drm/ast: Pass struct ast_private instance to cursor init/fini functions

Removes some typecasting.

v2:
	* use to_ast_private() instead of struct drm_device.dev_private
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20200702115029.5281-3-tzimmermann@suse.de

drivers/gpu/drm/ast/ast_cursor.c

@@ -34,9 +34,9 @@
 /*
  * Allocate cursor BOs and pins them at the end of VRAM.
  */
-int ast_cursor_init(struct drm_device *dev)
+int ast_cursor_init(struct ast_private *ast)
 {
-	struct ast_private *ast = to_ast_private(dev);
+	struct drm_device *dev = ast->dev;
 	size_t size, i;
 	struct drm_gem_vram_object *gbo;
 	int ret;
@@ -72,9 +72,8 @@ int ast_cursor_init(struct drm_device *dev)
 	return ret;
 }
 
-void ast_cursor_fini(struct drm_device *dev)
+void ast_cursor_fini(struct ast_private *ast)
 {
-	struct ast_private *ast = to_ast_private(dev);
 	size_t i;
 	struct drm_gem_vram_object *gbo;
 

drivers/gpu/drm/ast/ast_drv.h

@@ -316,8 +316,8 @@ void ast_init_3rdtx(struct drm_device *dev);
 void ast_release_firmware(struct drm_device *dev);
 
 /* ast_cursor.c */
-int ast_cursor_init(struct drm_device *dev);
-void ast_cursor_fini(struct drm_device *dev);
+int ast_cursor_init(struct ast_private *ast);
+void ast_cursor_fini(struct ast_private *ast);
 int ast_cursor_update(void *dst, void *src, unsigned int width,
 		      unsigned int height);
 void ast_cursor_set_base(struct ast_private *ast, u64 address);

drivers/gpu/drm/ast/ast_mode.c

@@ -1149,7 +1149,7 @@ int ast_mode_init(struct drm_device *dev)
 	drm_plane_helper_add(&ast->cursor_plane,
 			     &ast_cursor_plane_helper_funcs);
 
-	ast_cursor_init(dev);
+	ast_cursor_init(ast);
 	ast_crtc_init(dev);
 	ast_encoder_init(dev);
 	ast_connector_init(dev);
@@ -1159,7 +1159,9 @@ int ast_mode_init(struct drm_device *dev)
 
 void ast_mode_fini(struct drm_device *dev)
 {
-	ast_cursor_fini(dev);
+	struct ast_private *ast = to_ast_private(dev);
+
+	ast_cursor_fini(ast);
 }
 
 static int get_clock(void *i2c_priv)