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