Commit | Line | Data |
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97e873e5 SR |
1 | /* |
2 | * Procedures for creating, accessing and interpreting the device tree. | |
3 | * | |
4 | * Paul Mackerras August 1996. | |
5 | * Copyright (C) 1996-2005 Paul Mackerras. | |
6 | * | |
7 | * Adapted for 64bit PowerPC by Dave Engebretsen and Peter Bergner. | |
8 | * {engebret|bergner}@us.ibm.com | |
9 | * | |
10 | * Adapted for sparc and sparc64 by David S. Miller davem@davemloft.net | |
11 | * | |
e91edcf5 GL |
12 | * Reconsolidated from arch/x/kernel/prom.c by Stephen Rothwell and |
13 | * Grant Likely. | |
97e873e5 SR |
14 | * |
15 | * This program is free software; you can redistribute it and/or | |
16 | * modify it under the terms of the GNU General Public License | |
17 | * as published by the Free Software Foundation; either version | |
18 | * 2 of the License, or (at your option) any later version. | |
19 | */ | |
611cad72 | 20 | #include <linux/ctype.h> |
97e873e5 SR |
21 | #include <linux/module.h> |
22 | #include <linux/of.h> | |
581b605a | 23 | #include <linux/spinlock.h> |
5a0e3ad6 | 24 | #include <linux/slab.h> |
a9f2f63a | 25 | #include <linux/proc_fs.h> |
581b605a | 26 | |
611cad72 SG |
27 | /** |
28 | * struct alias_prop - Alias property in 'aliases' node | |
29 | * @link: List node to link the structure in aliases_lookup list | |
30 | * @alias: Alias property name | |
31 | * @np: Pointer to device_node that the alias stands for | |
32 | * @id: Index value from end of alias name | |
33 | * @stem: Alias string without the index | |
34 | * | |
35 | * The structure represents one alias property of 'aliases' node as | |
36 | * an entry in aliases_lookup list. | |
37 | */ | |
38 | struct alias_prop { | |
39 | struct list_head link; | |
40 | const char *alias; | |
41 | struct device_node *np; | |
42 | int id; | |
43 | char stem[0]; | |
44 | }; | |
45 | ||
46 | static LIST_HEAD(aliases_lookup); | |
47 | ||
1ef4d424 | 48 | struct device_node *allnodes; |
fc0bdae4 | 49 | struct device_node *of_chosen; |
611cad72 SG |
50 | struct device_node *of_aliases; |
51 | ||
52 | static DEFINE_MUTEX(of_aliases_mutex); | |
1ef4d424 | 53 | |
581b605a SR |
54 | /* use when traversing tree through the allnext, child, sibling, |
55 | * or parent members of struct device_node. | |
56 | */ | |
57 | DEFINE_RWLOCK(devtree_lock); | |
97e873e5 SR |
58 | |
59 | int of_n_addr_cells(struct device_node *np) | |
60 | { | |
a9fadeef | 61 | const __be32 *ip; |
97e873e5 SR |
62 | |
63 | do { | |
64 | if (np->parent) | |
65 | np = np->parent; | |
66 | ip = of_get_property(np, "#address-cells", NULL); | |
67 | if (ip) | |
33714881 | 68 | return be32_to_cpup(ip); |
97e873e5 SR |
69 | } while (np->parent); |
70 | /* No #address-cells property for the root node */ | |
71 | return OF_ROOT_NODE_ADDR_CELLS_DEFAULT; | |
72 | } | |
73 | EXPORT_SYMBOL(of_n_addr_cells); | |
74 | ||
75 | int of_n_size_cells(struct device_node *np) | |
76 | { | |
a9fadeef | 77 | const __be32 *ip; |
97e873e5 SR |
78 | |
79 | do { | |
80 | if (np->parent) | |
81 | np = np->parent; | |
82 | ip = of_get_property(np, "#size-cells", NULL); | |
83 | if (ip) | |
33714881 | 84 | return be32_to_cpup(ip); |
97e873e5 SR |
85 | } while (np->parent); |
86 | /* No #size-cells property for the root node */ | |
87 | return OF_ROOT_NODE_SIZE_CELLS_DEFAULT; | |
88 | } | |
89 | EXPORT_SYMBOL(of_n_size_cells); | |
90 | ||
923f7e30 GL |
91 | #if !defined(CONFIG_SPARC) /* SPARC doesn't do ref counting (yet) */ |
92 | /** | |
93 | * of_node_get - Increment refcount of a node | |
94 | * @node: Node to inc refcount, NULL is supported to | |
95 | * simplify writing of callers | |
96 | * | |
97 | * Returns node. | |
98 | */ | |
99 | struct device_node *of_node_get(struct device_node *node) | |
100 | { | |
101 | if (node) | |
102 | kref_get(&node->kref); | |
103 | return node; | |
104 | } | |
105 | EXPORT_SYMBOL(of_node_get); | |
106 | ||
107 | static inline struct device_node *kref_to_device_node(struct kref *kref) | |
108 | { | |
109 | return container_of(kref, struct device_node, kref); | |
110 | } | |
111 | ||
112 | /** | |
113 | * of_node_release - release a dynamically allocated node | |
114 | * @kref: kref element of the node to be released | |
115 | * | |
116 | * In of_node_put() this function is passed to kref_put() | |
117 | * as the destructor. | |
118 | */ | |
119 | static void of_node_release(struct kref *kref) | |
120 | { | |
121 | struct device_node *node = kref_to_device_node(kref); | |
122 | struct property *prop = node->properties; | |
123 | ||
124 | /* We should never be releasing nodes that haven't been detached. */ | |
125 | if (!of_node_check_flag(node, OF_DETACHED)) { | |
126 | pr_err("ERROR: Bad of_node_put() on %s\n", node->full_name); | |
127 | dump_stack(); | |
128 | kref_init(&node->kref); | |
129 | return; | |
130 | } | |
131 | ||
132 | if (!of_node_check_flag(node, OF_DYNAMIC)) | |
133 | return; | |
134 | ||
135 | while (prop) { | |
136 | struct property *next = prop->next; | |
137 | kfree(prop->name); | |
138 | kfree(prop->value); | |
139 | kfree(prop); | |
140 | prop = next; | |
141 | ||
142 | if (!prop) { | |
143 | prop = node->deadprops; | |
144 | node->deadprops = NULL; | |
145 | } | |
146 | } | |
147 | kfree(node->full_name); | |
148 | kfree(node->data); | |
149 | kfree(node); | |
150 | } | |
151 | ||
152 | /** | |
153 | * of_node_put - Decrement refcount of a node | |
154 | * @node: Node to dec refcount, NULL is supported to | |
155 | * simplify writing of callers | |
156 | * | |
157 | */ | |
158 | void of_node_put(struct device_node *node) | |
159 | { | |
160 | if (node) | |
161 | kref_put(&node->kref, of_node_release); | |
162 | } | |
163 | EXPORT_SYMBOL(of_node_put); | |
164 | #endif /* !CONFIG_SPARC */ | |
165 | ||
581b605a SR |
166 | struct property *of_find_property(const struct device_node *np, |
167 | const char *name, | |
168 | int *lenp) | |
169 | { | |
170 | struct property *pp; | |
171 | ||
64e4566f TT |
172 | if (!np) |
173 | return NULL; | |
174 | ||
581b605a SR |
175 | read_lock(&devtree_lock); |
176 | for (pp = np->properties; pp != 0; pp = pp->next) { | |
177 | if (of_prop_cmp(pp->name, name) == 0) { | |
178 | if (lenp != 0) | |
179 | *lenp = pp->length; | |
180 | break; | |
181 | } | |
182 | } | |
183 | read_unlock(&devtree_lock); | |
184 | ||
185 | return pp; | |
186 | } | |
187 | EXPORT_SYMBOL(of_find_property); | |
188 | ||
e91edcf5 GL |
189 | /** |
190 | * of_find_all_nodes - Get next node in global list | |
191 | * @prev: Previous node or NULL to start iteration | |
192 | * of_node_put() will be called on it | |
193 | * | |
194 | * Returns a node pointer with refcount incremented, use | |
195 | * of_node_put() on it when done. | |
196 | */ | |
197 | struct device_node *of_find_all_nodes(struct device_node *prev) | |
198 | { | |
199 | struct device_node *np; | |
200 | ||
201 | read_lock(&devtree_lock); | |
202 | np = prev ? prev->allnext : allnodes; | |
203 | for (; np != NULL; np = np->allnext) | |
204 | if (of_node_get(np)) | |
205 | break; | |
206 | of_node_put(prev); | |
207 | read_unlock(&devtree_lock); | |
208 | return np; | |
209 | } | |
210 | EXPORT_SYMBOL(of_find_all_nodes); | |
211 | ||
97e873e5 SR |
212 | /* |
213 | * Find a property with a given name for a given node | |
214 | * and return the value. | |
215 | */ | |
216 | const void *of_get_property(const struct device_node *np, const char *name, | |
217 | int *lenp) | |
218 | { | |
219 | struct property *pp = of_find_property(np, name, lenp); | |
220 | ||
221 | return pp ? pp->value : NULL; | |
222 | } | |
223 | EXPORT_SYMBOL(of_get_property); | |
0081cbc3 SR |
224 | |
225 | /** Checks if the given "compat" string matches one of the strings in | |
226 | * the device's "compatible" property | |
227 | */ | |
228 | int of_device_is_compatible(const struct device_node *device, | |
229 | const char *compat) | |
230 | { | |
231 | const char* cp; | |
232 | int cplen, l; | |
233 | ||
234 | cp = of_get_property(device, "compatible", &cplen); | |
235 | if (cp == NULL) | |
236 | return 0; | |
237 | while (cplen > 0) { | |
238 | if (of_compat_cmp(cp, compat, strlen(compat)) == 0) | |
239 | return 1; | |
240 | l = strlen(cp) + 1; | |
241 | cp += l; | |
242 | cplen -= l; | |
243 | } | |
244 | ||
245 | return 0; | |
246 | } | |
247 | EXPORT_SYMBOL(of_device_is_compatible); | |
e679c5f4 | 248 | |
1f43cfb9 | 249 | /** |
71a157e8 | 250 | * of_machine_is_compatible - Test root of device tree for a given compatible value |
1f43cfb9 GL |
251 | * @compat: compatible string to look for in root node's compatible property. |
252 | * | |
253 | * Returns true if the root node has the given value in its | |
254 | * compatible property. | |
255 | */ | |
71a157e8 | 256 | int of_machine_is_compatible(const char *compat) |
1f43cfb9 GL |
257 | { |
258 | struct device_node *root; | |
259 | int rc = 0; | |
260 | ||
261 | root = of_find_node_by_path("/"); | |
262 | if (root) { | |
263 | rc = of_device_is_compatible(root, compat); | |
264 | of_node_put(root); | |
265 | } | |
266 | return rc; | |
267 | } | |
71a157e8 | 268 | EXPORT_SYMBOL(of_machine_is_compatible); |
1f43cfb9 | 269 | |
834d97d4 JB |
270 | /** |
271 | * of_device_is_available - check if a device is available for use | |
272 | * | |
273 | * @device: Node to check for availability | |
274 | * | |
275 | * Returns 1 if the status property is absent or set to "okay" or "ok", | |
276 | * 0 otherwise | |
277 | */ | |
278 | int of_device_is_available(const struct device_node *device) | |
279 | { | |
280 | const char *status; | |
281 | int statlen; | |
282 | ||
283 | status = of_get_property(device, "status", &statlen); | |
284 | if (status == NULL) | |
285 | return 1; | |
286 | ||
287 | if (statlen > 0) { | |
288 | if (!strcmp(status, "okay") || !strcmp(status, "ok")) | |
289 | return 1; | |
290 | } | |
291 | ||
292 | return 0; | |
293 | } | |
294 | EXPORT_SYMBOL(of_device_is_available); | |
295 | ||
e679c5f4 SR |
296 | /** |
297 | * of_get_parent - Get a node's parent if any | |
298 | * @node: Node to get parent | |
299 | * | |
300 | * Returns a node pointer with refcount incremented, use | |
301 | * of_node_put() on it when done. | |
302 | */ | |
303 | struct device_node *of_get_parent(const struct device_node *node) | |
304 | { | |
305 | struct device_node *np; | |
306 | ||
307 | if (!node) | |
308 | return NULL; | |
309 | ||
310 | read_lock(&devtree_lock); | |
311 | np = of_node_get(node->parent); | |
312 | read_unlock(&devtree_lock); | |
313 | return np; | |
314 | } | |
315 | EXPORT_SYMBOL(of_get_parent); | |
d1cd355a | 316 | |
f4eb0107 ME |
317 | /** |
318 | * of_get_next_parent - Iterate to a node's parent | |
319 | * @node: Node to get parent of | |
320 | * | |
321 | * This is like of_get_parent() except that it drops the | |
322 | * refcount on the passed node, making it suitable for iterating | |
323 | * through a node's parents. | |
324 | * | |
325 | * Returns a node pointer with refcount incremented, use | |
326 | * of_node_put() on it when done. | |
327 | */ | |
328 | struct device_node *of_get_next_parent(struct device_node *node) | |
329 | { | |
330 | struct device_node *parent; | |
331 | ||
332 | if (!node) | |
333 | return NULL; | |
334 | ||
335 | read_lock(&devtree_lock); | |
336 | parent = of_node_get(node->parent); | |
337 | of_node_put(node); | |
338 | read_unlock(&devtree_lock); | |
339 | return parent; | |
340 | } | |
341 | ||
d1cd355a SR |
342 | /** |
343 | * of_get_next_child - Iterate a node childs | |
344 | * @node: parent node | |
345 | * @prev: previous child of the parent node, or NULL to get first | |
346 | * | |
347 | * Returns a node pointer with refcount incremented, use | |
348 | * of_node_put() on it when done. | |
349 | */ | |
350 | struct device_node *of_get_next_child(const struct device_node *node, | |
351 | struct device_node *prev) | |
352 | { | |
353 | struct device_node *next; | |
354 | ||
355 | read_lock(&devtree_lock); | |
356 | next = prev ? prev->sibling : node->child; | |
357 | for (; next; next = next->sibling) | |
358 | if (of_node_get(next)) | |
359 | break; | |
360 | of_node_put(prev); | |
361 | read_unlock(&devtree_lock); | |
362 | return next; | |
363 | } | |
364 | EXPORT_SYMBOL(of_get_next_child); | |
1ef4d424 SR |
365 | |
366 | /** | |
367 | * of_find_node_by_path - Find a node matching a full OF path | |
368 | * @path: The full path to match | |
369 | * | |
370 | * Returns a node pointer with refcount incremented, use | |
371 | * of_node_put() on it when done. | |
372 | */ | |
373 | struct device_node *of_find_node_by_path(const char *path) | |
374 | { | |
375 | struct device_node *np = allnodes; | |
376 | ||
377 | read_lock(&devtree_lock); | |
378 | for (; np; np = np->allnext) { | |
379 | if (np->full_name && (of_node_cmp(np->full_name, path) == 0) | |
380 | && of_node_get(np)) | |
381 | break; | |
382 | } | |
383 | read_unlock(&devtree_lock); | |
384 | return np; | |
385 | } | |
386 | EXPORT_SYMBOL(of_find_node_by_path); | |
387 | ||
388 | /** | |
389 | * of_find_node_by_name - Find a node by its "name" property | |
390 | * @from: The node to start searching from or NULL, the node | |
391 | * you pass will not be searched, only the next one | |
392 | * will; typically, you pass what the previous call | |
393 | * returned. of_node_put() will be called on it | |
394 | * @name: The name string to match against | |
395 | * | |
396 | * Returns a node pointer with refcount incremented, use | |
397 | * of_node_put() on it when done. | |
398 | */ | |
399 | struct device_node *of_find_node_by_name(struct device_node *from, | |
400 | const char *name) | |
401 | { | |
402 | struct device_node *np; | |
403 | ||
404 | read_lock(&devtree_lock); | |
405 | np = from ? from->allnext : allnodes; | |
406 | for (; np; np = np->allnext) | |
407 | if (np->name && (of_node_cmp(np->name, name) == 0) | |
408 | && of_node_get(np)) | |
409 | break; | |
410 | of_node_put(from); | |
411 | read_unlock(&devtree_lock); | |
412 | return np; | |
413 | } | |
414 | EXPORT_SYMBOL(of_find_node_by_name); | |
415 | ||
416 | /** | |
417 | * of_find_node_by_type - Find a node by its "device_type" property | |
418 | * @from: The node to start searching from, or NULL to start searching | |
419 | * the entire device tree. The node you pass will not be | |
420 | * searched, only the next one will; typically, you pass | |
421 | * what the previous call returned. of_node_put() will be | |
422 | * called on from for you. | |
423 | * @type: The type string to match against | |
424 | * | |
425 | * Returns a node pointer with refcount incremented, use | |
426 | * of_node_put() on it when done. | |
427 | */ | |
428 | struct device_node *of_find_node_by_type(struct device_node *from, | |
429 | const char *type) | |
430 | { | |
431 | struct device_node *np; | |
432 | ||
433 | read_lock(&devtree_lock); | |
434 | np = from ? from->allnext : allnodes; | |
435 | for (; np; np = np->allnext) | |
436 | if (np->type && (of_node_cmp(np->type, type) == 0) | |
437 | && of_node_get(np)) | |
438 | break; | |
439 | of_node_put(from); | |
440 | read_unlock(&devtree_lock); | |
441 | return np; | |
442 | } | |
443 | EXPORT_SYMBOL(of_find_node_by_type); | |
444 | ||
445 | /** | |
446 | * of_find_compatible_node - Find a node based on type and one of the | |
447 | * tokens in its "compatible" property | |
448 | * @from: The node to start searching from or NULL, the node | |
449 | * you pass will not be searched, only the next one | |
450 | * will; typically, you pass what the previous call | |
451 | * returned. of_node_put() will be called on it | |
452 | * @type: The type string to match "device_type" or NULL to ignore | |
453 | * @compatible: The string to match to one of the tokens in the device | |
454 | * "compatible" list. | |
455 | * | |
456 | * Returns a node pointer with refcount incremented, use | |
457 | * of_node_put() on it when done. | |
458 | */ | |
459 | struct device_node *of_find_compatible_node(struct device_node *from, | |
460 | const char *type, const char *compatible) | |
461 | { | |
462 | struct device_node *np; | |
463 | ||
464 | read_lock(&devtree_lock); | |
465 | np = from ? from->allnext : allnodes; | |
466 | for (; np; np = np->allnext) { | |
467 | if (type | |
468 | && !(np->type && (of_node_cmp(np->type, type) == 0))) | |
469 | continue; | |
470 | if (of_device_is_compatible(np, compatible) && of_node_get(np)) | |
471 | break; | |
472 | } | |
473 | of_node_put(from); | |
474 | read_unlock(&devtree_lock); | |
475 | return np; | |
476 | } | |
477 | EXPORT_SYMBOL(of_find_compatible_node); | |
283029d1 | 478 | |
1e291b14 ME |
479 | /** |
480 | * of_find_node_with_property - Find a node which has a property with | |
481 | * the given name. | |
482 | * @from: The node to start searching from or NULL, the node | |
483 | * you pass will not be searched, only the next one | |
484 | * will; typically, you pass what the previous call | |
485 | * returned. of_node_put() will be called on it | |
486 | * @prop_name: The name of the property to look for. | |
487 | * | |
488 | * Returns a node pointer with refcount incremented, use | |
489 | * of_node_put() on it when done. | |
490 | */ | |
491 | struct device_node *of_find_node_with_property(struct device_node *from, | |
492 | const char *prop_name) | |
493 | { | |
494 | struct device_node *np; | |
495 | struct property *pp; | |
496 | ||
497 | read_lock(&devtree_lock); | |
498 | np = from ? from->allnext : allnodes; | |
499 | for (; np; np = np->allnext) { | |
500 | for (pp = np->properties; pp != 0; pp = pp->next) { | |
501 | if (of_prop_cmp(pp->name, prop_name) == 0) { | |
502 | of_node_get(np); | |
503 | goto out; | |
504 | } | |
505 | } | |
506 | } | |
507 | out: | |
508 | of_node_put(from); | |
509 | read_unlock(&devtree_lock); | |
510 | return np; | |
511 | } | |
512 | EXPORT_SYMBOL(of_find_node_with_property); | |
513 | ||
283029d1 GL |
514 | /** |
515 | * of_match_node - Tell if an device_node has a matching of_match structure | |
516 | * @matches: array of of device match structures to search in | |
517 | * @node: the of device structure to match against | |
518 | * | |
519 | * Low level utility function used by device matching. | |
520 | */ | |
521 | const struct of_device_id *of_match_node(const struct of_device_id *matches, | |
522 | const struct device_node *node) | |
523 | { | |
a52f07ec GL |
524 | if (!matches) |
525 | return NULL; | |
526 | ||
283029d1 GL |
527 | while (matches->name[0] || matches->type[0] || matches->compatible[0]) { |
528 | int match = 1; | |
529 | if (matches->name[0]) | |
530 | match &= node->name | |
531 | && !strcmp(matches->name, node->name); | |
532 | if (matches->type[0]) | |
533 | match &= node->type | |
534 | && !strcmp(matches->type, node->type); | |
535 | if (matches->compatible[0]) | |
536 | match &= of_device_is_compatible(node, | |
537 | matches->compatible); | |
538 | if (match) | |
539 | return matches; | |
540 | matches++; | |
541 | } | |
542 | return NULL; | |
543 | } | |
544 | EXPORT_SYMBOL(of_match_node); | |
545 | ||
546 | /** | |
547 | * of_find_matching_node - Find a node based on an of_device_id match | |
548 | * table. | |
549 | * @from: The node to start searching from or NULL, the node | |
550 | * you pass will not be searched, only the next one | |
551 | * will; typically, you pass what the previous call | |
552 | * returned. of_node_put() will be called on it | |
553 | * @matches: array of of device match structures to search in | |
554 | * | |
555 | * Returns a node pointer with refcount incremented, use | |
556 | * of_node_put() on it when done. | |
557 | */ | |
558 | struct device_node *of_find_matching_node(struct device_node *from, | |
559 | const struct of_device_id *matches) | |
560 | { | |
561 | struct device_node *np; | |
562 | ||
563 | read_lock(&devtree_lock); | |
564 | np = from ? from->allnext : allnodes; | |
565 | for (; np; np = np->allnext) { | |
566 | if (of_match_node(matches, np) && of_node_get(np)) | |
567 | break; | |
568 | } | |
569 | of_node_put(from); | |
570 | read_unlock(&devtree_lock); | |
571 | return np; | |
572 | } | |
573 | EXPORT_SYMBOL(of_find_matching_node); | |
3f07af49 | 574 | |
3f07af49 GL |
575 | /** |
576 | * of_modalias_node - Lookup appropriate modalias for a device node | |
577 | * @node: pointer to a device tree node | |
578 | * @modalias: Pointer to buffer that modalias value will be copied into | |
579 | * @len: Length of modalias value | |
580 | * | |
2ffe8c5f GL |
581 | * Based on the value of the compatible property, this routine will attempt |
582 | * to choose an appropriate modalias value for a particular device tree node. | |
583 | * It does this by stripping the manufacturer prefix (as delimited by a ',') | |
584 | * from the first entry in the compatible list property. | |
3f07af49 | 585 | * |
2ffe8c5f | 586 | * This routine returns 0 on success, <0 on failure. |
3f07af49 GL |
587 | */ |
588 | int of_modalias_node(struct device_node *node, char *modalias, int len) | |
589 | { | |
2ffe8c5f GL |
590 | const char *compatible, *p; |
591 | int cplen; | |
3f07af49 GL |
592 | |
593 | compatible = of_get_property(node, "compatible", &cplen); | |
2ffe8c5f | 594 | if (!compatible || strlen(compatible) > cplen) |
3f07af49 | 595 | return -ENODEV; |
3f07af49 | 596 | p = strchr(compatible, ','); |
2ffe8c5f | 597 | strlcpy(modalias, p ? p + 1 : compatible, len); |
3f07af49 GL |
598 | return 0; |
599 | } | |
600 | EXPORT_SYMBOL_GPL(of_modalias_node); | |
601 | ||
89751a7c JK |
602 | /** |
603 | * of_find_node_by_phandle - Find a node given a phandle | |
604 | * @handle: phandle of the node to find | |
605 | * | |
606 | * Returns a node pointer with refcount incremented, use | |
607 | * of_node_put() on it when done. | |
608 | */ | |
609 | struct device_node *of_find_node_by_phandle(phandle handle) | |
610 | { | |
611 | struct device_node *np; | |
612 | ||
613 | read_lock(&devtree_lock); | |
614 | for (np = allnodes; np; np = np->allnext) | |
615 | if (np->phandle == handle) | |
616 | break; | |
617 | of_node_get(np); | |
618 | read_unlock(&devtree_lock); | |
619 | return np; | |
620 | } | |
621 | EXPORT_SYMBOL(of_find_node_by_phandle); | |
622 | ||
a3b85363 | 623 | /** |
0e373639 RH |
624 | * of_property_read_u32_array - Find and read an array of 32 bit integers |
625 | * from a property. | |
626 | * | |
a3b85363 TA |
627 | * @np: device node from which the property value is to be read. |
628 | * @propname: name of the property to be searched. | |
629 | * @out_value: pointer to return value, modified only if return value is 0. | |
630 | * | |
0e373639 | 631 | * Search for a property in a device node and read 32-bit value(s) from |
a3b85363 TA |
632 | * it. Returns 0 on success, -EINVAL if the property does not exist, |
633 | * -ENODATA if property does not have a value, and -EOVERFLOW if the | |
634 | * property data isn't large enough. | |
635 | * | |
636 | * The out_value is modified only if a valid u32 value can be decoded. | |
637 | */ | |
aac285c6 JI |
638 | int of_property_read_u32_array(const struct device_node *np, |
639 | const char *propname, u32 *out_values, | |
640 | size_t sz) | |
a3b85363 TA |
641 | { |
642 | struct property *prop = of_find_property(np, propname, NULL); | |
0e373639 | 643 | const __be32 *val; |
a3b85363 TA |
644 | |
645 | if (!prop) | |
646 | return -EINVAL; | |
647 | if (!prop->value) | |
648 | return -ENODATA; | |
0e373639 | 649 | if ((sz * sizeof(*out_values)) > prop->length) |
a3b85363 | 650 | return -EOVERFLOW; |
0e373639 RH |
651 | |
652 | val = prop->value; | |
653 | while (sz--) | |
654 | *out_values++ = be32_to_cpup(val++); | |
a3b85363 TA |
655 | return 0; |
656 | } | |
0e373639 | 657 | EXPORT_SYMBOL_GPL(of_property_read_u32_array); |
a3b85363 TA |
658 | |
659 | /** | |
660 | * of_property_read_string - Find and read a string from a property | |
661 | * @np: device node from which the property value is to be read. | |
662 | * @propname: name of the property to be searched. | |
663 | * @out_string: pointer to null terminated return string, modified only if | |
664 | * return value is 0. | |
665 | * | |
666 | * Search for a property in a device tree node and retrieve a null | |
667 | * terminated string value (pointer to data, not a copy). Returns 0 on | |
668 | * success, -EINVAL if the property does not exist, -ENODATA if property | |
669 | * does not have a value, and -EILSEQ if the string is not null-terminated | |
670 | * within the length of the property data. | |
671 | * | |
672 | * The out_string pointer is modified only if a valid string can be decoded. | |
673 | */ | |
aac285c6 | 674 | int of_property_read_string(struct device_node *np, const char *propname, |
f09bc831 | 675 | const char **out_string) |
a3b85363 TA |
676 | { |
677 | struct property *prop = of_find_property(np, propname, NULL); | |
678 | if (!prop) | |
679 | return -EINVAL; | |
680 | if (!prop->value) | |
681 | return -ENODATA; | |
682 | if (strnlen(prop->value, prop->length) >= prop->length) | |
683 | return -EILSEQ; | |
684 | *out_string = prop->value; | |
685 | return 0; | |
686 | } | |
687 | EXPORT_SYMBOL_GPL(of_property_read_string); | |
688 | ||
739649c5 GL |
689 | /** |
690 | * of_parse_phandle - Resolve a phandle property to a device_node pointer | |
691 | * @np: Pointer to device node holding phandle property | |
692 | * @phandle_name: Name of property holding a phandle value | |
693 | * @index: For properties holding a table of phandles, this is the index into | |
694 | * the table | |
695 | * | |
696 | * Returns the device_node pointer with refcount incremented. Use | |
697 | * of_node_put() on it when done. | |
698 | */ | |
699 | struct device_node * | |
700 | of_parse_phandle(struct device_node *np, const char *phandle_name, int index) | |
701 | { | |
9a6b2e58 | 702 | const __be32 *phandle; |
739649c5 GL |
703 | int size; |
704 | ||
705 | phandle = of_get_property(np, phandle_name, &size); | |
706 | if ((!phandle) || (size < sizeof(*phandle) * (index + 1))) | |
707 | return NULL; | |
708 | ||
9a6b2e58 | 709 | return of_find_node_by_phandle(be32_to_cpup(phandle + index)); |
739649c5 GL |
710 | } |
711 | EXPORT_SYMBOL(of_parse_phandle); | |
712 | ||
64b60e09 AV |
713 | /** |
714 | * of_parse_phandles_with_args - Find a node pointed by phandle in a list | |
715 | * @np: pointer to a device tree node containing a list | |
716 | * @list_name: property name that contains a list | |
717 | * @cells_name: property name that specifies phandles' arguments count | |
718 | * @index: index of a phandle to parse out | |
7736a3db AV |
719 | * @out_node: optional pointer to device_node struct pointer (will be filled) |
720 | * @out_args: optional pointer to arguments pointer (will be filled) | |
64b60e09 AV |
721 | * |
722 | * This function is useful to parse lists of phandles and their arguments. | |
723 | * Returns 0 on success and fills out_node and out_args, on error returns | |
724 | * appropriate errno value. | |
725 | * | |
726 | * Example: | |
727 | * | |
728 | * phandle1: node1 { | |
729 | * #list-cells = <2>; | |
730 | * } | |
731 | * | |
732 | * phandle2: node2 { | |
733 | * #list-cells = <1>; | |
734 | * } | |
735 | * | |
736 | * node3 { | |
737 | * list = <&phandle1 1 2 &phandle2 3>; | |
738 | * } | |
739 | * | |
740 | * To get a device_node of the `node2' node you may call this: | |
741 | * of_parse_phandles_with_args(node3, "list", "#list-cells", 2, &node2, &args); | |
742 | */ | |
743 | int of_parse_phandles_with_args(struct device_node *np, const char *list_name, | |
744 | const char *cells_name, int index, | |
745 | struct device_node **out_node, | |
746 | const void **out_args) | |
747 | { | |
748 | int ret = -EINVAL; | |
33714881 JK |
749 | const __be32 *list; |
750 | const __be32 *list_end; | |
64b60e09 AV |
751 | int size; |
752 | int cur_index = 0; | |
753 | struct device_node *node = NULL; | |
7736a3db | 754 | const void *args = NULL; |
64b60e09 AV |
755 | |
756 | list = of_get_property(np, list_name, &size); | |
757 | if (!list) { | |
758 | ret = -ENOENT; | |
759 | goto err0; | |
760 | } | |
761 | list_end = list + size / sizeof(*list); | |
762 | ||
763 | while (list < list_end) { | |
33714881 | 764 | const __be32 *cells; |
9a6b2e58 | 765 | phandle phandle; |
64b60e09 | 766 | |
9a6b2e58 | 767 | phandle = be32_to_cpup(list++); |
c1bb7c6d | 768 | args = list; |
64b60e09 AV |
769 | |
770 | /* one cell hole in the list = <>; */ | |
9a6b2e58 | 771 | if (!phandle) |
64b60e09 | 772 | goto next; |
64b60e09 | 773 | |
9a6b2e58 | 774 | node = of_find_node_by_phandle(phandle); |
64b60e09 AV |
775 | if (!node) { |
776 | pr_debug("%s: could not find phandle\n", | |
777 | np->full_name); | |
778 | goto err0; | |
779 | } | |
780 | ||
781 | cells = of_get_property(node, cells_name, &size); | |
782 | if (!cells || size != sizeof(*cells)) { | |
783 | pr_debug("%s: could not get %s for %s\n", | |
784 | np->full_name, cells_name, node->full_name); | |
785 | goto err1; | |
786 | } | |
787 | ||
33714881 | 788 | list += be32_to_cpup(cells); |
64b60e09 AV |
789 | if (list > list_end) { |
790 | pr_debug("%s: insufficient arguments length\n", | |
791 | np->full_name); | |
792 | goto err1; | |
793 | } | |
794 | next: | |
795 | if (cur_index == index) | |
796 | break; | |
797 | ||
798 | of_node_put(node); | |
799 | node = NULL; | |
7736a3db | 800 | args = NULL; |
64b60e09 AV |
801 | cur_index++; |
802 | } | |
803 | ||
804 | if (!node) { | |
7736a3db AV |
805 | /* |
806 | * args w/o node indicates that the loop above has stopped at | |
807 | * the 'hole' cell. Report this differently. | |
808 | */ | |
809 | if (args) | |
810 | ret = -EEXIST; | |
811 | else | |
812 | ret = -ENOENT; | |
64b60e09 AV |
813 | goto err0; |
814 | } | |
815 | ||
7736a3db AV |
816 | if (out_node) |
817 | *out_node = node; | |
818 | if (out_args) | |
819 | *out_args = args; | |
64b60e09 AV |
820 | |
821 | return 0; | |
822 | err1: | |
823 | of_node_put(node); | |
824 | err0: | |
825 | pr_debug("%s failed with status %d\n", __func__, ret); | |
826 | return ret; | |
827 | } | |
828 | EXPORT_SYMBOL(of_parse_phandles_with_args); | |
02af11b0 GL |
829 | |
830 | /** | |
831 | * prom_add_property - Add a property to a node | |
832 | */ | |
833 | int prom_add_property(struct device_node *np, struct property *prop) | |
834 | { | |
835 | struct property **next; | |
836 | unsigned long flags; | |
837 | ||
838 | prop->next = NULL; | |
839 | write_lock_irqsave(&devtree_lock, flags); | |
840 | next = &np->properties; | |
841 | while (*next) { | |
842 | if (strcmp(prop->name, (*next)->name) == 0) { | |
843 | /* duplicate ! don't insert it */ | |
844 | write_unlock_irqrestore(&devtree_lock, flags); | |
845 | return -1; | |
846 | } | |
847 | next = &(*next)->next; | |
848 | } | |
849 | *next = prop; | |
850 | write_unlock_irqrestore(&devtree_lock, flags); | |
851 | ||
852 | #ifdef CONFIG_PROC_DEVICETREE | |
853 | /* try to add to proc as well if it was initialized */ | |
854 | if (np->pde) | |
855 | proc_device_tree_add_prop(np->pde, prop); | |
856 | #endif /* CONFIG_PROC_DEVICETREE */ | |
857 | ||
858 | return 0; | |
859 | } | |
860 | ||
861 | /** | |
862 | * prom_remove_property - Remove a property from a node. | |
863 | * | |
864 | * Note that we don't actually remove it, since we have given out | |
865 | * who-knows-how-many pointers to the data using get-property. | |
866 | * Instead we just move the property to the "dead properties" | |
867 | * list, so it won't be found any more. | |
868 | */ | |
869 | int prom_remove_property(struct device_node *np, struct property *prop) | |
870 | { | |
871 | struct property **next; | |
872 | unsigned long flags; | |
873 | int found = 0; | |
874 | ||
875 | write_lock_irqsave(&devtree_lock, flags); | |
876 | next = &np->properties; | |
877 | while (*next) { | |
878 | if (*next == prop) { | |
879 | /* found the node */ | |
880 | *next = prop->next; | |
881 | prop->next = np->deadprops; | |
882 | np->deadprops = prop; | |
883 | found = 1; | |
884 | break; | |
885 | } | |
886 | next = &(*next)->next; | |
887 | } | |
888 | write_unlock_irqrestore(&devtree_lock, flags); | |
889 | ||
890 | if (!found) | |
891 | return -ENODEV; | |
892 | ||
893 | #ifdef CONFIG_PROC_DEVICETREE | |
894 | /* try to remove the proc node as well */ | |
895 | if (np->pde) | |
896 | proc_device_tree_remove_prop(np->pde, prop); | |
897 | #endif /* CONFIG_PROC_DEVICETREE */ | |
898 | ||
899 | return 0; | |
900 | } | |
901 | ||
902 | /* | |
903 | * prom_update_property - Update a property in a node. | |
904 | * | |
905 | * Note that we don't actually remove it, since we have given out | |
906 | * who-knows-how-many pointers to the data using get-property. | |
907 | * Instead we just move the property to the "dead properties" list, | |
908 | * and add the new property to the property list | |
909 | */ | |
910 | int prom_update_property(struct device_node *np, | |
911 | struct property *newprop, | |
912 | struct property *oldprop) | |
913 | { | |
914 | struct property **next; | |
915 | unsigned long flags; | |
916 | int found = 0; | |
917 | ||
918 | write_lock_irqsave(&devtree_lock, flags); | |
919 | next = &np->properties; | |
920 | while (*next) { | |
921 | if (*next == oldprop) { | |
922 | /* found the node */ | |
923 | newprop->next = oldprop->next; | |
924 | *next = newprop; | |
925 | oldprop->next = np->deadprops; | |
926 | np->deadprops = oldprop; | |
927 | found = 1; | |
928 | break; | |
929 | } | |
930 | next = &(*next)->next; | |
931 | } | |
932 | write_unlock_irqrestore(&devtree_lock, flags); | |
933 | ||
934 | if (!found) | |
935 | return -ENODEV; | |
936 | ||
937 | #ifdef CONFIG_PROC_DEVICETREE | |
938 | /* try to add to proc as well if it was initialized */ | |
939 | if (np->pde) | |
940 | proc_device_tree_update_prop(np->pde, newprop, oldprop); | |
941 | #endif /* CONFIG_PROC_DEVICETREE */ | |
942 | ||
943 | return 0; | |
944 | } | |
fcdeb7fe GL |
945 | |
946 | #if defined(CONFIG_OF_DYNAMIC) | |
947 | /* | |
948 | * Support for dynamic device trees. | |
949 | * | |
950 | * On some platforms, the device tree can be manipulated at runtime. | |
951 | * The routines in this section support adding, removing and changing | |
952 | * device tree nodes. | |
953 | */ | |
954 | ||
955 | /** | |
956 | * of_attach_node - Plug a device node into the tree and global list. | |
957 | */ | |
958 | void of_attach_node(struct device_node *np) | |
959 | { | |
960 | unsigned long flags; | |
961 | ||
962 | write_lock_irqsave(&devtree_lock, flags); | |
963 | np->sibling = np->parent->child; | |
964 | np->allnext = allnodes; | |
965 | np->parent->child = np; | |
966 | allnodes = np; | |
967 | write_unlock_irqrestore(&devtree_lock, flags); | |
968 | } | |
969 | ||
970 | /** | |
971 | * of_detach_node - "Unplug" a node from the device tree. | |
972 | * | |
973 | * The caller must hold a reference to the node. The memory associated with | |
974 | * the node is not freed until its refcount goes to zero. | |
975 | */ | |
976 | void of_detach_node(struct device_node *np) | |
977 | { | |
978 | struct device_node *parent; | |
979 | unsigned long flags; | |
980 | ||
981 | write_lock_irqsave(&devtree_lock, flags); | |
982 | ||
983 | parent = np->parent; | |
984 | if (!parent) | |
985 | goto out_unlock; | |
986 | ||
987 | if (allnodes == np) | |
988 | allnodes = np->allnext; | |
989 | else { | |
990 | struct device_node *prev; | |
991 | for (prev = allnodes; | |
992 | prev->allnext != np; | |
993 | prev = prev->allnext) | |
994 | ; | |
995 | prev->allnext = np->allnext; | |
996 | } | |
997 | ||
998 | if (parent->child == np) | |
999 | parent->child = np->sibling; | |
1000 | else { | |
1001 | struct device_node *prevsib; | |
1002 | for (prevsib = np->parent->child; | |
1003 | prevsib->sibling != np; | |
1004 | prevsib = prevsib->sibling) | |
1005 | ; | |
1006 | prevsib->sibling = np->sibling; | |
1007 | } | |
1008 | ||
1009 | of_node_set_flag(np, OF_DETACHED); | |
1010 | ||
1011 | out_unlock: | |
1012 | write_unlock_irqrestore(&devtree_lock, flags); | |
1013 | } | |
1014 | #endif /* defined(CONFIG_OF_DYNAMIC) */ | |
1015 | ||
611cad72 SG |
1016 | static void of_alias_add(struct alias_prop *ap, struct device_node *np, |
1017 | int id, const char *stem, int stem_len) | |
1018 | { | |
1019 | ap->np = np; | |
1020 | ap->id = id; | |
1021 | strncpy(ap->stem, stem, stem_len); | |
1022 | ap->stem[stem_len] = 0; | |
1023 | list_add_tail(&ap->link, &aliases_lookup); | |
1024 | pr_debug("adding DT alias:%s: stem=%s id=%i node=%s\n", | |
1025 | ap->alias, ap->stem, ap->id, np ? np->full_name : NULL); | |
1026 | } | |
1027 | ||
1028 | /** | |
1029 | * of_alias_scan - Scan all properties of 'aliases' node | |
1030 | * | |
1031 | * The function scans all the properties of 'aliases' node and populate | |
1032 | * the the global lookup table with the properties. It returns the | |
1033 | * number of alias_prop found, or error code in error case. | |
1034 | * | |
1035 | * @dt_alloc: An allocator that provides a virtual address to memory | |
1036 | * for the resulting tree | |
1037 | */ | |
1038 | void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align)) | |
1039 | { | |
1040 | struct property *pp; | |
1041 | ||
1042 | of_chosen = of_find_node_by_path("/chosen"); | |
1043 | if (of_chosen == NULL) | |
1044 | of_chosen = of_find_node_by_path("/chosen@0"); | |
1045 | of_aliases = of_find_node_by_path("/aliases"); | |
1046 | if (!of_aliases) | |
1047 | return; | |
1048 | ||
1049 | for_each_property(pp, of_aliases->properties) { | |
1050 | const char *start = pp->name; | |
1051 | const char *end = start + strlen(start); | |
1052 | struct device_node *np; | |
1053 | struct alias_prop *ap; | |
1054 | int id, len; | |
1055 | ||
1056 | /* Skip those we do not want to proceed */ | |
1057 | if (!strcmp(pp->name, "name") || | |
1058 | !strcmp(pp->name, "phandle") || | |
1059 | !strcmp(pp->name, "linux,phandle")) | |
1060 | continue; | |
1061 | ||
1062 | np = of_find_node_by_path(pp->value); | |
1063 | if (!np) | |
1064 | continue; | |
1065 | ||
1066 | /* walk the alias backwards to extract the id and work out | |
1067 | * the 'stem' string */ | |
1068 | while (isdigit(*(end-1)) && end > start) | |
1069 | end--; | |
1070 | len = end - start; | |
1071 | ||
1072 | if (kstrtoint(end, 10, &id) < 0) | |
1073 | continue; | |
1074 | ||
1075 | /* Allocate an alias_prop with enough space for the stem */ | |
1076 | ap = dt_alloc(sizeof(*ap) + len + 1, 4); | |
1077 | if (!ap) | |
1078 | continue; | |
1079 | ap->alias = start; | |
1080 | of_alias_add(ap, np, id, start, len); | |
1081 | } | |
1082 | } | |
1083 | ||
1084 | /** | |
1085 | * of_alias_get_id - Get alias id for the given device_node | |
1086 | * @np: Pointer to the given device_node | |
1087 | * @stem: Alias stem of the given device_node | |
1088 | * | |
1089 | * The function travels the lookup table to get alias id for the given | |
1090 | * device_node and alias stem. It returns the alias id if find it. | |
1091 | */ | |
1092 | int of_alias_get_id(struct device_node *np, const char *stem) | |
1093 | { | |
1094 | struct alias_prop *app; | |
1095 | int id = -ENODEV; | |
1096 | ||
1097 | mutex_lock(&of_aliases_mutex); | |
1098 | list_for_each_entry(app, &aliases_lookup, link) { | |
1099 | if (strcmp(app->stem, stem) != 0) | |
1100 | continue; | |
1101 | ||
1102 | if (np == app->np) { | |
1103 | id = app->id; | |
1104 | break; | |
1105 | } | |
1106 | } | |
1107 | mutex_unlock(&of_aliases_mutex); | |
1108 | ||
1109 | return id; | |
1110 | } | |
1111 | EXPORT_SYMBOL_GPL(of_alias_get_id); |