drm/mediatek: mtk_dpi: Add local helpers for bus format parameters

In preparation for adding support for additional color formats,
add local helpers to map media bus format parameters to this
driver's bit_num, channel_swap and color_format.

This commit brings no functional changes.

Signed-off-by: AngeloGioacchino Del Regno <[email protected]>
Reviewed-by: CK Hu <[email protected]>
Link: https://patchwork.kernel.org/project/dri-devel/patch/[email protected]/
Signed-off-by: Chun-Kuang Hu <[email protected]>

Author: AngeloGioacchino Del Regno

drivers/gpu/drm/mediatek/mtk_dpi.c

@@ -738,6 +738,43 @@ static u32 *mtk_dpi_bridge_atomic_get_input_bus_fmts(struct drm_bridge *bridge,
 	return input_fmts;
 }
 
+static unsigned int mtk_dpi_bus_fmt_bit_num(unsigned int out_bus_format)
+{
+	switch (out_bus_format) {
+	default:
+	case MEDIA_BUS_FMT_RGB888_1X24:
+	case MEDIA_BUS_FMT_RGB888_2X12_LE:
+	case MEDIA_BUS_FMT_RGB888_2X12_BE:
+	case MEDIA_BUS_FMT_YUYV8_1X16:
+		return MTK_DPI_OUT_BIT_NUM_8BITS;
+	}
+}
+
+static unsigned int mtk_dpi_bus_fmt_channel_swap(unsigned int out_bus_format)
+{
+	switch (out_bus_format) {
+	default:
+	case MEDIA_BUS_FMT_RGB888_1X24:
+	case MEDIA_BUS_FMT_RGB888_2X12_LE:
+	case MEDIA_BUS_FMT_RGB888_2X12_BE:
+	case MEDIA_BUS_FMT_YUYV8_1X16:
+		return MTK_DPI_OUT_CHANNEL_SWAP_RGB;
+	}
+}
+
+static unsigned int mtk_dpi_bus_fmt_color_format(unsigned int out_bus_format)
+{
+	switch (out_bus_format) {
+	default:
+	case MEDIA_BUS_FMT_RGB888_1X24:
+	case MEDIA_BUS_FMT_RGB888_2X12_LE:
+	case MEDIA_BUS_FMT_RGB888_2X12_BE:
+		return MTK_DPI_COLOR_FORMAT_RGB;
+	case MEDIA_BUS_FMT_YUYV8_1X16:
+		return MTK_DPI_COLOR_FORMAT_YCBCR_422;
+	}
+}
+
 static int mtk_dpi_bridge_atomic_check(struct drm_bridge *bridge,
 				       struct drm_bridge_state *bridge_state,
 				       struct drm_crtc_state *crtc_state,
@@ -757,13 +794,10 @@ static int mtk_dpi_bridge_atomic_check(struct drm_bridge *bridge,
 		bridge_state->output_bus_cfg.format);
 
 	dpi->output_fmt = out_bus_format;
-	dpi->bit_num = MTK_DPI_OUT_BIT_NUM_8BITS;
-	dpi->channel_swap = MTK_DPI_OUT_CHANNEL_SWAP_RGB;
+	dpi->bit_num = mtk_dpi_bus_fmt_bit_num(out_bus_format);
+	dpi->channel_swap = mtk_dpi_bus_fmt_channel_swap(out_bus_format);
 	dpi->yc_map = MTK_DPI_OUT_YC_MAP_RGB;
-	if (out_bus_format == MEDIA_BUS_FMT_YUYV8_1X16)
-		dpi->color_format = MTK_DPI_COLOR_FORMAT_YCBCR_422;
-	else
-		dpi->color_format = MTK_DPI_COLOR_FORMAT_RGB;
+	dpi->color_format = mtk_dpi_bus_fmt_color_format(out_bus_format);
 
 	return 0;
 }