drm: rcar-du: Implement planes atomic operations

Implement the CRTC .atomic_begin() and .atomic_flush() operations, the
plane .atomic_check(), .atomic_update() and operations, and use the
transitional atomic helpers to implement the plane update and disable
operations on top of the new atomic operations.

The plane setup code can't be moved out of the CRTC start function
completely yet, as the atomic code paths are not taken every time the
CRTC needs to be started. This results in some code duplication that
will be fixed after switching to atomic updates completely.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>

1 files changed, 36 insertions, 1 deletions

diff --git a/drivers/gpu/drm/rcar-du/rcar_du_crtc.c b/drivers/gpu/drm/rcar-du/rcar_du_crtc.c
index c2ca2a302f44..3d862a894b17 100644
--- a/drivers/gpu/drm/rcar-du/rcar_du_crtc.c
+++ b/drivers/gpu/drm/rcar-du/rcar_du_crtc.c
@@ -357,12 +357,21 @@ static void rcar_du_crtc_start(struct rcar_du_crtc *rcrtc)
 	rcar_du_crtc_set_display_timing(rcrtc);
 	rcar_du_group_set_routing(rcrtc->group);
 
+	/* FIXME: Commit the planes state. This is required here as the CRTC can
+	 * be started from the DPMS and system resume handler, which don't go
+	 * through .atomic_plane_update() and .atomic_flush() to commit plane
+	 * state. Similarly a mode set operation without any update to planes
+	 * will not go through atomic plane configuration either. Additionally,
+	 * given that the plane state atomic commit occurs between CRTC disable
+	 * and enable, the hardware state could also be lost due to runtime PM,
+	 * requiring a full commit here. This will be fixed later after
+	 * switching to atomic updates completely.
+	 */
 	mutex_lock(&rcrtc->group->planes.lock);
 	rcrtc->plane->enabled = true;
 	rcar_du_crtc_update_planes(crtc);
 	mutex_unlock(&rcrtc->group->planes.lock);
 
-	/* Setup planes. */
 	for (i = 0; i < ARRAY_SIZE(rcrtc->group->planes.planes); ++i) {
 		struct rcar_du_plane *plane = &rcrtc->group->planes.planes[i];
 
@@ -570,6 +579,30 @@ static void rcar_du_crtc_disable(struct drm_crtc *crtc)
 	rcar_du_plane_release(rcrtc->plane);
 }
 
+static void rcar_du_crtc_atomic_begin(struct drm_crtc *crtc)
+{
+	struct rcar_du_crtc *rcrtc = to_rcar_crtc(crtc);
+
+	/* We need to access the hardware during atomic update, acquire a
+	 * reference to the CRTC.
+	 */
+	rcar_du_crtc_get(rcrtc);
+}
+
+static void rcar_du_crtc_atomic_flush(struct drm_crtc *crtc)
+{
+	struct rcar_du_crtc *rcrtc = to_rcar_crtc(crtc);
+
+	/* We're done, apply the configuration and drop the reference acquired
+	 * in .atomic_begin().
+	 */
+	mutex_lock(&rcrtc->group->planes.lock);
+	rcar_du_crtc_update_planes(crtc);
+	mutex_unlock(&rcrtc->group->planes.lock);
+
+	rcar_du_crtc_put(rcrtc);
+}
+
 static const struct drm_crtc_helper_funcs crtc_helper_funcs = {
 	.dpms = rcar_du_crtc_dpms,
 	.mode_fixup = rcar_du_crtc_mode_fixup,
@@ -578,6 +611,8 @@ static const struct drm_crtc_helper_funcs crtc_helper_funcs = {
 	.mode_set = rcar_du_crtc_mode_set,
 	.mode_set_base = rcar_du_crtc_mode_set_base,
 	.disable = rcar_du_crtc_disable,
+	.atomic_begin = rcar_du_crtc_atomic_begin,
+	.atomic_flush = rcar_du_crtc_atomic_flush,
 };
 
 static int rcar_du_crtc_page_flip(struct drm_crtc *crtc,