1 files changed, 90 insertions, 2 deletions
diff --git a/drivers/gpu/drm/drm_panel.c b/drivers/gpu/drm/drm_panel.c
index c627e42a7ce7..99b348782ce3 100644
--- a/drivers/gpu/drm/drm_panel.c
+++ b/drivers/gpu/drm/drm_panel.c
@@ -74,8 +74,9 @@ EXPORT_SYMBOL(drm_panel_init);
  * drm_panel_add - add a panel to the global registry
  * @panel: panel to add
  *
- * Add a panel to the global registry so that it can be looked up by display
- * drivers.
+ * Add a panel to the global registry so that it can be looked
+ * up by display drivers. The panel to be added must have been
+ * allocated by devm_drm_panel_alloc().
  */
 void drm_panel_add(struct drm_panel *panel)
 {
@@ -317,6 +318,93 @@ int drm_panel_get_modes(struct drm_panel *panel,
 }
 EXPORT_SYMBOL(drm_panel_get_modes);
 
+static void __drm_panel_free(struct kref *kref)
+{
+	struct drm_panel *panel = container_of(kref, struct drm_panel, refcount);
+
+	kfree(panel->container);
+}
+
+/**
+ * drm_panel_get - Acquire a panel reference
+ * @panel: DRM panel
+ *
+ * This function increments the panel's refcount.
+ * Returns:
+ * Pointer to @panel
+ */
+struct drm_panel *drm_panel_get(struct drm_panel *panel)
+{
+	if (!panel)
+		return panel;
+
+	kref_get(&panel->refcount);
+
+	return panel;
+}
+EXPORT_SYMBOL(drm_panel_get);
+
+/**
+ * drm_panel_put - Release a panel reference
+ * @panel: DRM panel
+ *
+ * This function decrements the panel's reference count and frees the
+ * object if the reference count drops to zero.
+ */
+void drm_panel_put(struct drm_panel *panel)
+{
+	if (panel)
+		kref_put(&panel->refcount, __drm_panel_free);
+}
+EXPORT_SYMBOL(drm_panel_put);
+
+/**
+ * drm_panel_put_void - wrapper to drm_panel_put() taking a void pointer
+ *
+ * @data: pointer to @struct drm_panel, cast to a void pointer
+ *
+ * Wrapper of drm_panel_put() to be used when a function taking a void
+ * pointer is needed, for example as a devm action.
+ */
+static void drm_panel_put_void(void *data)
+{
+	struct drm_panel *panel = (struct drm_panel *)data;
+
+	drm_panel_put(panel);
+}
+
+void *__devm_drm_panel_alloc(struct device *dev, size_t size, size_t offset,
+			     const struct drm_panel_funcs *funcs,
+			     int connector_type)
+{
+	void *container;
+	struct drm_panel *panel;
+	int err;
+
+	if (!funcs) {
+		dev_warn(dev, "Missing funcs pointer\n");
+		return ERR_PTR(-EINVAL);
+	}
+
+	container = kzalloc(size, GFP_KERNEL);
+	if (!container)
+		return ERR_PTR(-ENOMEM);
+
+	panel = container + offset;
+	panel->container = container;
+	panel->funcs = funcs;
+	kref_init(&panel->refcount);
+
+	err = devm_add_action_or_reset(dev, drm_panel_put_void, panel);
+	if (err)
+		return ERR_PTR(err);
+
+	drm_panel_init(panel, dev, funcs, connector_type);
+
+	return container;
+}
+EXPORT_SYMBOL(__devm_drm_panel_alloc);
+
 #ifdef CONFIG_OF
 /**
  * of_drm_find_panel - look up a panel using a device tree node