xref: /openbmc/linux/drivers/of/base.c (revision dd3cb467)
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 
33 LIST_HEAD(aliases_lookup);
34 
35 struct device_node *of_root;
36 EXPORT_SYMBOL(of_root);
37 struct device_node *of_chosen;
38 EXPORT_SYMBOL(of_chosen);
39 struct device_node *of_aliases;
40 struct device_node *of_stdout;
41 static const char *of_stdout_options;
42 
43 struct 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  */
51 DEFINE_MUTEX(of_mutex);
52 
53 /* use when traversing tree through the child, sibling,
54  * or parent members of struct device_node.
55  */
56 DEFINE_RAW_SPINLOCK(devtree_lock);
57 
58 bool 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 }
71 EXPORT_SYMBOL(of_node_name_eq);
72 
73 bool 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 }
80 EXPORT_SYMBOL(of_node_name_prefix);
81 
82 static 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 
89 int 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 
101 int 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 }
108 EXPORT_SYMBOL(of_n_addr_cells);
109 
110 int 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 
122 int 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 }
129 EXPORT_SYMBOL(of_n_size_cells);
130 
131 #ifdef CONFIG_NUMA
132 int __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 
141 static struct device_node *phandle_cache[OF_PHANDLE_CACHE_SZ];
142 
143 static 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  */
151 void __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 
166 void __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 
191 static 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 
210 struct 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 }
223 EXPORT_SYMBOL(of_find_property);
224 
225 struct 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  */
250 struct 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 }
262 EXPORT_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  */
268 const 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  */
280 const 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 }
287 EXPORT_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  */
297 u64 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  */
325 bool __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  */
335 static 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  */
367 bool __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  */
402 struct 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 }
412 EXPORT_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  */
422 int 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 }
438 EXPORT_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  */
455 struct 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 }
474 EXPORT_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  */
506 static 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  */
547 int 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 }
558 EXPORT_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  */
564 int of_device_compatible_match(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 }
581 
582 /**
583  * of_machine_is_compatible - Test root of device tree for a given compatible value
584  * @compat: compatible string to look for in root node's compatible property.
585  *
586  * Return: A positive integer if the root node has the given value in its
587  * compatible property.
588  */
589 int of_machine_is_compatible(const char *compat)
590 {
591 	struct device_node *root;
592 	int rc = 0;
593 
594 	root = of_find_node_by_path("/");
595 	if (root) {
596 		rc = of_device_is_compatible(root, compat);
597 		of_node_put(root);
598 	}
599 	return rc;
600 }
601 EXPORT_SYMBOL(of_machine_is_compatible);
602 
603 /**
604  *  __of_device_is_available - check if a device is available for use
605  *
606  *  @device: Node to check for availability, with locks already held
607  *
608  *  Return: True if the status property is absent or set to "okay" or "ok",
609  *  false otherwise
610  */
611 static bool __of_device_is_available(const struct device_node *device)
612 {
613 	const char *status;
614 	int statlen;
615 
616 	if (!device)
617 		return false;
618 
619 	status = __of_get_property(device, "status", &statlen);
620 	if (status == NULL)
621 		return true;
622 
623 	if (statlen > 0) {
624 		if (!strcmp(status, "okay") || !strcmp(status, "ok"))
625 			return true;
626 	}
627 
628 	return false;
629 }
630 
631 /**
632  *  of_device_is_available - check if a device is available for use
633  *
634  *  @device: Node to check for availability
635  *
636  *  Return: True if the status property is absent or set to "okay" or "ok",
637  *  false otherwise
638  */
639 bool of_device_is_available(const struct device_node *device)
640 {
641 	unsigned long flags;
642 	bool res;
643 
644 	raw_spin_lock_irqsave(&devtree_lock, flags);
645 	res = __of_device_is_available(device);
646 	raw_spin_unlock_irqrestore(&devtree_lock, flags);
647 	return res;
648 
649 }
650 EXPORT_SYMBOL(of_device_is_available);
651 
652 /**
653  *  __of_device_is_fail - check if a device has status "fail" or "fail-..."
654  *
655  *  @device: Node to check status for, with locks already held
656  *
657  *  Return: True if the status property is set to "fail" or "fail-..." (for any
658  *  error code suffix), false otherwise
659  */
660 static bool __of_device_is_fail(const struct device_node *device)
661 {
662 	const char *status;
663 
664 	if (!device)
665 		return false;
666 
667 	status = __of_get_property(device, "status", NULL);
668 	if (status == NULL)
669 		return false;
670 
671 	return !strcmp(status, "fail") || !strncmp(status, "fail-", 5);
672 }
673 
674 /**
675  *  of_device_is_big_endian - check if a device has BE registers
676  *
677  *  @device: Node to check for endianness
678  *
679  *  Return: True if the device has a "big-endian" property, or if the kernel
680  *  was compiled for BE *and* the device has a "native-endian" property.
681  *  Returns false otherwise.
682  *
683  *  Callers would nominally use ioread32be/iowrite32be if
684  *  of_device_is_big_endian() == true, or readl/writel otherwise.
685  */
686 bool of_device_is_big_endian(const struct device_node *device)
687 {
688 	if (of_property_read_bool(device, "big-endian"))
689 		return true;
690 	if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) &&
691 	    of_property_read_bool(device, "native-endian"))
692 		return true;
693 	return false;
694 }
695 EXPORT_SYMBOL(of_device_is_big_endian);
696 
697 /**
698  * of_get_parent - Get a node's parent if any
699  * @node:	Node to get parent
700  *
701  * Return: A node pointer with refcount incremented, use
702  * of_node_put() on it when done.
703  */
704 struct device_node *of_get_parent(const struct device_node *node)
705 {
706 	struct device_node *np;
707 	unsigned long flags;
708 
709 	if (!node)
710 		return NULL;
711 
712 	raw_spin_lock_irqsave(&devtree_lock, flags);
713 	np = of_node_get(node->parent);
714 	raw_spin_unlock_irqrestore(&devtree_lock, flags);
715 	return np;
716 }
717 EXPORT_SYMBOL(of_get_parent);
718 
719 /**
720  * of_get_next_parent - Iterate to a node's parent
721  * @node:	Node to get parent of
722  *
723  * This is like of_get_parent() except that it drops the
724  * refcount on the passed node, making it suitable for iterating
725  * through a node's parents.
726  *
727  * Return: A node pointer with refcount incremented, use
728  * of_node_put() on it when done.
729  */
730 struct device_node *of_get_next_parent(struct device_node *node)
731 {
732 	struct device_node *parent;
733 	unsigned long flags;
734 
735 	if (!node)
736 		return NULL;
737 
738 	raw_spin_lock_irqsave(&devtree_lock, flags);
739 	parent = of_node_get(node->parent);
740 	of_node_put(node);
741 	raw_spin_unlock_irqrestore(&devtree_lock, flags);
742 	return parent;
743 }
744 EXPORT_SYMBOL(of_get_next_parent);
745 
746 static struct device_node *__of_get_next_child(const struct device_node *node,
747 						struct device_node *prev)
748 {
749 	struct device_node *next;
750 
751 	if (!node)
752 		return NULL;
753 
754 	next = prev ? prev->sibling : node->child;
755 	of_node_get(next);
756 	of_node_put(prev);
757 	return next;
758 }
759 #define __for_each_child_of_node(parent, child) \
760 	for (child = __of_get_next_child(parent, NULL); child != NULL; \
761 	     child = __of_get_next_child(parent, child))
762 
763 /**
764  * of_get_next_child - Iterate a node childs
765  * @node:	parent node
766  * @prev:	previous child of the parent node, or NULL to get first
767  *
768  * Return: A node pointer with refcount incremented, use of_node_put() on
769  * it when done. Returns NULL when prev is the last child. Decrements the
770  * refcount of prev.
771  */
772 struct device_node *of_get_next_child(const struct device_node *node,
773 	struct device_node *prev)
774 {
775 	struct device_node *next;
776 	unsigned long flags;
777 
778 	raw_spin_lock_irqsave(&devtree_lock, flags);
779 	next = __of_get_next_child(node, prev);
780 	raw_spin_unlock_irqrestore(&devtree_lock, flags);
781 	return next;
782 }
783 EXPORT_SYMBOL(of_get_next_child);
784 
785 /**
786  * of_get_next_available_child - Find the next available child node
787  * @node:	parent node
788  * @prev:	previous child of the parent node, or NULL to get first
789  *
790  * This function is like of_get_next_child(), except that it
791  * automatically skips any disabled nodes (i.e. status = "disabled").
792  */
793 struct device_node *of_get_next_available_child(const struct device_node *node,
794 	struct device_node *prev)
795 {
796 	struct device_node *next;
797 	unsigned long flags;
798 
799 	if (!node)
800 		return NULL;
801 
802 	raw_spin_lock_irqsave(&devtree_lock, flags);
803 	next = prev ? prev->sibling : node->child;
804 	for (; next; next = next->sibling) {
805 		if (!__of_device_is_available(next))
806 			continue;
807 		if (of_node_get(next))
808 			break;
809 	}
810 	of_node_put(prev);
811 	raw_spin_unlock_irqrestore(&devtree_lock, flags);
812 	return next;
813 }
814 EXPORT_SYMBOL(of_get_next_available_child);
815 
816 /**
817  * of_get_next_cpu_node - Iterate on cpu nodes
818  * @prev:	previous child of the /cpus node, or NULL to get first
819  *
820  * Unusable CPUs (those with the status property set to "fail" or "fail-...")
821  * will be skipped.
822  *
823  * Return: A cpu node pointer with refcount incremented, use of_node_put()
824  * on it when done. Returns NULL when prev is the last child. Decrements
825  * the refcount of prev.
826  */
827 struct device_node *of_get_next_cpu_node(struct device_node *prev)
828 {
829 	struct device_node *next = NULL;
830 	unsigned long flags;
831 	struct device_node *node;
832 
833 	if (!prev)
834 		node = of_find_node_by_path("/cpus");
835 
836 	raw_spin_lock_irqsave(&devtree_lock, flags);
837 	if (prev)
838 		next = prev->sibling;
839 	else if (node) {
840 		next = node->child;
841 		of_node_put(node);
842 	}
843 	for (; next; next = next->sibling) {
844 		if (__of_device_is_fail(next))
845 			continue;
846 		if (!(of_node_name_eq(next, "cpu") ||
847 		      __of_node_is_type(next, "cpu")))
848 			continue;
849 		if (of_node_get(next))
850 			break;
851 	}
852 	of_node_put(prev);
853 	raw_spin_unlock_irqrestore(&devtree_lock, flags);
854 	return next;
855 }
856 EXPORT_SYMBOL(of_get_next_cpu_node);
857 
858 /**
859  * of_get_compatible_child - Find compatible child node
860  * @parent:	parent node
861  * @compatible:	compatible string
862  *
863  * Lookup child node whose compatible property contains the given compatible
864  * string.
865  *
866  * Return: a node pointer with refcount incremented, use of_node_put() on it
867  * when done; or NULL if not found.
868  */
869 struct device_node *of_get_compatible_child(const struct device_node *parent,
870 				const char *compatible)
871 {
872 	struct device_node *child;
873 
874 	for_each_child_of_node(parent, child) {
875 		if (of_device_is_compatible(child, compatible))
876 			break;
877 	}
878 
879 	return child;
880 }
881 EXPORT_SYMBOL(of_get_compatible_child);
882 
883 /**
884  * of_get_child_by_name - Find the child node by name for a given parent
885  * @node:	parent node
886  * @name:	child name to look for.
887  *
888  * This function looks for child node for given matching name
889  *
890  * Return: A node pointer if found, with refcount incremented, use
891  * of_node_put() on it when done.
892  * Returns NULL if node is not found.
893  */
894 struct device_node *of_get_child_by_name(const struct device_node *node,
895 				const char *name)
896 {
897 	struct device_node *child;
898 
899 	for_each_child_of_node(node, child)
900 		if (of_node_name_eq(child, name))
901 			break;
902 	return child;
903 }
904 EXPORT_SYMBOL(of_get_child_by_name);
905 
906 struct device_node *__of_find_node_by_path(struct device_node *parent,
907 						const char *path)
908 {
909 	struct device_node *child;
910 	int len;
911 
912 	len = strcspn(path, "/:");
913 	if (!len)
914 		return NULL;
915 
916 	__for_each_child_of_node(parent, child) {
917 		const char *name = kbasename(child->full_name);
918 		if (strncmp(path, name, len) == 0 && (strlen(name) == len))
919 			return child;
920 	}
921 	return NULL;
922 }
923 
924 struct device_node *__of_find_node_by_full_path(struct device_node *node,
925 						const char *path)
926 {
927 	const char *separator = strchr(path, ':');
928 
929 	while (node && *path == '/') {
930 		struct device_node *tmp = node;
931 
932 		path++; /* Increment past '/' delimiter */
933 		node = __of_find_node_by_path(node, path);
934 		of_node_put(tmp);
935 		path = strchrnul(path, '/');
936 		if (separator && separator < path)
937 			break;
938 	}
939 	return node;
940 }
941 
942 /**
943  * of_find_node_opts_by_path - Find a node matching a full OF path
944  * @path: Either the full path to match, or if the path does not
945  *       start with '/', the name of a property of the /aliases
946  *       node (an alias).  In the case of an alias, the node
947  *       matching the alias' value will be returned.
948  * @opts: Address of a pointer into which to store the start of
949  *       an options string appended to the end of the path with
950  *       a ':' separator.
951  *
952  * Valid paths:
953  *  * /foo/bar	Full path
954  *  * foo	Valid alias
955  *  * foo/bar	Valid alias + relative path
956  *
957  * Return: A node pointer with refcount incremented, use
958  * of_node_put() on it when done.
959  */
960 struct device_node *of_find_node_opts_by_path(const char *path, const char **opts)
961 {
962 	struct device_node *np = NULL;
963 	struct property *pp;
964 	unsigned long flags;
965 	const char *separator = strchr(path, ':');
966 
967 	if (opts)
968 		*opts = separator ? separator + 1 : NULL;
969 
970 	if (strcmp(path, "/") == 0)
971 		return of_node_get(of_root);
972 
973 	/* The path could begin with an alias */
974 	if (*path != '/') {
975 		int len;
976 		const char *p = separator;
977 
978 		if (!p)
979 			p = strchrnul(path, '/');
980 		len = p - path;
981 
982 		/* of_aliases must not be NULL */
983 		if (!of_aliases)
984 			return NULL;
985 
986 		for_each_property_of_node(of_aliases, pp) {
987 			if (strlen(pp->name) == len && !strncmp(pp->name, path, len)) {
988 				np = of_find_node_by_path(pp->value);
989 				break;
990 			}
991 		}
992 		if (!np)
993 			return NULL;
994 		path = p;
995 	}
996 
997 	/* Step down the tree matching path components */
998 	raw_spin_lock_irqsave(&devtree_lock, flags);
999 	if (!np)
1000 		np = of_node_get(of_root);
1001 	np = __of_find_node_by_full_path(np, path);
1002 	raw_spin_unlock_irqrestore(&devtree_lock, flags);
1003 	return np;
1004 }
1005 EXPORT_SYMBOL(of_find_node_opts_by_path);
1006 
1007 /**
1008  * of_find_node_by_name - Find a node by its "name" property
1009  * @from:	The node to start searching from or NULL; the node
1010  *		you pass will not be searched, only the next one
1011  *		will. Typically, you pass what the previous call
1012  *		returned. of_node_put() will be called on @from.
1013  * @name:	The name string to match against
1014  *
1015  * Return: A node pointer with refcount incremented, use
1016  * of_node_put() on it when done.
1017  */
1018 struct device_node *of_find_node_by_name(struct device_node *from,
1019 	const char *name)
1020 {
1021 	struct device_node *np;
1022 	unsigned long flags;
1023 
1024 	raw_spin_lock_irqsave(&devtree_lock, flags);
1025 	for_each_of_allnodes_from(from, np)
1026 		if (of_node_name_eq(np, name) && of_node_get(np))
1027 			break;
1028 	of_node_put(from);
1029 	raw_spin_unlock_irqrestore(&devtree_lock, flags);
1030 	return np;
1031 }
1032 EXPORT_SYMBOL(of_find_node_by_name);
1033 
1034 /**
1035  * of_find_node_by_type - Find a node by its "device_type" property
1036  * @from:	The node to start searching from, or NULL to start searching
1037  *		the entire device tree. The node you pass will not be
1038  *		searched, only the next one will; typically, you pass
1039  *		what the previous call returned. of_node_put() will be
1040  *		called on from for you.
1041  * @type:	The type string to match against
1042  *
1043  * Return: A node pointer with refcount incremented, use
1044  * of_node_put() on it when done.
1045  */
1046 struct device_node *of_find_node_by_type(struct device_node *from,
1047 	const char *type)
1048 {
1049 	struct device_node *np;
1050 	unsigned long flags;
1051 
1052 	raw_spin_lock_irqsave(&devtree_lock, flags);
1053 	for_each_of_allnodes_from(from, np)
1054 		if (__of_node_is_type(np, type) && of_node_get(np))
1055 			break;
1056 	of_node_put(from);
1057 	raw_spin_unlock_irqrestore(&devtree_lock, flags);
1058 	return np;
1059 }
1060 EXPORT_SYMBOL(of_find_node_by_type);
1061 
1062 /**
1063  * of_find_compatible_node - Find a node based on type and one of the
1064  *                                tokens in its "compatible" property
1065  * @from:	The node to start searching from or NULL, the node
1066  *		you pass will not be searched, only the next one
1067  *		will; typically, you pass what the previous call
1068  *		returned. of_node_put() will be called on it
1069  * @type:	The type string to match "device_type" or NULL to ignore
1070  * @compatible:	The string to match to one of the tokens in the device
1071  *		"compatible" list.
1072  *
1073  * Return: A node pointer with refcount incremented, use
1074  * of_node_put() on it when done.
1075  */
1076 struct device_node *of_find_compatible_node(struct device_node *from,
1077 	const char *type, const char *compatible)
1078 {
1079 	struct device_node *np;
1080 	unsigned long flags;
1081 
1082 	raw_spin_lock_irqsave(&devtree_lock, flags);
1083 	for_each_of_allnodes_from(from, np)
1084 		if (__of_device_is_compatible(np, compatible, type, NULL) &&
1085 		    of_node_get(np))
1086 			break;
1087 	of_node_put(from);
1088 	raw_spin_unlock_irqrestore(&devtree_lock, flags);
1089 	return np;
1090 }
1091 EXPORT_SYMBOL(of_find_compatible_node);
1092 
1093 /**
1094  * of_find_node_with_property - Find a node which has a property with
1095  *                              the given name.
1096  * @from:	The node to start searching from or NULL, the node
1097  *		you pass will not be searched, only the next one
1098  *		will; typically, you pass what the previous call
1099  *		returned. of_node_put() will be called on it
1100  * @prop_name:	The name of the property to look for.
1101  *
1102  * Return: A node pointer with refcount incremented, use
1103  * of_node_put() on it when done.
1104  */
1105 struct device_node *of_find_node_with_property(struct device_node *from,
1106 	const char *prop_name)
1107 {
1108 	struct device_node *np;
1109 	struct property *pp;
1110 	unsigned long flags;
1111 
1112 	raw_spin_lock_irqsave(&devtree_lock, flags);
1113 	for_each_of_allnodes_from(from, np) {
1114 		for (pp = np->properties; pp; pp = pp->next) {
1115 			if (of_prop_cmp(pp->name, prop_name) == 0) {
1116 				of_node_get(np);
1117 				goto out;
1118 			}
1119 		}
1120 	}
1121 out:
1122 	of_node_put(from);
1123 	raw_spin_unlock_irqrestore(&devtree_lock, flags);
1124 	return np;
1125 }
1126 EXPORT_SYMBOL(of_find_node_with_property);
1127 
1128 static
1129 const struct of_device_id *__of_match_node(const struct of_device_id *matches,
1130 					   const struct device_node *node)
1131 {
1132 	const struct of_device_id *best_match = NULL;
1133 	int score, best_score = 0;
1134 
1135 	if (!matches)
1136 		return NULL;
1137 
1138 	for (; matches->name[0] || matches->type[0] || matches->compatible[0]; matches++) {
1139 		score = __of_device_is_compatible(node, matches->compatible,
1140 						  matches->type, matches->name);
1141 		if (score > best_score) {
1142 			best_match = matches;
1143 			best_score = score;
1144 		}
1145 	}
1146 
1147 	return best_match;
1148 }
1149 
1150 /**
1151  * of_match_node - Tell if a device_node has a matching of_match structure
1152  * @matches:	array of of device match structures to search in
1153  * @node:	the of device structure to match against
1154  *
1155  * Low level utility function used by device matching.
1156  */
1157 const struct of_device_id *of_match_node(const struct of_device_id *matches,
1158 					 const struct device_node *node)
1159 {
1160 	const struct of_device_id *match;
1161 	unsigned long flags;
1162 
1163 	raw_spin_lock_irqsave(&devtree_lock, flags);
1164 	match = __of_match_node(matches, node);
1165 	raw_spin_unlock_irqrestore(&devtree_lock, flags);
1166 	return match;
1167 }
1168 EXPORT_SYMBOL(of_match_node);
1169 
1170 /**
1171  * of_find_matching_node_and_match - Find a node based on an of_device_id
1172  *				     match table.
1173  * @from:	The node to start searching from or NULL, the node
1174  *		you pass will not be searched, only the next one
1175  *		will; typically, you pass what the previous call
1176  *		returned. of_node_put() will be called on it
1177  * @matches:	array of of device match structures to search in
1178  * @match:	Updated to point at the matches entry which matched
1179  *
1180  * Return: A node pointer with refcount incremented, use
1181  * of_node_put() on it when done.
1182  */
1183 struct device_node *of_find_matching_node_and_match(struct device_node *from,
1184 					const struct of_device_id *matches,
1185 					const struct of_device_id **match)
1186 {
1187 	struct device_node *np;
1188 	const struct of_device_id *m;
1189 	unsigned long flags;
1190 
1191 	if (match)
1192 		*match = NULL;
1193 
1194 	raw_spin_lock_irqsave(&devtree_lock, flags);
1195 	for_each_of_allnodes_from(from, np) {
1196 		m = __of_match_node(matches, np);
1197 		if (m && of_node_get(np)) {
1198 			if (match)
1199 				*match = m;
1200 			break;
1201 		}
1202 	}
1203 	of_node_put(from);
1204 	raw_spin_unlock_irqrestore(&devtree_lock, flags);
1205 	return np;
1206 }
1207 EXPORT_SYMBOL(of_find_matching_node_and_match);
1208 
1209 /**
1210  * of_modalias_node - Lookup appropriate modalias for a device node
1211  * @node:	pointer to a device tree node
1212  * @modalias:	Pointer to buffer that modalias value will be copied into
1213  * @len:	Length of modalias value
1214  *
1215  * Based on the value of the compatible property, this routine will attempt
1216  * to choose an appropriate modalias value for a particular device tree node.
1217  * It does this by stripping the manufacturer prefix (as delimited by a ',')
1218  * from the first entry in the compatible list property.
1219  *
1220  * Return: This routine returns 0 on success, <0 on failure.
1221  */
1222 int of_modalias_node(struct device_node *node, char *modalias, int len)
1223 {
1224 	const char *compatible, *p;
1225 	int cplen;
1226 
1227 	compatible = of_get_property(node, "compatible", &cplen);
1228 	if (!compatible || strlen(compatible) > cplen)
1229 		return -ENODEV;
1230 	p = strchr(compatible, ',');
1231 	strscpy(modalias, p ? p + 1 : compatible, len);
1232 	return 0;
1233 }
1234 EXPORT_SYMBOL_GPL(of_modalias_node);
1235 
1236 /**
1237  * of_find_node_by_phandle - Find a node given a phandle
1238  * @handle:	phandle of the node to find
1239  *
1240  * Return: A node pointer with refcount incremented, use
1241  * of_node_put() on it when done.
1242  */
1243 struct device_node *of_find_node_by_phandle(phandle handle)
1244 {
1245 	struct device_node *np = NULL;
1246 	unsigned long flags;
1247 	u32 handle_hash;
1248 
1249 	if (!handle)
1250 		return NULL;
1251 
1252 	handle_hash = of_phandle_cache_hash(handle);
1253 
1254 	raw_spin_lock_irqsave(&devtree_lock, flags);
1255 
1256 	if (phandle_cache[handle_hash] &&
1257 	    handle == phandle_cache[handle_hash]->phandle)
1258 		np = phandle_cache[handle_hash];
1259 
1260 	if (!np) {
1261 		for_each_of_allnodes(np)
1262 			if (np->phandle == handle &&
1263 			    !of_node_check_flag(np, OF_DETACHED)) {
1264 				phandle_cache[handle_hash] = np;
1265 				break;
1266 			}
1267 	}
1268 
1269 	of_node_get(np);
1270 	raw_spin_unlock_irqrestore(&devtree_lock, flags);
1271 	return np;
1272 }
1273 EXPORT_SYMBOL(of_find_node_by_phandle);
1274 
1275 void of_print_phandle_args(const char *msg, const struct of_phandle_args *args)
1276 {
1277 	int i;
1278 	printk("%s %pOF", msg, args->np);
1279 	for (i = 0; i < args->args_count; i++) {
1280 		const char delim = i ? ',' : ':';
1281 
1282 		pr_cont("%c%08x", delim, args->args[i]);
1283 	}
1284 	pr_cont("\n");
1285 }
1286 
1287 int of_phandle_iterator_init(struct of_phandle_iterator *it,
1288 		const struct device_node *np,
1289 		const char *list_name,
1290 		const char *cells_name,
1291 		int cell_count)
1292 {
1293 	const __be32 *list;
1294 	int size;
1295 
1296 	memset(it, 0, sizeof(*it));
1297 
1298 	/*
1299 	 * one of cell_count or cells_name must be provided to determine the
1300 	 * argument length.
1301 	 */
1302 	if (cell_count < 0 && !cells_name)
1303 		return -EINVAL;
1304 
1305 	list = of_get_property(np, list_name, &size);
1306 	if (!list)
1307 		return -ENOENT;
1308 
1309 	it->cells_name = cells_name;
1310 	it->cell_count = cell_count;
1311 	it->parent = np;
1312 	it->list_end = list + size / sizeof(*list);
1313 	it->phandle_end = list;
1314 	it->cur = list;
1315 
1316 	return 0;
1317 }
1318 EXPORT_SYMBOL_GPL(of_phandle_iterator_init);
1319 
1320 int of_phandle_iterator_next(struct of_phandle_iterator *it)
1321 {
1322 	uint32_t count = 0;
1323 
1324 	if (it->node) {
1325 		of_node_put(it->node);
1326 		it->node = NULL;
1327 	}
1328 
1329 	if (!it->cur || it->phandle_end >= it->list_end)
1330 		return -ENOENT;
1331 
1332 	it->cur = it->phandle_end;
1333 
1334 	/* If phandle is 0, then it is an empty entry with no arguments. */
1335 	it->phandle = be32_to_cpup(it->cur++);
1336 
1337 	if (it->phandle) {
1338 
1339 		/*
1340 		 * Find the provider node and parse the #*-cells property to
1341 		 * determine the argument length.
1342 		 */
1343 		it->node = of_find_node_by_phandle(it->phandle);
1344 
1345 		if (it->cells_name) {
1346 			if (!it->node) {
1347 				pr_err("%pOF: could not find phandle %d\n",
1348 				       it->parent, it->phandle);
1349 				goto err;
1350 			}
1351 
1352 			if (of_property_read_u32(it->node, it->cells_name,
1353 						 &count)) {
1354 				/*
1355 				 * If both cell_count and cells_name is given,
1356 				 * fall back to cell_count in absence
1357 				 * of the cells_name property
1358 				 */
1359 				if (it->cell_count >= 0) {
1360 					count = it->cell_count;
1361 				} else {
1362 					pr_err("%pOF: could not get %s for %pOF\n",
1363 					       it->parent,
1364 					       it->cells_name,
1365 					       it->node);
1366 					goto err;
1367 				}
1368 			}
1369 		} else {
1370 			count = it->cell_count;
1371 		}
1372 
1373 		/*
1374 		 * Make sure that the arguments actually fit in the remaining
1375 		 * property data length
1376 		 */
1377 		if (it->cur + count > it->list_end) {
1378 			if (it->cells_name)
1379 				pr_err("%pOF: %s = %d found %td\n",
1380 					it->parent, it->cells_name,
1381 					count, it->list_end - it->cur);
1382 			else
1383 				pr_err("%pOF: phandle %s needs %d, found %td\n",
1384 					it->parent, of_node_full_name(it->node),
1385 					count, it->list_end - it->cur);
1386 			goto err;
1387 		}
1388 	}
1389 
1390 	it->phandle_end = it->cur + count;
1391 	it->cur_count = count;
1392 
1393 	return 0;
1394 
1395 err:
1396 	if (it->node) {
1397 		of_node_put(it->node);
1398 		it->node = NULL;
1399 	}
1400 
1401 	return -EINVAL;
1402 }
1403 EXPORT_SYMBOL_GPL(of_phandle_iterator_next);
1404 
1405 int of_phandle_iterator_args(struct of_phandle_iterator *it,
1406 			     uint32_t *args,
1407 			     int size)
1408 {
1409 	int i, count;
1410 
1411 	count = it->cur_count;
1412 
1413 	if (WARN_ON(size < count))
1414 		count = size;
1415 
1416 	for (i = 0; i < count; i++)
1417 		args[i] = be32_to_cpup(it->cur++);
1418 
1419 	return count;
1420 }
1421 
1422 int __of_parse_phandle_with_args(const struct device_node *np,
1423 				 const char *list_name,
1424 				 const char *cells_name,
1425 				 int cell_count, int index,
1426 				 struct of_phandle_args *out_args)
1427 {
1428 	struct of_phandle_iterator it;
1429 	int rc, cur_index = 0;
1430 
1431 	if (index < 0)
1432 		return -EINVAL;
1433 
1434 	/* Loop over the phandles until all the requested entry is found */
1435 	of_for_each_phandle(&it, rc, np, list_name, cells_name, cell_count) {
1436 		/*
1437 		 * All of the error cases bail out of the loop, so at
1438 		 * this point, the parsing is successful. If the requested
1439 		 * index matches, then fill the out_args structure and return,
1440 		 * or return -ENOENT for an empty entry.
1441 		 */
1442 		rc = -ENOENT;
1443 		if (cur_index == index) {
1444 			if (!it.phandle)
1445 				goto err;
1446 
1447 			if (out_args) {
1448 				int c;
1449 
1450 				c = of_phandle_iterator_args(&it,
1451 							     out_args->args,
1452 							     MAX_PHANDLE_ARGS);
1453 				out_args->np = it.node;
1454 				out_args->args_count = c;
1455 			} else {
1456 				of_node_put(it.node);
1457 			}
1458 
1459 			/* Found it! return success */
1460 			return 0;
1461 		}
1462 
1463 		cur_index++;
1464 	}
1465 
1466 	/*
1467 	 * Unlock node before returning result; will be one of:
1468 	 * -ENOENT : index is for empty phandle
1469 	 * -EINVAL : parsing error on data
1470 	 */
1471 
1472  err:
1473 	of_node_put(it.node);
1474 	return rc;
1475 }
1476 EXPORT_SYMBOL(__of_parse_phandle_with_args);
1477 
1478 /**
1479  * of_parse_phandle_with_args_map() - Find a node pointed by phandle in a list and remap it
1480  * @np:		pointer to a device tree node containing a list
1481  * @list_name:	property name that contains a list
1482  * @stem_name:	stem of property names that specify phandles' arguments count
1483  * @index:	index of a phandle to parse out
1484  * @out_args:	optional pointer to output arguments structure (will be filled)
1485  *
1486  * This function is useful to parse lists of phandles and their arguments.
1487  * Returns 0 on success and fills out_args, on error returns appropriate errno
1488  * value. The difference between this function and of_parse_phandle_with_args()
1489  * is that this API remaps a phandle if the node the phandle points to has
1490  * a <@stem_name>-map property.
1491  *
1492  * Caller is responsible to call of_node_put() on the returned out_args->np
1493  * pointer.
1494  *
1495  * Example::
1496  *
1497  *  phandle1: node1 {
1498  *  	#list-cells = <2>;
1499  *  };
1500  *
1501  *  phandle2: node2 {
1502  *  	#list-cells = <1>;
1503  *  };
1504  *
1505  *  phandle3: node3 {
1506  *  	#list-cells = <1>;
1507  *  	list-map = <0 &phandle2 3>,
1508  *  		   <1 &phandle2 2>,
1509  *  		   <2 &phandle1 5 1>;
1510  *  	list-map-mask = <0x3>;
1511  *  };
1512  *
1513  *  node4 {
1514  *  	list = <&phandle1 1 2 &phandle3 0>;
1515  *  };
1516  *
1517  * To get a device_node of the ``node2`` node you may call this:
1518  * of_parse_phandle_with_args(node4, "list", "list", 1, &args);
1519  */
1520 int of_parse_phandle_with_args_map(const struct device_node *np,
1521 				   const char *list_name,
1522 				   const char *stem_name,
1523 				   int index, struct of_phandle_args *out_args)
1524 {
1525 	char *cells_name, *map_name = NULL, *mask_name = NULL;
1526 	char *pass_name = NULL;
1527 	struct device_node *cur, *new = NULL;
1528 	const __be32 *map, *mask, *pass;
1529 	static const __be32 dummy_mask[] = { [0 ... MAX_PHANDLE_ARGS] = ~0 };
1530 	static const __be32 dummy_pass[] = { [0 ... MAX_PHANDLE_ARGS] = 0 };
1531 	__be32 initial_match_array[MAX_PHANDLE_ARGS];
1532 	const __be32 *match_array = initial_match_array;
1533 	int i, ret, map_len, match;
1534 	u32 list_size, new_size;
1535 
1536 	if (index < 0)
1537 		return -EINVAL;
1538 
1539 	cells_name = kasprintf(GFP_KERNEL, "#%s-cells", stem_name);
1540 	if (!cells_name)
1541 		return -ENOMEM;
1542 
1543 	ret = -ENOMEM;
1544 	map_name = kasprintf(GFP_KERNEL, "%s-map", stem_name);
1545 	if (!map_name)
1546 		goto free;
1547 
1548 	mask_name = kasprintf(GFP_KERNEL, "%s-map-mask", stem_name);
1549 	if (!mask_name)
1550 		goto free;
1551 
1552 	pass_name = kasprintf(GFP_KERNEL, "%s-map-pass-thru", stem_name);
1553 	if (!pass_name)
1554 		goto free;
1555 
1556 	ret = __of_parse_phandle_with_args(np, list_name, cells_name, -1, index,
1557 					   out_args);
1558 	if (ret)
1559 		goto free;
1560 
1561 	/* Get the #<list>-cells property */
1562 	cur = out_args->np;
1563 	ret = of_property_read_u32(cur, cells_name, &list_size);
1564 	if (ret < 0)
1565 		goto put;
1566 
1567 	/* Precalculate the match array - this simplifies match loop */
1568 	for (i = 0; i < list_size; i++)
1569 		initial_match_array[i] = cpu_to_be32(out_args->args[i]);
1570 
1571 	ret = -EINVAL;
1572 	while (cur) {
1573 		/* Get the <list>-map property */
1574 		map = of_get_property(cur, map_name, &map_len);
1575 		if (!map) {
1576 			ret = 0;
1577 			goto free;
1578 		}
1579 		map_len /= sizeof(u32);
1580 
1581 		/* Get the <list>-map-mask property (optional) */
1582 		mask = of_get_property(cur, mask_name, NULL);
1583 		if (!mask)
1584 			mask = dummy_mask;
1585 		/* Iterate through <list>-map property */
1586 		match = 0;
1587 		while (map_len > (list_size + 1) && !match) {
1588 			/* Compare specifiers */
1589 			match = 1;
1590 			for (i = 0; i < list_size; i++, map_len--)
1591 				match &= !((match_array[i] ^ *map++) & mask[i]);
1592 
1593 			of_node_put(new);
1594 			new = of_find_node_by_phandle(be32_to_cpup(map));
1595 			map++;
1596 			map_len--;
1597 
1598 			/* Check if not found */
1599 			if (!new)
1600 				goto put;
1601 
1602 			if (!of_device_is_available(new))
1603 				match = 0;
1604 
1605 			ret = of_property_read_u32(new, cells_name, &new_size);
1606 			if (ret)
1607 				goto put;
1608 
1609 			/* Check for malformed properties */
1610 			if (WARN_ON(new_size > MAX_PHANDLE_ARGS))
1611 				goto put;
1612 			if (map_len < new_size)
1613 				goto put;
1614 
1615 			/* Move forward by new node's #<list>-cells amount */
1616 			map += new_size;
1617 			map_len -= new_size;
1618 		}
1619 		if (!match)
1620 			goto put;
1621 
1622 		/* Get the <list>-map-pass-thru property (optional) */
1623 		pass = of_get_property(cur, pass_name, NULL);
1624 		if (!pass)
1625 			pass = dummy_pass;
1626 
1627 		/*
1628 		 * Successfully parsed a <list>-map translation; copy new
1629 		 * specifier into the out_args structure, keeping the
1630 		 * bits specified in <list>-map-pass-thru.
1631 		 */
1632 		match_array = map - new_size;
1633 		for (i = 0; i < new_size; i++) {
1634 			__be32 val = *(map - new_size + i);
1635 
1636 			if (i < list_size) {
1637 				val &= ~pass[i];
1638 				val |= cpu_to_be32(out_args->args[i]) & pass[i];
1639 			}
1640 
1641 			out_args->args[i] = be32_to_cpu(val);
1642 		}
1643 		out_args->args_count = list_size = new_size;
1644 		/* Iterate again with new provider */
1645 		out_args->np = new;
1646 		of_node_put(cur);
1647 		cur = new;
1648 	}
1649 put:
1650 	of_node_put(cur);
1651 	of_node_put(new);
1652 free:
1653 	kfree(mask_name);
1654 	kfree(map_name);
1655 	kfree(cells_name);
1656 	kfree(pass_name);
1657 
1658 	return ret;
1659 }
1660 EXPORT_SYMBOL(of_parse_phandle_with_args_map);
1661 
1662 /**
1663  * of_count_phandle_with_args() - Find the number of phandles references in a property
1664  * @np:		pointer to a device tree node containing a list
1665  * @list_name:	property name that contains a list
1666  * @cells_name:	property name that specifies phandles' arguments count
1667  *
1668  * Return: The number of phandle + argument tuples within a property. It
1669  * is a typical pattern to encode a list of phandle and variable
1670  * arguments into a single property. The number of arguments is encoded
1671  * by a property in the phandle-target node. For example, a gpios
1672  * property would contain a list of GPIO specifies consisting of a
1673  * phandle and 1 or more arguments. The number of arguments are
1674  * determined by the #gpio-cells property in the node pointed to by the
1675  * phandle.
1676  */
1677 int of_count_phandle_with_args(const struct device_node *np, const char *list_name,
1678 				const char *cells_name)
1679 {
1680 	struct of_phandle_iterator it;
1681 	int rc, cur_index = 0;
1682 
1683 	/*
1684 	 * If cells_name is NULL we assume a cell count of 0. This makes
1685 	 * counting the phandles trivial as each 32bit word in the list is a
1686 	 * phandle and no arguments are to consider. So we don't iterate through
1687 	 * the list but just use the length to determine the phandle count.
1688 	 */
1689 	if (!cells_name) {
1690 		const __be32 *list;
1691 		int size;
1692 
1693 		list = of_get_property(np, list_name, &size);
1694 		if (!list)
1695 			return -ENOENT;
1696 
1697 		return size / sizeof(*list);
1698 	}
1699 
1700 	rc = of_phandle_iterator_init(&it, np, list_name, cells_name, -1);
1701 	if (rc)
1702 		return rc;
1703 
1704 	while ((rc = of_phandle_iterator_next(&it)) == 0)
1705 		cur_index += 1;
1706 
1707 	if (rc != -ENOENT)
1708 		return rc;
1709 
1710 	return cur_index;
1711 }
1712 EXPORT_SYMBOL(of_count_phandle_with_args);
1713 
1714 /**
1715  * __of_add_property - Add a property to a node without lock operations
1716  * @np:		Caller's Device Node
1717  * @prop:	Property to add
1718  */
1719 int __of_add_property(struct device_node *np, struct property *prop)
1720 {
1721 	struct property **next;
1722 
1723 	prop->next = NULL;
1724 	next = &np->properties;
1725 	while (*next) {
1726 		if (strcmp(prop->name, (*next)->name) == 0)
1727 			/* duplicate ! don't insert it */
1728 			return -EEXIST;
1729 
1730 		next = &(*next)->next;
1731 	}
1732 	*next = prop;
1733 
1734 	return 0;
1735 }
1736 
1737 /**
1738  * of_add_property - Add a property to a node
1739  * @np:		Caller's Device Node
1740  * @prop:	Property to add
1741  */
1742 int of_add_property(struct device_node *np, struct property *prop)
1743 {
1744 	unsigned long flags;
1745 	int rc;
1746 
1747 	mutex_lock(&of_mutex);
1748 
1749 	raw_spin_lock_irqsave(&devtree_lock, flags);
1750 	rc = __of_add_property(np, prop);
1751 	raw_spin_unlock_irqrestore(&devtree_lock, flags);
1752 
1753 	if (!rc)
1754 		__of_add_property_sysfs(np, prop);
1755 
1756 	mutex_unlock(&of_mutex);
1757 
1758 	if (!rc)
1759 		of_property_notify(OF_RECONFIG_ADD_PROPERTY, np, prop, NULL);
1760 
1761 	return rc;
1762 }
1763 EXPORT_SYMBOL_GPL(of_add_property);
1764 
1765 int __of_remove_property(struct device_node *np, struct property *prop)
1766 {
1767 	struct property **next;
1768 
1769 	for (next = &np->properties; *next; next = &(*next)->next) {
1770 		if (*next == prop)
1771 			break;
1772 	}
1773 	if (*next == NULL)
1774 		return -ENODEV;
1775 
1776 	/* found the node */
1777 	*next = prop->next;
1778 	prop->next = np->deadprops;
1779 	np->deadprops = prop;
1780 
1781 	return 0;
1782 }
1783 
1784 /**
1785  * of_remove_property - Remove a property from a node.
1786  * @np:		Caller's Device Node
1787  * @prop:	Property to remove
1788  *
1789  * Note that we don't actually remove it, since we have given out
1790  * who-knows-how-many pointers to the data using get-property.
1791  * Instead we just move the property to the "dead properties"
1792  * list, so it won't be found any more.
1793  */
1794 int of_remove_property(struct device_node *np, struct property *prop)
1795 {
1796 	unsigned long flags;
1797 	int rc;
1798 
1799 	if (!prop)
1800 		return -ENODEV;
1801 
1802 	mutex_lock(&of_mutex);
1803 
1804 	raw_spin_lock_irqsave(&devtree_lock, flags);
1805 	rc = __of_remove_property(np, prop);
1806 	raw_spin_unlock_irqrestore(&devtree_lock, flags);
1807 
1808 	if (!rc)
1809 		__of_remove_property_sysfs(np, prop);
1810 
1811 	mutex_unlock(&of_mutex);
1812 
1813 	if (!rc)
1814 		of_property_notify(OF_RECONFIG_REMOVE_PROPERTY, np, prop, NULL);
1815 
1816 	return rc;
1817 }
1818 EXPORT_SYMBOL_GPL(of_remove_property);
1819 
1820 int __of_update_property(struct device_node *np, struct property *newprop,
1821 		struct property **oldpropp)
1822 {
1823 	struct property **next, *oldprop;
1824 
1825 	for (next = &np->properties; *next; next = &(*next)->next) {
1826 		if (of_prop_cmp((*next)->name, newprop->name) == 0)
1827 			break;
1828 	}
1829 	*oldpropp = oldprop = *next;
1830 
1831 	if (oldprop) {
1832 		/* replace the node */
1833 		newprop->next = oldprop->next;
1834 		*next = newprop;
1835 		oldprop->next = np->deadprops;
1836 		np->deadprops = oldprop;
1837 	} else {
1838 		/* new node */
1839 		newprop->next = NULL;
1840 		*next = newprop;
1841 	}
1842 
1843 	return 0;
1844 }
1845 
1846 /*
1847  * of_update_property - Update a property in a node, if the property does
1848  * not exist, add it.
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" list,
1853  * and add the new property to the property list
1854  */
1855 int of_update_property(struct device_node *np, struct property *newprop)
1856 {
1857 	struct property *oldprop;
1858 	unsigned long flags;
1859 	int rc;
1860 
1861 	if (!newprop->name)
1862 		return -EINVAL;
1863 
1864 	mutex_lock(&of_mutex);
1865 
1866 	raw_spin_lock_irqsave(&devtree_lock, flags);
1867 	rc = __of_update_property(np, newprop, &oldprop);
1868 	raw_spin_unlock_irqrestore(&devtree_lock, flags);
1869 
1870 	if (!rc)
1871 		__of_update_property_sysfs(np, newprop, oldprop);
1872 
1873 	mutex_unlock(&of_mutex);
1874 
1875 	if (!rc)
1876 		of_property_notify(OF_RECONFIG_UPDATE_PROPERTY, np, newprop, oldprop);
1877 
1878 	return rc;
1879 }
1880 
1881 static void of_alias_add(struct alias_prop *ap, struct device_node *np,
1882 			 int id, const char *stem, int stem_len)
1883 {
1884 	ap->np = np;
1885 	ap->id = id;
1886 	strncpy(ap->stem, stem, stem_len);
1887 	ap->stem[stem_len] = 0;
1888 	list_add_tail(&ap->link, &aliases_lookup);
1889 	pr_debug("adding DT alias:%s: stem=%s id=%i node=%pOF\n",
1890 		 ap->alias, ap->stem, ap->id, np);
1891 }
1892 
1893 /**
1894  * of_alias_scan - Scan all properties of the 'aliases' node
1895  * @dt_alloc:	An allocator that provides a virtual address to memory
1896  *		for storing the resulting tree
1897  *
1898  * The function scans all the properties of the 'aliases' node and populates
1899  * the global lookup table with the properties.  It returns the
1900  * number of alias properties found, or an error code in case of failure.
1901  */
1902 void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align))
1903 {
1904 	struct property *pp;
1905 
1906 	of_aliases = of_find_node_by_path("/aliases");
1907 	of_chosen = of_find_node_by_path("/chosen");
1908 	if (of_chosen == NULL)
1909 		of_chosen = of_find_node_by_path("/chosen@0");
1910 
1911 	if (of_chosen) {
1912 		/* linux,stdout-path and /aliases/stdout are for legacy compatibility */
1913 		const char *name = NULL;
1914 
1915 		if (of_property_read_string(of_chosen, "stdout-path", &name))
1916 			of_property_read_string(of_chosen, "linux,stdout-path",
1917 						&name);
1918 		if (IS_ENABLED(CONFIG_PPC) && !name)
1919 			of_property_read_string(of_aliases, "stdout", &name);
1920 		if (name)
1921 			of_stdout = of_find_node_opts_by_path(name, &of_stdout_options);
1922 		if (of_stdout)
1923 			of_stdout->fwnode.flags |= FWNODE_FLAG_BEST_EFFORT;
1924 	}
1925 
1926 	if (!of_aliases)
1927 		return;
1928 
1929 	for_each_property_of_node(of_aliases, pp) {
1930 		const char *start = pp->name;
1931 		const char *end = start + strlen(start);
1932 		struct device_node *np;
1933 		struct alias_prop *ap;
1934 		int id, len;
1935 
1936 		/* Skip those we do not want to proceed */
1937 		if (!strcmp(pp->name, "name") ||
1938 		    !strcmp(pp->name, "phandle") ||
1939 		    !strcmp(pp->name, "linux,phandle"))
1940 			continue;
1941 
1942 		np = of_find_node_by_path(pp->value);
1943 		if (!np)
1944 			continue;
1945 
1946 		/* walk the alias backwards to extract the id and work out
1947 		 * the 'stem' string */
1948 		while (isdigit(*(end-1)) && end > start)
1949 			end--;
1950 		len = end - start;
1951 
1952 		if (kstrtoint(end, 10, &id) < 0)
1953 			continue;
1954 
1955 		/* Allocate an alias_prop with enough space for the stem */
1956 		ap = dt_alloc(sizeof(*ap) + len + 1, __alignof__(*ap));
1957 		if (!ap)
1958 			continue;
1959 		memset(ap, 0, sizeof(*ap) + len + 1);
1960 		ap->alias = start;
1961 		of_alias_add(ap, np, id, start, len);
1962 	}
1963 }
1964 
1965 /**
1966  * of_alias_get_id - Get alias id for the given device_node
1967  * @np:		Pointer to the given device_node
1968  * @stem:	Alias stem of the given device_node
1969  *
1970  * The function travels the lookup table to get the alias id for the given
1971  * device_node and alias stem.
1972  *
1973  * Return: The alias id if found.
1974  */
1975 int of_alias_get_id(struct device_node *np, const char *stem)
1976 {
1977 	struct alias_prop *app;
1978 	int id = -ENODEV;
1979 
1980 	mutex_lock(&of_mutex);
1981 	list_for_each_entry(app, &aliases_lookup, link) {
1982 		if (strcmp(app->stem, stem) != 0)
1983 			continue;
1984 
1985 		if (np == app->np) {
1986 			id = app->id;
1987 			break;
1988 		}
1989 	}
1990 	mutex_unlock(&of_mutex);
1991 
1992 	return id;
1993 }
1994 EXPORT_SYMBOL_GPL(of_alias_get_id);
1995 
1996 /**
1997  * of_alias_get_highest_id - Get highest alias id for the given stem
1998  * @stem:	Alias stem to be examined
1999  *
2000  * The function travels the lookup table to get the highest alias id for the
2001  * given alias stem.  It returns the alias id if found.
2002  */
2003 int of_alias_get_highest_id(const char *stem)
2004 {
2005 	struct alias_prop *app;
2006 	int id = -ENODEV;
2007 
2008 	mutex_lock(&of_mutex);
2009 	list_for_each_entry(app, &aliases_lookup, link) {
2010 		if (strcmp(app->stem, stem) != 0)
2011 			continue;
2012 
2013 		if (app->id > id)
2014 			id = app->id;
2015 	}
2016 	mutex_unlock(&of_mutex);
2017 
2018 	return id;
2019 }
2020 EXPORT_SYMBOL_GPL(of_alias_get_highest_id);
2021 
2022 /**
2023  * of_console_check() - Test and setup console for DT setup
2024  * @dn: Pointer to device node
2025  * @name: Name to use for preferred console without index. ex. "ttyS"
2026  * @index: Index to use for preferred console.
2027  *
2028  * Check if the given device node matches the stdout-path property in the
2029  * /chosen node. If it does then register it as the preferred console.
2030  *
2031  * Return: TRUE if console successfully setup. Otherwise return FALSE.
2032  */
2033 bool of_console_check(struct device_node *dn, char *name, int index)
2034 {
2035 	if (!dn || dn != of_stdout || console_set_on_cmdline)
2036 		return false;
2037 
2038 	/*
2039 	 * XXX: cast `options' to char pointer to suppress complication
2040 	 * warnings: printk, UART and console drivers expect char pointer.
2041 	 */
2042 	return !add_preferred_console(name, index, (char *)of_stdout_options);
2043 }
2044 EXPORT_SYMBOL_GPL(of_console_check);
2045 
2046 /**
2047  * of_find_next_cache_node - Find a node's subsidiary cache
2048  * @np:	node of type "cpu" or "cache"
2049  *
2050  * Return: A node pointer with refcount incremented, use
2051  * of_node_put() on it when done.  Caller should hold a reference
2052  * to np.
2053  */
2054 struct device_node *of_find_next_cache_node(const struct device_node *np)
2055 {
2056 	struct device_node *child, *cache_node;
2057 
2058 	cache_node = of_parse_phandle(np, "l2-cache", 0);
2059 	if (!cache_node)
2060 		cache_node = of_parse_phandle(np, "next-level-cache", 0);
2061 
2062 	if (cache_node)
2063 		return cache_node;
2064 
2065 	/* OF on pmac has nodes instead of properties named "l2-cache"
2066 	 * beneath CPU nodes.
2067 	 */
2068 	if (IS_ENABLED(CONFIG_PPC_PMAC) && of_node_is_type(np, "cpu"))
2069 		for_each_child_of_node(np, child)
2070 			if (of_node_is_type(child, "cache"))
2071 				return child;
2072 
2073 	return NULL;
2074 }
2075 
2076 /**
2077  * of_find_last_cache_level - Find the level at which the last cache is
2078  * 		present for the given logical cpu
2079  *
2080  * @cpu: cpu number(logical index) for which the last cache level is needed
2081  *
2082  * Return: The level at which the last cache is present. It is exactly
2083  * same as  the total number of cache levels for the given logical cpu.
2084  */
2085 int of_find_last_cache_level(unsigned int cpu)
2086 {
2087 	u32 cache_level = 0;
2088 	struct device_node *prev = NULL, *np = of_cpu_device_node_get(cpu);
2089 
2090 	while (np) {
2091 		prev = np;
2092 		of_node_put(np);
2093 		np = of_find_next_cache_node(np);
2094 	}
2095 
2096 	of_property_read_u32(prev, "cache-level", &cache_level);
2097 
2098 	return cache_level;
2099 }
2100 
2101 /**
2102  * of_map_id - Translate an ID through a downstream mapping.
2103  * @np: root complex device node.
2104  * @id: device ID to map.
2105  * @map_name: property name of the map to use.
2106  * @map_mask_name: optional property name of the mask to use.
2107  * @target: optional pointer to a target device node.
2108  * @id_out: optional pointer to receive the translated ID.
2109  *
2110  * Given a device ID, look up the appropriate implementation-defined
2111  * platform ID and/or the target device which receives transactions on that
2112  * ID, as per the "iommu-map" and "msi-map" bindings. Either of @target or
2113  * @id_out may be NULL if only the other is required. If @target points to
2114  * a non-NULL device node pointer, only entries targeting that node will be
2115  * matched; if it points to a NULL value, it will receive the device node of
2116  * the first matching target phandle, with a reference held.
2117  *
2118  * Return: 0 on success or a standard error code on failure.
2119  */
2120 int of_map_id(struct device_node *np, u32 id,
2121 	       const char *map_name, const char *map_mask_name,
2122 	       struct device_node **target, u32 *id_out)
2123 {
2124 	u32 map_mask, masked_id;
2125 	int map_len;
2126 	const __be32 *map = NULL;
2127 
2128 	if (!np || !map_name || (!target && !id_out))
2129 		return -EINVAL;
2130 
2131 	map = of_get_property(np, map_name, &map_len);
2132 	if (!map) {
2133 		if (target)
2134 			return -ENODEV;
2135 		/* Otherwise, no map implies no translation */
2136 		*id_out = id;
2137 		return 0;
2138 	}
2139 
2140 	if (!map_len || map_len % (4 * sizeof(*map))) {
2141 		pr_err("%pOF: Error: Bad %s length: %d\n", np,
2142 			map_name, map_len);
2143 		return -EINVAL;
2144 	}
2145 
2146 	/* The default is to select all bits. */
2147 	map_mask = 0xffffffff;
2148 
2149 	/*
2150 	 * Can be overridden by "{iommu,msi}-map-mask" property.
2151 	 * If of_property_read_u32() fails, the default is used.
2152 	 */
2153 	if (map_mask_name)
2154 		of_property_read_u32(np, map_mask_name, &map_mask);
2155 
2156 	masked_id = map_mask & id;
2157 	for ( ; map_len > 0; map_len -= 4 * sizeof(*map), map += 4) {
2158 		struct device_node *phandle_node;
2159 		u32 id_base = be32_to_cpup(map + 0);
2160 		u32 phandle = be32_to_cpup(map + 1);
2161 		u32 out_base = be32_to_cpup(map + 2);
2162 		u32 id_len = be32_to_cpup(map + 3);
2163 
2164 		if (id_base & ~map_mask) {
2165 			pr_err("%pOF: Invalid %s translation - %s-mask (0x%x) ignores id-base (0x%x)\n",
2166 				np, map_name, map_name,
2167 				map_mask, id_base);
2168 			return -EFAULT;
2169 		}
2170 
2171 		if (masked_id < id_base || masked_id >= id_base + id_len)
2172 			continue;
2173 
2174 		phandle_node = of_find_node_by_phandle(phandle);
2175 		if (!phandle_node)
2176 			return -ENODEV;
2177 
2178 		if (target) {
2179 			if (*target)
2180 				of_node_put(phandle_node);
2181 			else
2182 				*target = phandle_node;
2183 
2184 			if (*target != phandle_node)
2185 				continue;
2186 		}
2187 
2188 		if (id_out)
2189 			*id_out = masked_id - id_base + out_base;
2190 
2191 		pr_debug("%pOF: %s, using mask %08x, id-base: %08x, out-base: %08x, length: %08x, id: %08x -> %08x\n",
2192 			np, map_name, map_mask, id_base, out_base,
2193 			id_len, id, masked_id - id_base + out_base);
2194 		return 0;
2195 	}
2196 
2197 	pr_info("%pOF: no %s translation for id 0x%x on %pOF\n", np, map_name,
2198 		id, target && *target ? *target : NULL);
2199 
2200 	/* Bypasses translation */
2201 	if (id_out)
2202 		*id_out = id;
2203 	return 0;
2204 }
2205 EXPORT_SYMBOL_GPL(of_map_id);
2206