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