Loading...
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);
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/console.h>
21#include <linux/ctype.h>
22#include <linux/cpu.h>
23#include <linux/module.h>
24#include <linux/of.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;
38struct device_node *of_aliases;
39struct device_node *of_stdout;
40static const char *of_stdout_options;
41
42struct kset *of_kset;
43
44/*
45 * Used to protect the of_aliases, to hold off addition of nodes to sysfs.
46 * This mutex must be held whenever modifications are being made to the
47 * device tree. The of_{attach,detach}_node() and
48 * of_{add,remove,update}_property() helpers make sure this happens.
49 */
50DEFINE_MUTEX(of_mutex);
51
52/* use when traversing tree through the child, sibling,
53 * or parent members of struct device_node.
54 */
55DEFINE_RAW_SPINLOCK(devtree_lock);
56
57int of_n_addr_cells(struct device_node *np)
58{
59 const __be32 *ip;
60
61 do {
62 if (np->parent)
63 np = np->parent;
64 ip = of_get_property(np, "#address-cells", NULL);
65 if (ip)
66 return be32_to_cpup(ip);
67 } while (np->parent);
68 /* No #address-cells property for the root node */
69 return OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
70}
71EXPORT_SYMBOL(of_n_addr_cells);
72
73int of_n_size_cells(struct device_node *np)
74{
75 const __be32 *ip;
76
77 do {
78 if (np->parent)
79 np = np->parent;
80 ip = of_get_property(np, "#size-cells", NULL);
81 if (ip)
82 return be32_to_cpup(ip);
83 } while (np->parent);
84 /* No #size-cells property for the root node */
85 return OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
86}
87EXPORT_SYMBOL(of_n_size_cells);
88
89#ifdef CONFIG_NUMA
90int __weak of_node_to_nid(struct device_node *np)
91{
92 return NUMA_NO_NODE;
93}
94#endif
95
96#ifndef CONFIG_OF_DYNAMIC
97static void of_node_release(struct kobject *kobj)
98{
99 /* Without CONFIG_OF_DYNAMIC, no nodes gets freed */
100}
101#endif /* CONFIG_OF_DYNAMIC */
102
103struct kobj_type of_node_ktype = {
104 .release = of_node_release,
105};
106
107static ssize_t of_node_property_read(struct file *filp, struct kobject *kobj,
108 struct bin_attribute *bin_attr, char *buf,
109 loff_t offset, size_t count)
110{
111 struct property *pp = container_of(bin_attr, struct property, attr);
112 return memory_read_from_buffer(buf, count, &offset, pp->value, pp->length);
113}
114
115static const char *safe_name(struct kobject *kobj, const char *orig_name)
116{
117 const char *name = orig_name;
118 struct kernfs_node *kn;
119 int i = 0;
120
121 /* don't be a hero. After 16 tries give up */
122 while (i < 16 && (kn = sysfs_get_dirent(kobj->sd, name))) {
123 sysfs_put(kn);
124 if (name != orig_name)
125 kfree(name);
126 name = kasprintf(GFP_KERNEL, "%s#%i", orig_name, ++i);
127 }
128
129 if (name != orig_name)
130 pr_warn("device-tree: Duplicate name in %s, renamed to \"%s\"\n",
131 kobject_name(kobj), name);
132 return name;
133}
134
135int __of_add_property_sysfs(struct device_node *np, struct property *pp)
136{
137 int rc;
138
139 /* Important: Don't leak passwords */
140 bool secure = strncmp(pp->name, "security-", 9) == 0;
141
142 if (!IS_ENABLED(CONFIG_SYSFS))
143 return 0;
144
145 if (!of_kset || !of_node_is_attached(np))
146 return 0;
147
148 sysfs_bin_attr_init(&pp->attr);
149 pp->attr.attr.name = safe_name(&np->kobj, pp->name);
150 pp->attr.attr.mode = secure ? S_IRUSR : S_IRUGO;
151 pp->attr.size = secure ? 0 : pp->length;
152 pp->attr.read = of_node_property_read;
153
154 rc = sysfs_create_bin_file(&np->kobj, &pp->attr);
155 WARN(rc, "error adding attribute %s to node %s\n", pp->name, np->full_name);
156 return rc;
157}
158
159int __of_attach_node_sysfs(struct device_node *np)
160{
161 const char *name;
162 struct property *pp;
163 int rc;
164
165 if (!IS_ENABLED(CONFIG_SYSFS))
166 return 0;
167
168 if (!of_kset)
169 return 0;
170
171 np->kobj.kset = of_kset;
172 if (!np->parent) {
173 /* Nodes without parents are new top level trees */
174 rc = kobject_add(&np->kobj, NULL, "%s",
175 safe_name(&of_kset->kobj, "base"));
176 } else {
177 name = safe_name(&np->parent->kobj, kbasename(np->full_name));
178 if (!name || !name[0])
179 return -EINVAL;
180
181 rc = kobject_add(&np->kobj, &np->parent->kobj, "%s", name);
182 }
183 if (rc)
184 return rc;
185
186 for_each_property_of_node(np, pp)
187 __of_add_property_sysfs(np, pp);
188
189 return 0;
190}
191
192void __init of_core_init(void)
193{
194 struct device_node *np;
195
196 /* Create the kset, and register existing nodes */
197 mutex_lock(&of_mutex);
198 of_kset = kset_create_and_add("devicetree", NULL, firmware_kobj);
199 if (!of_kset) {
200 mutex_unlock(&of_mutex);
201 pr_err("devicetree: failed to register existing nodes\n");
202 return;
203 }
204 for_each_of_allnodes(np)
205 __of_attach_node_sysfs(np);
206 mutex_unlock(&of_mutex);
207
208 /* Symlink in /proc as required by userspace ABI */
209 if (of_root)
210 proc_symlink("device-tree", NULL, "/sys/firmware/devicetree/base");
211}
212
213static struct property *__of_find_property(const struct device_node *np,
214 const char *name, int *lenp)
215{
216 struct property *pp;
217
218 if (!np)
219 return NULL;
220
221 for (pp = np->properties; pp; pp = pp->next) {
222 if (of_prop_cmp(pp->name, name) == 0) {
223 if (lenp)
224 *lenp = pp->length;
225 break;
226 }
227 }
228
229 return pp;
230}
231
232struct property *of_find_property(const struct device_node *np,
233 const char *name,
234 int *lenp)
235{
236 struct property *pp;
237 unsigned long flags;
238
239 raw_spin_lock_irqsave(&devtree_lock, flags);
240 pp = __of_find_property(np, name, lenp);
241 raw_spin_unlock_irqrestore(&devtree_lock, flags);
242
243 return pp;
244}
245EXPORT_SYMBOL(of_find_property);
246
247struct device_node *__of_find_all_nodes(struct device_node *prev)
248{
249 struct device_node *np;
250 if (!prev) {
251 np = of_root;
252 } else if (prev->child) {
253 np = prev->child;
254 } else {
255 /* Walk back up looking for a sibling, or the end of the structure */
256 np = prev;
257 while (np->parent && !np->sibling)
258 np = np->parent;
259 np = np->sibling; /* Might be null at the end of the tree */
260 }
261 return np;
262}
263
264/**
265 * of_find_all_nodes - Get next node in global list
266 * @prev: Previous node or NULL to start iteration
267 * of_node_put() will be called on it
268 *
269 * Returns a node pointer with refcount incremented, use
270 * of_node_put() on it when done.
271 */
272struct device_node *of_find_all_nodes(struct device_node *prev)
273{
274 struct device_node *np;
275 unsigned long flags;
276
277 raw_spin_lock_irqsave(&devtree_lock, flags);
278 np = __of_find_all_nodes(prev);
279 of_node_get(np);
280 of_node_put(prev);
281 raw_spin_unlock_irqrestore(&devtree_lock, flags);
282 return np;
283}
284EXPORT_SYMBOL(of_find_all_nodes);
285
286/*
287 * Find a property with a given name for a given node
288 * and return the value.
289 */
290const void *__of_get_property(const struct device_node *np,
291 const char *name, int *lenp)
292{
293 struct property *pp = __of_find_property(np, name, lenp);
294
295 return pp ? pp->value : NULL;
296}
297
298/*
299 * Find a property with a given name for a given node
300 * and return the value.
301 */
302const void *of_get_property(const struct device_node *np, const char *name,
303 int *lenp)
304{
305 struct property *pp = of_find_property(np, name, lenp);
306
307 return pp ? pp->value : NULL;
308}
309EXPORT_SYMBOL(of_get_property);
310
311/*
312 * arch_match_cpu_phys_id - Match the given logical CPU and physical id
313 *
314 * @cpu: logical cpu index of a core/thread
315 * @phys_id: physical identifier of a core/thread
316 *
317 * CPU logical to physical index mapping is architecture specific.
318 * However this __weak function provides a default match of physical
319 * id to logical cpu index. phys_id provided here is usually values read
320 * from the device tree which must match the hardware internal registers.
321 *
322 * Returns true if the physical identifier and the logical cpu index
323 * correspond to the same core/thread, false otherwise.
324 */
325bool __weak arch_match_cpu_phys_id(int cpu, u64 phys_id)
326{
327 return (u32)phys_id == cpu;
328}
329
330/**
331 * Checks if the given "prop_name" property holds the physical id of the
332 * core/thread corresponding to the logical cpu 'cpu'. If 'thread' is not
333 * NULL, local thread number within the core is returned in it.
334 */
335static bool __of_find_n_match_cpu_property(struct device_node *cpun,
336 const char *prop_name, int cpu, unsigned int *thread)
337{
338 const __be32 *cell;
339 int ac, prop_len, tid;
340 u64 hwid;
341
342 ac = of_n_addr_cells(cpun);
343 cell = of_get_property(cpun, prop_name, &prop_len);
344 if (!cell || !ac)
345 return false;
346 prop_len /= sizeof(*cell) * ac;
347 for (tid = 0; tid < prop_len; tid++) {
348 hwid = of_read_number(cell, ac);
349 if (arch_match_cpu_phys_id(cpu, hwid)) {
350 if (thread)
351 *thread = tid;
352 return true;
353 }
354 cell += ac;
355 }
356 return false;
357}
358
359/*
360 * arch_find_n_match_cpu_physical_id - See if the given device node is
361 * for the cpu corresponding to logical cpu 'cpu'. Return true if so,
362 * else false. If 'thread' is non-NULL, the local thread number within the
363 * core is returned in it.
364 */
365bool __weak arch_find_n_match_cpu_physical_id(struct device_node *cpun,
366 int cpu, unsigned int *thread)
367{
368 /* Check for non-standard "ibm,ppc-interrupt-server#s" property
369 * for thread ids on PowerPC. If it doesn't exist fallback to
370 * standard "reg" property.
371 */
372 if (IS_ENABLED(CONFIG_PPC) &&
373 __of_find_n_match_cpu_property(cpun,
374 "ibm,ppc-interrupt-server#s",
375 cpu, thread))
376 return true;
377
378 return __of_find_n_match_cpu_property(cpun, "reg", cpu, thread);
379}
380
381/**
382 * of_get_cpu_node - Get device node associated with the given logical CPU
383 *
384 * @cpu: CPU number(logical index) for which device node is required
385 * @thread: if not NULL, local thread number within the physical core is
386 * returned
387 *
388 * The main purpose of this function is to retrieve the device node for the
389 * given logical CPU index. It should be used to initialize the of_node in
390 * cpu device. Once of_node in cpu device is populated, all the further
391 * references can use that instead.
392 *
393 * CPU logical to physical index mapping is architecture specific and is built
394 * before booting secondary cores. This function uses arch_match_cpu_phys_id
395 * which can be overridden by architecture specific implementation.
396 *
397 * Returns a node pointer for the logical cpu if found, else NULL.
398 */
399struct device_node *of_get_cpu_node(int cpu, unsigned int *thread)
400{
401 struct device_node *cpun;
402
403 for_each_node_by_type(cpun, "cpu") {
404 if (arch_find_n_match_cpu_physical_id(cpun, cpu, thread))
405 return cpun;
406 }
407 return NULL;
408}
409EXPORT_SYMBOL(of_get_cpu_node);
410
411/**
412 * __of_device_is_compatible() - Check if the node matches given constraints
413 * @device: pointer to node
414 * @compat: required compatible string, NULL or "" for any match
415 * @type: required device_type value, NULL or "" for any match
416 * @name: required node name, NULL or "" for any match
417 *
418 * Checks if the given @compat, @type and @name strings match the
419 * properties of the given @device. A constraints can be skipped by
420 * passing NULL or an empty string as the constraint.
421 *
422 * Returns 0 for no match, and a positive integer on match. The return
423 * value is a relative score with larger values indicating better
424 * matches. The score is weighted for the most specific compatible value
425 * to get the highest score. Matching type is next, followed by matching
426 * name. Practically speaking, this results in the following priority
427 * order for matches:
428 *
429 * 1. specific compatible && type && name
430 * 2. specific compatible && type
431 * 3. specific compatible && name
432 * 4. specific compatible
433 * 5. general compatible && type && name
434 * 6. general compatible && type
435 * 7. general compatible && name
436 * 8. general compatible
437 * 9. type && name
438 * 10. type
439 * 11. name
440 */
441static int __of_device_is_compatible(const struct device_node *device,
442 const char *compat, const char *type, const char *name)
443{
444 struct property *prop;
445 const char *cp;
446 int index = 0, score = 0;
447
448 /* Compatible match has highest priority */
449 if (compat && compat[0]) {
450 prop = __of_find_property(device, "compatible", NULL);
451 for (cp = of_prop_next_string(prop, NULL); cp;
452 cp = of_prop_next_string(prop, cp), index++) {
453 if (of_compat_cmp(cp, compat, strlen(compat)) == 0) {
454 score = INT_MAX/2 - (index << 2);
455 break;
456 }
457 }
458 if (!score)
459 return 0;
460 }
461
462 /* Matching type is better than matching name */
463 if (type && type[0]) {
464 if (!device->type || of_node_cmp(type, device->type))
465 return 0;
466 score += 2;
467 }
468
469 /* Matching name is a bit better than not */
470 if (name && name[0]) {
471 if (!device->name || of_node_cmp(name, device->name))
472 return 0;
473 score++;
474 }
475
476 return score;
477}
478
479/** Checks if the given "compat" string matches one of the strings in
480 * the device's "compatible" property
481 */
482int of_device_is_compatible(const struct device_node *device,
483 const char *compat)
484{
485 unsigned long flags;
486 int res;
487
488 raw_spin_lock_irqsave(&devtree_lock, flags);
489 res = __of_device_is_compatible(device, compat, NULL, NULL);
490 raw_spin_unlock_irqrestore(&devtree_lock, flags);
491 return res;
492}
493EXPORT_SYMBOL(of_device_is_compatible);
494
495/**
496 * of_machine_is_compatible - Test root of device tree for a given compatible value
497 * @compat: compatible string to look for in root node's compatible property.
498 *
499 * Returns a positive integer if the root node has the given value in its
500 * compatible property.
501 */
502int of_machine_is_compatible(const char *compat)
503{
504 struct device_node *root;
505 int rc = 0;
506
507 root = of_find_node_by_path("/");
508 if (root) {
509 rc = of_device_is_compatible(root, compat);
510 of_node_put(root);
511 }
512 return rc;
513}
514EXPORT_SYMBOL(of_machine_is_compatible);
515
516/**
517 * __of_device_is_available - check if a device is available for use
518 *
519 * @device: Node to check for availability, with locks already held
520 *
521 * Returns true if the status property is absent or set to "okay" or "ok",
522 * false otherwise
523 */
524static bool __of_device_is_available(const struct device_node *device)
525{
526 const char *status;
527 int statlen;
528
529 if (!device)
530 return false;
531
532 status = __of_get_property(device, "status", &statlen);
533 if (status == NULL)
534 return true;
535
536 if (statlen > 0) {
537 if (!strcmp(status, "okay") || !strcmp(status, "ok"))
538 return true;
539 }
540
541 return false;
542}
543
544/**
545 * of_device_is_available - check if a device is available for use
546 *
547 * @device: Node to check for availability
548 *
549 * Returns true if the status property is absent or set to "okay" or "ok",
550 * false otherwise
551 */
552bool of_device_is_available(const struct device_node *device)
553{
554 unsigned long flags;
555 bool res;
556
557 raw_spin_lock_irqsave(&devtree_lock, flags);
558 res = __of_device_is_available(device);
559 raw_spin_unlock_irqrestore(&devtree_lock, flags);
560 return res;
561
562}
563EXPORT_SYMBOL(of_device_is_available);
564
565/**
566 * of_device_is_big_endian - check if a device has BE registers
567 *
568 * @device: Node to check for endianness
569 *
570 * Returns true if the device has a "big-endian" property, or if the kernel
571 * was compiled for BE *and* the device has a "native-endian" property.
572 * Returns false otherwise.
573 *
574 * Callers would nominally use ioread32be/iowrite32be if
575 * of_device_is_big_endian() == true, or readl/writel otherwise.
576 */
577bool of_device_is_big_endian(const struct device_node *device)
578{
579 if (of_property_read_bool(device, "big-endian"))
580 return true;
581 if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) &&
582 of_property_read_bool(device, "native-endian"))
583 return true;
584 return false;
585}
586EXPORT_SYMBOL(of_device_is_big_endian);
587
588/**
589 * of_get_parent - Get a node's parent if any
590 * @node: Node to get parent
591 *
592 * Returns a node pointer with refcount incremented, use
593 * of_node_put() on it when done.
594 */
595struct device_node *of_get_parent(const struct device_node *node)
596{
597 struct device_node *np;
598 unsigned long flags;
599
600 if (!node)
601 return NULL;
602
603 raw_spin_lock_irqsave(&devtree_lock, flags);
604 np = of_node_get(node->parent);
605 raw_spin_unlock_irqrestore(&devtree_lock, flags);
606 return np;
607}
608EXPORT_SYMBOL(of_get_parent);
609
610/**
611 * of_get_next_parent - Iterate to a node's parent
612 * @node: Node to get parent of
613 *
614 * This is like of_get_parent() except that it drops the
615 * refcount on the passed node, making it suitable for iterating
616 * through a node's parents.
617 *
618 * Returns a node pointer with refcount incremented, use
619 * of_node_put() on it when done.
620 */
621struct device_node *of_get_next_parent(struct device_node *node)
622{
623 struct device_node *parent;
624 unsigned long flags;
625
626 if (!node)
627 return NULL;
628
629 raw_spin_lock_irqsave(&devtree_lock, flags);
630 parent = of_node_get(node->parent);
631 of_node_put(node);
632 raw_spin_unlock_irqrestore(&devtree_lock, flags);
633 return parent;
634}
635EXPORT_SYMBOL(of_get_next_parent);
636
637static struct device_node *__of_get_next_child(const struct device_node *node,
638 struct device_node *prev)
639{
640 struct device_node *next;
641
642 if (!node)
643 return NULL;
644
645 next = prev ? prev->sibling : node->child;
646 for (; next; next = next->sibling)
647 if (of_node_get(next))
648 break;
649 of_node_put(prev);
650 return next;
651}
652#define __for_each_child_of_node(parent, child) \
653 for (child = __of_get_next_child(parent, NULL); child != NULL; \
654 child = __of_get_next_child(parent, child))
655
656/**
657 * of_get_next_child - Iterate a node childs
658 * @node: parent node
659 * @prev: previous child of the parent node, or NULL to get first
660 *
661 * Returns a node pointer with refcount incremented, use of_node_put() on
662 * it when done. Returns NULL when prev is the last child. Decrements the
663 * refcount of prev.
664 */
665struct device_node *of_get_next_child(const struct device_node *node,
666 struct device_node *prev)
667{
668 struct device_node *next;
669 unsigned long flags;
670
671 raw_spin_lock_irqsave(&devtree_lock, flags);
672 next = __of_get_next_child(node, prev);
673 raw_spin_unlock_irqrestore(&devtree_lock, flags);
674 return next;
675}
676EXPORT_SYMBOL(of_get_next_child);
677
678/**
679 * of_get_next_available_child - Find the next available child node
680 * @node: parent node
681 * @prev: previous child of the parent node, or NULL to get first
682 *
683 * This function is like of_get_next_child(), except that it
684 * automatically skips any disabled nodes (i.e. status = "disabled").
685 */
686struct device_node *of_get_next_available_child(const struct device_node *node,
687 struct device_node *prev)
688{
689 struct device_node *next;
690 unsigned long flags;
691
692 if (!node)
693 return NULL;
694
695 raw_spin_lock_irqsave(&devtree_lock, flags);
696 next = prev ? prev->sibling : node->child;
697 for (; next; next = next->sibling) {
698 if (!__of_device_is_available(next))
699 continue;
700 if (of_node_get(next))
701 break;
702 }
703 of_node_put(prev);
704 raw_spin_unlock_irqrestore(&devtree_lock, flags);
705 return next;
706}
707EXPORT_SYMBOL(of_get_next_available_child);
708
709/**
710 * of_get_child_by_name - Find the child node by name for a given parent
711 * @node: parent node
712 * @name: child name to look for.
713 *
714 * This function looks for child node for given matching name
715 *
716 * Returns a node pointer if found, with refcount incremented, use
717 * of_node_put() on it when done.
718 * Returns NULL if node is not found.
719 */
720struct device_node *of_get_child_by_name(const struct device_node *node,
721 const char *name)
722{
723 struct device_node *child;
724
725 for_each_child_of_node(node, child)
726 if (child->name && (of_node_cmp(child->name, name) == 0))
727 break;
728 return child;
729}
730EXPORT_SYMBOL(of_get_child_by_name);
731
732static struct device_node *__of_find_node_by_path(struct device_node *parent,
733 const char *path)
734{
735 struct device_node *child;
736 int len;
737
738 len = strcspn(path, "/:");
739 if (!len)
740 return NULL;
741
742 __for_each_child_of_node(parent, child) {
743 const char *name = strrchr(child->full_name, '/');
744 if (WARN(!name, "malformed device_node %s\n", child->full_name))
745 continue;
746 name++;
747 if (strncmp(path, name, len) == 0 && (strlen(name) == len))
748 return child;
749 }
750 return NULL;
751}
752
753/**
754 * of_find_node_opts_by_path - Find a node matching a full OF path
755 * @path: Either the full path to match, or if the path does not
756 * start with '/', the name of a property of the /aliases
757 * node (an alias). In the case of an alias, the node
758 * matching the alias' value will be returned.
759 * @opts: Address of a pointer into which to store the start of
760 * an options string appended to the end of the path with
761 * a ':' separator.
762 *
763 * Valid paths:
764 * /foo/bar Full path
765 * foo Valid alias
766 * foo/bar Valid alias + relative path
767 *
768 * Returns a node pointer with refcount incremented, use
769 * of_node_put() on it when done.
770 */
771struct device_node *of_find_node_opts_by_path(const char *path, const char **opts)
772{
773 struct device_node *np = NULL;
774 struct property *pp;
775 unsigned long flags;
776 const char *separator = strchr(path, ':');
777
778 if (opts)
779 *opts = separator ? separator + 1 : NULL;
780
781 if (strcmp(path, "/") == 0)
782 return of_node_get(of_root);
783
784 /* The path could begin with an alias */
785 if (*path != '/') {
786 int len;
787 const char *p = separator;
788
789 if (!p)
790 p = strchrnul(path, '/');
791 len = p - path;
792
793 /* of_aliases must not be NULL */
794 if (!of_aliases)
795 return NULL;
796
797 for_each_property_of_node(of_aliases, pp) {
798 if (strlen(pp->name) == len && !strncmp(pp->name, path, len)) {
799 np = of_find_node_by_path(pp->value);
800 break;
801 }
802 }
803 if (!np)
804 return NULL;
805 path = p;
806 }
807
808 /* Step down the tree matching path components */
809 raw_spin_lock_irqsave(&devtree_lock, flags);
810 if (!np)
811 np = of_node_get(of_root);
812 while (np && *path == '/') {
813 path++; /* Increment past '/' delimiter */
814 np = __of_find_node_by_path(np, path);
815 path = strchrnul(path, '/');
816 if (separator && separator < path)
817 break;
818 }
819 raw_spin_unlock_irqrestore(&devtree_lock, flags);
820 return np;
821}
822EXPORT_SYMBOL(of_find_node_opts_by_path);
823
824/**
825 * of_find_node_by_name - Find a node by its "name" property
826 * @from: The node to start searching from or NULL, the node
827 * you pass will not be searched, only the next one
828 * will; typically, you pass what the previous call
829 * returned. of_node_put() will be called on it
830 * @name: The name string to match against
831 *
832 * Returns a node pointer with refcount incremented, use
833 * of_node_put() on it when done.
834 */
835struct device_node *of_find_node_by_name(struct device_node *from,
836 const char *name)
837{
838 struct device_node *np;
839 unsigned long flags;
840
841 raw_spin_lock_irqsave(&devtree_lock, flags);
842 for_each_of_allnodes_from(from, np)
843 if (np->name && (of_node_cmp(np->name, name) == 0)
844 && of_node_get(np))
845 break;
846 of_node_put(from);
847 raw_spin_unlock_irqrestore(&devtree_lock, flags);
848 return np;
849}
850EXPORT_SYMBOL(of_find_node_by_name);
851
852/**
853 * of_find_node_by_type - Find a node by its "device_type" property
854 * @from: The node to start searching from, or NULL to start searching
855 * the entire device tree. The node you pass will not be
856 * searched, only the next one will; typically, you pass
857 * what the previous call returned. of_node_put() will be
858 * called on from for you.
859 * @type: The type string to match against
860 *
861 * Returns a node pointer with refcount incremented, use
862 * of_node_put() on it when done.
863 */
864struct device_node *of_find_node_by_type(struct device_node *from,
865 const char *type)
866{
867 struct device_node *np;
868 unsigned long flags;
869
870 raw_spin_lock_irqsave(&devtree_lock, flags);
871 for_each_of_allnodes_from(from, np)
872 if (np->type && (of_node_cmp(np->type, type) == 0)
873 && of_node_get(np))
874 break;
875 of_node_put(from);
876 raw_spin_unlock_irqrestore(&devtree_lock, flags);
877 return np;
878}
879EXPORT_SYMBOL(of_find_node_by_type);
880
881/**
882 * of_find_compatible_node - Find a node based on type and one of the
883 * tokens in its "compatible" property
884 * @from: The node to start searching from or NULL, the node
885 * you pass will not be searched, only the next one
886 * will; typically, you pass what the previous call
887 * returned. of_node_put() will be called on it
888 * @type: The type string to match "device_type" or NULL to ignore
889 * @compatible: The string to match to one of the tokens in the device
890 * "compatible" list.
891 *
892 * Returns a node pointer with refcount incremented, use
893 * of_node_put() on it when done.
894 */
895struct device_node *of_find_compatible_node(struct device_node *from,
896 const char *type, const char *compatible)
897{
898 struct device_node *np;
899 unsigned long flags;
900
901 raw_spin_lock_irqsave(&devtree_lock, flags);
902 for_each_of_allnodes_from(from, np)
903 if (__of_device_is_compatible(np, compatible, type, NULL) &&
904 of_node_get(np))
905 break;
906 of_node_put(from);
907 raw_spin_unlock_irqrestore(&devtree_lock, flags);
908 return np;
909}
910EXPORT_SYMBOL(of_find_compatible_node);
911
912/**
913 * of_find_node_with_property - Find a node which has a property with
914 * the given name.
915 * @from: The node to start searching from or NULL, the node
916 * you pass will not be searched, only the next one
917 * will; typically, you pass what the previous call
918 * returned. of_node_put() will be called on it
919 * @prop_name: The name of the property to look for.
920 *
921 * Returns a node pointer with refcount incremented, use
922 * of_node_put() on it when done.
923 */
924struct device_node *of_find_node_with_property(struct device_node *from,
925 const char *prop_name)
926{
927 struct device_node *np;
928 struct property *pp;
929 unsigned long flags;
930
931 raw_spin_lock_irqsave(&devtree_lock, flags);
932 for_each_of_allnodes_from(from, np) {
933 for (pp = np->properties; pp; pp = pp->next) {
934 if (of_prop_cmp(pp->name, prop_name) == 0) {
935 of_node_get(np);
936 goto out;
937 }
938 }
939 }
940out:
941 of_node_put(from);
942 raw_spin_unlock_irqrestore(&devtree_lock, flags);
943 return np;
944}
945EXPORT_SYMBOL(of_find_node_with_property);
946
947static
948const struct of_device_id *__of_match_node(const struct of_device_id *matches,
949 const struct device_node *node)
950{
951 const struct of_device_id *best_match = NULL;
952 int score, best_score = 0;
953
954 if (!matches)
955 return NULL;
956
957 for (; matches->name[0] || matches->type[0] || matches->compatible[0]; matches++) {
958 score = __of_device_is_compatible(node, matches->compatible,
959 matches->type, matches->name);
960 if (score > best_score) {
961 best_match = matches;
962 best_score = score;
963 }
964 }
965
966 return best_match;
967}
968
969/**
970 * of_match_node - Tell if a device_node has a matching of_match structure
971 * @matches: array of of device match structures to search in
972 * @node: the of device structure to match against
973 *
974 * Low level utility function used by device matching.
975 */
976const struct of_device_id *of_match_node(const struct of_device_id *matches,
977 const struct device_node *node)
978{
979 const struct of_device_id *match;
980 unsigned long flags;
981
982 raw_spin_lock_irqsave(&devtree_lock, flags);
983 match = __of_match_node(matches, node);
984 raw_spin_unlock_irqrestore(&devtree_lock, flags);
985 return match;
986}
987EXPORT_SYMBOL(of_match_node);
988
989/**
990 * of_find_matching_node_and_match - Find a node based on an of_device_id
991 * match table.
992 * @from: The node to start searching from or NULL, the node
993 * you pass will not be searched, only the next one
994 * will; typically, you pass what the previous call
995 * returned. of_node_put() will be called on it
996 * @matches: array of of device match structures to search in
997 * @match Updated to point at the matches entry which matched
998 *
999 * Returns a node pointer with refcount incremented, use
1000 * of_node_put() on it when done.
1001 */
1002struct device_node *of_find_matching_node_and_match(struct device_node *from,
1003 const struct of_device_id *matches,
1004 const struct of_device_id **match)
1005{
1006 struct device_node *np;
1007 const struct of_device_id *m;
1008 unsigned long flags;
1009
1010 if (match)
1011 *match = NULL;
1012
1013 raw_spin_lock_irqsave(&devtree_lock, flags);
1014 for_each_of_allnodes_from(from, np) {
1015 m = __of_match_node(matches, np);
1016 if (m && of_node_get(np)) {
1017 if (match)
1018 *match = m;
1019 break;
1020 }
1021 }
1022 of_node_put(from);
1023 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1024 return np;
1025}
1026EXPORT_SYMBOL(of_find_matching_node_and_match);
1027
1028/**
1029 * of_modalias_node - Lookup appropriate modalias for a device node
1030 * @node: pointer to a device tree node
1031 * @modalias: Pointer to buffer that modalias value will be copied into
1032 * @len: Length of modalias value
1033 *
1034 * Based on the value of the compatible property, this routine will attempt
1035 * to choose an appropriate modalias value for a particular device tree node.
1036 * It does this by stripping the manufacturer prefix (as delimited by a ',')
1037 * from the first entry in the compatible list property.
1038 *
1039 * This routine returns 0 on success, <0 on failure.
1040 */
1041int of_modalias_node(struct device_node *node, char *modalias, 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 strlcpy(modalias, p ? p + 1 : compatible, len);
1051 return 0;
1052}
1053EXPORT_SYMBOL_GPL(of_modalias_node);
1054
1055/**
1056 * of_find_node_by_phandle - Find a node given a phandle
1057 * @handle: phandle of the node to find
1058 *
1059 * Returns 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;
1065 unsigned long flags;
1066
1067 if (!handle)
1068 return NULL;
1069
1070 raw_spin_lock_irqsave(&devtree_lock, flags);
1071 for_each_of_allnodes(np)
1072 if (np->phandle == handle)
1073 break;
1074 of_node_get(np);
1075 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1076 return np;
1077}
1078EXPORT_SYMBOL(of_find_node_by_phandle);
1079
1080/**
1081 * of_property_count_elems_of_size - Count the number of elements in a property
1082 *
1083 * @np: device node from which the property value is to be read.
1084 * @propname: name of the property to be searched.
1085 * @elem_size: size of the individual element
1086 *
1087 * Search for a property in a device node and count the number of elements of
1088 * size elem_size in it. Returns number of elements on sucess, -EINVAL if the
1089 * property does not exist or its length does not match a multiple of elem_size
1090 * and -ENODATA if the property does not have a value.
1091 */
1092int of_property_count_elems_of_size(const struct device_node *np,
1093 const char *propname, int elem_size)
1094{
1095 struct property *prop = of_find_property(np, propname, NULL);
1096
1097 if (!prop)
1098 return -EINVAL;
1099 if (!prop->value)
1100 return -ENODATA;
1101
1102 if (prop->length % elem_size != 0) {
1103 pr_err("size of %s in node %s is not a multiple of %d\n",
1104 propname, np->full_name, elem_size);
1105 return -EINVAL;
1106 }
1107
1108 return prop->length / elem_size;
1109}
1110EXPORT_SYMBOL_GPL(of_property_count_elems_of_size);
1111
1112/**
1113 * of_find_property_value_of_size
1114 *
1115 * @np: device node from which the property value is to be read.
1116 * @propname: name of the property to be searched.
1117 * @len: requested length of property value
1118 *
1119 * Search for a property in a device node and valid the requested size.
1120 * Returns the property value on success, -EINVAL if the property does not
1121 * exist, -ENODATA if property does not have a value, and -EOVERFLOW if the
1122 * property data isn't large enough.
1123 *
1124 */
1125static void *of_find_property_value_of_size(const struct device_node *np,
1126 const char *propname, u32 len)
1127{
1128 struct property *prop = of_find_property(np, propname, NULL);
1129
1130 if (!prop)
1131 return ERR_PTR(-EINVAL);
1132 if (!prop->value)
1133 return ERR_PTR(-ENODATA);
1134 if (len > prop->length)
1135 return ERR_PTR(-EOVERFLOW);
1136
1137 return prop->value;
1138}
1139
1140/**
1141 * of_property_read_u32_index - Find and read a u32 from a multi-value property.
1142 *
1143 * @np: device node from which the property value is to be read.
1144 * @propname: name of the property to be searched.
1145 * @index: index of the u32 in the list of values
1146 * @out_value: pointer to return value, modified only if no error.
1147 *
1148 * Search for a property in a device node and read nth 32-bit value from
1149 * it. Returns 0 on success, -EINVAL if the property does not exist,
1150 * -ENODATA if property does not have a value, and -EOVERFLOW if the
1151 * property data isn't large enough.
1152 *
1153 * The out_value is modified only if a valid u32 value can be decoded.
1154 */
1155int of_property_read_u32_index(const struct device_node *np,
1156 const char *propname,
1157 u32 index, u32 *out_value)
1158{
1159 const u32 *val = of_find_property_value_of_size(np, propname,
1160 ((index + 1) * sizeof(*out_value)));
1161
1162 if (IS_ERR(val))
1163 return PTR_ERR(val);
1164
1165 *out_value = be32_to_cpup(((__be32 *)val) + index);
1166 return 0;
1167}
1168EXPORT_SYMBOL_GPL(of_property_read_u32_index);
1169
1170/**
1171 * of_property_read_u8_array - Find and read an array of u8 from a property.
1172 *
1173 * @np: device node from which the property value is to be read.
1174 * @propname: name of the property to be searched.
1175 * @out_values: pointer to return value, modified only if return value is 0.
1176 * @sz: number of array elements to read
1177 *
1178 * Search for a property in a device node and read 8-bit value(s) from
1179 * it. Returns 0 on success, -EINVAL if the property does not exist,
1180 * -ENODATA if property does not have a value, and -EOVERFLOW if the
1181 * property data isn't large enough.
1182 *
1183 * dts entry of array should be like:
1184 * property = /bits/ 8 <0x50 0x60 0x70>;
1185 *
1186 * The out_values is modified only if a valid u8 value can be decoded.
1187 */
1188int of_property_read_u8_array(const struct device_node *np,
1189 const char *propname, u8 *out_values, size_t sz)
1190{
1191 const u8 *val = of_find_property_value_of_size(np, propname,
1192 (sz * sizeof(*out_values)));
1193
1194 if (IS_ERR(val))
1195 return PTR_ERR(val);
1196
1197 while (sz--)
1198 *out_values++ = *val++;
1199 return 0;
1200}
1201EXPORT_SYMBOL_GPL(of_property_read_u8_array);
1202
1203/**
1204 * of_property_read_u16_array - Find and read an array of u16 from a property.
1205 *
1206 * @np: device node from which the property value is to be read.
1207 * @propname: name of the property to be searched.
1208 * @out_values: pointer to return value, modified only if return value is 0.
1209 * @sz: number of array elements to read
1210 *
1211 * Search for a property in a device node and read 16-bit value(s) from
1212 * it. Returns 0 on success, -EINVAL if the property does not exist,
1213 * -ENODATA if property does not have a value, and -EOVERFLOW if the
1214 * property data isn't large enough.
1215 *
1216 * dts entry of array should be like:
1217 * property = /bits/ 16 <0x5000 0x6000 0x7000>;
1218 *
1219 * The out_values is modified only if a valid u16 value can be decoded.
1220 */
1221int of_property_read_u16_array(const struct device_node *np,
1222 const char *propname, u16 *out_values, size_t sz)
1223{
1224 const __be16 *val = of_find_property_value_of_size(np, propname,
1225 (sz * sizeof(*out_values)));
1226
1227 if (IS_ERR(val))
1228 return PTR_ERR(val);
1229
1230 while (sz--)
1231 *out_values++ = be16_to_cpup(val++);
1232 return 0;
1233}
1234EXPORT_SYMBOL_GPL(of_property_read_u16_array);
1235
1236/**
1237 * of_property_read_u32_array - Find and read an array of 32 bit integers
1238 * from a property.
1239 *
1240 * @np: device node from which the property value is to be read.
1241 * @propname: name of the property to be searched.
1242 * @out_values: pointer to return value, modified only if return value is 0.
1243 * @sz: number of array elements to read
1244 *
1245 * Search for a property in a device node and read 32-bit value(s) from
1246 * it. Returns 0 on success, -EINVAL if the property does not exist,
1247 * -ENODATA if property does not have a value, and -EOVERFLOW if the
1248 * property data isn't large enough.
1249 *
1250 * The out_values is modified only if a valid u32 value can be decoded.
1251 */
1252int of_property_read_u32_array(const struct device_node *np,
1253 const char *propname, u32 *out_values,
1254 size_t sz)
1255{
1256 const __be32 *val = of_find_property_value_of_size(np, propname,
1257 (sz * sizeof(*out_values)));
1258
1259 if (IS_ERR(val))
1260 return PTR_ERR(val);
1261
1262 while (sz--)
1263 *out_values++ = be32_to_cpup(val++);
1264 return 0;
1265}
1266EXPORT_SYMBOL_GPL(of_property_read_u32_array);
1267
1268/**
1269 * of_property_read_u64 - Find and read a 64 bit integer from a property
1270 * @np: device node from which the property value is to be read.
1271 * @propname: name of the property to be searched.
1272 * @out_value: pointer to return value, modified only if return value is 0.
1273 *
1274 * Search for a property in a device node and read a 64-bit value from
1275 * it. Returns 0 on success, -EINVAL if the property does not exist,
1276 * -ENODATA if property does not have a value, and -EOVERFLOW if the
1277 * property data isn't large enough.
1278 *
1279 * The out_value is modified only if a valid u64 value can be decoded.
1280 */
1281int of_property_read_u64(const struct device_node *np, const char *propname,
1282 u64 *out_value)
1283{
1284 const __be32 *val = of_find_property_value_of_size(np, propname,
1285 sizeof(*out_value));
1286
1287 if (IS_ERR(val))
1288 return PTR_ERR(val);
1289
1290 *out_value = of_read_number(val, 2);
1291 return 0;
1292}
1293EXPORT_SYMBOL_GPL(of_property_read_u64);
1294
1295/**
1296 * of_property_read_u64_array - Find and read an array of 64 bit integers
1297 * from a property.
1298 *
1299 * @np: device node from which the property value is to be read.
1300 * @propname: name of the property to be searched.
1301 * @out_values: pointer to return value, modified only if return value is 0.
1302 * @sz: number of array elements to read
1303 *
1304 * Search for a property in a device node and read 64-bit value(s) from
1305 * it. Returns 0 on success, -EINVAL if the property does not exist,
1306 * -ENODATA if property does not have a value, and -EOVERFLOW if the
1307 * property data isn't large enough.
1308 *
1309 * The out_values is modified only if a valid u64 value can be decoded.
1310 */
1311int of_property_read_u64_array(const struct device_node *np,
1312 const char *propname, u64 *out_values,
1313 size_t sz)
1314{
1315 const __be32 *val = of_find_property_value_of_size(np, propname,
1316 (sz * sizeof(*out_values)));
1317
1318 if (IS_ERR(val))
1319 return PTR_ERR(val);
1320
1321 while (sz--) {
1322 *out_values++ = of_read_number(val, 2);
1323 val += 2;
1324 }
1325 return 0;
1326}
1327EXPORT_SYMBOL_GPL(of_property_read_u64_array);
1328
1329/**
1330 * of_property_read_string - Find and read a string from a property
1331 * @np: device node from which the property value is to be read.
1332 * @propname: name of the property to be searched.
1333 * @out_string: pointer to null terminated return string, modified only if
1334 * return value is 0.
1335 *
1336 * Search for a property in a device tree node and retrieve a null
1337 * terminated string value (pointer to data, not a copy). Returns 0 on
1338 * success, -EINVAL if the property does not exist, -ENODATA if property
1339 * does not have a value, and -EILSEQ if the string is not null-terminated
1340 * within the length of the property data.
1341 *
1342 * The out_string pointer is modified only if a valid string can be decoded.
1343 */
1344int of_property_read_string(const struct device_node *np, const char *propname,
1345 const char **out_string)
1346{
1347 const struct property *prop = of_find_property(np, propname, NULL);
1348 if (!prop)
1349 return -EINVAL;
1350 if (!prop->value)
1351 return -ENODATA;
1352 if (strnlen(prop->value, prop->length) >= prop->length)
1353 return -EILSEQ;
1354 *out_string = prop->value;
1355 return 0;
1356}
1357EXPORT_SYMBOL_GPL(of_property_read_string);
1358
1359/**
1360 * of_property_match_string() - Find string in a list and return index
1361 * @np: pointer to node containing string list property
1362 * @propname: string list property name
1363 * @string: pointer to string to search for in string list
1364 *
1365 * This function searches a string list property and returns the index
1366 * of a specific string value.
1367 */
1368int of_property_match_string(const struct device_node *np, const char *propname,
1369 const char *string)
1370{
1371 const struct property *prop = of_find_property(np, propname, NULL);
1372 size_t l;
1373 int i;
1374 const char *p, *end;
1375
1376 if (!prop)
1377 return -EINVAL;
1378 if (!prop->value)
1379 return -ENODATA;
1380
1381 p = prop->value;
1382 end = p + prop->length;
1383
1384 for (i = 0; p < end; i++, p += l) {
1385 l = strnlen(p, end - p) + 1;
1386 if (p + l > end)
1387 return -EILSEQ;
1388 pr_debug("comparing %s with %s\n", string, p);
1389 if (strcmp(string, p) == 0)
1390 return i; /* Found it; return index */
1391 }
1392 return -ENODATA;
1393}
1394EXPORT_SYMBOL_GPL(of_property_match_string);
1395
1396/**
1397 * of_property_read_string_helper() - Utility helper for parsing string properties
1398 * @np: device node from which the property value is to be read.
1399 * @propname: name of the property to be searched.
1400 * @out_strs: output array of string pointers.
1401 * @sz: number of array elements to read.
1402 * @skip: Number of strings to skip over at beginning of list.
1403 *
1404 * Don't call this function directly. It is a utility helper for the
1405 * of_property_read_string*() family of functions.
1406 */
1407int of_property_read_string_helper(const struct device_node *np,
1408 const char *propname, const char **out_strs,
1409 size_t sz, int skip)
1410{
1411 const struct property *prop = of_find_property(np, propname, NULL);
1412 int l = 0, i = 0;
1413 const char *p, *end;
1414
1415 if (!prop)
1416 return -EINVAL;
1417 if (!prop->value)
1418 return -ENODATA;
1419 p = prop->value;
1420 end = p + prop->length;
1421
1422 for (i = 0; p < end && (!out_strs || i < skip + sz); i++, p += l) {
1423 l = strnlen(p, end - p) + 1;
1424 if (p + l > end)
1425 return -EILSEQ;
1426 if (out_strs && i >= skip)
1427 *out_strs++ = p;
1428 }
1429 i -= skip;
1430 return i <= 0 ? -ENODATA : i;
1431}
1432EXPORT_SYMBOL_GPL(of_property_read_string_helper);
1433
1434void of_print_phandle_args(const char *msg, const struct of_phandle_args *args)
1435{
1436 int i;
1437 printk("%s %s", msg, of_node_full_name(args->np));
1438 for (i = 0; i < args->args_count; i++)
1439 printk(i ? ",%08x" : ":%08x", args->args[i]);
1440 printk("\n");
1441}
1442
1443static int __of_parse_phandle_with_args(const struct device_node *np,
1444 const char *list_name,
1445 const char *cells_name,
1446 int cell_count, int index,
1447 struct of_phandle_args *out_args)
1448{
1449 const __be32 *list, *list_end;
1450 int rc = 0, size, cur_index = 0;
1451 uint32_t count = 0;
1452 struct device_node *node = NULL;
1453 phandle phandle;
1454
1455 /* Retrieve the phandle list property */
1456 list = of_get_property(np, list_name, &size);
1457 if (!list)
1458 return -ENOENT;
1459 list_end = list + size / sizeof(*list);
1460
1461 /* Loop over the phandles until all the requested entry is found */
1462 while (list < list_end) {
1463 rc = -EINVAL;
1464 count = 0;
1465
1466 /*
1467 * If phandle is 0, then it is an empty entry with no
1468 * arguments. Skip forward to the next entry.
1469 */
1470 phandle = be32_to_cpup(list++);
1471 if (phandle) {
1472 /*
1473 * Find the provider node and parse the #*-cells
1474 * property to determine the argument length.
1475 *
1476 * This is not needed if the cell count is hard-coded
1477 * (i.e. cells_name not set, but cell_count is set),
1478 * except when we're going to return the found node
1479 * below.
1480 */
1481 if (cells_name || cur_index == index) {
1482 node = of_find_node_by_phandle(phandle);
1483 if (!node) {
1484 pr_err("%s: could not find phandle\n",
1485 np->full_name);
1486 goto err;
1487 }
1488 }
1489
1490 if (cells_name) {
1491 if (of_property_read_u32(node, cells_name,
1492 &count)) {
1493 pr_err("%s: could not get %s for %s\n",
1494 np->full_name, cells_name,
1495 node->full_name);
1496 goto err;
1497 }
1498 } else {
1499 count = cell_count;
1500 }
1501
1502 /*
1503 * Make sure that the arguments actually fit in the
1504 * remaining property data length
1505 */
1506 if (list + count > list_end) {
1507 pr_err("%s: arguments longer than property\n",
1508 np->full_name);
1509 goto err;
1510 }
1511 }
1512
1513 /*
1514 * All of the error cases above bail out of the loop, so at
1515 * this point, the parsing is successful. If the requested
1516 * index matches, then fill the out_args structure and return,
1517 * or return -ENOENT for an empty entry.
1518 */
1519 rc = -ENOENT;
1520 if (cur_index == index) {
1521 if (!phandle)
1522 goto err;
1523
1524 if (out_args) {
1525 int i;
1526 if (WARN_ON(count > MAX_PHANDLE_ARGS))
1527 count = MAX_PHANDLE_ARGS;
1528 out_args->np = node;
1529 out_args->args_count = count;
1530 for (i = 0; i < count; i++)
1531 out_args->args[i] = be32_to_cpup(list++);
1532 } else {
1533 of_node_put(node);
1534 }
1535
1536 /* Found it! return success */
1537 return 0;
1538 }
1539
1540 of_node_put(node);
1541 node = NULL;
1542 list += count;
1543 cur_index++;
1544 }
1545
1546 /*
1547 * Unlock node before returning result; will be one of:
1548 * -ENOENT : index is for empty phandle
1549 * -EINVAL : parsing error on data
1550 * [1..n] : Number of phandle (count mode; when index = -1)
1551 */
1552 rc = index < 0 ? cur_index : -ENOENT;
1553 err:
1554 if (node)
1555 of_node_put(node);
1556 return rc;
1557}
1558
1559/**
1560 * of_parse_phandle - Resolve a phandle property to a device_node pointer
1561 * @np: Pointer to device node holding phandle property
1562 * @phandle_name: Name of property holding a phandle value
1563 * @index: For properties holding a table of phandles, this is the index into
1564 * the table
1565 *
1566 * Returns the device_node pointer with refcount incremented. Use
1567 * of_node_put() on it when done.
1568 */
1569struct device_node *of_parse_phandle(const struct device_node *np,
1570 const char *phandle_name, int index)
1571{
1572 struct of_phandle_args args;
1573
1574 if (index < 0)
1575 return NULL;
1576
1577 if (__of_parse_phandle_with_args(np, phandle_name, NULL, 0,
1578 index, &args))
1579 return NULL;
1580
1581 return args.np;
1582}
1583EXPORT_SYMBOL(of_parse_phandle);
1584
1585/**
1586 * of_parse_phandle_with_args() - Find a node pointed by phandle in a list
1587 * @np: pointer to a device tree node containing a list
1588 * @list_name: property name that contains a list
1589 * @cells_name: property name that specifies phandles' arguments count
1590 * @index: index of a phandle to parse out
1591 * @out_args: optional pointer to output arguments structure (will be filled)
1592 *
1593 * This function is useful to parse lists of phandles and their arguments.
1594 * Returns 0 on success and fills out_args, on error returns appropriate
1595 * errno value.
1596 *
1597 * Caller is responsible to call of_node_put() on the returned out_args->np
1598 * pointer.
1599 *
1600 * Example:
1601 *
1602 * phandle1: node1 {
1603 * #list-cells = <2>;
1604 * }
1605 *
1606 * phandle2: node2 {
1607 * #list-cells = <1>;
1608 * }
1609 *
1610 * node3 {
1611 * list = <&phandle1 1 2 &phandle2 3>;
1612 * }
1613 *
1614 * To get a device_node of the `node2' node you may call this:
1615 * of_parse_phandle_with_args(node3, "list", "#list-cells", 1, &args);
1616 */
1617int of_parse_phandle_with_args(const struct device_node *np, const char *list_name,
1618 const char *cells_name, int index,
1619 struct of_phandle_args *out_args)
1620{
1621 if (index < 0)
1622 return -EINVAL;
1623 return __of_parse_phandle_with_args(np, list_name, cells_name, 0,
1624 index, out_args);
1625}
1626EXPORT_SYMBOL(of_parse_phandle_with_args);
1627
1628/**
1629 * of_parse_phandle_with_fixed_args() - Find a node pointed by phandle in a list
1630 * @np: pointer to a device tree node containing a list
1631 * @list_name: property name that contains a list
1632 * @cell_count: number of argument cells following the phandle
1633 * @index: index of a phandle to parse out
1634 * @out_args: optional pointer to output arguments structure (will be filled)
1635 *
1636 * This function is useful to parse lists of phandles and their arguments.
1637 * Returns 0 on success and fills out_args, on error returns appropriate
1638 * errno value.
1639 *
1640 * Caller is responsible to call of_node_put() on the returned out_args->np
1641 * pointer.
1642 *
1643 * Example:
1644 *
1645 * phandle1: node1 {
1646 * }
1647 *
1648 * phandle2: node2 {
1649 * }
1650 *
1651 * node3 {
1652 * list = <&phandle1 0 2 &phandle2 2 3>;
1653 * }
1654 *
1655 * To get a device_node of the `node2' node you may call this:
1656 * of_parse_phandle_with_fixed_args(node3, "list", 2, 1, &args);
1657 */
1658int of_parse_phandle_with_fixed_args(const struct device_node *np,
1659 const char *list_name, int cell_count,
1660 int index, struct of_phandle_args *out_args)
1661{
1662 if (index < 0)
1663 return -EINVAL;
1664 return __of_parse_phandle_with_args(np, list_name, NULL, cell_count,
1665 index, out_args);
1666}
1667EXPORT_SYMBOL(of_parse_phandle_with_fixed_args);
1668
1669/**
1670 * of_count_phandle_with_args() - Find the number of phandles references in a property
1671 * @np: pointer to a device tree node containing a list
1672 * @list_name: property name that contains a list
1673 * @cells_name: property name that specifies phandles' arguments count
1674 *
1675 * Returns the number of phandle + argument tuples within a property. It
1676 * is a typical pattern to encode a list of phandle and variable
1677 * arguments into a single property. The number of arguments is encoded
1678 * by a property in the phandle-target node. For example, a gpios
1679 * property would contain a list of GPIO specifies consisting of a
1680 * phandle and 1 or more arguments. The number of arguments are
1681 * determined by the #gpio-cells property in the node pointed to by the
1682 * phandle.
1683 */
1684int of_count_phandle_with_args(const struct device_node *np, const char *list_name,
1685 const char *cells_name)
1686{
1687 return __of_parse_phandle_with_args(np, list_name, cells_name, 0, -1,
1688 NULL);
1689}
1690EXPORT_SYMBOL(of_count_phandle_with_args);
1691
1692/**
1693 * __of_add_property - Add a property to a node without lock operations
1694 */
1695int __of_add_property(struct device_node *np, struct property *prop)
1696{
1697 struct property **next;
1698
1699 prop->next = NULL;
1700 next = &np->properties;
1701 while (*next) {
1702 if (strcmp(prop->name, (*next)->name) == 0)
1703 /* duplicate ! don't insert it */
1704 return -EEXIST;
1705
1706 next = &(*next)->next;
1707 }
1708 *next = prop;
1709
1710 return 0;
1711}
1712
1713/**
1714 * of_add_property - Add a property to a node
1715 */
1716int of_add_property(struct device_node *np, struct property *prop)
1717{
1718 unsigned long flags;
1719 int rc;
1720
1721 mutex_lock(&of_mutex);
1722
1723 raw_spin_lock_irqsave(&devtree_lock, flags);
1724 rc = __of_add_property(np, prop);
1725 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1726
1727 if (!rc)
1728 __of_add_property_sysfs(np, prop);
1729
1730 mutex_unlock(&of_mutex);
1731
1732 if (!rc)
1733 of_property_notify(OF_RECONFIG_ADD_PROPERTY, np, prop, NULL);
1734
1735 return rc;
1736}
1737
1738int __of_remove_property(struct device_node *np, struct property *prop)
1739{
1740 struct property **next;
1741
1742 for (next = &np->properties; *next; next = &(*next)->next) {
1743 if (*next == prop)
1744 break;
1745 }
1746 if (*next == NULL)
1747 return -ENODEV;
1748
1749 /* found the node */
1750 *next = prop->next;
1751 prop->next = np->deadprops;
1752 np->deadprops = prop;
1753
1754 return 0;
1755}
1756
1757void __of_remove_property_sysfs(struct device_node *np, struct property *prop)
1758{
1759 if (!IS_ENABLED(CONFIG_SYSFS))
1760 return;
1761
1762 /* at early boot, bail here and defer setup to of_init() */
1763 if (of_kset && of_node_is_attached(np))
1764 sysfs_remove_bin_file(&np->kobj, &prop->attr);
1765}
1766
1767/**
1768 * of_remove_property - Remove a property from a node.
1769 *
1770 * Note that we don't actually remove it, since we have given out
1771 * who-knows-how-many pointers to the data using get-property.
1772 * Instead we just move the property to the "dead properties"
1773 * list, so it won't be found any more.
1774 */
1775int of_remove_property(struct device_node *np, struct property *prop)
1776{
1777 unsigned long flags;
1778 int rc;
1779
1780 mutex_lock(&of_mutex);
1781
1782 raw_spin_lock_irqsave(&devtree_lock, flags);
1783 rc = __of_remove_property(np, prop);
1784 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1785
1786 if (!rc)
1787 __of_remove_property_sysfs(np, prop);
1788
1789 mutex_unlock(&of_mutex);
1790
1791 if (!rc)
1792 of_property_notify(OF_RECONFIG_REMOVE_PROPERTY, np, prop, NULL);
1793
1794 return rc;
1795}
1796
1797int __of_update_property(struct device_node *np, struct property *newprop,
1798 struct property **oldpropp)
1799{
1800 struct property **next, *oldprop;
1801
1802 for (next = &np->properties; *next; next = &(*next)->next) {
1803 if (of_prop_cmp((*next)->name, newprop->name) == 0)
1804 break;
1805 }
1806 *oldpropp = oldprop = *next;
1807
1808 if (oldprop) {
1809 /* replace the node */
1810 newprop->next = oldprop->next;
1811 *next = newprop;
1812 oldprop->next = np->deadprops;
1813 np->deadprops = oldprop;
1814 } else {
1815 /* new node */
1816 newprop->next = NULL;
1817 *next = newprop;
1818 }
1819
1820 return 0;
1821}
1822
1823void __of_update_property_sysfs(struct device_node *np, struct property *newprop,
1824 struct property *oldprop)
1825{
1826 if (!IS_ENABLED(CONFIG_SYSFS))
1827 return;
1828
1829 /* At early boot, bail out and defer setup to of_init() */
1830 if (!of_kset)
1831 return;
1832
1833 if (oldprop)
1834 sysfs_remove_bin_file(&np->kobj, &oldprop->attr);
1835 __of_add_property_sysfs(np, newprop);
1836}
1837
1838/*
1839 * of_update_property - Update a property in a node, if the property does
1840 * not exist, add it.
1841 *
1842 * Note that we don't actually remove it, since we have given out
1843 * who-knows-how-many pointers to the data using get-property.
1844 * Instead we just move the property to the "dead properties" list,
1845 * and add the new property to the property list
1846 */
1847int of_update_property(struct device_node *np, struct property *newprop)
1848{
1849 struct property *oldprop;
1850 unsigned long flags;
1851 int rc;
1852
1853 if (!newprop->name)
1854 return -EINVAL;
1855
1856 mutex_lock(&of_mutex);
1857
1858 raw_spin_lock_irqsave(&devtree_lock, flags);
1859 rc = __of_update_property(np, newprop, &oldprop);
1860 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1861
1862 if (!rc)
1863 __of_update_property_sysfs(np, newprop, oldprop);
1864
1865 mutex_unlock(&of_mutex);
1866
1867 if (!rc)
1868 of_property_notify(OF_RECONFIG_UPDATE_PROPERTY, np, newprop, oldprop);
1869
1870 return rc;
1871}
1872
1873static void of_alias_add(struct alias_prop *ap, struct device_node *np,
1874 int id, const char *stem, int stem_len)
1875{
1876 ap->np = np;
1877 ap->id = id;
1878 strncpy(ap->stem, stem, stem_len);
1879 ap->stem[stem_len] = 0;
1880 list_add_tail(&ap->link, &aliases_lookup);
1881 pr_debug("adding DT alias:%s: stem=%s id=%i node=%s\n",
1882 ap->alias, ap->stem, ap->id, of_node_full_name(np));
1883}
1884
1885/**
1886 * of_alias_scan - Scan all properties of the 'aliases' node
1887 *
1888 * The function scans all the properties of the 'aliases' node and populates
1889 * the global lookup table with the properties. It returns the
1890 * number of alias properties found, or an error code in case of failure.
1891 *
1892 * @dt_alloc: An allocator that provides a virtual address to memory
1893 * for storing the resulting tree
1894 */
1895void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align))
1896{
1897 struct property *pp;
1898
1899 of_aliases = of_find_node_by_path("/aliases");
1900 of_chosen = of_find_node_by_path("/chosen");
1901 if (of_chosen == NULL)
1902 of_chosen = of_find_node_by_path("/chosen@0");
1903
1904 if (of_chosen) {
1905 /* linux,stdout-path and /aliases/stdout are for legacy compatibility */
1906 const char *name = of_get_property(of_chosen, "stdout-path", NULL);
1907 if (!name)
1908 name = of_get_property(of_chosen, "linux,stdout-path", NULL);
1909 if (IS_ENABLED(CONFIG_PPC) && !name)
1910 name = of_get_property(of_aliases, "stdout", NULL);
1911 if (name)
1912 of_stdout = of_find_node_opts_by_path(name, &of_stdout_options);
1913 }
1914
1915 if (!of_aliases)
1916 return;
1917
1918 for_each_property_of_node(of_aliases, pp) {
1919 const char *start = pp->name;
1920 const char *end = start + strlen(start);
1921 struct device_node *np;
1922 struct alias_prop *ap;
1923 int id, len;
1924
1925 /* Skip those we do not want to proceed */
1926 if (!strcmp(pp->name, "name") ||
1927 !strcmp(pp->name, "phandle") ||
1928 !strcmp(pp->name, "linux,phandle"))
1929 continue;
1930
1931 np = of_find_node_by_path(pp->value);
1932 if (!np)
1933 continue;
1934
1935 /* walk the alias backwards to extract the id and work out
1936 * the 'stem' string */
1937 while (isdigit(*(end-1)) && end > start)
1938 end--;
1939 len = end - start;
1940
1941 if (kstrtoint(end, 10, &id) < 0)
1942 continue;
1943
1944 /* Allocate an alias_prop with enough space for the stem */
1945 ap = dt_alloc(sizeof(*ap) + len + 1, 4);
1946 if (!ap)
1947 continue;
1948 memset(ap, 0, sizeof(*ap) + len + 1);
1949 ap->alias = start;
1950 of_alias_add(ap, np, id, start, len);
1951 }
1952}
1953
1954/**
1955 * of_alias_get_id - Get alias id for the given device_node
1956 * @np: Pointer to the given device_node
1957 * @stem: Alias stem of the given device_node
1958 *
1959 * The function travels the lookup table to get the alias id for the given
1960 * device_node and alias stem. It returns the alias id if found.
1961 */
1962int of_alias_get_id(struct device_node *np, const char *stem)
1963{
1964 struct alias_prop *app;
1965 int id = -ENODEV;
1966
1967 mutex_lock(&of_mutex);
1968 list_for_each_entry(app, &aliases_lookup, link) {
1969 if (strcmp(app->stem, stem) != 0)
1970 continue;
1971
1972 if (np == app->np) {
1973 id = app->id;
1974 break;
1975 }
1976 }
1977 mutex_unlock(&of_mutex);
1978
1979 return id;
1980}
1981EXPORT_SYMBOL_GPL(of_alias_get_id);
1982
1983/**
1984 * of_alias_get_highest_id - Get highest alias id for the given stem
1985 * @stem: Alias stem to be examined
1986 *
1987 * The function travels the lookup table to get the highest alias id for the
1988 * given alias stem. It returns the alias id if found.
1989 */
1990int of_alias_get_highest_id(const char *stem)
1991{
1992 struct alias_prop *app;
1993 int id = -ENODEV;
1994
1995 mutex_lock(&of_mutex);
1996 list_for_each_entry(app, &aliases_lookup, link) {
1997 if (strcmp(app->stem, stem) != 0)
1998 continue;
1999
2000 if (app->id > id)
2001 id = app->id;
2002 }
2003 mutex_unlock(&of_mutex);
2004
2005 return id;
2006}
2007EXPORT_SYMBOL_GPL(of_alias_get_highest_id);
2008
2009const __be32 *of_prop_next_u32(struct property *prop, const __be32 *cur,
2010 u32 *pu)
2011{
2012 const void *curv = cur;
2013
2014 if (!prop)
2015 return NULL;
2016
2017 if (!cur) {
2018 curv = prop->value;
2019 goto out_val;
2020 }
2021
2022 curv += sizeof(*cur);
2023 if (curv >= prop->value + prop->length)
2024 return NULL;
2025
2026out_val:
2027 *pu = be32_to_cpup(curv);
2028 return curv;
2029}
2030EXPORT_SYMBOL_GPL(of_prop_next_u32);
2031
2032const char *of_prop_next_string(struct property *prop, const char *cur)
2033{
2034 const void *curv = cur;
2035
2036 if (!prop)
2037 return NULL;
2038
2039 if (!cur)
2040 return prop->value;
2041
2042 curv += strlen(cur) + 1;
2043 if (curv >= prop->value + prop->length)
2044 return NULL;
2045
2046 return curv;
2047}
2048EXPORT_SYMBOL_GPL(of_prop_next_string);
2049
2050/**
2051 * of_console_check() - Test and setup console for DT setup
2052 * @dn - Pointer to device node
2053 * @name - Name to use for preferred console without index. ex. "ttyS"
2054 * @index - Index to use for preferred console.
2055 *
2056 * Check if the given device node matches the stdout-path property in the
2057 * /chosen node. If it does then register it as the preferred console and return
2058 * TRUE. Otherwise return FALSE.
2059 */
2060bool of_console_check(struct device_node *dn, char *name, int index)
2061{
2062 if (!dn || dn != of_stdout || console_set_on_cmdline)
2063 return false;
2064 return !add_preferred_console(name, index,
2065 kstrdup(of_stdout_options, GFP_KERNEL));
2066}
2067EXPORT_SYMBOL_GPL(of_console_check);
2068
2069/**
2070 * of_find_next_cache_node - Find a node's subsidiary cache
2071 * @np: node of type "cpu" or "cache"
2072 *
2073 * Returns a node pointer with refcount incremented, use
2074 * of_node_put() on it when done. Caller should hold a reference
2075 * to np.
2076 */
2077struct device_node *of_find_next_cache_node(const struct device_node *np)
2078{
2079 struct device_node *child;
2080 const phandle *handle;
2081
2082 handle = of_get_property(np, "l2-cache", NULL);
2083 if (!handle)
2084 handle = of_get_property(np, "next-level-cache", NULL);
2085
2086 if (handle)
2087 return of_find_node_by_phandle(be32_to_cpup(handle));
2088
2089 /* OF on pmac has nodes instead of properties named "l2-cache"
2090 * beneath CPU nodes.
2091 */
2092 if (!strcmp(np->type, "cpu"))
2093 for_each_child_of_node(np, child)
2094 if (!strcmp(child->type, "cache"))
2095 return child;
2096
2097 return NULL;
2098}
2099
2100/**
2101 * of_graph_parse_endpoint() - parse common endpoint node properties
2102 * @node: pointer to endpoint device_node
2103 * @endpoint: pointer to the OF endpoint data structure
2104 *
2105 * The caller should hold a reference to @node.
2106 */
2107int of_graph_parse_endpoint(const struct device_node *node,
2108 struct of_endpoint *endpoint)
2109{
2110 struct device_node *port_node = of_get_parent(node);
2111
2112 WARN_ONCE(!port_node, "%s(): endpoint %s has no parent node\n",
2113 __func__, node->full_name);
2114
2115 memset(endpoint, 0, sizeof(*endpoint));
2116
2117 endpoint->local_node = node;
2118 /*
2119 * It doesn't matter whether the two calls below succeed.
2120 * If they don't then the default value 0 is used.
2121 */
2122 of_property_read_u32(port_node, "reg", &endpoint->port);
2123 of_property_read_u32(node, "reg", &endpoint->id);
2124
2125 of_node_put(port_node);
2126
2127 return 0;
2128}
2129EXPORT_SYMBOL(of_graph_parse_endpoint);
2130
2131/**
2132 * of_graph_get_port_by_id() - get the port matching a given id
2133 * @parent: pointer to the parent device node
2134 * @id: id of the port
2135 *
2136 * Return: A 'port' node pointer with refcount incremented. The caller
2137 * has to use of_node_put() on it when done.
2138 */
2139struct device_node *of_graph_get_port_by_id(struct device_node *parent, u32 id)
2140{
2141 struct device_node *node, *port;
2142
2143 node = of_get_child_by_name(parent, "ports");
2144 if (node)
2145 parent = node;
2146
2147 for_each_child_of_node(parent, port) {
2148 u32 port_id = 0;
2149
2150 if (of_node_cmp(port->name, "port") != 0)
2151 continue;
2152 of_property_read_u32(port, "reg", &port_id);
2153 if (id == port_id)
2154 break;
2155 }
2156
2157 of_node_put(node);
2158
2159 return port;
2160}
2161EXPORT_SYMBOL(of_graph_get_port_by_id);
2162
2163/**
2164 * of_graph_get_next_endpoint() - get next endpoint node
2165 * @parent: pointer to the parent device node
2166 * @prev: previous endpoint node, or NULL to get first
2167 *
2168 * Return: An 'endpoint' node pointer with refcount incremented. Refcount
2169 * of the passed @prev node is decremented.
2170 */
2171struct device_node *of_graph_get_next_endpoint(const struct device_node *parent,
2172 struct device_node *prev)
2173{
2174 struct device_node *endpoint;
2175 struct device_node *port;
2176
2177 if (!parent)
2178 return NULL;
2179
2180 /*
2181 * Start by locating the port node. If no previous endpoint is specified
2182 * search for the first port node, otherwise get the previous endpoint
2183 * parent port node.
2184 */
2185 if (!prev) {
2186 struct device_node *node;
2187
2188 node = of_get_child_by_name(parent, "ports");
2189 if (node)
2190 parent = node;
2191
2192 port = of_get_child_by_name(parent, "port");
2193 of_node_put(node);
2194
2195 if (!port) {
2196 pr_err("%s(): no port node found in %s\n",
2197 __func__, parent->full_name);
2198 return NULL;
2199 }
2200 } else {
2201 port = of_get_parent(prev);
2202 if (WARN_ONCE(!port, "%s(): endpoint %s has no parent node\n",
2203 __func__, prev->full_name))
2204 return NULL;
2205 }
2206
2207 while (1) {
2208 /*
2209 * Now that we have a port node, get the next endpoint by
2210 * getting the next child. If the previous endpoint is NULL this
2211 * will return the first child.
2212 */
2213 endpoint = of_get_next_child(port, prev);
2214 if (endpoint) {
2215 of_node_put(port);
2216 return endpoint;
2217 }
2218
2219 /* No more endpoints under this port, try the next one. */
2220 prev = NULL;
2221
2222 do {
2223 port = of_get_next_child(parent, port);
2224 if (!port)
2225 return NULL;
2226 } while (of_node_cmp(port->name, "port"));
2227 }
2228}
2229EXPORT_SYMBOL(of_graph_get_next_endpoint);
2230
2231/**
2232 * of_graph_get_endpoint_by_regs() - get endpoint node of specific identifiers
2233 * @parent: pointer to the parent device node
2234 * @port_reg: identifier (value of reg property) of the parent port node
2235 * @reg: identifier (value of reg property) of the endpoint node
2236 *
2237 * Return: An 'endpoint' node pointer which is identified by reg and at the same
2238 * is the child of a port node identified by port_reg. reg and port_reg are
2239 * ignored when they are -1.
2240 */
2241struct device_node *of_graph_get_endpoint_by_regs(
2242 const struct device_node *parent, int port_reg, int reg)
2243{
2244 struct of_endpoint endpoint;
2245 struct device_node *node, *prev_node = NULL;
2246
2247 while (1) {
2248 node = of_graph_get_next_endpoint(parent, prev_node);
2249 of_node_put(prev_node);
2250 if (!node)
2251 break;
2252
2253 of_graph_parse_endpoint(node, &endpoint);
2254 if (((port_reg == -1) || (endpoint.port == port_reg)) &&
2255 ((reg == -1) || (endpoint.id == reg)))
2256 return node;
2257
2258 prev_node = node;
2259 }
2260
2261 return NULL;
2262}
2263EXPORT_SYMBOL(of_graph_get_endpoint_by_regs);
2264
2265/**
2266 * of_graph_get_remote_port_parent() - get remote port's parent node
2267 * @node: pointer to a local endpoint device_node
2268 *
2269 * Return: Remote device node associated with remote endpoint node linked
2270 * to @node. Use of_node_put() on it when done.
2271 */
2272struct device_node *of_graph_get_remote_port_parent(
2273 const struct device_node *node)
2274{
2275 struct device_node *np;
2276 unsigned int depth;
2277
2278 /* Get remote endpoint node. */
2279 np = of_parse_phandle(node, "remote-endpoint", 0);
2280
2281 /* Walk 3 levels up only if there is 'ports' node. */
2282 for (depth = 3; depth && np; depth--) {
2283 np = of_get_next_parent(np);
2284 if (depth == 2 && of_node_cmp(np->name, "ports"))
2285 break;
2286 }
2287 return np;
2288}
2289EXPORT_SYMBOL(of_graph_get_remote_port_parent);
2290
2291/**
2292 * of_graph_get_remote_port() - get remote port node
2293 * @node: pointer to a local endpoint device_node
2294 *
2295 * Return: Remote port node associated with remote endpoint node linked
2296 * to @node. Use of_node_put() on it when done.
2297 */
2298struct device_node *of_graph_get_remote_port(const struct device_node *node)
2299{
2300 struct device_node *np;
2301
2302 /* Get remote endpoint node. */
2303 np = of_parse_phandle(node, "remote-endpoint", 0);
2304 if (!np)
2305 return NULL;
2306 return of_get_next_parent(np);
2307}
2308EXPORT_SYMBOL(of_graph_get_remote_port);