drm: add RGB formats with separate alpha plane

Some hardware can read the alpha components separately and then
conditionally fetch color components only for non-zero alpha values.
This patch adds fourcc definitions for two-plane RGB formats with an
8-bit alpha channel on a second plane.

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>

1 files changed, 14 insertions, 0 deletions

diff --git a/include/uapi/drm/drm_fourcc.h b/include/uapi/drm/drm_fourcc.h
index ef20abb8119b..995c8f9c692f 100644
--- a/include/uapi/drm/drm_fourcc.h
+++ b/include/uapi/drm/drm_fourcc.h
@@ -114,6 +114,20 @@ extern "C" {
 #define DRM_FORMAT_AYUV		fourcc_code('A', 'Y', 'U', 'V') /* [31:0] A:Y:Cb:Cr 8:8:8:8 little endian */
 
 /*
+ * 2 plane RGB + A
+ * index 0 = RGB plane, same format as the corresponding non _A8 format has
+ * index 1 = A plane, [7:0] A
+ */
+#define DRM_FORMAT_XRGB8888_A8	fourcc_code('X', 'R', 'A', '8')
+#define DRM_FORMAT_XBGR8888_A8	fourcc_code('X', 'B', 'A', '8')
+#define DRM_FORMAT_RGBX8888_A8	fourcc_code('R', 'X', 'A', '8')
+#define DRM_FORMAT_BGRX8888_A8	fourcc_code('B', 'X', 'A', '8')
+#define DRM_FORMAT_RGB888_A8	fourcc_code('R', '8', 'A', '8')
+#define DRM_FORMAT_BGR888_A8	fourcc_code('B', '8', 'A', '8')
+#define DRM_FORMAT_RGB565_A8	fourcc_code('R', '5', 'A', '8')
+#define DRM_FORMAT_BGR565_A8	fourcc_code('B', '5', 'A', '8')
+
+/*
  * 2 plane YCbCr
  * index 0 = Y plane, [7:0] Y
  * index 1 = Cr:Cb plane, [15:0] Cr:Cb little endian