[PATCH v3 3/4] drm/vkms: add XRGB planes composition

[Melissa Wen]

Add support for composing XRGB888 planes in addition to the
ARGB8888 format. In the case of an XRGB plane at the top, the
composition consists of just copying the RGB values of a
pixel from src to dst, without the need for alpha blending
operations for each pixel.

Signed-off-by: Melissa Wen <melissa.srw at gmail.com>
---
 drivers/gpu/drm/vkms/vkms_composer.c | 22 ++++++++++++++++++----
 drivers/gpu/drm/vkms/vkms_plane.c    |  7 ++++---
 2 files changed, 22 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/vkms/vkms_composer.c b/drivers/gpu/drm/vkms/vkms_composer.c
index be8f1d33c645..7fe1fdb3af39 100644
--- a/drivers/gpu/drm/vkms/vkms_composer.c
+++ b/drivers/gpu/drm/vkms/vkms_composer.c
@@ -4,6 +4,7 @@
 
 #include <drm/drm_atomic.h>
 #include <drm/drm_atomic_helper.h>
+#include <drm/drm_fourcc.h>
 #include <drm/drm_gem_framebuffer_helper.h>
 #include <drm/drm_gem_shmem_helper.h>
 #include <drm/drm_vblank.h>
@@ -76,6 +77,11 @@ static void alpha_blending(const u8 *argb_src, u8 *argb_dst)
 	argb_dst[3] = 0xFF;
 }
 
+static void x_blending(const u8 *xrgb_src, u8 *xrgb_dst)
+{
+	memcpy(xrgb_dst, xrgb_src, sizeof(u8) * 3);
+}
+
 /**
  * blend - blend value at vaddr_src with value at vaddr_dst
  * @vaddr_dst: destination address
@@ -91,7 +97,8 @@ static void alpha_blending(const u8 *argb_src, u8 *argb_dst)
  */
 static void blend(void *vaddr_dst, void *vaddr_src,
 		  struct vkms_composer *dst_composer,
-		  struct vkms_composer *src_composer)
+		  struct vkms_composer *src_composer,
+		  void (*pixel_blend)(const u8 *, u8 *))
 {
 	int i, j, j_dst, i_dst;
 	int offset_src, offset_dst;
@@ -119,7 +126,7 @@ static void blend(void *vaddr_dst, void *vaddr_src,
 
 			pixel_src = (u8 *)(vaddr_src + offset_src);
 			pixel_dst = (u8 *)(vaddr_dst + offset_dst);
-			alpha_blending(pixel_src, pixel_dst);
+			pixel_blend(pixel_src, pixel_dst);
 		}
 		i_dst++;
 	}
@@ -131,6 +138,8 @@ static void compose_planes(struct vkms_composer *primary_composer,
 {
 	struct drm_gem_object *plane_obj;
 	struct drm_gem_shmem_object *plane_shmem_obj;
+	struct drm_framebuffer *fb = &plane_composer->fb;
+	void (*pixel_blend)(const u8 *p_src, u8 *p_dst);
 
 	plane_obj = drm_gem_fb_get_obj(&plane_composer->fb, 0);
 	plane_shmem_obj = to_drm_gem_shmem_obj(plane_obj);
@@ -138,8 +147,13 @@ static void compose_planes(struct vkms_composer *primary_composer,
 	if (WARN_ON(!plane_shmem_obj->vaddr))
 		return;
 
-	blend(vaddr_out, plane_shmem_obj->vaddr,
-	      primary_composer, plane_composer);
+	if (fb->format->format == DRM_FORMAT_ARGB8888)
+		pixel_blend = &alpha_blending;
+	else
+		pixel_blend = &x_blending;
+
+	blend(vaddr_out, plane_shmem_obj->vaddr, primary_composer,
+	      plane_composer, pixel_blend);
 }
 
 static int composite(void **vaddr_out,
diff --git a/drivers/gpu/drm/vkms/vkms_plane.c b/drivers/gpu/drm/vkms/vkms_plane.c
index 135140f8e87a..da4251aff67f 100644
--- a/drivers/gpu/drm/vkms/vkms_plane.c
+++ b/drivers/gpu/drm/vkms/vkms_plane.c
@@ -16,8 +16,9 @@ static const u32 vkms_formats[] = {
 	DRM_FORMAT_XRGB8888,
 };
 
-static const u32 vkms_cursor_formats[] = {
+static const u32 vkms_plane_formats[] = {
 	DRM_FORMAT_ARGB8888,
+	DRM_FORMAT_XRGB8888
 };
 
 static struct drm_plane_state *
@@ -200,8 +201,8 @@ struct vkms_plane *vkms_plane_init(struct vkms_device *vkmsdev,
 	int nformats;
 
 	if (type == DRM_PLANE_TYPE_CURSOR) {
-		formats = vkms_cursor_formats;
-		nformats = ARRAY_SIZE(vkms_cursor_formats);
+		formats = vkms_plane_formats;
+		nformats = ARRAY_SIZE(vkms_plane_formats);
 		funcs = &vkms_primary_helper_funcs;
 	} else {
 		formats = vkms_formats;
-- 
2.30.2