drm/vc4: dpi: Add option for inverting pixel clock and output enable

DRM provides flags for inverting pixel clock and output enable
signals, but these were not mapped to the relevant registers.

Add those mappings.
Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.com>
Link: https://lore.kernel.org/r/20220613144800.326124-10-maxime@cerno.techSigned-off-by: Maxime Ripard <maxime@cerno.tech>

drivers/gpu/drm/vc4/vc4_dpi.c

@@ -148,7 +148,8 @@ static void vc4_dpi_encoder_enable(struct drm_encoder *encoder)
 	}
 	drm_connector_list_iter_end(&conn_iter);
 
-	if (connector && connector->display_info.num_bus_formats) {
+	if (connector) {
+		if (connector->display_info.num_bus_formats) {
 			u32 bus_format = connector->display_info.bus_formats[0];
 
 			switch (bus_format) {
@@ -159,7 +160,8 @@ static void vc4_dpi_encoder_enable(struct drm_encoder *encoder)
 			case MEDIA_BUS_FMT_BGR888_1X24:
 				dpi_c |= VC4_SET_FIELD(DPI_FORMAT_24BIT_888_RGB,
 						       DPI_FORMAT);
-			dpi_c |= VC4_SET_FIELD(DPI_ORDER_BGR, DPI_ORDER);
+				dpi_c |= VC4_SET_FIELD(DPI_ORDER_BGR,
+						       DPI_ORDER);
 				break;
 			case MEDIA_BUS_FMT_RGB666_1X24_CPADHI:
 				dpi_c |= VC4_SET_FIELD(DPI_FORMAT_18BIT_666_RGB_2,
@@ -174,9 +176,17 @@ static void vc4_dpi_encoder_enable(struct drm_encoder *encoder)
 						       DPI_FORMAT);
 				break;
 			default:
-			DRM_ERROR("Unknown media bus format %d\n", bus_format);
+				DRM_ERROR("Unknown media bus format %d\n",
+					  bus_format);
 				break;
 			}
+		}
+
+		if (connector->display_info.bus_flags & DRM_BUS_FLAG_PIXDATA_DRIVE_NEGEDGE)
+			dpi_c |= DPI_PIXEL_CLK_INVERT;
+
+		if (connector->display_info.bus_flags & DRM_BUS_FLAG_DE_LOW)
+			dpi_c |= DPI_OUTPUT_ENABLE_INVERT;
 	} else {
 		/* Default to 24bit if no connector found. */
 		dpi_c |= VC4_SET_FIELD(DPI_FORMAT_24BIT_888_RGB, DPI_FORMAT);