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