libfdt.h revision 302408
1#ifndef _LIBFDT_H
2#define _LIBFDT_H
3/*
4 * libfdt - Flat Device Tree manipulation
5 * Copyright (C) 2006 David Gibson, IBM Corporation.
6 *
7 * libfdt is dual licensed: you can use it either under the terms of
8 * the GPL, or the BSD license, at your option.
9 *
10 *  a) This library is free software; you can redistribute it and/or
11 *     modify it under the terms of the GNU General Public License as
12 *     published by the Free Software Foundation; either version 2 of the
13 *     License, or (at your option) any later version.
14 *
15 *     This library is distributed in the hope that it will be useful,
16 *     but WITHOUT ANY WARRANTY; without even the implied warranty of
17 *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18 *     GNU General Public License for more details.
19 *
20 *     You should have received a copy of the GNU General Public
21 *     License along with this library; if not, write to the Free
22 *     Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston,
23 *     MA 02110-1301 USA
24 *
25 * Alternatively,
26 *
27 *  b) Redistribution and use in source and binary forms, with or
28 *     without modification, are permitted provided that the following
29 *     conditions are met:
30 *
31 *     1. Redistributions of source code must retain the above
32 *        copyright notice, this list of conditions and the following
33 *        disclaimer.
34 *     2. Redistributions in binary form must reproduce the above
35 *        copyright notice, this list of conditions and the following
36 *        disclaimer in the documentation and/or other materials
37 *        provided with the distribution.
38 *
39 *     THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
40 *     CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
41 *     INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
42 *     MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
43 *     DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
44 *     CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
45 *     SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
46 *     NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
47 *     LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48 *     HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
49 *     CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
50 *     OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
51 *     EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
52 */
53
54#include <libfdt_env.h>
55#include <fdt.h>
56
57#define FDT_FIRST_SUPPORTED_VERSION	0x10
58#define FDT_LAST_SUPPORTED_VERSION	0x11
59
60/* Error codes: informative error codes */
61#define FDT_ERR_NOTFOUND	1
62	/* FDT_ERR_NOTFOUND: The requested node or property does not exist */
63#define FDT_ERR_EXISTS		2
64	/* FDT_ERR_EXISTS: Attemped to create a node or property which
65	 * already exists */
66#define FDT_ERR_NOSPACE		3
67	/* FDT_ERR_NOSPACE: Operation needed to expand the device
68	 * tree, but its buffer did not have sufficient space to
69	 * contain the expanded tree. Use fdt_open_into() to move the
70	 * device tree to a buffer with more space. */
71
72/* Error codes: codes for bad parameters */
73#define FDT_ERR_BADOFFSET	4
74	/* FDT_ERR_BADOFFSET: Function was passed a structure block
75	 * offset which is out-of-bounds, or which points to an
76	 * unsuitable part of the structure for the operation. */
77#define FDT_ERR_BADPATH		5
78	/* FDT_ERR_BADPATH: Function was passed a badly formatted path
79	 * (e.g. missing a leading / for a function which requires an
80	 * absolute path) */
81#define FDT_ERR_BADPHANDLE	6
82	/* FDT_ERR_BADPHANDLE: Function was passed an invalid phandle
83	 * value.  phandle values of 0 and -1 are not permitted. */
84#define FDT_ERR_BADSTATE	7
85	/* FDT_ERR_BADSTATE: Function was passed an incomplete device
86	 * tree created by the sequential-write functions, which is
87	 * not sufficiently complete for the requested operation. */
88
89/* Error codes: codes for bad device tree blobs */
90#define FDT_ERR_TRUNCATED	8
91	/* FDT_ERR_TRUNCATED: Structure block of the given device tree
92	 * ends without an FDT_END tag. */
93#define FDT_ERR_BADMAGIC	9
94	/* FDT_ERR_BADMAGIC: Given "device tree" appears not to be a
95	 * device tree at all - it is missing the flattened device
96	 * tree magic number. */
97#define FDT_ERR_BADVERSION	10
98	/* FDT_ERR_BADVERSION: Given device tree has a version which
99	 * can't be handled by the requested operation.  For
100	 * read-write functions, this may mean that fdt_open_into() is
101	 * required to convert the tree to the expected version. */
102#define FDT_ERR_BADSTRUCTURE	11
103	/* FDT_ERR_BADSTRUCTURE: Given device tree has a corrupt
104	 * structure block or other serious error (e.g. misnested
105	 * nodes, or subnodes preceding properties). */
106#define FDT_ERR_BADLAYOUT	12
107	/* FDT_ERR_BADLAYOUT: For read-write functions, the given
108	 * device tree has it's sub-blocks in an order that the
109	 * function can't handle (memory reserve map, then structure,
110	 * then strings).  Use fdt_open_into() to reorganize the tree
111	 * into a form suitable for the read-write operations. */
112
113/* "Can't happen" error indicating a bug in libfdt */
114#define FDT_ERR_INTERNAL	13
115	/* FDT_ERR_INTERNAL: libfdt has failed an internal assertion.
116	 * Should never be returned, if it is, it indicates a bug in
117	 * libfdt itself. */
118
119#define FDT_ERR_MAX		13
120
121/**********************************************************************/
122/* Low-level functions (you probably don't need these)                */
123/**********************************************************************/
124
125const void *fdt_offset_ptr(const void *fdt, int offset, unsigned int checklen);
126static inline void *fdt_offset_ptr_w(void *fdt, int offset, int checklen)
127{
128	return (void *)(uintptr_t)fdt_offset_ptr(fdt, offset, checklen);
129}
130
131uint32_t fdt_next_tag(const void *fdt, int offset, int *nextoffset);
132
133/**********************************************************************/
134/* Traversal functions                                                */
135/**********************************************************************/
136
137int fdt_next_node(const void *fdt, int offset, int *depth);
138
139/**
140 * fdt_first_subnode() - get offset of first direct subnode
141 *
142 * @fdt:	FDT blob
143 * @offset:	Offset of node to check
144 * @return offset of first subnode, or -FDT_ERR_NOTFOUND if there is none
145 */
146int fdt_first_subnode(const void *fdt, int offset);
147
148/**
149 * fdt_next_subnode() - get offset of next direct subnode
150 *
151 * After first calling fdt_first_subnode(), call this function repeatedly to
152 * get direct subnodes of a parent node.
153 *
154 * @fdt:	FDT blob
155 * @offset:	Offset of previous subnode
156 * @return offset of next subnode, or -FDT_ERR_NOTFOUND if there are no more
157 * subnodes
158 */
159int fdt_next_subnode(const void *fdt, int offset);
160
161/**********************************************************************/
162/* General functions                                                  */
163/**********************************************************************/
164
165#define fdt_get_header(fdt, field) \
166	(fdt32_to_cpu(((const struct fdt_header *)(fdt))->field))
167#define fdt_magic(fdt) 			(fdt_get_header(fdt, magic))
168#define fdt_totalsize(fdt)		(fdt_get_header(fdt, totalsize))
169#define fdt_off_dt_struct(fdt)		(fdt_get_header(fdt, off_dt_struct))
170#define fdt_off_dt_strings(fdt)		(fdt_get_header(fdt, off_dt_strings))
171#define fdt_off_mem_rsvmap(fdt)		(fdt_get_header(fdt, off_mem_rsvmap))
172#define fdt_version(fdt)		(fdt_get_header(fdt, version))
173#define fdt_last_comp_version(fdt) 	(fdt_get_header(fdt, last_comp_version))
174#define fdt_boot_cpuid_phys(fdt) 	(fdt_get_header(fdt, boot_cpuid_phys))
175#define fdt_size_dt_strings(fdt) 	(fdt_get_header(fdt, size_dt_strings))
176#define fdt_size_dt_struct(fdt)		(fdt_get_header(fdt, size_dt_struct))
177
178#define __fdt_set_hdr(name) \
179	static inline void fdt_set_##name(void *fdt, uint32_t val) \
180	{ \
181		struct fdt_header *fdth = (struct fdt_header*)fdt; \
182		fdth->name = cpu_to_fdt32(val); \
183	}
184__fdt_set_hdr(magic);
185__fdt_set_hdr(totalsize);
186__fdt_set_hdr(off_dt_struct);
187__fdt_set_hdr(off_dt_strings);
188__fdt_set_hdr(off_mem_rsvmap);
189__fdt_set_hdr(version);
190__fdt_set_hdr(last_comp_version);
191__fdt_set_hdr(boot_cpuid_phys);
192__fdt_set_hdr(size_dt_strings);
193__fdt_set_hdr(size_dt_struct);
194#undef __fdt_set_hdr
195
196/**
197 * fdt_check_header - sanity check a device tree or possible device tree
198 * @fdt: pointer to data which might be a flattened device tree
199 *
200 * fdt_check_header() checks that the given buffer contains what
201 * appears to be a flattened device tree with sane information in its
202 * header.
203 *
204 * returns:
205 *     0, if the buffer appears to contain a valid device tree
206 *     -FDT_ERR_BADMAGIC,
207 *     -FDT_ERR_BADVERSION,
208 *     -FDT_ERR_BADSTATE, standard meanings, as above
209 */
210int fdt_check_header(const void *fdt);
211
212/**
213 * fdt_move - move a device tree around in memory
214 * @fdt: pointer to the device tree to move
215 * @buf: pointer to memory where the device is to be moved
216 * @bufsize: size of the memory space at buf
217 *
218 * fdt_move() relocates, if possible, the device tree blob located at
219 * fdt to the buffer at buf of size bufsize.  The buffer may overlap
220 * with the existing device tree blob at fdt.  Therefore,
221 *     fdt_move(fdt, fdt, fdt_totalsize(fdt))
222 * should always succeed.
223 *
224 * returns:
225 *     0, on success
226 *     -FDT_ERR_NOSPACE, bufsize is insufficient to contain the device tree
227 *     -FDT_ERR_BADMAGIC,
228 *     -FDT_ERR_BADVERSION,
229 *     -FDT_ERR_BADSTATE, standard meanings
230 */
231int fdt_move(const void *fdt, void *buf, int bufsize);
232
233/**********************************************************************/
234/* Read-only functions                                                */
235/**********************************************************************/
236
237/**
238 * fdt_string - retrieve a string from the strings block of a device tree
239 * @fdt: pointer to the device tree blob
240 * @stroffset: offset of the string within the strings block (native endian)
241 *
242 * fdt_string() retrieves a pointer to a single string from the
243 * strings block of the device tree blob at fdt.
244 *
245 * returns:
246 *     a pointer to the string, on success
247 *     NULL, if stroffset is out of bounds
248 */
249const char *fdt_string(const void *fdt, int stroffset);
250
251/**
252 * fdt_num_mem_rsv - retrieve the number of memory reserve map entries
253 * @fdt: pointer to the device tree blob
254 *
255 * Returns the number of entries in the device tree blob's memory
256 * reservation map.  This does not include the terminating 0,0 entry
257 * or any other (0,0) entries reserved for expansion.
258 *
259 * returns:
260 *     the number of entries
261 */
262int fdt_num_mem_rsv(const void *fdt);
263
264/**
265 * fdt_get_mem_rsv - retrieve one memory reserve map entry
266 * @fdt: pointer to the device tree blob
267 * @address, @size: pointers to 64-bit variables
268 *
269 * On success, *address and *size will contain the address and size of
270 * the n-th reserve map entry from the device tree blob, in
271 * native-endian format.
272 *
273 * returns:
274 *     0, on success
275 *     -FDT_ERR_BADMAGIC,
276 *     -FDT_ERR_BADVERSION,
277 *     -FDT_ERR_BADSTATE, standard meanings
278 */
279int fdt_get_mem_rsv(const void *fdt, int n, uint64_t *address, uint64_t *size);
280
281/**
282 * fdt_subnode_offset_namelen - find a subnode based on substring
283 * @fdt: pointer to the device tree blob
284 * @parentoffset: structure block offset of a node
285 * @name: name of the subnode to locate
286 * @namelen: number of characters of name to consider
287 *
288 * Identical to fdt_subnode_offset(), but only examine the first
289 * namelen characters of name for matching the subnode name.  This is
290 * useful for finding subnodes based on a portion of a larger string,
291 * such as a full path.
292 */
293int fdt_subnode_offset_namelen(const void *fdt, int parentoffset,
294			       const char *name, int namelen);
295/**
296 * fdt_subnode_offset - find a subnode of a given node
297 * @fdt: pointer to the device tree blob
298 * @parentoffset: structure block offset of a node
299 * @name: name of the subnode to locate
300 *
301 * fdt_subnode_offset() finds a subnode of the node at structure block
302 * offset parentoffset with the given name.  name may include a unit
303 * address, in which case fdt_subnode_offset() will find the subnode
304 * with that unit address, or the unit address may be omitted, in
305 * which case fdt_subnode_offset() will find an arbitrary subnode
306 * whose name excluding unit address matches the given name.
307 *
308 * returns:
309 *	structure block offset of the requested subnode (>=0), on success
310 *	-FDT_ERR_NOTFOUND, if the requested subnode does not exist
311 *	-FDT_ERR_BADOFFSET, if parentoffset did not point to an FDT_BEGIN_NODE tag
312 *      -FDT_ERR_BADMAGIC,
313 *	-FDT_ERR_BADVERSION,
314 *	-FDT_ERR_BADSTATE,
315 *	-FDT_ERR_BADSTRUCTURE,
316 *	-FDT_ERR_TRUNCATED, standard meanings.
317 */
318int fdt_subnode_offset(const void *fdt, int parentoffset, const char *name);
319
320/**
321 * fdt_path_offset - find a tree node by its full path
322 * @fdt: pointer to the device tree blob
323 * @path: full path of the node to locate
324 *
325 * fdt_path_offset() finds a node of a given path in the device tree.
326 * Each path component may omit the unit address portion, but the
327 * results of this are undefined if any such path component is
328 * ambiguous (that is if there are multiple nodes at the relevant
329 * level matching the given component, differentiated only by unit
330 * address).
331 *
332 * returns:
333 *	structure block offset of the node with the requested path (>=0), on success
334 *	-FDT_ERR_BADPATH, given path does not begin with '/' or is invalid
335 *	-FDT_ERR_NOTFOUND, if the requested node does not exist
336 *      -FDT_ERR_BADMAGIC,
337 *	-FDT_ERR_BADVERSION,
338 *	-FDT_ERR_BADSTATE,
339 *	-FDT_ERR_BADSTRUCTURE,
340 *	-FDT_ERR_TRUNCATED, standard meanings.
341 */
342int fdt_path_offset(const void *fdt, const char *path);
343
344/**
345 * fdt_get_name - retrieve the name of a given node
346 * @fdt: pointer to the device tree blob
347 * @nodeoffset: structure block offset of the starting node
348 * @lenp: pointer to an integer variable (will be overwritten) or NULL
349 *
350 * fdt_get_name() retrieves the name (including unit address) of the
351 * device tree node at structure block offset nodeoffset.  If lenp is
352 * non-NULL, the length of this name is also returned, in the integer
353 * pointed to by lenp.
354 *
355 * returns:
356 *	pointer to the node's name, on success
357 *		If lenp is non-NULL, *lenp contains the length of that name (>=0)
358 *	NULL, on error
359 *		if lenp is non-NULL *lenp contains an error code (<0):
360 *		-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
361 *		-FDT_ERR_BADMAGIC,
362 *		-FDT_ERR_BADVERSION,
363 *		-FDT_ERR_BADSTATE, standard meanings
364 */
365const char *fdt_get_name(const void *fdt, int nodeoffset, int *lenp);
366
367/**
368 * fdt_first_property_offset - find the offset of a node's first property
369 * @fdt: pointer to the device tree blob
370 * @nodeoffset: structure block offset of a node
371 *
372 * fdt_first_property_offset() finds the first property of the node at
373 * the given structure block offset.
374 *
375 * returns:
376 *	structure block offset of the property (>=0), on success
377 *	-FDT_ERR_NOTFOUND, if the requested node has no properties
378 *	-FDT_ERR_BADOFFSET, if nodeoffset did not point to an FDT_BEGIN_NODE tag
379 *      -FDT_ERR_BADMAGIC,
380 *	-FDT_ERR_BADVERSION,
381 *	-FDT_ERR_BADSTATE,
382 *	-FDT_ERR_BADSTRUCTURE,
383 *	-FDT_ERR_TRUNCATED, standard meanings.
384 */
385int fdt_first_property_offset(const void *fdt, int nodeoffset);
386
387/**
388 * fdt_next_property_offset - step through a node's properties
389 * @fdt: pointer to the device tree blob
390 * @offset: structure block offset of a property
391 *
392 * fdt_next_property_offset() finds the property immediately after the
393 * one at the given structure block offset.  This will be a property
394 * of the same node as the given property.
395 *
396 * returns:
397 *	structure block offset of the next property (>=0), on success
398 *	-FDT_ERR_NOTFOUND, if the given property is the last in its node
399 *	-FDT_ERR_BADOFFSET, if nodeoffset did not point to an FDT_PROP tag
400 *      -FDT_ERR_BADMAGIC,
401 *	-FDT_ERR_BADVERSION,
402 *	-FDT_ERR_BADSTATE,
403 *	-FDT_ERR_BADSTRUCTURE,
404 *	-FDT_ERR_TRUNCATED, standard meanings.
405 */
406int fdt_next_property_offset(const void *fdt, int offset);
407
408/**
409 * fdt_get_property_by_offset - retrieve the property at a given offset
410 * @fdt: pointer to the device tree blob
411 * @offset: offset of the property to retrieve
412 * @lenp: pointer to an integer variable (will be overwritten) or NULL
413 *
414 * fdt_get_property_by_offset() retrieves a pointer to the
415 * fdt_property structure within the device tree blob at the given
416 * offset.  If lenp is non-NULL, the length of the property value is
417 * also returned, in the integer pointed to by lenp.
418 *
419 * returns:
420 *	pointer to the structure representing the property
421 *		if lenp is non-NULL, *lenp contains the length of the property
422 *		value (>=0)
423 *	NULL, on error
424 *		if lenp is non-NULL, *lenp contains an error code (<0):
425 *		-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_PROP tag
426 *		-FDT_ERR_BADMAGIC,
427 *		-FDT_ERR_BADVERSION,
428 *		-FDT_ERR_BADSTATE,
429 *		-FDT_ERR_BADSTRUCTURE,
430 *		-FDT_ERR_TRUNCATED, standard meanings
431 */
432const struct fdt_property *fdt_get_property_by_offset(const void *fdt,
433						      int offset,
434						      int *lenp);
435
436/**
437 * fdt_get_property_namelen - find a property based on substring
438 * @fdt: pointer to the device tree blob
439 * @nodeoffset: offset of the node whose property to find
440 * @name: name of the property to find
441 * @namelen: number of characters of name to consider
442 * @lenp: pointer to an integer variable (will be overwritten) or NULL
443 *
444 * Identical to fdt_get_property_namelen(), but only examine the first
445 * namelen characters of name for matching the property name.
446 */
447const struct fdt_property *fdt_get_property_namelen(const void *fdt,
448						    int nodeoffset,
449						    const char *name,
450						    int namelen, int *lenp);
451
452/**
453 * fdt_get_property - find a given property in a given node
454 * @fdt: pointer to the device tree blob
455 * @nodeoffset: offset of the node whose property to find
456 * @name: name of the property to find
457 * @lenp: pointer to an integer variable (will be overwritten) or NULL
458 *
459 * fdt_get_property() retrieves a pointer to the fdt_property
460 * structure within the device tree blob corresponding to the property
461 * named 'name' of the node at offset nodeoffset.  If lenp is
462 * non-NULL, the length of the property value is also returned, in the
463 * integer pointed to by lenp.
464 *
465 * returns:
466 *	pointer to the structure representing the property
467 *		if lenp is non-NULL, *lenp contains the length of the property
468 *		value (>=0)
469 *	NULL, on error
470 *		if lenp is non-NULL, *lenp contains an error code (<0):
471 *		-FDT_ERR_NOTFOUND, node does not have named property
472 *		-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
473 *		-FDT_ERR_BADMAGIC,
474 *		-FDT_ERR_BADVERSION,
475 *		-FDT_ERR_BADSTATE,
476 *		-FDT_ERR_BADSTRUCTURE,
477 *		-FDT_ERR_TRUNCATED, standard meanings
478 */
479const struct fdt_property *fdt_get_property(const void *fdt, int nodeoffset,
480					    const char *name, int *lenp);
481static inline struct fdt_property *fdt_get_property_w(void *fdt, int nodeoffset,
482						      const char *name,
483						      int *lenp)
484{
485	return (struct fdt_property *)(uintptr_t)
486		fdt_get_property(fdt, nodeoffset, name, lenp);
487}
488
489/**
490 * fdt_getprop_by_offset - retrieve the value of a property at a given offset
491 * @fdt: pointer to the device tree blob
492 * @ffset: offset of the property to read
493 * @namep: pointer to a string variable (will be overwritten) or NULL
494 * @lenp: pointer to an integer variable (will be overwritten) or NULL
495 *
496 * fdt_getprop_by_offset() retrieves a pointer to the value of the
497 * property at structure block offset 'offset' (this will be a pointer
498 * to within the device blob itself, not a copy of the value).  If
499 * lenp is non-NULL, the length of the property value is also
500 * returned, in the integer pointed to by lenp.  If namep is non-NULL,
501 * the property's namne will also be returned in the char * pointed to
502 * by namep (this will be a pointer to within the device tree's string
503 * block, not a new copy of the name).
504 *
505 * returns:
506 *	pointer to the property's value
507 *		if lenp is non-NULL, *lenp contains the length of the property
508 *		value (>=0)
509 *		if namep is non-NULL *namep contiains a pointer to the property
510 *		name.
511 *	NULL, on error
512 *		if lenp is non-NULL, *lenp contains an error code (<0):
513 *		-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_PROP tag
514 *		-FDT_ERR_BADMAGIC,
515 *		-FDT_ERR_BADVERSION,
516 *		-FDT_ERR_BADSTATE,
517 *		-FDT_ERR_BADSTRUCTURE,
518 *		-FDT_ERR_TRUNCATED, standard meanings
519 */
520const void *fdt_getprop_by_offset(const void *fdt, int offset,
521				  const char **namep, int *lenp);
522
523/**
524 * fdt_getprop_namelen - get property value based on substring
525 * @fdt: pointer to the device tree blob
526 * @nodeoffset: offset of the node whose property to find
527 * @name: name of the property to find
528 * @namelen: number of characters of name to consider
529 * @lenp: pointer to an integer variable (will be overwritten) or NULL
530 *
531 * Identical to fdt_getprop(), but only examine the first namelen
532 * characters of name for matching the property name.
533 */
534const void *fdt_getprop_namelen(const void *fdt, int nodeoffset,
535				const char *name, int namelen, int *lenp);
536
537/**
538 * fdt_getprop - retrieve the value of a given property
539 * @fdt: pointer to the device tree blob
540 * @nodeoffset: offset of the node whose property to find
541 * @name: name of the property to find
542 * @lenp: pointer to an integer variable (will be overwritten) or NULL
543 *
544 * fdt_getprop() retrieves a pointer to the value of the property
545 * named 'name' of the node at offset nodeoffset (this will be a
546 * pointer to within the device blob itself, not a copy of the value).
547 * If lenp is non-NULL, the length of the property value is also
548 * returned, in the integer pointed to by lenp.
549 *
550 * returns:
551 *	pointer to the property's value
552 *		if lenp is non-NULL, *lenp contains the length of the property
553 *		value (>=0)
554 *	NULL, on error
555 *		if lenp is non-NULL, *lenp contains an error code (<0):
556 *		-FDT_ERR_NOTFOUND, node does not have named property
557 *		-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
558 *		-FDT_ERR_BADMAGIC,
559 *		-FDT_ERR_BADVERSION,
560 *		-FDT_ERR_BADSTATE,
561 *		-FDT_ERR_BADSTRUCTURE,
562 *		-FDT_ERR_TRUNCATED, standard meanings
563 */
564const void *fdt_getprop(const void *fdt, int nodeoffset,
565			const char *name, int *lenp);
566static inline void *fdt_getprop_w(void *fdt, int nodeoffset,
567				  const char *name, int *lenp)
568{
569	return (void *)(uintptr_t)fdt_getprop(fdt, nodeoffset, name, lenp);
570}
571
572/**
573 * fdt_get_phandle - retrieve the phandle of a given node
574 * @fdt: pointer to the device tree blob
575 * @nodeoffset: structure block offset of the node
576 *
577 * fdt_get_phandle() retrieves the phandle of the device tree node at
578 * structure block offset nodeoffset.
579 *
580 * returns:
581 *	the phandle of the node at nodeoffset, on success (!= 0, != -1)
582 *	0, if the node has no phandle, or another error occurs
583 */
584uint32_t fdt_get_phandle(const void *fdt, int nodeoffset);
585
586/**
587 * fdt_get_alias_namelen - get alias based on substring
588 * @fdt: pointer to the device tree blob
589 * @name: name of the alias th look up
590 * @namelen: number of characters of name to consider
591 *
592 * Identical to fdt_get_alias(), but only examine the first namelen
593 * characters of name for matching the alias name.
594 */
595const char *fdt_get_alias_namelen(const void *fdt,
596				  const char *name, int namelen);
597
598/**
599 * fdt_get_alias - retreive the path referenced by a given alias
600 * @fdt: pointer to the device tree blob
601 * @name: name of the alias th look up
602 *
603 * fdt_get_alias() retrieves the value of a given alias.  That is, the
604 * value of the property named 'name' in the node /aliases.
605 *
606 * returns:
607 *	a pointer to the expansion of the alias named 'name', if it exists
608 *	NULL, if the given alias or the /aliases node does not exist
609 */
610const char *fdt_get_alias(const void *fdt, const char *name);
611
612/**
613 * fdt_get_path - determine the full path of a node
614 * @fdt: pointer to the device tree blob
615 * @nodeoffset: offset of the node whose path to find
616 * @buf: character buffer to contain the returned path (will be overwritten)
617 * @buflen: size of the character buffer at buf
618 *
619 * fdt_get_path() computes the full path of the node at offset
620 * nodeoffset, and records that path in the buffer at buf.
621 *
622 * NOTE: This function is expensive, as it must scan the device tree
623 * structure from the start to nodeoffset.
624 *
625 * returns:
626 *	0, on success
627 *		buf contains the absolute path of the node at
628 *		nodeoffset, as a NUL-terminated string.
629 * 	-FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
630 *	-FDT_ERR_NOSPACE, the path of the given node is longer than (bufsize-1)
631 *		characters and will not fit in the given buffer.
632 *	-FDT_ERR_BADMAGIC,
633 *	-FDT_ERR_BADVERSION,
634 *	-FDT_ERR_BADSTATE,
635 *	-FDT_ERR_BADSTRUCTURE, standard meanings
636 */
637int fdt_get_path(const void *fdt, int nodeoffset, char *buf, int buflen);
638
639/**
640 * fdt_supernode_atdepth_offset - find a specific ancestor of a node
641 * @fdt: pointer to the device tree blob
642 * @nodeoffset: offset of the node whose parent to find
643 * @supernodedepth: depth of the ancestor to find
644 * @nodedepth: pointer to an integer variable (will be overwritten) or NULL
645 *
646 * fdt_supernode_atdepth_offset() finds an ancestor of the given node
647 * at a specific depth from the root (where the root itself has depth
648 * 0, its immediate subnodes depth 1 and so forth).  So
649 *	fdt_supernode_atdepth_offset(fdt, nodeoffset, 0, NULL);
650 * will always return 0, the offset of the root node.  If the node at
651 * nodeoffset has depth D, then:
652 *	fdt_supernode_atdepth_offset(fdt, nodeoffset, D, NULL);
653 * will return nodeoffset itself.
654 *
655 * NOTE: This function is expensive, as it must scan the device tree
656 * structure from the start to nodeoffset.
657 *
658 * returns:
659
660 *	structure block offset of the node at node offset's ancestor
661 *		of depth supernodedepth (>=0), on success
662 * 	-FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
663*	-FDT_ERR_NOTFOUND, supernodedepth was greater than the depth of nodeoffset
664 *	-FDT_ERR_BADMAGIC,
665 *	-FDT_ERR_BADVERSION,
666 *	-FDT_ERR_BADSTATE,
667 *	-FDT_ERR_BADSTRUCTURE, standard meanings
668 */
669int fdt_supernode_atdepth_offset(const void *fdt, int nodeoffset,
670				 int supernodedepth, int *nodedepth);
671
672/**
673 * fdt_node_depth - find the depth of a given node
674 * @fdt: pointer to the device tree blob
675 * @nodeoffset: offset of the node whose parent to find
676 *
677 * fdt_node_depth() finds the depth of a given node.  The root node
678 * has depth 0, its immediate subnodes depth 1 and so forth.
679 *
680 * NOTE: This function is expensive, as it must scan the device tree
681 * structure from the start to nodeoffset.
682 *
683 * returns:
684 *	depth of the node at nodeoffset (>=0), on success
685 * 	-FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
686 *	-FDT_ERR_BADMAGIC,
687 *	-FDT_ERR_BADVERSION,
688 *	-FDT_ERR_BADSTATE,
689 *	-FDT_ERR_BADSTRUCTURE, standard meanings
690 */
691int fdt_node_depth(const void *fdt, int nodeoffset);
692
693/**
694 * fdt_parent_offset - find the parent of a given node
695 * @fdt: pointer to the device tree blob
696 * @nodeoffset: offset of the node whose parent to find
697 *
698 * fdt_parent_offset() locates the parent node of a given node (that
699 * is, it finds the offset of the node which contains the node at
700 * nodeoffset as a subnode).
701 *
702 * NOTE: This function is expensive, as it must scan the device tree
703 * structure from the start to nodeoffset, *twice*.
704 *
705 * returns:
706 *	structure block offset of the parent of the node at nodeoffset
707 *		(>=0), on success
708 * 	-FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
709 *	-FDT_ERR_BADMAGIC,
710 *	-FDT_ERR_BADVERSION,
711 *	-FDT_ERR_BADSTATE,
712 *	-FDT_ERR_BADSTRUCTURE, standard meanings
713 */
714int fdt_parent_offset(const void *fdt, int nodeoffset);
715
716/**
717 * fdt_node_offset_by_prop_value - find nodes with a given property value
718 * @fdt: pointer to the device tree blob
719 * @startoffset: only find nodes after this offset
720 * @propname: property name to check
721 * @propval: property value to search for
722 * @proplen: length of the value in propval
723 *
724 * fdt_node_offset_by_prop_value() returns the offset of the first
725 * node after startoffset, which has a property named propname whose
726 * value is of length proplen and has value equal to propval; or if
727 * startoffset is -1, the very first such node in the tree.
728 *
729 * To iterate through all nodes matching the criterion, the following
730 * idiom can be used:
731 *	offset = fdt_node_offset_by_prop_value(fdt, -1, propname,
732 *					       propval, proplen);
733 *	while (offset != -FDT_ERR_NOTFOUND) {
734 *		// other code here
735 *		offset = fdt_node_offset_by_prop_value(fdt, offset, propname,
736 *						       propval, proplen);
737 *	}
738 *
739 * Note the -1 in the first call to the function, if 0 is used here
740 * instead, the function will never locate the root node, even if it
741 * matches the criterion.
742 *
743 * returns:
744 *	structure block offset of the located node (>= 0, >startoffset),
745 *		 on success
746 *	-FDT_ERR_NOTFOUND, no node matching the criterion exists in the
747 *		tree after startoffset
748 * 	-FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
749 *	-FDT_ERR_BADMAGIC,
750 *	-FDT_ERR_BADVERSION,
751 *	-FDT_ERR_BADSTATE,
752 *	-FDT_ERR_BADSTRUCTURE, standard meanings
753 */
754int fdt_node_offset_by_prop_value(const void *fdt, int startoffset,
755				  const char *propname,
756				  const void *propval, int proplen);
757
758/**
759 * fdt_node_offset_by_phandle - find the node with a given phandle
760 * @fdt: pointer to the device tree blob
761 * @phandle: phandle value
762 *
763 * fdt_node_offset_by_phandle() returns the offset of the node
764 * which has the given phandle value.  If there is more than one node
765 * in the tree with the given phandle (an invalid tree), results are
766 * undefined.
767 *
768 * returns:
769 *	structure block offset of the located node (>= 0), on success
770 *	-FDT_ERR_NOTFOUND, no node with that phandle exists
771 *	-FDT_ERR_BADPHANDLE, given phandle value was invalid (0 or -1)
772 *	-FDT_ERR_BADMAGIC,
773 *	-FDT_ERR_BADVERSION,
774 *	-FDT_ERR_BADSTATE,
775 *	-FDT_ERR_BADSTRUCTURE, standard meanings
776 */
777int fdt_node_offset_by_phandle(const void *fdt, uint32_t phandle);
778
779/**
780 * fdt_node_check_compatible: check a node's compatible property
781 * @fdt: pointer to the device tree blob
782 * @nodeoffset: offset of a tree node
783 * @compatible: string to match against
784 *
785 *
786 * fdt_node_check_compatible() returns 0 if the given node contains a
787 * 'compatible' property with the given string as one of its elements,
788 * it returns non-zero otherwise, or on error.
789 *
790 * returns:
791 *	0, if the node has a 'compatible' property listing the given string
792 *	1, if the node has a 'compatible' property, but it does not list
793 *		the given string
794 *	-FDT_ERR_NOTFOUND, if the given node has no 'compatible' property
795 * 	-FDT_ERR_BADOFFSET, if nodeoffset does not refer to a BEGIN_NODE tag
796 *	-FDT_ERR_BADMAGIC,
797 *	-FDT_ERR_BADVERSION,
798 *	-FDT_ERR_BADSTATE,
799 *	-FDT_ERR_BADSTRUCTURE, standard meanings
800 */
801int fdt_node_check_compatible(const void *fdt, int nodeoffset,
802			      const char *compatible);
803
804/**
805 * fdt_node_offset_by_compatible - find nodes with a given 'compatible' value
806 * @fdt: pointer to the device tree blob
807 * @startoffset: only find nodes after this offset
808 * @compatible: 'compatible' string to match against
809 *
810 * fdt_node_offset_by_compatible() returns the offset of the first
811 * node after startoffset, which has a 'compatible' property which
812 * lists the given compatible string; or if startoffset is -1, the
813 * very first such node in the tree.
814 *
815 * To iterate through all nodes matching the criterion, the following
816 * idiom can be used:
817 *	offset = fdt_node_offset_by_compatible(fdt, -1, compatible);
818 *	while (offset != -FDT_ERR_NOTFOUND) {
819 *		// other code here
820 *		offset = fdt_node_offset_by_compatible(fdt, offset, compatible);
821 *	}
822 *
823 * Note the -1 in the first call to the function, if 0 is used here
824 * instead, the function will never locate the root node, even if it
825 * matches the criterion.
826 *
827 * returns:
828 *	structure block offset of the located node (>= 0, >startoffset),
829 *		 on success
830 *	-FDT_ERR_NOTFOUND, no node matching the criterion exists in the
831 *		tree after startoffset
832 * 	-FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
833 *	-FDT_ERR_BADMAGIC,
834 *	-FDT_ERR_BADVERSION,
835 *	-FDT_ERR_BADSTATE,
836 *	-FDT_ERR_BADSTRUCTURE, standard meanings
837 */
838int fdt_node_offset_by_compatible(const void *fdt, int startoffset,
839				  const char *compatible);
840
841/**
842 * fdt_stringlist_contains - check a string list property for a string
843 * @strlist: Property containing a list of strings to check
844 * @listlen: Length of property
845 * @str: String to search for
846 *
847 * This is a utility function provided for convenience. The list contains
848 * one or more strings, each terminated by \0, as is found in a device tree
849 * "compatible" property.
850 *
851 * @return: 1 if the string is found in the list, 0 not found, or invalid list
852 */
853int fdt_stringlist_contains(const char *strlist, int listlen, const char *str);
854
855/**********************************************************************/
856/* Write-in-place functions                                           */
857/**********************************************************************/
858
859/**
860 * fdt_setprop_inplace - change a property's value, but not its size
861 * @fdt: pointer to the device tree blob
862 * @nodeoffset: offset of the node whose property to change
863 * @name: name of the property to change
864 * @val: pointer to data to replace the property value with
865 * @len: length of the property value
866 *
867 * fdt_setprop_inplace() replaces the value of a given property with
868 * the data in val, of length len.  This function cannot change the
869 * size of a property, and so will only work if len is equal to the
870 * current length of the property.
871 *
872 * This function will alter only the bytes in the blob which contain
873 * the given property value, and will not alter or move any other part
874 * of the tree.
875 *
876 * returns:
877 *	0, on success
878 *	-FDT_ERR_NOSPACE, if len is not equal to the property's current length
879 *	-FDT_ERR_NOTFOUND, node does not have the named property
880 *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
881 *	-FDT_ERR_BADMAGIC,
882 *	-FDT_ERR_BADVERSION,
883 *	-FDT_ERR_BADSTATE,
884 *	-FDT_ERR_BADSTRUCTURE,
885 *	-FDT_ERR_TRUNCATED, standard meanings
886 */
887int fdt_setprop_inplace(void *fdt, int nodeoffset, const char *name,
888			const void *val, int len);
889
890/**
891 * fdt_setprop_inplace_u32 - change the value of a 32-bit integer property
892 * @fdt: pointer to the device tree blob
893 * @nodeoffset: offset of the node whose property to change
894 * @name: name of the property to change
895 * @val: 32-bit integer value to replace the property with
896 *
897 * fdt_setprop_inplace_u32() replaces the value of a given property
898 * with the 32-bit integer value in val, converting val to big-endian
899 * if necessary.  This function cannot change the size of a property,
900 * and so will only work if the property already exists and has length
901 * 4.
902 *
903 * This function will alter only the bytes in the blob which contain
904 * the given property value, and will not alter or move any other part
905 * of the tree.
906 *
907 * returns:
908 *	0, on success
909 *	-FDT_ERR_NOSPACE, if the property's length is not equal to 4
910 *	-FDT_ERR_NOTFOUND, node does not have the named property
911 *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
912 *	-FDT_ERR_BADMAGIC,
913 *	-FDT_ERR_BADVERSION,
914 *	-FDT_ERR_BADSTATE,
915 *	-FDT_ERR_BADSTRUCTURE,
916 *	-FDT_ERR_TRUNCATED, standard meanings
917 */
918static inline int fdt_setprop_inplace_u32(void *fdt, int nodeoffset,
919					  const char *name, uint32_t val)
920{
921	fdt32_t tmp = cpu_to_fdt32(val);
922	return fdt_setprop_inplace(fdt, nodeoffset, name, &tmp, sizeof(tmp));
923}
924
925/**
926 * fdt_setprop_inplace_u64 - change the value of a 64-bit integer property
927 * @fdt: pointer to the device tree blob
928 * @nodeoffset: offset of the node whose property to change
929 * @name: name of the property to change
930 * @val: 64-bit integer value to replace the property with
931 *
932 * fdt_setprop_inplace_u64() replaces the value of a given property
933 * with the 64-bit integer value in val, converting val to big-endian
934 * if necessary.  This function cannot change the size of a property,
935 * and so will only work if the property already exists and has length
936 * 8.
937 *
938 * This function will alter only the bytes in the blob which contain
939 * the given property value, and will not alter or move any other part
940 * of the tree.
941 *
942 * returns:
943 *	0, on success
944 *	-FDT_ERR_NOSPACE, if the property's length is not equal to 8
945 *	-FDT_ERR_NOTFOUND, node does not have the named property
946 *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
947 *	-FDT_ERR_BADMAGIC,
948 *	-FDT_ERR_BADVERSION,
949 *	-FDT_ERR_BADSTATE,
950 *	-FDT_ERR_BADSTRUCTURE,
951 *	-FDT_ERR_TRUNCATED, standard meanings
952 */
953static inline int fdt_setprop_inplace_u64(void *fdt, int nodeoffset,
954					  const char *name, uint64_t val)
955{
956	fdt64_t tmp = cpu_to_fdt64(val);
957	return fdt_setprop_inplace(fdt, nodeoffset, name, &tmp, sizeof(tmp));
958}
959
960/**
961 * fdt_setprop_inplace_cell - change the value of a single-cell property
962 *
963 * This is an alternative name for fdt_setprop_inplace_u32()
964 */
965static inline int fdt_setprop_inplace_cell(void *fdt, int nodeoffset,
966					   const char *name, uint32_t val)
967{
968	return fdt_setprop_inplace_u32(fdt, nodeoffset, name, val);
969}
970
971/**
972 * fdt_nop_property - replace a property with nop tags
973 * @fdt: pointer to the device tree blob
974 * @nodeoffset: offset of the node whose property to nop
975 * @name: name of the property to nop
976 *
977 * fdt_nop_property() will replace a given property's representation
978 * in the blob with FDT_NOP tags, effectively removing it from the
979 * tree.
980 *
981 * This function will alter only the bytes in the blob which contain
982 * the property, and will not alter or move any other part of the
983 * tree.
984 *
985 * returns:
986 *	0, on success
987 *	-FDT_ERR_NOTFOUND, node does not have the named property
988 *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
989 *	-FDT_ERR_BADMAGIC,
990 *	-FDT_ERR_BADVERSION,
991 *	-FDT_ERR_BADSTATE,
992 *	-FDT_ERR_BADSTRUCTURE,
993 *	-FDT_ERR_TRUNCATED, standard meanings
994 */
995int fdt_nop_property(void *fdt, int nodeoffset, const char *name);
996
997/**
998 * fdt_nop_node - replace a node (subtree) with nop tags
999 * @fdt: pointer to the device tree blob
1000 * @nodeoffset: offset of the node to nop
1001 *
1002 * fdt_nop_node() will replace a given node's representation in the
1003 * blob, including all its subnodes, if any, with FDT_NOP tags,
1004 * effectively removing it from the tree.
1005 *
1006 * This function will alter only the bytes in the blob which contain
1007 * the node and its properties and subnodes, and will not alter or
1008 * move any other part of the tree.
1009 *
1010 * returns:
1011 *	0, on success
1012 *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1013 *	-FDT_ERR_BADMAGIC,
1014 *	-FDT_ERR_BADVERSION,
1015 *	-FDT_ERR_BADSTATE,
1016 *	-FDT_ERR_BADSTRUCTURE,
1017 *	-FDT_ERR_TRUNCATED, standard meanings
1018 */
1019int fdt_nop_node(void *fdt, int nodeoffset);
1020
1021/**********************************************************************/
1022/* Sequential write functions                                         */
1023/**********************************************************************/
1024
1025int fdt_create(void *buf, int bufsize);
1026int fdt_resize(void *fdt, void *buf, int bufsize);
1027int fdt_add_reservemap_entry(void *fdt, uint64_t addr, uint64_t size);
1028int fdt_finish_reservemap(void *fdt);
1029int fdt_begin_node(void *fdt, const char *name);
1030int fdt_property(void *fdt, const char *name, const void *val, int len);
1031static inline int fdt_property_u32(void *fdt, const char *name, uint32_t val)
1032{
1033	fdt32_t tmp = cpu_to_fdt32(val);
1034	return fdt_property(fdt, name, &tmp, sizeof(tmp));
1035}
1036static inline int fdt_property_u64(void *fdt, const char *name, uint64_t val)
1037{
1038	fdt64_t tmp = cpu_to_fdt64(val);
1039	return fdt_property(fdt, name, &tmp, sizeof(tmp));
1040}
1041static inline int fdt_property_cell(void *fdt, const char *name, uint32_t val)
1042{
1043	return fdt_property_u32(fdt, name, val);
1044}
1045#define fdt_property_string(fdt, name, str) \
1046	fdt_property(fdt, name, str, strlen(str)+1)
1047int fdt_end_node(void *fdt);
1048int fdt_finish(void *fdt);
1049
1050/**********************************************************************/
1051/* Read-write functions                                               */
1052/**********************************************************************/
1053
1054int fdt_create_empty_tree(void *buf, int bufsize);
1055int fdt_open_into(const void *fdt, void *buf, int bufsize);
1056int fdt_pack(void *fdt);
1057
1058/**
1059 * fdt_add_mem_rsv - add one memory reserve map entry
1060 * @fdt: pointer to the device tree blob
1061 * @address, @size: 64-bit values (native endian)
1062 *
1063 * Adds a reserve map entry to the given blob reserving a region at
1064 * address address of length size.
1065 *
1066 * This function will insert data into the reserve map and will
1067 * therefore change the indexes of some entries in the table.
1068 *
1069 * returns:
1070 *	0, on success
1071 *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1072 *		contain the new reservation entry
1073 *	-FDT_ERR_BADMAGIC,
1074 *	-FDT_ERR_BADVERSION,
1075 *	-FDT_ERR_BADSTATE,
1076 *	-FDT_ERR_BADSTRUCTURE,
1077 *	-FDT_ERR_BADLAYOUT,
1078 *	-FDT_ERR_TRUNCATED, standard meanings
1079 */
1080int fdt_add_mem_rsv(void *fdt, uint64_t address, uint64_t size);
1081
1082/**
1083 * fdt_del_mem_rsv - remove a memory reserve map entry
1084 * @fdt: pointer to the device tree blob
1085 * @n: entry to remove
1086 *
1087 * fdt_del_mem_rsv() removes the n-th memory reserve map entry from
1088 * the blob.
1089 *
1090 * This function will delete data from the reservation table and will
1091 * therefore change the indexes of some entries in the table.
1092 *
1093 * returns:
1094 *	0, on success
1095 *	-FDT_ERR_NOTFOUND, there is no entry of the given index (i.e. there
1096 *		are less than n+1 reserve map entries)
1097 *	-FDT_ERR_BADMAGIC,
1098 *	-FDT_ERR_BADVERSION,
1099 *	-FDT_ERR_BADSTATE,
1100 *	-FDT_ERR_BADSTRUCTURE,
1101 *	-FDT_ERR_BADLAYOUT,
1102 *	-FDT_ERR_TRUNCATED, standard meanings
1103 */
1104int fdt_del_mem_rsv(void *fdt, int n);
1105
1106/**
1107 * fdt_set_name - change the name of a given node
1108 * @fdt: pointer to the device tree blob
1109 * @nodeoffset: structure block offset of a node
1110 * @name: name to give the node
1111 *
1112 * fdt_set_name() replaces the name (including unit address, if any)
1113 * of the given node with the given string.  NOTE: this function can't
1114 * efficiently check if the new name is unique amongst the given
1115 * node's siblings; results are undefined if this function is invoked
1116 * with a name equal to one of the given node's siblings.
1117 *
1118 * This function may insert or delete data from the blob, and will
1119 * therefore change the offsets of some existing nodes.
1120 *
1121 * returns:
1122 *	0, on success
1123 *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob
1124 *		to contain the new name
1125 *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1126 *	-FDT_ERR_BADMAGIC,
1127 *	-FDT_ERR_BADVERSION,
1128 *	-FDT_ERR_BADSTATE, standard meanings
1129 */
1130int fdt_set_name(void *fdt, int nodeoffset, const char *name);
1131
1132/**
1133 * fdt_setprop - create or change a property
1134 * @fdt: pointer to the device tree blob
1135 * @nodeoffset: offset of the node whose property to change
1136 * @name: name of the property to change
1137 * @val: pointer to data to set the property value to
1138 * @len: length of the property value
1139 *
1140 * fdt_setprop() sets the value of the named property in the given
1141 * node to the given value and length, creating the property if it
1142 * does not already exist.
1143 *
1144 * This function may insert or delete data from the blob, and will
1145 * therefore change the offsets of some existing nodes.
1146 *
1147 * returns:
1148 *	0, on success
1149 *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1150 *		contain the new property value
1151 *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1152 *	-FDT_ERR_BADLAYOUT,
1153 *	-FDT_ERR_BADMAGIC,
1154 *	-FDT_ERR_BADVERSION,
1155 *	-FDT_ERR_BADSTATE,
1156 *	-FDT_ERR_BADSTRUCTURE,
1157 *	-FDT_ERR_BADLAYOUT,
1158 *	-FDT_ERR_TRUNCATED, standard meanings
1159 */
1160int fdt_setprop(void *fdt, int nodeoffset, const char *name,
1161		const void *val, int len);
1162
1163/**
1164 * fdt_setprop_u32 - set a property to a 32-bit integer
1165 * @fdt: pointer to the device tree blob
1166 * @nodeoffset: offset of the node whose property to change
1167 * @name: name of the property to change
1168 * @val: 32-bit integer value for the property (native endian)
1169 *
1170 * fdt_setprop_u32() sets the value of the named property in the given
1171 * node to the given 32-bit integer value (converting to big-endian if
1172 * necessary), or creates a new property with that value if it does
1173 * not already exist.
1174 *
1175 * This function may insert or delete data from the blob, and will
1176 * therefore change the offsets of some existing nodes.
1177 *
1178 * returns:
1179 *	0, on success
1180 *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1181 *		contain the new property value
1182 *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1183 *	-FDT_ERR_BADLAYOUT,
1184 *	-FDT_ERR_BADMAGIC,
1185 *	-FDT_ERR_BADVERSION,
1186 *	-FDT_ERR_BADSTATE,
1187 *	-FDT_ERR_BADSTRUCTURE,
1188 *	-FDT_ERR_BADLAYOUT,
1189 *	-FDT_ERR_TRUNCATED, standard meanings
1190 */
1191static inline int fdt_setprop_u32(void *fdt, int nodeoffset, const char *name,
1192				  uint32_t val)
1193{
1194	fdt32_t tmp = cpu_to_fdt32(val);
1195	return fdt_setprop(fdt, nodeoffset, name, &tmp, sizeof(tmp));
1196}
1197
1198/**
1199 * fdt_setprop_u64 - set a property to a 64-bit integer
1200 * @fdt: pointer to the device tree blob
1201 * @nodeoffset: offset of the node whose property to change
1202 * @name: name of the property to change
1203 * @val: 64-bit integer value for the property (native endian)
1204 *
1205 * fdt_setprop_u64() sets the value of the named property in the given
1206 * node to the given 64-bit integer value (converting to big-endian if
1207 * necessary), or creates a new property with that value if it does
1208 * not already exist.
1209 *
1210 * This function may insert or delete data from the blob, and will
1211 * therefore change the offsets of some existing nodes.
1212 *
1213 * returns:
1214 *	0, on success
1215 *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1216 *		contain the new property value
1217 *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1218 *	-FDT_ERR_BADLAYOUT,
1219 *	-FDT_ERR_BADMAGIC,
1220 *	-FDT_ERR_BADVERSION,
1221 *	-FDT_ERR_BADSTATE,
1222 *	-FDT_ERR_BADSTRUCTURE,
1223 *	-FDT_ERR_BADLAYOUT,
1224 *	-FDT_ERR_TRUNCATED, standard meanings
1225 */
1226static inline int fdt_setprop_u64(void *fdt, int nodeoffset, const char *name,
1227				  uint64_t val)
1228{
1229	fdt64_t tmp = cpu_to_fdt64(val);
1230	return fdt_setprop(fdt, nodeoffset, name, &tmp, sizeof(tmp));
1231}
1232
1233/**
1234 * fdt_setprop_cell - set a property to a single cell value
1235 *
1236 * This is an alternative name for fdt_setprop_u32()
1237 */
1238static inline int fdt_setprop_cell(void *fdt, int nodeoffset, const char *name,
1239				   uint32_t val)
1240{
1241	return fdt_setprop_u32(fdt, nodeoffset, name, val);
1242}
1243
1244/**
1245 * fdt_setprop_string - set a property to a string value
1246 * @fdt: pointer to the device tree blob
1247 * @nodeoffset: offset of the node whose property to change
1248 * @name: name of the property to change
1249 * @str: string value for the property
1250 *
1251 * fdt_setprop_string() sets the value of the named property in the
1252 * given node to the given string value (using the length of the
1253 * string to determine the new length of the property), or creates a
1254 * new property with that value if it does not already exist.
1255 *
1256 * This function may insert or delete data from the blob, and will
1257 * therefore change the offsets of some existing nodes.
1258 *
1259 * returns:
1260 *	0, on success
1261 *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1262 *		contain the new property value
1263 *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1264 *	-FDT_ERR_BADLAYOUT,
1265 *	-FDT_ERR_BADMAGIC,
1266 *	-FDT_ERR_BADVERSION,
1267 *	-FDT_ERR_BADSTATE,
1268 *	-FDT_ERR_BADSTRUCTURE,
1269 *	-FDT_ERR_BADLAYOUT,
1270 *	-FDT_ERR_TRUNCATED, standard meanings
1271 */
1272#define fdt_setprop_string(fdt, nodeoffset, name, str) \
1273	fdt_setprop((fdt), (nodeoffset), (name), (str), strlen(str)+1)
1274
1275/**
1276 * fdt_appendprop - append to or create a property
1277 * @fdt: pointer to the device tree blob
1278 * @nodeoffset: offset of the node whose property to change
1279 * @name: name of the property to append to
1280 * @val: pointer to data to append to the property value
1281 * @len: length of the data to append to the property value
1282 *
1283 * fdt_appendprop() appends the value to the named property in the
1284 * given node, creating the property if it does not already exist.
1285 *
1286 * This function may insert data into the blob, and will therefore
1287 * change the offsets of some existing nodes.
1288 *
1289 * returns:
1290 *	0, on success
1291 *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1292 *		contain the new property value
1293 *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1294 *	-FDT_ERR_BADLAYOUT,
1295 *	-FDT_ERR_BADMAGIC,
1296 *	-FDT_ERR_BADVERSION,
1297 *	-FDT_ERR_BADSTATE,
1298 *	-FDT_ERR_BADSTRUCTURE,
1299 *	-FDT_ERR_BADLAYOUT,
1300 *	-FDT_ERR_TRUNCATED, standard meanings
1301 */
1302int fdt_appendprop(void *fdt, int nodeoffset, const char *name,
1303		   const void *val, int len);
1304
1305/**
1306 * fdt_appendprop_u32 - append a 32-bit integer value to a property
1307 * @fdt: pointer to the device tree blob
1308 * @nodeoffset: offset of the node whose property to change
1309 * @name: name of the property to change
1310 * @val: 32-bit integer value to append to the property (native endian)
1311 *
1312 * fdt_appendprop_u32() appends the given 32-bit integer value
1313 * (converting to big-endian if necessary) to the value of the named
1314 * property in the given node, or creates a new property with that
1315 * value if it does not already exist.
1316 *
1317 * This function may insert data into the blob, and will therefore
1318 * change the offsets of some existing nodes.
1319 *
1320 * returns:
1321 *	0, on success
1322 *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1323 *		contain the new property value
1324 *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1325 *	-FDT_ERR_BADLAYOUT,
1326 *	-FDT_ERR_BADMAGIC,
1327 *	-FDT_ERR_BADVERSION,
1328 *	-FDT_ERR_BADSTATE,
1329 *	-FDT_ERR_BADSTRUCTURE,
1330 *	-FDT_ERR_BADLAYOUT,
1331 *	-FDT_ERR_TRUNCATED, standard meanings
1332 */
1333static inline int fdt_appendprop_u32(void *fdt, int nodeoffset,
1334				     const char *name, uint32_t val)
1335{
1336	fdt32_t tmp = cpu_to_fdt32(val);
1337	return fdt_appendprop(fdt, nodeoffset, name, &tmp, sizeof(tmp));
1338}
1339
1340/**
1341 * fdt_appendprop_u64 - append a 64-bit integer value to a property
1342 * @fdt: pointer to the device tree blob
1343 * @nodeoffset: offset of the node whose property to change
1344 * @name: name of the property to change
1345 * @val: 64-bit integer value to append to the property (native endian)
1346 *
1347 * fdt_appendprop_u64() appends the given 64-bit integer value
1348 * (converting to big-endian if necessary) to the value of the named
1349 * property in the given node, or creates a new property with that
1350 * value if it does not already exist.
1351 *
1352 * This function may insert data into the blob, and will therefore
1353 * change the offsets of some existing nodes.
1354 *
1355 * returns:
1356 *	0, on success
1357 *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1358 *		contain the new property value
1359 *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1360 *	-FDT_ERR_BADLAYOUT,
1361 *	-FDT_ERR_BADMAGIC,
1362 *	-FDT_ERR_BADVERSION,
1363 *	-FDT_ERR_BADSTATE,
1364 *	-FDT_ERR_BADSTRUCTURE,
1365 *	-FDT_ERR_BADLAYOUT,
1366 *	-FDT_ERR_TRUNCATED, standard meanings
1367 */
1368static inline int fdt_appendprop_u64(void *fdt, int nodeoffset,
1369				     const char *name, uint64_t val)
1370{
1371	fdt64_t tmp = cpu_to_fdt64(val);
1372	return fdt_appendprop(fdt, nodeoffset, name, &tmp, sizeof(tmp));
1373}
1374
1375/**
1376 * fdt_appendprop_cell - append a single cell value to a property
1377 *
1378 * This is an alternative name for fdt_appendprop_u32()
1379 */
1380static inline int fdt_appendprop_cell(void *fdt, int nodeoffset,
1381				      const char *name, uint32_t val)
1382{
1383	return fdt_appendprop_u32(fdt, nodeoffset, name, val);
1384}
1385
1386/**
1387 * fdt_appendprop_string - append a string to a property
1388 * @fdt: pointer to the device tree blob
1389 * @nodeoffset: offset of the node whose property to change
1390 * @name: name of the property to change
1391 * @str: string value to append to the property
1392 *
1393 * fdt_appendprop_string() appends the given string to the value of
1394 * the named property in the given node, or creates a new property
1395 * with that value if it does not already exist.
1396 *
1397 * This function may insert data into the blob, and will therefore
1398 * change the offsets of some existing nodes.
1399 *
1400 * returns:
1401 *	0, on success
1402 *	-FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1403 *		contain the new property value
1404 *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1405 *	-FDT_ERR_BADLAYOUT,
1406 *	-FDT_ERR_BADMAGIC,
1407 *	-FDT_ERR_BADVERSION,
1408 *	-FDT_ERR_BADSTATE,
1409 *	-FDT_ERR_BADSTRUCTURE,
1410 *	-FDT_ERR_BADLAYOUT,
1411 *	-FDT_ERR_TRUNCATED, standard meanings
1412 */
1413#define fdt_appendprop_string(fdt, nodeoffset, name, str) \
1414	fdt_appendprop((fdt), (nodeoffset), (name), (str), strlen(str)+1)
1415
1416/**
1417 * fdt_delprop - delete a property
1418 * @fdt: pointer to the device tree blob
1419 * @nodeoffset: offset of the node whose property to nop
1420 * @name: name of the property to nop
1421 *
1422 * fdt_del_property() will delete the given property.
1423 *
1424 * This function will delete data from the blob, and will therefore
1425 * change the offsets of some existing nodes.
1426 *
1427 * returns:
1428 *	0, on success
1429 *	-FDT_ERR_NOTFOUND, node does not have the named property
1430 *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1431 *	-FDT_ERR_BADLAYOUT,
1432 *	-FDT_ERR_BADMAGIC,
1433 *	-FDT_ERR_BADVERSION,
1434 *	-FDT_ERR_BADSTATE,
1435 *	-FDT_ERR_BADSTRUCTURE,
1436 *	-FDT_ERR_TRUNCATED, standard meanings
1437 */
1438int fdt_delprop(void *fdt, int nodeoffset, const char *name);
1439
1440/**
1441 * fdt_add_subnode_namelen - creates a new node based on substring
1442 * @fdt: pointer to the device tree blob
1443 * @parentoffset: structure block offset of a node
1444 * @name: name of the subnode to locate
1445 * @namelen: number of characters of name to consider
1446 *
1447 * Identical to fdt_add_subnode(), but use only the first namelen
1448 * characters of name as the name of the new node.  This is useful for
1449 * creating subnodes based on a portion of a larger string, such as a
1450 * full path.
1451 */
1452int fdt_add_subnode_namelen(void *fdt, int parentoffset,
1453			    const char *name, int namelen);
1454
1455/**
1456 * fdt_add_subnode - creates a new node
1457 * @fdt: pointer to the device tree blob
1458 * @parentoffset: structure block offset of a node
1459 * @name: name of the subnode to locate
1460 *
1461 * fdt_add_subnode() creates a new node as a subnode of the node at
1462 * structure block offset parentoffset, with the given name (which
1463 * should include the unit address, if any).
1464 *
1465 * This function will insert data into the blob, and will therefore
1466 * change the offsets of some existing nodes.
1467
1468 * returns:
1469 *	structure block offset of the created nodeequested subnode (>=0), on success
1470 *	-FDT_ERR_NOTFOUND, if the requested subnode does not exist
1471 *	-FDT_ERR_BADOFFSET, if parentoffset did not point to an FDT_BEGIN_NODE tag
1472 *	-FDT_ERR_EXISTS, if the node at parentoffset already has a subnode of
1473 *		the given name
1474 *	-FDT_ERR_NOSPACE, if there is insufficient free space in the
1475 *		blob to contain the new node
1476 *	-FDT_ERR_NOSPACE
1477 *	-FDT_ERR_BADLAYOUT
1478 *      -FDT_ERR_BADMAGIC,
1479 *	-FDT_ERR_BADVERSION,
1480 *	-FDT_ERR_BADSTATE,
1481 *	-FDT_ERR_BADSTRUCTURE,
1482 *	-FDT_ERR_TRUNCATED, standard meanings.
1483 */
1484int fdt_add_subnode(void *fdt, int parentoffset, const char *name);
1485
1486/**
1487 * fdt_del_node - delete a node (subtree)
1488 * @fdt: pointer to the device tree blob
1489 * @nodeoffset: offset of the node to nop
1490 *
1491 * fdt_del_node() will remove the given node, including all its
1492 * subnodes if any, from the blob.
1493 *
1494 * This function will delete data from the blob, and will therefore
1495 * change the offsets of some existing nodes.
1496 *
1497 * returns:
1498 *	0, on success
1499 *	-FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1500 *	-FDT_ERR_BADLAYOUT,
1501 *	-FDT_ERR_BADMAGIC,
1502 *	-FDT_ERR_BADVERSION,
1503 *	-FDT_ERR_BADSTATE,
1504 *	-FDT_ERR_BADSTRUCTURE,
1505 *	-FDT_ERR_TRUNCATED, standard meanings
1506 */
1507int fdt_del_node(void *fdt, int nodeoffset);
1508
1509/**********************************************************************/
1510/* Debugging / informational functions                                */
1511/**********************************************************************/
1512
1513const char *fdt_strerror(int errval);
1514
1515#endif /* _LIBFDT_H */
1516