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.
14 * This program is free software; you can redistribute it and/or
15 * modify it under the terms of the GNU General Public License
16 * as published by the Free Software Foundation; either version
17 * 2 of the License, or (at your option) any later version.
19 #include <linux/module.h>
21 #include <linux/spinlock.h>
23 struct device_node
*allnodes
;
25 /* use when traversing tree through the allnext, child, sibling,
26 * or parent members of struct device_node.
28 DEFINE_RWLOCK(devtree_lock
);
30 int of_n_addr_cells(struct device_node
*np
)
37 ip
= of_get_property(np
, "#address-cells", NULL
);
41 /* No #address-cells property for the root node */
42 return OF_ROOT_NODE_ADDR_CELLS_DEFAULT
;
44 EXPORT_SYMBOL(of_n_addr_cells
);
46 int of_n_size_cells(struct device_node
*np
)
53 ip
= of_get_property(np
, "#size-cells", NULL
);
57 /* No #size-cells property for the root node */
58 return OF_ROOT_NODE_SIZE_CELLS_DEFAULT
;
60 EXPORT_SYMBOL(of_n_size_cells
);
62 struct property
*of_find_property(const struct device_node
*np
,
68 read_lock(&devtree_lock
);
69 for (pp
= np
->properties
; pp
!= 0; pp
= pp
->next
) {
70 if (of_prop_cmp(pp
->name
, name
) == 0) {
76 read_unlock(&devtree_lock
);
80 EXPORT_SYMBOL(of_find_property
);
83 * Find a property with a given name for a given node
84 * and return the value.
86 const void *of_get_property(const struct device_node
*np
, const char *name
,
89 struct property
*pp
= of_find_property(np
, name
, lenp
);
91 return pp
? pp
->value
: NULL
;
93 EXPORT_SYMBOL(of_get_property
);
95 /** Checks if the given "compat" string matches one of the strings in
96 * the device's "compatible" property
98 int of_device_is_compatible(const struct device_node
*device
,
104 cp
= of_get_property(device
, "compatible", &cplen
);
108 if (of_compat_cmp(cp
, compat
, strlen(compat
)) == 0)
117 EXPORT_SYMBOL(of_device_is_compatible
);
120 * of_get_parent - Get a node's parent if any
121 * @node: Node to get parent
123 * Returns a node pointer with refcount incremented, use
124 * of_node_put() on it when done.
126 struct device_node
*of_get_parent(const struct device_node
*node
)
128 struct device_node
*np
;
133 read_lock(&devtree_lock
);
134 np
= of_node_get(node
->parent
);
135 read_unlock(&devtree_lock
);
138 EXPORT_SYMBOL(of_get_parent
);
141 * of_get_next_parent - Iterate to a node's parent
142 * @node: Node to get parent of
144 * This is like of_get_parent() except that it drops the
145 * refcount on the passed node, making it suitable for iterating
146 * through a node's parents.
148 * Returns a node pointer with refcount incremented, use
149 * of_node_put() on it when done.
151 struct device_node
*of_get_next_parent(struct device_node
*node
)
153 struct device_node
*parent
;
158 read_lock(&devtree_lock
);
159 parent
= of_node_get(node
->parent
);
161 read_unlock(&devtree_lock
);
166 * of_get_next_child - Iterate a node childs
168 * @prev: previous child of the parent node, or NULL to get first
170 * Returns a node pointer with refcount incremented, use
171 * of_node_put() on it when done.
173 struct device_node
*of_get_next_child(const struct device_node
*node
,
174 struct device_node
*prev
)
176 struct device_node
*next
;
178 read_lock(&devtree_lock
);
179 next
= prev
? prev
->sibling
: node
->child
;
180 for (; next
; next
= next
->sibling
)
181 if (of_node_get(next
))
184 read_unlock(&devtree_lock
);
187 EXPORT_SYMBOL(of_get_next_child
);
190 * of_find_node_by_path - Find a node matching a full OF path
191 * @path: The full path to match
193 * Returns a node pointer with refcount incremented, use
194 * of_node_put() on it when done.
196 struct device_node
*of_find_node_by_path(const char *path
)
198 struct device_node
*np
= allnodes
;
200 read_lock(&devtree_lock
);
201 for (; np
; np
= np
->allnext
) {
202 if (np
->full_name
&& (of_node_cmp(np
->full_name
, path
) == 0)
206 read_unlock(&devtree_lock
);
209 EXPORT_SYMBOL(of_find_node_by_path
);
212 * of_find_node_by_name - Find a node by its "name" property
213 * @from: The node to start searching from or NULL, the node
214 * you pass will not be searched, only the next one
215 * will; typically, you pass what the previous call
216 * returned. of_node_put() will be called on it
217 * @name: The name string to match against
219 * Returns a node pointer with refcount incremented, use
220 * of_node_put() on it when done.
222 struct device_node
*of_find_node_by_name(struct device_node
*from
,
225 struct device_node
*np
;
227 read_lock(&devtree_lock
);
228 np
= from
? from
->allnext
: allnodes
;
229 for (; np
; np
= np
->allnext
)
230 if (np
->name
&& (of_node_cmp(np
->name
, name
) == 0)
234 read_unlock(&devtree_lock
);
237 EXPORT_SYMBOL(of_find_node_by_name
);
240 * of_find_node_by_type - Find a node by its "device_type" property
241 * @from: The node to start searching from, or NULL to start searching
242 * the entire device tree. The node you pass will not be
243 * searched, only the next one will; typically, you pass
244 * what the previous call returned. of_node_put() will be
245 * called on from for you.
246 * @type: The type string to match against
248 * Returns a node pointer with refcount incremented, use
249 * of_node_put() on it when done.
251 struct device_node
*of_find_node_by_type(struct device_node
*from
,
254 struct device_node
*np
;
256 read_lock(&devtree_lock
);
257 np
= from
? from
->allnext
: allnodes
;
258 for (; np
; np
= np
->allnext
)
259 if (np
->type
&& (of_node_cmp(np
->type
, type
) == 0)
263 read_unlock(&devtree_lock
);
266 EXPORT_SYMBOL(of_find_node_by_type
);
269 * of_find_compatible_node - Find a node based on type and one of the
270 * tokens in its "compatible" property
271 * @from: The node to start searching from or NULL, the node
272 * you pass will not be searched, only the next one
273 * will; typically, you pass what the previous call
274 * returned. of_node_put() will be called on it
275 * @type: The type string to match "device_type" or NULL to ignore
276 * @compatible: The string to match to one of the tokens in the device
279 * Returns a node pointer with refcount incremented, use
280 * of_node_put() on it when done.
282 struct device_node
*of_find_compatible_node(struct device_node
*from
,
283 const char *type
, const char *compatible
)
285 struct device_node
*np
;
287 read_lock(&devtree_lock
);
288 np
= from
? from
->allnext
: allnodes
;
289 for (; np
; np
= np
->allnext
) {
291 && !(np
->type
&& (of_node_cmp(np
->type
, type
) == 0)))
293 if (of_device_is_compatible(np
, compatible
) && of_node_get(np
))
297 read_unlock(&devtree_lock
);
300 EXPORT_SYMBOL(of_find_compatible_node
);
303 * of_match_node - Tell if an device_node has a matching of_match structure
304 * @matches: array of of device match structures to search in
305 * @node: the of device structure to match against
307 * Low level utility function used by device matching.
309 const struct of_device_id
*of_match_node(const struct of_device_id
*matches
,
310 const struct device_node
*node
)
312 while (matches
->name
[0] || matches
->type
[0] || matches
->compatible
[0]) {
314 if (matches
->name
[0])
316 && !strcmp(matches
->name
, node
->name
);
317 if (matches
->type
[0])
319 && !strcmp(matches
->type
, node
->type
);
320 if (matches
->compatible
[0])
321 match
&= of_device_is_compatible(node
,
322 matches
->compatible
);
329 EXPORT_SYMBOL(of_match_node
);
332 * of_find_matching_node - Find a node based on an of_device_id match
334 * @from: The node to start searching from or NULL, the node
335 * you pass will not be searched, only the next one
336 * will; typically, you pass what the previous call
337 * returned. of_node_put() will be called on it
338 * @matches: array of of device match structures to search in
340 * Returns a node pointer with refcount incremented, use
341 * of_node_put() on it when done.
343 struct device_node
*of_find_matching_node(struct device_node
*from
,
344 const struct of_device_id
*matches
)
346 struct device_node
*np
;
348 read_lock(&devtree_lock
);
349 np
= from
? from
->allnext
: allnodes
;
350 for (; np
; np
= np
->allnext
) {
351 if (of_match_node(matches
, np
) && of_node_get(np
))
355 read_unlock(&devtree_lock
);
358 EXPORT_SYMBOL(of_find_matching_node
);