blob: d4a1c9a043e12d3572faefe9a9fd11a1683cdd97 [file] [log] [blame]
Stephen Rothwell97e873e2007-05-01 16:26:07 +10001/*
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 *
Grant Likelye91edcf2009-10-15 10:58:09 -060012 * Reconsolidated from arch/x/kernel/prom.c by Stephen Rothwell and
13 * Grant Likely.
Stephen Rothwell97e873e2007-05-01 16:26:07 +100014 *
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 */
Shawn Guo611cad72011-08-15 15:28:14 +080020#include <linux/ctype.h>
Stephen Rothwell97e873e2007-05-01 16:26:07 +100021#include <linux/module.h>
22#include <linux/of.h>
Stephen Rothwell581b6052007-04-24 16:46:53 +100023#include <linux/spinlock.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090024#include <linux/slab.h>
Jeremy Kerra9f2f632010-02-01 21:34:14 -070025#include <linux/proc_fs.h>
Stephen Rothwell581b6052007-04-24 16:46:53 +100026
Shawn Guo611cad72011-08-15 15:28:14 +080027/**
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 */
38struct 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
46static LIST_HEAD(aliases_lookup);
47
Stephen Rothwell1ef4d422007-04-24 17:57:33 +100048struct device_node *allnodes;
Grant Likelyfc0bdae2010-02-14 07:13:55 -070049struct device_node *of_chosen;
Shawn Guo611cad72011-08-15 15:28:14 +080050struct device_node *of_aliases;
51
52static DEFINE_MUTEX(of_aliases_mutex);
Stephen Rothwell1ef4d422007-04-24 17:57:33 +100053
Stephen Rothwell581b6052007-04-24 16:46:53 +100054/* use when traversing tree through the allnext, child, sibling,
55 * or parent members of struct device_node.
56 */
57DEFINE_RWLOCK(devtree_lock);
Stephen Rothwell97e873e2007-05-01 16:26:07 +100058
59int of_n_addr_cells(struct device_node *np)
60{
Jeremy Kerra9fadee2010-10-10 21:24:10 -060061 const __be32 *ip;
Stephen Rothwell97e873e2007-05-01 16:26:07 +100062
63 do {
64 if (np->parent)
65 np = np->parent;
66 ip = of_get_property(np, "#address-cells", NULL);
67 if (ip)
Jeremy Kerr33714882010-01-30 01:45:26 -070068 return be32_to_cpup(ip);
Stephen Rothwell97e873e2007-05-01 16:26:07 +100069 } while (np->parent);
70 /* No #address-cells property for the root node */
71 return OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
72}
73EXPORT_SYMBOL(of_n_addr_cells);
74
75int of_n_size_cells(struct device_node *np)
76{
Jeremy Kerra9fadee2010-10-10 21:24:10 -060077 const __be32 *ip;
Stephen Rothwell97e873e2007-05-01 16:26:07 +100078
79 do {
80 if (np->parent)
81 np = np->parent;
82 ip = of_get_property(np, "#size-cells", NULL);
83 if (ip)
Jeremy Kerr33714882010-01-30 01:45:26 -070084 return be32_to_cpup(ip);
Stephen Rothwell97e873e2007-05-01 16:26:07 +100085 } while (np->parent);
86 /* No #size-cells property for the root node */
87 return OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
88}
89EXPORT_SYMBOL(of_n_size_cells);
90
Grant Likely0f22dd32012-02-15 20:38:40 -070091#if defined(CONFIG_OF_DYNAMIC)
Grant Likely923f7e32010-01-28 13:52:53 -070092/**
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 */
99struct device_node *of_node_get(struct device_node *node)
100{
101 if (node)
102 kref_get(&node->kref);
103 return node;
104}
105EXPORT_SYMBOL(of_node_get);
106
107static 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 */
119static 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 */
158void of_node_put(struct device_node *node)
159{
160 if (node)
161 kref_put(&node->kref, of_node_release);
162}
163EXPORT_SYMBOL(of_node_put);
Grant Likely0f22dd32012-02-15 20:38:40 -0700164#endif /* CONFIG_OF_DYNAMIC */
Grant Likely923f7e32010-01-28 13:52:53 -0700165
Stephen Rothwell581b6052007-04-24 16:46:53 +1000166struct property *of_find_property(const struct device_node *np,
167 const char *name,
168 int *lenp)
169{
170 struct property *pp;
171
Timur Tabi64e45662008-05-08 05:19:59 +1000172 if (!np)
173 return NULL;
174
Stephen Rothwell581b6052007-04-24 16:46:53 +1000175 read_lock(&devtree_lock);
Sachin Kamata3a7cab2012-06-27 09:44:45 +0530176 for (pp = np->properties; pp; pp = pp->next) {
Stephen Rothwell581b6052007-04-24 16:46:53 +1000177 if (of_prop_cmp(pp->name, name) == 0) {
Sachin Kamata3a7cab2012-06-27 09:44:45 +0530178 if (lenp)
Stephen Rothwell581b6052007-04-24 16:46:53 +1000179 *lenp = pp->length;
180 break;
181 }
182 }
183 read_unlock(&devtree_lock);
184
185 return pp;
186}
187EXPORT_SYMBOL(of_find_property);
188
Grant Likelye91edcf2009-10-15 10:58:09 -0600189/**
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 */
197struct 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}
210EXPORT_SYMBOL(of_find_all_nodes);
211
Stephen Rothwell97e873e2007-05-01 16:26:07 +1000212/*
213 * Find a property with a given name for a given node
214 * and return the value.
215 */
216const 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}
223EXPORT_SYMBOL(of_get_property);
Stephen Rothwell0081cbc2007-05-01 16:29:19 +1000224
225/** Checks if the given "compat" string matches one of the strings in
226 * the device's "compatible" property
227 */
228int 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}
247EXPORT_SYMBOL(of_device_is_compatible);
Stephen Rothwelle679c5f2007-04-24 17:16:16 +1000248
249/**
Grant Likely71a157e2010-02-01 21:34:14 -0700250 * of_machine_is_compatible - Test root of device tree for a given compatible value
Grant Likely1f43cfb2010-01-28 13:47:25 -0700251 * @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 */
Grant Likely71a157e2010-02-01 21:34:14 -0700256int of_machine_is_compatible(const char *compat)
Grant Likely1f43cfb2010-01-28 13:47:25 -0700257{
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}
Grant Likely71a157e2010-02-01 21:34:14 -0700268EXPORT_SYMBOL(of_machine_is_compatible);
Grant Likely1f43cfb2010-01-28 13:47:25 -0700269
270/**
Josh Boyer834d97d2008-03-27 00:33:14 +1100271 * 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 */
278int 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}
294EXPORT_SYMBOL(of_device_is_available);
295
296/**
Stephen Rothwelle679c5f2007-04-24 17:16:16 +1000297 * 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 */
303struct 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}
315EXPORT_SYMBOL(of_get_parent);
Stephen Rothwelld1cd3552007-04-24 17:21:29 +1000316
317/**
Michael Ellermanf4eb0102007-10-26 16:54:31 +1000318 * 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 */
328struct 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
342/**
Stephen Rothwelld1cd3552007-04-24 17:21:29 +1000343 * 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 */
350struct 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}
364EXPORT_SYMBOL(of_get_next_child);
Stephen Rothwell1ef4d422007-04-24 17:57:33 +1000365
366/**
Timur Tabi32961932012-08-14 13:20:23 +0000367 * of_get_next_available_child - Find the next available child node
368 * @node: parent node
369 * @prev: previous child of the parent node, or NULL to get first
370 *
371 * This function is like of_get_next_child(), except that it
372 * automatically skips any disabled nodes (i.e. status = "disabled").
373 */
374struct device_node *of_get_next_available_child(const struct device_node *node,
375 struct device_node *prev)
376{
377 struct device_node *next;
378
379 read_lock(&devtree_lock);
380 next = prev ? prev->sibling : node->child;
381 for (; next; next = next->sibling) {
382 if (!of_device_is_available(next))
383 continue;
384 if (of_node_get(next))
385 break;
386 }
387 of_node_put(prev);
388 read_unlock(&devtree_lock);
389 return next;
390}
391EXPORT_SYMBOL(of_get_next_available_child);
392
393/**
Stephen Rothwell1ef4d422007-04-24 17:57:33 +1000394 * of_find_node_by_path - Find a node matching a full OF path
395 * @path: The full path to match
396 *
397 * Returns a node pointer with refcount incremented, use
398 * of_node_put() on it when done.
399 */
400struct device_node *of_find_node_by_path(const char *path)
401{
402 struct device_node *np = allnodes;
403
404 read_lock(&devtree_lock);
405 for (; np; np = np->allnext) {
406 if (np->full_name && (of_node_cmp(np->full_name, path) == 0)
407 && of_node_get(np))
408 break;
409 }
410 read_unlock(&devtree_lock);
411 return np;
412}
413EXPORT_SYMBOL(of_find_node_by_path);
414
415/**
416 * of_find_node_by_name - Find a node by its "name" property
417 * @from: The node to start searching from or NULL, the node
418 * you pass will not be searched, only the next one
419 * will; typically, you pass what the previous call
420 * returned. of_node_put() will be called on it
421 * @name: The name string to match against
422 *
423 * Returns a node pointer with refcount incremented, use
424 * of_node_put() on it when done.
425 */
426struct device_node *of_find_node_by_name(struct device_node *from,
427 const char *name)
428{
429 struct device_node *np;
430
431 read_lock(&devtree_lock);
432 np = from ? from->allnext : allnodes;
433 for (; np; np = np->allnext)
434 if (np->name && (of_node_cmp(np->name, name) == 0)
435 && of_node_get(np))
436 break;
437 of_node_put(from);
438 read_unlock(&devtree_lock);
439 return np;
440}
441EXPORT_SYMBOL(of_find_node_by_name);
442
443/**
444 * of_find_node_by_type - Find a node by its "device_type" property
445 * @from: The node to start searching from, or NULL to start searching
446 * the entire device tree. The node you pass will not be
447 * searched, only the next one will; typically, you pass
448 * what the previous call returned. of_node_put() will be
449 * called on from for you.
450 * @type: The type string to match against
451 *
452 * Returns a node pointer with refcount incremented, use
453 * of_node_put() on it when done.
454 */
455struct device_node *of_find_node_by_type(struct device_node *from,
456 const char *type)
457{
458 struct device_node *np;
459
460 read_lock(&devtree_lock);
461 np = from ? from->allnext : allnodes;
462 for (; np; np = np->allnext)
463 if (np->type && (of_node_cmp(np->type, type) == 0)
464 && of_node_get(np))
465 break;
466 of_node_put(from);
467 read_unlock(&devtree_lock);
468 return np;
469}
470EXPORT_SYMBOL(of_find_node_by_type);
471
472/**
473 * of_find_compatible_node - Find a node based on type and one of the
474 * tokens in its "compatible" property
475 * @from: The node to start searching from or NULL, the node
476 * you pass will not be searched, only the next one
477 * will; typically, you pass what the previous call
478 * returned. of_node_put() will be called on it
479 * @type: The type string to match "device_type" or NULL to ignore
480 * @compatible: The string to match to one of the tokens in the device
481 * "compatible" list.
482 *
483 * Returns a node pointer with refcount incremented, use
484 * of_node_put() on it when done.
485 */
486struct device_node *of_find_compatible_node(struct device_node *from,
487 const char *type, const char *compatible)
488{
489 struct device_node *np;
490
491 read_lock(&devtree_lock);
492 np = from ? from->allnext : allnodes;
493 for (; np; np = np->allnext) {
494 if (type
495 && !(np->type && (of_node_cmp(np->type, type) == 0)))
496 continue;
497 if (of_device_is_compatible(np, compatible) && of_node_get(np))
498 break;
499 }
500 of_node_put(from);
501 read_unlock(&devtree_lock);
502 return np;
503}
504EXPORT_SYMBOL(of_find_compatible_node);
Grant Likely283029d2008-01-09 06:20:40 +1100505
506/**
Michael Ellerman1e291b12008-11-12 18:54:42 +0000507 * of_find_node_with_property - Find a node which has a property with
508 * the given name.
509 * @from: The node to start searching from or NULL, the node
510 * you pass will not be searched, only the next one
511 * will; typically, you pass what the previous call
512 * returned. of_node_put() will be called on it
513 * @prop_name: The name of the property to look for.
514 *
515 * Returns a node pointer with refcount incremented, use
516 * of_node_put() on it when done.
517 */
518struct device_node *of_find_node_with_property(struct device_node *from,
519 const char *prop_name)
520{
521 struct device_node *np;
522 struct property *pp;
523
524 read_lock(&devtree_lock);
525 np = from ? from->allnext : allnodes;
526 for (; np; np = np->allnext) {
Sachin Kamata3a7cab2012-06-27 09:44:45 +0530527 for (pp = np->properties; pp; pp = pp->next) {
Michael Ellerman1e291b12008-11-12 18:54:42 +0000528 if (of_prop_cmp(pp->name, prop_name) == 0) {
529 of_node_get(np);
530 goto out;
531 }
532 }
533 }
534out:
535 of_node_put(from);
536 read_unlock(&devtree_lock);
537 return np;
538}
539EXPORT_SYMBOL(of_find_node_with_property);
540
541/**
Grant Likely283029d2008-01-09 06:20:40 +1100542 * of_match_node - Tell if an device_node has a matching of_match structure
543 * @matches: array of of device match structures to search in
544 * @node: the of device structure to match against
545 *
546 * Low level utility function used by device matching.
547 */
548const struct of_device_id *of_match_node(const struct of_device_id *matches,
549 const struct device_node *node)
550{
Grant Likelya52f07e2011-03-18 10:21:29 -0600551 if (!matches)
552 return NULL;
553
Grant Likely283029d2008-01-09 06:20:40 +1100554 while (matches->name[0] || matches->type[0] || matches->compatible[0]) {
555 int match = 1;
556 if (matches->name[0])
557 match &= node->name
558 && !strcmp(matches->name, node->name);
559 if (matches->type[0])
560 match &= node->type
561 && !strcmp(matches->type, node->type);
Linus Torvaldsbc51b0c2012-07-10 12:49:32 -0700562 if (matches->compatible[0])
563 match &= of_device_is_compatible(node,
564 matches->compatible);
565 if (match)
Grant Likely283029d2008-01-09 06:20:40 +1100566 return matches;
567 matches++;
568 }
569 return NULL;
570}
571EXPORT_SYMBOL(of_match_node);
572
573/**
574 * of_find_matching_node - Find a node based on an of_device_id match
575 * table.
576 * @from: The node to start searching from or NULL, the node
577 * you pass will not be searched, only the next one
578 * will; typically, you pass what the previous call
579 * returned. of_node_put() will be called on it
580 * @matches: array of of device match structures to search in
581 *
582 * Returns a node pointer with refcount incremented, use
583 * of_node_put() on it when done.
584 */
585struct device_node *of_find_matching_node(struct device_node *from,
586 const struct of_device_id *matches)
587{
588 struct device_node *np;
589
590 read_lock(&devtree_lock);
591 np = from ? from->allnext : allnodes;
592 for (; np; np = np->allnext) {
593 if (of_match_node(matches, np) && of_node_get(np))
594 break;
595 }
596 of_node_put(from);
597 read_unlock(&devtree_lock);
598 return np;
599}
600EXPORT_SYMBOL(of_find_matching_node);
Grant Likely3f07af42008-07-25 22:25:13 -0400601
602/**
Grant Likely3f07af42008-07-25 22:25:13 -0400603 * of_modalias_node - Lookup appropriate modalias for a device node
604 * @node: pointer to a device tree node
605 * @modalias: Pointer to buffer that modalias value will be copied into
606 * @len: Length of modalias value
607 *
Grant Likely2ffe8c52010-06-08 07:48:19 -0600608 * Based on the value of the compatible property, this routine will attempt
609 * to choose an appropriate modalias value for a particular device tree node.
610 * It does this by stripping the manufacturer prefix (as delimited by a ',')
611 * from the first entry in the compatible list property.
Grant Likely3f07af42008-07-25 22:25:13 -0400612 *
Grant Likely2ffe8c52010-06-08 07:48:19 -0600613 * This routine returns 0 on success, <0 on failure.
Grant Likely3f07af42008-07-25 22:25:13 -0400614 */
615int of_modalias_node(struct device_node *node, char *modalias, int len)
616{
Grant Likely2ffe8c52010-06-08 07:48:19 -0600617 const char *compatible, *p;
618 int cplen;
Grant Likely3f07af42008-07-25 22:25:13 -0400619
620 compatible = of_get_property(node, "compatible", &cplen);
Grant Likely2ffe8c52010-06-08 07:48:19 -0600621 if (!compatible || strlen(compatible) > cplen)
Grant Likely3f07af42008-07-25 22:25:13 -0400622 return -ENODEV;
Grant Likely3f07af42008-07-25 22:25:13 -0400623 p = strchr(compatible, ',');
Grant Likely2ffe8c52010-06-08 07:48:19 -0600624 strlcpy(modalias, p ? p + 1 : compatible, len);
Grant Likely3f07af42008-07-25 22:25:13 -0400625 return 0;
626}
627EXPORT_SYMBOL_GPL(of_modalias_node);
628
Anton Vorontsov64b60e02008-10-10 04:43:17 +0000629/**
Jeremy Kerr89751a72010-02-01 21:34:11 -0700630 * of_find_node_by_phandle - Find a node given a phandle
631 * @handle: phandle of the node to find
632 *
633 * Returns a node pointer with refcount incremented, use
634 * of_node_put() on it when done.
635 */
636struct device_node *of_find_node_by_phandle(phandle handle)
637{
638 struct device_node *np;
639
640 read_lock(&devtree_lock);
641 for (np = allnodes; np; np = np->allnext)
642 if (np->phandle == handle)
643 break;
644 of_node_get(np);
645 read_unlock(&devtree_lock);
646 return np;
647}
648EXPORT_SYMBOL(of_find_node_by_phandle);
649
650/**
Rob Herring0e373632011-07-06 15:42:58 -0500651 * of_property_read_u32_array - Find and read an array of 32 bit integers
652 * from a property.
653 *
Thomas Abrahama3b85362011-06-30 21:26:10 +0530654 * @np: device node from which the property value is to be read.
655 * @propname: name of the property to be searched.
656 * @out_value: pointer to return value, modified only if return value is 0.
657 *
Rob Herring0e373632011-07-06 15:42:58 -0500658 * Search for a property in a device node and read 32-bit value(s) from
Thomas Abrahama3b85362011-06-30 21:26:10 +0530659 * it. Returns 0 on success, -EINVAL if the property does not exist,
660 * -ENODATA if property does not have a value, and -EOVERFLOW if the
661 * property data isn't large enough.
662 *
663 * The out_value is modified only if a valid u32 value can be decoded.
664 */
Jamie Ilesaac285c2011-08-02 15:45:07 +0100665int of_property_read_u32_array(const struct device_node *np,
666 const char *propname, u32 *out_values,
667 size_t sz)
Thomas Abrahama3b85362011-06-30 21:26:10 +0530668{
669 struct property *prop = of_find_property(np, propname, NULL);
Rob Herring0e373632011-07-06 15:42:58 -0500670 const __be32 *val;
Thomas Abrahama3b85362011-06-30 21:26:10 +0530671
672 if (!prop)
673 return -EINVAL;
674 if (!prop->value)
675 return -ENODATA;
Rob Herring0e373632011-07-06 15:42:58 -0500676 if ((sz * sizeof(*out_values)) > prop->length)
Thomas Abrahama3b85362011-06-30 21:26:10 +0530677 return -EOVERFLOW;
Rob Herring0e373632011-07-06 15:42:58 -0500678
679 val = prop->value;
680 while (sz--)
681 *out_values++ = be32_to_cpup(val++);
Thomas Abrahama3b85362011-06-30 21:26:10 +0530682 return 0;
683}
Rob Herring0e373632011-07-06 15:42:58 -0500684EXPORT_SYMBOL_GPL(of_property_read_u32_array);
Thomas Abrahama3b85362011-06-30 21:26:10 +0530685
686/**
Jamie Iles4cd7f7a2011-09-14 20:49:59 +0100687 * of_property_read_u64 - Find and read a 64 bit integer from a property
688 * @np: device node from which the property value is to be read.
689 * @propname: name of the property to be searched.
690 * @out_value: pointer to return value, modified only if return value is 0.
691 *
692 * Search for a property in a device node and read a 64-bit value from
693 * it. Returns 0 on success, -EINVAL if the property does not exist,
694 * -ENODATA if property does not have a value, and -EOVERFLOW if the
695 * property data isn't large enough.
696 *
697 * The out_value is modified only if a valid u64 value can be decoded.
698 */
699int of_property_read_u64(const struct device_node *np, const char *propname,
700 u64 *out_value)
701{
702 struct property *prop = of_find_property(np, propname, NULL);
703
704 if (!prop)
705 return -EINVAL;
706 if (!prop->value)
707 return -ENODATA;
708 if (sizeof(*out_value) > prop->length)
709 return -EOVERFLOW;
710 *out_value = of_read_number(prop->value, 2);
711 return 0;
712}
713EXPORT_SYMBOL_GPL(of_property_read_u64);
714
715/**
Thomas Abrahama3b85362011-06-30 21:26:10 +0530716 * of_property_read_string - Find and read a string from a property
717 * @np: device node from which the property value is to be read.
718 * @propname: name of the property to be searched.
719 * @out_string: pointer to null terminated return string, modified only if
720 * return value is 0.
721 *
722 * Search for a property in a device tree node and retrieve a null
723 * terminated string value (pointer to data, not a copy). Returns 0 on
724 * success, -EINVAL if the property does not exist, -ENODATA if property
725 * does not have a value, and -EILSEQ if the string is not null-terminated
726 * within the length of the property data.
727 *
728 * The out_string pointer is modified only if a valid string can be decoded.
729 */
Jamie Ilesaac285c2011-08-02 15:45:07 +0100730int of_property_read_string(struct device_node *np, const char *propname,
Shawn Guof09bc832011-07-04 09:01:18 +0800731 const char **out_string)
Thomas Abrahama3b85362011-06-30 21:26:10 +0530732{
733 struct property *prop = of_find_property(np, propname, NULL);
734 if (!prop)
735 return -EINVAL;
736 if (!prop->value)
737 return -ENODATA;
738 if (strnlen(prop->value, prop->length) >= prop->length)
739 return -EILSEQ;
740 *out_string = prop->value;
741 return 0;
742}
743EXPORT_SYMBOL_GPL(of_property_read_string);
744
745/**
Benoit Cousson4fcd15a2011-09-27 17:45:43 +0200746 * of_property_read_string_index - Find and read a string from a multiple
747 * strings property.
748 * @np: device node from which the property value is to be read.
749 * @propname: name of the property to be searched.
750 * @index: index of the string in the list of strings
751 * @out_string: pointer to null terminated return string, modified only if
752 * return value is 0.
753 *
754 * Search for a property in a device tree node and retrieve a null
755 * terminated string value (pointer to data, not a copy) in the list of strings
756 * contained in that property.
757 * Returns 0 on success, -EINVAL if the property does not exist, -ENODATA if
758 * property does not have a value, and -EILSEQ if the string is not
759 * null-terminated within the length of the property data.
760 *
761 * The out_string pointer is modified only if a valid string can be decoded.
762 */
763int of_property_read_string_index(struct device_node *np, const char *propname,
764 int index, const char **output)
765{
766 struct property *prop = of_find_property(np, propname, NULL);
767 int i = 0;
768 size_t l = 0, total = 0;
769 const char *p;
770
771 if (!prop)
772 return -EINVAL;
773 if (!prop->value)
774 return -ENODATA;
775 if (strnlen(prop->value, prop->length) >= prop->length)
776 return -EILSEQ;
777
778 p = prop->value;
779
780 for (i = 0; total < prop->length; total += l, p += l) {
781 l = strlen(p) + 1;
Benoit Cousson88af7f52011-12-05 15:23:54 +0100782 if (i++ == index) {
Benoit Cousson4fcd15a2011-09-27 17:45:43 +0200783 *output = p;
784 return 0;
785 }
786 }
787 return -ENODATA;
788}
789EXPORT_SYMBOL_GPL(of_property_read_string_index);
790
Grant Likely7aff0fe2011-12-12 09:25:58 -0700791/**
792 * of_property_match_string() - Find string in a list and return index
793 * @np: pointer to node containing string list property
794 * @propname: string list property name
795 * @string: pointer to string to search for in string list
796 *
797 * This function searches a string list property and returns the index
798 * of a specific string value.
799 */
800int of_property_match_string(struct device_node *np, const char *propname,
801 const char *string)
802{
803 struct property *prop = of_find_property(np, propname, NULL);
804 size_t l;
805 int i;
806 const char *p, *end;
807
808 if (!prop)
809 return -EINVAL;
810 if (!prop->value)
811 return -ENODATA;
812
813 p = prop->value;
814 end = p + prop->length;
815
816 for (i = 0; p < end; i++, p += l) {
817 l = strlen(p) + 1;
818 if (p + l > end)
819 return -EILSEQ;
820 pr_debug("comparing %s with %s\n", string, p);
821 if (strcmp(string, p) == 0)
822 return i; /* Found it; return index */
823 }
824 return -ENODATA;
825}
826EXPORT_SYMBOL_GPL(of_property_match_string);
Benoit Cousson4fcd15a2011-09-27 17:45:43 +0200827
828/**
829 * of_property_count_strings - Find and return the number of strings from a
830 * multiple strings property.
831 * @np: device node from which the property value is to be read.
832 * @propname: name of the property to be searched.
833 *
834 * Search for a property in a device tree node and retrieve the number of null
835 * terminated string contain in it. Returns the number of strings on
836 * success, -EINVAL if the property does not exist, -ENODATA if property
837 * does not have a value, and -EILSEQ if the string is not null-terminated
838 * within the length of the property data.
839 */
840int of_property_count_strings(struct device_node *np, const char *propname)
841{
842 struct property *prop = of_find_property(np, propname, NULL);
843 int i = 0;
844 size_t l = 0, total = 0;
845 const char *p;
846
847 if (!prop)
848 return -EINVAL;
849 if (!prop->value)
850 return -ENODATA;
851 if (strnlen(prop->value, prop->length) >= prop->length)
852 return -EILSEQ;
853
854 p = prop->value;
855
Benoit Cousson88af7f52011-12-05 15:23:54 +0100856 for (i = 0; total < prop->length; total += l, p += l, i++)
Benoit Cousson4fcd15a2011-09-27 17:45:43 +0200857 l = strlen(p) + 1;
Benoit Cousson88af7f52011-12-05 15:23:54 +0100858
Benoit Cousson4fcd15a2011-09-27 17:45:43 +0200859 return i;
860}
861EXPORT_SYMBOL_GPL(of_property_count_strings);
862
863/**
Grant Likely739649c2009-04-25 12:52:40 +0000864 * of_parse_phandle - Resolve a phandle property to a device_node pointer
865 * @np: Pointer to device node holding phandle property
866 * @phandle_name: Name of property holding a phandle value
867 * @index: For properties holding a table of phandles, this is the index into
868 * the table
869 *
870 * Returns the device_node pointer with refcount incremented. Use
871 * of_node_put() on it when done.
872 */
873struct device_node *
874of_parse_phandle(struct device_node *np, const char *phandle_name, int index)
875{
Grant Likely9a6b2e52010-07-23 01:48:25 -0600876 const __be32 *phandle;
Grant Likely739649c2009-04-25 12:52:40 +0000877 int size;
878
879 phandle = of_get_property(np, phandle_name, &size);
880 if ((!phandle) || (size < sizeof(*phandle) * (index + 1)))
881 return NULL;
882
Grant Likely9a6b2e52010-07-23 01:48:25 -0600883 return of_find_node_by_phandle(be32_to_cpup(phandle + index));
Grant Likely739649c2009-04-25 12:52:40 +0000884}
885EXPORT_SYMBOL(of_parse_phandle);
886
887/**
Grant Likely15c9a0a2011-12-12 09:25:57 -0700888 * of_parse_phandle_with_args() - Find a node pointed by phandle in a list
Anton Vorontsov64b60e02008-10-10 04:43:17 +0000889 * @np: pointer to a device tree node containing a list
890 * @list_name: property name that contains a list
891 * @cells_name: property name that specifies phandles' arguments count
892 * @index: index of a phandle to parse out
Grant Likely15c9a0a2011-12-12 09:25:57 -0700893 * @out_args: optional pointer to output arguments structure (will be filled)
Anton Vorontsov64b60e02008-10-10 04:43:17 +0000894 *
895 * This function is useful to parse lists of phandles and their arguments.
Grant Likely15c9a0a2011-12-12 09:25:57 -0700896 * Returns 0 on success and fills out_args, on error returns appropriate
897 * errno value.
898 *
899 * Caller is responsible to call of_node_put() on the returned out_args->node
900 * pointer.
Anton Vorontsov64b60e02008-10-10 04:43:17 +0000901 *
902 * Example:
903 *
904 * phandle1: node1 {
905 * #list-cells = <2>;
906 * }
907 *
908 * phandle2: node2 {
909 * #list-cells = <1>;
910 * }
911 *
912 * node3 {
913 * list = <&phandle1 1 2 &phandle2 3>;
914 * }
915 *
916 * To get a device_node of the `node2' node you may call this:
Grant Likely15c9a0a2011-12-12 09:25:57 -0700917 * of_parse_phandle_with_args(node3, "list", "#list-cells", 1, &args);
Anton Vorontsov64b60e02008-10-10 04:43:17 +0000918 */
Grant Likely15c9a0a2011-12-12 09:25:57 -0700919int of_parse_phandle_with_args(struct device_node *np, const char *list_name,
Anton Vorontsov64b60e02008-10-10 04:43:17 +0000920 const char *cells_name, int index,
Grant Likely15c9a0a2011-12-12 09:25:57 -0700921 struct of_phandle_args *out_args)
Anton Vorontsov64b60e02008-10-10 04:43:17 +0000922{
Grant Likely15c9a0a2011-12-12 09:25:57 -0700923 const __be32 *list, *list_end;
924 int size, cur_index = 0;
925 uint32_t count = 0;
Anton Vorontsov64b60e02008-10-10 04:43:17 +0000926 struct device_node *node = NULL;
Grant Likely15c9a0a2011-12-12 09:25:57 -0700927 phandle phandle;
Anton Vorontsov64b60e02008-10-10 04:43:17 +0000928
Grant Likely15c9a0a2011-12-12 09:25:57 -0700929 /* Retrieve the phandle list property */
Anton Vorontsov64b60e02008-10-10 04:43:17 +0000930 list = of_get_property(np, list_name, &size);
Grant Likely15c9a0a2011-12-12 09:25:57 -0700931 if (!list)
Alexandre Courbot1af4c7f2012-06-29 13:57:58 +0900932 return -ENOENT;
Anton Vorontsov64b60e02008-10-10 04:43:17 +0000933 list_end = list + size / sizeof(*list);
934
Grant Likely15c9a0a2011-12-12 09:25:57 -0700935 /* Loop over the phandles until all the requested entry is found */
Anton Vorontsov64b60e02008-10-10 04:43:17 +0000936 while (list < list_end) {
Grant Likely15c9a0a2011-12-12 09:25:57 -0700937 count = 0;
Anton Vorontsov64b60e02008-10-10 04:43:17 +0000938
Grant Likely15c9a0a2011-12-12 09:25:57 -0700939 /*
940 * If phandle is 0, then it is an empty entry with no
941 * arguments. Skip forward to the next entry.
942 */
Grant Likely9a6b2e52010-07-23 01:48:25 -0600943 phandle = be32_to_cpup(list++);
Grant Likely15c9a0a2011-12-12 09:25:57 -0700944 if (phandle) {
945 /*
946 * Find the provider node and parse the #*-cells
947 * property to determine the argument length
948 */
949 node = of_find_node_by_phandle(phandle);
950 if (!node) {
951 pr_err("%s: could not find phandle\n",
952 np->full_name);
953 break;
954 }
955 if (of_property_read_u32(node, cells_name, &count)) {
956 pr_err("%s: could not get %s for %s\n",
957 np->full_name, cells_name,
958 node->full_name);
959 break;
960 }
Anton Vorontsov64b60e02008-10-10 04:43:17 +0000961
Grant Likely15c9a0a2011-12-12 09:25:57 -0700962 /*
963 * Make sure that the arguments actually fit in the
964 * remaining property data length
965 */
966 if (list + count > list_end) {
967 pr_err("%s: arguments longer than property\n",
968 np->full_name);
969 break;
970 }
Anton Vorontsov64b60e02008-10-10 04:43:17 +0000971 }
972
Grant Likely15c9a0a2011-12-12 09:25:57 -0700973 /*
974 * All of the error cases above bail out of the loop, so at
975 * this point, the parsing is successful. If the requested
976 * index matches, then fill the out_args structure and return,
977 * or return -ENOENT for an empty entry.
978 */
979 if (cur_index == index) {
980 if (!phandle)
981 return -ENOENT;
Anton Vorontsov64b60e02008-10-10 04:43:17 +0000982
Grant Likely15c9a0a2011-12-12 09:25:57 -0700983 if (out_args) {
984 int i;
985 if (WARN_ON(count > MAX_PHANDLE_ARGS))
986 count = MAX_PHANDLE_ARGS;
987 out_args->np = node;
988 out_args->args_count = count;
989 for (i = 0; i < count; i++)
990 out_args->args[i] = be32_to_cpup(list++);
991 }
992 return 0;
Anton Vorontsov64b60e02008-10-10 04:43:17 +0000993 }
Anton Vorontsov64b60e02008-10-10 04:43:17 +0000994
995 of_node_put(node);
996 node = NULL;
Grant Likely15c9a0a2011-12-12 09:25:57 -0700997 list += count;
Anton Vorontsov64b60e02008-10-10 04:43:17 +0000998 cur_index++;
999 }
1000
Grant Likely15c9a0a2011-12-12 09:25:57 -07001001 /* Loop exited without finding a valid entry; return an error */
1002 if (node)
1003 of_node_put(node);
1004 return -EINVAL;
Anton Vorontsov64b60e02008-10-10 04:43:17 +00001005}
Grant Likely15c9a0a2011-12-12 09:25:57 -07001006EXPORT_SYMBOL(of_parse_phandle_with_args);
Grant Likely02af11b2009-11-23 20:16:45 -07001007
1008/**
1009 * prom_add_property - Add a property to a node
1010 */
1011int prom_add_property(struct device_node *np, struct property *prop)
1012{
1013 struct property **next;
1014 unsigned long flags;
1015
1016 prop->next = NULL;
1017 write_lock_irqsave(&devtree_lock, flags);
1018 next = &np->properties;
1019 while (*next) {
1020 if (strcmp(prop->name, (*next)->name) == 0) {
1021 /* duplicate ! don't insert it */
1022 write_unlock_irqrestore(&devtree_lock, flags);
1023 return -1;
1024 }
1025 next = &(*next)->next;
1026 }
1027 *next = prop;
1028 write_unlock_irqrestore(&devtree_lock, flags);
1029
1030#ifdef CONFIG_PROC_DEVICETREE
1031 /* try to add to proc as well if it was initialized */
1032 if (np->pde)
1033 proc_device_tree_add_prop(np->pde, prop);
1034#endif /* CONFIG_PROC_DEVICETREE */
1035
1036 return 0;
1037}
1038
1039/**
1040 * prom_remove_property - Remove a property from a node.
1041 *
1042 * Note that we don't actually remove it, since we have given out
1043 * who-knows-how-many pointers to the data using get-property.
1044 * Instead we just move the property to the "dead properties"
1045 * list, so it won't be found any more.
1046 */
1047int prom_remove_property(struct device_node *np, struct property *prop)
1048{
1049 struct property **next;
1050 unsigned long flags;
1051 int found = 0;
1052
1053 write_lock_irqsave(&devtree_lock, flags);
1054 next = &np->properties;
1055 while (*next) {
1056 if (*next == prop) {
1057 /* found the node */
1058 *next = prop->next;
1059 prop->next = np->deadprops;
1060 np->deadprops = prop;
1061 found = 1;
1062 break;
1063 }
1064 next = &(*next)->next;
1065 }
1066 write_unlock_irqrestore(&devtree_lock, flags);
1067
1068 if (!found)
1069 return -ENODEV;
1070
1071#ifdef CONFIG_PROC_DEVICETREE
1072 /* try to remove the proc node as well */
1073 if (np->pde)
1074 proc_device_tree_remove_prop(np->pde, prop);
1075#endif /* CONFIG_PROC_DEVICETREE */
1076
1077 return 0;
1078}
1079
1080/*
Dong Aisheng475d0092012-07-11 15:16:37 +10001081 * prom_update_property - Update a property in a node, if the property does
1082 * not exist, add it.
Grant Likely02af11b2009-11-23 20:16:45 -07001083 *
1084 * Note that we don't actually remove it, since we have given out
1085 * who-knows-how-many pointers to the data using get-property.
1086 * Instead we just move the property to the "dead properties" list,
1087 * and add the new property to the property list
1088 */
1089int prom_update_property(struct device_node *np,
Dong Aisheng475d0092012-07-11 15:16:37 +10001090 struct property *newprop)
Grant Likely02af11b2009-11-23 20:16:45 -07001091{
Dong Aisheng475d0092012-07-11 15:16:37 +10001092 struct property **next, *oldprop;
Grant Likely02af11b2009-11-23 20:16:45 -07001093 unsigned long flags;
1094 int found = 0;
1095
Dong Aisheng475d0092012-07-11 15:16:37 +10001096 if (!newprop->name)
1097 return -EINVAL;
1098
1099 oldprop = of_find_property(np, newprop->name, NULL);
1100 if (!oldprop)
1101 return prom_add_property(np, newprop);
1102
Grant Likely02af11b2009-11-23 20:16:45 -07001103 write_lock_irqsave(&devtree_lock, flags);
1104 next = &np->properties;
1105 while (*next) {
1106 if (*next == oldprop) {
1107 /* found the node */
1108 newprop->next = oldprop->next;
1109 *next = newprop;
1110 oldprop->next = np->deadprops;
1111 np->deadprops = oldprop;
1112 found = 1;
1113 break;
1114 }
1115 next = &(*next)->next;
1116 }
1117 write_unlock_irqrestore(&devtree_lock, flags);
1118
1119 if (!found)
1120 return -ENODEV;
1121
1122#ifdef CONFIG_PROC_DEVICETREE
1123 /* try to add to proc as well if it was initialized */
1124 if (np->pde)
1125 proc_device_tree_update_prop(np->pde, newprop, oldprop);
1126#endif /* CONFIG_PROC_DEVICETREE */
1127
1128 return 0;
1129}
Grant Likelyfcdeb7f2010-01-29 05:04:33 -07001130
1131#if defined(CONFIG_OF_DYNAMIC)
1132/*
1133 * Support for dynamic device trees.
1134 *
1135 * On some platforms, the device tree can be manipulated at runtime.
1136 * The routines in this section support adding, removing and changing
1137 * device tree nodes.
1138 */
1139
1140/**
1141 * of_attach_node - Plug a device node into the tree and global list.
1142 */
1143void of_attach_node(struct device_node *np)
1144{
1145 unsigned long flags;
1146
1147 write_lock_irqsave(&devtree_lock, flags);
1148 np->sibling = np->parent->child;
1149 np->allnext = allnodes;
1150 np->parent->child = np;
1151 allnodes = np;
1152 write_unlock_irqrestore(&devtree_lock, flags);
1153}
1154
1155/**
1156 * of_detach_node - "Unplug" a node from the device tree.
1157 *
1158 * The caller must hold a reference to the node. The memory associated with
1159 * the node is not freed until its refcount goes to zero.
1160 */
1161void of_detach_node(struct device_node *np)
1162{
1163 struct device_node *parent;
1164 unsigned long flags;
1165
1166 write_lock_irqsave(&devtree_lock, flags);
1167
1168 parent = np->parent;
1169 if (!parent)
1170 goto out_unlock;
1171
1172 if (allnodes == np)
1173 allnodes = np->allnext;
1174 else {
1175 struct device_node *prev;
1176 for (prev = allnodes;
1177 prev->allnext != np;
1178 prev = prev->allnext)
1179 ;
1180 prev->allnext = np->allnext;
1181 }
1182
1183 if (parent->child == np)
1184 parent->child = np->sibling;
1185 else {
1186 struct device_node *prevsib;
1187 for (prevsib = np->parent->child;
1188 prevsib->sibling != np;
1189 prevsib = prevsib->sibling)
1190 ;
1191 prevsib->sibling = np->sibling;
1192 }
1193
1194 of_node_set_flag(np, OF_DETACHED);
1195
1196out_unlock:
1197 write_unlock_irqrestore(&devtree_lock, flags);
1198}
1199#endif /* defined(CONFIG_OF_DYNAMIC) */
1200
Shawn Guo611cad72011-08-15 15:28:14 +08001201static void of_alias_add(struct alias_prop *ap, struct device_node *np,
1202 int id, const char *stem, int stem_len)
1203{
1204 ap->np = np;
1205 ap->id = id;
1206 strncpy(ap->stem, stem, stem_len);
1207 ap->stem[stem_len] = 0;
1208 list_add_tail(&ap->link, &aliases_lookup);
1209 pr_debug("adding DT alias:%s: stem=%s id=%i node=%s\n",
Grant Likely74a7f082012-06-15 11:50:25 -06001210 ap->alias, ap->stem, ap->id, of_node_full_name(np));
Shawn Guo611cad72011-08-15 15:28:14 +08001211}
1212
1213/**
1214 * of_alias_scan - Scan all properties of 'aliases' node
1215 *
1216 * The function scans all the properties of 'aliases' node and populate
1217 * the the global lookup table with the properties. It returns the
1218 * number of alias_prop found, or error code in error case.
1219 *
1220 * @dt_alloc: An allocator that provides a virtual address to memory
1221 * for the resulting tree
1222 */
1223void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align))
1224{
1225 struct property *pp;
1226
1227 of_chosen = of_find_node_by_path("/chosen");
1228 if (of_chosen == NULL)
1229 of_chosen = of_find_node_by_path("/chosen@0");
1230 of_aliases = of_find_node_by_path("/aliases");
1231 if (!of_aliases)
1232 return;
1233
Dong Aisheng8af0da92011-12-22 20:19:24 +08001234 for_each_property_of_node(of_aliases, pp) {
Shawn Guo611cad72011-08-15 15:28:14 +08001235 const char *start = pp->name;
1236 const char *end = start + strlen(start);
1237 struct device_node *np;
1238 struct alias_prop *ap;
1239 int id, len;
1240
1241 /* Skip those we do not want to proceed */
1242 if (!strcmp(pp->name, "name") ||
1243 !strcmp(pp->name, "phandle") ||
1244 !strcmp(pp->name, "linux,phandle"))
1245 continue;
1246
1247 np = of_find_node_by_path(pp->value);
1248 if (!np)
1249 continue;
1250
1251 /* walk the alias backwards to extract the id and work out
1252 * the 'stem' string */
1253 while (isdigit(*(end-1)) && end > start)
1254 end--;
1255 len = end - start;
1256
1257 if (kstrtoint(end, 10, &id) < 0)
1258 continue;
1259
1260 /* Allocate an alias_prop with enough space for the stem */
1261 ap = dt_alloc(sizeof(*ap) + len + 1, 4);
1262 if (!ap)
1263 continue;
1264 ap->alias = start;
1265 of_alias_add(ap, np, id, start, len);
1266 }
1267}
1268
1269/**
1270 * of_alias_get_id - Get alias id for the given device_node
1271 * @np: Pointer to the given device_node
1272 * @stem: Alias stem of the given device_node
1273 *
1274 * The function travels the lookup table to get alias id for the given
1275 * device_node and alias stem. It returns the alias id if find it.
1276 */
1277int of_alias_get_id(struct device_node *np, const char *stem)
1278{
1279 struct alias_prop *app;
1280 int id = -ENODEV;
1281
1282 mutex_lock(&of_aliases_mutex);
1283 list_for_each_entry(app, &aliases_lookup, link) {
1284 if (strcmp(app->stem, stem) != 0)
1285 continue;
1286
1287 if (np == app->np) {
1288 id = app->id;
1289 break;
1290 }
1291 }
1292 mutex_unlock(&of_aliases_mutex);
1293
1294 return id;
1295}
1296EXPORT_SYMBOL_GPL(of_alias_get_id);
Stephen Warrenc541adc2012-04-04 09:27:46 -06001297
1298const __be32 *of_prop_next_u32(struct property *prop, const __be32 *cur,
1299 u32 *pu)
1300{
1301 const void *curv = cur;
1302
1303 if (!prop)
1304 return NULL;
1305
1306 if (!cur) {
1307 curv = prop->value;
1308 goto out_val;
1309 }
1310
1311 curv += sizeof(*cur);
1312 if (curv >= prop->value + prop->length)
1313 return NULL;
1314
1315out_val:
1316 *pu = be32_to_cpup(curv);
1317 return curv;
1318}
1319EXPORT_SYMBOL_GPL(of_prop_next_u32);
1320
1321const char *of_prop_next_string(struct property *prop, const char *cur)
1322{
1323 const void *curv = cur;
1324
1325 if (!prop)
1326 return NULL;
1327
1328 if (!cur)
1329 return prop->value;
1330
1331 curv += strlen(cur) + 1;
1332 if (curv >= prop->value + prop->length)
1333 return NULL;
1334
1335 return curv;
1336}
1337EXPORT_SYMBOL_GPL(of_prop_next_string);