-)

diff --git a/drivers/media/i2c/imx471.c b/drivers/media/i2c/imx471.c
index 4053aed84..96d96256d 100644
--- a/drivers/media/i2c/imx471.c
+++ b/drivers/media/i2c/imx471.c
@@ -431,6 +431,21 @@ static int imx471_set_pad_format(struct v4l2_subdev *sd,
 
 	*v4l2_subdev_state_get_format(sd_state, fmt->pad) = fmt->format;
 
+	/* Analog crop: 2x bin, centered in the native array (same idea as imx219). */
+	{
+		struct v4l2_rect *crop;
+		u8 bin_h, bin_v, binning;
+
+		crop = v4l2_subdev_state_get_crop(sd_state, fmt->pad);
+		bin_h = min_t(u32, IMX471_PIXEL_ARRAY_WIDTH / fmt->format.width, 2);
+		bin_v = min_t(u32, IMX471_PIXEL_ARRAY_HEIGHT / fmt->format.height, 2);
+		binning = min(bin_h, bin_v);
+		crop->width = fmt->format.width * binning;
+		crop->height = fmt->format.height * binning;
+		crop->left = (IMX471_NATIVE_WIDTH - crop->width) / 2;
+		crop->top = (IMX471_NATIVE_HEIGHT - crop->height) / 2;
+	}
+
 	if (fmt->which == V4L2_SUBDEV_FORMAT_TRY)
 		return 0;
 
@@ -468,7 +483,7 @@ static int imx471_get_selection(struct v4l2_subdev *sd,
 		sel->r.left = 0;
 		sel->r.width = IMX471_NATIVE_WIDTH;
 		sel->r.height = IMX471_NATIVE_HEIGHT;
-		return 0;
+		break;
 
 	case V4L2_SEL_TGT_CROP_DEFAULT:
 	case V4L2_SEL_TGT_CROP_BOUNDS:
@@ -476,10 +491,13 @@ static int imx471_get_selection(struct v4l2_subdev *sd,
 		sel->r.left = IMX471_PIXEL_ARRAY_LEFT;
 		sel->r.width = IMX471_PIXEL_ARRAY_WIDTH;
 		sel->r.height = IMX471_PIXEL_ARRAY_HEIGHT;
-		return 0;
+		break;
+
+	default:
+		return -EINVAL;
 	}
 
-	return -EINVAL;
+	return 0;
 }
 
 static int imx471_init_state(struct v4l2_subdev *sd,
-- 
2.55.0