blob: 9b6588ef067334a51558c333eb9a0467dd3ca3c2 [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 Likely923f7e32010-01-28 13:52:53 -070091#if !defined(CONFIG_SPARC) /* SPARC doesn't do ref counting (yet) */
92/**
93 * of_node_get - Increment refcount of a node
94 * @node: Node to inc refcount, NULL is supported to
95 * simplify writing of callers
96 *
97 * Returns node.
98 */
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);
164#endif /* !CONFIG_SPARC */
165
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);
176 for (pp = np->properties; pp != 0; pp = pp->next) {
177 if (of_prop_cmp(pp->name, name) == 0) {
178 if (lenp != 0)
179 *lenp = pp->length;
180 break;
181 }
182 }
183 read_unlock(&devtree_lock);
184
185 return pp;
186}
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/**
367 * of_find_node_by_path - Find a node matching a full OF path
368 * @path: The full path to match
369 *
370 * Returns a node pointer with refcount incremented, use
371 * of_node_put() on it when done.
372 */
373struct device_node *of_find_node_by_path(const char *path)
374{
375 struct device_node *np = allnodes;
376
377 read_lock(&devtree_lock);
378 for (; np; np = np->allnext) {
379 if (np->full_name && (of_node_cmp(np->full_name, path) == 0)
380 && of_node_get(np))
381 break;
382 }
383 read_unlock(&devtree_lock);
384 return np;
385}
386EXPORT_SYMBOL(of_find_node_by_path);
387
388/**
389 * of_find_node_by_name - Find a node by its "name" property
390 * @from: The node to start searching from or NULL, the node
391 * you pass will not be searched, only the next one
392 * will; typically, you pass what the previous call
393 * returned. of_node_put() will be called on it
394 * @name: The name string to match against
395 *
396 * Returns a node pointer with refcount incremented, use
397 * of_node_put() on it when done.
398 */
399struct device_node *of_find_node_by_name(struct device_node *from,
400 const char *name)
401{
402 struct device_node *np;
403
404 read_lock(&devtree_lock);
405 np = from ? from->allnext : allnodes;
406 for (; np; np = np->allnext)
407 if (np->name && (of_node_cmp(np->name, name) == 0)
408 && of_node_get(np))
409 break;
410 of_node_put(from);
411 read_unlock(&devtree_lock);
412 return np;
413}
414EXPORT_SYMBOL(of_find_node_by_name);
415
416/**
417 * of_find_node_by_type - Find a node by its "device_type" property
418 * @from: The node to start searching from, or NULL to start searching
419 * the entire device tree. The node you pass will not be
420 * searched, only the next one will; typically, you pass
421 * what the previous call returned. of_node_put() will be
422 * called on from for you.
423 * @type: The type string to match against
424 *
425 * Returns a node pointer with refcount incremented, use
426 * of_node_put() on it when done.
427 */
428struct device_node *of_find_node_by_type(struct device_node *from,
429 const char *type)
430{
431 struct device_node *np;
432
433 read_lock(&devtree_lock);
434 np = from ? from->allnext : allnodes;
435 for (; np; np = np->allnext)
436 if (np->type && (of_node_cmp(np->type, type) == 0)
437 && of_node_get(np))
438 break;
439 of_node_put(from);
440 read_unlock(&devtree_lock);
441 return np;
442}
443EXPORT_SYMBOL(of_find_node_by_type);
444
445/**
446 * of_find_compatible_node - Find a node based on type and one of the
447 * tokens in its "compatible" property
448 * @from: The node to start searching from or NULL, the node
449 * you pass will not be searched, only the next one
450 * will; typically, you pass what the previous call
451 * returned. of_node_put() will be called on it
452 * @type: The type string to match "device_type" or NULL to ignore
453 * @compatible: The string to match to one of the tokens in the device
454 * "compatible" list.
455 *
456 * Returns a node pointer with refcount incremented, use
457 * of_node_put() on it when done.
458 */
459struct device_node *of_find_compatible_node(struct device_node *from,
460 const char *type, const char *compatible)
461{
462 struct device_node *np;
463
464 read_lock(&devtree_lock);
465 np = from ? from->allnext : allnodes;
466 for (; np; np = np->allnext) {
467 if (type
468 && !(np->type && (of_node_cmp(np->type, type) == 0)))
469 continue;
470 if (of_device_is_compatible(np, compatible) && of_node_get(np))
471 break;
472 }
473 of_node_put(from);
474 read_unlock(&devtree_lock);
475 return np;
476}
477EXPORT_SYMBOL(of_find_compatible_node);
Grant Likely283029d2008-01-09 06:20:40 +1100478
479/**
Michael Ellerman1e291b12008-11-12 18:54:42 +0000480 * of_find_node_with_property - Find a node which has a property with
481 * the given name.
482 * @from: The node to start searching from or NULL, the node
483 * you pass will not be searched, only the next one
484 * will; typically, you pass what the previous call
485 * returned. of_node_put() will be called on it
486 * @prop_name: The name of the property to look for.
487 *
488 * Returns a node pointer with refcount incremented, use
489 * of_node_put() on it when done.
490 */
491struct device_node *of_find_node_with_property(struct device_node *from,
492 const char *prop_name)
493{
494 struct device_node *np;
495 struct property *pp;
496
497 read_lock(&devtree_lock);
498 np = from ? from->allnext : allnodes;
499 for (; np; np = np->allnext) {
500 for (pp = np->properties; pp != 0; pp = pp->next) {
501 if (of_prop_cmp(pp->name, prop_name) == 0) {
502 of_node_get(np);
503 goto out;
504 }
505 }
506 }
507out:
508 of_node_put(from);
509 read_unlock(&devtree_lock);
510 return np;
511}
512EXPORT_SYMBOL(of_find_node_with_property);
513
514/**
Grant Likely283029d2008-01-09 06:20:40 +1100515 * of_match_node - Tell if an device_node has a matching of_match structure
516 * @matches: array of of device match structures to search in
517 * @node: the of device structure to match against
518 *
519 * Low level utility function used by device matching.
520 */
521const struct of_device_id *of_match_node(const struct of_device_id *matches,
522 const struct device_node *node)
523{
Grant Likelya52f07e2011-03-18 10:21:29 -0600524 if (!matches)
525 return NULL;
526
Grant Likely283029d2008-01-09 06:20:40 +1100527 while (matches->name[0] || matches->type[0] || matches->compatible[0]) {
528 int match = 1;
529 if (matches->name[0])
530 match &= node->name
531 && !strcmp(matches->name, node->name);
532 if (matches->type[0])
533 match &= node->type
534 && !strcmp(matches->type, node->type);
535 if (matches->compatible[0])
536 match &= of_device_is_compatible(node,
537 matches->compatible);
538 if (match)
539 return matches;
540 matches++;
541 }
542 return NULL;
543}
544EXPORT_SYMBOL(of_match_node);
545
546/**
547 * of_find_matching_node - Find a node based on an of_device_id match
548 * table.
549 * @from: The node to start searching from or NULL, the node
550 * you pass will not be searched, only the next one
551 * will; typically, you pass what the previous call
552 * returned. of_node_put() will be called on it
553 * @matches: array of of device match structures to search in
554 *
555 * Returns a node pointer with refcount incremented, use
556 * of_node_put() on it when done.
557 */
558struct device_node *of_find_matching_node(struct device_node *from,
559 const struct of_device_id *matches)
560{
561 struct device_node *np;
562
563 read_lock(&devtree_lock);
564 np = from ? from->allnext : allnodes;
565 for (; np; np = np->allnext) {
566 if (of_match_node(matches, np) && of_node_get(np))
567 break;
568 }
569 of_node_put(from);
570 read_unlock(&devtree_lock);
571 return np;
572}
573EXPORT_SYMBOL(of_find_matching_node);
Grant Likely3f07af42008-07-25 22:25:13 -0400574
575/**
Grant Likely3f07af42008-07-25 22:25:13 -0400576 * of_modalias_node - Lookup appropriate modalias for a device node
577 * @node: pointer to a device tree node
578 * @modalias: Pointer to buffer that modalias value will be copied into
579 * @len: Length of modalias value
580 *
Grant Likely2ffe8c52010-06-08 07:48:19 -0600581 * Based on the value of the compatible property, this routine will attempt
582 * to choose an appropriate modalias value for a particular device tree node.
583 * It does this by stripping the manufacturer prefix (as delimited by a ',')
584 * from the first entry in the compatible list property.
Grant Likely3f07af42008-07-25 22:25:13 -0400585 *
Grant Likely2ffe8c52010-06-08 07:48:19 -0600586 * This routine returns 0 on success, <0 on failure.
Grant Likely3f07af42008-07-25 22:25:13 -0400587 */
588int of_modalias_node(struct device_node *node, char *modalias, int len)
589{
Grant Likely2ffe8c52010-06-08 07:48:19 -0600590 const char *compatible, *p;
591 int cplen;
Grant Likely3f07af42008-07-25 22:25:13 -0400592
593 compatible = of_get_property(node, "compatible", &cplen);
Grant Likely2ffe8c52010-06-08 07:48:19 -0600594 if (!compatible || strlen(compatible) > cplen)
Grant Likely3f07af42008-07-25 22:25:13 -0400595 return -ENODEV;
Grant Likely3f07af42008-07-25 22:25:13 -0400596 p = strchr(compatible, ',');
Grant Likely2ffe8c52010-06-08 07:48:19 -0600597 strlcpy(modalias, p ? p + 1 : compatible, len);
Grant Likely3f07af42008-07-25 22:25:13 -0400598 return 0;
599}
600EXPORT_SYMBOL_GPL(of_modalias_node);
601
Anton Vorontsov64b60e02008-10-10 04:43:17 +0000602/**
Jeremy Kerr89751a72010-02-01 21:34:11 -0700603 * of_find_node_by_phandle - Find a node given a phandle
604 * @handle: phandle of the node to find
605 *
606 * Returns a node pointer with refcount incremented, use
607 * of_node_put() on it when done.
608 */
609struct device_node *of_find_node_by_phandle(phandle handle)
610{
611 struct device_node *np;
612
613 read_lock(&devtree_lock);
614 for (np = allnodes; np; np = np->allnext)
615 if (np->phandle == handle)
616 break;
617 of_node_get(np);
618 read_unlock(&devtree_lock);
619 return np;
620}
621EXPORT_SYMBOL(of_find_node_by_phandle);
622
623/**
Rob Herring0e373632011-07-06 15:42:58 -0500624 * of_property_read_u32_array - Find and read an array of 32 bit integers
625 * from a property.
626 *
Thomas Abrahama3b85362011-06-30 21:26:10 +0530627 * @np: device node from which the property value is to be read.
628 * @propname: name of the property to be searched.
629 * @out_value: pointer to return value, modified only if return value is 0.
630 *
Rob Herring0e373632011-07-06 15:42:58 -0500631 * Search for a property in a device node and read 32-bit value(s) from
Thomas Abrahama3b85362011-06-30 21:26:10 +0530632 * it. Returns 0 on success, -EINVAL if the property does not exist,
633 * -ENODATA if property does not have a value, and -EOVERFLOW if the
634 * property data isn't large enough.
635 *
636 * The out_value is modified only if a valid u32 value can be decoded.
637 */
Jamie Ilesaac285c2011-08-02 15:45:07 +0100638int of_property_read_u32_array(const struct device_node *np,
639 const char *propname, u32 *out_values,
640 size_t sz)
Thomas Abrahama3b85362011-06-30 21:26:10 +0530641{
642 struct property *prop = of_find_property(np, propname, NULL);
Rob Herring0e373632011-07-06 15:42:58 -0500643 const __be32 *val;
Thomas Abrahama3b85362011-06-30 21:26:10 +0530644
645 if (!prop)
646 return -EINVAL;
647 if (!prop->value)
648 return -ENODATA;
Rob Herring0e373632011-07-06 15:42:58 -0500649 if ((sz * sizeof(*out_values)) > prop->length)
Thomas Abrahama3b85362011-06-30 21:26:10 +0530650 return -EOVERFLOW;
Rob Herring0e373632011-07-06 15:42:58 -0500651
652 val = prop->value;
653 while (sz--)
654 *out_values++ = be32_to_cpup(val++);
Thomas Abrahama3b85362011-06-30 21:26:10 +0530655 return 0;
656}
Rob Herring0e373632011-07-06 15:42:58 -0500657EXPORT_SYMBOL_GPL(of_property_read_u32_array);
Thomas Abrahama3b85362011-06-30 21:26:10 +0530658
659/**
Jamie Iles4cd7f7a2011-09-14 20:49:59 +0100660 * of_property_read_u64 - Find and read a 64 bit integer from a property
661 * @np: device node from which the property value is to be read.
662 * @propname: name of the property to be searched.
663 * @out_value: pointer to return value, modified only if return value is 0.
664 *
665 * Search for a property in a device node and read a 64-bit value from
666 * it. Returns 0 on success, -EINVAL if the property does not exist,
667 * -ENODATA if property does not have a value, and -EOVERFLOW if the
668 * property data isn't large enough.
669 *
670 * The out_value is modified only if a valid u64 value can be decoded.
671 */
672int of_property_read_u64(const struct device_node *np, const char *propname,
673 u64 *out_value)
674{
675 struct property *prop = of_find_property(np, propname, NULL);
676
677 if (!prop)
678 return -EINVAL;
679 if (!prop->value)
680 return -ENODATA;
681 if (sizeof(*out_value) > prop->length)
682 return -EOVERFLOW;
683 *out_value = of_read_number(prop->value, 2);
684 return 0;
685}
686EXPORT_SYMBOL_GPL(of_property_read_u64);
687
688/**
Thomas Abrahama3b85362011-06-30 21:26:10 +0530689 * of_property_read_string - Find and read a string from a property
690 * @np: device node from which the property value is to be read.
691 * @propname: name of the property to be searched.
692 * @out_string: pointer to null terminated return string, modified only if
693 * return value is 0.
694 *
695 * Search for a property in a device tree node and retrieve a null
696 * terminated string value (pointer to data, not a copy). Returns 0 on
697 * success, -EINVAL if the property does not exist, -ENODATA if property
698 * does not have a value, and -EILSEQ if the string is not null-terminated
699 * within the length of the property data.
700 *
701 * The out_string pointer is modified only if a valid string can be decoded.
702 */
Jamie Ilesaac285c2011-08-02 15:45:07 +0100703int of_property_read_string(struct device_node *np, const char *propname,
Shawn Guof09bc832011-07-04 09:01:18 +0800704 const char **out_string)
Thomas Abrahama3b85362011-06-30 21:26:10 +0530705{
706 struct property *prop = of_find_property(np, propname, NULL);
707 if (!prop)
708 return -EINVAL;
709 if (!prop->value)
710 return -ENODATA;
711 if (strnlen(prop->value, prop->length) >= prop->length)
712 return -EILSEQ;
713 *out_string = prop->value;
714 return 0;
715}
716EXPORT_SYMBOL_GPL(of_property_read_string);
717
718/**
Benoit Cousson4fcd15a2011-09-27 17:45:43 +0200719 * of_property_read_string_index - Find and read a string from a multiple
720 * strings property.
721 * @np: device node from which the property value is to be read.
722 * @propname: name of the property to be searched.
723 * @index: index of the string in the list of strings
724 * @out_string: pointer to null terminated return string, modified only if
725 * return value is 0.
726 *
727 * Search for a property in a device tree node and retrieve a null
728 * terminated string value (pointer to data, not a copy) in the list of strings
729 * contained in that property.
730 * Returns 0 on success, -EINVAL if the property does not exist, -ENODATA if
731 * property does not have a value, and -EILSEQ if the string is not
732 * null-terminated within the length of the property data.
733 *
734 * The out_string pointer is modified only if a valid string can be decoded.
735 */
736int of_property_read_string_index(struct device_node *np, const char *propname,
737 int index, const char **output)
738{
739 struct property *prop = of_find_property(np, propname, NULL);
740 int i = 0;
741 size_t l = 0, total = 0;
742 const char *p;
743
744 if (!prop)
745 return -EINVAL;
746 if (!prop->value)
747 return -ENODATA;
748 if (strnlen(prop->value, prop->length) >= prop->length)
749 return -EILSEQ;
750
751 p = prop->value;
752
753 for (i = 0; total < prop->length; total += l, p += l) {
754 l = strlen(p) + 1;
755 if ((*p != 0) && (i++ == index)) {
756 *output = p;
757 return 0;
758 }
759 }
760 return -ENODATA;
761}
762EXPORT_SYMBOL_GPL(of_property_read_string_index);
763
764
765/**
766 * of_property_count_strings - Find and return the number of strings from a
767 * multiple strings property.
768 * @np: device node from which the property value is to be read.
769 * @propname: name of the property to be searched.
770 *
771 * Search for a property in a device tree node and retrieve the number of null
772 * terminated string contain in it. Returns the number of strings on
773 * success, -EINVAL if the property does not exist, -ENODATA if property
774 * does not have a value, and -EILSEQ if the string is not null-terminated
775 * within the length of the property data.
776 */
777int of_property_count_strings(struct device_node *np, const char *propname)
778{
779 struct property *prop = of_find_property(np, propname, NULL);
780 int i = 0;
781 size_t l = 0, total = 0;
782 const char *p;
783
784 if (!prop)
785 return -EINVAL;
786 if (!prop->value)
787 return -ENODATA;
788 if (strnlen(prop->value, prop->length) >= prop->length)
789 return -EILSEQ;
790
791 p = prop->value;
792
793 for (i = 0; total < prop->length; total += l, p += l) {
794 l = strlen(p) + 1;
795 if (*p != 0)
796 i++;
797 }
798 return i;
799}
800EXPORT_SYMBOL_GPL(of_property_count_strings);
801
802/**
Grant Likely739649c2009-04-25 12:52:40 +0000803 * of_parse_phandle - Resolve a phandle property to a device_node pointer
804 * @np: Pointer to device node holding phandle property
805 * @phandle_name: Name of property holding a phandle value
806 * @index: For properties holding a table of phandles, this is the index into
807 * the table
808 *
809 * Returns the device_node pointer with refcount incremented. Use
810 * of_node_put() on it when done.
811 */
812struct device_node *
813of_parse_phandle(struct device_node *np, const char *phandle_name, int index)
814{
Grant Likely9a6b2e52010-07-23 01:48:25 -0600815 const __be32 *phandle;
Grant Likely739649c2009-04-25 12:52:40 +0000816 int size;
817
818 phandle = of_get_property(np, phandle_name, &size);
819 if ((!phandle) || (size < sizeof(*phandle) * (index + 1)))
820 return NULL;
821
Grant Likely9a6b2e52010-07-23 01:48:25 -0600822 return of_find_node_by_phandle(be32_to_cpup(phandle + index));
Grant Likely739649c2009-04-25 12:52:40 +0000823}
824EXPORT_SYMBOL(of_parse_phandle);
825
826/**
Anton Vorontsov64b60e02008-10-10 04:43:17 +0000827 * of_parse_phandles_with_args - Find a node pointed by phandle in a list
828 * @np: pointer to a device tree node containing a list
829 * @list_name: property name that contains a list
830 * @cells_name: property name that specifies phandles' arguments count
831 * @index: index of a phandle to parse out
Anton Vorontsov7736a3d2008-12-05 08:15:46 +0000832 * @out_node: optional pointer to device_node struct pointer (will be filled)
833 * @out_args: optional pointer to arguments pointer (will be filled)
Anton Vorontsov64b60e02008-10-10 04:43:17 +0000834 *
835 * This function is useful to parse lists of phandles and their arguments.
836 * Returns 0 on success and fills out_node and out_args, on error returns
837 * appropriate errno value.
838 *
839 * Example:
840 *
841 * phandle1: node1 {
842 * #list-cells = <2>;
843 * }
844 *
845 * phandle2: node2 {
846 * #list-cells = <1>;
847 * }
848 *
849 * node3 {
850 * list = <&phandle1 1 2 &phandle2 3>;
851 * }
852 *
853 * To get a device_node of the `node2' node you may call this:
854 * of_parse_phandles_with_args(node3, "list", "#list-cells", 2, &node2, &args);
855 */
856int of_parse_phandles_with_args(struct device_node *np, const char *list_name,
857 const char *cells_name, int index,
858 struct device_node **out_node,
859 const void **out_args)
860{
861 int ret = -EINVAL;
Jeremy Kerr33714882010-01-30 01:45:26 -0700862 const __be32 *list;
863 const __be32 *list_end;
Anton Vorontsov64b60e02008-10-10 04:43:17 +0000864 int size;
865 int cur_index = 0;
866 struct device_node *node = NULL;
Anton Vorontsov7736a3d2008-12-05 08:15:46 +0000867 const void *args = NULL;
Anton Vorontsov64b60e02008-10-10 04:43:17 +0000868
869 list = of_get_property(np, list_name, &size);
870 if (!list) {
871 ret = -ENOENT;
872 goto err0;
873 }
874 list_end = list + size / sizeof(*list);
875
876 while (list < list_end) {
Jeremy Kerr33714882010-01-30 01:45:26 -0700877 const __be32 *cells;
Grant Likely9a6b2e52010-07-23 01:48:25 -0600878 phandle phandle;
Anton Vorontsov64b60e02008-10-10 04:43:17 +0000879
Grant Likely9a6b2e52010-07-23 01:48:25 -0600880 phandle = be32_to_cpup(list++);
Anton Vorontsovc1bb7c62008-12-05 08:15:39 +0000881 args = list;
Anton Vorontsov64b60e02008-10-10 04:43:17 +0000882
883 /* one cell hole in the list = <>; */
Grant Likely9a6b2e52010-07-23 01:48:25 -0600884 if (!phandle)
Anton Vorontsov64b60e02008-10-10 04:43:17 +0000885 goto next;
Anton Vorontsov64b60e02008-10-10 04:43:17 +0000886
Grant Likely9a6b2e52010-07-23 01:48:25 -0600887 node = of_find_node_by_phandle(phandle);
Anton Vorontsov64b60e02008-10-10 04:43:17 +0000888 if (!node) {
889 pr_debug("%s: could not find phandle\n",
890 np->full_name);
891 goto err0;
892 }
893
894 cells = of_get_property(node, cells_name, &size);
895 if (!cells || size != sizeof(*cells)) {
896 pr_debug("%s: could not get %s for %s\n",
897 np->full_name, cells_name, node->full_name);
898 goto err1;
899 }
900
Jeremy Kerr33714882010-01-30 01:45:26 -0700901 list += be32_to_cpup(cells);
Anton Vorontsov64b60e02008-10-10 04:43:17 +0000902 if (list > list_end) {
903 pr_debug("%s: insufficient arguments length\n",
904 np->full_name);
905 goto err1;
906 }
907next:
908 if (cur_index == index)
909 break;
910
911 of_node_put(node);
912 node = NULL;
Anton Vorontsov7736a3d2008-12-05 08:15:46 +0000913 args = NULL;
Anton Vorontsov64b60e02008-10-10 04:43:17 +0000914 cur_index++;
915 }
916
917 if (!node) {
Anton Vorontsov7736a3d2008-12-05 08:15:46 +0000918 /*
919 * args w/o node indicates that the loop above has stopped at
920 * the 'hole' cell. Report this differently.
921 */
922 if (args)
923 ret = -EEXIST;
924 else
925 ret = -ENOENT;
Anton Vorontsov64b60e02008-10-10 04:43:17 +0000926 goto err0;
927 }
928
Anton Vorontsov7736a3d2008-12-05 08:15:46 +0000929 if (out_node)
930 *out_node = node;
931 if (out_args)
932 *out_args = args;
Anton Vorontsov64b60e02008-10-10 04:43:17 +0000933
934 return 0;
935err1:
936 of_node_put(node);
937err0:
938 pr_debug("%s failed with status %d\n", __func__, ret);
939 return ret;
940}
941EXPORT_SYMBOL(of_parse_phandles_with_args);
Grant Likely02af11b2009-11-23 20:16:45 -0700942
943/**
944 * prom_add_property - Add a property to a node
945 */
946int prom_add_property(struct device_node *np, struct property *prop)
947{
948 struct property **next;
949 unsigned long flags;
950
951 prop->next = NULL;
952 write_lock_irqsave(&devtree_lock, flags);
953 next = &np->properties;
954 while (*next) {
955 if (strcmp(prop->name, (*next)->name) == 0) {
956 /* duplicate ! don't insert it */
957 write_unlock_irqrestore(&devtree_lock, flags);
958 return -1;
959 }
960 next = &(*next)->next;
961 }
962 *next = prop;
963 write_unlock_irqrestore(&devtree_lock, flags);
964
965#ifdef CONFIG_PROC_DEVICETREE
966 /* try to add to proc as well if it was initialized */
967 if (np->pde)
968 proc_device_tree_add_prop(np->pde, prop);
969#endif /* CONFIG_PROC_DEVICETREE */
970
971 return 0;
972}
973
974/**
975 * prom_remove_property - Remove a property from a node.
976 *
977 * Note that we don't actually remove it, since we have given out
978 * who-knows-how-many pointers to the data using get-property.
979 * Instead we just move the property to the "dead properties"
980 * list, so it won't be found any more.
981 */
982int prom_remove_property(struct device_node *np, struct property *prop)
983{
984 struct property **next;
985 unsigned long flags;
986 int found = 0;
987
988 write_lock_irqsave(&devtree_lock, flags);
989 next = &np->properties;
990 while (*next) {
991 if (*next == prop) {
992 /* found the node */
993 *next = prop->next;
994 prop->next = np->deadprops;
995 np->deadprops = prop;
996 found = 1;
997 break;
998 }
999 next = &(*next)->next;
1000 }
1001 write_unlock_irqrestore(&devtree_lock, flags);
1002
1003 if (!found)
1004 return -ENODEV;
1005
1006#ifdef CONFIG_PROC_DEVICETREE
1007 /* try to remove the proc node as well */
1008 if (np->pde)
1009 proc_device_tree_remove_prop(np->pde, prop);
1010#endif /* CONFIG_PROC_DEVICETREE */
1011
1012 return 0;
1013}
1014
1015/*
1016 * prom_update_property - Update a property in a node.
1017 *
1018 * Note that we don't actually remove it, since we have given out
1019 * who-knows-how-many pointers to the data using get-property.
1020 * Instead we just move the property to the "dead properties" list,
1021 * and add the new property to the property list
1022 */
1023int prom_update_property(struct device_node *np,
1024 struct property *newprop,
1025 struct property *oldprop)
1026{
1027 struct property **next;
1028 unsigned long flags;
1029 int found = 0;
1030
1031 write_lock_irqsave(&devtree_lock, flags);
1032 next = &np->properties;
1033 while (*next) {
1034 if (*next == oldprop) {
1035 /* found the node */
1036 newprop->next = oldprop->next;
1037 *next = newprop;
1038 oldprop->next = np->deadprops;
1039 np->deadprops = oldprop;
1040 found = 1;
1041 break;
1042 }
1043 next = &(*next)->next;
1044 }
1045 write_unlock_irqrestore(&devtree_lock, flags);
1046
1047 if (!found)
1048 return -ENODEV;
1049
1050#ifdef CONFIG_PROC_DEVICETREE
1051 /* try to add to proc as well if it was initialized */
1052 if (np->pde)
1053 proc_device_tree_update_prop(np->pde, newprop, oldprop);
1054#endif /* CONFIG_PROC_DEVICETREE */
1055
1056 return 0;
1057}
Grant Likelyfcdeb7f2010-01-29 05:04:33 -07001058
1059#if defined(CONFIG_OF_DYNAMIC)
1060/*
1061 * Support for dynamic device trees.
1062 *
1063 * On some platforms, the device tree can be manipulated at runtime.
1064 * The routines in this section support adding, removing and changing
1065 * device tree nodes.
1066 */
1067
1068/**
1069 * of_attach_node - Plug a device node into the tree and global list.
1070 */
1071void of_attach_node(struct device_node *np)
1072{
1073 unsigned long flags;
1074
1075 write_lock_irqsave(&devtree_lock, flags);
1076 np->sibling = np->parent->child;
1077 np->allnext = allnodes;
1078 np->parent->child = np;
1079 allnodes = np;
1080 write_unlock_irqrestore(&devtree_lock, flags);
1081}
1082
1083/**
1084 * of_detach_node - "Unplug" a node from the device tree.
1085 *
1086 * The caller must hold a reference to the node. The memory associated with
1087 * the node is not freed until its refcount goes to zero.
1088 */
1089void of_detach_node(struct device_node *np)
1090{
1091 struct device_node *parent;
1092 unsigned long flags;
1093
1094 write_lock_irqsave(&devtree_lock, flags);
1095
1096 parent = np->parent;
1097 if (!parent)
1098 goto out_unlock;
1099
1100 if (allnodes == np)
1101 allnodes = np->allnext;
1102 else {
1103 struct device_node *prev;
1104 for (prev = allnodes;
1105 prev->allnext != np;
1106 prev = prev->allnext)
1107 ;
1108 prev->allnext = np->allnext;
1109 }
1110
1111 if (parent->child == np)
1112 parent->child = np->sibling;
1113 else {
1114 struct device_node *prevsib;
1115 for (prevsib = np->parent->child;
1116 prevsib->sibling != np;
1117 prevsib = prevsib->sibling)
1118 ;
1119 prevsib->sibling = np->sibling;
1120 }
1121
1122 of_node_set_flag(np, OF_DETACHED);
1123
1124out_unlock:
1125 write_unlock_irqrestore(&devtree_lock, flags);
1126}
1127#endif /* defined(CONFIG_OF_DYNAMIC) */
1128
Shawn Guo611cad72011-08-15 15:28:14 +08001129static void of_alias_add(struct alias_prop *ap, struct device_node *np,
1130 int id, const char *stem, int stem_len)
1131{
1132 ap->np = np;
1133 ap->id = id;
1134 strncpy(ap->stem, stem, stem_len);
1135 ap->stem[stem_len] = 0;
1136 list_add_tail(&ap->link, &aliases_lookup);
1137 pr_debug("adding DT alias:%s: stem=%s id=%i node=%s\n",
1138 ap->alias, ap->stem, ap->id, np ? np->full_name : NULL);
1139}
1140
1141/**
1142 * of_alias_scan - Scan all properties of 'aliases' node
1143 *
1144 * The function scans all the properties of 'aliases' node and populate
1145 * the the global lookup table with the properties. It returns the
1146 * number of alias_prop found, or error code in error case.
1147 *
1148 * @dt_alloc: An allocator that provides a virtual address to memory
1149 * for the resulting tree
1150 */
1151void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align))
1152{
1153 struct property *pp;
1154
1155 of_chosen = of_find_node_by_path("/chosen");
1156 if (of_chosen == NULL)
1157 of_chosen = of_find_node_by_path("/chosen@0");
1158 of_aliases = of_find_node_by_path("/aliases");
1159 if (!of_aliases)
1160 return;
1161
1162 for_each_property(pp, of_aliases->properties) {
1163 const char *start = pp->name;
1164 const char *end = start + strlen(start);
1165 struct device_node *np;
1166 struct alias_prop *ap;
1167 int id, len;
1168
1169 /* Skip those we do not want to proceed */
1170 if (!strcmp(pp->name, "name") ||
1171 !strcmp(pp->name, "phandle") ||
1172 !strcmp(pp->name, "linux,phandle"))
1173 continue;
1174
1175 np = of_find_node_by_path(pp->value);
1176 if (!np)
1177 continue;
1178
1179 /* walk the alias backwards to extract the id and work out
1180 * the 'stem' string */
1181 while (isdigit(*(end-1)) && end > start)
1182 end--;
1183 len = end - start;
1184
1185 if (kstrtoint(end, 10, &id) < 0)
1186 continue;
1187
1188 /* Allocate an alias_prop with enough space for the stem */
1189 ap = dt_alloc(sizeof(*ap) + len + 1, 4);
1190 if (!ap)
1191 continue;
1192 ap->alias = start;
1193 of_alias_add(ap, np, id, start, len);
1194 }
1195}
1196
1197/**
1198 * of_alias_get_id - Get alias id for the given device_node
1199 * @np: Pointer to the given device_node
1200 * @stem: Alias stem of the given device_node
1201 *
1202 * The function travels the lookup table to get alias id for the given
1203 * device_node and alias stem. It returns the alias id if find it.
1204 */
1205int of_alias_get_id(struct device_node *np, const char *stem)
1206{
1207 struct alias_prop *app;
1208 int id = -ENODEV;
1209
1210 mutex_lock(&of_aliases_mutex);
1211 list_for_each_entry(app, &aliases_lookup, link) {
1212 if (strcmp(app->stem, stem) != 0)
1213 continue;
1214
1215 if (np == app->np) {
1216 id = app->id;
1217 break;
1218 }
1219 }
1220 mutex_unlock(&of_aliases_mutex);
1221
1222 return id;
1223}
1224EXPORT_SYMBOL_GPL(of_alias_get_id);