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_hide_property() - hide a property 109 * 110 * @np: Pointer to device node holding property 111 * @name: Name of property to hide 112 * @return hidden name if ok, otherwise NULL 113 */ 114 const char *of_hide_property(struct device_node *np, const char *name); 115 116 /** 117 * of_present_property() - present a property hidden before 118 * 119 * @np: Pointer to device node holding property 120 * @name: Hidden name of property 121 * @return 0 if ok, otherwise failed 122 */ 123 int of_present_property(struct device_node *np, const char *name); 124 125 /** 126 * of_device_is_compatible() - Check if the node matches given constraints 127 * @device: pointer to node 128 * @compat: required compatible string, NULL or "" for any match 129 * @type: required device_type value, NULL or "" for any match 130 * @name: required node name, NULL or "" for any match 131 * 132 * Checks if the given @compat, @type and @name strings match the 133 * properties of the given @device. A constraints can be skipped by 134 * passing NULL or an empty string as the constraint. 135 * 136 * @return 0 for no match, and a positive integer on match. The return 137 * value is a relative score with larger values indicating better 138 * matches. The score is weighted for the most specific compatible value 139 * to get the highest score. Matching type is next, followed by matching 140 * name. Practically speaking, this results in the following priority 141 * order for matches: 142 * 143 * 1. specific compatible && type && name 144 * 2. specific compatible && type 145 * 3. specific compatible && name 146 * 4. specific compatible 147 * 5. general compatible && type && name 148 * 6. general compatible && type 149 * 7. general compatible && name 150 * 8. general compatible 151 * 9. type && name 152 * 10. type 153 * 11. name 154 */ 155 int of_device_is_compatible(const struct device_node *np, const char *compat, 156 const char *type, const char *name); 157 158 /** 159 * of_device_is_available() - check if a device is available for use 160 * 161 * @device: Node to check for availability 162 * 163 * @return true if the status property is absent or set to "okay", false 164 * otherwise 165 */ 166 bool of_device_is_available(const struct device_node *np); 167 168 /** 169 * of_get_parent() - Get a node's parent, if any 170 * 171 * @node: Node to check 172 * @eturns a node pointer, or NULL if none 173 */ 174 struct device_node *of_get_parent(const struct device_node *np); 175 176 /** 177 * of_find_node_opts_by_path() - Find a node matching a full OF path 178 * 179 * @path: Either the full path to match, or if the path does not start with 180 * '/', the name of a property of the /aliases node (an alias). In the 181 * case of an alias, the node matching the alias' value will be returned. 182 * @opts: Address of a pointer into which to store the start of an options 183 * string appended to the end of the path with a ':' separator. Can be NULL 184 * 185 * Valid paths: 186 * /foo/bar Full path 187 * foo Valid alias 188 * foo/bar Valid alias + relative path 189 * 190 * @return a node pointer or NULL if not found 191 */ 192 struct device_node *of_find_node_opts_by_path(const char *path, 193 const char **opts); 194 195 static inline struct device_node *of_find_node_by_path(const char *path) 196 { 197 return of_find_node_opts_by_path(path, NULL); 198 } 199 200 /** 201 * of_find_compatible_node() - find a node based on its compatible string 202 * 203 * Find a node based on type and one of the tokens in its "compatible" property 204 * @from: Node to start searching from or NULL. the node you pass will not be 205 * searched, only the next one will; typically, you pass what the previous 206 * call returned. 207 * @type: The type string to match "device_type" or NULL to ignore 208 * @compatible: The string to match to one of the tokens in the device 209 * "compatible" list. 210 * @return node pointer or NULL if not found 211 */ 212 struct device_node *of_find_compatible_node(struct device_node *from, 213 const char *type, const char *compatible); 214 215 /** 216 * of_find_node_by_phandle() - Find a node given a phandle 217 * 218 * @handle: phandle of the node to find 219 * 220 * @return node pointer, or NULL if not found 221 */ 222 struct device_node *of_find_node_by_phandle(phandle handle); 223 224 /** 225 * of_read_u32() - Find and read a 32-bit integer from a property 226 * 227 * Search for a property in a device node and read a 32-bit value from 228 * it. 229 * 230 * @np: device node from which the property value is to be read. 231 * @propname: name of the property to be searched. 232 * @outp: pointer to return value, modified only if return value is 0. 233 * 234 * @return 0 on success, -EINVAL if the property does not exist, 235 * -ENODATA if property does not have a value, and -EOVERFLOW if the 236 * property data isn't large enough. 237 */ 238 int of_read_u32(const struct device_node *np, const char *propname, u32 *outp); 239 240 /** 241 * of_property_read_u64 - Find and read a 64 bit integer from a property 242 * @np: device node from which the property value is to be read. 243 * @propname: name of the property to be searched. 244 * @out_value: pointer to return value, modified only if return value is 0. 245 * 246 * Search for a property in a device node and read a 64-bit value from 247 * it. Returns 0 on success, -EINVAL if the property does not exist, 248 * -ENODATA if property does not have a value, and -EOVERFLOW if the 249 * property data isn't large enough. 250 * 251 * The out_value is modified only if a valid u64 value can be decoded. 252 */ 253 int of_property_read_u64(const struct device_node *np, const char *propname, 254 u64 *out_value); 255 256 /** 257 * of_read_u32_array() - Find and read an array of 32 bit integers 258 * 259 * Search for a property in a device node and read 32-bit value(s) from 260 * it. 261 * 262 * @np: device node from which the property value is to be read. 263 * @propname: name of the property to be searched. 264 * @out_values: pointer to return value, modified only if return value is 0. 265 * @sz: number of array elements to read 266 * @return 0 on success, -EINVAL if the property does not exist, -ENODATA 267 * if property does not have a value, and -EOVERFLOW is longer than sz. 268 */ 269 int of_read_u32_array(const struct device_node *np, const char *propname, 270 u32 *out_values, size_t sz); 271 272 /** 273 * of_write_u32_array() - Find and write an array of 32 bit integers 274 * 275 * Search for a property in a device node and write 32-bit value(s) to 276 * it. 277 * 278 * @np: device node from which the property value is to be read. 279 * @propname: name of the property to be searched. 280 * @values: pointer to update value, modified only if return value is 0. 281 * @sz: number of array elements to read 282 * @return 0 on success, -EINVAL if the property does not exist, -ENODATA 283 * if property does not have a value, and -EOVERFLOW is longer than sz. 284 */ 285 int of_write_u32_array(const struct device_node *np, const char *propname, 286 u32 *values, size_t sz); 287 288 /** 289 * of_property_match_string() - Find string in a list and return index 290 * 291 * This function searches a string list property and returns the index 292 * of a specific string value. 293 * 294 * @np: pointer to node containing string list property 295 * @propname: string list property name 296 * @string: pointer to string to search for in string list 297 * @return 0 on success, -EINVAL if the property does not exist, -ENODATA 298 * if property does not have a value, and -EOVERFLOW is longer than sz. 299 */ 300 int of_property_match_string(const struct device_node *np, const char *propname, 301 const char *string); 302 303 int of_property_read_string_helper(const struct device_node *np, 304 const char *propname, const char **out_strs, 305 size_t sz, int index); 306 307 /** 308 * of_property_read_string_index() - Find and read a string from a multiple 309 * strings property. 310 * @np: device node from which the property value is to be read. 311 * @propname: name of the property to be searched. 312 * @index: index of the string in the list of strings 313 * @out_string: pointer to null terminated return string, modified only if 314 * return value is 0. 315 * 316 * Search for a property in a device tree node and retrieve a null 317 * terminated string value (pointer to data, not a copy) in the list of strings 318 * contained in that property. 319 * Returns 0 on success, -EINVAL if the property does not exist, -ENODATA if 320 * property does not have a value, and -EILSEQ if the string is not 321 * null-terminated within the length of the property data. 322 * 323 * The out_string pointer is modified only if a valid string can be decoded. 324 */ 325 static inline int of_property_read_string_index(const struct device_node *np, 326 const char *propname, 327 int index, const char **output) 328 { 329 int rc = of_property_read_string_helper(np, propname, output, 1, index); 330 return rc < 0 ? rc : 0; 331 } 332 333 /** 334 * of_property_count_strings() - Find and return the number of strings from a 335 * multiple strings property. 336 * @np: device node from which the property value is to be read. 337 * @propname: name of the property to be searched. 338 * 339 * Search for a property in a device tree node and retrieve the number of null 340 * terminated string contain in it. Returns the number of strings on 341 * success, -EINVAL if the property does not exist, -ENODATA if property 342 * does not have a value, and -EILSEQ if the string is not null-terminated 343 * within the length of the property data. 344 */ 345 static inline int of_property_count_strings(const struct device_node *np, 346 const char *propname) 347 { 348 return of_property_read_string_helper(np, propname, NULL, 0, 0); 349 } 350 351 /** 352 * of_parse_phandle - Resolve a phandle property to a device_node pointer 353 * @np: Pointer to device node holding phandle property 354 * @phandle_name: Name of property holding a phandle value 355 * @index: For properties holding a table of phandles, this is the index into 356 * the table 357 * 358 * Returns the device_node pointer with refcount incremented. Use 359 * of_node_put() on it when done. 360 */ 361 struct device_node *of_parse_phandle(const struct device_node *np, 362 const char *phandle_name, int index); 363 364 /** 365 * of_parse_phandle_with_args() - Find a node pointed by phandle in a list 366 * 367 * @np: pointer to a device tree node containing a list 368 * @list_name: property name that contains a list 369 * @cells_name: property name that specifies phandles' arguments count 370 * @index: index of a phandle to parse out 371 * @out_args: optional pointer to output arguments structure (will be filled) 372 * @return 0 on success (with @out_args filled out if not NULL), -ENOENT if 373 * @list_name does not exist, -EINVAL if a phandle was not found, 374 * @cells_name could not be found, the arguments were truncated or there 375 * were too many arguments. 376 * 377 * This function is useful to parse lists of phandles and their arguments. 378 * Returns 0 on success and fills out_args, on error returns appropriate 379 * errno value. 380 * 381 * Caller is responsible to call of_node_put() on the returned out_args->np 382 * pointer. 383 * 384 * Example: 385 * 386 * phandle1: node1 { 387 * #list-cells = <2>; 388 * } 389 * 390 * phandle2: node2 { 391 * #list-cells = <1>; 392 * } 393 * 394 * node3 { 395 * list = <&phandle1 1 2 &phandle2 3>; 396 * } 397 * 398 * To get a device_node of the `node2' node you may call this: 399 * of_parse_phandle_with_args(node3, "list", "#list-cells", 1, &args); 400 */ 401 int of_parse_phandle_with_args(const struct device_node *np, 402 const char *list_name, const char *cells_name, 403 int index, struct of_phandle_args *out_args); 404 405 /** 406 * of_count_phandle_with_args() - Count the number of phandle in a list 407 * 408 * @np: pointer to a device tree node containing a list 409 * @list_name: property name that contains a list 410 * @cells_name: property name that specifies phandles' arguments count 411 * @return number of phandle found, -ENOENT if 412 * @list_name does not exist, -EINVAL if a phandle was not found, 413 * @cells_name could not be found, the arguments were truncated or there 414 * were too many arguments. 415 * 416 * Returns number of phandle found on success, on error returns appropriate 417 * errno value. 418 * 419 */ 420 int of_count_phandle_with_args(const struct device_node *np, 421 const char *list_name, const char *cells_name); 422 423 /** 424 * of_alias_scan() - Scan all properties of the 'aliases' node 425 * 426 * The function scans all the properties of the 'aliases' node and populates 427 * the lookup table with the properties. It returns the number of alias 428 * properties found, or an error code in case of failure. 429 * 430 * @return 9 if OK, -ENOMEM if not enough memory 431 */ 432 int of_alias_scan(void); 433 434 /** 435 * of_alias_get_id - Get alias id for the given device_node 436 * 437 * Travels the lookup table to get the alias id for the given device_node and 438 * alias stem. 439 * 440 * @np: Pointer to the given device_node 441 * @stem: Alias stem of the given device_node 442 * @return alias ID, if found, else -ENODEV 443 */ 444 int of_alias_get_id(const struct device_node *np, const char *stem); 445 446 /** 447 * of_alias_get_dev - Get device_node by given stem and alias id 448 * 449 * Travels the lookup table to get the device_node by given stem and alias id. 450 * 451 * @stem: Alias stem of the given device_node 452 * @id: Alias id of the given device_node 453 * @return device_node, if found, else NULL 454 */ 455 struct device_node *of_alias_get_dev(const char *stem, int id); 456 457 /** 458 * of_alias_dump - Dump of alias nodes added in aliases_lookup. 459 */ 460 struct device_node *of_alias_dump(void); 461 462 /** 463 * of_get_stdout() - Get node to use for stdout 464 * 465 * @return node referred to by stdout-path alias, or NULL if none 466 */ 467 struct device_node *of_get_stdout(void); 468 469 #endif 470