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