[PATCH 1/4] drm/fsl-dcu: support overlay and cursor planes

[Stefan Agner <stefan@agner.ch>]

Add support for overlay plane and a cursor plane. The driver uses
the topmost plane as cursor plane. The DCU IP would have dedicated
cursor support, but that lacks proper color support and hence is
not practical to use for Linux systems.

Signed-off-by: Stefan Agner <stefan@agner.ch>
---
 drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_crtc.c  | 47 ++++++++++++++++++++++++-----
 drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_plane.c | 37 ++++++++++++-----------
 drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_plane.h |  3 +-
 3 files changed, 60 insertions(+), 27 deletions(-)

diff --git a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_crtc.c b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_crtc.c
index 3371635..d30b61e 100644
--- a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_crtc.c
+++ b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_crtc.c
@@ -139,20 +139,51 @@ static const struct drm_crtc_funcs fsl_dcu_drm_crtc_funcs = {
 
 int fsl_dcu_drm_crtc_create(struct fsl_dcu_drm_device *fsl_dev)
 {
-	struct drm_plane *primary;
+	struct drm_device *drm = fsl_dev->drm;
+	struct drm_plane *primary, *cursor;
 	struct drm_crtc *crtc = &fsl_dev->crtc;
-	int ret;
+	int total_layer = fsl_dev->soc->total_layer;
+	int ret, i;
 
-	fsl_dcu_drm_init_planes(fsl_dev->drm);
+	fsl_dcu_drm_init_planes(drm);
 
-	primary = fsl_dcu_drm_primary_create_plane(fsl_dev->drm);
-	if (!primary)
-		return -ENOMEM;
+	primary = fsl_dcu_drm_create_plane(drm, DRM_PLANE_TYPE_PRIMARY);
+	if (IS_ERR(primary)) {
+		dev_err(fsl_dev->dev, "failed to construct primary plane\n");
+		ret = PTR_ERR(primary);
+		return ret;
+	}
+
+	/*
+	 * Initialize overlay layers. The hardware does not have specific
+	 * layer types, we just happen to use one layer as primary layer
+	 * and one layer as cursor layer, hence total_layer - 2 = overlays.
+	 */
+	for (i = 0; i < total_layer - 2; i++) {
+		struct drm_plane *plane =
+			fsl_dcu_drm_create_plane(drm, DRM_PLANE_TYPE_OVERLAY);
+
+		if (IS_ERR(plane))
+			continue;
+	}
 
-	ret = drm_crtc_init_with_planes(fsl_dev->drm, crtc, primary, NULL,
+	cursor = fsl_dcu_drm_create_plane(drm, DRM_PLANE_TYPE_CURSOR);
+	if (IS_ERR(cursor)) {
+		dev_warn(fsl_dev->dev, "failed to construct cursor plane\n");
+		cursor = NULL;
+	}
+
+	/*
+	 * Initialize cursor plane after overlay planes since the initialization
+	 * order is crucial to the layer id (and hence layer stacking order).
+	 */
+	ret = drm_crtc_init_with_planes(drm, crtc, primary, cursor,
 					&fsl_dcu_drm_crtc_funcs, NULL);
 	if (ret) {
-		primary->funcs->destroy(primary);
+		struct drm_plane *plane;
+
+		list_for_each_entry(plane, &drm->mode_config.plane_list, head)
+			drm_plane_cleanup(plane);
 		return ret;
 	}
 
diff --git a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_plane.c b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_plane.c
index a7e5486..a6af3d9 100644
--- a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_plane.c
+++ b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_plane.c
@@ -178,7 +178,6 @@ static const struct drm_plane_helper_funcs fsl_dcu_drm_plane_helper_funcs = {
 static void fsl_dcu_drm_plane_destroy(struct drm_plane *plane)
 {
 	drm_plane_cleanup(plane);
-	kfree(plane);
 }
 
 static const struct drm_plane_funcs fsl_dcu_drm_plane_funcs = {
@@ -218,28 +217,30 @@ void fsl_dcu_drm_init_planes(struct drm_device *dev)
 		     DCU_UPDATE_MODE_READREG);
 }
 
-struct drm_plane *fsl_dcu_drm_primary_create_plane(struct drm_device *dev)
+struct drm_plane *fsl_dcu_drm_create_plane(struct drm_device *dev,
+					   enum drm_plane_type type)
 {
-	struct drm_plane *primary;
+	struct drm_plane *plane;
 	int ret;
 
-	primary = kzalloc(sizeof(*primary), GFP_KERNEL);
-	if (!primary) {
-		DRM_DEBUG_KMS("Failed to allocate primary plane\n");
-		return NULL;
-	}
+	plane = devm_kzalloc(dev->dev, sizeof(struct drm_plane),
+			      GFP_KERNEL);
+	if (!plane)
+		return ERR_PTR(-ENOMEM);
 
-	/* possible_crtc's will be filled in later by crtc_init */
-	ret = drm_universal_plane_init(dev, primary, 0,
-				       &fsl_dcu_drm_plane_funcs,
+	ret = drm_universal_plane_init(dev, plane, 1, &fsl_dcu_drm_plane_funcs,
 				       fsl_dcu_drm_plane_formats,
 				       ARRAY_SIZE(fsl_dcu_drm_plane_formats),
-				       DRM_PLANE_TYPE_PRIMARY, NULL);
-	if (ret) {
-		kfree(primary);
-		primary = NULL;
-	}
-	drm_plane_helper_add(primary, &fsl_dcu_drm_plane_helper_funcs);
+				       type, NULL);
+	if (ret)
+		goto err_cleanup_plane;
+
+	drm_plane_helper_add(plane, &fsl_dcu_drm_plane_helper_funcs);
+
+	return plane;
+
+err_cleanup_plane:
+	drm_plane_cleanup(plane);
 
-	return primary;
+	return ERR_PTR(ret);
 }
diff --git a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_plane.h b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_plane.h
index 8ee45f8..bd36166 100644
--- a/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_plane.h
+++ b/drivers/gpu/drm/fsl-dcu/fsl_dcu_drm_plane.h
@@ -13,6 +13,7 @@
 #define __FSL_DCU_DRM_PLANE_H__
 
 void fsl_dcu_drm_init_planes(struct drm_device *dev);
-struct drm_plane *fsl_dcu_drm_primary_create_plane(struct drm_device *dev);
+struct drm_plane *fsl_dcu_drm_create_plane(struct drm_device *dev,
+					   enum drm_plane_type type);
 
 #endif /* __FSL_DCU_DRM_PLANE_H__ */
-- 
2.9.3