Loading...
1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Procedures for creating, accessing and interpreting the device tree.
4 *
5 * Paul Mackerras August 1996.
6 * Copyright (C) 1996-2005 Paul Mackerras.
7 *
8 * Adapted for 64bit PowerPC by Dave Engebretsen and Peter Bergner.
9 * {engebret|bergner}@us.ibm.com
10 *
11 * Adapted for sparc and sparc64 by David S. Miller davem@davemloft.net
12 *
13 * Reconsolidated from arch/x/kernel/prom.c by Stephen Rothwell and
14 * Grant Likely.
15 */
16
17#define pr_fmt(fmt) "OF: " fmt
18
19#include <linux/console.h>
20#include <linux/ctype.h>
21#include <linux/cpu.h>
22#include <linux/module.h>
23#include <linux/of.h>
24#include <linux/of_device.h>
25#include <linux/of_graph.h>
26#include <linux/spinlock.h>
27#include <linux/slab.h>
28#include <linux/string.h>
29#include <linux/proc_fs.h>
30
31#include "of_private.h"
32
33LIST_HEAD(aliases_lookup);
34
35struct device_node *of_root;
36EXPORT_SYMBOL(of_root);
37struct device_node *of_chosen;
38EXPORT_SYMBOL(of_chosen);
39struct device_node *of_aliases;
40struct device_node *of_stdout;
41static const char *of_stdout_options;
42
43struct kset *of_kset;
44
45/*
46 * Used to protect the of_aliases, to hold off addition of nodes to sysfs.
47 * This mutex must be held whenever modifications are being made to the
48 * device tree. The of_{attach,detach}_node() and
49 * of_{add,remove,update}_property() helpers make sure this happens.
50 */
51DEFINE_MUTEX(of_mutex);
52
53/* use when traversing tree through the child, sibling,
54 * or parent members of struct device_node.
55 */
56DEFINE_RAW_SPINLOCK(devtree_lock);
57
58bool of_node_name_eq(const struct device_node *np, const char *name)
59{
60 const char *node_name;
61 size_t len;
62
63 if (!np)
64 return false;
65
66 node_name = kbasename(np->full_name);
67 len = strchrnul(node_name, '@') - node_name;
68
69 return (strlen(name) == len) && (strncmp(node_name, name, len) == 0);
70}
71EXPORT_SYMBOL(of_node_name_eq);
72
73bool of_node_name_prefix(const struct device_node *np, const char *prefix)
74{
75 if (!np)
76 return false;
77
78 return strncmp(kbasename(np->full_name), prefix, strlen(prefix)) == 0;
79}
80EXPORT_SYMBOL(of_node_name_prefix);
81
82static bool __of_node_is_type(const struct device_node *np, const char *type)
83{
84 const char *match = __of_get_property(np, "device_type", NULL);
85
86 return np && match && type && !strcmp(match, type);
87}
88
89int of_bus_n_addr_cells(struct device_node *np)
90{
91 u32 cells;
92
93 for (; np; np = np->parent)
94 if (!of_property_read_u32(np, "#address-cells", &cells))
95 return cells;
96
97 /* No #address-cells property for the root node */
98 return OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
99}
100
101int of_n_addr_cells(struct device_node *np)
102{
103 if (np->parent)
104 np = np->parent;
105
106 return of_bus_n_addr_cells(np);
107}
108EXPORT_SYMBOL(of_n_addr_cells);
109
110int of_bus_n_size_cells(struct device_node *np)
111{
112 u32 cells;
113
114 for (; np; np = np->parent)
115 if (!of_property_read_u32(np, "#size-cells", &cells))
116 return cells;
117
118 /* No #size-cells property for the root node */
119 return OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
120}
121
122int of_n_size_cells(struct device_node *np)
123{
124 if (np->parent)
125 np = np->parent;
126
127 return of_bus_n_size_cells(np);
128}
129EXPORT_SYMBOL(of_n_size_cells);
130
131#ifdef CONFIG_NUMA
132int __weak of_node_to_nid(struct device_node *np)
133{
134 return NUMA_NO_NODE;
135}
136#endif
137
138#define OF_PHANDLE_CACHE_BITS 7
139#define OF_PHANDLE_CACHE_SZ BIT(OF_PHANDLE_CACHE_BITS)
140
141static struct device_node *phandle_cache[OF_PHANDLE_CACHE_SZ];
142
143static u32 of_phandle_cache_hash(phandle handle)
144{
145 return hash_32(handle, OF_PHANDLE_CACHE_BITS);
146}
147
148/*
149 * Caller must hold devtree_lock.
150 */
151void __of_phandle_cache_inv_entry(phandle handle)
152{
153 u32 handle_hash;
154 struct device_node *np;
155
156 if (!handle)
157 return;
158
159 handle_hash = of_phandle_cache_hash(handle);
160
161 np = phandle_cache[handle_hash];
162 if (np && handle == np->phandle)
163 phandle_cache[handle_hash] = NULL;
164}
165
166void __init of_core_init(void)
167{
168 struct device_node *np;
169
170 of_platform_register_reconfig_notifier();
171
172 /* Create the kset, and register existing nodes */
173 mutex_lock(&of_mutex);
174 of_kset = kset_create_and_add("devicetree", NULL, firmware_kobj);
175 if (!of_kset) {
176 mutex_unlock(&of_mutex);
177 pr_err("failed to register existing nodes\n");
178 return;
179 }
180 for_each_of_allnodes(np) {
181 __of_attach_node_sysfs(np);
182 if (np->phandle && !phandle_cache[of_phandle_cache_hash(np->phandle)])
183 phandle_cache[of_phandle_cache_hash(np->phandle)] = np;
184 }
185 mutex_unlock(&of_mutex);
186
187 /* Symlink in /proc as required by userspace ABI */
188 if (of_root)
189 proc_symlink("device-tree", NULL, "/sys/firmware/devicetree/base");
190}
191
192static struct property *__of_find_property(const struct device_node *np,
193 const char *name, int *lenp)
194{
195 struct property *pp;
196
197 if (!np)
198 return NULL;
199
200 for (pp = np->properties; pp; pp = pp->next) {
201 if (of_prop_cmp(pp->name, name) == 0) {
202 if (lenp)
203 *lenp = pp->length;
204 break;
205 }
206 }
207
208 return pp;
209}
210
211struct property *of_find_property(const struct device_node *np,
212 const char *name,
213 int *lenp)
214{
215 struct property *pp;
216 unsigned long flags;
217
218 raw_spin_lock_irqsave(&devtree_lock, flags);
219 pp = __of_find_property(np, name, lenp);
220 raw_spin_unlock_irqrestore(&devtree_lock, flags);
221
222 return pp;
223}
224EXPORT_SYMBOL(of_find_property);
225
226struct device_node *__of_find_all_nodes(struct device_node *prev)
227{
228 struct device_node *np;
229 if (!prev) {
230 np = of_root;
231 } else if (prev->child) {
232 np = prev->child;
233 } else {
234 /* Walk back up looking for a sibling, or the end of the structure */
235 np = prev;
236 while (np->parent && !np->sibling)
237 np = np->parent;
238 np = np->sibling; /* Might be null at the end of the tree */
239 }
240 return np;
241}
242
243/**
244 * of_find_all_nodes - Get next node in global list
245 * @prev: Previous node or NULL to start iteration
246 * of_node_put() will be called on it
247 *
248 * Return: A node pointer with refcount incremented, use
249 * of_node_put() on it when done.
250 */
251struct device_node *of_find_all_nodes(struct device_node *prev)
252{
253 struct device_node *np;
254 unsigned long flags;
255
256 raw_spin_lock_irqsave(&devtree_lock, flags);
257 np = __of_find_all_nodes(prev);
258 of_node_get(np);
259 of_node_put(prev);
260 raw_spin_unlock_irqrestore(&devtree_lock, flags);
261 return np;
262}
263EXPORT_SYMBOL(of_find_all_nodes);
264
265/*
266 * Find a property with a given name for a given node
267 * and return the value.
268 */
269const void *__of_get_property(const struct device_node *np,
270 const char *name, int *lenp)
271{
272 struct property *pp = __of_find_property(np, name, lenp);
273
274 return pp ? pp->value : NULL;
275}
276
277/*
278 * Find a property with a given name for a given node
279 * and return the value.
280 */
281const void *of_get_property(const struct device_node *np, const char *name,
282 int *lenp)
283{
284 struct property *pp = of_find_property(np, name, lenp);
285
286 return pp ? pp->value : NULL;
287}
288EXPORT_SYMBOL(of_get_property);
289
290/**
291 * __of_device_is_compatible() - Check if the node matches given constraints
292 * @device: pointer to node
293 * @compat: required compatible string, NULL or "" for any match
294 * @type: required device_type value, NULL or "" for any match
295 * @name: required node name, NULL or "" for any match
296 *
297 * Checks if the given @compat, @type and @name strings match the
298 * properties of the given @device. A constraints can be skipped by
299 * passing NULL or an empty string as the constraint.
300 *
301 * Returns 0 for no match, and a positive integer on match. The return
302 * value is a relative score with larger values indicating better
303 * matches. The score is weighted for the most specific compatible value
304 * to get the highest score. Matching type is next, followed by matching
305 * name. Practically speaking, this results in the following priority
306 * order for matches:
307 *
308 * 1. specific compatible && type && name
309 * 2. specific compatible && type
310 * 3. specific compatible && name
311 * 4. specific compatible
312 * 5. general compatible && type && name
313 * 6. general compatible && type
314 * 7. general compatible && name
315 * 8. general compatible
316 * 9. type && name
317 * 10. type
318 * 11. name
319 */
320static int __of_device_is_compatible(const struct device_node *device,
321 const char *compat, const char *type, const char *name)
322{
323 struct property *prop;
324 const char *cp;
325 int index = 0, score = 0;
326
327 /* Compatible match has highest priority */
328 if (compat && compat[0]) {
329 prop = __of_find_property(device, "compatible", NULL);
330 for (cp = of_prop_next_string(prop, NULL); cp;
331 cp = of_prop_next_string(prop, cp), index++) {
332 if (of_compat_cmp(cp, compat, strlen(compat)) == 0) {
333 score = INT_MAX/2 - (index << 2);
334 break;
335 }
336 }
337 if (!score)
338 return 0;
339 }
340
341 /* Matching type is better than matching name */
342 if (type && type[0]) {
343 if (!__of_node_is_type(device, type))
344 return 0;
345 score += 2;
346 }
347
348 /* Matching name is a bit better than not */
349 if (name && name[0]) {
350 if (!of_node_name_eq(device, name))
351 return 0;
352 score++;
353 }
354
355 return score;
356}
357
358/** Checks if the given "compat" string matches one of the strings in
359 * the device's "compatible" property
360 */
361int of_device_is_compatible(const struct device_node *device,
362 const char *compat)
363{
364 unsigned long flags;
365 int res;
366
367 raw_spin_lock_irqsave(&devtree_lock, flags);
368 res = __of_device_is_compatible(device, compat, NULL, NULL);
369 raw_spin_unlock_irqrestore(&devtree_lock, flags);
370 return res;
371}
372EXPORT_SYMBOL(of_device_is_compatible);
373
374/** Checks if the device is compatible with any of the entries in
375 * a NULL terminated array of strings. Returns the best match
376 * score or 0.
377 */
378int of_device_compatible_match(const struct device_node *device,
379 const char *const *compat)
380{
381 unsigned int tmp, score = 0;
382
383 if (!compat)
384 return 0;
385
386 while (*compat) {
387 tmp = of_device_is_compatible(device, *compat);
388 if (tmp > score)
389 score = tmp;
390 compat++;
391 }
392
393 return score;
394}
395EXPORT_SYMBOL_GPL(of_device_compatible_match);
396
397/**
398 * of_machine_is_compatible - Test root of device tree for a given compatible value
399 * @compat: compatible string to look for in root node's compatible property.
400 *
401 * Return: A positive integer if the root node has the given value in its
402 * compatible property.
403 */
404int of_machine_is_compatible(const char *compat)
405{
406 struct device_node *root;
407 int rc = 0;
408
409 root = of_find_node_by_path("/");
410 if (root) {
411 rc = of_device_is_compatible(root, compat);
412 of_node_put(root);
413 }
414 return rc;
415}
416EXPORT_SYMBOL(of_machine_is_compatible);
417
418/**
419 * __of_device_is_available - check if a device is available for use
420 *
421 * @device: Node to check for availability, with locks already held
422 *
423 * Return: True if the status property is absent or set to "okay" or "ok",
424 * false otherwise
425 */
426static bool __of_device_is_available(const struct device_node *device)
427{
428 const char *status;
429 int statlen;
430
431 if (!device)
432 return false;
433
434 status = __of_get_property(device, "status", &statlen);
435 if (status == NULL)
436 return true;
437
438 if (statlen > 0) {
439 if (!strcmp(status, "okay") || !strcmp(status, "ok"))
440 return true;
441 }
442
443 return false;
444}
445
446/**
447 * of_device_is_available - check if a device is available for use
448 *
449 * @device: Node to check for availability
450 *
451 * Return: True if the status property is absent or set to "okay" or "ok",
452 * false otherwise
453 */
454bool of_device_is_available(const struct device_node *device)
455{
456 unsigned long flags;
457 bool res;
458
459 raw_spin_lock_irqsave(&devtree_lock, flags);
460 res = __of_device_is_available(device);
461 raw_spin_unlock_irqrestore(&devtree_lock, flags);
462 return res;
463
464}
465EXPORT_SYMBOL(of_device_is_available);
466
467/**
468 * __of_device_is_fail - check if a device has status "fail" or "fail-..."
469 *
470 * @device: Node to check status for, with locks already held
471 *
472 * Return: True if the status property is set to "fail" or "fail-..." (for any
473 * error code suffix), false otherwise
474 */
475static bool __of_device_is_fail(const struct device_node *device)
476{
477 const char *status;
478
479 if (!device)
480 return false;
481
482 status = __of_get_property(device, "status", NULL);
483 if (status == NULL)
484 return false;
485
486 return !strcmp(status, "fail") || !strncmp(status, "fail-", 5);
487}
488
489/**
490 * of_device_is_big_endian - check if a device has BE registers
491 *
492 * @device: Node to check for endianness
493 *
494 * Return: True if the device has a "big-endian" property, or if the kernel
495 * was compiled for BE *and* the device has a "native-endian" property.
496 * Returns false otherwise.
497 *
498 * Callers would nominally use ioread32be/iowrite32be if
499 * of_device_is_big_endian() == true, or readl/writel otherwise.
500 */
501bool of_device_is_big_endian(const struct device_node *device)
502{
503 if (of_property_read_bool(device, "big-endian"))
504 return true;
505 if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) &&
506 of_property_read_bool(device, "native-endian"))
507 return true;
508 return false;
509}
510EXPORT_SYMBOL(of_device_is_big_endian);
511
512/**
513 * of_get_parent - Get a node's parent if any
514 * @node: Node to get parent
515 *
516 * Return: A node pointer with refcount incremented, use
517 * of_node_put() on it when done.
518 */
519struct device_node *of_get_parent(const struct device_node *node)
520{
521 struct device_node *np;
522 unsigned long flags;
523
524 if (!node)
525 return NULL;
526
527 raw_spin_lock_irqsave(&devtree_lock, flags);
528 np = of_node_get(node->parent);
529 raw_spin_unlock_irqrestore(&devtree_lock, flags);
530 return np;
531}
532EXPORT_SYMBOL(of_get_parent);
533
534/**
535 * of_get_next_parent - Iterate to a node's parent
536 * @node: Node to get parent of
537 *
538 * This is like of_get_parent() except that it drops the
539 * refcount on the passed node, making it suitable for iterating
540 * through a node's parents.
541 *
542 * Return: A node pointer with refcount incremented, use
543 * of_node_put() on it when done.
544 */
545struct device_node *of_get_next_parent(struct device_node *node)
546{
547 struct device_node *parent;
548 unsigned long flags;
549
550 if (!node)
551 return NULL;
552
553 raw_spin_lock_irqsave(&devtree_lock, flags);
554 parent = of_node_get(node->parent);
555 of_node_put(node);
556 raw_spin_unlock_irqrestore(&devtree_lock, flags);
557 return parent;
558}
559EXPORT_SYMBOL(of_get_next_parent);
560
561static struct device_node *__of_get_next_child(const struct device_node *node,
562 struct device_node *prev)
563{
564 struct device_node *next;
565
566 if (!node)
567 return NULL;
568
569 next = prev ? prev->sibling : node->child;
570 of_node_get(next);
571 of_node_put(prev);
572 return next;
573}
574#define __for_each_child_of_node(parent, child) \
575 for (child = __of_get_next_child(parent, NULL); child != NULL; \
576 child = __of_get_next_child(parent, child))
577
578/**
579 * of_get_next_child - Iterate a node childs
580 * @node: parent node
581 * @prev: previous child of the parent node, or NULL to get first
582 *
583 * Return: A node pointer with refcount incremented, use of_node_put() on
584 * it when done. Returns NULL when prev is the last child. Decrements the
585 * refcount of prev.
586 */
587struct device_node *of_get_next_child(const struct device_node *node,
588 struct device_node *prev)
589{
590 struct device_node *next;
591 unsigned long flags;
592
593 raw_spin_lock_irqsave(&devtree_lock, flags);
594 next = __of_get_next_child(node, prev);
595 raw_spin_unlock_irqrestore(&devtree_lock, flags);
596 return next;
597}
598EXPORT_SYMBOL(of_get_next_child);
599
600/**
601 * of_get_next_available_child - Find the next available child node
602 * @node: parent node
603 * @prev: previous child of the parent node, or NULL to get first
604 *
605 * This function is like of_get_next_child(), except that it
606 * automatically skips any disabled nodes (i.e. status = "disabled").
607 */
608struct device_node *of_get_next_available_child(const struct device_node *node,
609 struct device_node *prev)
610{
611 struct device_node *next;
612 unsigned long flags;
613
614 if (!node)
615 return NULL;
616
617 raw_spin_lock_irqsave(&devtree_lock, flags);
618 next = prev ? prev->sibling : node->child;
619 for (; next; next = next->sibling) {
620 if (!__of_device_is_available(next))
621 continue;
622 if (of_node_get(next))
623 break;
624 }
625 of_node_put(prev);
626 raw_spin_unlock_irqrestore(&devtree_lock, flags);
627 return next;
628}
629EXPORT_SYMBOL(of_get_next_available_child);
630
631/**
632 * of_get_next_cpu_node - Iterate on cpu nodes
633 * @prev: previous child of the /cpus node, or NULL to get first
634 *
635 * Unusable CPUs (those with the status property set to "fail" or "fail-...")
636 * will be skipped.
637 *
638 * Return: A cpu node pointer with refcount incremented, use of_node_put()
639 * on it when done. Returns NULL when prev is the last child. Decrements
640 * the refcount of prev.
641 */
642struct device_node *of_get_next_cpu_node(struct device_node *prev)
643{
644 struct device_node *next = NULL;
645 unsigned long flags;
646 struct device_node *node;
647
648 if (!prev)
649 node = of_find_node_by_path("/cpus");
650
651 raw_spin_lock_irqsave(&devtree_lock, flags);
652 if (prev)
653 next = prev->sibling;
654 else if (node) {
655 next = node->child;
656 of_node_put(node);
657 }
658 for (; next; next = next->sibling) {
659 if (__of_device_is_fail(next))
660 continue;
661 if (!(of_node_name_eq(next, "cpu") ||
662 __of_node_is_type(next, "cpu")))
663 continue;
664 if (of_node_get(next))
665 break;
666 }
667 of_node_put(prev);
668 raw_spin_unlock_irqrestore(&devtree_lock, flags);
669 return next;
670}
671EXPORT_SYMBOL(of_get_next_cpu_node);
672
673/**
674 * of_get_compatible_child - Find compatible child node
675 * @parent: parent node
676 * @compatible: compatible string
677 *
678 * Lookup child node whose compatible property contains the given compatible
679 * string.
680 *
681 * Return: a node pointer with refcount incremented, use of_node_put() on it
682 * when done; or NULL if not found.
683 */
684struct device_node *of_get_compatible_child(const struct device_node *parent,
685 const char *compatible)
686{
687 struct device_node *child;
688
689 for_each_child_of_node(parent, child) {
690 if (of_device_is_compatible(child, compatible))
691 break;
692 }
693
694 return child;
695}
696EXPORT_SYMBOL(of_get_compatible_child);
697
698/**
699 * of_get_child_by_name - Find the child node by name for a given parent
700 * @node: parent node
701 * @name: child name to look for.
702 *
703 * This function looks for child node for given matching name
704 *
705 * Return: A node pointer if found, with refcount incremented, use
706 * of_node_put() on it when done.
707 * Returns NULL if node is not found.
708 */
709struct device_node *of_get_child_by_name(const struct device_node *node,
710 const char *name)
711{
712 struct device_node *child;
713
714 for_each_child_of_node(node, child)
715 if (of_node_name_eq(child, name))
716 break;
717 return child;
718}
719EXPORT_SYMBOL(of_get_child_by_name);
720
721struct device_node *__of_find_node_by_path(struct device_node *parent,
722 const char *path)
723{
724 struct device_node *child;
725 int len;
726
727 len = strcspn(path, "/:");
728 if (!len)
729 return NULL;
730
731 __for_each_child_of_node(parent, child) {
732 const char *name = kbasename(child->full_name);
733 if (strncmp(path, name, len) == 0 && (strlen(name) == len))
734 return child;
735 }
736 return NULL;
737}
738
739struct device_node *__of_find_node_by_full_path(struct device_node *node,
740 const char *path)
741{
742 const char *separator = strchr(path, ':');
743
744 while (node && *path == '/') {
745 struct device_node *tmp = node;
746
747 path++; /* Increment past '/' delimiter */
748 node = __of_find_node_by_path(node, path);
749 of_node_put(tmp);
750 path = strchrnul(path, '/');
751 if (separator && separator < path)
752 break;
753 }
754 return node;
755}
756
757/**
758 * of_find_node_opts_by_path - Find a node matching a full OF path
759 * @path: Either the full path to match, or if the path does not
760 * start with '/', the name of a property of the /aliases
761 * node (an alias). In the case of an alias, the node
762 * matching the alias' value will be returned.
763 * @opts: Address of a pointer into which to store the start of
764 * an options string appended to the end of the path with
765 * a ':' separator.
766 *
767 * Valid paths:
768 * * /foo/bar Full path
769 * * foo Valid alias
770 * * foo/bar Valid alias + relative path
771 *
772 * Return: A node pointer with refcount incremented, use
773 * of_node_put() on it when done.
774 */
775struct device_node *of_find_node_opts_by_path(const char *path, const char **opts)
776{
777 struct device_node *np = NULL;
778 struct property *pp;
779 unsigned long flags;
780 const char *separator = strchr(path, ':');
781
782 if (opts)
783 *opts = separator ? separator + 1 : NULL;
784
785 if (strcmp(path, "/") == 0)
786 return of_node_get(of_root);
787
788 /* The path could begin with an alias */
789 if (*path != '/') {
790 int len;
791 const char *p = separator;
792
793 if (!p)
794 p = strchrnul(path, '/');
795 len = p - path;
796
797 /* of_aliases must not be NULL */
798 if (!of_aliases)
799 return NULL;
800
801 for_each_property_of_node(of_aliases, pp) {
802 if (strlen(pp->name) == len && !strncmp(pp->name, path, len)) {
803 np = of_find_node_by_path(pp->value);
804 break;
805 }
806 }
807 if (!np)
808 return NULL;
809 path = p;
810 }
811
812 /* Step down the tree matching path components */
813 raw_spin_lock_irqsave(&devtree_lock, flags);
814 if (!np)
815 np = of_node_get(of_root);
816 np = __of_find_node_by_full_path(np, path);
817 raw_spin_unlock_irqrestore(&devtree_lock, flags);
818 return np;
819}
820EXPORT_SYMBOL(of_find_node_opts_by_path);
821
822/**
823 * of_find_node_by_name - Find a node by its "name" property
824 * @from: The node to start searching from or NULL; the node
825 * you pass will not be searched, only the next one
826 * will. Typically, you pass what the previous call
827 * returned. of_node_put() will be called on @from.
828 * @name: The name string to match against
829 *
830 * Return: A node pointer with refcount incremented, use
831 * of_node_put() on it when done.
832 */
833struct device_node *of_find_node_by_name(struct device_node *from,
834 const char *name)
835{
836 struct device_node *np;
837 unsigned long flags;
838
839 raw_spin_lock_irqsave(&devtree_lock, flags);
840 for_each_of_allnodes_from(from, np)
841 if (of_node_name_eq(np, name) && of_node_get(np))
842 break;
843 of_node_put(from);
844 raw_spin_unlock_irqrestore(&devtree_lock, flags);
845 return np;
846}
847EXPORT_SYMBOL(of_find_node_by_name);
848
849/**
850 * of_find_node_by_type - Find a node by its "device_type" property
851 * @from: The node to start searching from, or NULL to start searching
852 * the entire device tree. The node you pass will not be
853 * searched, only the next one will; typically, you pass
854 * what the previous call returned. of_node_put() will be
855 * called on from for you.
856 * @type: The type string to match against
857 *
858 * Return: A node pointer with refcount incremented, use
859 * of_node_put() on it when done.
860 */
861struct device_node *of_find_node_by_type(struct device_node *from,
862 const char *type)
863{
864 struct device_node *np;
865 unsigned long flags;
866
867 raw_spin_lock_irqsave(&devtree_lock, flags);
868 for_each_of_allnodes_from(from, np)
869 if (__of_node_is_type(np, type) && of_node_get(np))
870 break;
871 of_node_put(from);
872 raw_spin_unlock_irqrestore(&devtree_lock, flags);
873 return np;
874}
875EXPORT_SYMBOL(of_find_node_by_type);
876
877/**
878 * of_find_compatible_node - Find a node based on type and one of the
879 * tokens in its "compatible" property
880 * @from: The node to start searching from or NULL, the node
881 * you pass will not be searched, only the next one
882 * will; typically, you pass what the previous call
883 * returned. of_node_put() will be called on it
884 * @type: The type string to match "device_type" or NULL to ignore
885 * @compatible: The string to match to one of the tokens in the device
886 * "compatible" list.
887 *
888 * Return: A node pointer with refcount incremented, use
889 * of_node_put() on it when done.
890 */
891struct device_node *of_find_compatible_node(struct device_node *from,
892 const char *type, const char *compatible)
893{
894 struct device_node *np;
895 unsigned long flags;
896
897 raw_spin_lock_irqsave(&devtree_lock, flags);
898 for_each_of_allnodes_from(from, np)
899 if (__of_device_is_compatible(np, compatible, type, NULL) &&
900 of_node_get(np))
901 break;
902 of_node_put(from);
903 raw_spin_unlock_irqrestore(&devtree_lock, flags);
904 return np;
905}
906EXPORT_SYMBOL(of_find_compatible_node);
907
908/**
909 * of_find_node_with_property - Find a node which has a property with
910 * the given name.
911 * @from: The node to start searching from or NULL, the node
912 * you pass will not be searched, only the next one
913 * will; typically, you pass what the previous call
914 * returned. of_node_put() will be called on it
915 * @prop_name: The name of the property to look for.
916 *
917 * Return: A node pointer with refcount incremented, use
918 * of_node_put() on it when done.
919 */
920struct device_node *of_find_node_with_property(struct device_node *from,
921 const char *prop_name)
922{
923 struct device_node *np;
924 struct property *pp;
925 unsigned long flags;
926
927 raw_spin_lock_irqsave(&devtree_lock, flags);
928 for_each_of_allnodes_from(from, np) {
929 for (pp = np->properties; pp; pp = pp->next) {
930 if (of_prop_cmp(pp->name, prop_name) == 0) {
931 of_node_get(np);
932 goto out;
933 }
934 }
935 }
936out:
937 of_node_put(from);
938 raw_spin_unlock_irqrestore(&devtree_lock, flags);
939 return np;
940}
941EXPORT_SYMBOL(of_find_node_with_property);
942
943static
944const struct of_device_id *__of_match_node(const struct of_device_id *matches,
945 const struct device_node *node)
946{
947 const struct of_device_id *best_match = NULL;
948 int score, best_score = 0;
949
950 if (!matches)
951 return NULL;
952
953 for (; matches->name[0] || matches->type[0] || matches->compatible[0]; matches++) {
954 score = __of_device_is_compatible(node, matches->compatible,
955 matches->type, matches->name);
956 if (score > best_score) {
957 best_match = matches;
958 best_score = score;
959 }
960 }
961
962 return best_match;
963}
964
965/**
966 * of_match_node - Tell if a device_node has a matching of_match structure
967 * @matches: array of of device match structures to search in
968 * @node: the of device structure to match against
969 *
970 * Low level utility function used by device matching.
971 */
972const struct of_device_id *of_match_node(const struct of_device_id *matches,
973 const struct device_node *node)
974{
975 const struct of_device_id *match;
976 unsigned long flags;
977
978 raw_spin_lock_irqsave(&devtree_lock, flags);
979 match = __of_match_node(matches, node);
980 raw_spin_unlock_irqrestore(&devtree_lock, flags);
981 return match;
982}
983EXPORT_SYMBOL(of_match_node);
984
985/**
986 * of_find_matching_node_and_match - Find a node based on an of_device_id
987 * match table.
988 * @from: The node to start searching from or NULL, the node
989 * you pass will not be searched, only the next one
990 * will; typically, you pass what the previous call
991 * returned. of_node_put() will be called on it
992 * @matches: array of of device match structures to search in
993 * @match: Updated to point at the matches entry which matched
994 *
995 * Return: A node pointer with refcount incremented, use
996 * of_node_put() on it when done.
997 */
998struct device_node *of_find_matching_node_and_match(struct device_node *from,
999 const struct of_device_id *matches,
1000 const struct of_device_id **match)
1001{
1002 struct device_node *np;
1003 const struct of_device_id *m;
1004 unsigned long flags;
1005
1006 if (match)
1007 *match = NULL;
1008
1009 raw_spin_lock_irqsave(&devtree_lock, flags);
1010 for_each_of_allnodes_from(from, np) {
1011 m = __of_match_node(matches, np);
1012 if (m && of_node_get(np)) {
1013 if (match)
1014 *match = m;
1015 break;
1016 }
1017 }
1018 of_node_put(from);
1019 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1020 return np;
1021}
1022EXPORT_SYMBOL(of_find_matching_node_and_match);
1023
1024/**
1025 * of_alias_from_compatible - Lookup appropriate alias for a device node
1026 * depending on compatible
1027 * @node: pointer to a device tree node
1028 * @alias: Pointer to buffer that alias value will be copied into
1029 * @len: Length of alias value
1030 *
1031 * Based on the value of the compatible property, this routine will attempt
1032 * to choose an appropriate alias value for a particular device tree node.
1033 * It does this by stripping the manufacturer prefix (as delimited by a ',')
1034 * from the first entry in the compatible list property.
1035 *
1036 * Note: The matching on just the "product" side of the compatible is a relic
1037 * from I2C and SPI. Please do not add any new user.
1038 *
1039 * Return: This routine returns 0 on success, <0 on failure.
1040 */
1041int of_alias_from_compatible(const struct device_node *node, char *alias, int len)
1042{
1043 const char *compatible, *p;
1044 int cplen;
1045
1046 compatible = of_get_property(node, "compatible", &cplen);
1047 if (!compatible || strlen(compatible) > cplen)
1048 return -ENODEV;
1049 p = strchr(compatible, ',');
1050 strscpy(alias, p ? p + 1 : compatible, len);
1051 return 0;
1052}
1053EXPORT_SYMBOL_GPL(of_alias_from_compatible);
1054
1055/**
1056 * of_find_node_by_phandle - Find a node given a phandle
1057 * @handle: phandle of the node to find
1058 *
1059 * Return: A node pointer with refcount incremented, use
1060 * of_node_put() on it when done.
1061 */
1062struct device_node *of_find_node_by_phandle(phandle handle)
1063{
1064 struct device_node *np = NULL;
1065 unsigned long flags;
1066 u32 handle_hash;
1067
1068 if (!handle)
1069 return NULL;
1070
1071 handle_hash = of_phandle_cache_hash(handle);
1072
1073 raw_spin_lock_irqsave(&devtree_lock, flags);
1074
1075 if (phandle_cache[handle_hash] &&
1076 handle == phandle_cache[handle_hash]->phandle)
1077 np = phandle_cache[handle_hash];
1078
1079 if (!np) {
1080 for_each_of_allnodes(np)
1081 if (np->phandle == handle &&
1082 !of_node_check_flag(np, OF_DETACHED)) {
1083 phandle_cache[handle_hash] = np;
1084 break;
1085 }
1086 }
1087
1088 of_node_get(np);
1089 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1090 return np;
1091}
1092EXPORT_SYMBOL(of_find_node_by_phandle);
1093
1094void of_print_phandle_args(const char *msg, const struct of_phandle_args *args)
1095{
1096 int i;
1097 printk("%s %pOF", msg, args->np);
1098 for (i = 0; i < args->args_count; i++) {
1099 const char delim = i ? ',' : ':';
1100
1101 pr_cont("%c%08x", delim, args->args[i]);
1102 }
1103 pr_cont("\n");
1104}
1105
1106int of_phandle_iterator_init(struct of_phandle_iterator *it,
1107 const struct device_node *np,
1108 const char *list_name,
1109 const char *cells_name,
1110 int cell_count)
1111{
1112 const __be32 *list;
1113 int size;
1114
1115 memset(it, 0, sizeof(*it));
1116
1117 /*
1118 * one of cell_count or cells_name must be provided to determine the
1119 * argument length.
1120 */
1121 if (cell_count < 0 && !cells_name)
1122 return -EINVAL;
1123
1124 list = of_get_property(np, list_name, &size);
1125 if (!list)
1126 return -ENOENT;
1127
1128 it->cells_name = cells_name;
1129 it->cell_count = cell_count;
1130 it->parent = np;
1131 it->list_end = list + size / sizeof(*list);
1132 it->phandle_end = list;
1133 it->cur = list;
1134
1135 return 0;
1136}
1137EXPORT_SYMBOL_GPL(of_phandle_iterator_init);
1138
1139int of_phandle_iterator_next(struct of_phandle_iterator *it)
1140{
1141 uint32_t count = 0;
1142
1143 if (it->node) {
1144 of_node_put(it->node);
1145 it->node = NULL;
1146 }
1147
1148 if (!it->cur || it->phandle_end >= it->list_end)
1149 return -ENOENT;
1150
1151 it->cur = it->phandle_end;
1152
1153 /* If phandle is 0, then it is an empty entry with no arguments. */
1154 it->phandle = be32_to_cpup(it->cur++);
1155
1156 if (it->phandle) {
1157
1158 /*
1159 * Find the provider node and parse the #*-cells property to
1160 * determine the argument length.
1161 */
1162 it->node = of_find_node_by_phandle(it->phandle);
1163
1164 if (it->cells_name) {
1165 if (!it->node) {
1166 pr_err("%pOF: could not find phandle %d\n",
1167 it->parent, it->phandle);
1168 goto err;
1169 }
1170
1171 if (of_property_read_u32(it->node, it->cells_name,
1172 &count)) {
1173 /*
1174 * If both cell_count and cells_name is given,
1175 * fall back to cell_count in absence
1176 * of the cells_name property
1177 */
1178 if (it->cell_count >= 0) {
1179 count = it->cell_count;
1180 } else {
1181 pr_err("%pOF: could not get %s for %pOF\n",
1182 it->parent,
1183 it->cells_name,
1184 it->node);
1185 goto err;
1186 }
1187 }
1188 } else {
1189 count = it->cell_count;
1190 }
1191
1192 /*
1193 * Make sure that the arguments actually fit in the remaining
1194 * property data length
1195 */
1196 if (it->cur + count > it->list_end) {
1197 if (it->cells_name)
1198 pr_err("%pOF: %s = %d found %td\n",
1199 it->parent, it->cells_name,
1200 count, it->list_end - it->cur);
1201 else
1202 pr_err("%pOF: phandle %s needs %d, found %td\n",
1203 it->parent, of_node_full_name(it->node),
1204 count, it->list_end - it->cur);
1205 goto err;
1206 }
1207 }
1208
1209 it->phandle_end = it->cur + count;
1210 it->cur_count = count;
1211
1212 return 0;
1213
1214err:
1215 if (it->node) {
1216 of_node_put(it->node);
1217 it->node = NULL;
1218 }
1219
1220 return -EINVAL;
1221}
1222EXPORT_SYMBOL_GPL(of_phandle_iterator_next);
1223
1224int of_phandle_iterator_args(struct of_phandle_iterator *it,
1225 uint32_t *args,
1226 int size)
1227{
1228 int i, count;
1229
1230 count = it->cur_count;
1231
1232 if (WARN_ON(size < count))
1233 count = size;
1234
1235 for (i = 0; i < count; i++)
1236 args[i] = be32_to_cpup(it->cur++);
1237
1238 return count;
1239}
1240
1241int __of_parse_phandle_with_args(const struct device_node *np,
1242 const char *list_name,
1243 const char *cells_name,
1244 int cell_count, int index,
1245 struct of_phandle_args *out_args)
1246{
1247 struct of_phandle_iterator it;
1248 int rc, cur_index = 0;
1249
1250 if (index < 0)
1251 return -EINVAL;
1252
1253 /* Loop over the phandles until all the requested entry is found */
1254 of_for_each_phandle(&it, rc, np, list_name, cells_name, cell_count) {
1255 /*
1256 * All of the error cases bail out of the loop, so at
1257 * this point, the parsing is successful. If the requested
1258 * index matches, then fill the out_args structure and return,
1259 * or return -ENOENT for an empty entry.
1260 */
1261 rc = -ENOENT;
1262 if (cur_index == index) {
1263 if (!it.phandle)
1264 goto err;
1265
1266 if (out_args) {
1267 int c;
1268
1269 c = of_phandle_iterator_args(&it,
1270 out_args->args,
1271 MAX_PHANDLE_ARGS);
1272 out_args->np = it.node;
1273 out_args->args_count = c;
1274 } else {
1275 of_node_put(it.node);
1276 }
1277
1278 /* Found it! return success */
1279 return 0;
1280 }
1281
1282 cur_index++;
1283 }
1284
1285 /*
1286 * Unlock node before returning result; will be one of:
1287 * -ENOENT : index is for empty phandle
1288 * -EINVAL : parsing error on data
1289 */
1290
1291 err:
1292 of_node_put(it.node);
1293 return rc;
1294}
1295EXPORT_SYMBOL(__of_parse_phandle_with_args);
1296
1297/**
1298 * of_parse_phandle_with_args_map() - Find a node pointed by phandle in a list and remap it
1299 * @np: pointer to a device tree node containing a list
1300 * @list_name: property name that contains a list
1301 * @stem_name: stem of property names that specify phandles' arguments count
1302 * @index: index of a phandle to parse out
1303 * @out_args: optional pointer to output arguments structure (will be filled)
1304 *
1305 * This function is useful to parse lists of phandles and their arguments.
1306 * Returns 0 on success and fills out_args, on error returns appropriate errno
1307 * value. The difference between this function and of_parse_phandle_with_args()
1308 * is that this API remaps a phandle if the node the phandle points to has
1309 * a <@stem_name>-map property.
1310 *
1311 * Caller is responsible to call of_node_put() on the returned out_args->np
1312 * pointer.
1313 *
1314 * Example::
1315 *
1316 * phandle1: node1 {
1317 * #list-cells = <2>;
1318 * };
1319 *
1320 * phandle2: node2 {
1321 * #list-cells = <1>;
1322 * };
1323 *
1324 * phandle3: node3 {
1325 * #list-cells = <1>;
1326 * list-map = <0 &phandle2 3>,
1327 * <1 &phandle2 2>,
1328 * <2 &phandle1 5 1>;
1329 * list-map-mask = <0x3>;
1330 * };
1331 *
1332 * node4 {
1333 * list = <&phandle1 1 2 &phandle3 0>;
1334 * };
1335 *
1336 * To get a device_node of the ``node2`` node you may call this:
1337 * of_parse_phandle_with_args(node4, "list", "list", 1, &args);
1338 */
1339int of_parse_phandle_with_args_map(const struct device_node *np,
1340 const char *list_name,
1341 const char *stem_name,
1342 int index, struct of_phandle_args *out_args)
1343{
1344 char *cells_name, *map_name = NULL, *mask_name = NULL;
1345 char *pass_name = NULL;
1346 struct device_node *cur, *new = NULL;
1347 const __be32 *map, *mask, *pass;
1348 static const __be32 dummy_mask[] = { [0 ... MAX_PHANDLE_ARGS] = ~0 };
1349 static const __be32 dummy_pass[] = { [0 ... MAX_PHANDLE_ARGS] = 0 };
1350 __be32 initial_match_array[MAX_PHANDLE_ARGS];
1351 const __be32 *match_array = initial_match_array;
1352 int i, ret, map_len, match;
1353 u32 list_size, new_size;
1354
1355 if (index < 0)
1356 return -EINVAL;
1357
1358 cells_name = kasprintf(GFP_KERNEL, "#%s-cells", stem_name);
1359 if (!cells_name)
1360 return -ENOMEM;
1361
1362 ret = -ENOMEM;
1363 map_name = kasprintf(GFP_KERNEL, "%s-map", stem_name);
1364 if (!map_name)
1365 goto free;
1366
1367 mask_name = kasprintf(GFP_KERNEL, "%s-map-mask", stem_name);
1368 if (!mask_name)
1369 goto free;
1370
1371 pass_name = kasprintf(GFP_KERNEL, "%s-map-pass-thru", stem_name);
1372 if (!pass_name)
1373 goto free;
1374
1375 ret = __of_parse_phandle_with_args(np, list_name, cells_name, -1, index,
1376 out_args);
1377 if (ret)
1378 goto free;
1379
1380 /* Get the #<list>-cells property */
1381 cur = out_args->np;
1382 ret = of_property_read_u32(cur, cells_name, &list_size);
1383 if (ret < 0)
1384 goto put;
1385
1386 /* Precalculate the match array - this simplifies match loop */
1387 for (i = 0; i < list_size; i++)
1388 initial_match_array[i] = cpu_to_be32(out_args->args[i]);
1389
1390 ret = -EINVAL;
1391 while (cur) {
1392 /* Get the <list>-map property */
1393 map = of_get_property(cur, map_name, &map_len);
1394 if (!map) {
1395 ret = 0;
1396 goto free;
1397 }
1398 map_len /= sizeof(u32);
1399
1400 /* Get the <list>-map-mask property (optional) */
1401 mask = of_get_property(cur, mask_name, NULL);
1402 if (!mask)
1403 mask = dummy_mask;
1404 /* Iterate through <list>-map property */
1405 match = 0;
1406 while (map_len > (list_size + 1) && !match) {
1407 /* Compare specifiers */
1408 match = 1;
1409 for (i = 0; i < list_size; i++, map_len--)
1410 match &= !((match_array[i] ^ *map++) & mask[i]);
1411
1412 of_node_put(new);
1413 new = of_find_node_by_phandle(be32_to_cpup(map));
1414 map++;
1415 map_len--;
1416
1417 /* Check if not found */
1418 if (!new)
1419 goto put;
1420
1421 if (!of_device_is_available(new))
1422 match = 0;
1423
1424 ret = of_property_read_u32(new, cells_name, &new_size);
1425 if (ret)
1426 goto put;
1427
1428 /* Check for malformed properties */
1429 if (WARN_ON(new_size > MAX_PHANDLE_ARGS))
1430 goto put;
1431 if (map_len < new_size)
1432 goto put;
1433
1434 /* Move forward by new node's #<list>-cells amount */
1435 map += new_size;
1436 map_len -= new_size;
1437 }
1438 if (!match)
1439 goto put;
1440
1441 /* Get the <list>-map-pass-thru property (optional) */
1442 pass = of_get_property(cur, pass_name, NULL);
1443 if (!pass)
1444 pass = dummy_pass;
1445
1446 /*
1447 * Successfully parsed a <list>-map translation; copy new
1448 * specifier into the out_args structure, keeping the
1449 * bits specified in <list>-map-pass-thru.
1450 */
1451 match_array = map - new_size;
1452 for (i = 0; i < new_size; i++) {
1453 __be32 val = *(map - new_size + i);
1454
1455 if (i < list_size) {
1456 val &= ~pass[i];
1457 val |= cpu_to_be32(out_args->args[i]) & pass[i];
1458 }
1459
1460 out_args->args[i] = be32_to_cpu(val);
1461 }
1462 out_args->args_count = list_size = new_size;
1463 /* Iterate again with new provider */
1464 out_args->np = new;
1465 of_node_put(cur);
1466 cur = new;
1467 new = NULL;
1468 }
1469put:
1470 of_node_put(cur);
1471 of_node_put(new);
1472free:
1473 kfree(mask_name);
1474 kfree(map_name);
1475 kfree(cells_name);
1476 kfree(pass_name);
1477
1478 return ret;
1479}
1480EXPORT_SYMBOL(of_parse_phandle_with_args_map);
1481
1482/**
1483 * of_count_phandle_with_args() - Find the number of phandles references in a property
1484 * @np: pointer to a device tree node containing a list
1485 * @list_name: property name that contains a list
1486 * @cells_name: property name that specifies phandles' arguments count
1487 *
1488 * Return: The number of phandle + argument tuples within a property. It
1489 * is a typical pattern to encode a list of phandle and variable
1490 * arguments into a single property. The number of arguments is encoded
1491 * by a property in the phandle-target node. For example, a gpios
1492 * property would contain a list of GPIO specifies consisting of a
1493 * phandle and 1 or more arguments. The number of arguments are
1494 * determined by the #gpio-cells property in the node pointed to by the
1495 * phandle.
1496 */
1497int of_count_phandle_with_args(const struct device_node *np, const char *list_name,
1498 const char *cells_name)
1499{
1500 struct of_phandle_iterator it;
1501 int rc, cur_index = 0;
1502
1503 /*
1504 * If cells_name is NULL we assume a cell count of 0. This makes
1505 * counting the phandles trivial as each 32bit word in the list is a
1506 * phandle and no arguments are to consider. So we don't iterate through
1507 * the list but just use the length to determine the phandle count.
1508 */
1509 if (!cells_name) {
1510 const __be32 *list;
1511 int size;
1512
1513 list = of_get_property(np, list_name, &size);
1514 if (!list)
1515 return -ENOENT;
1516
1517 return size / sizeof(*list);
1518 }
1519
1520 rc = of_phandle_iterator_init(&it, np, list_name, cells_name, -1);
1521 if (rc)
1522 return rc;
1523
1524 while ((rc = of_phandle_iterator_next(&it)) == 0)
1525 cur_index += 1;
1526
1527 if (rc != -ENOENT)
1528 return rc;
1529
1530 return cur_index;
1531}
1532EXPORT_SYMBOL(of_count_phandle_with_args);
1533
1534static struct property *__of_remove_property_from_list(struct property **list, struct property *prop)
1535{
1536 struct property **next;
1537
1538 for (next = list; *next; next = &(*next)->next) {
1539 if (*next == prop) {
1540 *next = prop->next;
1541 prop->next = NULL;
1542 return prop;
1543 }
1544 }
1545 return NULL;
1546}
1547
1548/**
1549 * __of_add_property - Add a property to a node without lock operations
1550 * @np: Caller's Device Node
1551 * @prop: Property to add
1552 */
1553int __of_add_property(struct device_node *np, struct property *prop)
1554{
1555 int rc = 0;
1556 unsigned long flags;
1557 struct property **next;
1558
1559 raw_spin_lock_irqsave(&devtree_lock, flags);
1560
1561 __of_remove_property_from_list(&np->deadprops, prop);
1562
1563 prop->next = NULL;
1564 next = &np->properties;
1565 while (*next) {
1566 if (strcmp(prop->name, (*next)->name) == 0) {
1567 /* duplicate ! don't insert it */
1568 rc = -EEXIST;
1569 goto out_unlock;
1570 }
1571 next = &(*next)->next;
1572 }
1573 *next = prop;
1574
1575out_unlock:
1576 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1577 if (rc)
1578 return rc;
1579
1580 __of_add_property_sysfs(np, prop);
1581 return 0;
1582}
1583
1584/**
1585 * of_add_property - Add a property to a node
1586 * @np: Caller's Device Node
1587 * @prop: Property to add
1588 */
1589int of_add_property(struct device_node *np, struct property *prop)
1590{
1591 int rc;
1592
1593 mutex_lock(&of_mutex);
1594 rc = __of_add_property(np, prop);
1595 mutex_unlock(&of_mutex);
1596
1597 if (!rc)
1598 of_property_notify(OF_RECONFIG_ADD_PROPERTY, np, prop, NULL);
1599
1600 return rc;
1601}
1602EXPORT_SYMBOL_GPL(of_add_property);
1603
1604int __of_remove_property(struct device_node *np, struct property *prop)
1605{
1606 unsigned long flags;
1607 int rc = -ENODEV;
1608
1609 raw_spin_lock_irqsave(&devtree_lock, flags);
1610
1611 if (__of_remove_property_from_list(&np->properties, prop)) {
1612 /* Found the property, add it to deadprops list */
1613 prop->next = np->deadprops;
1614 np->deadprops = prop;
1615 rc = 0;
1616 }
1617
1618 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1619 if (rc)
1620 return rc;
1621
1622 __of_remove_property_sysfs(np, prop);
1623 return 0;
1624}
1625
1626/**
1627 * of_remove_property - Remove a property from a node.
1628 * @np: Caller's Device Node
1629 * @prop: Property to remove
1630 *
1631 * Note that we don't actually remove it, since we have given out
1632 * who-knows-how-many pointers to the data using get-property.
1633 * Instead we just move the property to the "dead properties"
1634 * list, so it won't be found any more.
1635 */
1636int of_remove_property(struct device_node *np, struct property *prop)
1637{
1638 int rc;
1639
1640 if (!prop)
1641 return -ENODEV;
1642
1643 mutex_lock(&of_mutex);
1644 rc = __of_remove_property(np, prop);
1645 mutex_unlock(&of_mutex);
1646
1647 if (!rc)
1648 of_property_notify(OF_RECONFIG_REMOVE_PROPERTY, np, prop, NULL);
1649
1650 return rc;
1651}
1652EXPORT_SYMBOL_GPL(of_remove_property);
1653
1654int __of_update_property(struct device_node *np, struct property *newprop,
1655 struct property **oldpropp)
1656{
1657 struct property **next, *oldprop;
1658 unsigned long flags;
1659
1660 raw_spin_lock_irqsave(&devtree_lock, flags);
1661
1662 __of_remove_property_from_list(&np->deadprops, newprop);
1663
1664 for (next = &np->properties; *next; next = &(*next)->next) {
1665 if (of_prop_cmp((*next)->name, newprop->name) == 0)
1666 break;
1667 }
1668 *oldpropp = oldprop = *next;
1669
1670 if (oldprop) {
1671 /* replace the node */
1672 newprop->next = oldprop->next;
1673 *next = newprop;
1674 oldprop->next = np->deadprops;
1675 np->deadprops = oldprop;
1676 } else {
1677 /* new node */
1678 newprop->next = NULL;
1679 *next = newprop;
1680 }
1681
1682 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1683
1684 __of_update_property_sysfs(np, newprop, oldprop);
1685
1686 return 0;
1687}
1688
1689/*
1690 * of_update_property - Update a property in a node, if the property does
1691 * not exist, add it.
1692 *
1693 * Note that we don't actually remove it, since we have given out
1694 * who-knows-how-many pointers to the data using get-property.
1695 * Instead we just move the property to the "dead properties" list,
1696 * and add the new property to the property list
1697 */
1698int of_update_property(struct device_node *np, struct property *newprop)
1699{
1700 struct property *oldprop;
1701 int rc;
1702
1703 if (!newprop->name)
1704 return -EINVAL;
1705
1706 mutex_lock(&of_mutex);
1707 rc = __of_update_property(np, newprop, &oldprop);
1708 mutex_unlock(&of_mutex);
1709
1710 if (!rc)
1711 of_property_notify(OF_RECONFIG_UPDATE_PROPERTY, np, newprop, oldprop);
1712
1713 return rc;
1714}
1715
1716static void of_alias_add(struct alias_prop *ap, struct device_node *np,
1717 int id, const char *stem, int stem_len)
1718{
1719 ap->np = np;
1720 ap->id = id;
1721 strscpy(ap->stem, stem, stem_len + 1);
1722 list_add_tail(&ap->link, &aliases_lookup);
1723 pr_debug("adding DT alias:%s: stem=%s id=%i node=%pOF\n",
1724 ap->alias, ap->stem, ap->id, np);
1725}
1726
1727/**
1728 * of_alias_scan - Scan all properties of the 'aliases' node
1729 * @dt_alloc: An allocator that provides a virtual address to memory
1730 * for storing the resulting tree
1731 *
1732 * The function scans all the properties of the 'aliases' node and populates
1733 * the global lookup table with the properties. It returns the
1734 * number of alias properties found, or an error code in case of failure.
1735 */
1736void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align))
1737{
1738 struct property *pp;
1739
1740 of_aliases = of_find_node_by_path("/aliases");
1741 of_chosen = of_find_node_by_path("/chosen");
1742 if (of_chosen == NULL)
1743 of_chosen = of_find_node_by_path("/chosen@0");
1744
1745 if (of_chosen) {
1746 /* linux,stdout-path and /aliases/stdout are for legacy compatibility */
1747 const char *name = NULL;
1748
1749 if (of_property_read_string(of_chosen, "stdout-path", &name))
1750 of_property_read_string(of_chosen, "linux,stdout-path",
1751 &name);
1752 if (IS_ENABLED(CONFIG_PPC) && !name)
1753 of_property_read_string(of_aliases, "stdout", &name);
1754 if (name)
1755 of_stdout = of_find_node_opts_by_path(name, &of_stdout_options);
1756 if (of_stdout)
1757 of_stdout->fwnode.flags |= FWNODE_FLAG_BEST_EFFORT;
1758 }
1759
1760 if (!of_aliases)
1761 return;
1762
1763 for_each_property_of_node(of_aliases, pp) {
1764 const char *start = pp->name;
1765 const char *end = start + strlen(start);
1766 struct device_node *np;
1767 struct alias_prop *ap;
1768 int id, len;
1769
1770 /* Skip those we do not want to proceed */
1771 if (!strcmp(pp->name, "name") ||
1772 !strcmp(pp->name, "phandle") ||
1773 !strcmp(pp->name, "linux,phandle"))
1774 continue;
1775
1776 np = of_find_node_by_path(pp->value);
1777 if (!np)
1778 continue;
1779
1780 /* walk the alias backwards to extract the id and work out
1781 * the 'stem' string */
1782 while (isdigit(*(end-1)) && end > start)
1783 end--;
1784 len = end - start;
1785
1786 if (kstrtoint(end, 10, &id) < 0)
1787 continue;
1788
1789 /* Allocate an alias_prop with enough space for the stem */
1790 ap = dt_alloc(sizeof(*ap) + len + 1, __alignof__(*ap));
1791 if (!ap)
1792 continue;
1793 memset(ap, 0, sizeof(*ap) + len + 1);
1794 ap->alias = start;
1795 of_alias_add(ap, np, id, start, len);
1796 }
1797}
1798
1799/**
1800 * of_alias_get_id - Get alias id for the given device_node
1801 * @np: Pointer to the given device_node
1802 * @stem: Alias stem of the given device_node
1803 *
1804 * The function travels the lookup table to get the alias id for the given
1805 * device_node and alias stem.
1806 *
1807 * Return: The alias id if found.
1808 */
1809int of_alias_get_id(struct device_node *np, const char *stem)
1810{
1811 struct alias_prop *app;
1812 int id = -ENODEV;
1813
1814 mutex_lock(&of_mutex);
1815 list_for_each_entry(app, &aliases_lookup, link) {
1816 if (strcmp(app->stem, stem) != 0)
1817 continue;
1818
1819 if (np == app->np) {
1820 id = app->id;
1821 break;
1822 }
1823 }
1824 mutex_unlock(&of_mutex);
1825
1826 return id;
1827}
1828EXPORT_SYMBOL_GPL(of_alias_get_id);
1829
1830/**
1831 * of_alias_get_highest_id - Get highest alias id for the given stem
1832 * @stem: Alias stem to be examined
1833 *
1834 * The function travels the lookup table to get the highest alias id for the
1835 * given alias stem. It returns the alias id if found.
1836 */
1837int of_alias_get_highest_id(const char *stem)
1838{
1839 struct alias_prop *app;
1840 int id = -ENODEV;
1841
1842 mutex_lock(&of_mutex);
1843 list_for_each_entry(app, &aliases_lookup, link) {
1844 if (strcmp(app->stem, stem) != 0)
1845 continue;
1846
1847 if (app->id > id)
1848 id = app->id;
1849 }
1850 mutex_unlock(&of_mutex);
1851
1852 return id;
1853}
1854EXPORT_SYMBOL_GPL(of_alias_get_highest_id);
1855
1856/**
1857 * of_console_check() - Test and setup console for DT setup
1858 * @dn: Pointer to device node
1859 * @name: Name to use for preferred console without index. ex. "ttyS"
1860 * @index: Index to use for preferred console.
1861 *
1862 * Check if the given device node matches the stdout-path property in the
1863 * /chosen node. If it does then register it as the preferred console.
1864 *
1865 * Return: TRUE if console successfully setup. Otherwise return FALSE.
1866 */
1867bool of_console_check(struct device_node *dn, char *name, int index)
1868{
1869 if (!dn || dn != of_stdout || console_set_on_cmdline)
1870 return false;
1871
1872 /*
1873 * XXX: cast `options' to char pointer to suppress complication
1874 * warnings: printk, UART and console drivers expect char pointer.
1875 */
1876 return !add_preferred_console(name, index, (char *)of_stdout_options);
1877}
1878EXPORT_SYMBOL_GPL(of_console_check);
1879
1880/**
1881 * of_find_next_cache_node - Find a node's subsidiary cache
1882 * @np: node of type "cpu" or "cache"
1883 *
1884 * Return: A node pointer with refcount incremented, use
1885 * of_node_put() on it when done. Caller should hold a reference
1886 * to np.
1887 */
1888struct device_node *of_find_next_cache_node(const struct device_node *np)
1889{
1890 struct device_node *child, *cache_node;
1891
1892 cache_node = of_parse_phandle(np, "l2-cache", 0);
1893 if (!cache_node)
1894 cache_node = of_parse_phandle(np, "next-level-cache", 0);
1895
1896 if (cache_node)
1897 return cache_node;
1898
1899 /* OF on pmac has nodes instead of properties named "l2-cache"
1900 * beneath CPU nodes.
1901 */
1902 if (IS_ENABLED(CONFIG_PPC_PMAC) && of_node_is_type(np, "cpu"))
1903 for_each_child_of_node(np, child)
1904 if (of_node_is_type(child, "cache"))
1905 return child;
1906
1907 return NULL;
1908}
1909
1910/**
1911 * of_find_last_cache_level - Find the level at which the last cache is
1912 * present for the given logical cpu
1913 *
1914 * @cpu: cpu number(logical index) for which the last cache level is needed
1915 *
1916 * Return: The level at which the last cache is present. It is exactly
1917 * same as the total number of cache levels for the given logical cpu.
1918 */
1919int of_find_last_cache_level(unsigned int cpu)
1920{
1921 u32 cache_level = 0;
1922 struct device_node *prev = NULL, *np = of_cpu_device_node_get(cpu);
1923
1924 while (np) {
1925 of_node_put(prev);
1926 prev = np;
1927 np = of_find_next_cache_node(np);
1928 }
1929
1930 of_property_read_u32(prev, "cache-level", &cache_level);
1931 of_node_put(prev);
1932
1933 return cache_level;
1934}
1935
1936/**
1937 * of_map_id - Translate an ID through a downstream mapping.
1938 * @np: root complex device node.
1939 * @id: device ID to map.
1940 * @map_name: property name of the map to use.
1941 * @map_mask_name: optional property name of the mask to use.
1942 * @target: optional pointer to a target device node.
1943 * @id_out: optional pointer to receive the translated ID.
1944 *
1945 * Given a device ID, look up the appropriate implementation-defined
1946 * platform ID and/or the target device which receives transactions on that
1947 * ID, as per the "iommu-map" and "msi-map" bindings. Either of @target or
1948 * @id_out may be NULL if only the other is required. If @target points to
1949 * a non-NULL device node pointer, only entries targeting that node will be
1950 * matched; if it points to a NULL value, it will receive the device node of
1951 * the first matching target phandle, with a reference held.
1952 *
1953 * Return: 0 on success or a standard error code on failure.
1954 */
1955int of_map_id(struct device_node *np, u32 id,
1956 const char *map_name, const char *map_mask_name,
1957 struct device_node **target, u32 *id_out)
1958{
1959 u32 map_mask, masked_id;
1960 int map_len;
1961 const __be32 *map = NULL;
1962
1963 if (!np || !map_name || (!target && !id_out))
1964 return -EINVAL;
1965
1966 map = of_get_property(np, map_name, &map_len);
1967 if (!map) {
1968 if (target)
1969 return -ENODEV;
1970 /* Otherwise, no map implies no translation */
1971 *id_out = id;
1972 return 0;
1973 }
1974
1975 if (!map_len || map_len % (4 * sizeof(*map))) {
1976 pr_err("%pOF: Error: Bad %s length: %d\n", np,
1977 map_name, map_len);
1978 return -EINVAL;
1979 }
1980
1981 /* The default is to select all bits. */
1982 map_mask = 0xffffffff;
1983
1984 /*
1985 * Can be overridden by "{iommu,msi}-map-mask" property.
1986 * If of_property_read_u32() fails, the default is used.
1987 */
1988 if (map_mask_name)
1989 of_property_read_u32(np, map_mask_name, &map_mask);
1990
1991 masked_id = map_mask & id;
1992 for ( ; map_len > 0; map_len -= 4 * sizeof(*map), map += 4) {
1993 struct device_node *phandle_node;
1994 u32 id_base = be32_to_cpup(map + 0);
1995 u32 phandle = be32_to_cpup(map + 1);
1996 u32 out_base = be32_to_cpup(map + 2);
1997 u32 id_len = be32_to_cpup(map + 3);
1998
1999 if (id_base & ~map_mask) {
2000 pr_err("%pOF: Invalid %s translation - %s-mask (0x%x) ignores id-base (0x%x)\n",
2001 np, map_name, map_name,
2002 map_mask, id_base);
2003 return -EFAULT;
2004 }
2005
2006 if (masked_id < id_base || masked_id >= id_base + id_len)
2007 continue;
2008
2009 phandle_node = of_find_node_by_phandle(phandle);
2010 if (!phandle_node)
2011 return -ENODEV;
2012
2013 if (target) {
2014 if (*target)
2015 of_node_put(phandle_node);
2016 else
2017 *target = phandle_node;
2018
2019 if (*target != phandle_node)
2020 continue;
2021 }
2022
2023 if (id_out)
2024 *id_out = masked_id - id_base + out_base;
2025
2026 pr_debug("%pOF: %s, using mask %08x, id-base: %08x, out-base: %08x, length: %08x, id: %08x -> %08x\n",
2027 np, map_name, map_mask, id_base, out_base,
2028 id_len, id, masked_id - id_base + out_base);
2029 return 0;
2030 }
2031
2032 pr_info("%pOF: no %s translation for id 0x%x on %pOF\n", np, map_name,
2033 id, target && *target ? *target : NULL);
2034
2035 /* Bypasses translation */
2036 if (id_out)
2037 *id_out = id;
2038 return 0;
2039}
2040EXPORT_SYMBOL_GPL(of_map_id);
1/*
2 * Procedures for creating, accessing and interpreting the device tree.
3 *
4 * Paul Mackerras August 1996.
5 * Copyright (C) 1996-2005 Paul Mackerras.
6 *
7 * Adapted for 64bit PowerPC by Dave Engebretsen and Peter Bergner.
8 * {engebret|bergner}@us.ibm.com
9 *
10 * Adapted for sparc and sparc64 by David S. Miller davem@davemloft.net
11 *
12 * Reconsolidated from arch/x/kernel/prom.c by Stephen Rothwell and
13 * Grant Likely.
14 *
15 * This program is free software; you can redistribute it and/or
16 * modify it under the terms of the GNU General Public License
17 * as published by the Free Software Foundation; either version
18 * 2 of the License, or (at your option) any later version.
19 */
20#include <linux/ctype.h>
21#include <linux/module.h>
22#include <linux/of.h>
23#include <linux/spinlock.h>
24#include <linux/slab.h>
25#include <linux/proc_fs.h>
26
27/**
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
48struct device_node *allnodes;
49struct device_node *of_chosen;
50struct device_node *of_aliases;
51
52static DEFINE_MUTEX(of_aliases_mutex);
53
54/* use when traversing tree through the allnext, child, sibling,
55 * or parent members of struct device_node.
56 */
57DEFINE_RWLOCK(devtree_lock);
58
59int of_n_addr_cells(struct device_node *np)
60{
61 const __be32 *ip;
62
63 do {
64 if (np->parent)
65 np = np->parent;
66 ip = of_get_property(np, "#address-cells", NULL);
67 if (ip)
68 return be32_to_cpup(ip);
69 } 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{
77 const __be32 *ip;
78
79 do {
80 if (np->parent)
81 np = np->parent;
82 ip = of_get_property(np, "#size-cells", NULL);
83 if (ip)
84 return be32_to_cpup(ip);
85 } 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
91#if defined(CONFIG_OF_DYNAMIC)
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_OF_DYNAMIC */
165
166struct property *of_find_property(const struct device_node *np,
167 const char *name,
168 int *lenp)
169{
170 struct property *pp;
171
172 if (!np)
173 return NULL;
174
175 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
189/**
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
212/*
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);
224
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);
248
249/**
250 * of_machine_is_compatible - Test root of device tree for a given compatible value
251 * @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 */
256int of_machine_is_compatible(const char *compat)
257{
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}
268EXPORT_SYMBOL(of_machine_is_compatible);
269
270/**
271 * 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/**
297 * 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);
316
317/**
318 * 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/**
343 * 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);
365
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);
478
479/**
480 * 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/**
515 * 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{
524 if (!matches)
525 return NULL;
526
527 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);
574
575/**
576 * of_modalias_node - Lookup appropriate modalias for a device node
577 * @node: pointer to a device tree node
578 * @modalias: Pointer to buffer that modalias value will be copied into
579 * @len: Length of modalias value
580 *
581 * Based on the value of the compatible property, this routine will 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.
585 *
586 * This routine returns 0 on success, <0 on failure.
587 */
588int of_modalias_node(struct device_node *node, char *modalias, int len)
589{
590 const char *compatible, *p;
591 int cplen;
592
593 compatible = of_get_property(node, "compatible", &cplen);
594 if (!compatible || strlen(compatible) > cplen)
595 return -ENODEV;
596 p = strchr(compatible, ',');
597 strlcpy(modalias, p ? p + 1 : compatible, len);
598 return 0;
599}
600EXPORT_SYMBOL_GPL(of_modalias_node);
601
602/**
603 * 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/**
624 * of_property_read_u32_array - Find and read an array of 32 bit integers
625 * from a property.
626 *
627 * @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 *
631 * Search for a property in a device node and read 32-bit value(s) from
632 * 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 */
638int of_property_read_u32_array(const struct device_node *np,
639 const char *propname, u32 *out_values,
640 size_t sz)
641{
642 struct property *prop = of_find_property(np, propname, NULL);
643 const __be32 *val;
644
645 if (!prop)
646 return -EINVAL;
647 if (!prop->value)
648 return -ENODATA;
649 if ((sz * sizeof(*out_values)) > prop->length)
650 return -EOVERFLOW;
651
652 val = prop->value;
653 while (sz--)
654 *out_values++ = be32_to_cpup(val++);
655 return 0;
656}
657EXPORT_SYMBOL_GPL(of_property_read_u32_array);
658
659/**
660 * 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/**
689 * 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 */
703int of_property_read_string(struct device_node *np, const char *propname,
704 const char **out_string)
705{
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/**
719 * 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 (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 * of_property_match_string() - Find string in a list and return index
766 * @np: pointer to node containing string list property
767 * @propname: string list property name
768 * @string: pointer to string to search for in string list
769 *
770 * This function searches a string list property and returns the index
771 * of a specific string value.
772 */
773int of_property_match_string(struct device_node *np, const char *propname,
774 const char *string)
775{
776 struct property *prop = of_find_property(np, propname, NULL);
777 size_t l;
778 int i;
779 const char *p, *end;
780
781 if (!prop)
782 return -EINVAL;
783 if (!prop->value)
784 return -ENODATA;
785
786 p = prop->value;
787 end = p + prop->length;
788
789 for (i = 0; p < end; i++, p += l) {
790 l = strlen(p) + 1;
791 if (p + l > end)
792 return -EILSEQ;
793 pr_debug("comparing %s with %s\n", string, p);
794 if (strcmp(string, p) == 0)
795 return i; /* Found it; return index */
796 }
797 return -ENODATA;
798}
799EXPORT_SYMBOL_GPL(of_property_match_string);
800
801/**
802 * of_property_count_strings - Find and return the number of strings from a
803 * multiple strings property.
804 * @np: device node from which the property value is to be read.
805 * @propname: name of the property to be searched.
806 *
807 * Search for a property in a device tree node and retrieve the number of null
808 * terminated string contain in it. Returns the number of strings on
809 * success, -EINVAL if the property does not exist, -ENODATA if property
810 * does not have a value, and -EILSEQ if the string is not null-terminated
811 * within the length of the property data.
812 */
813int of_property_count_strings(struct device_node *np, const char *propname)
814{
815 struct property *prop = of_find_property(np, propname, NULL);
816 int i = 0;
817 size_t l = 0, total = 0;
818 const char *p;
819
820 if (!prop)
821 return -EINVAL;
822 if (!prop->value)
823 return -ENODATA;
824 if (strnlen(prop->value, prop->length) >= prop->length)
825 return -EILSEQ;
826
827 p = prop->value;
828
829 for (i = 0; total < prop->length; total += l, p += l, i++)
830 l = strlen(p) + 1;
831
832 return i;
833}
834EXPORT_SYMBOL_GPL(of_property_count_strings);
835
836/**
837 * of_parse_phandle - Resolve a phandle property to a device_node pointer
838 * @np: Pointer to device node holding phandle property
839 * @phandle_name: Name of property holding a phandle value
840 * @index: For properties holding a table of phandles, this is the index into
841 * the table
842 *
843 * Returns the device_node pointer with refcount incremented. Use
844 * of_node_put() on it when done.
845 */
846struct device_node *
847of_parse_phandle(struct device_node *np, const char *phandle_name, int index)
848{
849 const __be32 *phandle;
850 int size;
851
852 phandle = of_get_property(np, phandle_name, &size);
853 if ((!phandle) || (size < sizeof(*phandle) * (index + 1)))
854 return NULL;
855
856 return of_find_node_by_phandle(be32_to_cpup(phandle + index));
857}
858EXPORT_SYMBOL(of_parse_phandle);
859
860/**
861 * of_parse_phandle_with_args() - Find a node pointed by phandle in a list
862 * @np: pointer to a device tree node containing a list
863 * @list_name: property name that contains a list
864 * @cells_name: property name that specifies phandles' arguments count
865 * @index: index of a phandle to parse out
866 * @out_args: optional pointer to output arguments structure (will be filled)
867 *
868 * This function is useful to parse lists of phandles and their arguments.
869 * Returns 0 on success and fills out_args, on error returns appropriate
870 * errno value.
871 *
872 * Caller is responsible to call of_node_put() on the returned out_args->node
873 * pointer.
874 *
875 * Example:
876 *
877 * phandle1: node1 {
878 * #list-cells = <2>;
879 * }
880 *
881 * phandle2: node2 {
882 * #list-cells = <1>;
883 * }
884 *
885 * node3 {
886 * list = <&phandle1 1 2 &phandle2 3>;
887 * }
888 *
889 * To get a device_node of the `node2' node you may call this:
890 * of_parse_phandle_with_args(node3, "list", "#list-cells", 1, &args);
891 */
892int of_parse_phandle_with_args(struct device_node *np, const char *list_name,
893 const char *cells_name, int index,
894 struct of_phandle_args *out_args)
895{
896 const __be32 *list, *list_end;
897 int size, cur_index = 0;
898 uint32_t count = 0;
899 struct device_node *node = NULL;
900 phandle phandle;
901
902 /* Retrieve the phandle list property */
903 list = of_get_property(np, list_name, &size);
904 if (!list)
905 return -EINVAL;
906 list_end = list + size / sizeof(*list);
907
908 /* Loop over the phandles until all the requested entry is found */
909 while (list < list_end) {
910 count = 0;
911
912 /*
913 * If phandle is 0, then it is an empty entry with no
914 * arguments. Skip forward to the next entry.
915 */
916 phandle = be32_to_cpup(list++);
917 if (phandle) {
918 /*
919 * Find the provider node and parse the #*-cells
920 * property to determine the argument length
921 */
922 node = of_find_node_by_phandle(phandle);
923 if (!node) {
924 pr_err("%s: could not find phandle\n",
925 np->full_name);
926 break;
927 }
928 if (of_property_read_u32(node, cells_name, &count)) {
929 pr_err("%s: could not get %s for %s\n",
930 np->full_name, cells_name,
931 node->full_name);
932 break;
933 }
934
935 /*
936 * Make sure that the arguments actually fit in the
937 * remaining property data length
938 */
939 if (list + count > list_end) {
940 pr_err("%s: arguments longer than property\n",
941 np->full_name);
942 break;
943 }
944 }
945
946 /*
947 * All of the error cases above bail out of the loop, so at
948 * this point, the parsing is successful. If the requested
949 * index matches, then fill the out_args structure and return,
950 * or return -ENOENT for an empty entry.
951 */
952 if (cur_index == index) {
953 if (!phandle)
954 return -ENOENT;
955
956 if (out_args) {
957 int i;
958 if (WARN_ON(count > MAX_PHANDLE_ARGS))
959 count = MAX_PHANDLE_ARGS;
960 out_args->np = node;
961 out_args->args_count = count;
962 for (i = 0; i < count; i++)
963 out_args->args[i] = be32_to_cpup(list++);
964 }
965 return 0;
966 }
967
968 of_node_put(node);
969 node = NULL;
970 list += count;
971 cur_index++;
972 }
973
974 /* Loop exited without finding a valid entry; return an error */
975 if (node)
976 of_node_put(node);
977 return -EINVAL;
978}
979EXPORT_SYMBOL(of_parse_phandle_with_args);
980
981/**
982 * prom_add_property - Add a property to a node
983 */
984int prom_add_property(struct device_node *np, struct property *prop)
985{
986 struct property **next;
987 unsigned long flags;
988
989 prop->next = NULL;
990 write_lock_irqsave(&devtree_lock, flags);
991 next = &np->properties;
992 while (*next) {
993 if (strcmp(prop->name, (*next)->name) == 0) {
994 /* duplicate ! don't insert it */
995 write_unlock_irqrestore(&devtree_lock, flags);
996 return -1;
997 }
998 next = &(*next)->next;
999 }
1000 *next = prop;
1001 write_unlock_irqrestore(&devtree_lock, flags);
1002
1003#ifdef CONFIG_PROC_DEVICETREE
1004 /* try to add to proc as well if it was initialized */
1005 if (np->pde)
1006 proc_device_tree_add_prop(np->pde, prop);
1007#endif /* CONFIG_PROC_DEVICETREE */
1008
1009 return 0;
1010}
1011
1012/**
1013 * prom_remove_property - Remove a property from a node.
1014 *
1015 * Note that we don't actually remove it, since we have given out
1016 * who-knows-how-many pointers to the data using get-property.
1017 * Instead we just move the property to the "dead properties"
1018 * list, so it won't be found any more.
1019 */
1020int prom_remove_property(struct device_node *np, struct property *prop)
1021{
1022 struct property **next;
1023 unsigned long flags;
1024 int found = 0;
1025
1026 write_lock_irqsave(&devtree_lock, flags);
1027 next = &np->properties;
1028 while (*next) {
1029 if (*next == prop) {
1030 /* found the node */
1031 *next = prop->next;
1032 prop->next = np->deadprops;
1033 np->deadprops = prop;
1034 found = 1;
1035 break;
1036 }
1037 next = &(*next)->next;
1038 }
1039 write_unlock_irqrestore(&devtree_lock, flags);
1040
1041 if (!found)
1042 return -ENODEV;
1043
1044#ifdef CONFIG_PROC_DEVICETREE
1045 /* try to remove the proc node as well */
1046 if (np->pde)
1047 proc_device_tree_remove_prop(np->pde, prop);
1048#endif /* CONFIG_PROC_DEVICETREE */
1049
1050 return 0;
1051}
1052
1053/*
1054 * prom_update_property - Update a property in a node.
1055 *
1056 * Note that we don't actually remove it, since we have given out
1057 * who-knows-how-many pointers to the data using get-property.
1058 * Instead we just move the property to the "dead properties" list,
1059 * and add the new property to the property list
1060 */
1061int prom_update_property(struct device_node *np,
1062 struct property *newprop,
1063 struct property *oldprop)
1064{
1065 struct property **next;
1066 unsigned long flags;
1067 int found = 0;
1068
1069 write_lock_irqsave(&devtree_lock, flags);
1070 next = &np->properties;
1071 while (*next) {
1072 if (*next == oldprop) {
1073 /* found the node */
1074 newprop->next = oldprop->next;
1075 *next = newprop;
1076 oldprop->next = np->deadprops;
1077 np->deadprops = oldprop;
1078 found = 1;
1079 break;
1080 }
1081 next = &(*next)->next;
1082 }
1083 write_unlock_irqrestore(&devtree_lock, flags);
1084
1085 if (!found)
1086 return -ENODEV;
1087
1088#ifdef CONFIG_PROC_DEVICETREE
1089 /* try to add to proc as well if it was initialized */
1090 if (np->pde)
1091 proc_device_tree_update_prop(np->pde, newprop, oldprop);
1092#endif /* CONFIG_PROC_DEVICETREE */
1093
1094 return 0;
1095}
1096
1097#if defined(CONFIG_OF_DYNAMIC)
1098/*
1099 * Support for dynamic device trees.
1100 *
1101 * On some platforms, the device tree can be manipulated at runtime.
1102 * The routines in this section support adding, removing and changing
1103 * device tree nodes.
1104 */
1105
1106/**
1107 * of_attach_node - Plug a device node into the tree and global list.
1108 */
1109void of_attach_node(struct device_node *np)
1110{
1111 unsigned long flags;
1112
1113 write_lock_irqsave(&devtree_lock, flags);
1114 np->sibling = np->parent->child;
1115 np->allnext = allnodes;
1116 np->parent->child = np;
1117 allnodes = np;
1118 write_unlock_irqrestore(&devtree_lock, flags);
1119}
1120
1121/**
1122 * of_detach_node - "Unplug" a node from the device tree.
1123 *
1124 * The caller must hold a reference to the node. The memory associated with
1125 * the node is not freed until its refcount goes to zero.
1126 */
1127void of_detach_node(struct device_node *np)
1128{
1129 struct device_node *parent;
1130 unsigned long flags;
1131
1132 write_lock_irqsave(&devtree_lock, flags);
1133
1134 parent = np->parent;
1135 if (!parent)
1136 goto out_unlock;
1137
1138 if (allnodes == np)
1139 allnodes = np->allnext;
1140 else {
1141 struct device_node *prev;
1142 for (prev = allnodes;
1143 prev->allnext != np;
1144 prev = prev->allnext)
1145 ;
1146 prev->allnext = np->allnext;
1147 }
1148
1149 if (parent->child == np)
1150 parent->child = np->sibling;
1151 else {
1152 struct device_node *prevsib;
1153 for (prevsib = np->parent->child;
1154 prevsib->sibling != np;
1155 prevsib = prevsib->sibling)
1156 ;
1157 prevsib->sibling = np->sibling;
1158 }
1159
1160 of_node_set_flag(np, OF_DETACHED);
1161
1162out_unlock:
1163 write_unlock_irqrestore(&devtree_lock, flags);
1164}
1165#endif /* defined(CONFIG_OF_DYNAMIC) */
1166
1167static void of_alias_add(struct alias_prop *ap, struct device_node *np,
1168 int id, const char *stem, int stem_len)
1169{
1170 ap->np = np;
1171 ap->id = id;
1172 strncpy(ap->stem, stem, stem_len);
1173 ap->stem[stem_len] = 0;
1174 list_add_tail(&ap->link, &aliases_lookup);
1175 pr_debug("adding DT alias:%s: stem=%s id=%i node=%s\n",
1176 ap->alias, ap->stem, ap->id, np ? np->full_name : NULL);
1177}
1178
1179/**
1180 * of_alias_scan - Scan all properties of 'aliases' node
1181 *
1182 * The function scans all the properties of 'aliases' node and populate
1183 * the the global lookup table with the properties. It returns the
1184 * number of alias_prop found, or error code in error case.
1185 *
1186 * @dt_alloc: An allocator that provides a virtual address to memory
1187 * for the resulting tree
1188 */
1189void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align))
1190{
1191 struct property *pp;
1192
1193 of_chosen = of_find_node_by_path("/chosen");
1194 if (of_chosen == NULL)
1195 of_chosen = of_find_node_by_path("/chosen@0");
1196 of_aliases = of_find_node_by_path("/aliases");
1197 if (!of_aliases)
1198 return;
1199
1200 for_each_property_of_node(of_aliases, pp) {
1201 const char *start = pp->name;
1202 const char *end = start + strlen(start);
1203 struct device_node *np;
1204 struct alias_prop *ap;
1205 int id, len;
1206
1207 /* Skip those we do not want to proceed */
1208 if (!strcmp(pp->name, "name") ||
1209 !strcmp(pp->name, "phandle") ||
1210 !strcmp(pp->name, "linux,phandle"))
1211 continue;
1212
1213 np = of_find_node_by_path(pp->value);
1214 if (!np)
1215 continue;
1216
1217 /* walk the alias backwards to extract the id and work out
1218 * the 'stem' string */
1219 while (isdigit(*(end-1)) && end > start)
1220 end--;
1221 len = end - start;
1222
1223 if (kstrtoint(end, 10, &id) < 0)
1224 continue;
1225
1226 /* Allocate an alias_prop with enough space for the stem */
1227 ap = dt_alloc(sizeof(*ap) + len + 1, 4);
1228 if (!ap)
1229 continue;
1230 ap->alias = start;
1231 of_alias_add(ap, np, id, start, len);
1232 }
1233}
1234
1235/**
1236 * of_alias_get_id - Get alias id for the given device_node
1237 * @np: Pointer to the given device_node
1238 * @stem: Alias stem of the given device_node
1239 *
1240 * The function travels the lookup table to get alias id for the given
1241 * device_node and alias stem. It returns the alias id if find it.
1242 */
1243int of_alias_get_id(struct device_node *np, const char *stem)
1244{
1245 struct alias_prop *app;
1246 int id = -ENODEV;
1247
1248 mutex_lock(&of_aliases_mutex);
1249 list_for_each_entry(app, &aliases_lookup, link) {
1250 if (strcmp(app->stem, stem) != 0)
1251 continue;
1252
1253 if (np == app->np) {
1254 id = app->id;
1255 break;
1256 }
1257 }
1258 mutex_unlock(&of_aliases_mutex);
1259
1260 return id;
1261}
1262EXPORT_SYMBOL_GPL(of_alias_get_id);
1263
1264const __be32 *of_prop_next_u32(struct property *prop, const __be32 *cur,
1265 u32 *pu)
1266{
1267 const void *curv = cur;
1268
1269 if (!prop)
1270 return NULL;
1271
1272 if (!cur) {
1273 curv = prop->value;
1274 goto out_val;
1275 }
1276
1277 curv += sizeof(*cur);
1278 if (curv >= prop->value + prop->length)
1279 return NULL;
1280
1281out_val:
1282 *pu = be32_to_cpup(curv);
1283 return curv;
1284}
1285EXPORT_SYMBOL_GPL(of_prop_next_u32);
1286
1287const char *of_prop_next_string(struct property *prop, const char *cur)
1288{
1289 const void *curv = cur;
1290
1291 if (!prop)
1292 return NULL;
1293
1294 if (!cur)
1295 return prop->value;
1296
1297 curv += strlen(cur) + 1;
1298 if (curv >= prop->value + prop->length)
1299 return NULL;
1300
1301 return curv;
1302}
1303EXPORT_SYMBOL_GPL(of_prop_next_string);