drm/simple-kms: Support custom CRTC state

Simple KMS helpers already support custom state for planes. Extend the
helpers to support custom CRTC state as well. Drivers can set the reset,
duplicate and destroy callbacks for the display pipeline's CRTC state
and inherit from struct drm_crtc_state by embedding an instance.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210714142240.21979-12-tzimmermann@suse.de

drivers/gpu/drm/drm_simple_kms_helper.c

@@ -145,6 +145,39 @@ static const struct drm_crtc_helper_funcs drm_simple_kms_crtc_helper_funcs = {
 	.atomic_disable = drm_simple_kms_crtc_disable,
 };
 
+static void drm_simple_kms_crtc_reset(struct drm_crtc *crtc)
+{
+	struct drm_simple_display_pipe *pipe;
+
+	pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
+	if (!pipe->funcs || !pipe->funcs->reset_crtc)
+		return drm_atomic_helper_crtc_reset(crtc);
+
+	return pipe->funcs->reset_crtc(pipe);
+}
+
+static struct drm_crtc_state *drm_simple_kms_crtc_duplicate_state(struct drm_crtc *crtc)
+{
+	struct drm_simple_display_pipe *pipe;
+
+	pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
+	if (!pipe->funcs || !pipe->funcs->duplicate_crtc_state)
+		return drm_atomic_helper_crtc_duplicate_state(crtc);
+
+	return pipe->funcs->duplicate_crtc_state(pipe);
+}
+
+static void drm_simple_kms_crtc_destroy_state(struct drm_crtc *crtc, struct drm_crtc_state *state)
+{
+	struct drm_simple_display_pipe *pipe;
+
+	pipe = container_of(crtc, struct drm_simple_display_pipe, crtc);
+	if (!pipe->funcs || !pipe->funcs->destroy_crtc_state)
+		drm_atomic_helper_crtc_destroy_state(crtc, state);
+	else
+		pipe->funcs->destroy_crtc_state(pipe, state);
+}
+
 static int drm_simple_kms_crtc_enable_vblank(struct drm_crtc *crtc)
 {
 	struct drm_simple_display_pipe *pipe;
@@ -168,12 +201,12 @@ static void drm_simple_kms_crtc_disable_vblank(struct drm_crtc *crtc)
 }
 
 static const struct drm_crtc_funcs drm_simple_kms_crtc_funcs = {
-	.reset = drm_atomic_helper_crtc_reset,
+	.reset = drm_simple_kms_crtc_reset,
 	.destroy = drm_crtc_cleanup,
 	.set_config = drm_atomic_helper_set_config,
 	.page_flip = drm_atomic_helper_page_flip,
-	.atomic_duplicate_state = drm_atomic_helper_crtc_duplicate_state,
-	.atomic_destroy_state = drm_atomic_helper_crtc_destroy_state,
+	.atomic_duplicate_state = drm_simple_kms_crtc_duplicate_state,
+	.atomic_destroy_state = drm_simple_kms_crtc_destroy_state,
 	.enable_vblank = drm_simple_kms_crtc_enable_vblank,
 	.disable_vblank = drm_simple_kms_crtc_disable_vblank,
 };

include/drm/drm_simple_kms_helper.h

@@ -153,6 +153,33 @@ struct drm_simple_display_pipe_funcs {
 	 */
 	void (*disable_vblank)(struct drm_simple_display_pipe *pipe);
 
+	/**
+	 * @reset_crtc:
+	 *
+	 * Optional, called by &drm_crtc_funcs.reset. Please read the
+	 * documentation for the &drm_crtc_funcs.reset hook for more details.
+	 */
+	void (*reset_crtc)(struct drm_simple_display_pipe *pipe);
+
+	/**
+	 * @duplicate_crtc_state:
+	 *
+	 * Optional, called by &drm_crtc_funcs.atomic_duplicate_state. Please
+	 * read the documentation for the &drm_crtc_funcs.atomic_duplicate_state
+	 * hook for more details.
+	 */
+	struct drm_crtc_state * (*duplicate_crtc_state)(struct drm_simple_display_pipe *pipe);
+
+	/**
+	 * @destroy_crtc_state:
+	 *
+	 * Optional, called by &drm_crtc_funcs.atomic_destroy_state. Please
+	 * read the documentation for the &drm_crtc_funcs.atomic_destroy_state
+	 * hook for more details.
+	 */
+	void (*destroy_crtc_state)(struct drm_simple_display_pipe *pipe,
+				   struct drm_crtc_state *crtc_state);
+
 	/**
 	 * @reset_plane:
 	 *