drm: sti: add support of ABGR8888 for gdp plane

Use GDP capabilities to support DRM_FORMAT_ABGR8888 (AB24)
Signed-off-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>

drivers/gpu/drm/sti/sti_gdp.c

@@ -14,7 +14,9 @@
 #include "sti_layer.h"
 #include "sti_vtg.h"
 
+#define ALPHASWITCH     BIT(6)
 #define ENA_COLOR_FILL  BIT(8)
+#define BIGNOTLITTLE    BIT(23)
 #define WAIT_NEXT_VSYNC BIT(31)
 
 /* GDP color formats */
@@ -23,6 +25,7 @@
 #define GDP_RGB888_32   0x02
 #define GDP_ARGB8565    0x04
 #define GDP_ARGB8888    0x05
+#define GDP_ABGR8888	(GDP_ARGB8888 | BIGNOTLITTLE | ALPHASWITCH)
 #define GDP_ARGB1555    0x06
 #define GDP_ARGB4444    0x07
 #define GDP_CLUT8       0x0B
@@ -104,6 +107,7 @@ struct sti_gdp {
 static const uint32_t gdp_supported_formats[] = {
 	DRM_FORMAT_XRGB8888,
 	DRM_FORMAT_ARGB8888,
+	DRM_FORMAT_ABGR8888,
 	DRM_FORMAT_ARGB4444,
 	DRM_FORMAT_ARGB1555,
 	DRM_FORMAT_RGB565,
@@ -131,6 +135,8 @@ static int sti_gdp_fourcc2format(int fourcc)
 		return GDP_RGB888_32;
 	case DRM_FORMAT_ARGB8888:
 		return GDP_ARGB8888;
+	case DRM_FORMAT_ABGR8888:
+		return GDP_ABGR8888;
 	case DRM_FORMAT_ARGB4444:
 		return GDP_ARGB4444;
 	case DRM_FORMAT_ARGB1555:
@@ -157,6 +163,7 @@ static int sti_gdp_get_alpharange(int format)
 	case GDP_ARGB8565:
 	case GDP_ARGB8888:
 	case GDP_AYCBR8888:
+	case GDP_ABGR8888:
 		return GAM_GDP_ALPHARANGE_255;
 	}
 	return 0;