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_root;
36 EXPORT_SYMBOL(of_root);
37 struct device_node *of_chosen;
38 struct device_node *of_aliases;
39 struct device_node *of_stdout;
40 static const char *of_stdout_options;
45 * Used to protect the of_aliases, to hold off addition of nodes to sysfs.
46 * This mutex must be held whenever modifications are being made to the
47 * device tree. The of_{attach,detach}_node() and
48 * of_{add,remove,update}_property() helpers make sure this happens.
50 DEFINE_MUTEX(of_mutex);
52 /* use when traversing tree through the child, sibling,
53 * or parent members of struct device_node.
55 DEFINE_RAW_SPINLOCK(devtree_lock);
57 int of_n_addr_cells(struct device_node *np)
64 ip = of_get_property(np, "#address-cells", NULL);
66 return be32_to_cpup(ip);
68 /* No #address-cells property for the root node */
69 return OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
71 EXPORT_SYMBOL(of_n_addr_cells);
73 int of_n_size_cells(struct device_node *np)
80 ip = of_get_property(np, "#size-cells", NULL);
82 return be32_to_cpup(ip);
84 /* No #size-cells property for the root node */
85 return OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
87 EXPORT_SYMBOL(of_n_size_cells);
90 int __weak of_node_to_nid(struct device_node *np)
96 #ifndef CONFIG_OF_DYNAMIC
97 static void of_node_release(struct kobject *kobj)
99 /* Without CONFIG_OF_DYNAMIC, no nodes gets freed */
101 #endif /* CONFIG_OF_DYNAMIC */
103 struct kobj_type of_node_ktype = {
104 .release = of_node_release,
107 static ssize_t of_node_property_read(struct file *filp, struct kobject *kobj,
108 struct bin_attribute *bin_attr, char *buf,
109 loff_t offset, size_t count)
111 struct property *pp = container_of(bin_attr, struct property, attr);
112 return memory_read_from_buffer(buf, count, &offset, pp->value, pp->length);
115 /* always return newly allocated name, caller must free after use */
116 static const char *safe_name(struct kobject *kobj, const char *orig_name)
118 const char *name = orig_name;
119 struct kernfs_node *kn;
122 /* don't be a hero. After 16 tries give up */
123 while (i < 16 && (kn = sysfs_get_dirent(kobj->sd, name))) {
125 if (name != orig_name)
127 name = kasprintf(GFP_KERNEL, "%s#%i", orig_name, ++i);
130 if (name == orig_name) {
131 name = kstrdup(orig_name, GFP_KERNEL);
133 pr_warn("device-tree: Duplicate name in %s, renamed to \"%s\"\n",
134 kobject_name(kobj), name);
139 int __of_add_property_sysfs(struct device_node *np, struct property *pp)
143 /* Important: Don't leak passwords */
144 bool secure = strncmp(pp->name, "security-", 9) == 0;
146 if (!IS_ENABLED(CONFIG_SYSFS))
149 if (!of_kset || !of_node_is_attached(np))
152 sysfs_bin_attr_init(&pp->attr);
153 pp->attr.attr.name = safe_name(&np->kobj, pp->name);
154 pp->attr.attr.mode = secure ? S_IRUSR : S_IRUGO;
155 pp->attr.size = secure ? 0 : pp->length;
156 pp->attr.read = of_node_property_read;
158 rc = sysfs_create_bin_file(&np->kobj, &pp->attr);
159 WARN(rc, "error adding attribute %s to node %s\n", pp->name, np->full_name);
163 int __of_attach_node_sysfs(struct device_node *np)
166 struct kobject *parent;
170 if (!IS_ENABLED(CONFIG_SYSFS))
176 np->kobj.kset = of_kset;
178 /* Nodes without parents are new top level trees */
179 name = safe_name(&of_kset->kobj, "base");
182 name = safe_name(&np->parent->kobj, kbasename(np->full_name));
183 parent = &np->parent->kobj;
187 rc = kobject_add(&np->kobj, parent, "%s", name);
192 for_each_property_of_node(np, pp)
193 __of_add_property_sysfs(np, pp);
198 void __init of_core_init(void)
200 struct device_node *np;
202 /* Create the kset, and register existing nodes */
203 mutex_lock(&of_mutex);
204 of_kset = kset_create_and_add("devicetree", NULL, firmware_kobj);
206 mutex_unlock(&of_mutex);
207 pr_err("devicetree: failed to register existing nodes\n");
210 for_each_of_allnodes(np)
211 __of_attach_node_sysfs(np);
212 mutex_unlock(&of_mutex);
214 /* Symlink in /proc as required by userspace ABI */
216 proc_symlink("device-tree", NULL, "/sys/firmware/devicetree/base");
219 static struct property *__of_find_property(const struct device_node *np,
220 const char *name, int *lenp)
227 for (pp = np->properties; pp; pp = pp->next) {
228 if (of_prop_cmp(pp->name, name) == 0) {
238 struct property *of_find_property(const struct device_node *np,
245 raw_spin_lock_irqsave(&devtree_lock, flags);
246 pp = __of_find_property(np, name, lenp);
247 raw_spin_unlock_irqrestore(&devtree_lock, flags);
251 EXPORT_SYMBOL(of_find_property);
253 struct device_node *__of_find_all_nodes(struct device_node *prev)
255 struct device_node *np;
258 } else if (prev->child) {
261 /* Walk back up looking for a sibling, or the end of the structure */
263 while (np->parent && !np->sibling)
265 np = np->sibling; /* Might be null at the end of the tree */
271 * of_find_all_nodes - Get next node in global list
272 * @prev: Previous node or NULL to start iteration
273 * of_node_put() will be called on it
275 * Returns a node pointer with refcount incremented, use
276 * of_node_put() on it when done.
278 struct device_node *of_find_all_nodes(struct device_node *prev)
280 struct device_node *np;
283 raw_spin_lock_irqsave(&devtree_lock, flags);
284 np = __of_find_all_nodes(prev);
287 raw_spin_unlock_irqrestore(&devtree_lock, flags);
290 EXPORT_SYMBOL(of_find_all_nodes);
293 * Find a property with a given name for a given node
294 * and return the value.
296 const void *__of_get_property(const struct device_node *np,
297 const char *name, int *lenp)
299 struct property *pp = __of_find_property(np, name, lenp);
301 return pp ? pp->value : NULL;
305 * Find a property with a given name for a given node
306 * and return the value.
308 const void *of_get_property(const struct device_node *np, const char *name,
311 struct property *pp = of_find_property(np, name, lenp);
313 return pp ? pp->value : NULL;
315 EXPORT_SYMBOL(of_get_property);
318 * arch_match_cpu_phys_id - Match the given logical CPU and physical id
320 * @cpu: logical cpu index of a core/thread
321 * @phys_id: physical identifier of a core/thread
323 * CPU logical to physical index mapping is architecture specific.
324 * However this __weak function provides a default match of physical
325 * id to logical cpu index. phys_id provided here is usually values read
326 * from the device tree which must match the hardware internal registers.
328 * Returns true if the physical identifier and the logical cpu index
329 * correspond to the same core/thread, false otherwise.
331 bool __weak arch_match_cpu_phys_id(int cpu, u64 phys_id)
333 return (u32)phys_id == cpu;
337 * Checks if the given "prop_name" property holds the physical id of the
338 * core/thread corresponding to the logical cpu 'cpu'. If 'thread' is not
339 * NULL, local thread number within the core is returned in it.
341 static bool __of_find_n_match_cpu_property(struct device_node *cpun,
342 const char *prop_name, int cpu, unsigned int *thread)
345 int ac, prop_len, tid;
348 ac = of_n_addr_cells(cpun);
349 cell = of_get_property(cpun, prop_name, &prop_len);
352 prop_len /= sizeof(*cell) * ac;
353 for (tid = 0; tid < prop_len; tid++) {
354 hwid = of_read_number(cell, ac);
355 if (arch_match_cpu_phys_id(cpu, hwid)) {
366 * arch_find_n_match_cpu_physical_id - See if the given device node is
367 * for the cpu corresponding to logical cpu 'cpu'. Return true if so,
368 * else false. If 'thread' is non-NULL, the local thread number within the
369 * core is returned in it.
371 bool __weak arch_find_n_match_cpu_physical_id(struct device_node *cpun,
372 int cpu, unsigned int *thread)
374 /* Check for non-standard "ibm,ppc-interrupt-server#s" property
375 * for thread ids on PowerPC. If it doesn't exist fallback to
376 * standard "reg" property.
378 if (IS_ENABLED(CONFIG_PPC) &&
379 __of_find_n_match_cpu_property(cpun,
380 "ibm,ppc-interrupt-server#s",
384 return __of_find_n_match_cpu_property(cpun, "reg", cpu, thread);
388 * of_get_cpu_node - Get device node associated with the given logical CPU
390 * @cpu: CPU number(logical index) for which device node is required
391 * @thread: if not NULL, local thread number within the physical core is
394 * The main purpose of this function is to retrieve the device node for the
395 * given logical CPU index. It should be used to initialize the of_node in
396 * cpu device. Once of_node in cpu device is populated, all the further
397 * references can use that instead.
399 * CPU logical to physical index mapping is architecture specific and is built
400 * before booting secondary cores. This function uses arch_match_cpu_phys_id
401 * which can be overridden by architecture specific implementation.
403 * Returns a node pointer for the logical cpu with refcount incremented, use
404 * of_node_put() on it when done. Returns NULL if not found.
406 struct device_node *of_get_cpu_node(int cpu, unsigned int *thread)
408 struct device_node *cpun;
410 for_each_node_by_type(cpun, "cpu") {
411 if (arch_find_n_match_cpu_physical_id(cpun, cpu, thread))
416 EXPORT_SYMBOL(of_get_cpu_node);
419 * __of_device_is_compatible() - Check if the node matches given constraints
420 * @device: pointer to node
421 * @compat: required compatible string, NULL or "" for any match
422 * @type: required device_type value, NULL or "" for any match
423 * @name: required node name, NULL or "" for any match
425 * Checks if the given @compat, @type and @name strings match the
426 * properties of the given @device. A constraints can be skipped by
427 * passing NULL or an empty string as the constraint.
429 * Returns 0 for no match, and a positive integer on match. The return
430 * value is a relative score with larger values indicating better
431 * matches. The score is weighted for the most specific compatible value
432 * to get the highest score. Matching type is next, followed by matching
433 * name. Practically speaking, this results in the following priority
436 * 1. specific compatible && type && name
437 * 2. specific compatible && type
438 * 3. specific compatible && name
439 * 4. specific compatible
440 * 5. general compatible && type && name
441 * 6. general compatible && type
442 * 7. general compatible && name
443 * 8. general compatible
448 static int __of_device_is_compatible(const struct device_node *device,
449 const char *compat, const char *type, const char *name)
451 struct property *prop;
453 int index = 0, score = 0;
455 /* Compatible match has highest priority */
456 if (compat && compat[0]) {
457 prop = __of_find_property(device, "compatible", NULL);
458 for (cp = of_prop_next_string(prop, NULL); cp;
459 cp = of_prop_next_string(prop, cp), index++) {
460 if (of_compat_cmp(cp, compat, strlen(compat)) == 0) {
461 score = INT_MAX/2 - (index << 2);
469 /* Matching type is better than matching name */
470 if (type && type[0]) {
471 if (!device->type || of_node_cmp(type, device->type))
476 /* Matching name is a bit better than not */
477 if (name && name[0]) {
478 if (!device->name || of_node_cmp(name, device->name))
486 /** Checks if the given "compat" string matches one of the strings in
487 * the device's "compatible" property
489 int of_device_is_compatible(const struct device_node *device,
495 raw_spin_lock_irqsave(&devtree_lock, flags);
496 res = __of_device_is_compatible(device, compat, NULL, NULL);
497 raw_spin_unlock_irqrestore(&devtree_lock, flags);
500 EXPORT_SYMBOL(of_device_is_compatible);
503 * of_machine_is_compatible - Test root of device tree for a given compatible value
504 * @compat: compatible string to look for in root node's compatible property.
506 * Returns a positive integer if the root node has the given value in its
507 * compatible property.
509 int of_machine_is_compatible(const char *compat)
511 struct device_node *root;
514 root = of_find_node_by_path("/");
516 rc = of_device_is_compatible(root, compat);
521 EXPORT_SYMBOL(of_machine_is_compatible);
524 * __of_device_is_available - check if a device is available for use
526 * @device: Node to check for availability, with locks already held
528 * Returns true if the status property is absent or set to "okay" or "ok",
531 static bool __of_device_is_available(const struct device_node *device)
539 status = __of_get_property(device, "status", &statlen);
544 if (!strcmp(status, "okay") || !strcmp(status, "ok"))
552 * of_device_is_available - check if a device is available for use
554 * @device: Node to check for availability
556 * Returns true if the status property is absent or set to "okay" or "ok",
559 bool of_device_is_available(const struct device_node *device)
564 raw_spin_lock_irqsave(&devtree_lock, flags);
565 res = __of_device_is_available(device);
566 raw_spin_unlock_irqrestore(&devtree_lock, flags);
570 EXPORT_SYMBOL(of_device_is_available);
573 * of_device_is_big_endian - check if a device has BE registers
575 * @device: Node to check for endianness
577 * Returns true if the device has a "big-endian" property, or if the kernel
578 * was compiled for BE *and* the device has a "native-endian" property.
579 * Returns false otherwise.
581 * Callers would nominally use ioread32be/iowrite32be if
582 * of_device_is_big_endian() == true, or readl/writel otherwise.
584 bool of_device_is_big_endian(const struct device_node *device)
586 if (of_property_read_bool(device, "big-endian"))
588 if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) &&
589 of_property_read_bool(device, "native-endian"))
593 EXPORT_SYMBOL(of_device_is_big_endian);
596 * of_get_parent - Get a node's parent if any
597 * @node: Node to get parent
599 * Returns a node pointer with refcount incremented, use
600 * of_node_put() on it when done.
602 struct device_node *of_get_parent(const struct device_node *node)
604 struct device_node *np;
610 raw_spin_lock_irqsave(&devtree_lock, flags);
611 np = of_node_get(node->parent);
612 raw_spin_unlock_irqrestore(&devtree_lock, flags);
615 EXPORT_SYMBOL(of_get_parent);
618 * of_get_next_parent - Iterate to a node's parent
619 * @node: Node to get parent of
621 * This is like of_get_parent() except that it drops the
622 * refcount on the passed node, making it suitable for iterating
623 * through a node's parents.
625 * Returns a node pointer with refcount incremented, use
626 * of_node_put() on it when done.
628 struct device_node *of_get_next_parent(struct device_node *node)
630 struct device_node *parent;
636 raw_spin_lock_irqsave(&devtree_lock, flags);
637 parent = of_node_get(node->parent);
639 raw_spin_unlock_irqrestore(&devtree_lock, flags);
642 EXPORT_SYMBOL(of_get_next_parent);
644 static struct device_node *__of_get_next_child(const struct device_node *node,
645 struct device_node *prev)
647 struct device_node *next;
652 next = prev ? prev->sibling : node->child;
653 for (; next; next = next->sibling)
654 if (of_node_get(next))
659 #define __for_each_child_of_node(parent, child) \
660 for (child = __of_get_next_child(parent, NULL); child != NULL; \
661 child = __of_get_next_child(parent, child))
664 * of_get_next_child - Iterate a node childs
666 * @prev: previous child of the parent node, or NULL to get first
668 * Returns a node pointer with refcount incremented, use of_node_put() on
669 * it when done. Returns NULL when prev is the last child. Decrements the
672 struct device_node *of_get_next_child(const struct device_node *node,
673 struct device_node *prev)
675 struct device_node *next;
678 raw_spin_lock_irqsave(&devtree_lock, flags);
679 next = __of_get_next_child(node, prev);
680 raw_spin_unlock_irqrestore(&devtree_lock, flags);
683 EXPORT_SYMBOL(of_get_next_child);
686 * of_get_next_available_child - Find the next available child node
688 * @prev: previous child of the parent node, or NULL to get first
690 * This function is like of_get_next_child(), except that it
691 * automatically skips any disabled nodes (i.e. status = "disabled").
693 struct device_node *of_get_next_available_child(const struct device_node *node,
694 struct device_node *prev)
696 struct device_node *next;
702 raw_spin_lock_irqsave(&devtree_lock, flags);
703 next = prev ? prev->sibling : node->child;
704 for (; next; next = next->sibling) {
705 if (!__of_device_is_available(next))
707 if (of_node_get(next))
711 raw_spin_unlock_irqrestore(&devtree_lock, flags);
714 EXPORT_SYMBOL(of_get_next_available_child);
717 * of_get_child_by_name - Find the child node by name for a given parent
719 * @name: child name to look for.
721 * This function looks for child node for given matching name
723 * Returns a node pointer if found, with refcount incremented, use
724 * of_node_put() on it when done.
725 * Returns NULL if node is not found.
727 struct device_node *of_get_child_by_name(const struct device_node *node,
730 struct device_node *child;
732 for_each_child_of_node(node, child)
733 if (child->name && (of_node_cmp(child->name, name) == 0))
737 EXPORT_SYMBOL(of_get_child_by_name);
739 static struct device_node *__of_find_node_by_path(struct device_node *parent,
742 struct device_node *child;
745 len = strcspn(path, "/:");
749 __for_each_child_of_node(parent, child) {
750 const char *name = strrchr(child->full_name, '/');
751 if (WARN(!name, "malformed device_node %s\n", child->full_name))
754 if (strncmp(path, name, len) == 0 && (strlen(name) == len))
761 * of_find_node_opts_by_path - Find a node matching a full OF path
762 * @path: Either the full path to match, or if the path does not
763 * start with '/', the name of a property of the /aliases
764 * node (an alias). In the case of an alias, the node
765 * matching the alias' value will be returned.
766 * @opts: Address of a pointer into which to store the start of
767 * an options string appended to the end of the path with
773 * foo/bar Valid alias + relative path
775 * Returns a node pointer with refcount incremented, use
776 * of_node_put() on it when done.
778 struct device_node *of_find_node_opts_by_path(const char *path, const char **opts)
780 struct device_node *np = NULL;
783 const char *separator = strchr(path, ':');
786 *opts = separator ? separator + 1 : NULL;
788 if (strcmp(path, "/") == 0)
789 return of_node_get(of_root);
791 /* The path could begin with an alias */
794 const char *p = separator;
797 p = strchrnul(path, '/');
800 /* of_aliases must not be NULL */
804 for_each_property_of_node(of_aliases, pp) {
805 if (strlen(pp->name) == len && !strncmp(pp->name, path, len)) {
806 np = of_find_node_by_path(pp->value);
815 /* Step down the tree matching path components */
816 raw_spin_lock_irqsave(&devtree_lock, flags);
818 np = of_node_get(of_root);
819 while (np && *path == '/') {
820 path++; /* Increment past '/' delimiter */
821 np = __of_find_node_by_path(np, path);
822 path = strchrnul(path, '/');
823 if (separator && separator < path)
826 raw_spin_unlock_irqrestore(&devtree_lock, flags);
829 EXPORT_SYMBOL(of_find_node_opts_by_path);
832 * of_find_node_by_name - Find a node by its "name" property
833 * @from: The node to start searching from or NULL, the node
834 * you pass will not be searched, only the next one
835 * will; typically, you pass what the previous call
836 * returned. of_node_put() will be called on it
837 * @name: The name string to match against
839 * Returns a node pointer with refcount incremented, use
840 * of_node_put() on it when done.
842 struct device_node *of_find_node_by_name(struct device_node *from,
845 struct device_node *np;
848 raw_spin_lock_irqsave(&devtree_lock, flags);
849 for_each_of_allnodes_from(from, np)
850 if (np->name && (of_node_cmp(np->name, name) == 0)
854 raw_spin_unlock_irqrestore(&devtree_lock, flags);
857 EXPORT_SYMBOL(of_find_node_by_name);
860 * of_find_node_by_type - Find a node by its "device_type" property
861 * @from: The node to start searching from, or NULL to start searching
862 * the entire device tree. The node you pass will not be
863 * searched, only the next one will; typically, you pass
864 * what the previous call returned. of_node_put() will be
865 * called on from for you.
866 * @type: The type string to match against
868 * Returns a node pointer with refcount incremented, use
869 * of_node_put() on it when done.
871 struct device_node *of_find_node_by_type(struct device_node *from,
874 struct device_node *np;
877 raw_spin_lock_irqsave(&devtree_lock, flags);
878 for_each_of_allnodes_from(from, np)
879 if (np->type && (of_node_cmp(np->type, type) == 0)
883 raw_spin_unlock_irqrestore(&devtree_lock, flags);
886 EXPORT_SYMBOL(of_find_node_by_type);
889 * of_find_compatible_node - Find a node based on type and one of the
890 * tokens in its "compatible" property
891 * @from: The node to start searching from or NULL, the node
892 * you pass will not be searched, only the next one
893 * will; typically, you pass what the previous call
894 * returned. of_node_put() will be called on it
895 * @type: The type string to match "device_type" or NULL to ignore
896 * @compatible: The string to match to one of the tokens in the device
899 * Returns a node pointer with refcount incremented, use
900 * of_node_put() on it when done.
902 struct device_node *of_find_compatible_node(struct device_node *from,
903 const char *type, const char *compatible)
905 struct device_node *np;
908 raw_spin_lock_irqsave(&devtree_lock, flags);
909 for_each_of_allnodes_from(from, np)
910 if (__of_device_is_compatible(np, compatible, type, NULL) &&
914 raw_spin_unlock_irqrestore(&devtree_lock, flags);
917 EXPORT_SYMBOL(of_find_compatible_node);
920 * of_find_node_with_property - Find a node which has a property with
922 * @from: The node to start searching from or NULL, the node
923 * you pass will not be searched, only the next one
924 * will; typically, you pass what the previous call
925 * returned. of_node_put() will be called on it
926 * @prop_name: The name of the property to look for.
928 * Returns a node pointer with refcount incremented, use
929 * of_node_put() on it when done.
931 struct device_node *of_find_node_with_property(struct device_node *from,
932 const char *prop_name)
934 struct device_node *np;
938 raw_spin_lock_irqsave(&devtree_lock, flags);
939 for_each_of_allnodes_from(from, np) {
940 for (pp = np->properties; pp; pp = pp->next) {
941 if (of_prop_cmp(pp->name, prop_name) == 0) {
949 raw_spin_unlock_irqrestore(&devtree_lock, flags);
952 EXPORT_SYMBOL(of_find_node_with_property);
955 const struct of_device_id *__of_match_node(const struct of_device_id *matches,
956 const struct device_node *node)
958 const struct of_device_id *best_match = NULL;
959 int score, best_score = 0;
964 for (; matches->name[0] || matches->type[0] || matches->compatible[0]; matches++) {
965 score = __of_device_is_compatible(node, matches->compatible,
966 matches->type, matches->name);
967 if (score > best_score) {
968 best_match = matches;
977 * of_match_node - Tell if a device_node has a matching of_match structure
978 * @matches: array of of device match structures to search in
979 * @node: the of device structure to match against
981 * Low level utility function used by device matching.
983 const struct of_device_id *of_match_node(const struct of_device_id *matches,
984 const struct device_node *node)
986 const struct of_device_id *match;
989 raw_spin_lock_irqsave(&devtree_lock, flags);
990 match = __of_match_node(matches, node);
991 raw_spin_unlock_irqrestore(&devtree_lock, flags);
994 EXPORT_SYMBOL(of_match_node);
997 * of_find_matching_node_and_match - Find a node based on an of_device_id
999 * @from: The node to start searching from or NULL, the node
1000 * you pass will not be searched, only the next one
1001 * will; typically, you pass what the previous call
1002 * returned. of_node_put() will be called on it
1003 * @matches: array of of device match structures to search in
1004 * @match Updated to point at the matches entry which matched
1006 * Returns a node pointer with refcount incremented, use
1007 * of_node_put() on it when done.
1009 struct device_node *of_find_matching_node_and_match(struct device_node *from,
1010 const struct of_device_id *matches,
1011 const struct of_device_id **match)
1013 struct device_node *np;
1014 const struct of_device_id *m;
1015 unsigned long flags;
1020 raw_spin_lock_irqsave(&devtree_lock, flags);
1021 for_each_of_allnodes_from(from, np) {
1022 m = __of_match_node(matches, np);
1023 if (m && of_node_get(np)) {
1030 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1033 EXPORT_SYMBOL(of_find_matching_node_and_match);
1036 * of_modalias_node - Lookup appropriate modalias for a device node
1037 * @node: pointer to a device tree node
1038 * @modalias: Pointer to buffer that modalias value will be copied into
1039 * @len: Length of modalias value
1041 * Based on the value of the compatible property, this routine will attempt
1042 * to choose an appropriate modalias value for a particular device tree node.
1043 * It does this by stripping the manufacturer prefix (as delimited by a ',')
1044 * from the first entry in the compatible list property.
1046 * This routine returns 0 on success, <0 on failure.
1048 int of_modalias_node(struct device_node *node, char *modalias, int len)
1050 const char *compatible, *p;
1053 compatible = of_get_property(node, "compatible", &cplen);
1054 if (!compatible || strlen(compatible) > cplen)
1056 p = strchr(compatible, ',');
1057 strlcpy(modalias, p ? p + 1 : compatible, len);
1060 EXPORT_SYMBOL_GPL(of_modalias_node);
1063 * of_find_node_by_phandle - Find a node given a phandle
1064 * @handle: phandle of the node to find
1066 * Returns a node pointer with refcount incremented, use
1067 * of_node_put() on it when done.
1069 struct device_node *of_find_node_by_phandle(phandle handle)
1071 struct device_node *np;
1072 unsigned long flags;
1077 raw_spin_lock_irqsave(&devtree_lock, flags);
1078 for_each_of_allnodes(np)
1079 if (np->phandle == handle)
1082 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1085 EXPORT_SYMBOL(of_find_node_by_phandle);
1088 * of_property_count_elems_of_size - Count the number of elements in a property
1090 * @np: device node from which the property value is to be read.
1091 * @propname: name of the property to be searched.
1092 * @elem_size: size of the individual element
1094 * Search for a property in a device node and count the number of elements of
1095 * size elem_size in it. Returns number of elements on sucess, -EINVAL if the
1096 * property does not exist or its length does not match a multiple of elem_size
1097 * and -ENODATA if the property does not have a value.
1099 int of_property_count_elems_of_size(const struct device_node *np,
1100 const char *propname, int elem_size)
1102 struct property *prop = of_find_property(np, propname, NULL);
1109 if (prop->length % elem_size != 0) {
1110 pr_err("size of %s in node %s is not a multiple of %d\n",
1111 propname, np->full_name, elem_size);
1115 return prop->length / elem_size;
1117 EXPORT_SYMBOL_GPL(of_property_count_elems_of_size);
1120 * of_find_property_value_of_size
1122 * @np: device node from which the property value is to be read.
1123 * @propname: name of the property to be searched.
1124 * @len: requested length of property value
1126 * Search for a property in a device node and valid the requested size.
1127 * Returns the property value on success, -EINVAL if the property does not
1128 * exist, -ENODATA if property does not have a value, and -EOVERFLOW if the
1129 * property data isn't large enough.
1132 static void *of_find_property_value_of_size(const struct device_node *np,
1133 const char *propname, u32 len)
1135 struct property *prop = of_find_property(np, propname, NULL);
1138 return ERR_PTR(-EINVAL);
1140 return ERR_PTR(-ENODATA);
1141 if (len > prop->length)
1142 return ERR_PTR(-EOVERFLOW);
1148 * of_property_read_u32_index - Find and read a u32 from a multi-value property.
1150 * @np: device node from which the property value is to be read.
1151 * @propname: name of the property to be searched.
1152 * @index: index of the u32 in the list of values
1153 * @out_value: pointer to return value, modified only if no error.
1155 * Search for a property in a device node and read nth 32-bit value from
1156 * it. Returns 0 on success, -EINVAL if the property does not exist,
1157 * -ENODATA if property does not have a value, and -EOVERFLOW if the
1158 * property data isn't large enough.
1160 * The out_value is modified only if a valid u32 value can be decoded.
1162 int of_property_read_u32_index(const struct device_node *np,
1163 const char *propname,
1164 u32 index, u32 *out_value)
1166 const u32 *val = of_find_property_value_of_size(np, propname,
1167 ((index + 1) * sizeof(*out_value)));
1170 return PTR_ERR(val);
1172 *out_value = be32_to_cpup(((__be32 *)val) + index);
1175 EXPORT_SYMBOL_GPL(of_property_read_u32_index);
1178 * of_property_read_u8_array - Find and read an array of u8 from a property.
1180 * @np: device node from which the property value is to be read.
1181 * @propname: name of the property to be searched.
1182 * @out_values: pointer to return value, modified only if return value is 0.
1183 * @sz: number of array elements to read
1185 * Search for a property in a device node and read 8-bit value(s) from
1186 * it. Returns 0 on success, -EINVAL if the property does not exist,
1187 * -ENODATA if property does not have a value, and -EOVERFLOW if the
1188 * property data isn't large enough.
1190 * dts entry of array should be like:
1191 * property = /bits/ 8 <0x50 0x60 0x70>;
1193 * The out_values is modified only if a valid u8 value can be decoded.
1195 int of_property_read_u8_array(const struct device_node *np,
1196 const char *propname, u8 *out_values, size_t sz)
1198 const u8 *val = of_find_property_value_of_size(np, propname,
1199 (sz * sizeof(*out_values)));
1202 return PTR_ERR(val);
1205 *out_values++ = *val++;
1208 EXPORT_SYMBOL_GPL(of_property_read_u8_array);
1211 * of_property_read_u16_array - Find and read an array of u16 from a property.
1213 * @np: device node from which the property value is to be read.
1214 * @propname: name of the property to be searched.
1215 * @out_values: pointer to return value, modified only if return value is 0.
1216 * @sz: number of array elements to read
1218 * Search for a property in a device node and read 16-bit value(s) from
1219 * it. Returns 0 on success, -EINVAL if the property does not exist,
1220 * -ENODATA if property does not have a value, and -EOVERFLOW if the
1221 * property data isn't large enough.
1223 * dts entry of array should be like:
1224 * property = /bits/ 16 <0x5000 0x6000 0x7000>;
1226 * The out_values is modified only if a valid u16 value can be decoded.
1228 int of_property_read_u16_array(const struct device_node *np,
1229 const char *propname, u16 *out_values, size_t sz)
1231 const __be16 *val = of_find_property_value_of_size(np, propname,
1232 (sz * sizeof(*out_values)));
1235 return PTR_ERR(val);
1238 *out_values++ = be16_to_cpup(val++);
1241 EXPORT_SYMBOL_GPL(of_property_read_u16_array);
1244 * of_property_read_u32_array - Find and read an array of 32 bit integers
1247 * @np: device node from which the property value is to be read.
1248 * @propname: name of the property to be searched.
1249 * @out_values: pointer to return value, modified only if return value is 0.
1250 * @sz: number of array elements to read
1252 * Search for a property in a device node and read 32-bit value(s) from
1253 * it. Returns 0 on success, -EINVAL if the property does not exist,
1254 * -ENODATA if property does not have a value, and -EOVERFLOW if the
1255 * property data isn't large enough.
1257 * The out_values is modified only if a valid u32 value can be decoded.
1259 int of_property_read_u32_array(const struct device_node *np,
1260 const char *propname, u32 *out_values,
1263 const __be32 *val = of_find_property_value_of_size(np, propname,
1264 (sz * sizeof(*out_values)));
1267 return PTR_ERR(val);
1270 *out_values++ = be32_to_cpup(val++);
1273 EXPORT_SYMBOL_GPL(of_property_read_u32_array);
1276 * of_property_read_u64 - Find and read a 64 bit integer from a property
1277 * @np: device node from which the property value is to be read.
1278 * @propname: name of the property to be searched.
1279 * @out_value: pointer to return value, modified only if return value is 0.
1281 * Search for a property in a device node and read a 64-bit value from
1282 * it. Returns 0 on success, -EINVAL if the property does not exist,
1283 * -ENODATA if property does not have a value, and -EOVERFLOW if the
1284 * property data isn't large enough.
1286 * The out_value is modified only if a valid u64 value can be decoded.
1288 int of_property_read_u64(const struct device_node *np, const char *propname,
1291 const __be32 *val = of_find_property_value_of_size(np, propname,
1292 sizeof(*out_value));
1295 return PTR_ERR(val);
1297 *out_value = of_read_number(val, 2);
1300 EXPORT_SYMBOL_GPL(of_property_read_u64);
1303 * of_property_read_u64_array - Find and read an array of 64 bit integers
1306 * @np: device node from which the property value is to be read.
1307 * @propname: name of the property to be searched.
1308 * @out_values: pointer to return value, modified only if return value is 0.
1309 * @sz: number of array elements to read
1311 * Search for a property in a device node and read 64-bit value(s) from
1312 * it. Returns 0 on success, -EINVAL if the property does not exist,
1313 * -ENODATA if property does not have a value, and -EOVERFLOW if the
1314 * property data isn't large enough.
1316 * The out_values is modified only if a valid u64 value can be decoded.
1318 int of_property_read_u64_array(const struct device_node *np,
1319 const char *propname, u64 *out_values,
1322 const __be32 *val = of_find_property_value_of_size(np, propname,
1323 (sz * sizeof(*out_values)));
1326 return PTR_ERR(val);
1329 *out_values++ = of_read_number(val, 2);
1334 EXPORT_SYMBOL_GPL(of_property_read_u64_array);
1337 * of_property_read_string - Find and read a string from a property
1338 * @np: device node from which the property value is to be read.
1339 * @propname: name of the property to be searched.
1340 * @out_string: pointer to null terminated return string, modified only if
1341 * return value is 0.
1343 * Search for a property in a device tree node and retrieve a null
1344 * terminated string value (pointer to data, not a copy). Returns 0 on
1345 * success, -EINVAL if the property does not exist, -ENODATA if property
1346 * does not have a value, and -EILSEQ if the string is not null-terminated
1347 * within the length of the property data.
1349 * The out_string pointer is modified only if a valid string can be decoded.
1351 int of_property_read_string(const struct device_node *np, const char *propname,
1352 const char **out_string)
1354 const struct property *prop = of_find_property(np, propname, NULL);
1359 if (strnlen(prop->value, prop->length) >= prop->length)
1361 *out_string = prop->value;
1364 EXPORT_SYMBOL_GPL(of_property_read_string);
1367 * of_property_match_string() - Find string in a list and return index
1368 * @np: pointer to node containing string list property
1369 * @propname: string list property name
1370 * @string: pointer to string to search for in string list
1372 * This function searches a string list property and returns the index
1373 * of a specific string value.
1375 int of_property_match_string(const struct device_node *np, const char *propname,
1378 const struct property *prop = of_find_property(np, propname, NULL);
1381 const char *p, *end;
1389 end = p + prop->length;
1391 for (i = 0; p < end; i++, p += l) {
1392 l = strnlen(p, end - p) + 1;
1395 pr_debug("comparing %s with %s\n", string, p);
1396 if (strcmp(string, p) == 0)
1397 return i; /* Found it; return index */
1401 EXPORT_SYMBOL_GPL(of_property_match_string);
1404 * of_property_read_string_helper() - Utility helper for parsing string properties
1405 * @np: device node from which the property value is to be read.
1406 * @propname: name of the property to be searched.
1407 * @out_strs: output array of string pointers.
1408 * @sz: number of array elements to read.
1409 * @skip: Number of strings to skip over at beginning of list.
1411 * Don't call this function directly. It is a utility helper for the
1412 * of_property_read_string*() family of functions.
1414 int of_property_read_string_helper(const struct device_node *np,
1415 const char *propname, const char **out_strs,
1416 size_t sz, int skip)
1418 const struct property *prop = of_find_property(np, propname, NULL);
1420 const char *p, *end;
1427 end = p + prop->length;
1429 for (i = 0; p < end && (!out_strs || i < skip + sz); i++, p += l) {
1430 l = strnlen(p, end - p) + 1;
1433 if (out_strs && i >= skip)
1437 return i <= 0 ? -ENODATA : i;
1439 EXPORT_SYMBOL_GPL(of_property_read_string_helper);
1441 void of_print_phandle_args(const char *msg, const struct of_phandle_args *args)
1444 printk("%s %s", msg, of_node_full_name(args->np));
1445 for (i = 0; i < args->args_count; i++)
1446 printk(i ? ",%08x" : ":%08x", args->args[i]);
1450 int of_phandle_iterator_init(struct of_phandle_iterator *it,
1451 const struct device_node *np,
1452 const char *list_name,
1453 const char *cells_name,
1459 memset(it, 0, sizeof(*it));
1461 list = of_get_property(np, list_name, &size);
1465 it->cells_name = cells_name;
1466 it->cell_count = cell_count;
1468 it->list_end = list + size / sizeof(*list);
1469 it->phandle_end = list;
1475 int of_phandle_iterator_next(struct of_phandle_iterator *it)
1480 of_node_put(it->node);
1484 if (!it->cur || it->phandle_end >= it->list_end)
1487 it->cur = it->phandle_end;
1489 /* If phandle is 0, then it is an empty entry with no arguments. */
1490 it->phandle = be32_to_cpup(it->cur++);
1495 * Find the provider node and parse the #*-cells property to
1496 * determine the argument length.
1498 it->node = of_find_node_by_phandle(it->phandle);
1500 if (it->cells_name) {
1502 pr_err("%s: could not find phandle\n",
1503 it->parent->full_name);
1507 if (of_property_read_u32(it->node, it->cells_name,
1509 pr_err("%s: could not get %s for %s\n",
1510 it->parent->full_name,
1512 it->node->full_name);
1516 count = it->cell_count;
1520 * Make sure that the arguments actually fit in the remaining
1521 * property data length
1523 if (it->cur + count > it->list_end) {
1524 pr_err("%s: arguments longer than property\n",
1525 it->parent->full_name);
1530 it->phandle_end = it->cur + count;
1531 it->cur_count = count;
1537 of_node_put(it->node);
1544 int of_phandle_iterator_args(struct of_phandle_iterator *it,
1550 count = it->cur_count;
1552 if (WARN_ON(size < count))
1555 for (i = 0; i < count; i++)
1556 args[i] = be32_to_cpup(it->cur++);
1561 static int __of_parse_phandle_with_args(const struct device_node *np,
1562 const char *list_name,
1563 const char *cells_name,
1564 int cell_count, int index,
1565 struct of_phandle_args *out_args)
1567 struct of_phandle_iterator it;
1568 int rc, cur_index = 0;
1570 /* Loop over the phandles until all the requested entry is found */
1571 of_for_each_phandle(&it, rc, np, list_name, cells_name, cell_count) {
1573 * All of the error cases bail out of the loop, so at
1574 * this point, the parsing is successful. If the requested
1575 * index matches, then fill the out_args structure and return,
1576 * or return -ENOENT for an empty entry.
1579 if (cur_index == index) {
1586 c = of_phandle_iterator_args(&it,
1589 out_args->np = it.node;
1590 out_args->args_count = c;
1592 of_node_put(it.node);
1595 /* Found it! return success */
1603 * Unlock node before returning result; will be one of:
1604 * -ENOENT : index is for empty phandle
1605 * -EINVAL : parsing error on data
1610 of_node_put(it.node);
1615 * of_parse_phandle - Resolve a phandle property to a device_node pointer
1616 * @np: Pointer to device node holding phandle property
1617 * @phandle_name: Name of property holding a phandle value
1618 * @index: For properties holding a table of phandles, this is the index into
1621 * Returns the device_node pointer with refcount incremented. Use
1622 * of_node_put() on it when done.
1624 struct device_node *of_parse_phandle(const struct device_node *np,
1625 const char *phandle_name, int index)
1627 struct of_phandle_args args;
1632 if (__of_parse_phandle_with_args(np, phandle_name, NULL, 0,
1638 EXPORT_SYMBOL(of_parse_phandle);
1641 * of_parse_phandle_with_args() - Find a node pointed by phandle in a list
1642 * @np: pointer to a device tree node containing a list
1643 * @list_name: property name that contains a list
1644 * @cells_name: property name that specifies phandles' arguments count
1645 * @index: index of a phandle to parse out
1646 * @out_args: optional pointer to output arguments structure (will be filled)
1648 * This function is useful to parse lists of phandles and their arguments.
1649 * Returns 0 on success and fills out_args, on error returns appropriate
1652 * Caller is responsible to call of_node_put() on the returned out_args->np
1658 * #list-cells = <2>;
1662 * #list-cells = <1>;
1666 * list = <&phandle1 1 2 &phandle2 3>;
1669 * To get a device_node of the `node2' node you may call this:
1670 * of_parse_phandle_with_args(node3, "list", "#list-cells", 1, &args);
1672 int of_parse_phandle_with_args(const struct device_node *np, const char *list_name,
1673 const char *cells_name, int index,
1674 struct of_phandle_args *out_args)
1678 return __of_parse_phandle_with_args(np, list_name, cells_name, 0,
1681 EXPORT_SYMBOL(of_parse_phandle_with_args);
1684 * of_parse_phandle_with_fixed_args() - Find a node pointed by phandle in a list
1685 * @np: pointer to a device tree node containing a list
1686 * @list_name: property name that contains a list
1687 * @cell_count: number of argument cells following the phandle
1688 * @index: index of a phandle to parse out
1689 * @out_args: optional pointer to output arguments structure (will be filled)
1691 * This function is useful to parse lists of phandles and their arguments.
1692 * Returns 0 on success and fills out_args, on error returns appropriate
1695 * Caller is responsible to call of_node_put() on the returned out_args->np
1707 * list = <&phandle1 0 2 &phandle2 2 3>;
1710 * To get a device_node of the `node2' node you may call this:
1711 * of_parse_phandle_with_fixed_args(node3, "list", 2, 1, &args);
1713 int of_parse_phandle_with_fixed_args(const struct device_node *np,
1714 const char *list_name, int cell_count,
1715 int index, struct of_phandle_args *out_args)
1719 return __of_parse_phandle_with_args(np, list_name, NULL, cell_count,
1722 EXPORT_SYMBOL(of_parse_phandle_with_fixed_args);
1725 * of_count_phandle_with_args() - Find the number of phandles references in a property
1726 * @np: pointer to a device tree node containing a list
1727 * @list_name: property name that contains a list
1728 * @cells_name: property name that specifies phandles' arguments count
1730 * Returns the number of phandle + argument tuples within a property. It
1731 * is a typical pattern to encode a list of phandle and variable
1732 * arguments into a single property. The number of arguments is encoded
1733 * by a property in the phandle-target node. For example, a gpios
1734 * property would contain a list of GPIO specifies consisting of a
1735 * phandle and 1 or more arguments. The number of arguments are
1736 * determined by the #gpio-cells property in the node pointed to by the
1739 int of_count_phandle_with_args(const struct device_node *np, const char *list_name,
1740 const char *cells_name)
1742 struct of_phandle_iterator it;
1743 int rc, cur_index = 0;
1745 rc = of_phandle_iterator_init(&it, np, list_name, cells_name, 0);
1749 while ((rc = of_phandle_iterator_next(&it)) == 0)
1757 EXPORT_SYMBOL(of_count_phandle_with_args);
1760 * __of_add_property - Add a property to a node without lock operations
1762 int __of_add_property(struct device_node *np, struct property *prop)
1764 struct property **next;
1767 next = &np->properties;
1769 if (strcmp(prop->name, (*next)->name) == 0)
1770 /* duplicate ! don't insert it */
1773 next = &(*next)->next;
1781 * of_add_property - Add a property to a node
1783 int of_add_property(struct device_node *np, struct property *prop)
1785 unsigned long flags;
1788 mutex_lock(&of_mutex);
1790 raw_spin_lock_irqsave(&devtree_lock, flags);
1791 rc = __of_add_property(np, prop);
1792 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1795 __of_add_property_sysfs(np, prop);
1797 mutex_unlock(&of_mutex);
1800 of_property_notify(OF_RECONFIG_ADD_PROPERTY, np, prop, NULL);
1805 int __of_remove_property(struct device_node *np, struct property *prop)
1807 struct property **next;
1809 for (next = &np->properties; *next; next = &(*next)->next) {
1816 /* found the node */
1818 prop->next = np->deadprops;
1819 np->deadprops = prop;
1824 void __of_sysfs_remove_bin_file(struct device_node *np, struct property *prop)
1826 sysfs_remove_bin_file(&np->kobj, &prop->attr);
1827 kfree(prop->attr.attr.name);
1830 void __of_remove_property_sysfs(struct device_node *np, struct property *prop)
1832 if (!IS_ENABLED(CONFIG_SYSFS))
1835 /* at early boot, bail here and defer setup to of_init() */
1836 if (of_kset && of_node_is_attached(np))
1837 __of_sysfs_remove_bin_file(np, prop);
1841 * of_remove_property - Remove a property from a node.
1843 * Note that we don't actually remove it, since we have given out
1844 * who-knows-how-many pointers to the data using get-property.
1845 * Instead we just move the property to the "dead properties"
1846 * list, so it won't be found any more.
1848 int of_remove_property(struct device_node *np, struct property *prop)
1850 unsigned long flags;
1856 mutex_lock(&of_mutex);
1858 raw_spin_lock_irqsave(&devtree_lock, flags);
1859 rc = __of_remove_property(np, prop);
1860 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1863 __of_remove_property_sysfs(np, prop);
1865 mutex_unlock(&of_mutex);
1868 of_property_notify(OF_RECONFIG_REMOVE_PROPERTY, np, prop, NULL);
1873 int __of_update_property(struct device_node *np, struct property *newprop,
1874 struct property **oldpropp)
1876 struct property **next, *oldprop;
1878 for (next = &np->properties; *next; next = &(*next)->next) {
1879 if (of_prop_cmp((*next)->name, newprop->name) == 0)
1882 *oldpropp = oldprop = *next;
1885 /* replace the node */
1886 newprop->next = oldprop->next;
1888 oldprop->next = np->deadprops;
1889 np->deadprops = oldprop;
1892 newprop->next = NULL;
1899 void __of_update_property_sysfs(struct device_node *np, struct property *newprop,
1900 struct property *oldprop)
1902 if (!IS_ENABLED(CONFIG_SYSFS))
1905 /* At early boot, bail out and defer setup to of_init() */
1910 __of_sysfs_remove_bin_file(np, oldprop);
1911 __of_add_property_sysfs(np, newprop);
1915 * of_update_property - Update a property in a node, if the property does
1916 * not exist, add it.
1918 * Note that we don't actually remove it, since we have given out
1919 * who-knows-how-many pointers to the data using get-property.
1920 * Instead we just move the property to the "dead properties" list,
1921 * and add the new property to the property list
1923 int of_update_property(struct device_node *np, struct property *newprop)
1925 struct property *oldprop;
1926 unsigned long flags;
1932 mutex_lock(&of_mutex);
1934 raw_spin_lock_irqsave(&devtree_lock, flags);
1935 rc = __of_update_property(np, newprop, &oldprop);
1936 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1939 __of_update_property_sysfs(np, newprop, oldprop);
1941 mutex_unlock(&of_mutex);
1944 of_property_notify(OF_RECONFIG_UPDATE_PROPERTY, np, newprop, oldprop);
1949 static void of_alias_add(struct alias_prop *ap, struct device_node *np,
1950 int id, const char *stem, int stem_len)
1954 strncpy(ap->stem, stem, stem_len);
1955 ap->stem[stem_len] = 0;
1956 list_add_tail(&ap->link, &aliases_lookup);
1957 pr_debug("adding DT alias:%s: stem=%s id=%i node=%s\n",
1958 ap->alias, ap->stem, ap->id, of_node_full_name(np));
1962 * of_alias_scan - Scan all properties of the 'aliases' node
1964 * The function scans all the properties of the 'aliases' node and populates
1965 * the global lookup table with the properties. It returns the
1966 * number of alias properties found, or an error code in case of failure.
1968 * @dt_alloc: An allocator that provides a virtual address to memory
1969 * for storing the resulting tree
1971 void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align))
1973 struct property *pp;
1975 of_aliases = of_find_node_by_path("/aliases");
1976 of_chosen = of_find_node_by_path("/chosen");
1977 if (of_chosen == NULL)
1978 of_chosen = of_find_node_by_path("/chosen@0");
1981 /* linux,stdout-path and /aliases/stdout are for legacy compatibility */
1982 const char *name = of_get_property(of_chosen, "stdout-path", NULL);
1984 name = of_get_property(of_chosen, "linux,stdout-path", NULL);
1985 if (IS_ENABLED(CONFIG_PPC) && !name)
1986 name = of_get_property(of_aliases, "stdout", NULL);
1988 of_stdout = of_find_node_opts_by_path(name, &of_stdout_options);
1994 for_each_property_of_node(of_aliases, pp) {
1995 const char *start = pp->name;
1996 const char *end = start + strlen(start);
1997 struct device_node *np;
1998 struct alias_prop *ap;
2001 /* Skip those we do not want to proceed */
2002 if (!strcmp(pp->name, "name") ||
2003 !strcmp(pp->name, "phandle") ||
2004 !strcmp(pp->name, "linux,phandle"))
2007 np = of_find_node_by_path(pp->value);
2011 /* walk the alias backwards to extract the id and work out
2012 * the 'stem' string */
2013 while (isdigit(*(end-1)) && end > start)
2017 if (kstrtoint(end, 10, &id) < 0)
2020 /* Allocate an alias_prop with enough space for the stem */
2021 ap = dt_alloc(sizeof(*ap) + len + 1, 4);
2024 memset(ap, 0, sizeof(*ap) + len + 1);
2026 of_alias_add(ap, np, id, start, len);
2031 * of_alias_get_id - Get alias id for the given device_node
2032 * @np: Pointer to the given device_node
2033 * @stem: Alias stem of the given device_node
2035 * The function travels the lookup table to get the alias id for the given
2036 * device_node and alias stem. It returns the alias id if found.
2038 int of_alias_get_id(struct device_node *np, const char *stem)
2040 struct alias_prop *app;
2043 mutex_lock(&of_mutex);
2044 list_for_each_entry(app, &aliases_lookup, link) {
2045 if (strcmp(app->stem, stem) != 0)
2048 if (np == app->np) {
2053 mutex_unlock(&of_mutex);
2057 EXPORT_SYMBOL_GPL(of_alias_get_id);
2060 * of_alias_get_highest_id - Get highest alias id for the given stem
2061 * @stem: Alias stem to be examined
2063 * The function travels the lookup table to get the highest alias id for the
2064 * given alias stem. It returns the alias id if found.
2066 int of_alias_get_highest_id(const char *stem)
2068 struct alias_prop *app;
2071 mutex_lock(&of_mutex);
2072 list_for_each_entry(app, &aliases_lookup, link) {
2073 if (strcmp(app->stem, stem) != 0)
2079 mutex_unlock(&of_mutex);
2083 EXPORT_SYMBOL_GPL(of_alias_get_highest_id);
2085 const __be32 *of_prop_next_u32(struct property *prop, const __be32 *cur,
2088 const void *curv = cur;
2098 curv += sizeof(*cur);
2099 if (curv >= prop->value + prop->length)
2103 *pu = be32_to_cpup(curv);
2106 EXPORT_SYMBOL_GPL(of_prop_next_u32);
2108 const char *of_prop_next_string(struct property *prop, const char *cur)
2110 const void *curv = cur;
2118 curv += strlen(cur) + 1;
2119 if (curv >= prop->value + prop->length)
2124 EXPORT_SYMBOL_GPL(of_prop_next_string);
2127 * of_console_check() - Test and setup console for DT setup
2128 * @dn - Pointer to device node
2129 * @name - Name to use for preferred console without index. ex. "ttyS"
2130 * @index - Index to use for preferred console.
2132 * Check if the given device node matches the stdout-path property in the
2133 * /chosen node. If it does then register it as the preferred console and return
2134 * TRUE. Otherwise return FALSE.
2136 bool of_console_check(struct device_node *dn, char *name, int index)
2138 if (!dn || dn != of_stdout || console_set_on_cmdline)
2140 return !add_preferred_console(name, index,
2141 kstrdup(of_stdout_options, GFP_KERNEL));
2143 EXPORT_SYMBOL_GPL(of_console_check);
2146 * of_find_next_cache_node - Find a node's subsidiary cache
2147 * @np: node of type "cpu" or "cache"
2149 * Returns a node pointer with refcount incremented, use
2150 * of_node_put() on it when done. Caller should hold a reference
2153 struct device_node *of_find_next_cache_node(const struct device_node *np)
2155 struct device_node *child;
2156 const phandle *handle;
2158 handle = of_get_property(np, "l2-cache", NULL);
2160 handle = of_get_property(np, "next-level-cache", NULL);
2163 return of_find_node_by_phandle(be32_to_cpup(handle));
2165 /* OF on pmac has nodes instead of properties named "l2-cache"
2166 * beneath CPU nodes.
2168 if (!strcmp(np->type, "cpu"))
2169 for_each_child_of_node(np, child)
2170 if (!strcmp(child->type, "cache"))
2177 * of_graph_parse_endpoint() - parse common endpoint node properties
2178 * @node: pointer to endpoint device_node
2179 * @endpoint: pointer to the OF endpoint data structure
2181 * The caller should hold a reference to @node.
2183 int of_graph_parse_endpoint(const struct device_node *node,
2184 struct of_endpoint *endpoint)
2186 struct device_node *port_node = of_get_parent(node);
2188 WARN_ONCE(!port_node, "%s(): endpoint %s has no parent node\n",
2189 __func__, node->full_name);
2191 memset(endpoint, 0, sizeof(*endpoint));
2193 endpoint->local_node = node;
2195 * It doesn't matter whether the two calls below succeed.
2196 * If they don't then the default value 0 is used.
2198 of_property_read_u32(port_node, "reg", &endpoint->port);
2199 of_property_read_u32(node, "reg", &endpoint->id);
2201 of_node_put(port_node);
2205 EXPORT_SYMBOL(of_graph_parse_endpoint);
2208 * of_graph_get_port_by_id() - get the port matching a given id
2209 * @parent: pointer to the parent device node
2210 * @id: id of the port
2212 * Return: A 'port' node pointer with refcount incremented. The caller
2213 * has to use of_node_put() on it when done.
2215 struct device_node *of_graph_get_port_by_id(struct device_node *parent, u32 id)
2217 struct device_node *node, *port;
2219 node = of_get_child_by_name(parent, "ports");
2223 for_each_child_of_node(parent, port) {
2226 if (of_node_cmp(port->name, "port") != 0)
2228 of_property_read_u32(port, "reg", &port_id);
2237 EXPORT_SYMBOL(of_graph_get_port_by_id);
2240 * of_graph_get_next_endpoint() - get next endpoint node
2241 * @parent: pointer to the parent device node
2242 * @prev: previous endpoint node, or NULL to get first
2244 * Return: An 'endpoint' node pointer with refcount incremented. Refcount
2245 * of the passed @prev node is decremented.
2247 struct device_node *of_graph_get_next_endpoint(const struct device_node *parent,
2248 struct device_node *prev)
2250 struct device_node *endpoint;
2251 struct device_node *port;
2257 * Start by locating the port node. If no previous endpoint is specified
2258 * search for the first port node, otherwise get the previous endpoint
2262 struct device_node *node;
2264 node = of_get_child_by_name(parent, "ports");
2268 port = of_get_child_by_name(parent, "port");
2272 pr_err("%s(): no port node found in %s\n",
2273 __func__, parent->full_name);
2277 port = of_get_parent(prev);
2278 if (WARN_ONCE(!port, "%s(): endpoint %s has no parent node\n",
2279 __func__, prev->full_name))
2285 * Now that we have a port node, get the next endpoint by
2286 * getting the next child. If the previous endpoint is NULL this
2287 * will return the first child.
2289 endpoint = of_get_next_child(port, prev);
2295 /* No more endpoints under this port, try the next one. */
2299 port = of_get_next_child(parent, port);
2302 } while (of_node_cmp(port->name, "port"));
2305 EXPORT_SYMBOL(of_graph_get_next_endpoint);
2308 * of_graph_get_endpoint_by_regs() - get endpoint node of specific identifiers
2309 * @parent: pointer to the parent device node
2310 * @port_reg: identifier (value of reg property) of the parent port node
2311 * @reg: identifier (value of reg property) of the endpoint node
2313 * Return: An 'endpoint' node pointer which is identified by reg and at the same
2314 * is the child of a port node identified by port_reg. reg and port_reg are
2315 * ignored when they are -1.
2317 struct device_node *of_graph_get_endpoint_by_regs(
2318 const struct device_node *parent, int port_reg, int reg)
2320 struct of_endpoint endpoint;
2321 struct device_node *node, *prev_node = NULL;
2324 node = of_graph_get_next_endpoint(parent, prev_node);
2325 of_node_put(prev_node);
2329 of_graph_parse_endpoint(node, &endpoint);
2330 if (((port_reg == -1) || (endpoint.port == port_reg)) &&
2331 ((reg == -1) || (endpoint.id == reg)))
2339 EXPORT_SYMBOL(of_graph_get_endpoint_by_regs);
2342 * of_graph_get_remote_port_parent() - get remote port's parent node
2343 * @node: pointer to a local endpoint device_node
2345 * Return: Remote device node associated with remote endpoint node linked
2346 * to @node. Use of_node_put() on it when done.
2348 struct device_node *of_graph_get_remote_port_parent(
2349 const struct device_node *node)
2351 struct device_node *np;
2354 /* Get remote endpoint node. */
2355 np = of_parse_phandle(node, "remote-endpoint", 0);
2357 /* Walk 3 levels up only if there is 'ports' node. */
2358 for (depth = 3; depth && np; depth--) {
2359 np = of_get_next_parent(np);
2360 if (depth == 2 && of_node_cmp(np->name, "ports"))
2365 EXPORT_SYMBOL(of_graph_get_remote_port_parent);
2368 * of_graph_get_remote_port() - get remote port node
2369 * @node: pointer to a local endpoint device_node
2371 * Return: Remote port node associated with remote endpoint node linked
2372 * to @node. Use of_node_put() on it when done.
2374 struct device_node *of_graph_get_remote_port(const struct device_node *node)
2376 struct device_node *np;
2378 /* Get remote endpoint node. */
2379 np = of_parse_phandle(node, "remote-endpoint", 0);
2382 return of_get_next_parent(np);
2384 EXPORT_SYMBOL(of_graph_get_remote_port);