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;
173 np->kobj.kset = of_kset;
175 /* Nodes without parents are new top level trees */
176 name = safe_name(&of_kset->kobj, "base");
179 name = safe_name(&np->parent->kobj, kbasename(np->full_name));
180 parent = &np->parent->kobj;
184 rc = kobject_add(&np->kobj, parent, "%s", name);
189 for_each_property_of_node(np, pp)
190 __of_add_property_sysfs(np, pp);
195 void __init of_core_init(void)
197 struct device_node *np;
199 /* Create the kset, and register existing nodes */
200 mutex_lock(&of_mutex);
201 of_kset = kset_create_and_add("devicetree", NULL, firmware_kobj);
203 mutex_unlock(&of_mutex);
204 pr_err("devicetree: failed to register existing nodes\n");
207 for_each_of_allnodes(np)
208 __of_attach_node_sysfs(np);
209 mutex_unlock(&of_mutex);
211 /* Symlink in /proc as required by userspace ABI */
213 proc_symlink("device-tree", NULL, "/sys/firmware/devicetree/base");
216 static struct property *__of_find_property(const struct device_node *np,
217 const char *name, int *lenp)
224 for (pp = np->properties; pp; pp = pp->next) {
225 if (of_prop_cmp(pp->name, name) == 0) {
235 struct property *of_find_property(const struct device_node *np,
242 raw_spin_lock_irqsave(&devtree_lock, flags);
243 pp = __of_find_property(np, name, lenp);
244 raw_spin_unlock_irqrestore(&devtree_lock, flags);
248 EXPORT_SYMBOL(of_find_property);
250 struct device_node *__of_find_all_nodes(struct device_node *prev)
252 struct device_node *np;
255 } else if (prev->child) {
258 /* Walk back up looking for a sibling, or the end of the structure */
260 while (np->parent && !np->sibling)
262 np = np->sibling; /* Might be null at the end of the tree */
268 * of_find_all_nodes - Get next node in global list
269 * @prev: Previous node or NULL to start iteration
270 * of_node_put() will be called on it
272 * Returns a node pointer with refcount incremented, use
273 * of_node_put() on it when done.
275 struct device_node *of_find_all_nodes(struct device_node *prev)
277 struct device_node *np;
280 raw_spin_lock_irqsave(&devtree_lock, flags);
281 np = __of_find_all_nodes(prev);
284 raw_spin_unlock_irqrestore(&devtree_lock, flags);
287 EXPORT_SYMBOL(of_find_all_nodes);
290 * Find a property with a given name for a given node
291 * and return the value.
293 const void *__of_get_property(const struct device_node *np,
294 const char *name, int *lenp)
296 struct property *pp = __of_find_property(np, name, lenp);
298 return pp ? pp->value : NULL;
302 * Find a property with a given name for a given node
303 * and return the value.
305 const void *of_get_property(const struct device_node *np, const char *name,
308 struct property *pp = of_find_property(np, name, lenp);
310 return pp ? pp->value : NULL;
312 EXPORT_SYMBOL(of_get_property);
315 * arch_match_cpu_phys_id - Match the given logical CPU and physical id
317 * @cpu: logical cpu index of a core/thread
318 * @phys_id: physical identifier of a core/thread
320 * CPU logical to physical index mapping is architecture specific.
321 * However this __weak function provides a default match of physical
322 * id to logical cpu index. phys_id provided here is usually values read
323 * from the device tree which must match the hardware internal registers.
325 * Returns true if the physical identifier and the logical cpu index
326 * correspond to the same core/thread, false otherwise.
328 bool __weak arch_match_cpu_phys_id(int cpu, u64 phys_id)
330 return (u32)phys_id == cpu;
334 * Checks if the given "prop_name" property holds the physical id of the
335 * core/thread corresponding to the logical cpu 'cpu'. If 'thread' is not
336 * NULL, local thread number within the core is returned in it.
338 static bool __of_find_n_match_cpu_property(struct device_node *cpun,
339 const char *prop_name, int cpu, unsigned int *thread)
342 int ac, prop_len, tid;
345 ac = of_n_addr_cells(cpun);
346 cell = of_get_property(cpun, prop_name, &prop_len);
349 prop_len /= sizeof(*cell) * ac;
350 for (tid = 0; tid < prop_len; tid++) {
351 hwid = of_read_number(cell, ac);
352 if (arch_match_cpu_phys_id(cpu, hwid)) {
363 * arch_find_n_match_cpu_physical_id - See if the given device node is
364 * for the cpu corresponding to logical cpu 'cpu'. Return true if so,
365 * else false. If 'thread' is non-NULL, the local thread number within the
366 * core is returned in it.
368 bool __weak arch_find_n_match_cpu_physical_id(struct device_node *cpun,
369 int cpu, unsigned int *thread)
371 /* Check for non-standard "ibm,ppc-interrupt-server#s" property
372 * for thread ids on PowerPC. If it doesn't exist fallback to
373 * standard "reg" property.
375 if (IS_ENABLED(CONFIG_PPC) &&
376 __of_find_n_match_cpu_property(cpun,
377 "ibm,ppc-interrupt-server#s",
381 return __of_find_n_match_cpu_property(cpun, "reg", cpu, thread);
385 * of_get_cpu_node - Get device node associated with the given logical CPU
387 * @cpu: CPU number(logical index) for which device node is required
388 * @thread: if not NULL, local thread number within the physical core is
391 * The main purpose of this function is to retrieve the device node for the
392 * given logical CPU index. It should be used to initialize the of_node in
393 * cpu device. Once of_node in cpu device is populated, all the further
394 * references can use that instead.
396 * CPU logical to physical index mapping is architecture specific and is built
397 * before booting secondary cores. This function uses arch_match_cpu_phys_id
398 * which can be overridden by architecture specific implementation.
400 * Returns a node pointer for the logical cpu if found, else NULL.
402 struct device_node *of_get_cpu_node(int cpu, unsigned int *thread)
404 struct device_node *cpun;
406 for_each_node_by_type(cpun, "cpu") {
407 if (arch_find_n_match_cpu_physical_id(cpun, cpu, thread))
412 EXPORT_SYMBOL(of_get_cpu_node);
415 * __of_device_is_compatible() - Check if the node matches given constraints
416 * @device: pointer to node
417 * @compat: required compatible string, NULL or "" for any match
418 * @type: required device_type value, NULL or "" for any match
419 * @name: required node name, NULL or "" for any match
421 * Checks if the given @compat, @type and @name strings match the
422 * properties of the given @device. A constraints can be skipped by
423 * passing NULL or an empty string as the constraint.
425 * Returns 0 for no match, and a positive integer on match. The return
426 * value is a relative score with larger values indicating better
427 * matches. The score is weighted for the most specific compatible value
428 * to get the highest score. Matching type is next, followed by matching
429 * name. Practically speaking, this results in the following priority
432 * 1. specific compatible && type && name
433 * 2. specific compatible && type
434 * 3. specific compatible && name
435 * 4. specific compatible
436 * 5. general compatible && type && name
437 * 6. general compatible && type
438 * 7. general compatible && name
439 * 8. general compatible
444 static int __of_device_is_compatible(const struct device_node *device,
445 const char *compat, const char *type, const char *name)
447 struct property *prop;
449 int index = 0, score = 0;
451 /* Compatible match has highest priority */
452 if (compat && compat[0]) {
453 prop = __of_find_property(device, "compatible", NULL);
454 for (cp = of_prop_next_string(prop, NULL); cp;
455 cp = of_prop_next_string(prop, cp), index++) {
456 if (of_compat_cmp(cp, compat, strlen(compat)) == 0) {
457 score = INT_MAX/2 - (index << 2);
465 /* Matching type is better than matching name */
466 if (type && type[0]) {
467 if (!device->type || of_node_cmp(type, device->type))
472 /* Matching name is a bit better than not */
473 if (name && name[0]) {
474 if (!device->name || of_node_cmp(name, device->name))
482 /** Checks if the given "compat" string matches one of the strings in
483 * the device's "compatible" property
485 int of_device_is_compatible(const struct device_node *device,
491 raw_spin_lock_irqsave(&devtree_lock, flags);
492 res = __of_device_is_compatible(device, compat, NULL, NULL);
493 raw_spin_unlock_irqrestore(&devtree_lock, flags);
496 EXPORT_SYMBOL(of_device_is_compatible);
499 * of_machine_is_compatible - Test root of device tree for a given compatible value
500 * @compat: compatible string to look for in root node's compatible property.
502 * Returns a positive integer if the root node has the given value in its
503 * compatible property.
505 int of_machine_is_compatible(const char *compat)
507 struct device_node *root;
510 root = of_find_node_by_path("/");
512 rc = of_device_is_compatible(root, compat);
517 EXPORT_SYMBOL(of_machine_is_compatible);
520 * __of_device_is_available - check if a device is available for use
522 * @device: Node to check for availability, with locks already held
524 * Returns true if the status property is absent or set to "okay" or "ok",
527 static bool __of_device_is_available(const struct device_node *device)
535 status = __of_get_property(device, "status", &statlen);
540 if (!strcmp(status, "okay") || !strcmp(status, "ok"))
548 * of_device_is_available - check if a device is available for use
550 * @device: Node to check for availability
552 * Returns true if the status property is absent or set to "okay" or "ok",
555 bool of_device_is_available(const struct device_node *device)
560 raw_spin_lock_irqsave(&devtree_lock, flags);
561 res = __of_device_is_available(device);
562 raw_spin_unlock_irqrestore(&devtree_lock, flags);
566 EXPORT_SYMBOL(of_device_is_available);
569 * of_device_is_big_endian - check if a device has BE registers
571 * @device: Node to check for endianness
573 * Returns true if the device has a "big-endian" property, or if the kernel
574 * was compiled for BE *and* the device has a "native-endian" property.
575 * Returns false otherwise.
577 * Callers would nominally use ioread32be/iowrite32be if
578 * of_device_is_big_endian() == true, or readl/writel otherwise.
580 bool of_device_is_big_endian(const struct device_node *device)
582 if (of_property_read_bool(device, "big-endian"))
584 if (IS_ENABLED(CONFIG_CPU_BIG_ENDIAN) &&
585 of_property_read_bool(device, "native-endian"))
589 EXPORT_SYMBOL(of_device_is_big_endian);
592 * of_get_parent - Get a node's parent if any
593 * @node: Node to get parent
595 * Returns a node pointer with refcount incremented, use
596 * of_node_put() on it when done.
598 struct device_node *of_get_parent(const struct device_node *node)
600 struct device_node *np;
606 raw_spin_lock_irqsave(&devtree_lock, flags);
607 np = of_node_get(node->parent);
608 raw_spin_unlock_irqrestore(&devtree_lock, flags);
611 EXPORT_SYMBOL(of_get_parent);
614 * of_get_next_parent - Iterate to a node's parent
615 * @node: Node to get parent of
617 * This is like of_get_parent() except that it drops the
618 * refcount on the passed node, making it suitable for iterating
619 * through a node's parents.
621 * Returns a node pointer with refcount incremented, use
622 * of_node_put() on it when done.
624 struct device_node *of_get_next_parent(struct device_node *node)
626 struct device_node *parent;
632 raw_spin_lock_irqsave(&devtree_lock, flags);
633 parent = of_node_get(node->parent);
635 raw_spin_unlock_irqrestore(&devtree_lock, flags);
638 EXPORT_SYMBOL(of_get_next_parent);
640 static struct device_node *__of_get_next_child(const struct device_node *node,
641 struct device_node *prev)
643 struct device_node *next;
648 next = prev ? prev->sibling : node->child;
649 for (; next; next = next->sibling)
650 if (of_node_get(next))
655 #define __for_each_child_of_node(parent, child) \
656 for (child = __of_get_next_child(parent, NULL); child != NULL; \
657 child = __of_get_next_child(parent, child))
660 * of_get_next_child - Iterate a node childs
662 * @prev: previous child of the parent node, or NULL to get first
664 * Returns a node pointer with refcount incremented, use of_node_put() on
665 * it when done. Returns NULL when prev is the last child. Decrements the
668 struct device_node *of_get_next_child(const struct device_node *node,
669 struct device_node *prev)
671 struct device_node *next;
674 raw_spin_lock_irqsave(&devtree_lock, flags);
675 next = __of_get_next_child(node, prev);
676 raw_spin_unlock_irqrestore(&devtree_lock, flags);
679 EXPORT_SYMBOL(of_get_next_child);
682 * of_get_next_available_child - Find the next available child node
684 * @prev: previous child of the parent node, or NULL to get first
686 * This function is like of_get_next_child(), except that it
687 * automatically skips any disabled nodes (i.e. status = "disabled").
689 struct device_node *of_get_next_available_child(const struct device_node *node,
690 struct device_node *prev)
692 struct device_node *next;
698 raw_spin_lock_irqsave(&devtree_lock, flags);
699 next = prev ? prev->sibling : node->child;
700 for (; next; next = next->sibling) {
701 if (!__of_device_is_available(next))
703 if (of_node_get(next))
707 raw_spin_unlock_irqrestore(&devtree_lock, flags);
710 EXPORT_SYMBOL(of_get_next_available_child);
713 * of_get_compatible_child - Find compatible child node
714 * @parent: parent node
715 * @compatible: compatible string
717 * Lookup child node whose compatible property contains the given compatible
720 * Returns a node pointer with refcount incremented, use of_node_put() on it
721 * when done; or NULL if not found.
723 struct device_node *of_get_compatible_child(const struct device_node *parent,
724 const char *compatible)
726 struct device_node *child;
728 for_each_child_of_node(parent, child) {
729 if (of_device_is_compatible(child, compatible))
735 EXPORT_SYMBOL(of_get_compatible_child);
738 * of_get_child_by_name - Find the child node by name for a given parent
740 * @name: child name to look for.
742 * This function looks for child node for given matching name
744 * Returns a node pointer if found, with refcount incremented, use
745 * of_node_put() on it when done.
746 * Returns NULL if node is not found.
748 struct device_node *of_get_child_by_name(const struct device_node *node,
751 struct device_node *child;
753 for_each_child_of_node(node, child)
754 if (child->name && (of_node_cmp(child->name, name) == 0))
758 EXPORT_SYMBOL(of_get_child_by_name);
760 static struct device_node *__of_find_node_by_path(struct device_node *parent,
763 struct device_node *child;
766 len = strcspn(path, "/:");
770 __for_each_child_of_node(parent, child) {
771 const char *name = strrchr(child->full_name, '/');
772 if (WARN(!name, "malformed device_node %s\n", child->full_name))
775 if (strncmp(path, name, len) == 0 && (strlen(name) == len))
782 * of_find_node_opts_by_path - Find a node matching a full OF path
783 * @path: Either the full path to match, or if the path does not
784 * start with '/', the name of a property of the /aliases
785 * node (an alias). In the case of an alias, the node
786 * matching the alias' value will be returned.
787 * @opts: Address of a pointer into which to store the start of
788 * an options string appended to the end of the path with
794 * foo/bar Valid alias + relative path
796 * Returns a node pointer with refcount incremented, use
797 * of_node_put() on it when done.
799 struct device_node *of_find_node_opts_by_path(const char *path, const char **opts)
801 struct device_node *np = NULL;
804 const char *separator = strchr(path, ':');
807 *opts = separator ? separator + 1 : NULL;
809 if (strcmp(path, "/") == 0)
810 return of_node_get(of_root);
812 /* The path could begin with an alias */
815 const char *p = separator;
818 p = strchrnul(path, '/');
821 /* of_aliases must not be NULL */
825 for_each_property_of_node(of_aliases, pp) {
826 if (strlen(pp->name) == len && !strncmp(pp->name, path, len)) {
827 np = of_find_node_by_path(pp->value);
836 /* Step down the tree matching path components */
837 raw_spin_lock_irqsave(&devtree_lock, flags);
839 np = of_node_get(of_root);
840 while (np && *path == '/') {
841 path++; /* Increment past '/' delimiter */
842 np = __of_find_node_by_path(np, path);
843 path = strchrnul(path, '/');
844 if (separator && separator < path)
847 raw_spin_unlock_irqrestore(&devtree_lock, flags);
850 EXPORT_SYMBOL(of_find_node_opts_by_path);
853 * of_find_node_by_name - Find a node by its "name" property
854 * @from: The node to start searching from or NULL, the node
855 * you pass will not be searched, only the next one
856 * will; typically, you pass what the previous call
857 * returned. of_node_put() will be called on it
858 * @name: The name string to match against
860 * Returns a node pointer with refcount incremented, use
861 * of_node_put() on it when done.
863 struct device_node *of_find_node_by_name(struct device_node *from,
866 struct device_node *np;
869 raw_spin_lock_irqsave(&devtree_lock, flags);
870 for_each_of_allnodes_from(from, np)
871 if (np->name && (of_node_cmp(np->name, name) == 0)
875 raw_spin_unlock_irqrestore(&devtree_lock, flags);
878 EXPORT_SYMBOL(of_find_node_by_name);
881 * of_find_node_by_type - Find a node by its "device_type" property
882 * @from: The node to start searching from, or NULL to start searching
883 * the entire device tree. The node you pass will not be
884 * searched, only the next one will; typically, you pass
885 * what the previous call returned. of_node_put() will be
886 * called on from for you.
887 * @type: The type string to match against
889 * Returns a node pointer with refcount incremented, use
890 * of_node_put() on it when done.
892 struct device_node *of_find_node_by_type(struct device_node *from,
895 struct device_node *np;
898 raw_spin_lock_irqsave(&devtree_lock, flags);
899 for_each_of_allnodes_from(from, np)
900 if (np->type && (of_node_cmp(np->type, type) == 0)
904 raw_spin_unlock_irqrestore(&devtree_lock, flags);
907 EXPORT_SYMBOL(of_find_node_by_type);
910 * of_find_compatible_node - Find a node based on type and one of the
911 * tokens in its "compatible" property
912 * @from: The node to start searching from or NULL, the node
913 * you pass will not be searched, only the next one
914 * will; typically, you pass what the previous call
915 * returned. of_node_put() will be called on it
916 * @type: The type string to match "device_type" or NULL to ignore
917 * @compatible: The string to match to one of the tokens in the device
920 * Returns a node pointer with refcount incremented, use
921 * of_node_put() on it when done.
923 struct device_node *of_find_compatible_node(struct device_node *from,
924 const char *type, const char *compatible)
926 struct device_node *np;
929 raw_spin_lock_irqsave(&devtree_lock, flags);
930 for_each_of_allnodes_from(from, np)
931 if (__of_device_is_compatible(np, compatible, type, NULL) &&
935 raw_spin_unlock_irqrestore(&devtree_lock, flags);
938 EXPORT_SYMBOL(of_find_compatible_node);
941 * of_find_node_with_property - Find a node which has a property with
943 * @from: The node to start searching from or NULL, the node
944 * you pass will not be searched, only the next one
945 * will; typically, you pass what the previous call
946 * returned. of_node_put() will be called on it
947 * @prop_name: The name of the property to look for.
949 * Returns a node pointer with refcount incremented, use
950 * of_node_put() on it when done.
952 struct device_node *of_find_node_with_property(struct device_node *from,
953 const char *prop_name)
955 struct device_node *np;
959 raw_spin_lock_irqsave(&devtree_lock, flags);
960 for_each_of_allnodes_from(from, np) {
961 for (pp = np->properties; pp; pp = pp->next) {
962 if (of_prop_cmp(pp->name, prop_name) == 0) {
970 raw_spin_unlock_irqrestore(&devtree_lock, flags);
973 EXPORT_SYMBOL(of_find_node_with_property);
976 const struct of_device_id *__of_match_node(const struct of_device_id *matches,
977 const struct device_node *node)
979 const struct of_device_id *best_match = NULL;
980 int score, best_score = 0;
985 for (; matches->name[0] || matches->type[0] || matches->compatible[0]; matches++) {
986 score = __of_device_is_compatible(node, matches->compatible,
987 matches->type, matches->name);
988 if (score > best_score) {
989 best_match = matches;
998 * of_match_node - Tell if a device_node has a matching of_match structure
999 * @matches: array of of device match structures to search in
1000 * @node: the of device structure to match against
1002 * Low level utility function used by device matching.
1004 const struct of_device_id *of_match_node(const struct of_device_id *matches,
1005 const struct device_node *node)
1007 const struct of_device_id *match;
1008 unsigned long flags;
1010 raw_spin_lock_irqsave(&devtree_lock, flags);
1011 match = __of_match_node(matches, node);
1012 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1015 EXPORT_SYMBOL(of_match_node);
1018 * of_find_matching_node_and_match - Find a node based on an of_device_id
1020 * @from: The node to start searching from or NULL, the node
1021 * you pass will not be searched, only the next one
1022 * will; typically, you pass what the previous call
1023 * returned. of_node_put() will be called on it
1024 * @matches: array of of device match structures to search in
1025 * @match Updated to point at the matches entry which matched
1027 * Returns a node pointer with refcount incremented, use
1028 * of_node_put() on it when done.
1030 struct device_node *of_find_matching_node_and_match(struct device_node *from,
1031 const struct of_device_id *matches,
1032 const struct of_device_id **match)
1034 struct device_node *np;
1035 const struct of_device_id *m;
1036 unsigned long flags;
1041 raw_spin_lock_irqsave(&devtree_lock, flags);
1042 for_each_of_allnodes_from(from, np) {
1043 m = __of_match_node(matches, np);
1044 if (m && of_node_get(np)) {
1051 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1054 EXPORT_SYMBOL(of_find_matching_node_and_match);
1057 * of_modalias_node - Lookup appropriate modalias for a device node
1058 * @node: pointer to a device tree node
1059 * @modalias: Pointer to buffer that modalias value will be copied into
1060 * @len: Length of modalias value
1062 * Based on the value of the compatible property, this routine will attempt
1063 * to choose an appropriate modalias value for a particular device tree node.
1064 * It does this by stripping the manufacturer prefix (as delimited by a ',')
1065 * from the first entry in the compatible list property.
1067 * This routine returns 0 on success, <0 on failure.
1069 int of_modalias_node(struct device_node *node, char *modalias, int len)
1071 const char *compatible, *p;
1074 compatible = of_get_property(node, "compatible", &cplen);
1075 if (!compatible || strlen(compatible) > cplen)
1077 p = strchr(compatible, ',');
1078 strlcpy(modalias, p ? p + 1 : compatible, len);
1081 EXPORT_SYMBOL_GPL(of_modalias_node);
1084 * of_find_node_by_phandle - Find a node given a phandle
1085 * @handle: phandle of the node to find
1087 * Returns a node pointer with refcount incremented, use
1088 * of_node_put() on it when done.
1090 struct device_node *of_find_node_by_phandle(phandle handle)
1092 struct device_node *np;
1093 unsigned long flags;
1098 raw_spin_lock_irqsave(&devtree_lock, flags);
1099 for_each_of_allnodes(np)
1100 if (np->phandle == handle)
1103 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1106 EXPORT_SYMBOL(of_find_node_by_phandle);
1109 * of_property_count_elems_of_size - Count the number of elements in a property
1111 * @np: device node from which the property value is to be read.
1112 * @propname: name of the property to be searched.
1113 * @elem_size: size of the individual element
1115 * Search for a property in a device node and count the number of elements of
1116 * size elem_size in it. Returns number of elements on sucess, -EINVAL if the
1117 * property does not exist or its length does not match a multiple of elem_size
1118 * and -ENODATA if the property does not have a value.
1120 int of_property_count_elems_of_size(const struct device_node *np,
1121 const char *propname, int elem_size)
1123 struct property *prop = of_find_property(np, propname, NULL);
1130 if (prop->length % elem_size != 0) {
1131 pr_err("size of %s in node %s is not a multiple of %d\n",
1132 propname, np->full_name, elem_size);
1136 return prop->length / elem_size;
1138 EXPORT_SYMBOL_GPL(of_property_count_elems_of_size);
1141 * of_find_property_value_of_size
1143 * @np: device node from which the property value is to be read.
1144 * @propname: name of the property to be searched.
1145 * @len: requested length of property value
1147 * Search for a property in a device node and valid the requested size.
1148 * Returns the property value on success, -EINVAL if the property does not
1149 * exist, -ENODATA if property does not have a value, and -EOVERFLOW if the
1150 * property data isn't large enough.
1153 static void *of_find_property_value_of_size(const struct device_node *np,
1154 const char *propname, u32 len)
1156 struct property *prop = of_find_property(np, propname, NULL);
1159 return ERR_PTR(-EINVAL);
1161 return ERR_PTR(-ENODATA);
1162 if (len > prop->length)
1163 return ERR_PTR(-EOVERFLOW);
1169 * of_property_read_u32_index - Find and read a u32 from a multi-value property.
1171 * @np: device node from which the property value is to be read.
1172 * @propname: name of the property to be searched.
1173 * @index: index of the u32 in the list of values
1174 * @out_value: pointer to return value, modified only if no error.
1176 * Search for a property in a device node and read nth 32-bit value from
1177 * it. Returns 0 on success, -EINVAL if the property does not exist,
1178 * -ENODATA if property does not have a value, and -EOVERFLOW if the
1179 * property data isn't large enough.
1181 * The out_value is modified only if a valid u32 value can be decoded.
1183 int of_property_read_u32_index(const struct device_node *np,
1184 const char *propname,
1185 u32 index, u32 *out_value)
1187 const u32 *val = of_find_property_value_of_size(np, propname,
1188 ((index + 1) * sizeof(*out_value)));
1191 return PTR_ERR(val);
1193 *out_value = be32_to_cpup(((__be32 *)val) + index);
1196 EXPORT_SYMBOL_GPL(of_property_read_u32_index);
1199 * of_property_read_u8_array - Find and read an array of u8 from a property.
1201 * @np: device node from which the property value is to be read.
1202 * @propname: name of the property to be searched.
1203 * @out_values: pointer to return value, modified only if return value is 0.
1204 * @sz: number of array elements to read
1206 * Search for a property in a device node and read 8-bit value(s) from
1207 * it. Returns 0 on success, -EINVAL if the property does not exist,
1208 * -ENODATA if property does not have a value, and -EOVERFLOW if the
1209 * property data isn't large enough.
1211 * dts entry of array should be like:
1212 * property = /bits/ 8 <0x50 0x60 0x70>;
1214 * The out_values is modified only if a valid u8 value can be decoded.
1216 int of_property_read_u8_array(const struct device_node *np,
1217 const char *propname, u8 *out_values, size_t sz)
1219 const u8 *val = of_find_property_value_of_size(np, propname,
1220 (sz * sizeof(*out_values)));
1223 return PTR_ERR(val);
1226 *out_values++ = *val++;
1229 EXPORT_SYMBOL_GPL(of_property_read_u8_array);
1232 * of_property_read_u16_array - Find and read an array of u16 from a property.
1234 * @np: device node from which the property value is to be read.
1235 * @propname: name of the property to be searched.
1236 * @out_values: pointer to return value, modified only if return value is 0.
1237 * @sz: number of array elements to read
1239 * Search for a property in a device node and read 16-bit value(s) from
1240 * it. Returns 0 on success, -EINVAL if the property does not exist,
1241 * -ENODATA if property does not have a value, and -EOVERFLOW if the
1242 * property data isn't large enough.
1244 * dts entry of array should be like:
1245 * property = /bits/ 16 <0x5000 0x6000 0x7000>;
1247 * The out_values is modified only if a valid u16 value can be decoded.
1249 int of_property_read_u16_array(const struct device_node *np,
1250 const char *propname, u16 *out_values, size_t sz)
1252 const __be16 *val = of_find_property_value_of_size(np, propname,
1253 (sz * sizeof(*out_values)));
1256 return PTR_ERR(val);
1259 *out_values++ = be16_to_cpup(val++);
1262 EXPORT_SYMBOL_GPL(of_property_read_u16_array);
1265 * of_property_read_u32_array - Find and read an array of 32 bit integers
1268 * @np: device node from which the property value is to be read.
1269 * @propname: name of the property to be searched.
1270 * @out_values: pointer to return value, modified only if return value is 0.
1271 * @sz: number of array elements to read
1273 * Search for a property in a device node and read 32-bit value(s) from
1274 * it. Returns 0 on success, -EINVAL if the property does not exist,
1275 * -ENODATA if property does not have a value, and -EOVERFLOW if the
1276 * property data isn't large enough.
1278 * The out_values is modified only if a valid u32 value can be decoded.
1280 int of_property_read_u32_array(const struct device_node *np,
1281 const char *propname, u32 *out_values,
1284 const __be32 *val = of_find_property_value_of_size(np, propname,
1285 (sz * sizeof(*out_values)));
1288 return PTR_ERR(val);
1291 *out_values++ = be32_to_cpup(val++);
1294 EXPORT_SYMBOL_GPL(of_property_read_u32_array);
1297 * of_property_read_u64 - Find and read a 64 bit integer from a property
1298 * @np: device node from which the property value is to be read.
1299 * @propname: name of the property to be searched.
1300 * @out_value: pointer to return value, modified only if return value is 0.
1302 * Search for a property in a device node and read a 64-bit value from
1303 * it. Returns 0 on success, -EINVAL if the property does not exist,
1304 * -ENODATA if property does not have a value, and -EOVERFLOW if the
1305 * property data isn't large enough.
1307 * The out_value is modified only if a valid u64 value can be decoded.
1309 int of_property_read_u64(const struct device_node *np, const char *propname,
1312 const __be32 *val = of_find_property_value_of_size(np, propname,
1313 sizeof(*out_value));
1316 return PTR_ERR(val);
1318 *out_value = of_read_number(val, 2);
1321 EXPORT_SYMBOL_GPL(of_property_read_u64);
1324 * of_property_read_u64_array - Find and read an array of 64 bit integers
1327 * @np: device node from which the property value is to be read.
1328 * @propname: name of the property to be searched.
1329 * @out_values: pointer to return value, modified only if return value is 0.
1330 * @sz: number of array elements to read
1332 * Search for a property in a device node and read 64-bit value(s) from
1333 * it. Returns 0 on success, -EINVAL if the property does not exist,
1334 * -ENODATA if property does not have a value, and -EOVERFLOW if the
1335 * property data isn't large enough.
1337 * The out_values is modified only if a valid u64 value can be decoded.
1339 int of_property_read_u64_array(const struct device_node *np,
1340 const char *propname, u64 *out_values,
1343 const __be32 *val = of_find_property_value_of_size(np, propname,
1344 (sz * sizeof(*out_values)));
1347 return PTR_ERR(val);
1350 *out_values++ = of_read_number(val, 2);
1355 EXPORT_SYMBOL_GPL(of_property_read_u64_array);
1358 * of_property_read_string - Find and read a string from a property
1359 * @np: device node from which the property value is to be read.
1360 * @propname: name of the property to be searched.
1361 * @out_string: pointer to null terminated return string, modified only if
1362 * return value is 0.
1364 * Search for a property in a device tree node and retrieve a null
1365 * terminated string value (pointer to data, not a copy). Returns 0 on
1366 * success, -EINVAL if the property does not exist, -ENODATA if property
1367 * does not have a value, and -EILSEQ if the string is not null-terminated
1368 * within the length of the property data.
1370 * The out_string pointer is modified only if a valid string can be decoded.
1372 int of_property_read_string(struct device_node *np, const char *propname,
1373 const char **out_string)
1375 struct property *prop = of_find_property(np, propname, NULL);
1380 if (strnlen(prop->value, prop->length) >= prop->length)
1382 *out_string = prop->value;
1385 EXPORT_SYMBOL_GPL(of_property_read_string);
1388 * of_property_match_string() - Find string in a list and return index
1389 * @np: pointer to node containing string list property
1390 * @propname: string list property name
1391 * @string: pointer to string to search for in string list
1393 * This function searches a string list property and returns the index
1394 * of a specific string value.
1396 int of_property_match_string(struct device_node *np, const char *propname,
1399 struct property *prop = of_find_property(np, propname, NULL);
1402 const char *p, *end;
1410 end = p + prop->length;
1412 for (i = 0; p < end; i++, p += l) {
1413 l = strnlen(p, end - p) + 1;
1416 pr_debug("comparing %s with %s\n", string, p);
1417 if (strcmp(string, p) == 0)
1418 return i; /* Found it; return index */
1422 EXPORT_SYMBOL_GPL(of_property_match_string);
1425 * of_property_read_string_helper() - Utility helper for parsing string properties
1426 * @np: device node from which the property value is to be read.
1427 * @propname: name of the property to be searched.
1428 * @out_strs: output array of string pointers.
1429 * @sz: number of array elements to read.
1430 * @skip: Number of strings to skip over at beginning of list.
1432 * Don't call this function directly. It is a utility helper for the
1433 * of_property_read_string*() family of functions.
1435 int of_property_read_string_helper(struct device_node *np, const char *propname,
1436 const char **out_strs, size_t sz, int skip)
1438 struct property *prop = of_find_property(np, propname, NULL);
1440 const char *p, *end;
1447 end = p + prop->length;
1449 for (i = 0; p < end && (!out_strs || i < skip + sz); i++, p += l) {
1450 l = strnlen(p, end - p) + 1;
1453 if (out_strs && i >= skip)
1457 return i <= 0 ? -ENODATA : i;
1459 EXPORT_SYMBOL_GPL(of_property_read_string_helper);
1461 void of_print_phandle_args(const char *msg, const struct of_phandle_args *args)
1464 printk("%s %s", msg, of_node_full_name(args->np));
1465 for (i = 0; i < args->args_count; i++)
1466 printk(i ? ",%08x" : ":%08x", args->args[i]);
1470 static int __of_parse_phandle_with_args(const struct device_node *np,
1471 const char *list_name,
1472 const char *cells_name,
1473 int cell_count, int index,
1474 struct of_phandle_args *out_args)
1476 const __be32 *list, *list_end;
1477 int rc = 0, size, cur_index = 0;
1479 struct device_node *node = NULL;
1482 /* Retrieve the phandle list property */
1483 list = of_get_property(np, list_name, &size);
1486 list_end = list + size / sizeof(*list);
1488 /* Loop over the phandles until all the requested entry is found */
1489 while (list < list_end) {
1494 * If phandle is 0, then it is an empty entry with no
1495 * arguments. Skip forward to the next entry.
1497 phandle = be32_to_cpup(list++);
1500 * Find the provider node and parse the #*-cells
1501 * property to determine the argument length.
1503 * This is not needed if the cell count is hard-coded
1504 * (i.e. cells_name not set, but cell_count is set),
1505 * except when we're going to return the found node
1508 if (cells_name || cur_index == index) {
1509 node = of_find_node_by_phandle(phandle);
1511 pr_err("%s: could not find phandle\n",
1518 if (of_property_read_u32(node, cells_name,
1520 pr_err("%s: could not get %s for %s\n",
1521 np->full_name, cells_name,
1530 * Make sure that the arguments actually fit in the
1531 * remaining property data length
1533 if (list + count > list_end) {
1534 pr_err("%s: arguments longer than property\n",
1541 * All of the error cases above bail out of the loop, so at
1542 * this point, the parsing is successful. If the requested
1543 * index matches, then fill the out_args structure and return,
1544 * or return -ENOENT for an empty entry.
1547 if (cur_index == index) {
1553 if (WARN_ON(count > MAX_PHANDLE_ARGS))
1554 count = MAX_PHANDLE_ARGS;
1555 out_args->np = node;
1556 out_args->args_count = count;
1557 for (i = 0; i < count; i++)
1558 out_args->args[i] = be32_to_cpup(list++);
1563 /* Found it! return success */
1574 * Unlock node before returning result; will be one of:
1575 * -ENOENT : index is for empty phandle
1576 * -EINVAL : parsing error on data
1577 * [1..n] : Number of phandle (count mode; when index = -1)
1579 rc = index < 0 ? cur_index : -ENOENT;
1587 * of_parse_phandle - Resolve a phandle property to a device_node pointer
1588 * @np: Pointer to device node holding phandle property
1589 * @phandle_name: Name of property holding a phandle value
1590 * @index: For properties holding a table of phandles, this is the index into
1593 * Returns the device_node pointer with refcount incremented. Use
1594 * of_node_put() on it when done.
1596 struct device_node *of_parse_phandle(const struct device_node *np,
1597 const char *phandle_name, int index)
1599 struct of_phandle_args args;
1604 if (__of_parse_phandle_with_args(np, phandle_name, NULL, 0,
1610 EXPORT_SYMBOL(of_parse_phandle);
1613 * of_parse_phandle_with_args() - Find a node pointed by phandle in a list
1614 * @np: pointer to a device tree node containing a list
1615 * @list_name: property name that contains a list
1616 * @cells_name: property name that specifies phandles' arguments count
1617 * @index: index of a phandle to parse out
1618 * @out_args: optional pointer to output arguments structure (will be filled)
1620 * This function is useful to parse lists of phandles and their arguments.
1621 * Returns 0 on success and fills out_args, on error returns appropriate
1624 * Caller is responsible to call of_node_put() on the returned out_args->np
1630 * #list-cells = <2>;
1634 * #list-cells = <1>;
1638 * list = <&phandle1 1 2 &phandle2 3>;
1641 * To get a device_node of the `node2' node you may call this:
1642 * of_parse_phandle_with_args(node3, "list", "#list-cells", 1, &args);
1644 int of_parse_phandle_with_args(const struct device_node *np, const char *list_name,
1645 const char *cells_name, int index,
1646 struct of_phandle_args *out_args)
1650 return __of_parse_phandle_with_args(np, list_name, cells_name, 0,
1653 EXPORT_SYMBOL(of_parse_phandle_with_args);
1656 * of_parse_phandle_with_fixed_args() - Find a node pointed by phandle in a list
1657 * @np: pointer to a device tree node containing a list
1658 * @list_name: property name that contains a list
1659 * @cell_count: number of argument cells following the phandle
1660 * @index: index of a phandle to parse out
1661 * @out_args: optional pointer to output arguments structure (will be filled)
1663 * This function is useful to parse lists of phandles and their arguments.
1664 * Returns 0 on success and fills out_args, on error returns appropriate
1667 * Caller is responsible to call of_node_put() on the returned out_args->np
1679 * list = <&phandle1 0 2 &phandle2 2 3>;
1682 * To get a device_node of the `node2' node you may call this:
1683 * of_parse_phandle_with_fixed_args(node3, "list", 2, 1, &args);
1685 int of_parse_phandle_with_fixed_args(const struct device_node *np,
1686 const char *list_name, int cell_count,
1687 int index, struct of_phandle_args *out_args)
1691 return __of_parse_phandle_with_args(np, list_name, NULL, cell_count,
1694 EXPORT_SYMBOL(of_parse_phandle_with_fixed_args);
1697 * of_count_phandle_with_args() - Find the number of phandles references in a property
1698 * @np: pointer to a device tree node containing a list
1699 * @list_name: property name that contains a list
1700 * @cells_name: property name that specifies phandles' arguments count
1702 * Returns the number of phandle + argument tuples within a property. It
1703 * is a typical pattern to encode a list of phandle and variable
1704 * arguments into a single property. The number of arguments is encoded
1705 * by a property in the phandle-target node. For example, a gpios
1706 * property would contain a list of GPIO specifies consisting of a
1707 * phandle and 1 or more arguments. The number of arguments are
1708 * determined by the #gpio-cells property in the node pointed to by the
1711 int of_count_phandle_with_args(const struct device_node *np, const char *list_name,
1712 const char *cells_name)
1714 return __of_parse_phandle_with_args(np, list_name, cells_name, 0, -1,
1717 EXPORT_SYMBOL(of_count_phandle_with_args);
1720 * __of_add_property - Add a property to a node without lock operations
1722 int __of_add_property(struct device_node *np, struct property *prop)
1724 struct property **next;
1727 next = &np->properties;
1729 if (strcmp(prop->name, (*next)->name) == 0)
1730 /* duplicate ! don't insert it */
1733 next = &(*next)->next;
1741 * of_add_property - Add a property to a node
1743 int of_add_property(struct device_node *np, struct property *prop)
1745 unsigned long flags;
1748 mutex_lock(&of_mutex);
1750 raw_spin_lock_irqsave(&devtree_lock, flags);
1751 rc = __of_add_property(np, prop);
1752 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1755 __of_add_property_sysfs(np, prop);
1757 mutex_unlock(&of_mutex);
1760 of_property_notify(OF_RECONFIG_ADD_PROPERTY, np, prop, NULL);
1765 int __of_remove_property(struct device_node *np, struct property *prop)
1767 struct property **next;
1769 for (next = &np->properties; *next; next = &(*next)->next) {
1776 /* found the node */
1778 prop->next = np->deadprops;
1779 np->deadprops = prop;
1784 void __of_sysfs_remove_bin_file(struct device_node *np, struct property *prop)
1786 sysfs_remove_bin_file(&np->kobj, &prop->attr);
1787 kfree(prop->attr.attr.name);
1790 void __of_remove_property_sysfs(struct device_node *np, struct property *prop)
1792 if (!IS_ENABLED(CONFIG_SYSFS))
1795 /* at early boot, bail here and defer setup to of_init() */
1796 if (of_kset && of_node_is_attached(np))
1797 __of_sysfs_remove_bin_file(np, prop);
1801 * of_remove_property - Remove a property from a node.
1803 * Note that we don't actually remove it, since we have given out
1804 * who-knows-how-many pointers to the data using get-property.
1805 * Instead we just move the property to the "dead properties"
1806 * list, so it won't be found any more.
1808 int of_remove_property(struct device_node *np, struct property *prop)
1810 unsigned long flags;
1813 mutex_lock(&of_mutex);
1815 raw_spin_lock_irqsave(&devtree_lock, flags);
1816 rc = __of_remove_property(np, prop);
1817 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1820 __of_remove_property_sysfs(np, prop);
1822 mutex_unlock(&of_mutex);
1825 of_property_notify(OF_RECONFIG_REMOVE_PROPERTY, np, prop, NULL);
1830 int __of_update_property(struct device_node *np, struct property *newprop,
1831 struct property **oldpropp)
1833 struct property **next, *oldprop;
1835 for (next = &np->properties; *next; next = &(*next)->next) {
1836 if (of_prop_cmp((*next)->name, newprop->name) == 0)
1839 *oldpropp = oldprop = *next;
1842 /* replace the node */
1843 newprop->next = oldprop->next;
1845 oldprop->next = np->deadprops;
1846 np->deadprops = oldprop;
1849 newprop->next = NULL;
1856 void __of_update_property_sysfs(struct device_node *np, struct property *newprop,
1857 struct property *oldprop)
1859 if (!IS_ENABLED(CONFIG_SYSFS))
1862 /* At early boot, bail out and defer setup to of_init() */
1867 __of_sysfs_remove_bin_file(np, oldprop);
1868 __of_add_property_sysfs(np, newprop);
1872 * of_update_property - Update a property in a node, if the property does
1873 * not exist, add it.
1875 * Note that we don't actually remove it, since we have given out
1876 * who-knows-how-many pointers to the data using get-property.
1877 * Instead we just move the property to the "dead properties" list,
1878 * and add the new property to the property list
1880 int of_update_property(struct device_node *np, struct property *newprop)
1882 struct property *oldprop;
1883 unsigned long flags;
1889 mutex_lock(&of_mutex);
1891 raw_spin_lock_irqsave(&devtree_lock, flags);
1892 rc = __of_update_property(np, newprop, &oldprop);
1893 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1896 __of_update_property_sysfs(np, newprop, oldprop);
1898 mutex_unlock(&of_mutex);
1901 of_property_notify(OF_RECONFIG_UPDATE_PROPERTY, np, newprop, oldprop);
1906 static void of_alias_add(struct alias_prop *ap, struct device_node *np,
1907 int id, const char *stem, int stem_len)
1911 strncpy(ap->stem, stem, stem_len);
1912 ap->stem[stem_len] = 0;
1913 list_add_tail(&ap->link, &aliases_lookup);
1914 pr_debug("adding DT alias:%s: stem=%s id=%i node=%s\n",
1915 ap->alias, ap->stem, ap->id, of_node_full_name(np));
1919 * of_alias_scan - Scan all properties of the 'aliases' node
1921 * The function scans all the properties of the 'aliases' node and populates
1922 * the global lookup table with the properties. It returns the
1923 * number of alias properties found, or an error code in case of failure.
1925 * @dt_alloc: An allocator that provides a virtual address to memory
1926 * for storing the resulting tree
1928 void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align))
1930 struct property *pp;
1932 of_aliases = of_find_node_by_path("/aliases");
1933 of_chosen = of_find_node_by_path("/chosen");
1934 if (of_chosen == NULL)
1935 of_chosen = of_find_node_by_path("/chosen@0");
1938 /* linux,stdout-path and /aliases/stdout are for legacy compatibility */
1939 const char *name = of_get_property(of_chosen, "stdout-path", NULL);
1941 name = of_get_property(of_chosen, "linux,stdout-path", NULL);
1942 if (IS_ENABLED(CONFIG_PPC) && !name)
1943 name = of_get_property(of_aliases, "stdout", NULL);
1945 of_stdout = of_find_node_opts_by_path(name, &of_stdout_options);
1951 for_each_property_of_node(of_aliases, pp) {
1952 const char *start = pp->name;
1953 const char *end = start + strlen(start);
1954 struct device_node *np;
1955 struct alias_prop *ap;
1958 /* Skip those we do not want to proceed */
1959 if (!strcmp(pp->name, "name") ||
1960 !strcmp(pp->name, "phandle") ||
1961 !strcmp(pp->name, "linux,phandle"))
1964 np = of_find_node_by_path(pp->value);
1968 /* walk the alias backwards to extract the id and work out
1969 * the 'stem' string */
1970 while (isdigit(*(end-1)) && end > start)
1974 if (kstrtoint(end, 10, &id) < 0)
1977 /* Allocate an alias_prop with enough space for the stem */
1978 ap = dt_alloc(sizeof(*ap) + len + 1, 4);
1981 memset(ap, 0, sizeof(*ap) + len + 1);
1983 of_alias_add(ap, np, id, start, len);
1988 * of_alias_get_id - Get alias id for the given device_node
1989 * @np: Pointer to the given device_node
1990 * @stem: Alias stem of the given device_node
1992 * The function travels the lookup table to get the alias id for the given
1993 * device_node and alias stem. It returns the alias id if found.
1995 int of_alias_get_id(struct device_node *np, const char *stem)
1997 struct alias_prop *app;
2000 mutex_lock(&of_mutex);
2001 list_for_each_entry(app, &aliases_lookup, link) {
2002 if (strcmp(app->stem, stem) != 0)
2005 if (np == app->np) {
2010 mutex_unlock(&of_mutex);
2014 EXPORT_SYMBOL_GPL(of_alias_get_id);
2017 * of_alias_get_highest_id - Get highest alias id for the given stem
2018 * @stem: Alias stem to be examined
2020 * The function travels the lookup table to get the highest alias id for the
2021 * given alias stem. It returns the alias id if found.
2023 int of_alias_get_highest_id(const char *stem)
2025 struct alias_prop *app;
2028 mutex_lock(&of_mutex);
2029 list_for_each_entry(app, &aliases_lookup, link) {
2030 if (strcmp(app->stem, stem) != 0)
2036 mutex_unlock(&of_mutex);
2040 EXPORT_SYMBOL_GPL(of_alias_get_highest_id);
2042 const __be32 *of_prop_next_u32(struct property *prop, const __be32 *cur,
2045 const void *curv = cur;
2055 curv += sizeof(*cur);
2056 if (curv >= prop->value + prop->length)
2060 *pu = be32_to_cpup(curv);
2063 EXPORT_SYMBOL_GPL(of_prop_next_u32);
2065 const char *of_prop_next_string(struct property *prop, const char *cur)
2067 const void *curv = cur;
2075 curv += strlen(cur) + 1;
2076 if (curv >= prop->value + prop->length)
2081 EXPORT_SYMBOL_GPL(of_prop_next_string);
2084 * of_console_check() - Test and setup console for DT setup
2085 * @dn - Pointer to device node
2086 * @name - Name to use for preferred console without index. ex. "ttyS"
2087 * @index - Index to use for preferred console.
2089 * Check if the given device node matches the stdout-path property in the
2090 * /chosen node. If it does then register it as the preferred console and return
2091 * TRUE. Otherwise return FALSE.
2093 bool of_console_check(struct device_node *dn, char *name, int index)
2095 if (!dn || dn != of_stdout || console_set_on_cmdline)
2097 return !add_preferred_console(name, index,
2098 kstrdup(of_stdout_options, GFP_KERNEL));
2100 EXPORT_SYMBOL_GPL(of_console_check);
2103 * of_find_next_cache_node - Find a node's subsidiary cache
2104 * @np: node of type "cpu" or "cache"
2106 * Returns a node pointer with refcount incremented, use
2107 * of_node_put() on it when done. Caller should hold a reference
2110 struct device_node *of_find_next_cache_node(const struct device_node *np)
2112 struct device_node *child;
2113 const phandle *handle;
2115 handle = of_get_property(np, "l2-cache", NULL);
2117 handle = of_get_property(np, "next-level-cache", NULL);
2120 return of_find_node_by_phandle(be32_to_cpup(handle));
2122 /* OF on pmac has nodes instead of properties named "l2-cache"
2123 * beneath CPU nodes.
2125 if (IS_ENABLED(CONFIG_PPC_PMAC) && !strcmp(np->type, "cpu"))
2126 for_each_child_of_node(np, child)
2127 if (!strcmp(child->type, "cache"))
2134 * of_graph_parse_endpoint() - parse common endpoint node properties
2135 * @node: pointer to endpoint device_node
2136 * @endpoint: pointer to the OF endpoint data structure
2138 * The caller should hold a reference to @node.
2140 int of_graph_parse_endpoint(const struct device_node *node,
2141 struct of_endpoint *endpoint)
2143 struct device_node *port_node = of_get_parent(node);
2145 WARN_ONCE(!port_node, "%s(): endpoint %s has no parent node\n",
2146 __func__, node->full_name);
2148 memset(endpoint, 0, sizeof(*endpoint));
2150 endpoint->local_node = node;
2152 * It doesn't matter whether the two calls below succeed.
2153 * If they don't then the default value 0 is used.
2155 of_property_read_u32(port_node, "reg", &endpoint->port);
2156 of_property_read_u32(node, "reg", &endpoint->id);
2158 of_node_put(port_node);
2162 EXPORT_SYMBOL(of_graph_parse_endpoint);
2165 * of_graph_get_port_by_id() - get the port matching a given id
2166 * @parent: pointer to the parent device node
2167 * @id: id of the port
2169 * Return: A 'port' node pointer with refcount incremented. The caller
2170 * has to use of_node_put() on it when done.
2172 struct device_node *of_graph_get_port_by_id(struct device_node *parent, u32 id)
2174 struct device_node *node, *port;
2176 node = of_get_child_by_name(parent, "ports");
2180 for_each_child_of_node(parent, port) {
2183 if (of_node_cmp(port->name, "port") != 0)
2185 of_property_read_u32(port, "reg", &port_id);
2194 EXPORT_SYMBOL(of_graph_get_port_by_id);
2197 * of_graph_get_next_endpoint() - get next endpoint node
2198 * @parent: pointer to the parent device node
2199 * @prev: previous endpoint node, or NULL to get first
2201 * Return: An 'endpoint' node pointer with refcount incremented. Refcount
2202 * of the passed @prev node is decremented.
2204 struct device_node *of_graph_get_next_endpoint(const struct device_node *parent,
2205 struct device_node *prev)
2207 struct device_node *endpoint;
2208 struct device_node *port;
2214 * Start by locating the port node. If no previous endpoint is specified
2215 * search for the first port node, otherwise get the previous endpoint
2219 struct device_node *node;
2221 node = of_get_child_by_name(parent, "ports");
2225 port = of_get_child_by_name(parent, "port");
2229 pr_err("%s(): no port node found in %s\n",
2230 __func__, parent->full_name);
2234 port = of_get_parent(prev);
2235 if (WARN_ONCE(!port, "%s(): endpoint %s has no parent node\n",
2236 __func__, prev->full_name))
2242 * Now that we have a port node, get the next endpoint by
2243 * getting the next child. If the previous endpoint is NULL this
2244 * will return the first child.
2246 endpoint = of_get_next_child(port, prev);
2252 /* No more endpoints under this port, try the next one. */
2256 port = of_get_next_child(parent, port);
2259 } while (of_node_cmp(port->name, "port"));
2262 EXPORT_SYMBOL(of_graph_get_next_endpoint);
2265 * of_graph_get_endpoint_by_regs() - get endpoint node of specific identifiers
2266 * @parent: pointer to the parent device node
2267 * @port_reg: identifier (value of reg property) of the parent port node
2268 * @reg: identifier (value of reg property) of the endpoint node
2270 * Return: An 'endpoint' node pointer which is identified by reg and at the same
2271 * is the child of a port node identified by port_reg. reg and port_reg are
2272 * ignored when they are -1.
2274 struct device_node *of_graph_get_endpoint_by_regs(
2275 const struct device_node *parent, int port_reg, int reg)
2277 struct of_endpoint endpoint;
2278 struct device_node *node = NULL;
2280 for_each_endpoint_of_node(parent, node) {
2281 of_graph_parse_endpoint(node, &endpoint);
2282 if (((port_reg == -1) || (endpoint.port == port_reg)) &&
2283 ((reg == -1) || (endpoint.id == reg)))
2289 EXPORT_SYMBOL(of_graph_get_endpoint_by_regs);
2292 * of_graph_get_remote_port_parent() - get remote port's parent node
2293 * @node: pointer to a local endpoint device_node
2295 * Return: Remote device node associated with remote endpoint node linked
2296 * to @node. Use of_node_put() on it when done.
2298 struct device_node *of_graph_get_remote_port_parent(
2299 const struct device_node *node)
2301 struct device_node *np;
2304 /* Get remote endpoint node. */
2305 np = of_parse_phandle(node, "remote-endpoint", 0);
2307 /* Walk 3 levels up only if there is 'ports' node. */
2308 for (depth = 3; depth && np; depth--) {
2309 np = of_get_next_parent(np);
2310 if (depth == 2 && of_node_cmp(np->name, "ports"))
2315 EXPORT_SYMBOL(of_graph_get_remote_port_parent);
2318 * of_graph_get_remote_port() - get remote port node
2319 * @node: pointer to a local endpoint device_node
2321 * Return: Remote port node associated with remote endpoint node linked
2322 * to @node. Use of_node_put() on it when done.
2324 struct device_node *of_graph_get_remote_port(const struct device_node *node)
2326 struct device_node *np;
2328 /* Get remote endpoint node. */
2329 np = of_parse_phandle(node, "remote-endpoint", 0);
2332 return of_get_next_parent(np);
2334 EXPORT_SYMBOL(of_graph_get_remote_port);