blob: c3724110a2888179512074da056a048c5b71db7b [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/**
Stephen Warren50c8af42012-11-20 16:12:20 -0700597 * of_find_matching_node_and_match - Find a node based on an of_device_id
598 * match table.
Grant Likely283029d2008-01-09 06:20:40 +1100599 * @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
Stephen Warren50c8af42012-11-20 16:12:20 -0700604 * @match Updated to point at the matches entry which matched
Grant Likely283029d2008-01-09 06:20:40 +1100605 *
606 * Returns a node pointer with refcount incremented, use
607 * of_node_put() on it when done.
608 */
Stephen Warren50c8af42012-11-20 16:12:20 -0700609struct device_node *of_find_matching_node_and_match(struct device_node *from,
610 const struct of_device_id *matches,
611 const struct of_device_id **match)
Grant Likely283029d2008-01-09 06:20:40 +1100612{
613 struct device_node *np;
614
Stephen Warren50c8af42012-11-20 16:12:20 -0700615 if (match)
616 *match = NULL;
617
Grant Likely283029d2008-01-09 06:20:40 +1100618 read_lock(&devtree_lock);
619 np = from ? from->allnext : allnodes;
620 for (; np; np = np->allnext) {
Stephen Warren50c8af42012-11-20 16:12:20 -0700621 if (of_match_node(matches, np) && of_node_get(np)) {
622 if (match)
623 *match = matches;
Grant Likely283029d2008-01-09 06:20:40 +1100624 break;
Stephen Warren50c8af42012-11-20 16:12:20 -0700625 }
Grant Likely283029d2008-01-09 06:20:40 +1100626 }
627 of_node_put(from);
628 read_unlock(&devtree_lock);
629 return np;
630}
631EXPORT_SYMBOL(of_find_matching_node);
Grant Likely3f07af42008-07-25 22:25:13 -0400632
633/**
Grant Likely3f07af42008-07-25 22:25:13 -0400634 * of_modalias_node - Lookup appropriate modalias for a device node
635 * @node: pointer to a device tree node
636 * @modalias: Pointer to buffer that modalias value will be copied into
637 * @len: Length of modalias value
638 *
Grant Likely2ffe8c52010-06-08 07:48:19 -0600639 * Based on the value of the compatible property, this routine will attempt
640 * to choose an appropriate modalias value for a particular device tree node.
641 * It does this by stripping the manufacturer prefix (as delimited by a ',')
642 * from the first entry in the compatible list property.
Grant Likely3f07af42008-07-25 22:25:13 -0400643 *
Grant Likely2ffe8c52010-06-08 07:48:19 -0600644 * This routine returns 0 on success, <0 on failure.
Grant Likely3f07af42008-07-25 22:25:13 -0400645 */
646int of_modalias_node(struct device_node *node, char *modalias, int len)
647{
Grant Likely2ffe8c52010-06-08 07:48:19 -0600648 const char *compatible, *p;
649 int cplen;
Grant Likely3f07af42008-07-25 22:25:13 -0400650
651 compatible = of_get_property(node, "compatible", &cplen);
Grant Likely2ffe8c52010-06-08 07:48:19 -0600652 if (!compatible || strlen(compatible) > cplen)
Grant Likely3f07af42008-07-25 22:25:13 -0400653 return -ENODEV;
Grant Likely3f07af42008-07-25 22:25:13 -0400654 p = strchr(compatible, ',');
Grant Likely2ffe8c52010-06-08 07:48:19 -0600655 strlcpy(modalias, p ? p + 1 : compatible, len);
Grant Likely3f07af42008-07-25 22:25:13 -0400656 return 0;
657}
658EXPORT_SYMBOL_GPL(of_modalias_node);
659
Anton Vorontsov64b60e02008-10-10 04:43:17 +0000660/**
Jeremy Kerr89751a72010-02-01 21:34:11 -0700661 * of_find_node_by_phandle - Find a node given a phandle
662 * @handle: phandle of the node to find
663 *
664 * Returns a node pointer with refcount incremented, use
665 * of_node_put() on it when done.
666 */
667struct device_node *of_find_node_by_phandle(phandle handle)
668{
669 struct device_node *np;
670
671 read_lock(&devtree_lock);
672 for (np = allnodes; np; np = np->allnext)
673 if (np->phandle == handle)
674 break;
675 of_node_get(np);
676 read_unlock(&devtree_lock);
677 return np;
678}
679EXPORT_SYMBOL(of_find_node_by_phandle);
680
681/**
Viresh Kumarbe193242012-11-20 10:15:19 +0530682 * of_property_read_u8_array - Find and read an array of u8 from a property.
683 *
684 * @np: device node from which the property value is to be read.
685 * @propname: name of the property to be searched.
686 * @out_value: pointer to return value, modified only if return value is 0.
687 * @sz: number of array elements to read
688 *
689 * Search for a property in a device node and read 8-bit value(s) from
690 * it. Returns 0 on success, -EINVAL if the property does not exist,
691 * -ENODATA if property does not have a value, and -EOVERFLOW if the
692 * property data isn't large enough.
693 *
694 * dts entry of array should be like:
695 * property = /bits/ 8 <0x50 0x60 0x70>;
696 *
697 * The out_value is modified only if a valid u8 value can be decoded.
698 */
699int of_property_read_u8_array(const struct device_node *np,
700 const char *propname, u8 *out_values, size_t sz)
701{
702 struct property *prop = of_find_property(np, propname, NULL);
703 const u8 *val;
704
705 if (!prop)
706 return -EINVAL;
707 if (!prop->value)
708 return -ENODATA;
709 if ((sz * sizeof(*out_values)) > prop->length)
710 return -EOVERFLOW;
711
712 val = prop->value;
713 while (sz--)
714 *out_values++ = *val++;
715 return 0;
716}
717EXPORT_SYMBOL_GPL(of_property_read_u8_array);
718
719/**
720 * of_property_read_u16_array - Find and read an array of u16 from a property.
721 *
722 * @np: device node from which the property value is to be read.
723 * @propname: name of the property to be searched.
724 * @out_value: pointer to return value, modified only if return value is 0.
725 * @sz: number of array elements to read
726 *
727 * Search for a property in a device node and read 16-bit value(s) from
728 * it. Returns 0 on success, -EINVAL if the property does not exist,
729 * -ENODATA if property does not have a value, and -EOVERFLOW if the
730 * property data isn't large enough.
731 *
732 * dts entry of array should be like:
733 * property = /bits/ 16 <0x5000 0x6000 0x7000>;
734 *
735 * The out_value is modified only if a valid u16 value can be decoded.
736 */
737int of_property_read_u16_array(const struct device_node *np,
738 const char *propname, u16 *out_values, size_t sz)
739{
740 struct property *prop = of_find_property(np, propname, NULL);
741 const __be16 *val;
742
743 if (!prop)
744 return -EINVAL;
745 if (!prop->value)
746 return -ENODATA;
747 if ((sz * sizeof(*out_values)) > prop->length)
748 return -EOVERFLOW;
749
750 val = prop->value;
751 while (sz--)
752 *out_values++ = be16_to_cpup(val++);
753 return 0;
754}
755EXPORT_SYMBOL_GPL(of_property_read_u16_array);
756
757/**
Rob Herring0e373632011-07-06 15:42:58 -0500758 * of_property_read_u32_array - Find and read an array of 32 bit integers
759 * from a property.
760 *
Thomas Abrahama3b85362011-06-30 21:26:10 +0530761 * @np: device node from which the property value is to be read.
762 * @propname: name of the property to be searched.
763 * @out_value: pointer to return value, modified only if return value is 0.
Viresh Kumarbe193242012-11-20 10:15:19 +0530764 * @sz: number of array elements to read
Thomas Abrahama3b85362011-06-30 21:26:10 +0530765 *
Rob Herring0e373632011-07-06 15:42:58 -0500766 * Search for a property in a device node and read 32-bit value(s) from
Thomas Abrahama3b85362011-06-30 21:26:10 +0530767 * it. Returns 0 on success, -EINVAL if the property does not exist,
768 * -ENODATA if property does not have a value, and -EOVERFLOW if the
769 * property data isn't large enough.
770 *
771 * The out_value is modified only if a valid u32 value can be decoded.
772 */
Jamie Ilesaac285c2011-08-02 15:45:07 +0100773int of_property_read_u32_array(const struct device_node *np,
774 const char *propname, u32 *out_values,
775 size_t sz)
Thomas Abrahama3b85362011-06-30 21:26:10 +0530776{
777 struct property *prop = of_find_property(np, propname, NULL);
Rob Herring0e373632011-07-06 15:42:58 -0500778 const __be32 *val;
Thomas Abrahama3b85362011-06-30 21:26:10 +0530779
780 if (!prop)
781 return -EINVAL;
782 if (!prop->value)
783 return -ENODATA;
Rob Herring0e373632011-07-06 15:42:58 -0500784 if ((sz * sizeof(*out_values)) > prop->length)
Thomas Abrahama3b85362011-06-30 21:26:10 +0530785 return -EOVERFLOW;
Rob Herring0e373632011-07-06 15:42:58 -0500786
787 val = prop->value;
788 while (sz--)
789 *out_values++ = be32_to_cpup(val++);
Thomas Abrahama3b85362011-06-30 21:26:10 +0530790 return 0;
791}
Rob Herring0e373632011-07-06 15:42:58 -0500792EXPORT_SYMBOL_GPL(of_property_read_u32_array);
Thomas Abrahama3b85362011-06-30 21:26:10 +0530793
794/**
Jamie Iles4cd7f7a2011-09-14 20:49:59 +0100795 * of_property_read_u64 - Find and read a 64 bit integer from a property
796 * @np: device node from which the property value is to be read.
797 * @propname: name of the property to be searched.
798 * @out_value: pointer to return value, modified only if return value is 0.
799 *
800 * Search for a property in a device node and read a 64-bit value from
801 * it. Returns 0 on success, -EINVAL if the property does not exist,
802 * -ENODATA if property does not have a value, and -EOVERFLOW if the
803 * property data isn't large enough.
804 *
805 * The out_value is modified only if a valid u64 value can be decoded.
806 */
807int of_property_read_u64(const struct device_node *np, const char *propname,
808 u64 *out_value)
809{
810 struct property *prop = of_find_property(np, propname, NULL);
811
812 if (!prop)
813 return -EINVAL;
814 if (!prop->value)
815 return -ENODATA;
816 if (sizeof(*out_value) > prop->length)
817 return -EOVERFLOW;
818 *out_value = of_read_number(prop->value, 2);
819 return 0;
820}
821EXPORT_SYMBOL_GPL(of_property_read_u64);
822
823/**
Thomas Abrahama3b85362011-06-30 21:26:10 +0530824 * of_property_read_string - Find and read a string from a property
825 * @np: device node from which the property value is to be read.
826 * @propname: name of the property to be searched.
827 * @out_string: pointer to null terminated return string, modified only if
828 * return value is 0.
829 *
830 * Search for a property in a device tree node and retrieve a null
831 * terminated string value (pointer to data, not a copy). Returns 0 on
832 * success, -EINVAL if the property does not exist, -ENODATA if property
833 * does not have a value, and -EILSEQ if the string is not null-terminated
834 * within the length of the property data.
835 *
836 * The out_string pointer is modified only if a valid string can be decoded.
837 */
Jamie Ilesaac285c2011-08-02 15:45:07 +0100838int of_property_read_string(struct device_node *np, const char *propname,
Shawn Guof09bc832011-07-04 09:01:18 +0800839 const char **out_string)
Thomas Abrahama3b85362011-06-30 21:26:10 +0530840{
841 struct property *prop = of_find_property(np, propname, NULL);
842 if (!prop)
843 return -EINVAL;
844 if (!prop->value)
845 return -ENODATA;
846 if (strnlen(prop->value, prop->length) >= prop->length)
847 return -EILSEQ;
848 *out_string = prop->value;
849 return 0;
850}
851EXPORT_SYMBOL_GPL(of_property_read_string);
852
853/**
Benoit Cousson4fcd15a2011-09-27 17:45:43 +0200854 * of_property_read_string_index - Find and read a string from a multiple
855 * strings property.
856 * @np: device node from which the property value is to be read.
857 * @propname: name of the property to be searched.
858 * @index: index of the string in the list of strings
859 * @out_string: pointer to null terminated return string, modified only if
860 * return value is 0.
861 *
862 * Search for a property in a device tree node and retrieve a null
863 * terminated string value (pointer to data, not a copy) in the list of strings
864 * contained in that property.
865 * Returns 0 on success, -EINVAL if the property does not exist, -ENODATA if
866 * property does not have a value, and -EILSEQ if the string is not
867 * null-terminated within the length of the property data.
868 *
869 * The out_string pointer is modified only if a valid string can be decoded.
870 */
871int of_property_read_string_index(struct device_node *np, const char *propname,
872 int index, const char **output)
873{
874 struct property *prop = of_find_property(np, propname, NULL);
875 int i = 0;
876 size_t l = 0, total = 0;
877 const char *p;
878
879 if (!prop)
880 return -EINVAL;
881 if (!prop->value)
882 return -ENODATA;
883 if (strnlen(prop->value, prop->length) >= prop->length)
884 return -EILSEQ;
885
886 p = prop->value;
887
888 for (i = 0; total < prop->length; total += l, p += l) {
889 l = strlen(p) + 1;
Benoit Cousson88af7f52011-12-05 15:23:54 +0100890 if (i++ == index) {
Benoit Cousson4fcd15a2011-09-27 17:45:43 +0200891 *output = p;
892 return 0;
893 }
894 }
895 return -ENODATA;
896}
897EXPORT_SYMBOL_GPL(of_property_read_string_index);
898
Grant Likely7aff0fe2011-12-12 09:25:58 -0700899/**
900 * of_property_match_string() - Find string in a list and return index
901 * @np: pointer to node containing string list property
902 * @propname: string list property name
903 * @string: pointer to string to search for in string list
904 *
905 * This function searches a string list property and returns the index
906 * of a specific string value.
907 */
908int of_property_match_string(struct device_node *np, const char *propname,
909 const char *string)
910{
911 struct property *prop = of_find_property(np, propname, NULL);
912 size_t l;
913 int i;
914 const char *p, *end;
915
916 if (!prop)
917 return -EINVAL;
918 if (!prop->value)
919 return -ENODATA;
920
921 p = prop->value;
922 end = p + prop->length;
923
924 for (i = 0; p < end; i++, p += l) {
925 l = strlen(p) + 1;
926 if (p + l > end)
927 return -EILSEQ;
928 pr_debug("comparing %s with %s\n", string, p);
929 if (strcmp(string, p) == 0)
930 return i; /* Found it; return index */
931 }
932 return -ENODATA;
933}
934EXPORT_SYMBOL_GPL(of_property_match_string);
Benoit Cousson4fcd15a2011-09-27 17:45:43 +0200935
936/**
937 * of_property_count_strings - Find and return the number of strings from a
938 * multiple strings property.
939 * @np: device node from which the property value is to be read.
940 * @propname: name of the property to be searched.
941 *
942 * Search for a property in a device tree node and retrieve the number of null
943 * terminated string contain in it. Returns the number of strings on
944 * success, -EINVAL if the property does not exist, -ENODATA if property
945 * does not have a value, and -EILSEQ if the string is not null-terminated
946 * within the length of the property data.
947 */
948int of_property_count_strings(struct device_node *np, const char *propname)
949{
950 struct property *prop = of_find_property(np, propname, NULL);
951 int i = 0;
952 size_t l = 0, total = 0;
953 const char *p;
954
955 if (!prop)
956 return -EINVAL;
957 if (!prop->value)
958 return -ENODATA;
959 if (strnlen(prop->value, prop->length) >= prop->length)
960 return -EILSEQ;
961
962 p = prop->value;
963
Benoit Cousson88af7f52011-12-05 15:23:54 +0100964 for (i = 0; total < prop->length; total += l, p += l, i++)
Benoit Cousson4fcd15a2011-09-27 17:45:43 +0200965 l = strlen(p) + 1;
Benoit Cousson88af7f52011-12-05 15:23:54 +0100966
Benoit Cousson4fcd15a2011-09-27 17:45:43 +0200967 return i;
968}
969EXPORT_SYMBOL_GPL(of_property_count_strings);
970
971/**
Grant Likely739649c2009-04-25 12:52:40 +0000972 * of_parse_phandle - Resolve a phandle property to a device_node pointer
973 * @np: Pointer to device node holding phandle property
974 * @phandle_name: Name of property holding a phandle value
975 * @index: For properties holding a table of phandles, this is the index into
976 * the table
977 *
978 * Returns the device_node pointer with refcount incremented. Use
979 * of_node_put() on it when done.
980 */
Steffen Trumtrarb8fbdc42012-11-22 12:16:43 +0100981struct device_node *of_parse_phandle(const struct device_node *np,
982 const char *phandle_name, int index)
Grant Likely739649c2009-04-25 12:52:40 +0000983{
Grant Likely9a6b2e52010-07-23 01:48:25 -0600984 const __be32 *phandle;
Grant Likely739649c2009-04-25 12:52:40 +0000985 int size;
986
987 phandle = of_get_property(np, phandle_name, &size);
988 if ((!phandle) || (size < sizeof(*phandle) * (index + 1)))
989 return NULL;
990
Grant Likely9a6b2e52010-07-23 01:48:25 -0600991 return of_find_node_by_phandle(be32_to_cpup(phandle + index));
Grant Likely739649c2009-04-25 12:52:40 +0000992}
993EXPORT_SYMBOL(of_parse_phandle);
994
995/**
Grant Likely15c9a0a2011-12-12 09:25:57 -0700996 * of_parse_phandle_with_args() - Find a node pointed by phandle in a list
Anton Vorontsov64b60e02008-10-10 04:43:17 +0000997 * @np: pointer to a device tree node containing a list
998 * @list_name: property name that contains a list
999 * @cells_name: property name that specifies phandles' arguments count
1000 * @index: index of a phandle to parse out
Grant Likely15c9a0a2011-12-12 09:25:57 -07001001 * @out_args: optional pointer to output arguments structure (will be filled)
Anton Vorontsov64b60e02008-10-10 04:43:17 +00001002 *
1003 * This function is useful to parse lists of phandles and their arguments.
Grant Likely15c9a0a2011-12-12 09:25:57 -07001004 * Returns 0 on success and fills out_args, on error returns appropriate
1005 * errno value.
1006 *
1007 * Caller is responsible to call of_node_put() on the returned out_args->node
1008 * pointer.
Anton Vorontsov64b60e02008-10-10 04:43:17 +00001009 *
1010 * Example:
1011 *
1012 * phandle1: node1 {
1013 * #list-cells = <2>;
1014 * }
1015 *
1016 * phandle2: node2 {
1017 * #list-cells = <1>;
1018 * }
1019 *
1020 * node3 {
1021 * list = <&phandle1 1 2 &phandle2 3>;
1022 * }
1023 *
1024 * To get a device_node of the `node2' node you may call this:
Grant Likely15c9a0a2011-12-12 09:25:57 -07001025 * of_parse_phandle_with_args(node3, "list", "#list-cells", 1, &args);
Anton Vorontsov64b60e02008-10-10 04:43:17 +00001026 */
Grant Likely15c9a0a2011-12-12 09:25:57 -07001027int of_parse_phandle_with_args(struct device_node *np, const char *list_name,
Anton Vorontsov64b60e02008-10-10 04:43:17 +00001028 const char *cells_name, int index,
Grant Likely15c9a0a2011-12-12 09:25:57 -07001029 struct of_phandle_args *out_args)
Anton Vorontsov64b60e02008-10-10 04:43:17 +00001030{
Grant Likely15c9a0a2011-12-12 09:25:57 -07001031 const __be32 *list, *list_end;
1032 int size, cur_index = 0;
1033 uint32_t count = 0;
Anton Vorontsov64b60e02008-10-10 04:43:17 +00001034 struct device_node *node = NULL;
Grant Likely15c9a0a2011-12-12 09:25:57 -07001035 phandle phandle;
Anton Vorontsov64b60e02008-10-10 04:43:17 +00001036
Grant Likely15c9a0a2011-12-12 09:25:57 -07001037 /* Retrieve the phandle list property */
Anton Vorontsov64b60e02008-10-10 04:43:17 +00001038 list = of_get_property(np, list_name, &size);
Grant Likely15c9a0a2011-12-12 09:25:57 -07001039 if (!list)
Alexandre Courbot1af4c7f2012-06-29 13:57:58 +09001040 return -ENOENT;
Anton Vorontsov64b60e02008-10-10 04:43:17 +00001041 list_end = list + size / sizeof(*list);
1042
Grant Likely15c9a0a2011-12-12 09:25:57 -07001043 /* Loop over the phandles until all the requested entry is found */
Anton Vorontsov64b60e02008-10-10 04:43:17 +00001044 while (list < list_end) {
Grant Likely15c9a0a2011-12-12 09:25:57 -07001045 count = 0;
Anton Vorontsov64b60e02008-10-10 04:43:17 +00001046
Grant Likely15c9a0a2011-12-12 09:25:57 -07001047 /*
1048 * If phandle is 0, then it is an empty entry with no
1049 * arguments. Skip forward to the next entry.
1050 */
Grant Likely9a6b2e52010-07-23 01:48:25 -06001051 phandle = be32_to_cpup(list++);
Grant Likely15c9a0a2011-12-12 09:25:57 -07001052 if (phandle) {
1053 /*
1054 * Find the provider node and parse the #*-cells
1055 * property to determine the argument length
1056 */
1057 node = of_find_node_by_phandle(phandle);
1058 if (!node) {
1059 pr_err("%s: could not find phandle\n",
1060 np->full_name);
1061 break;
1062 }
1063 if (of_property_read_u32(node, cells_name, &count)) {
1064 pr_err("%s: could not get %s for %s\n",
1065 np->full_name, cells_name,
1066 node->full_name);
1067 break;
1068 }
Anton Vorontsov64b60e02008-10-10 04:43:17 +00001069
Grant Likely15c9a0a2011-12-12 09:25:57 -07001070 /*
1071 * Make sure that the arguments actually fit in the
1072 * remaining property data length
1073 */
1074 if (list + count > list_end) {
1075 pr_err("%s: arguments longer than property\n",
1076 np->full_name);
1077 break;
1078 }
Anton Vorontsov64b60e02008-10-10 04:43:17 +00001079 }
1080
Grant Likely15c9a0a2011-12-12 09:25:57 -07001081 /*
1082 * All of the error cases above bail out of the loop, so at
1083 * this point, the parsing is successful. If the requested
1084 * index matches, then fill the out_args structure and return,
1085 * or return -ENOENT for an empty entry.
1086 */
1087 if (cur_index == index) {
1088 if (!phandle)
1089 return -ENOENT;
Anton Vorontsov64b60e02008-10-10 04:43:17 +00001090
Grant Likely15c9a0a2011-12-12 09:25:57 -07001091 if (out_args) {
1092 int i;
1093 if (WARN_ON(count > MAX_PHANDLE_ARGS))
1094 count = MAX_PHANDLE_ARGS;
1095 out_args->np = node;
1096 out_args->args_count = count;
1097 for (i = 0; i < count; i++)
1098 out_args->args[i] = be32_to_cpup(list++);
1099 }
1100 return 0;
Anton Vorontsov64b60e02008-10-10 04:43:17 +00001101 }
Anton Vorontsov64b60e02008-10-10 04:43:17 +00001102
1103 of_node_put(node);
1104 node = NULL;
Grant Likely15c9a0a2011-12-12 09:25:57 -07001105 list += count;
Anton Vorontsov64b60e02008-10-10 04:43:17 +00001106 cur_index++;
1107 }
1108
Grant Likely15c9a0a2011-12-12 09:25:57 -07001109 /* Loop exited without finding a valid entry; return an error */
1110 if (node)
1111 of_node_put(node);
1112 return -EINVAL;
Anton Vorontsov64b60e02008-10-10 04:43:17 +00001113}
Grant Likely15c9a0a2011-12-12 09:25:57 -07001114EXPORT_SYMBOL(of_parse_phandle_with_args);
Grant Likely02af11b2009-11-23 20:16:45 -07001115
1116/**
1117 * prom_add_property - Add a property to a node
1118 */
1119int prom_add_property(struct device_node *np, struct property *prop)
1120{
1121 struct property **next;
1122 unsigned long flags;
1123
1124 prop->next = NULL;
1125 write_lock_irqsave(&devtree_lock, flags);
1126 next = &np->properties;
1127 while (*next) {
1128 if (strcmp(prop->name, (*next)->name) == 0) {
1129 /* duplicate ! don't insert it */
1130 write_unlock_irqrestore(&devtree_lock, flags);
1131 return -1;
1132 }
1133 next = &(*next)->next;
1134 }
1135 *next = prop;
1136 write_unlock_irqrestore(&devtree_lock, flags);
1137
1138#ifdef CONFIG_PROC_DEVICETREE
1139 /* try to add to proc as well if it was initialized */
1140 if (np->pde)
1141 proc_device_tree_add_prop(np->pde, prop);
1142#endif /* CONFIG_PROC_DEVICETREE */
1143
1144 return 0;
1145}
1146
1147/**
1148 * prom_remove_property - Remove a property from a node.
1149 *
1150 * Note that we don't actually remove it, since we have given out
1151 * who-knows-how-many pointers to the data using get-property.
1152 * Instead we just move the property to the "dead properties"
1153 * list, so it won't be found any more.
1154 */
1155int prom_remove_property(struct device_node *np, struct property *prop)
1156{
1157 struct property **next;
1158 unsigned long flags;
1159 int found = 0;
1160
1161 write_lock_irqsave(&devtree_lock, flags);
1162 next = &np->properties;
1163 while (*next) {
1164 if (*next == prop) {
1165 /* found the node */
1166 *next = prop->next;
1167 prop->next = np->deadprops;
1168 np->deadprops = prop;
1169 found = 1;
1170 break;
1171 }
1172 next = &(*next)->next;
1173 }
1174 write_unlock_irqrestore(&devtree_lock, flags);
1175
1176 if (!found)
1177 return -ENODEV;
1178
1179#ifdef CONFIG_PROC_DEVICETREE
1180 /* try to remove the proc node as well */
1181 if (np->pde)
1182 proc_device_tree_remove_prop(np->pde, prop);
1183#endif /* CONFIG_PROC_DEVICETREE */
1184
1185 return 0;
1186}
1187
1188/*
Dong Aisheng475d0092012-07-11 15:16:37 +10001189 * prom_update_property - Update a property in a node, if the property does
1190 * not exist, add it.
Grant Likely02af11b2009-11-23 20:16:45 -07001191 *
1192 * Note that we don't actually remove it, since we have given out
1193 * who-knows-how-many pointers to the data using get-property.
1194 * Instead we just move the property to the "dead properties" list,
1195 * and add the new property to the property list
1196 */
1197int prom_update_property(struct device_node *np,
Dong Aisheng475d0092012-07-11 15:16:37 +10001198 struct property *newprop)
Grant Likely02af11b2009-11-23 20:16:45 -07001199{
Dong Aisheng475d0092012-07-11 15:16:37 +10001200 struct property **next, *oldprop;
Grant Likely02af11b2009-11-23 20:16:45 -07001201 unsigned long flags;
1202 int found = 0;
1203
Dong Aisheng475d0092012-07-11 15:16:37 +10001204 if (!newprop->name)
1205 return -EINVAL;
1206
1207 oldprop = of_find_property(np, newprop->name, NULL);
1208 if (!oldprop)
1209 return prom_add_property(np, newprop);
1210
Grant Likely02af11b2009-11-23 20:16:45 -07001211 write_lock_irqsave(&devtree_lock, flags);
1212 next = &np->properties;
1213 while (*next) {
1214 if (*next == oldprop) {
1215 /* found the node */
1216 newprop->next = oldprop->next;
1217 *next = newprop;
1218 oldprop->next = np->deadprops;
1219 np->deadprops = oldprop;
1220 found = 1;
1221 break;
1222 }
1223 next = &(*next)->next;
1224 }
1225 write_unlock_irqrestore(&devtree_lock, flags);
1226
1227 if (!found)
1228 return -ENODEV;
1229
1230#ifdef CONFIG_PROC_DEVICETREE
1231 /* try to add to proc as well if it was initialized */
1232 if (np->pde)
1233 proc_device_tree_update_prop(np->pde, newprop, oldprop);
1234#endif /* CONFIG_PROC_DEVICETREE */
1235
1236 return 0;
1237}
Grant Likelyfcdeb7f2010-01-29 05:04:33 -07001238
1239#if defined(CONFIG_OF_DYNAMIC)
1240/*
1241 * Support for dynamic device trees.
1242 *
1243 * On some platforms, the device tree can be manipulated at runtime.
1244 * The routines in this section support adding, removing and changing
1245 * device tree nodes.
1246 */
1247
1248/**
1249 * of_attach_node - Plug a device node into the tree and global list.
1250 */
1251void of_attach_node(struct device_node *np)
1252{
1253 unsigned long flags;
1254
1255 write_lock_irqsave(&devtree_lock, flags);
1256 np->sibling = np->parent->child;
1257 np->allnext = allnodes;
1258 np->parent->child = np;
1259 allnodes = np;
1260 write_unlock_irqrestore(&devtree_lock, flags);
1261}
1262
1263/**
1264 * of_detach_node - "Unplug" a node from the device tree.
1265 *
1266 * The caller must hold a reference to the node. The memory associated with
1267 * the node is not freed until its refcount goes to zero.
1268 */
1269void of_detach_node(struct device_node *np)
1270{
1271 struct device_node *parent;
1272 unsigned long flags;
1273
1274 write_lock_irqsave(&devtree_lock, flags);
1275
1276 parent = np->parent;
1277 if (!parent)
1278 goto out_unlock;
1279
1280 if (allnodes == np)
1281 allnodes = np->allnext;
1282 else {
1283 struct device_node *prev;
1284 for (prev = allnodes;
1285 prev->allnext != np;
1286 prev = prev->allnext)
1287 ;
1288 prev->allnext = np->allnext;
1289 }
1290
1291 if (parent->child == np)
1292 parent->child = np->sibling;
1293 else {
1294 struct device_node *prevsib;
1295 for (prevsib = np->parent->child;
1296 prevsib->sibling != np;
1297 prevsib = prevsib->sibling)
1298 ;
1299 prevsib->sibling = np->sibling;
1300 }
1301
1302 of_node_set_flag(np, OF_DETACHED);
1303
1304out_unlock:
1305 write_unlock_irqrestore(&devtree_lock, flags);
1306}
1307#endif /* defined(CONFIG_OF_DYNAMIC) */
1308
Shawn Guo611cad72011-08-15 15:28:14 +08001309static void of_alias_add(struct alias_prop *ap, struct device_node *np,
1310 int id, const char *stem, int stem_len)
1311{
1312 ap->np = np;
1313 ap->id = id;
1314 strncpy(ap->stem, stem, stem_len);
1315 ap->stem[stem_len] = 0;
1316 list_add_tail(&ap->link, &aliases_lookup);
1317 pr_debug("adding DT alias:%s: stem=%s id=%i node=%s\n",
Grant Likely74a7f082012-06-15 11:50:25 -06001318 ap->alias, ap->stem, ap->id, of_node_full_name(np));
Shawn Guo611cad72011-08-15 15:28:14 +08001319}
1320
1321/**
1322 * of_alias_scan - Scan all properties of 'aliases' node
1323 *
1324 * The function scans all the properties of 'aliases' node and populate
1325 * the the global lookup table with the properties. It returns the
1326 * number of alias_prop found, or error code in error case.
1327 *
1328 * @dt_alloc: An allocator that provides a virtual address to memory
1329 * for the resulting tree
1330 */
1331void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align))
1332{
1333 struct property *pp;
1334
1335 of_chosen = of_find_node_by_path("/chosen");
1336 if (of_chosen == NULL)
1337 of_chosen = of_find_node_by_path("/chosen@0");
1338 of_aliases = of_find_node_by_path("/aliases");
1339 if (!of_aliases)
1340 return;
1341
Dong Aisheng8af0da92011-12-22 20:19:24 +08001342 for_each_property_of_node(of_aliases, pp) {
Shawn Guo611cad72011-08-15 15:28:14 +08001343 const char *start = pp->name;
1344 const char *end = start + strlen(start);
1345 struct device_node *np;
1346 struct alias_prop *ap;
1347 int id, len;
1348
1349 /* Skip those we do not want to proceed */
1350 if (!strcmp(pp->name, "name") ||
1351 !strcmp(pp->name, "phandle") ||
1352 !strcmp(pp->name, "linux,phandle"))
1353 continue;
1354
1355 np = of_find_node_by_path(pp->value);
1356 if (!np)
1357 continue;
1358
1359 /* walk the alias backwards to extract the id and work out
1360 * the 'stem' string */
1361 while (isdigit(*(end-1)) && end > start)
1362 end--;
1363 len = end - start;
1364
1365 if (kstrtoint(end, 10, &id) < 0)
1366 continue;
1367
1368 /* Allocate an alias_prop with enough space for the stem */
1369 ap = dt_alloc(sizeof(*ap) + len + 1, 4);
1370 if (!ap)
1371 continue;
1372 ap->alias = start;
1373 of_alias_add(ap, np, id, start, len);
1374 }
1375}
1376
1377/**
1378 * of_alias_get_id - Get alias id for the given device_node
1379 * @np: Pointer to the given device_node
1380 * @stem: Alias stem of the given device_node
1381 *
1382 * The function travels the lookup table to get alias id for the given
1383 * device_node and alias stem. It returns the alias id if find it.
1384 */
1385int of_alias_get_id(struct device_node *np, const char *stem)
1386{
1387 struct alias_prop *app;
1388 int id = -ENODEV;
1389
1390 mutex_lock(&of_aliases_mutex);
1391 list_for_each_entry(app, &aliases_lookup, link) {
1392 if (strcmp(app->stem, stem) != 0)
1393 continue;
1394
1395 if (np == app->np) {
1396 id = app->id;
1397 break;
1398 }
1399 }
1400 mutex_unlock(&of_aliases_mutex);
1401
1402 return id;
1403}
1404EXPORT_SYMBOL_GPL(of_alias_get_id);
Stephen Warrenc541adc2012-04-04 09:27:46 -06001405
1406const __be32 *of_prop_next_u32(struct property *prop, const __be32 *cur,
1407 u32 *pu)
1408{
1409 const void *curv = cur;
1410
1411 if (!prop)
1412 return NULL;
1413
1414 if (!cur) {
1415 curv = prop->value;
1416 goto out_val;
1417 }
1418
1419 curv += sizeof(*cur);
1420 if (curv >= prop->value + prop->length)
1421 return NULL;
1422
1423out_val:
1424 *pu = be32_to_cpup(curv);
1425 return curv;
1426}
1427EXPORT_SYMBOL_GPL(of_prop_next_u32);
1428
1429const char *of_prop_next_string(struct property *prop, const char *cur)
1430{
1431 const void *curv = cur;
1432
1433 if (!prop)
1434 return NULL;
1435
1436 if (!cur)
1437 return prop->value;
1438
1439 curv += strlen(cur) + 1;
1440 if (curv >= prop->value + prop->length)
1441 return NULL;
1442
1443 return curv;
1444}
1445EXPORT_SYMBOL_GPL(of_prop_next_string);