[PATCH v2 06/11] drm/mediatek: Support alpha blending in display driver

[Hsiao Chien Sung <shawn.sung@mediatek.com>]

Support alpha blending by adding correct blend mode and
alpha property in plane initialization.

Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Hsiao Chien Sung <shawn.sung@mediatek.com>
---
 drivers/gpu/drm/mediatek/mtk_drm_plane.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/drivers/gpu/drm/mediatek/mtk_drm_plane.c b/drivers/gpu/drm/mediatek/mtk_drm_plane.c
index db2f70ae060d..f87cf56fb846 100644
--- a/drivers/gpu/drm/mediatek/mtk_drm_plane.c
+++ b/drivers/gpu/drm/mediatek/mtk_drm_plane.c
@@ -301,6 +301,9 @@ int mtk_plane_init(struct drm_device *dev, struct drm_plane *plane,
 		   size_t num_formats)
 {
 	int err;
+	u32 blend_mode = BIT(DRM_MODE_BLEND_PIXEL_NONE) |
+			 BIT(DRM_MODE_BLEND_PREMULTI)   |
+			 BIT(DRM_MODE_BLEND_COVERAGE);
 
 	if (!formats || !num_formats) {
 		DRM_ERROR("no formats for plane\n");
@@ -323,6 +326,14 @@ int mtk_plane_init(struct drm_device *dev, struct drm_plane *plane,
 			DRM_INFO("Create rotation property failed\n");
 	}
 
+	err = drm_plane_create_alpha_property(plane);
+	if (err)
+		DRM_ERROR("failed to create property: alpha\n");
+
+	err = drm_plane_create_blend_mode_property(plane, blend_mode);
+	if (err)
+		DRM_ERROR("failed to create property: blend_mode\n");
+
 	drm_plane_helper_add(plane, &mtk_plane_helper_funcs);
 
 	return 0;
-- 
2.18.0