Stephen Rothwell | 97e873e | 2007-05-01 16:26:07 +1000 | [diff] [blame] | 1 | /* |
| 2 | * Procedures for creating, accessing and interpreting the device tree. |
| 3 | * |
| 4 | * Paul Mackerras August 1996. |
| 5 | * Copyright (C) 1996-2005 Paul Mackerras. |
| 6 | * |
| 7 | * Adapted for 64bit PowerPC by Dave Engebretsen and Peter Bergner. |
| 8 | * {engebret|bergner}@us.ibm.com |
| 9 | * |
| 10 | * Adapted for sparc and sparc64 by David S. Miller davem@davemloft.net |
| 11 | * |
Grant Likely | e91edcf | 2009-10-15 10:58:09 -0600 | [diff] [blame] | 12 | * Reconsolidated from arch/x/kernel/prom.c by Stephen Rothwell and |
| 13 | * Grant Likely. |
Stephen Rothwell | 97e873e | 2007-05-01 16:26:07 +1000 | [diff] [blame] | 14 | * |
| 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. |
| 19 | */ |
| 20 | #include <linux/module.h> |
| 21 | #include <linux/of.h> |
Stephen Rothwell | 581b605 | 2007-04-24 16:46:53 +1000 | [diff] [blame] | 22 | #include <linux/spinlock.h> |
Tejun Heo | 5a0e3ad | 2010-03-24 17:04:11 +0900 | [diff] [blame] | 23 | #include <linux/slab.h> |
Jeremy Kerr | a9f2f63 | 2010-02-01 21:34:14 -0700 | [diff] [blame] | 24 | #include <linux/proc_fs.h> |
Stephen Rothwell | 581b605 | 2007-04-24 16:46:53 +1000 | [diff] [blame] | 25 | |
Stephen Rothwell | 1ef4d42 | 2007-04-24 17:57:33 +1000 | [diff] [blame] | 26 | struct device_node *allnodes; |
Grant Likely | fc0bdae | 2010-02-14 07:13:55 -0700 | [diff] [blame] | 27 | struct device_node *of_chosen; |
Stephen Rothwell | 1ef4d42 | 2007-04-24 17:57:33 +1000 | [diff] [blame] | 28 | |
Stephen Rothwell | 581b605 | 2007-04-24 16:46:53 +1000 | [diff] [blame] | 29 | /* use when traversing tree through the allnext, child, sibling, |
| 30 | * or parent members of struct device_node. |
| 31 | */ |
| 32 | DEFINE_RWLOCK(devtree_lock); |
Stephen Rothwell | 97e873e | 2007-05-01 16:26:07 +1000 | [diff] [blame] | 33 | |
| 34 | int of_n_addr_cells(struct device_node *np) |
| 35 | { |
Jeremy Kerr | a9fadee | 2010-10-10 21:24:10 -0600 | [diff] [blame] | 36 | const __be32 *ip; |
Stephen Rothwell | 97e873e | 2007-05-01 16:26:07 +1000 | [diff] [blame] | 37 | |
| 38 | do { |
| 39 | if (np->parent) |
| 40 | np = np->parent; |
| 41 | ip = of_get_property(np, "#address-cells", NULL); |
| 42 | if (ip) |
Jeremy Kerr | 3371488 | 2010-01-30 01:45:26 -0700 | [diff] [blame] | 43 | return be32_to_cpup(ip); |
Stephen Rothwell | 97e873e | 2007-05-01 16:26:07 +1000 | [diff] [blame] | 44 | } while (np->parent); |
| 45 | /* No #address-cells property for the root node */ |
| 46 | return OF_ROOT_NODE_ADDR_CELLS_DEFAULT; |
| 47 | } |
| 48 | EXPORT_SYMBOL(of_n_addr_cells); |
| 49 | |
| 50 | int of_n_size_cells(struct device_node *np) |
| 51 | { |
Jeremy Kerr | a9fadee | 2010-10-10 21:24:10 -0600 | [diff] [blame] | 52 | const __be32 *ip; |
Stephen Rothwell | 97e873e | 2007-05-01 16:26:07 +1000 | [diff] [blame] | 53 | |
| 54 | do { |
| 55 | if (np->parent) |
| 56 | np = np->parent; |
| 57 | ip = of_get_property(np, "#size-cells", NULL); |
| 58 | if (ip) |
Jeremy Kerr | 3371488 | 2010-01-30 01:45:26 -0700 | [diff] [blame] | 59 | return be32_to_cpup(ip); |
Stephen Rothwell | 97e873e | 2007-05-01 16:26:07 +1000 | [diff] [blame] | 60 | } while (np->parent); |
| 61 | /* No #size-cells property for the root node */ |
| 62 | return OF_ROOT_NODE_SIZE_CELLS_DEFAULT; |
| 63 | } |
| 64 | EXPORT_SYMBOL(of_n_size_cells); |
| 65 | |
Grant Likely | 923f7e3 | 2010-01-28 13:52:53 -0700 | [diff] [blame] | 66 | #if !defined(CONFIG_SPARC) /* SPARC doesn't do ref counting (yet) */ |
| 67 | /** |
| 68 | * of_node_get - Increment refcount of a node |
| 69 | * @node: Node to inc refcount, NULL is supported to |
| 70 | * simplify writing of callers |
| 71 | * |
| 72 | * Returns node. |
| 73 | */ |
| 74 | struct device_node *of_node_get(struct device_node *node) |
| 75 | { |
| 76 | if (node) |
| 77 | kref_get(&node->kref); |
| 78 | return node; |
| 79 | } |
| 80 | EXPORT_SYMBOL(of_node_get); |
| 81 | |
| 82 | static inline struct device_node *kref_to_device_node(struct kref *kref) |
| 83 | { |
| 84 | return container_of(kref, struct device_node, kref); |
| 85 | } |
| 86 | |
| 87 | /** |
| 88 | * of_node_release - release a dynamically allocated node |
| 89 | * @kref: kref element of the node to be released |
| 90 | * |
| 91 | * In of_node_put() this function is passed to kref_put() |
| 92 | * as the destructor. |
| 93 | */ |
| 94 | static void of_node_release(struct kref *kref) |
| 95 | { |
| 96 | struct device_node *node = kref_to_device_node(kref); |
| 97 | struct property *prop = node->properties; |
| 98 | |
| 99 | /* We should never be releasing nodes that haven't been detached. */ |
| 100 | if (!of_node_check_flag(node, OF_DETACHED)) { |
| 101 | pr_err("ERROR: Bad of_node_put() on %s\n", node->full_name); |
| 102 | dump_stack(); |
| 103 | kref_init(&node->kref); |
| 104 | return; |
| 105 | } |
| 106 | |
| 107 | if (!of_node_check_flag(node, OF_DYNAMIC)) |
| 108 | return; |
| 109 | |
| 110 | while (prop) { |
| 111 | struct property *next = prop->next; |
| 112 | kfree(prop->name); |
| 113 | kfree(prop->value); |
| 114 | kfree(prop); |
| 115 | prop = next; |
| 116 | |
| 117 | if (!prop) { |
| 118 | prop = node->deadprops; |
| 119 | node->deadprops = NULL; |
| 120 | } |
| 121 | } |
| 122 | kfree(node->full_name); |
| 123 | kfree(node->data); |
| 124 | kfree(node); |
| 125 | } |
| 126 | |
| 127 | /** |
| 128 | * of_node_put - Decrement refcount of a node |
| 129 | * @node: Node to dec refcount, NULL is supported to |
| 130 | * simplify writing of callers |
| 131 | * |
| 132 | */ |
| 133 | void of_node_put(struct device_node *node) |
| 134 | { |
| 135 | if (node) |
| 136 | kref_put(&node->kref, of_node_release); |
| 137 | } |
| 138 | EXPORT_SYMBOL(of_node_put); |
| 139 | #endif /* !CONFIG_SPARC */ |
| 140 | |
Stephen Rothwell | 581b605 | 2007-04-24 16:46:53 +1000 | [diff] [blame] | 141 | struct property *of_find_property(const struct device_node *np, |
| 142 | const char *name, |
| 143 | int *lenp) |
| 144 | { |
| 145 | struct property *pp; |
| 146 | |
Timur Tabi | 64e4566 | 2008-05-08 05:19:59 +1000 | [diff] [blame] | 147 | if (!np) |
| 148 | return NULL; |
| 149 | |
Stephen Rothwell | 581b605 | 2007-04-24 16:46:53 +1000 | [diff] [blame] | 150 | read_lock(&devtree_lock); |
| 151 | for (pp = np->properties; pp != 0; pp = pp->next) { |
| 152 | if (of_prop_cmp(pp->name, name) == 0) { |
| 153 | if (lenp != 0) |
| 154 | *lenp = pp->length; |
| 155 | break; |
| 156 | } |
| 157 | } |
| 158 | read_unlock(&devtree_lock); |
| 159 | |
| 160 | return pp; |
| 161 | } |
| 162 | EXPORT_SYMBOL(of_find_property); |
| 163 | |
Grant Likely | e91edcf | 2009-10-15 10:58:09 -0600 | [diff] [blame] | 164 | /** |
| 165 | * of_find_all_nodes - Get next node in global list |
| 166 | * @prev: Previous node or NULL to start iteration |
| 167 | * of_node_put() will be called on it |
| 168 | * |
| 169 | * Returns a node pointer with refcount incremented, use |
| 170 | * of_node_put() on it when done. |
| 171 | */ |
| 172 | struct device_node *of_find_all_nodes(struct device_node *prev) |
| 173 | { |
| 174 | struct device_node *np; |
| 175 | |
| 176 | read_lock(&devtree_lock); |
| 177 | np = prev ? prev->allnext : allnodes; |
| 178 | for (; np != NULL; np = np->allnext) |
| 179 | if (of_node_get(np)) |
| 180 | break; |
| 181 | of_node_put(prev); |
| 182 | read_unlock(&devtree_lock); |
| 183 | return np; |
| 184 | } |
| 185 | EXPORT_SYMBOL(of_find_all_nodes); |
| 186 | |
Stephen Rothwell | 97e873e | 2007-05-01 16:26:07 +1000 | [diff] [blame] | 187 | /* |
| 188 | * Find a property with a given name for a given node |
| 189 | * and return the value. |
| 190 | */ |
| 191 | const void *of_get_property(const struct device_node *np, const char *name, |
| 192 | int *lenp) |
| 193 | { |
| 194 | struct property *pp = of_find_property(np, name, lenp); |
| 195 | |
| 196 | return pp ? pp->value : NULL; |
| 197 | } |
| 198 | EXPORT_SYMBOL(of_get_property); |
Stephen Rothwell | 0081cbc | 2007-05-01 16:29:19 +1000 | [diff] [blame] | 199 | |
| 200 | /** Checks if the given "compat" string matches one of the strings in |
| 201 | * the device's "compatible" property |
| 202 | */ |
| 203 | int of_device_is_compatible(const struct device_node *device, |
| 204 | const char *compat) |
| 205 | { |
| 206 | const char* cp; |
| 207 | int cplen, l; |
| 208 | |
| 209 | cp = of_get_property(device, "compatible", &cplen); |
| 210 | if (cp == NULL) |
| 211 | return 0; |
| 212 | while (cplen > 0) { |
| 213 | if (of_compat_cmp(cp, compat, strlen(compat)) == 0) |
| 214 | return 1; |
| 215 | l = strlen(cp) + 1; |
| 216 | cp += l; |
| 217 | cplen -= l; |
| 218 | } |
| 219 | |
| 220 | return 0; |
| 221 | } |
| 222 | EXPORT_SYMBOL(of_device_is_compatible); |
Stephen Rothwell | e679c5f | 2007-04-24 17:16:16 +1000 | [diff] [blame] | 223 | |
| 224 | /** |
Grant Likely | 71a157e | 2010-02-01 21:34:14 -0700 | [diff] [blame] | 225 | * of_machine_is_compatible - Test root of device tree for a given compatible value |
Grant Likely | 1f43cfb | 2010-01-28 13:47:25 -0700 | [diff] [blame] | 226 | * @compat: compatible string to look for in root node's compatible property. |
| 227 | * |
| 228 | * Returns true if the root node has the given value in its |
| 229 | * compatible property. |
| 230 | */ |
Grant Likely | 71a157e | 2010-02-01 21:34:14 -0700 | [diff] [blame] | 231 | int of_machine_is_compatible(const char *compat) |
Grant Likely | 1f43cfb | 2010-01-28 13:47:25 -0700 | [diff] [blame] | 232 | { |
| 233 | struct device_node *root; |
| 234 | int rc = 0; |
| 235 | |
| 236 | root = of_find_node_by_path("/"); |
| 237 | if (root) { |
| 238 | rc = of_device_is_compatible(root, compat); |
| 239 | of_node_put(root); |
| 240 | } |
| 241 | return rc; |
| 242 | } |
Grant Likely | 71a157e | 2010-02-01 21:34:14 -0700 | [diff] [blame] | 243 | EXPORT_SYMBOL(of_machine_is_compatible); |
Grant Likely | 1f43cfb | 2010-01-28 13:47:25 -0700 | [diff] [blame] | 244 | |
| 245 | /** |
Josh Boyer | 834d97d | 2008-03-27 00:33:14 +1100 | [diff] [blame] | 246 | * of_device_is_available - check if a device is available for use |
| 247 | * |
| 248 | * @device: Node to check for availability |
| 249 | * |
| 250 | * Returns 1 if the status property is absent or set to "okay" or "ok", |
| 251 | * 0 otherwise |
| 252 | */ |
| 253 | int of_device_is_available(const struct device_node *device) |
| 254 | { |
| 255 | const char *status; |
| 256 | int statlen; |
| 257 | |
| 258 | status = of_get_property(device, "status", &statlen); |
| 259 | if (status == NULL) |
| 260 | return 1; |
| 261 | |
| 262 | if (statlen > 0) { |
| 263 | if (!strcmp(status, "okay") || !strcmp(status, "ok")) |
| 264 | return 1; |
| 265 | } |
| 266 | |
| 267 | return 0; |
| 268 | } |
| 269 | EXPORT_SYMBOL(of_device_is_available); |
| 270 | |
| 271 | /** |
Stephen Rothwell | e679c5f | 2007-04-24 17:16:16 +1000 | [diff] [blame] | 272 | * of_get_parent - Get a node's parent if any |
| 273 | * @node: Node to get parent |
| 274 | * |
| 275 | * Returns a node pointer with refcount incremented, use |
| 276 | * of_node_put() on it when done. |
| 277 | */ |
| 278 | struct device_node *of_get_parent(const struct device_node *node) |
| 279 | { |
| 280 | struct device_node *np; |
| 281 | |
| 282 | if (!node) |
| 283 | return NULL; |
| 284 | |
| 285 | read_lock(&devtree_lock); |
| 286 | np = of_node_get(node->parent); |
| 287 | read_unlock(&devtree_lock); |
| 288 | return np; |
| 289 | } |
| 290 | EXPORT_SYMBOL(of_get_parent); |
Stephen Rothwell | d1cd355 | 2007-04-24 17:21:29 +1000 | [diff] [blame] | 291 | |
| 292 | /** |
Michael Ellerman | f4eb010 | 2007-10-26 16:54:31 +1000 | [diff] [blame] | 293 | * of_get_next_parent - Iterate to a node's parent |
| 294 | * @node: Node to get parent of |
| 295 | * |
| 296 | * This is like of_get_parent() except that it drops the |
| 297 | * refcount on the passed node, making it suitable for iterating |
| 298 | * through a node's parents. |
| 299 | * |
| 300 | * Returns a node pointer with refcount incremented, use |
| 301 | * of_node_put() on it when done. |
| 302 | */ |
| 303 | struct device_node *of_get_next_parent(struct device_node *node) |
| 304 | { |
| 305 | struct device_node *parent; |
| 306 | |
| 307 | if (!node) |
| 308 | return NULL; |
| 309 | |
| 310 | read_lock(&devtree_lock); |
| 311 | parent = of_node_get(node->parent); |
| 312 | of_node_put(node); |
| 313 | read_unlock(&devtree_lock); |
| 314 | return parent; |
| 315 | } |
| 316 | |
| 317 | /** |
Stephen Rothwell | d1cd355 | 2007-04-24 17:21:29 +1000 | [diff] [blame] | 318 | * of_get_next_child - Iterate a node childs |
| 319 | * @node: parent node |
| 320 | * @prev: previous child of the parent node, or NULL to get first |
| 321 | * |
| 322 | * Returns a node pointer with refcount incremented, use |
| 323 | * of_node_put() on it when done. |
| 324 | */ |
| 325 | struct device_node *of_get_next_child(const struct device_node *node, |
| 326 | struct device_node *prev) |
| 327 | { |
| 328 | struct device_node *next; |
| 329 | |
| 330 | read_lock(&devtree_lock); |
| 331 | next = prev ? prev->sibling : node->child; |
| 332 | for (; next; next = next->sibling) |
| 333 | if (of_node_get(next)) |
| 334 | break; |
| 335 | of_node_put(prev); |
| 336 | read_unlock(&devtree_lock); |
| 337 | return next; |
| 338 | } |
| 339 | EXPORT_SYMBOL(of_get_next_child); |
Stephen Rothwell | 1ef4d42 | 2007-04-24 17:57:33 +1000 | [diff] [blame] | 340 | |
| 341 | /** |
| 342 | * of_find_node_by_path - Find a node matching a full OF path |
| 343 | * @path: The full path to match |
| 344 | * |
| 345 | * Returns a node pointer with refcount incremented, use |
| 346 | * of_node_put() on it when done. |
| 347 | */ |
| 348 | struct device_node *of_find_node_by_path(const char *path) |
| 349 | { |
| 350 | struct device_node *np = allnodes; |
| 351 | |
| 352 | read_lock(&devtree_lock); |
| 353 | for (; np; np = np->allnext) { |
| 354 | if (np->full_name && (of_node_cmp(np->full_name, path) == 0) |
| 355 | && of_node_get(np)) |
| 356 | break; |
| 357 | } |
| 358 | read_unlock(&devtree_lock); |
| 359 | return np; |
| 360 | } |
| 361 | EXPORT_SYMBOL(of_find_node_by_path); |
| 362 | |
| 363 | /** |
| 364 | * of_find_node_by_name - Find a node by its "name" property |
| 365 | * @from: The node to start searching from or NULL, the node |
| 366 | * you pass will not be searched, only the next one |
| 367 | * will; typically, you pass what the previous call |
| 368 | * returned. of_node_put() will be called on it |
| 369 | * @name: The name string to match against |
| 370 | * |
| 371 | * Returns a node pointer with refcount incremented, use |
| 372 | * of_node_put() on it when done. |
| 373 | */ |
| 374 | struct device_node *of_find_node_by_name(struct device_node *from, |
| 375 | const char *name) |
| 376 | { |
| 377 | struct device_node *np; |
| 378 | |
| 379 | read_lock(&devtree_lock); |
| 380 | np = from ? from->allnext : allnodes; |
| 381 | for (; np; np = np->allnext) |
| 382 | if (np->name && (of_node_cmp(np->name, name) == 0) |
| 383 | && of_node_get(np)) |
| 384 | break; |
| 385 | of_node_put(from); |
| 386 | read_unlock(&devtree_lock); |
| 387 | return np; |
| 388 | } |
| 389 | EXPORT_SYMBOL(of_find_node_by_name); |
| 390 | |
| 391 | /** |
| 392 | * of_find_node_by_type - Find a node by its "device_type" property |
| 393 | * @from: The node to start searching from, or NULL to start searching |
| 394 | * the entire device tree. The node you pass will not be |
| 395 | * searched, only the next one will; typically, you pass |
| 396 | * what the previous call returned. of_node_put() will be |
| 397 | * called on from for you. |
| 398 | * @type: The type string to match against |
| 399 | * |
| 400 | * Returns a node pointer with refcount incremented, use |
| 401 | * of_node_put() on it when done. |
| 402 | */ |
| 403 | struct device_node *of_find_node_by_type(struct device_node *from, |
| 404 | const char *type) |
| 405 | { |
| 406 | struct device_node *np; |
| 407 | |
| 408 | read_lock(&devtree_lock); |
| 409 | np = from ? from->allnext : allnodes; |
| 410 | for (; np; np = np->allnext) |
| 411 | if (np->type && (of_node_cmp(np->type, type) == 0) |
| 412 | && of_node_get(np)) |
| 413 | break; |
| 414 | of_node_put(from); |
| 415 | read_unlock(&devtree_lock); |
| 416 | return np; |
| 417 | } |
| 418 | EXPORT_SYMBOL(of_find_node_by_type); |
| 419 | |
| 420 | /** |
| 421 | * of_find_compatible_node - Find a node based on type and one of the |
| 422 | * tokens in its "compatible" property |
| 423 | * @from: The node to start searching from or NULL, the node |
| 424 | * you pass will not be searched, only the next one |
| 425 | * will; typically, you pass what the previous call |
| 426 | * returned. of_node_put() will be called on it |
| 427 | * @type: The type string to match "device_type" or NULL to ignore |
| 428 | * @compatible: The string to match to one of the tokens in the device |
| 429 | * "compatible" list. |
| 430 | * |
| 431 | * Returns a node pointer with refcount incremented, use |
| 432 | * of_node_put() on it when done. |
| 433 | */ |
| 434 | struct device_node *of_find_compatible_node(struct device_node *from, |
| 435 | const char *type, const char *compatible) |
| 436 | { |
| 437 | struct device_node *np; |
| 438 | |
| 439 | read_lock(&devtree_lock); |
| 440 | np = from ? from->allnext : allnodes; |
| 441 | for (; np; np = np->allnext) { |
| 442 | if (type |
| 443 | && !(np->type && (of_node_cmp(np->type, type) == 0))) |
| 444 | continue; |
| 445 | if (of_device_is_compatible(np, compatible) && of_node_get(np)) |
| 446 | break; |
| 447 | } |
| 448 | of_node_put(from); |
| 449 | read_unlock(&devtree_lock); |
| 450 | return np; |
| 451 | } |
| 452 | EXPORT_SYMBOL(of_find_compatible_node); |
Grant Likely | 283029d | 2008-01-09 06:20:40 +1100 | [diff] [blame] | 453 | |
| 454 | /** |
Michael Ellerman | 1e291b1 | 2008-11-12 18:54:42 +0000 | [diff] [blame] | 455 | * of_find_node_with_property - Find a node which has a property with |
| 456 | * the given name. |
| 457 | * @from: The node to start searching from or NULL, the node |
| 458 | * you pass will not be searched, only the next one |
| 459 | * will; typically, you pass what the previous call |
| 460 | * returned. of_node_put() will be called on it |
| 461 | * @prop_name: The name of the property to look for. |
| 462 | * |
| 463 | * Returns a node pointer with refcount incremented, use |
| 464 | * of_node_put() on it when done. |
| 465 | */ |
| 466 | struct device_node *of_find_node_with_property(struct device_node *from, |
| 467 | const char *prop_name) |
| 468 | { |
| 469 | struct device_node *np; |
| 470 | struct property *pp; |
| 471 | |
| 472 | read_lock(&devtree_lock); |
| 473 | np = from ? from->allnext : allnodes; |
| 474 | for (; np; np = np->allnext) { |
| 475 | for (pp = np->properties; pp != 0; pp = pp->next) { |
| 476 | if (of_prop_cmp(pp->name, prop_name) == 0) { |
| 477 | of_node_get(np); |
| 478 | goto out; |
| 479 | } |
| 480 | } |
| 481 | } |
| 482 | out: |
| 483 | of_node_put(from); |
| 484 | read_unlock(&devtree_lock); |
| 485 | return np; |
| 486 | } |
| 487 | EXPORT_SYMBOL(of_find_node_with_property); |
| 488 | |
| 489 | /** |
Grant Likely | 283029d | 2008-01-09 06:20:40 +1100 | [diff] [blame] | 490 | * of_match_node - Tell if an device_node has a matching of_match structure |
| 491 | * @matches: array of of device match structures to search in |
| 492 | * @node: the of device structure to match against |
| 493 | * |
| 494 | * Low level utility function used by device matching. |
| 495 | */ |
| 496 | const struct of_device_id *of_match_node(const struct of_device_id *matches, |
| 497 | const struct device_node *node) |
| 498 | { |
| 499 | while (matches->name[0] || matches->type[0] || matches->compatible[0]) { |
| 500 | int match = 1; |
| 501 | if (matches->name[0]) |
| 502 | match &= node->name |
| 503 | && !strcmp(matches->name, node->name); |
| 504 | if (matches->type[0]) |
| 505 | match &= node->type |
| 506 | && !strcmp(matches->type, node->type); |
| 507 | if (matches->compatible[0]) |
| 508 | match &= of_device_is_compatible(node, |
| 509 | matches->compatible); |
| 510 | if (match) |
| 511 | return matches; |
| 512 | matches++; |
| 513 | } |
| 514 | return NULL; |
| 515 | } |
| 516 | EXPORT_SYMBOL(of_match_node); |
| 517 | |
| 518 | /** |
| 519 | * of_find_matching_node - Find a node based on an of_device_id match |
| 520 | * table. |
| 521 | * @from: The node to start searching from or NULL, the node |
| 522 | * you pass will not be searched, only the next one |
| 523 | * will; typically, you pass what the previous call |
| 524 | * returned. of_node_put() will be called on it |
| 525 | * @matches: array of of device match structures to search in |
| 526 | * |
| 527 | * Returns a node pointer with refcount incremented, use |
| 528 | * of_node_put() on it when done. |
| 529 | */ |
| 530 | struct device_node *of_find_matching_node(struct device_node *from, |
| 531 | const struct of_device_id *matches) |
| 532 | { |
| 533 | struct device_node *np; |
| 534 | |
| 535 | read_lock(&devtree_lock); |
| 536 | np = from ? from->allnext : allnodes; |
| 537 | for (; np; np = np->allnext) { |
| 538 | if (of_match_node(matches, np) && of_node_get(np)) |
| 539 | break; |
| 540 | } |
| 541 | of_node_put(from); |
| 542 | read_unlock(&devtree_lock); |
| 543 | return np; |
| 544 | } |
| 545 | EXPORT_SYMBOL(of_find_matching_node); |
Grant Likely | 3f07af4 | 2008-07-25 22:25:13 -0400 | [diff] [blame] | 546 | |
| 547 | /** |
Grant Likely | 3f07af4 | 2008-07-25 22:25:13 -0400 | [diff] [blame] | 548 | * of_modalias_node - Lookup appropriate modalias for a device node |
| 549 | * @node: pointer to a device tree node |
| 550 | * @modalias: Pointer to buffer that modalias value will be copied into |
| 551 | * @len: Length of modalias value |
| 552 | * |
Grant Likely | 2ffe8c5 | 2010-06-08 07:48:19 -0600 | [diff] [blame] | 553 | * Based on the value of the compatible property, this routine will attempt |
| 554 | * to choose an appropriate modalias value for a particular device tree node. |
| 555 | * It does this by stripping the manufacturer prefix (as delimited by a ',') |
| 556 | * from the first entry in the compatible list property. |
Grant Likely | 3f07af4 | 2008-07-25 22:25:13 -0400 | [diff] [blame] | 557 | * |
Grant Likely | 2ffe8c5 | 2010-06-08 07:48:19 -0600 | [diff] [blame] | 558 | * This routine returns 0 on success, <0 on failure. |
Grant Likely | 3f07af4 | 2008-07-25 22:25:13 -0400 | [diff] [blame] | 559 | */ |
| 560 | int of_modalias_node(struct device_node *node, char *modalias, int len) |
| 561 | { |
Grant Likely | 2ffe8c5 | 2010-06-08 07:48:19 -0600 | [diff] [blame] | 562 | const char *compatible, *p; |
| 563 | int cplen; |
Grant Likely | 3f07af4 | 2008-07-25 22:25:13 -0400 | [diff] [blame] | 564 | |
| 565 | compatible = of_get_property(node, "compatible", &cplen); |
Grant Likely | 2ffe8c5 | 2010-06-08 07:48:19 -0600 | [diff] [blame] | 566 | if (!compatible || strlen(compatible) > cplen) |
Grant Likely | 3f07af4 | 2008-07-25 22:25:13 -0400 | [diff] [blame] | 567 | return -ENODEV; |
Grant Likely | 3f07af4 | 2008-07-25 22:25:13 -0400 | [diff] [blame] | 568 | p = strchr(compatible, ','); |
Grant Likely | 2ffe8c5 | 2010-06-08 07:48:19 -0600 | [diff] [blame] | 569 | strlcpy(modalias, p ? p + 1 : compatible, len); |
Grant Likely | 3f07af4 | 2008-07-25 22:25:13 -0400 | [diff] [blame] | 570 | return 0; |
| 571 | } |
| 572 | EXPORT_SYMBOL_GPL(of_modalias_node); |
| 573 | |
Anton Vorontsov | 64b60e0 | 2008-10-10 04:43:17 +0000 | [diff] [blame] | 574 | /** |
Jeremy Kerr | 89751a7 | 2010-02-01 21:34:11 -0700 | [diff] [blame] | 575 | * of_find_node_by_phandle - Find a node given a phandle |
| 576 | * @handle: phandle of the node to find |
| 577 | * |
| 578 | * Returns a node pointer with refcount incremented, use |
| 579 | * of_node_put() on it when done. |
| 580 | */ |
| 581 | struct device_node *of_find_node_by_phandle(phandle handle) |
| 582 | { |
| 583 | struct device_node *np; |
| 584 | |
| 585 | read_lock(&devtree_lock); |
| 586 | for (np = allnodes; np; np = np->allnext) |
| 587 | if (np->phandle == handle) |
| 588 | break; |
| 589 | of_node_get(np); |
| 590 | read_unlock(&devtree_lock); |
| 591 | return np; |
| 592 | } |
| 593 | EXPORT_SYMBOL(of_find_node_by_phandle); |
| 594 | |
| 595 | /** |
Grant Likely | 739649c | 2009-04-25 12:52:40 +0000 | [diff] [blame] | 596 | * of_parse_phandle - Resolve a phandle property to a device_node pointer |
| 597 | * @np: Pointer to device node holding phandle property |
| 598 | * @phandle_name: Name of property holding a phandle value |
| 599 | * @index: For properties holding a table of phandles, this is the index into |
| 600 | * the table |
| 601 | * |
| 602 | * Returns the device_node pointer with refcount incremented. Use |
| 603 | * of_node_put() on it when done. |
| 604 | */ |
| 605 | struct device_node * |
| 606 | of_parse_phandle(struct device_node *np, const char *phandle_name, int index) |
| 607 | { |
Grant Likely | 9a6b2e5 | 2010-07-23 01:48:25 -0600 | [diff] [blame] | 608 | const __be32 *phandle; |
Grant Likely | 739649c | 2009-04-25 12:52:40 +0000 | [diff] [blame] | 609 | int size; |
| 610 | |
| 611 | phandle = of_get_property(np, phandle_name, &size); |
| 612 | if ((!phandle) || (size < sizeof(*phandle) * (index + 1))) |
| 613 | return NULL; |
| 614 | |
Grant Likely | 9a6b2e5 | 2010-07-23 01:48:25 -0600 | [diff] [blame] | 615 | return of_find_node_by_phandle(be32_to_cpup(phandle + index)); |
Grant Likely | 739649c | 2009-04-25 12:52:40 +0000 | [diff] [blame] | 616 | } |
| 617 | EXPORT_SYMBOL(of_parse_phandle); |
| 618 | |
| 619 | /** |
Anton Vorontsov | 64b60e0 | 2008-10-10 04:43:17 +0000 | [diff] [blame] | 620 | * of_parse_phandles_with_args - Find a node pointed by phandle in a list |
| 621 | * @np: pointer to a device tree node containing a list |
| 622 | * @list_name: property name that contains a list |
| 623 | * @cells_name: property name that specifies phandles' arguments count |
| 624 | * @index: index of a phandle to parse out |
Anton Vorontsov | 7736a3d | 2008-12-05 08:15:46 +0000 | [diff] [blame] | 625 | * @out_node: optional pointer to device_node struct pointer (will be filled) |
| 626 | * @out_args: optional pointer to arguments pointer (will be filled) |
Anton Vorontsov | 64b60e0 | 2008-10-10 04:43:17 +0000 | [diff] [blame] | 627 | * |
| 628 | * This function is useful to parse lists of phandles and their arguments. |
| 629 | * Returns 0 on success and fills out_node and out_args, on error returns |
| 630 | * appropriate errno value. |
| 631 | * |
| 632 | * Example: |
| 633 | * |
| 634 | * phandle1: node1 { |
| 635 | * #list-cells = <2>; |
| 636 | * } |
| 637 | * |
| 638 | * phandle2: node2 { |
| 639 | * #list-cells = <1>; |
| 640 | * } |
| 641 | * |
| 642 | * node3 { |
| 643 | * list = <&phandle1 1 2 &phandle2 3>; |
| 644 | * } |
| 645 | * |
| 646 | * To get a device_node of the `node2' node you may call this: |
| 647 | * of_parse_phandles_with_args(node3, "list", "#list-cells", 2, &node2, &args); |
| 648 | */ |
| 649 | int of_parse_phandles_with_args(struct device_node *np, const char *list_name, |
| 650 | const char *cells_name, int index, |
| 651 | struct device_node **out_node, |
| 652 | const void **out_args) |
| 653 | { |
| 654 | int ret = -EINVAL; |
Jeremy Kerr | 3371488 | 2010-01-30 01:45:26 -0700 | [diff] [blame] | 655 | const __be32 *list; |
| 656 | const __be32 *list_end; |
Anton Vorontsov | 64b60e0 | 2008-10-10 04:43:17 +0000 | [diff] [blame] | 657 | int size; |
| 658 | int cur_index = 0; |
| 659 | struct device_node *node = NULL; |
Anton Vorontsov | 7736a3d | 2008-12-05 08:15:46 +0000 | [diff] [blame] | 660 | const void *args = NULL; |
Anton Vorontsov | 64b60e0 | 2008-10-10 04:43:17 +0000 | [diff] [blame] | 661 | |
| 662 | list = of_get_property(np, list_name, &size); |
| 663 | if (!list) { |
| 664 | ret = -ENOENT; |
| 665 | goto err0; |
| 666 | } |
| 667 | list_end = list + size / sizeof(*list); |
| 668 | |
| 669 | while (list < list_end) { |
Jeremy Kerr | 3371488 | 2010-01-30 01:45:26 -0700 | [diff] [blame] | 670 | const __be32 *cells; |
Grant Likely | 9a6b2e5 | 2010-07-23 01:48:25 -0600 | [diff] [blame] | 671 | phandle phandle; |
Anton Vorontsov | 64b60e0 | 2008-10-10 04:43:17 +0000 | [diff] [blame] | 672 | |
Grant Likely | 9a6b2e5 | 2010-07-23 01:48:25 -0600 | [diff] [blame] | 673 | phandle = be32_to_cpup(list++); |
Anton Vorontsov | c1bb7c6 | 2008-12-05 08:15:39 +0000 | [diff] [blame] | 674 | args = list; |
Anton Vorontsov | 64b60e0 | 2008-10-10 04:43:17 +0000 | [diff] [blame] | 675 | |
| 676 | /* one cell hole in the list = <>; */ |
Grant Likely | 9a6b2e5 | 2010-07-23 01:48:25 -0600 | [diff] [blame] | 677 | if (!phandle) |
Anton Vorontsov | 64b60e0 | 2008-10-10 04:43:17 +0000 | [diff] [blame] | 678 | goto next; |
Anton Vorontsov | 64b60e0 | 2008-10-10 04:43:17 +0000 | [diff] [blame] | 679 | |
Grant Likely | 9a6b2e5 | 2010-07-23 01:48:25 -0600 | [diff] [blame] | 680 | node = of_find_node_by_phandle(phandle); |
Anton Vorontsov | 64b60e0 | 2008-10-10 04:43:17 +0000 | [diff] [blame] | 681 | if (!node) { |
| 682 | pr_debug("%s: could not find phandle\n", |
| 683 | np->full_name); |
| 684 | goto err0; |
| 685 | } |
| 686 | |
| 687 | cells = of_get_property(node, cells_name, &size); |
| 688 | if (!cells || size != sizeof(*cells)) { |
| 689 | pr_debug("%s: could not get %s for %s\n", |
| 690 | np->full_name, cells_name, node->full_name); |
| 691 | goto err1; |
| 692 | } |
| 693 | |
Jeremy Kerr | 3371488 | 2010-01-30 01:45:26 -0700 | [diff] [blame] | 694 | list += be32_to_cpup(cells); |
Anton Vorontsov | 64b60e0 | 2008-10-10 04:43:17 +0000 | [diff] [blame] | 695 | if (list > list_end) { |
| 696 | pr_debug("%s: insufficient arguments length\n", |
| 697 | np->full_name); |
| 698 | goto err1; |
| 699 | } |
| 700 | next: |
| 701 | if (cur_index == index) |
| 702 | break; |
| 703 | |
| 704 | of_node_put(node); |
| 705 | node = NULL; |
Anton Vorontsov | 7736a3d | 2008-12-05 08:15:46 +0000 | [diff] [blame] | 706 | args = NULL; |
Anton Vorontsov | 64b60e0 | 2008-10-10 04:43:17 +0000 | [diff] [blame] | 707 | cur_index++; |
| 708 | } |
| 709 | |
| 710 | if (!node) { |
Anton Vorontsov | 7736a3d | 2008-12-05 08:15:46 +0000 | [diff] [blame] | 711 | /* |
| 712 | * args w/o node indicates that the loop above has stopped at |
| 713 | * the 'hole' cell. Report this differently. |
| 714 | */ |
| 715 | if (args) |
| 716 | ret = -EEXIST; |
| 717 | else |
| 718 | ret = -ENOENT; |
Anton Vorontsov | 64b60e0 | 2008-10-10 04:43:17 +0000 | [diff] [blame] | 719 | goto err0; |
| 720 | } |
| 721 | |
Anton Vorontsov | 7736a3d | 2008-12-05 08:15:46 +0000 | [diff] [blame] | 722 | if (out_node) |
| 723 | *out_node = node; |
| 724 | if (out_args) |
| 725 | *out_args = args; |
Anton Vorontsov | 64b60e0 | 2008-10-10 04:43:17 +0000 | [diff] [blame] | 726 | |
| 727 | return 0; |
| 728 | err1: |
| 729 | of_node_put(node); |
| 730 | err0: |
| 731 | pr_debug("%s failed with status %d\n", __func__, ret); |
| 732 | return ret; |
| 733 | } |
| 734 | EXPORT_SYMBOL(of_parse_phandles_with_args); |
Grant Likely | 02af11b | 2009-11-23 20:16:45 -0700 | [diff] [blame] | 735 | |
| 736 | /** |
| 737 | * prom_add_property - Add a property to a node |
| 738 | */ |
| 739 | int prom_add_property(struct device_node *np, struct property *prop) |
| 740 | { |
| 741 | struct property **next; |
| 742 | unsigned long flags; |
| 743 | |
| 744 | prop->next = NULL; |
| 745 | write_lock_irqsave(&devtree_lock, flags); |
| 746 | next = &np->properties; |
| 747 | while (*next) { |
| 748 | if (strcmp(prop->name, (*next)->name) == 0) { |
| 749 | /* duplicate ! don't insert it */ |
| 750 | write_unlock_irqrestore(&devtree_lock, flags); |
| 751 | return -1; |
| 752 | } |
| 753 | next = &(*next)->next; |
| 754 | } |
| 755 | *next = prop; |
| 756 | write_unlock_irqrestore(&devtree_lock, flags); |
| 757 | |
| 758 | #ifdef CONFIG_PROC_DEVICETREE |
| 759 | /* try to add to proc as well if it was initialized */ |
| 760 | if (np->pde) |
| 761 | proc_device_tree_add_prop(np->pde, prop); |
| 762 | #endif /* CONFIG_PROC_DEVICETREE */ |
| 763 | |
| 764 | return 0; |
| 765 | } |
| 766 | |
| 767 | /** |
| 768 | * prom_remove_property - Remove a property from a node. |
| 769 | * |
| 770 | * Note that we don't actually remove it, since we have given out |
| 771 | * who-knows-how-many pointers to the data using get-property. |
| 772 | * Instead we just move the property to the "dead properties" |
| 773 | * list, so it won't be found any more. |
| 774 | */ |
| 775 | int prom_remove_property(struct device_node *np, struct property *prop) |
| 776 | { |
| 777 | struct property **next; |
| 778 | unsigned long flags; |
| 779 | int found = 0; |
| 780 | |
| 781 | write_lock_irqsave(&devtree_lock, flags); |
| 782 | next = &np->properties; |
| 783 | while (*next) { |
| 784 | if (*next == prop) { |
| 785 | /* found the node */ |
| 786 | *next = prop->next; |
| 787 | prop->next = np->deadprops; |
| 788 | np->deadprops = prop; |
| 789 | found = 1; |
| 790 | break; |
| 791 | } |
| 792 | next = &(*next)->next; |
| 793 | } |
| 794 | write_unlock_irqrestore(&devtree_lock, flags); |
| 795 | |
| 796 | if (!found) |
| 797 | return -ENODEV; |
| 798 | |
| 799 | #ifdef CONFIG_PROC_DEVICETREE |
| 800 | /* try to remove the proc node as well */ |
| 801 | if (np->pde) |
| 802 | proc_device_tree_remove_prop(np->pde, prop); |
| 803 | #endif /* CONFIG_PROC_DEVICETREE */ |
| 804 | |
| 805 | return 0; |
| 806 | } |
| 807 | |
| 808 | /* |
| 809 | * prom_update_property - Update a property in a node. |
| 810 | * |
| 811 | * Note that we don't actually remove it, since we have given out |
| 812 | * who-knows-how-many pointers to the data using get-property. |
| 813 | * Instead we just move the property to the "dead properties" list, |
| 814 | * and add the new property to the property list |
| 815 | */ |
| 816 | int prom_update_property(struct device_node *np, |
| 817 | struct property *newprop, |
| 818 | struct property *oldprop) |
| 819 | { |
| 820 | struct property **next; |
| 821 | unsigned long flags; |
| 822 | int found = 0; |
| 823 | |
| 824 | write_lock_irqsave(&devtree_lock, flags); |
| 825 | next = &np->properties; |
| 826 | while (*next) { |
| 827 | if (*next == oldprop) { |
| 828 | /* found the node */ |
| 829 | newprop->next = oldprop->next; |
| 830 | *next = newprop; |
| 831 | oldprop->next = np->deadprops; |
| 832 | np->deadprops = oldprop; |
| 833 | found = 1; |
| 834 | break; |
| 835 | } |
| 836 | next = &(*next)->next; |
| 837 | } |
| 838 | write_unlock_irqrestore(&devtree_lock, flags); |
| 839 | |
| 840 | if (!found) |
| 841 | return -ENODEV; |
| 842 | |
| 843 | #ifdef CONFIG_PROC_DEVICETREE |
| 844 | /* try to add to proc as well if it was initialized */ |
| 845 | if (np->pde) |
| 846 | proc_device_tree_update_prop(np->pde, newprop, oldprop); |
| 847 | #endif /* CONFIG_PROC_DEVICETREE */ |
| 848 | |
| 849 | return 0; |
| 850 | } |
Grant Likely | fcdeb7f | 2010-01-29 05:04:33 -0700 | [diff] [blame] | 851 | |
| 852 | #if defined(CONFIG_OF_DYNAMIC) |
| 853 | /* |
| 854 | * Support for dynamic device trees. |
| 855 | * |
| 856 | * On some platforms, the device tree can be manipulated at runtime. |
| 857 | * The routines in this section support adding, removing and changing |
| 858 | * device tree nodes. |
| 859 | */ |
| 860 | |
| 861 | /** |
| 862 | * of_attach_node - Plug a device node into the tree and global list. |
| 863 | */ |
| 864 | void of_attach_node(struct device_node *np) |
| 865 | { |
| 866 | unsigned long flags; |
| 867 | |
| 868 | write_lock_irqsave(&devtree_lock, flags); |
| 869 | np->sibling = np->parent->child; |
| 870 | np->allnext = allnodes; |
| 871 | np->parent->child = np; |
| 872 | allnodes = np; |
| 873 | write_unlock_irqrestore(&devtree_lock, flags); |
| 874 | } |
| 875 | |
| 876 | /** |
| 877 | * of_detach_node - "Unplug" a node from the device tree. |
| 878 | * |
| 879 | * The caller must hold a reference to the node. The memory associated with |
| 880 | * the node is not freed until its refcount goes to zero. |
| 881 | */ |
| 882 | void of_detach_node(struct device_node *np) |
| 883 | { |
| 884 | struct device_node *parent; |
| 885 | unsigned long flags; |
| 886 | |
| 887 | write_lock_irqsave(&devtree_lock, flags); |
| 888 | |
| 889 | parent = np->parent; |
| 890 | if (!parent) |
| 891 | goto out_unlock; |
| 892 | |
| 893 | if (allnodes == np) |
| 894 | allnodes = np->allnext; |
| 895 | else { |
| 896 | struct device_node *prev; |
| 897 | for (prev = allnodes; |
| 898 | prev->allnext != np; |
| 899 | prev = prev->allnext) |
| 900 | ; |
| 901 | prev->allnext = np->allnext; |
| 902 | } |
| 903 | |
| 904 | if (parent->child == np) |
| 905 | parent->child = np->sibling; |
| 906 | else { |
| 907 | struct device_node *prevsib; |
| 908 | for (prevsib = np->parent->child; |
| 909 | prevsib->sibling != np; |
| 910 | prevsib = prevsib->sibling) |
| 911 | ; |
| 912 | prevsib->sibling = np->sibling; |
| 913 | } |
| 914 | |
| 915 | of_node_set_flag(np, OF_DETACHED); |
| 916 | |
| 917 | out_unlock: |
| 918 | write_unlock_irqrestore(&devtree_lock, flags); |
| 919 | } |
| 920 | #endif /* defined(CONFIG_OF_DYNAMIC) */ |
| 921 | |