Loading...
1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Procedures for creating, accessing and interpreting the device tree.
4 *
5 * Paul Mackerras August 1996.
6 * Copyright (C) 1996-2005 Paul Mackerras.
7 *
8 * Adapted for 64bit PowerPC by Dave Engebretsen and Peter Bergner.
9 * {engebret|bergner}@us.ibm.com
10 *
11 * Adapted for sparc and sparc64 by David S. Miller davem@davemloft.net
12 *
13 * Reconsolidated from arch/x/kernel/prom.c by Stephen Rothwell and
14 * Grant Likely.
15 */
16
17#define pr_fmt(fmt) "OF: " fmt
18
19#include <linux/console.h>
20#include <linux/ctype.h>
21#include <linux/cpu.h>
22#include <linux/module.h>
23#include <linux/of.h>
24#include <linux/of_device.h>
25#include <linux/of_graph.h>
26#include <linux/spinlock.h>
27#include <linux/slab.h>
28#include <linux/string.h>
29#include <linux/proc_fs.h>
30
31#include "of_private.h"
32
33LIST_HEAD(aliases_lookup);
34
35struct device_node *of_root;
36EXPORT_SYMBOL(of_root);
37struct device_node *of_chosen;
38EXPORT_SYMBOL(of_chosen);
39struct device_node *of_aliases;
40struct device_node *of_stdout;
41static const char *of_stdout_options;
42
43struct kset *of_kset;
44
45/*
46 * Used to protect the of_aliases, to hold off addition of nodes to sysfs.
47 * This mutex must be held whenever modifications are being made to the
48 * device tree. The of_{attach,detach}_node() and
49 * of_{add,remove,update}_property() helpers make sure this happens.
50 */
51DEFINE_MUTEX(of_mutex);
52
53/* use when traversing tree through the child, sibling,
54 * or parent members of struct device_node.
55 */
56DEFINE_RAW_SPINLOCK(devtree_lock);
57
58bool of_node_name_eq(const struct device_node *np, const char *name)
59{
60 const char *node_name;
61 size_t len;
62
63 if (!np)
64 return false;
65
66 node_name = kbasename(np->full_name);
67 len = strchrnul(node_name, '@') - node_name;
68
69 return (strlen(name) == len) && (strncmp(node_name, name, len) == 0);
70}
71EXPORT_SYMBOL(of_node_name_eq);
72
73bool of_node_name_prefix(const struct device_node *np, const char *prefix)
74{
75 if (!np)
76 return false;
77
78 return strncmp(kbasename(np->full_name), prefix, strlen(prefix)) == 0;
79}
80EXPORT_SYMBOL(of_node_name_prefix);
81
82static bool __of_node_is_type(const struct device_node *np, const char *type)
83{
84 const char *match = __of_get_property(np, "device_type", NULL);
85
86 return np && match && type && !strcmp(match, type);
87}
88
89int of_bus_n_addr_cells(struct device_node *np)
90{
91 u32 cells;
92
93 for (; np; np = np->parent)
94 if (!of_property_read_u32(np, "#address-cells", &cells))
95 return cells;
96
97 /* No #address-cells property for the root node */
98 return OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
99}
100
101int of_n_addr_cells(struct device_node *np)
102{
103 if (np->parent)
104 np = np->parent;
105
106 return of_bus_n_addr_cells(np);
107}
108EXPORT_SYMBOL(of_n_addr_cells);
109
110int of_bus_n_size_cells(struct device_node *np)
111{
112 u32 cells;
113
114 for (; np; np = np->parent)
115 if (!of_property_read_u32(np, "#size-cells", &cells))
116 return cells;
117
118 /* No #size-cells property for the root node */
119 return OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
120}
121
122int of_n_size_cells(struct device_node *np)
123{
124 if (np->parent)
125 np = np->parent;
126
127 return of_bus_n_size_cells(np);
128}
129EXPORT_SYMBOL(of_n_size_cells);
130
131#ifdef CONFIG_NUMA
132int __weak of_node_to_nid(struct device_node *np)
133{
134 return NUMA_NO_NODE;
135}
136#endif
137
138#define OF_PHANDLE_CACHE_BITS 7
139#define OF_PHANDLE_CACHE_SZ BIT(OF_PHANDLE_CACHE_BITS)
140
141static struct device_node *phandle_cache[OF_PHANDLE_CACHE_SZ];
142
143static u32 of_phandle_cache_hash(phandle handle)
144{
145 return hash_32(handle, OF_PHANDLE_CACHE_BITS);
146}
147
148/*
149 * Caller must hold devtree_lock.
150 */
151void __of_phandle_cache_inv_entry(phandle handle)
152{
153 u32 handle_hash;
154 struct device_node *np;
155
156 if (!handle)
157 return;
158
159 handle_hash = of_phandle_cache_hash(handle);
160
161 np = phandle_cache[handle_hash];
162 if (np && handle == np->phandle)
163 phandle_cache[handle_hash] = NULL;
164}
165
166void __init of_core_init(void)
167{
168 struct device_node *np;
169
170 of_platform_register_reconfig_notifier();
171
172 /* Create the kset, and register existing nodes */
173 mutex_lock(&of_mutex);
174 of_kset = kset_create_and_add("devicetree", NULL, firmware_kobj);
175 if (!of_kset) {
176 mutex_unlock(&of_mutex);
177 pr_err("failed to register existing nodes\n");
178 return;
179 }
180 for_each_of_allnodes(np) {
181 __of_attach_node_sysfs(np);
182 if (np->phandle && !phandle_cache[of_phandle_cache_hash(np->phandle)])
183 phandle_cache[of_phandle_cache_hash(np->phandle)] = np;
184 }
185 mutex_unlock(&of_mutex);
186
187 /* Symlink in /proc as required by userspace ABI */
188 if (of_root)
189 proc_symlink("device-tree", NULL, "/sys/firmware/devicetree/base");
190}
191
192static struct property *__of_find_property(const struct device_node *np,
193 const char *name, int *lenp)
194{
195 struct property *pp;
196
197 if (!np)
198 return NULL;
199
200 for (pp = np->properties; pp; pp = pp->next) {
201 if (of_prop_cmp(pp->name, name) == 0) {
202 if (lenp)
203 *lenp = pp->length;
204 break;
205 }
206 }
207
208 return pp;
209}
210
211struct property *of_find_property(const struct device_node *np,
212 const char *name,
213 int *lenp)
214{
215 struct property *pp;
216 unsigned long flags;
217
218 raw_spin_lock_irqsave(&devtree_lock, flags);
219 pp = __of_find_property(np, name, lenp);
220 raw_spin_unlock_irqrestore(&devtree_lock, flags);
221
222 return pp;
223}
224EXPORT_SYMBOL(of_find_property);
225
226struct device_node *__of_find_all_nodes(struct device_node *prev)
227{
228 struct device_node *np;
229 if (!prev) {
230 np = of_root;
231 } else if (prev->child) {
232 np = prev->child;
233 } else {
234 /* Walk back up looking for a sibling, or the end of the structure */
235 np = prev;
236 while (np->parent && !np->sibling)
237 np = np->parent;
238 np = np->sibling; /* Might be null at the end of the tree */
239 }
240 return np;
241}
242
243/**
244 * of_find_all_nodes - Get next node in global list
245 * @prev: Previous node or NULL to start iteration
246 * of_node_put() will be called on it
247 *
248 * Return: A node pointer with refcount incremented, use
249 * of_node_put() on it when done.
250 */
251struct device_node *of_find_all_nodes(struct device_node *prev)
252{
253 struct device_node *np;
254 unsigned long flags;
255
256 raw_spin_lock_irqsave(&devtree_lock, flags);
257 np = __of_find_all_nodes(prev);
258 of_node_get(np);
259 of_node_put(prev);
260 raw_spin_unlock_irqrestore(&devtree_lock, flags);
261 return np;
262}
263EXPORT_SYMBOL(of_find_all_nodes);
264
265/*
266 * Find a property with a given name for a given node
267 * and return the value.
268 */
269const void *__of_get_property(const struct device_node *np,
270 const char *name, int *lenp)
271{
272 struct property *pp = __of_find_property(np, name, lenp);
273
274 return pp ? pp->value : NULL;
275}
276
277/*
278 * Find a property with a given name for a given node
279 * and return the value.
280 */
281const void *of_get_property(const struct device_node *np, const char *name,
282 int *lenp)
283{
284 struct property *pp = of_find_property(np, name, lenp);
285
286 return pp ? pp->value : NULL;
287}
288EXPORT_SYMBOL(of_get_property);
289
290/**
291 * __of_device_is_compatible() - Check if the node matches given constraints
292 * @device: pointer to node
293 * @compat: required compatible string, NULL or "" for any match
294 * @type: required device_type value, NULL or "" for any match
295 * @name: required node name, NULL or "" for any match
296 *
297 * Checks if the given @compat, @type and @name strings match the
298 * properties of the given @device. A constraints can be skipped by
299 * passing NULL or an empty string as the constraint.
300 *
301 * Returns 0 for no match, and a positive integer on match. The return
302 * value is a relative score with larger values indicating better
303 * matches. The score is weighted for the most specific compatible value
304 * to get the highest score. Matching type is next, followed by matching
305 * name. Practically speaking, this results in the following priority
306 * order for matches:
307 *
308 * 1. specific compatible && type && name
309 * 2. specific compatible && type
310 * 3. specific compatible && name
311 * 4. specific compatible
312 * 5. general compatible && type && name
313 * 6. general compatible && type
314 * 7. general compatible && name
315 * 8. general compatible
316 * 9. type && name
317 * 10. type
318 * 11. name
319 */
320static int __of_device_is_compatible(const struct device_node *device,
321 const char *compat, const char *type, const char *name)
322{
323 struct property *prop;
324 const char *cp;
325 int index = 0, score = 0;
326
327 /* Compatible match has highest priority */
328 if (compat && compat[0]) {
329 prop = __of_find_property(device, "compatible", NULL);
330 for (cp = of_prop_next_string(prop, NULL); cp;
331 cp = of_prop_next_string(prop, cp), index++) {
332 if (of_compat_cmp(cp, compat, strlen(compat)) == 0) {
333 score = INT_MAX/2 - (index << 2);
334 break;
335 }
336 }
337 if (!score)
338 return 0;
339 }
340
341 /* Matching type is better than matching name */
342 if (type && type[0]) {
343 if (!__of_node_is_type(device, type))
344 return 0;
345 score += 2;
346 }
347
348 /* Matching name is a bit better than not */
349 if (name && name[0]) {
350 if (!of_node_name_eq(device, name))
351 return 0;
352 score++;
353 }
354
355 return score;
356}
357
358/** Checks if the given "compat" string matches one of the strings in
359 * the device's "compatible" property
360 */
361int of_device_is_compatible(const struct device_node *device,
362 const char *compat)
363{
364 unsigned long flags;
365 int res;
366
367 raw_spin_lock_irqsave(&devtree_lock, flags);
368 res = __of_device_is_compatible(device, compat, NULL, NULL);
369 raw_spin_unlock_irqrestore(&devtree_lock, flags);
370 return res;
371}
372EXPORT_SYMBOL(of_device_is_compatible);
373
374/** Checks if the device is compatible with any of the entries in
375 * a NULL terminated array of strings. Returns the best match
376 * score or 0.
377 */
378int of_device_compatible_match(const struct device_node *device,
379 const char *const *compat)
380{
381 unsigned int tmp, score = 0;
382
383 if (!compat)
384 return 0;
385
386 while (*compat) {
387 tmp = of_device_is_compatible(device, *compat);
388 if (tmp > score)
389 score = tmp;
390 compat++;
391 }
392
393 return score;
394}
395EXPORT_SYMBOL_GPL(of_device_compatible_match);
396
397/**
398 * of_machine_is_compatible - Test root of device tree for a given compatible value
399 * @compat: compatible string to look for in root node's compatible property.
400 *
401 * Return: A positive integer if the root node has the given value in its
402 * compatible property.
403 */
404int of_machine_is_compatible(const char *compat)
405{
406 struct device_node *root;
407 int rc = 0;
408
409 root = of_find_node_by_path("/");
410 if (root) {
411 rc = of_device_is_compatible(root, compat);
412 of_node_put(root);
413 }
414 return rc;
415}
416EXPORT_SYMBOL(of_machine_is_compatible);
417
418/**
419 * __of_device_is_available - check if a device is available for use
420 *
421 * @device: Node to check for availability, with locks already held
422 *
423 * Return: True if the status property is absent or set to "okay" or "ok",
424 * false otherwise
425 */
426static bool __of_device_is_available(const struct device_node *device)
427{
428 const char *status;
429 int statlen;
430
431 if (!device)
432 return false;
433
434 status = __of_get_property(device, "status", &statlen);
435 if (status == NULL)
436 return true;
437
438 if (statlen > 0) {
439 if (!strcmp(status, "okay") || !strcmp(status, "ok"))
440 return true;
441 }
442
443 return false;
444}
445
446/**
447 * of_device_is_available - check if a device is available for use
448 *
449 * @device: Node to check for availability
450 *
451 * Return: True if the status property is absent or set to "okay" or "ok",
452 * false otherwise
453 */
454bool of_device_is_available(const struct device_node *device)
455{
456 unsigned long flags;
457 bool res;
458
459 raw_spin_lock_irqsave(&devtree_lock, flags);
460 res = __of_device_is_available(device);
461 raw_spin_unlock_irqrestore(&devtree_lock, flags);
462 return res;
463
464}
465EXPORT_SYMBOL(of_device_is_available);
466
467/**
468 * __of_device_is_fail - check if a device has status "fail" or "fail-..."
469 *
470 * @device: Node to check status for, with locks already held
471 *
472 * Return: True if the status property is set to "fail" or "fail-..." (for any
473 * error code suffix), false otherwise
474 */
475static bool __of_device_is_fail(const struct device_node *device)
476{
477 const char *status;
478
479 if (!device)
480 return false;
481
482 status = __of_get_property(device, "status", NULL);
483 if (status == NULL)
484 return false;
485
486 return !strcmp(status, "fail") || !strncmp(status, "fail-", 5);
487}
488
489/**
490 * of_device_is_big_endian - check if a device has BE registers
491 *
492 * @device: Node to check for endianness
493 *
494 * Return: True if the device has a "big-endian" property, or if the kernel
495 * was compiled for BE *and* the device has a "native-endian" property.
496 * Returns false otherwise.
497 *
498 * Callers would nominally use ioread32be/iowrite32be if
499 * of_device_is_big_endian() == true, or readl/writel otherwise.
500 */
501bool of_device_is_big_endian(const struct device_node *device)
502{
503 if (of_property_read_bool(device, "big-endian"))
504 return true;
505 if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) &&
506 of_property_read_bool(device, "native-endian"))
507 return true;
508 return false;
509}
510EXPORT_SYMBOL(of_device_is_big_endian);
511
512/**
513 * of_get_parent - Get a node's parent if any
514 * @node: Node to get parent
515 *
516 * Return: A node pointer with refcount incremented, use
517 * of_node_put() on it when done.
518 */
519struct device_node *of_get_parent(const struct device_node *node)
520{
521 struct device_node *np;
522 unsigned long flags;
523
524 if (!node)
525 return NULL;
526
527 raw_spin_lock_irqsave(&devtree_lock, flags);
528 np = of_node_get(node->parent);
529 raw_spin_unlock_irqrestore(&devtree_lock, flags);
530 return np;
531}
532EXPORT_SYMBOL(of_get_parent);
533
534/**
535 * of_get_next_parent - Iterate to a node's parent
536 * @node: Node to get parent of
537 *
538 * This is like of_get_parent() except that it drops the
539 * refcount on the passed node, making it suitable for iterating
540 * through a node's parents.
541 *
542 * Return: A node pointer with refcount incremented, use
543 * of_node_put() on it when done.
544 */
545struct device_node *of_get_next_parent(struct device_node *node)
546{
547 struct device_node *parent;
548 unsigned long flags;
549
550 if (!node)
551 return NULL;
552
553 raw_spin_lock_irqsave(&devtree_lock, flags);
554 parent = of_node_get(node->parent);
555 of_node_put(node);
556 raw_spin_unlock_irqrestore(&devtree_lock, flags);
557 return parent;
558}
559EXPORT_SYMBOL(of_get_next_parent);
560
561static struct device_node *__of_get_next_child(const struct device_node *node,
562 struct device_node *prev)
563{
564 struct device_node *next;
565
566 if (!node)
567 return NULL;
568
569 next = prev ? prev->sibling : node->child;
570 of_node_get(next);
571 of_node_put(prev);
572 return next;
573}
574#define __for_each_child_of_node(parent, child) \
575 for (child = __of_get_next_child(parent, NULL); child != NULL; \
576 child = __of_get_next_child(parent, child))
577
578/**
579 * of_get_next_child - Iterate a node childs
580 * @node: parent node
581 * @prev: previous child of the parent node, or NULL to get first
582 *
583 * Return: A node pointer with refcount incremented, use of_node_put() on
584 * it when done. Returns NULL when prev is the last child. Decrements the
585 * refcount of prev.
586 */
587struct device_node *of_get_next_child(const struct device_node *node,
588 struct device_node *prev)
589{
590 struct device_node *next;
591 unsigned long flags;
592
593 raw_spin_lock_irqsave(&devtree_lock, flags);
594 next = __of_get_next_child(node, prev);
595 raw_spin_unlock_irqrestore(&devtree_lock, flags);
596 return next;
597}
598EXPORT_SYMBOL(of_get_next_child);
599
600/**
601 * of_get_next_available_child - Find the next available child node
602 * @node: parent node
603 * @prev: previous child of the parent node, or NULL to get first
604 *
605 * This function is like of_get_next_child(), except that it
606 * automatically skips any disabled nodes (i.e. status = "disabled").
607 */
608struct device_node *of_get_next_available_child(const struct device_node *node,
609 struct device_node *prev)
610{
611 struct device_node *next;
612 unsigned long flags;
613
614 if (!node)
615 return NULL;
616
617 raw_spin_lock_irqsave(&devtree_lock, flags);
618 next = prev ? prev->sibling : node->child;
619 for (; next; next = next->sibling) {
620 if (!__of_device_is_available(next))
621 continue;
622 if (of_node_get(next))
623 break;
624 }
625 of_node_put(prev);
626 raw_spin_unlock_irqrestore(&devtree_lock, flags);
627 return next;
628}
629EXPORT_SYMBOL(of_get_next_available_child);
630
631/**
632 * of_get_next_cpu_node - Iterate on cpu nodes
633 * @prev: previous child of the /cpus node, or NULL to get first
634 *
635 * Unusable CPUs (those with the status property set to "fail" or "fail-...")
636 * will be skipped.
637 *
638 * Return: A cpu node pointer with refcount incremented, use of_node_put()
639 * on it when done. Returns NULL when prev is the last child. Decrements
640 * the refcount of prev.
641 */
642struct device_node *of_get_next_cpu_node(struct device_node *prev)
643{
644 struct device_node *next = NULL;
645 unsigned long flags;
646 struct device_node *node;
647
648 if (!prev)
649 node = of_find_node_by_path("/cpus");
650
651 raw_spin_lock_irqsave(&devtree_lock, flags);
652 if (prev)
653 next = prev->sibling;
654 else if (node) {
655 next = node->child;
656 of_node_put(node);
657 }
658 for (; next; next = next->sibling) {
659 if (__of_device_is_fail(next))
660 continue;
661 if (!(of_node_name_eq(next, "cpu") ||
662 __of_node_is_type(next, "cpu")))
663 continue;
664 if (of_node_get(next))
665 break;
666 }
667 of_node_put(prev);
668 raw_spin_unlock_irqrestore(&devtree_lock, flags);
669 return next;
670}
671EXPORT_SYMBOL(of_get_next_cpu_node);
672
673/**
674 * of_get_compatible_child - Find compatible child node
675 * @parent: parent node
676 * @compatible: compatible string
677 *
678 * Lookup child node whose compatible property contains the given compatible
679 * string.
680 *
681 * Return: a node pointer with refcount incremented, use of_node_put() on it
682 * when done; or NULL if not found.
683 */
684struct device_node *of_get_compatible_child(const struct device_node *parent,
685 const char *compatible)
686{
687 struct device_node *child;
688
689 for_each_child_of_node(parent, child) {
690 if (of_device_is_compatible(child, compatible))
691 break;
692 }
693
694 return child;
695}
696EXPORT_SYMBOL(of_get_compatible_child);
697
698/**
699 * of_get_child_by_name - Find the child node by name for a given parent
700 * @node: parent node
701 * @name: child name to look for.
702 *
703 * This function looks for child node for given matching name
704 *
705 * Return: A node pointer if found, with refcount incremented, use
706 * of_node_put() on it when done.
707 * Returns NULL if node is not found.
708 */
709struct device_node *of_get_child_by_name(const struct device_node *node,
710 const char *name)
711{
712 struct device_node *child;
713
714 for_each_child_of_node(node, child)
715 if (of_node_name_eq(child, name))
716 break;
717 return child;
718}
719EXPORT_SYMBOL(of_get_child_by_name);
720
721struct device_node *__of_find_node_by_path(struct device_node *parent,
722 const char *path)
723{
724 struct device_node *child;
725 int len;
726
727 len = strcspn(path, "/:");
728 if (!len)
729 return NULL;
730
731 __for_each_child_of_node(parent, child) {
732 const char *name = kbasename(child->full_name);
733 if (strncmp(path, name, len) == 0 && (strlen(name) == len))
734 return child;
735 }
736 return NULL;
737}
738
739struct device_node *__of_find_node_by_full_path(struct device_node *node,
740 const char *path)
741{
742 const char *separator = strchr(path, ':');
743
744 while (node && *path == '/') {
745 struct device_node *tmp = node;
746
747 path++; /* Increment past '/' delimiter */
748 node = __of_find_node_by_path(node, path);
749 of_node_put(tmp);
750 path = strchrnul(path, '/');
751 if (separator && separator < path)
752 break;
753 }
754 return node;
755}
756
757/**
758 * of_find_node_opts_by_path - Find a node matching a full OF path
759 * @path: Either the full path to match, or if the path does not
760 * start with '/', the name of a property of the /aliases
761 * node (an alias). In the case of an alias, the node
762 * matching the alias' value will be returned.
763 * @opts: Address of a pointer into which to store the start of
764 * an options string appended to the end of the path with
765 * a ':' separator.
766 *
767 * Valid paths:
768 * * /foo/bar Full path
769 * * foo Valid alias
770 * * foo/bar Valid alias + relative path
771 *
772 * Return: A node pointer with refcount incremented, use
773 * of_node_put() on it when done.
774 */
775struct device_node *of_find_node_opts_by_path(const char *path, const char **opts)
776{
777 struct device_node *np = NULL;
778 struct property *pp;
779 unsigned long flags;
780 const char *separator = strchr(path, ':');
781
782 if (opts)
783 *opts = separator ? separator + 1 : NULL;
784
785 if (strcmp(path, "/") == 0)
786 return of_node_get(of_root);
787
788 /* The path could begin with an alias */
789 if (*path != '/') {
790 int len;
791 const char *p = separator;
792
793 if (!p)
794 p = strchrnul(path, '/');
795 len = p - path;
796
797 /* of_aliases must not be NULL */
798 if (!of_aliases)
799 return NULL;
800
801 for_each_property_of_node(of_aliases, pp) {
802 if (strlen(pp->name) == len && !strncmp(pp->name, path, len)) {
803 np = of_find_node_by_path(pp->value);
804 break;
805 }
806 }
807 if (!np)
808 return NULL;
809 path = p;
810 }
811
812 /* Step down the tree matching path components */
813 raw_spin_lock_irqsave(&devtree_lock, flags);
814 if (!np)
815 np = of_node_get(of_root);
816 np = __of_find_node_by_full_path(np, path);
817 raw_spin_unlock_irqrestore(&devtree_lock, flags);
818 return np;
819}
820EXPORT_SYMBOL(of_find_node_opts_by_path);
821
822/**
823 * of_find_node_by_name - Find a node by its "name" property
824 * @from: The node to start searching from or NULL; the node
825 * you pass will not be searched, only the next one
826 * will. Typically, you pass what the previous call
827 * returned. of_node_put() will be called on @from.
828 * @name: The name string to match against
829 *
830 * Return: A node pointer with refcount incremented, use
831 * of_node_put() on it when done.
832 */
833struct device_node *of_find_node_by_name(struct device_node *from,
834 const char *name)
835{
836 struct device_node *np;
837 unsigned long flags;
838
839 raw_spin_lock_irqsave(&devtree_lock, flags);
840 for_each_of_allnodes_from(from, np)
841 if (of_node_name_eq(np, name) && of_node_get(np))
842 break;
843 of_node_put(from);
844 raw_spin_unlock_irqrestore(&devtree_lock, flags);
845 return np;
846}
847EXPORT_SYMBOL(of_find_node_by_name);
848
849/**
850 * of_find_node_by_type - Find a node by its "device_type" property
851 * @from: The node to start searching from, or NULL to start searching
852 * the entire device tree. The node you pass will not be
853 * searched, only the next one will; typically, you pass
854 * what the previous call returned. of_node_put() will be
855 * called on from for you.
856 * @type: The type string to match against
857 *
858 * Return: A node pointer with refcount incremented, use
859 * of_node_put() on it when done.
860 */
861struct device_node *of_find_node_by_type(struct device_node *from,
862 const char *type)
863{
864 struct device_node *np;
865 unsigned long flags;
866
867 raw_spin_lock_irqsave(&devtree_lock, flags);
868 for_each_of_allnodes_from(from, np)
869 if (__of_node_is_type(np, type) && of_node_get(np))
870 break;
871 of_node_put(from);
872 raw_spin_unlock_irqrestore(&devtree_lock, flags);
873 return np;
874}
875EXPORT_SYMBOL(of_find_node_by_type);
876
877/**
878 * of_find_compatible_node - Find a node based on type and one of the
879 * tokens in its "compatible" property
880 * @from: The node to start searching from or NULL, the node
881 * you pass will not be searched, only the next one
882 * will; typically, you pass what the previous call
883 * returned. of_node_put() will be called on it
884 * @type: The type string to match "device_type" or NULL to ignore
885 * @compatible: The string to match to one of the tokens in the device
886 * "compatible" list.
887 *
888 * Return: A node pointer with refcount incremented, use
889 * of_node_put() on it when done.
890 */
891struct device_node *of_find_compatible_node(struct device_node *from,
892 const char *type, const char *compatible)
893{
894 struct device_node *np;
895 unsigned long flags;
896
897 raw_spin_lock_irqsave(&devtree_lock, flags);
898 for_each_of_allnodes_from(from, np)
899 if (__of_device_is_compatible(np, compatible, type, NULL) &&
900 of_node_get(np))
901 break;
902 of_node_put(from);
903 raw_spin_unlock_irqrestore(&devtree_lock, flags);
904 return np;
905}
906EXPORT_SYMBOL(of_find_compatible_node);
907
908/**
909 * of_find_node_with_property - Find a node which has a property with
910 * the given name.
911 * @from: The node to start searching from or NULL, the node
912 * you pass will not be searched, only the next one
913 * will; typically, you pass what the previous call
914 * returned. of_node_put() will be called on it
915 * @prop_name: The name of the property to look for.
916 *
917 * Return: A node pointer with refcount incremented, use
918 * of_node_put() on it when done.
919 */
920struct device_node *of_find_node_with_property(struct device_node *from,
921 const char *prop_name)
922{
923 struct device_node *np;
924 struct property *pp;
925 unsigned long flags;
926
927 raw_spin_lock_irqsave(&devtree_lock, flags);
928 for_each_of_allnodes_from(from, np) {
929 for (pp = np->properties; pp; pp = pp->next) {
930 if (of_prop_cmp(pp->name, prop_name) == 0) {
931 of_node_get(np);
932 goto out;
933 }
934 }
935 }
936out:
937 of_node_put(from);
938 raw_spin_unlock_irqrestore(&devtree_lock, flags);
939 return np;
940}
941EXPORT_SYMBOL(of_find_node_with_property);
942
943static
944const struct of_device_id *__of_match_node(const struct of_device_id *matches,
945 const struct device_node *node)
946{
947 const struct of_device_id *best_match = NULL;
948 int score, best_score = 0;
949
950 if (!matches)
951 return NULL;
952
953 for (; matches->name[0] || matches->type[0] || matches->compatible[0]; matches++) {
954 score = __of_device_is_compatible(node, matches->compatible,
955 matches->type, matches->name);
956 if (score > best_score) {
957 best_match = matches;
958 best_score = score;
959 }
960 }
961
962 return best_match;
963}
964
965/**
966 * of_match_node - Tell if a device_node has a matching of_match structure
967 * @matches: array of of device match structures to search in
968 * @node: the of device structure to match against
969 *
970 * Low level utility function used by device matching.
971 */
972const struct of_device_id *of_match_node(const struct of_device_id *matches,
973 const struct device_node *node)
974{
975 const struct of_device_id *match;
976 unsigned long flags;
977
978 raw_spin_lock_irqsave(&devtree_lock, flags);
979 match = __of_match_node(matches, node);
980 raw_spin_unlock_irqrestore(&devtree_lock, flags);
981 return match;
982}
983EXPORT_SYMBOL(of_match_node);
984
985/**
986 * of_find_matching_node_and_match - Find a node based on an of_device_id
987 * match table.
988 * @from: The node to start searching from or NULL, the node
989 * you pass will not be searched, only the next one
990 * will; typically, you pass what the previous call
991 * returned. of_node_put() will be called on it
992 * @matches: array of of device match structures to search in
993 * @match: Updated to point at the matches entry which matched
994 *
995 * Return: A node pointer with refcount incremented, use
996 * of_node_put() on it when done.
997 */
998struct device_node *of_find_matching_node_and_match(struct device_node *from,
999 const struct of_device_id *matches,
1000 const struct of_device_id **match)
1001{
1002 struct device_node *np;
1003 const struct of_device_id *m;
1004 unsigned long flags;
1005
1006 if (match)
1007 *match = NULL;
1008
1009 raw_spin_lock_irqsave(&devtree_lock, flags);
1010 for_each_of_allnodes_from(from, np) {
1011 m = __of_match_node(matches, np);
1012 if (m && of_node_get(np)) {
1013 if (match)
1014 *match = m;
1015 break;
1016 }
1017 }
1018 of_node_put(from);
1019 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1020 return np;
1021}
1022EXPORT_SYMBOL(of_find_matching_node_and_match);
1023
1024/**
1025 * of_alias_from_compatible - Lookup appropriate alias for a device node
1026 * depending on compatible
1027 * @node: pointer to a device tree node
1028 * @alias: Pointer to buffer that alias value will be copied into
1029 * @len: Length of alias value
1030 *
1031 * Based on the value of the compatible property, this routine will attempt
1032 * to choose an appropriate alias value for a particular device tree node.
1033 * It does this by stripping the manufacturer prefix (as delimited by a ',')
1034 * from the first entry in the compatible list property.
1035 *
1036 * Note: The matching on just the "product" side of the compatible is a relic
1037 * from I2C and SPI. Please do not add any new user.
1038 *
1039 * Return: This routine returns 0 on success, <0 on failure.
1040 */
1041int of_alias_from_compatible(const struct device_node *node, char *alias, int len)
1042{
1043 const char *compatible, *p;
1044 int cplen;
1045
1046 compatible = of_get_property(node, "compatible", &cplen);
1047 if (!compatible || strlen(compatible) > cplen)
1048 return -ENODEV;
1049 p = strchr(compatible, ',');
1050 strscpy(alias, p ? p + 1 : compatible, len);
1051 return 0;
1052}
1053EXPORT_SYMBOL_GPL(of_alias_from_compatible);
1054
1055/**
1056 * of_find_node_by_phandle - Find a node given a phandle
1057 * @handle: phandle of the node to find
1058 *
1059 * Return: A node pointer with refcount incremented, use
1060 * of_node_put() on it when done.
1061 */
1062struct device_node *of_find_node_by_phandle(phandle handle)
1063{
1064 struct device_node *np = NULL;
1065 unsigned long flags;
1066 u32 handle_hash;
1067
1068 if (!handle)
1069 return NULL;
1070
1071 handle_hash = of_phandle_cache_hash(handle);
1072
1073 raw_spin_lock_irqsave(&devtree_lock, flags);
1074
1075 if (phandle_cache[handle_hash] &&
1076 handle == phandle_cache[handle_hash]->phandle)
1077 np = phandle_cache[handle_hash];
1078
1079 if (!np) {
1080 for_each_of_allnodes(np)
1081 if (np->phandle == handle &&
1082 !of_node_check_flag(np, OF_DETACHED)) {
1083 phandle_cache[handle_hash] = np;
1084 break;
1085 }
1086 }
1087
1088 of_node_get(np);
1089 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1090 return np;
1091}
1092EXPORT_SYMBOL(of_find_node_by_phandle);
1093
1094void of_print_phandle_args(const char *msg, const struct of_phandle_args *args)
1095{
1096 int i;
1097 printk("%s %pOF", msg, args->np);
1098 for (i = 0; i < args->args_count; i++) {
1099 const char delim = i ? ',' : ':';
1100
1101 pr_cont("%c%08x", delim, args->args[i]);
1102 }
1103 pr_cont("\n");
1104}
1105
1106int of_phandle_iterator_init(struct of_phandle_iterator *it,
1107 const struct device_node *np,
1108 const char *list_name,
1109 const char *cells_name,
1110 int cell_count)
1111{
1112 const __be32 *list;
1113 int size;
1114
1115 memset(it, 0, sizeof(*it));
1116
1117 /*
1118 * one of cell_count or cells_name must be provided to determine the
1119 * argument length.
1120 */
1121 if (cell_count < 0 && !cells_name)
1122 return -EINVAL;
1123
1124 list = of_get_property(np, list_name, &size);
1125 if (!list)
1126 return -ENOENT;
1127
1128 it->cells_name = cells_name;
1129 it->cell_count = cell_count;
1130 it->parent = np;
1131 it->list_end = list + size / sizeof(*list);
1132 it->phandle_end = list;
1133 it->cur = list;
1134
1135 return 0;
1136}
1137EXPORT_SYMBOL_GPL(of_phandle_iterator_init);
1138
1139int of_phandle_iterator_next(struct of_phandle_iterator *it)
1140{
1141 uint32_t count = 0;
1142
1143 if (it->node) {
1144 of_node_put(it->node);
1145 it->node = NULL;
1146 }
1147
1148 if (!it->cur || it->phandle_end >= it->list_end)
1149 return -ENOENT;
1150
1151 it->cur = it->phandle_end;
1152
1153 /* If phandle is 0, then it is an empty entry with no arguments. */
1154 it->phandle = be32_to_cpup(it->cur++);
1155
1156 if (it->phandle) {
1157
1158 /*
1159 * Find the provider node and parse the #*-cells property to
1160 * determine the argument length.
1161 */
1162 it->node = of_find_node_by_phandle(it->phandle);
1163
1164 if (it->cells_name) {
1165 if (!it->node) {
1166 pr_err("%pOF: could not find phandle %d\n",
1167 it->parent, it->phandle);
1168 goto err;
1169 }
1170
1171 if (of_property_read_u32(it->node, it->cells_name,
1172 &count)) {
1173 /*
1174 * If both cell_count and cells_name is given,
1175 * fall back to cell_count in absence
1176 * of the cells_name property
1177 */
1178 if (it->cell_count >= 0) {
1179 count = it->cell_count;
1180 } else {
1181 pr_err("%pOF: could not get %s for %pOF\n",
1182 it->parent,
1183 it->cells_name,
1184 it->node);
1185 goto err;
1186 }
1187 }
1188 } else {
1189 count = it->cell_count;
1190 }
1191
1192 /*
1193 * Make sure that the arguments actually fit in the remaining
1194 * property data length
1195 */
1196 if (it->cur + count > it->list_end) {
1197 if (it->cells_name)
1198 pr_err("%pOF: %s = %d found %td\n",
1199 it->parent, it->cells_name,
1200 count, it->list_end - it->cur);
1201 else
1202 pr_err("%pOF: phandle %s needs %d, found %td\n",
1203 it->parent, of_node_full_name(it->node),
1204 count, it->list_end - it->cur);
1205 goto err;
1206 }
1207 }
1208
1209 it->phandle_end = it->cur + count;
1210 it->cur_count = count;
1211
1212 return 0;
1213
1214err:
1215 if (it->node) {
1216 of_node_put(it->node);
1217 it->node = NULL;
1218 }
1219
1220 return -EINVAL;
1221}
1222EXPORT_SYMBOL_GPL(of_phandle_iterator_next);
1223
1224int of_phandle_iterator_args(struct of_phandle_iterator *it,
1225 uint32_t *args,
1226 int size)
1227{
1228 int i, count;
1229
1230 count = it->cur_count;
1231
1232 if (WARN_ON(size < count))
1233 count = size;
1234
1235 for (i = 0; i < count; i++)
1236 args[i] = be32_to_cpup(it->cur++);
1237
1238 return count;
1239}
1240
1241int __of_parse_phandle_with_args(const struct device_node *np,
1242 const char *list_name,
1243 const char *cells_name,
1244 int cell_count, int index,
1245 struct of_phandle_args *out_args)
1246{
1247 struct of_phandle_iterator it;
1248 int rc, cur_index = 0;
1249
1250 if (index < 0)
1251 return -EINVAL;
1252
1253 /* Loop over the phandles until all the requested entry is found */
1254 of_for_each_phandle(&it, rc, np, list_name, cells_name, cell_count) {
1255 /*
1256 * All of the error cases bail out of the loop, so at
1257 * this point, the parsing is successful. If the requested
1258 * index matches, then fill the out_args structure and return,
1259 * or return -ENOENT for an empty entry.
1260 */
1261 rc = -ENOENT;
1262 if (cur_index == index) {
1263 if (!it.phandle)
1264 goto err;
1265
1266 if (out_args) {
1267 int c;
1268
1269 c = of_phandle_iterator_args(&it,
1270 out_args->args,
1271 MAX_PHANDLE_ARGS);
1272 out_args->np = it.node;
1273 out_args->args_count = c;
1274 } else {
1275 of_node_put(it.node);
1276 }
1277
1278 /* Found it! return success */
1279 return 0;
1280 }
1281
1282 cur_index++;
1283 }
1284
1285 /*
1286 * Unlock node before returning result; will be one of:
1287 * -ENOENT : index is for empty phandle
1288 * -EINVAL : parsing error on data
1289 */
1290
1291 err:
1292 of_node_put(it.node);
1293 return rc;
1294}
1295EXPORT_SYMBOL(__of_parse_phandle_with_args);
1296
1297/**
1298 * of_parse_phandle_with_args_map() - Find a node pointed by phandle in a list and remap it
1299 * @np: pointer to a device tree node containing a list
1300 * @list_name: property name that contains a list
1301 * @stem_name: stem of property names that specify phandles' arguments count
1302 * @index: index of a phandle to parse out
1303 * @out_args: optional pointer to output arguments structure (will be filled)
1304 *
1305 * This function is useful to parse lists of phandles and their arguments.
1306 * Returns 0 on success and fills out_args, on error returns appropriate errno
1307 * value. The difference between this function and of_parse_phandle_with_args()
1308 * is that this API remaps a phandle if the node the phandle points to has
1309 * a <@stem_name>-map property.
1310 *
1311 * Caller is responsible to call of_node_put() on the returned out_args->np
1312 * pointer.
1313 *
1314 * Example::
1315 *
1316 * phandle1: node1 {
1317 * #list-cells = <2>;
1318 * };
1319 *
1320 * phandle2: node2 {
1321 * #list-cells = <1>;
1322 * };
1323 *
1324 * phandle3: node3 {
1325 * #list-cells = <1>;
1326 * list-map = <0 &phandle2 3>,
1327 * <1 &phandle2 2>,
1328 * <2 &phandle1 5 1>;
1329 * list-map-mask = <0x3>;
1330 * };
1331 *
1332 * node4 {
1333 * list = <&phandle1 1 2 &phandle3 0>;
1334 * };
1335 *
1336 * To get a device_node of the ``node2`` node you may call this:
1337 * of_parse_phandle_with_args(node4, "list", "list", 1, &args);
1338 */
1339int of_parse_phandle_with_args_map(const struct device_node *np,
1340 const char *list_name,
1341 const char *stem_name,
1342 int index, struct of_phandle_args *out_args)
1343{
1344 char *cells_name, *map_name = NULL, *mask_name = NULL;
1345 char *pass_name = NULL;
1346 struct device_node *cur, *new = NULL;
1347 const __be32 *map, *mask, *pass;
1348 static const __be32 dummy_mask[] = { [0 ... MAX_PHANDLE_ARGS] = ~0 };
1349 static const __be32 dummy_pass[] = { [0 ... MAX_PHANDLE_ARGS] = 0 };
1350 __be32 initial_match_array[MAX_PHANDLE_ARGS];
1351 const __be32 *match_array = initial_match_array;
1352 int i, ret, map_len, match;
1353 u32 list_size, new_size;
1354
1355 if (index < 0)
1356 return -EINVAL;
1357
1358 cells_name = kasprintf(GFP_KERNEL, "#%s-cells", stem_name);
1359 if (!cells_name)
1360 return -ENOMEM;
1361
1362 ret = -ENOMEM;
1363 map_name = kasprintf(GFP_KERNEL, "%s-map", stem_name);
1364 if (!map_name)
1365 goto free;
1366
1367 mask_name = kasprintf(GFP_KERNEL, "%s-map-mask", stem_name);
1368 if (!mask_name)
1369 goto free;
1370
1371 pass_name = kasprintf(GFP_KERNEL, "%s-map-pass-thru", stem_name);
1372 if (!pass_name)
1373 goto free;
1374
1375 ret = __of_parse_phandle_with_args(np, list_name, cells_name, -1, index,
1376 out_args);
1377 if (ret)
1378 goto free;
1379
1380 /* Get the #<list>-cells property */
1381 cur = out_args->np;
1382 ret = of_property_read_u32(cur, cells_name, &list_size);
1383 if (ret < 0)
1384 goto put;
1385
1386 /* Precalculate the match array - this simplifies match loop */
1387 for (i = 0; i < list_size; i++)
1388 initial_match_array[i] = cpu_to_be32(out_args->args[i]);
1389
1390 ret = -EINVAL;
1391 while (cur) {
1392 /* Get the <list>-map property */
1393 map = of_get_property(cur, map_name, &map_len);
1394 if (!map) {
1395 ret = 0;
1396 goto free;
1397 }
1398 map_len /= sizeof(u32);
1399
1400 /* Get the <list>-map-mask property (optional) */
1401 mask = of_get_property(cur, mask_name, NULL);
1402 if (!mask)
1403 mask = dummy_mask;
1404 /* Iterate through <list>-map property */
1405 match = 0;
1406 while (map_len > (list_size + 1) && !match) {
1407 /* Compare specifiers */
1408 match = 1;
1409 for (i = 0; i < list_size; i++, map_len--)
1410 match &= !((match_array[i] ^ *map++) & mask[i]);
1411
1412 of_node_put(new);
1413 new = of_find_node_by_phandle(be32_to_cpup(map));
1414 map++;
1415 map_len--;
1416
1417 /* Check if not found */
1418 if (!new)
1419 goto put;
1420
1421 if (!of_device_is_available(new))
1422 match = 0;
1423
1424 ret = of_property_read_u32(new, cells_name, &new_size);
1425 if (ret)
1426 goto put;
1427
1428 /* Check for malformed properties */
1429 if (WARN_ON(new_size > MAX_PHANDLE_ARGS))
1430 goto put;
1431 if (map_len < new_size)
1432 goto put;
1433
1434 /* Move forward by new node's #<list>-cells amount */
1435 map += new_size;
1436 map_len -= new_size;
1437 }
1438 if (!match)
1439 goto put;
1440
1441 /* Get the <list>-map-pass-thru property (optional) */
1442 pass = of_get_property(cur, pass_name, NULL);
1443 if (!pass)
1444 pass = dummy_pass;
1445
1446 /*
1447 * Successfully parsed a <list>-map translation; copy new
1448 * specifier into the out_args structure, keeping the
1449 * bits specified in <list>-map-pass-thru.
1450 */
1451 match_array = map - new_size;
1452 for (i = 0; i < new_size; i++) {
1453 __be32 val = *(map - new_size + i);
1454
1455 if (i < list_size) {
1456 val &= ~pass[i];
1457 val |= cpu_to_be32(out_args->args[i]) & pass[i];
1458 }
1459
1460 out_args->args[i] = be32_to_cpu(val);
1461 }
1462 out_args->args_count = list_size = new_size;
1463 /* Iterate again with new provider */
1464 out_args->np = new;
1465 of_node_put(cur);
1466 cur = new;
1467 new = NULL;
1468 }
1469put:
1470 of_node_put(cur);
1471 of_node_put(new);
1472free:
1473 kfree(mask_name);
1474 kfree(map_name);
1475 kfree(cells_name);
1476 kfree(pass_name);
1477
1478 return ret;
1479}
1480EXPORT_SYMBOL(of_parse_phandle_with_args_map);
1481
1482/**
1483 * of_count_phandle_with_args() - Find the number of phandles references in a property
1484 * @np: pointer to a device tree node containing a list
1485 * @list_name: property name that contains a list
1486 * @cells_name: property name that specifies phandles' arguments count
1487 *
1488 * Return: The number of phandle + argument tuples within a property. It
1489 * is a typical pattern to encode a list of phandle and variable
1490 * arguments into a single property. The number of arguments is encoded
1491 * by a property in the phandle-target node. For example, a gpios
1492 * property would contain a list of GPIO specifies consisting of a
1493 * phandle and 1 or more arguments. The number of arguments are
1494 * determined by the #gpio-cells property in the node pointed to by the
1495 * phandle.
1496 */
1497int of_count_phandle_with_args(const struct device_node *np, const char *list_name,
1498 const char *cells_name)
1499{
1500 struct of_phandle_iterator it;
1501 int rc, cur_index = 0;
1502
1503 /*
1504 * If cells_name is NULL we assume a cell count of 0. This makes
1505 * counting the phandles trivial as each 32bit word in the list is a
1506 * phandle and no arguments are to consider. So we don't iterate through
1507 * the list but just use the length to determine the phandle count.
1508 */
1509 if (!cells_name) {
1510 const __be32 *list;
1511 int size;
1512
1513 list = of_get_property(np, list_name, &size);
1514 if (!list)
1515 return -ENOENT;
1516
1517 return size / sizeof(*list);
1518 }
1519
1520 rc = of_phandle_iterator_init(&it, np, list_name, cells_name, -1);
1521 if (rc)
1522 return rc;
1523
1524 while ((rc = of_phandle_iterator_next(&it)) == 0)
1525 cur_index += 1;
1526
1527 if (rc != -ENOENT)
1528 return rc;
1529
1530 return cur_index;
1531}
1532EXPORT_SYMBOL(of_count_phandle_with_args);
1533
1534static struct property *__of_remove_property_from_list(struct property **list, struct property *prop)
1535{
1536 struct property **next;
1537
1538 for (next = list; *next; next = &(*next)->next) {
1539 if (*next == prop) {
1540 *next = prop->next;
1541 prop->next = NULL;
1542 return prop;
1543 }
1544 }
1545 return NULL;
1546}
1547
1548/**
1549 * __of_add_property - Add a property to a node without lock operations
1550 * @np: Caller's Device Node
1551 * @prop: Property to add
1552 */
1553int __of_add_property(struct device_node *np, struct property *prop)
1554{
1555 int rc = 0;
1556 unsigned long flags;
1557 struct property **next;
1558
1559 raw_spin_lock_irqsave(&devtree_lock, flags);
1560
1561 __of_remove_property_from_list(&np->deadprops, prop);
1562
1563 prop->next = NULL;
1564 next = &np->properties;
1565 while (*next) {
1566 if (strcmp(prop->name, (*next)->name) == 0) {
1567 /* duplicate ! don't insert it */
1568 rc = -EEXIST;
1569 goto out_unlock;
1570 }
1571 next = &(*next)->next;
1572 }
1573 *next = prop;
1574
1575out_unlock:
1576 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1577 if (rc)
1578 return rc;
1579
1580 __of_add_property_sysfs(np, prop);
1581 return 0;
1582}
1583
1584/**
1585 * of_add_property - Add a property to a node
1586 * @np: Caller's Device Node
1587 * @prop: Property to add
1588 */
1589int of_add_property(struct device_node *np, struct property *prop)
1590{
1591 int rc;
1592
1593 mutex_lock(&of_mutex);
1594 rc = __of_add_property(np, prop);
1595 mutex_unlock(&of_mutex);
1596
1597 if (!rc)
1598 of_property_notify(OF_RECONFIG_ADD_PROPERTY, np, prop, NULL);
1599
1600 return rc;
1601}
1602EXPORT_SYMBOL_GPL(of_add_property);
1603
1604int __of_remove_property(struct device_node *np, struct property *prop)
1605{
1606 unsigned long flags;
1607 int rc = -ENODEV;
1608
1609 raw_spin_lock_irqsave(&devtree_lock, flags);
1610
1611 if (__of_remove_property_from_list(&np->properties, prop)) {
1612 /* Found the property, add it to deadprops list */
1613 prop->next = np->deadprops;
1614 np->deadprops = prop;
1615 rc = 0;
1616 }
1617
1618 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1619 if (rc)
1620 return rc;
1621
1622 __of_remove_property_sysfs(np, prop);
1623 return 0;
1624}
1625
1626/**
1627 * of_remove_property - Remove a property from a node.
1628 * @np: Caller's Device Node
1629 * @prop: Property to remove
1630 *
1631 * Note that we don't actually remove it, since we have given out
1632 * who-knows-how-many pointers to the data using get-property.
1633 * Instead we just move the property to the "dead properties"
1634 * list, so it won't be found any more.
1635 */
1636int of_remove_property(struct device_node *np, struct property *prop)
1637{
1638 int rc;
1639
1640 if (!prop)
1641 return -ENODEV;
1642
1643 mutex_lock(&of_mutex);
1644 rc = __of_remove_property(np, prop);
1645 mutex_unlock(&of_mutex);
1646
1647 if (!rc)
1648 of_property_notify(OF_RECONFIG_REMOVE_PROPERTY, np, prop, NULL);
1649
1650 return rc;
1651}
1652EXPORT_SYMBOL_GPL(of_remove_property);
1653
1654int __of_update_property(struct device_node *np, struct property *newprop,
1655 struct property **oldpropp)
1656{
1657 struct property **next, *oldprop;
1658 unsigned long flags;
1659
1660 raw_spin_lock_irqsave(&devtree_lock, flags);
1661
1662 __of_remove_property_from_list(&np->deadprops, newprop);
1663
1664 for (next = &np->properties; *next; next = &(*next)->next) {
1665 if (of_prop_cmp((*next)->name, newprop->name) == 0)
1666 break;
1667 }
1668 *oldpropp = oldprop = *next;
1669
1670 if (oldprop) {
1671 /* replace the node */
1672 newprop->next = oldprop->next;
1673 *next = newprop;
1674 oldprop->next = np->deadprops;
1675 np->deadprops = oldprop;
1676 } else {
1677 /* new node */
1678 newprop->next = NULL;
1679 *next = newprop;
1680 }
1681
1682 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1683
1684 __of_update_property_sysfs(np, newprop, oldprop);
1685
1686 return 0;
1687}
1688
1689/*
1690 * of_update_property - Update a property in a node, if the property does
1691 * not exist, add it.
1692 *
1693 * Note that we don't actually remove it, since we have given out
1694 * who-knows-how-many pointers to the data using get-property.
1695 * Instead we just move the property to the "dead properties" list,
1696 * and add the new property to the property list
1697 */
1698int of_update_property(struct device_node *np, struct property *newprop)
1699{
1700 struct property *oldprop;
1701 int rc;
1702
1703 if (!newprop->name)
1704 return -EINVAL;
1705
1706 mutex_lock(&of_mutex);
1707 rc = __of_update_property(np, newprop, &oldprop);
1708 mutex_unlock(&of_mutex);
1709
1710 if (!rc)
1711 of_property_notify(OF_RECONFIG_UPDATE_PROPERTY, np, newprop, oldprop);
1712
1713 return rc;
1714}
1715
1716static void of_alias_add(struct alias_prop *ap, struct device_node *np,
1717 int id, const char *stem, int stem_len)
1718{
1719 ap->np = np;
1720 ap->id = id;
1721 strscpy(ap->stem, stem, stem_len + 1);
1722 list_add_tail(&ap->link, &aliases_lookup);
1723 pr_debug("adding DT alias:%s: stem=%s id=%i node=%pOF\n",
1724 ap->alias, ap->stem, ap->id, np);
1725}
1726
1727/**
1728 * of_alias_scan - Scan all properties of the 'aliases' node
1729 * @dt_alloc: An allocator that provides a virtual address to memory
1730 * for storing the resulting tree
1731 *
1732 * The function scans all the properties of the 'aliases' node and populates
1733 * the global lookup table with the properties. It returns the
1734 * number of alias properties found, or an error code in case of failure.
1735 */
1736void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align))
1737{
1738 struct property *pp;
1739
1740 of_aliases = of_find_node_by_path("/aliases");
1741 of_chosen = of_find_node_by_path("/chosen");
1742 if (of_chosen == NULL)
1743 of_chosen = of_find_node_by_path("/chosen@0");
1744
1745 if (of_chosen) {
1746 /* linux,stdout-path and /aliases/stdout are for legacy compatibility */
1747 const char *name = NULL;
1748
1749 if (of_property_read_string(of_chosen, "stdout-path", &name))
1750 of_property_read_string(of_chosen, "linux,stdout-path",
1751 &name);
1752 if (IS_ENABLED(CONFIG_PPC) && !name)
1753 of_property_read_string(of_aliases, "stdout", &name);
1754 if (name)
1755 of_stdout = of_find_node_opts_by_path(name, &of_stdout_options);
1756 if (of_stdout)
1757 of_stdout->fwnode.flags |= FWNODE_FLAG_BEST_EFFORT;
1758 }
1759
1760 if (!of_aliases)
1761 return;
1762
1763 for_each_property_of_node(of_aliases, pp) {
1764 const char *start = pp->name;
1765 const char *end = start + strlen(start);
1766 struct device_node *np;
1767 struct alias_prop *ap;
1768 int id, len;
1769
1770 /* Skip those we do not want to proceed */
1771 if (!strcmp(pp->name, "name") ||
1772 !strcmp(pp->name, "phandle") ||
1773 !strcmp(pp->name, "linux,phandle"))
1774 continue;
1775
1776 np = of_find_node_by_path(pp->value);
1777 if (!np)
1778 continue;
1779
1780 /* walk the alias backwards to extract the id and work out
1781 * the 'stem' string */
1782 while (isdigit(*(end-1)) && end > start)
1783 end--;
1784 len = end - start;
1785
1786 if (kstrtoint(end, 10, &id) < 0)
1787 continue;
1788
1789 /* Allocate an alias_prop with enough space for the stem */
1790 ap = dt_alloc(sizeof(*ap) + len + 1, __alignof__(*ap));
1791 if (!ap)
1792 continue;
1793 memset(ap, 0, sizeof(*ap) + len + 1);
1794 ap->alias = start;
1795 of_alias_add(ap, np, id, start, len);
1796 }
1797}
1798
1799/**
1800 * of_alias_get_id - Get alias id for the given device_node
1801 * @np: Pointer to the given device_node
1802 * @stem: Alias stem of the given device_node
1803 *
1804 * The function travels the lookup table to get the alias id for the given
1805 * device_node and alias stem.
1806 *
1807 * Return: The alias id if found.
1808 */
1809int of_alias_get_id(struct device_node *np, const char *stem)
1810{
1811 struct alias_prop *app;
1812 int id = -ENODEV;
1813
1814 mutex_lock(&of_mutex);
1815 list_for_each_entry(app, &aliases_lookup, link) {
1816 if (strcmp(app->stem, stem) != 0)
1817 continue;
1818
1819 if (np == app->np) {
1820 id = app->id;
1821 break;
1822 }
1823 }
1824 mutex_unlock(&of_mutex);
1825
1826 return id;
1827}
1828EXPORT_SYMBOL_GPL(of_alias_get_id);
1829
1830/**
1831 * of_alias_get_highest_id - Get highest alias id for the given stem
1832 * @stem: Alias stem to be examined
1833 *
1834 * The function travels the lookup table to get the highest alias id for the
1835 * given alias stem. It returns the alias id if found.
1836 */
1837int of_alias_get_highest_id(const char *stem)
1838{
1839 struct alias_prop *app;
1840 int id = -ENODEV;
1841
1842 mutex_lock(&of_mutex);
1843 list_for_each_entry(app, &aliases_lookup, link) {
1844 if (strcmp(app->stem, stem) != 0)
1845 continue;
1846
1847 if (app->id > id)
1848 id = app->id;
1849 }
1850 mutex_unlock(&of_mutex);
1851
1852 return id;
1853}
1854EXPORT_SYMBOL_GPL(of_alias_get_highest_id);
1855
1856/**
1857 * of_console_check() - Test and setup console for DT setup
1858 * @dn: Pointer to device node
1859 * @name: Name to use for preferred console without index. ex. "ttyS"
1860 * @index: Index to use for preferred console.
1861 *
1862 * Check if the given device node matches the stdout-path property in the
1863 * /chosen node. If it does then register it as the preferred console.
1864 *
1865 * Return: TRUE if console successfully setup. Otherwise return FALSE.
1866 */
1867bool of_console_check(struct device_node *dn, char *name, int index)
1868{
1869 if (!dn || dn != of_stdout || console_set_on_cmdline)
1870 return false;
1871
1872 /*
1873 * XXX: cast `options' to char pointer to suppress complication
1874 * warnings: printk, UART and console drivers expect char pointer.
1875 */
1876 return !add_preferred_console(name, index, (char *)of_stdout_options);
1877}
1878EXPORT_SYMBOL_GPL(of_console_check);
1879
1880/**
1881 * of_find_next_cache_node - Find a node's subsidiary cache
1882 * @np: node of type "cpu" or "cache"
1883 *
1884 * Return: A node pointer with refcount incremented, use
1885 * of_node_put() on it when done. Caller should hold a reference
1886 * to np.
1887 */
1888struct device_node *of_find_next_cache_node(const struct device_node *np)
1889{
1890 struct device_node *child, *cache_node;
1891
1892 cache_node = of_parse_phandle(np, "l2-cache", 0);
1893 if (!cache_node)
1894 cache_node = of_parse_phandle(np, "next-level-cache", 0);
1895
1896 if (cache_node)
1897 return cache_node;
1898
1899 /* OF on pmac has nodes instead of properties named "l2-cache"
1900 * beneath CPU nodes.
1901 */
1902 if (IS_ENABLED(CONFIG_PPC_PMAC) && of_node_is_type(np, "cpu"))
1903 for_each_child_of_node(np, child)
1904 if (of_node_is_type(child, "cache"))
1905 return child;
1906
1907 return NULL;
1908}
1909
1910/**
1911 * of_find_last_cache_level - Find the level at which the last cache is
1912 * present for the given logical cpu
1913 *
1914 * @cpu: cpu number(logical index) for which the last cache level is needed
1915 *
1916 * Return: The level at which the last cache is present. It is exactly
1917 * same as the total number of cache levels for the given logical cpu.
1918 */
1919int of_find_last_cache_level(unsigned int cpu)
1920{
1921 u32 cache_level = 0;
1922 struct device_node *prev = NULL, *np = of_cpu_device_node_get(cpu);
1923
1924 while (np) {
1925 of_node_put(prev);
1926 prev = np;
1927 np = of_find_next_cache_node(np);
1928 }
1929
1930 of_property_read_u32(prev, "cache-level", &cache_level);
1931 of_node_put(prev);
1932
1933 return cache_level;
1934}
1935
1936/**
1937 * of_map_id - Translate an ID through a downstream mapping.
1938 * @np: root complex device node.
1939 * @id: device ID to map.
1940 * @map_name: property name of the map to use.
1941 * @map_mask_name: optional property name of the mask to use.
1942 * @target: optional pointer to a target device node.
1943 * @id_out: optional pointer to receive the translated ID.
1944 *
1945 * Given a device ID, look up the appropriate implementation-defined
1946 * platform ID and/or the target device which receives transactions on that
1947 * ID, as per the "iommu-map" and "msi-map" bindings. Either of @target or
1948 * @id_out may be NULL if only the other is required. If @target points to
1949 * a non-NULL device node pointer, only entries targeting that node will be
1950 * matched; if it points to a NULL value, it will receive the device node of
1951 * the first matching target phandle, with a reference held.
1952 *
1953 * Return: 0 on success or a standard error code on failure.
1954 */
1955int of_map_id(struct device_node *np, u32 id,
1956 const char *map_name, const char *map_mask_name,
1957 struct device_node **target, u32 *id_out)
1958{
1959 u32 map_mask, masked_id;
1960 int map_len;
1961 const __be32 *map = NULL;
1962
1963 if (!np || !map_name || (!target && !id_out))
1964 return -EINVAL;
1965
1966 map = of_get_property(np, map_name, &map_len);
1967 if (!map) {
1968 if (target)
1969 return -ENODEV;
1970 /* Otherwise, no map implies no translation */
1971 *id_out = id;
1972 return 0;
1973 }
1974
1975 if (!map_len || map_len % (4 * sizeof(*map))) {
1976 pr_err("%pOF: Error: Bad %s length: %d\n", np,
1977 map_name, map_len);
1978 return -EINVAL;
1979 }
1980
1981 /* The default is to select all bits. */
1982 map_mask = 0xffffffff;
1983
1984 /*
1985 * Can be overridden by "{iommu,msi}-map-mask" property.
1986 * If of_property_read_u32() fails, the default is used.
1987 */
1988 if (map_mask_name)
1989 of_property_read_u32(np, map_mask_name, &map_mask);
1990
1991 masked_id = map_mask & id;
1992 for ( ; map_len > 0; map_len -= 4 * sizeof(*map), map += 4) {
1993 struct device_node *phandle_node;
1994 u32 id_base = be32_to_cpup(map + 0);
1995 u32 phandle = be32_to_cpup(map + 1);
1996 u32 out_base = be32_to_cpup(map + 2);
1997 u32 id_len = be32_to_cpup(map + 3);
1998
1999 if (id_base & ~map_mask) {
2000 pr_err("%pOF: Invalid %s translation - %s-mask (0x%x) ignores id-base (0x%x)\n",
2001 np, map_name, map_name,
2002 map_mask, id_base);
2003 return -EFAULT;
2004 }
2005
2006 if (masked_id < id_base || masked_id >= id_base + id_len)
2007 continue;
2008
2009 phandle_node = of_find_node_by_phandle(phandle);
2010 if (!phandle_node)
2011 return -ENODEV;
2012
2013 if (target) {
2014 if (*target)
2015 of_node_put(phandle_node);
2016 else
2017 *target = phandle_node;
2018
2019 if (*target != phandle_node)
2020 continue;
2021 }
2022
2023 if (id_out)
2024 *id_out = masked_id - id_base + out_base;
2025
2026 pr_debug("%pOF: %s, using mask %08x, id-base: %08x, out-base: %08x, length: %08x, id: %08x -> %08x\n",
2027 np, map_name, map_mask, id_base, out_base,
2028 id_len, id, masked_id - id_base + out_base);
2029 return 0;
2030 }
2031
2032 pr_info("%pOF: no %s translation for id 0x%x on %pOF\n", np, map_name,
2033 id, target && *target ? *target : NULL);
2034
2035 /* Bypasses translation */
2036 if (id_out)
2037 *id_out = id;
2038 return 0;
2039}
2040EXPORT_SYMBOL_GPL(of_map_id);
1// 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/bitmap.h>
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_device.h>
26#include <linux/of_graph.h>
27#include <linux/spinlock.h>
28#include <linux/slab.h>
29#include <linux/string.h>
30#include <linux/proc_fs.h>
31
32#include "of_private.h"
33
34LIST_HEAD(aliases_lookup);
35
36struct device_node *of_root;
37EXPORT_SYMBOL(of_root);
38struct device_node *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_n_addr_cells(struct device_node *np)
90{
91 u32 cells;
92
93 do {
94 if (np->parent)
95 np = np->parent;
96 if (!of_property_read_u32(np, "#address-cells", &cells))
97 return cells;
98 } while (np->parent);
99 /* No #address-cells property for the root node */
100 return OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
101}
102EXPORT_SYMBOL(of_n_addr_cells);
103
104int of_n_size_cells(struct device_node *np)
105{
106 u32 cells;
107
108 do {
109 if (np->parent)
110 np = np->parent;
111 if (!of_property_read_u32(np, "#size-cells", &cells))
112 return cells;
113 } while (np->parent);
114 /* No #size-cells property for the root node */
115 return OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
116}
117EXPORT_SYMBOL(of_n_size_cells);
118
119#ifdef CONFIG_NUMA
120int __weak of_node_to_nid(struct device_node *np)
121{
122 return NUMA_NO_NODE;
123}
124#endif
125
126/*
127 * Assumptions behind phandle_cache implementation:
128 * - phandle property values are in a contiguous range of 1..n
129 *
130 * If the assumptions do not hold, then
131 * - the phandle lookup overhead reduction provided by the cache
132 * will likely be less
133 */
134
135static struct device_node **phandle_cache;
136static u32 phandle_cache_mask;
137
138/*
139 * Caller must hold devtree_lock.
140 */
141static void __of_free_phandle_cache(void)
142{
143 u32 cache_entries = phandle_cache_mask + 1;
144 u32 k;
145
146 if (!phandle_cache)
147 return;
148
149 for (k = 0; k < cache_entries; k++)
150 of_node_put(phandle_cache[k]);
151
152 kfree(phandle_cache);
153 phandle_cache = NULL;
154}
155
156int of_free_phandle_cache(void)
157{
158 unsigned long flags;
159
160 raw_spin_lock_irqsave(&devtree_lock, flags);
161
162 __of_free_phandle_cache();
163
164 raw_spin_unlock_irqrestore(&devtree_lock, flags);
165
166 return 0;
167}
168#if !defined(CONFIG_MODULES)
169late_initcall_sync(of_free_phandle_cache);
170#endif
171
172/*
173 * Caller must hold devtree_lock.
174 */
175void __of_free_phandle_cache_entry(phandle handle)
176{
177 phandle masked_handle;
178 struct device_node *np;
179
180 if (!handle)
181 return;
182
183 masked_handle = handle & phandle_cache_mask;
184
185 if (phandle_cache) {
186 np = phandle_cache[masked_handle];
187 if (np && handle == np->phandle) {
188 of_node_put(np);
189 phandle_cache[masked_handle] = NULL;
190 }
191 }
192}
193
194void of_populate_phandle_cache(void)
195{
196 unsigned long flags;
197 u32 cache_entries;
198 struct device_node *np;
199 u32 phandles = 0;
200
201 raw_spin_lock_irqsave(&devtree_lock, flags);
202
203 __of_free_phandle_cache();
204
205 for_each_of_allnodes(np)
206 if (np->phandle && np->phandle != OF_PHANDLE_ILLEGAL)
207 phandles++;
208
209 if (!phandles)
210 goto out;
211
212 cache_entries = roundup_pow_of_two(phandles);
213 phandle_cache_mask = cache_entries - 1;
214
215 phandle_cache = kcalloc(cache_entries, sizeof(*phandle_cache),
216 GFP_ATOMIC);
217 if (!phandle_cache)
218 goto out;
219
220 for_each_of_allnodes(np)
221 if (np->phandle && np->phandle != OF_PHANDLE_ILLEGAL) {
222 of_node_get(np);
223 phandle_cache[np->phandle & phandle_cache_mask] = np;
224 }
225
226out:
227 raw_spin_unlock_irqrestore(&devtree_lock, flags);
228}
229
230void __init of_core_init(void)
231{
232 struct device_node *np;
233
234 of_populate_phandle_cache();
235
236 /* Create the kset, and register existing nodes */
237 mutex_lock(&of_mutex);
238 of_kset = kset_create_and_add("devicetree", NULL, firmware_kobj);
239 if (!of_kset) {
240 mutex_unlock(&of_mutex);
241 pr_err("failed to register existing nodes\n");
242 return;
243 }
244 for_each_of_allnodes(np)
245 __of_attach_node_sysfs(np);
246 mutex_unlock(&of_mutex);
247
248 /* Symlink in /proc as required by userspace ABI */
249 if (of_root)
250 proc_symlink("device-tree", NULL, "/sys/firmware/devicetree/base");
251}
252
253static struct property *__of_find_property(const struct device_node *np,
254 const char *name, int *lenp)
255{
256 struct property *pp;
257
258 if (!np)
259 return NULL;
260
261 for (pp = np->properties; pp; pp = pp->next) {
262 if (of_prop_cmp(pp->name, name) == 0) {
263 if (lenp)
264 *lenp = pp->length;
265 break;
266 }
267 }
268
269 return pp;
270}
271
272struct property *of_find_property(const struct device_node *np,
273 const char *name,
274 int *lenp)
275{
276 struct property *pp;
277 unsigned long flags;
278
279 raw_spin_lock_irqsave(&devtree_lock, flags);
280 pp = __of_find_property(np, name, lenp);
281 raw_spin_unlock_irqrestore(&devtree_lock, flags);
282
283 return pp;
284}
285EXPORT_SYMBOL(of_find_property);
286
287struct device_node *__of_find_all_nodes(struct device_node *prev)
288{
289 struct device_node *np;
290 if (!prev) {
291 np = of_root;
292 } else if (prev->child) {
293 np = prev->child;
294 } else {
295 /* Walk back up looking for a sibling, or the end of the structure */
296 np = prev;
297 while (np->parent && !np->sibling)
298 np = np->parent;
299 np = np->sibling; /* Might be null at the end of the tree */
300 }
301 return np;
302}
303
304/**
305 * of_find_all_nodes - Get next node in global list
306 * @prev: Previous node or NULL to start iteration
307 * of_node_put() will be called on it
308 *
309 * Returns a node pointer with refcount incremented, use
310 * of_node_put() on it when done.
311 */
312struct device_node *of_find_all_nodes(struct device_node *prev)
313{
314 struct device_node *np;
315 unsigned long flags;
316
317 raw_spin_lock_irqsave(&devtree_lock, flags);
318 np = __of_find_all_nodes(prev);
319 of_node_get(np);
320 of_node_put(prev);
321 raw_spin_unlock_irqrestore(&devtree_lock, flags);
322 return np;
323}
324EXPORT_SYMBOL(of_find_all_nodes);
325
326/*
327 * Find a property with a given name for a given node
328 * and return the value.
329 */
330const void *__of_get_property(const struct device_node *np,
331 const char *name, int *lenp)
332{
333 struct property *pp = __of_find_property(np, name, lenp);
334
335 return pp ? pp->value : NULL;
336}
337
338/*
339 * Find a property with a given name for a given node
340 * and return the value.
341 */
342const void *of_get_property(const struct device_node *np, const char *name,
343 int *lenp)
344{
345 struct property *pp = of_find_property(np, name, lenp);
346
347 return pp ? pp->value : NULL;
348}
349EXPORT_SYMBOL(of_get_property);
350
351/*
352 * arch_match_cpu_phys_id - Match the given logical CPU and physical id
353 *
354 * @cpu: logical cpu index of a core/thread
355 * @phys_id: physical identifier of a core/thread
356 *
357 * CPU logical to physical index mapping is architecture specific.
358 * However this __weak function provides a default match of physical
359 * id to logical cpu index. phys_id provided here is usually values read
360 * from the device tree which must match the hardware internal registers.
361 *
362 * Returns true if the physical identifier and the logical cpu index
363 * correspond to the same core/thread, false otherwise.
364 */
365bool __weak arch_match_cpu_phys_id(int cpu, u64 phys_id)
366{
367 return (u32)phys_id == cpu;
368}
369
370/**
371 * Checks if the given "prop_name" property holds the physical id of the
372 * core/thread corresponding to the logical cpu 'cpu'. If 'thread' is not
373 * NULL, local thread number within the core is returned in it.
374 */
375static bool __of_find_n_match_cpu_property(struct device_node *cpun,
376 const char *prop_name, int cpu, unsigned int *thread)
377{
378 const __be32 *cell;
379 int ac, prop_len, tid;
380 u64 hwid;
381
382 ac = of_n_addr_cells(cpun);
383 cell = of_get_property(cpun, prop_name, &prop_len);
384 if (!cell && !ac && arch_match_cpu_phys_id(cpu, 0))
385 return true;
386 if (!cell || !ac)
387 return false;
388 prop_len /= sizeof(*cell) * ac;
389 for (tid = 0; tid < prop_len; tid++) {
390 hwid = of_read_number(cell, ac);
391 if (arch_match_cpu_phys_id(cpu, hwid)) {
392 if (thread)
393 *thread = tid;
394 return true;
395 }
396 cell += ac;
397 }
398 return false;
399}
400
401/*
402 * arch_find_n_match_cpu_physical_id - See if the given device node is
403 * for the cpu corresponding to logical cpu 'cpu'. Return true if so,
404 * else false. If 'thread' is non-NULL, the local thread number within the
405 * core is returned in it.
406 */
407bool __weak arch_find_n_match_cpu_physical_id(struct device_node *cpun,
408 int cpu, unsigned int *thread)
409{
410 /* Check for non-standard "ibm,ppc-interrupt-server#s" property
411 * for thread ids on PowerPC. If it doesn't exist fallback to
412 * standard "reg" property.
413 */
414 if (IS_ENABLED(CONFIG_PPC) &&
415 __of_find_n_match_cpu_property(cpun,
416 "ibm,ppc-interrupt-server#s",
417 cpu, thread))
418 return true;
419
420 return __of_find_n_match_cpu_property(cpun, "reg", cpu, thread);
421}
422
423/**
424 * of_get_cpu_node - Get device node associated with the given logical CPU
425 *
426 * @cpu: CPU number(logical index) for which device node is required
427 * @thread: if not NULL, local thread number within the physical core is
428 * returned
429 *
430 * The main purpose of this function is to retrieve the device node for the
431 * given logical CPU index. It should be used to initialize the of_node in
432 * cpu device. Once of_node in cpu device is populated, all the further
433 * references can use that instead.
434 *
435 * CPU logical to physical index mapping is architecture specific and is built
436 * before booting secondary cores. This function uses arch_match_cpu_phys_id
437 * which can be overridden by architecture specific implementation.
438 *
439 * Returns a node pointer for the logical cpu with refcount incremented, use
440 * of_node_put() on it when done. Returns NULL if not found.
441 */
442struct device_node *of_get_cpu_node(int cpu, unsigned int *thread)
443{
444 struct device_node *cpun;
445
446 for_each_of_cpu_node(cpun) {
447 if (arch_find_n_match_cpu_physical_id(cpun, cpu, thread))
448 return cpun;
449 }
450 return NULL;
451}
452EXPORT_SYMBOL(of_get_cpu_node);
453
454/**
455 * of_cpu_node_to_id: Get the logical CPU number for a given device_node
456 *
457 * @cpu_node: Pointer to the device_node for CPU.
458 *
459 * Returns the logical CPU number of the given CPU device_node.
460 * Returns -ENODEV if the CPU is not found.
461 */
462int of_cpu_node_to_id(struct device_node *cpu_node)
463{
464 int cpu;
465 bool found = false;
466 struct device_node *np;
467
468 for_each_possible_cpu(cpu) {
469 np = of_cpu_device_node_get(cpu);
470 found = (cpu_node == np);
471 of_node_put(np);
472 if (found)
473 return cpu;
474 }
475
476 return -ENODEV;
477}
478EXPORT_SYMBOL(of_cpu_node_to_id);
479
480/**
481 * __of_device_is_compatible() - Check if the node matches given constraints
482 * @device: pointer to node
483 * @compat: required compatible string, NULL or "" for any match
484 * @type: required device_type value, NULL or "" for any match
485 * @name: required node name, NULL or "" for any match
486 *
487 * Checks if the given @compat, @type and @name strings match the
488 * properties of the given @device. A constraints can be skipped by
489 * passing NULL or an empty string as the constraint.
490 *
491 * Returns 0 for no match, and a positive integer on match. The return
492 * value is a relative score with larger values indicating better
493 * matches. The score is weighted for the most specific compatible value
494 * to get the highest score. Matching type is next, followed by matching
495 * name. Practically speaking, this results in the following priority
496 * order for matches:
497 *
498 * 1. specific compatible && type && name
499 * 2. specific compatible && type
500 * 3. specific compatible && name
501 * 4. specific compatible
502 * 5. general compatible && type && name
503 * 6. general compatible && type
504 * 7. general compatible && name
505 * 8. general compatible
506 * 9. type && name
507 * 10. type
508 * 11. name
509 */
510static int __of_device_is_compatible(const struct device_node *device,
511 const char *compat, const char *type, const char *name)
512{
513 struct property *prop;
514 const char *cp;
515 int index = 0, score = 0;
516
517 /* Compatible match has highest priority */
518 if (compat && compat[0]) {
519 prop = __of_find_property(device, "compatible", NULL);
520 for (cp = of_prop_next_string(prop, NULL); cp;
521 cp = of_prop_next_string(prop, cp), index++) {
522 if (of_compat_cmp(cp, compat, strlen(compat)) == 0) {
523 score = INT_MAX/2 - (index << 2);
524 break;
525 }
526 }
527 if (!score)
528 return 0;
529 }
530
531 /* Matching type is better than matching name */
532 if (type && type[0]) {
533 if (!__of_node_is_type(device, type))
534 return 0;
535 score += 2;
536 }
537
538 /* Matching name is a bit better than not */
539 if (name && name[0]) {
540 if (!of_node_name_eq(device, name))
541 return 0;
542 score++;
543 }
544
545 return score;
546}
547
548/** Checks if the given "compat" string matches one of the strings in
549 * the device's "compatible" property
550 */
551int of_device_is_compatible(const struct device_node *device,
552 const char *compat)
553{
554 unsigned long flags;
555 int res;
556
557 raw_spin_lock_irqsave(&devtree_lock, flags);
558 res = __of_device_is_compatible(device, compat, NULL, NULL);
559 raw_spin_unlock_irqrestore(&devtree_lock, flags);
560 return res;
561}
562EXPORT_SYMBOL(of_device_is_compatible);
563
564/** Checks if the device is compatible with any of the entries in
565 * a NULL terminated array of strings. Returns the best match
566 * score or 0.
567 */
568int of_device_compatible_match(struct device_node *device,
569 const char *const *compat)
570{
571 unsigned int tmp, score = 0;
572
573 if (!compat)
574 return 0;
575
576 while (*compat) {
577 tmp = of_device_is_compatible(device, *compat);
578 if (tmp > score)
579 score = tmp;
580 compat++;
581 }
582
583 return score;
584}
585
586/**
587 * of_machine_is_compatible - Test root of device tree for a given compatible value
588 * @compat: compatible string to look for in root node's compatible property.
589 *
590 * Returns a positive integer if the root node has the given value in its
591 * compatible property.
592 */
593int of_machine_is_compatible(const char *compat)
594{
595 struct device_node *root;
596 int rc = 0;
597
598 root = of_find_node_by_path("/");
599 if (root) {
600 rc = of_device_is_compatible(root, compat);
601 of_node_put(root);
602 }
603 return rc;
604}
605EXPORT_SYMBOL(of_machine_is_compatible);
606
607/**
608 * __of_device_is_available - check if a device is available for use
609 *
610 * @device: Node to check for availability, with locks already held
611 *
612 * Returns true if the status property is absent or set to "okay" or "ok",
613 * false otherwise
614 */
615static bool __of_device_is_available(const struct device_node *device)
616{
617 const char *status;
618 int statlen;
619
620 if (!device)
621 return false;
622
623 status = __of_get_property(device, "status", &statlen);
624 if (status == NULL)
625 return true;
626
627 if (statlen > 0) {
628 if (!strcmp(status, "okay") || !strcmp(status, "ok"))
629 return true;
630 }
631
632 return false;
633}
634
635/**
636 * of_device_is_available - check if a device is available for use
637 *
638 * @device: Node to check for availability
639 *
640 * Returns true if the status property is absent or set to "okay" or "ok",
641 * false otherwise
642 */
643bool of_device_is_available(const struct device_node *device)
644{
645 unsigned long flags;
646 bool res;
647
648 raw_spin_lock_irqsave(&devtree_lock, flags);
649 res = __of_device_is_available(device);
650 raw_spin_unlock_irqrestore(&devtree_lock, flags);
651 return res;
652
653}
654EXPORT_SYMBOL(of_device_is_available);
655
656/**
657 * of_device_is_big_endian - check if a device has BE registers
658 *
659 * @device: Node to check for endianness
660 *
661 * Returns true if the device has a "big-endian" property, or if the kernel
662 * was compiled for BE *and* the device has a "native-endian" property.
663 * Returns false otherwise.
664 *
665 * Callers would nominally use ioread32be/iowrite32be if
666 * of_device_is_big_endian() == true, or readl/writel otherwise.
667 */
668bool of_device_is_big_endian(const struct device_node *device)
669{
670 if (of_property_read_bool(device, "big-endian"))
671 return true;
672 if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) &&
673 of_property_read_bool(device, "native-endian"))
674 return true;
675 return false;
676}
677EXPORT_SYMBOL(of_device_is_big_endian);
678
679/**
680 * of_get_parent - Get a node's parent if any
681 * @node: Node to get parent
682 *
683 * Returns a node pointer with refcount incremented, use
684 * of_node_put() on it when done.
685 */
686struct device_node *of_get_parent(const struct device_node *node)
687{
688 struct device_node *np;
689 unsigned long flags;
690
691 if (!node)
692 return NULL;
693
694 raw_spin_lock_irqsave(&devtree_lock, flags);
695 np = of_node_get(node->parent);
696 raw_spin_unlock_irqrestore(&devtree_lock, flags);
697 return np;
698}
699EXPORT_SYMBOL(of_get_parent);
700
701/**
702 * of_get_next_parent - Iterate to a node's parent
703 * @node: Node to get parent of
704 *
705 * This is like of_get_parent() except that it drops the
706 * refcount on the passed node, making it suitable for iterating
707 * through a node's parents.
708 *
709 * Returns a node pointer with refcount incremented, use
710 * of_node_put() on it when done.
711 */
712struct device_node *of_get_next_parent(struct device_node *node)
713{
714 struct device_node *parent;
715 unsigned long flags;
716
717 if (!node)
718 return NULL;
719
720 raw_spin_lock_irqsave(&devtree_lock, flags);
721 parent = of_node_get(node->parent);
722 of_node_put(node);
723 raw_spin_unlock_irqrestore(&devtree_lock, flags);
724 return parent;
725}
726EXPORT_SYMBOL(of_get_next_parent);
727
728static struct device_node *__of_get_next_child(const struct device_node *node,
729 struct device_node *prev)
730{
731 struct device_node *next;
732
733 if (!node)
734 return NULL;
735
736 next = prev ? prev->sibling : node->child;
737 for (; next; next = next->sibling)
738 if (of_node_get(next))
739 break;
740 of_node_put(prev);
741 return next;
742}
743#define __for_each_child_of_node(parent, child) \
744 for (child = __of_get_next_child(parent, NULL); child != NULL; \
745 child = __of_get_next_child(parent, child))
746
747/**
748 * of_get_next_child - Iterate a node childs
749 * @node: parent node
750 * @prev: previous child of the parent node, or NULL to get first
751 *
752 * Returns a node pointer with refcount incremented, use of_node_put() on
753 * it when done. Returns NULL when prev is the last child. Decrements the
754 * refcount of prev.
755 */
756struct device_node *of_get_next_child(const struct device_node *node,
757 struct device_node *prev)
758{
759 struct device_node *next;
760 unsigned long flags;
761
762 raw_spin_lock_irqsave(&devtree_lock, flags);
763 next = __of_get_next_child(node, prev);
764 raw_spin_unlock_irqrestore(&devtree_lock, flags);
765 return next;
766}
767EXPORT_SYMBOL(of_get_next_child);
768
769/**
770 * of_get_next_available_child - Find the next available child node
771 * @node: parent node
772 * @prev: previous child of the parent node, or NULL to get first
773 *
774 * This function is like of_get_next_child(), except that it
775 * automatically skips any disabled nodes (i.e. status = "disabled").
776 */
777struct device_node *of_get_next_available_child(const struct device_node *node,
778 struct device_node *prev)
779{
780 struct device_node *next;
781 unsigned long flags;
782
783 if (!node)
784 return NULL;
785
786 raw_spin_lock_irqsave(&devtree_lock, flags);
787 next = prev ? prev->sibling : node->child;
788 for (; next; next = next->sibling) {
789 if (!__of_device_is_available(next))
790 continue;
791 if (of_node_get(next))
792 break;
793 }
794 of_node_put(prev);
795 raw_spin_unlock_irqrestore(&devtree_lock, flags);
796 return next;
797}
798EXPORT_SYMBOL(of_get_next_available_child);
799
800/**
801 * of_get_next_cpu_node - Iterate on cpu nodes
802 * @prev: previous child of the /cpus node, or NULL to get first
803 *
804 * Returns a cpu node pointer with refcount incremented, use of_node_put()
805 * on it when done. Returns NULL when prev is the last child. Decrements
806 * the refcount of prev.
807 */
808struct device_node *of_get_next_cpu_node(struct device_node *prev)
809{
810 struct device_node *next = NULL;
811 unsigned long flags;
812 struct device_node *node;
813
814 if (!prev)
815 node = of_find_node_by_path("/cpus");
816
817 raw_spin_lock_irqsave(&devtree_lock, flags);
818 if (prev)
819 next = prev->sibling;
820 else if (node) {
821 next = node->child;
822 of_node_put(node);
823 }
824 for (; next; next = next->sibling) {
825 if (!(of_node_name_eq(next, "cpu") ||
826 __of_node_is_type(next, "cpu")))
827 continue;
828 if (of_node_get(next))
829 break;
830 }
831 of_node_put(prev);
832 raw_spin_unlock_irqrestore(&devtree_lock, flags);
833 return next;
834}
835EXPORT_SYMBOL(of_get_next_cpu_node);
836
837/**
838 * of_get_compatible_child - Find compatible child node
839 * @parent: parent node
840 * @compatible: compatible string
841 *
842 * Lookup child node whose compatible property contains the given compatible
843 * string.
844 *
845 * Returns a node pointer with refcount incremented, use of_node_put() on it
846 * when done; or NULL if not found.
847 */
848struct device_node *of_get_compatible_child(const struct device_node *parent,
849 const char *compatible)
850{
851 struct device_node *child;
852
853 for_each_child_of_node(parent, child) {
854 if (of_device_is_compatible(child, compatible))
855 break;
856 }
857
858 return child;
859}
860EXPORT_SYMBOL(of_get_compatible_child);
861
862/**
863 * of_get_child_by_name - Find the child node by name for a given parent
864 * @node: parent node
865 * @name: child name to look for.
866 *
867 * This function looks for child node for given matching name
868 *
869 * Returns a node pointer if found, with refcount incremented, use
870 * of_node_put() on it when done.
871 * Returns NULL if node is not found.
872 */
873struct device_node *of_get_child_by_name(const struct device_node *node,
874 const char *name)
875{
876 struct device_node *child;
877
878 for_each_child_of_node(node, child)
879 if (of_node_name_eq(child, name))
880 break;
881 return child;
882}
883EXPORT_SYMBOL(of_get_child_by_name);
884
885struct device_node *__of_find_node_by_path(struct device_node *parent,
886 const char *path)
887{
888 struct device_node *child;
889 int len;
890
891 len = strcspn(path, "/:");
892 if (!len)
893 return NULL;
894
895 __for_each_child_of_node(parent, child) {
896 const char *name = kbasename(child->full_name);
897 if (strncmp(path, name, len) == 0 && (strlen(name) == len))
898 return child;
899 }
900 return NULL;
901}
902
903struct device_node *__of_find_node_by_full_path(struct device_node *node,
904 const char *path)
905{
906 const char *separator = strchr(path, ':');
907
908 while (node && *path == '/') {
909 struct device_node *tmp = node;
910
911 path++; /* Increment past '/' delimiter */
912 node = __of_find_node_by_path(node, path);
913 of_node_put(tmp);
914 path = strchrnul(path, '/');
915 if (separator && separator < path)
916 break;
917 }
918 return node;
919}
920
921/**
922 * of_find_node_opts_by_path - Find a node matching a full OF path
923 * @path: Either the full path to match, or if the path does not
924 * start with '/', the name of a property of the /aliases
925 * node (an alias). In the case of an alias, the node
926 * matching the alias' value will be returned.
927 * @opts: Address of a pointer into which to store the start of
928 * an options string appended to the end of the path with
929 * a ':' separator.
930 *
931 * Valid paths:
932 * /foo/bar Full path
933 * foo Valid alias
934 * foo/bar Valid alias + relative path
935 *
936 * Returns a node pointer with refcount incremented, use
937 * of_node_put() on it when done.
938 */
939struct device_node *of_find_node_opts_by_path(const char *path, const char **opts)
940{
941 struct device_node *np = NULL;
942 struct property *pp;
943 unsigned long flags;
944 const char *separator = strchr(path, ':');
945
946 if (opts)
947 *opts = separator ? separator + 1 : NULL;
948
949 if (strcmp(path, "/") == 0)
950 return of_node_get(of_root);
951
952 /* The path could begin with an alias */
953 if (*path != '/') {
954 int len;
955 const char *p = separator;
956
957 if (!p)
958 p = strchrnul(path, '/');
959 len = p - path;
960
961 /* of_aliases must not be NULL */
962 if (!of_aliases)
963 return NULL;
964
965 for_each_property_of_node(of_aliases, pp) {
966 if (strlen(pp->name) == len && !strncmp(pp->name, path, len)) {
967 np = of_find_node_by_path(pp->value);
968 break;
969 }
970 }
971 if (!np)
972 return NULL;
973 path = p;
974 }
975
976 /* Step down the tree matching path components */
977 raw_spin_lock_irqsave(&devtree_lock, flags);
978 if (!np)
979 np = of_node_get(of_root);
980 np = __of_find_node_by_full_path(np, path);
981 raw_spin_unlock_irqrestore(&devtree_lock, flags);
982 return np;
983}
984EXPORT_SYMBOL(of_find_node_opts_by_path);
985
986/**
987 * of_find_node_by_name - Find a node by its "name" property
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 @from.
992 * @name: The name string to match against
993 *
994 * Returns a node pointer with refcount incremented, use
995 * of_node_put() on it when done.
996 */
997struct device_node *of_find_node_by_name(struct device_node *from,
998 const char *name)
999{
1000 struct device_node *np;
1001 unsigned long flags;
1002
1003 raw_spin_lock_irqsave(&devtree_lock, flags);
1004 for_each_of_allnodes_from(from, np)
1005 if (of_node_name_eq(np, name) && of_node_get(np))
1006 break;
1007 of_node_put(from);
1008 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1009 return np;
1010}
1011EXPORT_SYMBOL(of_find_node_by_name);
1012
1013/**
1014 * of_find_node_by_type - Find a node by its "device_type" property
1015 * @from: The node to start searching from, or NULL to start searching
1016 * the entire device tree. The node you pass will not be
1017 * searched, only the next one will; typically, you pass
1018 * what the previous call returned. of_node_put() will be
1019 * called on from for you.
1020 * @type: The type string to match against
1021 *
1022 * Returns a node pointer with refcount incremented, use
1023 * of_node_put() on it when done.
1024 */
1025struct device_node *of_find_node_by_type(struct device_node *from,
1026 const char *type)
1027{
1028 struct device_node *np;
1029 unsigned long flags;
1030
1031 raw_spin_lock_irqsave(&devtree_lock, flags);
1032 for_each_of_allnodes_from(from, np)
1033 if (__of_node_is_type(np, type) && of_node_get(np))
1034 break;
1035 of_node_put(from);
1036 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1037 return np;
1038}
1039EXPORT_SYMBOL(of_find_node_by_type);
1040
1041/**
1042 * of_find_compatible_node - Find a node based on type and one of the
1043 * tokens in its "compatible" property
1044 * @from: The node to start searching from or NULL, the node
1045 * you pass will not be searched, only the next one
1046 * will; typically, you pass what the previous call
1047 * returned. of_node_put() will be called on it
1048 * @type: The type string to match "device_type" or NULL to ignore
1049 * @compatible: The string to match to one of the tokens in the device
1050 * "compatible" list.
1051 *
1052 * Returns a node pointer with refcount incremented, use
1053 * of_node_put() on it when done.
1054 */
1055struct device_node *of_find_compatible_node(struct device_node *from,
1056 const char *type, const char *compatible)
1057{
1058 struct device_node *np;
1059 unsigned long flags;
1060
1061 raw_spin_lock_irqsave(&devtree_lock, flags);
1062 for_each_of_allnodes_from(from, np)
1063 if (__of_device_is_compatible(np, compatible, type, NULL) &&
1064 of_node_get(np))
1065 break;
1066 of_node_put(from);
1067 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1068 return np;
1069}
1070EXPORT_SYMBOL(of_find_compatible_node);
1071
1072/**
1073 * of_find_node_with_property - Find a node which has a property with
1074 * the given name.
1075 * @from: The node to start searching from or NULL, the node
1076 * you pass will not be searched, only the next one
1077 * will; typically, you pass what the previous call
1078 * returned. of_node_put() will be called on it
1079 * @prop_name: The name of the property to look for.
1080 *
1081 * Returns a node pointer with refcount incremented, use
1082 * of_node_put() on it when done.
1083 */
1084struct device_node *of_find_node_with_property(struct device_node *from,
1085 const char *prop_name)
1086{
1087 struct device_node *np;
1088 struct property *pp;
1089 unsigned long flags;
1090
1091 raw_spin_lock_irqsave(&devtree_lock, flags);
1092 for_each_of_allnodes_from(from, np) {
1093 for (pp = np->properties; pp; pp = pp->next) {
1094 if (of_prop_cmp(pp->name, prop_name) == 0) {
1095 of_node_get(np);
1096 goto out;
1097 }
1098 }
1099 }
1100out:
1101 of_node_put(from);
1102 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1103 return np;
1104}
1105EXPORT_SYMBOL(of_find_node_with_property);
1106
1107static
1108const struct of_device_id *__of_match_node(const struct of_device_id *matches,
1109 const struct device_node *node)
1110{
1111 const struct of_device_id *best_match = NULL;
1112 int score, best_score = 0;
1113
1114 if (!matches)
1115 return NULL;
1116
1117 for (; matches->name[0] || matches->type[0] || matches->compatible[0]; matches++) {
1118 score = __of_device_is_compatible(node, matches->compatible,
1119 matches->type, matches->name);
1120 if (score > best_score) {
1121 best_match = matches;
1122 best_score = score;
1123 }
1124 }
1125
1126 return best_match;
1127}
1128
1129/**
1130 * of_match_node - Tell if a device_node has a matching of_match structure
1131 * @matches: array of of device match structures to search in
1132 * @node: the of device structure to match against
1133 *
1134 * Low level utility function used by device matching.
1135 */
1136const struct of_device_id *of_match_node(const struct of_device_id *matches,
1137 const struct device_node *node)
1138{
1139 const struct of_device_id *match;
1140 unsigned long flags;
1141
1142 raw_spin_lock_irqsave(&devtree_lock, flags);
1143 match = __of_match_node(matches, node);
1144 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1145 return match;
1146}
1147EXPORT_SYMBOL(of_match_node);
1148
1149/**
1150 * of_find_matching_node_and_match - Find a node based on an of_device_id
1151 * match table.
1152 * @from: The node to start searching from or NULL, the node
1153 * you pass will not be searched, only the next one
1154 * will; typically, you pass what the previous call
1155 * returned. of_node_put() will be called on it
1156 * @matches: array of of device match structures to search in
1157 * @match Updated to point at the matches entry which matched
1158 *
1159 * Returns a node pointer with refcount incremented, use
1160 * of_node_put() on it when done.
1161 */
1162struct device_node *of_find_matching_node_and_match(struct device_node *from,
1163 const struct of_device_id *matches,
1164 const struct of_device_id **match)
1165{
1166 struct device_node *np;
1167 const struct of_device_id *m;
1168 unsigned long flags;
1169
1170 if (match)
1171 *match = NULL;
1172
1173 raw_spin_lock_irqsave(&devtree_lock, flags);
1174 for_each_of_allnodes_from(from, np) {
1175 m = __of_match_node(matches, np);
1176 if (m && of_node_get(np)) {
1177 if (match)
1178 *match = m;
1179 break;
1180 }
1181 }
1182 of_node_put(from);
1183 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1184 return np;
1185}
1186EXPORT_SYMBOL(of_find_matching_node_and_match);
1187
1188/**
1189 * of_modalias_node - Lookup appropriate modalias for a device node
1190 * @node: pointer to a device tree node
1191 * @modalias: Pointer to buffer that modalias value will be copied into
1192 * @len: Length of modalias value
1193 *
1194 * Based on the value of the compatible property, this routine will attempt
1195 * to choose an appropriate modalias value for a particular device tree node.
1196 * It does this by stripping the manufacturer prefix (as delimited by a ',')
1197 * from the first entry in the compatible list property.
1198 *
1199 * This routine returns 0 on success, <0 on failure.
1200 */
1201int of_modalias_node(struct device_node *node, char *modalias, int len)
1202{
1203 const char *compatible, *p;
1204 int cplen;
1205
1206 compatible = of_get_property(node, "compatible", &cplen);
1207 if (!compatible || strlen(compatible) > cplen)
1208 return -ENODEV;
1209 p = strchr(compatible, ',');
1210 strlcpy(modalias, p ? p + 1 : compatible, len);
1211 return 0;
1212}
1213EXPORT_SYMBOL_GPL(of_modalias_node);
1214
1215/**
1216 * of_find_node_by_phandle - Find a node given a phandle
1217 * @handle: phandle of the node to find
1218 *
1219 * Returns a node pointer with refcount incremented, use
1220 * of_node_put() on it when done.
1221 */
1222struct device_node *of_find_node_by_phandle(phandle handle)
1223{
1224 struct device_node *np = NULL;
1225 unsigned long flags;
1226 phandle masked_handle;
1227
1228 if (!handle)
1229 return NULL;
1230
1231 raw_spin_lock_irqsave(&devtree_lock, flags);
1232
1233 masked_handle = handle & phandle_cache_mask;
1234
1235 if (phandle_cache) {
1236 if (phandle_cache[masked_handle] &&
1237 handle == phandle_cache[masked_handle]->phandle)
1238 np = phandle_cache[masked_handle];
1239 if (np && of_node_check_flag(np, OF_DETACHED)) {
1240 WARN_ON(1); /* did not uncache np on node removal */
1241 of_node_put(np);
1242 phandle_cache[masked_handle] = NULL;
1243 np = NULL;
1244 }
1245 }
1246
1247 if (!np) {
1248 for_each_of_allnodes(np)
1249 if (np->phandle == handle &&
1250 !of_node_check_flag(np, OF_DETACHED)) {
1251 if (phandle_cache) {
1252 /* will put when removed from cache */
1253 of_node_get(np);
1254 phandle_cache[masked_handle] = np;
1255 }
1256 break;
1257 }
1258 }
1259
1260 of_node_get(np);
1261 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1262 return np;
1263}
1264EXPORT_SYMBOL(of_find_node_by_phandle);
1265
1266void of_print_phandle_args(const char *msg, const struct of_phandle_args *args)
1267{
1268 int i;
1269 printk("%s %pOF", msg, args->np);
1270 for (i = 0; i < args->args_count; i++) {
1271 const char delim = i ? ',' : ':';
1272
1273 pr_cont("%c%08x", delim, args->args[i]);
1274 }
1275 pr_cont("\n");
1276}
1277
1278int of_phandle_iterator_init(struct of_phandle_iterator *it,
1279 const struct device_node *np,
1280 const char *list_name,
1281 const char *cells_name,
1282 int cell_count)
1283{
1284 const __be32 *list;
1285 int size;
1286
1287 memset(it, 0, sizeof(*it));
1288
1289 /*
1290 * one of cell_count or cells_name must be provided to determine the
1291 * argument length.
1292 */
1293 if (cell_count < 0 && !cells_name)
1294 return -EINVAL;
1295
1296 list = of_get_property(np, list_name, &size);
1297 if (!list)
1298 return -ENOENT;
1299
1300 it->cells_name = cells_name;
1301 it->cell_count = cell_count;
1302 it->parent = np;
1303 it->list_end = list + size / sizeof(*list);
1304 it->phandle_end = list;
1305 it->cur = list;
1306
1307 return 0;
1308}
1309EXPORT_SYMBOL_GPL(of_phandle_iterator_init);
1310
1311int of_phandle_iterator_next(struct of_phandle_iterator *it)
1312{
1313 uint32_t count = 0;
1314
1315 if (it->node) {
1316 of_node_put(it->node);
1317 it->node = NULL;
1318 }
1319
1320 if (!it->cur || it->phandle_end >= it->list_end)
1321 return -ENOENT;
1322
1323 it->cur = it->phandle_end;
1324
1325 /* If phandle is 0, then it is an empty entry with no arguments. */
1326 it->phandle = be32_to_cpup(it->cur++);
1327
1328 if (it->phandle) {
1329
1330 /*
1331 * Find the provider node and parse the #*-cells property to
1332 * determine the argument length.
1333 */
1334 it->node = of_find_node_by_phandle(it->phandle);
1335
1336 if (it->cells_name) {
1337 if (!it->node) {
1338 pr_err("%pOF: could not find phandle\n",
1339 it->parent);
1340 goto err;
1341 }
1342
1343 if (of_property_read_u32(it->node, it->cells_name,
1344 &count)) {
1345 /*
1346 * If both cell_count and cells_name is given,
1347 * fall back to cell_count in absence
1348 * of the cells_name property
1349 */
1350 if (it->cell_count >= 0) {
1351 count = it->cell_count;
1352 } else {
1353 pr_err("%pOF: could not get %s for %pOF\n",
1354 it->parent,
1355 it->cells_name,
1356 it->node);
1357 goto err;
1358 }
1359 }
1360 } else {
1361 count = it->cell_count;
1362 }
1363
1364 /*
1365 * Make sure that the arguments actually fit in the remaining
1366 * property data length
1367 */
1368 if (it->cur + count > it->list_end) {
1369 pr_err("%pOF: %s = %d found %d\n",
1370 it->parent, it->cells_name,
1371 count, it->cell_count);
1372 goto err;
1373 }
1374 }
1375
1376 it->phandle_end = it->cur + count;
1377 it->cur_count = count;
1378
1379 return 0;
1380
1381err:
1382 if (it->node) {
1383 of_node_put(it->node);
1384 it->node = NULL;
1385 }
1386
1387 return -EINVAL;
1388}
1389EXPORT_SYMBOL_GPL(of_phandle_iterator_next);
1390
1391int of_phandle_iterator_args(struct of_phandle_iterator *it,
1392 uint32_t *args,
1393 int size)
1394{
1395 int i, count;
1396
1397 count = it->cur_count;
1398
1399 if (WARN_ON(size < count))
1400 count = size;
1401
1402 for (i = 0; i < count; i++)
1403 args[i] = be32_to_cpup(it->cur++);
1404
1405 return count;
1406}
1407
1408static int __of_parse_phandle_with_args(const struct device_node *np,
1409 const char *list_name,
1410 const char *cells_name,
1411 int cell_count, int index,
1412 struct of_phandle_args *out_args)
1413{
1414 struct of_phandle_iterator it;
1415 int rc, cur_index = 0;
1416
1417 /* Loop over the phandles until all the requested entry is found */
1418 of_for_each_phandle(&it, rc, np, list_name, cells_name, cell_count) {
1419 /*
1420 * All of the error cases bail out of the loop, so at
1421 * this point, the parsing is successful. If the requested
1422 * index matches, then fill the out_args structure and return,
1423 * or return -ENOENT for an empty entry.
1424 */
1425 rc = -ENOENT;
1426 if (cur_index == index) {
1427 if (!it.phandle)
1428 goto err;
1429
1430 if (out_args) {
1431 int c;
1432
1433 c = of_phandle_iterator_args(&it,
1434 out_args->args,
1435 MAX_PHANDLE_ARGS);
1436 out_args->np = it.node;
1437 out_args->args_count = c;
1438 } else {
1439 of_node_put(it.node);
1440 }
1441
1442 /* Found it! return success */
1443 return 0;
1444 }
1445
1446 cur_index++;
1447 }
1448
1449 /*
1450 * Unlock node before returning result; will be one of:
1451 * -ENOENT : index is for empty phandle
1452 * -EINVAL : parsing error on data
1453 */
1454
1455 err:
1456 of_node_put(it.node);
1457 return rc;
1458}
1459
1460/**
1461 * of_parse_phandle - Resolve a phandle property to a device_node pointer
1462 * @np: Pointer to device node holding phandle property
1463 * @phandle_name: Name of property holding a phandle value
1464 * @index: For properties holding a table of phandles, this is the index into
1465 * the table
1466 *
1467 * Returns the device_node pointer with refcount incremented. Use
1468 * of_node_put() on it when done.
1469 */
1470struct device_node *of_parse_phandle(const struct device_node *np,
1471 const char *phandle_name, int index)
1472{
1473 struct of_phandle_args args;
1474
1475 if (index < 0)
1476 return NULL;
1477
1478 if (__of_parse_phandle_with_args(np, phandle_name, NULL, 0,
1479 index, &args))
1480 return NULL;
1481
1482 return args.np;
1483}
1484EXPORT_SYMBOL(of_parse_phandle);
1485
1486/**
1487 * of_parse_phandle_with_args() - Find a node pointed by phandle in a list
1488 * @np: pointer to a device tree node containing a list
1489 * @list_name: property name that contains a list
1490 * @cells_name: property name that specifies phandles' arguments count
1491 * @index: index of a phandle to parse out
1492 * @out_args: optional pointer to output arguments structure (will be filled)
1493 *
1494 * This function is useful to parse lists of phandles and their arguments.
1495 * Returns 0 on success and fills out_args, on error returns appropriate
1496 * errno value.
1497 *
1498 * Caller is responsible to call of_node_put() on the returned out_args->np
1499 * pointer.
1500 *
1501 * Example:
1502 *
1503 * phandle1: node1 {
1504 * #list-cells = <2>;
1505 * }
1506 *
1507 * phandle2: node2 {
1508 * #list-cells = <1>;
1509 * }
1510 *
1511 * node3 {
1512 * list = <&phandle1 1 2 &phandle2 3>;
1513 * }
1514 *
1515 * To get a device_node of the `node2' node you may call this:
1516 * of_parse_phandle_with_args(node3, "list", "#list-cells", 1, &args);
1517 */
1518int of_parse_phandle_with_args(const struct device_node *np, const char *list_name,
1519 const char *cells_name, int index,
1520 struct of_phandle_args *out_args)
1521{
1522 int cell_count = -1;
1523
1524 if (index < 0)
1525 return -EINVAL;
1526
1527 /* If cells_name is NULL we assume a cell count of 0 */
1528 if (!cells_name)
1529 cell_count = 0;
1530
1531 return __of_parse_phandle_with_args(np, list_name, cells_name,
1532 cell_count, index, out_args);
1533}
1534EXPORT_SYMBOL(of_parse_phandle_with_args);
1535
1536/**
1537 * of_parse_phandle_with_args_map() - Find a node pointed by phandle in a list and remap it
1538 * @np: pointer to a device tree node containing a list
1539 * @list_name: property name that contains a list
1540 * @stem_name: stem of property names that specify phandles' arguments count
1541 * @index: index of a phandle to parse out
1542 * @out_args: optional pointer to output arguments structure (will be filled)
1543 *
1544 * This function is useful to parse lists of phandles and their arguments.
1545 * Returns 0 on success and fills out_args, on error returns appropriate errno
1546 * value. The difference between this function and of_parse_phandle_with_args()
1547 * is that this API remaps a phandle if the node the phandle points to has
1548 * a <@stem_name>-map property.
1549 *
1550 * Caller is responsible to call of_node_put() on the returned out_args->np
1551 * pointer.
1552 *
1553 * Example:
1554 *
1555 * phandle1: node1 {
1556 * #list-cells = <2>;
1557 * }
1558 *
1559 * phandle2: node2 {
1560 * #list-cells = <1>;
1561 * }
1562 *
1563 * phandle3: node3 {
1564 * #list-cells = <1>;
1565 * list-map = <0 &phandle2 3>,
1566 * <1 &phandle2 2>,
1567 * <2 &phandle1 5 1>;
1568 * list-map-mask = <0x3>;
1569 * };
1570 *
1571 * node4 {
1572 * list = <&phandle1 1 2 &phandle3 0>;
1573 * }
1574 *
1575 * To get a device_node of the `node2' node you may call this:
1576 * of_parse_phandle_with_args(node4, "list", "list", 1, &args);
1577 */
1578int of_parse_phandle_with_args_map(const struct device_node *np,
1579 const char *list_name,
1580 const char *stem_name,
1581 int index, struct of_phandle_args *out_args)
1582{
1583 char *cells_name, *map_name = NULL, *mask_name = NULL;
1584 char *pass_name = NULL;
1585 struct device_node *cur, *new = NULL;
1586 const __be32 *map, *mask, *pass;
1587 static const __be32 dummy_mask[] = { [0 ... MAX_PHANDLE_ARGS] = ~0 };
1588 static const __be32 dummy_pass[] = { [0 ... MAX_PHANDLE_ARGS] = 0 };
1589 __be32 initial_match_array[MAX_PHANDLE_ARGS];
1590 const __be32 *match_array = initial_match_array;
1591 int i, ret, map_len, match;
1592 u32 list_size, new_size;
1593
1594 if (index < 0)
1595 return -EINVAL;
1596
1597 cells_name = kasprintf(GFP_KERNEL, "#%s-cells", stem_name);
1598 if (!cells_name)
1599 return -ENOMEM;
1600
1601 ret = -ENOMEM;
1602 map_name = kasprintf(GFP_KERNEL, "%s-map", stem_name);
1603 if (!map_name)
1604 goto free;
1605
1606 mask_name = kasprintf(GFP_KERNEL, "%s-map-mask", stem_name);
1607 if (!mask_name)
1608 goto free;
1609
1610 pass_name = kasprintf(GFP_KERNEL, "%s-map-pass-thru", stem_name);
1611 if (!pass_name)
1612 goto free;
1613
1614 ret = __of_parse_phandle_with_args(np, list_name, cells_name, -1, index,
1615 out_args);
1616 if (ret)
1617 goto free;
1618
1619 /* Get the #<list>-cells property */
1620 cur = out_args->np;
1621 ret = of_property_read_u32(cur, cells_name, &list_size);
1622 if (ret < 0)
1623 goto put;
1624
1625 /* Precalculate the match array - this simplifies match loop */
1626 for (i = 0; i < list_size; i++)
1627 initial_match_array[i] = cpu_to_be32(out_args->args[i]);
1628
1629 ret = -EINVAL;
1630 while (cur) {
1631 /* Get the <list>-map property */
1632 map = of_get_property(cur, map_name, &map_len);
1633 if (!map) {
1634 ret = 0;
1635 goto free;
1636 }
1637 map_len /= sizeof(u32);
1638
1639 /* Get the <list>-map-mask property (optional) */
1640 mask = of_get_property(cur, mask_name, NULL);
1641 if (!mask)
1642 mask = dummy_mask;
1643 /* Iterate through <list>-map property */
1644 match = 0;
1645 while (map_len > (list_size + 1) && !match) {
1646 /* Compare specifiers */
1647 match = 1;
1648 for (i = 0; i < list_size; i++, map_len--)
1649 match &= !((match_array[i] ^ *map++) & mask[i]);
1650
1651 of_node_put(new);
1652 new = of_find_node_by_phandle(be32_to_cpup(map));
1653 map++;
1654 map_len--;
1655
1656 /* Check if not found */
1657 if (!new)
1658 goto put;
1659
1660 if (!of_device_is_available(new))
1661 match = 0;
1662
1663 ret = of_property_read_u32(new, cells_name, &new_size);
1664 if (ret)
1665 goto put;
1666
1667 /* Check for malformed properties */
1668 if (WARN_ON(new_size > MAX_PHANDLE_ARGS))
1669 goto put;
1670 if (map_len < new_size)
1671 goto put;
1672
1673 /* Move forward by new node's #<list>-cells amount */
1674 map += new_size;
1675 map_len -= new_size;
1676 }
1677 if (!match)
1678 goto put;
1679
1680 /* Get the <list>-map-pass-thru property (optional) */
1681 pass = of_get_property(cur, pass_name, NULL);
1682 if (!pass)
1683 pass = dummy_pass;
1684
1685 /*
1686 * Successfully parsed a <list>-map translation; copy new
1687 * specifier into the out_args structure, keeping the
1688 * bits specified in <list>-map-pass-thru.
1689 */
1690 match_array = map - new_size;
1691 for (i = 0; i < new_size; i++) {
1692 __be32 val = *(map - new_size + i);
1693
1694 if (i < list_size) {
1695 val &= ~pass[i];
1696 val |= cpu_to_be32(out_args->args[i]) & pass[i];
1697 }
1698
1699 out_args->args[i] = be32_to_cpu(val);
1700 }
1701 out_args->args_count = list_size = new_size;
1702 /* Iterate again with new provider */
1703 out_args->np = new;
1704 of_node_put(cur);
1705 cur = new;
1706 }
1707put:
1708 of_node_put(cur);
1709 of_node_put(new);
1710free:
1711 kfree(mask_name);
1712 kfree(map_name);
1713 kfree(cells_name);
1714 kfree(pass_name);
1715
1716 return ret;
1717}
1718EXPORT_SYMBOL(of_parse_phandle_with_args_map);
1719
1720/**
1721 * of_parse_phandle_with_fixed_args() - Find a node pointed by phandle in a list
1722 * @np: pointer to a device tree node containing a list
1723 * @list_name: property name that contains a list
1724 * @cell_count: number of argument cells following the phandle
1725 * @index: index of a phandle to parse out
1726 * @out_args: optional pointer to output arguments structure (will be filled)
1727 *
1728 * This function is useful to parse lists of phandles and their arguments.
1729 * Returns 0 on success and fills out_args, on error returns appropriate
1730 * errno value.
1731 *
1732 * Caller is responsible to call of_node_put() on the returned out_args->np
1733 * pointer.
1734 *
1735 * Example:
1736 *
1737 * phandle1: node1 {
1738 * }
1739 *
1740 * phandle2: node2 {
1741 * }
1742 *
1743 * node3 {
1744 * list = <&phandle1 0 2 &phandle2 2 3>;
1745 * }
1746 *
1747 * To get a device_node of the `node2' node you may call this:
1748 * of_parse_phandle_with_fixed_args(node3, "list", 2, 1, &args);
1749 */
1750int of_parse_phandle_with_fixed_args(const struct device_node *np,
1751 const char *list_name, int cell_count,
1752 int index, struct of_phandle_args *out_args)
1753{
1754 if (index < 0)
1755 return -EINVAL;
1756 return __of_parse_phandle_with_args(np, list_name, NULL, cell_count,
1757 index, out_args);
1758}
1759EXPORT_SYMBOL(of_parse_phandle_with_fixed_args);
1760
1761/**
1762 * of_count_phandle_with_args() - Find the number of phandles references in a property
1763 * @np: pointer to a device tree node containing a list
1764 * @list_name: property name that contains a list
1765 * @cells_name: property name that specifies phandles' arguments count
1766 *
1767 * Returns the number of phandle + argument tuples within a property. It
1768 * is a typical pattern to encode a list of phandle and variable
1769 * arguments into a single property. The number of arguments is encoded
1770 * by a property in the phandle-target node. For example, a gpios
1771 * property would contain a list of GPIO specifies consisting of a
1772 * phandle and 1 or more arguments. The number of arguments are
1773 * determined by the #gpio-cells property in the node pointed to by the
1774 * phandle.
1775 */
1776int of_count_phandle_with_args(const struct device_node *np, const char *list_name,
1777 const char *cells_name)
1778{
1779 struct of_phandle_iterator it;
1780 int rc, cur_index = 0;
1781
1782 /*
1783 * If cells_name is NULL we assume a cell count of 0. This makes
1784 * counting the phandles trivial as each 32bit word in the list is a
1785 * phandle and no arguments are to consider. So we don't iterate through
1786 * the list but just use the length to determine the phandle count.
1787 */
1788 if (!cells_name) {
1789 const __be32 *list;
1790 int size;
1791
1792 list = of_get_property(np, list_name, &size);
1793 if (!list)
1794 return -ENOENT;
1795
1796 return size / sizeof(*list);
1797 }
1798
1799 rc = of_phandle_iterator_init(&it, np, list_name, cells_name, -1);
1800 if (rc)
1801 return rc;
1802
1803 while ((rc = of_phandle_iterator_next(&it)) == 0)
1804 cur_index += 1;
1805
1806 if (rc != -ENOENT)
1807 return rc;
1808
1809 return cur_index;
1810}
1811EXPORT_SYMBOL(of_count_phandle_with_args);
1812
1813/**
1814 * __of_add_property - Add a property to a node without lock operations
1815 */
1816int __of_add_property(struct device_node *np, struct property *prop)
1817{
1818 struct property **next;
1819
1820 prop->next = NULL;
1821 next = &np->properties;
1822 while (*next) {
1823 if (strcmp(prop->name, (*next)->name) == 0)
1824 /* duplicate ! don't insert it */
1825 return -EEXIST;
1826
1827 next = &(*next)->next;
1828 }
1829 *next = prop;
1830
1831 return 0;
1832}
1833
1834/**
1835 * of_add_property - Add a property to a node
1836 */
1837int of_add_property(struct device_node *np, struct property *prop)
1838{
1839 unsigned long flags;
1840 int rc;
1841
1842 mutex_lock(&of_mutex);
1843
1844 raw_spin_lock_irqsave(&devtree_lock, flags);
1845 rc = __of_add_property(np, prop);
1846 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1847
1848 if (!rc)
1849 __of_add_property_sysfs(np, prop);
1850
1851 mutex_unlock(&of_mutex);
1852
1853 if (!rc)
1854 of_property_notify(OF_RECONFIG_ADD_PROPERTY, np, prop, NULL);
1855
1856 return rc;
1857}
1858
1859int __of_remove_property(struct device_node *np, struct property *prop)
1860{
1861 struct property **next;
1862
1863 for (next = &np->properties; *next; next = &(*next)->next) {
1864 if (*next == prop)
1865 break;
1866 }
1867 if (*next == NULL)
1868 return -ENODEV;
1869
1870 /* found the node */
1871 *next = prop->next;
1872 prop->next = np->deadprops;
1873 np->deadprops = prop;
1874
1875 return 0;
1876}
1877
1878/**
1879 * of_remove_property - Remove a property from a node.
1880 *
1881 * Note that we don't actually remove it, since we have given out
1882 * who-knows-how-many pointers to the data using get-property.
1883 * Instead we just move the property to the "dead properties"
1884 * list, so it won't be found any more.
1885 */
1886int of_remove_property(struct device_node *np, struct property *prop)
1887{
1888 unsigned long flags;
1889 int rc;
1890
1891 if (!prop)
1892 return -ENODEV;
1893
1894 mutex_lock(&of_mutex);
1895
1896 raw_spin_lock_irqsave(&devtree_lock, flags);
1897 rc = __of_remove_property(np, prop);
1898 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1899
1900 if (!rc)
1901 __of_remove_property_sysfs(np, prop);
1902
1903 mutex_unlock(&of_mutex);
1904
1905 if (!rc)
1906 of_property_notify(OF_RECONFIG_REMOVE_PROPERTY, np, prop, NULL);
1907
1908 return rc;
1909}
1910
1911int __of_update_property(struct device_node *np, struct property *newprop,
1912 struct property **oldpropp)
1913{
1914 struct property **next, *oldprop;
1915
1916 for (next = &np->properties; *next; next = &(*next)->next) {
1917 if (of_prop_cmp((*next)->name, newprop->name) == 0)
1918 break;
1919 }
1920 *oldpropp = oldprop = *next;
1921
1922 if (oldprop) {
1923 /* replace the node */
1924 newprop->next = oldprop->next;
1925 *next = newprop;
1926 oldprop->next = np->deadprops;
1927 np->deadprops = oldprop;
1928 } else {
1929 /* new node */
1930 newprop->next = NULL;
1931 *next = newprop;
1932 }
1933
1934 return 0;
1935}
1936
1937/*
1938 * of_update_property - Update a property in a node, if the property does
1939 * not exist, add it.
1940 *
1941 * Note that we don't actually remove it, since we have given out
1942 * who-knows-how-many pointers to the data using get-property.
1943 * Instead we just move the property to the "dead properties" list,
1944 * and add the new property to the property list
1945 */
1946int of_update_property(struct device_node *np, struct property *newprop)
1947{
1948 struct property *oldprop;
1949 unsigned long flags;
1950 int rc;
1951
1952 if (!newprop->name)
1953 return -EINVAL;
1954
1955 mutex_lock(&of_mutex);
1956
1957 raw_spin_lock_irqsave(&devtree_lock, flags);
1958 rc = __of_update_property(np, newprop, &oldprop);
1959 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1960
1961 if (!rc)
1962 __of_update_property_sysfs(np, newprop, oldprop);
1963
1964 mutex_unlock(&of_mutex);
1965
1966 if (!rc)
1967 of_property_notify(OF_RECONFIG_UPDATE_PROPERTY, np, newprop, oldprop);
1968
1969 return rc;
1970}
1971
1972static void of_alias_add(struct alias_prop *ap, struct device_node *np,
1973 int id, const char *stem, int stem_len)
1974{
1975 ap->np = np;
1976 ap->id = id;
1977 strncpy(ap->stem, stem, stem_len);
1978 ap->stem[stem_len] = 0;
1979 list_add_tail(&ap->link, &aliases_lookup);
1980 pr_debug("adding DT alias:%s: stem=%s id=%i node=%pOF\n",
1981 ap->alias, ap->stem, ap->id, np);
1982}
1983
1984/**
1985 * of_alias_scan - Scan all properties of the 'aliases' node
1986 *
1987 * The function scans all the properties of the 'aliases' node and populates
1988 * the global lookup table with the properties. It returns the
1989 * number of alias properties found, or an error code in case of failure.
1990 *
1991 * @dt_alloc: An allocator that provides a virtual address to memory
1992 * for storing the resulting tree
1993 */
1994void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align))
1995{
1996 struct property *pp;
1997
1998 of_aliases = of_find_node_by_path("/aliases");
1999 of_chosen = of_find_node_by_path("/chosen");
2000 if (of_chosen == NULL)
2001 of_chosen = of_find_node_by_path("/chosen@0");
2002
2003 if (of_chosen) {
2004 /* linux,stdout-path and /aliases/stdout are for legacy compatibility */
2005 const char *name = NULL;
2006
2007 if (of_property_read_string(of_chosen, "stdout-path", &name))
2008 of_property_read_string(of_chosen, "linux,stdout-path",
2009 &name);
2010 if (IS_ENABLED(CONFIG_PPC) && !name)
2011 of_property_read_string(of_aliases, "stdout", &name);
2012 if (name)
2013 of_stdout = of_find_node_opts_by_path(name, &of_stdout_options);
2014 }
2015
2016 if (!of_aliases)
2017 return;
2018
2019 for_each_property_of_node(of_aliases, pp) {
2020 const char *start = pp->name;
2021 const char *end = start + strlen(start);
2022 struct device_node *np;
2023 struct alias_prop *ap;
2024 int id, len;
2025
2026 /* Skip those we do not want to proceed */
2027 if (!strcmp(pp->name, "name") ||
2028 !strcmp(pp->name, "phandle") ||
2029 !strcmp(pp->name, "linux,phandle"))
2030 continue;
2031
2032 np = of_find_node_by_path(pp->value);
2033 if (!np)
2034 continue;
2035
2036 /* walk the alias backwards to extract the id and work out
2037 * the 'stem' string */
2038 while (isdigit(*(end-1)) && end > start)
2039 end--;
2040 len = end - start;
2041
2042 if (kstrtoint(end, 10, &id) < 0)
2043 continue;
2044
2045 /* Allocate an alias_prop with enough space for the stem */
2046 ap = dt_alloc(sizeof(*ap) + len + 1, __alignof__(*ap));
2047 if (!ap)
2048 continue;
2049 memset(ap, 0, sizeof(*ap) + len + 1);
2050 ap->alias = start;
2051 of_alias_add(ap, np, id, start, len);
2052 }
2053}
2054
2055/**
2056 * of_alias_get_id - Get alias id for the given device_node
2057 * @np: Pointer to the given device_node
2058 * @stem: Alias stem of the given device_node
2059 *
2060 * The function travels the lookup table to get the alias id for the given
2061 * device_node and alias stem. It returns the alias id if found.
2062 */
2063int of_alias_get_id(struct device_node *np, const char *stem)
2064{
2065 struct alias_prop *app;
2066 int id = -ENODEV;
2067
2068 mutex_lock(&of_mutex);
2069 list_for_each_entry(app, &aliases_lookup, link) {
2070 if (strcmp(app->stem, stem) != 0)
2071 continue;
2072
2073 if (np == app->np) {
2074 id = app->id;
2075 break;
2076 }
2077 }
2078 mutex_unlock(&of_mutex);
2079
2080 return id;
2081}
2082EXPORT_SYMBOL_GPL(of_alias_get_id);
2083
2084/**
2085 * of_alias_get_alias_list - Get alias list for the given device driver
2086 * @matches: Array of OF device match structures to search in
2087 * @stem: Alias stem of the given device_node
2088 * @bitmap: Bitmap field pointer
2089 * @nbits: Maximum number of alias IDs which can be recorded in bitmap
2090 *
2091 * The function travels the lookup table to record alias ids for the given
2092 * device match structures and alias stem.
2093 *
2094 * Return: 0 or -ENOSYS when !CONFIG_OF or
2095 * -EOVERFLOW if alias ID is greater then allocated nbits
2096 */
2097int of_alias_get_alias_list(const struct of_device_id *matches,
2098 const char *stem, unsigned long *bitmap,
2099 unsigned int nbits)
2100{
2101 struct alias_prop *app;
2102 int ret = 0;
2103
2104 /* Zero bitmap field to make sure that all the time it is clean */
2105 bitmap_zero(bitmap, nbits);
2106
2107 mutex_lock(&of_mutex);
2108 pr_debug("%s: Looking for stem: %s\n", __func__, stem);
2109 list_for_each_entry(app, &aliases_lookup, link) {
2110 pr_debug("%s: stem: %s, id: %d\n",
2111 __func__, app->stem, app->id);
2112
2113 if (strcmp(app->stem, stem) != 0) {
2114 pr_debug("%s: stem comparison didn't pass %s\n",
2115 __func__, app->stem);
2116 continue;
2117 }
2118
2119 if (of_match_node(matches, app->np)) {
2120 pr_debug("%s: Allocated ID %d\n", __func__, app->id);
2121
2122 if (app->id >= nbits) {
2123 pr_warn("%s: ID %d >= than bitmap field %d\n",
2124 __func__, app->id, nbits);
2125 ret = -EOVERFLOW;
2126 } else {
2127 set_bit(app->id, bitmap);
2128 }
2129 }
2130 }
2131 mutex_unlock(&of_mutex);
2132
2133 return ret;
2134}
2135EXPORT_SYMBOL_GPL(of_alias_get_alias_list);
2136
2137/**
2138 * of_alias_get_highest_id - Get highest alias id for the given stem
2139 * @stem: Alias stem to be examined
2140 *
2141 * The function travels the lookup table to get the highest alias id for the
2142 * given alias stem. It returns the alias id if found.
2143 */
2144int of_alias_get_highest_id(const char *stem)
2145{
2146 struct alias_prop *app;
2147 int id = -ENODEV;
2148
2149 mutex_lock(&of_mutex);
2150 list_for_each_entry(app, &aliases_lookup, link) {
2151 if (strcmp(app->stem, stem) != 0)
2152 continue;
2153
2154 if (app->id > id)
2155 id = app->id;
2156 }
2157 mutex_unlock(&of_mutex);
2158
2159 return id;
2160}
2161EXPORT_SYMBOL_GPL(of_alias_get_highest_id);
2162
2163/**
2164 * of_console_check() - Test and setup console for DT setup
2165 * @dn - Pointer to device node
2166 * @name - Name to use for preferred console without index. ex. "ttyS"
2167 * @index - Index to use for preferred console.
2168 *
2169 * Check if the given device node matches the stdout-path property in the
2170 * /chosen node. If it does then register it as the preferred console and return
2171 * TRUE. Otherwise return FALSE.
2172 */
2173bool of_console_check(struct device_node *dn, char *name, int index)
2174{
2175 if (!dn || dn != of_stdout || console_set_on_cmdline)
2176 return false;
2177
2178 /*
2179 * XXX: cast `options' to char pointer to suppress complication
2180 * warnings: printk, UART and console drivers expect char pointer.
2181 */
2182 return !add_preferred_console(name, index, (char *)of_stdout_options);
2183}
2184EXPORT_SYMBOL_GPL(of_console_check);
2185
2186/**
2187 * of_find_next_cache_node - Find a node's subsidiary cache
2188 * @np: node of type "cpu" or "cache"
2189 *
2190 * Returns a node pointer with refcount incremented, use
2191 * of_node_put() on it when done. Caller should hold a reference
2192 * to np.
2193 */
2194struct device_node *of_find_next_cache_node(const struct device_node *np)
2195{
2196 struct device_node *child, *cache_node;
2197
2198 cache_node = of_parse_phandle(np, "l2-cache", 0);
2199 if (!cache_node)
2200 cache_node = of_parse_phandle(np, "next-level-cache", 0);
2201
2202 if (cache_node)
2203 return cache_node;
2204
2205 /* OF on pmac has nodes instead of properties named "l2-cache"
2206 * beneath CPU nodes.
2207 */
2208 if (IS_ENABLED(CONFIG_PPC_PMAC) && of_node_is_type(np, "cpu"))
2209 for_each_child_of_node(np, child)
2210 if (of_node_is_type(child, "cache"))
2211 return child;
2212
2213 return NULL;
2214}
2215
2216/**
2217 * of_find_last_cache_level - Find the level at which the last cache is
2218 * present for the given logical cpu
2219 *
2220 * @cpu: cpu number(logical index) for which the last cache level is needed
2221 *
2222 * Returns the the level at which the last cache is present. It is exactly
2223 * same as the total number of cache levels for the given logical cpu.
2224 */
2225int of_find_last_cache_level(unsigned int cpu)
2226{
2227 u32 cache_level = 0;
2228 struct device_node *prev = NULL, *np = of_cpu_device_node_get(cpu);
2229
2230 while (np) {
2231 prev = np;
2232 of_node_put(np);
2233 np = of_find_next_cache_node(np);
2234 }
2235
2236 of_property_read_u32(prev, "cache-level", &cache_level);
2237
2238 return cache_level;
2239}
2240
2241/**
2242 * of_map_rid - Translate a requester ID through a downstream mapping.
2243 * @np: root complex device node.
2244 * @rid: device requester ID to map.
2245 * @map_name: property name of the map to use.
2246 * @map_mask_name: optional property name of the mask to use.
2247 * @target: optional pointer to a target device node.
2248 * @id_out: optional pointer to receive the translated ID.
2249 *
2250 * Given a device requester ID, look up the appropriate implementation-defined
2251 * platform ID and/or the target device which receives transactions on that
2252 * ID, as per the "iommu-map" and "msi-map" bindings. Either of @target or
2253 * @id_out may be NULL if only the other is required. If @target points to
2254 * a non-NULL device node pointer, only entries targeting that node will be
2255 * matched; if it points to a NULL value, it will receive the device node of
2256 * the first matching target phandle, with a reference held.
2257 *
2258 * Return: 0 on success or a standard error code on failure.
2259 */
2260int of_map_rid(struct device_node *np, u32 rid,
2261 const char *map_name, const char *map_mask_name,
2262 struct device_node **target, u32 *id_out)
2263{
2264 u32 map_mask, masked_rid;
2265 int map_len;
2266 const __be32 *map = NULL;
2267
2268 if (!np || !map_name || (!target && !id_out))
2269 return -EINVAL;
2270
2271 map = of_get_property(np, map_name, &map_len);
2272 if (!map) {
2273 if (target)
2274 return -ENODEV;
2275 /* Otherwise, no map implies no translation */
2276 *id_out = rid;
2277 return 0;
2278 }
2279
2280 if (!map_len || map_len % (4 * sizeof(*map))) {
2281 pr_err("%pOF: Error: Bad %s length: %d\n", np,
2282 map_name, map_len);
2283 return -EINVAL;
2284 }
2285
2286 /* The default is to select all bits. */
2287 map_mask = 0xffffffff;
2288
2289 /*
2290 * Can be overridden by "{iommu,msi}-map-mask" property.
2291 * If of_property_read_u32() fails, the default is used.
2292 */
2293 if (map_mask_name)
2294 of_property_read_u32(np, map_mask_name, &map_mask);
2295
2296 masked_rid = map_mask & rid;
2297 for ( ; map_len > 0; map_len -= 4 * sizeof(*map), map += 4) {
2298 struct device_node *phandle_node;
2299 u32 rid_base = be32_to_cpup(map + 0);
2300 u32 phandle = be32_to_cpup(map + 1);
2301 u32 out_base = be32_to_cpup(map + 2);
2302 u32 rid_len = be32_to_cpup(map + 3);
2303
2304 if (rid_base & ~map_mask) {
2305 pr_err("%pOF: Invalid %s translation - %s-mask (0x%x) ignores rid-base (0x%x)\n",
2306 np, map_name, map_name,
2307 map_mask, rid_base);
2308 return -EFAULT;
2309 }
2310
2311 if (masked_rid < rid_base || masked_rid >= rid_base + rid_len)
2312 continue;
2313
2314 phandle_node = of_find_node_by_phandle(phandle);
2315 if (!phandle_node)
2316 return -ENODEV;
2317
2318 if (target) {
2319 if (*target)
2320 of_node_put(phandle_node);
2321 else
2322 *target = phandle_node;
2323
2324 if (*target != phandle_node)
2325 continue;
2326 }
2327
2328 if (id_out)
2329 *id_out = masked_rid - rid_base + out_base;
2330
2331 pr_debug("%pOF: %s, using mask %08x, rid-base: %08x, out-base: %08x, length: %08x, rid: %08x -> %08x\n",
2332 np, map_name, map_mask, rid_base, out_base,
2333 rid_len, rid, masked_rid - rid_base + out_base);
2334 return 0;
2335 }
2336
2337 pr_info("%pOF: no %s translation for rid 0x%x on %pOF\n", np, map_name,
2338 rid, target && *target ? *target : NULL);
2339
2340 /* Bypasses translation */
2341 if (id_out)
2342 *id_out = rid;
2343 return 0;
2344}
2345EXPORT_SYMBOL_GPL(of_map_rid);