drm: rcar-du: Switch plane update to atomic helpers

This removes the legacy plane update code. Wire up the default atomic
check and atomic commit mode config helpers as needed by the plane
update atomic helpers.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

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

@@ -12,6 +12,7 @@
  */
 
 #include <drm/drmP.h>
+#include <drm/drm_atomic_helper.h>
 #include <drm/drm_crtc.h>
 #include <drm/drm_crtc_helper.h>
 #include <drm/drm_fb_cma_helper.h>
@@ -188,6 +189,8 @@ static void rcar_du_output_poll_changed(struct drm_device *dev)
 static const struct drm_mode_config_funcs rcar_du_mode_config_funcs = {
 	.fb_create = rcar_du_fb_create,
 	.output_poll_changed = rcar_du_output_poll_changed,
+	.atomic_check = drm_atomic_helper_check,
+	.atomic_commit = drm_atomic_helper_commit,
 };
 
 static int rcar_du_encoders_init_one(struct rcar_du_device *rcdu,

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

@@ -480,8 +480,8 @@ static int rcar_du_plane_set_property(struct drm_plane *plane,
 }
 
 static const struct drm_plane_funcs rcar_du_plane_funcs = {
-	.update_plane = drm_plane_helper_update,
-	.disable_plane = drm_plane_helper_disable,
+	.update_plane = drm_atomic_helper_update_plane,
+	.disable_plane = drm_atomic_helper_disable_plane,
 	.reset = drm_atomic_helper_plane_reset,
 	.set_property = rcar_du_plane_set_property,
 	.destroy = drm_plane_cleanup,