drm/omap: omap_plane: subclass drm_plane_state

In preparation to add omap plane state specific extensions we need to
subclass drm_plane_state and add the relevant helpers.

The addition of specific extension will be done separately.
Signed-off-by: Benoit Parrot <bparrot@ti.com>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Reviewed-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20211117141928.771082-6-narmstrong@baylibre.com

drivers/gpu/drm/omapdrm/omap_plane.c

@@ -16,6 +16,13 @@
  * plane funcs
  */
 
+#define to_omap_plane_state(x) container_of(x, struct omap_plane_state, base)
+
+struct omap_plane_state {
+	/* Must be first. */
+	struct drm_plane_state base;
+};
+
 #define to_omap_plane(x) container_of(x, struct omap_plane, base)
 
 struct omap_plane {
@@ -221,11 +228,17 @@ void omap_plane_install_properties(struct drm_plane *plane,
 static void omap_plane_reset(struct drm_plane *plane)
 {
 	struct omap_plane *omap_plane = to_omap_plane(plane);
+	struct omap_plane_state *omap_state;
 
-	drm_atomic_helper_plane_reset(plane);
-	if (!plane->state)
+	if (plane->state)
+		drm_atomic_helper_plane_destroy_state(plane, plane->state);
+
+	omap_state = kzalloc(sizeof(*omap_state), GFP_KERNEL);
+	if (!omap_state)
 		return;
 
+	__drm_atomic_helper_plane_reset(plane, &omap_state->base);
+
 	/*
 	 * Set the zpos default depending on whether we are a primary or overlay
 	 * plane.
@@ -236,6 +249,23 @@ static void omap_plane_reset(struct drm_plane *plane)
 	plane->state->color_range = DRM_COLOR_YCBCR_FULL_RANGE;
 }
 
+static struct drm_plane_state *
+omap_plane_atomic_duplicate_state(struct drm_plane *plane)
+{
+	struct omap_plane_state *state;
+
+	if (WARN_ON(!plane->state))
+		return NULL;
+
+	state = kmalloc(sizeof(*state), GFP_KERNEL);
+	if (!state)
+		return NULL;
+
+	__drm_atomic_helper_plane_duplicate_state(plane, &state->base);
+
+	return &state->base;
+}
+
 static int omap_plane_atomic_set_property(struct drm_plane *plane,
 					  struct drm_plane_state *state,
 					  struct drm_property *property,
@@ -271,7 +301,7 @@ static const struct drm_plane_funcs omap_plane_funcs = {
 	.disable_plane = drm_atomic_helper_disable_plane,
 	.reset = omap_plane_reset,
 	.destroy = omap_plane_destroy,
-	.atomic_duplicate_state = drm_atomic_helper_plane_duplicate_state,
+	.atomic_duplicate_state = omap_plane_atomic_duplicate_state,
 	.atomic_destroy_state = drm_atomic_helper_plane_destroy_state,
 	.atomic_set_property = omap_plane_atomic_set_property,
 	.atomic_get_property = omap_plane_atomic_get_property,