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