void tinydrm_xrgb8888_to_rgb565(u16 *dst, void *vaddr,
struct drm_framebuffer *fb,
struct drm_clip_rect *clip, bool swap);
+void tinydrm_xrgb8888_to_gray8(u8 *dst, void *vaddr, struct drm_framebuffer *fb,
+ struct drm_clip_rect *clip);
struct backlight_device *tinydrm_of_find_backlight(struct device *dev);
int tinydrm_enable_backlight(struct backlight_device *backlight);