drm/sun4i: Pass pointer for underlying backend into layer init

sun4i_layer only controls the backend hardware block of the display
pipeline.

Pass pointers to the underlying backend in the layer init function,
instead of trying to fetch it from the drm_device structure. This
avoids the headache of trying to figure out which device the layers
actually belong to.
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

drivers/gpu/drm/sun4i/sun4i_crtc.c

@@ -149,7 +149,7 @@ struct sun4i_crtc *sun4i_crtc_init(struct drm_device *drm,
 	scrtc->tcon = tcon;
 
 	/* Create our layers */
-	scrtc->layers = sun4i_layers_init(drm);
+	scrtc->layers = sun4i_layers_init(drm, scrtc->backend);
 	if (IS_ERR(scrtc->layers)) {
 		dev_err(drm->dev, "Couldn't create the planes\n");
 		return NULL;

drivers/gpu/drm/sun4i/sun4i_layer.c

@@ -16,7 +16,6 @@
 #include <drm/drmP.h>
 
 #include "sun4i_backend.h"
-#include "sun4i_drv.h"
 #include "sun4i_layer.h"
 
 struct sun4i_plane_desc {
@@ -102,9 +101,9 @@ static const struct sun4i_plane_desc sun4i_backend_planes[] = {
 };
 
 static struct sun4i_layer *sun4i_layer_init_one(struct drm_device *drm,
+						struct sun4i_backend *backend,
 						const struct sun4i_plane_desc *plane)
 {
-	struct sun4i_drv *drv = drm->dev_private;
 	struct sun4i_layer *layer;
 	int ret;
 
@@ -124,14 +123,14 @@ static struct sun4i_layer *sun4i_layer_init_one(struct drm_device *drm,
 
 	drm_plane_helper_add(&layer->plane,
 			     &sun4i_backend_layer_helper_funcs);
-	layer->backend = drv->backend;
+	layer->backend = backend;
 
 	return layer;
 }
 
-struct sun4i_layer **sun4i_layers_init(struct drm_device *drm)
+struct sun4i_layer **sun4i_layers_init(struct drm_device *drm,
+				       struct sun4i_backend *backend)
 {
-	struct sun4i_drv *drv = drm->dev_private;
 	struct sun4i_layer **layers;
 	int i;
 
@@ -165,7 +164,7 @@ struct sun4i_layer **sun4i_layers_init(struct drm_device *drm)
 		const struct sun4i_plane_desc *plane = &sun4i_backend_planes[i];
 		struct sun4i_layer *layer;
 
-		layer = sun4i_layer_init_one(drm, plane);
+		layer = sun4i_layer_init_one(drm, backend, plane);
 		if (IS_ERR(layer)) {
 			dev_err(drm->dev, "Couldn't initialize %s plane\n",
 				i ? "overlay" : "primary");
@@ -174,7 +173,7 @@ struct sun4i_layer **sun4i_layers_init(struct drm_device *drm)
 
 		DRM_DEBUG_DRIVER("Assigning %s plane to pipe %d\n",
 				 i ? "overlay" : "primary", plane->pipe);
-		regmap_update_bits(drv->backend->regs, SUN4I_BACKEND_ATTCTL_REG0(i),
+		regmap_update_bits(backend->regs, SUN4I_BACKEND_ATTCTL_REG0(i),
 				   SUN4I_BACKEND_ATTCTL_REG0_LAY_PIPESEL_MASK,
 				   SUN4I_BACKEND_ATTCTL_REG0_LAY_PIPESEL(plane->pipe));
 

drivers/gpu/drm/sun4i/sun4i_layer.h

@@ -26,6 +26,7 @@ plane_to_sun4i_layer(struct drm_plane *plane)
 	return container_of(plane, struct sun4i_layer, plane);
 }
 
-struct sun4i_layer **sun4i_layers_init(struct drm_device *drm);
+struct sun4i_layer **sun4i_layers_init(struct drm_device *drm,
+				       struct sun4i_backend *backend);
 
 #endif /* _SUN4I_LAYER_H_ */