drm/mediatek: dpi: Remove output format of YUV

DPI is not support output format as YUV, but there is the setting of
configuring output YUV. Therefore, remove them in this patch.

Fixes: 9e629c17 ("drm/mediatek: Add DPI sub driver")
Signed-off-by: Bo-Chen Chen <rex-bc.chen@mediatek.com>
Link: https://patchwork.kernel.org/project/linux-mediatek/patch/20220701035845.16458-5-rex-bc.chen@mediatek.com/Signed-off-by: Chun-Kuang Hu <chunkuang.hu@kernel.org>

drivers/gpu/drm/mediatek/mtk_dpi.c

@@ -54,13 +54,7 @@ enum mtk_dpi_out_channel_swap {
 };
 
 enum mtk_dpi_out_color_format {
-	MTK_DPI_COLOR_FORMAT_RGB,
-	MTK_DPI_COLOR_FORMAT_RGB_FULL,
-	MTK_DPI_COLOR_FORMAT_YCBCR_444,
-	MTK_DPI_COLOR_FORMAT_YCBCR_422,
-	MTK_DPI_COLOR_FORMAT_XV_YCC,
-	MTK_DPI_COLOR_FORMAT_YCBCR_444_FULL,
-	MTK_DPI_COLOR_FORMAT_YCBCR_422_FULL
+	MTK_DPI_COLOR_FORMAT_RGB
 };
 
 struct mtk_dpi {
@@ -373,24 +367,11 @@ static void mtk_dpi_config_disable_edge(struct mtk_dpi *dpi)
 static void mtk_dpi_config_color_format(struct mtk_dpi *dpi,
 					enum mtk_dpi_out_color_format format)
 {
-	if ((format == MTK_DPI_COLOR_FORMAT_YCBCR_444) ||
-	    (format == MTK_DPI_COLOR_FORMAT_YCBCR_444_FULL)) {
-		mtk_dpi_config_yuv422_enable(dpi, false);
-		mtk_dpi_config_csc_enable(dpi, true);
-		mtk_dpi_config_swap_input(dpi, false);
-		mtk_dpi_config_channel_swap(dpi, MTK_DPI_OUT_CHANNEL_SWAP_BGR);
-	} else if ((format == MTK_DPI_COLOR_FORMAT_YCBCR_422) ||
-		   (format == MTK_DPI_COLOR_FORMAT_YCBCR_422_FULL)) {
-		mtk_dpi_config_yuv422_enable(dpi, true);
-		mtk_dpi_config_csc_enable(dpi, true);
-		mtk_dpi_config_swap_input(dpi, true);
-		mtk_dpi_config_channel_swap(dpi, MTK_DPI_OUT_CHANNEL_SWAP_RGB);
-	} else {
-		mtk_dpi_config_yuv422_enable(dpi, false);
-		mtk_dpi_config_csc_enable(dpi, false);
-		mtk_dpi_config_swap_input(dpi, false);
-		mtk_dpi_config_channel_swap(dpi, MTK_DPI_OUT_CHANNEL_SWAP_RGB);
-	}
+	/* only support RGB888 */
+	mtk_dpi_config_yuv422_enable(dpi, false);
+	mtk_dpi_config_csc_enable(dpi, false);
+	mtk_dpi_config_swap_input(dpi, false);
+	mtk_dpi_config_channel_swap(dpi, MTK_DPI_OUT_CHANNEL_SWAP_RGB);
 }
 
 static void mtk_dpi_dual_edge(struct mtk_dpi *dpi)