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/of_graph.h>
25 #include <linux/spinlock.h>
26 #include <linux/slab.h>
27 #include <linux/string.h>
28 #include <linux/proc_fs.h>
30 #include "of_private.h"
32 LIST_HEAD(aliases_lookup);
34 struct device_node *of_allnodes;
35 EXPORT_SYMBOL(of_allnodes);
36 struct device_node *of_chosen;
37 struct device_node *of_aliases;
38 static struct device_node *of_stdout;
40 static struct kset *of_kset;
43 * Used to protect the of_aliases; but also overloaded to hold off addition of
46 DEFINE_MUTEX(of_aliases_mutex);
48 /* use when traversing tree through the allnext, child, sibling,
49 * or parent members of struct device_node.
51 DEFINE_RAW_SPINLOCK(devtree_lock);
53 int of_n_addr_cells(struct device_node *np)
60 ip = of_get_property(np, "#address-cells", NULL);
62 return be32_to_cpup(ip);
64 /* No #address-cells property for the root node */
65 return OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
67 EXPORT_SYMBOL(of_n_addr_cells);
69 int of_n_size_cells(struct device_node *np)
76 ip = of_get_property(np, "#size-cells", NULL);
78 return be32_to_cpup(ip);
80 /* No #size-cells property for the root node */
81 return OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
83 EXPORT_SYMBOL(of_n_size_cells);
86 int __weak of_node_to_nid(struct device_node *np)
88 return numa_node_id();
92 #if defined(CONFIG_OF_DYNAMIC)
94 * of_node_get - Increment refcount of a node
95 * @node: Node to inc refcount, NULL is supported to
96 * simplify writing of callers
100 struct device_node *of_node_get(struct device_node *node)
103 kobject_get(&node->kobj);
106 EXPORT_SYMBOL(of_node_get);
108 static inline struct device_node *kobj_to_device_node(struct kobject *kobj)
110 return container_of(kobj, struct device_node, kobj);
114 * of_node_release - release a dynamically allocated node
115 * @kref: kref element of the node to be released
117 * In of_node_put() this function is passed to kref_put()
120 static void of_node_release(struct kobject *kobj)
122 struct device_node *node = kobj_to_device_node(kobj);
123 struct property *prop = node->properties;
125 /* We should never be releasing nodes that haven't been detached. */
126 if (!of_node_check_flag(node, OF_DETACHED)) {
127 pr_err("ERROR: Bad of_node_put() on %s\n", node->full_name);
132 if (!of_node_check_flag(node, OF_DYNAMIC))
136 struct property *next = prop->next;
143 prop = node->deadprops;
144 node->deadprops = NULL;
147 kfree(node->full_name);
153 * of_node_put - Decrement refcount of a node
154 * @node: Node to dec refcount, NULL is supported to
155 * simplify writing of callers
158 void of_node_put(struct device_node *node)
161 kobject_put(&node->kobj);
163 EXPORT_SYMBOL(of_node_put);
165 static void of_node_release(struct kobject *kobj)
167 /* Without CONFIG_OF_DYNAMIC, no nodes gets freed */
169 #endif /* CONFIG_OF_DYNAMIC */
171 struct kobj_type of_node_ktype = {
172 .release = of_node_release,
175 static ssize_t of_node_property_read(struct file *filp, struct kobject *kobj,
176 struct bin_attribute *bin_attr, char *buf,
177 loff_t offset, size_t count)
179 struct property *pp = container_of(bin_attr, struct property, attr);
180 return memory_read_from_buffer(buf, count, &offset, pp->value, pp->length);
183 static const char *safe_name(struct kobject *kobj, const char *orig_name)
185 const char *name = orig_name;
186 struct kernfs_node *kn;
189 /* don't be a hero. After 16 tries give up */
190 while (i < 16 && (kn = sysfs_get_dirent(kobj->sd, name))) {
192 if (name != orig_name)
194 name = kasprintf(GFP_KERNEL, "%s#%i", orig_name, ++i);
197 if (name != orig_name)
198 pr_warn("device-tree: Duplicate name in %s, renamed to \"%s\"\n",
199 kobject_name(kobj), name);
203 static int __of_add_property_sysfs(struct device_node *np, struct property *pp)
207 /* Important: Don't leak passwords */
208 bool secure = strncmp(pp->name, "security-", 9) == 0;
210 sysfs_bin_attr_init(&pp->attr);
211 pp->attr.attr.name = safe_name(&np->kobj, pp->name);
212 pp->attr.attr.mode = secure ? S_IRUSR : S_IRUGO;
213 pp->attr.size = secure ? 0 : pp->length;
214 pp->attr.read = of_node_property_read;
216 rc = sysfs_create_bin_file(&np->kobj, &pp->attr);
217 WARN(rc, "error adding attribute %s to node %s\n", pp->name, np->full_name);
221 static int __of_node_add(struct device_node *np)
227 np->kobj.kset = of_kset;
229 /* Nodes without parents are new top level trees */
230 rc = kobject_add(&np->kobj, NULL, safe_name(&of_kset->kobj, "base"));
232 name = safe_name(&np->parent->kobj, kbasename(np->full_name));
233 if (!name || !name[0])
236 rc = kobject_add(&np->kobj, &np->parent->kobj, "%s", name);
241 for_each_property_of_node(np, pp)
242 __of_add_property_sysfs(np, pp);
247 int of_node_add(struct device_node *np)
251 BUG_ON(!of_node_is_initialized(np));
254 * Grab the mutex here so that in a race condition between of_init() and
255 * of_node_add(), node addition will still be consistent.
257 mutex_lock(&of_aliases_mutex);
259 rc = __of_node_add(np);
261 /* This scenario may be perfectly valid, but report it anyway */
262 pr_info("of_node_add(%s) before of_init()\n", np->full_name);
263 mutex_unlock(&of_aliases_mutex);
267 #if defined(CONFIG_OF_DYNAMIC)
268 static void of_node_remove(struct device_node *np)
272 BUG_ON(!of_node_is_initialized(np));
274 /* only remove properties if on sysfs */
275 if (of_node_is_attached(np)) {
276 for_each_property_of_node(np, pp)
277 sysfs_remove_bin_file(&np->kobj, &pp->attr);
278 kobject_del(&np->kobj);
281 /* finally remove the kobj_init ref */
286 static int __init of_init(void)
288 struct device_node *np;
290 /* Create the kset, and register existing nodes */
291 mutex_lock(&of_aliases_mutex);
292 of_kset = kset_create_and_add("devicetree", NULL, firmware_kobj);
294 mutex_unlock(&of_aliases_mutex);
297 for_each_of_allnodes(np)
299 mutex_unlock(&of_aliases_mutex);
301 /* Symlink in /proc as required by userspace ABI */
303 proc_symlink("device-tree", NULL, "/sys/firmware/devicetree/base");
307 core_initcall(of_init);
309 static struct property *__of_find_property(const struct device_node *np,
310 const char *name, int *lenp)
317 for (pp = np->properties; pp; pp = pp->next) {
318 if (of_prop_cmp(pp->name, name) == 0) {
328 struct property *of_find_property(const struct device_node *np,
335 raw_spin_lock_irqsave(&devtree_lock, flags);
336 pp = __of_find_property(np, name, lenp);
337 raw_spin_unlock_irqrestore(&devtree_lock, flags);
341 EXPORT_SYMBOL(of_find_property);
344 * of_find_all_nodes - Get next node in global list
345 * @prev: Previous node or NULL to start iteration
346 * of_node_put() will be called on it
348 * Returns a node pointer with refcount incremented, use
349 * of_node_put() on it when done.
351 struct device_node *of_find_all_nodes(struct device_node *prev)
353 struct device_node *np;
356 raw_spin_lock_irqsave(&devtree_lock, flags);
357 np = prev ? prev->allnext : of_allnodes;
358 for (; np != NULL; np = np->allnext)
362 raw_spin_unlock_irqrestore(&devtree_lock, flags);
365 EXPORT_SYMBOL(of_find_all_nodes);
368 * Find a property with a given name for a given node
369 * and return the value.
371 static const void *__of_get_property(const struct device_node *np,
372 const char *name, int *lenp)
374 struct property *pp = __of_find_property(np, name, lenp);
376 return pp ? pp->value : NULL;
380 * Find a property with a given name for a given node
381 * and return the value.
383 const void *of_get_property(const struct device_node *np, const char *name,
386 struct property *pp = of_find_property(np, name, lenp);
388 return pp ? pp->value : NULL;
390 EXPORT_SYMBOL(of_get_property);
393 * arch_match_cpu_phys_id - Match the given logical CPU and physical id
395 * @cpu: logical cpu index of a core/thread
396 * @phys_id: physical identifier of a core/thread
398 * CPU logical to physical index mapping is architecture specific.
399 * However this __weak function provides a default match of physical
400 * id to logical cpu index. phys_id provided here is usually values read
401 * from the device tree which must match the hardware internal registers.
403 * Returns true if the physical identifier and the logical cpu index
404 * correspond to the same core/thread, false otherwise.
406 bool __weak arch_match_cpu_phys_id(int cpu, u64 phys_id)
408 return (u32)phys_id == cpu;
412 * Checks if the given "prop_name" property holds the physical id of the
413 * core/thread corresponding to the logical cpu 'cpu'. If 'thread' is not
414 * NULL, local thread number within the core is returned in it.
416 static bool __of_find_n_match_cpu_property(struct device_node *cpun,
417 const char *prop_name, int cpu, unsigned int *thread)
420 int ac, prop_len, tid;
423 ac = of_n_addr_cells(cpun);
424 cell = of_get_property(cpun, prop_name, &prop_len);
427 prop_len /= sizeof(*cell) * ac;
428 for (tid = 0; tid < prop_len; tid++) {
429 hwid = of_read_number(cell, ac);
430 if (arch_match_cpu_phys_id(cpu, hwid)) {
441 * arch_find_n_match_cpu_physical_id - See if the given device node is
442 * for the cpu corresponding to logical cpu 'cpu'. Return true if so,
443 * else false. If 'thread' is non-NULL, the local thread number within the
444 * core is returned in it.
446 bool __weak arch_find_n_match_cpu_physical_id(struct device_node *cpun,
447 int cpu, unsigned int *thread)
449 /* Check for non-standard "ibm,ppc-interrupt-server#s" property
450 * for thread ids on PowerPC. If it doesn't exist fallback to
451 * standard "reg" property.
453 if (IS_ENABLED(CONFIG_PPC) &&
454 __of_find_n_match_cpu_property(cpun,
455 "ibm,ppc-interrupt-server#s",
459 if (__of_find_n_match_cpu_property(cpun, "reg", cpu, thread))
466 * of_get_cpu_node - Get device node associated with the given logical CPU
468 * @cpu: CPU number(logical index) for which device node is required
469 * @thread: if not NULL, local thread number within the physical core is
472 * The main purpose of this function is to retrieve the device node for the
473 * given logical CPU index. It should be used to initialize the of_node in
474 * cpu device. Once of_node in cpu device is populated, all the further
475 * references can use that instead.
477 * CPU logical to physical index mapping is architecture specific and is built
478 * before booting secondary cores. This function uses arch_match_cpu_phys_id
479 * which can be overridden by architecture specific implementation.
481 * Returns a node pointer for the logical cpu if found, else NULL.
483 struct device_node *of_get_cpu_node(int cpu, unsigned int *thread)
485 struct device_node *cpun;
487 for_each_node_by_type(cpun, "cpu") {
488 if (arch_find_n_match_cpu_physical_id(cpun, cpu, thread))
493 EXPORT_SYMBOL(of_get_cpu_node);
496 * __of_device_is_compatible() - Check if the node matches given constraints
497 * @device: pointer to node
498 * @compat: required compatible string, NULL or "" for any match
499 * @type: required device_type value, NULL or "" for any match
500 * @name: required node name, NULL or "" for any match
502 * Checks if the given @compat, @type and @name strings match the
503 * properties of the given @device. A constraints can be skipped by
504 * passing NULL or an empty string as the constraint.
506 * Returns 0 for no match, and a positive integer on match. The return
507 * value is a relative score with larger values indicating better
508 * matches. The score is weighted for the most specific compatible value
509 * to get the highest score. Matching type is next, followed by matching
510 * name. Practically speaking, this results in the following priority
513 * 1. specific compatible && type && name
514 * 2. specific compatible && type
515 * 3. specific compatible && name
516 * 4. specific compatible
517 * 5. general compatible && type && name
518 * 6. general compatible && type
519 * 7. general compatible && name
520 * 8. general compatible
525 static int __of_device_is_compatible(const struct device_node *device,
526 const char *compat, const char *type, const char *name)
528 struct property *prop;
530 int index = 0, score = 0;
532 /* Compatible match has highest priority */
533 if (compat && compat[0]) {
534 prop = __of_find_property(device, "compatible", NULL);
535 for (cp = of_prop_next_string(prop, NULL); cp;
536 cp = of_prop_next_string(prop, cp), index++) {
537 if (of_compat_cmp(cp, compat, strlen(compat)) == 0) {
538 score = INT_MAX/2 - (index << 2);
546 /* Matching type is better than matching name */
547 if (type && type[0]) {
548 if (!device->type || of_node_cmp(type, device->type))
553 /* Matching name is a bit better than not */
554 if (name && name[0]) {
555 if (!device->name || of_node_cmp(name, device->name))
563 /** Checks if the given "compat" string matches one of the strings in
564 * the device's "compatible" property
566 int of_device_is_compatible(const struct device_node *device,
572 raw_spin_lock_irqsave(&devtree_lock, flags);
573 res = __of_device_is_compatible(device, compat, NULL, NULL);
574 raw_spin_unlock_irqrestore(&devtree_lock, flags);
577 EXPORT_SYMBOL(of_device_is_compatible);
580 * of_machine_is_compatible - Test root of device tree for a given compatible value
581 * @compat: compatible string to look for in root node's compatible property.
583 * Returns true if the root node has the given value in its
584 * compatible property.
586 int of_machine_is_compatible(const char *compat)
588 struct device_node *root;
591 root = of_find_node_by_path("/");
593 rc = of_device_is_compatible(root, compat);
598 EXPORT_SYMBOL(of_machine_is_compatible);
601 * __of_device_is_available - check if a device is available for use
603 * @device: Node to check for availability, with locks already held
605 * Returns 1 if the status property is absent or set to "okay" or "ok",
608 static int __of_device_is_available(const struct device_node *device)
616 status = __of_get_property(device, "status", &statlen);
621 if (!strcmp(status, "okay") || !strcmp(status, "ok"))
629 * of_device_is_available - check if a device is available for use
631 * @device: Node to check for availability
633 * Returns 1 if the status property is absent or set to "okay" or "ok",
636 int of_device_is_available(const struct device_node *device)
641 raw_spin_lock_irqsave(&devtree_lock, flags);
642 res = __of_device_is_available(device);
643 raw_spin_unlock_irqrestore(&devtree_lock, flags);
647 EXPORT_SYMBOL(of_device_is_available);
650 * of_get_parent - Get a node's parent if any
651 * @node: Node to get parent
653 * Returns a node pointer with refcount incremented, use
654 * of_node_put() on it when done.
656 struct device_node *of_get_parent(const struct device_node *node)
658 struct device_node *np;
664 raw_spin_lock_irqsave(&devtree_lock, flags);
665 np = of_node_get(node->parent);
666 raw_spin_unlock_irqrestore(&devtree_lock, flags);
669 EXPORT_SYMBOL(of_get_parent);
672 * of_get_next_parent - Iterate to a node's parent
673 * @node: Node to get parent of
675 * This is like of_get_parent() except that it drops the
676 * refcount on the passed node, making it suitable for iterating
677 * through a node's parents.
679 * Returns a node pointer with refcount incremented, use
680 * of_node_put() on it when done.
682 struct device_node *of_get_next_parent(struct device_node *node)
684 struct device_node *parent;
690 raw_spin_lock_irqsave(&devtree_lock, flags);
691 parent = of_node_get(node->parent);
693 raw_spin_unlock_irqrestore(&devtree_lock, flags);
696 EXPORT_SYMBOL(of_get_next_parent);
698 static struct device_node *__of_get_next_child(const struct device_node *node,
699 struct device_node *prev)
701 struct device_node *next;
706 next = prev ? prev->sibling : node->child;
707 for (; next; next = next->sibling)
708 if (of_node_get(next))
713 #define __for_each_child_of_node(parent, child) \
714 for (child = __of_get_next_child(parent, NULL); child != NULL; \
715 child = __of_get_next_child(parent, child))
718 * of_get_next_child - Iterate a node childs
720 * @prev: previous child of the parent node, or NULL to get first
722 * Returns a node pointer with refcount incremented, use
723 * of_node_put() on it when done.
725 struct device_node *of_get_next_child(const struct device_node *node,
726 struct device_node *prev)
728 struct device_node *next;
731 raw_spin_lock_irqsave(&devtree_lock, flags);
732 next = __of_get_next_child(node, prev);
733 raw_spin_unlock_irqrestore(&devtree_lock, flags);
736 EXPORT_SYMBOL(of_get_next_child);
739 * of_get_next_available_child - Find the next available child node
741 * @prev: previous child of the parent node, or NULL to get first
743 * This function is like of_get_next_child(), except that it
744 * automatically skips any disabled nodes (i.e. status = "disabled").
746 struct device_node *of_get_next_available_child(const struct device_node *node,
747 struct device_node *prev)
749 struct device_node *next;
755 raw_spin_lock_irqsave(&devtree_lock, flags);
756 next = prev ? prev->sibling : node->child;
757 for (; next; next = next->sibling) {
758 if (!__of_device_is_available(next))
760 if (of_node_get(next))
764 raw_spin_unlock_irqrestore(&devtree_lock, flags);
767 EXPORT_SYMBOL(of_get_next_available_child);
770 * of_get_child_by_name - Find the child node by name for a given parent
772 * @name: child name to look for.
774 * This function looks for child node for given matching name
776 * Returns a node pointer if found, with refcount incremented, use
777 * of_node_put() on it when done.
778 * Returns NULL if node is not found.
780 struct device_node *of_get_child_by_name(const struct device_node *node,
783 struct device_node *child;
785 for_each_child_of_node(node, child)
786 if (child->name && (of_node_cmp(child->name, name) == 0))
790 EXPORT_SYMBOL(of_get_child_by_name);
792 static struct device_node *__of_find_node_by_path(struct device_node *parent,
795 struct device_node *child;
796 int len = strchrnul(path, '/') - path;
801 __for_each_child_of_node(parent, child) {
802 const char *name = strrchr(child->full_name, '/');
803 if (WARN(!name, "malformed device_node %s\n", child->full_name))
806 if (strncmp(path, name, len) == 0 && (strlen(name) == len))
813 * of_find_node_by_path - Find a node matching a full OF path
814 * @path: Either the full path to match, or if the path does not
815 * start with '/', the name of a property of the /aliases
816 * node (an alias). In the case of an alias, the node
817 * matching the alias' value will be returned.
822 * foo/bar Valid alias + relative path
824 * Returns a node pointer with refcount incremented, use
825 * of_node_put() on it when done.
827 struct device_node *of_find_node_by_path(const char *path)
829 struct device_node *np = NULL;
833 if (strcmp(path, "/") == 0)
834 return of_node_get(of_allnodes);
836 /* The path could begin with an alias */
838 char *p = strchrnul(path, '/');
841 /* of_aliases must not be NULL */
845 for_each_property_of_node(of_aliases, pp) {
846 if (strlen(pp->name) == len && !strncmp(pp->name, path, len)) {
847 np = of_find_node_by_path(pp->value);
856 /* Step down the tree matching path components */
857 raw_spin_lock_irqsave(&devtree_lock, flags);
859 np = of_node_get(of_allnodes);
860 while (np && *path == '/') {
861 path++; /* Increment past '/' delimiter */
862 np = __of_find_node_by_path(np, path);
863 path = strchrnul(path, '/');
865 raw_spin_unlock_irqrestore(&devtree_lock, flags);
868 EXPORT_SYMBOL(of_find_node_by_path);
871 * of_find_node_by_name - Find a node by its "name" property
872 * @from: The node to start searching from or NULL, the node
873 * you pass will not be searched, only the next one
874 * will; typically, you pass what the previous call
875 * returned. of_node_put() will be called on it
876 * @name: The name string to match against
878 * Returns a node pointer with refcount incremented, use
879 * of_node_put() on it when done.
881 struct device_node *of_find_node_by_name(struct device_node *from,
884 struct device_node *np;
887 raw_spin_lock_irqsave(&devtree_lock, flags);
888 np = from ? from->allnext : of_allnodes;
889 for (; np; np = np->allnext)
890 if (np->name && (of_node_cmp(np->name, name) == 0)
894 raw_spin_unlock_irqrestore(&devtree_lock, flags);
897 EXPORT_SYMBOL(of_find_node_by_name);
900 * of_find_node_by_type - Find a node by its "device_type" property
901 * @from: The node to start searching from, or NULL to start searching
902 * the entire device tree. The node you pass will not be
903 * searched, only the next one will; typically, you pass
904 * what the previous call returned. of_node_put() will be
905 * called on from for you.
906 * @type: The type string to match against
908 * Returns a node pointer with refcount incremented, use
909 * of_node_put() on it when done.
911 struct device_node *of_find_node_by_type(struct device_node *from,
914 struct device_node *np;
917 raw_spin_lock_irqsave(&devtree_lock, flags);
918 np = from ? from->allnext : of_allnodes;
919 for (; np; np = np->allnext)
920 if (np->type && (of_node_cmp(np->type, type) == 0)
924 raw_spin_unlock_irqrestore(&devtree_lock, flags);
927 EXPORT_SYMBOL(of_find_node_by_type);
930 * of_find_compatible_node - Find a node based on type and one of the
931 * tokens in its "compatible" property
932 * @from: The node to start searching from or NULL, the node
933 * you pass will not be searched, only the next one
934 * will; typically, you pass what the previous call
935 * returned. of_node_put() will be called on it
936 * @type: The type string to match "device_type" or NULL to ignore
937 * @compatible: The string to match to one of the tokens in the device
940 * Returns a node pointer with refcount incremented, use
941 * of_node_put() on it when done.
943 struct device_node *of_find_compatible_node(struct device_node *from,
944 const char *type, const char *compatible)
946 struct device_node *np;
949 raw_spin_lock_irqsave(&devtree_lock, flags);
950 np = from ? from->allnext : of_allnodes;
951 for (; np; np = np->allnext) {
952 if (__of_device_is_compatible(np, compatible, type, NULL) &&
957 raw_spin_unlock_irqrestore(&devtree_lock, flags);
960 EXPORT_SYMBOL(of_find_compatible_node);
963 * of_find_node_with_property - Find a node which has a property with
965 * @from: The node to start searching from or NULL, the node
966 * you pass will not be searched, only the next one
967 * will; typically, you pass what the previous call
968 * returned. of_node_put() will be called on it
969 * @prop_name: The name of the property to look for.
971 * Returns a node pointer with refcount incremented, use
972 * of_node_put() on it when done.
974 struct device_node *of_find_node_with_property(struct device_node *from,
975 const char *prop_name)
977 struct device_node *np;
981 raw_spin_lock_irqsave(&devtree_lock, flags);
982 np = from ? from->allnext : of_allnodes;
983 for (; np; np = np->allnext) {
984 for (pp = np->properties; pp; pp = pp->next) {
985 if (of_prop_cmp(pp->name, prop_name) == 0) {
993 raw_spin_unlock_irqrestore(&devtree_lock, flags);
996 EXPORT_SYMBOL(of_find_node_with_property);
999 const struct of_device_id *__of_match_node(const struct of_device_id *matches,
1000 const struct device_node *node)
1002 const struct of_device_id *best_match = NULL;
1003 int score, best_score = 0;
1008 for (; matches->name[0] || matches->type[0] || matches->compatible[0]; matches++) {
1009 score = __of_device_is_compatible(node, matches->compatible,
1010 matches->type, matches->name);
1011 if (score > best_score) {
1012 best_match = matches;
1021 * of_match_node - Tell if an device_node has a matching of_match structure
1022 * @matches: array of of device match structures to search in
1023 * @node: the of device structure to match against
1025 * Low level utility function used by device matching.
1027 const struct of_device_id *of_match_node(const struct of_device_id *matches,
1028 const struct device_node *node)
1030 const struct of_device_id *match;
1031 unsigned long flags;
1033 raw_spin_lock_irqsave(&devtree_lock, flags);
1034 match = __of_match_node(matches, node);
1035 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1038 EXPORT_SYMBOL(of_match_node);
1041 * of_find_matching_node_and_match - Find a node based on an of_device_id
1043 * @from: The node to start searching from or NULL, the node
1044 * you pass will not be searched, only the next one
1045 * will; typically, you pass what the previous call
1046 * returned. of_node_put() will be called on it
1047 * @matches: array of of device match structures to search in
1048 * @match Updated to point at the matches entry which matched
1050 * Returns a node pointer with refcount incremented, use
1051 * of_node_put() on it when done.
1053 struct device_node *of_find_matching_node_and_match(struct device_node *from,
1054 const struct of_device_id *matches,
1055 const struct of_device_id **match)
1057 struct device_node *np;
1058 const struct of_device_id *m;
1059 unsigned long flags;
1064 raw_spin_lock_irqsave(&devtree_lock, flags);
1065 np = from ? from->allnext : of_allnodes;
1066 for (; np; np = np->allnext) {
1067 m = __of_match_node(matches, np);
1068 if (m && of_node_get(np)) {
1075 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1078 EXPORT_SYMBOL(of_find_matching_node_and_match);
1081 * of_modalias_node - Lookup appropriate modalias for a device node
1082 * @node: pointer to a device tree node
1083 * @modalias: Pointer to buffer that modalias value will be copied into
1084 * @len: Length of modalias value
1086 * Based on the value of the compatible property, this routine will attempt
1087 * to choose an appropriate modalias value for a particular device tree node.
1088 * It does this by stripping the manufacturer prefix (as delimited by a ',')
1089 * from the first entry in the compatible list property.
1091 * This routine returns 0 on success, <0 on failure.
1093 int of_modalias_node(struct device_node *node, char *modalias, int len)
1095 const char *compatible, *p;
1098 compatible = of_get_property(node, "compatible", &cplen);
1099 if (!compatible || strlen(compatible) > cplen)
1101 p = strchr(compatible, ',');
1102 strlcpy(modalias, p ? p + 1 : compatible, len);
1105 EXPORT_SYMBOL_GPL(of_modalias_node);
1108 * of_find_node_by_phandle - Find a node given a phandle
1109 * @handle: phandle of the node to find
1111 * Returns a node pointer with refcount incremented, use
1112 * of_node_put() on it when done.
1114 struct device_node *of_find_node_by_phandle(phandle handle)
1116 struct device_node *np;
1117 unsigned long flags;
1119 raw_spin_lock_irqsave(&devtree_lock, flags);
1120 for (np = of_allnodes; np; np = np->allnext)
1121 if (np->phandle == handle)
1124 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1127 EXPORT_SYMBOL(of_find_node_by_phandle);
1130 * of_property_count_elems_of_size - Count the number of elements in a property
1132 * @np: device node from which the property value is to be read.
1133 * @propname: name of the property to be searched.
1134 * @elem_size: size of the individual element
1136 * Search for a property in a device node and count the number of elements of
1137 * size elem_size in it. Returns number of elements on sucess, -EINVAL if the
1138 * property does not exist or its length does not match a multiple of elem_size
1139 * and -ENODATA if the property does not have a value.
1141 int of_property_count_elems_of_size(const struct device_node *np,
1142 const char *propname, int elem_size)
1144 struct property *prop = of_find_property(np, propname, NULL);
1151 if (prop->length % elem_size != 0) {
1152 pr_err("size of %s in node %s is not a multiple of %d\n",
1153 propname, np->full_name, elem_size);
1157 return prop->length / elem_size;
1159 EXPORT_SYMBOL_GPL(of_property_count_elems_of_size);
1162 * of_find_property_value_of_size
1164 * @np: device node from which the property value is to be read.
1165 * @propname: name of the property to be searched.
1166 * @len: requested length of property value
1168 * Search for a property in a device node and valid the requested size.
1169 * Returns the property value on success, -EINVAL if the property does not
1170 * exist, -ENODATA if property does not have a value, and -EOVERFLOW if the
1171 * property data isn't large enough.
1174 static void *of_find_property_value_of_size(const struct device_node *np,
1175 const char *propname, u32 len)
1177 struct property *prop = of_find_property(np, propname, NULL);
1180 return ERR_PTR(-EINVAL);
1182 return ERR_PTR(-ENODATA);
1183 if (len > prop->length)
1184 return ERR_PTR(-EOVERFLOW);
1190 * of_property_read_u32_index - Find and read a u32 from a multi-value property.
1192 * @np: device node from which the property value is to be read.
1193 * @propname: name of the property to be searched.
1194 * @index: index of the u32 in the list of values
1195 * @out_value: pointer to return value, modified only if no error.
1197 * Search for a property in a device node and read nth 32-bit value from
1198 * it. Returns 0 on success, -EINVAL if the property does not exist,
1199 * -ENODATA if property does not have a value, and -EOVERFLOW if the
1200 * property data isn't large enough.
1202 * The out_value is modified only if a valid u32 value can be decoded.
1204 int of_property_read_u32_index(const struct device_node *np,
1205 const char *propname,
1206 u32 index, u32 *out_value)
1208 const u32 *val = of_find_property_value_of_size(np, propname,
1209 ((index + 1) * sizeof(*out_value)));
1212 return PTR_ERR(val);
1214 *out_value = be32_to_cpup(((__be32 *)val) + index);
1217 EXPORT_SYMBOL_GPL(of_property_read_u32_index);
1220 * of_property_read_u8_array - Find and read an array of u8 from a property.
1222 * @np: device node from which the property value is to be read.
1223 * @propname: name of the property to be searched.
1224 * @out_values: pointer to return value, modified only if return value is 0.
1225 * @sz: number of array elements to read
1227 * Search for a property in a device node and read 8-bit value(s) from
1228 * it. Returns 0 on success, -EINVAL if the property does not exist,
1229 * -ENODATA if property does not have a value, and -EOVERFLOW if the
1230 * property data isn't large enough.
1232 * dts entry of array should be like:
1233 * property = /bits/ 8 <0x50 0x60 0x70>;
1235 * The out_values is modified only if a valid u8 value can be decoded.
1237 int of_property_read_u8_array(const struct device_node *np,
1238 const char *propname, u8 *out_values, size_t sz)
1240 const u8 *val = of_find_property_value_of_size(np, propname,
1241 (sz * sizeof(*out_values)));
1244 return PTR_ERR(val);
1247 *out_values++ = *val++;
1250 EXPORT_SYMBOL_GPL(of_property_read_u8_array);
1253 * of_property_read_u16_array - Find and read an array of u16 from a property.
1255 * @np: device node from which the property value is to be read.
1256 * @propname: name of the property to be searched.
1257 * @out_values: pointer to return value, modified only if return value is 0.
1258 * @sz: number of array elements to read
1260 * Search for a property in a device node and read 16-bit value(s) from
1261 * it. Returns 0 on success, -EINVAL if the property does not exist,
1262 * -ENODATA if property does not have a value, and -EOVERFLOW if the
1263 * property data isn't large enough.
1265 * dts entry of array should be like:
1266 * property = /bits/ 16 <0x5000 0x6000 0x7000>;
1268 * The out_values is modified only if a valid u16 value can be decoded.
1270 int of_property_read_u16_array(const struct device_node *np,
1271 const char *propname, u16 *out_values, size_t sz)
1273 const __be16 *val = of_find_property_value_of_size(np, propname,
1274 (sz * sizeof(*out_values)));
1277 return PTR_ERR(val);
1280 *out_values++ = be16_to_cpup(val++);
1283 EXPORT_SYMBOL_GPL(of_property_read_u16_array);
1286 * of_property_read_u32_array - Find and read an array of 32 bit integers
1289 * @np: device node from which the property value is to be read.
1290 * @propname: name of the property to be searched.
1291 * @out_values: pointer to return value, modified only if return value is 0.
1292 * @sz: number of array elements to read
1294 * Search for a property in a device node and read 32-bit value(s) from
1295 * it. Returns 0 on success, -EINVAL if the property does not exist,
1296 * -ENODATA if property does not have a value, and -EOVERFLOW if the
1297 * property data isn't large enough.
1299 * The out_values is modified only if a valid u32 value can be decoded.
1301 int of_property_read_u32_array(const struct device_node *np,
1302 const char *propname, u32 *out_values,
1305 const __be32 *val = of_find_property_value_of_size(np, propname,
1306 (sz * sizeof(*out_values)));
1309 return PTR_ERR(val);
1312 *out_values++ = be32_to_cpup(val++);
1315 EXPORT_SYMBOL_GPL(of_property_read_u32_array);
1318 * of_property_read_u64 - Find and read a 64 bit integer from a property
1319 * @np: device node from which the property value is to be read.
1320 * @propname: name of the property to be searched.
1321 * @out_value: pointer to return value, modified only if return value is 0.
1323 * Search for a property in a device node and read a 64-bit value from
1324 * it. Returns 0 on success, -EINVAL if the property does not exist,
1325 * -ENODATA if property does not have a value, and -EOVERFLOW if the
1326 * property data isn't large enough.
1328 * The out_value is modified only if a valid u64 value can be decoded.
1330 int of_property_read_u64(const struct device_node *np, const char *propname,
1333 const __be32 *val = of_find_property_value_of_size(np, propname,
1334 sizeof(*out_value));
1337 return PTR_ERR(val);
1339 *out_value = of_read_number(val, 2);
1342 EXPORT_SYMBOL_GPL(of_property_read_u64);
1345 * of_property_read_string - Find and read a string from a property
1346 * @np: device node from which the property value is to be read.
1347 * @propname: name of the property to be searched.
1348 * @out_string: pointer to null terminated return string, modified only if
1349 * return value is 0.
1351 * Search for a property in a device tree node and retrieve a null
1352 * terminated string value (pointer to data, not a copy). Returns 0 on
1353 * success, -EINVAL if the property does not exist, -ENODATA if property
1354 * does not have a value, and -EILSEQ if the string is not null-terminated
1355 * within the length of the property data.
1357 * The out_string pointer is modified only if a valid string can be decoded.
1359 int of_property_read_string(struct device_node *np, const char *propname,
1360 const char **out_string)
1362 struct property *prop = of_find_property(np, propname, NULL);
1367 if (strnlen(prop->value, prop->length) >= prop->length)
1369 *out_string = prop->value;
1372 EXPORT_SYMBOL_GPL(of_property_read_string);
1375 * of_property_read_string_index - Find and read a string from a multiple
1377 * @np: device node from which the property value is to be read.
1378 * @propname: name of the property to be searched.
1379 * @index: index of the string in the list of strings
1380 * @out_string: pointer to null terminated return string, modified only if
1381 * return value is 0.
1383 * Search for a property in a device tree node and retrieve a null
1384 * terminated string value (pointer to data, not a copy) in the list of strings
1385 * contained in that property.
1386 * Returns 0 on success, -EINVAL if the property does not exist, -ENODATA if
1387 * property does not have a value, and -EILSEQ if the string is not
1388 * null-terminated within the length of the property data.
1390 * The out_string pointer is modified only if a valid string can be decoded.
1392 int of_property_read_string_index(struct device_node *np, const char *propname,
1393 int index, const char **output)
1395 struct property *prop = of_find_property(np, propname, NULL);
1397 size_t l = 0, total = 0;
1404 if (strnlen(prop->value, prop->length) >= prop->length)
1409 for (i = 0; total < prop->length; total += l, p += l) {
1418 EXPORT_SYMBOL_GPL(of_property_read_string_index);
1421 * of_property_match_string() - Find string in a list and return index
1422 * @np: pointer to node containing string list property
1423 * @propname: string list property name
1424 * @string: pointer to string to search for in string list
1426 * This function searches a string list property and returns the index
1427 * of a specific string value.
1429 int of_property_match_string(struct device_node *np, const char *propname,
1432 struct property *prop = of_find_property(np, propname, NULL);
1435 const char *p, *end;
1443 end = p + prop->length;
1445 for (i = 0; p < end; i++, p += l) {
1449 pr_debug("comparing %s with %s\n", string, p);
1450 if (strcmp(string, p) == 0)
1451 return i; /* Found it; return index */
1455 EXPORT_SYMBOL_GPL(of_property_match_string);
1458 * of_property_count_strings - Find and return the number of strings from a
1459 * multiple strings property.
1460 * @np: device node from which the property value is to be read.
1461 * @propname: name of the property to be searched.
1463 * Search for a property in a device tree node and retrieve the number of null
1464 * terminated string contain in it. Returns the number of strings on
1465 * success, -EINVAL if the property does not exist, -ENODATA if property
1466 * does not have a value, and -EILSEQ if the string is not null-terminated
1467 * within the length of the property data.
1469 int of_property_count_strings(struct device_node *np, const char *propname)
1471 struct property *prop = of_find_property(np, propname, NULL);
1473 size_t l = 0, total = 0;
1480 if (strnlen(prop->value, prop->length) >= prop->length)
1485 for (i = 0; total < prop->length; total += l, p += l, i++)
1490 EXPORT_SYMBOL_GPL(of_property_count_strings);
1492 void of_print_phandle_args(const char *msg, const struct of_phandle_args *args)
1495 printk("%s %s", msg, of_node_full_name(args->np));
1496 for (i = 0; i < args->args_count; i++)
1497 printk(i ? ",%08x" : ":%08x", args->args[i]);
1501 static int __of_parse_phandle_with_args(const struct device_node *np,
1502 const char *list_name,
1503 const char *cells_name,
1504 int cell_count, int index,
1505 struct of_phandle_args *out_args)
1507 const __be32 *list, *list_end;
1508 int rc = 0, size, cur_index = 0;
1510 struct device_node *node = NULL;
1513 /* Retrieve the phandle list property */
1514 list = of_get_property(np, list_name, &size);
1517 list_end = list + size / sizeof(*list);
1519 /* Loop over the phandles until all the requested entry is found */
1520 while (list < list_end) {
1525 * If phandle is 0, then it is an empty entry with no
1526 * arguments. Skip forward to the next entry.
1528 phandle = be32_to_cpup(list++);
1531 * Find the provider node and parse the #*-cells
1532 * property to determine the argument length.
1534 * This is not needed if the cell count is hard-coded
1535 * (i.e. cells_name not set, but cell_count is set),
1536 * except when we're going to return the found node
1539 if (cells_name || cur_index == index) {
1540 node = of_find_node_by_phandle(phandle);
1542 pr_err("%s: could not find phandle\n",
1549 if (of_property_read_u32(node, cells_name,
1551 pr_err("%s: could not get %s for %s\n",
1552 np->full_name, cells_name,
1561 * Make sure that the arguments actually fit in the
1562 * remaining property data length
1564 if (list + count > list_end) {
1565 pr_err("%s: arguments longer than property\n",
1572 * All of the error cases above bail out of the loop, so at
1573 * this point, the parsing is successful. If the requested
1574 * index matches, then fill the out_args structure and return,
1575 * or return -ENOENT for an empty entry.
1578 if (cur_index == index) {
1584 if (WARN_ON(count > MAX_PHANDLE_ARGS))
1585 count = MAX_PHANDLE_ARGS;
1586 out_args->np = node;
1587 out_args->args_count = count;
1588 for (i = 0; i < count; i++)
1589 out_args->args[i] = be32_to_cpup(list++);
1594 /* Found it! return success */
1605 * Unlock node before returning result; will be one of:
1606 * -ENOENT : index is for empty phandle
1607 * -EINVAL : parsing error on data
1608 * [1..n] : Number of phandle (count mode; when index = -1)
1610 rc = index < 0 ? cur_index : -ENOENT;
1618 * of_parse_phandle - Resolve a phandle property to a device_node pointer
1619 * @np: Pointer to device node holding phandle property
1620 * @phandle_name: Name of property holding a phandle value
1621 * @index: For properties holding a table of phandles, this is the index into
1624 * Returns the device_node pointer with refcount incremented. Use
1625 * of_node_put() on it when done.
1627 struct device_node *of_parse_phandle(const struct device_node *np,
1628 const char *phandle_name, int index)
1630 struct of_phandle_args args;
1635 if (__of_parse_phandle_with_args(np, phandle_name, NULL, 0,
1641 EXPORT_SYMBOL(of_parse_phandle);
1644 * of_parse_phandle_with_args() - Find a node pointed by phandle in a list
1645 * @np: pointer to a device tree node containing a list
1646 * @list_name: property name that contains a list
1647 * @cells_name: property name that specifies phandles' arguments count
1648 * @index: index of a phandle to parse out
1649 * @out_args: optional pointer to output arguments structure (will be filled)
1651 * This function is useful to parse lists of phandles and their arguments.
1652 * Returns 0 on success and fills out_args, on error returns appropriate
1655 * Caller is responsible to call of_node_put() on the returned out_args->node
1661 * #list-cells = <2>;
1665 * #list-cells = <1>;
1669 * list = <&phandle1 1 2 &phandle2 3>;
1672 * To get a device_node of the `node2' node you may call this:
1673 * of_parse_phandle_with_args(node3, "list", "#list-cells", 1, &args);
1675 int of_parse_phandle_with_args(const struct device_node *np, const char *list_name,
1676 const char *cells_name, int index,
1677 struct of_phandle_args *out_args)
1681 return __of_parse_phandle_with_args(np, list_name, cells_name, 0,
1684 EXPORT_SYMBOL(of_parse_phandle_with_args);
1687 * of_parse_phandle_with_fixed_args() - Find a node pointed by phandle in a list
1688 * @np: pointer to a device tree node containing a list
1689 * @list_name: property name that contains a list
1690 * @cell_count: number of argument cells following the phandle
1691 * @index: index of a phandle to parse out
1692 * @out_args: optional pointer to output arguments structure (will be filled)
1694 * This function is useful to parse lists of phandles and their arguments.
1695 * Returns 0 on success and fills out_args, on error returns appropriate
1698 * Caller is responsible to call of_node_put() on the returned out_args->node
1710 * list = <&phandle1 0 2 &phandle2 2 3>;
1713 * To get a device_node of the `node2' node you may call this:
1714 * of_parse_phandle_with_fixed_args(node3, "list", 2, 1, &args);
1716 int of_parse_phandle_with_fixed_args(const struct device_node *np,
1717 const char *list_name, int cell_count,
1718 int index, struct of_phandle_args *out_args)
1722 return __of_parse_phandle_with_args(np, list_name, NULL, cell_count,
1725 EXPORT_SYMBOL(of_parse_phandle_with_fixed_args);
1728 * of_count_phandle_with_args() - Find the number of phandles references in a property
1729 * @np: pointer to a device tree node containing a list
1730 * @list_name: property name that contains a list
1731 * @cells_name: property name that specifies phandles' arguments count
1733 * Returns the number of phandle + argument tuples within a property. It
1734 * is a typical pattern to encode a list of phandle and variable
1735 * arguments into a single property. The number of arguments is encoded
1736 * by a property in the phandle-target node. For example, a gpios
1737 * property would contain a list of GPIO specifies consisting of a
1738 * phandle and 1 or more arguments. The number of arguments are
1739 * determined by the #gpio-cells property in the node pointed to by the
1742 int of_count_phandle_with_args(const struct device_node *np, const char *list_name,
1743 const char *cells_name)
1745 return __of_parse_phandle_with_args(np, list_name, cells_name, 0, -1,
1748 EXPORT_SYMBOL(of_count_phandle_with_args);
1750 #if defined(CONFIG_OF_DYNAMIC)
1751 static int of_property_notify(int action, struct device_node *np,
1752 struct property *prop)
1754 struct of_prop_reconfig pr;
1756 /* only call notifiers if the node is attached */
1757 if (!of_node_is_attached(np))
1762 return of_reconfig_notify(action, &pr);
1765 static int of_property_notify(int action, struct device_node *np,
1766 struct property *prop)
1773 * __of_add_property - Add a property to a node without lock operations
1775 static int __of_add_property(struct device_node *np, struct property *prop)
1777 struct property **next;
1780 next = &np->properties;
1782 if (strcmp(prop->name, (*next)->name) == 0)
1783 /* duplicate ! don't insert it */
1786 next = &(*next)->next;
1794 * of_add_property - Add a property to a node
1796 int of_add_property(struct device_node *np, struct property *prop)
1798 unsigned long flags;
1801 rc = of_property_notify(OF_RECONFIG_ADD_PROPERTY, np, prop);
1805 raw_spin_lock_irqsave(&devtree_lock, flags);
1806 rc = __of_add_property(np, prop);
1807 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1811 if (of_node_is_attached(np))
1812 __of_add_property_sysfs(np, prop);
1818 * of_remove_property - Remove a property from a node.
1820 * Note that we don't actually remove it, since we have given out
1821 * who-knows-how-many pointers to the data using get-property.
1822 * Instead we just move the property to the "dead properties"
1823 * list, so it won't be found any more.
1825 int of_remove_property(struct device_node *np, struct property *prop)
1827 struct property **next;
1828 unsigned long flags;
1832 rc = of_property_notify(OF_RECONFIG_REMOVE_PROPERTY, np, prop);
1836 raw_spin_lock_irqsave(&devtree_lock, flags);
1837 next = &np->properties;
1839 if (*next == prop) {
1840 /* found the node */
1842 prop->next = np->deadprops;
1843 np->deadprops = prop;
1847 next = &(*next)->next;
1849 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1854 /* at early boot, bail hear and defer setup to of_init() */
1858 sysfs_remove_bin_file(&np->kobj, &prop->attr);
1864 * of_update_property - Update a property in a node, if the property does
1865 * not exist, add it.
1867 * Note that we don't actually remove it, since we have given out
1868 * who-knows-how-many pointers to the data using get-property.
1869 * Instead we just move the property to the "dead properties" list,
1870 * and add the new property to the property list
1872 int of_update_property(struct device_node *np, struct property *newprop)
1874 struct property **next, *oldprop;
1875 unsigned long flags;
1878 rc = of_property_notify(OF_RECONFIG_UPDATE_PROPERTY, np, newprop);
1885 raw_spin_lock_irqsave(&devtree_lock, flags);
1886 next = &np->properties;
1887 oldprop = __of_find_property(np, newprop->name, NULL);
1889 /* add the new node */
1890 rc = __of_add_property(np, newprop);
1891 } else while (*next) {
1892 /* replace the node */
1893 if (*next == oldprop) {
1894 newprop->next = oldprop->next;
1896 oldprop->next = np->deadprops;
1897 np->deadprops = oldprop;
1900 next = &(*next)->next;
1902 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1906 /* At early boot, bail out and defer setup to of_init() */
1910 /* Update the sysfs attribute */
1912 sysfs_remove_bin_file(&np->kobj, &oldprop->attr);
1913 __of_add_property_sysfs(np, newprop);
1918 #if defined(CONFIG_OF_DYNAMIC)
1920 * Support for dynamic device trees.
1922 * On some platforms, the device tree can be manipulated at runtime.
1923 * The routines in this section support adding, removing and changing
1924 * device tree nodes.
1927 static BLOCKING_NOTIFIER_HEAD(of_reconfig_chain);
1929 int of_reconfig_notifier_register(struct notifier_block *nb)
1931 return blocking_notifier_chain_register(&of_reconfig_chain, nb);
1933 EXPORT_SYMBOL_GPL(of_reconfig_notifier_register);
1935 int of_reconfig_notifier_unregister(struct notifier_block *nb)
1937 return blocking_notifier_chain_unregister(&of_reconfig_chain, nb);
1939 EXPORT_SYMBOL_GPL(of_reconfig_notifier_unregister);
1941 int of_reconfig_notify(unsigned long action, void *p)
1945 rc = blocking_notifier_call_chain(&of_reconfig_chain, action, p);
1946 return notifier_to_errno(rc);
1950 * of_attach_node - Plug a device node into the tree and global list.
1952 int of_attach_node(struct device_node *np)
1954 unsigned long flags;
1957 rc = of_reconfig_notify(OF_RECONFIG_ATTACH_NODE, np);
1961 raw_spin_lock_irqsave(&devtree_lock, flags);
1962 np->sibling = np->parent->child;
1963 np->allnext = of_allnodes;
1964 np->parent->child = np;
1966 of_node_clear_flag(np, OF_DETACHED);
1967 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1974 * of_detach_node - "Unplug" a node from the device tree.
1976 * The caller must hold a reference to the node. The memory associated with
1977 * the node is not freed until its refcount goes to zero.
1979 int of_detach_node(struct device_node *np)
1981 struct device_node *parent;
1982 unsigned long flags;
1985 rc = of_reconfig_notify(OF_RECONFIG_DETACH_NODE, np);
1989 raw_spin_lock_irqsave(&devtree_lock, flags);
1991 if (of_node_check_flag(np, OF_DETACHED)) {
1992 /* someone already detached it */
1993 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1997 parent = np->parent;
1999 raw_spin_unlock_irqrestore(&devtree_lock, flags);
2003 if (of_allnodes == np)
2004 of_allnodes = np->allnext;
2006 struct device_node *prev;
2007 for (prev = of_allnodes;
2008 prev->allnext != np;
2009 prev = prev->allnext)
2011 prev->allnext = np->allnext;
2014 if (parent->child == np)
2015 parent->child = np->sibling;
2017 struct device_node *prevsib;
2018 for (prevsib = np->parent->child;
2019 prevsib->sibling != np;
2020 prevsib = prevsib->sibling)
2022 prevsib->sibling = np->sibling;
2025 of_node_set_flag(np, OF_DETACHED);
2026 raw_spin_unlock_irqrestore(&devtree_lock, flags);
2031 #endif /* defined(CONFIG_OF_DYNAMIC) */
2033 static void of_alias_add(struct alias_prop *ap, struct device_node *np,
2034 int id, const char *stem, int stem_len)
2038 strncpy(ap->stem, stem, stem_len);
2039 ap->stem[stem_len] = 0;
2040 list_add_tail(&ap->link, &aliases_lookup);
2041 pr_debug("adding DT alias:%s: stem=%s id=%i node=%s\n",
2042 ap->alias, ap->stem, ap->id, of_node_full_name(np));
2046 * of_alias_scan - Scan all properties of 'aliases' node
2048 * The function scans all the properties of 'aliases' node and populate
2049 * the the global lookup table with the properties. It returns the
2050 * number of alias_prop found, or error code in error case.
2052 * @dt_alloc: An allocator that provides a virtual address to memory
2053 * for the resulting tree
2055 void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align))
2057 struct property *pp;
2059 of_chosen = of_find_node_by_path("/chosen");
2060 if (of_chosen == NULL)
2061 of_chosen = of_find_node_by_path("/chosen@0");
2064 const char *name = of_get_property(of_chosen, "stdout-path", NULL);
2066 name = of_get_property(of_chosen, "linux,stdout-path", NULL);
2068 of_stdout = of_find_node_by_path(name);
2071 of_aliases = of_find_node_by_path("/aliases");
2075 for_each_property_of_node(of_aliases, pp) {
2076 const char *start = pp->name;
2077 const char *end = start + strlen(start);
2078 struct device_node *np;
2079 struct alias_prop *ap;
2082 /* Skip those we do not want to proceed */
2083 if (!strcmp(pp->name, "name") ||
2084 !strcmp(pp->name, "phandle") ||
2085 !strcmp(pp->name, "linux,phandle"))
2088 np = of_find_node_by_path(pp->value);
2092 /* walk the alias backwards to extract the id and work out
2093 * the 'stem' string */
2094 while (isdigit(*(end-1)) && end > start)
2098 if (kstrtoint(end, 10, &id) < 0)
2101 /* Allocate an alias_prop with enough space for the stem */
2102 ap = dt_alloc(sizeof(*ap) + len + 1, 4);
2105 memset(ap, 0, sizeof(*ap) + len + 1);
2107 of_alias_add(ap, np, id, start, len);
2112 * of_alias_get_id - Get alias id for the given device_node
2113 * @np: Pointer to the given device_node
2114 * @stem: Alias stem of the given device_node
2116 * The function travels the lookup table to get the alias id for the given
2117 * device_node and alias stem. It returns the alias id if found.
2119 int of_alias_get_id(struct device_node *np, const char *stem)
2121 struct alias_prop *app;
2124 mutex_lock(&of_aliases_mutex);
2125 list_for_each_entry(app, &aliases_lookup, link) {
2126 if (strcmp(app->stem, stem) != 0)
2129 if (np == app->np) {
2134 mutex_unlock(&of_aliases_mutex);
2138 EXPORT_SYMBOL_GPL(of_alias_get_id);
2140 const __be32 *of_prop_next_u32(struct property *prop, const __be32 *cur,
2143 const void *curv = cur;
2153 curv += sizeof(*cur);
2154 if (curv >= prop->value + prop->length)
2158 *pu = be32_to_cpup(curv);
2161 EXPORT_SYMBOL_GPL(of_prop_next_u32);
2163 const char *of_prop_next_string(struct property *prop, const char *cur)
2165 const void *curv = cur;
2173 curv += strlen(cur) + 1;
2174 if (curv >= prop->value + prop->length)
2179 EXPORT_SYMBOL_GPL(of_prop_next_string);
2182 * of_device_is_stdout_path - check if a device node matches the
2183 * linux,stdout-path property
2185 * Check if this device node matches the linux,stdout-path property
2186 * in the chosen node. return true if yes, false otherwise.
2188 int of_device_is_stdout_path(struct device_node *dn)
2193 return of_stdout == dn;
2195 EXPORT_SYMBOL_GPL(of_device_is_stdout_path);
2198 * of_find_next_cache_node - Find a node's subsidiary cache
2199 * @np: node of type "cpu" or "cache"
2201 * Returns a node pointer with refcount incremented, use
2202 * of_node_put() on it when done. Caller should hold a reference
2205 struct device_node *of_find_next_cache_node(const struct device_node *np)
2207 struct device_node *child;
2208 const phandle *handle;
2210 handle = of_get_property(np, "l2-cache", NULL);
2212 handle = of_get_property(np, "next-level-cache", NULL);
2215 return of_find_node_by_phandle(be32_to_cpup(handle));
2217 /* OF on pmac has nodes instead of properties named "l2-cache"
2218 * beneath CPU nodes.
2220 if (!strcmp(np->type, "cpu"))
2221 for_each_child_of_node(np, child)
2222 if (!strcmp(child->type, "cache"))
2229 * of_graph_parse_endpoint() - parse common endpoint node properties
2230 * @node: pointer to endpoint device_node
2231 * @endpoint: pointer to the OF endpoint data structure
2233 * The caller should hold a reference to @node.
2235 int of_graph_parse_endpoint(const struct device_node *node,
2236 struct of_endpoint *endpoint)
2238 struct device_node *port_node = of_get_parent(node);
2240 WARN_ONCE(!port_node, "%s(): endpoint %s has no parent node\n",
2241 __func__, node->full_name);
2243 memset(endpoint, 0, sizeof(*endpoint));
2245 endpoint->local_node = node;
2247 * It doesn't matter whether the two calls below succeed.
2248 * If they don't then the default value 0 is used.
2250 of_property_read_u32(port_node, "reg", &endpoint->port);
2251 of_property_read_u32(node, "reg", &endpoint->id);
2253 of_node_put(port_node);
2257 EXPORT_SYMBOL(of_graph_parse_endpoint);
2260 * of_graph_get_next_endpoint() - get next endpoint node
2261 * @parent: pointer to the parent device node
2262 * @prev: previous endpoint node, or NULL to get first
2264 * Return: An 'endpoint' node pointer with refcount incremented. Refcount
2265 * of the passed @prev node is not decremented, the caller have to use
2266 * of_node_put() on it when done.
2268 struct device_node *of_graph_get_next_endpoint(const struct device_node *parent,
2269 struct device_node *prev)
2271 struct device_node *endpoint;
2272 struct device_node *port;
2278 * Start by locating the port node. If no previous endpoint is specified
2279 * search for the first port node, otherwise get the previous endpoint
2283 struct device_node *node;
2285 node = of_get_child_by_name(parent, "ports");
2289 port = of_get_child_by_name(parent, "port");
2293 pr_err("%s(): no port node found in %s\n",
2294 __func__, parent->full_name);
2298 port = of_get_parent(prev);
2299 if (WARN_ONCE(!port, "%s(): endpoint %s has no parent node\n",
2300 __func__, prev->full_name))
2304 * Avoid dropping prev node refcount to 0 when getting the next
2312 * Now that we have a port node, get the next endpoint by
2313 * getting the next child. If the previous endpoint is NULL this
2314 * will return the first child.
2316 endpoint = of_get_next_child(port, prev);
2322 /* No more endpoints under this port, try the next one. */
2326 port = of_get_next_child(parent, port);
2329 } while (of_node_cmp(port->name, "port"));
2332 EXPORT_SYMBOL(of_graph_get_next_endpoint);
2335 * of_graph_get_remote_port_parent() - get remote port's parent node
2336 * @node: pointer to a local endpoint device_node
2338 * Return: Remote device node associated with remote endpoint node linked
2339 * to @node. Use of_node_put() on it when done.
2341 struct device_node *of_graph_get_remote_port_parent(
2342 const struct device_node *node)
2344 struct device_node *np;
2347 /* Get remote endpoint node. */
2348 np = of_parse_phandle(node, "remote-endpoint", 0);
2350 /* Walk 3 levels up only if there is 'ports' node. */
2351 for (depth = 3; depth && np; depth--) {
2352 np = of_get_next_parent(np);
2353 if (depth == 2 && of_node_cmp(np->name, "ports"))
2358 EXPORT_SYMBOL(of_graph_get_remote_port_parent);
2361 * of_graph_get_remote_port() - get remote port node
2362 * @node: pointer to a local endpoint device_node
2364 * Return: Remote port node associated with remote endpoint node linked
2365 * to @node. Use of_node_put() on it when done.
2367 struct device_node *of_graph_get_remote_port(const struct device_node *node)
2369 struct device_node *np;
2371 /* Get remote endpoint node. */
2372 np = of_parse_phandle(node, "remote-endpoint", 0);
2375 return of_get_next_parent(np);
2377 EXPORT_SYMBOL(of_graph_get_remote_port);