drm/rcar-du: Add support for DEFR8 register

The R8A7790 DU has a new extended function control register. Support it.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

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

@@ -222,7 +222,8 @@ static const struct rcar_du_device_info rcar_du_r8a7779_info = {
 };
 
 static const struct rcar_du_device_info rcar_du_r8a7790_info = {
-	.features = RCAR_DU_FEATURE_CRTC_IRQ_CLOCK | RCAR_DU_FEATURE_ALIGN_128B,
+	.features = RCAR_DU_FEATURE_CRTC_IRQ_CLOCK | RCAR_DU_FEATURE_ALIGN_128B
+		  | RCAR_DU_FEATURE_DEFR8,
 	.num_crtcs = 3,
 };
 

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

@@ -27,6 +27,7 @@ struct rcar_du_device;
 
 #define RCAR_DU_FEATURE_CRTC_IRQ_CLOCK	(1 << 0)	/* Per-CRTC IRQ and clock */
 #define RCAR_DU_FEATURE_ALIGN_128B	(1 << 1)	/* Align pitches to 128 bytes */
+#define RCAR_DU_FEATURE_DEFR8		(1 << 2)	/* Has DEFR8 register */
 
 /*
  * struct rcar_du_device_info - DU model-specific information

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

@@ -51,6 +51,8 @@ static void rcar_du_group_setup(struct rcar_du_group *rgrp)
 	rcar_du_group_write(rgrp, DEFR3, DEFR3_CODE | DEFR3_DEFE3);
 	rcar_du_group_write(rgrp, DEFR4, DEFR4_CODE);
 	rcar_du_group_write(rgrp, DEFR5, DEFR5_CODE | DEFR5_DEFE5);
+	if (rcar_du_has(rgrp->dev, RCAR_DU_FEATURE_DEFR8))
+		rcar_du_group_write(rgrp, DEFR8, DEFR8_CODE | DEFR8_DEFE8);
 
 	/* Use DS1PR and DS2PR to configure planes priorities and connects the
 	 * superposition 0 to DU0 pins. DU1 pins will be configured dynamically.