2 * Procedures for creating, accessing and interpreting the device tree.
4 * Paul Mackerras August 1996.
5 * Copyright (C) 1996-2005 Paul Mackerras.
7 * Adapted for 64bit PowerPC by Dave Engebretsen and Peter Bergner.
8 * {engebret|bergner}@us.ibm.com
10 * Adapted for sparc and sparc64 by David S. Miller davem@davemloft.net
12 * Reconsolidated from arch/x/kernel/prom.c by Stephen Rothwell and
15 * This program is free software; you can redistribute it and/or
16 * modify it under the terms of the GNU General Public License
17 * as published by the Free Software Foundation; either version
18 * 2 of the License, or (at your option) any later version.
20 #include <linux/ctype.h>
21 #include <linux/cpu.h>
22 #include <linux/module.h>
24 #include <linux/spinlock.h>
25 #include <linux/slab.h>
26 #include <linux/proc_fs.h>
28 #include "of_private.h"
30 LIST_HEAD(aliases_lookup);
32 struct device_node *of_allnodes;
33 EXPORT_SYMBOL(of_allnodes);
34 struct device_node *of_chosen;
35 struct device_node *of_aliases;
36 static struct device_node *of_stdout;
38 DEFINE_MUTEX(of_aliases_mutex);
40 /* use when traversing tree through the allnext, child, sibling,
41 * or parent members of struct device_node.
43 DEFINE_RAW_SPINLOCK(devtree_lock);
45 int of_n_addr_cells(struct device_node *np)
52 ip = of_get_property(np, "#address-cells", NULL);
54 return be32_to_cpup(ip);
56 /* No #address-cells property for the root node */
57 return OF_ROOT_NODE_ADDR_CELLS_DEFAULT;
59 EXPORT_SYMBOL(of_n_addr_cells);
61 int of_n_size_cells(struct device_node *np)
68 ip = of_get_property(np, "#size-cells", NULL);
70 return be32_to_cpup(ip);
72 /* No #size-cells property for the root node */
73 return OF_ROOT_NODE_SIZE_CELLS_DEFAULT;
75 EXPORT_SYMBOL(of_n_size_cells);
77 #if defined(CONFIG_OF_DYNAMIC)
79 * of_node_get - Increment refcount of a node
80 * @node: Node to inc refcount, NULL is supported to
81 * simplify writing of callers
85 struct device_node *of_node_get(struct device_node *node)
88 kref_get(&node->kref);
91 EXPORT_SYMBOL(of_node_get);
93 static inline struct device_node *kref_to_device_node(struct kref *kref)
95 return container_of(kref, struct device_node, kref);
99 * of_node_release - release a dynamically allocated node
100 * @kref: kref element of the node to be released
102 * In of_node_put() this function is passed to kref_put()
105 static void of_node_release(struct kref *kref)
107 struct device_node *node = kref_to_device_node(kref);
108 struct property *prop = node->properties;
110 /* We should never be releasing nodes that haven't been detached. */
111 if (!of_node_check_flag(node, OF_DETACHED)) {
112 pr_err("ERROR: Bad of_node_put() on %s\n", node->full_name);
114 kref_init(&node->kref);
118 if (!of_node_check_flag(node, OF_DYNAMIC))
122 struct property *next = prop->next;
129 prop = node->deadprops;
130 node->deadprops = NULL;
133 kfree(node->full_name);
139 * of_node_put - Decrement refcount of a node
140 * @node: Node to dec refcount, NULL is supported to
141 * simplify writing of callers
144 void of_node_put(struct device_node *node)
147 kref_put(&node->kref, of_node_release);
149 EXPORT_SYMBOL(of_node_put);
150 #endif /* CONFIG_OF_DYNAMIC */
152 static struct property *__of_find_property(const struct device_node *np,
153 const char *name, int *lenp)
160 for (pp = np->properties; pp; pp = pp->next) {
161 if (of_prop_cmp(pp->name, name) == 0) {
171 struct property *of_find_property(const struct device_node *np,
178 raw_spin_lock_irqsave(&devtree_lock, flags);
179 pp = __of_find_property(np, name, lenp);
180 raw_spin_unlock_irqrestore(&devtree_lock, flags);
184 EXPORT_SYMBOL(of_find_property);
187 * of_find_all_nodes - Get next node in global list
188 * @prev: Previous node or NULL to start iteration
189 * of_node_put() will be called on it
191 * Returns a node pointer with refcount incremented, use
192 * of_node_put() on it when done.
194 struct device_node *of_find_all_nodes(struct device_node *prev)
196 struct device_node *np;
199 raw_spin_lock_irqsave(&devtree_lock, flags);
200 np = prev ? prev->allnext : of_allnodes;
201 for (; np != NULL; np = np->allnext)
205 raw_spin_unlock_irqrestore(&devtree_lock, flags);
208 EXPORT_SYMBOL(of_find_all_nodes);
211 * Find a property with a given name for a given node
212 * and return the value.
214 static const void *__of_get_property(const struct device_node *np,
215 const char *name, int *lenp)
217 struct property *pp = __of_find_property(np, name, lenp);
219 return pp ? pp->value : NULL;
223 * Find a property with a given name for a given node
224 * and return the value.
226 const void *of_get_property(const struct device_node *np, const char *name,
229 struct property *pp = of_find_property(np, name, lenp);
231 return pp ? pp->value : NULL;
233 EXPORT_SYMBOL(of_get_property);
236 * arch_match_cpu_phys_id - Match the given logical CPU and physical id
238 * @cpu: logical cpu index of a core/thread
239 * @phys_id: physical identifier of a core/thread
241 * CPU logical to physical index mapping is architecture specific.
242 * However this __weak function provides a default match of physical
243 * id to logical cpu index. phys_id provided here is usually values read
244 * from the device tree which must match the hardware internal registers.
246 * Returns true if the physical identifier and the logical cpu index
247 * correspond to the same core/thread, false otherwise.
249 bool __weak arch_match_cpu_phys_id(int cpu, u64 phys_id)
251 return (u32)phys_id == cpu;
255 * Checks if the given "prop_name" property holds the physical id of the
256 * core/thread corresponding to the logical cpu 'cpu'. If 'thread' is not
257 * NULL, local thread number within the core is returned in it.
259 static bool __of_find_n_match_cpu_property(struct device_node *cpun,
260 const char *prop_name, int cpu, unsigned int *thread)
263 int ac, prop_len, tid;
266 ac = of_n_addr_cells(cpun);
267 cell = of_get_property(cpun, prop_name, &prop_len);
270 prop_len /= sizeof(*cell);
271 for (tid = 0; tid < prop_len; tid++) {
272 hwid = of_read_number(cell, ac);
273 if (arch_match_cpu_phys_id(cpu, hwid)) {
284 * of_get_cpu_node - Get device node associated with the given logical CPU
286 * @cpu: CPU number(logical index) for which device node is required
287 * @thread: if not NULL, local thread number within the physical core is
290 * The main purpose of this function is to retrieve the device node for the
291 * given logical CPU index. It should be used to initialize the of_node in
292 * cpu device. Once of_node in cpu device is populated, all the further
293 * references can use that instead.
295 * CPU logical to physical index mapping is architecture specific and is built
296 * before booting secondary cores. This function uses arch_match_cpu_phys_id
297 * which can be overridden by architecture specific implementation.
299 * Returns a node pointer for the logical cpu if found, else NULL.
301 struct device_node *of_get_cpu_node(int cpu, unsigned int *thread)
303 struct device_node *cpun, *cpus;
305 cpus = of_find_node_by_path("/cpus");
309 for_each_child_of_node(cpus, cpun) {
310 if (of_node_cmp(cpun->type, "cpu"))
312 /* Check for non-standard "ibm,ppc-interrupt-server#s" property
313 * for thread ids on PowerPC. If it doesn't exist fallback to
314 * standard "reg" property.
316 if (IS_ENABLED(CONFIG_PPC) &&
317 __of_find_n_match_cpu_property(cpun,
318 "ibm,ppc-interrupt-server#s", cpu, thread))
320 if (__of_find_n_match_cpu_property(cpun, "reg", cpu, thread))
325 EXPORT_SYMBOL(of_get_cpu_node);
327 /** Checks if the given "compat" string matches one of the strings in
328 * the device's "compatible" property
330 static int __of_device_is_compatible(const struct device_node *device,
336 cp = __of_get_property(device, "compatible", &cplen);
340 if (of_compat_cmp(cp, compat, strlen(compat)) == 0)
350 /** Checks if the given "compat" string matches one of the strings in
351 * the device's "compatible" property
353 int of_device_is_compatible(const struct device_node *device,
359 raw_spin_lock_irqsave(&devtree_lock, flags);
360 res = __of_device_is_compatible(device, compat);
361 raw_spin_unlock_irqrestore(&devtree_lock, flags);
364 EXPORT_SYMBOL(of_device_is_compatible);
367 * of_machine_is_compatible - Test root of device tree for a given compatible value
368 * @compat: compatible string to look for in root node's compatible property.
370 * Returns true if the root node has the given value in its
371 * compatible property.
373 int of_machine_is_compatible(const char *compat)
375 struct device_node *root;
378 root = of_find_node_by_path("/");
380 rc = of_device_is_compatible(root, compat);
385 EXPORT_SYMBOL(of_machine_is_compatible);
388 * __of_device_is_available - check if a device is available for use
390 * @device: Node to check for availability, with locks already held
392 * Returns 1 if the status property is absent or set to "okay" or "ok",
395 static int __of_device_is_available(const struct device_node *device)
400 status = __of_get_property(device, "status", &statlen);
405 if (!strcmp(status, "okay") || !strcmp(status, "ok"))
413 * of_device_is_available - check if a device is available for use
415 * @device: Node to check for availability
417 * Returns 1 if the status property is absent or set to "okay" or "ok",
420 int of_device_is_available(const struct device_node *device)
425 raw_spin_lock_irqsave(&devtree_lock, flags);
426 res = __of_device_is_available(device);
427 raw_spin_unlock_irqrestore(&devtree_lock, flags);
431 EXPORT_SYMBOL(of_device_is_available);
434 * of_get_parent - Get a node's parent if any
435 * @node: Node to get parent
437 * Returns a node pointer with refcount incremented, use
438 * of_node_put() on it when done.
440 struct device_node *of_get_parent(const struct device_node *node)
442 struct device_node *np;
448 raw_spin_lock_irqsave(&devtree_lock, flags);
449 np = of_node_get(node->parent);
450 raw_spin_unlock_irqrestore(&devtree_lock, flags);
453 EXPORT_SYMBOL(of_get_parent);
456 * of_get_next_parent - Iterate to a node's parent
457 * @node: Node to get parent of
459 * This is like of_get_parent() except that it drops the
460 * refcount on the passed node, making it suitable for iterating
461 * through a node's parents.
463 * Returns a node pointer with refcount incremented, use
464 * of_node_put() on it when done.
466 struct device_node *of_get_next_parent(struct device_node *node)
468 struct device_node *parent;
474 raw_spin_lock_irqsave(&devtree_lock, flags);
475 parent = of_node_get(node->parent);
477 raw_spin_unlock_irqrestore(&devtree_lock, flags);
480 EXPORT_SYMBOL(of_get_next_parent);
483 * of_get_next_child - Iterate a node childs
485 * @prev: previous child of the parent node, or NULL to get first
487 * Returns a node pointer with refcount incremented, use
488 * of_node_put() on it when done.
490 struct device_node *of_get_next_child(const struct device_node *node,
491 struct device_node *prev)
493 struct device_node *next;
496 raw_spin_lock_irqsave(&devtree_lock, flags);
497 next = prev ? prev->sibling : node->child;
498 for (; next; next = next->sibling)
499 if (of_node_get(next))
502 raw_spin_unlock_irqrestore(&devtree_lock, flags);
505 EXPORT_SYMBOL(of_get_next_child);
508 * of_get_next_available_child - Find the next available child node
510 * @prev: previous child of the parent node, or NULL to get first
512 * This function is like of_get_next_child(), except that it
513 * automatically skips any disabled nodes (i.e. status = "disabled").
515 struct device_node *of_get_next_available_child(const struct device_node *node,
516 struct device_node *prev)
518 struct device_node *next;
521 raw_spin_lock_irqsave(&devtree_lock, flags);
522 next = prev ? prev->sibling : node->child;
523 for (; next; next = next->sibling) {
524 if (!__of_device_is_available(next))
526 if (of_node_get(next))
530 raw_spin_unlock_irqrestore(&devtree_lock, flags);
533 EXPORT_SYMBOL(of_get_next_available_child);
536 * of_get_child_by_name - Find the child node by name for a given parent
538 * @name: child name to look for.
540 * This function looks for child node for given matching name
542 * Returns a node pointer if found, with refcount incremented, use
543 * of_node_put() on it when done.
544 * Returns NULL if node is not found.
546 struct device_node *of_get_child_by_name(const struct device_node *node,
549 struct device_node *child;
551 for_each_child_of_node(node, child)
552 if (child->name && (of_node_cmp(child->name, name) == 0))
556 EXPORT_SYMBOL(of_get_child_by_name);
559 * of_find_node_by_path - Find a node matching a full OF path
560 * @path: The full path to match
562 * Returns a node pointer with refcount incremented, use
563 * of_node_put() on it when done.
565 struct device_node *of_find_node_by_path(const char *path)
567 struct device_node *np = of_allnodes;
570 raw_spin_lock_irqsave(&devtree_lock, flags);
571 for (; np; np = np->allnext) {
572 if (np->full_name && (of_node_cmp(np->full_name, path) == 0)
576 raw_spin_unlock_irqrestore(&devtree_lock, flags);
579 EXPORT_SYMBOL(of_find_node_by_path);
582 * of_find_node_by_name - Find a node by its "name" property
583 * @from: The node to start searching from or NULL, the node
584 * you pass will not be searched, only the next one
585 * will; typically, you pass what the previous call
586 * returned. of_node_put() will be called on it
587 * @name: The name string to match against
589 * Returns a node pointer with refcount incremented, use
590 * of_node_put() on it when done.
592 struct device_node *of_find_node_by_name(struct device_node *from,
595 struct device_node *np;
598 raw_spin_lock_irqsave(&devtree_lock, flags);
599 np = from ? from->allnext : of_allnodes;
600 for (; np; np = np->allnext)
601 if (np->name && (of_node_cmp(np->name, name) == 0)
605 raw_spin_unlock_irqrestore(&devtree_lock, flags);
608 EXPORT_SYMBOL(of_find_node_by_name);
611 * of_find_node_by_type - Find a node by its "device_type" property
612 * @from: The node to start searching from, or NULL to start searching
613 * the entire device tree. The node you pass will not be
614 * searched, only the next one will; typically, you pass
615 * what the previous call returned. of_node_put() will be
616 * called on from for you.
617 * @type: The type string to match against
619 * Returns a node pointer with refcount incremented, use
620 * of_node_put() on it when done.
622 struct device_node *of_find_node_by_type(struct device_node *from,
625 struct device_node *np;
628 raw_spin_lock_irqsave(&devtree_lock, flags);
629 np = from ? from->allnext : of_allnodes;
630 for (; np; np = np->allnext)
631 if (np->type && (of_node_cmp(np->type, type) == 0)
635 raw_spin_unlock_irqrestore(&devtree_lock, flags);
638 EXPORT_SYMBOL(of_find_node_by_type);
641 * of_find_compatible_node - Find a node based on type and one of the
642 * tokens in its "compatible" property
643 * @from: The node to start searching from or NULL, the node
644 * you pass will not be searched, only the next one
645 * will; typically, you pass what the previous call
646 * returned. of_node_put() will be called on it
647 * @type: The type string to match "device_type" or NULL to ignore
648 * @compatible: The string to match to one of the tokens in the device
651 * Returns a node pointer with refcount incremented, use
652 * of_node_put() on it when done.
654 struct device_node *of_find_compatible_node(struct device_node *from,
655 const char *type, const char *compatible)
657 struct device_node *np;
660 raw_spin_lock_irqsave(&devtree_lock, flags);
661 np = from ? from->allnext : of_allnodes;
662 for (; np; np = np->allnext) {
664 && !(np->type && (of_node_cmp(np->type, type) == 0)))
666 if (__of_device_is_compatible(np, compatible) &&
671 raw_spin_unlock_irqrestore(&devtree_lock, flags);
674 EXPORT_SYMBOL(of_find_compatible_node);
677 * of_find_node_with_property - Find a node which has a property with
679 * @from: The node to start searching from or NULL, the node
680 * you pass will not be searched, only the next one
681 * will; typically, you pass what the previous call
682 * returned. of_node_put() will be called on it
683 * @prop_name: The name of the property to look for.
685 * Returns a node pointer with refcount incremented, use
686 * of_node_put() on it when done.
688 struct device_node *of_find_node_with_property(struct device_node *from,
689 const char *prop_name)
691 struct device_node *np;
695 raw_spin_lock_irqsave(&devtree_lock, flags);
696 np = from ? from->allnext : of_allnodes;
697 for (; np; np = np->allnext) {
698 for (pp = np->properties; pp; pp = pp->next) {
699 if (of_prop_cmp(pp->name, prop_name) == 0) {
707 raw_spin_unlock_irqrestore(&devtree_lock, flags);
710 EXPORT_SYMBOL(of_find_node_with_property);
713 const struct of_device_id *__of_match_node(const struct of_device_id *matches,
714 const struct device_node *node)
719 while (matches->name[0] || matches->type[0] || matches->compatible[0]) {
721 if (matches->name[0])
723 && !strcmp(matches->name, node->name);
724 if (matches->type[0])
726 && !strcmp(matches->type, node->type);
727 if (matches->compatible[0])
728 match &= __of_device_is_compatible(node,
729 matches->compatible);
738 * of_match_node - Tell if an device_node has a matching of_match structure
739 * @matches: array of of device match structures to search in
740 * @node: the of device structure to match against
742 * Low level utility function used by device matching.
744 const struct of_device_id *of_match_node(const struct of_device_id *matches,
745 const struct device_node *node)
747 const struct of_device_id *match;
750 raw_spin_lock_irqsave(&devtree_lock, flags);
751 match = __of_match_node(matches, node);
752 raw_spin_unlock_irqrestore(&devtree_lock, flags);
755 EXPORT_SYMBOL(of_match_node);
758 * of_find_matching_node_and_match - Find a node based on an of_device_id
760 * @from: The node to start searching from or NULL, the node
761 * you pass will not be searched, only the next one
762 * will; typically, you pass what the previous call
763 * returned. of_node_put() will be called on it
764 * @matches: array of of device match structures to search in
765 * @match Updated to point at the matches entry which matched
767 * Returns a node pointer with refcount incremented, use
768 * of_node_put() on it when done.
770 struct device_node *of_find_matching_node_and_match(struct device_node *from,
771 const struct of_device_id *matches,
772 const struct of_device_id **match)
774 struct device_node *np;
775 const struct of_device_id *m;
781 raw_spin_lock_irqsave(&devtree_lock, flags);
782 np = from ? from->allnext : of_allnodes;
783 for (; np; np = np->allnext) {
784 m = __of_match_node(matches, np);
785 if (m && of_node_get(np)) {
792 raw_spin_unlock_irqrestore(&devtree_lock, flags);
795 EXPORT_SYMBOL(of_find_matching_node_and_match);
798 * of_modalias_node - Lookup appropriate modalias for a device node
799 * @node: pointer to a device tree node
800 * @modalias: Pointer to buffer that modalias value will be copied into
801 * @len: Length of modalias value
803 * Based on the value of the compatible property, this routine will attempt
804 * to choose an appropriate modalias value for a particular device tree node.
805 * It does this by stripping the manufacturer prefix (as delimited by a ',')
806 * from the first entry in the compatible list property.
808 * This routine returns 0 on success, <0 on failure.
810 int of_modalias_node(struct device_node *node, char *modalias, int len)
812 const char *compatible, *p;
815 compatible = of_get_property(node, "compatible", &cplen);
816 if (!compatible || strlen(compatible) > cplen)
818 p = strchr(compatible, ',');
819 strlcpy(modalias, p ? p + 1 : compatible, len);
822 EXPORT_SYMBOL_GPL(of_modalias_node);
825 * of_find_node_by_phandle - Find a node given a phandle
826 * @handle: phandle of the node to find
828 * Returns a node pointer with refcount incremented, use
829 * of_node_put() on it when done.
831 struct device_node *of_find_node_by_phandle(phandle handle)
833 struct device_node *np;
836 raw_spin_lock_irqsave(&devtree_lock, flags);
837 for (np = of_allnodes; np; np = np->allnext)
838 if (np->phandle == handle)
841 raw_spin_unlock_irqrestore(&devtree_lock, flags);
844 EXPORT_SYMBOL(of_find_node_by_phandle);
847 * of_find_property_value_of_size
849 * @np: device node from which the property value is to be read.
850 * @propname: name of the property to be searched.
851 * @len: requested length of property value
853 * Search for a property in a device node and valid the requested size.
854 * Returns the property value on success, -EINVAL if the property does not
855 * exist, -ENODATA if property does not have a value, and -EOVERFLOW if the
856 * property data isn't large enough.
859 static void *of_find_property_value_of_size(const struct device_node *np,
860 const char *propname, u32 len)
862 struct property *prop = of_find_property(np, propname, NULL);
865 return ERR_PTR(-EINVAL);
867 return ERR_PTR(-ENODATA);
868 if (len > prop->length)
869 return ERR_PTR(-EOVERFLOW);
875 * of_property_read_u32_index - Find and read a u32 from a multi-value property.
877 * @np: device node from which the property value is to be read.
878 * @propname: name of the property to be searched.
879 * @index: index of the u32 in the list of values
880 * @out_value: pointer to return value, modified only if no error.
882 * Search for a property in a device node and read nth 32-bit value from
883 * it. Returns 0 on success, -EINVAL if the property does not exist,
884 * -ENODATA if property does not have a value, and -EOVERFLOW if the
885 * property data isn't large enough.
887 * The out_value is modified only if a valid u32 value can be decoded.
889 int of_property_read_u32_index(const struct device_node *np,
890 const char *propname,
891 u32 index, u32 *out_value)
893 const u32 *val = of_find_property_value_of_size(np, propname,
894 ((index + 1) * sizeof(*out_value)));
899 *out_value = be32_to_cpup(((__be32 *)val) + index);
902 EXPORT_SYMBOL_GPL(of_property_read_u32_index);
905 * of_property_read_u8_array - Find and read an array of u8 from a property.
907 * @np: device node from which the property value is to be read.
908 * @propname: name of the property to be searched.
909 * @out_values: pointer to return value, modified only if return value is 0.
910 * @sz: number of array elements to read
912 * Search for a property in a device node and read 8-bit value(s) from
913 * it. Returns 0 on success, -EINVAL if the property does not exist,
914 * -ENODATA if property does not have a value, and -EOVERFLOW if the
915 * property data isn't large enough.
917 * dts entry of array should be like:
918 * property = /bits/ 8 <0x50 0x60 0x70>;
920 * The out_values is modified only if a valid u8 value can be decoded.
922 int of_property_read_u8_array(const struct device_node *np,
923 const char *propname, u8 *out_values, size_t sz)
925 const u8 *val = of_find_property_value_of_size(np, propname,
926 (sz * sizeof(*out_values)));
932 *out_values++ = *val++;
935 EXPORT_SYMBOL_GPL(of_property_read_u8_array);
938 * of_property_read_u16_array - Find and read an array of u16 from a property.
940 * @np: device node from which the property value is to be read.
941 * @propname: name of the property to be searched.
942 * @out_values: pointer to return value, modified only if return value is 0.
943 * @sz: number of array elements to read
945 * Search for a property in a device node and read 16-bit value(s) from
946 * it. Returns 0 on success, -EINVAL if the property does not exist,
947 * -ENODATA if property does not have a value, and -EOVERFLOW if the
948 * property data isn't large enough.
950 * dts entry of array should be like:
951 * property = /bits/ 16 <0x5000 0x6000 0x7000>;
953 * The out_values is modified only if a valid u16 value can be decoded.
955 int of_property_read_u16_array(const struct device_node *np,
956 const char *propname, u16 *out_values, size_t sz)
958 const __be16 *val = of_find_property_value_of_size(np, propname,
959 (sz * sizeof(*out_values)));
965 *out_values++ = be16_to_cpup(val++);
968 EXPORT_SYMBOL_GPL(of_property_read_u16_array);
971 * of_property_read_u32_array - Find and read an array of 32 bit integers
974 * @np: device node from which the property value is to be read.
975 * @propname: name of the property to be searched.
976 * @out_values: pointer to return value, modified only if return value is 0.
977 * @sz: number of array elements to read
979 * Search for a property in a device node and read 32-bit value(s) from
980 * it. Returns 0 on success, -EINVAL if the property does not exist,
981 * -ENODATA if property does not have a value, and -EOVERFLOW if the
982 * property data isn't large enough.
984 * The out_values is modified only if a valid u32 value can be decoded.
986 int of_property_read_u32_array(const struct device_node *np,
987 const char *propname, u32 *out_values,
990 const __be32 *val = of_find_property_value_of_size(np, propname,
991 (sz * sizeof(*out_values)));
997 *out_values++ = be32_to_cpup(val++);
1000 EXPORT_SYMBOL_GPL(of_property_read_u32_array);
1003 * of_property_read_u64 - Find and read a 64 bit integer from a property
1004 * @np: device node from which the property value is to be read.
1005 * @propname: name of the property to be searched.
1006 * @out_value: pointer to return value, modified only if return value is 0.
1008 * Search for a property in a device node and read a 64-bit value from
1009 * it. Returns 0 on success, -EINVAL if the property does not exist,
1010 * -ENODATA if property does not have a value, and -EOVERFLOW if the
1011 * property data isn't large enough.
1013 * The out_value is modified only if a valid u64 value can be decoded.
1015 int of_property_read_u64(const struct device_node *np, const char *propname,
1018 const __be32 *val = of_find_property_value_of_size(np, propname,
1019 sizeof(*out_value));
1022 return PTR_ERR(val);
1024 *out_value = of_read_number(val, 2);
1027 EXPORT_SYMBOL_GPL(of_property_read_u64);
1030 * of_property_read_string - Find and read a string from a property
1031 * @np: device node from which the property value is to be read.
1032 * @propname: name of the property to be searched.
1033 * @out_string: pointer to null terminated return string, modified only if
1034 * return value is 0.
1036 * Search for a property in a device tree node and retrieve a null
1037 * terminated string value (pointer to data, not a copy). Returns 0 on
1038 * success, -EINVAL if the property does not exist, -ENODATA if property
1039 * does not have a value, and -EILSEQ if the string is not null-terminated
1040 * within the length of the property data.
1042 * The out_string pointer is modified only if a valid string can be decoded.
1044 int of_property_read_string(struct device_node *np, const char *propname,
1045 const char **out_string)
1047 struct property *prop = of_find_property(np, propname, NULL);
1052 if (strnlen(prop->value, prop->length) >= prop->length)
1054 *out_string = prop->value;
1057 EXPORT_SYMBOL_GPL(of_property_read_string);
1060 * of_property_read_string_index - Find and read a string from a multiple
1062 * @np: device node from which the property value is to be read.
1063 * @propname: name of the property to be searched.
1064 * @index: index of the string in the list of strings
1065 * @out_string: pointer to null terminated return string, modified only if
1066 * return value is 0.
1068 * Search for a property in a device tree node and retrieve a null
1069 * terminated string value (pointer to data, not a copy) in the list of strings
1070 * contained in that property.
1071 * Returns 0 on success, -EINVAL if the property does not exist, -ENODATA if
1072 * property does not have a value, and -EILSEQ if the string is not
1073 * null-terminated within the length of the property data.
1075 * The out_string pointer is modified only if a valid string can be decoded.
1077 int of_property_read_string_index(struct device_node *np, const char *propname,
1078 int index, const char **output)
1080 struct property *prop = of_find_property(np, propname, NULL);
1082 size_t l = 0, total = 0;
1089 if (strnlen(prop->value, prop->length) >= prop->length)
1094 for (i = 0; total < prop->length; total += l, p += l) {
1103 EXPORT_SYMBOL_GPL(of_property_read_string_index);
1106 * of_property_match_string() - Find string in a list and return index
1107 * @np: pointer to node containing string list property
1108 * @propname: string list property name
1109 * @string: pointer to string to search for in string list
1111 * This function searches a string list property and returns the index
1112 * of a specific string value.
1114 int of_property_match_string(struct device_node *np, const char *propname,
1117 struct property *prop = of_find_property(np, propname, NULL);
1120 const char *p, *end;
1128 end = p + prop->length;
1130 for (i = 0; p < end; i++, p += l) {
1134 pr_debug("comparing %s with %s\n", string, p);
1135 if (strcmp(string, p) == 0)
1136 return i; /* Found it; return index */
1140 EXPORT_SYMBOL_GPL(of_property_match_string);
1143 * of_property_count_strings - Find and return the number of strings from a
1144 * multiple strings property.
1145 * @np: device node from which the property value is to be read.
1146 * @propname: name of the property to be searched.
1148 * Search for a property in a device tree node and retrieve the number of null
1149 * terminated string contain in it. Returns the number of strings on
1150 * success, -EINVAL if the property does not exist, -ENODATA if property
1151 * does not have a value, and -EILSEQ if the string is not null-terminated
1152 * within the length of the property data.
1154 int of_property_count_strings(struct device_node *np, const char *propname)
1156 struct property *prop = of_find_property(np, propname, NULL);
1158 size_t l = 0, total = 0;
1165 if (strnlen(prop->value, prop->length) >= prop->length)
1170 for (i = 0; total < prop->length; total += l, p += l, i++)
1175 EXPORT_SYMBOL_GPL(of_property_count_strings);
1177 static int __of_parse_phandle_with_args(const struct device_node *np,
1178 const char *list_name,
1179 const char *cells_name,
1180 int cell_count, int index,
1181 struct of_phandle_args *out_args)
1183 const __be32 *list, *list_end;
1184 int rc = 0, size, cur_index = 0;
1186 struct device_node *node = NULL;
1189 /* Retrieve the phandle list property */
1190 list = of_get_property(np, list_name, &size);
1193 list_end = list + size / sizeof(*list);
1195 /* Loop over the phandles until all the requested entry is found */
1196 while (list < list_end) {
1201 * If phandle is 0, then it is an empty entry with no
1202 * arguments. Skip forward to the next entry.
1204 phandle = be32_to_cpup(list++);
1207 * Find the provider node and parse the #*-cells
1208 * property to determine the argument length.
1210 * This is not needed if the cell count is hard-coded
1211 * (i.e. cells_name not set, but cell_count is set),
1212 * except when we're going to return the found node
1215 if (cells_name || cur_index == index) {
1216 node = of_find_node_by_phandle(phandle);
1218 pr_err("%s: could not find phandle\n",
1225 if (of_property_read_u32(node, cells_name,
1227 pr_err("%s: could not get %s for %s\n",
1228 np->full_name, cells_name,
1237 * Make sure that the arguments actually fit in the
1238 * remaining property data length
1240 if (list + count > list_end) {
1241 pr_err("%s: arguments longer than property\n",
1248 * All of the error cases above bail out of the loop, so at
1249 * this point, the parsing is successful. If the requested
1250 * index matches, then fill the out_args structure and return,
1251 * or return -ENOENT for an empty entry.
1254 if (cur_index == index) {
1260 if (WARN_ON(count > MAX_PHANDLE_ARGS))
1261 count = MAX_PHANDLE_ARGS;
1262 out_args->np = node;
1263 out_args->args_count = count;
1264 for (i = 0; i < count; i++)
1265 out_args->args[i] = be32_to_cpup(list++);
1270 /* Found it! return success */
1281 * Unlock node before returning result; will be one of:
1282 * -ENOENT : index is for empty phandle
1283 * -EINVAL : parsing error on data
1284 * [1..n] : Number of phandle (count mode; when index = -1)
1286 rc = index < 0 ? cur_index : -ENOENT;
1294 * of_parse_phandle - Resolve a phandle property to a device_node pointer
1295 * @np: Pointer to device node holding phandle property
1296 * @phandle_name: Name of property holding a phandle value
1297 * @index: For properties holding a table of phandles, this is the index into
1300 * Returns the device_node pointer with refcount incremented. Use
1301 * of_node_put() on it when done.
1303 struct device_node *of_parse_phandle(const struct device_node *np,
1304 const char *phandle_name, int index)
1306 struct of_phandle_args args;
1311 if (__of_parse_phandle_with_args(np, phandle_name, NULL, 0,
1317 EXPORT_SYMBOL(of_parse_phandle);
1320 * of_parse_phandle_with_args() - Find a node pointed by phandle in a list
1321 * @np: pointer to a device tree node containing a list
1322 * @list_name: property name that contains a list
1323 * @cells_name: property name that specifies phandles' arguments count
1324 * @index: index of a phandle to parse out
1325 * @out_args: optional pointer to output arguments structure (will be filled)
1327 * This function is useful to parse lists of phandles and their arguments.
1328 * Returns 0 on success and fills out_args, on error returns appropriate
1331 * Caller is responsible to call of_node_put() on the returned out_args->node
1337 * #list-cells = <2>;
1341 * #list-cells = <1>;
1345 * list = <&phandle1 1 2 &phandle2 3>;
1348 * To get a device_node of the `node2' node you may call this:
1349 * of_parse_phandle_with_args(node3, "list", "#list-cells", 1, &args);
1351 int of_parse_phandle_with_args(const struct device_node *np, const char *list_name,
1352 const char *cells_name, int index,
1353 struct of_phandle_args *out_args)
1357 return __of_parse_phandle_with_args(np, list_name, cells_name, 0,
1360 EXPORT_SYMBOL(of_parse_phandle_with_args);
1363 * of_parse_phandle_with_fixed_args() - Find a node pointed by phandle in a list
1364 * @np: pointer to a device tree node containing a list
1365 * @list_name: property name that contains a list
1366 * @cell_count: number of argument cells following the phandle
1367 * @index: index of a phandle to parse out
1368 * @out_args: optional pointer to output arguments structure (will be filled)
1370 * This function is useful to parse lists of phandles and their arguments.
1371 * Returns 0 on success and fills out_args, on error returns appropriate
1374 * Caller is responsible to call of_node_put() on the returned out_args->node
1386 * list = <&phandle1 0 2 &phandle2 2 3>;
1389 * To get a device_node of the `node2' node you may call this:
1390 * of_parse_phandle_with_fixed_args(node3, "list", 2, 1, &args);
1392 int of_parse_phandle_with_fixed_args(const struct device_node *np,
1393 const char *list_name, int cell_count,
1394 int index, struct of_phandle_args *out_args)
1398 return __of_parse_phandle_with_args(np, list_name, NULL, cell_count,
1401 EXPORT_SYMBOL(of_parse_phandle_with_fixed_args);
1404 * of_count_phandle_with_args() - Find the number of phandles references in a property
1405 * @np: pointer to a device tree node containing a list
1406 * @list_name: property name that contains a list
1407 * @cells_name: property name that specifies phandles' arguments count
1409 * Returns the number of phandle + argument tuples within a property. It
1410 * is a typical pattern to encode a list of phandle and variable
1411 * arguments into a single property. The number of arguments is encoded
1412 * by a property in the phandle-target node. For example, a gpios
1413 * property would contain a list of GPIO specifies consisting of a
1414 * phandle and 1 or more arguments. The number of arguments are
1415 * determined by the #gpio-cells property in the node pointed to by the
1418 int of_count_phandle_with_args(const struct device_node *np, const char *list_name,
1419 const char *cells_name)
1421 return __of_parse_phandle_with_args(np, list_name, cells_name, 0, -1,
1424 EXPORT_SYMBOL(of_count_phandle_with_args);
1426 #if defined(CONFIG_OF_DYNAMIC)
1427 static int of_property_notify(int action, struct device_node *np,
1428 struct property *prop)
1430 struct of_prop_reconfig pr;
1434 return of_reconfig_notify(action, &pr);
1437 static int of_property_notify(int action, struct device_node *np,
1438 struct property *prop)
1445 * of_add_property - Add a property to a node
1447 int of_add_property(struct device_node *np, struct property *prop)
1449 struct property **next;
1450 unsigned long flags;
1453 rc = of_property_notify(OF_RECONFIG_ADD_PROPERTY, np, prop);
1458 raw_spin_lock_irqsave(&devtree_lock, flags);
1459 next = &np->properties;
1461 if (strcmp(prop->name, (*next)->name) == 0) {
1462 /* duplicate ! don't insert it */
1463 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1466 next = &(*next)->next;
1469 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1471 #ifdef CONFIG_PROC_DEVICETREE
1472 /* try to add to proc as well if it was initialized */
1474 proc_device_tree_add_prop(np->pde, prop);
1475 #endif /* CONFIG_PROC_DEVICETREE */
1481 * of_remove_property - Remove a property from a node.
1483 * Note that we don't actually remove it, since we have given out
1484 * who-knows-how-many pointers to the data using get-property.
1485 * Instead we just move the property to the "dead properties"
1486 * list, so it won't be found any more.
1488 int of_remove_property(struct device_node *np, struct property *prop)
1490 struct property **next;
1491 unsigned long flags;
1495 rc = of_property_notify(OF_RECONFIG_REMOVE_PROPERTY, np, prop);
1499 raw_spin_lock_irqsave(&devtree_lock, flags);
1500 next = &np->properties;
1502 if (*next == prop) {
1503 /* found the node */
1505 prop->next = np->deadprops;
1506 np->deadprops = prop;
1510 next = &(*next)->next;
1512 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1517 #ifdef CONFIG_PROC_DEVICETREE
1518 /* try to remove the proc node as well */
1520 proc_device_tree_remove_prop(np->pde, prop);
1521 #endif /* CONFIG_PROC_DEVICETREE */
1527 * of_update_property - Update a property in a node, if the property does
1528 * not exist, add it.
1530 * Note that we don't actually remove it, since we have given out
1531 * who-knows-how-many pointers to the data using get-property.
1532 * Instead we just move the property to the "dead properties" list,
1533 * and add the new property to the property list
1535 int of_update_property(struct device_node *np, struct property *newprop)
1537 struct property **next, *oldprop;
1538 unsigned long flags;
1541 rc = of_property_notify(OF_RECONFIG_UPDATE_PROPERTY, np, newprop);
1548 oldprop = of_find_property(np, newprop->name, NULL);
1550 return of_add_property(np, newprop);
1552 raw_spin_lock_irqsave(&devtree_lock, flags);
1553 next = &np->properties;
1555 if (*next == oldprop) {
1556 /* found the node */
1557 newprop->next = oldprop->next;
1559 oldprop->next = np->deadprops;
1560 np->deadprops = oldprop;
1564 next = &(*next)->next;
1566 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1571 #ifdef CONFIG_PROC_DEVICETREE
1572 /* try to add to proc as well if it was initialized */
1574 proc_device_tree_update_prop(np->pde, newprop, oldprop);
1575 #endif /* CONFIG_PROC_DEVICETREE */
1580 #if defined(CONFIG_OF_DYNAMIC)
1582 * Support for dynamic device trees.
1584 * On some platforms, the device tree can be manipulated at runtime.
1585 * The routines in this section support adding, removing and changing
1586 * device tree nodes.
1589 static BLOCKING_NOTIFIER_HEAD(of_reconfig_chain);
1591 int of_reconfig_notifier_register(struct notifier_block *nb)
1593 return blocking_notifier_chain_register(&of_reconfig_chain, nb);
1595 EXPORT_SYMBOL_GPL(of_reconfig_notifier_register);
1597 int of_reconfig_notifier_unregister(struct notifier_block *nb)
1599 return blocking_notifier_chain_unregister(&of_reconfig_chain, nb);
1601 EXPORT_SYMBOL_GPL(of_reconfig_notifier_unregister);
1603 int of_reconfig_notify(unsigned long action, void *p)
1607 rc = blocking_notifier_call_chain(&of_reconfig_chain, action, p);
1608 return notifier_to_errno(rc);
1611 #ifdef CONFIG_PROC_DEVICETREE
1612 static void of_add_proc_dt_entry(struct device_node *dn)
1614 struct proc_dir_entry *ent;
1616 ent = proc_mkdir(strrchr(dn->full_name, '/') + 1, dn->parent->pde);
1618 proc_device_tree_add_node(dn, ent);
1621 static void of_add_proc_dt_entry(struct device_node *dn)
1628 * of_attach_node - Plug a device node into the tree and global list.
1630 int of_attach_node(struct device_node *np)
1632 unsigned long flags;
1635 rc = of_reconfig_notify(OF_RECONFIG_ATTACH_NODE, np);
1639 raw_spin_lock_irqsave(&devtree_lock, flags);
1640 np->sibling = np->parent->child;
1641 np->allnext = of_allnodes;
1642 np->parent->child = np;
1644 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1646 of_add_proc_dt_entry(np);
1650 #ifdef CONFIG_PROC_DEVICETREE
1651 static void of_remove_proc_dt_entry(struct device_node *dn)
1653 proc_remove(dn->pde);
1656 static void of_remove_proc_dt_entry(struct device_node *dn)
1663 * of_detach_node - "Unplug" a node from the device tree.
1665 * The caller must hold a reference to the node. The memory associated with
1666 * the node is not freed until its refcount goes to zero.
1668 int of_detach_node(struct device_node *np)
1670 struct device_node *parent;
1671 unsigned long flags;
1674 rc = of_reconfig_notify(OF_RECONFIG_DETACH_NODE, np);
1678 raw_spin_lock_irqsave(&devtree_lock, flags);
1680 if (of_node_check_flag(np, OF_DETACHED)) {
1681 /* someone already detached it */
1682 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1686 parent = np->parent;
1688 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1692 if (of_allnodes == np)
1693 of_allnodes = np->allnext;
1695 struct device_node *prev;
1696 for (prev = of_allnodes;
1697 prev->allnext != np;
1698 prev = prev->allnext)
1700 prev->allnext = np->allnext;
1703 if (parent->child == np)
1704 parent->child = np->sibling;
1706 struct device_node *prevsib;
1707 for (prevsib = np->parent->child;
1708 prevsib->sibling != np;
1709 prevsib = prevsib->sibling)
1711 prevsib->sibling = np->sibling;
1714 of_node_set_flag(np, OF_DETACHED);
1715 raw_spin_unlock_irqrestore(&devtree_lock, flags);
1717 of_remove_proc_dt_entry(np);
1720 #endif /* defined(CONFIG_OF_DYNAMIC) */
1722 static void of_alias_add(struct alias_prop *ap, struct device_node *np,
1723 int id, const char *stem, int stem_len)
1727 strncpy(ap->stem, stem, stem_len);
1728 ap->stem[stem_len] = 0;
1729 list_add_tail(&ap->link, &aliases_lookup);
1730 pr_debug("adding DT alias:%s: stem=%s id=%i node=%s\n",
1731 ap->alias, ap->stem, ap->id, of_node_full_name(np));
1735 * of_alias_scan - Scan all properties of 'aliases' node
1737 * The function scans all the properties of 'aliases' node and populate
1738 * the the global lookup table with the properties. It returns the
1739 * number of alias_prop found, or error code in error case.
1741 * @dt_alloc: An allocator that provides a virtual address to memory
1742 * for the resulting tree
1744 void of_alias_scan(void * (*dt_alloc)(u64 size, u64 align))
1746 struct property *pp;
1748 of_chosen = of_find_node_by_path("/chosen");
1749 if (of_chosen == NULL)
1750 of_chosen = of_find_node_by_path("/chosen@0");
1755 name = of_get_property(of_chosen, "linux,stdout-path", NULL);
1757 of_stdout = of_find_node_by_path(name);
1760 of_aliases = of_find_node_by_path("/aliases");
1764 for_each_property_of_node(of_aliases, pp) {
1765 const char *start = pp->name;
1766 const char *end = start + strlen(start);
1767 struct device_node *np;
1768 struct alias_prop *ap;
1771 /* Skip those we do not want to proceed */
1772 if (!strcmp(pp->name, "name") ||
1773 !strcmp(pp->name, "phandle") ||
1774 !strcmp(pp->name, "linux,phandle"))
1777 np = of_find_node_by_path(pp->value);
1781 /* walk the alias backwards to extract the id and work out
1782 * the 'stem' string */
1783 while (isdigit(*(end-1)) && end > start)
1787 if (kstrtoint(end, 10, &id) < 0)
1790 /* Allocate an alias_prop with enough space for the stem */
1791 ap = dt_alloc(sizeof(*ap) + len + 1, 4);
1794 memset(ap, 0, sizeof(*ap) + len + 1);
1796 of_alias_add(ap, np, id, start, len);
1801 * of_alias_get_id - Get alias id for the given device_node
1802 * @np: Pointer to the given device_node
1803 * @stem: Alias stem of the given device_node
1805 * The function travels the lookup table to get alias id for the given
1806 * device_node and alias stem. It returns the alias id if find it.
1808 int of_alias_get_id(struct device_node *np, const char *stem)
1810 struct alias_prop *app;
1813 mutex_lock(&of_aliases_mutex);
1814 list_for_each_entry(app, &aliases_lookup, link) {
1815 if (strcmp(app->stem, stem) != 0)
1818 if (np == app->np) {
1823 mutex_unlock(&of_aliases_mutex);
1827 EXPORT_SYMBOL_GPL(of_alias_get_id);
1829 const __be32 *of_prop_next_u32(struct property *prop, const __be32 *cur,
1832 const void *curv = cur;
1842 curv += sizeof(*cur);
1843 if (curv >= prop->value + prop->length)
1847 *pu = be32_to_cpup(curv);
1850 EXPORT_SYMBOL_GPL(of_prop_next_u32);
1852 const char *of_prop_next_string(struct property *prop, const char *cur)
1854 const void *curv = cur;
1862 curv += strlen(cur) + 1;
1863 if (curv >= prop->value + prop->length)
1868 EXPORT_SYMBOL_GPL(of_prop_next_string);
1871 * of_device_is_stdout_path - check if a device node matches the
1872 * linux,stdout-path property
1874 * Check if this device node matches the linux,stdout-path property
1875 * in the chosen node. return true if yes, false otherwise.
1877 int of_device_is_stdout_path(struct device_node *dn)
1882 return of_stdout == dn;
1884 EXPORT_SYMBOL_GPL(of_device_is_stdout_path);