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_find_property() - find a property in a node 65 * 66 * @np: Pointer to device node holding property 67 * @name: Name of property 68 * @lenp: If non-NULL, returns length of property 69 * @return pointer to property, or NULL if not found 70 */ 71 struct property *of_find_property(const struct device_node *np, 72 const char *name, int *lenp); 73 74 /** 75 * of_get_property() - get a property value 76 * 77 * Find a property with a given name for a given node and return the value. 78 * 79 * @np: Pointer to device node holding property 80 * @name: Name of property 81 * @lenp: If non-NULL, returns length of property 82 * @return pointer to property value, or NULL if not found 83 */ 84 const void *of_get_property(const struct device_node *np, const char *name, 85 int *lenp); 86 87 /** 88 * of_device_is_compatible() - Check if the node matches given constraints 89 * @device: pointer to node 90 * @compat: required compatible string, NULL or "" for any match 91 * @type: required device_type value, NULL or "" for any match 92 * @name: required node name, NULL or "" for any match 93 * 94 * Checks if the given @compat, @type and @name strings match the 95 * properties of the given @device. A constraints can be skipped by 96 * passing NULL or an empty string as the constraint. 97 * 98 * @return 0 for no match, and a positive integer on match. The return 99 * value is a relative score with larger values indicating better 100 * matches. The score is weighted for the most specific compatible value 101 * to get the highest score. Matching type is next, followed by matching 102 * name. Practically speaking, this results in the following priority 103 * order for matches: 104 * 105 * 1. specific compatible && type && name 106 * 2. specific compatible && type 107 * 3. specific compatible && name 108 * 4. specific compatible 109 * 5. general compatible && type && name 110 * 6. general compatible && type 111 * 7. general compatible && name 112 * 8. general compatible 113 * 9. type && name 114 * 10. type 115 * 11. name 116 */ 117 int of_device_is_compatible(const struct device_node *np, const char *compat, 118 const char *type, const char *name); 119 120 /** 121 * of_device_is_available() - check if a device is available for use 122 * 123 * @device: Node to check for availability 124 * 125 * @return true if the status property is absent or set to "okay", false 126 * otherwise 127 */ 128 bool of_device_is_available(const struct device_node *np); 129 130 /** 131 * of_get_parent() - Get a node's parent, if any 132 * 133 * @node: Node to check 134 * @eturns a node pointer, or NULL if none 135 */ 136 struct device_node *of_get_parent(const struct device_node *np); 137 138 /** 139 * of_find_node_opts_by_path() - Find a node matching a full OF path 140 * 141 * @path: Either the full path to match, or if the path does not start with 142 * '/', the name of a property of the /aliases node (an alias). In the 143 * case of an alias, the node matching the alias' value will be returned. 144 * @opts: Address of a pointer into which to store the start of an options 145 * string appended to the end of the path with a ':' separator. Can be NULL 146 * 147 * Valid paths: 148 * /foo/bar Full path 149 * foo Valid alias 150 * foo/bar Valid alias + relative path 151 * 152 * @return a node pointer or NULL if not found 153 */ 154 struct device_node *of_find_node_opts_by_path(const char *path, 155 const char **opts); 156 157 static inline struct device_node *of_find_node_by_path(const char *path) 158 { 159 return of_find_node_opts_by_path(path, NULL); 160 } 161 162 /** 163 * of_find_compatible_node() - find a node based on its compatible string 164 * 165 * Find a node based on type and one of the tokens in its "compatible" property 166 * @from: Node to start searching from or NULL. the node you pass will not be 167 * searched, only the next one will; typically, you pass what the previous 168 * call returned. 169 * @type: The type string to match "device_type" or NULL to ignore 170 * @compatible: The string to match to one of the tokens in the device 171 * "compatible" list. 172 * @return node pointer or NULL if not found 173 */ 174 struct device_node *of_find_compatible_node(struct device_node *from, 175 const char *type, const char *compatible); 176 177 /** 178 * of_find_node_by_phandle() - Find a node given a phandle 179 * 180 * @handle: phandle of the node to find 181 * 182 * @return node pointer, or NULL if not found 183 */ 184 struct device_node *of_find_node_by_phandle(phandle handle); 185 186 /** 187 * of_read_u32() - Find and read a 32-bit integer from a property 188 * 189 * Search for a property in a device node and read a 32-bit value from 190 * it. 191 * 192 * @np: device node from which the property value is to be read. 193 * @propname: name of the property to be searched. 194 * @outp: pointer to return value, modified only if return value is 0. 195 * 196 * @return 0 on success, -EINVAL if the property does not exist, 197 * -ENODATA if property does not have a value, and -EOVERFLOW if the 198 * property data isn't large enough. 199 */ 200 int of_read_u32(const struct device_node *np, const char *propname, u32 *outp); 201 202 /** 203 * of_read_u32_array() - Find and read an array of 32 bit integers 204 * 205 * Search for a property in a device node and read 32-bit value(s) from 206 * it. 207 * 208 * @np: device node from which the property value is to be read. 209 * @propname: name of the property to be searched. 210 * @out_values: pointer to return value, modified only if return value is 0. 211 * @sz: number of array elements to read 212 * @return 0 on success, -EINVAL if the property does not exist, -ENODATA 213 * if property does not have a value, and -EOVERFLOW is longer than sz. 214 */ 215 int of_read_u32_array(const struct device_node *np, const char *propname, 216 u32 *out_values, size_t sz); 217 218 /** 219 * of_property_match_string() - Find string in a list and return index 220 * 221 * This function searches a string list property and returns the index 222 * of a specific string value. 223 * 224 * @np: pointer to node containing string list property 225 * @propname: string list property name 226 * @string: pointer to string to search for in string list 227 * @return 0 on success, -EINVAL if the property does not exist, -ENODATA 228 * if property does not have a value, and -EOVERFLOW is longer than sz. 229 */ 230 int of_property_match_string(const struct device_node *np, const char *propname, 231 const char *string); 232 233 int of_property_read_string_helper(const struct device_node *np, 234 const char *propname, const char **out_strs, 235 size_t sz, int index); 236 237 /** 238 * of_property_read_string_index() - Find and read a string from a multiple 239 * strings property. 240 * @np: device node from which the property value is to be read. 241 * @propname: name of the property to be searched. 242 * @index: index of the string in the list of strings 243 * @out_string: pointer to null terminated return string, modified only if 244 * return value is 0. 245 * 246 * Search for a property in a device tree node and retrieve a null 247 * terminated string value (pointer to data, not a copy) in the list of strings 248 * contained in that property. 249 * Returns 0 on success, -EINVAL if the property does not exist, -ENODATA if 250 * property does not have a value, and -EILSEQ if the string is not 251 * null-terminated within the length of the property data. 252 * 253 * The out_string pointer is modified only if a valid string can be decoded. 254 */ 255 static inline int of_property_read_string_index(const struct device_node *np, 256 const char *propname, 257 int index, const char **output) 258 { 259 int rc = of_property_read_string_helper(np, propname, output, 1, index); 260 return rc < 0 ? rc : 0; 261 } 262 263 /** 264 * of_parse_phandle - Resolve a phandle property to a device_node pointer 265 * @np: Pointer to device node holding phandle property 266 * @phandle_name: Name of property holding a phandle value 267 * @index: For properties holding a table of phandles, this is the index into 268 * the table 269 * 270 * Returns the device_node pointer with refcount incremented. Use 271 * of_node_put() on it when done. 272 */ 273 struct device_node *of_parse_phandle(const struct device_node *np, 274 const char *phandle_name, int index); 275 276 /** 277 * of_parse_phandle_with_args() - Find a node pointed by phandle in a list 278 * 279 * @np: pointer to a device tree node containing a list 280 * @list_name: property name that contains a list 281 * @cells_name: property name that specifies phandles' arguments count 282 * @index: index of a phandle to parse out 283 * @out_args: optional pointer to output arguments structure (will be filled) 284 * @return 0 on success (with @out_args filled out if not NULL), -ENOENT if 285 * @list_name does not exist, -EINVAL if a phandle was not found, 286 * @cells_name could not be found, the arguments were truncated or there 287 * were too many arguments. 288 * 289 * This function is useful to parse lists of phandles and their arguments. 290 * Returns 0 on success and fills out_args, on error returns appropriate 291 * errno value. 292 * 293 * Caller is responsible to call of_node_put() on the returned out_args->np 294 * pointer. 295 * 296 * Example: 297 * 298 * phandle1: node1 { 299 * #list-cells = <2>; 300 * } 301 * 302 * phandle2: node2 { 303 * #list-cells = <1>; 304 * } 305 * 306 * node3 { 307 * list = <&phandle1 1 2 &phandle2 3>; 308 * } 309 * 310 * To get a device_node of the `node2' node you may call this: 311 * of_parse_phandle_with_args(node3, "list", "#list-cells", 1, &args); 312 */ 313 int of_parse_phandle_with_args(const struct device_node *np, 314 const char *list_name, const char *cells_name, 315 int index, struct of_phandle_args *out_args); 316 317 /** 318 * of_alias_scan() - Scan all properties of the 'aliases' node 319 * 320 * The function scans all the properties of the 'aliases' node and populates 321 * the lookup table with the properties. It returns the number of alias 322 * properties found, or an error code in case of failure. 323 * 324 * @return 9 if OK, -ENOMEM if not enough memory 325 */ 326 int of_alias_scan(void); 327 328 /** 329 * of_alias_get_id - Get alias id for the given device_node 330 * 331 * Travels the lookup table to get the alias id for the given device_node and 332 * alias stem. 333 * 334 * @np: Pointer to the given device_node 335 * @stem: Alias stem of the given device_node 336 * @return alias ID, if found, else -ENODEV 337 */ 338 int of_alias_get_id(const struct device_node *np, const char *stem); 339 340 /** 341 * of_get_stdout() - Get node to use for stdout 342 * 343 * @return node referred to by stdout-path alias, or NULL if none 344 */ 345 struct device_node *of_get_stdout(void); 346 347 #endif 348