[media] v4l: vsp1: Implement atomic update for the DRM driver

Add two API functions named vsp1_du_atomic_begin() and
vsp1_du_atomic_flush() to signal the start and end of an atomic update.
The vsp1_du_setup_rpf() function is renamed to vsp1_du_atomic_update()
for consistency.

With this new API, the driver will reprogram all modified inputs
atomically before restarting the video stream.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

include/media/vsp1.h

@@ -23,8 +23,11 @@ int vsp1_du_init(struct device *dev);
 int vsp1_du_setup_lif(struct device *dev, unsigned int width,
 		      unsigned int height);
 
-int vsp1_du_setup_rpf(struct device *dev, unsigned int rpf, u32 pixelformat,
-		      unsigned int pitch, dma_addr_t mem[2],
-		      const struct v4l2_rect *src, const struct v4l2_rect *dst);
+int vsp1_du_atomic_begin(struct device *dev);
+int vsp1_du_atomic_update(struct device *dev, unsigned int rpf, u32 pixelformat,
+			  unsigned int pitch, dma_addr_t mem[2],
+			  const struct v4l2_rect *src,
+			  const struct v4l2_rect *dst);
+int vsp1_du_atomic_flush(struct device *dev);
 
 #endif /* __MEDIA_VSP1_H__ */