Add drm_draw_can_convert_from_xrgb8888() function that can be used to
determine if a XRGB8888 color can be converted to the specified format.

Reviewed-by: Jocelyn Falempe <jfalempe@redhat.com>
Signed-off-by: Francesco Valla <francesco@valla.it>
---
 drivers/gpu/drm/drm_draw.c          | 29 +++++++++++++++++++++++++++++
 drivers/gpu/drm/drm_draw_internal.h |  2 ++
 2 files changed, 31 insertions(+)

diff --git a/drivers/gpu/drm/drm_draw.c b/drivers/gpu/drm/drm_draw.c
index 5b956229c82fb6e232e3342705a226c8e14c8568..5043baf901b82e730cb7c3fe55aab99c91cd9fdf 100644
--- a/drivers/gpu/drm/drm_draw.c
+++ b/drivers/gpu/drm/drm_draw.c
@@ -15,6 +15,35 @@
 #include "drm_draw_internal.h"
 #include "drm_format_internal.h"
 
+/**
+ * drm_draw_can_convert_from_xrgb8888 - check if xrgb8888 can be converted to the desired format
+ * @format: format
+ *
+ * Returns:
+ * True if XRGB8888 can be converted to the specified format, false otherwise.
+ */
+bool drm_draw_can_convert_from_xrgb8888(u32 format)
+{
+	switch (format) {
+	case DRM_FORMAT_RGB565:
+	case DRM_FORMAT_RGBA5551:
+	case DRM_FORMAT_XRGB1555:
+	case DRM_FORMAT_ARGB1555:
+	case DRM_FORMAT_RGB888:
+	case DRM_FORMAT_XRGB8888:
+	case DRM_FORMAT_ARGB8888:
+	case DRM_FORMAT_XBGR8888:
+	case DRM_FORMAT_ABGR8888:
+	case DRM_FORMAT_XRGB2101010:
+	case DRM_FORMAT_ARGB2101010:
+	case DRM_FORMAT_ABGR2101010:
+		return true;
+	default:
+		return false;
+	}
+}
+EXPORT_SYMBOL(drm_draw_can_convert_from_xrgb8888);
+
 /**
  * drm_draw_color_from_xrgb8888 - convert one pixel from xrgb8888 to the desired format
  * @color: input color, in xrgb8888 format
diff --git a/drivers/gpu/drm/drm_draw_internal.h b/drivers/gpu/drm/drm_draw_internal.h
index 20cb404e23ea6263b535ea2b81b25f84c37be8a2..2619671456359efa3406a480890a0b5ac63dd9ea 100644
--- a/drivers/gpu/drm/drm_draw_internal.h
+++ b/drivers/gpu/drm/drm_draw_internal.h
@@ -24,6 +24,8 @@ static inline const u8 *drm_draw_get_char_bitmap(const struct font_desc *font,
 	return font->data + (c * font->height) * font_pitch;
 }
 
+bool drm_draw_can_convert_from_xrgb8888(u32 format);
+
 u32 drm_draw_color_from_xrgb8888(u32 color, u32 format);
 
 void drm_draw_blit16(struct iosys_map *dmap, unsigned int dpitch,

-- 
2.52.0