1 /* 2 * Originally from Linux v4.9 3 * Copyright (C) 1996-2005 Paul Mackerras. 4 * 5 * Updates for PPC64 by Peter Bergner & David Engebretsen, IBM Corp. 6 * Updates for SPARC64 by David S. Miller 7 * Derived from PowerPC and Sparc prom.h files by Stephen Rothwell, IBM Corp. 8 * 9 * Copyright (c) 2017 Google, Inc 10 * Written by Simon Glass <sjg@chromium.org> 11 * 12 * Modified for U-Boot 13 * Copyright (c) 2017 Google, Inc 14 * 15 * SPDX-License-Identifier: GPL-2.0+ 16 */ 17 18 #ifndef _DM_OF_ACCESS_H 19 #define _DM_OF_ACCESS_H 20 21 #include <dm/of.h> 22 23 /** 24 * of_find_all_nodes - Get next node in global list 25 * @prev: Previous node or NULL to start iteration 26 * of_node_put() will be called on it 27 * 28 * Returns a node pointer with refcount incremented, use 29 * of_node_put() on it when done. 30 */ 31 struct device_node *of_find_all_nodes(struct device_node *prev); 32 33 #define for_each_of_allnodes_from(from, dn) \ 34 for (dn = of_find_all_nodes(from); dn; dn = of_find_all_nodes(dn)) 35 #define for_each_of_allnodes(dn) for_each_of_allnodes_from(NULL, dn) 36 37 /* Dummy functions to mirror Linux. These are not used in U-Boot */ 38 #define of_node_get(x) (x) 39 static inline void of_node_put(const struct device_node *np) { } 40 41 /** 42 * of_n_addr_cells() - Get the number of address cells for a node 43 * 44 * This walks back up the tree to find the closest #address-cells property 45 * which controls the given node. 46 * 47 * @np: Node pointer to check 48 * @return number of address cells this node uses 49 */ 50 int of_n_addr_cells(const struct device_node *np); 51 52 /** 53 * of_n_size_cells() - Get the number of size cells for a node 54 * 55 * This walks back up the tree to find the closest #size-cells property 56 * which controls the given node. 57 * 58 * @np: Node pointer to check 59 * @return number of size cells this node uses 60 */ 61 int of_n_size_cells(const struct device_node *np); 62 63 /** 64 * of_simple_addr_cells() - Get the address cells property in a node 65 * 66 * This function matches fdt_address_cells(). 67 * 68 * @np: Node pointer to check 69 * @return value of #address-cells property in this node, or 2 if none 70 */ 71 int of_simple_addr_cells(const struct device_node *np); 72 73 /** 74 * of_simple_size_cells() - Get the size cells property in a node 75 * 76 * This function matches fdt_size_cells(). 77 * 78 * @np: Node pointer to check 79 * @return value of #size-cells property in this node, or 2 if none 80 */ 81 int of_simple_size_cells(const struct device_node *np); 82 83 /** 84 * of_find_property() - find a property in a node 85 * 86 * @np: Pointer to device node holding property 87 * @name: Name of property 88 * @lenp: If non-NULL, returns length of property 89 * @return pointer to property, or NULL if not found 90 */ 91 struct property *of_find_property(const struct device_node *np, 92 const char *name, int *lenp); 93 94 /** 95 * of_get_property() - get a property value 96 * 97 * Find a property with a given name for a given node and return the value. 98 * 99 * @np: Pointer to device node holding property 100 * @name: Name of property 101 * @lenp: If non-NULL, returns length of property 102 * @return pointer to property value, or NULL if not found 103 */ 104 const void *of_get_property(const struct device_node *np, const char *name, 105 int *lenp); 106 107 /** 108 * of_get_first_property()- get to the pointer of the first property 109 * 110 * Get pointer to the first property of the node, it is used to iterate 111 * and read all the property with of_get_next_property_by_prop(). 112 * 113 * @np: Pointer to device node 114 * @return pointer to property or NULL if not found 115 */ 116 const struct property *of_get_first_property(const struct device_node *np); 117 118 /** 119 * of_get_next_property() - get to the pointer of the next property 120 * 121 * Get pointer to the next property of the node, it is used to iterate 122 * and read all the property with of_get_property_by_prop(). 123 * 124 * @np: Pointer to device node 125 * @property: pointer of the current property 126 * @return pointer to next property or NULL if not found 127 */ 128 const struct property *of_get_next_property(const struct device_node *np, 129 const struct property *property); 130 131 /** 132 * of_get_property_by_prop() - get a property value of a node property 133 * 134 * Get value for the property identified by node and property pointer. 135 * 136 * @node: node to read 137 * @property: pointer of the property to read 138 * @propname: place to property name on success 139 * @lenp: place to put length on success 140 * @return pointer to property value or NULL if error 141 */ 142 const void *of_get_property_by_prop(const struct device_node *np, 143 const struct property *property, 144 const char **name, 145 int *lenp); 146 147 /** 148 * of_device_is_compatible() - Check if the node matches given constraints 149 * @device: pointer to node 150 * @compat: required compatible string, NULL or "" for any match 151 * @type: required device_type value, NULL or "" for any match 152 * @name: required node name, NULL or "" for any match 153 * 154 * Checks if the given @compat, @type and @name strings match the 155 * properties of the given @device. A constraints can be skipped by 156 * passing NULL or an empty string as the constraint. 157 * 158 * @return 0 for no match, and a positive integer on match. The return 159 * value is a relative score with larger values indicating better 160 * matches. The score is weighted for the most specific compatible value 161 * to get the highest score. Matching type is next, followed by matching 162 * name. Practically speaking, this results in the following priority 163 * order for matches: 164 * 165 * 1. specific compatible && type && name 166 * 2. specific compatible && type 167 * 3. specific compatible && name 168 * 4. specific compatible 169 * 5. general compatible && type && name 170 * 6. general compatible && type 171 * 7. general compatible && name 172 * 8. general compatible 173 * 9. type && name 174 * 10. type 175 * 11. name 176 */ 177 int of_device_is_compatible(const struct device_node *np, const char *compat, 178 const char *type, const char *name); 179 180 /** 181 * of_device_is_available() - check if a device is available for use 182 * 183 * @device: Node to check for availability 184 * 185 * @return true if the status property is absent or set to "okay", false 186 * otherwise 187 */ 188 bool of_device_is_available(const struct device_node *np); 189 190 /** 191 * of_get_parent() - Get a node's parent, if any 192 * 193 * @node: Node to check 194 * @eturns a node pointer, or NULL if none 195 */ 196 struct device_node *of_get_parent(const struct device_node *np); 197 198 /** 199 * of_find_node_opts_by_path() - Find a node matching a full OF path 200 * 201 * @path: Either the full path to match, or if the path does not start with 202 * '/', the name of a property of the /aliases node (an alias). In the 203 * case of an alias, the node matching the alias' value will be returned. 204 * @opts: Address of a pointer into which to store the start of an options 205 * string appended to the end of the path with a ':' separator. Can be NULL 206 * 207 * Valid paths: 208 * /foo/bar Full path 209 * foo Valid alias 210 * foo/bar Valid alias + relative path 211 * 212 * @return a node pointer or NULL if not found 213 */ 214 struct device_node *of_find_node_opts_by_path(const char *path, 215 const char **opts); 216 217 static inline struct device_node *of_find_node_by_path(const char *path) 218 { 219 return of_find_node_opts_by_path(path, NULL); 220 } 221 222 /** 223 * of_find_compatible_node() - find a node based on its compatible string 224 * 225 * Find a node based on type and one of the tokens in its "compatible" property 226 * @from: Node to start searching from or NULL. the node you pass will not be 227 * searched, only the next one will; typically, you pass what the previous 228 * call returned. 229 * @type: The type string to match "device_type" or NULL to ignore 230 * @compatible: The string to match to one of the tokens in the device 231 * "compatible" list. 232 * @return node pointer or NULL if not found 233 */ 234 struct device_node *of_find_compatible_node(struct device_node *from, 235 const char *type, const char *compatible); 236 237 /** 238 * of_find_node_by_phandle() - Find a node given a phandle 239 * 240 * @handle: phandle of the node to find 241 * 242 * @return node pointer, or NULL if not found 243 */ 244 struct device_node *of_find_node_by_phandle(phandle handle); 245 246 /** 247 * of_read_u32() - Find and read a 32-bit integer from a property 248 * 249 * Search for a property in a device node and read a 32-bit value from 250 * it. 251 * 252 * @np: device node from which the property value is to be read. 253 * @propname: name of the property to be searched. 254 * @outp: pointer to return value, modified only if return value is 0. 255 * 256 * @return 0 on success, -EINVAL if the property does not exist, 257 * -ENODATA if property does not have a value, and -EOVERFLOW if the 258 * property data isn't large enough. 259 */ 260 int of_read_u32(const struct device_node *np, const char *propname, u32 *outp); 261 262 /** 263 * of_property_read_u64 - Find and read a 64 bit integer from a property 264 * @np: device node from which the property value is to be read. 265 * @propname: name of the property to be searched. 266 * @out_value: pointer to return value, modified only if return value is 0. 267 * 268 * Search for a property in a device node and read a 64-bit value from 269 * it. Returns 0 on success, -EINVAL if the property does not exist, 270 * -ENODATA if property does not have a value, and -EOVERFLOW if the 271 * property data isn't large enough. 272 * 273 * The out_value is modified only if a valid u64 value can be decoded. 274 */ 275 int of_property_read_u64(const struct device_node *np, const char *propname, 276 u64 *out_value); 277 278 /** 279 * of_read_u32_array() - Find and read an array of 32 bit integers 280 * 281 * Search for a property in a device node and read 32-bit value(s) from 282 * it. 283 * 284 * @np: device node from which the property value is to be read. 285 * @propname: name of the property to be searched. 286 * @out_values: pointer to return value, modified only if return value is 0. 287 * @sz: number of array elements to read 288 * @return 0 on success, -EINVAL if the property does not exist, -ENODATA 289 * if property does not have a value, and -EOVERFLOW is longer than sz. 290 */ 291 int of_read_u32_array(const struct device_node *np, const char *propname, 292 u32 *out_values, size_t sz); 293 294 /** 295 * of_write_u32_array() - Find and write an array of 32 bit integers 296 * 297 * Search for a property in a device node and write 32-bit value(s) to 298 * it. 299 * 300 * @np: device node from which the property value is to be read. 301 * @propname: name of the property to be searched. 302 * @values: pointer to update value, modified only if return value is 0. 303 * @sz: number of array elements to read 304 * @return 0 on success, -EINVAL if the property does not exist, -ENODATA 305 * if property does not have a value, and -EOVERFLOW is longer than sz. 306 */ 307 int of_write_u32_array(const struct device_node *np, const char *propname, 308 u32 *values, size_t sz); 309 310 /** 311 * of_property_match_string() - Find string in a list and return index 312 * 313 * This function searches a string list property and returns the index 314 * of a specific string value. 315 * 316 * @np: pointer to node containing string list property 317 * @propname: string list property name 318 * @string: pointer to string to search for in string list 319 * @return 0 on success, -EINVAL if the property does not exist, -ENODATA 320 * if property does not have a value, and -EOVERFLOW is longer than sz. 321 */ 322 int of_property_match_string(const struct device_node *np, const char *propname, 323 const char *string); 324 325 int of_property_read_string_helper(const struct device_node *np, 326 const char *propname, const char **out_strs, 327 size_t sz, int index); 328 329 /** 330 * of_property_read_string_index() - Find and read a string from a multiple 331 * strings property. 332 * @np: device node from which the property value is to be read. 333 * @propname: name of the property to be searched. 334 * @index: index of the string in the list of strings 335 * @out_string: pointer to null terminated return string, modified only if 336 * return value is 0. 337 * 338 * Search for a property in a device tree node and retrieve a null 339 * terminated string value (pointer to data, not a copy) in the list of strings 340 * contained in that property. 341 * Returns 0 on success, -EINVAL if the property does not exist, -ENODATA if 342 * property does not have a value, and -EILSEQ if the string is not 343 * null-terminated within the length of the property data. 344 * 345 * The out_string pointer is modified only if a valid string can be decoded. 346 */ 347 static inline int of_property_read_string_index(const struct device_node *np, 348 const char *propname, 349 int index, const char **output) 350 { 351 int rc = of_property_read_string_helper(np, propname, output, 1, index); 352 return rc < 0 ? rc : 0; 353 } 354 355 /** 356 * of_property_count_strings() - Find and return the number of strings from a 357 * multiple strings property. 358 * @np: device node from which the property value is to be read. 359 * @propname: name of the property to be searched. 360 * 361 * Search for a property in a device tree node and retrieve the number of null 362 * terminated string contain in it. Returns the number of strings on 363 * success, -EINVAL if the property does not exist, -ENODATA if property 364 * does not have a value, and -EILSEQ if the string is not null-terminated 365 * within the length of the property data. 366 */ 367 static inline int of_property_count_strings(const struct device_node *np, 368 const char *propname) 369 { 370 return of_property_read_string_helper(np, propname, NULL, 0, 0); 371 } 372 373 /** 374 * of_parse_phandle - Resolve a phandle property to a device_node pointer 375 * @np: Pointer to device node holding phandle property 376 * @phandle_name: Name of property holding a phandle value 377 * @index: For properties holding a table of phandles, this is the index into 378 * the table 379 * 380 * Returns the device_node pointer with refcount incremented. Use 381 * of_node_put() on it when done. 382 */ 383 struct device_node *of_parse_phandle(const struct device_node *np, 384 const char *phandle_name, int index); 385 386 /** 387 * of_parse_phandle_with_args() - Find a node pointed by phandle in a list 388 * 389 * @np: pointer to a device tree node containing a list 390 * @list_name: property name that contains a list 391 * @cells_name: property name that specifies phandles' arguments count 392 * @index: index of a phandle to parse out 393 * @out_args: optional pointer to output arguments structure (will be filled) 394 * @return 0 on success (with @out_args filled out if not NULL), -ENOENT if 395 * @list_name does not exist, -EINVAL if a phandle was not found, 396 * @cells_name could not be found, the arguments were truncated or there 397 * were too many arguments. 398 * 399 * This function is useful to parse lists of phandles and their arguments. 400 * Returns 0 on success and fills out_args, on error returns appropriate 401 * errno value. 402 * 403 * Caller is responsible to call of_node_put() on the returned out_args->np 404 * pointer. 405 * 406 * Example: 407 * 408 * phandle1: node1 { 409 * #list-cells = <2>; 410 * } 411 * 412 * phandle2: node2 { 413 * #list-cells = <1>; 414 * } 415 * 416 * node3 { 417 * list = <&phandle1 1 2 &phandle2 3>; 418 * } 419 * 420 * To get a device_node of the `node2' node you may call this: 421 * of_parse_phandle_with_args(node3, "list", "#list-cells", 1, &args); 422 */ 423 int of_parse_phandle_with_args(const struct device_node *np, 424 const char *list_name, const char *cells_name, 425 int index, struct of_phandle_args *out_args); 426 427 /** 428 * of_count_phandle_with_args() - Count the number of phandle in a list 429 * 430 * @np: pointer to a device tree node containing a list 431 * @list_name: property name that contains a list 432 * @cells_name: property name that specifies phandles' arguments count 433 * @return number of phandle found, -ENOENT if 434 * @list_name does not exist, -EINVAL if a phandle was not found, 435 * @cells_name could not be found, the arguments were truncated or there 436 * were too many arguments. 437 * 438 * Returns number of phandle found on success, on error returns appropriate 439 * errno value. 440 * 441 */ 442 int of_count_phandle_with_args(const struct device_node *np, 443 const char *list_name, const char *cells_name); 444 445 /** 446 * of_alias_scan() - Scan all properties of the 'aliases' node 447 * 448 * The function scans all the properties of the 'aliases' node and populates 449 * the lookup table with the properties. It returns the number of alias 450 * properties found, or an error code in case of failure. 451 * 452 * @return 9 if OK, -ENOMEM if not enough memory 453 */ 454 int of_alias_scan(void); 455 456 /** 457 * of_alias_get_id - Get alias id for the given device_node 458 * 459 * Travels the lookup table to get the alias id for the given device_node and 460 * alias stem. 461 * 462 * @np: Pointer to the given device_node 463 * @stem: Alias stem of the given device_node 464 * @return alias ID, if found, else -ENODEV 465 */ 466 int of_alias_get_id(const struct device_node *np, const char *stem); 467 468 /** 469 * of_alias_get_dev - Get device_node by given stem and alias id 470 * 471 * Travels the lookup table to get the device_node by given stem and alias id. 472 * 473 * @stem: Alias stem of the given device_node 474 * @id: Alias id of the given device_node 475 * @return device_node, if found, else NULL 476 */ 477 struct device_node *of_alias_get_dev(const char *stem, int id); 478 479 /** 480 * of_alias_dump - Dump of alias nodes added in aliases_lookup. 481 */ 482 struct device_node *of_alias_dump(void); 483 484 /** 485 * of_get_stdout() - Get node to use for stdout 486 * 487 * @return node referred to by stdout-path alias, or NULL if none 488 */ 489 struct device_node *of_get_stdout(void); 490 491 #endif 492