2 * Procedures for creating, accessing and interpreting the device tree.
4 * Paul Mackerras August 1996.
5 * Copyright (C) 1996-2005 Paul Mackerras.
7 * Adapted for 64bit PowerPC by Dave Engebretsen and Peter Bergner.
8 * {engebret|bergner}@us.ibm.com
10 * Adapted for sparc and sparc64 by David S. Miller davem@davemloft.net
12 * Reconsolidated from arch/x/kernel/prom.c by Stephen Rothwell and
15 * This program is free software; you can redistribute it and/or
16 * modify it under the terms of the GNU General Public License
17 * as published by the Free Software Foundation; either version
18 * 2 of the License, or (at your option) any later version.
20 #include <linux/ctype.h>
21 #include <linux/cpu.h>
22 #include <linux/module.h>
24 #include <linux/spinlock.h>
25 #include <linux/slab.h>
26 #include <linux/proc_fs.h>
28 #include "of_private.h"
30 LIST_HEAD(aliases_lookup);
32 struct device_node *of_allnodes;
33 EXPORT_SYMBOL(of_allnodes);
34 struct device_node *of_chosen;
35 struct device_node *of_aliases;
36 static struct device_node *of_stdout;
38 DEFINE_MUTEX(of_aliases_mutex);
40 /* use when traversing tree through the allnext, child, sibling,
41 * or parent members of struct device_node.
43 DEFINE_RAW_SPINLOCK(devtree_lock);
45 int of_n_addr_cells(struct device_node *np)
52 ip = of_get_property(np, "#address-cells", NULL);
54 return be32_to_cpup(ip);
56 /* No #address-cells property for the root node */
57 return OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
59 EXPORT_SYMBOL(of_n_addr_cells);
61 int of_n_size_cells(struct device_node *np)
68 ip = of_get_property(np, "#size-cells", NULL);
70 return be32_to_cpup(ip);
72 /* No #size-cells property for the root node */
73 return OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
75 EXPORT_SYMBOL(of_n_size_cells);
78 int __weak of_node_to_nid(struct device_node *np)
80 return numa_node_id();
84 #if defined(CONFIG_OF_DYNAMIC)
86 * of_node_get - Increment refcount of a node
87 * @node: Node to inc refcount, NULL is supported to
88 * simplify writing of callers
92 struct device_node *of_node_get(struct device_node *node)
95 kref_get(&node->kref);
98 EXPORT_SYMBOL(of_node_get);
100 static inline struct device_node *kref_to_device_node(struct kref *kref)
102 return container_of(kref, struct device_node, kref);
106 * of_node_release - release a dynamically allocated node
107 * @kref: kref element of the node to be released
109 * In of_node_put() this function is passed to kref_put()
112 static void of_node_release(struct kref *kref)
114 struct device_node *node = kref_to_device_node(kref);
115 struct property *prop = node->properties;
117 /* We should never be releasing nodes that haven't been detached. */
118 if (!of_node_check_flag(node, OF_DETACHED)) {
119 pr_err("ERROR: Bad of_node_put() on %s\n", node->full_name);
121 kref_init(&node->kref);
125 if (!of_node_check_flag(node, OF_DYNAMIC))
129 struct property *next = prop->next;
136 prop = node->deadprops;
137 node->deadprops = NULL;
140 kfree(node->full_name);
146 * of_node_put - Decrement refcount of a node
147 * @node: Node to dec refcount, NULL is supported to
148 * simplify writing of callers
151 void of_node_put(struct device_node *node)
154 kref_put(&node->kref, of_node_release);
156 EXPORT_SYMBOL(of_node_put);
157 #endif /* CONFIG_OF_DYNAMIC */
159 static struct property *__of_find_property(const struct device_node *np,
160 const char *name, int *lenp)
167 for (pp = np->properties; pp; pp = pp->next) {
168 if (of_prop_cmp(pp->name, name) == 0) {
178 struct property *of_find_property(const struct device_node *np,
185 raw_spin_lock_irqsave(&devtree_lock, flags);
186 pp = __of_find_property(np, name, lenp);
187 raw_spin_unlock_irqrestore(&devtree_lock, flags);
191 EXPORT_SYMBOL(of_find_property);
194 * of_find_all_nodes - Get next node in global list
195 * @prev: Previous node or NULL to start iteration
196 * of_node_put() will be called on it
198 * Returns a node pointer with refcount incremented, use
199 * of_node_put() on it when done.
201 struct device_node *of_find_all_nodes(struct device_node *prev)
203 struct device_node *np;
206 raw_spin_lock_irqsave(&devtree_lock, flags);
207 np = prev ? prev->allnext : of_allnodes;
208 for (; np != NULL; np = np->allnext)
212 raw_spin_unlock_irqrestore(&devtree_lock, flags);
215 EXPORT_SYMBOL(of_find_all_nodes);
218 * Find a property with a given name for a given node
219 * and return the value.
221 static const void *__of_get_property(const struct device_node *np,
222 const char *name, int *lenp)
224 struct property *pp = __of_find_property(np, name, lenp);
226 return pp ? pp->value : NULL;
230 * Find a property with a given name for a given node
231 * and return the value.
233 const void *of_get_property(const struct device_node *np, const char *name,
236 struct property *pp = of_find_property(np, name, lenp);
238 return pp ? pp->value : NULL;
240 EXPORT_SYMBOL(of_get_property);
243 * arch_match_cpu_phys_id - Match the given logical CPU and physical id
245 * @cpu: logical cpu index of a core/thread
246 * @phys_id: physical identifier of a core/thread
248 * CPU logical to physical index mapping is architecture specific.
249 * However this __weak function provides a default match of physical
250 * id to logical cpu index. phys_id provided here is usually values read
251 * from the device tree which must match the hardware internal registers.
253 * Returns true if the physical identifier and the logical cpu index
254 * correspond to the same core/thread, false otherwise.
256 bool __weak arch_match_cpu_phys_id(int cpu, u64 phys_id)
258 return (u32)phys_id == cpu;
262 * Checks if the given "prop_name" property holds the physical id of the
263 * core/thread corresponding to the logical cpu 'cpu'. If 'thread' is not
264 * NULL, local thread number within the core is returned in it.
266 static bool __of_find_n_match_cpu_property(struct device_node *cpun,
267 const char *prop_name, int cpu, unsigned int *thread)
270 int ac, prop_len, tid;
273 ac = of_n_addr_cells(cpun);
274 cell = of_get_property(cpun, prop_name, &prop_len);
277 prop_len /= sizeof(*cell) * ac;
278 for (tid = 0; tid < prop_len; tid++) {
279 hwid = of_read_number(cell, ac);
280 if (arch_match_cpu_phys_id(cpu, hwid)) {
291 * arch_find_n_match_cpu_physical_id - See if the given device node is
292 * for the cpu corresponding to logical cpu 'cpu'. Return true if so,
293 * else false. If 'thread' is non-NULL, the local thread number within the
294 * core is returned in it.
296 bool __weak arch_find_n_match_cpu_physical_id(struct device_node *cpun,
297 int cpu, unsigned int *thread)
299 /* Check for non-standard "ibm,ppc-interrupt-server#s" property
300 * for thread ids on PowerPC. If it doesn't exist fallback to
301 * standard "reg" property.
303 if (IS_ENABLED(CONFIG_PPC) &&
304 __of_find_n_match_cpu_property(cpun,
305 "ibm,ppc-interrupt-server#s",
309 if (__of_find_n_match_cpu_property(cpun, "reg", cpu, thread))
316 * of_get_cpu_node - Get device node associated with the given logical CPU
318 * @cpu: CPU number(logical index) for which device node is required
319 * @thread: if not NULL, local thread number within the physical core is
322 * The main purpose of this function is to retrieve the device node for the
323 * given logical CPU index. It should be used to initialize the of_node in
324 * cpu device. Once of_node in cpu device is populated, all the further
325 * references can use that instead.
327 * CPU logical to physical index mapping is architecture specific and is built
328 * before booting secondary cores. This function uses arch_match_cpu_phys_id
329 * which can be overridden by architecture specific implementation.
331 * Returns a node pointer for the logical cpu if found, else NULL.
333 struct device_node *of_get_cpu_node(int cpu, unsigned int *thread)
335 struct device_node *cpun;
337 for_each_node_by_type(cpun, "cpu") {
338 if (arch_find_n_match_cpu_physical_id(cpun, cpu, thread))
343 EXPORT_SYMBOL(of_get_cpu_node);
346 * __of_device_is_compatible() - Check if the node matches given constraints
347 * @device: pointer to node
348 * @compat: required compatible string, NULL or "" for any match
349 * @type: required device_type value, NULL or "" for any match
350 * @name: required node name, NULL or "" for any match
352 * Checks if the given @compat, @type and @name strings match the
353 * properties of the given @device. A constraints can be skipped by
354 * passing NULL or an empty string as the constraint.
356 * Returns 0 for no match, and a positive integer on match. The return
357 * value is a relative score with larger values indicating better
358 * matches. The score is weighted for the most specific compatible value
359 * to get the highest score. Matching type is next, followed by matching
360 * name. Practically speaking, this results in the following priority
363 * 1. specific compatible && type && name
364 * 2. specific compatible && type
365 * 3. specific compatible && name
366 * 4. specific compatible
367 * 5. general compatible && type && name
368 * 6. general compatible && type
369 * 7. general compatible && name
370 * 8. general compatible
375 static int __of_device_is_compatible(const struct device_node *device,
376 const char *compat, const char *type, const char *name)
378 struct property *prop;
380 int index = 0, score = 0;
382 /* Compatible match has highest priority */
383 if (compat && compat[0]) {
384 prop = __of_find_property(device, "compatible", NULL);
385 for (cp = of_prop_next_string(prop, NULL); cp;
386 cp = of_prop_next_string(prop, cp), index++) {
387 if (of_compat_cmp(cp, compat, strlen(compat)) == 0) {
388 score = INT_MAX/2 - (index << 2);
396 /* Matching type is better than matching name */
397 if (type && type[0]) {
398 if (!device->type || of_node_cmp(type, device->type))
403 /* Matching name is a bit better than not */
404 if (name && name[0]) {
405 if (!device->name || of_node_cmp(name, device->name))
413 /** Checks if the given "compat" string matches one of the strings in
414 * the device's "compatible" property
416 int of_device_is_compatible(const struct device_node *device,
422 raw_spin_lock_irqsave(&devtree_lock, flags);
423 res = __of_device_is_compatible(device, compat, NULL, NULL);
424 raw_spin_unlock_irqrestore(&devtree_lock, flags);
427 EXPORT_SYMBOL(of_device_is_compatible);
430 * of_machine_is_compatible - Test root of device tree for a given compatible value
431 * @compat: compatible string to look for in root node's compatible property.
433 * Returns true if the root node has the given value in its
434 * compatible property.
436 int of_machine_is_compatible(const char *compat)
438 struct device_node *root;
441 root = of_find_node_by_path("/");
443 rc = of_device_is_compatible(root, compat);
448 EXPORT_SYMBOL(of_machine_is_compatible);
451 * __of_device_is_available - check if a device is available for use
453 * @device: Node to check for availability, with locks already held
455 * Returns 1 if the status property is absent or set to "okay" or "ok",
458 static int __of_device_is_available(const struct device_node *device)
466 status = __of_get_property(device, "status", &statlen);
471 if (!strcmp(status, "okay") || !strcmp(status, "ok"))
479 * of_device_is_available - check if a device is available for use
481 * @device: Node to check for availability
483 * Returns 1 if the status property is absent or set to "okay" or "ok",
486 int of_device_is_available(const struct device_node *device)
491 raw_spin_lock_irqsave(&devtree_lock, flags);
492 res = __of_device_is_available(device);
493 raw_spin_unlock_irqrestore(&devtree_lock, flags);
497 EXPORT_SYMBOL(of_device_is_available);
500 * of_get_parent - Get a node's parent if any
501 * @node: Node to get parent
503 * Returns a node pointer with refcount incremented, use
504 * of_node_put() on it when done.
506 struct device_node *of_get_parent(const struct device_node *node)
508 struct device_node *np;
514 raw_spin_lock_irqsave(&devtree_lock, flags);
515 np = of_node_get(node->parent);
516 raw_spin_unlock_irqrestore(&devtree_lock, flags);
519 EXPORT_SYMBOL(of_get_parent);
522 * of_get_next_parent - Iterate to a node's parent
523 * @node: Node to get parent of
525 * This is like of_get_parent() except that it drops the
526 * refcount on the passed node, making it suitable for iterating
527 * through a node's parents.
529 * Returns a node pointer with refcount incremented, use
530 * of_node_put() on it when done.
532 struct device_node *of_get_next_parent(struct device_node *node)
534 struct device_node *parent;
540 raw_spin_lock_irqsave(&devtree_lock, flags);
541 parent = of_node_get(node->parent);
543 raw_spin_unlock_irqrestore(&devtree_lock, flags);
546 EXPORT_SYMBOL(of_get_next_parent);
549 * of_get_next_child - Iterate a node childs
551 * @prev: previous child of the parent node, or NULL to get first
553 * Returns a node pointer with refcount incremented, use
554 * of_node_put() on it when done.
556 struct device_node *of_get_next_child(const struct device_node *node,
557 struct device_node *prev)
559 struct device_node *next;
562 raw_spin_lock_irqsave(&devtree_lock, flags);
563 next = prev ? prev->sibling : node->child;
564 for (; next; next = next->sibling)
565 if (of_node_get(next))
568 raw_spin_unlock_irqrestore(&devtree_lock, flags);
571 EXPORT_SYMBOL(of_get_next_child);
574 * of_get_next_available_child - Find the next available child node
576 * @prev: previous child of the parent node, or NULL to get first
578 * This function is like of_get_next_child(), except that it
579 * automatically skips any disabled nodes (i.e. status = "disabled").
581 struct device_node *of_get_next_available_child(const struct device_node *node,
582 struct device_node *prev)
584 struct device_node *next;
587 raw_spin_lock_irqsave(&devtree_lock, flags);
588 next = prev ? prev->sibling : node->child;
589 for (; next; next = next->sibling) {
590 if (!__of_device_is_available(next))
592 if (of_node_get(next))
596 raw_spin_unlock_irqrestore(&devtree_lock, flags);
599 EXPORT_SYMBOL(of_get_next_available_child);
602 * of_get_child_by_name - Find the child node by name for a given parent
604 * @name: child name to look for.
606 * This function looks for child node for given matching name
608 * Returns a node pointer if found, with refcount incremented, use
609 * of_node_put() on it when done.
610 * Returns NULL if node is not found.
612 struct device_node *of_get_child_by_name(const struct device_node *node,
615 struct device_node *child;
617 for_each_child_of_node(node, child)
618 if (child->name && (of_node_cmp(child->name, name) == 0))
622 EXPORT_SYMBOL(of_get_child_by_name);
625 * of_find_node_by_path - Find a node matching a full OF path
626 * @path: The full path to match
628 * Returns a node pointer with refcount incremented, use
629 * of_node_put() on it when done.
631 struct device_node *of_find_node_by_path(const char *path)
633 struct device_node *np = of_allnodes;
636 raw_spin_lock_irqsave(&devtree_lock, flags);
637 for (; np; np = np->allnext) {
638 if (np->full_name && (of_node_cmp(np->full_name, path) == 0)
642 raw_spin_unlock_irqrestore(&devtree_lock, flags);
645 EXPORT_SYMBOL(of_find_node_by_path);
648 * of_find_node_by_name - Find a node by its "name" property
649 * @from: The node to start searching from or NULL, the node
650 * you pass will not be searched, only the next one
651 * will; typically, you pass what the previous call
652 * returned. of_node_put() will be called on it
653 * @name: The name string to match against
655 * Returns a node pointer with refcount incremented, use
656 * of_node_put() on it when done.
658 struct device_node *of_find_node_by_name(struct device_node *from,
661 struct device_node *np;
664 raw_spin_lock_irqsave(&devtree_lock, flags);
665 np = from ? from->allnext : of_allnodes;
666 for (; np; np = np->allnext)
667 if (np->name && (of_node_cmp(np->name, name) == 0)
671 raw_spin_unlock_irqrestore(&devtree_lock, flags);
674 EXPORT_SYMBOL(of_find_node_by_name);
677 * of_find_node_by_type - Find a node by its "device_type" property
678 * @from: The node to start searching from, or NULL to start searching
679 * the entire device tree. The node you pass will not be
680 * searched, only the next one will; typically, you pass
681 * what the previous call returned. of_node_put() will be
682 * called on from for you.
683 * @type: The type string to match against
685 * Returns a node pointer with refcount incremented, use
686 * of_node_put() on it when done.
688 struct device_node *of_find_node_by_type(struct device_node *from,
691 struct device_node *np;
694 raw_spin_lock_irqsave(&devtree_lock, flags);
695 np = from ? from->allnext : of_allnodes;
696 for (; np; np = np->allnext)
697 if (np->type && (of_node_cmp(np->type, type) == 0)
701 raw_spin_unlock_irqrestore(&devtree_lock, flags);
704 EXPORT_SYMBOL(of_find_node_by_type);
707 * of_find_compatible_node - Find a node based on type and one of the
708 * tokens in its "compatible" property
709 * @from: The node to start searching from or NULL, the node
710 * you pass will not be searched, only the next one
711 * will; typically, you pass what the previous call
712 * returned. of_node_put() will be called on it
713 * @type: The type string to match "device_type" or NULL to ignore
714 * @compatible: The string to match to one of the tokens in the device
717 * Returns a node pointer with refcount incremented, use
718 * of_node_put() on it when done.
720 struct device_node *of_find_compatible_node(struct device_node *from,
721 const char *type, const char *compatible)
723 struct device_node *np;
726 raw_spin_lock_irqsave(&devtree_lock, flags);
727 np = from ? from->allnext : of_allnodes;
728 for (; np; np = np->allnext) {
729 if (__of_device_is_compatible(np, compatible, type, NULL) &&
734 raw_spin_unlock_irqrestore(&devtree_lock, flags);
737 EXPORT_SYMBOL(of_find_compatible_node);
740 * of_find_node_with_property - Find a node which has a property with
742 * @from: The node to start searching from or NULL, the node
743 * you pass will not be searched, only the next one
744 * will; typically, you pass what the previous call
745 * returned. of_node_put() will be called on it
746 * @prop_name: The name of the property to look for.
748 * Returns a node pointer with refcount incremented, use
749 * of_node_put() on it when done.
751 struct device_node *of_find_node_with_property(struct device_node *from,
752 const char *prop_name)
754 struct device_node *np;
758 raw_spin_lock_irqsave(&devtree_lock, flags);
759 np = from ? from->allnext : of_allnodes;
760 for (; np; np = np->allnext) {
761 for (pp = np->properties; pp; pp = pp->next) {
762 if (of_prop_cmp(pp->name, prop_name) == 0) {
770 raw_spin_unlock_irqrestore(&devtree_lock, flags);
773 EXPORT_SYMBOL(of_find_node_with_property);
776 const struct of_device_id *__of_match_node(const struct of_device_id *matches,
777 const struct device_node *node)
779 const struct of_device_id *best_match = NULL;
780 int score, best_score = 0;
785 for (; matches->name[0] || matches->type[0] || matches->compatible[0]; matches++) {
786 score = __of_device_is_compatible(node, matches->compatible,
787 matches->type, matches->name);
788 if (score > best_score) {
789 best_match = matches;
798 * of_match_node - Tell if an device_node has a matching of_match structure
799 * @matches: array of of device match structures to search in
800 * @node: the of device structure to match against
802 * Low level utility function used by device matching.
804 const struct of_device_id *of_match_node(const struct of_device_id *matches,
805 const struct device_node *node)
807 const struct of_device_id *match;
810 raw_spin_lock_irqsave(&devtree_lock, flags);
811 match = __of_match_node(matches, node);
812 raw_spin_unlock_irqrestore(&devtree_lock, flags);
815 EXPORT_SYMBOL(of_match_node);
818 * of_find_matching_node_and_match - Find a node based on an of_device_id
820 * @from: The node to start searching from or NULL, the node
821 * you pass will not be searched, only the next one
822 * will; typically, you pass what the previous call
823 * returned. of_node_put() will be called on it
824 * @matches: array of of device match structures to search in
825 * @match Updated to point at the matches entry which matched
827 * Returns a node pointer with refcount incremented, use
828 * of_node_put() on it when done.
830 struct device_node *of_find_matching_node_and_match(struct device_node *from,
831 const struct of_device_id *matches,
832 const struct of_device_id **match)
834 struct device_node *np;
835 const struct of_device_id *m;
841 raw_spin_lock_irqsave(&devtree_lock, flags);
842 np = from ? from->allnext : of_allnodes;
843 for (; np; np = np->allnext) {
844 m = __of_match_node(matches, np);
845 if (m && of_node_get(np)) {
852 raw_spin_unlock_irqrestore(&devtree_lock, flags);
855 EXPORT_SYMBOL(of_find_matching_node_and_match);
858 * of_modalias_node - Lookup appropriate modalias for a device node
859 * @node: pointer to a device tree node
860 * @modalias: Pointer to buffer that modalias value will be copied into
861 * @len: Length of modalias value
863 * Based on the value of the compatible property, this routine will attempt
864 * to choose an appropriate modalias value for a particular device tree node.
865 * It does this by stripping the manufacturer prefix (as delimited by a ',')
866 * from the first entry in the compatible list property.
868 * This routine returns 0 on success, <0 on failure.
870 int of_modalias_node(struct device_node *node, char *modalias, int len)
872 const char *compatible, *p;
875 compatible = of_get_property(node, "compatible", &cplen);
876 if (!compatible || strlen(compatible) > cplen)
878 p = strchr(compatible, ',');
879 strlcpy(modalias, p ? p + 1 : compatible, len);
882 EXPORT_SYMBOL_GPL(of_modalias_node);
885 * of_find_node_by_phandle - Find a node given a phandle
886 * @handle: phandle of the node to find
888 * Returns a node pointer with refcount incremented, use
889 * of_node_put() on it when done.
891 struct device_node *of_find_node_by_phandle(phandle handle)
893 struct device_node *np;
896 raw_spin_lock_irqsave(&devtree_lock, flags);
897 for (np = of_allnodes; np; np = np->allnext)
898 if (np->phandle == handle)
901 raw_spin_unlock_irqrestore(&devtree_lock, flags);
904 EXPORT_SYMBOL(of_find_node_by_phandle);
907 * of_property_count_elems_of_size - Count the number of elements in a property
909 * @np: device node from which the property value is to be read.
910 * @propname: name of the property to be searched.
911 * @elem_size: size of the individual element
913 * Search for a property in a device node and count the number of elements of
914 * size elem_size in it. Returns number of elements on sucess, -EINVAL if the
915 * property does not exist or its length does not match a multiple of elem_size
916 * and -ENODATA if the property does not have a value.
918 int of_property_count_elems_of_size(const struct device_node *np,
919 const char *propname, int elem_size)
921 struct property *prop = of_find_property(np, propname, NULL);
928 if (prop->length % elem_size != 0) {
929 pr_err("size of %s in node %s is not a multiple of %d\n",
930 propname, np->full_name, elem_size);
934 return prop->length / elem_size;
936 EXPORT_SYMBOL_GPL(of_property_count_elems_of_size);
939 * of_find_property_value_of_size
941 * @np: device node from which the property value is to be read.
942 * @propname: name of the property to be searched.
943 * @len: requested length of property value
945 * Search for a property in a device node and valid the requested size.
946 * Returns the property value on success, -EINVAL if the property does not
947 * exist, -ENODATA if property does not have a value, and -EOVERFLOW if the
948 * property data isn't large enough.
951 static void *of_find_property_value_of_size(const struct device_node *np,
952 const char *propname, u32 len)
954 struct property *prop = of_find_property(np, propname, NULL);
957 return ERR_PTR(-EINVAL);
959 return ERR_PTR(-ENODATA);
960 if (len > prop->length)
961 return ERR_PTR(-EOVERFLOW);
967 * of_property_read_u32_index - Find and read a u32 from a multi-value property.
969 * @np: device node from which the property value is to be read.
970 * @propname: name of the property to be searched.
971 * @index: index of the u32 in the list of values
972 * @out_value: pointer to return value, modified only if no error.
974 * Search for a property in a device node and read nth 32-bit value from
975 * it. Returns 0 on success, -EINVAL if the property does not exist,
976 * -ENODATA if property does not have a value, and -EOVERFLOW if the
977 * property data isn't large enough.
979 * The out_value is modified only if a valid u32 value can be decoded.
981 int of_property_read_u32_index(const struct device_node *np,
982 const char *propname,
983 u32 index, u32 *out_value)
985 const u32 *val = of_find_property_value_of_size(np, propname,
986 ((index + 1) * sizeof(*out_value)));
991 *out_value = be32_to_cpup(((__be32 *)val) + index);
994 EXPORT_SYMBOL_GPL(of_property_read_u32_index);
997 * of_property_read_u8_array - Find and read an array of u8 from a property.
999 * @np: device node from which the property value is to be read.
1000 * @propname: name of the property to be searched.
1001 * @out_values: pointer to return value, modified only if return value is 0.
1002 * @sz: number of array elements to read
1004 * Search for a property in a device node and read 8-bit value(s) from
1005 * it. Returns 0 on success, -EINVAL if the property does not exist,
1006 * -ENODATA if property does not have a value, and -EOVERFLOW if the
1007 * property data isn't large enough.
1009 * dts entry of array should be like:
1010 * property = /bits/ 8 <0x50 0x60 0x70>;
1012 * The out_values is modified only if a valid u8 value can be decoded.
1014 int of_property_read_u8_array(const struct device_node *np,
1015 const char *propname, u8 *out_values, size_t sz)
1017 const u8 *val = of_find_property_value_of_size(np, propname,
1018 (sz * sizeof(*out_values)));
1021 return PTR_ERR(val);
1024 *out_values++ = *val++;
1027 EXPORT_SYMBOL_GPL(of_property_read_u8_array);
1030 * of_property_read_u16_array - Find and read an array of u16 from a property.
1032 * @np: device node from which the property value is to be read.
1033 * @propname: name of the property to be searched.
1034 * @out_values: pointer to return value, modified only if return value is 0.
1035 * @sz: number of array elements to read
1037 * Search for a property in a device node and read 16-bit value(s) from
1038 * it. Returns 0 on success, -EINVAL if the property does not exist,
1039 * -ENODATA if property does not have a value, and -EOVERFLOW if the
1040 * property data isn't large enough.
1042 * dts entry of array should be like:
1043 * property = /bits/ 16 <0x5000 0x6000 0x7000>;
1045 * The out_values is modified only if a valid u16 value can be decoded.
1047 int of_property_read_u16_array(const struct device_node *np,
1048 const char *propname, u16 *out_values, size_t sz)
1050 const __be16 *val = of_find_property_value_of_size(np, propname,
1051 (sz * sizeof(*out_values)));
1054 return PTR_ERR(val);
1057 *out_values++ = be16_to_cpup(val++);
1060 EXPORT_SYMBOL_GPL(of_property_read_u16_array);
1063 * of_property_read_u32_array - Find and read an array of 32 bit integers
1066 * @np: device node from which the property value is to be read.
1067 * @propname: name of the property to be searched.
1068 * @out_values: pointer to return value, modified only if return value is 0.
1069 * @sz: number of array elements to read
1071 * Search for a property in a device node and read 32-bit value(s) from
1072 * it. Returns 0 on success, -EINVAL if the property does not exist,
1073 * -ENODATA if property does not have a value, and -EOVERFLOW if the
1074 * property data isn't large enough.
1076 * The out_values is modified only if a valid u32 value can be decoded.
1078 int of_property_read_u32_array(const struct device_node *np,
1079 const char *propname, u32 *out_values,
1082 const __be32 *val = of_find_property_value_of_size(np, propname,
1083 (sz * sizeof(*out_values)));
1086 return PTR_ERR(val);
1089 *out_values++ = be32_to_cpup(val++);
1092 EXPORT_SYMBOL_GPL(of_property_read_u32_array);
1095 * of_property_read_u64 - Find and read a 64 bit integer from a property
1096 * @np: device node from which the property value is to be read.
1097 * @propname: name of the property to be searched.
1098 * @out_value: pointer to return value, modified only if return value is 0.
1100 * Search for a property in a device node and read a 64-bit value from
1101 * it. Returns 0 on success, -EINVAL if the property does not exist,
1102 * -ENODATA if property does not have a value, and -EOVERFLOW if the
1103 * property data isn't large enough.
1105 * The out_value is modified only if a valid u64 value can be decoded.
1107 int of_property_read_u64(const struct device_node *np, const char *propname,
1110 const __be32 *val = of_find_property_value_of_size(np, propname,
1111 sizeof(*out_value));
1114 return PTR_ERR(val);
1116 *out_value = of_read_number(val, 2);
1119 EXPORT_SYMBOL_GPL(of_property_read_u64);
1122 * of_property_read_string - Find and read a string from a property
1123 * @np: device node from which the property value is to be read.
1124 * @propname: name of the property to be searched.
1125 * @out_string: pointer to null terminated return string, modified only if
1126 * return value is 0.
1128 * Search for a property in a device tree node and retrieve a null
1129 * terminated string value (pointer to data, not a copy). Returns 0 on
1130 * success, -EINVAL if the property does not exist, -ENODATA if property
1131 * does not have a value, and -EILSEQ if the string is not null-terminated
1132 * within the length of the property data.
1134 * The out_string pointer is modified only if a valid string can be decoded.
1136 int of_property_read_string(struct device_node *np, const char *propname,
1137 const char **out_string)
1139 struct property *prop = of_find_property(np, propname, NULL);
1144 if (strnlen(prop->value, prop->length) >= prop->length)
1146 *out_string = prop->value;
1149 EXPORT_SYMBOL_GPL(of_property_read_string);
1152 * of_property_read_string_index - Find and read a string from a multiple
1154 * @np: device node from which the property value is to be read.
1155 * @propname: name of the property to be searched.
1156 * @index: index of the string in the list of strings
1157 * @out_string: pointer to null terminated return string, modified only if
1158 * return value is 0.
1160 * Search for a property in a device tree node and retrieve a null
1161 * terminated string value (pointer to data, not a copy) in the list of strings
1162 * contained in that property.
1163 * Returns 0 on success, -EINVAL if the property does not exist, -ENODATA if
1164 * property does not have a value, and -EILSEQ if the string is not
1165 * null-terminated within the length of the property data.
1167 * The out_string pointer is modified only if a valid string can be decoded.
1169 int of_property_read_string_index(struct device_node *np, const char *propname,
1170 int index, const char **output)
1172 struct property *prop = of_find_property(np, propname, NULL);
1174 size_t l = 0, total = 0;
1181 if (strnlen(prop->value, prop->length) >= prop->length)
1186 for (i = 0; total < prop->length; total += l, p += l) {
1195 EXPORT_SYMBOL_GPL(of_property_read_string_index);
1198 * of_property_match_string() - Find string in a list and return index
1199 * @np: pointer to node containing string list property
1200 * @propname: string list property name
1201 * @string: pointer to string to search for in string list
1203 * This function searches a string list property and returns the index
1204 * of a specific string value.
1206 int of_property_match_string(struct device_node *np, const char *propname,
1209 struct property *prop = of_find_property(np, propname, NULL);
1212 const char *p, *end;
1220 end = p + prop->length;
1222 for (i = 0; p < end; i++, p += l) {
1226 pr_debug("comparing %s with %s\n", string, p);
1227 if (strcmp(string, p) == 0)
1228 return i; /* Found it; return index */
1232 EXPORT_SYMBOL_GPL(of_property_match_string);
1235 * of_property_count_strings - Find and return the number of strings from a
1236 * multiple strings property.
1237 * @np: device node from which the property value is to be read.
1238 * @propname: name of the property to be searched.
1240 * Search for a property in a device tree node and retrieve the number of null
1241 * terminated string contain in it. Returns the number of strings on
1242 * success, -EINVAL if the property does not exist, -ENODATA if property
1243 * does not have a value, and -EILSEQ if the string is not null-terminated
1244 * within the length of the property data.
1246 int of_property_count_strings(struct device_node *np, const char *propname)
1248 struct property *prop = of_find_property(np, propname, NULL);
1250 size_t l = 0, total = 0;
1257 if (strnlen(prop->value, prop->length) >= prop->length)
1262 for (i = 0; total < prop->length; total += l, p += l, i++)
1267 EXPORT_SYMBOL_GPL(of_property_count_strings);
1269 void of_print_phandle_args(const char *msg, const struct of_phandle_args *args)
1272 printk("%s %s", msg, of_node_full_name(args->np));
1273 for (i = 0; i < args->args_count; i++)
1274 printk(i ? ",%08x" : ":%08x", args->args[i]);
1278 static int __of_parse_phandle_with_args(const struct device_node *np,
1279 const char *list_name,
1280 const char *cells_name,
1281 int cell_count, int index,
1282 struct of_phandle_args *out_args)
1284 const __be32 *list, *list_end;
1285 int rc = 0, size, cur_index = 0;
1287 struct device_node *node = NULL;
1290 /* Retrieve the phandle list property */
1291 list = of_get_property(np, list_name, &size);
1294 list_end = list + size / sizeof(*list);
1296 /* Loop over the phandles until all the requested entry is found */
1297 while (list < list_end) {
1302 * If phandle is 0, then it is an empty entry with no
1303 * arguments. Skip forward to the next entry.
1305 phandle = be32_to_cpup(list++);
1308 * Find the provider node and parse the #*-cells
1309 * property to determine the argument length.
1311 * This is not needed if the cell count is hard-coded
1312 * (i.e. cells_name not set, but cell_count is set),
1313 * except when we're going to return the found node
1316 if (cells_name || cur_index == index) {
1317 node = of_find_node_by_phandle(phandle);
1319 pr_err("%s: could not find phandle\n",
1326 if (of_property_read_u32(node, cells_name,
1328 pr_err("%s: could not get %s for %s\n",
1329 np->full_name, cells_name,
1338 * Make sure that the arguments actually fit in the
1339 * remaining property data length
1341 if (list + count > list_end) {
1342 pr_err("%s: arguments longer than property\n",
1349 * All of the error cases above bail out of the loop, so at
1350 * this point, the parsing is successful. If the requested
1351 * index matches, then fill the out_args structure and return,
1352 * or return -ENOENT for an empty entry.
1355 if (cur_index == index) {
1361 if (WARN_ON(count > MAX_PHANDLE_ARGS))
1362 count = MAX_PHANDLE_ARGS;
1363 out_args->np = node;
1364 out_args->args_count = count;
1365 for (i = 0; i < count; i++)
1366 out_args->args[i] = be32_to_cpup(list++);
1371 /* Found it! return success */
1382 * Unlock node before returning result; will be one of:
1383 * -ENOENT : index is for empty phandle
1384 * -EINVAL : parsing error on data
1385 * [1..n] : Number of phandle (count mode; when index = -1)
1387 rc = index < 0 ? cur_index : -ENOENT;
1395 * of_parse_phandle - Resolve a phandle property to a device_node pointer
1396 * @np: Pointer to device node holding phandle property
1397 * @phandle_name: Name of property holding a phandle value
1398 * @index: For properties holding a table of phandles, this is the index into
1401 * Returns the device_node pointer with refcount incremented. Use
1402 * of_node_put() on it when done.
1404 struct device_node *of_parse_phandle(const struct device_node *np,
1405 const char *phandle_name, int index)
1407 struct of_phandle_args args;
1412 if (__of_parse_phandle_with_args(np, phandle_name, NULL, 0,
1418 EXPORT_SYMBOL(of_parse_phandle);
1421 * of_parse_phandle_with_args() - Find a node pointed by phandle in a list
1422 * @np: pointer to a device tree node containing a list
1423 * @list_name: property name that contains a list
1424 * @cells_name: property name that specifies phandles' arguments count
1425 * @index: index of a phandle to parse out
1426 * @out_args: optional pointer to output arguments structure (will be filled)
1428 * This function is useful to parse lists of phandles and their arguments.
1429 * Returns 0 on success and fills out_args, on error returns appropriate
1432 * Caller is responsible to call of_node_put() on the returned out_args->node
1438 * #list-cells = <2>;
1442 * #list-cells = <1>;
1446 * list = <&phandle1 1 2 &phandle2 3>;
1449 * To get a device_node of the `node2' node you may call this:
1450 * of_parse_phandle_with_args(node3, "list", "#list-cells", 1, &args);
1452 int of_parse_phandle_with_args(const struct device_node *np, const char *list_name,
1453 const char *cells_name, int index,
1454 struct of_phandle_args *out_args)
1458 return __of_parse_phandle_with_args(np, list_name, cells_name, 0,
1461 EXPORT_SYMBOL(of_parse_phandle_with_args);
1464 * of_parse_phandle_with_fixed_args() - Find a node pointed by phandle in a list
1465 * @np: pointer to a device tree node containing a list
1466 * @list_name: property name that contains a list
1467 * @cell_count: number of argument cells following the phandle
1468 * @index: index of a phandle to parse out
1469 * @out_args: optional pointer to output arguments structure (will be filled)
1471 * This function is useful to parse lists of phandles and their arguments.
1472 * Returns 0 on success and fills out_args, on error returns appropriate
1475 * Caller is responsible to call of_node_put() on the returned out_args->node
1487 * list = <&phandle1 0 2 &phandle2 2 3>;
1490 * To get a device_node of the `node2' node you may call this:
1491 * of_parse_phandle_with_fixed_args(node3, "list", 2, 1, &args);
1493 int of_parse_phandle_with_fixed_args(const struct device_node *np,
1494 const char *list_name, int cell_count,
1495 int index, struct of_phandle_args *out_args)
1499 return __of_parse_phandle_with_args(np, list_name, NULL, cell_count,
1502 EXPORT_SYMBOL(of_parse_phandle_with_fixed_args);
1505 * of_count_phandle_with_args() - Find the number of phandles references in a property
1506 * @np: pointer to a device tree node containing a list
1507 * @list_name: property name that contains a list
1508 * @cells_name: property name that specifies phandles' arguments count
1510 * Returns the number of phandle + argument tuples within a property. It
1511 * is a typical pattern to encode a list of phandle and variable
1512 * arguments into a single property. The number of arguments is encoded
1513 * by a property in the phandle-target node. For example, a gpios
1514 * property would contain a list of GPIO specifies consisting of a
1515 * phandle and 1 or more arguments. The number of arguments are
1516 * determined by the #gpio-cells property in the node pointed to by the
1519 int of_count_phandle_with_args(const struct device_node *np, const char *list_name,
1520 const char *cells_name)
1522 return __of_parse_phandle_with_args(np, list_name, cells_name, 0, -1,
1525 EXPORT_SYMBOL(of_count_phandle_with_args);
1527 #if defined(CONFIG_OF_DYNAMIC)
1528 static int of_property_notify(int action, struct device_node *np,
1529 struct property *prop)
1531 struct of_prop_reconfig pr;
1535 return of_reconfig_notify(action, &pr);
1538 static int of_property_notify(int action, struct device_node *np,
1539 struct property *prop)
1546 * of_add_property - Add a property to a node
1548 int of_add_property(struct device_node *np, struct property *prop)
1550 struct property **next;
1551 unsigned long flags;
1554 rc = of_property_notify(OF_RECONFIG_ADD_PROPERTY, np, prop);
1559 raw_spin_lock_irqsave(&devtree_lock, flags);
1560 next = &np->properties;
1562 if (strcmp(prop->name, (*next)->name) == 0) {
1563 /* duplicate ! don't insert it */
1564 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1567 next = &(*next)->next;
1570 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1572 #ifdef CONFIG_PROC_DEVICETREE
1573 /* try to add to proc as well if it was initialized */
1575 proc_device_tree_add_prop(np->pde, prop);
1576 #endif /* CONFIG_PROC_DEVICETREE */
1582 * of_remove_property - Remove a property from a node.
1584 * Note that we don't actually remove it, since we have given out
1585 * who-knows-how-many pointers to the data using get-property.
1586 * Instead we just move the property to the "dead properties"
1587 * list, so it won't be found any more.
1589 int of_remove_property(struct device_node *np, struct property *prop)
1591 struct property **next;
1592 unsigned long flags;
1596 rc = of_property_notify(OF_RECONFIG_REMOVE_PROPERTY, np, prop);
1600 raw_spin_lock_irqsave(&devtree_lock, flags);
1601 next = &np->properties;
1603 if (*next == prop) {
1604 /* found the node */
1606 prop->next = np->deadprops;
1607 np->deadprops = prop;
1611 next = &(*next)->next;
1613 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1618 #ifdef CONFIG_PROC_DEVICETREE
1619 /* try to remove the proc node as well */
1621 proc_device_tree_remove_prop(np->pde, prop);
1622 #endif /* CONFIG_PROC_DEVICETREE */
1628 * of_update_property - Update a property in a node, if the property does
1629 * not exist, add it.
1631 * Note that we don't actually remove it, since we have given out
1632 * who-knows-how-many pointers to the data using get-property.
1633 * Instead we just move the property to the "dead properties" list,
1634 * and add the new property to the property list
1636 int of_update_property(struct device_node *np, struct property *newprop)
1638 struct property **next, *oldprop;
1639 unsigned long flags;
1642 rc = of_property_notify(OF_RECONFIG_UPDATE_PROPERTY, np, newprop);
1649 oldprop = of_find_property(np, newprop->name, NULL);
1651 return of_add_property(np, newprop);
1653 raw_spin_lock_irqsave(&devtree_lock, flags);
1654 next = &np->properties;
1656 if (*next == oldprop) {
1657 /* found the node */
1658 newprop->next = oldprop->next;
1660 oldprop->next = np->deadprops;
1661 np->deadprops = oldprop;
1665 next = &(*next)->next;
1667 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1672 #ifdef CONFIG_PROC_DEVICETREE
1673 /* try to add to proc as well if it was initialized */
1675 proc_device_tree_update_prop(np->pde, newprop, oldprop);
1676 #endif /* CONFIG_PROC_DEVICETREE */
1681 #if defined(CONFIG_OF_DYNAMIC)
1683 * Support for dynamic device trees.
1685 * On some platforms, the device tree can be manipulated at runtime.
1686 * The routines in this section support adding, removing and changing
1687 * device tree nodes.
1690 static BLOCKING_NOTIFIER_HEAD(of_reconfig_chain);
1692 int of_reconfig_notifier_register(struct notifier_block *nb)
1694 return blocking_notifier_chain_register(&of_reconfig_chain, nb);
1696 EXPORT_SYMBOL_GPL(of_reconfig_notifier_register);
1698 int of_reconfig_notifier_unregister(struct notifier_block *nb)
1700 return blocking_notifier_chain_unregister(&of_reconfig_chain, nb);
1702 EXPORT_SYMBOL_GPL(of_reconfig_notifier_unregister);
1704 int of_reconfig_notify(unsigned long action, void *p)
1708 rc = blocking_notifier_call_chain(&of_reconfig_chain, action, p);
1709 return notifier_to_errno(rc);
1712 #ifdef CONFIG_PROC_DEVICETREE
1713 static void of_add_proc_dt_entry(struct device_node *dn)
1715 struct proc_dir_entry *ent;
1717 ent = proc_mkdir(strrchr(dn->full_name, '/') + 1, dn->parent->pde);
1719 proc_device_tree_add_node(dn, ent);
1722 static void of_add_proc_dt_entry(struct device_node *dn)
1729 * of_attach_node - Plug a device node into the tree and global list.
1731 int of_attach_node(struct device_node *np)
1733 unsigned long flags;
1736 rc = of_reconfig_notify(OF_RECONFIG_ATTACH_NODE, np);
1740 raw_spin_lock_irqsave(&devtree_lock, flags);
1741 np->sibling = np->parent->child;
1742 np->allnext = of_allnodes;
1743 np->parent->child = np;
1745 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1747 of_add_proc_dt_entry(np);
1751 #ifdef CONFIG_PROC_DEVICETREE
1752 static void of_remove_proc_dt_entry(struct device_node *dn)
1754 proc_remove(dn->pde);
1757 static void of_remove_proc_dt_entry(struct device_node *dn)
1764 * of_detach_node - "Unplug" a node from the device tree.
1766 * The caller must hold a reference to the node. The memory associated with
1767 * the node is not freed until its refcount goes to zero.
1769 int of_detach_node(struct device_node *np)
1771 struct device_node *parent;
1772 unsigned long flags;
1775 rc = of_reconfig_notify(OF_RECONFIG_DETACH_NODE, np);
1779 raw_spin_lock_irqsave(&devtree_lock, flags);
1781 if (of_node_check_flag(np, OF_DETACHED)) {
1782 /* someone already detached it */
1783 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1787 parent = np->parent;
1789 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1793 if (of_allnodes == np)
1794 of_allnodes = np->allnext;
1796 struct device_node *prev;
1797 for (prev = of_allnodes;
1798 prev->allnext != np;
1799 prev = prev->allnext)
1801 prev->allnext = np->allnext;
1804 if (parent->child == np)
1805 parent->child = np->sibling;
1807 struct device_node *prevsib;
1808 for (prevsib = np->parent->child;
1809 prevsib->sibling != np;
1810 prevsib = prevsib->sibling)
1812 prevsib->sibling = np->sibling;
1815 of_node_set_flag(np, OF_DETACHED);
1816 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1818 of_remove_proc_dt_entry(np);
1821 #endif /* defined(CONFIG_OF_DYNAMIC) */
1823 static void of_alias_add(struct alias_prop *ap, struct device_node *np,
1824 int id, const char *stem, int stem_len)
1828 strncpy(ap->stem, stem, stem_len);
1829 ap->stem[stem_len] = 0;
1830 list_add_tail(&ap->link, &aliases_lookup);
1831 pr_debug("adding DT alias:%s: stem=%s id=%i node=%s\n",
1832 ap->alias, ap->stem, ap->id, of_node_full_name(np));
1836 * of_alias_scan - Scan all properties of 'aliases' node
1838 * The function scans all the properties of 'aliases' node and populate
1839 * the the global lookup table with the properties. It returns the
1840 * number of alias_prop found, or error code in error case.
1842 * @dt_alloc: An allocator that provides a virtual address to memory
1843 * for the resulting tree
1845 void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align))
1847 struct property *pp;
1849 of_chosen = of_find_node_by_path("/chosen");
1850 if (of_chosen == NULL)
1851 of_chosen = of_find_node_by_path("/chosen@0");
1856 name = of_get_property(of_chosen, "linux,stdout-path", NULL);
1858 of_stdout = of_find_node_by_path(name);
1861 of_aliases = of_find_node_by_path("/aliases");
1865 for_each_property_of_node(of_aliases, pp) {
1866 const char *start = pp->name;
1867 const char *end = start + strlen(start);
1868 struct device_node *np;
1869 struct alias_prop *ap;
1872 /* Skip those we do not want to proceed */
1873 if (!strcmp(pp->name, "name") ||
1874 !strcmp(pp->name, "phandle") ||
1875 !strcmp(pp->name, "linux,phandle"))
1878 np = of_find_node_by_path(pp->value);
1882 /* walk the alias backwards to extract the id and work out
1883 * the 'stem' string */
1884 while (isdigit(*(end-1)) && end > start)
1888 if (kstrtoint(end, 10, &id) < 0)
1891 /* Allocate an alias_prop with enough space for the stem */
1892 ap = dt_alloc(sizeof(*ap) + len + 1, 4);
1895 memset(ap, 0, sizeof(*ap) + len + 1);
1897 of_alias_add(ap, np, id, start, len);
1902 * of_alias_get_id - Get alias id for the given device_node
1903 * @np: Pointer to the given device_node
1904 * @stem: Alias stem of the given device_node
1906 * The function travels the lookup table to get alias id for the given
1907 * device_node and alias stem. It returns the alias id if find it.
1909 int of_alias_get_id(struct device_node *np, const char *stem)
1911 struct alias_prop *app;
1914 mutex_lock(&of_aliases_mutex);
1915 list_for_each_entry(app, &aliases_lookup, link) {
1916 if (strcmp(app->stem, stem) != 0)
1919 if (np == app->np) {
1924 mutex_unlock(&of_aliases_mutex);
1928 EXPORT_SYMBOL_GPL(of_alias_get_id);
1930 const __be32 *of_prop_next_u32(struct property *prop, const __be32 *cur,
1933 const void *curv = cur;
1943 curv += sizeof(*cur);
1944 if (curv >= prop->value + prop->length)
1948 *pu = be32_to_cpup(curv);
1951 EXPORT_SYMBOL_GPL(of_prop_next_u32);
1953 const char *of_prop_next_string(struct property *prop, const char *cur)
1955 const void *curv = cur;
1963 curv += strlen(cur) + 1;
1964 if (curv >= prop->value + prop->length)
1969 EXPORT_SYMBOL_GPL(of_prop_next_string);
1972 * of_device_is_stdout_path - check if a device node matches the
1973 * linux,stdout-path property
1975 * Check if this device node matches the linux,stdout-path property
1976 * in the chosen node. return true if yes, false otherwise.
1978 int of_device_is_stdout_path(struct device_node *dn)
1983 return of_stdout == dn;
1985 EXPORT_SYMBOL_GPL(of_device_is_stdout_path);
1988 * of_find_next_cache_node - Find a node's subsidiary cache
1989 * @np: node of type "cpu" or "cache"
1991 * Returns a node pointer with refcount incremented, use
1992 * of_node_put() on it when done. Caller should hold a reference
1995 struct device_node *of_find_next_cache_node(const struct device_node *np)
1997 struct device_node *child;
1998 const phandle *handle;
2000 handle = of_get_property(np, "l2-cache", NULL);
2002 handle = of_get_property(np, "next-level-cache", NULL);
2005 return of_find_node_by_phandle(be32_to_cpup(handle));
2007 /* OF on pmac has nodes instead of properties named "l2-cache"
2008 * beneath CPU nodes.
2010 if (!strcmp(np->type, "cpu"))
2011 for_each_child_of_node(np, child)
2012 if (!strcmp(child->type, "cache"))