media: v4l: Set line based metadata flag in V4L2 core

Set (and unset) the V4L2_FMT_FLAG_META_LINE_BASED flag in struct
v4l2_fmtdesc based on the format after returning the driver callback for
enumerating formats. This way the drivers don't need to care about the
flag.
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>

drivers/media/v4l2-core/v4l2-ioctl.c

@@ -1538,6 +1538,22 @@ static void v4l_fill_fmtdesc(struct v4l2_fmtdesc *fmt)
 		}
 	}
 
+	if (fmt->type == V4L2_BUF_TYPE_META_CAPTURE) {
+		switch (fmt->pixelformat) {
+		case V4L2_META_FMT_GENERIC_8:
+		case V4L2_META_FMT_GENERIC_CSI2_10:
+		case V4L2_META_FMT_GENERIC_CSI2_12:
+		case V4L2_META_FMT_GENERIC_CSI2_14:
+		case V4L2_META_FMT_GENERIC_CSI2_16:
+		case V4L2_META_FMT_GENERIC_CSI2_20:
+		case V4L2_META_FMT_GENERIC_CSI2_24:
+			fmt->flags |= V4L2_FMT_FLAG_META_LINE_BASED;
+			break;
+		default:
+			fmt->flags &= ~V4L2_FMT_FLAG_META_LINE_BASED;
+		}
+	}
+
 	if (descr)
 		WARN_ON(strscpy(fmt->description, descr, sz) < 0);
 	fmt->flags |= flags;

include/uapi/linux/videodev2.h

@@ -839,6 +839,10 @@ struct v4l2_pix_format {
 #define V4L2_META_FMT_RK_ISP1_PARAMS	v4l2_fourcc('R', 'K', '1', 'P') /* Rockchip ISP1 3A Parameters */
 #define V4L2_META_FMT_RK_ISP1_STAT_3A	v4l2_fourcc('R', 'K', '1', 'S') /* Rockchip ISP1 3A Statistics */
 
+/*
+ * Line-based metadata formats. Remember to update v4l_fill_fmtdesc() when
+ * adding new ones!
+ */
 #define V4L2_META_FMT_GENERIC_8		v4l2_fourcc('M', 'E', 'T', '8') /* Generic 8-bit metadata */
 #define V4L2_META_FMT_GENERIC_CSI2_10	v4l2_fourcc('M', 'C', '1', 'A') /* 10-bit CSI-2 packed 8-bit metadata */
 #define V4L2_META_FMT_GENERIC_CSI2_12	v4l2_fourcc('M', 'C', '1', 'C') /* 12-bit CSI-2 packed 8-bit metadata */