1 files changed, 84 insertions, 0 deletions
diff --git a/include/linux/of_reserved_mem.h b/include/linux/of_reserved_mem.h
new file mode 100644
index 000000000..4de2a24ca
--- /dev/null
+++ b/include/linux/of_reserved_mem.h
@@ -0,0 +1,84 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __OF_RESERVED_MEM_H
+#define __OF_RESERVED_MEM_H
+
+#include <linux/device.h>
+#include <linux/of.h>
+
+struct of_phandle_args;
+struct reserved_mem_ops;
+
+struct reserved_mem {
+	const char			*name;
+	unsigned long			fdt_node;
+	unsigned long			phandle;
+	const struct reserved_mem_ops	*ops;
+	phys_addr_t			base;
+	phys_addr_t			size;
+	void				*priv;
+};
+
+struct reserved_mem_ops {
+	int	(*device_init)(struct reserved_mem *rmem,
+			       struct device *dev);
+	void	(*device_release)(struct reserved_mem *rmem,
+				  struct device *dev);
+};
+
+typedef int (*reservedmem_of_init_fn)(struct reserved_mem *rmem);
+
+#ifdef CONFIG_OF_RESERVED_MEM
+
+#define RESERVEDMEM_OF_DECLARE(name, compat, init)			\
+	_OF_DECLARE(reservedmem, name, compat, init, reservedmem_of_init_fn)
+
+int of_reserved_mem_device_init_by_idx(struct device *dev,
+				       struct device_node *np, int idx);
+int of_reserved_mem_device_init_by_name(struct device *dev,
+					struct device_node *np,
+					const char *name);
+void of_reserved_mem_device_release(struct device *dev);
+
+struct reserved_mem *of_reserved_mem_lookup(struct device_node *np);
+#else
+
+#define RESERVEDMEM_OF_DECLARE(name, compat, init)			\
+	_OF_DECLARE_STUB(reservedmem, name, compat, init, reservedmem_of_init_fn)
+
+static inline int of_reserved_mem_device_init_by_idx(struct device *dev,
+					struct device_node *np, int idx)
+{
+	return -ENOSYS;
+}
+
+static inline int of_reserved_mem_device_init_by_name(struct device *dev,
+						      struct device_node *np,
+						      const char *name)
+{
+	return -ENOSYS;
+}
+
+static inline void of_reserved_mem_device_release(struct device *pdev) { }
+
+static inline struct reserved_mem *of_reserved_mem_lookup(struct device_node *np)
+{
+	return NULL;
+}
+#endif
+
+/**
+ * of_reserved_mem_device_init() - assign reserved memory region to given device
+ * @dev:	Pointer to the device to configure
+ *
+ * This function assigns respective DMA-mapping operations based on the first
+ * reserved memory region specified by 'memory-region' property in device tree
+ * node of the given device.
+ *
+ * Returns error code or zero on success.
+ */
+static inline int of_reserved_mem_device_init(struct device *dev)
+{
+	return of_reserved_mem_device_init_by_idx(dev, dev->of_node, 0);
+}
+
+#endif /* __OF_RESERVED_MEM_H */