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
!= 0; 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_find_node_by_path - Find a node matching a full OF path
368 * @path: The full path to match
370 * Returns a node pointer with refcount incremented, use
371 * of_node_put() on it when done.
373 struct device_node
*of_find_node_by_path(const char *path
)
375 struct device_node
*np
= allnodes
;
377 read_lock(&devtree_lock
);
378 for (; np
; np
= np
->allnext
) {
379 if (np
->full_name
&& (of_node_cmp(np
->full_name
, path
) == 0)
383 read_unlock(&devtree_lock
);
386 EXPORT_SYMBOL(of_find_node_by_path
);
389 * of_find_node_by_name - Find a node by its "name" property
390 * @from: The node to start searching from or NULL, the node
391 * you pass will not be searched, only the next one
392 * will; typically, you pass what the previous call
393 * returned. of_node_put() will be called on it
394 * @name: The name string to match against
396 * Returns a node pointer with refcount incremented, use
397 * of_node_put() on it when done.
399 struct device_node
*of_find_node_by_name(struct device_node
*from
,
402 struct device_node
*np
;
404 read_lock(&devtree_lock
);
405 np
= from
? from
->allnext
: allnodes
;
406 for (; np
; np
= np
->allnext
)
407 if (np
->name
&& (of_node_cmp(np
->name
, name
) == 0)
411 read_unlock(&devtree_lock
);
414 EXPORT_SYMBOL(of_find_node_by_name
);
417 * of_find_node_by_type - Find a node by its "device_type" property
418 * @from: The node to start searching from, or NULL to start searching
419 * the entire device tree. The node you pass will not be
420 * searched, only the next one will; typically, you pass
421 * what the previous call returned. of_node_put() will be
422 * called on from for you.
423 * @type: The type string to match against
425 * Returns a node pointer with refcount incremented, use
426 * of_node_put() on it when done.
428 struct device_node
*of_find_node_by_type(struct device_node
*from
,
431 struct device_node
*np
;
433 read_lock(&devtree_lock
);
434 np
= from
? from
->allnext
: allnodes
;
435 for (; np
; np
= np
->allnext
)
436 if (np
->type
&& (of_node_cmp(np
->type
, type
) == 0)
440 read_unlock(&devtree_lock
);
443 EXPORT_SYMBOL(of_find_node_by_type
);
446 * of_find_compatible_node - Find a node based on type and one of the
447 * tokens in its "compatible" property
448 * @from: The node to start searching from or NULL, the node
449 * you pass will not be searched, only the next one
450 * will; typically, you pass what the previous call
451 * returned. of_node_put() will be called on it
452 * @type: The type string to match "device_type" or NULL to ignore
453 * @compatible: The string to match to one of the tokens in the device
456 * Returns a node pointer with refcount incremented, use
457 * of_node_put() on it when done.
459 struct device_node
*of_find_compatible_node(struct device_node
*from
,
460 const char *type
, const char *compatible
)
462 struct device_node
*np
;
464 read_lock(&devtree_lock
);
465 np
= from
? from
->allnext
: allnodes
;
466 for (; np
; np
= np
->allnext
) {
468 && !(np
->type
&& (of_node_cmp(np
->type
, type
) == 0)))
470 if (of_device_is_compatible(np
, compatible
) && of_node_get(np
))
474 read_unlock(&devtree_lock
);
477 EXPORT_SYMBOL(of_find_compatible_node
);
480 * of_find_node_with_property - Find a node which has a property with
482 * @from: The node to start searching from or NULL, the node
483 * you pass will not be searched, only the next one
484 * will; typically, you pass what the previous call
485 * returned. of_node_put() will be called on it
486 * @prop_name: The name of the property to look for.
488 * Returns a node pointer with refcount incremented, use
489 * of_node_put() on it when done.
491 struct device_node
*of_find_node_with_property(struct device_node
*from
,
492 const char *prop_name
)
494 struct device_node
*np
;
497 read_lock(&devtree_lock
);
498 np
= from
? from
->allnext
: allnodes
;
499 for (; np
; np
= np
->allnext
) {
500 for (pp
= np
->properties
; pp
!= 0; pp
= pp
->next
) {
501 if (of_prop_cmp(pp
->name
, prop_name
) == 0) {
509 read_unlock(&devtree_lock
);
512 EXPORT_SYMBOL(of_find_node_with_property
);
514 static const struct of_device_id
*of_match_compat(const struct of_device_id
*matches
,
517 while (matches
->name
[0] || matches
->type
[0] || matches
->compatible
[0]) {
518 const char *cp
= matches
->compatible
;
519 int len
= strlen(cp
);
521 if (len
> 0 && of_compat_cmp(compat
, cp
, len
) == 0)
531 * of_match_node - Tell if an device_node has a matching of_match structure
532 * @matches: array of of device match structures to search in
533 * @node: the of device structure to match against
535 * Low level utility function used by device matching.
537 const struct of_device_id
*of_match_node(const struct of_device_id
*matches
,
538 const struct device_node
*node
)
540 struct property
*prop
;
546 of_property_for_each_string(node
, "compatible", prop
, cp
) {
547 const struct of_device_id
*match
= of_match_compat(matches
, cp
);
552 while (matches
->name
[0] || matches
->type
[0] || matches
->compatible
[0]) {
554 if (matches
->name
[0])
556 && !strcmp(matches
->name
, node
->name
);
557 if (matches
->type
[0])
559 && !strcmp(matches
->type
, node
->type
);
560 if (match
&& !matches
->compatible
[0])
566 EXPORT_SYMBOL(of_match_node
);
569 * of_find_matching_node - Find a node based on an of_device_id match
571 * @from: The node to start searching from or NULL, the node
572 * you pass will not be searched, only the next one
573 * will; typically, you pass what the previous call
574 * returned. of_node_put() will be called on it
575 * @matches: array of of device match structures to search in
577 * Returns a node pointer with refcount incremented, use
578 * of_node_put() on it when done.
580 struct device_node
*of_find_matching_node(struct device_node
*from
,
581 const struct of_device_id
*matches
)
583 struct device_node
*np
;
585 read_lock(&devtree_lock
);
586 np
= from
? from
->allnext
: allnodes
;
587 for (; np
; np
= np
->allnext
) {
588 if (of_match_node(matches
, np
) && of_node_get(np
))
592 read_unlock(&devtree_lock
);
595 EXPORT_SYMBOL(of_find_matching_node
);
598 * of_modalias_node - Lookup appropriate modalias for a device node
599 * @node: pointer to a device tree node
600 * @modalias: Pointer to buffer that modalias value will be copied into
601 * @len: Length of modalias value
603 * Based on the value of the compatible property, this routine will attempt
604 * to choose an appropriate modalias value for a particular device tree node.
605 * It does this by stripping the manufacturer prefix (as delimited by a ',')
606 * from the first entry in the compatible list property.
608 * This routine returns 0 on success, <0 on failure.
610 int of_modalias_node(struct device_node
*node
, char *modalias
, int len
)
612 const char *compatible
, *p
;
615 compatible
= of_get_property(node
, "compatible", &cplen
);
616 if (!compatible
|| strlen(compatible
) > cplen
)
618 p
= strchr(compatible
, ',');
619 strlcpy(modalias
, p
? p
+ 1 : compatible
, len
);
622 EXPORT_SYMBOL_GPL(of_modalias_node
);
625 * of_find_node_by_phandle - Find a node given a phandle
626 * @handle: phandle of the node to find
628 * Returns a node pointer with refcount incremented, use
629 * of_node_put() on it when done.
631 struct device_node
*of_find_node_by_phandle(phandle handle
)
633 struct device_node
*np
;
635 read_lock(&devtree_lock
);
636 for (np
= allnodes
; np
; np
= np
->allnext
)
637 if (np
->phandle
== handle
)
640 read_unlock(&devtree_lock
);
643 EXPORT_SYMBOL(of_find_node_by_phandle
);
646 * of_property_read_u32_array - Find and read an array of 32 bit integers
649 * @np: device node from which the property value is to be read.
650 * @propname: name of the property to be searched.
651 * @out_value: pointer to return value, modified only if return value is 0.
653 * Search for a property in a device node and read 32-bit value(s) from
654 * it. Returns 0 on success, -EINVAL if the property does not exist,
655 * -ENODATA if property does not have a value, and -EOVERFLOW if the
656 * property data isn't large enough.
658 * The out_value is modified only if a valid u32 value can be decoded.
660 int of_property_read_u32_array(const struct device_node
*np
,
661 const char *propname
, u32
*out_values
,
664 struct property
*prop
= of_find_property(np
, propname
, NULL
);
671 if ((sz
* sizeof(*out_values
)) > prop
->length
)
676 *out_values
++ = be32_to_cpup(val
++);
679 EXPORT_SYMBOL_GPL(of_property_read_u32_array
);
682 * of_property_read_u64 - Find and read a 64 bit integer from a property
683 * @np: device node from which the property value is to be read.
684 * @propname: name of the property to be searched.
685 * @out_value: pointer to return value, modified only if return value is 0.
687 * Search for a property in a device node and read a 64-bit value from
688 * it. Returns 0 on success, -EINVAL if the property does not exist,
689 * -ENODATA if property does not have a value, and -EOVERFLOW if the
690 * property data isn't large enough.
692 * The out_value is modified only if a valid u64 value can be decoded.
694 int of_property_read_u64(const struct device_node
*np
, const char *propname
,
697 struct property
*prop
= of_find_property(np
, propname
, NULL
);
703 if (sizeof(*out_value
) > prop
->length
)
705 *out_value
= of_read_number(prop
->value
, 2);
708 EXPORT_SYMBOL_GPL(of_property_read_u64
);
711 * of_property_read_string - Find and read a string from a property
712 * @np: device node from which the property value is to be read.
713 * @propname: name of the property to be searched.
714 * @out_string: pointer to null terminated return string, modified only if
717 * Search for a property in a device tree node and retrieve a null
718 * terminated string value (pointer to data, not a copy). Returns 0 on
719 * success, -EINVAL if the property does not exist, -ENODATA if property
720 * does not have a value, and -EILSEQ if the string is not null-terminated
721 * within the length of the property data.
723 * The out_string pointer is modified only if a valid string can be decoded.
725 int of_property_read_string(struct device_node
*np
, const char *propname
,
726 const char **out_string
)
728 struct property
*prop
= of_find_property(np
, propname
, NULL
);
733 if (strnlen(prop
->value
, prop
->length
) >= prop
->length
)
735 *out_string
= prop
->value
;
738 EXPORT_SYMBOL_GPL(of_property_read_string
);
741 * of_property_read_string_index - Find and read a string from a multiple
743 * @np: device node from which the property value is to be read.
744 * @propname: name of the property to be searched.
745 * @index: index of the string in the list of strings
746 * @out_string: pointer to null terminated return string, modified only if
749 * Search for a property in a device tree node and retrieve a null
750 * terminated string value (pointer to data, not a copy) in the list of strings
751 * contained in that property.
752 * Returns 0 on success, -EINVAL if the property does not exist, -ENODATA if
753 * property does not have a value, and -EILSEQ if the string is not
754 * null-terminated within the length of the property data.
756 * The out_string pointer is modified only if a valid string can be decoded.
758 int of_property_read_string_index(struct device_node
*np
, const char *propname
,
759 int index
, const char **output
)
761 struct property
*prop
= of_find_property(np
, propname
, NULL
);
763 size_t l
= 0, total
= 0;
770 if (strnlen(prop
->value
, prop
->length
) >= prop
->length
)
775 for (i
= 0; total
< prop
->length
; total
+= l
, p
+= l
) {
784 EXPORT_SYMBOL_GPL(of_property_read_string_index
);
787 * of_property_match_string() - Find string in a list and return index
788 * @np: pointer to node containing string list property
789 * @propname: string list property name
790 * @string: pointer to string to search for in string list
792 * This function searches a string list property and returns the index
793 * of a specific string value.
795 int of_property_match_string(struct device_node
*np
, const char *propname
,
798 struct property
*prop
= of_find_property(np
, propname
, NULL
);
809 end
= p
+ prop
->length
;
811 for (i
= 0; p
< end
; i
++, p
+= l
) {
815 pr_debug("comparing %s with %s\n", string
, p
);
816 if (strcmp(string
, p
) == 0)
817 return i
; /* Found it; return index */
821 EXPORT_SYMBOL_GPL(of_property_match_string
);
824 * of_property_count_strings - Find and return the number of strings from a
825 * multiple strings property.
826 * @np: device node from which the property value is to be read.
827 * @propname: name of the property to be searched.
829 * Search for a property in a device tree node and retrieve the number of null
830 * terminated string contain in it. Returns the number of strings on
831 * success, -EINVAL if the property does not exist, -ENODATA if property
832 * does not have a value, and -EILSEQ if the string is not null-terminated
833 * within the length of the property data.
835 int of_property_count_strings(struct device_node
*np
, const char *propname
)
837 struct property
*prop
= of_find_property(np
, propname
, NULL
);
839 size_t l
= 0, total
= 0;
846 if (strnlen(prop
->value
, prop
->length
) >= prop
->length
)
851 for (i
= 0; total
< prop
->length
; total
+= l
, p
+= l
, i
++)
856 EXPORT_SYMBOL_GPL(of_property_count_strings
);
859 * of_parse_phandle - Resolve a phandle property to a device_node pointer
860 * @np: Pointer to device node holding phandle property
861 * @phandle_name: Name of property holding a phandle value
862 * @index: For properties holding a table of phandles, this is the index into
865 * Returns the device_node pointer with refcount incremented. Use
866 * of_node_put() on it when done.
869 of_parse_phandle(struct device_node
*np
, const char *phandle_name
, int index
)
871 const __be32
*phandle
;
874 phandle
= of_get_property(np
, phandle_name
, &size
);
875 if ((!phandle
) || (size
< sizeof(*phandle
) * (index
+ 1)))
878 return of_find_node_by_phandle(be32_to_cpup(phandle
+ index
));
880 EXPORT_SYMBOL(of_parse_phandle
);
883 * of_parse_phandle_with_args() - Find a node pointed by phandle in a list
884 * @np: pointer to a device tree node containing a list
885 * @list_name: property name that contains a list
886 * @cells_name: property name that specifies phandles' arguments count
887 * @index: index of a phandle to parse out
888 * @out_args: optional pointer to output arguments structure (will be filled)
890 * This function is useful to parse lists of phandles and their arguments.
891 * Returns 0 on success and fills out_args, on error returns appropriate
894 * Caller is responsible to call of_node_put() on the returned out_args->node
908 * list = <&phandle1 1 2 &phandle2 3>;
911 * To get a device_node of the `node2' node you may call this:
912 * of_parse_phandle_with_args(node3, "list", "#list-cells", 1, &args);
914 int of_parse_phandle_with_args(struct device_node
*np
, const char *list_name
,
915 const char *cells_name
, int index
,
916 struct of_phandle_args
*out_args
)
918 const __be32
*list
, *list_end
;
919 int size
, cur_index
= 0;
921 struct device_node
*node
= NULL
;
924 /* Retrieve the phandle list property */
925 list
= of_get_property(np
, list_name
, &size
);
928 list_end
= list
+ size
/ sizeof(*list
);
930 /* Loop over the phandles until all the requested entry is found */
931 while (list
< list_end
) {
935 * If phandle is 0, then it is an empty entry with no
936 * arguments. Skip forward to the next entry.
938 phandle
= be32_to_cpup(list
++);
941 * Find the provider node and parse the #*-cells
942 * property to determine the argument length
944 node
= of_find_node_by_phandle(phandle
);
946 pr_err("%s: could not find phandle\n",
950 if (of_property_read_u32(node
, cells_name
, &count
)) {
951 pr_err("%s: could not get %s for %s\n",
952 np
->full_name
, cells_name
,
958 * Make sure that the arguments actually fit in the
959 * remaining property data length
961 if (list
+ count
> list_end
) {
962 pr_err("%s: arguments longer than property\n",
969 * All of the error cases above bail out of the loop, so at
970 * this point, the parsing is successful. If the requested
971 * index matches, then fill the out_args structure and return,
972 * or return -ENOENT for an empty entry.
974 if (cur_index
== index
) {
980 if (WARN_ON(count
> MAX_PHANDLE_ARGS
))
981 count
= MAX_PHANDLE_ARGS
;
983 out_args
->args_count
= count
;
984 for (i
= 0; i
< count
; i
++)
985 out_args
->args
[i
] = be32_to_cpup(list
++);
996 /* Loop exited without finding a valid entry; return an error */
1001 EXPORT_SYMBOL(of_parse_phandle_with_args
);
1004 * prom_add_property - Add a property to a node
1006 int prom_add_property(struct device_node
*np
, struct property
*prop
)
1008 struct property
**next
;
1009 unsigned long flags
;
1012 write_lock_irqsave(&devtree_lock
, flags
);
1013 next
= &np
->properties
;
1015 if (strcmp(prop
->name
, (*next
)->name
) == 0) {
1016 /* duplicate ! don't insert it */
1017 write_unlock_irqrestore(&devtree_lock
, flags
);
1020 next
= &(*next
)->next
;
1023 write_unlock_irqrestore(&devtree_lock
, flags
);
1025 #ifdef CONFIG_PROC_DEVICETREE
1026 /* try to add to proc as well if it was initialized */
1028 proc_device_tree_add_prop(np
->pde
, prop
);
1029 #endif /* CONFIG_PROC_DEVICETREE */
1035 * prom_remove_property - Remove a property from a node.
1037 * Note that we don't actually remove it, since we have given out
1038 * who-knows-how-many pointers to the data using get-property.
1039 * Instead we just move the property to the "dead properties"
1040 * list, so it won't be found any more.
1042 int prom_remove_property(struct device_node
*np
, struct property
*prop
)
1044 struct property
**next
;
1045 unsigned long flags
;
1048 write_lock_irqsave(&devtree_lock
, flags
);
1049 next
= &np
->properties
;
1051 if (*next
== prop
) {
1052 /* found the node */
1054 prop
->next
= np
->deadprops
;
1055 np
->deadprops
= prop
;
1059 next
= &(*next
)->next
;
1061 write_unlock_irqrestore(&devtree_lock
, flags
);
1066 #ifdef CONFIG_PROC_DEVICETREE
1067 /* try to remove the proc node as well */
1069 proc_device_tree_remove_prop(np
->pde
, prop
);
1070 #endif /* CONFIG_PROC_DEVICETREE */
1076 * prom_update_property - Update a property in a node.
1078 * Note that we don't actually remove it, since we have given out
1079 * who-knows-how-many pointers to the data using get-property.
1080 * Instead we just move the property to the "dead properties" list,
1081 * and add the new property to the property list
1083 int prom_update_property(struct device_node
*np
,
1084 struct property
*newprop
,
1085 struct property
*oldprop
)
1087 struct property
**next
;
1088 unsigned long flags
;
1091 write_lock_irqsave(&devtree_lock
, flags
);
1092 next
= &np
->properties
;
1094 if (*next
== oldprop
) {
1095 /* found the node */
1096 newprop
->next
= oldprop
->next
;
1098 oldprop
->next
= np
->deadprops
;
1099 np
->deadprops
= oldprop
;
1103 next
= &(*next
)->next
;
1105 write_unlock_irqrestore(&devtree_lock
, flags
);
1110 #ifdef CONFIG_PROC_DEVICETREE
1111 /* try to add to proc as well if it was initialized */
1113 proc_device_tree_update_prop(np
->pde
, newprop
, oldprop
);
1114 #endif /* CONFIG_PROC_DEVICETREE */
1119 #if defined(CONFIG_OF_DYNAMIC)
1121 * Support for dynamic device trees.
1123 * On some platforms, the device tree can be manipulated at runtime.
1124 * The routines in this section support adding, removing and changing
1125 * device tree nodes.
1129 * of_attach_node - Plug a device node into the tree and global list.
1131 void of_attach_node(struct device_node
*np
)
1133 unsigned long flags
;
1135 write_lock_irqsave(&devtree_lock
, flags
);
1136 np
->sibling
= np
->parent
->child
;
1137 np
->allnext
= allnodes
;
1138 np
->parent
->child
= np
;
1140 write_unlock_irqrestore(&devtree_lock
, flags
);
1144 * of_detach_node - "Unplug" a node from the device tree.
1146 * The caller must hold a reference to the node. The memory associated with
1147 * the node is not freed until its refcount goes to zero.
1149 void of_detach_node(struct device_node
*np
)
1151 struct device_node
*parent
;
1152 unsigned long flags
;
1154 write_lock_irqsave(&devtree_lock
, flags
);
1156 parent
= np
->parent
;
1161 allnodes
= np
->allnext
;
1163 struct device_node
*prev
;
1164 for (prev
= allnodes
;
1165 prev
->allnext
!= np
;
1166 prev
= prev
->allnext
)
1168 prev
->allnext
= np
->allnext
;
1171 if (parent
->child
== np
)
1172 parent
->child
= np
->sibling
;
1174 struct device_node
*prevsib
;
1175 for (prevsib
= np
->parent
->child
;
1176 prevsib
->sibling
!= np
;
1177 prevsib
= prevsib
->sibling
)
1179 prevsib
->sibling
= np
->sibling
;
1182 of_node_set_flag(np
, OF_DETACHED
);
1185 write_unlock_irqrestore(&devtree_lock
, flags
);
1187 #endif /* defined(CONFIG_OF_DYNAMIC) */
1189 static void of_alias_add(struct alias_prop
*ap
, struct device_node
*np
,
1190 int id
, const char *stem
, int stem_len
)
1194 strncpy(ap
->stem
, stem
, stem_len
);
1195 ap
->stem
[stem_len
] = 0;
1196 list_add_tail(&ap
->link
, &aliases_lookup
);
1197 pr_debug("adding DT alias:%s: stem=%s id=%i node=%s\n",
1198 ap
->alias
, ap
->stem
, ap
->id
, np
? np
->full_name
: NULL
);
1202 * of_alias_scan - Scan all properties of 'aliases' node
1204 * The function scans all the properties of 'aliases' node and populate
1205 * the the global lookup table with the properties. It returns the
1206 * number of alias_prop found, or error code in error case.
1208 * @dt_alloc: An allocator that provides a virtual address to memory
1209 * for the resulting tree
1211 void of_alias_scan(void * (*dt_alloc
)(u64 size
, u64 align
))
1213 struct property
*pp
;
1215 of_chosen
= of_find_node_by_path("/chosen");
1216 if (of_chosen
== NULL
)
1217 of_chosen
= of_find_node_by_path("/chosen@0");
1218 of_aliases
= of_find_node_by_path("/aliases");
1222 for_each_property_of_node(of_aliases
, pp
) {
1223 const char *start
= pp
->name
;
1224 const char *end
= start
+ strlen(start
);
1225 struct device_node
*np
;
1226 struct alias_prop
*ap
;
1229 /* Skip those we do not want to proceed */
1230 if (!strcmp(pp
->name
, "name") ||
1231 !strcmp(pp
->name
, "phandle") ||
1232 !strcmp(pp
->name
, "linux,phandle"))
1235 np
= of_find_node_by_path(pp
->value
);
1239 /* walk the alias backwards to extract the id and work out
1240 * the 'stem' string */
1241 while (isdigit(*(end
-1)) && end
> start
)
1245 if (kstrtoint(end
, 10, &id
) < 0)
1248 /* Allocate an alias_prop with enough space for the stem */
1249 ap
= dt_alloc(sizeof(*ap
) + len
+ 1, 4);
1253 of_alias_add(ap
, np
, id
, start
, len
);
1258 * of_alias_get_id - Get alias id for the given device_node
1259 * @np: Pointer to the given device_node
1260 * @stem: Alias stem of the given device_node
1262 * The function travels the lookup table to get alias id for the given
1263 * device_node and alias stem. It returns the alias id if find it.
1265 int of_alias_get_id(struct device_node
*np
, const char *stem
)
1267 struct alias_prop
*app
;
1270 mutex_lock(&of_aliases_mutex
);
1271 list_for_each_entry(app
, &aliases_lookup
, link
) {
1272 if (strcmp(app
->stem
, stem
) != 0)
1275 if (np
== app
->np
) {
1280 mutex_unlock(&of_aliases_mutex
);
1284 EXPORT_SYMBOL_GPL(of_alias_get_id
);
1286 const __be32
*of_prop_next_u32(struct property
*prop
, const __be32
*cur
,
1289 const void *curv
= cur
;
1299 curv
+= sizeof(*cur
);
1300 if (curv
>= prop
->value
+ prop
->length
)
1304 *pu
= be32_to_cpup(curv
);
1307 EXPORT_SYMBOL_GPL(of_prop_next_u32
);
1309 const char *of_prop_next_string(struct property
*prop
, const char *cur
)
1311 const void *curv
= cur
;
1319 curv
+= strlen(cur
) + 1;
1320 if (curv
>= prop
->value
+ prop
->length
)
1325 EXPORT_SYMBOL_GPL(of_prop_next_string
);