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);
699 * of_get_next_child - Iterate a node childs
701 * @prev: previous child of the parent node, or NULL to get first
703 * Returns a node pointer with refcount incremented, use
704 * of_node_put() on it when done.
706 struct device_node *of_get_next_child(const struct device_node *node,
707 struct device_node *prev)
709 struct device_node *next;
712 raw_spin_lock_irqsave(&devtree_lock, flags);
713 next = prev ? prev->sibling : node->child;
714 for (; next; next = next->sibling)
715 if (of_node_get(next))
718 raw_spin_unlock_irqrestore(&devtree_lock, flags);
721 EXPORT_SYMBOL(of_get_next_child);
724 * of_get_next_available_child - Find the next available child node
726 * @prev: previous child of the parent node, or NULL to get first
728 * This function is like of_get_next_child(), except that it
729 * automatically skips any disabled nodes (i.e. status = "disabled").
731 struct device_node *of_get_next_available_child(const struct device_node *node,
732 struct device_node *prev)
734 struct device_node *next;
737 raw_spin_lock_irqsave(&devtree_lock, flags);
738 next = prev ? prev->sibling : node->child;
739 for (; next; next = next->sibling) {
740 if (!__of_device_is_available(next))
742 if (of_node_get(next))
746 raw_spin_unlock_irqrestore(&devtree_lock, flags);
749 EXPORT_SYMBOL(of_get_next_available_child);
752 * of_get_child_by_name - Find the child node by name for a given parent
754 * @name: child name to look for.
756 * This function looks for child node for given matching name
758 * Returns a node pointer if found, with refcount incremented, use
759 * of_node_put() on it when done.
760 * Returns NULL if node is not found.
762 struct device_node *of_get_child_by_name(const struct device_node *node,
765 struct device_node *child;
767 for_each_child_of_node(node, child)
768 if (child->name && (of_node_cmp(child->name, name) == 0))
772 EXPORT_SYMBOL(of_get_child_by_name);
775 * of_find_node_by_path - Find a node matching a full OF path
776 * @path: The full path to match
778 * Returns a node pointer with refcount incremented, use
779 * of_node_put() on it when done.
781 struct device_node *of_find_node_by_path(const char *path)
783 struct device_node *np = of_allnodes;
786 raw_spin_lock_irqsave(&devtree_lock, flags);
787 for (; np; np = np->allnext) {
788 if (np->full_name && (of_node_cmp(np->full_name, path) == 0)
792 raw_spin_unlock_irqrestore(&devtree_lock, flags);
795 EXPORT_SYMBOL(of_find_node_by_path);
798 * of_find_node_by_name - Find a node by its "name" property
799 * @from: The node to start searching from or NULL, the node
800 * you pass will not be searched, only the next one
801 * will; typically, you pass what the previous call
802 * returned. of_node_put() will be called on it
803 * @name: The name string to match against
805 * Returns a node pointer with refcount incremented, use
806 * of_node_put() on it when done.
808 struct device_node *of_find_node_by_name(struct device_node *from,
811 struct device_node *np;
814 raw_spin_lock_irqsave(&devtree_lock, flags);
815 np = from ? from->allnext : of_allnodes;
816 for (; np; np = np->allnext)
817 if (np->name && (of_node_cmp(np->name, name) == 0)
821 raw_spin_unlock_irqrestore(&devtree_lock, flags);
824 EXPORT_SYMBOL(of_find_node_by_name);
827 * of_find_node_by_type - Find a node by its "device_type" property
828 * @from: The node to start searching from, or NULL to start searching
829 * the entire device tree. The node you pass will not be
830 * searched, only the next one will; typically, you pass
831 * what the previous call returned. of_node_put() will be
832 * called on from for you.
833 * @type: The type string to match against
835 * Returns a node pointer with refcount incremented, use
836 * of_node_put() on it when done.
838 struct device_node *of_find_node_by_type(struct device_node *from,
841 struct device_node *np;
844 raw_spin_lock_irqsave(&devtree_lock, flags);
845 np = from ? from->allnext : of_allnodes;
846 for (; np; np = np->allnext)
847 if (np->type && (of_node_cmp(np->type, type) == 0)
851 raw_spin_unlock_irqrestore(&devtree_lock, flags);
854 EXPORT_SYMBOL(of_find_node_by_type);
857 * of_find_compatible_node - Find a node based on type and one of the
858 * tokens in its "compatible" property
859 * @from: The node to start searching from or NULL, the node
860 * you pass will not be searched, only the next one
861 * will; typically, you pass what the previous call
862 * returned. of_node_put() will be called on it
863 * @type: The type string to match "device_type" or NULL to ignore
864 * @compatible: The string to match to one of the tokens in the device
867 * Returns a node pointer with refcount incremented, use
868 * of_node_put() on it when done.
870 struct device_node *of_find_compatible_node(struct device_node *from,
871 const char *type, const char *compatible)
873 struct device_node *np;
876 raw_spin_lock_irqsave(&devtree_lock, flags);
877 np = from ? from->allnext : of_allnodes;
878 for (; np; np = np->allnext) {
879 if (__of_device_is_compatible(np, compatible, type, NULL) &&
884 raw_spin_unlock_irqrestore(&devtree_lock, flags);
887 EXPORT_SYMBOL(of_find_compatible_node);
890 * of_find_node_with_property - Find a node which has a property with
892 * @from: The node to start searching from or NULL, the node
893 * you pass will not be searched, only the next one
894 * will; typically, you pass what the previous call
895 * returned. of_node_put() will be called on it
896 * @prop_name: The name of the property to look for.
898 * Returns a node pointer with refcount incremented, use
899 * of_node_put() on it when done.
901 struct device_node *of_find_node_with_property(struct device_node *from,
902 const char *prop_name)
904 struct device_node *np;
908 raw_spin_lock_irqsave(&devtree_lock, flags);
909 np = from ? from->allnext : of_allnodes;
910 for (; np; np = np->allnext) {
911 for (pp = np->properties; pp; pp = pp->next) {
912 if (of_prop_cmp(pp->name, prop_name) == 0) {
920 raw_spin_unlock_irqrestore(&devtree_lock, flags);
923 EXPORT_SYMBOL(of_find_node_with_property);
926 const struct of_device_id *__of_match_node(const struct of_device_id *matches,
927 const struct device_node *node)
929 const struct of_device_id *best_match = NULL;
930 int score, best_score = 0;
935 for (; matches->name[0] || matches->type[0] || matches->compatible[0]; matches++) {
936 score = __of_device_is_compatible(node, matches->compatible,
937 matches->type, matches->name);
938 if (score > best_score) {
939 best_match = matches;
948 * of_match_node - Tell if an device_node has a matching of_match structure
949 * @matches: array of of device match structures to search in
950 * @node: the of device structure to match against
952 * Low level utility function used by device matching.
954 const struct of_device_id *of_match_node(const struct of_device_id *matches,
955 const struct device_node *node)
957 const struct of_device_id *match;
960 raw_spin_lock_irqsave(&devtree_lock, flags);
961 match = __of_match_node(matches, node);
962 raw_spin_unlock_irqrestore(&devtree_lock, flags);
965 EXPORT_SYMBOL(of_match_node);
968 * of_find_matching_node_and_match - Find a node based on an of_device_id
970 * @from: The node to start searching from or NULL, the node
971 * you pass will not be searched, only the next one
972 * will; typically, you pass what the previous call
973 * returned. of_node_put() will be called on it
974 * @matches: array of of device match structures to search in
975 * @match Updated to point at the matches entry which matched
977 * Returns a node pointer with refcount incremented, use
978 * of_node_put() on it when done.
980 struct device_node *of_find_matching_node_and_match(struct device_node *from,
981 const struct of_device_id *matches,
982 const struct of_device_id **match)
984 struct device_node *np;
985 const struct of_device_id *m;
991 raw_spin_lock_irqsave(&devtree_lock, flags);
992 np = from ? from->allnext : of_allnodes;
993 for (; np; np = np->allnext) {
994 m = __of_match_node(matches, np);
995 if (m && of_node_get(np)) {
1002 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1005 EXPORT_SYMBOL(of_find_matching_node_and_match);
1008 * of_modalias_node - Lookup appropriate modalias for a device node
1009 * @node: pointer to a device tree node
1010 * @modalias: Pointer to buffer that modalias value will be copied into
1011 * @len: Length of modalias value
1013 * Based on the value of the compatible property, this routine will attempt
1014 * to choose an appropriate modalias value for a particular device tree node.
1015 * It does this by stripping the manufacturer prefix (as delimited by a ',')
1016 * from the first entry in the compatible list property.
1018 * This routine returns 0 on success, <0 on failure.
1020 int of_modalias_node(struct device_node *node, char *modalias, int len)
1022 const char *compatible, *p;
1025 compatible = of_get_property(node, "compatible", &cplen);
1026 if (!compatible || strlen(compatible) > cplen)
1028 p = strchr(compatible, ',');
1029 strlcpy(modalias, p ? p + 1 : compatible, len);
1032 EXPORT_SYMBOL_GPL(of_modalias_node);
1035 * of_find_node_by_phandle - Find a node given a phandle
1036 * @handle: phandle of the node to find
1038 * Returns a node pointer with refcount incremented, use
1039 * of_node_put() on it when done.
1041 struct device_node *of_find_node_by_phandle(phandle handle)
1043 struct device_node *np;
1044 unsigned long flags;
1046 raw_spin_lock_irqsave(&devtree_lock, flags);
1047 for (np = of_allnodes; np; np = np->allnext)
1048 if (np->phandle == handle)
1051 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1054 EXPORT_SYMBOL(of_find_node_by_phandle);
1057 * of_property_count_elems_of_size - Count the number of elements in a property
1059 * @np: device node from which the property value is to be read.
1060 * @propname: name of the property to be searched.
1061 * @elem_size: size of the individual element
1063 * Search for a property in a device node and count the number of elements of
1064 * size elem_size in it. Returns number of elements on sucess, -EINVAL if the
1065 * property does not exist or its length does not match a multiple of elem_size
1066 * and -ENODATA if the property does not have a value.
1068 int of_property_count_elems_of_size(const struct device_node *np,
1069 const char *propname, int elem_size)
1071 struct property *prop = of_find_property(np, propname, NULL);
1078 if (prop->length % elem_size != 0) {
1079 pr_err("size of %s in node %s is not a multiple of %d\n",
1080 propname, np->full_name, elem_size);
1084 return prop->length / elem_size;
1086 EXPORT_SYMBOL_GPL(of_property_count_elems_of_size);
1089 * of_find_property_value_of_size
1091 * @np: device node from which the property value is to be read.
1092 * @propname: name of the property to be searched.
1093 * @len: requested length of property value
1095 * Search for a property in a device node and valid the requested size.
1096 * Returns the property value on success, -EINVAL if the property does not
1097 * exist, -ENODATA if property does not have a value, and -EOVERFLOW if the
1098 * property data isn't large enough.
1101 static void *of_find_property_value_of_size(const struct device_node *np,
1102 const char *propname, u32 len)
1104 struct property *prop = of_find_property(np, propname, NULL);
1107 return ERR_PTR(-EINVAL);
1109 return ERR_PTR(-ENODATA);
1110 if (len > prop->length)
1111 return ERR_PTR(-EOVERFLOW);
1117 * of_property_read_u32_index - Find and read a u32 from a multi-value property.
1119 * @np: device node from which the property value is to be read.
1120 * @propname: name of the property to be searched.
1121 * @index: index of the u32 in the list of values
1122 * @out_value: pointer to return value, modified only if no error.
1124 * Search for a property in a device node and read nth 32-bit value from
1125 * it. Returns 0 on success, -EINVAL if the property does not exist,
1126 * -ENODATA if property does not have a value, and -EOVERFLOW if the
1127 * property data isn't large enough.
1129 * The out_value is modified only if a valid u32 value can be decoded.
1131 int of_property_read_u32_index(const struct device_node *np,
1132 const char *propname,
1133 u32 index, u32 *out_value)
1135 const u32 *val = of_find_property_value_of_size(np, propname,
1136 ((index + 1) * sizeof(*out_value)));
1139 return PTR_ERR(val);
1141 *out_value = be32_to_cpup(((__be32 *)val) + index);
1144 EXPORT_SYMBOL_GPL(of_property_read_u32_index);
1147 * of_property_read_u8_array - Find and read an array of u8 from a property.
1149 * @np: device node from which the property value is to be read.
1150 * @propname: name of the property to be searched.
1151 * @out_values: pointer to return value, modified only if return value is 0.
1152 * @sz: number of array elements to read
1154 * Search for a property in a device node and read 8-bit value(s) from
1155 * it. Returns 0 on success, -EINVAL if the property does not exist,
1156 * -ENODATA if property does not have a value, and -EOVERFLOW if the
1157 * property data isn't large enough.
1159 * dts entry of array should be like:
1160 * property = /bits/ 8 <0x50 0x60 0x70>;
1162 * The out_values is modified only if a valid u8 value can be decoded.
1164 int of_property_read_u8_array(const struct device_node *np,
1165 const char *propname, u8 *out_values, size_t sz)
1167 const u8 *val = of_find_property_value_of_size(np, propname,
1168 (sz * sizeof(*out_values)));
1171 return PTR_ERR(val);
1174 *out_values++ = *val++;
1177 EXPORT_SYMBOL_GPL(of_property_read_u8_array);
1180 * of_property_read_u16_array - Find and read an array of u16 from a property.
1182 * @np: device node from which the property value is to be read.
1183 * @propname: name of the property to be searched.
1184 * @out_values: pointer to return value, modified only if return value is 0.
1185 * @sz: number of array elements to read
1187 * Search for a property in a device node and read 16-bit value(s) from
1188 * it. Returns 0 on success, -EINVAL if the property does not exist,
1189 * -ENODATA if property does not have a value, and -EOVERFLOW if the
1190 * property data isn't large enough.
1192 * dts entry of array should be like:
1193 * property = /bits/ 16 <0x5000 0x6000 0x7000>;
1195 * The out_values is modified only if a valid u16 value can be decoded.
1197 int of_property_read_u16_array(const struct device_node *np,
1198 const char *propname, u16 *out_values, size_t sz)
1200 const __be16 *val = of_find_property_value_of_size(np, propname,
1201 (sz * sizeof(*out_values)));
1204 return PTR_ERR(val);
1207 *out_values++ = be16_to_cpup(val++);
1210 EXPORT_SYMBOL_GPL(of_property_read_u16_array);
1213 * of_property_read_u32_array - Find and read an array of 32 bit integers
1216 * @np: device node from which the property value is to be read.
1217 * @propname: name of the property to be searched.
1218 * @out_values: pointer to return value, modified only if return value is 0.
1219 * @sz: number of array elements to read
1221 * Search for a property in a device node and read 32-bit value(s) from
1222 * it. Returns 0 on success, -EINVAL if the property does not exist,
1223 * -ENODATA if property does not have a value, and -EOVERFLOW if the
1224 * property data isn't large enough.
1226 * The out_values is modified only if a valid u32 value can be decoded.
1228 int of_property_read_u32_array(const struct device_node *np,
1229 const char *propname, u32 *out_values,
1232 const __be32 *val = of_find_property_value_of_size(np, propname,
1233 (sz * sizeof(*out_values)));
1236 return PTR_ERR(val);
1239 *out_values++ = be32_to_cpup(val++);
1242 EXPORT_SYMBOL_GPL(of_property_read_u32_array);
1245 * of_property_read_u64 - Find and read a 64 bit integer from a property
1246 * @np: device node from which the property value is to be read.
1247 * @propname: name of the property to be searched.
1248 * @out_value: pointer to return value, modified only if return value is 0.
1250 * Search for a property in a device node and read a 64-bit value from
1251 * it. Returns 0 on success, -EINVAL if the property does not exist,
1252 * -ENODATA if property does not have a value, and -EOVERFLOW if the
1253 * property data isn't large enough.
1255 * The out_value is modified only if a valid u64 value can be decoded.
1257 int of_property_read_u64(const struct device_node *np, const char *propname,
1260 const __be32 *val = of_find_property_value_of_size(np, propname,
1261 sizeof(*out_value));
1264 return PTR_ERR(val);
1266 *out_value = of_read_number(val, 2);
1269 EXPORT_SYMBOL_GPL(of_property_read_u64);
1272 * of_property_read_string - Find and read a string from a property
1273 * @np: device node from which the property value is to be read.
1274 * @propname: name of the property to be searched.
1275 * @out_string: pointer to null terminated return string, modified only if
1276 * return value is 0.
1278 * Search for a property in a device tree node and retrieve a null
1279 * terminated string value (pointer to data, not a copy). Returns 0 on
1280 * success, -EINVAL if the property does not exist, -ENODATA if property
1281 * does not have a value, and -EILSEQ if the string is not null-terminated
1282 * within the length of the property data.
1284 * The out_string pointer is modified only if a valid string can be decoded.
1286 int of_property_read_string(struct device_node *np, const char *propname,
1287 const char **out_string)
1289 struct property *prop = of_find_property(np, propname, NULL);
1294 if (strnlen(prop->value, prop->length) >= prop->length)
1296 *out_string = prop->value;
1299 EXPORT_SYMBOL_GPL(of_property_read_string);
1302 * of_property_read_string_index - Find and read a string from a multiple
1304 * @np: device node from which the property value is to be read.
1305 * @propname: name of the property to be searched.
1306 * @index: index of the string in the list of strings
1307 * @out_string: pointer to null terminated return string, modified only if
1308 * return value is 0.
1310 * Search for a property in a device tree node and retrieve a null
1311 * terminated string value (pointer to data, not a copy) in the list of strings
1312 * contained in that property.
1313 * Returns 0 on success, -EINVAL if the property does not exist, -ENODATA if
1314 * property does not have a value, and -EILSEQ if the string is not
1315 * null-terminated within the length of the property data.
1317 * The out_string pointer is modified only if a valid string can be decoded.
1319 int of_property_read_string_index(struct device_node *np, const char *propname,
1320 int index, const char **output)
1322 struct property *prop = of_find_property(np, propname, NULL);
1324 size_t l = 0, total = 0;
1331 if (strnlen(prop->value, prop->length) >= prop->length)
1336 for (i = 0; total < prop->length; total += l, p += l) {
1345 EXPORT_SYMBOL_GPL(of_property_read_string_index);
1348 * of_property_match_string() - Find string in a list and return index
1349 * @np: pointer to node containing string list property
1350 * @propname: string list property name
1351 * @string: pointer to string to search for in string list
1353 * This function searches a string list property and returns the index
1354 * of a specific string value.
1356 int of_property_match_string(struct device_node *np, const char *propname,
1359 struct property *prop = of_find_property(np, propname, NULL);
1362 const char *p, *end;
1370 end = p + prop->length;
1372 for (i = 0; p < end; i++, p += l) {
1376 pr_debug("comparing %s with %s\n", string, p);
1377 if (strcmp(string, p) == 0)
1378 return i; /* Found it; return index */
1382 EXPORT_SYMBOL_GPL(of_property_match_string);
1385 * of_property_count_strings - Find and return the number of strings from a
1386 * multiple strings property.
1387 * @np: device node from which the property value is to be read.
1388 * @propname: name of the property to be searched.
1390 * Search for a property in a device tree node and retrieve the number of null
1391 * terminated string contain in it. Returns the number of strings on
1392 * success, -EINVAL if the property does not exist, -ENODATA if property
1393 * does not have a value, and -EILSEQ if the string is not null-terminated
1394 * within the length of the property data.
1396 int of_property_count_strings(struct device_node *np, const char *propname)
1398 struct property *prop = of_find_property(np, propname, NULL);
1400 size_t l = 0, total = 0;
1407 if (strnlen(prop->value, prop->length) >= prop->length)
1412 for (i = 0; total < prop->length; total += l, p += l, i++)
1417 EXPORT_SYMBOL_GPL(of_property_count_strings);
1419 void of_print_phandle_args(const char *msg, const struct of_phandle_args *args)
1422 printk("%s %s", msg, of_node_full_name(args->np));
1423 for (i = 0; i < args->args_count; i++)
1424 printk(i ? ",%08x" : ":%08x", args->args[i]);
1428 static int __of_parse_phandle_with_args(const struct device_node *np,
1429 const char *list_name,
1430 const char *cells_name,
1431 int cell_count, int index,
1432 struct of_phandle_args *out_args)
1434 const __be32 *list, *list_end;
1435 int rc = 0, size, cur_index = 0;
1437 struct device_node *node = NULL;
1440 /* Retrieve the phandle list property */
1441 list = of_get_property(np, list_name, &size);
1444 list_end = list + size / sizeof(*list);
1446 /* Loop over the phandles until all the requested entry is found */
1447 while (list < list_end) {
1452 * If phandle is 0, then it is an empty entry with no
1453 * arguments. Skip forward to the next entry.
1455 phandle = be32_to_cpup(list++);
1458 * Find the provider node and parse the #*-cells
1459 * property to determine the argument length.
1461 * This is not needed if the cell count is hard-coded
1462 * (i.e. cells_name not set, but cell_count is set),
1463 * except when we're going to return the found node
1466 if (cells_name || cur_index == index) {
1467 node = of_find_node_by_phandle(phandle);
1469 pr_err("%s: could not find phandle\n",
1476 if (of_property_read_u32(node, cells_name,
1478 pr_err("%s: could not get %s for %s\n",
1479 np->full_name, cells_name,
1488 * Make sure that the arguments actually fit in the
1489 * remaining property data length
1491 if (list + count > list_end) {
1492 pr_err("%s: arguments longer than property\n",
1499 * All of the error cases above bail out of the loop, so at
1500 * this point, the parsing is successful. If the requested
1501 * index matches, then fill the out_args structure and return,
1502 * or return -ENOENT for an empty entry.
1505 if (cur_index == index) {
1511 if (WARN_ON(count > MAX_PHANDLE_ARGS))
1512 count = MAX_PHANDLE_ARGS;
1513 out_args->np = node;
1514 out_args->args_count = count;
1515 for (i = 0; i < count; i++)
1516 out_args->args[i] = be32_to_cpup(list++);
1521 /* Found it! return success */
1532 * Unlock node before returning result; will be one of:
1533 * -ENOENT : index is for empty phandle
1534 * -EINVAL : parsing error on data
1535 * [1..n] : Number of phandle (count mode; when index = -1)
1537 rc = index < 0 ? cur_index : -ENOENT;
1545 * of_parse_phandle - Resolve a phandle property to a device_node pointer
1546 * @np: Pointer to device node holding phandle property
1547 * @phandle_name: Name of property holding a phandle value
1548 * @index: For properties holding a table of phandles, this is the index into
1551 * Returns the device_node pointer with refcount incremented. Use
1552 * of_node_put() on it when done.
1554 struct device_node *of_parse_phandle(const struct device_node *np,
1555 const char *phandle_name, int index)
1557 struct of_phandle_args args;
1562 if (__of_parse_phandle_with_args(np, phandle_name, NULL, 0,
1568 EXPORT_SYMBOL(of_parse_phandle);
1571 * of_parse_phandle_with_args() - Find a node pointed by phandle in a list
1572 * @np: pointer to a device tree node containing a list
1573 * @list_name: property name that contains a list
1574 * @cells_name: property name that specifies phandles' arguments count
1575 * @index: index of a phandle to parse out
1576 * @out_args: optional pointer to output arguments structure (will be filled)
1578 * This function is useful to parse lists of phandles and their arguments.
1579 * Returns 0 on success and fills out_args, on error returns appropriate
1582 * Caller is responsible to call of_node_put() on the returned out_args->node
1588 * #list-cells = <2>;
1592 * #list-cells = <1>;
1596 * list = <&phandle1 1 2 &phandle2 3>;
1599 * To get a device_node of the `node2' node you may call this:
1600 * of_parse_phandle_with_args(node3, "list", "#list-cells", 1, &args);
1602 int of_parse_phandle_with_args(const struct device_node *np, const char *list_name,
1603 const char *cells_name, int index,
1604 struct of_phandle_args *out_args)
1608 return __of_parse_phandle_with_args(np, list_name, cells_name, 0,
1611 EXPORT_SYMBOL(of_parse_phandle_with_args);
1614 * of_parse_phandle_with_fixed_args() - Find a node pointed by phandle in a list
1615 * @np: pointer to a device tree node containing a list
1616 * @list_name: property name that contains a list
1617 * @cell_count: number of argument cells following the phandle
1618 * @index: index of a phandle to parse out
1619 * @out_args: optional pointer to output arguments structure (will be filled)
1621 * This function is useful to parse lists of phandles and their arguments.
1622 * Returns 0 on success and fills out_args, on error returns appropriate
1625 * Caller is responsible to call of_node_put() on the returned out_args->node
1637 * list = <&phandle1 0 2 &phandle2 2 3>;
1640 * To get a device_node of the `node2' node you may call this:
1641 * of_parse_phandle_with_fixed_args(node3, "list", 2, 1, &args);
1643 int of_parse_phandle_with_fixed_args(const struct device_node *np,
1644 const char *list_name, int cell_count,
1645 int index, struct of_phandle_args *out_args)
1649 return __of_parse_phandle_with_args(np, list_name, NULL, cell_count,
1652 EXPORT_SYMBOL(of_parse_phandle_with_fixed_args);
1655 * of_count_phandle_with_args() - Find the number of phandles references in a property
1656 * @np: pointer to a device tree node containing a list
1657 * @list_name: property name that contains a list
1658 * @cells_name: property name that specifies phandles' arguments count
1660 * Returns the number of phandle + argument tuples within a property. It
1661 * is a typical pattern to encode a list of phandle and variable
1662 * arguments into a single property. The number of arguments is encoded
1663 * by a property in the phandle-target node. For example, a gpios
1664 * property would contain a list of GPIO specifies consisting of a
1665 * phandle and 1 or more arguments. The number of arguments are
1666 * determined by the #gpio-cells property in the node pointed to by the
1669 int of_count_phandle_with_args(const struct device_node *np, const char *list_name,
1670 const char *cells_name)
1672 return __of_parse_phandle_with_args(np, list_name, cells_name, 0, -1,
1675 EXPORT_SYMBOL(of_count_phandle_with_args);
1677 #if defined(CONFIG_OF_DYNAMIC)
1678 static int of_property_notify(int action, struct device_node *np,
1679 struct property *prop)
1681 struct of_prop_reconfig pr;
1683 /* only call notifiers if the node is attached */
1684 if (!of_node_is_attached(np))
1689 return of_reconfig_notify(action, &pr);
1692 static int of_property_notify(int action, struct device_node *np,
1693 struct property *prop)
1700 * __of_add_property - Add a property to a node without lock operations
1702 static int __of_add_property(struct device_node *np, struct property *prop)
1704 struct property **next;
1707 next = &np->properties;
1709 if (strcmp(prop->name, (*next)->name) == 0)
1710 /* duplicate ! don't insert it */
1713 next = &(*next)->next;
1721 * of_add_property - Add a property to a node
1723 int of_add_property(struct device_node *np, struct property *prop)
1725 unsigned long flags;
1728 rc = of_property_notify(OF_RECONFIG_ADD_PROPERTY, np, prop);
1732 raw_spin_lock_irqsave(&devtree_lock, flags);
1733 rc = __of_add_property(np, prop);
1734 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1738 if (of_node_is_attached(np))
1739 __of_add_property_sysfs(np, prop);
1745 * of_remove_property - Remove a property from a node.
1747 * Note that we don't actually remove it, since we have given out
1748 * who-knows-how-many pointers to the data using get-property.
1749 * Instead we just move the property to the "dead properties"
1750 * list, so it won't be found any more.
1752 int of_remove_property(struct device_node *np, struct property *prop)
1754 struct property **next;
1755 unsigned long flags;
1759 rc = of_property_notify(OF_RECONFIG_REMOVE_PROPERTY, np, prop);
1763 raw_spin_lock_irqsave(&devtree_lock, flags);
1764 next = &np->properties;
1766 if (*next == prop) {
1767 /* found the node */
1769 prop->next = np->deadprops;
1770 np->deadprops = prop;
1774 next = &(*next)->next;
1776 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1781 /* at early boot, bail hear and defer setup to of_init() */
1785 sysfs_remove_bin_file(&np->kobj, &prop->attr);
1791 * of_update_property - Update a property in a node, if the property does
1792 * not exist, add it.
1794 * Note that we don't actually remove it, since we have given out
1795 * who-knows-how-many pointers to the data using get-property.
1796 * Instead we just move the property to the "dead properties" list,
1797 * and add the new property to the property list
1799 int of_update_property(struct device_node *np, struct property *newprop)
1801 struct property **next, *oldprop;
1802 unsigned long flags;
1805 rc = of_property_notify(OF_RECONFIG_UPDATE_PROPERTY, np, newprop);
1812 oldprop = of_find_property(np, newprop->name, NULL);
1814 return of_add_property(np, newprop);
1816 raw_spin_lock_irqsave(&devtree_lock, flags);
1817 next = &np->properties;
1819 if (*next == oldprop) {
1820 /* found the node */
1821 newprop->next = oldprop->next;
1823 oldprop->next = np->deadprops;
1824 np->deadprops = oldprop;
1828 next = &(*next)->next;
1830 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1834 /* Update the sysfs attribute */
1836 sysfs_remove_bin_file(&np->kobj, &oldprop->attr);
1837 __of_add_property_sysfs(np, newprop);
1845 #if defined(CONFIG_OF_DYNAMIC)
1847 * Support for dynamic device trees.
1849 * On some platforms, the device tree can be manipulated at runtime.
1850 * The routines in this section support adding, removing and changing
1851 * device tree nodes.
1854 static BLOCKING_NOTIFIER_HEAD(of_reconfig_chain);
1856 int of_reconfig_notifier_register(struct notifier_block *nb)
1858 return blocking_notifier_chain_register(&of_reconfig_chain, nb);
1860 EXPORT_SYMBOL_GPL(of_reconfig_notifier_register);
1862 int of_reconfig_notifier_unregister(struct notifier_block *nb)
1864 return blocking_notifier_chain_unregister(&of_reconfig_chain, nb);
1866 EXPORT_SYMBOL_GPL(of_reconfig_notifier_unregister);
1868 int of_reconfig_notify(unsigned long action, void *p)
1872 rc = blocking_notifier_call_chain(&of_reconfig_chain, action, p);
1873 return notifier_to_errno(rc);
1877 * of_attach_node - Plug a device node into the tree and global list.
1879 int of_attach_node(struct device_node *np)
1881 unsigned long flags;
1884 rc = of_reconfig_notify(OF_RECONFIG_ATTACH_NODE, np);
1888 raw_spin_lock_irqsave(&devtree_lock, flags);
1889 np->sibling = np->parent->child;
1890 np->allnext = of_allnodes;
1891 np->parent->child = np;
1893 of_node_clear_flag(np, OF_DETACHED);
1894 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1901 * of_detach_node - "Unplug" a node from the device tree.
1903 * The caller must hold a reference to the node. The memory associated with
1904 * the node is not freed until its refcount goes to zero.
1906 int of_detach_node(struct device_node *np)
1908 struct device_node *parent;
1909 unsigned long flags;
1912 rc = of_reconfig_notify(OF_RECONFIG_DETACH_NODE, np);
1916 raw_spin_lock_irqsave(&devtree_lock, flags);
1918 if (of_node_check_flag(np, OF_DETACHED)) {
1919 /* someone already detached it */
1920 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1924 parent = np->parent;
1926 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1930 if (of_allnodes == np)
1931 of_allnodes = np->allnext;
1933 struct device_node *prev;
1934 for (prev = of_allnodes;
1935 prev->allnext != np;
1936 prev = prev->allnext)
1938 prev->allnext = np->allnext;
1941 if (parent->child == np)
1942 parent->child = np->sibling;
1944 struct device_node *prevsib;
1945 for (prevsib = np->parent->child;
1946 prevsib->sibling != np;
1947 prevsib = prevsib->sibling)
1949 prevsib->sibling = np->sibling;
1952 of_node_set_flag(np, OF_DETACHED);
1953 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1958 #endif /* defined(CONFIG_OF_DYNAMIC) */
1960 static void of_alias_add(struct alias_prop *ap, struct device_node *np,
1961 int id, const char *stem, int stem_len)
1965 strncpy(ap->stem, stem, stem_len);
1966 ap->stem[stem_len] = 0;
1967 list_add_tail(&ap->link, &aliases_lookup);
1968 pr_debug("adding DT alias:%s: stem=%s id=%i node=%s\n",
1969 ap->alias, ap->stem, ap->id, of_node_full_name(np));
1973 * of_alias_scan - Scan all properties of 'aliases' node
1975 * The function scans all the properties of 'aliases' node and populate
1976 * the the global lookup table with the properties. It returns the
1977 * number of alias_prop found, or error code in error case.
1979 * @dt_alloc: An allocator that provides a virtual address to memory
1980 * for the resulting tree
1982 void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align))
1984 struct property *pp;
1986 of_chosen = of_find_node_by_path("/chosen");
1987 if (of_chosen == NULL)
1988 of_chosen = of_find_node_by_path("/chosen@0");
1991 const char *name = of_get_property(of_chosen, "stdout-path", NULL);
1993 name = of_get_property(of_chosen, "linux,stdout-path", NULL);
1995 of_stdout = of_find_node_by_path(name);
1998 of_aliases = of_find_node_by_path("/aliases");
2002 for_each_property_of_node(of_aliases, pp) {
2003 const char *start = pp->name;
2004 const char *end = start + strlen(start);
2005 struct device_node *np;
2006 struct alias_prop *ap;
2009 /* Skip those we do not want to proceed */
2010 if (!strcmp(pp->name, "name") ||
2011 !strcmp(pp->name, "phandle") ||
2012 !strcmp(pp->name, "linux,phandle"))
2015 np = of_find_node_by_path(pp->value);
2019 /* walk the alias backwards to extract the id and work out
2020 * the 'stem' string */
2021 while (isdigit(*(end-1)) && end > start)
2025 if (kstrtoint(end, 10, &id) < 0)
2028 /* Allocate an alias_prop with enough space for the stem */
2029 ap = dt_alloc(sizeof(*ap) + len + 1, 4);
2032 memset(ap, 0, sizeof(*ap) + len + 1);
2034 of_alias_add(ap, np, id, start, len);
2039 * of_alias_get_id - Get alias id for the given device_node
2040 * @np: Pointer to the given device_node
2041 * @stem: Alias stem of the given device_node
2043 * The function travels the lookup table to get alias id for the given
2044 * device_node and alias stem. It returns the alias id if find it.
2046 int of_alias_get_id(struct device_node *np, const char *stem)
2048 struct alias_prop *app;
2051 mutex_lock(&of_aliases_mutex);
2052 list_for_each_entry(app, &aliases_lookup, link) {
2053 if (strcmp(app->stem, stem) != 0)
2056 if (np == app->np) {
2061 mutex_unlock(&of_aliases_mutex);
2065 EXPORT_SYMBOL_GPL(of_alias_get_id);
2067 const __be32 *of_prop_next_u32(struct property *prop, const __be32 *cur,
2070 const void *curv = cur;
2080 curv += sizeof(*cur);
2081 if (curv >= prop->value + prop->length)
2085 *pu = be32_to_cpup(curv);
2088 EXPORT_SYMBOL_GPL(of_prop_next_u32);
2090 const char *of_prop_next_string(struct property *prop, const char *cur)
2092 const void *curv = cur;
2100 curv += strlen(cur) + 1;
2101 if (curv >= prop->value + prop->length)
2106 EXPORT_SYMBOL_GPL(of_prop_next_string);
2109 * of_device_is_stdout_path - check if a device node matches the
2110 * linux,stdout-path property
2112 * Check if this device node matches the linux,stdout-path property
2113 * in the chosen node. return true if yes, false otherwise.
2115 int of_device_is_stdout_path(struct device_node *dn)
2120 return of_stdout == dn;
2122 EXPORT_SYMBOL_GPL(of_device_is_stdout_path);
2125 * of_find_next_cache_node - Find a node's subsidiary cache
2126 * @np: node of type "cpu" or "cache"
2128 * Returns a node pointer with refcount incremented, use
2129 * of_node_put() on it when done. Caller should hold a reference
2132 struct device_node *of_find_next_cache_node(const struct device_node *np)
2134 struct device_node *child;
2135 const phandle *handle;
2137 handle = of_get_property(np, "l2-cache", NULL);
2139 handle = of_get_property(np, "next-level-cache", NULL);
2142 return of_find_node_by_phandle(be32_to_cpup(handle));
2144 /* OF on pmac has nodes instead of properties named "l2-cache"
2145 * beneath CPU nodes.
2147 if (!strcmp(np->type, "cpu"))
2148 for_each_child_of_node(np, child)
2149 if (!strcmp(child->type, "cache"))
2156 * of_graph_parse_endpoint() - parse common endpoint node properties
2157 * @node: pointer to endpoint device_node
2158 * @endpoint: pointer to the OF endpoint data structure
2160 * The caller should hold a reference to @node.
2162 int of_graph_parse_endpoint(const struct device_node *node,
2163 struct of_endpoint *endpoint)
2165 struct device_node *port_node = of_get_parent(node);
2167 WARN_ONCE(!port_node, "%s(): endpoint %s has no parent node\n",
2168 __func__, node->full_name);
2170 memset(endpoint, 0, sizeof(*endpoint));
2172 endpoint->local_node = node;
2174 * It doesn't matter whether the two calls below succeed.
2175 * If they don't then the default value 0 is used.
2177 of_property_read_u32(port_node, "reg", &endpoint->port);
2178 of_property_read_u32(node, "reg", &endpoint->id);
2180 of_node_put(port_node);
2184 EXPORT_SYMBOL(of_graph_parse_endpoint);
2187 * of_graph_get_next_endpoint() - get next endpoint node
2188 * @parent: pointer to the parent device node
2189 * @prev: previous endpoint node, or NULL to get first
2191 * Return: An 'endpoint' node pointer with refcount incremented. Refcount
2192 * of the passed @prev node is not decremented, the caller have to use
2193 * of_node_put() on it when done.
2195 struct device_node *of_graph_get_next_endpoint(const struct device_node *parent,
2196 struct device_node *prev)
2198 struct device_node *endpoint;
2199 struct device_node *port;
2205 * Start by locating the port node. If no previous endpoint is specified
2206 * search for the first port node, otherwise get the previous endpoint
2210 struct device_node *node;
2212 node = of_get_child_by_name(parent, "ports");
2216 port = of_get_child_by_name(parent, "port");
2220 pr_err("%s(): no port node found in %s\n",
2221 __func__, parent->full_name);
2225 port = of_get_parent(prev);
2226 if (WARN_ONCE(!port, "%s(): endpoint %s has no parent node\n",
2227 __func__, prev->full_name))
2231 * Avoid dropping prev node refcount to 0 when getting the next
2239 * Now that we have a port node, get the next endpoint by
2240 * getting the next child. If the previous endpoint is NULL this
2241 * will return the first child.
2243 endpoint = of_get_next_child(port, prev);
2249 /* No more endpoints under this port, try the next one. */
2253 port = of_get_next_child(parent, port);
2256 } while (of_node_cmp(port->name, "port"));
2259 EXPORT_SYMBOL(of_graph_get_next_endpoint);
2262 * of_graph_get_remote_port_parent() - get remote port's parent node
2263 * @node: pointer to a local endpoint device_node
2265 * Return: Remote device node associated with remote endpoint node linked
2266 * to @node. Use of_node_put() on it when done.
2268 struct device_node *of_graph_get_remote_port_parent(
2269 const struct device_node *node)
2271 struct device_node *np;
2274 /* Get remote endpoint node. */
2275 np = of_parse_phandle(node, "remote-endpoint", 0);
2277 /* Walk 3 levels up only if there is 'ports' node. */
2278 for (depth = 3; depth && np; depth--) {
2279 np = of_get_next_parent(np);
2280 if (depth == 2 && of_node_cmp(np->name, "ports"))
2285 EXPORT_SYMBOL(of_graph_get_remote_port_parent);
2288 * of_graph_get_remote_port() - get remote port node
2289 * @node: pointer to a local endpoint device_node
2291 * Return: Remote port node associated with remote endpoint node linked
2292 * to @node. Use of_node_put() on it when done.
2294 struct device_node *of_graph_get_remote_port(const struct device_node *node)
2296 struct device_node *np;
2298 /* Get remote endpoint node. */
2299 np = of_parse_phandle(node, "remote-endpoint", 0);
2302 return of_get_next_parent(np);
2304 EXPORT_SYMBOL(of_graph_get_remote_port);