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 | */ | |
20 | #include <linux/module.h> | |
21 | #include <linux/of.h> | |
581b605a | 22 | #include <linux/spinlock.h> |
5a0e3ad6 | 23 | #include <linux/slab.h> |
a9f2f63a | 24 | #include <linux/proc_fs.h> |
581b605a | 25 | |
1ef4d424 | 26 | struct device_node *allnodes; |
fc0bdae4 | 27 | struct device_node *of_chosen; |
1ef4d424 | 28 | |
581b605a SR |
29 | /* use when traversing tree through the allnext, child, sibling, |
30 | * or parent members of struct device_node. | |
31 | */ | |
32 | DEFINE_RWLOCK(devtree_lock); | |
97e873e5 SR |
33 | |
34 | int of_n_addr_cells(struct device_node *np) | |
35 | { | |
36 | const int *ip; | |
37 | ||
38 | do { | |
39 | if (np->parent) | |
40 | np = np->parent; | |
41 | ip = of_get_property(np, "#address-cells", NULL); | |
42 | if (ip) | |
33714881 | 43 | return be32_to_cpup(ip); |
97e873e5 SR |
44 | } while (np->parent); |
45 | /* No #address-cells property for the root node */ | |
46 | return OF_ROOT_NODE_ADDR_CELLS_DEFAULT; | |
47 | } | |
48 | EXPORT_SYMBOL(of_n_addr_cells); | |
49 | ||
50 | int of_n_size_cells(struct device_node *np) | |
51 | { | |
52 | const int *ip; | |
53 | ||
54 | do { | |
55 | if (np->parent) | |
56 | np = np->parent; | |
57 | ip = of_get_property(np, "#size-cells", NULL); | |
58 | if (ip) | |
33714881 | 59 | return be32_to_cpup(ip); |
97e873e5 SR |
60 | } while (np->parent); |
61 | /* No #size-cells property for the root node */ | |
62 | return OF_ROOT_NODE_SIZE_CELLS_DEFAULT; | |
63 | } | |
64 | EXPORT_SYMBOL(of_n_size_cells); | |
65 | ||
923f7e30 GL |
66 | #if !defined(CONFIG_SPARC) /* SPARC doesn't do ref counting (yet) */ |
67 | /** | |
68 | * of_node_get - Increment refcount of a node | |
69 | * @node: Node to inc refcount, NULL is supported to | |
70 | * simplify writing of callers | |
71 | * | |
72 | * Returns node. | |
73 | */ | |
74 | struct device_node *of_node_get(struct device_node *node) | |
75 | { | |
76 | if (node) | |
77 | kref_get(&node->kref); | |
78 | return node; | |
79 | } | |
80 | EXPORT_SYMBOL(of_node_get); | |
81 | ||
82 | static inline struct device_node *kref_to_device_node(struct kref *kref) | |
83 | { | |
84 | return container_of(kref, struct device_node, kref); | |
85 | } | |
86 | ||
87 | /** | |
88 | * of_node_release - release a dynamically allocated node | |
89 | * @kref: kref element of the node to be released | |
90 | * | |
91 | * In of_node_put() this function is passed to kref_put() | |
92 | * as the destructor. | |
93 | */ | |
94 | static void of_node_release(struct kref *kref) | |
95 | { | |
96 | struct device_node *node = kref_to_device_node(kref); | |
97 | struct property *prop = node->properties; | |
98 | ||
99 | /* We should never be releasing nodes that haven't been detached. */ | |
100 | if (!of_node_check_flag(node, OF_DETACHED)) { | |
101 | pr_err("ERROR: Bad of_node_put() on %s\n", node->full_name); | |
102 | dump_stack(); | |
103 | kref_init(&node->kref); | |
104 | return; | |
105 | } | |
106 | ||
107 | if (!of_node_check_flag(node, OF_DYNAMIC)) | |
108 | return; | |
109 | ||
110 | while (prop) { | |
111 | struct property *next = prop->next; | |
112 | kfree(prop->name); | |
113 | kfree(prop->value); | |
114 | kfree(prop); | |
115 | prop = next; | |
116 | ||
117 | if (!prop) { | |
118 | prop = node->deadprops; | |
119 | node->deadprops = NULL; | |
120 | } | |
121 | } | |
122 | kfree(node->full_name); | |
123 | kfree(node->data); | |
124 | kfree(node); | |
125 | } | |
126 | ||
127 | /** | |
128 | * of_node_put - Decrement refcount of a node | |
129 | * @node: Node to dec refcount, NULL is supported to | |
130 | * simplify writing of callers | |
131 | * | |
132 | */ | |
133 | void of_node_put(struct device_node *node) | |
134 | { | |
135 | if (node) | |
136 | kref_put(&node->kref, of_node_release); | |
137 | } | |
138 | EXPORT_SYMBOL(of_node_put); | |
139 | #endif /* !CONFIG_SPARC */ | |
140 | ||
581b605a SR |
141 | struct property *of_find_property(const struct device_node *np, |
142 | const char *name, | |
143 | int *lenp) | |
144 | { | |
145 | struct property *pp; | |
146 | ||
64e4566f TT |
147 | if (!np) |
148 | return NULL; | |
149 | ||
581b605a SR |
150 | read_lock(&devtree_lock); |
151 | for (pp = np->properties; pp != 0; pp = pp->next) { | |
152 | if (of_prop_cmp(pp->name, name) == 0) { | |
153 | if (lenp != 0) | |
154 | *lenp = pp->length; | |
155 | break; | |
156 | } | |
157 | } | |
158 | read_unlock(&devtree_lock); | |
159 | ||
160 | return pp; | |
161 | } | |
162 | EXPORT_SYMBOL(of_find_property); | |
163 | ||
e91edcf5 GL |
164 | /** |
165 | * of_find_all_nodes - Get next node in global list | |
166 | * @prev: Previous node or NULL to start iteration | |
167 | * of_node_put() will be called on it | |
168 | * | |
169 | * Returns a node pointer with refcount incremented, use | |
170 | * of_node_put() on it when done. | |
171 | */ | |
172 | struct device_node *of_find_all_nodes(struct device_node *prev) | |
173 | { | |
174 | struct device_node *np; | |
175 | ||
176 | read_lock(&devtree_lock); | |
177 | np = prev ? prev->allnext : allnodes; | |
178 | for (; np != NULL; np = np->allnext) | |
179 | if (of_node_get(np)) | |
180 | break; | |
181 | of_node_put(prev); | |
182 | read_unlock(&devtree_lock); | |
183 | return np; | |
184 | } | |
185 | EXPORT_SYMBOL(of_find_all_nodes); | |
186 | ||
97e873e5 SR |
187 | /* |
188 | * Find a property with a given name for a given node | |
189 | * and return the value. | |
190 | */ | |
191 | const void *of_get_property(const struct device_node *np, const char *name, | |
192 | int *lenp) | |
193 | { | |
194 | struct property *pp = of_find_property(np, name, lenp); | |
195 | ||
196 | return pp ? pp->value : NULL; | |
197 | } | |
198 | EXPORT_SYMBOL(of_get_property); | |
0081cbc3 SR |
199 | |
200 | /** Checks if the given "compat" string matches one of the strings in | |
201 | * the device's "compatible" property | |
202 | */ | |
203 | int of_device_is_compatible(const struct device_node *device, | |
204 | const char *compat) | |
205 | { | |
206 | const char* cp; | |
207 | int cplen, l; | |
208 | ||
209 | cp = of_get_property(device, "compatible", &cplen); | |
210 | if (cp == NULL) | |
211 | return 0; | |
212 | while (cplen > 0) { | |
213 | if (of_compat_cmp(cp, compat, strlen(compat)) == 0) | |
214 | return 1; | |
215 | l = strlen(cp) + 1; | |
216 | cp += l; | |
217 | cplen -= l; | |
218 | } | |
219 | ||
220 | return 0; | |
221 | } | |
222 | EXPORT_SYMBOL(of_device_is_compatible); | |
e679c5f4 | 223 | |
1f43cfb9 | 224 | /** |
71a157e8 | 225 | * of_machine_is_compatible - Test root of device tree for a given compatible value |
1f43cfb9 GL |
226 | * @compat: compatible string to look for in root node's compatible property. |
227 | * | |
228 | * Returns true if the root node has the given value in its | |
229 | * compatible property. | |
230 | */ | |
71a157e8 | 231 | int of_machine_is_compatible(const char *compat) |
1f43cfb9 GL |
232 | { |
233 | struct device_node *root; | |
234 | int rc = 0; | |
235 | ||
236 | root = of_find_node_by_path("/"); | |
237 | if (root) { | |
238 | rc = of_device_is_compatible(root, compat); | |
239 | of_node_put(root); | |
240 | } | |
241 | return rc; | |
242 | } | |
71a157e8 | 243 | EXPORT_SYMBOL(of_machine_is_compatible); |
1f43cfb9 | 244 | |
834d97d4 JB |
245 | /** |
246 | * of_device_is_available - check if a device is available for use | |
247 | * | |
248 | * @device: Node to check for availability | |
249 | * | |
250 | * Returns 1 if the status property is absent or set to "okay" or "ok", | |
251 | * 0 otherwise | |
252 | */ | |
253 | int of_device_is_available(const struct device_node *device) | |
254 | { | |
255 | const char *status; | |
256 | int statlen; | |
257 | ||
258 | status = of_get_property(device, "status", &statlen); | |
259 | if (status == NULL) | |
260 | return 1; | |
261 | ||
262 | if (statlen > 0) { | |
263 | if (!strcmp(status, "okay") || !strcmp(status, "ok")) | |
264 | return 1; | |
265 | } | |
266 | ||
267 | return 0; | |
268 | } | |
269 | EXPORT_SYMBOL(of_device_is_available); | |
270 | ||
e679c5f4 SR |
271 | /** |
272 | * of_get_parent - Get a node's parent if any | |
273 | * @node: Node to get parent | |
274 | * | |
275 | * Returns a node pointer with refcount incremented, use | |
276 | * of_node_put() on it when done. | |
277 | */ | |
278 | struct device_node *of_get_parent(const struct device_node *node) | |
279 | { | |
280 | struct device_node *np; | |
281 | ||
282 | if (!node) | |
283 | return NULL; | |
284 | ||
285 | read_lock(&devtree_lock); | |
286 | np = of_node_get(node->parent); | |
287 | read_unlock(&devtree_lock); | |
288 | return np; | |
289 | } | |
290 | EXPORT_SYMBOL(of_get_parent); | |
d1cd355a | 291 | |
f4eb0107 ME |
292 | /** |
293 | * of_get_next_parent - Iterate to a node's parent | |
294 | * @node: Node to get parent of | |
295 | * | |
296 | * This is like of_get_parent() except that it drops the | |
297 | * refcount on the passed node, making it suitable for iterating | |
298 | * through a node's parents. | |
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_next_parent(struct device_node *node) | |
304 | { | |
305 | struct device_node *parent; | |
306 | ||
307 | if (!node) | |
308 | return NULL; | |
309 | ||
310 | read_lock(&devtree_lock); | |
311 | parent = of_node_get(node->parent); | |
312 | of_node_put(node); | |
313 | read_unlock(&devtree_lock); | |
314 | return parent; | |
315 | } | |
316 | ||
d1cd355a SR |
317 | /** |
318 | * of_get_next_child - Iterate a node childs | |
319 | * @node: parent node | |
320 | * @prev: previous child of the parent node, or NULL to get first | |
321 | * | |
322 | * Returns a node pointer with refcount incremented, use | |
323 | * of_node_put() on it when done. | |
324 | */ | |
325 | struct device_node *of_get_next_child(const struct device_node *node, | |
326 | struct device_node *prev) | |
327 | { | |
328 | struct device_node *next; | |
329 | ||
330 | read_lock(&devtree_lock); | |
331 | next = prev ? prev->sibling : node->child; | |
332 | for (; next; next = next->sibling) | |
333 | if (of_node_get(next)) | |
334 | break; | |
335 | of_node_put(prev); | |
336 | read_unlock(&devtree_lock); | |
337 | return next; | |
338 | } | |
339 | EXPORT_SYMBOL(of_get_next_child); | |
1ef4d424 SR |
340 | |
341 | /** | |
342 | * of_find_node_by_path - Find a node matching a full OF path | |
343 | * @path: The full path to match | |
344 | * | |
345 | * Returns a node pointer with refcount incremented, use | |
346 | * of_node_put() on it when done. | |
347 | */ | |
348 | struct device_node *of_find_node_by_path(const char *path) | |
349 | { | |
350 | struct device_node *np = allnodes; | |
351 | ||
352 | read_lock(&devtree_lock); | |
353 | for (; np; np = np->allnext) { | |
354 | if (np->full_name && (of_node_cmp(np->full_name, path) == 0) | |
355 | && of_node_get(np)) | |
356 | break; | |
357 | } | |
358 | read_unlock(&devtree_lock); | |
359 | return np; | |
360 | } | |
361 | EXPORT_SYMBOL(of_find_node_by_path); | |
362 | ||
363 | /** | |
364 | * of_find_node_by_name - Find a node by its "name" property | |
365 | * @from: The node to start searching from or NULL, the node | |
366 | * you pass will not be searched, only the next one | |
367 | * will; typically, you pass what the previous call | |
368 | * returned. of_node_put() will be called on it | |
369 | * @name: The name string to match against | |
370 | * | |
371 | * Returns a node pointer with refcount incremented, use | |
372 | * of_node_put() on it when done. | |
373 | */ | |
374 | struct device_node *of_find_node_by_name(struct device_node *from, | |
375 | const char *name) | |
376 | { | |
377 | struct device_node *np; | |
378 | ||
379 | read_lock(&devtree_lock); | |
380 | np = from ? from->allnext : allnodes; | |
381 | for (; np; np = np->allnext) | |
382 | if (np->name && (of_node_cmp(np->name, name) == 0) | |
383 | && of_node_get(np)) | |
384 | break; | |
385 | of_node_put(from); | |
386 | read_unlock(&devtree_lock); | |
387 | return np; | |
388 | } | |
389 | EXPORT_SYMBOL(of_find_node_by_name); | |
390 | ||
391 | /** | |
392 | * of_find_node_by_type - Find a node by its "device_type" property | |
393 | * @from: The node to start searching from, or NULL to start searching | |
394 | * the entire device tree. The node you pass will not be | |
395 | * searched, only the next one will; typically, you pass | |
396 | * what the previous call returned. of_node_put() will be | |
397 | * called on from for you. | |
398 | * @type: The type string to match against | |
399 | * | |
400 | * Returns a node pointer with refcount incremented, use | |
401 | * of_node_put() on it when done. | |
402 | */ | |
403 | struct device_node *of_find_node_by_type(struct device_node *from, | |
404 | const char *type) | |
405 | { | |
406 | struct device_node *np; | |
407 | ||
408 | read_lock(&devtree_lock); | |
409 | np = from ? from->allnext : allnodes; | |
410 | for (; np; np = np->allnext) | |
411 | if (np->type && (of_node_cmp(np->type, type) == 0) | |
412 | && of_node_get(np)) | |
413 | break; | |
414 | of_node_put(from); | |
415 | read_unlock(&devtree_lock); | |
416 | return np; | |
417 | } | |
418 | EXPORT_SYMBOL(of_find_node_by_type); | |
419 | ||
420 | /** | |
421 | * of_find_compatible_node - Find a node based on type and one of the | |
422 | * tokens in its "compatible" property | |
423 | * @from: The node to start searching from or NULL, the node | |
424 | * you pass will not be searched, only the next one | |
425 | * will; typically, you pass what the previous call | |
426 | * returned. of_node_put() will be called on it | |
427 | * @type: The type string to match "device_type" or NULL to ignore | |
428 | * @compatible: The string to match to one of the tokens in the device | |
429 | * "compatible" list. | |
430 | * | |
431 | * Returns a node pointer with refcount incremented, use | |
432 | * of_node_put() on it when done. | |
433 | */ | |
434 | struct device_node *of_find_compatible_node(struct device_node *from, | |
435 | const char *type, const char *compatible) | |
436 | { | |
437 | struct device_node *np; | |
438 | ||
439 | read_lock(&devtree_lock); | |
440 | np = from ? from->allnext : allnodes; | |
441 | for (; np; np = np->allnext) { | |
442 | if (type | |
443 | && !(np->type && (of_node_cmp(np->type, type) == 0))) | |
444 | continue; | |
445 | if (of_device_is_compatible(np, compatible) && of_node_get(np)) | |
446 | break; | |
447 | } | |
448 | of_node_put(from); | |
449 | read_unlock(&devtree_lock); | |
450 | return np; | |
451 | } | |
452 | EXPORT_SYMBOL(of_find_compatible_node); | |
283029d1 | 453 | |
1e291b14 ME |
454 | /** |
455 | * of_find_node_with_property - Find a node which has a property with | |
456 | * the given name. | |
457 | * @from: The node to start searching from or NULL, the node | |
458 | * you pass will not be searched, only the next one | |
459 | * will; typically, you pass what the previous call | |
460 | * returned. of_node_put() will be called on it | |
461 | * @prop_name: The name of the property to look for. | |
462 | * | |
463 | * Returns a node pointer with refcount incremented, use | |
464 | * of_node_put() on it when done. | |
465 | */ | |
466 | struct device_node *of_find_node_with_property(struct device_node *from, | |
467 | const char *prop_name) | |
468 | { | |
469 | struct device_node *np; | |
470 | struct property *pp; | |
471 | ||
472 | read_lock(&devtree_lock); | |
473 | np = from ? from->allnext : allnodes; | |
474 | for (; np; np = np->allnext) { | |
475 | for (pp = np->properties; pp != 0; pp = pp->next) { | |
476 | if (of_prop_cmp(pp->name, prop_name) == 0) { | |
477 | of_node_get(np); | |
478 | goto out; | |
479 | } | |
480 | } | |
481 | } | |
482 | out: | |
483 | of_node_put(from); | |
484 | read_unlock(&devtree_lock); | |
485 | return np; | |
486 | } | |
487 | EXPORT_SYMBOL(of_find_node_with_property); | |
488 | ||
283029d1 GL |
489 | /** |
490 | * of_match_node - Tell if an device_node has a matching of_match structure | |
491 | * @matches: array of of device match structures to search in | |
492 | * @node: the of device structure to match against | |
493 | * | |
494 | * Low level utility function used by device matching. | |
495 | */ | |
496 | const struct of_device_id *of_match_node(const struct of_device_id *matches, | |
497 | const struct device_node *node) | |
498 | { | |
499 | while (matches->name[0] || matches->type[0] || matches->compatible[0]) { | |
500 | int match = 1; | |
501 | if (matches->name[0]) | |
502 | match &= node->name | |
503 | && !strcmp(matches->name, node->name); | |
504 | if (matches->type[0]) | |
505 | match &= node->type | |
506 | && !strcmp(matches->type, node->type); | |
507 | if (matches->compatible[0]) | |
508 | match &= of_device_is_compatible(node, | |
509 | matches->compatible); | |
510 | if (match) | |
511 | return matches; | |
512 | matches++; | |
513 | } | |
514 | return NULL; | |
515 | } | |
516 | EXPORT_SYMBOL(of_match_node); | |
517 | ||
518 | /** | |
519 | * of_find_matching_node - Find a node based on an of_device_id match | |
520 | * table. | |
521 | * @from: The node to start searching from or NULL, the node | |
522 | * you pass will not be searched, only the next one | |
523 | * will; typically, you pass what the previous call | |
524 | * returned. of_node_put() will be called on it | |
525 | * @matches: array of of device match structures to search in | |
526 | * | |
527 | * Returns a node pointer with refcount incremented, use | |
528 | * of_node_put() on it when done. | |
529 | */ | |
530 | struct device_node *of_find_matching_node(struct device_node *from, | |
531 | const struct of_device_id *matches) | |
532 | { | |
533 | struct device_node *np; | |
534 | ||
535 | read_lock(&devtree_lock); | |
536 | np = from ? from->allnext : allnodes; | |
537 | for (; np; np = np->allnext) { | |
538 | if (of_match_node(matches, np) && of_node_get(np)) | |
539 | break; | |
540 | } | |
541 | of_node_put(from); | |
542 | read_unlock(&devtree_lock); | |
543 | return np; | |
544 | } | |
545 | EXPORT_SYMBOL(of_find_matching_node); | |
3f07af49 GL |
546 | |
547 | /** | |
548 | * of_modalias_table: Table of explicit compatible ==> modalias mappings | |
549 | * | |
550 | * This table allows particulare compatible property values to be mapped | |
551 | * to modalias strings. This is useful for busses which do not directly | |
552 | * understand the OF device tree but are populated based on data contained | |
553 | * within the device tree. SPI and I2C are the two current users of this | |
554 | * table. | |
555 | * | |
556 | * In most cases, devices do not need to be listed in this table because | |
557 | * the modalias value can be derived directly from the compatible table. | |
558 | * However, if for any reason a value cannot be derived, then this table | |
559 | * provides a method to override the implicit derivation. | |
560 | * | |
561 | * At the moment, a single table is used for all bus types because it is | |
562 | * assumed that the data size is small and that the compatible values | |
563 | * should already be distinct enough to differentiate between SPI, I2C | |
564 | * and other devices. | |
565 | */ | |
566 | struct of_modalias_table { | |
567 | char *of_device; | |
568 | char *modalias; | |
569 | }; | |
570 | static struct of_modalias_table of_modalias_table[] = { | |
4c3ed7d6 | 571 | { "fsl,mcu-mpc8349emitx", "mcu-mpc8349emitx" }, |
3f1c6ebf | 572 | { "mmc-spi-slot", "mmc_spi" }, |
3f07af49 GL |
573 | }; |
574 | ||
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 | * | |
581 | * Based on the value of the compatible property, this routine will determine | |
58f467ce GL |
582 | * an appropriate modalias value for a particular device tree node. Two |
583 | * separate methods are attempted to derive a modalias value. | |
3f07af49 GL |
584 | * |
585 | * First method is to lookup the compatible value in of_modalias_table. | |
58f467ce GL |
586 | * Second is to strip off the manufacturer prefix from the first |
587 | * compatible entry and use the remainder as modalias | |
3f07af49 GL |
588 | * |
589 | * This routine returns 0 on success | |
590 | */ | |
591 | int of_modalias_node(struct device_node *node, char *modalias, int len) | |
592 | { | |
593 | int i, cplen; | |
594 | const char *compatible; | |
595 | const char *p; | |
596 | ||
597 | /* 1. search for exception list entry */ | |
598 | for (i = 0; i < ARRAY_SIZE(of_modalias_table); i++) { | |
599 | compatible = of_modalias_table[i].of_device; | |
600 | if (!of_device_is_compatible(node, compatible)) | |
601 | continue; | |
602 | strlcpy(modalias, of_modalias_table[i].modalias, len); | |
603 | return 0; | |
604 | } | |
605 | ||
606 | compatible = of_get_property(node, "compatible", &cplen); | |
607 | if (!compatible) | |
608 | return -ENODEV; | |
609 | ||
58f467ce | 610 | /* 2. take first compatible entry and strip manufacturer */ |
3f07af49 GL |
611 | p = strchr(compatible, ','); |
612 | if (!p) | |
613 | return -ENODEV; | |
614 | p++; | |
615 | strlcpy(modalias, p, len); | |
616 | return 0; | |
617 | } | |
618 | EXPORT_SYMBOL_GPL(of_modalias_node); | |
619 | ||
89751a7c JK |
620 | /** |
621 | * of_find_node_by_phandle - Find a node given a phandle | |
622 | * @handle: phandle of the node to find | |
623 | * | |
624 | * Returns a node pointer with refcount incremented, use | |
625 | * of_node_put() on it when done. | |
626 | */ | |
627 | struct device_node *of_find_node_by_phandle(phandle handle) | |
628 | { | |
629 | struct device_node *np; | |
630 | ||
631 | read_lock(&devtree_lock); | |
632 | for (np = allnodes; np; np = np->allnext) | |
633 | if (np->phandle == handle) | |
634 | break; | |
635 | of_node_get(np); | |
636 | read_unlock(&devtree_lock); | |
637 | return np; | |
638 | } | |
639 | EXPORT_SYMBOL(of_find_node_by_phandle); | |
640 | ||
739649c5 GL |
641 | /** |
642 | * of_parse_phandle - Resolve a phandle property to a device_node pointer | |
643 | * @np: Pointer to device node holding phandle property | |
644 | * @phandle_name: Name of property holding a phandle value | |
645 | * @index: For properties holding a table of phandles, this is the index into | |
646 | * the table | |
647 | * | |
648 | * Returns the device_node pointer with refcount incremented. Use | |
649 | * of_node_put() on it when done. | |
650 | */ | |
651 | struct device_node * | |
652 | of_parse_phandle(struct device_node *np, const char *phandle_name, int index) | |
653 | { | |
654 | const phandle *phandle; | |
655 | int size; | |
656 | ||
657 | phandle = of_get_property(np, phandle_name, &size); | |
658 | if ((!phandle) || (size < sizeof(*phandle) * (index + 1))) | |
659 | return NULL; | |
660 | ||
661 | return of_find_node_by_phandle(phandle[index]); | |
662 | } | |
663 | EXPORT_SYMBOL(of_parse_phandle); | |
664 | ||
64b60e09 AV |
665 | /** |
666 | * of_parse_phandles_with_args - Find a node pointed by phandle in a list | |
667 | * @np: pointer to a device tree node containing a list | |
668 | * @list_name: property name that contains a list | |
669 | * @cells_name: property name that specifies phandles' arguments count | |
670 | * @index: index of a phandle to parse out | |
7736a3db AV |
671 | * @out_node: optional pointer to device_node struct pointer (will be filled) |
672 | * @out_args: optional pointer to arguments pointer (will be filled) | |
64b60e09 AV |
673 | * |
674 | * This function is useful to parse lists of phandles and their arguments. | |
675 | * Returns 0 on success and fills out_node and out_args, on error returns | |
676 | * appropriate errno value. | |
677 | * | |
678 | * Example: | |
679 | * | |
680 | * phandle1: node1 { | |
681 | * #list-cells = <2>; | |
682 | * } | |
683 | * | |
684 | * phandle2: node2 { | |
685 | * #list-cells = <1>; | |
686 | * } | |
687 | * | |
688 | * node3 { | |
689 | * list = <&phandle1 1 2 &phandle2 3>; | |
690 | * } | |
691 | * | |
692 | * To get a device_node of the `node2' node you may call this: | |
693 | * of_parse_phandles_with_args(node3, "list", "#list-cells", 2, &node2, &args); | |
694 | */ | |
695 | int of_parse_phandles_with_args(struct device_node *np, const char *list_name, | |
696 | const char *cells_name, int index, | |
697 | struct device_node **out_node, | |
698 | const void **out_args) | |
699 | { | |
700 | int ret = -EINVAL; | |
33714881 JK |
701 | const __be32 *list; |
702 | const __be32 *list_end; | |
64b60e09 AV |
703 | int size; |
704 | int cur_index = 0; | |
705 | struct device_node *node = NULL; | |
7736a3db | 706 | const void *args = NULL; |
64b60e09 AV |
707 | |
708 | list = of_get_property(np, list_name, &size); | |
709 | if (!list) { | |
710 | ret = -ENOENT; | |
711 | goto err0; | |
712 | } | |
713 | list_end = list + size / sizeof(*list); | |
714 | ||
715 | while (list < list_end) { | |
33714881 | 716 | const __be32 *cells; |
64b60e09 AV |
717 | const phandle *phandle; |
718 | ||
c1bb7c6d AV |
719 | phandle = list++; |
720 | args = list; | |
64b60e09 AV |
721 | |
722 | /* one cell hole in the list = <>; */ | |
c1bb7c6d | 723 | if (!*phandle) |
64b60e09 | 724 | goto next; |
64b60e09 AV |
725 | |
726 | node = of_find_node_by_phandle(*phandle); | |
727 | if (!node) { | |
728 | pr_debug("%s: could not find phandle\n", | |
729 | np->full_name); | |
730 | goto err0; | |
731 | } | |
732 | ||
733 | cells = of_get_property(node, cells_name, &size); | |
734 | if (!cells || size != sizeof(*cells)) { | |
735 | pr_debug("%s: could not get %s for %s\n", | |
736 | np->full_name, cells_name, node->full_name); | |
737 | goto err1; | |
738 | } | |
739 | ||
33714881 | 740 | list += be32_to_cpup(cells); |
64b60e09 AV |
741 | if (list > list_end) { |
742 | pr_debug("%s: insufficient arguments length\n", | |
743 | np->full_name); | |
744 | goto err1; | |
745 | } | |
746 | next: | |
747 | if (cur_index == index) | |
748 | break; | |
749 | ||
750 | of_node_put(node); | |
751 | node = NULL; | |
7736a3db | 752 | args = NULL; |
64b60e09 AV |
753 | cur_index++; |
754 | } | |
755 | ||
756 | if (!node) { | |
7736a3db AV |
757 | /* |
758 | * args w/o node indicates that the loop above has stopped at | |
759 | * the 'hole' cell. Report this differently. | |
760 | */ | |
761 | if (args) | |
762 | ret = -EEXIST; | |
763 | else | |
764 | ret = -ENOENT; | |
64b60e09 AV |
765 | goto err0; |
766 | } | |
767 | ||
7736a3db AV |
768 | if (out_node) |
769 | *out_node = node; | |
770 | if (out_args) | |
771 | *out_args = args; | |
64b60e09 AV |
772 | |
773 | return 0; | |
774 | err1: | |
775 | of_node_put(node); | |
776 | err0: | |
777 | pr_debug("%s failed with status %d\n", __func__, ret); | |
778 | return ret; | |
779 | } | |
780 | EXPORT_SYMBOL(of_parse_phandles_with_args); | |
02af11b0 GL |
781 | |
782 | /** | |
783 | * prom_add_property - Add a property to a node | |
784 | */ | |
785 | int prom_add_property(struct device_node *np, struct property *prop) | |
786 | { | |
787 | struct property **next; | |
788 | unsigned long flags; | |
789 | ||
790 | prop->next = NULL; | |
791 | write_lock_irqsave(&devtree_lock, flags); | |
792 | next = &np->properties; | |
793 | while (*next) { | |
794 | if (strcmp(prop->name, (*next)->name) == 0) { | |
795 | /* duplicate ! don't insert it */ | |
796 | write_unlock_irqrestore(&devtree_lock, flags); | |
797 | return -1; | |
798 | } | |
799 | next = &(*next)->next; | |
800 | } | |
801 | *next = prop; | |
802 | write_unlock_irqrestore(&devtree_lock, flags); | |
803 | ||
804 | #ifdef CONFIG_PROC_DEVICETREE | |
805 | /* try to add to proc as well if it was initialized */ | |
806 | if (np->pde) | |
807 | proc_device_tree_add_prop(np->pde, prop); | |
808 | #endif /* CONFIG_PROC_DEVICETREE */ | |
809 | ||
810 | return 0; | |
811 | } | |
812 | ||
813 | /** | |
814 | * prom_remove_property - Remove a property from a node. | |
815 | * | |
816 | * Note that we don't actually remove it, since we have given out | |
817 | * who-knows-how-many pointers to the data using get-property. | |
818 | * Instead we just move the property to the "dead properties" | |
819 | * list, so it won't be found any more. | |
820 | */ | |
821 | int prom_remove_property(struct device_node *np, struct property *prop) | |
822 | { | |
823 | struct property **next; | |
824 | unsigned long flags; | |
825 | int found = 0; | |
826 | ||
827 | write_lock_irqsave(&devtree_lock, flags); | |
828 | next = &np->properties; | |
829 | while (*next) { | |
830 | if (*next == prop) { | |
831 | /* found the node */ | |
832 | *next = prop->next; | |
833 | prop->next = np->deadprops; | |
834 | np->deadprops = prop; | |
835 | found = 1; | |
836 | break; | |
837 | } | |
838 | next = &(*next)->next; | |
839 | } | |
840 | write_unlock_irqrestore(&devtree_lock, flags); | |
841 | ||
842 | if (!found) | |
843 | return -ENODEV; | |
844 | ||
845 | #ifdef CONFIG_PROC_DEVICETREE | |
846 | /* try to remove the proc node as well */ | |
847 | if (np->pde) | |
848 | proc_device_tree_remove_prop(np->pde, prop); | |
849 | #endif /* CONFIG_PROC_DEVICETREE */ | |
850 | ||
851 | return 0; | |
852 | } | |
853 | ||
854 | /* | |
855 | * prom_update_property - Update a property in a node. | |
856 | * | |
857 | * Note that we don't actually remove it, since we have given out | |
858 | * who-knows-how-many pointers to the data using get-property. | |
859 | * Instead we just move the property to the "dead properties" list, | |
860 | * and add the new property to the property list | |
861 | */ | |
862 | int prom_update_property(struct device_node *np, | |
863 | struct property *newprop, | |
864 | struct property *oldprop) | |
865 | { | |
866 | struct property **next; | |
867 | unsigned long flags; | |
868 | int found = 0; | |
869 | ||
870 | write_lock_irqsave(&devtree_lock, flags); | |
871 | next = &np->properties; | |
872 | while (*next) { | |
873 | if (*next == oldprop) { | |
874 | /* found the node */ | |
875 | newprop->next = oldprop->next; | |
876 | *next = newprop; | |
877 | oldprop->next = np->deadprops; | |
878 | np->deadprops = oldprop; | |
879 | found = 1; | |
880 | break; | |
881 | } | |
882 | next = &(*next)->next; | |
883 | } | |
884 | write_unlock_irqrestore(&devtree_lock, flags); | |
885 | ||
886 | if (!found) | |
887 | return -ENODEV; | |
888 | ||
889 | #ifdef CONFIG_PROC_DEVICETREE | |
890 | /* try to add to proc as well if it was initialized */ | |
891 | if (np->pde) | |
892 | proc_device_tree_update_prop(np->pde, newprop, oldprop); | |
893 | #endif /* CONFIG_PROC_DEVICETREE */ | |
894 | ||
895 | return 0; | |
896 | } | |
fcdeb7fe GL |
897 | |
898 | #if defined(CONFIG_OF_DYNAMIC) | |
899 | /* | |
900 | * Support for dynamic device trees. | |
901 | * | |
902 | * On some platforms, the device tree can be manipulated at runtime. | |
903 | * The routines in this section support adding, removing and changing | |
904 | * device tree nodes. | |
905 | */ | |
906 | ||
907 | /** | |
908 | * of_attach_node - Plug a device node into the tree and global list. | |
909 | */ | |
910 | void of_attach_node(struct device_node *np) | |
911 | { | |
912 | unsigned long flags; | |
913 | ||
914 | write_lock_irqsave(&devtree_lock, flags); | |
915 | np->sibling = np->parent->child; | |
916 | np->allnext = allnodes; | |
917 | np->parent->child = np; | |
918 | allnodes = np; | |
919 | write_unlock_irqrestore(&devtree_lock, flags); | |
920 | } | |
921 | ||
922 | /** | |
923 | * of_detach_node - "Unplug" a node from the device tree. | |
924 | * | |
925 | * The caller must hold a reference to the node. The memory associated with | |
926 | * the node is not freed until its refcount goes to zero. | |
927 | */ | |
928 | void of_detach_node(struct device_node *np) | |
929 | { | |
930 | struct device_node *parent; | |
931 | unsigned long flags; | |
932 | ||
933 | write_lock_irqsave(&devtree_lock, flags); | |
934 | ||
935 | parent = np->parent; | |
936 | if (!parent) | |
937 | goto out_unlock; | |
938 | ||
939 | if (allnodes == np) | |
940 | allnodes = np->allnext; | |
941 | else { | |
942 | struct device_node *prev; | |
943 | for (prev = allnodes; | |
944 | prev->allnext != np; | |
945 | prev = prev->allnext) | |
946 | ; | |
947 | prev->allnext = np->allnext; | |
948 | } | |
949 | ||
950 | if (parent->child == np) | |
951 | parent->child = np->sibling; | |
952 | else { | |
953 | struct device_node *prevsib; | |
954 | for (prevsib = np->parent->child; | |
955 | prevsib->sibling != np; | |
956 | prevsib = prevsib->sibling) | |
957 | ; | |
958 | prevsib->sibling = np->sibling; | |
959 | } | |
960 | ||
961 | of_node_set_flag(np, OF_DETACHED); | |
962 | ||
963 | out_unlock: | |
964 | write_unlock_irqrestore(&devtree_lock, flags); | |
965 | } | |
966 | #endif /* defined(CONFIG_OF_DYNAMIC) */ | |
967 |