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>
28 * struct alias_prop - Alias property in 'aliases' node
29 * @link: List node to link the structure in aliases_lookup list
30 * @alias: Alias property name
31 * @np: Pointer to device_node that the alias stands for
32 * @id: Index value from end of alias name
33 * @stem: Alias string without the index
35 * The structure represents one alias property of 'aliases' node as
36 * an entry in aliases_lookup list.
39 struct list_head link
;
41 struct device_node
*np
;
46 static LIST_HEAD(aliases_lookup
);
48 struct device_node
*allnodes
;
49 struct device_node
*of_chosen
;
50 struct device_node
*of_aliases
;
52 static DEFINE_MUTEX(of_aliases_mutex
);
54 /* use when traversing tree through the allnext, child, sibling,
55 * or parent members of struct device_node.
57 DEFINE_RWLOCK(devtree_lock
);
59 int of_n_addr_cells(struct device_node
*np
)
66 ip
= of_get_property(np
, "#address-cells", NULL
);
68 return be32_to_cpup(ip
);
70 /* No #address-cells property for the root node */
71 return OF_ROOT_NODE_ADDR_CELLS_DEFAULT
;
73 EXPORT_SYMBOL(of_n_addr_cells
);
75 int of_n_size_cells(struct device_node
*np
)
82 ip
= of_get_property(np
, "#size-cells", NULL
);
84 return be32_to_cpup(ip
);
86 /* No #size-cells property for the root node */
87 return OF_ROOT_NODE_SIZE_CELLS_DEFAULT
;
89 EXPORT_SYMBOL(of_n_size_cells
);
91 #if defined(CONFIG_OF_DYNAMIC)
93 * of_node_get - Increment refcount of a node
94 * @node: Node to inc refcount, NULL is supported to
95 * simplify writing of callers
99 struct device_node
*of_node_get(struct device_node
*node
)
102 kref_get(&node
->kref
);
105 EXPORT_SYMBOL(of_node_get
);
107 static inline struct device_node
*kref_to_device_node(struct kref
*kref
)
109 return container_of(kref
, struct device_node
, kref
);
113 * of_node_release - release a dynamically allocated node
114 * @kref: kref element of the node to be released
116 * In of_node_put() this function is passed to kref_put()
119 static void of_node_release(struct kref
*kref
)
121 struct device_node
*node
= kref_to_device_node(kref
);
122 struct property
*prop
= node
->properties
;
124 /* We should never be releasing nodes that haven't been detached. */
125 if (!of_node_check_flag(node
, OF_DETACHED
)) {
126 pr_err("ERROR: Bad of_node_put() on %s\n", node
->full_name
);
128 kref_init(&node
->kref
);
132 if (!of_node_check_flag(node
, OF_DYNAMIC
))
136 struct property
*next
= prop
->next
;
143 prop
= node
->deadprops
;
144 node
->deadprops
= NULL
;
147 kfree(node
->full_name
);
153 * of_node_put - Decrement refcount of a node
154 * @node: Node to dec refcount, NULL is supported to
155 * simplify writing of callers
158 void of_node_put(struct device_node
*node
)
161 kref_put(&node
->kref
, of_node_release
);
163 EXPORT_SYMBOL(of_node_put
);
164 #endif /* CONFIG_OF_DYNAMIC */
166 struct property
*of_find_property(const struct device_node
*np
,
175 read_lock(&devtree_lock
);
176 for (pp
= np
->properties
; pp
; pp
= pp
->next
) {
177 if (of_prop_cmp(pp
->name
, name
) == 0) {
183 read_unlock(&devtree_lock
);
187 EXPORT_SYMBOL(of_find_property
);
190 * of_find_all_nodes - Get next node in global list
191 * @prev: Previous node or NULL to start iteration
192 * of_node_put() will be called on it
194 * Returns a node pointer with refcount incremented, use
195 * of_node_put() on it when done.
197 struct device_node
*of_find_all_nodes(struct device_node
*prev
)
199 struct device_node
*np
;
201 read_lock(&devtree_lock
);
202 np
= prev
? prev
->allnext
: allnodes
;
203 for (; np
!= NULL
; np
= np
->allnext
)
207 read_unlock(&devtree_lock
);
210 EXPORT_SYMBOL(of_find_all_nodes
);
213 * Find a property with a given name for a given node
214 * and return the value.
216 const void *of_get_property(const struct device_node
*np
, const char *name
,
219 struct property
*pp
= of_find_property(np
, name
, lenp
);
221 return pp
? pp
->value
: NULL
;
223 EXPORT_SYMBOL(of_get_property
);
225 /** Checks if the given "compat" string matches one of the strings in
226 * the device's "compatible" property
228 int of_device_is_compatible(const struct device_node
*device
,
234 cp
= of_get_property(device
, "compatible", &cplen
);
238 if (of_compat_cmp(cp
, compat
, strlen(compat
)) == 0)
247 EXPORT_SYMBOL(of_device_is_compatible
);
250 * of_machine_is_compatible - Test root of device tree for a given compatible value
251 * @compat: compatible string to look for in root node's compatible property.
253 * Returns true if the root node has the given value in its
254 * compatible property.
256 int of_machine_is_compatible(const char *compat
)
258 struct device_node
*root
;
261 root
= of_find_node_by_path("/");
263 rc
= of_device_is_compatible(root
, compat
);
268 EXPORT_SYMBOL(of_machine_is_compatible
);
271 * of_device_is_available - check if a device is available for use
273 * @device: Node to check for availability
275 * Returns 1 if the status property is absent or set to "okay" or "ok",
278 int of_device_is_available(const struct device_node
*device
)
283 status
= of_get_property(device
, "status", &statlen
);
288 if (!strcmp(status
, "okay") || !strcmp(status
, "ok"))
294 EXPORT_SYMBOL(of_device_is_available
);
297 * of_get_parent - Get a node's parent if any
298 * @node: Node to get parent
300 * Returns a node pointer with refcount incremented, use
301 * of_node_put() on it when done.
303 struct device_node
*of_get_parent(const struct device_node
*node
)
305 struct device_node
*np
;
310 read_lock(&devtree_lock
);
311 np
= of_node_get(node
->parent
);
312 read_unlock(&devtree_lock
);
315 EXPORT_SYMBOL(of_get_parent
);
318 * of_get_next_parent - Iterate to a node's parent
319 * @node: Node to get parent of
321 * This is like of_get_parent() except that it drops the
322 * refcount on the passed node, making it suitable for iterating
323 * through a node's parents.
325 * Returns a node pointer with refcount incremented, use
326 * of_node_put() on it when done.
328 struct device_node
*of_get_next_parent(struct device_node
*node
)
330 struct device_node
*parent
;
335 read_lock(&devtree_lock
);
336 parent
= of_node_get(node
->parent
);
338 read_unlock(&devtree_lock
);
343 * of_get_next_child - Iterate a node childs
345 * @prev: previous child of the parent node, or NULL to get first
347 * Returns a node pointer with refcount incremented, use
348 * of_node_put() on it when done.
350 struct device_node
*of_get_next_child(const struct device_node
*node
,
351 struct device_node
*prev
)
353 struct device_node
*next
;
355 read_lock(&devtree_lock
);
356 next
= prev
? prev
->sibling
: node
->child
;
357 for (; next
; next
= next
->sibling
)
358 if (of_node_get(next
))
361 read_unlock(&devtree_lock
);
364 EXPORT_SYMBOL(of_get_next_child
);
367 * of_get_next_available_child - Find the next available child node
369 * @prev: previous child of the parent node, or NULL to get first
371 * This function is like of_get_next_child(), except that it
372 * automatically skips any disabled nodes (i.e. status = "disabled").
374 struct device_node
*of_get_next_available_child(const struct device_node
*node
,
375 struct device_node
*prev
)
377 struct device_node
*next
;
379 read_lock(&devtree_lock
);
380 next
= prev
? prev
->sibling
: node
->child
;
381 for (; next
; next
= next
->sibling
) {
382 if (!of_device_is_available(next
))
384 if (of_node_get(next
))
388 read_unlock(&devtree_lock
);
391 EXPORT_SYMBOL(of_get_next_available_child
);
394 * of_find_node_by_path - Find a node matching a full OF path
395 * @path: The full path to match
397 * Returns a node pointer with refcount incremented, use
398 * of_node_put() on it when done.
400 struct device_node
*of_find_node_by_path(const char *path
)
402 struct device_node
*np
= allnodes
;
404 read_lock(&devtree_lock
);
405 for (; np
; np
= np
->allnext
) {
406 if (np
->full_name
&& (of_node_cmp(np
->full_name
, path
) == 0)
410 read_unlock(&devtree_lock
);
413 EXPORT_SYMBOL(of_find_node_by_path
);
416 * of_find_node_by_name - Find a node by its "name" property
417 * @from: The node to start searching from or NULL, the node
418 * you pass will not be searched, only the next one
419 * will; typically, you pass what the previous call
420 * returned. of_node_put() will be called on it
421 * @name: The name string to match against
423 * Returns a node pointer with refcount incremented, use
424 * of_node_put() on it when done.
426 struct device_node
*of_find_node_by_name(struct device_node
*from
,
429 struct device_node
*np
;
431 read_lock(&devtree_lock
);
432 np
= from
? from
->allnext
: allnodes
;
433 for (; np
; np
= np
->allnext
)
434 if (np
->name
&& (of_node_cmp(np
->name
, name
) == 0)
438 read_unlock(&devtree_lock
);
441 EXPORT_SYMBOL(of_find_node_by_name
);
444 * of_find_node_by_type - Find a node by its "device_type" property
445 * @from: The node to start searching from, or NULL to start searching
446 * the entire device tree. The node you pass will not be
447 * searched, only the next one will; typically, you pass
448 * what the previous call returned. of_node_put() will be
449 * called on from for you.
450 * @type: The type string to match against
452 * Returns a node pointer with refcount incremented, use
453 * of_node_put() on it when done.
455 struct device_node
*of_find_node_by_type(struct device_node
*from
,
458 struct device_node
*np
;
460 read_lock(&devtree_lock
);
461 np
= from
? from
->allnext
: allnodes
;
462 for (; np
; np
= np
->allnext
)
463 if (np
->type
&& (of_node_cmp(np
->type
, type
) == 0)
467 read_unlock(&devtree_lock
);
470 EXPORT_SYMBOL(of_find_node_by_type
);
473 * of_find_compatible_node - Find a node based on type and one of the
474 * tokens in its "compatible" property
475 * @from: The node to start searching from or NULL, the node
476 * you pass will not be searched, only the next one
477 * will; typically, you pass what the previous call
478 * returned. of_node_put() will be called on it
479 * @type: The type string to match "device_type" or NULL to ignore
480 * @compatible: The string to match to one of the tokens in the device
483 * Returns a node pointer with refcount incremented, use
484 * of_node_put() on it when done.
486 struct device_node
*of_find_compatible_node(struct device_node
*from
,
487 const char *type
, const char *compatible
)
489 struct device_node
*np
;
491 read_lock(&devtree_lock
);
492 np
= from
? from
->allnext
: allnodes
;
493 for (; np
; np
= np
->allnext
) {
495 && !(np
->type
&& (of_node_cmp(np
->type
, type
) == 0)))
497 if (of_device_is_compatible(np
, compatible
) && of_node_get(np
))
501 read_unlock(&devtree_lock
);
504 EXPORT_SYMBOL(of_find_compatible_node
);
507 * of_find_node_with_property - Find a node which has a property with
509 * @from: The node to start searching from or NULL, the node
510 * you pass will not be searched, only the next one
511 * will; typically, you pass what the previous call
512 * returned. of_node_put() will be called on it
513 * @prop_name: The name of the property to look for.
515 * Returns a node pointer with refcount incremented, use
516 * of_node_put() on it when done.
518 struct device_node
*of_find_node_with_property(struct device_node
*from
,
519 const char *prop_name
)
521 struct device_node
*np
;
524 read_lock(&devtree_lock
);
525 np
= from
? from
->allnext
: allnodes
;
526 for (; np
; np
= np
->allnext
) {
527 for (pp
= np
->properties
; pp
; pp
= pp
->next
) {
528 if (of_prop_cmp(pp
->name
, prop_name
) == 0) {
536 read_unlock(&devtree_lock
);
539 EXPORT_SYMBOL(of_find_node_with_property
);
542 * of_match_node - Tell if an device_node has a matching of_match structure
543 * @matches: array of of device match structures to search in
544 * @node: the of device structure to match against
546 * Low level utility function used by device matching.
548 const struct of_device_id
*of_match_node(const struct of_device_id
*matches
,
549 const struct device_node
*node
)
554 while (matches
->name
[0] || matches
->type
[0] || matches
->compatible
[0]) {
556 if (matches
->name
[0])
558 && !strcmp(matches
->name
, node
->name
);
559 if (matches
->type
[0])
561 && !strcmp(matches
->type
, node
->type
);
562 if (matches
->compatible
[0])
563 match
&= of_device_is_compatible(node
,
564 matches
->compatible
);
571 EXPORT_SYMBOL(of_match_node
);
574 * of_find_matching_node - Find a node based on an of_device_id match
576 * @from: The node to start searching from or NULL, the node
577 * you pass will not be searched, only the next one
578 * will; typically, you pass what the previous call
579 * returned. of_node_put() will be called on it
580 * @matches: array of of device match structures to search in
582 * Returns a node pointer with refcount incremented, use
583 * of_node_put() on it when done.
585 struct device_node
*of_find_matching_node(struct device_node
*from
,
586 const struct of_device_id
*matches
)
588 struct device_node
*np
;
590 read_lock(&devtree_lock
);
591 np
= from
? from
->allnext
: allnodes
;
592 for (; np
; np
= np
->allnext
) {
593 if (of_match_node(matches
, np
) && of_node_get(np
))
597 read_unlock(&devtree_lock
);
600 EXPORT_SYMBOL(of_find_matching_node
);
603 * of_modalias_node - Lookup appropriate modalias for a device node
604 * @node: pointer to a device tree node
605 * @modalias: Pointer to buffer that modalias value will be copied into
606 * @len: Length of modalias value
608 * Based on the value of the compatible property, this routine will attempt
609 * to choose an appropriate modalias value for a particular device tree node.
610 * It does this by stripping the manufacturer prefix (as delimited by a ',')
611 * from the first entry in the compatible list property.
613 * This routine returns 0 on success, <0 on failure.
615 int of_modalias_node(struct device_node
*node
, char *modalias
, int len
)
617 const char *compatible
, *p
;
620 compatible
= of_get_property(node
, "compatible", &cplen
);
621 if (!compatible
|| strlen(compatible
) > cplen
)
623 p
= strchr(compatible
, ',');
624 strlcpy(modalias
, p
? p
+ 1 : compatible
, len
);
627 EXPORT_SYMBOL_GPL(of_modalias_node
);
630 * of_find_node_by_phandle - Find a node given a phandle
631 * @handle: phandle of the node to find
633 * Returns a node pointer with refcount incremented, use
634 * of_node_put() on it when done.
636 struct device_node
*of_find_node_by_phandle(phandle handle
)
638 struct device_node
*np
;
640 read_lock(&devtree_lock
);
641 for (np
= allnodes
; np
; np
= np
->allnext
)
642 if (np
->phandle
== handle
)
645 read_unlock(&devtree_lock
);
648 EXPORT_SYMBOL(of_find_node_by_phandle
);
651 * of_property_read_u32_array - Find and read an array of 32 bit integers
654 * @np: device node from which the property value is to be read.
655 * @propname: name of the property to be searched.
656 * @out_value: pointer to return value, modified only if return value is 0.
658 * Search for a property in a device node and read 32-bit value(s) from
659 * it. Returns 0 on success, -EINVAL if the property does not exist,
660 * -ENODATA if property does not have a value, and -EOVERFLOW if the
661 * property data isn't large enough.
663 * The out_value is modified only if a valid u32 value can be decoded.
665 int of_property_read_u32_array(const struct device_node
*np
,
666 const char *propname
, u32
*out_values
,
669 struct property
*prop
= of_find_property(np
, propname
, NULL
);
676 if ((sz
* sizeof(*out_values
)) > prop
->length
)
681 *out_values
++ = be32_to_cpup(val
++);
684 EXPORT_SYMBOL_GPL(of_property_read_u32_array
);
687 * of_property_read_u64 - Find and read a 64 bit integer from a property
688 * @np: device node from which the property value is to be read.
689 * @propname: name of the property to be searched.
690 * @out_value: pointer to return value, modified only if return value is 0.
692 * Search for a property in a device node and read a 64-bit value from
693 * it. Returns 0 on success, -EINVAL if the property does not exist,
694 * -ENODATA if property does not have a value, and -EOVERFLOW if the
695 * property data isn't large enough.
697 * The out_value is modified only if a valid u64 value can be decoded.
699 int of_property_read_u64(const struct device_node
*np
, const char *propname
,
702 struct property
*prop
= of_find_property(np
, propname
, NULL
);
708 if (sizeof(*out_value
) > prop
->length
)
710 *out_value
= of_read_number(prop
->value
, 2);
713 EXPORT_SYMBOL_GPL(of_property_read_u64
);
716 * of_property_read_string - Find and read a string from a property
717 * @np: device node from which the property value is to be read.
718 * @propname: name of the property to be searched.
719 * @out_string: pointer to null terminated return string, modified only if
722 * Search for a property in a device tree node and retrieve a null
723 * terminated string value (pointer to data, not a copy). Returns 0 on
724 * success, -EINVAL if the property does not exist, -ENODATA if property
725 * does not have a value, and -EILSEQ if the string is not null-terminated
726 * within the length of the property data.
728 * The out_string pointer is modified only if a valid string can be decoded.
730 int of_property_read_string(struct device_node
*np
, const char *propname
,
731 const char **out_string
)
733 struct property
*prop
= of_find_property(np
, propname
, NULL
);
738 if (strnlen(prop
->value
, prop
->length
) >= prop
->length
)
740 *out_string
= prop
->value
;
743 EXPORT_SYMBOL_GPL(of_property_read_string
);
746 * of_property_read_string_index - Find and read a string from a multiple
748 * @np: device node from which the property value is to be read.
749 * @propname: name of the property to be searched.
750 * @index: index of the string in the list of strings
751 * @out_string: pointer to null terminated return string, modified only if
754 * Search for a property in a device tree node and retrieve a null
755 * terminated string value (pointer to data, not a copy) in the list of strings
756 * contained in that property.
757 * Returns 0 on success, -EINVAL if the property does not exist, -ENODATA if
758 * property does not have a value, and -EILSEQ if the string is not
759 * null-terminated within the length of the property data.
761 * The out_string pointer is modified only if a valid string can be decoded.
763 int of_property_read_string_index(struct device_node
*np
, const char *propname
,
764 int index
, const char **output
)
766 struct property
*prop
= of_find_property(np
, propname
, NULL
);
768 size_t l
= 0, total
= 0;
775 if (strnlen(prop
->value
, prop
->length
) >= prop
->length
)
780 for (i
= 0; total
< prop
->length
; total
+= l
, p
+= l
) {
789 EXPORT_SYMBOL_GPL(of_property_read_string_index
);
792 * of_property_match_string() - Find string in a list and return index
793 * @np: pointer to node containing string list property
794 * @propname: string list property name
795 * @string: pointer to string to search for in string list
797 * This function searches a string list property and returns the index
798 * of a specific string value.
800 int of_property_match_string(struct device_node
*np
, const char *propname
,
803 struct property
*prop
= of_find_property(np
, propname
, NULL
);
814 end
= p
+ prop
->length
;
816 for (i
= 0; p
< end
; i
++, p
+= l
) {
820 pr_debug("comparing %s with %s\n", string
, p
);
821 if (strcmp(string
, p
) == 0)
822 return i
; /* Found it; return index */
826 EXPORT_SYMBOL_GPL(of_property_match_string
);
829 * of_property_count_strings - Find and return the number of strings from a
830 * multiple strings property.
831 * @np: device node from which the property value is to be read.
832 * @propname: name of the property to be searched.
834 * Search for a property in a device tree node and retrieve the number of null
835 * terminated string contain in it. Returns the number of strings on
836 * success, -EINVAL if the property does not exist, -ENODATA if property
837 * does not have a value, and -EILSEQ if the string is not null-terminated
838 * within the length of the property data.
840 int of_property_count_strings(struct device_node
*np
, const char *propname
)
842 struct property
*prop
= of_find_property(np
, propname
, NULL
);
844 size_t l
= 0, total
= 0;
851 if (strnlen(prop
->value
, prop
->length
) >= prop
->length
)
856 for (i
= 0; total
< prop
->length
; total
+= l
, p
+= l
, i
++)
861 EXPORT_SYMBOL_GPL(of_property_count_strings
);
864 * of_parse_phandle - Resolve a phandle property to a device_node pointer
865 * @np: Pointer to device node holding phandle property
866 * @phandle_name: Name of property holding a phandle value
867 * @index: For properties holding a table of phandles, this is the index into
870 * Returns the device_node pointer with refcount incremented. Use
871 * of_node_put() on it when done.
874 of_parse_phandle(struct device_node
*np
, const char *phandle_name
, int index
)
876 const __be32
*phandle
;
879 phandle
= of_get_property(np
, phandle_name
, &size
);
880 if ((!phandle
) || (size
< sizeof(*phandle
) * (index
+ 1)))
883 return of_find_node_by_phandle(be32_to_cpup(phandle
+ index
));
885 EXPORT_SYMBOL(of_parse_phandle
);
888 * of_parse_phandle_with_args() - Find a node pointed by phandle in a list
889 * @np: pointer to a device tree node containing a list
890 * @list_name: property name that contains a list
891 * @cells_name: property name that specifies phandles' arguments count
892 * @index: index of a phandle to parse out
893 * @out_args: optional pointer to output arguments structure (will be filled)
895 * This function is useful to parse lists of phandles and their arguments.
896 * Returns 0 on success and fills out_args, on error returns appropriate
899 * Caller is responsible to call of_node_put() on the returned out_args->node
913 * list = <&phandle1 1 2 &phandle2 3>;
916 * To get a device_node of the `node2' node you may call this:
917 * of_parse_phandle_with_args(node3, "list", "#list-cells", 1, &args);
919 int of_parse_phandle_with_args(struct device_node
*np
, const char *list_name
,
920 const char *cells_name
, int index
,
921 struct of_phandle_args
*out_args
)
923 const __be32
*list
, *list_end
;
924 int size
, cur_index
= 0;
926 struct device_node
*node
= NULL
;
929 /* Retrieve the phandle list property */
930 list
= of_get_property(np
, list_name
, &size
);
933 list_end
= list
+ size
/ sizeof(*list
);
935 /* Loop over the phandles until all the requested entry is found */
936 while (list
< list_end
) {
940 * If phandle is 0, then it is an empty entry with no
941 * arguments. Skip forward to the next entry.
943 phandle
= be32_to_cpup(list
++);
946 * Find the provider node and parse the #*-cells
947 * property to determine the argument length
949 node
= of_find_node_by_phandle(phandle
);
951 pr_err("%s: could not find phandle\n",
955 if (of_property_read_u32(node
, cells_name
, &count
)) {
956 pr_err("%s: could not get %s for %s\n",
957 np
->full_name
, cells_name
,
963 * Make sure that the arguments actually fit in the
964 * remaining property data length
966 if (list
+ count
> list_end
) {
967 pr_err("%s: arguments longer than property\n",
974 * All of the error cases above bail out of the loop, so at
975 * this point, the parsing is successful. If the requested
976 * index matches, then fill the out_args structure and return,
977 * or return -ENOENT for an empty entry.
979 if (cur_index
== index
) {
985 if (WARN_ON(count
> MAX_PHANDLE_ARGS
))
986 count
= MAX_PHANDLE_ARGS
;
988 out_args
->args_count
= count
;
989 for (i
= 0; i
< count
; i
++)
990 out_args
->args
[i
] = be32_to_cpup(list
++);
1001 /* Loop exited without finding a valid entry; return an error */
1006 EXPORT_SYMBOL(of_parse_phandle_with_args
);
1009 * prom_add_property - Add a property to a node
1011 int prom_add_property(struct device_node
*np
, struct property
*prop
)
1013 struct property
**next
;
1014 unsigned long flags
;
1017 write_lock_irqsave(&devtree_lock
, flags
);
1018 next
= &np
->properties
;
1020 if (strcmp(prop
->name
, (*next
)->name
) == 0) {
1021 /* duplicate ! don't insert it */
1022 write_unlock_irqrestore(&devtree_lock
, flags
);
1025 next
= &(*next
)->next
;
1028 write_unlock_irqrestore(&devtree_lock
, flags
);
1030 #ifdef CONFIG_PROC_DEVICETREE
1031 /* try to add to proc as well if it was initialized */
1033 proc_device_tree_add_prop(np
->pde
, prop
);
1034 #endif /* CONFIG_PROC_DEVICETREE */
1040 * prom_remove_property - Remove a property from a node.
1042 * Note that we don't actually remove it, since we have given out
1043 * who-knows-how-many pointers to the data using get-property.
1044 * Instead we just move the property to the "dead properties"
1045 * list, so it won't be found any more.
1047 int prom_remove_property(struct device_node
*np
, struct property
*prop
)
1049 struct property
**next
;
1050 unsigned long flags
;
1053 write_lock_irqsave(&devtree_lock
, flags
);
1054 next
= &np
->properties
;
1056 if (*next
== prop
) {
1057 /* found the node */
1059 prop
->next
= np
->deadprops
;
1060 np
->deadprops
= prop
;
1064 next
= &(*next
)->next
;
1066 write_unlock_irqrestore(&devtree_lock
, flags
);
1071 #ifdef CONFIG_PROC_DEVICETREE
1072 /* try to remove the proc node as well */
1074 proc_device_tree_remove_prop(np
->pde
, prop
);
1075 #endif /* CONFIG_PROC_DEVICETREE */
1081 * prom_update_property - Update a property in a node, if the property does
1082 * not exist, add it.
1084 * Note that we don't actually remove it, since we have given out
1085 * who-knows-how-many pointers to the data using get-property.
1086 * Instead we just move the property to the "dead properties" list,
1087 * and add the new property to the property list
1089 int prom_update_property(struct device_node
*np
,
1090 struct property
*newprop
)
1092 struct property
**next
, *oldprop
;
1093 unsigned long flags
;
1099 oldprop
= of_find_property(np
, newprop
->name
, NULL
);
1101 return prom_add_property(np
, newprop
);
1103 write_lock_irqsave(&devtree_lock
, flags
);
1104 next
= &np
->properties
;
1106 if (*next
== oldprop
) {
1107 /* found the node */
1108 newprop
->next
= oldprop
->next
;
1110 oldprop
->next
= np
->deadprops
;
1111 np
->deadprops
= oldprop
;
1115 next
= &(*next
)->next
;
1117 write_unlock_irqrestore(&devtree_lock
, flags
);
1122 #ifdef CONFIG_PROC_DEVICETREE
1123 /* try to add to proc as well if it was initialized */
1125 proc_device_tree_update_prop(np
->pde
, newprop
, oldprop
);
1126 #endif /* CONFIG_PROC_DEVICETREE */
1131 #if defined(CONFIG_OF_DYNAMIC)
1133 * Support for dynamic device trees.
1135 * On some platforms, the device tree can be manipulated at runtime.
1136 * The routines in this section support adding, removing and changing
1137 * device tree nodes.
1141 * of_attach_node - Plug a device node into the tree and global list.
1143 void of_attach_node(struct device_node
*np
)
1145 unsigned long flags
;
1147 write_lock_irqsave(&devtree_lock
, flags
);
1148 np
->sibling
= np
->parent
->child
;
1149 np
->allnext
= allnodes
;
1150 np
->parent
->child
= np
;
1152 write_unlock_irqrestore(&devtree_lock
, flags
);
1156 * of_detach_node - "Unplug" a node from the device tree.
1158 * The caller must hold a reference to the node. The memory associated with
1159 * the node is not freed until its refcount goes to zero.
1161 void of_detach_node(struct device_node
*np
)
1163 struct device_node
*parent
;
1164 unsigned long flags
;
1166 write_lock_irqsave(&devtree_lock
, flags
);
1168 parent
= np
->parent
;
1173 allnodes
= np
->allnext
;
1175 struct device_node
*prev
;
1176 for (prev
= allnodes
;
1177 prev
->allnext
!= np
;
1178 prev
= prev
->allnext
)
1180 prev
->allnext
= np
->allnext
;
1183 if (parent
->child
== np
)
1184 parent
->child
= np
->sibling
;
1186 struct device_node
*prevsib
;
1187 for (prevsib
= np
->parent
->child
;
1188 prevsib
->sibling
!= np
;
1189 prevsib
= prevsib
->sibling
)
1191 prevsib
->sibling
= np
->sibling
;
1194 of_node_set_flag(np
, OF_DETACHED
);
1197 write_unlock_irqrestore(&devtree_lock
, flags
);
1199 #endif /* defined(CONFIG_OF_DYNAMIC) */
1201 static void of_alias_add(struct alias_prop
*ap
, struct device_node
*np
,
1202 int id
, const char *stem
, int stem_len
)
1206 strncpy(ap
->stem
, stem
, stem_len
);
1207 ap
->stem
[stem_len
] = 0;
1208 list_add_tail(&ap
->link
, &aliases_lookup
);
1209 pr_debug("adding DT alias:%s: stem=%s id=%i node=%s\n",
1210 ap
->alias
, ap
->stem
, ap
->id
, of_node_full_name(np
));
1214 * of_alias_scan - Scan all properties of 'aliases' node
1216 * The function scans all the properties of 'aliases' node and populate
1217 * the the global lookup table with the properties. It returns the
1218 * number of alias_prop found, or error code in error case.
1220 * @dt_alloc: An allocator that provides a virtual address to memory
1221 * for the resulting tree
1223 void of_alias_scan(void * (*dt_alloc
)(u64 size
, u64 align
))
1225 struct property
*pp
;
1227 of_chosen
= of_find_node_by_path("/chosen");
1228 if (of_chosen
== NULL
)
1229 of_chosen
= of_find_node_by_path("/chosen@0");
1230 of_aliases
= of_find_node_by_path("/aliases");
1234 for_each_property_of_node(of_aliases
, pp
) {
1235 const char *start
= pp
->name
;
1236 const char *end
= start
+ strlen(start
);
1237 struct device_node
*np
;
1238 struct alias_prop
*ap
;
1241 /* Skip those we do not want to proceed */
1242 if (!strcmp(pp
->name
, "name") ||
1243 !strcmp(pp
->name
, "phandle") ||
1244 !strcmp(pp
->name
, "linux,phandle"))
1247 np
= of_find_node_by_path(pp
->value
);
1251 /* walk the alias backwards to extract the id and work out
1252 * the 'stem' string */
1253 while (isdigit(*(end
-1)) && end
> start
)
1257 if (kstrtoint(end
, 10, &id
) < 0)
1260 /* Allocate an alias_prop with enough space for the stem */
1261 ap
= dt_alloc(sizeof(*ap
) + len
+ 1, 4);
1265 of_alias_add(ap
, np
, id
, start
, len
);
1270 * of_alias_get_id - Get alias id for the given device_node
1271 * @np: Pointer to the given device_node
1272 * @stem: Alias stem of the given device_node
1274 * The function travels the lookup table to get alias id for the given
1275 * device_node and alias stem. It returns the alias id if find it.
1277 int of_alias_get_id(struct device_node
*np
, const char *stem
)
1279 struct alias_prop
*app
;
1282 mutex_lock(&of_aliases_mutex
);
1283 list_for_each_entry(app
, &aliases_lookup
, link
) {
1284 if (strcmp(app
->stem
, stem
) != 0)
1287 if (np
== app
->np
) {
1292 mutex_unlock(&of_aliases_mutex
);
1296 EXPORT_SYMBOL_GPL(of_alias_get_id
);
1298 const __be32
*of_prop_next_u32(struct property
*prop
, const __be32
*cur
,
1301 const void *curv
= cur
;
1311 curv
+= sizeof(*cur
);
1312 if (curv
>= prop
->value
+ prop
->length
)
1316 *pu
= be32_to_cpup(curv
);
1319 EXPORT_SYMBOL_GPL(of_prop_next_u32
);
1321 const char *of_prop_next_string(struct property
*prop
, const char *cur
)
1323 const void *curv
= cur
;
1331 curv
+= strlen(cur
) + 1;
1332 if (curv
>= prop
->value
+ prop
->length
)
1337 EXPORT_SYMBOL_GPL(of_prop_next_string
);