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