drm/simple-kms: Remove drm_gem_simple_display_pipe_prepare_fb()

The helper drm_gem_simple_display_pipe_prepare_fb() is simple-KMS'
default implementation for prepare_fb. Remove the call from drivers
that set it explicitly. Then inline the helper into the only caller
within simple-kms helpers. No functional changes.

Simple-KMS drivers that implement the prepare_fb callback should call
drm_gem_plane_helper_prepare_fb() directly.

v2:
* fix typo in commit message

Signed-off-by: Thomas Zimmermann <[e-mail]>
Reviewed-by: Noralf Trønnes <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/[e-mail]

drivers/gpu/drm/drm_gem_atomic_helper.c

···
  * call drm_gem_plane_helper_prepare_fb() from their implementation of
  * struct &drm_plane_helper.prepare_fb . It sets the plane's fence from
  * the framebuffer so that the DRM core can synchronize access automatically.
- *
  * drm_gem_plane_helper_prepare_fb() can also be used directly as
- * implementation of prepare_fb. For drivers based on
- * struct drm_simple_display_pipe, drm_gem_simple_display_pipe_prepare_fb()
- * provides equivalent functionality.
+ * implementation of prepare_fb.
  *
  * .. code-block:: c
  *
···
  *	struct drm_plane_helper_funcs driver_plane_helper_funcs = {
  *		...,
  *		. prepare_fb = drm_gem_plane_helper_prepare_fb,
- *	};
- *
- *	struct drm_simple_display_pipe_funcs driver_pipe_funcs = {
- *		...,
- *		. prepare_fb = drm_gem_simple_display_pipe_prepare_fb,
  *	};
  *
  * A driver using a shadow buffer copies the content of the shadow buffers
···
 	return ret;
 }
 EXPORT_SYMBOL_GPL(drm_gem_plane_helper_prepare_fb);
-
-/**
- * drm_gem_simple_display_pipe_prepare_fb - prepare_fb helper for &drm_simple_display_pipe
- * @pipe: Simple display pipe
- * @plane_state: Plane state
- *
- * This function uses drm_gem_plane_helper_prepare_fb() to extract the fences
- * from &drm_gem_object.resv and attaches them to the plane state for the atomic
- * helper to wait on. This is necessary to correctly implement implicit
- * synchronization for any buffers shared as a struct &dma_buf. Drivers can use
- * this as their &drm_simple_display_pipe_funcs.prepare_fb callback.
- *
- * See drm_gem_plane_helper_prepare_fb() for a discussion of implicit and
- * explicit fencing in atomic modeset updates.
- */
-int drm_gem_simple_display_pipe_prepare_fb(struct drm_simple_display_pipe *pipe,
-					   struct drm_plane_state *plane_state)
-{
-	return drm_gem_plane_helper_prepare_fb(&pipe->plane, plane_state);
-}
-EXPORT_SYMBOL(drm_gem_simple_display_pipe_prepare_fb);
 
 /*
  * Shadow-buffered Planes

drivers/gpu/drm/drm_simple_kms_helper.c

···
 
 		WARN_ON_ONCE(pipe->funcs && pipe->funcs->cleanup_fb);
 
-		return drm_gem_simple_display_pipe_prepare_fb(pipe, state);
+		return drm_gem_plane_helper_prepare_fb(plane, state);
 	}
 
 	return pipe->funcs->prepare_fb(pipe, state);

drivers/gpu/drm/panel/panel-ilitek-ili9341.c

···
 	.enable = ili9341_dbi_enable,
 	.disable = mipi_dbi_pipe_disable,
 	.update = mipi_dbi_pipe_update,
-	.prepare_fb = drm_gem_simple_display_pipe_prepare_fb,
 };
 
 static const struct drm_display_mode ili9341_dbi_mode = {

drivers/gpu/drm/tiny/ili9163.c

···
 	.enable = yx240qv29_enable,
 	.disable = mipi_dbi_pipe_disable,
 	.update = mipi_dbi_pipe_update,
-	.prepare_fb = drm_gem_simple_display_pipe_prepare_fb,
 };
 
 static const struct drm_display_mode yx240qv29_mode = {

include/drm/drm_gem_atomic_helper.h

···
  */
 
 int drm_gem_plane_helper_prepare_fb(struct drm_plane *plane, struct drm_plane_state *state);
-int drm_gem_simple_display_pipe_prepare_fb(struct drm_simple_display_pipe *pipe,
-					   struct drm_plane_state *plane_state);
 
 /*
  * Helpers for planes with shadow buffers

include/drm/drm_plane.h

···
 	 * write this field directly for a driver's implicit fence.
 	 *
 	 * Drivers should store any implicit fence in this from their
-	 * &drm_plane_helper_funcs.prepare_fb callback. See drm_gem_plane_helper_prepare_fb()
-	 * and drm_gem_simple_display_pipe_prepare_fb() for suitable helpers.
+	 * &drm_plane_helper_funcs.prepare_fb callback. See
+	 * drm_gem_plane_helper_prepare_fb() for a suitable helper.
 	 */
 	struct dma_fence *fence;
 

include/drm/drm_simple_kms_helper.h

···
 	 * more details.
 	 *
 	 * For GEM drivers who neither have a @prepare_fb nor @cleanup_fb hook
-	 * set drm_gem_simple_display_pipe_prepare_fb() is called automatically
+	 * set, drm_gem_plane_helper_prepare_fb() is called automatically
 	 * to implement this. Other drivers which need additional plane
-	 * processing can call drm_gem_simple_display_pipe_prepare_fb() from
+	 * processing can call drm_gem_plane_helper_prepare_fb() from
 	 * their @prepare_fb hook.
 	 */
 	int (*prepare_fb)(struct drm_simple_display_pipe *pipe,