1	/* SPDX-License-Identifier: (GPL-2.0-or-later OR BSD-2-Clause) */
2	#ifndef LIBFDT_H
3	#define LIBFDT_H
4	/*
5	* libfdt - Flat Device Tree manipulation
6	* Copyright (C) 2006 David Gibson, IBM Corporation.
7	*/
8
9	#include "libfdt_env.h"
10	#include "fdt.h"
11
12	#ifdef __cplusplus
13	extern "C" {
14	#endif
15
16	#define FDT_FIRST_SUPPORTED_VERSION 0x02
17	#define FDT_LAST_COMPATIBLE_VERSION 0x10
18	#define FDT_LAST_SUPPORTED_VERSION 0x11
19
20	/* Error codes: informative error codes */
21	#define FDT_ERR_NOTFOUND 1
22	/* FDT_ERR_NOTFOUND: The requested node or property does not exist */
23	#define FDT_ERR_EXISTS 2
24	/* FDT_ERR_EXISTS: Attempted to create a node or property which
25	* already exists */
26	#define FDT_ERR_NOSPACE 3
27	/* FDT_ERR_NOSPACE: Operation needed to expand the device
28	* tree, but its buffer did not have sufficient space to
29	* contain the expanded tree. Use fdt_open_into() to move the
30	* device tree to a buffer with more space. */
31
32	/* Error codes: codes for bad parameters */
33	#define FDT_ERR_BADOFFSET 4
34	/* FDT_ERR_BADOFFSET: Function was passed a structure block
35	* offset which is out-of-bounds, or which points to an
36	* unsuitable part of the structure for the operation. */
37	#define FDT_ERR_BADPATH 5
38	/* FDT_ERR_BADPATH: Function was passed a badly formatted path
39	* (e.g. missing a leading / for a function which requires an
40	* absolute path) */
41	#define FDT_ERR_BADPHANDLE 6
42	/* FDT_ERR_BADPHANDLE: Function was passed an invalid phandle.
43	* This can be caused either by an invalid phandle property
44	* length, or the phandle value was either 0 or -1, which are
45	* not permitted. */
46	#define FDT_ERR_BADSTATE 7
47	/* FDT_ERR_BADSTATE: Function was passed an incomplete device
48	* tree created by the sequential-write functions, which is
49	* not sufficiently complete for the requested operation. */
50
51	/* Error codes: codes for bad device tree blobs */
52	#define FDT_ERR_TRUNCATED 8
53	/* FDT_ERR_TRUNCATED: FDT or a sub-block is improperly
54	* terminated (overflows, goes outside allowed bounds, or
55	* isn't properly terminated). */
56	#define FDT_ERR_BADMAGIC 9
57	/* FDT_ERR_BADMAGIC: Given "device tree" appears not to be a
58	* device tree at all - it is missing the flattened device
59	* tree magic number. */
60	#define FDT_ERR_BADVERSION 10
61	/* FDT_ERR_BADVERSION: Given device tree has a version which
62	* can't be handled by the requested operation. For
63	* read-write functions, this may mean that fdt_open_into() is
64	* required to convert the tree to the expected version. */
65	#define FDT_ERR_BADSTRUCTURE 11
66	/* FDT_ERR_BADSTRUCTURE: Given device tree has a corrupt
67	* structure block or other serious error (e.g. misnested
68	* nodes, or subnodes preceding properties). */
69	#define FDT_ERR_BADLAYOUT 12
70	/* FDT_ERR_BADLAYOUT: For read-write functions, the given
71	* device tree has it's sub-blocks in an order that the
72	* function can't handle (memory reserve map, then structure,
73	* then strings). Use fdt_open_into() to reorganize the tree
74	* into a form suitable for the read-write operations. */
75
76	/* "Can't happen" error indicating a bug in libfdt */
77	#define FDT_ERR_INTERNAL 13
78	/* FDT_ERR_INTERNAL: libfdt has failed an internal assertion.
79	* Should never be returned, if it is, it indicates a bug in
80	* libfdt itself. */
81
82	/* Errors in device tree content */
83	#define FDT_ERR_BADNCELLS 14
84	/* FDT_ERR_BADNCELLS: Device tree has a #address-cells, #size-cells
85	* or similar property with a bad format or value */
86
87	#define FDT_ERR_BADVALUE 15
88	/* FDT_ERR_BADVALUE: Device tree has a property with an unexpected
89	* value. For example: a property expected to contain a string list
90	* is not NUL-terminated within the length of its value. */
91
92	#define FDT_ERR_BADOVERLAY 16
93	/* FDT_ERR_BADOVERLAY: The device tree overlay, while
94	* correctly structured, cannot be applied due to some
95	* unexpected or missing value, property or node. */
96
97	#define FDT_ERR_NOPHANDLES 17
98	/* FDT_ERR_NOPHANDLES: The device tree doesn't have any
99	* phandle available anymore without causing an overflow */
100
101	#define FDT_ERR_BADFLAGS 18
102	/* FDT_ERR_BADFLAGS: The function was passed a flags field that
103	* contains invalid flags or an invalid combination of flags. */
104
105	#define FDT_ERR_ALIGNMENT 19
106	/* FDT_ERR_ALIGNMENT: The device tree base address is not 8-byte
107	* aligned. */
108
109	#define FDT_ERR_MAX 19
110
111	/* constants */
112	#define FDT_MAX_PHANDLE 0xfffffffe
113	/* Valid values for phandles range from 1 to 2^32-2. */
114
115	/**********************************************************************/
116	/* Low-level functions (you probably don't need these) */
117	/**********************************************************************/
118
119	#ifndef SWIG /* This function is not useful in Python */
120	const void *fdt_offset_ptr(const void *fdt, int offset, unsigned int checklen);
121	#endif
122	static inline void *fdt_offset_ptr_w(void *fdt, int offset, int checklen)
123	{
124	return (void *)(uintptr_t)fdt_offset_ptr(fdt, offset, checklen);
125	}
126
127	uint32_t fdt_next_tag(const void *fdt, int offset, int *nextoffset);
128
129	/*
130	* External helpers to access words from a device tree blob. They're built
131	* to work even with unaligned pointers on platforms (such as ARMv5) that don't
132	* like unaligned loads and stores.
133	*/
134	static inline uint16_t fdt16_ld(const fdt16_t *p)
135	{
136	const uint8_t *bp = (const uint8_t *)p;
137
138	return ((uint16_t)bp[0] << 8) | bp[1];
139	}
140
141	static inline uint32_t fdt32_ld(const fdt32_t *p)
142	{
143	const uint8_t *bp = (const uint8_t *)p;
144
145	return ((uint32_t)bp[0] << 24)
146	| ((uint32_t)bp[1] << 16)
147	| ((uint32_t)bp[2] << 8)
148	| bp[3];
149	}
150
151	static inline void fdt32_st(void *property, uint32_t value)
152	{
153	uint8_t *bp = (uint8_t *)property;
154
155	bp[0] = value >> 24;
156	bp[1] = (value >> 16) & 0xff;
157	bp[2] = (value >> 8) & 0xff;
158	bp[3] = value & 0xff;
159	}
160
161	static inline uint64_t fdt64_ld(const fdt64_t *p)
162	{
163	const uint8_t *bp = (const uint8_t *)p;
164
165	return ((uint64_t)bp[0] << 56)
166	| ((uint64_t)bp[1] << 48)
167	| ((uint64_t)bp[2] << 40)
168	| ((uint64_t)bp[3] << 32)
169	| ((uint64_t)bp[4] << 24)
170	| ((uint64_t)bp[5] << 16)
171	| ((uint64_t)bp[6] << 8)
172	| bp[7];
173	}
174
175	static inline void fdt64_st(void *property, uint64_t value)
176	{
177	uint8_t *bp = (uint8_t *)property;
178
179	bp[0] = value >> 56;
180	bp[1] = (value >> 48) & 0xff;
181	bp[2] = (value >> 40) & 0xff;
182	bp[3] = (value >> 32) & 0xff;
183	bp[4] = (value >> 24) & 0xff;
184	bp[5] = (value >> 16) & 0xff;
185	bp[6] = (value >> 8) & 0xff;
186	bp[7] = value & 0xff;
187	}
188
189	/**********************************************************************/
190	/* Traversal functions */
191	/**********************************************************************/
192
193	int fdt_next_node(const void *fdt, int offset, int *depth);
194
195	/**
196	* fdt_first_subnode() - get offset of first direct subnode
197	* @fdt: FDT blob
198	* @offset: Offset of node to check
199	*
200	* Return: offset of first subnode, or -FDT_ERR_NOTFOUND if there is none
201	*/
202	int fdt_first_subnode(const void *fdt, int offset);
203
204	/**
205	* fdt_next_subnode() - get offset of next direct subnode
206	* @fdt: FDT blob
207	* @offset: Offset of previous subnode
208	*
209	* After first calling fdt_first_subnode(), call this function repeatedly to
210	* get direct subnodes of a parent node.
211	*
212	* Return: offset of next subnode, or -FDT_ERR_NOTFOUND if there are no more
213	* subnodes
214	*/
215	int fdt_next_subnode(const void *fdt, int offset);
216
217	/**
218	* fdt_for_each_subnode - iterate over all subnodes of a parent
219	*
220	* @node: child node (int, lvalue)
221	* @fdt: FDT blob (const void *)
222	* @parent: parent node (int)
223	*
224	* This is actually a wrapper around a for loop and would be used like so:
225	*
226	* fdt_for_each_subnode(node, fdt, parent) {
227	* Use node
228	* ...
229	* }
230	*
231	* if ((node < 0) && (node != -FDT_ERR_NOTFOUND)) {
232	* Error handling
233	* }
234	*
235	* Note that this is implemented as a macro and @node is used as
236	* iterator in the loop. The parent variable be constant or even a
237	* literal.
238	*/
239	#define fdt_for_each_subnode(node, fdt, parent) \
240	for (node = fdt_first_subnode(fdt, parent); \
241	node >= 0; \
242	node = fdt_next_subnode(fdt, node))
243
244	/**********************************************************************/
245	/* General functions */
246	/**********************************************************************/
247	#define fdt_get_header(fdt, field) \
248	(fdt32_ld(&((const struct fdt_header *)(fdt))->field))
249	#define fdt_magic(fdt) (fdt_get_header(fdt, magic))
250	#define fdt_totalsize(fdt) (fdt_get_header(fdt, totalsize))
251	#define fdt_off_dt_struct(fdt) (fdt_get_header(fdt, off_dt_struct))
252	#define fdt_off_dt_strings(fdt) (fdt_get_header(fdt, off_dt_strings))
253	#define fdt_off_mem_rsvmap(fdt) (fdt_get_header(fdt, off_mem_rsvmap))
254	#define fdt_version(fdt) (fdt_get_header(fdt, version))
255	#define fdt_last_comp_version(fdt) (fdt_get_header(fdt, last_comp_version))
256	#define fdt_boot_cpuid_phys(fdt) (fdt_get_header(fdt, boot_cpuid_phys))
257	#define fdt_size_dt_strings(fdt) (fdt_get_header(fdt, size_dt_strings))
258	#define fdt_size_dt_struct(fdt) (fdt_get_header(fdt, size_dt_struct))
259
260	#define fdt_set_hdr_(name) \
261	static inline void fdt_set_##name(void *fdt, uint32_t val) \
262	{ \
263	struct fdt_header *fdth = (struct fdt_header *)fdt; \
264	fdth->name = cpu_to_fdt32(val); \
265	}
266	fdt_set_hdr_(magic);
267	fdt_set_hdr_(totalsize);
268	fdt_set_hdr_(off_dt_struct);
269	fdt_set_hdr_(off_dt_strings);
270	fdt_set_hdr_(off_mem_rsvmap);
271	fdt_set_hdr_(version);
272	fdt_set_hdr_(last_comp_version);
273	fdt_set_hdr_(boot_cpuid_phys);
274	fdt_set_hdr_(size_dt_strings);
275	fdt_set_hdr_(size_dt_struct);
276	#undef fdt_set_hdr_
277
278	/**
279	* fdt_header_size - return the size of the tree's header
280	* @fdt: pointer to a flattened device tree
281	*
282	* Return: size of DTB header in bytes
283	*/
284	size_t fdt_header_size(const void *fdt);
285
286	/**
287	* fdt_header_size_ - internal function to get header size from a version number
288	* @version: devicetree version number
289	*
290	* Return: size of DTB header in bytes
291	*/
292	size_t fdt_header_size_(uint32_t version);
293
294	/**
295	* fdt_check_header - sanity check a device tree header
296	* @fdt: pointer to data which might be a flattened device tree
297	*
298	* fdt_check_header() checks that the given buffer contains what
299	* appears to be a flattened device tree, and that the header contains
300	* valid information (to the extent that can be determined from the
301	* header alone).
302	*
303	* returns:
304	* 0, if the buffer appears to contain a valid device tree
305	* -FDT_ERR_BADMAGIC,
306	* -FDT_ERR_BADVERSION,
307	* -FDT_ERR_BADSTATE,
308	* -FDT_ERR_TRUNCATED, standard meanings, as above
309	*/
310	int fdt_check_header(const void *fdt);
311
312	/**
313	* fdt_move - move a device tree around in memory
314	* @fdt: pointer to the device tree to move
315	* @buf: pointer to memory where the device is to be moved
316	* @bufsize: size of the memory space at buf
317	*
318	* fdt_move() relocates, if possible, the device tree blob located at
319	* fdt to the buffer at buf of size bufsize. The buffer may overlap
320	* with the existing device tree blob at fdt. Therefore,
321	* fdt_move(fdt, fdt, fdt_totalsize(fdt))
322	* should always succeed.
323	*
324	* returns:
325	* 0, on success
326	* -FDT_ERR_NOSPACE, bufsize is insufficient to contain the device tree
327	* -FDT_ERR_BADMAGIC,
328	* -FDT_ERR_BADVERSION,
329	* -FDT_ERR_BADSTATE, standard meanings
330	*/
331	int fdt_move(const void *fdt, void *buf, int bufsize);
332
333	/**********************************************************************/
334	/* Read-only functions */
335	/**********************************************************************/
336
337	int fdt_check_full(const void *fdt, size_t bufsize);
338
339	/**
340	* fdt_get_string - retrieve a string from the strings block of a device tree
341	* @fdt: pointer to the device tree blob
342	* @stroffset: offset of the string within the strings block (native endian)
343	* @lenp: optional pointer to return the string's length
344	*
345	* fdt_get_string() retrieves a pointer to a single string from the
346	* strings block of the device tree blob at fdt, and optionally also
347	* returns the string's length in *lenp.
348	*
349	* returns:
350	* a pointer to the string, on success
351	* NULL, if stroffset is out of bounds, or doesn't point to a valid string
352	*/
353	const char *fdt_get_string(const void *fdt, int stroffset, int *lenp);
354
355	/**
356	* fdt_string - retrieve a string from the strings block of a device tree
357	* @fdt: pointer to the device tree blob
358	* @stroffset: offset of the string within the strings block (native endian)
359	*
360	* fdt_string() retrieves a pointer to a single string from the
361	* strings block of the device tree blob at fdt.
362	*
363	* returns:
364	* a pointer to the string, on success
365	* NULL, if stroffset is out of bounds, or doesn't point to a valid string
366	*/
367	const char *fdt_string(const void *fdt, int stroffset);
368
369	/**
370	* fdt_find_max_phandle - find and return the highest phandle in a tree
371	* @fdt: pointer to the device tree blob
372	* @phandle: return location for the highest phandle value found in the tree
373	*
374	* fdt_find_max_phandle() finds the highest phandle value in the given device
375	* tree. The value returned in @phandle is only valid if the function returns
376	* success.
377	*
378	* returns:
379	* 0 on success or a negative error code on failure
380	*/
381	int fdt_find_max_phandle(const void *fdt, uint32_t *phandle);
382
383	/**
384	* fdt_get_max_phandle - retrieves the highest phandle in a tree
385	* @fdt: pointer to the device tree blob
386	*
387	* fdt_get_max_phandle retrieves the highest phandle in the given
388	* device tree. This will ignore badly formatted phandles, or phandles
389	* with a value of 0 or -1.
390	*
391	* This function is deprecated in favour of fdt_find_max_phandle().
392	*
393	* returns:
394	* the highest phandle on success
395	* 0, if no phandle was found in the device tree
396	* -1, if an error occurred
397	*/
398	static inline uint32_t fdt_get_max_phandle(const void *fdt)
399	{
400	uint32_t phandle;
401	int err;
402
403	err = fdt_find_max_phandle(fdt, phandle: &phandle);
404	if (err < 0)
405	return (uint32_t)-1;
406
407	return phandle;
408	}
409
410	/**
411	* fdt_generate_phandle - return a new, unused phandle for a device tree blob
412	* @fdt: pointer to the device tree blob
413	* @phandle: return location for the new phandle
414	*
415	* Walks the device tree blob and looks for the highest phandle value. On
416	* success, the new, unused phandle value (one higher than the previously
417	* highest phandle value in the device tree blob) will be returned in the
418	* @phandle parameter.
419	*
420	* Return: 0 on success or a negative error-code on failure
421	*/
422	int fdt_generate_phandle(const void *fdt, uint32_t *phandle);
423
424	/**
425	* fdt_num_mem_rsv - retrieve the number of memory reserve map entries
426	* @fdt: pointer to the device tree blob
427	*
428	* Returns the number of entries in the device tree blob's memory
429	* reservation map. This does not include the terminating 0,0 entry
430	* or any other (0,0) entries reserved for expansion.
431	*
432	* returns:
433	* the number of entries
434	*/
435	int fdt_num_mem_rsv(const void *fdt);
436
437	/**
438	* fdt_get_mem_rsv - retrieve one memory reserve map entry
439	* @fdt: pointer to the device tree blob
440	* @n: index of reserve map entry
441	* @address: pointer to 64-bit variable to hold the start address
442	* @size: pointer to 64-bit variable to hold the size of the entry
443	*
444	* On success, @address and @size will contain the address and size of
445	* the n-th reserve map entry from the device tree blob, in
446	* native-endian format.
447	*
448	* returns:
449	* 0, on success
450	* -FDT_ERR_BADMAGIC,
451	* -FDT_ERR_BADVERSION,
452	* -FDT_ERR_BADSTATE, standard meanings
453	*/
454	int fdt_get_mem_rsv(const void *fdt, int n, uint64_t *address, uint64_t *size);
455
456	/**
457	* fdt_subnode_offset_namelen - find a subnode based on substring
458	* @fdt: pointer to the device tree blob
459	* @parentoffset: structure block offset of a node
460	* @name: name of the subnode to locate
461	* @namelen: number of characters of name to consider
462	*
463	* Identical to fdt_subnode_offset(), but only examine the first
464	* namelen characters of name for matching the subnode name. This is
465	* useful for finding subnodes based on a portion of a larger string,
466	* such as a full path.
467	*
468	* Return: offset of the subnode or -FDT_ERR_NOTFOUND if name not found.
469	*/
470	#ifndef SWIG /* Not available in Python */
471	int fdt_subnode_offset_namelen(const void *fdt, int parentoffset,
472	const char *name, int namelen);
473	#endif
474	/**
475	* fdt_subnode_offset - find a subnode of a given node
476	* @fdt: pointer to the device tree blob
477	* @parentoffset: structure block offset of a node
478	* @name: name of the subnode to locate
479	*
480	* fdt_subnode_offset() finds a subnode of the node at structure block
481	* offset parentoffset with the given name. name may include a unit
482	* address, in which case fdt_subnode_offset() will find the subnode
483	* with that unit address, or the unit address may be omitted, in
484	* which case fdt_subnode_offset() will find an arbitrary subnode
485	* whose name excluding unit address matches the given name.
486	*
487	* returns:
488	* structure block offset of the requested subnode (>=0), on success
489	* -FDT_ERR_NOTFOUND, if the requested subnode does not exist
490	* -FDT_ERR_BADOFFSET, if parentoffset did not point to an FDT_BEGIN_NODE
491	* tag
492	* -FDT_ERR_BADMAGIC,
493	* -FDT_ERR_BADVERSION,
494	* -FDT_ERR_BADSTATE,
495	* -FDT_ERR_BADSTRUCTURE,
496	* -FDT_ERR_TRUNCATED, standard meanings.
497	*/
498	int fdt_subnode_offset(const void *fdt, int parentoffset, const char *name);
499
500	/**
501	* fdt_path_offset_namelen - find a tree node by its full path
502	* @fdt: pointer to the device tree blob
503	* @path: full path of the node to locate
504	* @namelen: number of characters of path to consider
505	*
506	* Identical to fdt_path_offset(), but only consider the first namelen
507	* characters of path as the path name.
508	*
509	* Return: offset of the node or negative libfdt error value otherwise
510	*/
511	#ifndef SWIG /* Not available in Python */
512	int fdt_path_offset_namelen(const void *fdt, const char *path, int namelen);
513	#endif
514
515	/**
516	* fdt_path_offset - find a tree node by its full path
517	* @fdt: pointer to the device tree blob
518	* @path: full path of the node to locate
519	*
520	* fdt_path_offset() finds a node of a given path in the device tree.
521	* Each path component may omit the unit address portion, but the
522	* results of this are undefined if any such path component is
523	* ambiguous (that is if there are multiple nodes at the relevant
524	* level matching the given component, differentiated only by unit
525	* address).
526	*
527	* returns:
528	* structure block offset of the node with the requested path (>=0), on
529	* success
530	* -FDT_ERR_BADPATH, given path does not begin with '/' or is invalid
531	* -FDT_ERR_NOTFOUND, if the requested node does not exist
532	* -FDT_ERR_BADMAGIC,
533	* -FDT_ERR_BADVERSION,
534	* -FDT_ERR_BADSTATE,
535	* -FDT_ERR_BADSTRUCTURE,
536	* -FDT_ERR_TRUNCATED, standard meanings.
537	*/
538	int fdt_path_offset(const void *fdt, const char *path);
539
540	/**
541	* fdt_get_name - retrieve the name of a given node
542	* @fdt: pointer to the device tree blob
543	* @nodeoffset: structure block offset of the starting node
544	* @lenp: pointer to an integer variable (will be overwritten) or NULL
545	*
546	* fdt_get_name() retrieves the name (including unit address) of the
547	* device tree node at structure block offset nodeoffset. If lenp is
548	* non-NULL, the length of this name is also returned, in the integer
549	* pointed to by lenp.
550	*
551	* returns:
552	* pointer to the node's name, on success
553	* If lenp is non-NULL, *lenp contains the length of that name
554	* (>=0)
555	* NULL, on error
556	* if lenp is non-NULL *lenp contains an error code (<0):
557	* -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE
558	* tag
559	* -FDT_ERR_BADMAGIC,
560	* -FDT_ERR_BADVERSION,
561	* -FDT_ERR_BADSTATE, standard meanings
562	*/
563	const char *fdt_get_name(const void *fdt, int nodeoffset, int *lenp);
564
565	/**
566	* fdt_first_property_offset - find the offset of a node's first property
567	* @fdt: pointer to the device tree blob
568	* @nodeoffset: structure block offset of a node
569	*
570	* fdt_first_property_offset() finds the first property of the node at
571	* the given structure block offset.
572	*
573	* returns:
574	* structure block offset of the property (>=0), on success
575	* -FDT_ERR_NOTFOUND, if the requested node has no properties
576	* -FDT_ERR_BADOFFSET, if nodeoffset did not point to an FDT_BEGIN_NODE tag
577	* -FDT_ERR_BADMAGIC,
578	* -FDT_ERR_BADVERSION,
579	* -FDT_ERR_BADSTATE,
580	* -FDT_ERR_BADSTRUCTURE,
581	* -FDT_ERR_TRUNCATED, standard meanings.
582	*/
583	int fdt_first_property_offset(const void *fdt, int nodeoffset);
584
585	/**
586	* fdt_next_property_offset - step through a node's properties
587	* @fdt: pointer to the device tree blob
588	* @offset: structure block offset of a property
589	*
590	* fdt_next_property_offset() finds the property immediately after the
591	* one at the given structure block offset. This will be a property
592	* of the same node as the given property.
593	*
594	* returns:
595	* structure block offset of the next property (>=0), on success
596	* -FDT_ERR_NOTFOUND, if the given property is the last in its node
597	* -FDT_ERR_BADOFFSET, if nodeoffset did not point to an FDT_PROP tag
598	* -FDT_ERR_BADMAGIC,
599	* -FDT_ERR_BADVERSION,
600	* -FDT_ERR_BADSTATE,
601	* -FDT_ERR_BADSTRUCTURE,
602	* -FDT_ERR_TRUNCATED, standard meanings.
603	*/
604	int fdt_next_property_offset(const void *fdt, int offset);
605
606	/**
607	* fdt_for_each_property_offset - iterate over all properties of a node
608	*
609	* @property: property offset (int, lvalue)
610	* @fdt: FDT blob (const void *)
611	* @node: node offset (int)
612	*
613	* This is actually a wrapper around a for loop and would be used like so:
614	*
615	* fdt_for_each_property_offset(property, fdt, node) {
616	* Use property
617	* ...
618	* }
619	*
620	* if ((property < 0) && (property != -FDT_ERR_NOTFOUND)) {
621	* Error handling
622	* }
623	*
624	* Note that this is implemented as a macro and property is used as
625	* iterator in the loop. The node variable can be constant or even a
626	* literal.
627	*/
628	#define fdt_for_each_property_offset(property, fdt, node) \
629	for (property = fdt_first_property_offset(fdt, node); \
630	property >= 0; \
631	property = fdt_next_property_offset(fdt, property))
632
633	/**
634	* fdt_get_property_by_offset - retrieve the property at a given offset
635	* @fdt: pointer to the device tree blob
636	* @offset: offset of the property to retrieve
637	* @lenp: pointer to an integer variable (will be overwritten) or NULL
638	*
639	* fdt_get_property_by_offset() retrieves a pointer to the
640	* fdt_property structure within the device tree blob at the given
641	* offset. If lenp is non-NULL, the length of the property value is
642	* also returned, in the integer pointed to by lenp.
643	*
644	* Note that this code only works on device tree versions >= 16. fdt_getprop()
645	* works on all versions.
646	*
647	* returns:
648	* pointer to the structure representing the property
649	* if lenp is non-NULL, *lenp contains the length of the property
650	* value (>=0)
651	* NULL, on error
652	* if lenp is non-NULL, *lenp contains an error code (<0):
653	* -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_PROP tag
654	* -FDT_ERR_BADMAGIC,
655	* -FDT_ERR_BADVERSION,
656	* -FDT_ERR_BADSTATE,
657	* -FDT_ERR_BADSTRUCTURE,
658	* -FDT_ERR_TRUNCATED, standard meanings
659	*/
660	const struct fdt_property *fdt_get_property_by_offset(const void *fdt,
661	int offset,
662	int *lenp);
663	static inline struct fdt_property *fdt_get_property_by_offset_w(void *fdt,
664	int offset,
665	int *lenp)
666	{
667	return (struct fdt_property *)(uintptr_t)
668	fdt_get_property_by_offset(fdt, offset, lenp);
669	}
670
671	/**
672	* fdt_get_property_namelen - find a property based on substring
673	* @fdt: pointer to the device tree blob
674	* @nodeoffset: offset of the node whose property to find
675	* @name: name of the property to find
676	* @namelen: number of characters of name to consider
677	* @lenp: pointer to an integer variable (will be overwritten) or NULL
678	*
679	* Identical to fdt_get_property(), but only examine the first namelen
680	* characters of name for matching the property name.
681	*
682	* Return: pointer to the structure representing the property, or NULL
683	* if not found
684	*/
685	#ifndef SWIG /* Not available in Python */
686	const struct fdt_property *fdt_get_property_namelen(const void *fdt,
687	int nodeoffset,
688	const char *name,
689	int namelen, int *lenp);
690	#endif
691
692	/**
693	* fdt_get_property - find a given property in a given node
694	* @fdt: pointer to the device tree blob
695	* @nodeoffset: offset of the node whose property to find
696	* @name: name of the property to find
697	* @lenp: pointer to an integer variable (will be overwritten) or NULL
698	*
699	* fdt_get_property() retrieves a pointer to the fdt_property
700	* structure within the device tree blob corresponding to the property
701	* named 'name' of the node at offset nodeoffset. If lenp is
702	* non-NULL, the length of the property value is also returned, in the
703	* integer pointed to by lenp.
704	*
705	* returns:
706	* pointer to the structure representing the property
707	* if lenp is non-NULL, *lenp contains the length of the property
708	* value (>=0)
709	* NULL, on error
710	* if lenp is non-NULL, *lenp contains an error code (<0):
711	* -FDT_ERR_NOTFOUND, node does not have named property
712	* -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE
713	* tag
714	* -FDT_ERR_BADMAGIC,
715	* -FDT_ERR_BADVERSION,
716	* -FDT_ERR_BADSTATE,
717	* -FDT_ERR_BADSTRUCTURE,
718	* -FDT_ERR_TRUNCATED, standard meanings
719	*/
720	const struct fdt_property *fdt_get_property(const void *fdt, int nodeoffset,
721	const char *name, int *lenp);
722	static inline struct fdt_property *fdt_get_property_w(void *fdt, int nodeoffset,
723	const char *name,
724	int *lenp)
725	{
726	return (struct fdt_property *)(uintptr_t)
727	fdt_get_property(fdt, nodeoffset, name, lenp);
728	}
729
730	/**
731	* fdt_getprop_by_offset - retrieve the value of a property at a given offset
732	* @fdt: pointer to the device tree blob
733	* @offset: offset of the property to read
734	* @namep: pointer to a string variable (will be overwritten) or NULL
735	* @lenp: pointer to an integer variable (will be overwritten) or NULL
736	*
737	* fdt_getprop_by_offset() retrieves a pointer to the value of the
738	* property at structure block offset 'offset' (this will be a pointer
739	* to within the device blob itself, not a copy of the value). If
740	* lenp is non-NULL, the length of the property value is also
741	* returned, in the integer pointed to by lenp. If namep is non-NULL,
742	* the property's namne will also be returned in the char * pointed to
743	* by namep (this will be a pointer to within the device tree's string
744	* block, not a new copy of the name).
745	*
746	* returns:
747	* pointer to the property's value
748	* if lenp is non-NULL, *lenp contains the length of the property
749	* value (>=0)
750	* if namep is non-NULL *namep contiains a pointer to the property
751	* name.
752	* NULL, on error
753	* if lenp is non-NULL, *lenp contains an error code (<0):
754	* -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_PROP tag
755	* -FDT_ERR_BADMAGIC,
756	* -FDT_ERR_BADVERSION,
757	* -FDT_ERR_BADSTATE,
758	* -FDT_ERR_BADSTRUCTURE,
759	* -FDT_ERR_TRUNCATED, standard meanings
760	*/
761	#ifndef SWIG /* This function is not useful in Python */
762	const void *fdt_getprop_by_offset(const void *fdt, int offset,
763	const char **namep, int *lenp);
764	#endif
765
766	/**
767	* fdt_getprop_namelen - get property value based on substring
768	* @fdt: pointer to the device tree blob
769	* @nodeoffset: offset of the node whose property to find
770	* @name: name of the property to find
771	* @namelen: number of characters of name to consider
772	* @lenp: pointer to an integer variable (will be overwritten) or NULL
773	*
774	* Identical to fdt_getprop(), but only examine the first namelen
775	* characters of name for matching the property name.
776	*
777	* Return: pointer to the property's value or NULL on error
778	*/
779	#ifndef SWIG /* Not available in Python */
780	const void *fdt_getprop_namelen(const void *fdt, int nodeoffset,
781	const char *name, int namelen, int *lenp);
782	static inline void *fdt_getprop_namelen_w(void *fdt, int nodeoffset,
783	const char *name, int namelen,
784	int *lenp)
785	{
786	return (void *)(uintptr_t)fdt_getprop_namelen(fdt, nodeoffset, name,
787	namelen, lenp);
788	}
789	#endif
790
791	/**
792	* fdt_getprop - retrieve the value of a given property
793	* @fdt: pointer to the device tree blob
794	* @nodeoffset: offset of the node whose property to find
795	* @name: name of the property to find
796	* @lenp: pointer to an integer variable (will be overwritten) or NULL
797	*
798	* fdt_getprop() retrieves a pointer to the value of the property
799	* named @name of the node at offset @nodeoffset (this will be a
800	* pointer to within the device blob itself, not a copy of the value).
801	* If @lenp is non-NULL, the length of the property value is also
802	* returned, in the integer pointed to by @lenp.
803	*
804	* returns:
805	* pointer to the property's value
806	* if lenp is non-NULL, *lenp contains the length of the property
807	* value (>=0)
808	* NULL, on error
809	* if lenp is non-NULL, *lenp contains an error code (<0):
810	* -FDT_ERR_NOTFOUND, node does not have named property
811	* -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE
812	* tag
813	* -FDT_ERR_BADMAGIC,
814	* -FDT_ERR_BADVERSION,
815	* -FDT_ERR_BADSTATE,
816	* -FDT_ERR_BADSTRUCTURE,
817	* -FDT_ERR_TRUNCATED, standard meanings
818	*/
819	const void *fdt_getprop(const void *fdt, int nodeoffset,
820	const char *name, int *lenp);
821	static inline void *fdt_getprop_w(void *fdt, int nodeoffset,
822	const char *name, int *lenp)
823	{
824	return (void *)(uintptr_t)fdt_getprop(fdt, nodeoffset, name, lenp);
825	}
826
827	/**
828	* fdt_get_phandle - retrieve the phandle of a given node
829	* @fdt: pointer to the device tree blob
830	* @nodeoffset: structure block offset of the node
831	*
832	* fdt_get_phandle() retrieves the phandle of the device tree node at
833	* structure block offset nodeoffset.
834	*
835	* returns:
836	* the phandle of the node at nodeoffset, on success (!= 0, != -1)
837	* 0, if the node has no phandle, or another error occurs
838	*/
839	uint32_t fdt_get_phandle(const void *fdt, int nodeoffset);
840
841	/**
842	* fdt_get_alias_namelen - get alias based on substring
843	* @fdt: pointer to the device tree blob
844	* @name: name of the alias th look up
845	* @namelen: number of characters of name to consider
846	*
847	* Identical to fdt_get_alias(), but only examine the first @namelen
848	* characters of @name for matching the alias name.
849	*
850	* Return: a pointer to the expansion of the alias named @name, if it exists,
851	* NULL otherwise
852	*/
853	#ifndef SWIG /* Not available in Python */
854	const char *fdt_get_alias_namelen(const void *fdt,
855	const char *name, int namelen);
856	#endif
857
858	/**
859	* fdt_get_alias - retrieve the path referenced by a given alias
860	* @fdt: pointer to the device tree blob
861	* @name: name of the alias th look up
862	*
863	* fdt_get_alias() retrieves the value of a given alias. That is, the
864	* value of the property named @name in the node /aliases.
865	*
866	* returns:
867	* a pointer to the expansion of the alias named 'name', if it exists
868	* NULL, if the given alias or the /aliases node does not exist
869	*/
870	const char *fdt_get_alias(const void *fdt, const char *name);
871
872	/**
873	* fdt_get_path - determine the full path of a node
874	* @fdt: pointer to the device tree blob
875	* @nodeoffset: offset of the node whose path to find
876	* @buf: character buffer to contain the returned path (will be overwritten)
877	* @buflen: size of the character buffer at buf
878	*
879	* fdt_get_path() computes the full path of the node at offset
880	* nodeoffset, and records that path in the buffer at buf.
881	*
882	* NOTE: This function is expensive, as it must scan the device tree
883	* structure from the start to nodeoffset.
884	*
885	* returns:
886	* 0, on success
887	* buf contains the absolute path of the node at
888	* nodeoffset, as a NUL-terminated string.
889	* -FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
890	* -FDT_ERR_NOSPACE, the path of the given node is longer than (bufsize-1)
891	* characters and will not fit in the given buffer.
892	* -FDT_ERR_BADMAGIC,
893	* -FDT_ERR_BADVERSION,
894	* -FDT_ERR_BADSTATE,
895	* -FDT_ERR_BADSTRUCTURE, standard meanings
896	*/
897	int fdt_get_path(const void *fdt, int nodeoffset, char *buf, int buflen);
898
899	/**
900	* fdt_supernode_atdepth_offset - find a specific ancestor of a node
901	* @fdt: pointer to the device tree blob
902	* @nodeoffset: offset of the node whose parent to find
903	* @supernodedepth: depth of the ancestor to find
904	* @nodedepth: pointer to an integer variable (will be overwritten) or NULL
905	*
906	* fdt_supernode_atdepth_offset() finds an ancestor of the given node
907	* at a specific depth from the root (where the root itself has depth
908	* 0, its immediate subnodes depth 1 and so forth). So
909	* fdt_supernode_atdepth_offset(fdt, nodeoffset, 0, NULL);
910	* will always return 0, the offset of the root node. If the node at
911	* nodeoffset has depth D, then:
912	* fdt_supernode_atdepth_offset(fdt, nodeoffset, D, NULL);
913	* will return nodeoffset itself.
914	*
915	* NOTE: This function is expensive, as it must scan the device tree
916	* structure from the start to nodeoffset.
917	*
918	* returns:
919	* structure block offset of the node at node offset's ancestor
920	* of depth supernodedepth (>=0), on success
921	* -FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
922	* -FDT_ERR_NOTFOUND, supernodedepth was greater than the depth of
923	* nodeoffset
924	* -FDT_ERR_BADMAGIC,
925	* -FDT_ERR_BADVERSION,
926	* -FDT_ERR_BADSTATE,
927	* -FDT_ERR_BADSTRUCTURE, standard meanings
928	*/
929	int fdt_supernode_atdepth_offset(const void *fdt, int nodeoffset,
930	int supernodedepth, int *nodedepth);
931
932	/**
933	* fdt_node_depth - find the depth of a given node
934	* @fdt: pointer to the device tree blob
935	* @nodeoffset: offset of the node whose parent to find
936	*
937	* fdt_node_depth() finds the depth of a given node. The root node
938	* has depth 0, its immediate subnodes depth 1 and so forth.
939	*
940	* NOTE: This function is expensive, as it must scan the device tree
941	* structure from the start to nodeoffset.
942	*
943	* returns:
944	* depth of the node at nodeoffset (>=0), on success
945	* -FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
946	* -FDT_ERR_BADMAGIC,
947	* -FDT_ERR_BADVERSION,
948	* -FDT_ERR_BADSTATE,
949	* -FDT_ERR_BADSTRUCTURE, standard meanings
950	*/
951	int fdt_node_depth(const void *fdt, int nodeoffset);
952
953	/**
954	* fdt_parent_offset - find the parent of a given node
955	* @fdt: pointer to the device tree blob
956	* @nodeoffset: offset of the node whose parent to find
957	*
958	* fdt_parent_offset() locates the parent node of a given node (that
959	* is, it finds the offset of the node which contains the node at
960	* nodeoffset as a subnode).
961	*
962	* NOTE: This function is expensive, as it must scan the device tree
963	* structure from the start to nodeoffset, *twice*.
964	*
965	* returns:
966	* structure block offset of the parent of the node at nodeoffset
967	* (>=0), on success
968	* -FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
969	* -FDT_ERR_BADMAGIC,
970	* -FDT_ERR_BADVERSION,
971	* -FDT_ERR_BADSTATE,
972	* -FDT_ERR_BADSTRUCTURE, standard meanings
973	*/
974	int fdt_parent_offset(const void *fdt, int nodeoffset);
975
976	/**
977	* fdt_node_offset_by_prop_value - find nodes with a given property value
978	* @fdt: pointer to the device tree blob
979	* @startoffset: only find nodes after this offset
980	* @propname: property name to check
981	* @propval: property value to search for
982	* @proplen: length of the value in propval
983	*
984	* fdt_node_offset_by_prop_value() returns the offset of the first
985	* node after startoffset, which has a property named propname whose
986	* value is of length proplen and has value equal to propval; or if
987	* startoffset is -1, the very first such node in the tree.
988	*
989	* To iterate through all nodes matching the criterion, the following
990	* idiom can be used:
991	* offset = fdt_node_offset_by_prop_value(fdt, -1, propname,
992	* propval, proplen);
993	* while (offset != -FDT_ERR_NOTFOUND) {
994	* // other code here
995	* offset = fdt_node_offset_by_prop_value(fdt, offset, propname,
996	* propval, proplen);
997	* }
998	*
999	* Note the -1 in the first call to the function, if 0 is used here
1000	* instead, the function will never locate the root node, even if it
1001	* matches the criterion.
1002	*
1003	* returns:
1004	* structure block offset of the located node (>= 0, >startoffset),
1005	* on success
1006	* -FDT_ERR_NOTFOUND, no node matching the criterion exists in the
1007	* tree after startoffset
1008	* -FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
1009	* -FDT_ERR_BADMAGIC,
1010	* -FDT_ERR_BADVERSION,
1011	* -FDT_ERR_BADSTATE,
1012	* -FDT_ERR_BADSTRUCTURE, standard meanings
1013	*/
1014	int fdt_node_offset_by_prop_value(const void *fdt, int startoffset,
1015	const char *propname,
1016	const void *propval, int proplen);
1017
1018	/**
1019	* fdt_node_offset_by_phandle - find the node with a given phandle
1020	* @fdt: pointer to the device tree blob
1021	* @phandle: phandle value
1022	*
1023	* fdt_node_offset_by_phandle() returns the offset of the node
1024	* which has the given phandle value. If there is more than one node
1025	* in the tree with the given phandle (an invalid tree), results are
1026	* undefined.
1027	*
1028	* returns:
1029	* structure block offset of the located node (>= 0), on success
1030	* -FDT_ERR_NOTFOUND, no node with that phandle exists
1031	* -FDT_ERR_BADPHANDLE, given phandle value was invalid (0 or -1)
1032	* -FDT_ERR_BADMAGIC,
1033	* -FDT_ERR_BADVERSION,
1034	* -FDT_ERR_BADSTATE,
1035	* -FDT_ERR_BADSTRUCTURE, standard meanings
1036	*/
1037	int fdt_node_offset_by_phandle(const void *fdt, uint32_t phandle);
1038
1039	/**
1040	* fdt_node_check_compatible - check a node's compatible property
1041	* @fdt: pointer to the device tree blob
1042	* @nodeoffset: offset of a tree node
1043	* @compatible: string to match against
1044	*
1045	* fdt_node_check_compatible() returns 0 if the given node contains a
1046	* @compatible property with the given string as one of its elements,
1047	* it returns non-zero otherwise, or on error.
1048	*
1049	* returns:
1050	* 0, if the node has a 'compatible' property listing the given string
1051	* 1, if the node has a 'compatible' property, but it does not list
1052	* the given string
1053	* -FDT_ERR_NOTFOUND, if the given node has no 'compatible' property
1054	* -FDT_ERR_BADOFFSET, if nodeoffset does not refer to a BEGIN_NODE tag
1055	* -FDT_ERR_BADMAGIC,
1056	* -FDT_ERR_BADVERSION,
1057	* -FDT_ERR_BADSTATE,
1058	* -FDT_ERR_BADSTRUCTURE, standard meanings
1059	*/
1060	int fdt_node_check_compatible(const void *fdt, int nodeoffset,
1061	const char *compatible);
1062
1063	/**
1064	* fdt_node_offset_by_compatible - find nodes with a given 'compatible' value
1065	* @fdt: pointer to the device tree blob
1066	* @startoffset: only find nodes after this offset
1067	* @compatible: 'compatible' string to match against
1068	*
1069	* fdt_node_offset_by_compatible() returns the offset of the first
1070	* node after startoffset, which has a 'compatible' property which
1071	* lists the given compatible string; or if startoffset is -1, the
1072	* very first such node in the tree.
1073	*
1074	* To iterate through all nodes matching the criterion, the following
1075	* idiom can be used:
1076	* offset = fdt_node_offset_by_compatible(fdt, -1, compatible);
1077	* while (offset != -FDT_ERR_NOTFOUND) {
1078	* // other code here
1079	* offset = fdt_node_offset_by_compatible(fdt, offset, compatible);
1080	* }
1081	*
1082	* Note the -1 in the first call to the function, if 0 is used here
1083	* instead, the function will never locate the root node, even if it
1084	* matches the criterion.
1085	*
1086	* returns:
1087	* structure block offset of the located node (>= 0, >startoffset),
1088	* on success
1089	* -FDT_ERR_NOTFOUND, no node matching the criterion exists in the
1090	* tree after startoffset
1091	* -FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
1092	* -FDT_ERR_BADMAGIC,
1093	* -FDT_ERR_BADVERSION,
1094	* -FDT_ERR_BADSTATE,
1095	* -FDT_ERR_BADSTRUCTURE, standard meanings
1096	*/
1097	int fdt_node_offset_by_compatible(const void *fdt, int startoffset,
1098	const char *compatible);
1099
1100	/**
1101	* fdt_stringlist_contains - check a string list property for a string
1102	* @strlist: Property containing a list of strings to check
1103	* @listlen: Length of property
1104	* @str: String to search for
1105	*
1106	* This is a utility function provided for convenience. The list contains
1107	* one or more strings, each terminated by \0, as is found in a device tree
1108	* "compatible" property.
1109	*
1110	* Return: 1 if the string is found in the list, 0 not found, or invalid list
1111	*/
1112	int fdt_stringlist_contains(const char *strlist, int listlen, const char *str);
1113
1114	/**
1115	* fdt_stringlist_count - count the number of strings in a string list
1116	* @fdt: pointer to the device tree blob
1117	* @nodeoffset: offset of a tree node
1118	* @property: name of the property containing the string list
1119	*
1120	* Return:
1121	* the number of strings in the given property
1122	* -FDT_ERR_BADVALUE if the property value is not NUL-terminated
1123	* -FDT_ERR_NOTFOUND if the property does not exist
1124	*/
1125	int fdt_stringlist_count(const void *fdt, int nodeoffset, const char *property);
1126
1127	/**
1128	* fdt_stringlist_search - find a string in a string list and return its index
1129	* @fdt: pointer to the device tree blob
1130	* @nodeoffset: offset of a tree node
1131	* @property: name of the property containing the string list
1132	* @string: string to look up in the string list
1133	*
1134	* Note that it is possible for this function to succeed on property values
1135	* that are not NUL-terminated. That's because the function will stop after
1136	* finding the first occurrence of @string. This can for example happen with
1137	* small-valued cell properties, such as #address-cells, when searching for
1138	* the empty string.
1139	*
1140	* return:
1141	* the index of the string in the list of strings
1142	* -FDT_ERR_BADVALUE if the property value is not NUL-terminated
1143	* -FDT_ERR_NOTFOUND if the property does not exist or does not contain
1144	* the given string
1145	*/
1146	int fdt_stringlist_search(const void *fdt, int nodeoffset, const char *property,
1147	const char *string);
1148
1149	/**
1150	* fdt_stringlist_get() - obtain the string at a given index in a string list
1151	* @fdt: pointer to the device tree blob
1152	* @nodeoffset: offset of a tree node
1153	* @property: name of the property containing the string list
1154	* @index: index of the string to return
1155	* @lenp: return location for the string length or an error code on failure
1156	*
1157	* Note that this will successfully extract strings from properties with
1158	* non-NUL-terminated values. For example on small-valued cell properties
1159	* this function will return the empty string.
1160	*
1161	* If non-NULL, the length of the string (on success) or a negative error-code
1162	* (on failure) will be stored in the integer pointer to by lenp.
1163	*
1164	* Return:
1165	* A pointer to the string at the given index in the string list or NULL on
1166	* failure. On success the length of the string will be stored in the memory
1167	* location pointed to by the lenp parameter, if non-NULL. On failure one of
1168	* the following negative error codes will be returned in the lenp parameter
1169	* (if non-NULL):
1170	* -FDT_ERR_BADVALUE if the property value is not NUL-terminated
1171	* -FDT_ERR_NOTFOUND if the property does not exist
1172	*/
1173	const char *fdt_stringlist_get(const void *fdt, int nodeoffset,
1174	const char *property, int index,
1175	int *lenp);
1176
1177	/**********************************************************************/
1178	/* Read-only functions (addressing related) */
1179	/**********************************************************************/
1180
1181	/**
1182	* FDT_MAX_NCELLS - maximum value for #address-cells and #size-cells
1183	*
1184	* This is the maximum value for #address-cells, #size-cells and
1185	* similar properties that will be processed by libfdt. IEE1275
1186	* requires that OF implementations handle values up to 4.
1187	* Implementations may support larger values, but in practice higher
1188	* values aren't used.
1189	*/
1190	#define FDT_MAX_NCELLS 4
1191
1192	/**
1193	* fdt_address_cells - retrieve address size for a bus represented in the tree
1194	* @fdt: pointer to the device tree blob
1195	* @nodeoffset: offset of the node to find the address size for
1196	*
1197	* When the node has a valid #address-cells property, returns its value.
1198	*
1199	* returns:
1200	* 0 <= n < FDT_MAX_NCELLS, on success
1201	* 2, if the node has no #address-cells property
1202	* -FDT_ERR_BADNCELLS, if the node has a badly formatted or invalid
1203	* #address-cells property
1204	* -FDT_ERR_BADMAGIC,
1205	* -FDT_ERR_BADVERSION,
1206	* -FDT_ERR_BADSTATE,
1207	* -FDT_ERR_BADSTRUCTURE,
1208	* -FDT_ERR_TRUNCATED, standard meanings
1209	*/
1210	int fdt_address_cells(const void *fdt, int nodeoffset);
1211
1212	/**
1213	* fdt_size_cells - retrieve address range size for a bus represented in the
1214	* tree
1215	* @fdt: pointer to the device tree blob
1216	* @nodeoffset: offset of the node to find the address range size for
1217	*
1218	* When the node has a valid #size-cells property, returns its value.
1219	*
1220	* returns:
1221	* 0 <= n < FDT_MAX_NCELLS, on success
1222	* 1, if the node has no #size-cells property
1223	* -FDT_ERR_BADNCELLS, if the node has a badly formatted or invalid
1224	* #size-cells property
1225	* -FDT_ERR_BADMAGIC,
1226	* -FDT_ERR_BADVERSION,
1227	* -FDT_ERR_BADSTATE,
1228	* -FDT_ERR_BADSTRUCTURE,
1229	* -FDT_ERR_TRUNCATED, standard meanings
1230	*/
1231	int fdt_size_cells(const void *fdt, int nodeoffset);
1232
1233
1234	/**********************************************************************/
1235	/* Write-in-place functions */
1236	/**********************************************************************/
1237
1238	/**
1239	* fdt_setprop_inplace_namelen_partial - change a property's value,
1240	* but not its size
1241	* @fdt: pointer to the device tree blob
1242	* @nodeoffset: offset of the node whose property to change
1243	* @name: name of the property to change
1244	* @namelen: number of characters of name to consider
1245	* @idx: index of the property to change in the array
1246	* @val: pointer to data to replace the property value with
1247	* @len: length of the property value
1248	*
1249	* Identical to fdt_setprop_inplace(), but modifies the given property
1250	* starting from the given index, and using only the first characters
1251	* of the name. It is useful when you want to manipulate only one value of
1252	* an array and you have a string that doesn't end with \0.
1253	*
1254	* Return: 0 on success, negative libfdt error value otherwise
1255	*/
1256	#ifndef SWIG /* Not available in Python */
1257	int fdt_setprop_inplace_namelen_partial(void *fdt, int nodeoffset,
1258	const char *name, int namelen,
1259	uint32_t idx, const void *val,
1260	int len);
1261	#endif
1262
1263	/**
1264	* fdt_setprop_inplace - change a property's value, but not its size
1265	* @fdt: pointer to the device tree blob
1266	* @nodeoffset: offset of the node whose property to change
1267	* @name: name of the property to change
1268	* @val: pointer to data to replace the property value with
1269	* @len: length of the property value
1270	*
1271	* fdt_setprop_inplace() replaces the value of a given property with
1272	* the data in val, of length len. This function cannot change the
1273	* size of a property, and so will only work if len is equal to the
1274	* current length of the property.
1275	*
1276	* This function will alter only the bytes in the blob which contain
1277	* the given property value, and will not alter or move any other part
1278	* of the tree.
1279	*
1280	* returns:
1281	* 0, on success
1282	* -FDT_ERR_NOSPACE, if len is not equal to the property's current length
1283	* -FDT_ERR_NOTFOUND, node does not have the named property
1284	* -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1285	* -FDT_ERR_BADMAGIC,
1286	* -FDT_ERR_BADVERSION,
1287	* -FDT_ERR_BADSTATE,
1288	* -FDT_ERR_BADSTRUCTURE,
1289	* -FDT_ERR_TRUNCATED, standard meanings
1290	*/
1291	#ifndef SWIG /* Not available in Python */
1292	int fdt_setprop_inplace(void *fdt, int nodeoffset, const char *name,
1293	const void *val, int len);
1294	#endif
1295
1296	/**
1297	* fdt_setprop_inplace_u32 - change the value of a 32-bit integer property
1298	* @fdt: pointer to the device tree blob
1299	* @nodeoffset: offset of the node whose property to change
1300	* @name: name of the property to change
1301	* @val: 32-bit integer value to replace the property with
1302	*
1303	* fdt_setprop_inplace_u32() replaces the value of a given property
1304	* with the 32-bit integer value in val, converting val to big-endian
1305	* if necessary. This function cannot change the size of a property,
1306	* and so will only work if the property already exists and has length
1307	* 4.
1308	*
1309	* This function will alter only the bytes in the blob which contain
1310	* the given property value, and will not alter or move any other part
1311	* of the tree.
1312	*
1313	* returns:
1314	* 0, on success
1315	* -FDT_ERR_NOSPACE, if the property's length is not equal to 4
1316	* -FDT_ERR_NOTFOUND, node does not have the named property
1317	* -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1318	* -FDT_ERR_BADMAGIC,
1319	* -FDT_ERR_BADVERSION,
1320	* -FDT_ERR_BADSTATE,
1321	* -FDT_ERR_BADSTRUCTURE,
1322	* -FDT_ERR_TRUNCATED, standard meanings
1323	*/
1324	static inline int fdt_setprop_inplace_u32(void *fdt, int nodeoffset,
1325	const char *name, uint32_t val)
1326	{
1327	fdt32_t tmp = cpu_to_fdt32(val);
1328	return fdt_setprop_inplace(fdt, nodeoffset, name, val: &tmp, len: sizeof(tmp));
1329	}
1330
1331	/**
1332	* fdt_setprop_inplace_u64 - change the value of a 64-bit integer property
1333	* @fdt: pointer to the device tree blob
1334	* @nodeoffset: offset of the node whose property to change
1335	* @name: name of the property to change
1336	* @val: 64-bit integer value to replace the property with
1337	*
1338	* fdt_setprop_inplace_u64() replaces the value of a given property
1339	* with the 64-bit integer value in val, converting val to big-endian
1340	* if necessary. This function cannot change the size of a property,
1341	* and so will only work if the property already exists and has length
1342	* 8.
1343	*
1344	* This function will alter only the bytes in the blob which contain
1345	* the given property value, and will not alter or move any other part
1346	* of the tree.
1347	*
1348	* returns:
1349	* 0, on success
1350	* -FDT_ERR_NOSPACE, if the property's length is not equal to 8
1351	* -FDT_ERR_NOTFOUND, node does not have the named property
1352	* -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1353	* -FDT_ERR_BADMAGIC,
1354	* -FDT_ERR_BADVERSION,
1355	* -FDT_ERR_BADSTATE,
1356	* -FDT_ERR_BADSTRUCTURE,
1357	* -FDT_ERR_TRUNCATED, standard meanings
1358	*/
1359	static inline int fdt_setprop_inplace_u64(void *fdt, int nodeoffset,
1360	const char *name, uint64_t val)
1361	{
1362	fdt64_t tmp = cpu_to_fdt64(val);
1363	return fdt_setprop_inplace(fdt, nodeoffset, name, val: &tmp, len: sizeof(tmp));
1364	}
1365
1366	/**
1367	* fdt_setprop_inplace_cell - change the value of a single-cell property
1368	* @fdt: pointer to the device tree blob
1369	* @nodeoffset: offset of the node containing the property
1370	* @name: name of the property to change the value of
1371	* @val: new value of the 32-bit cell
1372	*
1373	* This is an alternative name for fdt_setprop_inplace_u32()
1374	* Return: 0 on success, negative libfdt error number otherwise.
1375	*/
1376	static inline int fdt_setprop_inplace_cell(void *fdt, int nodeoffset,
1377	const char *name, uint32_t val)
1378	{
1379	return fdt_setprop_inplace_u32(fdt, nodeoffset, name, val);
1380	}
1381
1382	/**
1383	* fdt_nop_property - replace a property with nop tags
1384	* @fdt: pointer to the device tree blob
1385	* @nodeoffset: offset of the node whose property to nop
1386	* @name: name of the property to nop
1387	*
1388	* fdt_nop_property() will replace a given property's representation
1389	* in the blob with FDT_NOP tags, effectively removing it from the
1390	* tree.
1391	*
1392	* This function will alter only the bytes in the blob which contain
1393	* the property, and will not alter or move any other part of the
1394	* tree.
1395	*
1396	* returns:
1397	* 0, on success
1398	* -FDT_ERR_NOTFOUND, node does not have the named property
1399	* -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1400	* -FDT_ERR_BADMAGIC,
1401	* -FDT_ERR_BADVERSION,
1402	* -FDT_ERR_BADSTATE,
1403	* -FDT_ERR_BADSTRUCTURE,
1404	* -FDT_ERR_TRUNCATED, standard meanings
1405	*/
1406	int fdt_nop_property(void *fdt, int nodeoffset, const char *name);
1407
1408	/**
1409	* fdt_nop_node - replace a node (subtree) with nop tags
1410	* @fdt: pointer to the device tree blob
1411	* @nodeoffset: offset of the node to nop
1412	*
1413	* fdt_nop_node() will replace a given node's representation in the
1414	* blob, including all its subnodes, if any, with FDT_NOP tags,
1415	* effectively removing it from the tree.
1416	*
1417	* This function will alter only the bytes in the blob which contain
1418	* the node and its properties and subnodes, and will not alter or
1419	* move any other part of the tree.
1420	*
1421	* returns:
1422	* 0, on success
1423	* -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1424	* -FDT_ERR_BADMAGIC,
1425	* -FDT_ERR_BADVERSION,
1426	* -FDT_ERR_BADSTATE,
1427	* -FDT_ERR_BADSTRUCTURE,
1428	* -FDT_ERR_TRUNCATED, standard meanings
1429	*/
1430	int fdt_nop_node(void *fdt, int nodeoffset);
1431
1432	/**********************************************************************/
1433	/* Sequential write functions */
1434	/**********************************************************************/
1435
1436	/* fdt_create_with_flags flags */
1437	#define FDT_CREATE_FLAG_NO_NAME_DEDUP 0x1
1438	/* FDT_CREATE_FLAG_NO_NAME_DEDUP: Do not try to de-duplicate property
1439	* names in the fdt. This can result in faster creation times, but
1440	* a larger fdt. */
1441
1442	#define FDT_CREATE_FLAGS_ALL (FDT_CREATE_FLAG_NO_NAME_DEDUP)
1443
1444	/**
1445	* fdt_create_with_flags - begin creation of a new fdt
1446	* @buf: pointer to memory allocated where fdt will be created
1447	* @bufsize: size of the memory space at fdt
1448	* @flags: a valid combination of FDT_CREATE_FLAG_ flags, or 0.
1449	*
1450	* fdt_create_with_flags() begins the process of creating a new fdt with
1451	* the sequential write interface.
1452	*
1453	* fdt creation process must end with fdt_finished() to produce a valid fdt.
1454	*
1455	* returns:
1456	* 0, on success
1457	* -FDT_ERR_NOSPACE, bufsize is insufficient for a minimal fdt
1458	* -FDT_ERR_BADFLAGS, flags is not valid
1459	*/
1460	int fdt_create_with_flags(void *buf, int bufsize, uint32_t flags);
1461
1462	/**
1463	* fdt_create - begin creation of a new fdt
1464	* @buf: pointer to memory allocated where fdt will be created
1465	* @bufsize: size of the memory space at fdt
1466	*
1467	* fdt_create() is equivalent to fdt_create_with_flags() with flags=0.
1468	*
1469	* returns:
1470	* 0, on success
1471	* -FDT_ERR_NOSPACE, bufsize is insufficient for a minimal fdt
1472	*/
1473	int fdt_create(void *buf, int bufsize);
1474
1475	int fdt_resize(void *fdt, void *buf, int bufsize);
1476	int fdt_add_reservemap_entry(void *fdt, uint64_t addr, uint64_t size);
1477	int fdt_finish_reservemap(void *fdt);
1478	int fdt_begin_node(void *fdt, const char *name);
1479	int fdt_property(void *fdt, const char *name, const void *val, int len);
1480	static inline int fdt_property_u32(void *fdt, const char *name, uint32_t val)
1481	{
1482	fdt32_t tmp = cpu_to_fdt32(val);
1483	return fdt_property(fdt, name, val: &tmp, len: sizeof(tmp));
1484	}
1485	static inline int fdt_property_u64(void *fdt, const char *name, uint64_t val)
1486	{
1487	fdt64_t tmp = cpu_to_fdt64(val);
1488	return fdt_property(fdt, name, val: &tmp, len: sizeof(tmp));
1489	}
1490
1491	#ifndef SWIG /* Not available in Python */
1492	static inline int fdt_property_cell(void *fdt, const char *name, uint32_t val)
1493	{
1494	return fdt_property_u32(fdt, name, val);
1495	}
1496	#endif
1497
1498	/**
1499	* fdt_property_placeholder - add a new property and return a ptr to its value
1500	*
1501	* @fdt: pointer to the device tree blob
1502	* @name: name of property to add
1503	* @len: length of property value in bytes
1504	* @valp: returns a pointer to where where the value should be placed
1505	*
1506	* returns:
1507	* 0, on success
1508	* -FDT_ERR_BADMAGIC,
1509	* -FDT_ERR_NOSPACE, standard meanings
1510	*/
1511	int fdt_property_placeholder(void *fdt, const char *name, int len, void **valp);
1512
1513	#define fdt_property_string(fdt, name, str) \
1514	fdt_property(fdt, name, str, strlen(str)+1)
1515	int fdt_end_node(void *fdt);
1516	int fdt_finish(void *fdt);
1517
1518	/**********************************************************************/
1519	/* Read-write functions */
1520	/**********************************************************************/
1521
1522	int fdt_create_empty_tree(void *buf, int bufsize);
1523	int fdt_open_into(const void *fdt, void *buf, int bufsize);
1524	int fdt_pack(void *fdt);
1525
1526	/**
1527	* fdt_add_mem_rsv - add one memory reserve map entry
1528	* @fdt: pointer to the device tree blob
1529	* @address: 64-bit start address of the reserve map entry
1530	* @size: 64-bit size of the reserved region
1531	*
1532	* Adds a reserve map entry to the given blob reserving a region at
1533	* address address of length size.
1534	*
1535	* This function will insert data into the reserve map and will
1536	* therefore change the indexes of some entries in the table.
1537	*
1538	* returns:
1539	* 0, on success
1540	* -FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1541	* contain the new reservation entry
1542	* -FDT_ERR_BADMAGIC,
1543	* -FDT_ERR_BADVERSION,
1544	* -FDT_ERR_BADSTATE,
1545	* -FDT_ERR_BADSTRUCTURE,
1546	* -FDT_ERR_BADLAYOUT,
1547	* -FDT_ERR_TRUNCATED, standard meanings
1548	*/
1549	int fdt_add_mem_rsv(void *fdt, uint64_t address, uint64_t size);
1550
1551	/**
1552	* fdt_del_mem_rsv - remove a memory reserve map entry
1553	* @fdt: pointer to the device tree blob
1554	* @n: entry to remove
1555	*
1556	* fdt_del_mem_rsv() removes the n-th memory reserve map entry from
1557	* the blob.
1558	*
1559	* This function will delete data from the reservation table and will
1560	* therefore change the indexes of some entries in the table.
1561	*
1562	* returns:
1563	* 0, on success
1564	* -FDT_ERR_NOTFOUND, there is no entry of the given index (i.e. there
1565	* are less than n+1 reserve map entries)
1566	* -FDT_ERR_BADMAGIC,
1567	* -FDT_ERR_BADVERSION,
1568	* -FDT_ERR_BADSTATE,
1569	* -FDT_ERR_BADSTRUCTURE,
1570	* -FDT_ERR_BADLAYOUT,
1571	* -FDT_ERR_TRUNCATED, standard meanings
1572	*/
1573	int fdt_del_mem_rsv(void *fdt, int n);
1574
1575	/**
1576	* fdt_set_name - change the name of a given node
1577	* @fdt: pointer to the device tree blob
1578	* @nodeoffset: structure block offset of a node
1579	* @name: name to give the node
1580	*
1581	* fdt_set_name() replaces the name (including unit address, if any)
1582	* of the given node with the given string. NOTE: this function can't
1583	* efficiently check if the new name is unique amongst the given
1584	* node's siblings; results are undefined if this function is invoked
1585	* with a name equal to one of the given node's siblings.
1586	*
1587	* This function may insert or delete data from the blob, and will
1588	* therefore change the offsets of some existing nodes.
1589	*
1590	* returns:
1591	* 0, on success
1592	* -FDT_ERR_NOSPACE, there is insufficient free space in the blob
1593	* to contain the new name
1594	* -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1595	* -FDT_ERR_BADMAGIC,
1596	* -FDT_ERR_BADVERSION,
1597	* -FDT_ERR_BADSTATE, standard meanings
1598	*/
1599	int fdt_set_name(void *fdt, int nodeoffset, const char *name);
1600
1601	/**
1602	* fdt_setprop - create or change a property
1603	* @fdt: pointer to the device tree blob
1604	* @nodeoffset: offset of the node whose property to change
1605	* @name: name of the property to change
1606	* @val: pointer to data to set the property value to
1607	* @len: length of the property value
1608	*
1609	* fdt_setprop() sets the value of the named property in the given
1610	* node to the given value and length, creating the property if it
1611	* does not already exist.
1612	*
1613	* This function may insert or delete data from the blob, and will
1614	* therefore change the offsets of some existing nodes.
1615	*
1616	* returns:
1617	* 0, on success
1618	* -FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1619	* contain the new property value
1620	* -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1621	* -FDT_ERR_BADLAYOUT,
1622	* -FDT_ERR_BADMAGIC,
1623	* -FDT_ERR_BADVERSION,
1624	* -FDT_ERR_BADSTATE,
1625	* -FDT_ERR_BADSTRUCTURE,
1626	* -FDT_ERR_BADLAYOUT,
1627	* -FDT_ERR_TRUNCATED, standard meanings
1628	*/
1629	int fdt_setprop(void *fdt, int nodeoffset, const char *name,
1630	const void *val, int len);
1631
1632	/**
1633	* fdt_setprop_placeholder - allocate space for a property
1634	* @fdt: pointer to the device tree blob
1635	* @nodeoffset: offset of the node whose property to change
1636	* @name: name of the property to change
1637	* @len: length of the property value
1638	* @prop_data: return pointer to property data
1639	*
1640	* fdt_setprop_placeholer() allocates the named property in the given node.
1641	* If the property exists it is resized. In either case a pointer to the
1642	* property data is returned.
1643	*
1644	* This function may insert or delete data from the blob, and will
1645	* therefore change the offsets of some existing nodes.
1646	*
1647	* returns:
1648	* 0, on success
1649	* -FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1650	* contain the new property value
1651	* -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1652	* -FDT_ERR_BADLAYOUT,
1653	* -FDT_ERR_BADMAGIC,
1654	* -FDT_ERR_BADVERSION,
1655	* -FDT_ERR_BADSTATE,
1656	* -FDT_ERR_BADSTRUCTURE,
1657	* -FDT_ERR_BADLAYOUT,
1658	* -FDT_ERR_TRUNCATED, standard meanings
1659	*/
1660	int fdt_setprop_placeholder(void *fdt, int nodeoffset, const char *name,
1661	int len, void **prop_data);
1662
1663	/**
1664	* fdt_setprop_u32 - set a property to a 32-bit integer
1665	* @fdt: pointer to the device tree blob
1666	* @nodeoffset: offset of the node whose property to change
1667	* @name: name of the property to change
1668	* @val: 32-bit integer value for the property (native endian)
1669	*
1670	* fdt_setprop_u32() sets the value of the named property in the given
1671	* node to the given 32-bit integer value (converting to big-endian if
1672	* necessary), or creates a new property with that value if it does
1673	* not already exist.
1674	*
1675	* This function may insert or delete data from the blob, and will
1676	* therefore change the offsets of some existing nodes.
1677	*
1678	* returns:
1679	* 0, on success
1680	* -FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1681	* contain the new property value
1682	* -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1683	* -FDT_ERR_BADLAYOUT,
1684	* -FDT_ERR_BADMAGIC,
1685	* -FDT_ERR_BADVERSION,
1686	* -FDT_ERR_BADSTATE,
1687	* -FDT_ERR_BADSTRUCTURE,
1688	* -FDT_ERR_BADLAYOUT,
1689	* -FDT_ERR_TRUNCATED, standard meanings
1690	*/
1691	static inline int fdt_setprop_u32(void *fdt, int nodeoffset, const char *name,
1692	uint32_t val)
1693	{
1694	fdt32_t tmp = cpu_to_fdt32(val);
1695	return fdt_setprop(fdt, nodeoffset, name, val: &tmp, len: sizeof(tmp));
1696	}
1697
1698	/**
1699	* fdt_setprop_u64 - set a property to a 64-bit integer
1700	* @fdt: pointer to the device tree blob
1701	* @nodeoffset: offset of the node whose property to change
1702	* @name: name of the property to change
1703	* @val: 64-bit integer value for the property (native endian)
1704	*
1705	* fdt_setprop_u64() sets the value of the named property in the given
1706	* node to the given 64-bit integer value (converting to big-endian if
1707	* necessary), or creates a new property with that value if it does
1708	* not already exist.
1709	*
1710	* This function may insert or delete data from the blob, and will
1711	* therefore change the offsets of some existing nodes.
1712	*
1713	* returns:
1714	* 0, on success
1715	* -FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1716	* contain the new property value
1717	* -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1718	* -FDT_ERR_BADLAYOUT,
1719	* -FDT_ERR_BADMAGIC,
1720	* -FDT_ERR_BADVERSION,
1721	* -FDT_ERR_BADSTATE,
1722	* -FDT_ERR_BADSTRUCTURE,
1723	* -FDT_ERR_BADLAYOUT,
1724	* -FDT_ERR_TRUNCATED, standard meanings
1725	*/
1726	static inline int fdt_setprop_u64(void *fdt, int nodeoffset, const char *name,
1727	uint64_t val)
1728	{
1729	fdt64_t tmp = cpu_to_fdt64(val);
1730	return fdt_setprop(fdt, nodeoffset, name, val: &tmp, len: sizeof(tmp));
1731	}
1732
1733	/**
1734	* fdt_setprop_cell - set a property to a single cell value
1735	* @fdt: pointer to the device tree blob
1736	* @nodeoffset: offset of the node whose property to change
1737	* @name: name of the property to change
1738	* @val: 32-bit integer value for the property (native endian)
1739	*
1740	* This is an alternative name for fdt_setprop_u32()
1741	*
1742	* Return: 0 on success, negative libfdt error value otherwise.
1743	*/
1744	static inline int fdt_setprop_cell(void *fdt, int nodeoffset, const char *name,
1745	uint32_t val)
1746	{
1747	return fdt_setprop_u32(fdt, nodeoffset, name, val);
1748	}
1749
1750	/**
1751	* fdt_setprop_string - set a property to a string value
1752	* @fdt: pointer to the device tree blob
1753	* @nodeoffset: offset of the node whose property to change
1754	* @name: name of the property to change
1755	* @str: string value for the property
1756	*
1757	* fdt_setprop_string() sets the value of the named property in the
1758	* given node to the given string value (using the length of the
1759	* string to determine the new length of the property), or creates a
1760	* new property with that value if it does not already exist.
1761	*
1762	* This function may insert or delete data from the blob, and will
1763	* therefore change the offsets of some existing nodes.
1764	*
1765	* returns:
1766	* 0, on success
1767	* -FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1768	* contain the new property value
1769	* -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1770	* -FDT_ERR_BADLAYOUT,
1771	* -FDT_ERR_BADMAGIC,
1772	* -FDT_ERR_BADVERSION,
1773	* -FDT_ERR_BADSTATE,
1774	* -FDT_ERR_BADSTRUCTURE,
1775	* -FDT_ERR_BADLAYOUT,
1776	* -FDT_ERR_TRUNCATED, standard meanings
1777	*/
1778	#define fdt_setprop_string(fdt, nodeoffset, name, str) \
1779	fdt_setprop((fdt), (nodeoffset), (name), (str), strlen(str)+1)
1780
1781
1782	/**
1783	* fdt_setprop_empty - set a property to an empty value
1784	* @fdt: pointer to the device tree blob
1785	* @nodeoffset: offset of the node whose property to change
1786	* @name: name of the property to change
1787	*
1788	* fdt_setprop_empty() sets the value of the named property in the
1789	* given node to an empty (zero length) value, or creates a new empty
1790	* property if it does not already exist.
1791	*
1792	* This function may insert or delete data from the blob, and will
1793	* therefore change the offsets of some existing nodes.
1794	*
1795	* returns:
1796	* 0, on success
1797	* -FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1798	* contain the new property value
1799	* -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1800	* -FDT_ERR_BADLAYOUT,
1801	* -FDT_ERR_BADMAGIC,
1802	* -FDT_ERR_BADVERSION,
1803	* -FDT_ERR_BADSTATE,
1804	* -FDT_ERR_BADSTRUCTURE,
1805	* -FDT_ERR_BADLAYOUT,
1806	* -FDT_ERR_TRUNCATED, standard meanings
1807	*/
1808	#define fdt_setprop_empty(fdt, nodeoffset, name) \
1809	fdt_setprop((fdt), (nodeoffset), (name), NULL, 0)
1810
1811	/**
1812	* fdt_appendprop - append to or create a property
1813	* @fdt: pointer to the device tree blob
1814	* @nodeoffset: offset of the node whose property to change
1815	* @name: name of the property to append to
1816	* @val: pointer to data to append to the property value
1817	* @len: length of the data to append to the property value
1818	*
1819	* fdt_appendprop() appends the value to the named property in the
1820	* given node, creating the property if it does not already exist.
1821	*
1822	* This function may insert data into the blob, and will therefore
1823	* change the offsets of some existing nodes.
1824	*
1825	* returns:
1826	* 0, on success
1827	* -FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1828	* contain the new property value
1829	* -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1830	* -FDT_ERR_BADLAYOUT,
1831	* -FDT_ERR_BADMAGIC,
1832	* -FDT_ERR_BADVERSION,
1833	* -FDT_ERR_BADSTATE,
1834	* -FDT_ERR_BADSTRUCTURE,
1835	* -FDT_ERR_BADLAYOUT,
1836	* -FDT_ERR_TRUNCATED, standard meanings
1837	*/
1838	int fdt_appendprop(void *fdt, int nodeoffset, const char *name,
1839	const void *val, int len);
1840
1841	/**
1842	* fdt_appendprop_u32 - append a 32-bit integer value to a property
1843	* @fdt: pointer to the device tree blob
1844	* @nodeoffset: offset of the node whose property to change
1845	* @name: name of the property to change
1846	* @val: 32-bit integer value to append to the property (native endian)
1847	*
1848	* fdt_appendprop_u32() appends the given 32-bit integer value
1849	* (converting to big-endian if necessary) to the value of the named
1850	* property in the given node, or creates a new property with that
1851	* value if it does not already exist.
1852	*
1853	* This function may insert data into the blob, and will therefore
1854	* change the offsets of some existing nodes.
1855	*
1856	* returns:
1857	* 0, on success
1858	* -FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1859	* contain the new property value
1860	* -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1861	* -FDT_ERR_BADLAYOUT,
1862	* -FDT_ERR_BADMAGIC,
1863	* -FDT_ERR_BADVERSION,
1864	* -FDT_ERR_BADSTATE,
1865	* -FDT_ERR_BADSTRUCTURE,
1866	* -FDT_ERR_BADLAYOUT,
1867	* -FDT_ERR_TRUNCATED, standard meanings
1868	*/
1869	static inline int fdt_appendprop_u32(void *fdt, int nodeoffset,
1870	const char *name, uint32_t val)
1871	{
1872	fdt32_t tmp = cpu_to_fdt32(val);
1873	return fdt_appendprop(fdt, nodeoffset, name, val: &tmp, len: sizeof(tmp));
1874	}
1875
1876	/**
1877	* fdt_appendprop_u64 - append a 64-bit integer value to a property
1878	* @fdt: pointer to the device tree blob
1879	* @nodeoffset: offset of the node whose property to change
1880	* @name: name of the property to change
1881	* @val: 64-bit integer value to append to the property (native endian)
1882	*
1883	* fdt_appendprop_u64() appends the given 64-bit integer value
1884	* (converting to big-endian if necessary) to the value of the named
1885	* property in the given node, or creates a new property with that
1886	* value if it does not already exist.
1887	*
1888	* This function may insert data into the blob, and will therefore
1889	* change the offsets of some existing nodes.
1890	*
1891	* returns:
1892	* 0, on success
1893	* -FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1894	* contain the new property value
1895	* -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1896	* -FDT_ERR_BADLAYOUT,
1897	* -FDT_ERR_BADMAGIC,
1898	* -FDT_ERR_BADVERSION,
1899	* -FDT_ERR_BADSTATE,
1900	* -FDT_ERR_BADSTRUCTURE,
1901	* -FDT_ERR_BADLAYOUT,
1902	* -FDT_ERR_TRUNCATED, standard meanings
1903	*/
1904	static inline int fdt_appendprop_u64(void *fdt, int nodeoffset,
1905	const char *name, uint64_t val)
1906	{
1907	fdt64_t tmp = cpu_to_fdt64(val);
1908	return fdt_appendprop(fdt, nodeoffset, name, val: &tmp, len: sizeof(tmp));
1909	}
1910
1911	/**
1912	* fdt_appendprop_cell - append a single cell value to a property
1913	* @fdt: pointer to the device tree blob
1914	* @nodeoffset: offset of the node whose property to change
1915	* @name: name of the property to change
1916	* @val: 32-bit integer value to append to the property (native endian)
1917	*
1918	* This is an alternative name for fdt_appendprop_u32()
1919	*
1920	* Return: 0 on success, negative libfdt error value otherwise.
1921	*/
1922	static inline int fdt_appendprop_cell(void *fdt, int nodeoffset,
1923	const char *name, uint32_t val)
1924	{
1925	return fdt_appendprop_u32(fdt, nodeoffset, name, val);
1926	}
1927
1928	/**
1929	* fdt_appendprop_string - append a string to a property
1930	* @fdt: pointer to the device tree blob
1931	* @nodeoffset: offset of the node whose property to change
1932	* @name: name of the property to change
1933	* @str: string value to append to the property
1934	*
1935	* fdt_appendprop_string() appends the given string to the value of
1936	* the named property in the given node, or creates a new property
1937	* with that value if it does not already exist.
1938	*
1939	* This function may insert data into the blob, and will therefore
1940	* change the offsets of some existing nodes.
1941	*
1942	* returns:
1943	* 0, on success
1944	* -FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1945	* contain the new property value
1946	* -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1947	* -FDT_ERR_BADLAYOUT,
1948	* -FDT_ERR_BADMAGIC,
1949	* -FDT_ERR_BADVERSION,
1950	* -FDT_ERR_BADSTATE,
1951	* -FDT_ERR_BADSTRUCTURE,
1952	* -FDT_ERR_BADLAYOUT,
1953	* -FDT_ERR_TRUNCATED, standard meanings
1954	*/
1955	#define fdt_appendprop_string(fdt, nodeoffset, name, str) \
1956	fdt_appendprop((fdt), (nodeoffset), (name), (str), strlen(str)+1)
1957
1958	/**
1959	* fdt_appendprop_addrrange - append a address range property
1960	* @fdt: pointer to the device tree blob
1961	* @parent: offset of the parent node
1962	* @nodeoffset: offset of the node to add a property at
1963	* @name: name of property
1964	* @addr: start address of a given range
1965	* @size: size of a given range
1966	*
1967	* fdt_appendprop_addrrange() appends an address range value (start
1968	* address and size) to the value of the named property in the given
1969	* node, or creates a new property with that value if it does not
1970	* already exist.
1971	* If "name" is not specified, a default "reg" is used.
1972	* Cell sizes are determined by parent's #address-cells and #size-cells.
1973	*
1974	* This function may insert data into the blob, and will therefore
1975	* change the offsets of some existing nodes.
1976	*
1977	* returns:
1978	* 0, on success
1979	* -FDT_ERR_BADLAYOUT,
1980	* -FDT_ERR_BADMAGIC,
1981	* -FDT_ERR_BADNCELLS, if the node has a badly formatted or invalid
1982	* #address-cells property
1983	* -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1984	* -FDT_ERR_BADSTATE,
1985	* -FDT_ERR_BADSTRUCTURE,
1986	* -FDT_ERR_BADVERSION,
1987	* -FDT_ERR_BADVALUE, addr or size doesn't fit to respective cells size
1988	* -FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1989	* contain a new property
1990	* -FDT_ERR_TRUNCATED, standard meanings
1991	*/
1992	int fdt_appendprop_addrrange(void *fdt, int parent, int nodeoffset,
1993	const char *name, uint64_t addr, uint64_t size);
1994
1995	/**
1996	* fdt_delprop - delete a property
1997	* @fdt: pointer to the device tree blob
1998	* @nodeoffset: offset of the node whose property to nop
1999	* @name: name of the property to nop
2000	*
2001	* fdt_del_property() will delete the given property.
2002	*
2003	* This function will delete data from the blob, and will therefore
2004	* change the offsets of some existing nodes.
2005	*
2006	* returns:
2007	* 0, on success
2008	* -FDT_ERR_NOTFOUND, node does not have the named property
2009	* -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
2010	* -FDT_ERR_BADLAYOUT,
2011	* -FDT_ERR_BADMAGIC,
2012	* -FDT_ERR_BADVERSION,
2013	* -FDT_ERR_BADSTATE,
2014	* -FDT_ERR_BADSTRUCTURE,
2015	* -FDT_ERR_TRUNCATED, standard meanings
2016	*/
2017	int fdt_delprop(void *fdt, int nodeoffset, const char *name);
2018
2019	/**
2020	* fdt_add_subnode_namelen - creates a new node based on substring
2021	* @fdt: pointer to the device tree blob
2022	* @parentoffset: structure block offset of a node
2023	* @name: name of the subnode to create
2024	* @namelen: number of characters of name to consider
2025	*
2026	* Identical to fdt_add_subnode(), but use only the first @namelen
2027	* characters of @name as the name of the new node. This is useful for
2028	* creating subnodes based on a portion of a larger string, such as a
2029	* full path.
2030	*
2031	* Return: structure block offset of the created subnode (>=0),
2032	* negative libfdt error value otherwise
2033	*/
2034	#ifndef SWIG /* Not available in Python */
2035	int fdt_add_subnode_namelen(void *fdt, int parentoffset,
2036	const char *name, int namelen);
2037	#endif
2038
2039	/**
2040	* fdt_add_subnode - creates a new node
2041	* @fdt: pointer to the device tree blob
2042	* @parentoffset: structure block offset of a node
2043	* @name: name of the subnode to locate
2044	*
2045	* fdt_add_subnode() creates a new node as a subnode of the node at
2046	* structure block offset parentoffset, with the given name (which
2047	* should include the unit address, if any).
2048	*
2049	* This function will insert data into the blob, and will therefore
2050	* change the offsets of some existing nodes.
2051	*
2052	* returns:
2053	* structure block offset of the created nodeequested subnode (>=0), on
2054	* success
2055	* -FDT_ERR_NOTFOUND, if the requested subnode does not exist
2056	* -FDT_ERR_BADOFFSET, if parentoffset did not point to an FDT_BEGIN_NODE
2057	* tag
2058	* -FDT_ERR_EXISTS, if the node at parentoffset already has a subnode of
2059	* the given name
2060	* -FDT_ERR_NOSPACE, if there is insufficient free space in the
2061	* blob to contain the new node
2062	* -FDT_ERR_NOSPACE
2063	* -FDT_ERR_BADLAYOUT
2064	* -FDT_ERR_BADMAGIC,
2065	* -FDT_ERR_BADVERSION,
2066	* -FDT_ERR_BADSTATE,
2067	* -FDT_ERR_BADSTRUCTURE,
2068	* -FDT_ERR_TRUNCATED, standard meanings.
2069	*/
2070	int fdt_add_subnode(void *fdt, int parentoffset, const char *name);
2071
2072	/**
2073	* fdt_del_node - delete a node (subtree)
2074	* @fdt: pointer to the device tree blob
2075	* @nodeoffset: offset of the node to nop
2076	*
2077	* fdt_del_node() will remove the given node, including all its
2078	* subnodes if any, from the blob.
2079	*
2080	* This function will delete data from the blob, and will therefore
2081	* change the offsets of some existing nodes.
2082	*
2083	* returns:
2084	* 0, on success
2085	* -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
2086	* -FDT_ERR_BADLAYOUT,
2087	* -FDT_ERR_BADMAGIC,
2088	* -FDT_ERR_BADVERSION,
2089	* -FDT_ERR_BADSTATE,
2090	* -FDT_ERR_BADSTRUCTURE,
2091	* -FDT_ERR_TRUNCATED, standard meanings
2092	*/
2093	int fdt_del_node(void *fdt, int nodeoffset);
2094
2095	/**
2096	* fdt_overlay_apply - Applies a DT overlay on a base DT
2097	* @fdt: pointer to the base device tree blob
2098	* @fdto: pointer to the device tree overlay blob
2099	*
2100	* fdt_overlay_apply() will apply the given device tree overlay on the
2101	* given base device tree.
2102	*
2103	* Expect the base device tree to be modified, even if the function
2104	* returns an error.
2105	*
2106	* returns:
2107	* 0, on success
2108	* -FDT_ERR_NOSPACE, there's not enough space in the base device tree
2109	* -FDT_ERR_NOTFOUND, the overlay points to some inexistant nodes or
2110	* properties in the base DT
2111	* -FDT_ERR_BADPHANDLE,
2112	* -FDT_ERR_BADOVERLAY,
2113	* -FDT_ERR_NOPHANDLES,
2114	* -FDT_ERR_INTERNAL,
2115	* -FDT_ERR_BADLAYOUT,
2116	* -FDT_ERR_BADMAGIC,
2117	* -FDT_ERR_BADOFFSET,
2118	* -FDT_ERR_BADPATH,
2119	* -FDT_ERR_BADVERSION,
2120	* -FDT_ERR_BADSTRUCTURE,
2121	* -FDT_ERR_BADSTATE,
2122	* -FDT_ERR_TRUNCATED, standard meanings
2123	*/
2124	int fdt_overlay_apply(void *fdt, void *fdto);
2125
2126	/**
2127	* fdt_overlay_target_offset - retrieves the offset of a fragment's target
2128	* @fdt: Base device tree blob
2129	* @fdto: Device tree overlay blob
2130	* @fragment_offset: node offset of the fragment in the overlay
2131	* @pathp: pointer which receives the path of the target (or NULL)
2132	*
2133	* fdt_overlay_target_offset() retrieves the target offset in the base
2134	* device tree of a fragment, no matter how the actual targeting is
2135	* done (through a phandle or a path)
2136	*
2137	* returns:
2138	* the targeted node offset in the base device tree
2139	* Negative error code on error
2140	*/
2141	int fdt_overlay_target_offset(const void *fdt, const void *fdto,
2142	int fragment_offset, char const **pathp);
2143
2144	/**********************************************************************/
2145	/* Debugging / informational functions */
2146	/**********************************************************************/
2147
2148	const char *fdt_strerror(int errval);
2149
2150	#ifdef __cplusplus
2151	}
2152	#endif
2153
2154	#endif /* LIBFDT_H */
2155