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(path: 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(path: 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, name: "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, propname: "#address-cells", out_value: &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, propname: "#size-cells", out_value: &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(val: 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(name: "devicetree", NULL, parent_kobj: firmware_kobj);
175 if (!of_kset) {
176 mutex_unlock(lock: &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(handle: np->phandle)])
183 phandle_cache[of_phandle_cache_hash(handle: np->phandle)] = np;
184 }
185 mutex_unlock(lock: &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(node: np);
259 of_node_put(node: 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(np: device, name: "compatible", NULL);
330 for (cp = of_prop_next_string(prop, NULL); cp;
331 cp = of_prop_next_string(prop, cur: 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(np: 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(path: "/");
410 if (root) {
411 rc = of_device_is_compatible(root, compat);
412 of_node_put(node: 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(np: device, name: "status", lenp: &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(np: device, name: "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(np: device, propname: "big-endian"))
504 return true;
505 if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) &&
506 of_property_read_bool(np: device, propname: "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: 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: 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(node: next);
571 of_node_put(node: 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(device: next))
621 continue;
622 if (of_node_get(node: next))
623 break;
624 }
625 of_node_put(node: 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(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(device: next))
660 continue;
661 if (!(of_node_name_eq(next, "cpu") ||
662 __of_node_is_type(np: next, type: "cpu")))
663 continue;
664 if (of_node_get(node: next))
665 break;
666 }
667 of_node_put(node: 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(path: 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(parent: node, path);
749 of_node_put(node: 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(node: 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(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(node: of_root);
816 np = __of_find_node_by_full_path(node: 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(node: np))
842 break;
843 of_node_put(node: 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(node: np))
870 break;
871 of_node_put(node: 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(device: np, compat: compatible, type, NULL) &&
900 of_node_get(node: np))
901 break;
902 of_node_put(node: 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(node: np);
932 goto out;
933 }
934 }
935 }
936out:
937 of_node_put(node: 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(device: node, compat: matches->compatible,
955 type: matches->type, name: 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, node: np);
1012 if (m && of_node_get(node: np)) {
1013 if (match)
1014 *match = m;
1015 break;
1016 }
1017 }
1018 of_node_put(node: 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(p: alias, q: p ? p + 1 : compatible, size: 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(n: np, OF_DETACHED)) {
1083 phandle_cache[handle_hash] = np;
1084 break;
1085 }
1086 }
1087
1088 of_node_get(node: 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(node: 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(p: 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(np: it->node, propname: it->cells_name,
1172 out_value: &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(node: 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(p: 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: &it,
1270 args: 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(node: 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(node: 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, fmt: "#%s-cells", stem_name);
1359 if (!cells_name)
1360 return -ENOMEM;
1361
1362 ret = -ENOMEM;
1363 map_name = kasprintf(GFP_KERNEL, fmt: "%s-map", stem_name);
1364 if (!map_name)
1365 goto free;
1366
1367 mask_name = kasprintf(GFP_KERNEL, fmt: "%s-map-mask", stem_name);
1368 if (!mask_name)
1369 goto free;
1370
1371 pass_name = kasprintf(GFP_KERNEL, fmt: "%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(np: cur, propname: cells_name, out_value: &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(node: new);
1413 new = of_find_node_by_phandle(be32_to_cpup(p: 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(np: new, propname: cells_name, out_value: &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(node: cur);
1466 cur = new;
1467 }
1468put:
1469 of_node_put(node: cur);
1470 of_node_put(node: new);
1471free:
1472 kfree(objp: mask_name);
1473 kfree(objp: map_name);
1474 kfree(objp: cells_name);
1475 kfree(objp: pass_name);
1476
1477 return ret;
1478}
1479EXPORT_SYMBOL(of_parse_phandle_with_args_map);
1480
1481/**
1482 * of_count_phandle_with_args() - Find the number of phandles references in a property
1483 * @np: pointer to a device tree node containing a list
1484 * @list_name: property name that contains a list
1485 * @cells_name: property name that specifies phandles' arguments count
1486 *
1487 * Return: The number of phandle + argument tuples within a property. It
1488 * is a typical pattern to encode a list of phandle and variable
1489 * arguments into a single property. The number of arguments is encoded
1490 * by a property in the phandle-target node. For example, a gpios
1491 * property would contain a list of GPIO specifies consisting of a
1492 * phandle and 1 or more arguments. The number of arguments are
1493 * determined by the #gpio-cells property in the node pointed to by the
1494 * phandle.
1495 */
1496int of_count_phandle_with_args(const struct device_node *np, const char *list_name,
1497 const char *cells_name)
1498{
1499 struct of_phandle_iterator it;
1500 int rc, cur_index = 0;
1501
1502 /*
1503 * If cells_name is NULL we assume a cell count of 0. This makes
1504 * counting the phandles trivial as each 32bit word in the list is a
1505 * phandle and no arguments are to consider. So we don't iterate through
1506 * the list but just use the length to determine the phandle count.
1507 */
1508 if (!cells_name) {
1509 const __be32 *list;
1510 int size;
1511
1512 list = of_get_property(np, list_name, &size);
1513 if (!list)
1514 return -ENOENT;
1515
1516 return size / sizeof(*list);
1517 }
1518
1519 rc = of_phandle_iterator_init(&it, np, list_name, cells_name, -1);
1520 if (rc)
1521 return rc;
1522
1523 while ((rc = of_phandle_iterator_next(&it)) == 0)
1524 cur_index += 1;
1525
1526 if (rc != -ENOENT)
1527 return rc;
1528
1529 return cur_index;
1530}
1531EXPORT_SYMBOL(of_count_phandle_with_args);
1532
1533static struct property *__of_remove_property_from_list(struct property **list, struct property *prop)
1534{
1535 struct property **next;
1536
1537 for (next = list; *next; next = &(*next)->next) {
1538 if (*next == prop) {
1539 *next = prop->next;
1540 prop->next = NULL;
1541 return prop;
1542 }
1543 }
1544 return NULL;
1545}
1546
1547/**
1548 * __of_add_property - Add a property to a node without lock operations
1549 * @np: Caller's Device Node
1550 * @prop: Property to add
1551 */
1552int __of_add_property(struct device_node *np, struct property *prop)
1553{
1554 int rc = 0;
1555 unsigned long flags;
1556 struct property **next;
1557
1558 raw_spin_lock_irqsave(&devtree_lock, flags);
1559
1560 __of_remove_property_from_list(list: &np->deadprops, prop);
1561
1562 prop->next = NULL;
1563 next = &np->properties;
1564 while (*next) {
1565 if (strcmp(prop->name, (*next)->name) == 0) {
1566 /* duplicate ! don't insert it */
1567 rc = -EEXIST;
1568 goto out_unlock;
1569 }
1570 next = &(*next)->next;
1571 }
1572 *next = prop;
1573
1574out_unlock:
1575 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1576 if (rc)
1577 return rc;
1578
1579 __of_add_property_sysfs(np, pp: prop);
1580 return 0;
1581}
1582
1583/**
1584 * of_add_property - Add a property to a node
1585 * @np: Caller's Device Node
1586 * @prop: Property to add
1587 */
1588int of_add_property(struct device_node *np, struct property *prop)
1589{
1590 int rc;
1591
1592 mutex_lock(&of_mutex);
1593 rc = __of_add_property(np, prop);
1594 mutex_unlock(lock: &of_mutex);
1595
1596 if (!rc)
1597 of_property_notify(OF_RECONFIG_ADD_PROPERTY, np, prop, NULL);
1598
1599 return rc;
1600}
1601EXPORT_SYMBOL_GPL(of_add_property);
1602
1603int __of_remove_property(struct device_node *np, struct property *prop)
1604{
1605 unsigned long flags;
1606 int rc = -ENODEV;
1607
1608 raw_spin_lock_irqsave(&devtree_lock, flags);
1609
1610 if (__of_remove_property_from_list(list: &np->properties, prop)) {
1611 /* Found the property, add it to deadprops list */
1612 prop->next = np->deadprops;
1613 np->deadprops = prop;
1614 rc = 0;
1615 }
1616
1617 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1618 if (rc)
1619 return rc;
1620
1621 __of_remove_property_sysfs(np, prop);
1622 return 0;
1623}
1624
1625/**
1626 * of_remove_property - Remove a property from a node.
1627 * @np: Caller's Device Node
1628 * @prop: Property to remove
1629 *
1630 * Note that we don't actually remove it, since we have given out
1631 * who-knows-how-many pointers to the data using get-property.
1632 * Instead we just move the property to the "dead properties"
1633 * list, so it won't be found any more.
1634 */
1635int of_remove_property(struct device_node *np, struct property *prop)
1636{
1637 int rc;
1638
1639 if (!prop)
1640 return -ENODEV;
1641
1642 mutex_lock(&of_mutex);
1643 rc = __of_remove_property(np, prop);
1644 mutex_unlock(lock: &of_mutex);
1645
1646 if (!rc)
1647 of_property_notify(OF_RECONFIG_REMOVE_PROPERTY, np, prop, NULL);
1648
1649 return rc;
1650}
1651EXPORT_SYMBOL_GPL(of_remove_property);
1652
1653int __of_update_property(struct device_node *np, struct property *newprop,
1654 struct property **oldpropp)
1655{
1656 struct property **next, *oldprop;
1657 unsigned long flags;
1658
1659 raw_spin_lock_irqsave(&devtree_lock, flags);
1660
1661 __of_remove_property_from_list(list: &np->deadprops, prop: newprop);
1662
1663 for (next = &np->properties; *next; next = &(*next)->next) {
1664 if (of_prop_cmp((*next)->name, newprop->name) == 0)
1665 break;
1666 }
1667 *oldpropp = oldprop = *next;
1668
1669 if (oldprop) {
1670 /* replace the node */
1671 newprop->next = oldprop->next;
1672 *next = newprop;
1673 oldprop->next = np->deadprops;
1674 np->deadprops = oldprop;
1675 } else {
1676 /* new node */
1677 newprop->next = NULL;
1678 *next = newprop;
1679 }
1680
1681 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1682
1683 __of_update_property_sysfs(np, newprop, oldprop);
1684
1685 return 0;
1686}
1687
1688/*
1689 * of_update_property - Update a property in a node, if the property does
1690 * not exist, add it.
1691 *
1692 * Note that we don't actually remove it, since we have given out
1693 * who-knows-how-many pointers to the data using get-property.
1694 * Instead we just move the property to the "dead properties" list,
1695 * and add the new property to the property list
1696 */
1697int of_update_property(struct device_node *np, struct property *newprop)
1698{
1699 struct property *oldprop;
1700 int rc;
1701
1702 if (!newprop->name)
1703 return -EINVAL;
1704
1705 mutex_lock(&of_mutex);
1706 rc = __of_update_property(np, newprop, oldpropp: &oldprop);
1707 mutex_unlock(lock: &of_mutex);
1708
1709 if (!rc)
1710 of_property_notify(OF_RECONFIG_UPDATE_PROPERTY, np, prop: newprop, old_prop: oldprop);
1711
1712 return rc;
1713}
1714
1715static void of_alias_add(struct alias_prop *ap, struct device_node *np,
1716 int id, const char *stem, int stem_len)
1717{
1718 ap->np = np;
1719 ap->id = id;
1720 strscpy(p: ap->stem, q: stem, size: stem_len + 1);
1721 list_add_tail(new: &ap->link, head: &aliases_lookup);
1722 pr_debug("adding DT alias:%s: stem=%s id=%i node=%pOF\n",
1723 ap->alias, ap->stem, ap->id, np);
1724}
1725
1726/**
1727 * of_alias_scan - Scan all properties of the 'aliases' node
1728 * @dt_alloc: An allocator that provides a virtual address to memory
1729 * for storing the resulting tree
1730 *
1731 * The function scans all the properties of the 'aliases' node and populates
1732 * the global lookup table with the properties. It returns the
1733 * number of alias properties found, or an error code in case of failure.
1734 */
1735void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align))
1736{
1737 struct property *pp;
1738
1739 of_aliases = of_find_node_by_path(path: "/aliases");
1740 of_chosen = of_find_node_by_path(path: "/chosen");
1741 if (of_chosen == NULL)
1742 of_chosen = of_find_node_by_path(path: "/chosen@0");
1743
1744 if (of_chosen) {
1745 /* linux,stdout-path and /aliases/stdout are for legacy compatibility */
1746 const char *name = NULL;
1747
1748 if (of_property_read_string(np: of_chosen, propname: "stdout-path", out_string: &name))
1749 of_property_read_string(np: of_chosen, propname: "linux,stdout-path",
1750 out_string: &name);
1751 if (IS_ENABLED(CONFIG_PPC) && !name)
1752 of_property_read_string(np: of_aliases, propname: "stdout", out_string: &name);
1753 if (name)
1754 of_stdout = of_find_node_opts_by_path(name, &of_stdout_options);
1755 if (of_stdout)
1756 of_stdout->fwnode.flags |= FWNODE_FLAG_BEST_EFFORT;
1757 }
1758
1759 if (!of_aliases)
1760 return;
1761
1762 for_each_property_of_node(of_aliases, pp) {
1763 const char *start = pp->name;
1764 const char *end = start + strlen(start);
1765 struct device_node *np;
1766 struct alias_prop *ap;
1767 int id, len;
1768
1769 /* Skip those we do not want to proceed */
1770 if (!strcmp(pp->name, "name") ||
1771 !strcmp(pp->name, "phandle") ||
1772 !strcmp(pp->name, "linux,phandle"))
1773 continue;
1774
1775 np = of_find_node_by_path(path: pp->value);
1776 if (!np)
1777 continue;
1778
1779 /* walk the alias backwards to extract the id and work out
1780 * the 'stem' string */
1781 while (isdigit(c: *(end-1)) && end > start)
1782 end--;
1783 len = end - start;
1784
1785 if (kstrtoint(s: end, base: 10, res: &id) < 0)
1786 continue;
1787
1788 /* Allocate an alias_prop with enough space for the stem */
1789 ap = dt_alloc(sizeof(*ap) + len + 1, __alignof__(*ap));
1790 if (!ap)
1791 continue;
1792 memset(ap, 0, sizeof(*ap) + len + 1);
1793 ap->alias = start;
1794 of_alias_add(ap, np, id, stem: start, stem_len: len);
1795 }
1796}
1797
1798/**
1799 * of_alias_get_id - Get alias id for the given device_node
1800 * @np: Pointer to the given device_node
1801 * @stem: Alias stem of the given device_node
1802 *
1803 * The function travels the lookup table to get the alias id for the given
1804 * device_node and alias stem.
1805 *
1806 * Return: The alias id if found.
1807 */
1808int of_alias_get_id(struct device_node *np, const char *stem)
1809{
1810 struct alias_prop *app;
1811 int id = -ENODEV;
1812
1813 mutex_lock(&of_mutex);
1814 list_for_each_entry(app, &aliases_lookup, link) {
1815 if (strcmp(app->stem, stem) != 0)
1816 continue;
1817
1818 if (np == app->np) {
1819 id = app->id;
1820 break;
1821 }
1822 }
1823 mutex_unlock(lock: &of_mutex);
1824
1825 return id;
1826}
1827EXPORT_SYMBOL_GPL(of_alias_get_id);
1828
1829/**
1830 * of_alias_get_highest_id - Get highest alias id for the given stem
1831 * @stem: Alias stem to be examined
1832 *
1833 * The function travels the lookup table to get the highest alias id for the
1834 * given alias stem. It returns the alias id if found.
1835 */
1836int of_alias_get_highest_id(const char *stem)
1837{
1838 struct alias_prop *app;
1839 int id = -ENODEV;
1840
1841 mutex_lock(&of_mutex);
1842 list_for_each_entry(app, &aliases_lookup, link) {
1843 if (strcmp(app->stem, stem) != 0)
1844 continue;
1845
1846 if (app->id > id)
1847 id = app->id;
1848 }
1849 mutex_unlock(lock: &of_mutex);
1850
1851 return id;
1852}
1853EXPORT_SYMBOL_GPL(of_alias_get_highest_id);
1854
1855/**
1856 * of_console_check() - Test and setup console for DT setup
1857 * @dn: Pointer to device node
1858 * @name: Name to use for preferred console without index. ex. "ttyS"
1859 * @index: Index to use for preferred console.
1860 *
1861 * Check if the given device node matches the stdout-path property in the
1862 * /chosen node. If it does then register it as the preferred console.
1863 *
1864 * Return: TRUE if console successfully setup. Otherwise return FALSE.
1865 */
1866bool of_console_check(struct device_node *dn, char *name, int index)
1867{
1868 if (!dn || dn != of_stdout || console_set_on_cmdline)
1869 return false;
1870
1871 /*
1872 * XXX: cast `options' to char pointer to suppress complication
1873 * warnings: printk, UART and console drivers expect char pointer.
1874 */
1875 return !add_preferred_console(name, idx: index, options: (char *)of_stdout_options);
1876}
1877EXPORT_SYMBOL_GPL(of_console_check);
1878
1879/**
1880 * of_find_next_cache_node - Find a node's subsidiary cache
1881 * @np: node of type "cpu" or "cache"
1882 *
1883 * Return: A node pointer with refcount incremented, use
1884 * of_node_put() on it when done. Caller should hold a reference
1885 * to np.
1886 */
1887struct device_node *of_find_next_cache_node(const struct device_node *np)
1888{
1889 struct device_node *child, *cache_node;
1890
1891 cache_node = of_parse_phandle(np, phandle_name: "l2-cache", index: 0);
1892 if (!cache_node)
1893 cache_node = of_parse_phandle(np, phandle_name: "next-level-cache", index: 0);
1894
1895 if (cache_node)
1896 return cache_node;
1897
1898 /* OF on pmac has nodes instead of properties named "l2-cache"
1899 * beneath CPU nodes.
1900 */
1901 if (IS_ENABLED(CONFIG_PPC_PMAC) && of_node_is_type(np, type: "cpu"))
1902 for_each_child_of_node(np, child)
1903 if (of_node_is_type(np: child, type: "cache"))
1904 return child;
1905
1906 return NULL;
1907}
1908
1909/**
1910 * of_find_last_cache_level - Find the level at which the last cache is
1911 * present for the given logical cpu
1912 *
1913 * @cpu: cpu number(logical index) for which the last cache level is needed
1914 *
1915 * Return: The level at which the last cache is present. It is exactly
1916 * same as the total number of cache levels for the given logical cpu.
1917 */
1918int of_find_last_cache_level(unsigned int cpu)
1919{
1920 u32 cache_level = 0;
1921 struct device_node *prev = NULL, *np = of_cpu_device_node_get(cpu);
1922
1923 while (np) {
1924 of_node_put(node: prev);
1925 prev = np;
1926 np = of_find_next_cache_node(np);
1927 }
1928
1929 of_property_read_u32(np: prev, propname: "cache-level", out_value: &cache_level);
1930 of_node_put(node: prev);
1931
1932 return cache_level;
1933}
1934
1935/**
1936 * of_map_id - Translate an ID through a downstream mapping.
1937 * @np: root complex device node.
1938 * @id: device ID to map.
1939 * @map_name: property name of the map to use.
1940 * @map_mask_name: optional property name of the mask to use.
1941 * @target: optional pointer to a target device node.
1942 * @id_out: optional pointer to receive the translated ID.
1943 *
1944 * Given a device ID, look up the appropriate implementation-defined
1945 * platform ID and/or the target device which receives transactions on that
1946 * ID, as per the "iommu-map" and "msi-map" bindings. Either of @target or
1947 * @id_out may be NULL if only the other is required. If @target points to
1948 * a non-NULL device node pointer, only entries targeting that node will be
1949 * matched; if it points to a NULL value, it will receive the device node of
1950 * the first matching target phandle, with a reference held.
1951 *
1952 * Return: 0 on success or a standard error code on failure.
1953 */
1954int of_map_id(struct device_node *np, u32 id,
1955 const char *map_name, const char *map_mask_name,
1956 struct device_node **target, u32 *id_out)
1957{
1958 u32 map_mask, masked_id;
1959 int map_len;
1960 const __be32 *map = NULL;
1961
1962 if (!np || !map_name || (!target && !id_out))
1963 return -EINVAL;
1964
1965 map = of_get_property(np, map_name, &map_len);
1966 if (!map) {
1967 if (target)
1968 return -ENODEV;
1969 /* Otherwise, no map implies no translation */
1970 *id_out = id;
1971 return 0;
1972 }
1973
1974 if (!map_len || map_len % (4 * sizeof(*map))) {
1975 pr_err("%pOF: Error: Bad %s length: %d\n", np,
1976 map_name, map_len);
1977 return -EINVAL;
1978 }
1979
1980 /* The default is to select all bits. */
1981 map_mask = 0xffffffff;
1982
1983 /*
1984 * Can be overridden by "{iommu,msi}-map-mask" property.
1985 * If of_property_read_u32() fails, the default is used.
1986 */
1987 if (map_mask_name)
1988 of_property_read_u32(np, propname: map_mask_name, out_value: &map_mask);
1989
1990 masked_id = map_mask & id;
1991 for ( ; map_len > 0; map_len -= 4 * sizeof(*map), map += 4) {
1992 struct device_node *phandle_node;
1993 u32 id_base = be32_to_cpup(p: map + 0);
1994 u32 phandle = be32_to_cpup(p: map + 1);
1995 u32 out_base = be32_to_cpup(p: map + 2);
1996 u32 id_len = be32_to_cpup(p: map + 3);
1997
1998 if (id_base & ~map_mask) {
1999 pr_err("%pOF: Invalid %s translation - %s-mask (0x%x) ignores id-base (0x%x)\n",
2000 np, map_name, map_name,
2001 map_mask, id_base);
2002 return -EFAULT;
2003 }
2004
2005 if (masked_id < id_base || masked_id >= id_base + id_len)
2006 continue;
2007
2008 phandle_node = of_find_node_by_phandle(phandle);
2009 if (!phandle_node)
2010 return -ENODEV;
2011
2012 if (target) {
2013 if (*target)
2014 of_node_put(node: phandle_node);
2015 else
2016 *target = phandle_node;
2017
2018 if (*target != phandle_node)
2019 continue;
2020 }
2021
2022 if (id_out)
2023 *id_out = masked_id - id_base + out_base;
2024
2025 pr_debug("%pOF: %s, using mask %08x, id-base: %08x, out-base: %08x, length: %08x, id: %08x -> %08x\n",
2026 np, map_name, map_mask, id_base, out_base,
2027 id_len, id, masked_id - id_base + out_base);
2028 return 0;
2029 }
2030
2031 pr_info("%pOF: no %s translation for id 0x%x on %pOF\n", np, map_name,
2032 id, target && *target ? *target : NULL);
2033
2034 /* Bypasses translation */
2035 if (id_out)
2036 *id_out = id;
2037 return 0;
2038}
2039EXPORT_SYMBOL_GPL(of_map_id);
2040

source code of linux/drivers/of/base.c