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/module.h>
23 #include <linux/spinlock.h>
24 #include <linux/slab.h>
25 #include <linux/proc_fs.h>
27 #include "of_private.h"
29 LIST_HEAD(aliases_lookup
);
31 struct device_node
*of_allnodes
;
32 EXPORT_SYMBOL(of_allnodes
);
33 struct device_node
*of_chosen
;
34 struct device_node
*of_aliases
;
36 DEFINE_MUTEX(of_aliases_mutex
);
38 /* use when traversing tree through the allnext, child, sibling,
39 * or parent members of struct device_node.
41 DEFINE_RAW_SPINLOCK(devtree_lock
);
43 int of_n_addr_cells(struct device_node
*np
)
50 ip
= of_get_property(np
, "#address-cells", NULL
);
52 return be32_to_cpup(ip
);
54 /* No #address-cells property for the root node */
55 return OF_ROOT_NODE_ADDR_CELLS_DEFAULT
;
57 EXPORT_SYMBOL(of_n_addr_cells
);
59 int of_n_size_cells(struct device_node
*np
)
66 ip
= of_get_property(np
, "#size-cells", NULL
);
68 return be32_to_cpup(ip
);
70 /* No #size-cells property for the root node */
71 return OF_ROOT_NODE_SIZE_CELLS_DEFAULT
;
73 EXPORT_SYMBOL(of_n_size_cells
);
75 #if defined(CONFIG_OF_DYNAMIC)
77 * of_node_get - Increment refcount of a node
78 * @node: Node to inc refcount, NULL is supported to
79 * simplify writing of callers
83 struct device_node
*of_node_get(struct device_node
*node
)
86 kref_get(&node
->kref
);
89 EXPORT_SYMBOL(of_node_get
);
91 static inline struct device_node
*kref_to_device_node(struct kref
*kref
)
93 return container_of(kref
, struct device_node
, kref
);
97 * of_node_release - release a dynamically allocated node
98 * @kref: kref element of the node to be released
100 * In of_node_put() this function is passed to kref_put()
103 static void of_node_release(struct kref
*kref
)
105 struct device_node
*node
= kref_to_device_node(kref
);
106 struct property
*prop
= node
->properties
;
108 /* We should never be releasing nodes that haven't been detached. */
109 if (!of_node_check_flag(node
, OF_DETACHED
)) {
110 pr_err("ERROR: Bad of_node_put() on %s\n", node
->full_name
);
112 kref_init(&node
->kref
);
116 if (!of_node_check_flag(node
, OF_DYNAMIC
))
120 struct property
*next
= prop
->next
;
127 prop
= node
->deadprops
;
128 node
->deadprops
= NULL
;
131 kfree(node
->full_name
);
137 * of_node_put - Decrement refcount of a node
138 * @node: Node to dec refcount, NULL is supported to
139 * simplify writing of callers
142 void of_node_put(struct device_node
*node
)
145 kref_put(&node
->kref
, of_node_release
);
147 EXPORT_SYMBOL(of_node_put
);
148 #endif /* CONFIG_OF_DYNAMIC */
150 static struct property
*__of_find_property(const struct device_node
*np
,
151 const char *name
, int *lenp
)
158 for (pp
= np
->properties
; pp
; pp
= pp
->next
) {
159 if (of_prop_cmp(pp
->name
, name
) == 0) {
169 struct property
*of_find_property(const struct device_node
*np
,
176 raw_spin_lock_irqsave(&devtree_lock
, flags
);
177 pp
= __of_find_property(np
, name
, lenp
);
178 raw_spin_unlock_irqrestore(&devtree_lock
, flags
);
182 EXPORT_SYMBOL(of_find_property
);
185 * of_find_all_nodes - Get next node in global list
186 * @prev: Previous node or NULL to start iteration
187 * of_node_put() will be called on it
189 * Returns a node pointer with refcount incremented, use
190 * of_node_put() on it when done.
192 struct device_node
*of_find_all_nodes(struct device_node
*prev
)
194 struct device_node
*np
;
196 raw_spin_lock(&devtree_lock
);
197 np
= prev
? prev
->allnext
: of_allnodes
;
198 for (; np
!= NULL
; np
= np
->allnext
)
202 raw_spin_unlock(&devtree_lock
);
205 EXPORT_SYMBOL(of_find_all_nodes
);
208 * Find a property with a given name for a given node
209 * and return the value.
211 static const void *__of_get_property(const struct device_node
*np
,
212 const char *name
, int *lenp
)
214 struct property
*pp
= __of_find_property(np
, name
, lenp
);
216 return pp
? pp
->value
: NULL
;
220 * Find a property with a given name for a given node
221 * and return the value.
223 const void *of_get_property(const struct device_node
*np
, const char *name
,
226 struct property
*pp
= of_find_property(np
, name
, lenp
);
228 return pp
? pp
->value
: NULL
;
230 EXPORT_SYMBOL(of_get_property
);
232 /** Checks if the given "compat" string matches one of the strings in
233 * the device's "compatible" property
235 static int __of_device_is_compatible(const struct device_node
*device
,
241 cp
= __of_get_property(device
, "compatible", &cplen
);
245 if (of_compat_cmp(cp
, compat
, strlen(compat
)) == 0)
255 /** Checks if the given "compat" string matches one of the strings in
256 * the device's "compatible" property
258 int of_device_is_compatible(const struct device_node
*device
,
264 raw_spin_lock_irqsave(&devtree_lock
, flags
);
265 res
= __of_device_is_compatible(device
, compat
);
266 raw_spin_unlock_irqrestore(&devtree_lock
, flags
);
269 EXPORT_SYMBOL(of_device_is_compatible
);
272 * of_machine_is_compatible - Test root of device tree for a given compatible value
273 * @compat: compatible string to look for in root node's compatible property.
275 * Returns true if the root node has the given value in its
276 * compatible property.
278 int of_machine_is_compatible(const char *compat
)
280 struct device_node
*root
;
283 root
= of_find_node_by_path("/");
285 rc
= of_device_is_compatible(root
, compat
);
290 EXPORT_SYMBOL(of_machine_is_compatible
);
293 * __of_device_is_available - check if a device is available for use
295 * @device: Node to check for availability, with locks already held
297 * Returns 1 if the status property is absent or set to "okay" or "ok",
300 static int __of_device_is_available(const struct device_node
*device
)
305 status
= __of_get_property(device
, "status", &statlen
);
310 if (!strcmp(status
, "okay") || !strcmp(status
, "ok"))
318 * of_device_is_available - check if a device is available for use
320 * @device: Node to check for availability
322 * Returns 1 if the status property is absent or set to "okay" or "ok",
325 int of_device_is_available(const struct device_node
*device
)
330 raw_spin_lock_irqsave(&devtree_lock
, flags
);
331 res
= __of_device_is_available(device
);
332 raw_spin_unlock_irqrestore(&devtree_lock
, flags
);
336 EXPORT_SYMBOL(of_device_is_available
);
339 * of_get_parent - Get a node's parent if any
340 * @node: Node to get parent
342 * Returns a node pointer with refcount incremented, use
343 * of_node_put() on it when done.
345 struct device_node
*of_get_parent(const struct device_node
*node
)
347 struct device_node
*np
;
353 raw_spin_lock_irqsave(&devtree_lock
, flags
);
354 np
= of_node_get(node
->parent
);
355 raw_spin_unlock_irqrestore(&devtree_lock
, flags
);
358 EXPORT_SYMBOL(of_get_parent
);
361 * of_get_next_parent - Iterate to a node's parent
362 * @node: Node to get parent of
364 * This is like of_get_parent() except that it drops the
365 * refcount on the passed node, making it suitable for iterating
366 * through a node's parents.
368 * Returns a node pointer with refcount incremented, use
369 * of_node_put() on it when done.
371 struct device_node
*of_get_next_parent(struct device_node
*node
)
373 struct device_node
*parent
;
379 raw_spin_lock_irqsave(&devtree_lock
, flags
);
380 parent
= of_node_get(node
->parent
);
382 raw_spin_unlock_irqrestore(&devtree_lock
, flags
);
385 EXPORT_SYMBOL(of_get_next_parent
);
388 * of_get_next_child - Iterate a node childs
390 * @prev: previous child of the parent node, or NULL to get first
392 * Returns a node pointer with refcount incremented, use
393 * of_node_put() on it when done.
395 struct device_node
*of_get_next_child(const struct device_node
*node
,
396 struct device_node
*prev
)
398 struct device_node
*next
;
401 raw_spin_lock_irqsave(&devtree_lock
, flags
);
402 next
= prev
? prev
->sibling
: node
->child
;
403 for (; next
; next
= next
->sibling
)
404 if (of_node_get(next
))
407 raw_spin_unlock_irqrestore(&devtree_lock
, flags
);
410 EXPORT_SYMBOL(of_get_next_child
);
413 * of_get_next_available_child - Find the next available child node
415 * @prev: previous child of the parent node, or NULL to get first
417 * This function is like of_get_next_child(), except that it
418 * automatically skips any disabled nodes (i.e. status = "disabled").
420 struct device_node
*of_get_next_available_child(const struct device_node
*node
,
421 struct device_node
*prev
)
423 struct device_node
*next
;
425 raw_spin_lock(&devtree_lock
);
426 next
= prev
? prev
->sibling
: node
->child
;
427 for (; next
; next
= next
->sibling
) {
428 if (!__of_device_is_available(next
))
430 if (of_node_get(next
))
434 raw_spin_unlock(&devtree_lock
);
437 EXPORT_SYMBOL(of_get_next_available_child
);
440 * of_get_child_by_name - Find the child node by name for a given parent
442 * @name: child name to look for.
444 * This function looks for child node for given matching name
446 * Returns a node pointer if found, with refcount incremented, use
447 * of_node_put() on it when done.
448 * Returns NULL if node is not found.
450 struct device_node
*of_get_child_by_name(const struct device_node
*node
,
453 struct device_node
*child
;
455 for_each_child_of_node(node
, child
)
456 if (child
->name
&& (of_node_cmp(child
->name
, name
) == 0))
460 EXPORT_SYMBOL(of_get_child_by_name
);
463 * of_find_node_by_path - Find a node matching a full OF path
464 * @path: The full path to match
466 * Returns a node pointer with refcount incremented, use
467 * of_node_put() on it when done.
469 struct device_node
*of_find_node_by_path(const char *path
)
471 struct device_node
*np
= of_allnodes
;
474 raw_spin_lock_irqsave(&devtree_lock
, flags
);
475 for (; np
; np
= np
->allnext
) {
476 if (np
->full_name
&& (of_node_cmp(np
->full_name
, path
) == 0)
480 raw_spin_unlock_irqrestore(&devtree_lock
, flags
);
483 EXPORT_SYMBOL(of_find_node_by_path
);
486 * of_find_node_by_name - Find a node by its "name" property
487 * @from: The node to start searching from or NULL, the node
488 * you pass will not be searched, only the next one
489 * will; typically, you pass what the previous call
490 * returned. of_node_put() will be called on it
491 * @name: The name string to match against
493 * Returns a node pointer with refcount incremented, use
494 * of_node_put() on it when done.
496 struct device_node
*of_find_node_by_name(struct device_node
*from
,
499 struct device_node
*np
;
502 raw_spin_lock_irqsave(&devtree_lock
, flags
);
503 np
= from
? from
->allnext
: of_allnodes
;
504 for (; np
; np
= np
->allnext
)
505 if (np
->name
&& (of_node_cmp(np
->name
, name
) == 0)
509 raw_spin_unlock_irqrestore(&devtree_lock
, flags
);
512 EXPORT_SYMBOL(of_find_node_by_name
);
515 * of_find_node_by_type - Find a node by its "device_type" property
516 * @from: The node to start searching from, or NULL to start searching
517 * the entire device tree. The node you pass will not be
518 * searched, only the next one will; typically, you pass
519 * what the previous call returned. of_node_put() will be
520 * called on from for you.
521 * @type: The type string to match against
523 * Returns a node pointer with refcount incremented, use
524 * of_node_put() on it when done.
526 struct device_node
*of_find_node_by_type(struct device_node
*from
,
529 struct device_node
*np
;
532 raw_spin_lock_irqsave(&devtree_lock
, flags
);
533 np
= from
? from
->allnext
: of_allnodes
;
534 for (; np
; np
= np
->allnext
)
535 if (np
->type
&& (of_node_cmp(np
->type
, type
) == 0)
539 raw_spin_unlock_irqrestore(&devtree_lock
, flags
);
542 EXPORT_SYMBOL(of_find_node_by_type
);
545 * of_find_compatible_node - Find a node based on type and one of the
546 * tokens in its "compatible" property
547 * @from: The node to start searching from or NULL, the node
548 * you pass will not be searched, only the next one
549 * will; typically, you pass what the previous call
550 * returned. of_node_put() will be called on it
551 * @type: The type string to match "device_type" or NULL to ignore
552 * @compatible: The string to match to one of the tokens in the device
555 * Returns a node pointer with refcount incremented, use
556 * of_node_put() on it when done.
558 struct device_node
*of_find_compatible_node(struct device_node
*from
,
559 const char *type
, const char *compatible
)
561 struct device_node
*np
;
564 raw_spin_lock_irqsave(&devtree_lock
, flags
);
565 np
= from
? from
->allnext
: of_allnodes
;
566 for (; np
; np
= np
->allnext
) {
568 && !(np
->type
&& (of_node_cmp(np
->type
, type
) == 0)))
570 if (__of_device_is_compatible(np
, compatible
) &&
575 raw_spin_unlock_irqrestore(&devtree_lock
, flags
);
578 EXPORT_SYMBOL(of_find_compatible_node
);
581 * of_find_node_with_property - Find a node which has a property with
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 * @prop_name: The name of the property to look for.
589 * Returns a node pointer with refcount incremented, use
590 * of_node_put() on it when done.
592 struct device_node
*of_find_node_with_property(struct device_node
*from
,
593 const char *prop_name
)
595 struct device_node
*np
;
599 raw_spin_lock_irqsave(&devtree_lock
, flags
);
600 np
= from
? from
->allnext
: of_allnodes
;
601 for (; np
; np
= np
->allnext
) {
602 for (pp
= np
->properties
; pp
; pp
= pp
->next
) {
603 if (of_prop_cmp(pp
->name
, prop_name
) == 0) {
611 raw_spin_unlock_irqrestore(&devtree_lock
, flags
);
614 EXPORT_SYMBOL(of_find_node_with_property
);
617 const struct of_device_id
*__of_match_node(const struct of_device_id
*matches
,
618 const struct device_node
*node
)
623 while (matches
->name
[0] || matches
->type
[0] || matches
->compatible
[0]) {
625 if (matches
->name
[0])
627 && !strcmp(matches
->name
, node
->name
);
628 if (matches
->type
[0])
630 && !strcmp(matches
->type
, node
->type
);
631 if (matches
->compatible
[0])
632 match
&= __of_device_is_compatible(node
,
633 matches
->compatible
);
642 * of_match_node - Tell if an device_node has a matching of_match structure
643 * @matches: array of of device match structures to search in
644 * @node: the of device structure to match against
646 * Low level utility function used by device matching.
648 const struct of_device_id
*of_match_node(const struct of_device_id
*matches
,
649 const struct device_node
*node
)
651 const struct of_device_id
*match
;
654 raw_spin_lock_irqsave(&devtree_lock
, flags
);
655 match
= __of_match_node(matches
, node
);
656 raw_spin_unlock_irqrestore(&devtree_lock
, flags
);
659 EXPORT_SYMBOL(of_match_node
);
662 * of_find_matching_node_and_match - Find a node based on an of_device_id
664 * @from: The node to start searching from or NULL, the node
665 * you pass will not be searched, only the next one
666 * will; typically, you pass what the previous call
667 * returned. of_node_put() will be called on it
668 * @matches: array of of device match structures to search in
669 * @match Updated to point at the matches entry which matched
671 * Returns a node pointer with refcount incremented, use
672 * of_node_put() on it when done.
674 struct device_node
*of_find_matching_node_and_match(struct device_node
*from
,
675 const struct of_device_id
*matches
,
676 const struct of_device_id
**match
)
678 struct device_node
*np
;
679 const struct of_device_id
*m
;
685 raw_spin_lock_irqsave(&devtree_lock
, flags
);
686 np
= from
? from
->allnext
: of_allnodes
;
687 for (; np
; np
= np
->allnext
) {
688 m
= __of_match_node(matches
, np
);
689 if (m
&& of_node_get(np
)) {
696 raw_spin_unlock_irqrestore(&devtree_lock
, flags
);
699 EXPORT_SYMBOL(of_find_matching_node_and_match
);
702 * of_modalias_node - Lookup appropriate modalias for a device node
703 * @node: pointer to a device tree node
704 * @modalias: Pointer to buffer that modalias value will be copied into
705 * @len: Length of modalias value
707 * Based on the value of the compatible property, this routine will attempt
708 * to choose an appropriate modalias value for a particular device tree node.
709 * It does this by stripping the manufacturer prefix (as delimited by a ',')
710 * from the first entry in the compatible list property.
712 * This routine returns 0 on success, <0 on failure.
714 int of_modalias_node(struct device_node
*node
, char *modalias
, int len
)
716 const char *compatible
, *p
;
719 compatible
= of_get_property(node
, "compatible", &cplen
);
720 if (!compatible
|| strlen(compatible
) > cplen
)
722 p
= strchr(compatible
, ',');
723 strlcpy(modalias
, p
? p
+ 1 : compatible
, len
);
726 EXPORT_SYMBOL_GPL(of_modalias_node
);
729 * of_find_node_by_phandle - Find a node given a phandle
730 * @handle: phandle of the node to find
732 * Returns a node pointer with refcount incremented, use
733 * of_node_put() on it when done.
735 struct device_node
*of_find_node_by_phandle(phandle handle
)
737 struct device_node
*np
;
739 raw_spin_lock(&devtree_lock
);
740 for (np
= of_allnodes
; np
; np
= np
->allnext
)
741 if (np
->phandle
== handle
)
744 raw_spin_unlock(&devtree_lock
);
747 EXPORT_SYMBOL(of_find_node_by_phandle
);
750 * of_find_property_value_of_size
752 * @np: device node from which the property value is to be read.
753 * @propname: name of the property to be searched.
754 * @len: requested length of property value
756 * Search for a property in a device node and valid the requested size.
757 * Returns the property value on success, -EINVAL if the property does not
758 * exist, -ENODATA if property does not have a value, and -EOVERFLOW if the
759 * property data isn't large enough.
762 static void *of_find_property_value_of_size(const struct device_node
*np
,
763 const char *propname
, u32 len
)
765 struct property
*prop
= of_find_property(np
, propname
, NULL
);
768 return ERR_PTR(-EINVAL
);
770 return ERR_PTR(-ENODATA
);
771 if (len
> prop
->length
)
772 return ERR_PTR(-EOVERFLOW
);
778 * of_property_read_u32_index - Find and read a u32 from a multi-value property.
780 * @np: device node from which the property value is to be read.
781 * @propname: name of the property to be searched.
782 * @index: index of the u32 in the list of values
783 * @out_value: pointer to return value, modified only if no error.
785 * Search for a property in a device node and read nth 32-bit value from
786 * it. Returns 0 on success, -EINVAL if the property does not exist,
787 * -ENODATA if property does not have a value, and -EOVERFLOW if the
788 * property data isn't large enough.
790 * The out_value is modified only if a valid u32 value can be decoded.
792 int of_property_read_u32_index(const struct device_node
*np
,
793 const char *propname
,
794 u32 index
, u32
*out_value
)
796 const u32
*val
= of_find_property_value_of_size(np
, propname
,
797 ((index
+ 1) * sizeof(*out_value
)));
802 *out_value
= be32_to_cpup(((__be32
*)val
) + index
);
805 EXPORT_SYMBOL_GPL(of_property_read_u32_index
);
808 * of_property_read_u8_array - Find and read an array of u8 from a property.
810 * @np: device node from which the property value is to be read.
811 * @propname: name of the property to be searched.
812 * @out_value: pointer to return value, modified only if return value is 0.
813 * @sz: number of array elements to read
815 * Search for a property in a device node and read 8-bit value(s) from
816 * it. Returns 0 on success, -EINVAL if the property does not exist,
817 * -ENODATA if property does not have a value, and -EOVERFLOW if the
818 * property data isn't large enough.
820 * dts entry of array should be like:
821 * property = /bits/ 8 <0x50 0x60 0x70>;
823 * The out_value is modified only if a valid u8 value can be decoded.
825 int of_property_read_u8_array(const struct device_node
*np
,
826 const char *propname
, u8
*out_values
, size_t sz
)
828 const u8
*val
= of_find_property_value_of_size(np
, propname
,
829 (sz
* sizeof(*out_values
)));
835 *out_values
++ = *val
++;
838 EXPORT_SYMBOL_GPL(of_property_read_u8_array
);
841 * of_property_read_u16_array - Find and read an array of u16 from a property.
843 * @np: device node from which the property value is to be read.
844 * @propname: name of the property to be searched.
845 * @out_value: pointer to return value, modified only if return value is 0.
846 * @sz: number of array elements to read
848 * Search for a property in a device node and read 16-bit value(s) from
849 * it. Returns 0 on success, -EINVAL if the property does not exist,
850 * -ENODATA if property does not have a value, and -EOVERFLOW if the
851 * property data isn't large enough.
853 * dts entry of array should be like:
854 * property = /bits/ 16 <0x5000 0x6000 0x7000>;
856 * The out_value is modified only if a valid u16 value can be decoded.
858 int of_property_read_u16_array(const struct device_node
*np
,
859 const char *propname
, u16
*out_values
, size_t sz
)
861 const __be16
*val
= of_find_property_value_of_size(np
, propname
,
862 (sz
* sizeof(*out_values
)));
868 *out_values
++ = be16_to_cpup(val
++);
871 EXPORT_SYMBOL_GPL(of_property_read_u16_array
);
874 * of_property_read_u32_array - Find and read an array of 32 bit integers
877 * @np: device node from which the property value is to be read.
878 * @propname: name of the property to be searched.
879 * @out_value: pointer to return value, modified only if return value is 0.
880 * @sz: number of array elements to read
882 * Search for a property in a device node and read 32-bit value(s) 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_array(const struct device_node
*np
,
890 const char *propname
, u32
*out_values
,
893 const __be32
*val
= of_find_property_value_of_size(np
, propname
,
894 (sz
* sizeof(*out_values
)));
900 *out_values
++ = be32_to_cpup(val
++);
903 EXPORT_SYMBOL_GPL(of_property_read_u32_array
);
906 * of_property_read_u64 - Find and read a 64 bit integer 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_value: pointer to return value, modified only if return value is 0.
911 * Search for a property in a device node and read a 64-bit value from
912 * it. Returns 0 on success, -EINVAL if the property does not exist,
913 * -ENODATA if property does not have a value, and -EOVERFLOW if the
914 * property data isn't large enough.
916 * The out_value is modified only if a valid u64 value can be decoded.
918 int of_property_read_u64(const struct device_node
*np
, const char *propname
,
921 const __be32
*val
= of_find_property_value_of_size(np
, propname
,
927 *out_value
= of_read_number(val
, 2);
930 EXPORT_SYMBOL_GPL(of_property_read_u64
);
933 * of_property_read_string - Find and read a string from a property
934 * @np: device node from which the property value is to be read.
935 * @propname: name of the property to be searched.
936 * @out_string: pointer to null terminated return string, modified only if
939 * Search for a property in a device tree node and retrieve a null
940 * terminated string value (pointer to data, not a copy). Returns 0 on
941 * success, -EINVAL if the property does not exist, -ENODATA if property
942 * does not have a value, and -EILSEQ if the string is not null-terminated
943 * within the length of the property data.
945 * The out_string pointer is modified only if a valid string can be decoded.
947 int of_property_read_string(struct device_node
*np
, const char *propname
,
948 const char **out_string
)
950 struct property
*prop
= of_find_property(np
, propname
, NULL
);
955 if (strnlen(prop
->value
, prop
->length
) >= prop
->length
)
957 *out_string
= prop
->value
;
960 EXPORT_SYMBOL_GPL(of_property_read_string
);
963 * of_property_read_string_index - Find and read a string from a multiple
965 * @np: device node from which the property value is to be read.
966 * @propname: name of the property to be searched.
967 * @index: index of the string in the list of strings
968 * @out_string: pointer to null terminated return string, modified only if
971 * Search for a property in a device tree node and retrieve a null
972 * terminated string value (pointer to data, not a copy) in the list of strings
973 * contained in that property.
974 * Returns 0 on success, -EINVAL if the property does not exist, -ENODATA if
975 * property does not have a value, and -EILSEQ if the string is not
976 * null-terminated within the length of the property data.
978 * The out_string pointer is modified only if a valid string can be decoded.
980 int of_property_read_string_index(struct device_node
*np
, const char *propname
,
981 int index
, const char **output
)
983 struct property
*prop
= of_find_property(np
, propname
, NULL
);
985 size_t l
= 0, total
= 0;
992 if (strnlen(prop
->value
, prop
->length
) >= prop
->length
)
997 for (i
= 0; total
< prop
->length
; total
+= l
, p
+= l
) {
1006 EXPORT_SYMBOL_GPL(of_property_read_string_index
);
1009 * of_property_match_string() - Find string in a list and return index
1010 * @np: pointer to node containing string list property
1011 * @propname: string list property name
1012 * @string: pointer to string to search for in string list
1014 * This function searches a string list property and returns the index
1015 * of a specific string value.
1017 int of_property_match_string(struct device_node
*np
, const char *propname
,
1020 struct property
*prop
= of_find_property(np
, propname
, NULL
);
1023 const char *p
, *end
;
1031 end
= p
+ prop
->length
;
1033 for (i
= 0; p
< end
; i
++, p
+= l
) {
1037 pr_debug("comparing %s with %s\n", string
, p
);
1038 if (strcmp(string
, p
) == 0)
1039 return i
; /* Found it; return index */
1043 EXPORT_SYMBOL_GPL(of_property_match_string
);
1046 * of_property_count_strings - Find and return the number of strings from a
1047 * multiple strings property.
1048 * @np: device node from which the property value is to be read.
1049 * @propname: name of the property to be searched.
1051 * Search for a property in a device tree node and retrieve the number of null
1052 * terminated string contain in it. Returns the number of strings on
1053 * success, -EINVAL if the property does not exist, -ENODATA if property
1054 * does not have a value, and -EILSEQ if the string is not null-terminated
1055 * within the length of the property data.
1057 int of_property_count_strings(struct device_node
*np
, const char *propname
)
1059 struct property
*prop
= of_find_property(np
, propname
, NULL
);
1061 size_t l
= 0, total
= 0;
1068 if (strnlen(prop
->value
, prop
->length
) >= prop
->length
)
1073 for (i
= 0; total
< prop
->length
; total
+= l
, p
+= l
, i
++)
1078 EXPORT_SYMBOL_GPL(of_property_count_strings
);
1081 * of_parse_phandle - Resolve a phandle property to a device_node pointer
1082 * @np: Pointer to device node holding phandle property
1083 * @phandle_name: Name of property holding a phandle value
1084 * @index: For properties holding a table of phandles, this is the index into
1087 * Returns the device_node pointer with refcount incremented. Use
1088 * of_node_put() on it when done.
1090 struct device_node
*of_parse_phandle(const struct device_node
*np
,
1091 const char *phandle_name
, int index
)
1093 const __be32
*phandle
;
1096 phandle
= of_get_property(np
, phandle_name
, &size
);
1097 if ((!phandle
) || (size
< sizeof(*phandle
) * (index
+ 1)))
1100 return of_find_node_by_phandle(be32_to_cpup(phandle
+ index
));
1102 EXPORT_SYMBOL(of_parse_phandle
);
1105 * of_parse_phandle_with_args() - Find a node pointed by phandle in a list
1106 * @np: pointer to a device tree node containing a list
1107 * @list_name: property name that contains a list
1108 * @cells_name: property name that specifies phandles' arguments count
1109 * @index: index of a phandle to parse out
1110 * @out_args: optional pointer to output arguments structure (will be filled)
1112 * This function is useful to parse lists of phandles and their arguments.
1113 * Returns 0 on success and fills out_args, on error returns appropriate
1116 * Caller is responsible to call of_node_put() on the returned out_args->node
1122 * #list-cells = <2>;
1126 * #list-cells = <1>;
1130 * list = <&phandle1 1 2 &phandle2 3>;
1133 * To get a device_node of the `node2' node you may call this:
1134 * of_parse_phandle_with_args(node3, "list", "#list-cells", 1, &args);
1136 static int __of_parse_phandle_with_args(const struct device_node
*np
,
1137 const char *list_name
,
1138 const char *cells_name
, int index
,
1139 struct of_phandle_args
*out_args
)
1141 const __be32
*list
, *list_end
;
1142 int rc
= 0, size
, cur_index
= 0;
1144 struct device_node
*node
= NULL
;
1147 /* Retrieve the phandle list property */
1148 list
= of_get_property(np
, list_name
, &size
);
1151 list_end
= list
+ size
/ sizeof(*list
);
1153 /* Loop over the phandles until all the requested entry is found */
1154 while (list
< list_end
) {
1159 * If phandle is 0, then it is an empty entry with no
1160 * arguments. Skip forward to the next entry.
1162 phandle
= be32_to_cpup(list
++);
1165 * Find the provider node and parse the #*-cells
1166 * property to determine the argument length
1168 node
= of_find_node_by_phandle(phandle
);
1170 pr_err("%s: could not find phandle\n",
1174 if (of_property_read_u32(node
, cells_name
, &count
)) {
1175 pr_err("%s: could not get %s for %s\n",
1176 np
->full_name
, cells_name
,
1182 * Make sure that the arguments actually fit in the
1183 * remaining property data length
1185 if (list
+ count
> list_end
) {
1186 pr_err("%s: arguments longer than property\n",
1193 * All of the error cases above bail out of the loop, so at
1194 * this point, the parsing is successful. If the requested
1195 * index matches, then fill the out_args structure and return,
1196 * or return -ENOENT for an empty entry.
1199 if (cur_index
== index
) {
1205 if (WARN_ON(count
> MAX_PHANDLE_ARGS
))
1206 count
= MAX_PHANDLE_ARGS
;
1207 out_args
->np
= node
;
1208 out_args
->args_count
= count
;
1209 for (i
= 0; i
< count
; i
++)
1210 out_args
->args
[i
] = be32_to_cpup(list
++);
1215 /* Found it! return success */
1226 * Unlock node before returning result; will be one of:
1227 * -ENOENT : index is for empty phandle
1228 * -EINVAL : parsing error on data
1229 * [1..n] : Number of phandle (count mode; when index = -1)
1231 rc
= index
< 0 ? cur_index
: -ENOENT
;
1238 int of_parse_phandle_with_args(const struct device_node
*np
, const char *list_name
,
1239 const char *cells_name
, int index
,
1240 struct of_phandle_args
*out_args
)
1244 return __of_parse_phandle_with_args(np
, list_name
, cells_name
, index
, out_args
);
1246 EXPORT_SYMBOL(of_parse_phandle_with_args
);
1249 * of_count_phandle_with_args() - Find the number of phandles references in a property
1250 * @np: pointer to a device tree node containing a list
1251 * @list_name: property name that contains a list
1252 * @cells_name: property name that specifies phandles' arguments count
1254 * Returns the number of phandle + argument tuples within a property. It
1255 * is a typical pattern to encode a list of phandle and variable
1256 * arguments into a single property. The number of arguments is encoded
1257 * by a property in the phandle-target node. For example, a gpios
1258 * property would contain a list of GPIO specifies consisting of a
1259 * phandle and 1 or more arguments. The number of arguments are
1260 * determined by the #gpio-cells property in the node pointed to by the
1263 int of_count_phandle_with_args(const struct device_node
*np
, const char *list_name
,
1264 const char *cells_name
)
1266 return __of_parse_phandle_with_args(np
, list_name
, cells_name
, -1, NULL
);
1268 EXPORT_SYMBOL(of_count_phandle_with_args
);
1270 #if defined(CONFIG_OF_DYNAMIC)
1271 static int of_property_notify(int action
, struct device_node
*np
,
1272 struct property
*prop
)
1274 struct of_prop_reconfig pr
;
1278 return of_reconfig_notify(action
, &pr
);
1281 static int of_property_notify(int action
, struct device_node
*np
,
1282 struct property
*prop
)
1289 * of_add_property - Add a property to a node
1291 int of_add_property(struct device_node
*np
, struct property
*prop
)
1293 struct property
**next
;
1294 unsigned long flags
;
1297 rc
= of_property_notify(OF_RECONFIG_ADD_PROPERTY
, np
, prop
);
1302 raw_spin_lock_irqsave(&devtree_lock
, flags
);
1303 next
= &np
->properties
;
1305 if (strcmp(prop
->name
, (*next
)->name
) == 0) {
1306 /* duplicate ! don't insert it */
1307 raw_spin_unlock_irqrestore(&devtree_lock
, flags
);
1310 next
= &(*next
)->next
;
1313 raw_spin_unlock_irqrestore(&devtree_lock
, flags
);
1315 #ifdef CONFIG_PROC_DEVICETREE
1316 /* try to add to proc as well if it was initialized */
1318 proc_device_tree_add_prop(np
->pde
, prop
);
1319 #endif /* CONFIG_PROC_DEVICETREE */
1325 * of_remove_property - Remove a property from a node.
1327 * Note that we don't actually remove it, since we have given out
1328 * who-knows-how-many pointers to the data using get-property.
1329 * Instead we just move the property to the "dead properties"
1330 * list, so it won't be found any more.
1332 int of_remove_property(struct device_node
*np
, struct property
*prop
)
1334 struct property
**next
;
1335 unsigned long flags
;
1339 rc
= of_property_notify(OF_RECONFIG_REMOVE_PROPERTY
, np
, prop
);
1343 raw_spin_lock_irqsave(&devtree_lock
, flags
);
1344 next
= &np
->properties
;
1346 if (*next
== prop
) {
1347 /* found the node */
1349 prop
->next
= np
->deadprops
;
1350 np
->deadprops
= prop
;
1354 next
= &(*next
)->next
;
1356 raw_spin_unlock_irqrestore(&devtree_lock
, flags
);
1361 #ifdef CONFIG_PROC_DEVICETREE
1362 /* try to remove the proc node as well */
1364 proc_device_tree_remove_prop(np
->pde
, prop
);
1365 #endif /* CONFIG_PROC_DEVICETREE */
1371 * of_update_property - Update a property in a node, if the property does
1372 * not exist, add it.
1374 * Note that we don't actually remove it, since we have given out
1375 * who-knows-how-many pointers to the data using get-property.
1376 * Instead we just move the property to the "dead properties" list,
1377 * and add the new property to the property list
1379 int of_update_property(struct device_node
*np
, struct property
*newprop
)
1381 struct property
**next
, *oldprop
;
1382 unsigned long flags
;
1385 rc
= of_property_notify(OF_RECONFIG_UPDATE_PROPERTY
, np
, newprop
);
1392 oldprop
= of_find_property(np
, newprop
->name
, NULL
);
1394 return of_add_property(np
, newprop
);
1396 raw_spin_lock_irqsave(&devtree_lock
, flags
);
1397 next
= &np
->properties
;
1399 if (*next
== oldprop
) {
1400 /* found the node */
1401 newprop
->next
= oldprop
->next
;
1403 oldprop
->next
= np
->deadprops
;
1404 np
->deadprops
= oldprop
;
1408 next
= &(*next
)->next
;
1410 raw_spin_unlock_irqrestore(&devtree_lock
, flags
);
1415 #ifdef CONFIG_PROC_DEVICETREE
1416 /* try to add to proc as well if it was initialized */
1418 proc_device_tree_update_prop(np
->pde
, newprop
, oldprop
);
1419 #endif /* CONFIG_PROC_DEVICETREE */
1424 #if defined(CONFIG_OF_DYNAMIC)
1426 * Support for dynamic device trees.
1428 * On some platforms, the device tree can be manipulated at runtime.
1429 * The routines in this section support adding, removing and changing
1430 * device tree nodes.
1433 static BLOCKING_NOTIFIER_HEAD(of_reconfig_chain
);
1435 int of_reconfig_notifier_register(struct notifier_block
*nb
)
1437 return blocking_notifier_chain_register(&of_reconfig_chain
, nb
);
1439 EXPORT_SYMBOL_GPL(of_reconfig_notifier_register
);
1441 int of_reconfig_notifier_unregister(struct notifier_block
*nb
)
1443 return blocking_notifier_chain_unregister(&of_reconfig_chain
, nb
);
1445 EXPORT_SYMBOL_GPL(of_reconfig_notifier_unregister
);
1447 int of_reconfig_notify(unsigned long action
, void *p
)
1451 rc
= blocking_notifier_call_chain(&of_reconfig_chain
, action
, p
);
1452 return notifier_to_errno(rc
);
1455 #ifdef CONFIG_PROC_DEVICETREE
1456 static void of_add_proc_dt_entry(struct device_node
*dn
)
1458 struct proc_dir_entry
*ent
;
1460 ent
= proc_mkdir(strrchr(dn
->full_name
, '/') + 1, dn
->parent
->pde
);
1462 proc_device_tree_add_node(dn
, ent
);
1465 static void of_add_proc_dt_entry(struct device_node
*dn
)
1472 * of_attach_node - Plug a device node into the tree and global list.
1474 int of_attach_node(struct device_node
*np
)
1476 unsigned long flags
;
1479 rc
= of_reconfig_notify(OF_RECONFIG_ATTACH_NODE
, np
);
1483 raw_spin_lock_irqsave(&devtree_lock
, flags
);
1484 np
->sibling
= np
->parent
->child
;
1485 np
->allnext
= of_allnodes
;
1486 np
->parent
->child
= np
;
1488 raw_spin_unlock_irqrestore(&devtree_lock
, flags
);
1490 of_add_proc_dt_entry(np
);
1494 #ifdef CONFIG_PROC_DEVICETREE
1495 static void of_remove_proc_dt_entry(struct device_node
*dn
)
1497 proc_remove(dn
->pde
);
1500 static void of_remove_proc_dt_entry(struct device_node
*dn
)
1507 * of_detach_node - "Unplug" a node from the device tree.
1509 * The caller must hold a reference to the node. The memory associated with
1510 * the node is not freed until its refcount goes to zero.
1512 int of_detach_node(struct device_node
*np
)
1514 struct device_node
*parent
;
1515 unsigned long flags
;
1518 rc
= of_reconfig_notify(OF_RECONFIG_DETACH_NODE
, np
);
1522 raw_spin_lock_irqsave(&devtree_lock
, flags
);
1524 if (of_node_check_flag(np
, OF_DETACHED
)) {
1525 /* someone already detached it */
1526 raw_spin_unlock_irqrestore(&devtree_lock
, flags
);
1530 parent
= np
->parent
;
1532 raw_spin_unlock_irqrestore(&devtree_lock
, flags
);
1536 if (of_allnodes
== np
)
1537 of_allnodes
= np
->allnext
;
1539 struct device_node
*prev
;
1540 for (prev
= of_allnodes
;
1541 prev
->allnext
!= np
;
1542 prev
= prev
->allnext
)
1544 prev
->allnext
= np
->allnext
;
1547 if (parent
->child
== np
)
1548 parent
->child
= np
->sibling
;
1550 struct device_node
*prevsib
;
1551 for (prevsib
= np
->parent
->child
;
1552 prevsib
->sibling
!= np
;
1553 prevsib
= prevsib
->sibling
)
1555 prevsib
->sibling
= np
->sibling
;
1558 of_node_set_flag(np
, OF_DETACHED
);
1559 raw_spin_unlock_irqrestore(&devtree_lock
, flags
);
1561 of_remove_proc_dt_entry(np
);
1564 #endif /* defined(CONFIG_OF_DYNAMIC) */
1566 static void of_alias_add(struct alias_prop
*ap
, struct device_node
*np
,
1567 int id
, const char *stem
, int stem_len
)
1571 strncpy(ap
->stem
, stem
, stem_len
);
1572 ap
->stem
[stem_len
] = 0;
1573 list_add_tail(&ap
->link
, &aliases_lookup
);
1574 pr_debug("adding DT alias:%s: stem=%s id=%i node=%s\n",
1575 ap
->alias
, ap
->stem
, ap
->id
, of_node_full_name(np
));
1579 * of_alias_scan - Scan all properties of 'aliases' node
1581 * The function scans all the properties of 'aliases' node and populate
1582 * the the global lookup table with the properties. It returns the
1583 * number of alias_prop found, or error code in error case.
1585 * @dt_alloc: An allocator that provides a virtual address to memory
1586 * for the resulting tree
1588 void of_alias_scan(void * (*dt_alloc
)(u64 size
, u64 align
))
1590 struct property
*pp
;
1592 of_chosen
= of_find_node_by_path("/chosen");
1593 if (of_chosen
== NULL
)
1594 of_chosen
= of_find_node_by_path("/chosen@0");
1595 of_aliases
= of_find_node_by_path("/aliases");
1599 for_each_property_of_node(of_aliases
, pp
) {
1600 const char *start
= pp
->name
;
1601 const char *end
= start
+ strlen(start
);
1602 struct device_node
*np
;
1603 struct alias_prop
*ap
;
1606 /* Skip those we do not want to proceed */
1607 if (!strcmp(pp
->name
, "name") ||
1608 !strcmp(pp
->name
, "phandle") ||
1609 !strcmp(pp
->name
, "linux,phandle"))
1612 np
= of_find_node_by_path(pp
->value
);
1616 /* walk the alias backwards to extract the id and work out
1617 * the 'stem' string */
1618 while (isdigit(*(end
-1)) && end
> start
)
1622 if (kstrtoint(end
, 10, &id
) < 0)
1625 /* Allocate an alias_prop with enough space for the stem */
1626 ap
= dt_alloc(sizeof(*ap
) + len
+ 1, 4);
1630 of_alias_add(ap
, np
, id
, start
, len
);
1635 * of_alias_get_id - Get alias id for the given device_node
1636 * @np: Pointer to the given device_node
1637 * @stem: Alias stem of the given device_node
1639 * The function travels the lookup table to get alias id for the given
1640 * device_node and alias stem. It returns the alias id if find it.
1642 int of_alias_get_id(struct device_node
*np
, const char *stem
)
1644 struct alias_prop
*app
;
1647 mutex_lock(&of_aliases_mutex
);
1648 list_for_each_entry(app
, &aliases_lookup
, link
) {
1649 if (strcmp(app
->stem
, stem
) != 0)
1652 if (np
== app
->np
) {
1657 mutex_unlock(&of_aliases_mutex
);
1661 EXPORT_SYMBOL_GPL(of_alias_get_id
);
1663 const __be32
*of_prop_next_u32(struct property
*prop
, const __be32
*cur
,
1666 const void *curv
= cur
;
1676 curv
+= sizeof(*cur
);
1677 if (curv
>= prop
->value
+ prop
->length
)
1681 *pu
= be32_to_cpup(curv
);
1684 EXPORT_SYMBOL_GPL(of_prop_next_u32
);
1686 const char *of_prop_next_string(struct property
*prop
, const char *cur
)
1688 const void *curv
= cur
;
1696 curv
+= strlen(cur
) + 1;
1697 if (curv
>= prop
->value
+ prop
->length
)
1702 EXPORT_SYMBOL_GPL(of_prop_next_string
);