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