v4.19.13 snapshot.
diff --git a/include/linux/of_graph.h b/include/linux/of_graph.h
new file mode 100644
index 0000000..01038a6
--- /dev/null
+++ b/include/linux/of_graph.h
@@ -0,0 +1,121 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * OF graph binding parsing helpers
+ *
+ * Copyright (C) 2012 - 2013 Samsung Electronics Co., Ltd.
+ * Author: Sylwester Nawrocki <s.nawrocki@samsung.com>
+ *
+ * Copyright (C) 2012 Renesas Electronics Corp.
+ * Author: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
+ */
+#ifndef __LINUX_OF_GRAPH_H
+#define __LINUX_OF_GRAPH_H
+
+#include <linux/types.h>
+#include <linux/errno.h>
+
+/**
+ * struct of_endpoint - the OF graph endpoint data structure
+ * @port: identifier (value of reg property) of a port this endpoint belongs to
+ * @id: identifier (value of reg property) of this endpoint
+ * @local_node: pointer to device_node of this endpoint
+ */
+struct of_endpoint {
+ unsigned int port;
+ unsigned int id;
+ const struct device_node *local_node;
+};
+
+/**
+ * for_each_endpoint_of_node - iterate over every endpoint in a device node
+ * @parent: parent device node containing ports and endpoints
+ * @child: loop variable pointing to the current endpoint node
+ *
+ * When breaking out of the loop, of_node_put(child) has to be called manually.
+ */
+#define for_each_endpoint_of_node(parent, child) \
+ for (child = of_graph_get_next_endpoint(parent, NULL); child != NULL; \
+ child = of_graph_get_next_endpoint(parent, child))
+
+#ifdef CONFIG_OF
+int of_graph_parse_endpoint(const struct device_node *node,
+ struct of_endpoint *endpoint);
+int of_graph_get_endpoint_count(const struct device_node *np);
+struct device_node *of_graph_get_port_by_id(struct device_node *node, u32 id);
+struct device_node *of_graph_get_next_endpoint(const struct device_node *parent,
+ struct device_node *previous);
+struct device_node *of_graph_get_endpoint_by_regs(
+ const struct device_node *parent, int port_reg, int reg);
+struct device_node *of_graph_get_remote_endpoint(
+ const struct device_node *node);
+struct device_node *of_graph_get_port_parent(struct device_node *node);
+struct device_node *of_graph_get_remote_port_parent(
+ const struct device_node *node);
+struct device_node *of_graph_get_remote_port(const struct device_node *node);
+struct device_node *of_graph_get_remote_node(const struct device_node *node,
+ u32 port, u32 endpoint);
+#else
+
+static inline int of_graph_parse_endpoint(const struct device_node *node,
+ struct of_endpoint *endpoint)
+{
+ return -ENOSYS;
+}
+
+static inline int of_graph_get_endpoint_count(const struct device_node *np)
+{
+ return 0;
+}
+
+static inline struct device_node *of_graph_get_port_by_id(
+ struct device_node *node, u32 id)
+{
+ return NULL;
+}
+
+static inline struct device_node *of_graph_get_next_endpoint(
+ const struct device_node *parent,
+ struct device_node *previous)
+{
+ return NULL;
+}
+
+static inline struct device_node *of_graph_get_endpoint_by_regs(
+ const struct device_node *parent, int port_reg, int reg)
+{
+ return NULL;
+}
+
+static inline struct device_node *of_graph_get_remote_endpoint(
+ const struct device_node *node)
+{
+ return NULL;
+}
+
+static inline struct device_node *of_graph_get_port_parent(
+ struct device_node *node)
+{
+ return NULL;
+}
+
+static inline struct device_node *of_graph_get_remote_port_parent(
+ const struct device_node *node)
+{
+ return NULL;
+}
+
+static inline struct device_node *of_graph_get_remote_port(
+ const struct device_node *node)
+{
+ return NULL;
+}
+static inline struct device_node *of_graph_get_remote_node(
+ const struct device_node *node,
+ u32 port, u32 endpoint)
+{
+ return NULL;
+}
+
+#endif /* CONFIG_OF */
+
+#endif /* __LINUX_OF_GRAPH_H */