drm: rcar-du: Add R-Car DSI driver

The driver supports the MIPI DSI/CSI-2 TX encoder found in the R-Car V3U
SoC. It currently supports DSI mode only.

Signed-off-by: LUU HOAI <hoai.luu.ub@renesas.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Tested-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Reviewed-by: Jagan Teki <jagan@amarulasolutions.com>

Author: hoailuu

drivers/gpu/drm/rcar-du/Kconfig

@@ -45,6 +45,13 @@ config DRM_RCAR_LVDS
 	select OF_FLATTREE
 	select OF_OVERLAY
 
+config DRM_RCAR_MIPI_DSI
+	tristate "R-Car DU MIPI DSI Encoder Support"
+	depends on DRM && DRM_BRIDGE && OF
+	select DRM_MIPI_DSI
+	help
+	  Enable support for the R-Car Display Unit embedded MIPI DSI encoders.
+
 config DRM_RCAR_VSP
 	bool "R-Car DU VSP Compositor Support" if ARM
 	default y if ARM64

drivers/gpu/drm/rcar-du/Makefile

@@ -19,6 +19,7 @@ obj-$(CONFIG_DRM_RCAR_CMM)		+= rcar_cmm.o
 obj-$(CONFIG_DRM_RCAR_DU)		+= rcar-du-drm.o
 obj-$(CONFIG_DRM_RCAR_DW_HDMI)		+= rcar_dw_hdmi.o
 obj-$(CONFIG_DRM_RCAR_LVDS)		+= rcar_lvds.o
+obj-$(CONFIG_DRM_RCAR_MIPI_DSI)		+= rcar_mipi_dsi.o
 
 # 'remote-endpoint' is fixed up at run-time
 DTC_FLAGS_rcar_du_of_lvds_r8a7790 += -Wno-graph_endpoint