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 */
54 #include <libfdt_env.h>
55 #include <fdt.h>
57 #define FDT_FIRST_SUPPORTED_VERSION 0x10
58 #define FDT_LAST_SUPPORTED_VERSION 0x11
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. */
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. */
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. */
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. */
119 #define FDT_ERR_MAX 13
121 /**********************************************************************/
122 /* Low-level functions (you probably don't need these) */
123 /**********************************************************************/
125 const void *fdt_offset_ptr(const void *fdt, int offset, unsigned int checklen);
126 static 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 }
131 uint32_t fdt_next_tag(const void *fdt, int offset, int *nextoffset);
133 /**********************************************************************/
134 /* Traversal functions */
135 /**********************************************************************/
137 int fdt_next_node(const void *fdt, int offset, int *depth);
139 /**********************************************************************/
140 /* General functions */
141 /**********************************************************************/
143 #define fdt_get_header(fdt, field) \
144 (fdt32_to_cpu(((const struct fdt_header *)(fdt))->field))
145 #define fdt_magic(fdt) (fdt_get_header(fdt, magic))
146 #define fdt_totalsize(fdt) (fdt_get_header(fdt, totalsize))
147 #define fdt_off_dt_struct(fdt) (fdt_get_header(fdt, off_dt_struct))
148 #define fdt_off_dt_strings(fdt) (fdt_get_header(fdt, off_dt_strings))
149 #define fdt_off_mem_rsvmap(fdt) (fdt_get_header(fdt, off_mem_rsvmap))
150 #define fdt_version(fdt) (fdt_get_header(fdt, version))
151 #define fdt_last_comp_version(fdt) (fdt_get_header(fdt, last_comp_version))
152 #define fdt_boot_cpuid_phys(fdt) (fdt_get_header(fdt, boot_cpuid_phys))
153 #define fdt_size_dt_strings(fdt) (fdt_get_header(fdt, size_dt_strings))
154 #define fdt_size_dt_struct(fdt) (fdt_get_header(fdt, size_dt_struct))
156 #define __fdt_set_hdr(name) \
157 static inline void fdt_set_##name(void *fdt, uint32_t val) \
158 { \
159 struct fdt_header *fdth = (struct fdt_header*)fdt; \
160 fdth->name = cpu_to_fdt32(val); \
161 }
162 __fdt_set_hdr(magic);
163 __fdt_set_hdr(totalsize);
164 __fdt_set_hdr(off_dt_struct);
165 __fdt_set_hdr(off_dt_strings);
166 __fdt_set_hdr(off_mem_rsvmap);
167 __fdt_set_hdr(version);
168 __fdt_set_hdr(last_comp_version);
169 __fdt_set_hdr(boot_cpuid_phys);
170 __fdt_set_hdr(size_dt_strings);
171 __fdt_set_hdr(size_dt_struct);
172 #undef __fdt_set_hdr
174 /**
175 * fdt_check_header - sanity check a device tree or possible device tree
176 * @fdt: pointer to data which might be a flattened device tree
177 *
178 * fdt_check_header() checks that the given buffer contains what
179 * appears to be a flattened device tree with sane information in its
180 * header.
181 *
182 * returns:
183 * 0, if the buffer appears to contain a valid device tree
184 * -FDT_ERR_BADMAGIC,
185 * -FDT_ERR_BADVERSION,
186 * -FDT_ERR_BADSTATE, standard meanings, as above
187 */
188 int fdt_check_header(const void *fdt);
190 /**
191 * fdt_move - move a device tree around in memory
192 * @fdt: pointer to the device tree to move
193 * @buf: pointer to memory where the device is to be moved
194 * @bufsize: size of the memory space at buf
195 *
196 * fdt_move() relocates, if possible, the device tree blob located at
197 * fdt to the buffer at buf of size bufsize. The buffer may overlap
198 * with the existing device tree blob at fdt. Therefore,
199 * fdt_move(fdt, fdt, fdt_totalsize(fdt))
200 * should always succeed.
201 *
202 * returns:
203 * 0, on success
204 * -FDT_ERR_NOSPACE, bufsize is insufficient to contain the device tree
205 * -FDT_ERR_BADMAGIC,
206 * -FDT_ERR_BADVERSION,
207 * -FDT_ERR_BADSTATE, standard meanings
208 */
209 int fdt_move(const void *fdt, void *buf, int bufsize);
211 /**********************************************************************/
212 /* Read-only functions */
213 /**********************************************************************/
215 /**
216 * fdt_string - retrieve a string from the strings block of a device tree
217 * @fdt: pointer to the device tree blob
218 * @stroffset: offset of the string within the strings block (native endian)
219 *
220 * fdt_string() retrieves a pointer to a single string from the
221 * strings block of the device tree blob at fdt.
222 *
223 * returns:
224 * a pointer to the string, on success
225 * NULL, if stroffset is out of bounds
226 */
227 const char *fdt_string(const void *fdt, int stroffset);
229 /**
230 * fdt_num_mem_rsv - retrieve the number of memory reserve map entries
231 * @fdt: pointer to the device tree blob
232 *
233 * Returns the number of entries in the device tree blob's memory
234 * reservation map. This does not include the terminating 0,0 entry
235 * or any other (0,0) entries reserved for expansion.
236 *
237 * returns:
238 * the number of entries
239 */
240 int fdt_num_mem_rsv(const void *fdt);
242 /**
243 * fdt_get_mem_rsv - retrieve one memory reserve map entry
244 * @fdt: pointer to the device tree blob
245 * @address, @size: pointers to 64-bit variables
246 *
247 * On success, *address and *size will contain the address and size of
248 * the n-th reserve map entry from the device tree blob, in
249 * native-endian format.
250 *
251 * returns:
252 * 0, on success
253 * -FDT_ERR_BADMAGIC,
254 * -FDT_ERR_BADVERSION,
255 * -FDT_ERR_BADSTATE, standard meanings
256 */
257 int fdt_get_mem_rsv(const void *fdt, int n, uint64_t *address, uint64_t *size);
259 /**
260 * fdt_subnode_offset_namelen - find a subnode based on substring
261 * @fdt: pointer to the device tree blob
262 * @parentoffset: structure block offset of a node
263 * @name: name of the subnode to locate
264 * @namelen: number of characters of name to consider
265 *
266 * Identical to fdt_subnode_offset(), but only examine the first
267 * namelen characters of name for matching the subnode name. This is
268 * useful for finding subnodes based on a portion of a larger string,
269 * such as a full path.
270 */
271 int fdt_subnode_offset_namelen(const void *fdt, int parentoffset,
272 const char *name, int namelen);
273 /**
274 * fdt_subnode_offset - find a subnode of a given node
275 * @fdt: pointer to the device tree blob
276 * @parentoffset: structure block offset of a node
277 * @name: name of the subnode to locate
278 *
279 * fdt_subnode_offset() finds a subnode of the node at structure block
280 * offset parentoffset with the given name. name may include a unit
281 * address, in which case fdt_subnode_offset() will find the subnode
282 * with that unit address, or the unit address may be omitted, in
283 * which case fdt_subnode_offset() will find an arbitrary subnode
284 * whose name excluding unit address matches the given name.
285 *
286 * returns:
287 * structure block offset of the requested subnode (>=0), on success
288 * -FDT_ERR_NOTFOUND, if the requested subnode does not exist
289 * -FDT_ERR_BADOFFSET, if parentoffset did not point to an FDT_BEGIN_NODE tag
290 * -FDT_ERR_BADMAGIC,
291 * -FDT_ERR_BADVERSION,
292 * -FDT_ERR_BADSTATE,
293 * -FDT_ERR_BADSTRUCTURE,
294 * -FDT_ERR_TRUNCATED, standard meanings.
295 */
296 int fdt_subnode_offset(const void *fdt, int parentoffset, const char *name);
298 /**
299 * fdt_path_offset - find a tree node by its full path
300 * @fdt: pointer to the device tree blob
301 * @path: full path of the node to locate
302 *
303 * fdt_path_offset() finds a node of a given path in the device tree.
304 * Each path component may omit the unit address portion, but the
305 * results of this are undefined if any such path component is
306 * ambiguous (that is if there are multiple nodes at the relevant
307 * level matching the given component, differentiated only by unit
308 * address).
309 *
310 * returns:
311 * structure block offset of the node with the requested path (>=0), on success
312 * -FDT_ERR_BADPATH, given path does not begin with '/' or is invalid
313 * -FDT_ERR_NOTFOUND, if the requested node does not exist
314 * -FDT_ERR_BADMAGIC,
315 * -FDT_ERR_BADVERSION,
316 * -FDT_ERR_BADSTATE,
317 * -FDT_ERR_BADSTRUCTURE,
318 * -FDT_ERR_TRUNCATED, standard meanings.
319 */
320 int fdt_path_offset(const void *fdt, const char *path);
322 /**
323 * fdt_get_name - retrieve the name of a given node
324 * @fdt: pointer to the device tree blob
325 * @nodeoffset: structure block offset of the starting node
326 * @lenp: pointer to an integer variable (will be overwritten) or NULL
327 *
328 * fdt_get_name() retrieves the name (including unit address) of the
329 * device tree node at structure block offset nodeoffset. If lenp is
330 * non-NULL, the length of this name is also returned, in the integer
331 * pointed to by lenp.
332 *
333 * returns:
334 * pointer to the node's name, on success
335 * If lenp is non-NULL, *lenp contains the length of that name (>=0)
336 * NULL, on error
337 * if lenp is non-NULL *lenp contains an error code (<0):
338 * -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
339 * -FDT_ERR_BADMAGIC,
340 * -FDT_ERR_BADVERSION,
341 * -FDT_ERR_BADSTATE, standard meanings
342 */
343 const char *fdt_get_name(const void *fdt, int nodeoffset, int *lenp);
345 /**
346 * fdt_first_property_offset - find the offset of a node's first property
347 * @fdt: pointer to the device tree blob
348 * @nodeoffset: structure block offset of a node
349 *
350 * fdt_first_property_offset() finds the first property of the node at
351 * the given structure block offset.
352 *
353 * returns:
354 * structure block offset of the property (>=0), on success
355 * -FDT_ERR_NOTFOUND, if the requested node has no properties
356 * -FDT_ERR_BADOFFSET, if nodeoffset did not point to an FDT_BEGIN_NODE tag
357 * -FDT_ERR_BADMAGIC,
358 * -FDT_ERR_BADVERSION,
359 * -FDT_ERR_BADSTATE,
360 * -FDT_ERR_BADSTRUCTURE,
361 * -FDT_ERR_TRUNCATED, standard meanings.
362 */
363 int fdt_first_property_offset(const void *fdt, int nodeoffset);
365 /**
366 * fdt_next_property_offset - step through a node's properties
367 * @fdt: pointer to the device tree blob
368 * @offset: structure block offset of a property
369 *
370 * fdt_next_property_offset() finds the property immediately after the
371 * one at the given structure block offset. This will be a property
372 * of the same node as the given property.
373 *
374 * returns:
375 * structure block offset of the next property (>=0), on success
376 * -FDT_ERR_NOTFOUND, if the given property is the last in its node
377 * -FDT_ERR_BADOFFSET, if nodeoffset did not point to an FDT_PROP tag
378 * -FDT_ERR_BADMAGIC,
379 * -FDT_ERR_BADVERSION,
380 * -FDT_ERR_BADSTATE,
381 * -FDT_ERR_BADSTRUCTURE,
382 * -FDT_ERR_TRUNCATED, standard meanings.
383 */
384 int fdt_next_property_offset(const void *fdt, int offset);
386 /**
387 * fdt_get_property_by_offset - retrieve the property at a given offset
388 * @fdt: pointer to the device tree blob
389 * @offset: offset of the property to retrieve
390 * @lenp: pointer to an integer variable (will be overwritten) or NULL
391 *
392 * fdt_get_property_by_offset() retrieves a pointer to the
393 * fdt_property structure within the device tree blob at the given
394 * offset. If lenp is non-NULL, the length of the property value is
395 * also returned, in the integer pointed to by lenp.
396 *
397 * returns:
398 * pointer to the structure representing the property
399 * if lenp is non-NULL, *lenp contains the length of the property
400 * value (>=0)
401 * NULL, on error
402 * if lenp is non-NULL, *lenp contains an error code (<0):
403 * -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_PROP tag
404 * -FDT_ERR_BADMAGIC,
405 * -FDT_ERR_BADVERSION,
406 * -FDT_ERR_BADSTATE,
407 * -FDT_ERR_BADSTRUCTURE,
408 * -FDT_ERR_TRUNCATED, standard meanings
409 */
410 const struct fdt_property *fdt_get_property_by_offset(const void *fdt,
411 int offset,
412 int *lenp);
414 /**
415 * fdt_get_property_namelen - find a property based on substring
416 * @fdt: pointer to the device tree blob
417 * @nodeoffset: offset of the node whose property to find
418 * @name: name of the property to find
419 * @namelen: number of characters of name to consider
420 * @lenp: pointer to an integer variable (will be overwritten) or NULL
421 *
422 * Identical to fdt_get_property_namelen(), but only examine the first
423 * namelen characters of name for matching the property name.
424 */
425 const struct fdt_property *fdt_get_property_namelen(const void *fdt,
426 int nodeoffset,
427 const char *name,
428 int namelen, int *lenp);
430 /**
431 * fdt_get_property - find a given property in a given node
432 * @fdt: pointer to the device tree blob
433 * @nodeoffset: offset of the node whose property to find
434 * @name: name of the property to find
435 * @lenp: pointer to an integer variable (will be overwritten) or NULL
436 *
437 * fdt_get_property() retrieves a pointer to the fdt_property
438 * structure within the device tree blob corresponding to the property
439 * named 'name' of the node at offset nodeoffset. If lenp is
440 * non-NULL, the length of the property value is also returned, in the
441 * integer pointed to by lenp.
442 *
443 * returns:
444 * pointer to the structure representing the property
445 * if lenp is non-NULL, *lenp contains the length of the property
446 * value (>=0)
447 * NULL, on error
448 * if lenp is non-NULL, *lenp contains an error code (<0):
449 * -FDT_ERR_NOTFOUND, node does not have named property
450 * -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
451 * -FDT_ERR_BADMAGIC,
452 * -FDT_ERR_BADVERSION,
453 * -FDT_ERR_BADSTATE,
454 * -FDT_ERR_BADSTRUCTURE,
455 * -FDT_ERR_TRUNCATED, standard meanings
456 */
457 const struct fdt_property *fdt_get_property(const void *fdt, int nodeoffset,
458 const char *name, int *lenp);
459 static inline struct fdt_property *fdt_get_property_w(void *fdt, int nodeoffset,
460 const char *name,
461 int *lenp)
462 {
463 return (struct fdt_property *)(uintptr_t)
464 fdt_get_property(fdt, nodeoffset, name, lenp);
465 }
467 /**
468 * fdt_getprop_by_offset - retrieve the value of a property at a given offset
469 * @fdt: pointer to the device tree blob
470 * @ffset: offset of the property to read
471 * @namep: pointer to a string variable (will be overwritten) or NULL
472 * @lenp: pointer to an integer variable (will be overwritten) or NULL
473 *
474 * fdt_getprop_by_offset() retrieves a pointer to the value of the
475 * property at structure block offset 'offset' (this will be a pointer
476 * to within the device blob itself, not a copy of the value). If
477 * lenp is non-NULL, the length of the property value is also
478 * returned, in the integer pointed to by lenp. If namep is non-NULL,
479 * the property's namne will also be returned in the char * pointed to
480 * by namep (this will be a pointer to within the device tree's string
481 * block, not a new copy of the name).
482 *
483 * returns:
484 * pointer to the property's value
485 * if lenp is non-NULL, *lenp contains the length of the property
486 * value (>=0)
487 * if namep is non-NULL *namep contiains a pointer to the property
488 * name.
489 * NULL, on error
490 * if lenp is non-NULL, *lenp contains an error code (<0):
491 * -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_PROP 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 const void *fdt_getprop_by_offset(const void *fdt, int offset,
499 const char **namep, int *lenp);
501 /**
502 * fdt_getprop_namelen - get property value based on substring
503 * @fdt: pointer to the device tree blob
504 * @nodeoffset: offset of the node whose property to find
505 * @name: name of the property to find
506 * @namelen: number of characters of name to consider
507 * @lenp: pointer to an integer variable (will be overwritten) or NULL
508 *
509 * Identical to fdt_getprop(), but only examine the first namelen
510 * characters of name for matching the property name.
511 */
512 const void *fdt_getprop_namelen(const void *fdt, int nodeoffset,
513 const char *name, int namelen, int *lenp);
515 /**
516 * fdt_getprop - retrieve the value of a given property
517 * @fdt: pointer to the device tree blob
518 * @nodeoffset: offset of the node whose property to find
519 * @name: name of the property to find
520 * @lenp: pointer to an integer variable (will be overwritten) or NULL
521 *
522 * fdt_getprop() retrieves a pointer to the value of the property
523 * named 'name' of the node at offset nodeoffset (this will be a
524 * pointer to within the device blob itself, not a copy of the value).
525 * If lenp is non-NULL, the length of the property value is also
526 * returned, in the integer pointed to by lenp.
527 *
528 * returns:
529 * pointer to the property's value
530 * if lenp is non-NULL, *lenp contains the length of the property
531 * value (>=0)
532 * NULL, on error
533 * if lenp is non-NULL, *lenp contains an error code (<0):
534 * -FDT_ERR_NOTFOUND, node does not have named property
535 * -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
536 * -FDT_ERR_BADMAGIC,
537 * -FDT_ERR_BADVERSION,
538 * -FDT_ERR_BADSTATE,
539 * -FDT_ERR_BADSTRUCTURE,
540 * -FDT_ERR_TRUNCATED, standard meanings
541 */
542 const void *fdt_getprop(const void *fdt, int nodeoffset,
543 const char *name, int *lenp);
544 static inline void *fdt_getprop_w(void *fdt, int nodeoffset,
545 const char *name, int *lenp)
546 {
547 return (void *)(uintptr_t)fdt_getprop(fdt, nodeoffset, name, lenp);
548 }
550 /**
551 * fdt_get_phandle - retrieve the phandle of a given node
552 * @fdt: pointer to the device tree blob
553 * @nodeoffset: structure block offset of the node
554 *
555 * fdt_get_phandle() retrieves the phandle of the device tree node at
556 * structure block offset nodeoffset.
557 *
558 * returns:
559 * the phandle of the node at nodeoffset, on success (!= 0, != -1)
560 * 0, if the node has no phandle, or another error occurs
561 */
562 uint32_t fdt_get_phandle(const void *fdt, int nodeoffset);
564 /**
565 * fdt_get_alias_namelen - get alias based on substring
566 * @fdt: pointer to the device tree blob
567 * @name: name of the alias th look up
568 * @namelen: number of characters of name to consider
569 *
570 * Identical to fdt_get_alias(), but only examine the first namelen
571 * characters of name for matching the alias name.
572 */
573 const char *fdt_get_alias_namelen(const void *fdt,
574 const char *name, int namelen);
576 /**
577 * fdt_get_alias - retreive the path referenced by a given alias
578 * @fdt: pointer to the device tree blob
579 * @name: name of the alias th look up
580 *
581 * fdt_get_alias() retrieves the value of a given alias. That is, the
582 * value of the property named 'name' in the node /aliases.
583 *
584 * returns:
585 * a pointer to the expansion of the alias named 'name', of it exists
586 * NULL, if the given alias or the /aliases node does not exist
587 */
588 const char *fdt_get_alias(const void *fdt, const char *name);
590 /**
591 * fdt_get_path - determine the full path of a node
592 * @fdt: pointer to the device tree blob
593 * @nodeoffset: offset of the node whose path to find
594 * @buf: character buffer to contain the returned path (will be overwritten)
595 * @buflen: size of the character buffer at buf
596 *
597 * fdt_get_path() computes the full path of the node at offset
598 * nodeoffset, and records that path in the buffer at buf.
599 *
600 * NOTE: This function is expensive, as it must scan the device tree
601 * structure from the start to nodeoffset.
602 *
603 * returns:
604 * 0, on success
605 * buf contains the absolute path of the node at
606 * nodeoffset, as a NUL-terminated string.
607 * -FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
608 * -FDT_ERR_NOSPACE, the path of the given node is longer than (bufsize-1)
609 * characters and will not fit in the given buffer.
610 * -FDT_ERR_BADMAGIC,
611 * -FDT_ERR_BADVERSION,
612 * -FDT_ERR_BADSTATE,
613 * -FDT_ERR_BADSTRUCTURE, standard meanings
614 */
615 int fdt_get_path(const void *fdt, int nodeoffset, char *buf, int buflen);
617 /**
618 * fdt_supernode_atdepth_offset - find a specific ancestor of a node
619 * @fdt: pointer to the device tree blob
620 * @nodeoffset: offset of the node whose parent to find
621 * @supernodedepth: depth of the ancestor to find
622 * @nodedepth: pointer to an integer variable (will be overwritten) or NULL
623 *
624 * fdt_supernode_atdepth_offset() finds an ancestor of the given node
625 * at a specific depth from the root (where the root itself has depth
626 * 0, its immediate subnodes depth 1 and so forth). So
627 * fdt_supernode_atdepth_offset(fdt, nodeoffset, 0, NULL);
628 * will always return 0, the offset of the root node. If the node at
629 * nodeoffset has depth D, then:
630 * fdt_supernode_atdepth_offset(fdt, nodeoffset, D, NULL);
631 * will return nodeoffset itself.
632 *
633 * NOTE: This function is expensive, as it must scan the device tree
634 * structure from the start to nodeoffset.
635 *
636 * returns:
638 * structure block offset of the node at node offset's ancestor
639 * of depth supernodedepth (>=0), on success
640 * -FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
641 * -FDT_ERR_NOTFOUND, supernodedepth was greater than the depth of nodeoffset
642 * -FDT_ERR_BADMAGIC,
643 * -FDT_ERR_BADVERSION,
644 * -FDT_ERR_BADSTATE,
645 * -FDT_ERR_BADSTRUCTURE, standard meanings
646 */
647 int fdt_supernode_atdepth_offset(const void *fdt, int nodeoffset,
648 int supernodedepth, int *nodedepth);
650 /**
651 * fdt_node_depth - find the depth of a given node
652 * @fdt: pointer to the device tree blob
653 * @nodeoffset: offset of the node whose parent to find
654 *
655 * fdt_node_depth() finds the depth of a given node. The root node
656 * has depth 0, its immediate subnodes depth 1 and so forth.
657 *
658 * NOTE: This function is expensive, as it must scan the device tree
659 * structure from the start to nodeoffset.
660 *
661 * returns:
662 * depth of the node at nodeoffset (>=0), on success
663 * -FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
664 * -FDT_ERR_BADMAGIC,
665 * -FDT_ERR_BADVERSION,
666 * -FDT_ERR_BADSTATE,
667 * -FDT_ERR_BADSTRUCTURE, standard meanings
668 */
669 int fdt_node_depth(const void *fdt, int nodeoffset);
671 /**
672 * fdt_parent_offset - find the parent of a given node
673 * @fdt: pointer to the device tree blob
674 * @nodeoffset: offset of the node whose parent to find
675 *
676 * fdt_parent_offset() locates the parent node of a given node (that
677 * is, it finds the offset of the node which contains the node at
678 * nodeoffset as a subnode).
679 *
680 * NOTE: This function is expensive, as it must scan the device tree
681 * structure from the start to nodeoffset, *twice*.
682 *
683 * returns:
684 * structure block offset of the parent of the node at nodeoffset
685 * (>=0), on success
686 * -FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
687 * -FDT_ERR_BADMAGIC,
688 * -FDT_ERR_BADVERSION,
689 * -FDT_ERR_BADSTATE,
690 * -FDT_ERR_BADSTRUCTURE, standard meanings
691 */
692 int fdt_parent_offset(const void *fdt, int nodeoffset);
694 /**
695 * fdt_node_offset_by_prop_value - find nodes with a given property value
696 * @fdt: pointer to the device tree blob
697 * @startoffset: only find nodes after this offset
698 * @propname: property name to check
699 * @propval: property value to search for
700 * @proplen: length of the value in propval
701 *
702 * fdt_node_offset_by_prop_value() returns the offset of the first
703 * node after startoffset, which has a property named propname whose
704 * value is of length proplen and has value equal to propval; or if
705 * startoffset is -1, the very first such node in the tree.
706 *
707 * To iterate through all nodes matching the criterion, the following
708 * idiom can be used:
709 * offset = fdt_node_offset_by_prop_value(fdt, -1, propname,
710 * propval, proplen);
711 * while (offset != -FDT_ERR_NOTFOUND) {
712 * // other code here
713 * offset = fdt_node_offset_by_prop_value(fdt, offset, propname,
714 * propval, proplen);
715 * }
716 *
717 * Note the -1 in the first call to the function, if 0 is used here
718 * instead, the function will never locate the root node, even if it
719 * matches the criterion.
720 *
721 * returns:
722 * structure block offset of the located node (>= 0, >startoffset),
723 * on success
724 * -FDT_ERR_NOTFOUND, no node matching the criterion exists in the
725 * tree after startoffset
726 * -FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
727 * -FDT_ERR_BADMAGIC,
728 * -FDT_ERR_BADVERSION,
729 * -FDT_ERR_BADSTATE,
730 * -FDT_ERR_BADSTRUCTURE, standard meanings
731 */
732 int fdt_node_offset_by_prop_value(const void *fdt, int startoffset,
733 const char *propname,
734 const void *propval, int proplen);
736 /**
737 * fdt_node_offset_by_phandle - find the node with a given phandle
738 * @fdt: pointer to the device tree blob
739 * @phandle: phandle value
740 *
741 * fdt_node_offset_by_phandle() returns the offset of the node
742 * which has the given phandle value. If there is more than one node
743 * in the tree with the given phandle (an invalid tree), results are
744 * undefined.
745 *
746 * returns:
747 * structure block offset of the located node (>= 0), on success
748 * -FDT_ERR_NOTFOUND, no node with that phandle exists
749 * -FDT_ERR_BADPHANDLE, given phandle value was invalid (0 or -1)
750 * -FDT_ERR_BADMAGIC,
751 * -FDT_ERR_BADVERSION,
752 * -FDT_ERR_BADSTATE,
753 * -FDT_ERR_BADSTRUCTURE, standard meanings
754 */
755 int fdt_node_offset_by_phandle(const void *fdt, uint32_t phandle);
757 /**
758 * fdt_node_check_compatible: check a node's compatible property
759 * @fdt: pointer to the device tree blob
760 * @nodeoffset: offset of a tree node
761 * @compatible: string to match against
762 *
763 *
764 * fdt_node_check_compatible() returns 0 if the given node contains a
765 * 'compatible' property with the given string as one of its elements,
766 * it returns non-zero otherwise, or on error.
767 *
768 * returns:
769 * 0, if the node has a 'compatible' property listing the given string
770 * 1, if the node has a 'compatible' property, but it does not list
771 * the given string
772 * -FDT_ERR_NOTFOUND, if the given node has no 'compatible' property
773 * -FDT_ERR_BADOFFSET, if nodeoffset does not refer to a BEGIN_NODE tag
774 * -FDT_ERR_BADMAGIC,
775 * -FDT_ERR_BADVERSION,
776 * -FDT_ERR_BADSTATE,
777 * -FDT_ERR_BADSTRUCTURE, standard meanings
778 */
779 int fdt_node_check_compatible(const void *fdt, int nodeoffset,
780 const char *compatible);
782 /**
783 * fdt_node_offset_by_compatible - find nodes with a given 'compatible' value
784 * @fdt: pointer to the device tree blob
785 * @startoffset: only find nodes after this offset
786 * @compatible: 'compatible' string to match against
787 *
788 * fdt_node_offset_by_compatible() returns the offset of the first
789 * node after startoffset, which has a 'compatible' property which
790 * lists the given compatible string; or if startoffset is -1, the
791 * very first such node in the tree.
792 *
793 * To iterate through all nodes matching the criterion, the following
794 * idiom can be used:
795 * offset = fdt_node_offset_by_compatible(fdt, -1, compatible);
796 * while (offset != -FDT_ERR_NOTFOUND) {
797 * // other code here
798 * offset = fdt_node_offset_by_compatible(fdt, offset, compatible);
799 * }
800 *
801 * Note the -1 in the first call to the function, if 0 is used here
802 * instead, the function will never locate the root node, even if it
803 * matches the criterion.
804 *
805 * returns:
806 * structure block offset of the located node (>= 0, >startoffset),
807 * on success
808 * -FDT_ERR_NOTFOUND, no node matching the criterion exists in the
809 * tree after startoffset
810 * -FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
811 * -FDT_ERR_BADMAGIC,
812 * -FDT_ERR_BADVERSION,
813 * -FDT_ERR_BADSTATE,
814 * -FDT_ERR_BADSTRUCTURE, standard meanings
815 */
816 int fdt_node_offset_by_compatible(const void *fdt, int startoffset,
817 const char *compatible);
819 /**********************************************************************/
820 /* Write-in-place functions */
821 /**********************************************************************/
823 /**
824 * fdt_setprop_inplace - change a property's value, but not its size
825 * @fdt: pointer to the device tree blob
826 * @nodeoffset: offset of the node whose property to change
827 * @name: name of the property to change
828 * @val: pointer to data to replace the property value with
829 * @len: length of the property value
830 *
831 * fdt_setprop_inplace() replaces the value of a given property with
832 * the data in val, of length len. This function cannot change the
833 * size of a property, and so will only work if len is equal to the
834 * current length of the property.
835 *
836 * This function will alter only the bytes in the blob which contain
837 * the given property value, and will not alter or move any other part
838 * of the tree.
839 *
840 * returns:
841 * 0, on success
842 * -FDT_ERR_NOSPACE, if len is not equal to the property's current length
843 * -FDT_ERR_NOTFOUND, node does not have the named property
844 * -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
845 * -FDT_ERR_BADMAGIC,
846 * -FDT_ERR_BADVERSION,
847 * -FDT_ERR_BADSTATE,
848 * -FDT_ERR_BADSTRUCTURE,
849 * -FDT_ERR_TRUNCATED, standard meanings
850 */
851 int fdt_setprop_inplace(void *fdt, int nodeoffset, const char *name,
852 const void *val, int len);
854 /**
855 * fdt_setprop_inplace_cell - change the value of a single-cell property
856 * @fdt: pointer to the device tree blob
857 * @nodeoffset: offset of the node whose property to change
858 * @name: name of the property to change
859 * @val: cell (32-bit integer) value to replace the property with
860 *
861 * fdt_setprop_inplace_cell() replaces the value of a given property
862 * with the 32-bit integer cell value in val, converting val to
863 * big-endian if necessary. This function cannot change the size of a
864 * property, and so will only work if the property already exists and
865 * has length 4.
866 *
867 * This function will alter only the bytes in the blob which contain
868 * the given property value, and will not alter or move any other part
869 * of the tree.
870 *
871 * returns:
872 * 0, on success
873 * -FDT_ERR_NOSPACE, if the property's length is not equal to 4
874 * -FDT_ERR_NOTFOUND, node does not have the named property
875 * -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
876 * -FDT_ERR_BADMAGIC,
877 * -FDT_ERR_BADVERSION,
878 * -FDT_ERR_BADSTATE,
879 * -FDT_ERR_BADSTRUCTURE,
880 * -FDT_ERR_TRUNCATED, standard meanings
881 */
882 static inline int fdt_setprop_inplace_cell(void *fdt, int nodeoffset,
883 const char *name, uint32_t val)
884 {
885 val = cpu_to_fdt32(val);
886 return fdt_setprop_inplace(fdt, nodeoffset, name, &val, sizeof(val));
887 }
889 /**
890 * fdt_nop_property - replace a property with nop tags
891 * @fdt: pointer to the device tree blob
892 * @nodeoffset: offset of the node whose property to nop
893 * @name: name of the property to nop
894 *
895 * fdt_nop_property() will replace a given property's representation
896 * in the blob with FDT_NOP tags, effectively removing it from the
897 * tree.
898 *
899 * This function will alter only the bytes in the blob which contain
900 * the property, and will not alter or move any other part of the
901 * tree.
902 *
903 * returns:
904 * 0, on success
905 * -FDT_ERR_NOTFOUND, node does not have the named property
906 * -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
907 * -FDT_ERR_BADMAGIC,
908 * -FDT_ERR_BADVERSION,
909 * -FDT_ERR_BADSTATE,
910 * -FDT_ERR_BADSTRUCTURE,
911 * -FDT_ERR_TRUNCATED, standard meanings
912 */
913 int fdt_nop_property(void *fdt, int nodeoffset, const char *name);
915 /**
916 * fdt_nop_node - replace a node (subtree) with nop tags
917 * @fdt: pointer to the device tree blob
918 * @nodeoffset: offset of the node to nop
919 *
920 * fdt_nop_node() will replace a given node's representation in the
921 * blob, including all its subnodes, if any, with FDT_NOP tags,
922 * effectively removing it from the tree.
923 *
924 * This function will alter only the bytes in the blob which contain
925 * the node and its properties and subnodes, and will not alter or
926 * move any other part of the tree.
927 *
928 * returns:
929 * 0, on success
930 * -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
931 * -FDT_ERR_BADMAGIC,
932 * -FDT_ERR_BADVERSION,
933 * -FDT_ERR_BADSTATE,
934 * -FDT_ERR_BADSTRUCTURE,
935 * -FDT_ERR_TRUNCATED, standard meanings
936 */
937 int fdt_nop_node(void *fdt, int nodeoffset);
939 /**********************************************************************/
940 /* Sequential write functions */
941 /**********************************************************************/
943 int fdt_create(void *buf, int bufsize);
944 int fdt_add_reservemap_entry(void *fdt, uint64_t addr, uint64_t size);
945 int fdt_finish_reservemap(void *fdt);
946 int fdt_begin_node(void *fdt, const char *name);
947 int fdt_property(void *fdt, const char *name, const void *val, int len);
948 static inline int fdt_property_cell(void *fdt, const char *name, uint32_t val)
949 {
950 val = cpu_to_fdt32(val);
951 return fdt_property(fdt, name, &val, sizeof(val));
952 }
953 #define fdt_property_string(fdt, name, str) \
954 fdt_property(fdt, name, str, strlen(str)+1)
955 int fdt_end_node(void *fdt);
956 int fdt_finish(void *fdt);
958 /**********************************************************************/
959 /* Read-write functions */
960 /**********************************************************************/
962 int fdt_open_into(const void *fdt, void *buf, int bufsize);
963 int fdt_pack(void *fdt);
965 /**
966 * fdt_add_mem_rsv - add one memory reserve map entry
967 * @fdt: pointer to the device tree blob
968 * @address, @size: 64-bit values (native endian)
969 *
970 * Adds a reserve map entry to the given blob reserving a region at
971 * address address of length size.
972 *
973 * This function will insert data into the reserve map and will
974 * therefore change the indexes of some entries in the table.
975 *
976 * returns:
977 * 0, on success
978 * -FDT_ERR_NOSPACE, there is insufficient free space in the blob to
979 * contain the new reservation entry
980 * -FDT_ERR_BADMAGIC,
981 * -FDT_ERR_BADVERSION,
982 * -FDT_ERR_BADSTATE,
983 * -FDT_ERR_BADSTRUCTURE,
984 * -FDT_ERR_BADLAYOUT,
985 * -FDT_ERR_TRUNCATED, standard meanings
986 */
987 int fdt_add_mem_rsv(void *fdt, uint64_t address, uint64_t size);
989 /**
990 * fdt_del_mem_rsv - remove a memory reserve map entry
991 * @fdt: pointer to the device tree blob
992 * @n: entry to remove
993 *
994 * fdt_del_mem_rsv() removes the n-th memory reserve map entry from
995 * the blob.
996 *
997 * This function will delete data from the reservation table and will
998 * therefore change the indexes of some entries in the table.
999 *
1000 * returns:
1001 * 0, on success
1002 * -FDT_ERR_NOTFOUND, there is no entry of the given index (i.e. there
1003 * are less than n+1 reserve map entries)
1004 * -FDT_ERR_BADMAGIC,
1005 * -FDT_ERR_BADVERSION,
1006 * -FDT_ERR_BADSTATE,
1007 * -FDT_ERR_BADSTRUCTURE,
1008 * -FDT_ERR_BADLAYOUT,
1009 * -FDT_ERR_TRUNCATED, standard meanings
1010 */
1011 int fdt_del_mem_rsv(void *fdt, int n);
1013 /**
1014 * fdt_set_name - change the name of a given node
1015 * @fdt: pointer to the device tree blob
1016 * @nodeoffset: structure block offset of a node
1017 * @name: name to give the node
1018 *
1019 * fdt_set_name() replaces the name (including unit address, if any)
1020 * of the given node with the given string. NOTE: this function can't
1021 * efficiently check if the new name is unique amongst the given
1022 * node's siblings; results are undefined if this function is invoked
1023 * with a name equal to one of the given node's siblings.
1024 *
1025 * This function may insert or delete data from the blob, and will
1026 * therefore change the offsets of some existing nodes.
1027 *
1028 * returns:
1029 * 0, on success
1030 * -FDT_ERR_NOSPACE, there is insufficient free space in the blob
1031 * to contain the new name
1032 * -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1033 * -FDT_ERR_BADMAGIC,
1034 * -FDT_ERR_BADVERSION,
1035 * -FDT_ERR_BADSTATE, standard meanings
1036 */
1037 int fdt_set_name(void *fdt, int nodeoffset, const char *name);
1039 /**
1040 * fdt_setprop - create or change a property
1041 * @fdt: pointer to the device tree blob
1042 * @nodeoffset: offset of the node whose property to change
1043 * @name: name of the property to change
1044 * @val: pointer to data to set the property value to
1045 * @len: length of the property value
1046 *
1047 * fdt_setprop() sets the value of the named property in the given
1048 * node to the given value and length, creating the property if it
1049 * does not already exist.
1050 *
1051 * This function may insert or delete data from the blob, and will
1052 * therefore change the offsets of some existing nodes.
1053 *
1054 * returns:
1055 * 0, on success
1056 * -FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1057 * contain the new property value
1058 * -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1059 * -FDT_ERR_BADLAYOUT,
1060 * -FDT_ERR_BADMAGIC,
1061 * -FDT_ERR_BADVERSION,
1062 * -FDT_ERR_BADSTATE,
1063 * -FDT_ERR_BADSTRUCTURE,
1064 * -FDT_ERR_BADLAYOUT,
1065 * -FDT_ERR_TRUNCATED, standard meanings
1066 */
1067 int fdt_setprop(void *fdt, int nodeoffset, const char *name,
1068 const void *val, int len);
1070 /**
1071 * fdt_setprop_cell - set a property to a single cell value
1072 * @fdt: pointer to the device tree blob
1073 * @nodeoffset: offset of the node whose property to change
1074 * @name: name of the property to change
1075 * @val: 32-bit integer value for the property (native endian)
1076 *
1077 * fdt_setprop_cell() sets the value of the named property in the
1078 * given node to the given cell value (converting to big-endian if
1079 * necessary), or creates a new property with that value if it does
1080 * not already exist.
1081 *
1082 * This function may insert or delete data from the blob, and will
1083 * therefore change the offsets of some existing nodes.
1084 *
1085 * returns:
1086 * 0, on success
1087 * -FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1088 * contain the new property value
1089 * -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1090 * -FDT_ERR_BADLAYOUT,
1091 * -FDT_ERR_BADMAGIC,
1092 * -FDT_ERR_BADVERSION,
1093 * -FDT_ERR_BADSTATE,
1094 * -FDT_ERR_BADSTRUCTURE,
1095 * -FDT_ERR_BADLAYOUT,
1096 * -FDT_ERR_TRUNCATED, standard meanings
1097 */
1098 static inline int fdt_setprop_cell(void *fdt, int nodeoffset, const char *name,
1099 uint32_t val)
1100 {
1101 val = cpu_to_fdt32(val);
1102 return fdt_setprop(fdt, nodeoffset, name, &val, sizeof(val));
1103 }
1105 /**
1106 * fdt_setprop_string - set a property to a string value
1107 * @fdt: pointer to the device tree blob
1108 * @nodeoffset: offset of the node whose property to change
1109 * @name: name of the property to change
1110 * @str: string value for the property
1111 *
1112 * fdt_setprop_string() sets the value of the named property in the
1113 * given node to the given string value (using the length of the
1114 * string to determine the new length of the property), or creates a
1115 * new property with that value if it does not already exist.
1116 *
1117 * This function may insert or delete data from the blob, and will
1118 * therefore change the offsets of some existing nodes.
1119 *
1120 * returns:
1121 * 0, on success
1122 * -FDT_ERR_NOSPACE, there is insufficient free space in the blob to
1123 * contain the new property value
1124 * -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1125 * -FDT_ERR_BADLAYOUT,
1126 * -FDT_ERR_BADMAGIC,
1127 * -FDT_ERR_BADVERSION,
1128 * -FDT_ERR_BADSTATE,
1129 * -FDT_ERR_BADSTRUCTURE,
1130 * -FDT_ERR_BADLAYOUT,
1131 * -FDT_ERR_TRUNCATED, standard meanings
1132 */
1133 #define fdt_setprop_string(fdt, nodeoffset, name, str) \
1134 fdt_setprop((fdt), (nodeoffset), (name), (str), strlen(str)+1)
1136 /**
1137 * fdt_delprop - delete a property
1138 * @fdt: pointer to the device tree blob
1139 * @nodeoffset: offset of the node whose property to nop
1140 * @name: name of the property to nop
1141 *
1142 * fdt_del_property() will delete the given property.
1143 *
1144 * This function will delete data from the blob, and will therefore
1145 * change the offsets of some existing nodes.
1146 *
1147 * returns:
1148 * 0, on success
1149 * -FDT_ERR_NOTFOUND, node does not have the named property
1150 * -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1151 * -FDT_ERR_BADLAYOUT,
1152 * -FDT_ERR_BADMAGIC,
1153 * -FDT_ERR_BADVERSION,
1154 * -FDT_ERR_BADSTATE,
1155 * -FDT_ERR_BADSTRUCTURE,
1156 * -FDT_ERR_TRUNCATED, standard meanings
1157 */
1158 int fdt_delprop(void *fdt, int nodeoffset, const char *name);
1160 /**
1161 * fdt_add_subnode_namelen - creates a new node based on substring
1162 * @fdt: pointer to the device tree blob
1163 * @parentoffset: structure block offset of a node
1164 * @name: name of the subnode to locate
1165 * @namelen: number of characters of name to consider
1166 *
1167 * Identical to fdt_add_subnode(), but use only the first namelen
1168 * characters of name as the name of the new node. This is useful for
1169 * creating subnodes based on a portion of a larger string, such as a
1170 * full path.
1171 */
1172 int fdt_add_subnode_namelen(void *fdt, int parentoffset,
1173 const char *name, int namelen);
1175 /**
1176 * fdt_add_subnode - creates a new node
1177 * @fdt: pointer to the device tree blob
1178 * @parentoffset: structure block offset of a node
1179 * @name: name of the subnode to locate
1180 *
1181 * fdt_add_subnode() creates a new node as a subnode of the node at
1182 * structure block offset parentoffset, with the given name (which
1183 * should include the unit address, if any).
1184 *
1185 * This function will insert data into the blob, and will therefore
1186 * change the offsets of some existing nodes.
1188 * returns:
1189 * structure block offset of the created nodeequested subnode (>=0), on success
1190 * -FDT_ERR_NOTFOUND, if the requested subnode does not exist
1191 * -FDT_ERR_BADOFFSET, if parentoffset did not point to an FDT_BEGIN_NODE tag
1192 * -FDT_ERR_EXISTS, if the node at parentoffset already has a subnode of
1193 * the given name
1194 * -FDT_ERR_NOSPACE, if there is insufficient free space in the
1195 * blob to contain the new node
1196 * -FDT_ERR_NOSPACE
1197 * -FDT_ERR_BADLAYOUT
1198 * -FDT_ERR_BADMAGIC,
1199 * -FDT_ERR_BADVERSION,
1200 * -FDT_ERR_BADSTATE,
1201 * -FDT_ERR_BADSTRUCTURE,
1202 * -FDT_ERR_TRUNCATED, standard meanings.
1203 */
1204 int fdt_add_subnode(void *fdt, int parentoffset, const char *name);
1206 /**
1207 * fdt_del_node - delete a node (subtree)
1208 * @fdt: pointer to the device tree blob
1209 * @nodeoffset: offset of the node to nop
1210 *
1211 * fdt_del_node() will remove the given node, including all its
1212 * subnodes if any, from the blob.
1213 *
1214 * This function will delete data from the blob, and will therefore
1215 * change the offsets of some existing nodes.
1216 *
1217 * returns:
1218 * 0, on success
1219 * -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1220 * -FDT_ERR_BADLAYOUT,
1221 * -FDT_ERR_BADMAGIC,
1222 * -FDT_ERR_BADVERSION,
1223 * -FDT_ERR_BADSTATE,
1224 * -FDT_ERR_BADSTRUCTURE,
1225 * -FDT_ERR_TRUNCATED, standard meanings
1226 */
1227 int fdt_del_node(void *fdt, int nodeoffset);
1229 /**********************************************************************/
1230 /* Debugging / informational functions */
1231 /**********************************************************************/
1233 const char *fdt_strerror(int errval);
1235 #endif /* _LIBFDT_H */