[PATCH v3 3/3] media: sun6i-csi: capture: Support MC-centric format enumeration

[Arash Golgol <arash.golgol@gmail.com>]

Extend vidioc_enum_fmt to support MC-centric enumeration by filtering
pixel formats based on the provided mbus code. Advertise MC I/O support
on the video device to reflect its intended usage within a media graph.

Signed-off-by: Arash Golgol <arash.golgol@gmail.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
Changes in v3:
 - No change
 - Link to v2: https://patchwork.kernel.org/project/linux-media/patch/20260508161721.94285-4-arash.golgol@gmail.com/

Changes in v2:
 - Return pixelformat directly instead of a pointer
 - Link to v1: https://patchwork.kernel.org/project/linux-media/patch/20260217064050.18388-4-arash.golgol@gmail.com/

 .../sunxi/sun6i-csi/sun6i_csi_capture.c       | 39 +++++++++++++++++--
 1 file changed, 36 insertions(+), 3 deletions(-)

diff --git a/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi_capture.c b/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi_capture.c
index f788b4234673..5737ebaa7297 100644
--- a/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi_capture.c
+++ b/drivers/media/platform/sunxi/sun6i-csi/sun6i_csi_capture.c
@@ -327,6 +327,22 @@ static bool sun6i_csi_capture_format_match(u32 pixelformat, u32 mbus_code)
 	return false;
 }
 
+static u32 sun6i_csi_capture_pixelformat_find(u32 mbus_code)
+{
+	unsigned int i;
+
+	for (i = 0; i < ARRAY_SIZE(sun6i_csi_capture_format_matches); i++) {
+		const struct sun6i_csi_capture_format_match *match =
+			&sun6i_csi_capture_format_matches[i];
+
+		if (match->mbus_code == mbus_code)
+			return match->pixelformat;
+	}
+
+	/* Valid fourcc is non-zero. */
+	return 0;
+}
+
 /* Capture */
 
 static void
@@ -729,11 +745,27 @@ static int sun6i_csi_capture_enum_fmt(struct file *file, void *priv,
 				      struct v4l2_fmtdesc *fmtdesc)
 {
 	u32 index = fmtdesc->index;
+	u32 mbus_code = fmtdesc->mbus_code;
+	u32 pixelformat;
+
+	/* MC-centric or Video-node-centric */
+	if (mbus_code) {
+		/* There is only one pixelformat for a mbus_code. */
+		if (index)
+			return -EINVAL;
+
+		pixelformat = sun6i_csi_capture_pixelformat_find(mbus_code);
+	} else {
+		if (index >= ARRAY_SIZE(sun6i_csi_capture_formats))
+			return -EINVAL;
+
+		pixelformat = sun6i_csi_capture_formats[index].pixelformat;
+	}
 
-	if (index >= ARRAY_SIZE(sun6i_csi_capture_formats))
+	if (!pixelformat)
 		return -EINVAL;
 
-	fmtdesc->pixelformat = sun6i_csi_capture_formats[index].pixelformat;
+	fmtdesc->pixelformat = pixelformat;
 
 	return 0;
 }
@@ -1065,7 +1097,8 @@ int sun6i_csi_capture_setup(struct sun6i_csi_device *csi_dev)
 
 	strscpy(video_dev->name, SUN6I_CSI_CAPTURE_NAME,
 		sizeof(video_dev->name));
-	video_dev->device_caps = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_STREAMING;
+	video_dev->device_caps = V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_STREAMING |
+				 V4L2_CAP_IO_MC;
 	video_dev->vfl_dir = VFL_DIR_RX;
 	video_dev->release = video_device_release_empty;
 	video_dev->fops = &sun6i_csi_capture_fops;
-- 
2.34.1