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: Attempted 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
125 const void *fdt_offset_ptr(const void *fdt, int offset, int checklen);
fdt_offset_ptr_w(void * fdt,int offset,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 }
130
131 uint32_t fdt_next_tag(const void *fdt, int offset, int *nextoffset);
132
133 /**********************************************************************/
134 /* Traversal functions */
135 /**********************************************************************/
136
137 int fdt_next_node(const void *fdt, int offset, int *depth);
138
139 /**********************************************************************/
140 /* General functions */
141 /**********************************************************************/
142
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))
155
156 #define __fdt_set_hdr(name) \
157 static inline void fdt_set_##name(void *fdt, uint32_t val) \
158 { \
159 struct fdt_header *fdth = 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
173
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);
189
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);
210
211 /**********************************************************************/
212 /* Read-only functions */
213 /**********************************************************************/
214
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);
228
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);
241
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);
258
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);
297
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);
321
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);
344
345 /**
346 * fdt_get_property - find a given property in a given node
347 * @fdt: pointer to the device tree blob
348 * @nodeoffset: offset of the node whose property to find
349 * @name: name of the property to find
350 * @lenp: pointer to an integer variable (will be overwritten) or NULL
351 *
352 * fdt_get_property() retrieves a pointer to the fdt_property
353 * structure within the device tree blob corresponding to the property
354 * named 'name' of the node at offset nodeoffset. If lenp is
355 * non-NULL, the length of the property value is also returned, in the
356 * integer pointed to by lenp.
357 *
358 * returns:
359 * pointer to the structure representing the property
360 * if lenp is non-NULL, *lenp contains the length of the property
361 * value (>=0)
362 * NULL, on error
363 * if lenp is non-NULL, *lenp contains an error code (<0):
364 * -FDT_ERR_NOTFOUND, node does not have named property
365 * -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
366 * -FDT_ERR_BADMAGIC,
367 * -FDT_ERR_BADVERSION,
368 * -FDT_ERR_BADSTATE,
369 * -FDT_ERR_BADSTRUCTURE,
370 * -FDT_ERR_TRUNCATED, standard meanings
371 */
372 const struct fdt_property *fdt_get_property(const void *fdt, int nodeoffset,
373 const char *name, int *lenp);
fdt_get_property_w(void * fdt,int nodeoffset,const char * name,int * lenp)374 static inline struct fdt_property *fdt_get_property_w(void *fdt, int nodeoffset,
375 const char *name,
376 int *lenp)
377 {
378 return (struct fdt_property *)(uintptr_t)
379 fdt_get_property(fdt, nodeoffset, name, lenp);
380 }
381
382 /**
383 * fdt_getprop - retrieve the value of a given property
384 * @fdt: pointer to the device tree blob
385 * @nodeoffset: offset of the node whose property to find
386 * @name: name of the property to find
387 * @lenp: pointer to an integer variable (will be overwritten) or NULL
388 *
389 * fdt_getprop() retrieves a pointer to the value of the property
390 * named 'name' of the node at offset nodeoffset (this will be a
391 * pointer to within the device blob itself, not a copy of the value).
392 * If lenp is non-NULL, the length of the property value is also
393 * returned, in the integer pointed to by lenp.
394 *
395 * returns:
396 * pointer to the property's value
397 * if lenp is non-NULL, *lenp contains the length of the property
398 * value (>=0)
399 * NULL, on error
400 * if lenp is non-NULL, *lenp contains an error code (<0):
401 * -FDT_ERR_NOTFOUND, node does not have named property
402 * -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
403 * -FDT_ERR_BADMAGIC,
404 * -FDT_ERR_BADVERSION,
405 * -FDT_ERR_BADSTATE,
406 * -FDT_ERR_BADSTRUCTURE,
407 * -FDT_ERR_TRUNCATED, standard meanings
408 */
409 const void *fdt_getprop(const void *fdt, int nodeoffset,
410 const char *name, int *lenp);
fdt_getprop_w(void * fdt,int nodeoffset,const char * name,int * lenp)411 static inline void *fdt_getprop_w(void *fdt, int nodeoffset,
412 const char *name, int *lenp)
413 {
414 return (void *)(uintptr_t)fdt_getprop(fdt, nodeoffset, name, lenp);
415 }
416
417 /**
418 * fdt_get_phandle - retrieve the phandle of a given node
419 * @fdt: pointer to the device tree blob
420 * @nodeoffset: structure block offset of the node
421 *
422 * fdt_get_phandle() retrieves the phandle of the device tree node at
423 * structure block offset nodeoffset.
424 *
425 * returns:
426 * the phandle of the node at nodeoffset, on success (!= 0, != -1)
427 * 0, if the node has no phandle, or another error occurs
428 */
429 uint32_t fdt_get_phandle(const void *fdt, int nodeoffset);
430
431 /**
432 * fdt_get_path - determine the full path of a node
433 * @fdt: pointer to the device tree blob
434 * @nodeoffset: offset of the node whose path to find
435 * @buf: character buffer to contain the returned path (will be overwritten)
436 * @buflen: size of the character buffer at buf
437 *
438 * fdt_get_path() computes the full path of the node at offset
439 * nodeoffset, and records that path in the buffer at buf.
440 *
441 * NOTE: This function is expensive, as it must scan the device tree
442 * structure from the start to nodeoffset.
443 *
444 * returns:
445 * 0, on success
446 * buf contains the absolute path of the node at
447 * nodeoffset, as a NUL-terminated string.
448 * -FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
449 * -FDT_ERR_NOSPACE, the path of the given node is longer than (bufsize-1)
450 * characters and will not fit in the given buffer.
451 * -FDT_ERR_BADMAGIC,
452 * -FDT_ERR_BADVERSION,
453 * -FDT_ERR_BADSTATE,
454 * -FDT_ERR_BADSTRUCTURE, standard meanings
455 */
456 int fdt_get_path(const void *fdt, int nodeoffset, char *buf, int buflen);
457
458 /**
459 * fdt_supernode_atdepth_offset - find a specific ancestor of a node
460 * @fdt: pointer to the device tree blob
461 * @nodeoffset: offset of the node whose parent to find
462 * @supernodedepth: depth of the ancestor to find
463 * @nodedepth: pointer to an integer variable (will be overwritten) or NULL
464 *
465 * fdt_supernode_atdepth_offset() finds an ancestor of the given node
466 * at a specific depth from the root (where the root itself has depth
467 * 0, its immediate subnodes depth 1 and so forth). So
468 * fdt_supernode_atdepth_offset(fdt, nodeoffset, 0, NULL);
469 * will always return 0, the offset of the root node. If the node at
470 * nodeoffset has depth D, then:
471 * fdt_supernode_atdepth_offset(fdt, nodeoffset, D, NULL);
472 * will return nodeoffset itself.
473 *
474 * NOTE: This function is expensive, as it must scan the device tree
475 * structure from the start to nodeoffset.
476 *
477 * returns:
478
479 * structure block offset of the node at node offset's ancestor
480 * of depth supernodedepth (>=0), on success
481 * -FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
482 * -FDT_ERR_NOTFOUND, supernodedepth was greater than the depth of nodeoffset
483 * -FDT_ERR_BADMAGIC,
484 * -FDT_ERR_BADVERSION,
485 * -FDT_ERR_BADSTATE,
486 * -FDT_ERR_BADSTRUCTURE, standard meanings
487 */
488 int fdt_supernode_atdepth_offset(const void *fdt, int nodeoffset,
489 int supernodedepth, int *nodedepth);
490
491 /**
492 * fdt_node_depth - find the depth of a given node
493 * @fdt: pointer to the device tree blob
494 * @nodeoffset: offset of the node whose parent to find
495 *
496 * fdt_node_depth() finds the depth of a given node. The root node
497 * has depth 0, its immediate subnodes depth 1 and so forth.
498 *
499 * NOTE: This function is expensive, as it must scan the device tree
500 * structure from the start to nodeoffset.
501 *
502 * returns:
503 * depth of the node at nodeoffset (>=0), on success
504 * -FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
505 * -FDT_ERR_BADMAGIC,
506 * -FDT_ERR_BADVERSION,
507 * -FDT_ERR_BADSTATE,
508 * -FDT_ERR_BADSTRUCTURE, standard meanings
509 */
510 int fdt_node_depth(const void *fdt, int nodeoffset);
511
512 /**
513 * fdt_parent_offset - find the parent of a given node
514 * @fdt: pointer to the device tree blob
515 * @nodeoffset: offset of the node whose parent to find
516 *
517 * fdt_parent_offset() locates the parent node of a given node (that
518 * is, it finds the offset of the node which contains the node at
519 * nodeoffset as a subnode).
520 *
521 * NOTE: This function is expensive, as it must scan the device tree
522 * structure from the start to nodeoffset, *twice*.
523 *
524 * returns:
525 * structure block offset of the parent of the node at nodeoffset
526 * (>=0), on success
527 * -FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
528 * -FDT_ERR_BADMAGIC,
529 * -FDT_ERR_BADVERSION,
530 * -FDT_ERR_BADSTATE,
531 * -FDT_ERR_BADSTRUCTURE, standard meanings
532 */
533 int fdt_parent_offset(const void *fdt, int nodeoffset);
534
535 /**
536 * fdt_node_offset_by_prop_value - find nodes with a given property value
537 * @fdt: pointer to the device tree blob
538 * @startoffset: only find nodes after this offset
539 * @propname: property name to check
540 * @propval: property value to search for
541 * @proplen: length of the value in propval
542 *
543 * fdt_node_offset_by_prop_value() returns the offset of the first
544 * node after startoffset, which has a property named propname whose
545 * value is of length proplen and has value equal to propval; or if
546 * startoffset is -1, the very first such node in the tree.
547 *
548 * To iterate through all nodes matching the criterion, the following
549 * idiom can be used:
550 * offset = fdt_node_offset_by_prop_value(fdt, -1, propname,
551 * propval, proplen);
552 * while (offset != -FDT_ERR_NOTFOUND) {
553 * // other code here
554 * offset = fdt_node_offset_by_prop_value(fdt, offset, propname,
555 * propval, proplen);
556 * }
557 *
558 * Note the -1 in the first call to the function, if 0 is used here
559 * instead, the function will never locate the root node, even if it
560 * matches the criterion.
561 *
562 * returns:
563 * structure block offset of the located node (>= 0, >startoffset),
564 * on success
565 * -FDT_ERR_NOTFOUND, no node matching the criterion exists in the
566 * tree after startoffset
567 * -FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
568 * -FDT_ERR_BADMAGIC,
569 * -FDT_ERR_BADVERSION,
570 * -FDT_ERR_BADSTATE,
571 * -FDT_ERR_BADSTRUCTURE, standard meanings
572 */
573 int fdt_node_offset_by_prop_value(const void *fdt, int startoffset,
574 const char *propname,
575 const void *propval, int proplen);
576
577 /**
578 * fdt_node_offset_by_phandle - find the node with a given phandle
579 * @fdt: pointer to the device tree blob
580 * @phandle: phandle value
581 *
582 * fdt_node_offset_by_phandle() returns the offset of the node
583 * which has the given phandle value. If there is more than one node
584 * in the tree with the given phandle (an invalid tree), results are
585 * undefined.
586 *
587 * returns:
588 * structure block offset of the located node (>= 0), on success
589 * -FDT_ERR_NOTFOUND, no node with that phandle exists
590 * -FDT_ERR_BADPHANDLE, given phandle value was invalid (0 or -1)
591 * -FDT_ERR_BADMAGIC,
592 * -FDT_ERR_BADVERSION,
593 * -FDT_ERR_BADSTATE,
594 * -FDT_ERR_BADSTRUCTURE, standard meanings
595 */
596 int fdt_node_offset_by_phandle(const void *fdt, uint32_t phandle);
597
598 /**
599 * fdt_node_check_compatible: check a node's compatible property
600 * @fdt: pointer to the device tree blob
601 * @nodeoffset: offset of a tree node
602 * @compatible: string to match against
603 *
604 *
605 * fdt_node_check_compatible() returns 0 if the given node contains a
606 * 'compatible' property with the given string as one of its elements,
607 * it returns non-zero otherwise, or on error.
608 *
609 * returns:
610 * 0, if the node has a 'compatible' property listing the given string
611 * 1, if the node has a 'compatible' property, but it does not list
612 * the given string
613 * -FDT_ERR_NOTFOUND, if the given node has no 'compatible' property
614 * -FDT_ERR_BADOFFSET, if nodeoffset does not refer to a BEGIN_NODE tag
615 * -FDT_ERR_BADMAGIC,
616 * -FDT_ERR_BADVERSION,
617 * -FDT_ERR_BADSTATE,
618 * -FDT_ERR_BADSTRUCTURE, standard meanings
619 */
620 int fdt_node_check_compatible(const void *fdt, int nodeoffset,
621 const char *compatible);
622
623 /**
624 * fdt_node_offset_by_compatible - find nodes with a given 'compatible' value
625 * @fdt: pointer to the device tree blob
626 * @startoffset: only find nodes after this offset
627 * @compatible: 'compatible' string to match against
628 *
629 * fdt_node_offset_by_compatible() returns the offset of the first
630 * node after startoffset, which has a 'compatible' property which
631 * lists the given compatible string; or if startoffset is -1, the
632 * very first such node in the tree.
633 *
634 * To iterate through all nodes matching the criterion, the following
635 * idiom can be used:
636 * offset = fdt_node_offset_by_compatible(fdt, -1, compatible);
637 * while (offset != -FDT_ERR_NOTFOUND) {
638 * // other code here
639 * offset = fdt_node_offset_by_compatible(fdt, offset, compatible);
640 * }
641 *
642 * Note the -1 in the first call to the function, if 0 is used here
643 * instead, the function will never locate the root node, even if it
644 * matches the criterion.
645 *
646 * returns:
647 * structure block offset of the located node (>= 0, >startoffset),
648 * on success
649 * -FDT_ERR_NOTFOUND, no node matching the criterion exists in the
650 * tree after startoffset
651 * -FDT_ERR_BADOFFSET, nodeoffset does not refer to a BEGIN_NODE tag
652 * -FDT_ERR_BADMAGIC,
653 * -FDT_ERR_BADVERSION,
654 * -FDT_ERR_BADSTATE,
655 * -FDT_ERR_BADSTRUCTURE, standard meanings
656 */
657 int fdt_node_offset_by_compatible(const void *fdt, int startoffset,
658 const char *compatible);
659
660 /**********************************************************************/
661 /* Write-in-place functions */
662 /**********************************************************************/
663
664 /**
665 * fdt_setprop_inplace - change a property's value, but not its size
666 * @fdt: pointer to the device tree blob
667 * @nodeoffset: offset of the node whose property to change
668 * @name: name of the property to change
669 * @val: pointer to data to replace the property value with
670 * @len: length of the property value
671 *
672 * fdt_setprop_inplace() replaces the value of a given property with
673 * the data in val, of length len. This function cannot change the
674 * size of a property, and so will only work if len is equal to the
675 * current length of the property.
676 *
677 * This function will alter only the bytes in the blob which contain
678 * the given property value, and will not alter or move any other part
679 * of the tree.
680 *
681 * returns:
682 * 0, on success
683 * -FDT_ERR_NOSPACE, if len is not equal to the property's current length
684 * -FDT_ERR_NOTFOUND, node does not have the named property
685 * -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
686 * -FDT_ERR_BADMAGIC,
687 * -FDT_ERR_BADVERSION,
688 * -FDT_ERR_BADSTATE,
689 * -FDT_ERR_BADSTRUCTURE,
690 * -FDT_ERR_TRUNCATED, standard meanings
691 */
692 int fdt_setprop_inplace(void *fdt, int nodeoffset, const char *name,
693 const void *val, int len);
694
695 /**
696 * fdt_setprop_inplace_cell - change the value of a single-cell property
697 * @fdt: pointer to the device tree blob
698 * @nodeoffset: offset of the node whose property to change
699 * @name: name of the property to change
700 * @val: cell (32-bit integer) value to replace the property with
701 *
702 * fdt_setprop_inplace_cell() replaces the value of a given property
703 * with the 32-bit integer cell value in val, converting val to
704 * big-endian if necessary. This function cannot change the size of a
705 * property, and so will only work if the property already exists and
706 * has length 4.
707 *
708 * This function will alter only the bytes in the blob which contain
709 * the given property value, and will not alter or move any other part
710 * of the tree.
711 *
712 * returns:
713 * 0, on success
714 * -FDT_ERR_NOSPACE, if the property's length is not equal to 4
715 * -FDT_ERR_NOTFOUND, node does not have the named property
716 * -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
717 * -FDT_ERR_BADMAGIC,
718 * -FDT_ERR_BADVERSION,
719 * -FDT_ERR_BADSTATE,
720 * -FDT_ERR_BADSTRUCTURE,
721 * -FDT_ERR_TRUNCATED, standard meanings
722 */
fdt_setprop_inplace_cell(void * fdt,int nodeoffset,const char * name,uint32_t val)723 static inline int fdt_setprop_inplace_cell(void *fdt, int nodeoffset,
724 const char *name, uint32_t val)
725 {
726 val = cpu_to_fdt32(val);
727 return fdt_setprop_inplace(fdt, nodeoffset, name, &val, sizeof(val));
728 }
729
730 /**
731 * fdt_nop_property - replace a property with nop tags
732 * @fdt: pointer to the device tree blob
733 * @nodeoffset: offset of the node whose property to nop
734 * @name: name of the property to nop
735 *
736 * fdt_nop_property() will replace a given property's representation
737 * in the blob with FDT_NOP tags, effectively removing it from the
738 * tree.
739 *
740 * This function will alter only the bytes in the blob which contain
741 * the property, and will not alter or move any other part of the
742 * tree.
743 *
744 * returns:
745 * 0, on success
746 * -FDT_ERR_NOTFOUND, node does not have the named property
747 * -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
748 * -FDT_ERR_BADMAGIC,
749 * -FDT_ERR_BADVERSION,
750 * -FDT_ERR_BADSTATE,
751 * -FDT_ERR_BADSTRUCTURE,
752 * -FDT_ERR_TRUNCATED, standard meanings
753 */
754 int fdt_nop_property(void *fdt, int nodeoffset, const char *name);
755
756 /**
757 * fdt_nop_node - replace a node (subtree) with nop tags
758 * @fdt: pointer to the device tree blob
759 * @nodeoffset: offset of the node to nop
760 *
761 * fdt_nop_node() will replace a given node's representation in the
762 * blob, including all its subnodes, if any, with FDT_NOP tags,
763 * effectively removing it from the tree.
764 *
765 * This function will alter only the bytes in the blob which contain
766 * the node and its properties and subnodes, and will not alter or
767 * move any other part of the tree.
768 *
769 * returns:
770 * 0, on success
771 * -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
772 * -FDT_ERR_BADMAGIC,
773 * -FDT_ERR_BADVERSION,
774 * -FDT_ERR_BADSTATE,
775 * -FDT_ERR_BADSTRUCTURE,
776 * -FDT_ERR_TRUNCATED, standard meanings
777 */
778 int fdt_nop_node(void *fdt, int nodeoffset);
779
780 /**********************************************************************/
781 /* Sequential write functions */
782 /**********************************************************************/
783
784 int fdt_create(void *buf, int bufsize);
785 int fdt_add_reservemap_entry(void *fdt, uint64_t addr, uint64_t size);
786 int fdt_finish_reservemap(void *fdt);
787 int fdt_begin_node(void *fdt, const char *name);
788 int fdt_property(void *fdt, const char *name, const void *val, int len);
fdt_property_cell(void * fdt,const char * name,uint32_t val)789 static inline int fdt_property_cell(void *fdt, const char *name, uint32_t val)
790 {
791 val = cpu_to_fdt32(val);
792 return fdt_property(fdt, name, &val, sizeof(val));
793 }
794 #define fdt_property_string(fdt, name, str) \
795 fdt_property(fdt, name, str, strlen(str)+1)
796 int fdt_end_node(void *fdt);
797 int fdt_finish(void *fdt);
798
799 /**********************************************************************/
800 /* Read-write functions */
801 /**********************************************************************/
802
803 int fdt_open_into(const void *fdt, void *buf, int bufsize);
804 int fdt_pack(void *fdt);
805
806 /**
807 * fdt_add_mem_rsv - add one memory reserve map entry
808 * @fdt: pointer to the device tree blob
809 * @address, @size: 64-bit values (native endian)
810 *
811 * Adds a reserve map entry to the given blob reserving a region at
812 * address address of length size.
813 *
814 * This function will insert data into the reserve map and will
815 * therefore change the indexes of some entries in the table.
816 *
817 * returns:
818 * 0, on success
819 * -FDT_ERR_NOSPACE, there is insufficient free space in the blob to
820 * contain the new reservation entry
821 * -FDT_ERR_BADMAGIC,
822 * -FDT_ERR_BADVERSION,
823 * -FDT_ERR_BADSTATE,
824 * -FDT_ERR_BADSTRUCTURE,
825 * -FDT_ERR_BADLAYOUT,
826 * -FDT_ERR_TRUNCATED, standard meanings
827 */
828 int fdt_add_mem_rsv(void *fdt, uint64_t address, uint64_t size);
829
830 /**
831 * fdt_del_mem_rsv - remove a memory reserve map entry
832 * @fdt: pointer to the device tree blob
833 * @n: entry to remove
834 *
835 * fdt_del_mem_rsv() removes the n-th memory reserve map entry from
836 * the blob.
837 *
838 * This function will delete data from the reservation table and will
839 * therefore change the indexes of some entries in the table.
840 *
841 * returns:
842 * 0, on success
843 * -FDT_ERR_NOTFOUND, there is no entry of the given index (i.e. there
844 * are less than n+1 reserve map entries)
845 * -FDT_ERR_BADMAGIC,
846 * -FDT_ERR_BADVERSION,
847 * -FDT_ERR_BADSTATE,
848 * -FDT_ERR_BADSTRUCTURE,
849 * -FDT_ERR_BADLAYOUT,
850 * -FDT_ERR_TRUNCATED, standard meanings
851 */
852 int fdt_del_mem_rsv(void *fdt, int n);
853
854 /**
855 * fdt_set_name - change the name of a given node
856 * @fdt: pointer to the device tree blob
857 * @nodeoffset: structure block offset of a node
858 * @name: name to give the node
859 *
860 * fdt_set_name() replaces the name (including unit address, if any)
861 * of the given node with the given string. NOTE: this function can't
862 * efficiently check if the new name is unique amongst the given
863 * node's siblings; results are undefined if this function is invoked
864 * with a name equal to one of the given node's siblings.
865 *
866 * This function may insert or delete data from the blob, and will
867 * therefore change the offsets of some existing nodes.
868 *
869 * returns:
870 * 0, on success
871 * -FDT_ERR_NOSPACE, there is insufficient free space in the blob
872 * to contain the new name
873 * -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
874 * -FDT_ERR_BADMAGIC,
875 * -FDT_ERR_BADVERSION,
876 * -FDT_ERR_BADSTATE, standard meanings
877 */
878 int fdt_set_name(void *fdt, int nodeoffset, const char *name);
879
880 /**
881 * fdt_setprop - create or change a property
882 * @fdt: pointer to the device tree blob
883 * @nodeoffset: offset of the node whose property to change
884 * @name: name of the property to change
885 * @val: pointer to data to set the property value to
886 * @len: length of the property value
887 *
888 * fdt_setprop() sets the value of the named property in the given
889 * node to the given value and length, creating the property if it
890 * does not already exist.
891 *
892 * This function may insert or delete data from the blob, and will
893 * therefore change the offsets of some existing nodes.
894 *
895 * returns:
896 * 0, on success
897 * -FDT_ERR_NOSPACE, there is insufficient free space in the blob to
898 * contain the new property value
899 * -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
900 * -FDT_ERR_BADLAYOUT,
901 * -FDT_ERR_BADMAGIC,
902 * -FDT_ERR_BADVERSION,
903 * -FDT_ERR_BADSTATE,
904 * -FDT_ERR_BADSTRUCTURE,
905 * -FDT_ERR_BADLAYOUT,
906 * -FDT_ERR_TRUNCATED, standard meanings
907 */
908 int fdt_setprop(void *fdt, int nodeoffset, const char *name,
909 const void *val, int len);
910
911 /**
912 * fdt_setprop_cell - set a property to a single cell value
913 * @fdt: pointer to the device tree blob
914 * @nodeoffset: offset of the node whose property to change
915 * @name: name of the property to change
916 * @val: 32-bit integer value for the property (native endian)
917 *
918 * fdt_setprop_cell() sets the value of the named property in the
919 * given node to the given cell value (converting to big-endian if
920 * necessary), or creates a new property with that value if it does
921 * not already exist.
922 *
923 * This function may insert or delete data from the blob, and will
924 * therefore change the offsets of some existing nodes.
925 *
926 * returns:
927 * 0, on success
928 * -FDT_ERR_NOSPACE, there is insufficient free space in the blob to
929 * contain the new property value
930 * -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
931 * -FDT_ERR_BADLAYOUT,
932 * -FDT_ERR_BADMAGIC,
933 * -FDT_ERR_BADVERSION,
934 * -FDT_ERR_BADSTATE,
935 * -FDT_ERR_BADSTRUCTURE,
936 * -FDT_ERR_BADLAYOUT,
937 * -FDT_ERR_TRUNCATED, standard meanings
938 */
fdt_setprop_cell(void * fdt,int nodeoffset,const char * name,uint32_t val)939 static inline int fdt_setprop_cell(void *fdt, int nodeoffset, const char *name,
940 uint32_t val)
941 {
942 val = cpu_to_fdt32(val);
943 return fdt_setprop(fdt, nodeoffset, name, &val, sizeof(val));
944 }
945
946 /**
947 * fdt_setprop_string - set a property to a string value
948 * @fdt: pointer to the device tree blob
949 * @nodeoffset: offset of the node whose property to change
950 * @name: name of the property to change
951 * @str: string value for the property
952 *
953 * fdt_setprop_string() sets the value of the named property in the
954 * given node to the given string value (using the length of the
955 * string to determine the new length of the property), or creates a
956 * new property with that value if it does not already exist.
957 *
958 * This function may insert or delete data from the blob, and will
959 * therefore change the offsets of some existing nodes.
960 *
961 * returns:
962 * 0, on success
963 * -FDT_ERR_NOSPACE, there is insufficient free space in the blob to
964 * contain the new property value
965 * -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
966 * -FDT_ERR_BADLAYOUT,
967 * -FDT_ERR_BADMAGIC,
968 * -FDT_ERR_BADVERSION,
969 * -FDT_ERR_BADSTATE,
970 * -FDT_ERR_BADSTRUCTURE,
971 * -FDT_ERR_BADLAYOUT,
972 * -FDT_ERR_TRUNCATED, standard meanings
973 */
974 #define fdt_setprop_string(fdt, nodeoffset, name, str) \
975 fdt_setprop((fdt), (nodeoffset), (name), (str), strlen(str)+1)
976
977 /**
978 * fdt_delprop - delete a property
979 * @fdt: pointer to the device tree blob
980 * @nodeoffset: offset of the node whose property to nop
981 * @name: name of the property to nop
982 *
983 * fdt_del_property() will delete the given property.
984 *
985 * This function will delete data from the blob, and will therefore
986 * change the offsets of some existing nodes.
987 *
988 * returns:
989 * 0, on success
990 * -FDT_ERR_NOTFOUND, node does not have the named property
991 * -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
992 * -FDT_ERR_BADLAYOUT,
993 * -FDT_ERR_BADMAGIC,
994 * -FDT_ERR_BADVERSION,
995 * -FDT_ERR_BADSTATE,
996 * -FDT_ERR_BADSTRUCTURE,
997 * -FDT_ERR_TRUNCATED, standard meanings
998 */
999 int fdt_delprop(void *fdt, int nodeoffset, const char *name);
1000
1001 /**
1002 * fdt_add_subnode_namelen - creates a new node based on substring
1003 * @fdt: pointer to the device tree blob
1004 * @parentoffset: structure block offset of a node
1005 * @name: name of the subnode to locate
1006 * @namelen: number of characters of name to consider
1007 *
1008 * Identical to fdt_add_subnode(), but use only the first namelen
1009 * characters of name as the name of the new node. This is useful for
1010 * creating subnodes based on a portion of a larger string, such as a
1011 * full path.
1012 */
1013 int fdt_add_subnode_namelen(void *fdt, int parentoffset,
1014 const char *name, int namelen);
1015
1016 /**
1017 * fdt_add_subnode - creates a new node
1018 * @fdt: pointer to the device tree blob
1019 * @parentoffset: structure block offset of a node
1020 * @name: name of the subnode to locate
1021 *
1022 * fdt_add_subnode() creates a new node as a subnode of the node at
1023 * structure block offset parentoffset, with the given name (which
1024 * should include the unit address, if any).
1025 *
1026 * This function will insert data into the blob, and will therefore
1027 * change the offsets of some existing nodes.
1028
1029 * returns:
1030 * structure block offset of the created nodeequested subnode (>=0), on success
1031 * -FDT_ERR_NOTFOUND, if the requested subnode does not exist
1032 * -FDT_ERR_BADOFFSET, if parentoffset did not point to an FDT_BEGIN_NODE tag
1033 * -FDT_ERR_EXISTS, if the node at parentoffset already has a subnode of
1034 * the given name
1035 * -FDT_ERR_NOSPACE, if there is insufficient free space in the
1036 * blob to contain the new node
1037 * -FDT_ERR_NOSPACE
1038 * -FDT_ERR_BADLAYOUT
1039 * -FDT_ERR_BADMAGIC,
1040 * -FDT_ERR_BADVERSION,
1041 * -FDT_ERR_BADSTATE,
1042 * -FDT_ERR_BADSTRUCTURE,
1043 * -FDT_ERR_TRUNCATED, standard meanings.
1044 */
1045 int fdt_add_subnode(void *fdt, int parentoffset, const char *name);
1046
1047 /**
1048 * fdt_del_node - delete a node (subtree)
1049 * @fdt: pointer to the device tree blob
1050 * @nodeoffset: offset of the node to nop
1051 *
1052 * fdt_del_node() will remove the given node, including all its
1053 * subnodes if any, from the blob.
1054 *
1055 * This function will delete data from the blob, and will therefore
1056 * change the offsets of some existing nodes.
1057 *
1058 * returns:
1059 * 0, on success
1060 * -FDT_ERR_BADOFFSET, nodeoffset did not point to FDT_BEGIN_NODE tag
1061 * -FDT_ERR_BADLAYOUT,
1062 * -FDT_ERR_BADMAGIC,
1063 * -FDT_ERR_BADVERSION,
1064 * -FDT_ERR_BADSTATE,
1065 * -FDT_ERR_BADSTRUCTURE,
1066 * -FDT_ERR_TRUNCATED, standard meanings
1067 */
1068 int fdt_del_node(void *fdt, int nodeoffset);
1069
1070 /**********************************************************************/
1071 /* Debugging / informational functions */
1072 /**********************************************************************/
1073
1074 const char *fdt_strerror(int errval);
1075
1076 #endif /* _LIBFDT_H */
1077