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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/*
2 * Procedures for creating, accessing and interpreting the device tree.
3 *
4 * Paul Mackerras August 1996.
5 * Copyright (C) 1996-2005 Paul Mackerras.
6 *
7 * Adapted for 64bit PowerPC by Dave Engebretsen and Peter Bergner.
8 * {engebret|bergner}@us.ibm.com
9 *
10 * Adapted for sparc and sparc64 by David S. Miller davem@davemloft.net
11 *
12 * Reconsolidated from arch/x/kernel/prom.c by Stephen Rothwell and
13 * Grant Likely.
14 *
15 * This program is free software; you can redistribute it and/or
16 * modify it under the terms of the GNU General Public License
17 * as published by the Free Software Foundation; either version
18 * 2 of the License, or (at your option) any later version.
19 */
20#include <linux/console.h>
21#include <linux/ctype.h>
22#include <linux/cpu.h>
23#include <linux/module.h>
24#include <linux/of.h>
25#include <linux/of_graph.h>
26#include <linux/spinlock.h>
27#include <linux/slab.h>
28#include <linux/string.h>
29#include <linux/proc_fs.h>
30
31#include "of_private.h"
32
33LIST_HEAD(aliases_lookup);
34
35struct device_node *of_root;
36EXPORT_SYMBOL(of_root);
37struct device_node *of_chosen;
38struct device_node *of_aliases;
39struct device_node *of_stdout;
40static const char *of_stdout_options;
41
42struct kset *of_kset;
43
44/*
45 * Used to protect the of_aliases, to hold off addition of nodes to sysfs.
46 * This mutex must be held whenever modifications are being made to the
47 * device tree. The of_{attach,detach}_node() and
48 * of_{add,remove,update}_property() helpers make sure this happens.
49 */
50DEFINE_MUTEX(of_mutex);
51
52/* use when traversing tree through the child, sibling,
53 * or parent members of struct device_node.
54 */
55DEFINE_RAW_SPINLOCK(devtree_lock);
56
57int of_n_addr_cells(struct device_node *np)
58{
59 const __be32 *ip;
60
61 do {
62 if (np->parent)
63 np = np->parent;
64 ip = of_get_property(np, "#address-cells", NULL);
65 if (ip)
66 return be32_to_cpup(ip);
67 } while (np->parent);
68 /* No #address-cells property for the root node */
69 return OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
70}
71EXPORT_SYMBOL(of_n_addr_cells);
72
73int of_n_size_cells(struct device_node *np)
74{
75 const __be32 *ip;
76
77 do {
78 if (np->parent)
79 np = np->parent;
80 ip = of_get_property(np, "#size-cells", NULL);
81 if (ip)
82 return be32_to_cpup(ip);
83 } while (np->parent);
84 /* No #size-cells property for the root node */
85 return OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
86}
87EXPORT_SYMBOL(of_n_size_cells);
88
89#ifdef CONFIG_NUMA
90int __weak of_node_to_nid(struct device_node *np)
91{
92 return NUMA_NO_NODE;
93}
94#endif
95
96#ifndef CONFIG_OF_DYNAMIC
97static void of_node_release(struct kobject *kobj)
98{
99 /* Without CONFIG_OF_DYNAMIC, no nodes gets freed */
100}
101#endif /* CONFIG_OF_DYNAMIC */
102
103struct kobj_type of_node_ktype = {
104 .release = of_node_release,
105};
106
107static ssize_t of_node_property_read(struct file *filp, struct kobject *kobj,
108 struct bin_attribute *bin_attr, char *buf,
109 loff_t offset, size_t count)
110{
111 struct property *pp = container_of(bin_attr, struct property, attr);
112 return memory_read_from_buffer(buf, count, &offset, pp->value, pp->length);
113}
114
115static const char *safe_name(struct kobject *kobj, const char *orig_name)
116{
117 const char *name = orig_name;
118 struct kernfs_node *kn;
119 int i = 0;
120
121 /* don't be a hero. After 16 tries give up */
122 while (i < 16 && (kn = sysfs_get_dirent(kobj->sd, name))) {
123 sysfs_put(kn);
124 if (name != orig_name)
125 kfree(name);
126 name = kasprintf(GFP_KERNEL, "%s#%i", orig_name, ++i);
127 }
128
129 if (name != orig_name)
130 pr_warn("device-tree: Duplicate name in %s, renamed to \"%s\"\n",
131 kobject_name(kobj), name);
132 return name;
133}
134
135int __of_add_property_sysfs(struct device_node *np, struct property *pp)
136{
137 int rc;
138
139 /* Important: Don't leak passwords */
140 bool secure = strncmp(pp->name, "security-", 9) == 0;
141
142 if (!IS_ENABLED(CONFIG_SYSFS))
143 return 0;
144
145 if (!of_kset || !of_node_is_attached(np))
146 return 0;
147
148 sysfs_bin_attr_init(&pp->attr);
149 pp->attr.attr.name = safe_name(&np->kobj, pp->name);
150 pp->attr.attr.mode = secure ? S_IRUSR : S_IRUGO;
151 pp->attr.size = secure ? 0 : pp->length;
152 pp->attr.read = of_node_property_read;
153
154 rc = sysfs_create_bin_file(&np->kobj, &pp->attr);
155 WARN(rc, "error adding attribute %s to node %s\n", pp->name, np->full_name);
156 return rc;
157}
158
159int __of_attach_node_sysfs(struct device_node *np)
160{
161 const char *name;
162 struct property *pp;
163 int rc;
164
165 if (!IS_ENABLED(CONFIG_SYSFS))
166 return 0;
167
168 if (!of_kset)
169 return 0;
170
171 np->kobj.kset = of_kset;
172 if (!np->parent) {
173 /* Nodes without parents are new top level trees */
174 rc = kobject_add(&np->kobj, NULL, "%s",
175 safe_name(&of_kset->kobj, "base"));
176 } else {
177 name = safe_name(&np->parent->kobj, kbasename(np->full_name));
178 if (!name || !name[0])
179 return -EINVAL;
180
181 rc = kobject_add(&np->kobj, &np->parent->kobj, "%s", name);
182 }
183 if (rc)
184 return rc;
185
186 for_each_property_of_node(np, pp)
187 __of_add_property_sysfs(np, pp);
188
189 return 0;
190}
191
192void __init of_core_init(void)
193{
194 struct device_node *np;
195
196 /* Create the kset, and register existing nodes */
197 mutex_lock(&of_mutex);
198 of_kset = kset_create_and_add("devicetree", NULL, firmware_kobj);
199 if (!of_kset) {
200 mutex_unlock(&of_mutex);
201 pr_err("devicetree: failed to register existing nodes\n");
202 return;
203 }
204 for_each_of_allnodes(np)
205 __of_attach_node_sysfs(np);
206 mutex_unlock(&of_mutex);
207
208 /* Symlink in /proc as required by userspace ABI */
209 if (of_root)
210 proc_symlink("device-tree", NULL, "/sys/firmware/devicetree/base");
211}
212
213static struct property *__of_find_property(const struct device_node *np,
214 const char *name, int *lenp)
215{
216 struct property *pp;
217
218 if (!np)
219 return NULL;
220
221 for (pp = np->properties; pp; pp = pp->next) {
222 if (of_prop_cmp(pp->name, name) == 0) {
223 if (lenp)
224 *lenp = pp->length;
225 break;
226 }
227 }
228
229 return pp;
230}
231
232struct property *of_find_property(const struct device_node *np,
233 const char *name,
234 int *lenp)
235{
236 struct property *pp;
237 unsigned long flags;
238
239 raw_spin_lock_irqsave(&devtree_lock, flags);
240 pp = __of_find_property(np, name, lenp);
241 raw_spin_unlock_irqrestore(&devtree_lock, flags);
242
243 return pp;
244}
245EXPORT_SYMBOL(of_find_property);
246
247struct device_node *__of_find_all_nodes(struct device_node *prev)
248{
249 struct device_node *np;
250 if (!prev) {
251 np = of_root;
252 } else if (prev->child) {
253 np = prev->child;
254 } else {
255 /* Walk back up looking for a sibling, or the end of the structure */
256 np = prev;
257 while (np->parent && !np->sibling)
258 np = np->parent;
259 np = np->sibling; /* Might be null at the end of the tree */
260 }
261 return np;
262}
263
264/**
265 * of_find_all_nodes - Get next node in global list
266 * @prev: Previous node or NULL to start iteration
267 * of_node_put() will be called on it
268 *
269 * Returns a node pointer with refcount incremented, use
270 * of_node_put() on it when done.
271 */
272struct device_node *of_find_all_nodes(struct device_node *prev)
273{
274 struct device_node *np;
275 unsigned long flags;
276
277 raw_spin_lock_irqsave(&devtree_lock, flags);
278 np = __of_find_all_nodes(prev);
279 of_node_get(np);
280 of_node_put(prev);
281 raw_spin_unlock_irqrestore(&devtree_lock, flags);
282 return np;
283}
284EXPORT_SYMBOL(of_find_all_nodes);
285
286/*
287 * Find a property with a given name for a given node
288 * and return the value.
289 */
290const void *__of_get_property(const struct device_node *np,
291 const char *name, int *lenp)
292{
293 struct property *pp = __of_find_property(np, name, lenp);
294
295 return pp ? pp->value : NULL;
296}
297
298/*
299 * Find a property with a given name for a given node
300 * and return the value.
301 */
302const void *of_get_property(const struct device_node *np, const char *name,
303 int *lenp)
304{
305 struct property *pp = of_find_property(np, name, lenp);
306
307 return pp ? pp->value : NULL;
308}
309EXPORT_SYMBOL(of_get_property);
310
311/*
312 * arch_match_cpu_phys_id - Match the given logical CPU and physical id
313 *
314 * @cpu: logical cpu index of a core/thread
315 * @phys_id: physical identifier of a core/thread
316 *
317 * CPU logical to physical index mapping is architecture specific.
318 * However this __weak function provides a default match of physical
319 * id to logical cpu index. phys_id provided here is usually values read
320 * from the device tree which must match the hardware internal registers.
321 *
322 * Returns true if the physical identifier and the logical cpu index
323 * correspond to the same core/thread, false otherwise.
324 */
325bool __weak arch_match_cpu_phys_id(int cpu, u64 phys_id)
326{
327 return (u32)phys_id == cpu;
328}
329
330/**
331 * Checks if the given "prop_name" property holds the physical id of the
332 * core/thread corresponding to the logical cpu 'cpu'. If 'thread' is not
333 * NULL, local thread number within the core is returned in it.
334 */
335static bool __of_find_n_match_cpu_property(struct device_node *cpun,
336 const char *prop_name, int cpu, unsigned int *thread)
337{
338 const __be32 *cell;
339 int ac, prop_len, tid;
340 u64 hwid;
341
342 ac = of_n_addr_cells(cpun);
343 cell = of_get_property(cpun, prop_name, &prop_len);
344 if (!cell || !ac)
345 return false;
346 prop_len /= sizeof(*cell) * ac;
347 for (tid = 0; tid < prop_len; tid++) {
348 hwid = of_read_number(cell, ac);
349 if (arch_match_cpu_phys_id(cpu, hwid)) {
350 if (thread)
351 *thread = tid;
352 return true;
353 }
354 cell += ac;
355 }
356 return false;
357}
358
359/*
360 * arch_find_n_match_cpu_physical_id - See if the given device node is
361 * for the cpu corresponding to logical cpu 'cpu'. Return true if so,
362 * else false. If 'thread' is non-NULL, the local thread number within the
363 * core is returned in it.
364 */
365bool __weak arch_find_n_match_cpu_physical_id(struct device_node *cpun,
366 int cpu, unsigned int *thread)
367{
368 /* Check for non-standard "ibm,ppc-interrupt-server#s" property
369 * for thread ids on PowerPC. If it doesn't exist fallback to
370 * standard "reg" property.
371 */
372 if (IS_ENABLED(CONFIG_PPC) &&
373 __of_find_n_match_cpu_property(cpun,
374 "ibm,ppc-interrupt-server#s",
375 cpu, thread))
376 return true;
377
378 return __of_find_n_match_cpu_property(cpun, "reg", cpu, thread);
379}
380
381/**
382 * of_get_cpu_node - Get device node associated with the given logical CPU
383 *
384 * @cpu: CPU number(logical index) for which device node is required
385 * @thread: if not NULL, local thread number within the physical core is
386 * returned
387 *
388 * The main purpose of this function is to retrieve the device node for the
389 * given logical CPU index. It should be used to initialize the of_node in
390 * cpu device. Once of_node in cpu device is populated, all the further
391 * references can use that instead.
392 *
393 * CPU logical to physical index mapping is architecture specific and is built
394 * before booting secondary cores. This function uses arch_match_cpu_phys_id
395 * which can be overridden by architecture specific implementation.
396 *
397 * Returns a node pointer for the logical cpu if found, else NULL.
398 */
399struct device_node *of_get_cpu_node(int cpu, unsigned int *thread)
400{
401 struct device_node *cpun;
402
403 for_each_node_by_type(cpun, "cpu") {
404 if (arch_find_n_match_cpu_physical_id(cpun, cpu, thread))
405 return cpun;
406 }
407 return NULL;
408}
409EXPORT_SYMBOL(of_get_cpu_node);
410
411/**
412 * __of_device_is_compatible() - Check if the node matches given constraints
413 * @device: pointer to node
414 * @compat: required compatible string, NULL or "" for any match
415 * @type: required device_type value, NULL or "" for any match
416 * @name: required node name, NULL or "" for any match
417 *
418 * Checks if the given @compat, @type and @name strings match the
419 * properties of the given @device. A constraints can be skipped by
420 * passing NULL or an empty string as the constraint.
421 *
422 * Returns 0 for no match, and a positive integer on match. The return
423 * value is a relative score with larger values indicating better
424 * matches. The score is weighted for the most specific compatible value
425 * to get the highest score. Matching type is next, followed by matching
426 * name. Practically speaking, this results in the following priority
427 * order for matches:
428 *
429 * 1. specific compatible && type && name
430 * 2. specific compatible && type
431 * 3. specific compatible && name
432 * 4. specific compatible
433 * 5. general compatible && type && name
434 * 6. general compatible && type
435 * 7. general compatible && name
436 * 8. general compatible
437 * 9. type && name
438 * 10. type
439 * 11. name
440 */
441static int __of_device_is_compatible(const struct device_node *device,
442 const char *compat, const char *type, const char *name)
443{
444 struct property *prop;
445 const char *cp;
446 int index = 0, score = 0;
447
448 /* Compatible match has highest priority */
449 if (compat && compat[0]) {
450 prop = __of_find_property(device, "compatible", NULL);
451 for (cp = of_prop_next_string(prop, NULL); cp;
452 cp = of_prop_next_string(prop, cp), index++) {
453 if (of_compat_cmp(cp, compat, strlen(compat)) == 0) {
454 score = INT_MAX/2 - (index << 2);
455 break;
456 }
457 }
458 if (!score)
459 return 0;
460 }
461
462 /* Matching type is better than matching name */
463 if (type && type[0]) {
464 if (!device->type || of_node_cmp(type, device->type))
465 return 0;
466 score += 2;
467 }
468
469 /* Matching name is a bit better than not */
470 if (name && name[0]) {
471 if (!device->name || of_node_cmp(name, device->name))
472 return 0;
473 score++;
474 }
475
476 return score;
477}
478
479/** Checks if the given "compat" string matches one of the strings in
480 * the device's "compatible" property
481 */
482int of_device_is_compatible(const struct device_node *device,
483 const char *compat)
484{
485 unsigned long flags;
486 int res;
487
488 raw_spin_lock_irqsave(&devtree_lock, flags);
489 res = __of_device_is_compatible(device, compat, NULL, NULL);
490 raw_spin_unlock_irqrestore(&devtree_lock, flags);
491 return res;
492}
493EXPORT_SYMBOL(of_device_is_compatible);
494
495/**
496 * of_machine_is_compatible - Test root of device tree for a given compatible value
497 * @compat: compatible string to look for in root node's compatible property.
498 *
499 * Returns a positive integer if the root node has the given value in its
500 * compatible property.
501 */
502int of_machine_is_compatible(const char *compat)
503{
504 struct device_node *root;
505 int rc = 0;
506
507 root = of_find_node_by_path("/");
508 if (root) {
509 rc = of_device_is_compatible(root, compat);
510 of_node_put(root);
511 }
512 return rc;
513}
514EXPORT_SYMBOL(of_machine_is_compatible);
515
516/**
517 * __of_device_is_available - check if a device is available for use
518 *
519 * @device: Node to check for availability, with locks already held
520 *
521 * Returns true if the status property is absent or set to "okay" or "ok",
522 * false otherwise
523 */
524static bool __of_device_is_available(const struct device_node *device)
525{
526 const char *status;
527 int statlen;
528
529 if (!device)
530 return false;
531
532 status = __of_get_property(device, "status", &statlen);
533 if (status == NULL)
534 return true;
535
536 if (statlen > 0) {
537 if (!strcmp(status, "okay") || !strcmp(status, "ok"))
538 return true;
539 }
540
541 return false;
542}
543
544/**
545 * of_device_is_available - check if a device is available for use
546 *
547 * @device: Node to check for availability
548 *
549 * Returns true if the status property is absent or set to "okay" or "ok",
550 * false otherwise
551 */
552bool of_device_is_available(const struct device_node *device)
553{
554 unsigned long flags;
555 bool res;
556
557 raw_spin_lock_irqsave(&devtree_lock, flags);
558 res = __of_device_is_available(device);
559 raw_spin_unlock_irqrestore(&devtree_lock, flags);
560 return res;
561
562}
563EXPORT_SYMBOL(of_device_is_available);
564
565/**
566 * of_device_is_big_endian - check if a device has BE registers
567 *
568 * @device: Node to check for endianness
569 *
570 * Returns true if the device has a "big-endian" property, or if the kernel
571 * was compiled for BE *and* the device has a "native-endian" property.
572 * Returns false otherwise.
573 *
574 * Callers would nominally use ioread32be/iowrite32be if
575 * of_device_is_big_endian() == true, or readl/writel otherwise.
576 */
577bool of_device_is_big_endian(const struct device_node *device)
578{
579 if (of_property_read_bool(device, "big-endian"))
580 return true;
581 if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) &&
582 of_property_read_bool(device, "native-endian"))
583 return true;
584 return false;
585}
586EXPORT_SYMBOL(of_device_is_big_endian);
587
588/**
589 * of_get_parent - Get a node's parent if any
590 * @node: Node to get parent
591 *
592 * Returns a node pointer with refcount incremented, use
593 * of_node_put() on it when done.
594 */
595struct device_node *of_get_parent(const struct device_node *node)
596{
597 struct device_node *np;
598 unsigned long flags;
599
600 if (!node)
601 return NULL;
602
603 raw_spin_lock_irqsave(&devtree_lock, flags);
604 np = of_node_get(node->parent);
605 raw_spin_unlock_irqrestore(&devtree_lock, flags);
606 return np;
607}
608EXPORT_SYMBOL(of_get_parent);
609
610/**
611 * of_get_next_parent - Iterate to a node's parent
612 * @node: Node to get parent of
613 *
614 * This is like of_get_parent() except that it drops the
615 * refcount on the passed node, making it suitable for iterating
616 * through a node's parents.
617 *
618 * Returns a node pointer with refcount incremented, use
619 * of_node_put() on it when done.
620 */
621struct device_node *of_get_next_parent(struct device_node *node)
622{
623 struct device_node *parent;
624 unsigned long flags;
625
626 if (!node)
627 return NULL;
628
629 raw_spin_lock_irqsave(&devtree_lock, flags);
630 parent = of_node_get(node->parent);
631 of_node_put(node);
632 raw_spin_unlock_irqrestore(&devtree_lock, flags);
633 return parent;
634}
635EXPORT_SYMBOL(of_get_next_parent);
636
637static struct device_node *__of_get_next_child(const struct device_node *node,
638 struct device_node *prev)
639{
640 struct device_node *next;
641
642 if (!node)
643 return NULL;
644
645 next = prev ? prev->sibling : node->child;
646 for (; next; next = next->sibling)
647 if (of_node_get(next))
648 break;
649 of_node_put(prev);
650 return next;
651}
652#define __for_each_child_of_node(parent, child) \
653 for (child = __of_get_next_child(parent, NULL); child != NULL; \
654 child = __of_get_next_child(parent, child))
655
656/**
657 * of_get_next_child - Iterate a node childs
658 * @node: parent node
659 * @prev: previous child of the parent node, or NULL to get first
660 *
661 * Returns a node pointer with refcount incremented, use of_node_put() on
662 * it when done. Returns NULL when prev is the last child. Decrements the
663 * refcount of prev.
664 */
665struct device_node *of_get_next_child(const struct device_node *node,
666 struct device_node *prev)
667{
668 struct device_node *next;
669 unsigned long flags;
670
671 raw_spin_lock_irqsave(&devtree_lock, flags);
672 next = __of_get_next_child(node, prev);
673 raw_spin_unlock_irqrestore(&devtree_lock, flags);
674 return next;
675}
676EXPORT_SYMBOL(of_get_next_child);
677
678/**
679 * of_get_next_available_child - Find the next available child node
680 * @node: parent node
681 * @prev: previous child of the parent node, or NULL to get first
682 *
683 * This function is like of_get_next_child(), except that it
684 * automatically skips any disabled nodes (i.e. status = "disabled").
685 */
686struct device_node *of_get_next_available_child(const struct device_node *node,
687 struct device_node *prev)
688{
689 struct device_node *next;
690 unsigned long flags;
691
692 if (!node)
693 return NULL;
694
695 raw_spin_lock_irqsave(&devtree_lock, flags);
696 next = prev ? prev->sibling : node->child;
697 for (; next; next = next->sibling) {
698 if (!__of_device_is_available(next))
699 continue;
700 if (of_node_get(next))
701 break;
702 }
703 of_node_put(prev);
704 raw_spin_unlock_irqrestore(&devtree_lock, flags);
705 return next;
706}
707EXPORT_SYMBOL(of_get_next_available_child);
708
709/**
710 * of_get_child_by_name - Find the child node by name for a given parent
711 * @node: parent node
712 * @name: child name to look for.
713 *
714 * This function looks for child node for given matching name
715 *
716 * Returns a node pointer if found, with refcount incremented, use
717 * of_node_put() on it when done.
718 * Returns NULL if node is not found.
719 */
720struct device_node *of_get_child_by_name(const struct device_node *node,
721 const char *name)
722{
723 struct device_node *child;
724
725 for_each_child_of_node(node, child)
726 if (child->name && (of_node_cmp(child->name, name) == 0))
727 break;
728 return child;
729}
730EXPORT_SYMBOL(of_get_child_by_name);
731
732static struct device_node *__of_find_node_by_path(struct device_node *parent,
733 const char *path)
734{
735 struct device_node *child;
736 int len;
737
738 len = strcspn(path, "/:");
739 if (!len)
740 return NULL;
741
742 __for_each_child_of_node(parent, child) {
743 const char *name = strrchr(child->full_name, '/');
744 if (WARN(!name, "malformed device_node %s\n", child->full_name))
745 continue;
746 name++;
747 if (strncmp(path, name, len) == 0 && (strlen(name) == len))
748 return child;
749 }
750 return NULL;
751}
752
753/**
754 * of_find_node_opts_by_path - Find a node matching a full OF path
755 * @path: Either the full path to match, or if the path does not
756 * start with '/', the name of a property of the /aliases
757 * node (an alias). In the case of an alias, the node
758 * matching the alias' value will be returned.
759 * @opts: Address of a pointer into which to store the start of
760 * an options string appended to the end of the path with
761 * a ':' separator.
762 *
763 * Valid paths:
764 * /foo/bar Full path
765 * foo Valid alias
766 * foo/bar Valid alias + relative path
767 *
768 * Returns a node pointer with refcount incremented, use
769 * of_node_put() on it when done.
770 */
771struct device_node *of_find_node_opts_by_path(const char *path, const char **opts)
772{
773 struct device_node *np = NULL;
774 struct property *pp;
775 unsigned long flags;
776 const char *separator = strchr(path, ':');
777
778 if (opts)
779 *opts = separator ? separator + 1 : NULL;
780
781 if (strcmp(path, "/") == 0)
782 return of_node_get(of_root);
783
784 /* The path could begin with an alias */
785 if (*path != '/') {
786 int len;
787 const char *p = separator;
788
789 if (!p)
790 p = strchrnul(path, '/');
791 len = p - path;
792
793 /* of_aliases must not be NULL */
794 if (!of_aliases)
795 return NULL;
796
797 for_each_property_of_node(of_aliases, pp) {
798 if (strlen(pp->name) == len && !strncmp(pp->name, path, len)) {
799 np = of_find_node_by_path(pp->value);
800 break;
801 }
802 }
803 if (!np)
804 return NULL;
805 path = p;
806 }
807
808 /* Step down the tree matching path components */
809 raw_spin_lock_irqsave(&devtree_lock, flags);
810 if (!np)
811 np = of_node_get(of_root);
812 while (np && *path == '/') {
813 path++; /* Increment past '/' delimiter */
814 np = __of_find_node_by_path(np, path);
815 path = strchrnul(path, '/');
816 if (separator && separator < path)
817 break;
818 }
819 raw_spin_unlock_irqrestore(&devtree_lock, flags);
820 return np;
821}
822EXPORT_SYMBOL(of_find_node_opts_by_path);
823
824/**
825 * of_find_node_by_name - Find a node by its "name" property
826 * @from: The node to start searching from or NULL, the node
827 * you pass will not be searched, only the next one
828 * will; typically, you pass what the previous call
829 * returned. of_node_put() will be called on it
830 * @name: The name string to match against
831 *
832 * Returns a node pointer with refcount incremented, use
833 * of_node_put() on it when done.
834 */
835struct device_node *of_find_node_by_name(struct device_node *from,
836 const char *name)
837{
838 struct device_node *np;
839 unsigned long flags;
840
841 raw_spin_lock_irqsave(&devtree_lock, flags);
842 for_each_of_allnodes_from(from, np)
843 if (np->name && (of_node_cmp(np->name, name) == 0)
844 && of_node_get(np))
845 break;
846 of_node_put(from);
847 raw_spin_unlock_irqrestore(&devtree_lock, flags);
848 return np;
849}
850EXPORT_SYMBOL(of_find_node_by_name);
851
852/**
853 * of_find_node_by_type - Find a node by its "device_type" property
854 * @from: The node to start searching from, or NULL to start searching
855 * the entire device tree. The node you pass will not be
856 * searched, only the next one will; typically, you pass
857 * what the previous call returned. of_node_put() will be
858 * called on from for you.
859 * @type: The type string to match against
860 *
861 * Returns a node pointer with refcount incremented, use
862 * of_node_put() on it when done.
863 */
864struct device_node *of_find_node_by_type(struct device_node *from,
865 const char *type)
866{
867 struct device_node *np;
868 unsigned long flags;
869
870 raw_spin_lock_irqsave(&devtree_lock, flags);
871 for_each_of_allnodes_from(from, np)
872 if (np->type && (of_node_cmp(np->type, type) == 0)
873 && of_node_get(np))
874 break;
875 of_node_put(from);
876 raw_spin_unlock_irqrestore(&devtree_lock, flags);
877 return np;
878}
879EXPORT_SYMBOL(of_find_node_by_type);
880
881/**
882 * of_find_compatible_node - Find a node based on type and one of the
883 * tokens in its "compatible" property
884 * @from: The node to start searching from or NULL, the node
885 * you pass will not be searched, only the next one
886 * will; typically, you pass what the previous call
887 * returned. of_node_put() will be called on it
888 * @type: The type string to match "device_type" or NULL to ignore
889 * @compatible: The string to match to one of the tokens in the device
890 * "compatible" list.
891 *
892 * Returns a node pointer with refcount incremented, use
893 * of_node_put() on it when done.
894 */
895struct device_node *of_find_compatible_node(struct device_node *from,
896 const char *type, const char *compatible)
897{
898 struct device_node *np;
899 unsigned long flags;
900
901 raw_spin_lock_irqsave(&devtree_lock, flags);
902 for_each_of_allnodes_from(from, np)
903 if (__of_device_is_compatible(np, compatible, type, NULL) &&
904 of_node_get(np))
905 break;
906 of_node_put(from);
907 raw_spin_unlock_irqrestore(&devtree_lock, flags);
908 return np;
909}
910EXPORT_SYMBOL(of_find_compatible_node);
911
912/**
913 * of_find_node_with_property - Find a node which has a property with
914 * the given name.
915 * @from: The node to start searching from or NULL, the node
916 * you pass will not be searched, only the next one
917 * will; typically, you pass what the previous call
918 * returned. of_node_put() will be called on it
919 * @prop_name: The name of the property to look for.
920 *
921 * Returns a node pointer with refcount incremented, use
922 * of_node_put() on it when done.
923 */
924struct device_node *of_find_node_with_property(struct device_node *from,
925 const char *prop_name)
926{
927 struct device_node *np;
928 struct property *pp;
929 unsigned long flags;
930
931 raw_spin_lock_irqsave(&devtree_lock, flags);
932 for_each_of_allnodes_from(from, np) {
933 for (pp = np->properties; pp; pp = pp->next) {
934 if (of_prop_cmp(pp->name, prop_name) == 0) {
935 of_node_get(np);
936 goto out;
937 }
938 }
939 }
940out:
941 of_node_put(from);
942 raw_spin_unlock_irqrestore(&devtree_lock, flags);
943 return np;
944}
945EXPORT_SYMBOL(of_find_node_with_property);
946
947static
948const struct of_device_id *__of_match_node(const struct of_device_id *matches,
949 const struct device_node *node)
950{
951 const struct of_device_id *best_match = NULL;
952 int score, best_score = 0;
953
954 if (!matches)
955 return NULL;
956
957 for (; matches->name[0] || matches->type[0] || matches->compatible[0]; matches++) {
958 score = __of_device_is_compatible(node, matches->compatible,
959 matches->type, matches->name);
960 if (score > best_score) {
961 best_match = matches;
962 best_score = score;
963 }
964 }
965
966 return best_match;
967}
968
969/**
970 * of_match_node - Tell if a device_node has a matching of_match structure
971 * @matches: array of of device match structures to search in
972 * @node: the of device structure to match against
973 *
974 * Low level utility function used by device matching.
975 */
976const struct of_device_id *of_match_node(const struct of_device_id *matches,
977 const struct device_node *node)
978{
979 const struct of_device_id *match;
980 unsigned long flags;
981
982 raw_spin_lock_irqsave(&devtree_lock, flags);
983 match = __of_match_node(matches, node);
984 raw_spin_unlock_irqrestore(&devtree_lock, flags);
985 return match;
986}
987EXPORT_SYMBOL(of_match_node);
988
989/**
990 * of_find_matching_node_and_match - Find a node based on an of_device_id
991 * match table.
992 * @from: The node to start searching from or NULL, the node
993 * you pass will not be searched, only the next one
994 * will; typically, you pass what the previous call
995 * returned. of_node_put() will be called on it
996 * @matches: array of of device match structures to search in
997 * @match Updated to point at the matches entry which matched
998 *
999 * Returns a node pointer with refcount incremented, use
1000 * of_node_put() on it when done.
1001 */
1002struct device_node *of_find_matching_node_and_match(struct device_node *from,
1003 const struct of_device_id *matches,
1004 const struct of_device_id **match)
1005{
1006 struct device_node *np;
1007 const struct of_device_id *m;
1008 unsigned long flags;
1009
1010 if (match)
1011 *match = NULL;
1012
1013 raw_spin_lock_irqsave(&devtree_lock, flags);
1014 for_each_of_allnodes_from(from, np) {
1015 m = __of_match_node(matches, np);
1016 if (m && of_node_get(np)) {
1017 if (match)
1018 *match = m;
1019 break;
1020 }
1021 }
1022 of_node_put(from);
1023 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1024 return np;
1025}
1026EXPORT_SYMBOL(of_find_matching_node_and_match);
1027
1028/**
1029 * of_modalias_node - Lookup appropriate modalias for a device node
1030 * @node: pointer to a device tree node
1031 * @modalias: Pointer to buffer that modalias value will be copied into
1032 * @len: Length of modalias value
1033 *
1034 * Based on the value of the compatible property, this routine will attempt
1035 * to choose an appropriate modalias value for a particular device tree node.
1036 * It does this by stripping the manufacturer prefix (as delimited by a ',')
1037 * from the first entry in the compatible list property.
1038 *
1039 * This routine returns 0 on success, <0 on failure.
1040 */
1041int of_modalias_node(struct device_node *node, char *modalias, int len)
1042{
1043 const char *compatible, *p;
1044 int cplen;
1045
1046 compatible = of_get_property(node, "compatible", &cplen);
1047 if (!compatible || strlen(compatible) > cplen)
1048 return -ENODEV;
1049 p = strchr(compatible, ',');
1050 strlcpy(modalias, p ? p + 1 : compatible, len);
1051 return 0;
1052}
1053EXPORT_SYMBOL_GPL(of_modalias_node);
1054
1055/**
1056 * of_find_node_by_phandle - Find a node given a phandle
1057 * @handle: phandle of the node to find
1058 *
1059 * Returns a node pointer with refcount incremented, use
1060 * of_node_put() on it when done.
1061 */
1062struct device_node *of_find_node_by_phandle(phandle handle)
1063{
1064 struct device_node *np;
1065 unsigned long flags;
1066
1067 if (!handle)
1068 return NULL;
1069
1070 raw_spin_lock_irqsave(&devtree_lock, flags);
1071 for_each_of_allnodes(np)
1072 if (np->phandle == handle)
1073 break;
1074 of_node_get(np);
1075 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1076 return np;
1077}
1078EXPORT_SYMBOL(of_find_node_by_phandle);
1079
1080/**
1081 * of_property_count_elems_of_size - Count the number of elements in a property
1082 *
1083 * @np: device node from which the property value is to be read.
1084 * @propname: name of the property to be searched.
1085 * @elem_size: size of the individual element
1086 *
1087 * Search for a property in a device node and count the number of elements of
1088 * size elem_size in it. Returns number of elements on sucess, -EINVAL if the
1089 * property does not exist or its length does not match a multiple of elem_size
1090 * and -ENODATA if the property does not have a value.
1091 */
1092int of_property_count_elems_of_size(const struct device_node *np,
1093 const char *propname, int elem_size)
1094{
1095 struct property *prop = of_find_property(np, propname, NULL);
1096
1097 if (!prop)
1098 return -EINVAL;
1099 if (!prop->value)
1100 return -ENODATA;
1101
1102 if (prop->length % elem_size != 0) {
1103 pr_err("size of %s in node %s is not a multiple of %d\n",
1104 propname, np->full_name, elem_size);
1105 return -EINVAL;
1106 }
1107
1108 return prop->length / elem_size;
1109}
1110EXPORT_SYMBOL_GPL(of_property_count_elems_of_size);
1111
1112/**
1113 * of_find_property_value_of_size
1114 *
1115 * @np: device node from which the property value is to be read.
1116 * @propname: name of the property to be searched.
1117 * @len: requested length of property value
1118 *
1119 * Search for a property in a device node and valid the requested size.
1120 * Returns the property value on success, -EINVAL if the property does not
1121 * exist, -ENODATA if property does not have a value, and -EOVERFLOW if the
1122 * property data isn't large enough.
1123 *
1124 */
1125static void *of_find_property_value_of_size(const struct device_node *np,
1126 const char *propname, u32 len)
1127{
1128 struct property *prop = of_find_property(np, propname, NULL);
1129
1130 if (!prop)
1131 return ERR_PTR(-EINVAL);
1132 if (!prop->value)
1133 return ERR_PTR(-ENODATA);
1134 if (len > prop->length)
1135 return ERR_PTR(-EOVERFLOW);
1136
1137 return prop->value;
1138}
1139
1140/**
1141 * of_property_read_u32_index - Find and read a u32 from a multi-value property.
1142 *
1143 * @np: device node from which the property value is to be read.
1144 * @propname: name of the property to be searched.
1145 * @index: index of the u32 in the list of values
1146 * @out_value: pointer to return value, modified only if no error.
1147 *
1148 * Search for a property in a device node and read nth 32-bit value from
1149 * it. Returns 0 on success, -EINVAL if the property does not exist,
1150 * -ENODATA if property does not have a value, and -EOVERFLOW if the
1151 * property data isn't large enough.
1152 *
1153 * The out_value is modified only if a valid u32 value can be decoded.
1154 */
1155int of_property_read_u32_index(const struct device_node *np,
1156 const char *propname,
1157 u32 index, u32 *out_value)
1158{
1159 const u32 *val = of_find_property_value_of_size(np, propname,
1160 ((index + 1) * sizeof(*out_value)));
1161
1162 if (IS_ERR(val))
1163 return PTR_ERR(val);
1164
1165 *out_value = be32_to_cpup(((__be32 *)val) + index);
1166 return 0;
1167}
1168EXPORT_SYMBOL_GPL(of_property_read_u32_index);
1169
1170/**
1171 * of_property_read_u8_array - Find and read an array of u8 from a property.
1172 *
1173 * @np: device node from which the property value is to be read.
1174 * @propname: name of the property to be searched.
1175 * @out_values: pointer to return value, modified only if return value is 0.
1176 * @sz: number of array elements to read
1177 *
1178 * Search for a property in a device node and read 8-bit value(s) from
1179 * it. Returns 0 on success, -EINVAL if the property does not exist,
1180 * -ENODATA if property does not have a value, and -EOVERFLOW if the
1181 * property data isn't large enough.
1182 *
1183 * dts entry of array should be like:
1184 * property = /bits/ 8 <0x50 0x60 0x70>;
1185 *
1186 * The out_values is modified only if a valid u8 value can be decoded.
1187 */
1188int of_property_read_u8_array(const struct device_node *np,
1189 const char *propname, u8 *out_values, size_t sz)
1190{
1191 const u8 *val = of_find_property_value_of_size(np, propname,
1192 (sz * sizeof(*out_values)));
1193
1194 if (IS_ERR(val))
1195 return PTR_ERR(val);
1196
1197 while (sz--)
1198 *out_values++ = *val++;
1199 return 0;
1200}
1201EXPORT_SYMBOL_GPL(of_property_read_u8_array);
1202
1203/**
1204 * of_property_read_u16_array - Find and read an array of u16 from a property.
1205 *
1206 * @np: device node from which the property value is to be read.
1207 * @propname: name of the property to be searched.
1208 * @out_values: pointer to return value, modified only if return value is 0.
1209 * @sz: number of array elements to read
1210 *
1211 * Search for a property in a device node and read 16-bit value(s) from
1212 * it. Returns 0 on success, -EINVAL if the property does not exist,
1213 * -ENODATA if property does not have a value, and -EOVERFLOW if the
1214 * property data isn't large enough.
1215 *
1216 * dts entry of array should be like:
1217 * property = /bits/ 16 <0x5000 0x6000 0x7000>;
1218 *
1219 * The out_values is modified only if a valid u16 value can be decoded.
1220 */
1221int of_property_read_u16_array(const struct device_node *np,
1222 const char *propname, u16 *out_values, size_t sz)
1223{
1224 const __be16 *val = of_find_property_value_of_size(np, propname,
1225 (sz * sizeof(*out_values)));
1226
1227 if (IS_ERR(val))
1228 return PTR_ERR(val);
1229
1230 while (sz--)
1231 *out_values++ = be16_to_cpup(val++);
1232 return 0;
1233}
1234EXPORT_SYMBOL_GPL(of_property_read_u16_array);
1235
1236/**
1237 * of_property_read_u32_array - Find and read an array of 32 bit integers
1238 * from a property.
1239 *
1240 * @np: device node from which the property value is to be read.
1241 * @propname: name of the property to be searched.
1242 * @out_values: pointer to return value, modified only if return value is 0.
1243 * @sz: number of array elements to read
1244 *
1245 * Search for a property in a device node and read 32-bit value(s) from
1246 * it. Returns 0 on success, -EINVAL if the property does not exist,
1247 * -ENODATA if property does not have a value, and -EOVERFLOW if the
1248 * property data isn't large enough.
1249 *
1250 * The out_values is modified only if a valid u32 value can be decoded.
1251 */
1252int of_property_read_u32_array(const struct device_node *np,
1253 const char *propname, u32 *out_values,
1254 size_t sz)
1255{
1256 const __be32 *val = of_find_property_value_of_size(np, propname,
1257 (sz * sizeof(*out_values)));
1258
1259 if (IS_ERR(val))
1260 return PTR_ERR(val);
1261
1262 while (sz--)
1263 *out_values++ = be32_to_cpup(val++);
1264 return 0;
1265}
1266EXPORT_SYMBOL_GPL(of_property_read_u32_array);
1267
1268/**
1269 * of_property_read_u64 - Find and read a 64 bit integer from a property
1270 * @np: device node from which the property value is to be read.
1271 * @propname: name of the property to be searched.
1272 * @out_value: pointer to return value, modified only if return value is 0.
1273 *
1274 * Search for a property in a device node and read a 64-bit value from
1275 * it. Returns 0 on success, -EINVAL if the property does not exist,
1276 * -ENODATA if property does not have a value, and -EOVERFLOW if the
1277 * property data isn't large enough.
1278 *
1279 * The out_value is modified only if a valid u64 value can be decoded.
1280 */
1281int of_property_read_u64(const struct device_node *np, const char *propname,
1282 u64 *out_value)
1283{
1284 const __be32 *val = of_find_property_value_of_size(np, propname,
1285 sizeof(*out_value));
1286
1287 if (IS_ERR(val))
1288 return PTR_ERR(val);
1289
1290 *out_value = of_read_number(val, 2);
1291 return 0;
1292}
1293EXPORT_SYMBOL_GPL(of_property_read_u64);
1294
1295/**
1296 * of_property_read_u64_array - Find and read an array of 64 bit integers
1297 * from a property.
1298 *
1299 * @np: device node from which the property value is to be read.
1300 * @propname: name of the property to be searched.
1301 * @out_values: pointer to return value, modified only if return value is 0.
1302 * @sz: number of array elements to read
1303 *
1304 * Search for a property in a device node and read 64-bit value(s) from
1305 * it. Returns 0 on success, -EINVAL if the property does not exist,
1306 * -ENODATA if property does not have a value, and -EOVERFLOW if the
1307 * property data isn't large enough.
1308 *
1309 * The out_values is modified only if a valid u64 value can be decoded.
1310 */
1311int of_property_read_u64_array(const struct device_node *np,
1312 const char *propname, u64 *out_values,
1313 size_t sz)
1314{
1315 const __be32 *val = of_find_property_value_of_size(np, propname,
1316 (sz * sizeof(*out_values)));
1317
1318 if (IS_ERR(val))
1319 return PTR_ERR(val);
1320
1321 while (sz--) {
1322 *out_values++ = of_read_number(val, 2);
1323 val += 2;
1324 }
1325 return 0;
1326}
1327EXPORT_SYMBOL_GPL(of_property_read_u64_array);
1328
1329/**
1330 * of_property_read_string - Find and read a string from a property
1331 * @np: device node from which the property value is to be read.
1332 * @propname: name of the property to be searched.
1333 * @out_string: pointer to null terminated return string, modified only if
1334 * return value is 0.
1335 *
1336 * Search for a property in a device tree node and retrieve a null
1337 * terminated string value (pointer to data, not a copy). Returns 0 on
1338 * success, -EINVAL if the property does not exist, -ENODATA if property
1339 * does not have a value, and -EILSEQ if the string is not null-terminated
1340 * within the length of the property data.
1341 *
1342 * The out_string pointer is modified only if a valid string can be decoded.
1343 */
1344int of_property_read_string(const struct device_node *np, const char *propname,
1345 const char **out_string)
1346{
1347 const struct property *prop = of_find_property(np, propname, NULL);
1348 if (!prop)
1349 return -EINVAL;
1350 if (!prop->value)
1351 return -ENODATA;
1352 if (strnlen(prop->value, prop->length) >= prop->length)
1353 return -EILSEQ;
1354 *out_string = prop->value;
1355 return 0;
1356}
1357EXPORT_SYMBOL_GPL(of_property_read_string);
1358
1359/**
1360 * of_property_match_string() - Find string in a list and return index
1361 * @np: pointer to node containing string list property
1362 * @propname: string list property name
1363 * @string: pointer to string to search for in string list
1364 *
1365 * This function searches a string list property and returns the index
1366 * of a specific string value.
1367 */
1368int of_property_match_string(const struct device_node *np, const char *propname,
1369 const char *string)
1370{
1371 const struct property *prop = of_find_property(np, propname, NULL);
1372 size_t l;
1373 int i;
1374 const char *p, *end;
1375
1376 if (!prop)
1377 return -EINVAL;
1378 if (!prop->value)
1379 return -ENODATA;
1380
1381 p = prop->value;
1382 end = p + prop->length;
1383
1384 for (i = 0; p < end; i++, p += l) {
1385 l = strnlen(p, end - p) + 1;
1386 if (p + l > end)
1387 return -EILSEQ;
1388 pr_debug("comparing %s with %s\n", string, p);
1389 if (strcmp(string, p) == 0)
1390 return i; /* Found it; return index */
1391 }
1392 return -ENODATA;
1393}
1394EXPORT_SYMBOL_GPL(of_property_match_string);
1395
1396/**
1397 * of_property_read_string_helper() - Utility helper for parsing string properties
1398 * @np: device node from which the property value is to be read.
1399 * @propname: name of the property to be searched.
1400 * @out_strs: output array of string pointers.
1401 * @sz: number of array elements to read.
1402 * @skip: Number of strings to skip over at beginning of list.
1403 *
1404 * Don't call this function directly. It is a utility helper for the
1405 * of_property_read_string*() family of functions.
1406 */
1407int of_property_read_string_helper(const struct device_node *np,
1408 const char *propname, const char **out_strs,
1409 size_t sz, int skip)
1410{
1411 const struct property *prop = of_find_property(np, propname, NULL);
1412 int l = 0, i = 0;
1413 const char *p, *end;
1414
1415 if (!prop)
1416 return -EINVAL;
1417 if (!prop->value)
1418 return -ENODATA;
1419 p = prop->value;
1420 end = p + prop->length;
1421
1422 for (i = 0; p < end && (!out_strs || i < skip + sz); i++, p += l) {
1423 l = strnlen(p, end - p) + 1;
1424 if (p + l > end)
1425 return -EILSEQ;
1426 if (out_strs && i >= skip)
1427 *out_strs++ = p;
1428 }
1429 i -= skip;
1430 return i <= 0 ? -ENODATA : i;
1431}
1432EXPORT_SYMBOL_GPL(of_property_read_string_helper);
1433
1434void of_print_phandle_args(const char *msg, const struct of_phandle_args *args)
1435{
1436 int i;
1437 printk("%s %s", msg, of_node_full_name(args->np));
1438 for (i = 0; i < args->args_count; i++)
1439 printk(i ? ",%08x" : ":%08x", args->args[i]);
1440 printk("\n");
1441}
1442
1443static int __of_parse_phandle_with_args(const struct device_node *np,
1444 const char *list_name,
1445 const char *cells_name,
1446 int cell_count, int index,
1447 struct of_phandle_args *out_args)
1448{
1449 const __be32 *list, *list_end;
1450 int rc = 0, size, cur_index = 0;
1451 uint32_t count = 0;
1452 struct device_node *node = NULL;
1453 phandle phandle;
1454
1455 /* Retrieve the phandle list property */
1456 list = of_get_property(np, list_name, &size);
1457 if (!list)
1458 return -ENOENT;
1459 list_end = list + size / sizeof(*list);
1460
1461 /* Loop over the phandles until all the requested entry is found */
1462 while (list < list_end) {
1463 rc = -EINVAL;
1464 count = 0;
1465
1466 /*
1467 * If phandle is 0, then it is an empty entry with no
1468 * arguments. Skip forward to the next entry.
1469 */
1470 phandle = be32_to_cpup(list++);
1471 if (phandle) {
1472 /*
1473 * Find the provider node and parse the #*-cells
1474 * property to determine the argument length.
1475 *
1476 * This is not needed if the cell count is hard-coded
1477 * (i.e. cells_name not set, but cell_count is set),
1478 * except when we're going to return the found node
1479 * below.
1480 */
1481 if (cells_name || cur_index == index) {
1482 node = of_find_node_by_phandle(phandle);
1483 if (!node) {
1484 pr_err("%s: could not find phandle\n",
1485 np->full_name);
1486 goto err;
1487 }
1488 }
1489
1490 if (cells_name) {
1491 if (of_property_read_u32(node, cells_name,
1492 &count)) {
1493 pr_err("%s: could not get %s for %s\n",
1494 np->full_name, cells_name,
1495 node->full_name);
1496 goto err;
1497 }
1498 } else {
1499 count = cell_count;
1500 }
1501
1502 /*
1503 * Make sure that the arguments actually fit in the
1504 * remaining property data length
1505 */
1506 if (list + count > list_end) {
1507 pr_err("%s: arguments longer than property\n",
1508 np->full_name);
1509 goto err;
1510 }
1511 }
1512
1513 /*
1514 * All of the error cases above bail out of the loop, so at
1515 * this point, the parsing is successful. If the requested
1516 * index matches, then fill the out_args structure and return,
1517 * or return -ENOENT for an empty entry.
1518 */
1519 rc = -ENOENT;
1520 if (cur_index == index) {
1521 if (!phandle)
1522 goto err;
1523
1524 if (out_args) {
1525 int i;
1526 if (WARN_ON(count > MAX_PHANDLE_ARGS))
1527 count = MAX_PHANDLE_ARGS;
1528 out_args->np = node;
1529 out_args->args_count = count;
1530 for (i = 0; i < count; i++)
1531 out_args->args[i] = be32_to_cpup(list++);
1532 } else {
1533 of_node_put(node);
1534 }
1535
1536 /* Found it! return success */
1537 return 0;
1538 }
1539
1540 of_node_put(node);
1541 node = NULL;
1542 list += count;
1543 cur_index++;
1544 }
1545
1546 /*
1547 * Unlock node before returning result; will be one of:
1548 * -ENOENT : index is for empty phandle
1549 * -EINVAL : parsing error on data
1550 * [1..n] : Number of phandle (count mode; when index = -1)
1551 */
1552 rc = index < 0 ? cur_index : -ENOENT;
1553 err:
1554 if (node)
1555 of_node_put(node);
1556 return rc;
1557}
1558
1559/**
1560 * of_parse_phandle - Resolve a phandle property to a device_node pointer
1561 * @np: Pointer to device node holding phandle property
1562 * @phandle_name: Name of property holding a phandle value
1563 * @index: For properties holding a table of phandles, this is the index into
1564 * the table
1565 *
1566 * Returns the device_node pointer with refcount incremented. Use
1567 * of_node_put() on it when done.
1568 */
1569struct device_node *of_parse_phandle(const struct device_node *np,
1570 const char *phandle_name, int index)
1571{
1572 struct of_phandle_args args;
1573
1574 if (index < 0)
1575 return NULL;
1576
1577 if (__of_parse_phandle_with_args(np, phandle_name, NULL, 0,
1578 index, &args))
1579 return NULL;
1580
1581 return args.np;
1582}
1583EXPORT_SYMBOL(of_parse_phandle);
1584
1585/**
1586 * of_parse_phandle_with_args() - Find a node pointed by phandle in a list
1587 * @np: pointer to a device tree node containing a list
1588 * @list_name: property name that contains a list
1589 * @cells_name: property name that specifies phandles' arguments count
1590 * @index: index of a phandle to parse out
1591 * @out_args: optional pointer to output arguments structure (will be filled)
1592 *
1593 * This function is useful to parse lists of phandles and their arguments.
1594 * Returns 0 on success and fills out_args, on error returns appropriate
1595 * errno value.
1596 *
1597 * Caller is responsible to call of_node_put() on the returned out_args->np
1598 * pointer.
1599 *
1600 * Example:
1601 *
1602 * phandle1: node1 {
1603 * #list-cells = <2>;
1604 * }
1605 *
1606 * phandle2: node2 {
1607 * #list-cells = <1>;
1608 * }
1609 *
1610 * node3 {
1611 * list = <&phandle1 1 2 &phandle2 3>;
1612 * }
1613 *
1614 * To get a device_node of the `node2' node you may call this:
1615 * of_parse_phandle_with_args(node3, "list", "#list-cells", 1, &args);
1616 */
1617int of_parse_phandle_with_args(const struct device_node *np, const char *list_name,
1618 const char *cells_name, int index,
1619 struct of_phandle_args *out_args)
1620{
1621 if (index < 0)
1622 return -EINVAL;
1623 return __of_parse_phandle_with_args(np, list_name, cells_name, 0,
1624 index, out_args);
1625}
1626EXPORT_SYMBOL(of_parse_phandle_with_args);
1627
1628/**
1629 * of_parse_phandle_with_fixed_args() - Find a node pointed by phandle in a list
1630 * @np: pointer to a device tree node containing a list
1631 * @list_name: property name that contains a list
1632 * @cell_count: number of argument cells following the phandle
1633 * @index: index of a phandle to parse out
1634 * @out_args: optional pointer to output arguments structure (will be filled)
1635 *
1636 * This function is useful to parse lists of phandles and their arguments.
1637 * Returns 0 on success and fills out_args, on error returns appropriate
1638 * errno value.
1639 *
1640 * Caller is responsible to call of_node_put() on the returned out_args->np
1641 * pointer.
1642 *
1643 * Example:
1644 *
1645 * phandle1: node1 {
1646 * }
1647 *
1648 * phandle2: node2 {
1649 * }
1650 *
1651 * node3 {
1652 * list = <&phandle1 0 2 &phandle2 2 3>;
1653 * }
1654 *
1655 * To get a device_node of the `node2' node you may call this:
1656 * of_parse_phandle_with_fixed_args(node3, "list", 2, 1, &args);
1657 */
1658int of_parse_phandle_with_fixed_args(const struct device_node *np,
1659 const char *list_name, int cell_count,
1660 int index, struct of_phandle_args *out_args)
1661{
1662 if (index < 0)
1663 return -EINVAL;
1664 return __of_parse_phandle_with_args(np, list_name, NULL, cell_count,
1665 index, out_args);
1666}
1667EXPORT_SYMBOL(of_parse_phandle_with_fixed_args);
1668
1669/**
1670 * of_count_phandle_with_args() - Find the number of phandles references in a property
1671 * @np: pointer to a device tree node containing a list
1672 * @list_name: property name that contains a list
1673 * @cells_name: property name that specifies phandles' arguments count
1674 *
1675 * Returns the number of phandle + argument tuples within a property. It
1676 * is a typical pattern to encode a list of phandle and variable
1677 * arguments into a single property. The number of arguments is encoded
1678 * by a property in the phandle-target node. For example, a gpios
1679 * property would contain a list of GPIO specifies consisting of a
1680 * phandle and 1 or more arguments. The number of arguments are
1681 * determined by the #gpio-cells property in the node pointed to by the
1682 * phandle.
1683 */
1684int of_count_phandle_with_args(const struct device_node *np, const char *list_name,
1685 const char *cells_name)
1686{
1687 return __of_parse_phandle_with_args(np, list_name, cells_name, 0, -1,
1688 NULL);
1689}
1690EXPORT_SYMBOL(of_count_phandle_with_args);
1691
1692/**
1693 * __of_add_property - Add a property to a node without lock operations
1694 */
1695int __of_add_property(struct device_node *np, struct property *prop)
1696{
1697 struct property **next;
1698
1699 prop->next = NULL;
1700 next = &np->properties;
1701 while (*next) {
1702 if (strcmp(prop->name, (*next)->name) == 0)
1703 /* duplicate ! don't insert it */
1704 return -EEXIST;
1705
1706 next = &(*next)->next;
1707 }
1708 *next = prop;
1709
1710 return 0;
1711}
1712
1713/**
1714 * of_add_property - Add a property to a node
1715 */
1716int of_add_property(struct device_node *np, struct property *prop)
1717{
1718 unsigned long flags;
1719 int rc;
1720
1721 mutex_lock(&of_mutex);
1722
1723 raw_spin_lock_irqsave(&devtree_lock, flags);
1724 rc = __of_add_property(np, prop);
1725 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1726
1727 if (!rc)
1728 __of_add_property_sysfs(np, prop);
1729
1730 mutex_unlock(&of_mutex);
1731
1732 if (!rc)
1733 of_property_notify(OF_RECONFIG_ADD_PROPERTY, np, prop, NULL);
1734
1735 return rc;
1736}
1737
1738int __of_remove_property(struct device_node *np, struct property *prop)
1739{
1740 struct property **next;
1741
1742 for (next = &np->properties; *next; next = &(*next)->next) {
1743 if (*next == prop)
1744 break;
1745 }
1746 if (*next == NULL)
1747 return -ENODEV;
1748
1749 /* found the node */
1750 *next = prop->next;
1751 prop->next = np->deadprops;
1752 np->deadprops = prop;
1753
1754 return 0;
1755}
1756
1757void __of_remove_property_sysfs(struct device_node *np, struct property *prop)
1758{
1759 if (!IS_ENABLED(CONFIG_SYSFS))
1760 return;
1761
1762 /* at early boot, bail here and defer setup to of_init() */
1763 if (of_kset && of_node_is_attached(np))
1764 sysfs_remove_bin_file(&np->kobj, &prop->attr);
1765}
1766
1767/**
1768 * of_remove_property - Remove a property from a node.
1769 *
1770 * Note that we don't actually remove it, since we have given out
1771 * who-knows-how-many pointers to the data using get-property.
1772 * Instead we just move the property to the "dead properties"
1773 * list, so it won't be found any more.
1774 */
1775int of_remove_property(struct device_node *np, struct property *prop)
1776{
1777 unsigned long flags;
1778 int rc;
1779
1780 mutex_lock(&of_mutex);
1781
1782 raw_spin_lock_irqsave(&devtree_lock, flags);
1783 rc = __of_remove_property(np, prop);
1784 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1785
1786 if (!rc)
1787 __of_remove_property_sysfs(np, prop);
1788
1789 mutex_unlock(&of_mutex);
1790
1791 if (!rc)
1792 of_property_notify(OF_RECONFIG_REMOVE_PROPERTY, np, prop, NULL);
1793
1794 return rc;
1795}
1796
1797int __of_update_property(struct device_node *np, struct property *newprop,
1798 struct property **oldpropp)
1799{
1800 struct property **next, *oldprop;
1801
1802 for (next = &np->properties; *next; next = &(*next)->next) {
1803 if (of_prop_cmp((*next)->name, newprop->name) == 0)
1804 break;
1805 }
1806 *oldpropp = oldprop = *next;
1807
1808 if (oldprop) {
1809 /* replace the node */
1810 newprop->next = oldprop->next;
1811 *next = newprop;
1812 oldprop->next = np->deadprops;
1813 np->deadprops = oldprop;
1814 } else {
1815 /* new node */
1816 newprop->next = NULL;
1817 *next = newprop;
1818 }
1819
1820 return 0;
1821}
1822
1823void __of_update_property_sysfs(struct device_node *np, struct property *newprop,
1824 struct property *oldprop)
1825{
1826 if (!IS_ENABLED(CONFIG_SYSFS))
1827 return;
1828
1829 /* At early boot, bail out and defer setup to of_init() */
1830 if (!of_kset)
1831 return;
1832
1833 if (oldprop)
1834 sysfs_remove_bin_file(&np->kobj, &oldprop->attr);
1835 __of_add_property_sysfs(np, newprop);
1836}
1837
1838/*
1839 * of_update_property - Update a property in a node, if the property does
1840 * not exist, add it.
1841 *
1842 * Note that we don't actually remove it, since we have given out
1843 * who-knows-how-many pointers to the data using get-property.
1844 * Instead we just move the property to the "dead properties" list,
1845 * and add the new property to the property list
1846 */
1847int of_update_property(struct device_node *np, struct property *newprop)
1848{
1849 struct property *oldprop;
1850 unsigned long flags;
1851 int rc;
1852
1853 if (!newprop->name)
1854 return -EINVAL;
1855
1856 mutex_lock(&of_mutex);
1857
1858 raw_spin_lock_irqsave(&devtree_lock, flags);
1859 rc = __of_update_property(np, newprop, &oldprop);
1860 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1861
1862 if (!rc)
1863 __of_update_property_sysfs(np, newprop, oldprop);
1864
1865 mutex_unlock(&of_mutex);
1866
1867 if (!rc)
1868 of_property_notify(OF_RECONFIG_UPDATE_PROPERTY, np, newprop, oldprop);
1869
1870 return rc;
1871}
1872
1873static void of_alias_add(struct alias_prop *ap, struct device_node *np,
1874 int id, const char *stem, int stem_len)
1875{
1876 ap->np = np;
1877 ap->id = id;
1878 strncpy(ap->stem, stem, stem_len);
1879 ap->stem[stem_len] = 0;
1880 list_add_tail(&ap->link, &aliases_lookup);
1881 pr_debug("adding DT alias:%s: stem=%s id=%i node=%s\n",
1882 ap->alias, ap->stem, ap->id, of_node_full_name(np));
1883}
1884
1885/**
1886 * of_alias_scan - Scan all properties of the 'aliases' node
1887 *
1888 * The function scans all the properties of the 'aliases' node and populates
1889 * the global lookup table with the properties. It returns the
1890 * number of alias properties found, or an error code in case of failure.
1891 *
1892 * @dt_alloc: An allocator that provides a virtual address to memory
1893 * for storing the resulting tree
1894 */
1895void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align))
1896{
1897 struct property *pp;
1898
1899 of_aliases = of_find_node_by_path("/aliases");
1900 of_chosen = of_find_node_by_path("/chosen");
1901 if (of_chosen == NULL)
1902 of_chosen = of_find_node_by_path("/chosen@0");
1903
1904 if (of_chosen) {
1905 /* linux,stdout-path and /aliases/stdout are for legacy compatibility */
1906 const char *name = of_get_property(of_chosen, "stdout-path", NULL);
1907 if (!name)
1908 name = of_get_property(of_chosen, "linux,stdout-path", NULL);
1909 if (IS_ENABLED(CONFIG_PPC) && !name)
1910 name = of_get_property(of_aliases, "stdout", NULL);
1911 if (name)
1912 of_stdout = of_find_node_opts_by_path(name, &of_stdout_options);
1913 }
1914
1915 if (!of_aliases)
1916 return;
1917
1918 for_each_property_of_node(of_aliases, pp) {
1919 const char *start = pp->name;
1920 const char *end = start + strlen(start);
1921 struct device_node *np;
1922 struct alias_prop *ap;
1923 int id, len;
1924
1925 /* Skip those we do not want to proceed */
1926 if (!strcmp(pp->name, "name") ||
1927 !strcmp(pp->name, "phandle") ||
1928 !strcmp(pp->name, "linux,phandle"))
1929 continue;
1930
1931 np = of_find_node_by_path(pp->value);
1932 if (!np)
1933 continue;
1934
1935 /* walk the alias backwards to extract the id and work out
1936 * the 'stem' string */
1937 while (isdigit(*(end-1)) && end > start)
1938 end--;
1939 len = end - start;
1940
1941 if (kstrtoint(end, 10, &id) < 0)
1942 continue;
1943
1944 /* Allocate an alias_prop with enough space for the stem */
1945 ap = dt_alloc(sizeof(*ap) + len + 1, 4);
1946 if (!ap)
1947 continue;
1948 memset(ap, 0, sizeof(*ap) + len + 1);
1949 ap->alias = start;
1950 of_alias_add(ap, np, id, start, len);
1951 }
1952}
1953
1954/**
1955 * of_alias_get_id - Get alias id for the given device_node
1956 * @np: Pointer to the given device_node
1957 * @stem: Alias stem of the given device_node
1958 *
1959 * The function travels the lookup table to get the alias id for the given
1960 * device_node and alias stem. It returns the alias id if found.
1961 */
1962int of_alias_get_id(struct device_node *np, const char *stem)
1963{
1964 struct alias_prop *app;
1965 int id = -ENODEV;
1966
1967 mutex_lock(&of_mutex);
1968 list_for_each_entry(app, &aliases_lookup, link) {
1969 if (strcmp(app->stem, stem) != 0)
1970 continue;
1971
1972 if (np == app->np) {
1973 id = app->id;
1974 break;
1975 }
1976 }
1977 mutex_unlock(&of_mutex);
1978
1979 return id;
1980}
1981EXPORT_SYMBOL_GPL(of_alias_get_id);
1982
1983/**
1984 * of_alias_get_highest_id - Get highest alias id for the given stem
1985 * @stem: Alias stem to be examined
1986 *
1987 * The function travels the lookup table to get the highest alias id for the
1988 * given alias stem. It returns the alias id if found.
1989 */
1990int of_alias_get_highest_id(const char *stem)
1991{
1992 struct alias_prop *app;
1993 int id = -ENODEV;
1994
1995 mutex_lock(&of_mutex);
1996 list_for_each_entry(app, &aliases_lookup, link) {
1997 if (strcmp(app->stem, stem) != 0)
1998 continue;
1999
2000 if (app->id > id)
2001 id = app->id;
2002 }
2003 mutex_unlock(&of_mutex);
2004
2005 return id;
2006}
2007EXPORT_SYMBOL_GPL(of_alias_get_highest_id);
2008
2009const __be32 *of_prop_next_u32(struct property *prop, const __be32 *cur,
2010 u32 *pu)
2011{
2012 const void *curv = cur;
2013
2014 if (!prop)
2015 return NULL;
2016
2017 if (!cur) {
2018 curv = prop->value;
2019 goto out_val;
2020 }
2021
2022 curv += sizeof(*cur);
2023 if (curv >= prop->value + prop->length)
2024 return NULL;
2025
2026out_val:
2027 *pu = be32_to_cpup(curv);
2028 return curv;
2029}
2030EXPORT_SYMBOL_GPL(of_prop_next_u32);
2031
2032const char *of_prop_next_string(struct property *prop, const char *cur)
2033{
2034 const void *curv = cur;
2035
2036 if (!prop)
2037 return NULL;
2038
2039 if (!cur)
2040 return prop->value;
2041
2042 curv += strlen(cur) + 1;
2043 if (curv >= prop->value + prop->length)
2044 return NULL;
2045
2046 return curv;
2047}
2048EXPORT_SYMBOL_GPL(of_prop_next_string);
2049
2050/**
2051 * of_console_check() - Test and setup console for DT setup
2052 * @dn - Pointer to device node
2053 * @name - Name to use for preferred console without index. ex. "ttyS"
2054 * @index - Index to use for preferred console.
2055 *
2056 * Check if the given device node matches the stdout-path property in the
2057 * /chosen node. If it does then register it as the preferred console and return
2058 * TRUE. Otherwise return FALSE.
2059 */
2060bool of_console_check(struct device_node *dn, char *name, int index)
2061{
2062 if (!dn || dn != of_stdout || console_set_on_cmdline)
2063 return false;
2064 return !add_preferred_console(name, index,
2065 kstrdup(of_stdout_options, GFP_KERNEL));
2066}
2067EXPORT_SYMBOL_GPL(of_console_check);
2068
2069/**
2070 * of_find_next_cache_node - Find a node's subsidiary cache
2071 * @np: node of type "cpu" or "cache"
2072 *
2073 * Returns a node pointer with refcount incremented, use
2074 * of_node_put() on it when done. Caller should hold a reference
2075 * to np.
2076 */
2077struct device_node *of_find_next_cache_node(const struct device_node *np)
2078{
2079 struct device_node *child;
2080 const phandle *handle;
2081
2082 handle = of_get_property(np, "l2-cache", NULL);
2083 if (!handle)
2084 handle = of_get_property(np, "next-level-cache", NULL);
2085
2086 if (handle)
2087 return of_find_node_by_phandle(be32_to_cpup(handle));
2088
2089 /* OF on pmac has nodes instead of properties named "l2-cache"
2090 * beneath CPU nodes.
2091 */
2092 if (!strcmp(np->type, "cpu"))
2093 for_each_child_of_node(np, child)
2094 if (!strcmp(child->type, "cache"))
2095 return child;
2096
2097 return NULL;
2098}
2099
2100/**
2101 * of_graph_parse_endpoint() - parse common endpoint node properties
2102 * @node: pointer to endpoint device_node
2103 * @endpoint: pointer to the OF endpoint data structure
2104 *
2105 * The caller should hold a reference to @node.
2106 */
2107int of_graph_parse_endpoint(const struct device_node *node,
2108 struct of_endpoint *endpoint)
2109{
2110 struct device_node *port_node = of_get_parent(node);
2111
2112 WARN_ONCE(!port_node, "%s(): endpoint %s has no parent node\n",
2113 __func__, node->full_name);
2114
2115 memset(endpoint, 0, sizeof(*endpoint));
2116
2117 endpoint->local_node = node;
2118 /*
2119 * It doesn't matter whether the two calls below succeed.
2120 * If they don't then the default value 0 is used.
2121 */
2122 of_property_read_u32(port_node, "reg", &endpoint->port);
2123 of_property_read_u32(node, "reg", &endpoint->id);
2124
2125 of_node_put(port_node);
2126
2127 return 0;
2128}
2129EXPORT_SYMBOL(of_graph_parse_endpoint);
2130
2131/**
2132 * of_graph_get_port_by_id() - get the port matching a given id
2133 * @parent: pointer to the parent device node
2134 * @id: id of the port
2135 *
2136 * Return: A 'port' node pointer with refcount incremented. The caller
2137 * has to use of_node_put() on it when done.
2138 */
2139struct device_node *of_graph_get_port_by_id(struct device_node *parent, u32 id)
2140{
2141 struct device_node *node, *port;
2142
2143 node = of_get_child_by_name(parent, "ports");
2144 if (node)
2145 parent = node;
2146
2147 for_each_child_of_node(parent, port) {
2148 u32 port_id = 0;
2149
2150 if (of_node_cmp(port->name, "port") != 0)
2151 continue;
2152 of_property_read_u32(port, "reg", &port_id);
2153 if (id == port_id)
2154 break;
2155 }
2156
2157 of_node_put(node);
2158
2159 return port;
2160}
2161EXPORT_SYMBOL(of_graph_get_port_by_id);
2162
2163/**
2164 * of_graph_get_next_endpoint() - get next endpoint node
2165 * @parent: pointer to the parent device node
2166 * @prev: previous endpoint node, or NULL to get first
2167 *
2168 * Return: An 'endpoint' node pointer with refcount incremented. Refcount
2169 * of the passed @prev node is decremented.
2170 */
2171struct device_node *of_graph_get_next_endpoint(const struct device_node *parent,
2172 struct device_node *prev)
2173{
2174 struct device_node *endpoint;
2175 struct device_node *port;
2176
2177 if (!parent)
2178 return NULL;
2179
2180 /*
2181 * Start by locating the port node. If no previous endpoint is specified
2182 * search for the first port node, otherwise get the previous endpoint
2183 * parent port node.
2184 */
2185 if (!prev) {
2186 struct device_node *node;
2187
2188 node = of_get_child_by_name(parent, "ports");
2189 if (node)
2190 parent = node;
2191
2192 port = of_get_child_by_name(parent, "port");
2193 of_node_put(node);
2194
2195 if (!port) {
2196 pr_err("%s(): no port node found in %s\n",
2197 __func__, parent->full_name);
2198 return NULL;
2199 }
2200 } else {
2201 port = of_get_parent(prev);
2202 if (WARN_ONCE(!port, "%s(): endpoint %s has no parent node\n",
2203 __func__, prev->full_name))
2204 return NULL;
2205 }
2206
2207 while (1) {
2208 /*
2209 * Now that we have a port node, get the next endpoint by
2210 * getting the next child. If the previous endpoint is NULL this
2211 * will return the first child.
2212 */
2213 endpoint = of_get_next_child(port, prev);
2214 if (endpoint) {
2215 of_node_put(port);
2216 return endpoint;
2217 }
2218
2219 /* No more endpoints under this port, try the next one. */
2220 prev = NULL;
2221
2222 do {
2223 port = of_get_next_child(parent, port);
2224 if (!port)
2225 return NULL;
2226 } while (of_node_cmp(port->name, "port"));
2227 }
2228}
2229EXPORT_SYMBOL(of_graph_get_next_endpoint);
2230
2231/**
2232 * of_graph_get_endpoint_by_regs() - get endpoint node of specific identifiers
2233 * @parent: pointer to the parent device node
2234 * @port_reg: identifier (value of reg property) of the parent port node
2235 * @reg: identifier (value of reg property) of the endpoint node
2236 *
2237 * Return: An 'endpoint' node pointer which is identified by reg and at the same
2238 * is the child of a port node identified by port_reg. reg and port_reg are
2239 * ignored when they are -1.
2240 */
2241struct device_node *of_graph_get_endpoint_by_regs(
2242 const struct device_node *parent, int port_reg, int reg)
2243{
2244 struct of_endpoint endpoint;
2245 struct device_node *node, *prev_node = NULL;
2246
2247 while (1) {
2248 node = of_graph_get_next_endpoint(parent, prev_node);
2249 of_node_put(prev_node);
2250 if (!node)
2251 break;
2252
2253 of_graph_parse_endpoint(node, &endpoint);
2254 if (((port_reg == -1) || (endpoint.port == port_reg)) &&
2255 ((reg == -1) || (endpoint.id == reg)))
2256 return node;
2257
2258 prev_node = node;
2259 }
2260
2261 return NULL;
2262}
2263EXPORT_SYMBOL(of_graph_get_endpoint_by_regs);
2264
2265/**
2266 * of_graph_get_remote_port_parent() - get remote port's parent node
2267 * @node: pointer to a local endpoint device_node
2268 *
2269 * Return: Remote device node associated with remote endpoint node linked
2270 * to @node. Use of_node_put() on it when done.
2271 */
2272struct device_node *of_graph_get_remote_port_parent(
2273 const struct device_node *node)
2274{
2275 struct device_node *np;
2276 unsigned int depth;
2277
2278 /* Get remote endpoint node. */
2279 np = of_parse_phandle(node, "remote-endpoint", 0);
2280
2281 /* Walk 3 levels up only if there is 'ports' node. */
2282 for (depth = 3; depth && np; depth--) {
2283 np = of_get_next_parent(np);
2284 if (depth == 2 && of_node_cmp(np->name, "ports"))
2285 break;
2286 }
2287 return np;
2288}
2289EXPORT_SYMBOL(of_graph_get_remote_port_parent);
2290
2291/**
2292 * of_graph_get_remote_port() - get remote port node
2293 * @node: pointer to a local endpoint device_node
2294 *
2295 * Return: Remote port node associated with remote endpoint node linked
2296 * to @node. Use of_node_put() on it when done.
2297 */
2298struct device_node *of_graph_get_remote_port(const struct device_node *node)
2299{
2300 struct device_node *np;
2301
2302 /* Get remote endpoint node. */
2303 np = of_parse_phandle(node, "remote-endpoint", 0);
2304 if (!np)
2305 return NULL;
2306 return of_get_next_parent(np);
2307}
2308EXPORT_SYMBOL(of_graph_get_remote_port);