blob: af3b22ac762755b532286ac505fb85ef936ca64b [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/**
Srinivas Kandagatla9c197612012-09-18 08:10:28 +0100394 * of_get_child_by_name - Find the child node by name for a given parent
395 * @node: parent node
396 * @name: child name to look for.
397 *
398 * This function looks for child node for given matching name
399 *
400 * Returns a node pointer if found, with refcount incremented, use
401 * of_node_put() on it when done.
402 * Returns NULL if node is not found.
403 */
404struct device_node *of_get_child_by_name(const struct device_node *node,
405 const char *name)
406{
407 struct device_node *child;
408
409 for_each_child_of_node(node, child)
410 if (child->name && (of_node_cmp(child->name, name) == 0))
411 break;
412 return child;
413}
414EXPORT_SYMBOL(of_get_child_by_name);
415
416/**
Stephen Rothwell1ef4d422007-04-24 17:57:33 +1000417 * of_find_node_by_path - Find a node matching a full OF path
418 * @path: The full path to match
419 *
420 * Returns a node pointer with refcount incremented, use
421 * of_node_put() on it when done.
422 */
423struct device_node *of_find_node_by_path(const char *path)
424{
425 struct device_node *np = allnodes;
426
427 read_lock(&devtree_lock);
428 for (; np; np = np->allnext) {
429 if (np->full_name && (of_node_cmp(np->full_name, path) == 0)
430 && of_node_get(np))
431 break;
432 }
433 read_unlock(&devtree_lock);
434 return np;
435}
436EXPORT_SYMBOL(of_find_node_by_path);
437
438/**
439 * of_find_node_by_name - Find a node by its "name" property
440 * @from: The node to start searching from or NULL, the node
441 * you pass will not be searched, only the next one
442 * will; typically, you pass what the previous call
443 * returned. of_node_put() will be called on it
444 * @name: The name string to match against
445 *
446 * Returns a node pointer with refcount incremented, use
447 * of_node_put() on it when done.
448 */
449struct device_node *of_find_node_by_name(struct device_node *from,
450 const char *name)
451{
452 struct device_node *np;
453
454 read_lock(&devtree_lock);
455 np = from ? from->allnext : allnodes;
456 for (; np; np = np->allnext)
457 if (np->name && (of_node_cmp(np->name, name) == 0)
458 && of_node_get(np))
459 break;
460 of_node_put(from);
461 read_unlock(&devtree_lock);
462 return np;
463}
464EXPORT_SYMBOL(of_find_node_by_name);
465
466/**
467 * of_find_node_by_type - Find a node by its "device_type" property
468 * @from: The node to start searching from, or NULL to start searching
469 * the entire device tree. The node you pass will not be
470 * searched, only the next one will; typically, you pass
471 * what the previous call returned. of_node_put() will be
472 * called on from for you.
473 * @type: The type string to match against
474 *
475 * Returns a node pointer with refcount incremented, use
476 * of_node_put() on it when done.
477 */
478struct device_node *of_find_node_by_type(struct device_node *from,
479 const char *type)
480{
481 struct device_node *np;
482
483 read_lock(&devtree_lock);
484 np = from ? from->allnext : allnodes;
485 for (; np; np = np->allnext)
486 if (np->type && (of_node_cmp(np->type, type) == 0)
487 && of_node_get(np))
488 break;
489 of_node_put(from);
490 read_unlock(&devtree_lock);
491 return np;
492}
493EXPORT_SYMBOL(of_find_node_by_type);
494
495/**
496 * of_find_compatible_node - Find a node based on type and one of the
497 * tokens in its "compatible" property
498 * @from: The node to start searching from or NULL, the node
499 * you pass will not be searched, only the next one
500 * will; typically, you pass what the previous call
501 * returned. of_node_put() will be called on it
502 * @type: The type string to match "device_type" or NULL to ignore
503 * @compatible: The string to match to one of the tokens in the device
504 * "compatible" list.
505 *
506 * Returns a node pointer with refcount incremented, use
507 * of_node_put() on it when done.
508 */
509struct device_node *of_find_compatible_node(struct device_node *from,
510 const char *type, const char *compatible)
511{
512 struct device_node *np;
513
514 read_lock(&devtree_lock);
515 np = from ? from->allnext : allnodes;
516 for (; np; np = np->allnext) {
517 if (type
518 && !(np->type && (of_node_cmp(np->type, type) == 0)))
519 continue;
520 if (of_device_is_compatible(np, compatible) && of_node_get(np))
521 break;
522 }
523 of_node_put(from);
524 read_unlock(&devtree_lock);
525 return np;
526}
527EXPORT_SYMBOL(of_find_compatible_node);
Grant Likely283029d2008-01-09 06:20:40 +1100528
529/**
Michael Ellerman1e291b12008-11-12 18:54:42 +0000530 * of_find_node_with_property - Find a node which has a property with
531 * the given name.
532 * @from: The node to start searching from or NULL, the node
533 * you pass will not be searched, only the next one
534 * will; typically, you pass what the previous call
535 * returned. of_node_put() will be called on it
536 * @prop_name: The name of the property to look for.
537 *
538 * Returns a node pointer with refcount incremented, use
539 * of_node_put() on it when done.
540 */
541struct device_node *of_find_node_with_property(struct device_node *from,
542 const char *prop_name)
543{
544 struct device_node *np;
545 struct property *pp;
546
547 read_lock(&devtree_lock);
548 np = from ? from->allnext : allnodes;
549 for (; np; np = np->allnext) {
Sachin Kamata3a7cab2012-06-27 09:44:45 +0530550 for (pp = np->properties; pp; pp = pp->next) {
Michael Ellerman1e291b12008-11-12 18:54:42 +0000551 if (of_prop_cmp(pp->name, prop_name) == 0) {
552 of_node_get(np);
553 goto out;
554 }
555 }
556 }
557out:
558 of_node_put(from);
559 read_unlock(&devtree_lock);
560 return np;
561}
562EXPORT_SYMBOL(of_find_node_with_property);
563
564/**
Grant Likely283029d2008-01-09 06:20:40 +1100565 * of_match_node - Tell if an device_node has a matching of_match structure
566 * @matches: array of of device match structures to search in
567 * @node: the of device structure to match against
568 *
569 * Low level utility function used by device matching.
570 */
571const struct of_device_id *of_match_node(const struct of_device_id *matches,
572 const struct device_node *node)
573{
Grant Likelya52f07e2011-03-18 10:21:29 -0600574 if (!matches)
575 return NULL;
576
Grant Likely283029d2008-01-09 06:20:40 +1100577 while (matches->name[0] || matches->type[0] || matches->compatible[0]) {
578 int match = 1;
579 if (matches->name[0])
580 match &= node->name
581 && !strcmp(matches->name, node->name);
582 if (matches->type[0])
583 match &= node->type
584 && !strcmp(matches->type, node->type);
Linus Torvaldsbc51b0c2012-07-10 12:49:32 -0700585 if (matches->compatible[0])
586 match &= of_device_is_compatible(node,
587 matches->compatible);
588 if (match)
Grant Likely283029d2008-01-09 06:20:40 +1100589 return matches;
590 matches++;
591 }
592 return NULL;
593}
594EXPORT_SYMBOL(of_match_node);
595
596/**
597 * of_find_matching_node - Find a node based on an of_device_id match
598 * table.
599 * @from: The node to start searching from or NULL, the node
600 * you pass will not be searched, only the next one
601 * will; typically, you pass what the previous call
602 * returned. of_node_put() will be called on it
603 * @matches: array of of device match structures to search in
604 *
605 * Returns a node pointer with refcount incremented, use
606 * of_node_put() on it when done.
607 */
608struct device_node *of_find_matching_node(struct device_node *from,
609 const struct of_device_id *matches)
610{
611 struct device_node *np;
612
613 read_lock(&devtree_lock);
614 np = from ? from->allnext : allnodes;
615 for (; np; np = np->allnext) {
616 if (of_match_node(matches, np) && of_node_get(np))
617 break;
618 }
619 of_node_put(from);
620 read_unlock(&devtree_lock);
621 return np;
622}
623EXPORT_SYMBOL(of_find_matching_node);
Grant Likely3f07af42008-07-25 22:25:13 -0400624
625/**
Grant Likely3f07af42008-07-25 22:25:13 -0400626 * of_modalias_node - Lookup appropriate modalias for a device node
627 * @node: pointer to a device tree node
628 * @modalias: Pointer to buffer that modalias value will be copied into
629 * @len: Length of modalias value
630 *
Grant Likely2ffe8c52010-06-08 07:48:19 -0600631 * Based on the value of the compatible property, this routine will attempt
632 * to choose an appropriate modalias value for a particular device tree node.
633 * It does this by stripping the manufacturer prefix (as delimited by a ',')
634 * from the first entry in the compatible list property.
Grant Likely3f07af42008-07-25 22:25:13 -0400635 *
Grant Likely2ffe8c52010-06-08 07:48:19 -0600636 * This routine returns 0 on success, <0 on failure.
Grant Likely3f07af42008-07-25 22:25:13 -0400637 */
638int of_modalias_node(struct device_node *node, char *modalias, int len)
639{
Grant Likely2ffe8c52010-06-08 07:48:19 -0600640 const char *compatible, *p;
641 int cplen;
Grant Likely3f07af42008-07-25 22:25:13 -0400642
643 compatible = of_get_property(node, "compatible", &cplen);
Grant Likely2ffe8c52010-06-08 07:48:19 -0600644 if (!compatible || strlen(compatible) > cplen)
Grant Likely3f07af42008-07-25 22:25:13 -0400645 return -ENODEV;
Grant Likely3f07af42008-07-25 22:25:13 -0400646 p = strchr(compatible, ',');
Grant Likely2ffe8c52010-06-08 07:48:19 -0600647 strlcpy(modalias, p ? p + 1 : compatible, len);
Grant Likely3f07af42008-07-25 22:25:13 -0400648 return 0;
649}
650EXPORT_SYMBOL_GPL(of_modalias_node);
651
Anton Vorontsov64b60e02008-10-10 04:43:17 +0000652/**
Jeremy Kerr89751a72010-02-01 21:34:11 -0700653 * of_find_node_by_phandle - Find a node given a phandle
654 * @handle: phandle of the node to find
655 *
656 * Returns a node pointer with refcount incremented, use
657 * of_node_put() on it when done.
658 */
659struct device_node *of_find_node_by_phandle(phandle handle)
660{
661 struct device_node *np;
662
663 read_lock(&devtree_lock);
664 for (np = allnodes; np; np = np->allnext)
665 if (np->phandle == handle)
666 break;
667 of_node_get(np);
668 read_unlock(&devtree_lock);
669 return np;
670}
671EXPORT_SYMBOL(of_find_node_by_phandle);
672
673/**
Rob Herring0e373632011-07-06 15:42:58 -0500674 * of_property_read_u32_array - Find and read an array of 32 bit integers
675 * from a property.
676 *
Thomas Abrahama3b85362011-06-30 21:26:10 +0530677 * @np: device node from which the property value is to be read.
678 * @propname: name of the property to be searched.
679 * @out_value: pointer to return value, modified only if return value is 0.
680 *
Rob Herring0e373632011-07-06 15:42:58 -0500681 * Search for a property in a device node and read 32-bit value(s) from
Thomas Abrahama3b85362011-06-30 21:26:10 +0530682 * it. Returns 0 on success, -EINVAL if the property does not exist,
683 * -ENODATA if property does not have a value, and -EOVERFLOW if the
684 * property data isn't large enough.
685 *
686 * The out_value is modified only if a valid u32 value can be decoded.
687 */
Jamie Ilesaac285c2011-08-02 15:45:07 +0100688int of_property_read_u32_array(const struct device_node *np,
689 const char *propname, u32 *out_values,
690 size_t sz)
Thomas Abrahama3b85362011-06-30 21:26:10 +0530691{
692 struct property *prop = of_find_property(np, propname, NULL);
Rob Herring0e373632011-07-06 15:42:58 -0500693 const __be32 *val;
Thomas Abrahama3b85362011-06-30 21:26:10 +0530694
695 if (!prop)
696 return -EINVAL;
697 if (!prop->value)
698 return -ENODATA;
Rob Herring0e373632011-07-06 15:42:58 -0500699 if ((sz * sizeof(*out_values)) > prop->length)
Thomas Abrahama3b85362011-06-30 21:26:10 +0530700 return -EOVERFLOW;
Rob Herring0e373632011-07-06 15:42:58 -0500701
702 val = prop->value;
703 while (sz--)
704 *out_values++ = be32_to_cpup(val++);
Thomas Abrahama3b85362011-06-30 21:26:10 +0530705 return 0;
706}
Rob Herring0e373632011-07-06 15:42:58 -0500707EXPORT_SYMBOL_GPL(of_property_read_u32_array);
Thomas Abrahama3b85362011-06-30 21:26:10 +0530708
709/**
Jamie Iles4cd7f7a2011-09-14 20:49:59 +0100710 * of_property_read_u64 - Find and read a 64 bit integer from a property
711 * @np: device node from which the property value is to be read.
712 * @propname: name of the property to be searched.
713 * @out_value: pointer to return value, modified only if return value is 0.
714 *
715 * Search for a property in a device node and read a 64-bit value from
716 * it. Returns 0 on success, -EINVAL if the property does not exist,
717 * -ENODATA if property does not have a value, and -EOVERFLOW if the
718 * property data isn't large enough.
719 *
720 * The out_value is modified only if a valid u64 value can be decoded.
721 */
722int of_property_read_u64(const struct device_node *np, const char *propname,
723 u64 *out_value)
724{
725 struct property *prop = of_find_property(np, propname, NULL);
726
727 if (!prop)
728 return -EINVAL;
729 if (!prop->value)
730 return -ENODATA;
731 if (sizeof(*out_value) > prop->length)
732 return -EOVERFLOW;
733 *out_value = of_read_number(prop->value, 2);
734 return 0;
735}
736EXPORT_SYMBOL_GPL(of_property_read_u64);
737
738/**
Thomas Abrahama3b85362011-06-30 21:26:10 +0530739 * of_property_read_string - Find and read a string from a property
740 * @np: device node from which the property value is to be read.
741 * @propname: name of the property to be searched.
742 * @out_string: pointer to null terminated return string, modified only if
743 * return value is 0.
744 *
745 * Search for a property in a device tree node and retrieve a null
746 * terminated string value (pointer to data, not a copy). Returns 0 on
747 * success, -EINVAL if the property does not exist, -ENODATA if property
748 * does not have a value, and -EILSEQ if the string is not null-terminated
749 * within the length of the property data.
750 *
751 * The out_string pointer is modified only if a valid string can be decoded.
752 */
Jamie Ilesaac285c2011-08-02 15:45:07 +0100753int of_property_read_string(struct device_node *np, const char *propname,
Shawn Guof09bc832011-07-04 09:01:18 +0800754 const char **out_string)
Thomas Abrahama3b85362011-06-30 21:26:10 +0530755{
756 struct property *prop = of_find_property(np, propname, NULL);
757 if (!prop)
758 return -EINVAL;
759 if (!prop->value)
760 return -ENODATA;
761 if (strnlen(prop->value, prop->length) >= prop->length)
762 return -EILSEQ;
763 *out_string = prop->value;
764 return 0;
765}
766EXPORT_SYMBOL_GPL(of_property_read_string);
767
768/**
Benoit Cousson4fcd15a2011-09-27 17:45:43 +0200769 * of_property_read_string_index - Find and read a string from a multiple
770 * strings property.
771 * @np: device node from which the property value is to be read.
772 * @propname: name of the property to be searched.
773 * @index: index of the string in the list of strings
774 * @out_string: pointer to null terminated return string, modified only if
775 * return value is 0.
776 *
777 * Search for a property in a device tree node and retrieve a null
778 * terminated string value (pointer to data, not a copy) in the list of strings
779 * contained in that property.
780 * Returns 0 on success, -EINVAL if the property does not exist, -ENODATA if
781 * property does not have a value, and -EILSEQ if the string is not
782 * null-terminated within the length of the property data.
783 *
784 * The out_string pointer is modified only if a valid string can be decoded.
785 */
786int of_property_read_string_index(struct device_node *np, const char *propname,
787 int index, const char **output)
788{
789 struct property *prop = of_find_property(np, propname, NULL);
790 int i = 0;
791 size_t l = 0, total = 0;
792 const char *p;
793
794 if (!prop)
795 return -EINVAL;
796 if (!prop->value)
797 return -ENODATA;
798 if (strnlen(prop->value, prop->length) >= prop->length)
799 return -EILSEQ;
800
801 p = prop->value;
802
803 for (i = 0; total < prop->length; total += l, p += l) {
804 l = strlen(p) + 1;
Benoit Cousson88af7f52011-12-05 15:23:54 +0100805 if (i++ == index) {
Benoit Cousson4fcd15a2011-09-27 17:45:43 +0200806 *output = p;
807 return 0;
808 }
809 }
810 return -ENODATA;
811}
812EXPORT_SYMBOL_GPL(of_property_read_string_index);
813
Grant Likely7aff0fe2011-12-12 09:25:58 -0700814/**
815 * of_property_match_string() - Find string in a list and return index
816 * @np: pointer to node containing string list property
817 * @propname: string list property name
818 * @string: pointer to string to search for in string list
819 *
820 * This function searches a string list property and returns the index
821 * of a specific string value.
822 */
823int of_property_match_string(struct device_node *np, const char *propname,
824 const char *string)
825{
826 struct property *prop = of_find_property(np, propname, NULL);
827 size_t l;
828 int i;
829 const char *p, *end;
830
831 if (!prop)
832 return -EINVAL;
833 if (!prop->value)
834 return -ENODATA;
835
836 p = prop->value;
837 end = p + prop->length;
838
839 for (i = 0; p < end; i++, p += l) {
840 l = strlen(p) + 1;
841 if (p + l > end)
842 return -EILSEQ;
843 pr_debug("comparing %s with %s\n", string, p);
844 if (strcmp(string, p) == 0)
845 return i; /* Found it; return index */
846 }
847 return -ENODATA;
848}
849EXPORT_SYMBOL_GPL(of_property_match_string);
Benoit Cousson4fcd15a2011-09-27 17:45:43 +0200850
851/**
852 * of_property_count_strings - Find and return the number of strings from a
853 * multiple strings property.
854 * @np: device node from which the property value is to be read.
855 * @propname: name of the property to be searched.
856 *
857 * Search for a property in a device tree node and retrieve the number of null
858 * terminated string contain in it. Returns the number of strings on
859 * success, -EINVAL if the property does not exist, -ENODATA if property
860 * does not have a value, and -EILSEQ if the string is not null-terminated
861 * within the length of the property data.
862 */
863int of_property_count_strings(struct device_node *np, const char *propname)
864{
865 struct property *prop = of_find_property(np, propname, NULL);
866 int i = 0;
867 size_t l = 0, total = 0;
868 const char *p;
869
870 if (!prop)
871 return -EINVAL;
872 if (!prop->value)
873 return -ENODATA;
874 if (strnlen(prop->value, prop->length) >= prop->length)
875 return -EILSEQ;
876
877 p = prop->value;
878
Benoit Cousson88af7f52011-12-05 15:23:54 +0100879 for (i = 0; total < prop->length; total += l, p += l, i++)
Benoit Cousson4fcd15a2011-09-27 17:45:43 +0200880 l = strlen(p) + 1;
Benoit Cousson88af7f52011-12-05 15:23:54 +0100881
Benoit Cousson4fcd15a2011-09-27 17:45:43 +0200882 return i;
883}
884EXPORT_SYMBOL_GPL(of_property_count_strings);
885
886/**
Grant Likely739649c2009-04-25 12:52:40 +0000887 * of_parse_phandle - Resolve a phandle property to a device_node pointer
888 * @np: Pointer to device node holding phandle property
889 * @phandle_name: Name of property holding a phandle value
890 * @index: For properties holding a table of phandles, this is the index into
891 * the table
892 *
893 * Returns the device_node pointer with refcount incremented. Use
894 * of_node_put() on it when done.
895 */
896struct device_node *
897of_parse_phandle(struct device_node *np, const char *phandle_name, int index)
898{
Grant Likely9a6b2e52010-07-23 01:48:25 -0600899 const __be32 *phandle;
Grant Likely739649c2009-04-25 12:52:40 +0000900 int size;
901
902 phandle = of_get_property(np, phandle_name, &size);
903 if ((!phandle) || (size < sizeof(*phandle) * (index + 1)))
904 return NULL;
905
Grant Likely9a6b2e52010-07-23 01:48:25 -0600906 return of_find_node_by_phandle(be32_to_cpup(phandle + index));
Grant Likely739649c2009-04-25 12:52:40 +0000907}
908EXPORT_SYMBOL(of_parse_phandle);
909
910/**
Grant Likely15c9a0a2011-12-12 09:25:57 -0700911 * of_parse_phandle_with_args() - Find a node pointed by phandle in a list
Anton Vorontsov64b60e02008-10-10 04:43:17 +0000912 * @np: pointer to a device tree node containing a list
913 * @list_name: property name that contains a list
914 * @cells_name: property name that specifies phandles' arguments count
915 * @index: index of a phandle to parse out
Grant Likely15c9a0a2011-12-12 09:25:57 -0700916 * @out_args: optional pointer to output arguments structure (will be filled)
Anton Vorontsov64b60e02008-10-10 04:43:17 +0000917 *
918 * This function is useful to parse lists of phandles and their arguments.
Grant Likely15c9a0a2011-12-12 09:25:57 -0700919 * Returns 0 on success and fills out_args, on error returns appropriate
920 * errno value.
921 *
922 * Caller is responsible to call of_node_put() on the returned out_args->node
923 * pointer.
Anton Vorontsov64b60e02008-10-10 04:43:17 +0000924 *
925 * Example:
926 *
927 * phandle1: node1 {
928 * #list-cells = <2>;
929 * }
930 *
931 * phandle2: node2 {
932 * #list-cells = <1>;
933 * }
934 *
935 * node3 {
936 * list = <&phandle1 1 2 &phandle2 3>;
937 * }
938 *
939 * To get a device_node of the `node2' node you may call this:
Grant Likely15c9a0a2011-12-12 09:25:57 -0700940 * of_parse_phandle_with_args(node3, "list", "#list-cells", 1, &args);
Anton Vorontsov64b60e02008-10-10 04:43:17 +0000941 */
Grant Likely15c9a0a2011-12-12 09:25:57 -0700942int of_parse_phandle_with_args(struct device_node *np, const char *list_name,
Anton Vorontsov64b60e02008-10-10 04:43:17 +0000943 const char *cells_name, int index,
Grant Likely15c9a0a2011-12-12 09:25:57 -0700944 struct of_phandle_args *out_args)
Anton Vorontsov64b60e02008-10-10 04:43:17 +0000945{
Grant Likely15c9a0a2011-12-12 09:25:57 -0700946 const __be32 *list, *list_end;
947 int size, cur_index = 0;
948 uint32_t count = 0;
Anton Vorontsov64b60e02008-10-10 04:43:17 +0000949 struct device_node *node = NULL;
Grant Likely15c9a0a2011-12-12 09:25:57 -0700950 phandle phandle;
Anton Vorontsov64b60e02008-10-10 04:43:17 +0000951
Grant Likely15c9a0a2011-12-12 09:25:57 -0700952 /* Retrieve the phandle list property */
Anton Vorontsov64b60e02008-10-10 04:43:17 +0000953 list = of_get_property(np, list_name, &size);
Grant Likely15c9a0a2011-12-12 09:25:57 -0700954 if (!list)
Alexandre Courbot1af4c7f2012-06-29 13:57:58 +0900955 return -ENOENT;
Anton Vorontsov64b60e02008-10-10 04:43:17 +0000956 list_end = list + size / sizeof(*list);
957
Grant Likely15c9a0a2011-12-12 09:25:57 -0700958 /* Loop over the phandles until all the requested entry is found */
Anton Vorontsov64b60e02008-10-10 04:43:17 +0000959 while (list < list_end) {
Grant Likely15c9a0a2011-12-12 09:25:57 -0700960 count = 0;
Anton Vorontsov64b60e02008-10-10 04:43:17 +0000961
Grant Likely15c9a0a2011-12-12 09:25:57 -0700962 /*
963 * If phandle is 0, then it is an empty entry with no
964 * arguments. Skip forward to the next entry.
965 */
Grant Likely9a6b2e52010-07-23 01:48:25 -0600966 phandle = be32_to_cpup(list++);
Grant Likely15c9a0a2011-12-12 09:25:57 -0700967 if (phandle) {
968 /*
969 * Find the provider node and parse the #*-cells
970 * property to determine the argument length
971 */
972 node = of_find_node_by_phandle(phandle);
973 if (!node) {
974 pr_err("%s: could not find phandle\n",
975 np->full_name);
976 break;
977 }
978 if (of_property_read_u32(node, cells_name, &count)) {
979 pr_err("%s: could not get %s for %s\n",
980 np->full_name, cells_name,
981 node->full_name);
982 break;
983 }
Anton Vorontsov64b60e02008-10-10 04:43:17 +0000984
Grant Likely15c9a0a2011-12-12 09:25:57 -0700985 /*
986 * Make sure that the arguments actually fit in the
987 * remaining property data length
988 */
989 if (list + count > list_end) {
990 pr_err("%s: arguments longer than property\n",
991 np->full_name);
992 break;
993 }
Anton Vorontsov64b60e02008-10-10 04:43:17 +0000994 }
995
Grant Likely15c9a0a2011-12-12 09:25:57 -0700996 /*
997 * All of the error cases above bail out of the loop, so at
998 * this point, the parsing is successful. If the requested
999 * index matches, then fill the out_args structure and return,
1000 * or return -ENOENT for an empty entry.
1001 */
1002 if (cur_index == index) {
1003 if (!phandle)
1004 return -ENOENT;
Anton Vorontsov64b60e02008-10-10 04:43:17 +00001005
Grant Likely15c9a0a2011-12-12 09:25:57 -07001006 if (out_args) {
1007 int i;
1008 if (WARN_ON(count > MAX_PHANDLE_ARGS))
1009 count = MAX_PHANDLE_ARGS;
1010 out_args->np = node;
1011 out_args->args_count = count;
1012 for (i = 0; i < count; i++)
1013 out_args->args[i] = be32_to_cpup(list++);
1014 }
1015 return 0;
Anton Vorontsov64b60e02008-10-10 04:43:17 +00001016 }
Anton Vorontsov64b60e02008-10-10 04:43:17 +00001017
1018 of_node_put(node);
1019 node = NULL;
Grant Likely15c9a0a2011-12-12 09:25:57 -07001020 list += count;
Anton Vorontsov64b60e02008-10-10 04:43:17 +00001021 cur_index++;
1022 }
1023
Grant Likely15c9a0a2011-12-12 09:25:57 -07001024 /* Loop exited without finding a valid entry; return an error */
1025 if (node)
1026 of_node_put(node);
1027 return -EINVAL;
Anton Vorontsov64b60e02008-10-10 04:43:17 +00001028}
Grant Likely15c9a0a2011-12-12 09:25:57 -07001029EXPORT_SYMBOL(of_parse_phandle_with_args);
Grant Likely02af11b2009-11-23 20:16:45 -07001030
1031/**
1032 * prom_add_property - Add a property to a node
1033 */
1034int prom_add_property(struct device_node *np, struct property *prop)
1035{
1036 struct property **next;
1037 unsigned long flags;
1038
1039 prop->next = NULL;
1040 write_lock_irqsave(&devtree_lock, flags);
1041 next = &np->properties;
1042 while (*next) {
1043 if (strcmp(prop->name, (*next)->name) == 0) {
1044 /* duplicate ! don't insert it */
1045 write_unlock_irqrestore(&devtree_lock, flags);
1046 return -1;
1047 }
1048 next = &(*next)->next;
1049 }
1050 *next = prop;
1051 write_unlock_irqrestore(&devtree_lock, flags);
1052
1053#ifdef CONFIG_PROC_DEVICETREE
1054 /* try to add to proc as well if it was initialized */
1055 if (np->pde)
1056 proc_device_tree_add_prop(np->pde, prop);
1057#endif /* CONFIG_PROC_DEVICETREE */
1058
1059 return 0;
1060}
1061
1062/**
1063 * prom_remove_property - Remove a property from a node.
1064 *
1065 * Note that we don't actually remove it, since we have given out
1066 * who-knows-how-many pointers to the data using get-property.
1067 * Instead we just move the property to the "dead properties"
1068 * list, so it won't be found any more.
1069 */
1070int prom_remove_property(struct device_node *np, struct property *prop)
1071{
1072 struct property **next;
1073 unsigned long flags;
1074 int found = 0;
1075
1076 write_lock_irqsave(&devtree_lock, flags);
1077 next = &np->properties;
1078 while (*next) {
1079 if (*next == prop) {
1080 /* found the node */
1081 *next = prop->next;
1082 prop->next = np->deadprops;
1083 np->deadprops = prop;
1084 found = 1;
1085 break;
1086 }
1087 next = &(*next)->next;
1088 }
1089 write_unlock_irqrestore(&devtree_lock, flags);
1090
1091 if (!found)
1092 return -ENODEV;
1093
1094#ifdef CONFIG_PROC_DEVICETREE
1095 /* try to remove the proc node as well */
1096 if (np->pde)
1097 proc_device_tree_remove_prop(np->pde, prop);
1098#endif /* CONFIG_PROC_DEVICETREE */
1099
1100 return 0;
1101}
1102
1103/*
Dong Aisheng475d0092012-07-11 15:16:37 +10001104 * prom_update_property - Update a property in a node, if the property does
1105 * not exist, add it.
Grant Likely02af11b2009-11-23 20:16:45 -07001106 *
1107 * Note that we don't actually remove it, since we have given out
1108 * who-knows-how-many pointers to the data using get-property.
1109 * Instead we just move the property to the "dead properties" list,
1110 * and add the new property to the property list
1111 */
1112int prom_update_property(struct device_node *np,
Dong Aisheng475d0092012-07-11 15:16:37 +10001113 struct property *newprop)
Grant Likely02af11b2009-11-23 20:16:45 -07001114{
Dong Aisheng475d0092012-07-11 15:16:37 +10001115 struct property **next, *oldprop;
Grant Likely02af11b2009-11-23 20:16:45 -07001116 unsigned long flags;
1117 int found = 0;
1118
Dong Aisheng475d0092012-07-11 15:16:37 +10001119 if (!newprop->name)
1120 return -EINVAL;
1121
1122 oldprop = of_find_property(np, newprop->name, NULL);
1123 if (!oldprop)
1124 return prom_add_property(np, newprop);
1125
Grant Likely02af11b2009-11-23 20:16:45 -07001126 write_lock_irqsave(&devtree_lock, flags);
1127 next = &np->properties;
1128 while (*next) {
1129 if (*next == oldprop) {
1130 /* found the node */
1131 newprop->next = oldprop->next;
1132 *next = newprop;
1133 oldprop->next = np->deadprops;
1134 np->deadprops = oldprop;
1135 found = 1;
1136 break;
1137 }
1138 next = &(*next)->next;
1139 }
1140 write_unlock_irqrestore(&devtree_lock, flags);
1141
1142 if (!found)
1143 return -ENODEV;
1144
1145#ifdef CONFIG_PROC_DEVICETREE
1146 /* try to add to proc as well if it was initialized */
1147 if (np->pde)
1148 proc_device_tree_update_prop(np->pde, newprop, oldprop);
1149#endif /* CONFIG_PROC_DEVICETREE */
1150
1151 return 0;
1152}
Grant Likelyfcdeb7f2010-01-29 05:04:33 -07001153
1154#if defined(CONFIG_OF_DYNAMIC)
1155/*
1156 * Support for dynamic device trees.
1157 *
1158 * On some platforms, the device tree can be manipulated at runtime.
1159 * The routines in this section support adding, removing and changing
1160 * device tree nodes.
1161 */
1162
1163/**
1164 * of_attach_node - Plug a device node into the tree and global list.
1165 */
1166void of_attach_node(struct device_node *np)
1167{
1168 unsigned long flags;
1169
1170 write_lock_irqsave(&devtree_lock, flags);
1171 np->sibling = np->parent->child;
1172 np->allnext = allnodes;
1173 np->parent->child = np;
1174 allnodes = np;
1175 write_unlock_irqrestore(&devtree_lock, flags);
1176}
1177
1178/**
1179 * of_detach_node - "Unplug" a node from the device tree.
1180 *
1181 * The caller must hold a reference to the node. The memory associated with
1182 * the node is not freed until its refcount goes to zero.
1183 */
1184void of_detach_node(struct device_node *np)
1185{
1186 struct device_node *parent;
1187 unsigned long flags;
1188
1189 write_lock_irqsave(&devtree_lock, flags);
1190
1191 parent = np->parent;
1192 if (!parent)
1193 goto out_unlock;
1194
1195 if (allnodes == np)
1196 allnodes = np->allnext;
1197 else {
1198 struct device_node *prev;
1199 for (prev = allnodes;
1200 prev->allnext != np;
1201 prev = prev->allnext)
1202 ;
1203 prev->allnext = np->allnext;
1204 }
1205
1206 if (parent->child == np)
1207 parent->child = np->sibling;
1208 else {
1209 struct device_node *prevsib;
1210 for (prevsib = np->parent->child;
1211 prevsib->sibling != np;
1212 prevsib = prevsib->sibling)
1213 ;
1214 prevsib->sibling = np->sibling;
1215 }
1216
1217 of_node_set_flag(np, OF_DETACHED);
1218
1219out_unlock:
1220 write_unlock_irqrestore(&devtree_lock, flags);
1221}
1222#endif /* defined(CONFIG_OF_DYNAMIC) */
1223
Shawn Guo611cad72011-08-15 15:28:14 +08001224static void of_alias_add(struct alias_prop *ap, struct device_node *np,
1225 int id, const char *stem, int stem_len)
1226{
1227 ap->np = np;
1228 ap->id = id;
1229 strncpy(ap->stem, stem, stem_len);
1230 ap->stem[stem_len] = 0;
1231 list_add_tail(&ap->link, &aliases_lookup);
1232 pr_debug("adding DT alias:%s: stem=%s id=%i node=%s\n",
Grant Likely74a7f082012-06-15 11:50:25 -06001233 ap->alias, ap->stem, ap->id, of_node_full_name(np));
Shawn Guo611cad72011-08-15 15:28:14 +08001234}
1235
1236/**
1237 * of_alias_scan - Scan all properties of 'aliases' node
1238 *
1239 * The function scans all the properties of 'aliases' node and populate
1240 * the the global lookup table with the properties. It returns the
1241 * number of alias_prop found, or error code in error case.
1242 *
1243 * @dt_alloc: An allocator that provides a virtual address to memory
1244 * for the resulting tree
1245 */
1246void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align))
1247{
1248 struct property *pp;
1249
1250 of_chosen = of_find_node_by_path("/chosen");
1251 if (of_chosen == NULL)
1252 of_chosen = of_find_node_by_path("/chosen@0");
1253 of_aliases = of_find_node_by_path("/aliases");
1254 if (!of_aliases)
1255 return;
1256
Dong Aisheng8af0da92011-12-22 20:19:24 +08001257 for_each_property_of_node(of_aliases, pp) {
Shawn Guo611cad72011-08-15 15:28:14 +08001258 const char *start = pp->name;
1259 const char *end = start + strlen(start);
1260 struct device_node *np;
1261 struct alias_prop *ap;
1262 int id, len;
1263
1264 /* Skip those we do not want to proceed */
1265 if (!strcmp(pp->name, "name") ||
1266 !strcmp(pp->name, "phandle") ||
1267 !strcmp(pp->name, "linux,phandle"))
1268 continue;
1269
1270 np = of_find_node_by_path(pp->value);
1271 if (!np)
1272 continue;
1273
1274 /* walk the alias backwards to extract the id and work out
1275 * the 'stem' string */
1276 while (isdigit(*(end-1)) && end > start)
1277 end--;
1278 len = end - start;
1279
1280 if (kstrtoint(end, 10, &id) < 0)
1281 continue;
1282
1283 /* Allocate an alias_prop with enough space for the stem */
1284 ap = dt_alloc(sizeof(*ap) + len + 1, 4);
1285 if (!ap)
1286 continue;
1287 ap->alias = start;
1288 of_alias_add(ap, np, id, start, len);
1289 }
1290}
1291
1292/**
1293 * of_alias_get_id - Get alias id for the given device_node
1294 * @np: Pointer to the given device_node
1295 * @stem: Alias stem of the given device_node
1296 *
1297 * The function travels the lookup table to get alias id for the given
1298 * device_node and alias stem. It returns the alias id if find it.
1299 */
1300int of_alias_get_id(struct device_node *np, const char *stem)
1301{
1302 struct alias_prop *app;
1303 int id = -ENODEV;
1304
1305 mutex_lock(&of_aliases_mutex);
1306 list_for_each_entry(app, &aliases_lookup, link) {
1307 if (strcmp(app->stem, stem) != 0)
1308 continue;
1309
1310 if (np == app->np) {
1311 id = app->id;
1312 break;
1313 }
1314 }
1315 mutex_unlock(&of_aliases_mutex);
1316
1317 return id;
1318}
1319EXPORT_SYMBOL_GPL(of_alias_get_id);
Stephen Warrenc541adc2012-04-04 09:27:46 -06001320
1321const __be32 *of_prop_next_u32(struct property *prop, const __be32 *cur,
1322 u32 *pu)
1323{
1324 const void *curv = cur;
1325
1326 if (!prop)
1327 return NULL;
1328
1329 if (!cur) {
1330 curv = prop->value;
1331 goto out_val;
1332 }
1333
1334 curv += sizeof(*cur);
1335 if (curv >= prop->value + prop->length)
1336 return NULL;
1337
1338out_val:
1339 *pu = be32_to_cpup(curv);
1340 return curv;
1341}
1342EXPORT_SYMBOL_GPL(of_prop_next_u32);
1343
1344const char *of_prop_next_string(struct property *prop, const char *cur)
1345{
1346 const void *curv = cur;
1347
1348 if (!prop)
1349 return NULL;
1350
1351 if (!cur)
1352 return prop->value;
1353
1354 curv += strlen(cur) + 1;
1355 if (curv >= prop->value + prop->length)
1356 return NULL;
1357
1358 return curv;
1359}
1360EXPORT_SYMBOL_GPL(of_prop_next_string);