drm/sti: atomic crtc/plane update

Better fit STI hardware structure.
Planes are no more responsible of updating mixer information such
as z-order and status. It is now up to the CRTC atomic flush to
do it. Plane actions (enable or disable) are performed atomically.
Disabling of a plane is synchronize with the vsync event.

Signed-off-by: Vincent Abriou <vincent.abriou@st.com>
Reviewed-by: Benjamin Gaignard <benjamin.gaignard@linaro.org>

drivers/gpu/drm/sti/sti_mixer.h

@@ -15,6 +15,12 @@
 
 #define to_sti_mixer(x) container_of(x, struct sti_mixer, drm_crtc)
 
+enum sti_mixer_status {
+	STI_MIXER_READY,
+	STI_MIXER_DISABLING,
+	STI_MIXER_DISABLED,
+};
+
 /**
  * STI Mixer subdevice structure
  *
@@ -23,7 +29,7 @@
  * @id: id of the mixer
  * @drm_crtc: crtc object link to the mixer
  * @pending_event: set if a flip event is pending on crtc
- * @enabled: to know if the mixer is active or not
+ * @status: to know the status of the mixer
  */
 struct sti_mixer {
 	struct device *dev;
@@ -31,7 +37,7 @@ struct sti_mixer {
 	int id;
 	struct drm_crtc drm_crtc;
 	struct drm_pending_vblank_event *pending_event;
-	bool enabled;
+	enum sti_mixer_status status;
 };
 
 const char *sti_mixer_to_str(struct sti_mixer *mixer);
@@ -41,7 +47,6 @@ struct sti_mixer *sti_mixer_create(struct device *dev, int id,
 
 int sti_mixer_set_plane_status(struct sti_mixer *mixer,
 			       struct sti_plane *plane, bool status);
-void sti_mixer_clear_all_planes(struct sti_mixer *mixer);
 int sti_mixer_set_plane_depth(struct sti_mixer *mixer, struct sti_plane *plane);
 int sti_mixer_active_video_area(struct sti_mixer *mixer,
 				struct drm_display_mode *mode);