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/console.h>
21 #include <linux/ctype.h>
22 #include <linux/cpu.h>
23 #include <linux/module.h>
25 #include <linux/of_graph.h>
26 #include <linux/spinlock.h>
27 #include <linux/slab.h>
28 #include <linux/string.h>
29 #include <linux/proc_fs.h>
31 #include "of_private.h"
33 LIST_HEAD(aliases_lookup);
35 struct device_node *of_allnodes;
36 EXPORT_SYMBOL(of_allnodes);
37 struct device_node *of_chosen;
38 struct device_node *of_aliases;
39 struct device_node *of_stdout;
44 * Used to protect the of_aliases, to hold off addition of nodes to sysfs.
45 * This mutex must be held whenever modifications are being made to the
46 * device tree. The of_{attach,detach}_node() and
47 * of_{add,remove,update}_property() helpers make sure this happens.
49 DEFINE_MUTEX(of_mutex);
51 /* use when traversing tree through the allnext, child, sibling,
52 * or parent members of struct device_node.
54 DEFINE_RAW_SPINLOCK(devtree_lock);
56 int of_n_addr_cells(struct device_node *np)
63 ip = of_get_property(np, "#address-cells", NULL);
65 return be32_to_cpup(ip);
67 /* No #address-cells property for the root node */
68 return OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
70 EXPORT_SYMBOL(of_n_addr_cells);
72 int of_n_size_cells(struct device_node *np)
79 ip = of_get_property(np, "#size-cells", NULL);
81 return be32_to_cpup(ip);
83 /* No #size-cells property for the root node */
84 return OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
86 EXPORT_SYMBOL(of_n_size_cells);
89 int __weak of_node_to_nid(struct device_node *np)
91 return numa_node_id();
95 #ifndef CONFIG_OF_DYNAMIC
96 static void of_node_release(struct kobject *kobj)
98 /* Without CONFIG_OF_DYNAMIC, no nodes gets freed */
100 #endif /* CONFIG_OF_DYNAMIC */
102 struct kobj_type of_node_ktype = {
103 .release = of_node_release,
106 static ssize_t of_node_property_read(struct file *filp, struct kobject *kobj,
107 struct bin_attribute *bin_attr, char *buf,
108 loff_t offset, size_t count)
110 struct property *pp = container_of(bin_attr, struct property, attr);
111 return memory_read_from_buffer(buf, count, &offset, pp->value, pp->length);
114 static const char *safe_name(struct kobject *kobj, const char *orig_name)
116 const char *name = orig_name;
117 struct kernfs_node *kn;
120 /* don't be a hero. After 16 tries give up */
121 while (i < 16 && (kn = sysfs_get_dirent(kobj->sd, name))) {
123 if (name != orig_name)
125 name = kasprintf(GFP_KERNEL, "%s#%i", orig_name, ++i);
128 if (name != orig_name)
129 pr_warn("device-tree: Duplicate name in %s, renamed to \"%s\"\n",
130 kobject_name(kobj), name);
134 int __of_add_property_sysfs(struct device_node *np, struct property *pp)
138 /* Important: Don't leak passwords */
139 bool secure = strncmp(pp->name, "security-", 9) == 0;
141 if (!of_kset || !of_node_is_attached(np))
144 sysfs_bin_attr_init(&pp->attr);
145 pp->attr.attr.name = safe_name(&np->kobj, pp->name);
146 pp->attr.attr.mode = secure ? S_IRUSR : S_IRUGO;
147 pp->attr.size = secure ? 0 : pp->length;
148 pp->attr.read = of_node_property_read;
150 rc = sysfs_create_bin_file(&np->kobj, &pp->attr);
151 WARN(rc, "error adding attribute %s to node %s\n", pp->name, np->full_name);
155 int __of_attach_node_sysfs(struct device_node *np)
164 np->kobj.kset = of_kset;
166 /* Nodes without parents are new top level trees */
167 rc = kobject_add(&np->kobj, NULL, "%s",
168 safe_name(&of_kset->kobj, "base"));
170 name = safe_name(&np->parent->kobj, kbasename(np->full_name));
171 if (!name || !name[0])
174 rc = kobject_add(&np->kobj, &np->parent->kobj, "%s", name);
179 for_each_property_of_node(np, pp)
180 __of_add_property_sysfs(np, pp);
185 static int __init of_init(void)
187 struct device_node *np;
189 /* Create the kset, and register existing nodes */
190 mutex_lock(&of_mutex);
191 of_kset = kset_create_and_add("devicetree", NULL, firmware_kobj);
193 mutex_unlock(&of_mutex);
196 for_each_of_allnodes(np)
197 __of_attach_node_sysfs(np);
198 mutex_unlock(&of_mutex);
200 /* Symlink in /proc as required by userspace ABI */
202 proc_symlink("device-tree", NULL, "/sys/firmware/devicetree/base");
206 core_initcall(of_init);
208 static struct property *__of_find_property(const struct device_node *np,
209 const char *name, int *lenp)
216 for (pp = np->properties; pp; pp = pp->next) {
217 if (of_prop_cmp(pp->name, name) == 0) {
227 struct property *of_find_property(const struct device_node *np,
234 raw_spin_lock_irqsave(&devtree_lock, flags);
235 pp = __of_find_property(np, name, lenp);
236 raw_spin_unlock_irqrestore(&devtree_lock, flags);
240 EXPORT_SYMBOL(of_find_property);
243 * of_find_all_nodes - Get next node in global list
244 * @prev: Previous node or NULL to start iteration
245 * of_node_put() will be called on it
247 * Returns a node pointer with refcount incremented, use
248 * of_node_put() on it when done.
250 struct device_node *of_find_all_nodes(struct device_node *prev)
252 struct device_node *np;
255 raw_spin_lock_irqsave(&devtree_lock, flags);
256 np = prev ? prev->allnext : of_allnodes;
257 for (; np != NULL; np = np->allnext)
261 raw_spin_unlock_irqrestore(&devtree_lock, flags);
264 EXPORT_SYMBOL(of_find_all_nodes);
267 * Find a property with a given name for a given node
268 * and return the value.
270 const void *__of_get_property(const struct device_node *np,
271 const char *name, int *lenp)
273 struct property *pp = __of_find_property(np, name, lenp);
275 return pp ? pp->value : NULL;
279 * Find a property with a given name for a given node
280 * and return the value.
282 const void *of_get_property(const struct device_node *np, const char *name,
285 struct property *pp = of_find_property(np, name, lenp);
287 return pp ? pp->value : NULL;
289 EXPORT_SYMBOL(of_get_property);
292 * arch_match_cpu_phys_id - Match the given logical CPU and physical id
294 * @cpu: logical cpu index of a core/thread
295 * @phys_id: physical identifier of a core/thread
297 * CPU logical to physical index mapping is architecture specific.
298 * However this __weak function provides a default match of physical
299 * id to logical cpu index. phys_id provided here is usually values read
300 * from the device tree which must match the hardware internal registers.
302 * Returns true if the physical identifier and the logical cpu index
303 * correspond to the same core/thread, false otherwise.
305 bool __weak arch_match_cpu_phys_id(int cpu, u64 phys_id)
307 return (u32)phys_id == cpu;
311 * Checks if the given "prop_name" property holds the physical id of the
312 * core/thread corresponding to the logical cpu 'cpu'. If 'thread' is not
313 * NULL, local thread number within the core is returned in it.
315 static bool __of_find_n_match_cpu_property(struct device_node *cpun,
316 const char *prop_name, int cpu, unsigned int *thread)
319 int ac, prop_len, tid;
322 ac = of_n_addr_cells(cpun);
323 cell = of_get_property(cpun, prop_name, &prop_len);
326 prop_len /= sizeof(*cell) * ac;
327 for (tid = 0; tid < prop_len; tid++) {
328 hwid = of_read_number(cell, ac);
329 if (arch_match_cpu_phys_id(cpu, hwid)) {
340 * arch_find_n_match_cpu_physical_id - See if the given device node is
341 * for the cpu corresponding to logical cpu 'cpu'. Return true if so,
342 * else false. If 'thread' is non-NULL, the local thread number within the
343 * core is returned in it.
345 bool __weak arch_find_n_match_cpu_physical_id(struct device_node *cpun,
346 int cpu, unsigned int *thread)
348 /* Check for non-standard "ibm,ppc-interrupt-server#s" property
349 * for thread ids on PowerPC. If it doesn't exist fallback to
350 * standard "reg" property.
352 if (IS_ENABLED(CONFIG_PPC) &&
353 __of_find_n_match_cpu_property(cpun,
354 "ibm,ppc-interrupt-server#s",
358 if (__of_find_n_match_cpu_property(cpun, "reg", cpu, thread))
365 * of_get_cpu_node - Get device node associated with the given logical CPU
367 * @cpu: CPU number(logical index) for which device node is required
368 * @thread: if not NULL, local thread number within the physical core is
371 * The main purpose of this function is to retrieve the device node for the
372 * given logical CPU index. It should be used to initialize the of_node in
373 * cpu device. Once of_node in cpu device is populated, all the further
374 * references can use that instead.
376 * CPU logical to physical index mapping is architecture specific and is built
377 * before booting secondary cores. This function uses arch_match_cpu_phys_id
378 * which can be overridden by architecture specific implementation.
380 * Returns a node pointer for the logical cpu if found, else NULL.
382 struct device_node *of_get_cpu_node(int cpu, unsigned int *thread)
384 struct device_node *cpun;
386 for_each_node_by_type(cpun, "cpu") {
387 if (arch_find_n_match_cpu_physical_id(cpun, cpu, thread))
392 EXPORT_SYMBOL(of_get_cpu_node);
395 * __of_device_is_compatible() - Check if the node matches given constraints
396 * @device: pointer to node
397 * @compat: required compatible string, NULL or "" for any match
398 * @type: required device_type value, NULL or "" for any match
399 * @name: required node name, NULL or "" for any match
401 * Checks if the given @compat, @type and @name strings match the
402 * properties of the given @device. A constraints can be skipped by
403 * passing NULL or an empty string as the constraint.
405 * Returns 0 for no match, and a positive integer on match. The return
406 * value is a relative score with larger values indicating better
407 * matches. The score is weighted for the most specific compatible value
408 * to get the highest score. Matching type is next, followed by matching
409 * name. Practically speaking, this results in the following priority
412 * 1. specific compatible && type && name
413 * 2. specific compatible && type
414 * 3. specific compatible && name
415 * 4. specific compatible
416 * 5. general compatible && type && name
417 * 6. general compatible && type
418 * 7. general compatible && name
419 * 8. general compatible
424 static int __of_device_is_compatible(const struct device_node *device,
425 const char *compat, const char *type, const char *name)
427 struct property *prop;
429 int index = 0, score = 0;
431 /* Compatible match has highest priority */
432 if (compat && compat[0]) {
433 prop = __of_find_property(device, "compatible", NULL);
434 for (cp = of_prop_next_string(prop, NULL); cp;
435 cp = of_prop_next_string(prop, cp), index++) {
436 if (of_compat_cmp(cp, compat, strlen(compat)) == 0) {
437 score = INT_MAX/2 - (index << 2);
445 /* Matching type is better than matching name */
446 if (type && type[0]) {
447 if (!device->type || of_node_cmp(type, device->type))
452 /* Matching name is a bit better than not */
453 if (name && name[0]) {
454 if (!device->name || of_node_cmp(name, device->name))
462 /** Checks if the given "compat" string matches one of the strings in
463 * the device's "compatible" property
465 int of_device_is_compatible(const struct device_node *device,
471 raw_spin_lock_irqsave(&devtree_lock, flags);
472 res = __of_device_is_compatible(device, compat, NULL, NULL);
473 raw_spin_unlock_irqrestore(&devtree_lock, flags);
476 EXPORT_SYMBOL(of_device_is_compatible);
479 * of_machine_is_compatible - Test root of device tree for a given compatible value
480 * @compat: compatible string to look for in root node's compatible property.
482 * Returns true if the root node has the given value in its
483 * compatible property.
485 int of_machine_is_compatible(const char *compat)
487 struct device_node *root;
490 root = of_find_node_by_path("/");
492 rc = of_device_is_compatible(root, compat);
497 EXPORT_SYMBOL(of_machine_is_compatible);
500 * __of_device_is_available - check if a device is available for use
502 * @device: Node to check for availability, with locks already held
504 * Returns 1 if the status property is absent or set to "okay" or "ok",
507 static int __of_device_is_available(const struct device_node *device)
515 status = __of_get_property(device, "status", &statlen);
520 if (!strcmp(status, "okay") || !strcmp(status, "ok"))
528 * of_device_is_available - check if a device is available for use
530 * @device: Node to check for availability
532 * Returns 1 if the status property is absent or set to "okay" or "ok",
535 int of_device_is_available(const struct device_node *device)
540 raw_spin_lock_irqsave(&devtree_lock, flags);
541 res = __of_device_is_available(device);
542 raw_spin_unlock_irqrestore(&devtree_lock, flags);
546 EXPORT_SYMBOL(of_device_is_available);
549 * of_get_parent - Get a node's parent if any
550 * @node: Node to get parent
552 * Returns a node pointer with refcount incremented, use
553 * of_node_put() on it when done.
555 struct device_node *of_get_parent(const struct device_node *node)
557 struct device_node *np;
563 raw_spin_lock_irqsave(&devtree_lock, flags);
564 np = of_node_get(node->parent);
565 raw_spin_unlock_irqrestore(&devtree_lock, flags);
568 EXPORT_SYMBOL(of_get_parent);
571 * of_get_next_parent - Iterate to a node's parent
572 * @node: Node to get parent of
574 * This is like of_get_parent() except that it drops the
575 * refcount on the passed node, making it suitable for iterating
576 * through a node's parents.
578 * Returns a node pointer with refcount incremented, use
579 * of_node_put() on it when done.
581 struct device_node *of_get_next_parent(struct device_node *node)
583 struct device_node *parent;
589 raw_spin_lock_irqsave(&devtree_lock, flags);
590 parent = of_node_get(node->parent);
592 raw_spin_unlock_irqrestore(&devtree_lock, flags);
595 EXPORT_SYMBOL(of_get_next_parent);
597 static struct device_node *__of_get_next_child(const struct device_node *node,
598 struct device_node *prev)
600 struct device_node *next;
605 next = prev ? prev->sibling : node->child;
606 for (; next; next = next->sibling)
607 if (of_node_get(next))
612 #define __for_each_child_of_node(parent, child) \
613 for (child = __of_get_next_child(parent, NULL); child != NULL; \
614 child = __of_get_next_child(parent, child))
617 * of_get_next_child - Iterate a node childs
619 * @prev: previous child of the parent node, or NULL to get first
621 * Returns a node pointer with refcount incremented, use
622 * of_node_put() on it when done.
624 struct device_node *of_get_next_child(const struct device_node *node,
625 struct device_node *prev)
627 struct device_node *next;
630 raw_spin_lock_irqsave(&devtree_lock, flags);
631 next = __of_get_next_child(node, prev);
632 raw_spin_unlock_irqrestore(&devtree_lock, flags);
635 EXPORT_SYMBOL(of_get_next_child);
638 * of_get_next_available_child - Find the next available child node
640 * @prev: previous child of the parent node, or NULL to get first
642 * This function is like of_get_next_child(), except that it
643 * automatically skips any disabled nodes (i.e. status = "disabled").
645 struct device_node *of_get_next_available_child(const struct device_node *node,
646 struct device_node *prev)
648 struct device_node *next;
654 raw_spin_lock_irqsave(&devtree_lock, flags);
655 next = prev ? prev->sibling : node->child;
656 for (; next; next = next->sibling) {
657 if (!__of_device_is_available(next))
659 if (of_node_get(next))
663 raw_spin_unlock_irqrestore(&devtree_lock, flags);
666 EXPORT_SYMBOL(of_get_next_available_child);
669 * of_get_child_by_name - Find the child node by name for a given parent
671 * @name: child name to look for.
673 * This function looks for child node for given matching name
675 * Returns a node pointer if found, with refcount incremented, use
676 * of_node_put() on it when done.
677 * Returns NULL if node is not found.
679 struct device_node *of_get_child_by_name(const struct device_node *node,
682 struct device_node *child;
684 for_each_child_of_node(node, child)
685 if (child->name && (of_node_cmp(child->name, name) == 0))
689 EXPORT_SYMBOL(of_get_child_by_name);
691 static struct device_node *__of_find_node_by_path(struct device_node *parent,
694 struct device_node *child;
695 int len = strchrnul(path, '/') - path;
700 __for_each_child_of_node(parent, child) {
701 const char *name = strrchr(child->full_name, '/');
702 if (WARN(!name, "malformed device_node %s\n", child->full_name))
705 if (strncmp(path, name, len) == 0 && (strlen(name) == len))
712 * of_find_node_by_path - Find a node matching a full OF path
713 * @path: Either the full path to match, or if the path does not
714 * start with '/', the name of a property of the /aliases
715 * node (an alias). In the case of an alias, the node
716 * matching the alias' value will be returned.
721 * foo/bar Valid alias + relative path
723 * Returns a node pointer with refcount incremented, use
724 * of_node_put() on it when done.
726 struct device_node *of_find_node_by_path(const char *path)
728 struct device_node *np = NULL;
732 if (strcmp(path, "/") == 0)
733 return of_node_get(of_allnodes);
735 /* The path could begin with an alias */
737 char *p = strchrnul(path, '/');
740 /* of_aliases must not be NULL */
744 for_each_property_of_node(of_aliases, pp) {
745 if (strlen(pp->name) == len && !strncmp(pp->name, path, len)) {
746 np = of_find_node_by_path(pp->value);
755 /* Step down the tree matching path components */
756 raw_spin_lock_irqsave(&devtree_lock, flags);
758 np = of_node_get(of_allnodes);
759 while (np && *path == '/') {
760 path++; /* Increment past '/' delimiter */
761 np = __of_find_node_by_path(np, path);
762 path = strchrnul(path, '/');
764 raw_spin_unlock_irqrestore(&devtree_lock, flags);
767 EXPORT_SYMBOL(of_find_node_by_path);
770 * of_find_node_by_name - Find a node by its "name" property
771 * @from: The node to start searching from or NULL, the node
772 * you pass will not be searched, only the next one
773 * will; typically, you pass what the previous call
774 * returned. of_node_put() will be called on it
775 * @name: The name string to match against
777 * Returns a node pointer with refcount incremented, use
778 * of_node_put() on it when done.
780 struct device_node *of_find_node_by_name(struct device_node *from,
783 struct device_node *np;
786 raw_spin_lock_irqsave(&devtree_lock, flags);
787 np = from ? from->allnext : of_allnodes;
788 for (; np; np = np->allnext)
789 if (np->name && (of_node_cmp(np->name, name) == 0)
793 raw_spin_unlock_irqrestore(&devtree_lock, flags);
796 EXPORT_SYMBOL(of_find_node_by_name);
799 * of_find_node_by_type - Find a node by its "device_type" property
800 * @from: The node to start searching from, or NULL to start searching
801 * the entire device tree. The node you pass will not be
802 * searched, only the next one will; typically, you pass
803 * what the previous call returned. of_node_put() will be
804 * called on from for you.
805 * @type: The type string to match against
807 * Returns a node pointer with refcount incremented, use
808 * of_node_put() on it when done.
810 struct device_node *of_find_node_by_type(struct device_node *from,
813 struct device_node *np;
816 raw_spin_lock_irqsave(&devtree_lock, flags);
817 np = from ? from->allnext : of_allnodes;
818 for (; np; np = np->allnext)
819 if (np->type && (of_node_cmp(np->type, type) == 0)
823 raw_spin_unlock_irqrestore(&devtree_lock, flags);
826 EXPORT_SYMBOL(of_find_node_by_type);
829 * of_find_compatible_node - Find a node based on type and one of the
830 * tokens in its "compatible" property
831 * @from: The node to start searching from or NULL, the node
832 * you pass will not be searched, only the next one
833 * will; typically, you pass what the previous call
834 * returned. of_node_put() will be called on it
835 * @type: The type string to match "device_type" or NULL to ignore
836 * @compatible: The string to match to one of the tokens in the device
839 * Returns a node pointer with refcount incremented, use
840 * of_node_put() on it when done.
842 struct device_node *of_find_compatible_node(struct device_node *from,
843 const char *type, const char *compatible)
845 struct device_node *np;
848 raw_spin_lock_irqsave(&devtree_lock, flags);
849 np = from ? from->allnext : of_allnodes;
850 for (; np; np = np->allnext) {
851 if (__of_device_is_compatible(np, compatible, type, NULL) &&
856 raw_spin_unlock_irqrestore(&devtree_lock, flags);
859 EXPORT_SYMBOL(of_find_compatible_node);
862 * of_find_node_with_property - Find a node which has a property with
864 * @from: The node to start searching from or NULL, the node
865 * you pass will not be searched, only the next one
866 * will; typically, you pass what the previous call
867 * returned. of_node_put() will be called on it
868 * @prop_name: The name of the property to look for.
870 * Returns a node pointer with refcount incremented, use
871 * of_node_put() on it when done.
873 struct device_node *of_find_node_with_property(struct device_node *from,
874 const char *prop_name)
876 struct device_node *np;
880 raw_spin_lock_irqsave(&devtree_lock, flags);
881 np = from ? from->allnext : of_allnodes;
882 for (; np; np = np->allnext) {
883 for (pp = np->properties; pp; pp = pp->next) {
884 if (of_prop_cmp(pp->name, prop_name) == 0) {
892 raw_spin_unlock_irqrestore(&devtree_lock, flags);
895 EXPORT_SYMBOL(of_find_node_with_property);
898 const struct of_device_id *__of_match_node(const struct of_device_id *matches,
899 const struct device_node *node)
901 const struct of_device_id *best_match = NULL;
902 int score, best_score = 0;
907 for (; matches->name[0] || matches->type[0] || matches->compatible[0]; matches++) {
908 score = __of_device_is_compatible(node, matches->compatible,
909 matches->type, matches->name);
910 if (score > best_score) {
911 best_match = matches;
920 * of_match_node - Tell if an device_node has a matching of_match structure
921 * @matches: array of of device match structures to search in
922 * @node: the of device structure to match against
924 * Low level utility function used by device matching.
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 *match;
932 raw_spin_lock_irqsave(&devtree_lock, flags);
933 match = __of_match_node(matches, node);
934 raw_spin_unlock_irqrestore(&devtree_lock, flags);
937 EXPORT_SYMBOL(of_match_node);
940 * of_find_matching_node_and_match - Find a node based on an of_device_id
942 * @from: The node to start searching from or NULL, the node
943 * you pass will not be searched, only the next one
944 * will; typically, you pass what the previous call
945 * returned. of_node_put() will be called on it
946 * @matches: array of of device match structures to search in
947 * @match Updated to point at the matches entry which matched
949 * Returns a node pointer with refcount incremented, use
950 * of_node_put() on it when done.
952 struct device_node *of_find_matching_node_and_match(struct device_node *from,
953 const struct of_device_id *matches,
954 const struct of_device_id **match)
956 struct device_node *np;
957 const struct of_device_id *m;
963 raw_spin_lock_irqsave(&devtree_lock, flags);
964 np = from ? from->allnext : of_allnodes;
965 for (; np; np = np->allnext) {
966 m = __of_match_node(matches, np);
967 if (m && of_node_get(np)) {
974 raw_spin_unlock_irqrestore(&devtree_lock, flags);
977 EXPORT_SYMBOL(of_find_matching_node_and_match);
980 * of_modalias_node - Lookup appropriate modalias for a device node
981 * @node: pointer to a device tree node
982 * @modalias: Pointer to buffer that modalias value will be copied into
983 * @len: Length of modalias value
985 * Based on the value of the compatible property, this routine will attempt
986 * to choose an appropriate modalias value for a particular device tree node.
987 * It does this by stripping the manufacturer prefix (as delimited by a ',')
988 * from the first entry in the compatible list property.
990 * This routine returns 0 on success, <0 on failure.
992 int of_modalias_node(struct device_node *node, char *modalias, int len)
994 const char *compatible, *p;
997 compatible = of_get_property(node, "compatible", &cplen);
998 if (!compatible || strlen(compatible) > cplen)
1000 p = strchr(compatible, ',');
1001 strlcpy(modalias, p ? p + 1 : compatible, len);
1004 EXPORT_SYMBOL_GPL(of_modalias_node);
1007 * of_find_node_by_phandle - Find a node given a phandle
1008 * @handle: phandle of the node to find
1010 * Returns a node pointer with refcount incremented, use
1011 * of_node_put() on it when done.
1013 struct device_node *of_find_node_by_phandle(phandle handle)
1015 struct device_node *np;
1016 unsigned long flags;
1018 raw_spin_lock_irqsave(&devtree_lock, flags);
1019 for (np = of_allnodes; np; np = np->allnext)
1020 if (np->phandle == handle)
1023 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1026 EXPORT_SYMBOL(of_find_node_by_phandle);
1029 * of_property_count_elems_of_size - Count the number of elements in a property
1031 * @np: device node from which the property value is to be read.
1032 * @propname: name of the property to be searched.
1033 * @elem_size: size of the individual element
1035 * Search for a property in a device node and count the number of elements of
1036 * size elem_size in it. Returns number of elements on sucess, -EINVAL if the
1037 * property does not exist or its length does not match a multiple of elem_size
1038 * and -ENODATA if the property does not have a value.
1040 int of_property_count_elems_of_size(const struct device_node *np,
1041 const char *propname, int elem_size)
1043 struct property *prop = of_find_property(np, propname, NULL);
1050 if (prop->length % elem_size != 0) {
1051 pr_err("size of %s in node %s is not a multiple of %d\n",
1052 propname, np->full_name, elem_size);
1056 return prop->length / elem_size;
1058 EXPORT_SYMBOL_GPL(of_property_count_elems_of_size);
1061 * of_find_property_value_of_size
1063 * @np: device node from which the property value is to be read.
1064 * @propname: name of the property to be searched.
1065 * @len: requested length of property value
1067 * Search for a property in a device node and valid the requested size.
1068 * Returns the property value on success, -EINVAL if the property does not
1069 * exist, -ENODATA if property does not have a value, and -EOVERFLOW if the
1070 * property data isn't large enough.
1073 static void *of_find_property_value_of_size(const struct device_node *np,
1074 const char *propname, u32 len)
1076 struct property *prop = of_find_property(np, propname, NULL);
1079 return ERR_PTR(-EINVAL);
1081 return ERR_PTR(-ENODATA);
1082 if (len > prop->length)
1083 return ERR_PTR(-EOVERFLOW);
1089 * of_property_read_u32_index - Find and read a u32 from a multi-value property.
1091 * @np: device node from which the property value is to be read.
1092 * @propname: name of the property to be searched.
1093 * @index: index of the u32 in the list of values
1094 * @out_value: pointer to return value, modified only if no error.
1096 * Search for a property in a device node and read nth 32-bit value from
1097 * it. Returns 0 on success, -EINVAL if the property does not exist,
1098 * -ENODATA if property does not have a value, and -EOVERFLOW if the
1099 * property data isn't large enough.
1101 * The out_value is modified only if a valid u32 value can be decoded.
1103 int of_property_read_u32_index(const struct device_node *np,
1104 const char *propname,
1105 u32 index, u32 *out_value)
1107 const u32 *val = of_find_property_value_of_size(np, propname,
1108 ((index + 1) * sizeof(*out_value)));
1111 return PTR_ERR(val);
1113 *out_value = be32_to_cpup(((__be32 *)val) + index);
1116 EXPORT_SYMBOL_GPL(of_property_read_u32_index);
1119 * of_property_read_u8_array - Find and read an array of u8 from a property.
1121 * @np: device node from which the property value is to be read.
1122 * @propname: name of the property to be searched.
1123 * @out_values: pointer to return value, modified only if return value is 0.
1124 * @sz: number of array elements to read
1126 * Search for a property in a device node and read 8-bit value(s) from
1127 * it. Returns 0 on success, -EINVAL if the property does not exist,
1128 * -ENODATA if property does not have a value, and -EOVERFLOW if the
1129 * property data isn't large enough.
1131 * dts entry of array should be like:
1132 * property = /bits/ 8 <0x50 0x60 0x70>;
1134 * The out_values is modified only if a valid u8 value can be decoded.
1136 int of_property_read_u8_array(const struct device_node *np,
1137 const char *propname, u8 *out_values, size_t sz)
1139 const u8 *val = of_find_property_value_of_size(np, propname,
1140 (sz * sizeof(*out_values)));
1143 return PTR_ERR(val);
1146 *out_values++ = *val++;
1149 EXPORT_SYMBOL_GPL(of_property_read_u8_array);
1152 * of_property_read_u16_array - Find and read an array of u16 from a property.
1154 * @np: device node from which the property value is to be read.
1155 * @propname: name of the property to be searched.
1156 * @out_values: pointer to return value, modified only if return value is 0.
1157 * @sz: number of array elements to read
1159 * Search for a property in a device node and read 16-bit value(s) from
1160 * it. Returns 0 on success, -EINVAL if the property does not exist,
1161 * -ENODATA if property does not have a value, and -EOVERFLOW if the
1162 * property data isn't large enough.
1164 * dts entry of array should be like:
1165 * property = /bits/ 16 <0x5000 0x6000 0x7000>;
1167 * The out_values is modified only if a valid u16 value can be decoded.
1169 int of_property_read_u16_array(const struct device_node *np,
1170 const char *propname, u16 *out_values, size_t sz)
1172 const __be16 *val = of_find_property_value_of_size(np, propname,
1173 (sz * sizeof(*out_values)));
1176 return PTR_ERR(val);
1179 *out_values++ = be16_to_cpup(val++);
1182 EXPORT_SYMBOL_GPL(of_property_read_u16_array);
1185 * of_property_read_u32_array - Find and read an array of 32 bit integers
1188 * @np: device node from which the property value is to be read.
1189 * @propname: name of the property to be searched.
1190 * @out_values: pointer to return value, modified only if return value is 0.
1191 * @sz: number of array elements to read
1193 * Search for a property in a device node and read 32-bit value(s) from
1194 * it. Returns 0 on success, -EINVAL if the property does not exist,
1195 * -ENODATA if property does not have a value, and -EOVERFLOW if the
1196 * property data isn't large enough.
1198 * The out_values is modified only if a valid u32 value can be decoded.
1200 int of_property_read_u32_array(const struct device_node *np,
1201 const char *propname, u32 *out_values,
1204 const __be32 *val = of_find_property_value_of_size(np, propname,
1205 (sz * sizeof(*out_values)));
1208 return PTR_ERR(val);
1211 *out_values++ = be32_to_cpup(val++);
1214 EXPORT_SYMBOL_GPL(of_property_read_u32_array);
1217 * of_property_read_u64 - Find and read a 64 bit integer from a property
1218 * @np: device node from which the property value is to be read.
1219 * @propname: name of the property to be searched.
1220 * @out_value: pointer to return value, modified only if return value is 0.
1222 * Search for a property in a device node and read a 64-bit value from
1223 * it. Returns 0 on success, -EINVAL if the property does not exist,
1224 * -ENODATA if property does not have a value, and -EOVERFLOW if the
1225 * property data isn't large enough.
1227 * The out_value is modified only if a valid u64 value can be decoded.
1229 int of_property_read_u64(const struct device_node *np, const char *propname,
1232 const __be32 *val = of_find_property_value_of_size(np, propname,
1233 sizeof(*out_value));
1236 return PTR_ERR(val);
1238 *out_value = of_read_number(val, 2);
1241 EXPORT_SYMBOL_GPL(of_property_read_u64);
1244 * of_property_read_string - Find and read a string from a property
1245 * @np: device node from which the property value is to be read.
1246 * @propname: name of the property to be searched.
1247 * @out_string: pointer to null terminated return string, modified only if
1248 * return value is 0.
1250 * Search for a property in a device tree node and retrieve a null
1251 * terminated string value (pointer to data, not a copy). Returns 0 on
1252 * success, -EINVAL if the property does not exist, -ENODATA if property
1253 * does not have a value, and -EILSEQ if the string is not null-terminated
1254 * within the length of the property data.
1256 * The out_string pointer is modified only if a valid string can be decoded.
1258 int of_property_read_string(struct device_node *np, const char *propname,
1259 const char **out_string)
1261 struct property *prop = of_find_property(np, propname, NULL);
1266 if (strnlen(prop->value, prop->length) >= prop->length)
1268 *out_string = prop->value;
1271 EXPORT_SYMBOL_GPL(of_property_read_string);
1274 * of_property_read_string_index - Find and read a string from a multiple
1276 * @np: device node from which the property value is to be read.
1277 * @propname: name of the property to be searched.
1278 * @index: index of the string in the list of strings
1279 * @out_string: pointer to null terminated return string, modified only if
1280 * return value is 0.
1282 * Search for a property in a device tree node and retrieve a null
1283 * terminated string value (pointer to data, not a copy) in the list of strings
1284 * contained in that property.
1285 * Returns 0 on success, -EINVAL if the property does not exist, -ENODATA if
1286 * property does not have a value, and -EILSEQ if the string is not
1287 * null-terminated within the length of the property data.
1289 * The out_string pointer is modified only if a valid string can be decoded.
1291 int of_property_read_string_index(struct device_node *np, const char *propname,
1292 int index, const char **output)
1294 struct property *prop = of_find_property(np, propname, NULL);
1296 size_t l = 0, total = 0;
1303 if (strnlen(prop->value, prop->length) >= prop->length)
1308 for (i = 0; total < prop->length; total += l, p += l) {
1317 EXPORT_SYMBOL_GPL(of_property_read_string_index);
1320 * of_property_match_string() - Find string in a list and return index
1321 * @np: pointer to node containing string list property
1322 * @propname: string list property name
1323 * @string: pointer to string to search for in string list
1325 * This function searches a string list property and returns the index
1326 * of a specific string value.
1328 int of_property_match_string(struct device_node *np, const char *propname,
1331 struct property *prop = of_find_property(np, propname, NULL);
1334 const char *p, *end;
1342 end = p + prop->length;
1344 for (i = 0; p < end; i++, p += l) {
1348 pr_debug("comparing %s with %s\n", string, p);
1349 if (strcmp(string, p) == 0)
1350 return i; /* Found it; return index */
1354 EXPORT_SYMBOL_GPL(of_property_match_string);
1357 * of_property_count_strings - Find and return the number of strings from a
1358 * multiple strings property.
1359 * @np: device node from which the property value is to be read.
1360 * @propname: name of the property to be searched.
1362 * Search for a property in a device tree node and retrieve the number of null
1363 * terminated string contain in it. Returns the number of strings on
1364 * success, -EINVAL if the property does not exist, -ENODATA if property
1365 * does not have a value, and -EILSEQ if the string is not null-terminated
1366 * within the length of the property data.
1368 int of_property_count_strings(struct device_node *np, const char *propname)
1370 struct property *prop = of_find_property(np, propname, NULL);
1372 size_t l = 0, total = 0;
1379 if (strnlen(prop->value, prop->length) >= prop->length)
1384 for (i = 0; total < prop->length; total += l, p += l, i++)
1389 EXPORT_SYMBOL_GPL(of_property_count_strings);
1391 void of_print_phandle_args(const char *msg, const struct of_phandle_args *args)
1394 printk("%s %s", msg, of_node_full_name(args->np));
1395 for (i = 0; i < args->args_count; i++)
1396 printk(i ? ",%08x" : ":%08x", args->args[i]);
1400 static int __of_parse_phandle_with_args(const struct device_node *np,
1401 const char *list_name,
1402 const char *cells_name,
1403 int cell_count, int index,
1404 struct of_phandle_args *out_args)
1406 const __be32 *list, *list_end;
1407 int rc = 0, size, cur_index = 0;
1409 struct device_node *node = NULL;
1412 /* Retrieve the phandle list property */
1413 list = of_get_property(np, list_name, &size);
1416 list_end = list + size / sizeof(*list);
1418 /* Loop over the phandles until all the requested entry is found */
1419 while (list < list_end) {
1424 * If phandle is 0, then it is an empty entry with no
1425 * arguments. Skip forward to the next entry.
1427 phandle = be32_to_cpup(list++);
1430 * Find the provider node and parse the #*-cells
1431 * property to determine the argument length.
1433 * This is not needed if the cell count is hard-coded
1434 * (i.e. cells_name not set, but cell_count is set),
1435 * except when we're going to return the found node
1438 if (cells_name || cur_index == index) {
1439 node = of_find_node_by_phandle(phandle);
1441 pr_err("%s: could not find phandle\n",
1448 if (of_property_read_u32(node, cells_name,
1450 pr_err("%s: could not get %s for %s\n",
1451 np->full_name, cells_name,
1460 * Make sure that the arguments actually fit in the
1461 * remaining property data length
1463 if (list + count > list_end) {
1464 pr_err("%s: arguments longer than property\n",
1471 * All of the error cases above bail out of the loop, so at
1472 * this point, the parsing is successful. If the requested
1473 * index matches, then fill the out_args structure and return,
1474 * or return -ENOENT for an empty entry.
1477 if (cur_index == index) {
1483 if (WARN_ON(count > MAX_PHANDLE_ARGS))
1484 count = MAX_PHANDLE_ARGS;
1485 out_args->np = node;
1486 out_args->args_count = count;
1487 for (i = 0; i < count; i++)
1488 out_args->args[i] = be32_to_cpup(list++);
1493 /* Found it! return success */
1504 * Unlock node before returning result; will be one of:
1505 * -ENOENT : index is for empty phandle
1506 * -EINVAL : parsing error on data
1507 * [1..n] : Number of phandle (count mode; when index = -1)
1509 rc = index < 0 ? cur_index : -ENOENT;
1517 * of_parse_phandle - Resolve a phandle property to a device_node pointer
1518 * @np: Pointer to device node holding phandle property
1519 * @phandle_name: Name of property holding a phandle value
1520 * @index: For properties holding a table of phandles, this is the index into
1523 * Returns the device_node pointer with refcount incremented. Use
1524 * of_node_put() on it when done.
1526 struct device_node *of_parse_phandle(const struct device_node *np,
1527 const char *phandle_name, int index)
1529 struct of_phandle_args args;
1534 if (__of_parse_phandle_with_args(np, phandle_name, NULL, 0,
1540 EXPORT_SYMBOL(of_parse_phandle);
1543 * of_parse_phandle_with_args() - Find a node pointed by phandle in a list
1544 * @np: pointer to a device tree node containing a list
1545 * @list_name: property name that contains a list
1546 * @cells_name: property name that specifies phandles' arguments count
1547 * @index: index of a phandle to parse out
1548 * @out_args: optional pointer to output arguments structure (will be filled)
1550 * This function is useful to parse lists of phandles and their arguments.
1551 * Returns 0 on success and fills out_args, on error returns appropriate
1554 * Caller is responsible to call of_node_put() on the returned out_args->node
1560 * #list-cells = <2>;
1564 * #list-cells = <1>;
1568 * list = <&phandle1 1 2 &phandle2 3>;
1571 * To get a device_node of the `node2' node you may call this:
1572 * of_parse_phandle_with_args(node3, "list", "#list-cells", 1, &args);
1574 int of_parse_phandle_with_args(const struct device_node *np, const char *list_name,
1575 const char *cells_name, int index,
1576 struct of_phandle_args *out_args)
1580 return __of_parse_phandle_with_args(np, list_name, cells_name, 0,
1583 EXPORT_SYMBOL(of_parse_phandle_with_args);
1586 * of_parse_phandle_with_fixed_args() - Find a node pointed by phandle in a list
1587 * @np: pointer to a device tree node containing a list
1588 * @list_name: property name that contains a list
1589 * @cell_count: number of argument cells following the phandle
1590 * @index: index of a phandle to parse out
1591 * @out_args: optional pointer to output arguments structure (will be filled)
1593 * This function is useful to parse lists of phandles and their arguments.
1594 * Returns 0 on success and fills out_args, on error returns appropriate
1597 * Caller is responsible to call of_node_put() on the returned out_args->node
1609 * list = <&phandle1 0 2 &phandle2 2 3>;
1612 * To get a device_node of the `node2' node you may call this:
1613 * of_parse_phandle_with_fixed_args(node3, "list", 2, 1, &args);
1615 int of_parse_phandle_with_fixed_args(const struct device_node *np,
1616 const char *list_name, int cell_count,
1617 int index, struct of_phandle_args *out_args)
1621 return __of_parse_phandle_with_args(np, list_name, NULL, cell_count,
1624 EXPORT_SYMBOL(of_parse_phandle_with_fixed_args);
1627 * of_count_phandle_with_args() - Find the number of phandles references in a property
1628 * @np: pointer to a device tree node containing a list
1629 * @list_name: property name that contains a list
1630 * @cells_name: property name that specifies phandles' arguments count
1632 * Returns the number of phandle + argument tuples within a property. It
1633 * is a typical pattern to encode a list of phandle and variable
1634 * arguments into a single property. The number of arguments is encoded
1635 * by a property in the phandle-target node. For example, a gpios
1636 * property would contain a list of GPIO specifies consisting of a
1637 * phandle and 1 or more arguments. The number of arguments are
1638 * determined by the #gpio-cells property in the node pointed to by the
1641 int of_count_phandle_with_args(const struct device_node *np, const char *list_name,
1642 const char *cells_name)
1644 return __of_parse_phandle_with_args(np, list_name, cells_name, 0, -1,
1647 EXPORT_SYMBOL(of_count_phandle_with_args);
1650 * __of_add_property - Add a property to a node without lock operations
1652 int __of_add_property(struct device_node *np, struct property *prop)
1654 struct property **next;
1657 next = &np->properties;
1659 if (strcmp(prop->name, (*next)->name) == 0)
1660 /* duplicate ! don't insert it */
1663 next = &(*next)->next;
1671 * of_add_property - Add a property to a node
1673 int of_add_property(struct device_node *np, struct property *prop)
1675 unsigned long flags;
1678 mutex_lock(&of_mutex);
1680 raw_spin_lock_irqsave(&devtree_lock, flags);
1681 rc = __of_add_property(np, prop);
1682 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1685 __of_add_property_sysfs(np, prop);
1687 mutex_unlock(&of_mutex);
1690 of_property_notify(OF_RECONFIG_ADD_PROPERTY, np, prop, NULL);
1695 int __of_remove_property(struct device_node *np, struct property *prop)
1697 struct property **next;
1699 for (next = &np->properties; *next; next = &(*next)->next) {
1706 /* found the node */
1708 prop->next = np->deadprops;
1709 np->deadprops = prop;
1714 void __of_remove_property_sysfs(struct device_node *np, struct property *prop)
1716 /* at early boot, bail here and defer setup to of_init() */
1717 if (of_kset && of_node_is_attached(np))
1718 sysfs_remove_bin_file(&np->kobj, &prop->attr);
1722 * of_remove_property - Remove a property from a node.
1724 * Note that we don't actually remove it, since we have given out
1725 * who-knows-how-many pointers to the data using get-property.
1726 * Instead we just move the property to the "dead properties"
1727 * list, so it won't be found any more.
1729 int of_remove_property(struct device_node *np, struct property *prop)
1731 unsigned long flags;
1734 mutex_lock(&of_mutex);
1736 raw_spin_lock_irqsave(&devtree_lock, flags);
1737 rc = __of_remove_property(np, prop);
1738 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1741 __of_remove_property_sysfs(np, prop);
1743 mutex_unlock(&of_mutex);
1746 of_property_notify(OF_RECONFIG_REMOVE_PROPERTY, np, prop, NULL);
1751 int __of_update_property(struct device_node *np, struct property *newprop,
1752 struct property **oldpropp)
1754 struct property **next, *oldprop;
1756 for (next = &np->properties; *next; next = &(*next)->next) {
1757 if (of_prop_cmp((*next)->name, newprop->name) == 0)
1760 *oldpropp = oldprop = *next;
1763 /* replace the node */
1764 newprop->next = oldprop->next;
1766 oldprop->next = np->deadprops;
1767 np->deadprops = oldprop;
1770 newprop->next = NULL;
1777 void __of_update_property_sysfs(struct device_node *np, struct property *newprop,
1778 struct property *oldprop)
1780 /* At early boot, bail out and defer setup to of_init() */
1785 sysfs_remove_bin_file(&np->kobj, &oldprop->attr);
1786 __of_add_property_sysfs(np, newprop);
1790 * of_update_property - Update a property in a node, if the property does
1791 * not exist, add it.
1793 * Note that we don't actually remove it, since we have given out
1794 * who-knows-how-many pointers to the data using get-property.
1795 * Instead we just move the property to the "dead properties" list,
1796 * and add the new property to the property list
1798 int of_update_property(struct device_node *np, struct property *newprop)
1800 struct property *oldprop;
1801 unsigned long flags;
1807 mutex_lock(&of_mutex);
1809 raw_spin_lock_irqsave(&devtree_lock, flags);
1810 rc = __of_update_property(np, newprop, &oldprop);
1811 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1814 __of_update_property_sysfs(np, newprop, oldprop);
1816 mutex_unlock(&of_mutex);
1819 of_property_notify(OF_RECONFIG_UPDATE_PROPERTY, np, newprop, oldprop);
1824 static void of_alias_add(struct alias_prop *ap, struct device_node *np,
1825 int id, const char *stem, int stem_len)
1829 strncpy(ap->stem, stem, stem_len);
1830 ap->stem[stem_len] = 0;
1831 list_add_tail(&ap->link, &aliases_lookup);
1832 pr_debug("adding DT alias:%s: stem=%s id=%i node=%s\n",
1833 ap->alias, ap->stem, ap->id, of_node_full_name(np));
1837 * of_alias_scan - Scan all properties of 'aliases' node
1839 * The function scans all the properties of 'aliases' node and populate
1840 * the the global lookup table with the properties. It returns the
1841 * number of alias_prop found, or error code in error case.
1843 * @dt_alloc: An allocator that provides a virtual address to memory
1844 * for the resulting tree
1846 void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align))
1848 struct property *pp;
1850 of_chosen = of_find_node_by_path("/chosen");
1851 if (of_chosen == NULL)
1852 of_chosen = of_find_node_by_path("/chosen@0");
1855 /* linux,stdout-path and /aliases/stdout are for legacy compatibility */
1856 const char *name = of_get_property(of_chosen, "stdout-path", NULL);
1858 name = of_get_property(of_chosen, "linux,stdout-path", NULL);
1859 if (IS_ENABLED(CONFIG_PPC) && !name)
1860 name = of_get_property(of_aliases, "stdout", NULL);
1862 of_stdout = of_find_node_by_path(name);
1865 of_aliases = of_find_node_by_path("/aliases");
1869 for_each_property_of_node(of_aliases, pp) {
1870 const char *start = pp->name;
1871 const char *end = start + strlen(start);
1872 struct device_node *np;
1873 struct alias_prop *ap;
1876 /* Skip those we do not want to proceed */
1877 if (!strcmp(pp->name, "name") ||
1878 !strcmp(pp->name, "phandle") ||
1879 !strcmp(pp->name, "linux,phandle"))
1882 np = of_find_node_by_path(pp->value);
1886 /* walk the alias backwards to extract the id and work out
1887 * the 'stem' string */
1888 while (isdigit(*(end-1)) && end > start)
1892 if (kstrtoint(end, 10, &id) < 0)
1895 /* Allocate an alias_prop with enough space for the stem */
1896 ap = dt_alloc(sizeof(*ap) + len + 1, 4);
1899 memset(ap, 0, sizeof(*ap) + len + 1);
1901 of_alias_add(ap, np, id, start, len);
1906 * of_alias_get_id - Get alias id for the given device_node
1907 * @np: Pointer to the given device_node
1908 * @stem: Alias stem of the given device_node
1910 * The function travels the lookup table to get the alias id for the given
1911 * device_node and alias stem. It returns the alias id if found.
1913 int of_alias_get_id(struct device_node *np, const char *stem)
1915 struct alias_prop *app;
1918 mutex_lock(&of_mutex);
1919 list_for_each_entry(app, &aliases_lookup, link) {
1920 if (strcmp(app->stem, stem) != 0)
1923 if (np == app->np) {
1928 mutex_unlock(&of_mutex);
1932 EXPORT_SYMBOL_GPL(of_alias_get_id);
1934 const __be32 *of_prop_next_u32(struct property *prop, const __be32 *cur,
1937 const void *curv = cur;
1947 curv += sizeof(*cur);
1948 if (curv >= prop->value + prop->length)
1952 *pu = be32_to_cpup(curv);
1955 EXPORT_SYMBOL_GPL(of_prop_next_u32);
1957 const char *of_prop_next_string(struct property *prop, const char *cur)
1959 const void *curv = cur;
1967 curv += strlen(cur) + 1;
1968 if (curv >= prop->value + prop->length)
1973 EXPORT_SYMBOL_GPL(of_prop_next_string);
1976 * of_console_check() - Test and setup console for DT setup
1977 * @dn - Pointer to device node
1978 * @name - Name to use for preferred console without index. ex. "ttyS"
1979 * @index - Index to use for preferred console.
1981 * Check if the given device node matches the stdout-path property in the
1982 * /chosen node. If it does then register it as the preferred console and return
1983 * TRUE. Otherwise return FALSE.
1985 bool of_console_check(struct device_node *dn, char *name, int index)
1987 if (!dn || dn != of_stdout || console_set_on_cmdline)
1989 return add_preferred_console(name, index, NULL);
1991 EXPORT_SYMBOL_GPL(of_console_check);
1994 * of_find_next_cache_node - Find a node's subsidiary cache
1995 * @np: node of type "cpu" or "cache"
1997 * Returns a node pointer with refcount incremented, use
1998 * of_node_put() on it when done. Caller should hold a reference
2001 struct device_node *of_find_next_cache_node(const struct device_node *np)
2003 struct device_node *child;
2004 const phandle *handle;
2006 handle = of_get_property(np, "l2-cache", NULL);
2008 handle = of_get_property(np, "next-level-cache", NULL);
2011 return of_find_node_by_phandle(be32_to_cpup(handle));
2013 /* OF on pmac has nodes instead of properties named "l2-cache"
2014 * beneath CPU nodes.
2016 if (!strcmp(np->type, "cpu"))
2017 for_each_child_of_node(np, child)
2018 if (!strcmp(child->type, "cache"))
2025 * of_graph_parse_endpoint() - parse common endpoint node properties
2026 * @node: pointer to endpoint device_node
2027 * @endpoint: pointer to the OF endpoint data structure
2029 * The caller should hold a reference to @node.
2031 int of_graph_parse_endpoint(const struct device_node *node,
2032 struct of_endpoint *endpoint)
2034 struct device_node *port_node = of_get_parent(node);
2036 WARN_ONCE(!port_node, "%s(): endpoint %s has no parent node\n",
2037 __func__, node->full_name);
2039 memset(endpoint, 0, sizeof(*endpoint));
2041 endpoint->local_node = node;
2043 * It doesn't matter whether the two calls below succeed.
2044 * If they don't then the default value 0 is used.
2046 of_property_read_u32(port_node, "reg", &endpoint->port);
2047 of_property_read_u32(node, "reg", &endpoint->id);
2049 of_node_put(port_node);
2053 EXPORT_SYMBOL(of_graph_parse_endpoint);
2056 * of_graph_get_next_endpoint() - get next endpoint node
2057 * @parent: pointer to the parent device node
2058 * @prev: previous endpoint node, or NULL to get first
2060 * Return: An 'endpoint' node pointer with refcount incremented. Refcount
2061 * of the passed @prev node is not decremented, the caller have to use
2062 * of_node_put() on it when done.
2064 struct device_node *of_graph_get_next_endpoint(const struct device_node *parent,
2065 struct device_node *prev)
2067 struct device_node *endpoint;
2068 struct device_node *port;
2074 * Start by locating the port node. If no previous endpoint is specified
2075 * search for the first port node, otherwise get the previous endpoint
2079 struct device_node *node;
2081 node = of_get_child_by_name(parent, "ports");
2085 port = of_get_child_by_name(parent, "port");
2089 pr_err("%s(): no port node found in %s\n",
2090 __func__, parent->full_name);
2094 port = of_get_parent(prev);
2095 if (WARN_ONCE(!port, "%s(): endpoint %s has no parent node\n",
2096 __func__, prev->full_name))
2100 * Avoid dropping prev node refcount to 0 when getting the next
2108 * Now that we have a port node, get the next endpoint by
2109 * getting the next child. If the previous endpoint is NULL this
2110 * will return the first child.
2112 endpoint = of_get_next_child(port, prev);
2118 /* No more endpoints under this port, try the next one. */
2122 port = of_get_next_child(parent, port);
2125 } while (of_node_cmp(port->name, "port"));
2128 EXPORT_SYMBOL(of_graph_get_next_endpoint);
2131 * of_graph_get_remote_port_parent() - get remote port's parent node
2132 * @node: pointer to a local endpoint device_node
2134 * Return: Remote device node associated with remote endpoint node linked
2135 * to @node. Use of_node_put() on it when done.
2137 struct device_node *of_graph_get_remote_port_parent(
2138 const struct device_node *node)
2140 struct device_node *np;
2143 /* Get remote endpoint node. */
2144 np = of_parse_phandle(node, "remote-endpoint", 0);
2146 /* Walk 3 levels up only if there is 'ports' node. */
2147 for (depth = 3; depth && np; depth--) {
2148 np = of_get_next_parent(np);
2149 if (depth == 2 && of_node_cmp(np->name, "ports"))
2154 EXPORT_SYMBOL(of_graph_get_remote_port_parent);
2157 * of_graph_get_remote_port() - get remote port node
2158 * @node: pointer to a local endpoint device_node
2160 * Return: Remote port node associated with remote endpoint node linked
2161 * to @node. Use of_node_put() on it when done.
2163 struct device_node *of_graph_get_remote_port(const struct device_node *node)
2165 struct device_node *np;
2167 /* Get remote endpoint node. */
2168 np = of_parse_phandle(node, "remote-endpoint", 0);
2171 return of_get_next_parent(np);
2173 EXPORT_SYMBOL(of_graph_get_remote_port);