include/dm/of_access.h

   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_alias_scan() - Scan all properties of the 'aliases' node
 357  *
 358  * The function scans all the properties of the 'aliases' node and populates
 359  * the lookup table with the properties.  It returns the number of alias
 360  * properties found, or an error code in case of failure.
 361  *
 362  * @return 9 if OK, -ENOMEM if not enough memory
 363  */
 364 int of_alias_scan(void);
 365
 366 /**
 367  * of_alias_get_id - Get alias id for the given device_node
 368  *
 369  * Travels the lookup table to get the alias id for the given device_node and
 370  * alias stem.
 371  *
 372  * @np:         Pointer to the given device_node
 373  * @stem:       Alias stem of the given device_node
 374  * @return alias ID, if found, else -ENODEV
 375  */
 376 int of_alias_get_id(const struct device_node *np, const char *stem);
 377
 378 /**
 379  * of_get_stdout() - Get node to use for stdout
 380  *
 381  * @return node referred to by stdout-path alias, or NULL if none
 382  */
 383 struct device_node *of_get_stdout(void);
 384
 385 #endif