drm: rcar-du: Support up to 4 CRTCs

The Gen3 R8A7795 DU has 4 CRTCs, support them all.
Signed-off-by: Koji Matsuoka <koji.matsuoka.xm@renesas.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

drivers/gpu/drm/rcar-du/rcar_du_crtc.c

@@ -571,7 +571,7 @@ static irqreturn_t rcar_du_crtc_irq(int irq, void *arg)
 int rcar_du_crtc_create(struct rcar_du_group *rgrp, unsigned int index)
 {
 	static const unsigned int mmio_offsets[] = {
-		DU0_REG_OFFSET, DU1_REG_OFFSET, DU2_REG_OFFSET
+		DU0_REG_OFFSET, DU1_REG_OFFSET, DU2_REG_OFFSET, DU3_REG_OFFSET
 	};
 
 	struct rcar_du_device *rcdu = rgrp->dev;

drivers/gpu/drm/rcar-du/rcar_du_drv.h

@@ -67,7 +67,7 @@ struct rcar_du_device_info {
 	unsigned int num_lvds;
 };
 
-#define RCAR_DU_MAX_CRTCS		3
+#define RCAR_DU_MAX_CRTCS		4
 #define RCAR_DU_MAX_GROUPS		DIV_ROUND_UP(RCAR_DU_MAX_CRTCS, 2)
 #define RCAR_DU_MAX_LVDS		2
 #define RCAR_DU_MAX_VSPS		4

drivers/gpu/drm/rcar-du/rcar_du_regs.h

@@ -16,6 +16,7 @@
 #define DU0_REG_OFFSET		0x00000
 #define DU1_REG_OFFSET		0x30000
 #define DU2_REG_OFFSET		0x40000
+#define DU3_REG_OFFSET		0x70000
 
 /* -----------------------------------------------------------------------------
  * Display Control Registers