[PATCH v4 07/13] drm/sun4i: engine: Create an atomic_begin callback

[Maxime Ripard]

We have to implement some display engine specific behaviours in
atomic_begin. Let's add a function for that.

Reviewed-by: Chen-Yu Tsai <w...@csie.org>
Signed-off-by: Maxime Ripard <maxime.rip...@free-electrons.com>
---
 drivers/gpu/drm/sun4i/sun4i_crtc.c   |  6 +++++-
 drivers/gpu/drm/sun4i/sunxi_engine.h | 13 +++++++++++++
 2 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/sun4i/sun4i_crtc.c 
b/drivers/gpu/drm/sun4i/sun4i_crtc.c
index 2a565325714f..f549f2874353 100644
--- a/drivers/gpu/drm/sun4i/sun4i_crtc.c
+++ b/drivers/gpu/drm/sun4i/sun4i_crtc.c
@@ -64,6 +64,7 @@ static void sun4i_crtc_atomic_begin(struct drm_crtc *crtc,
 {
        struct sun4i_crtc *scrtc = drm_crtc_to_sun4i_crtc(crtc);
        struct drm_device *dev = crtc->dev;
+       struct sunxi_engine *engine = scrtc->engine;
        unsigned long flags;
 
        if (crtc->state->event) {
@@ -73,7 +74,10 @@ static void sun4i_crtc_atomic_begin(struct drm_crtc *crtc,
                scrtc->event = crtc->state->event;
                spin_unlock_irqrestore(&dev->event_lock, flags);
                crtc->state->event = NULL;
-        }
+       }
+
+       if (engine->ops->atomic_begin)
+               engine->ops->atomic_begin(engine, old_state);
 }
 
 static void sun4i_crtc_atomic_flush(struct drm_crtc *crtc,
diff --git a/drivers/gpu/drm/sun4i/sunxi_engine.h 
b/drivers/gpu/drm/sun4i/sunxi_engine.h
index 54c029877531..baa7a1f95300 100644
--- a/drivers/gpu/drm/sun4i/sunxi_engine.h
+++ b/drivers/gpu/drm/sun4i/sunxi_engine.h
@@ -23,6 +23,19 @@ struct sunxi_engine;
  */
 struct sunxi_engine_ops {
        /**
+        * @atomic_begin:
+        *
+        * This callback allows to prepare our engine for an atomic
+        * update. This is mirroring the
+        * &drm_crtc_helper_funcs.atomic_begin callback, so any
+        * documentation there applies.
+        *
+        * This function is optional.
+        */
+       void (*atomic_begin)(struct sunxi_engine *engine,
+                            struct drm_crtc_state *old_state);
+
+       /**
         * @atomic_check:
         *
         * This callback allows to validate plane-update related CRTC
-- 
git-series 0.9.1