drm/sun4i: backend: Add a helper and a list for supported formats

In order to check whether the backend supports a specific format, an
explicit list and a related helper are introduced.

The prototype of this helper is added to the header so that it can be
called from sun4i_layer later (when introducing tiled mode support).

Signed-off-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181123092515.2511-5-paul.kocialkowski@bootlin.com

2 files changed, 28 insertions, 0 deletions

diff --git a/drivers/gpu/drm/sun4i/sun4i_backend.c b/drivers/gpu/drm/sun4i/sun4i_backend.c
index c3444246755b..7dd24eb03f89 100644
--- a/drivers/gpu/drm/sun4i/sun4i_backend.c
+++ b/drivers/gpu/drm/sun4i/sun4i_backend.c
@@ -155,6 +155,33 @@ static int sun4i_backend_drm_format_to_layer(u32 format, u32 *mode)
         return 0;
 }
 
+static const uint32_t sun4i_backend_formats[] = {
+        DRM_FORMAT_ARGB1555,
+        DRM_FORMAT_ARGB4444,
+        DRM_FORMAT_ARGB8888,
+        DRM_FORMAT_BGRX8888,
+        DRM_FORMAT_RGB565,
+        DRM_FORMAT_RGB888,
+        DRM_FORMAT_RGBA4444,
+        DRM_FORMAT_RGBA5551,
+        DRM_FORMAT_UYVY,
+        DRM_FORMAT_VYUY,
+        DRM_FORMAT_XRGB8888,
+        DRM_FORMAT_YUYV,
+        DRM_FORMAT_YVYU,
+};
+
+bool sun4i_backend_format_is_supported(uint32_t fmt)
+{
+        unsigned int i;
+
+        for (i = 0; i < ARRAY_SIZE(sun4i_backend_formats); i++)
+                if (sun4i_backend_formats[i] == fmt)
+                        return true;
+
+        return false;
+}
+
 int sun4i_backend_update_layer_coord(struct sun4i_backend *backend,
                                      int layer, struct drm_plane *plane)
 {
diff --git a/drivers/gpu/drm/sun4i/sun4i_backend.h b/drivers/gpu/drm/sun4i/sun4i_backend.h
index 339dbff1cce4..93db3af675b3 100644
--- a/drivers/gpu/drm/sun4i/sun4i_backend.h
+++ b/drivers/gpu/drm/sun4i/sun4i_backend.h
@@ -198,6 +198,7 @@ engine_to_sun4i_backend(struct sunxi_engine *engine)
 
 void sun4i_backend_layer_enable(struct sun4i_backend *backend,
                                 int layer, bool enable);
+bool sun4i_backend_format_is_supported(uint32_t fmt);
 int sun4i_backend_update_layer_coord(struct sun4i_backend *backend,
                                      int layer, struct drm_plane *plane);
 int sun4i_backend_update_layer_formats(struct sun4i_backend *backend,