1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * Definitions for working with the Flattened Device Tree data format
4 *
5 * Copyright 2009 Benjamin Herrenschmidt, IBM Corp
6 * benh@kernel.crashing.org
7 */
8
9#ifndef _LINUX_OF_FDT_H
10#define _LINUX_OF_FDT_H
11
12#include <linux/types.h>
13#include <linux/init.h>
14#include <linux/errno.h>
15
16/* Definitions used by the flattened device tree */
17#define OF_DT_HEADER 0xd00dfeed /* marker */
18
19#ifndef __ASSEMBLY__
20
21#if defined(CONFIG_OF_FLATTREE)
22
23struct device_node;
24
25/* For scanning an arbitrary device-tree at any time */
26extern void *of_fdt_unflatten_tree(const unsigned long *blob,
27 struct device_node *dad,
28 struct device_node **mynodes);
29
30/* TBD: Temporary export of fdt globals - remove when code fully merged */
31extern int __initdata dt_root_addr_cells;
32extern int __initdata dt_root_size_cells;
33extern void *initial_boot_params;
34
35extern char __dtb_start[];
36extern char __dtb_end[];
37
38/* Other Prototypes */
39extern u64 of_flat_dt_translate_address(unsigned long node);
40extern void of_fdt_limit_memory(int limit);
41#endif /* CONFIG_OF_FLATTREE */
42
43#ifdef CONFIG_OF_EARLY_FLATTREE
44/* For scanning the flat device-tree at boot time */
45extern int of_scan_flat_dt(int (*it)(unsigned long node, const char *uname,
46 int depth, void *data),
47 void *data);
48extern int of_scan_flat_dt_subnodes(unsigned long node,
49 int (*it)(unsigned long node,
50 const char *uname,
51 void *data),
52 void *data);
53extern int of_get_flat_dt_subnode_by_name(unsigned long node,
54 const char *uname);
55extern const void *of_get_flat_dt_prop(unsigned long node, const char *name,
56 int *size);
57extern int of_flat_dt_is_compatible(unsigned long node, const char *name);
58extern unsigned long of_get_flat_dt_root(void);
59extern uint32_t of_get_flat_dt_phandle(unsigned long node);
60
61extern int early_init_dt_scan_chosen(char *cmdline);
62extern int early_init_dt_scan_memory(void);
63extern void early_init_dt_check_for_usable_mem_range(void);
64extern int early_init_dt_scan_chosen_stdout(void);
65extern void early_init_fdt_scan_reserved_mem(void);
66extern void early_init_fdt_reserve_self(void);
67extern void early_init_dt_add_memory_arch(u64 base, u64 size);
68extern u64 dt_mem_next_cell(int s, const __be32 **cellp);
69
70/* Early flat tree scan hooks */
71extern int early_init_dt_scan_root(void);
72
73extern bool early_init_dt_scan(void *params);
74extern bool early_init_dt_verify(void *params);
75extern void early_init_dt_scan_nodes(void);
76
77extern const char *of_flat_dt_get_machine_name(void);
78extern const void *of_flat_dt_match_machine(const void *default_match,
79 const void * (*get_next_compat)(const char * const**));
80
81/* Other Prototypes */
82extern void unflatten_device_tree(void);
83extern void unflatten_and_copy_device_tree(void);
84extern void early_init_devtree(void *);
85extern void early_get_first_memblock_info(void *, phys_addr_t *);
86#else /* CONFIG_OF_EARLY_FLATTREE */
87static inline void early_init_dt_check_for_usable_mem_range(void) {}
88static inline int early_init_dt_scan_chosen_stdout(void) { return -ENODEV; }
89static inline void early_init_fdt_scan_reserved_mem(void) {}
90static inline void early_init_fdt_reserve_self(void) {}
91static inline const char *of_flat_dt_get_machine_name(void) { return NULL; }
92static inline void unflatten_device_tree(void) {}
93static inline void unflatten_and_copy_device_tree(void) {}
94#endif /* CONFIG_OF_EARLY_FLATTREE */
95
96#endif /* __ASSEMBLY__ */
97#endif /* _LINUX_OF_FDT_H */
98

source code of linux/include/linux/of_fdt.h