drm/sun4i: Introduce color encoding and range properties

In order to correctly convert YUV color space to RGB, we have to know
color encoding and range.

Introduce these two properties using helper method.
Signed-off-by: Jernej Skrabec <jernej.skrabec@siol.net>
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190713120346.30349-2-jernej.skrabec@siol.net

drivers/gpu/drm/sun4i/sun8i_vi_layer.c

@@ -440,6 +440,7 @@ struct sun8i_vi_layer *sun8i_vi_layer_init_one(struct drm_device *drm,
 					       struct sun8i_mixer *mixer,
 					       int index)
 {
+	u32 supported_encodings, supported_ranges;
 	struct sun8i_vi_layer *layer;
 	unsigned int plane_cnt;
 	int ret;
@@ -468,6 +469,22 @@ struct sun8i_vi_layer *sun8i_vi_layer_init_one(struct drm_device *drm,
 		return ERR_PTR(ret);
 	}
 
+	supported_encodings = BIT(DRM_COLOR_YCBCR_BT601) |
+			      BIT(DRM_COLOR_YCBCR_BT709);
+
+	supported_ranges = BIT(DRM_COLOR_YCBCR_LIMITED_RANGE) |
+			   BIT(DRM_COLOR_YCBCR_FULL_RANGE);
+
+	ret = drm_plane_create_color_properties(&layer->plane,
+						supported_encodings,
+						supported_ranges,
+						DRM_COLOR_YCBCR_BT709,
+						DRM_COLOR_YCBCR_LIMITED_RANGE);
+	if (ret) {
+		dev_err(drm->dev, "Couldn't add encoding and range properties!\n");
+		return ERR_PTR(ret);
+	}
+
 	drm_plane_helper_add(&layer->plane, &sun8i_vi_layer_helper_funcs);
 	layer->mixer = mixer;
 	layer->channel = index;