include/dm/read.h

   1 /*
   2  * Function to read values from the device tree node attached to a udevice.
   3  *
   4  * Copyright (c) 2017 Google, Inc
   5  * Written by Simon Glass <sjg@chromium.org>
   6  *
   7  * SPDX-License-Identifier:     GPL-2.0+
   8  */
   9
  10 #ifndef _DM_READ_H
  11 #define _DM_READ_H
  12
  13 #include <dm/fdtaddr.h>
  14 #include <dm/ofnode.h>
  15 #include <dm/uclass.h>
  16
  17 struct resource;
  18
  19 #if CONFIG_IS_ENABLED(OF_LIVE)
  20 static inline const struct device_node *dev_np(struct udevice *dev)
  21 {
  22         return ofnode_to_np(dev->node);
  23 }
  24 #else
  25 static inline const struct device_node *dev_np(struct udevice *dev)
  26 {
  27         return NULL;
  28 }
  29 #endif
  30
  31 /**
  32  * dev_ofnode() - get the DT node reference associated with a udevice
  33  *
  34  * @dev:        device to check
  35  * @return reference of the the device's DT node
  36  */
  37 static inline ofnode dev_ofnode(struct udevice *dev)
  38 {
  39         return dev->node;
  40 }
  41
  42 static inline bool dev_of_valid(struct udevice *dev)
  43 {
  44         return ofnode_valid(dev_ofnode(dev));
  45 }
  46
  47 #ifndef CONFIG_DM_DEV_READ_INLINE
  48 /**
  49  * dev_read_u32_default() - read a 32-bit integer from a device's DT property
  50  *
  51  * @dev:        device to read DT property from
  52  * @propname:   name of the property to read from
  53  * @def:        default value to return if the property has no value
  54  * @return property value, or @def if not found
  55  */
  56 int dev_read_u32_default(struct udevice *dev, const char *propname, int def);
  57
  58 /**
  59  * dev_read_string() - Read a string from a device's DT property
  60  *
  61  * @dev:        device to read DT property from
  62  * @propname:   name of the property to read
  63  * @return string from property value, or NULL if there is no such property
  64  */
  65 const char *dev_read_string(struct udevice *dev, const char *propname);
  66
  67 /**
  68  * dev_read_bool() - read a boolean value from a device's DT property
  69  *
  70  * @dev:        device to read DT property from
  71  * @propname:   name of property to read
  72  * @return true if property is present (meaning true), false if not present
  73  */
  74 bool dev_read_bool(struct udevice *dev, const char *propname);
  75
  76 /**
  77  * dev_read_subnode() - find a named subnode of a device
  78  *
  79  * @dev:        device whose DT node contains the subnode
  80  * @subnode_name: name of subnode to find
  81  * @return reference to subnode (which can be invalid if there is no such
  82  * subnode)
  83  */
  84 ofnode dev_read_subnode(struct udevice *dev, const char *subbnode_name);
  85
  86 /**
  87  * dev_read_size() - read the size of a property
  88  *
  89  * @dev: device to check
  90  * @propname: property to check
  91  * @return size of property if present, or -EINVAL if not
  92  */
  93 int dev_read_size(struct udevice *dev, const char *propname);
  94
  95 /**
  96  * dev_read_addr_index() - Get the indexed reg property of a device
  97  *
  98  * @dev: Device to read from
  99  * @index: the 'reg' property can hold a list of <addr, size> pairs
 100  *         and @index is used to select which one is required
 101  *
 102  * @return address or FDT_ADDR_T_NONE if not found
 103  */
 104 fdt_addr_t dev_read_addr_index(struct udevice *dev, int index);
 105
 106 /**
 107  * dev_read_addr() - Get the reg property of a device
 108  *
 109  * @dev: Device to read from
 110  *
 111  * @return address or FDT_ADDR_T_NONE if not found
 112  */
 113 fdt_addr_t dev_read_addr(struct udevice *dev);
 114
 115 /**
 116  * dev_read_addr_ptr() - Get the reg property of a device
 117  *                       as a pointer
 118  *
 119  * @dev: Device to read from
 120  *
 121  * @return pointer or NULL if not found
 122  */
 123 void *dev_read_addr_ptr(struct udevice *dev);
 124
 125 /**
 126  * dev_read_addr_size() - get address and size from a device property
 127  *
 128  * This does no address translation. It simply reads an property that contains
 129  * an address and a size value, one after the other.
 130  *
 131  * @dev: Device to read from
 132  * @propname: property to read
 133  * @sizep: place to put size value (on success)
 134  * @return address value, or FDT_ADDR_T_NONE on error
 135  */
 136 fdt_addr_t dev_read_addr_size(struct udevice *dev, const char *propname,
 137                                 fdt_size_t *sizep);
 138
 139 /**
 140  * dev_read_name() - get the name of a device's node
 141  *
 142  * @node: valid node to look up
 143  * @return name of node
 144  */
 145 const char *dev_read_name(struct udevice *dev);
 146
 147 /**
 148  * dev_read_stringlist_search() - find string in a string list and return index
 149  *
 150  * Note that it is possible for this function to succeed on property values
 151  * that are not NUL-terminated. That's because the function will stop after
 152  * finding the first occurrence of @string. This can for example happen with
 153  * small-valued cell properties, such as #address-cells, when searching for
 154  * the empty string.
 155  *
 156  * @dev: device to check
 157  * @propname: name of the property containing the string list
 158  * @string: string to look up in the string list
 159  *
 160  * @return:
 161  *   the index of the string in the list of strings
 162  *   -ENODATA if the property is not found
 163  *   -EINVAL on some other error
 164  */
 165 int dev_read_stringlist_search(struct udevice *dev, const char *property,
 166                           const char *string);
 167
 168 /**
 169  * dev_read_string_index() - obtain an indexed string from a string list
 170  *
 171  * @dev: device to examine
 172  * @propname: name of the property containing the string list
 173  * @index: index of the string to return
 174  * @out: return location for the string
 175  *
 176  * @return:
 177  *   length of string, if found or -ve error value if not found
 178  */
 179 int dev_read_string_index(struct udevice *dev, const char *propname, int index,
 180                           const char **outp);
 181
 182 /**
 183  * dev_read_string_count() - find the number of strings in a string list
 184  *
 185  * @dev: device to examine
 186  * @propname: name of the property containing the string list
 187  * @return:
 188  *   number of strings in the list, or -ve error value if not found
 189  */
 190 int dev_read_string_count(struct udevice *dev, const char *propname);
 191 /**
 192  * dev_read_phandle_with_args() - Find a node pointed by phandle in a list
 193  *
 194  * This function is useful to parse lists of phandles and their arguments.
 195  * Returns 0 on success and fills out_args, on error returns appropriate
 196  * errno value.
 197  *
 198  * Caller is responsible to call of_node_put() on the returned out_args->np
 199  * pointer.
 200  *
 201  * Example:
 202  *
 203  * phandle1: node1 {
 204  *      #list-cells = <2>;
 205  * }
 206  *
 207  * phandle2: node2 {
 208  *      #list-cells = <1>;
 209  * }
 210  *
 211  * node3 {
 212  *      list = <&phandle1 1 2 &phandle2 3>;
 213  * }
 214  *
 215  * To get a device_node of the `node2' node you may call this:
 216  * dev_read_phandle_with_args(dev, "list", "#list-cells", 0, 1, &args);
 217  *
 218  * @dev:        device whose node containing a list
 219  * @list_name:  property name that contains a list
 220  * @cells_name: property name that specifies phandles' arguments count
 221  * @cells_count: Cell count to use if @cells_name is NULL
 222  * @index:      index of a phandle to parse out
 223  * @out_args:   optional pointer to output arguments structure (will be filled)
 224  * @return 0 on success (with @out_args filled out if not NULL), -ENOENT if
 225  *      @list_name does not exist, -EINVAL if a phandle was not found,
 226  *      @cells_name could not be found, the arguments were truncated or there
 227  *      were too many arguments.
 228  */
 229 int dev_read_phandle_with_args(struct udevice *dev, const char *list_name,
 230                                 const char *cells_name, int cell_count,
 231                                 int index,
 232                                 struct ofnode_phandle_args *out_args);
 233
 234 /**
 235  * dev_count_phandle_with_args() - Return phandle number in a list
 236  *
 237  * This function is usefull to get phandle number contained in a property list.
 238  * For example, this allows to allocate the right amount of memory to keep
 239  * clock's reference contained into the "clocks" property.
 240  *
 241  *
 242  * @dev:        device whose node containing a list
 243  * @list_name:  property name that contains a list
 244  * @cells_name: property name that specifies phandles' arguments count
 245  * @Returns number of phandle found on success, on error returns appropriate
 246  * errno value.
 247  */
 248
 249 int dev_count_phandle_with_args(struct udevice *dev, const char *list_name,
 250                                 const char *cells_name);
 251
 252 /**
 253  * dev_read_addr_cells() - Get the number of address cells for a device's node
 254  *
 255  * This walks back up the tree to find the closest #address-cells property
 256  * which controls the given node.
 257  *
 258  * @dev: devioe to check
 259  * @return number of address cells this node uses
 260  */
 261 int dev_read_addr_cells(struct udevice *dev);
 262
 263 /**
 264  * dev_read_size_cells() - Get the number of size cells for a device's node
 265  *
 266  * This walks back up the tree to find the closest #size-cells property
 267  * which controls the given node.
 268  *
 269  * @dev: devioe to check
 270  * @return number of size cells this node uses
 271  */
 272 int dev_read_size_cells(struct udevice *dev);
 273
 274 /**
 275  * dev_read_addr_cells() - Get the address cells property in a node
 276  *
 277  * This function matches fdt_address_cells().
 278  *
 279  * @dev: devioe to check
 280  * @return number of address cells this node uses
 281  */
 282 int dev_read_simple_addr_cells(struct udevice *dev);
 283
 284 /**
 285  * dev_read_size_cells() - Get the size cells property in a node
 286  *
 287  * This function matches fdt_size_cells().
 288  *
 289  * @dev: devioe to check
 290  * @return number of size cells this node uses
 291  */
 292 int dev_read_simple_size_cells(struct udevice *dev);
 293
 294 /**
 295  * dev_read_phandle() - Get the phandle from a device
 296  *
 297  * @dev: device to check
 298  * @return phandle (1 or greater), or 0 if no phandle or other error
 299  */
 300 int dev_read_phandle(struct udevice *dev);
 301
 302 /**
 303  * dev_read_prop()- - read a property from a device's node
 304  *
 305  * @dev: device to check
 306  * @propname: property to read
 307  * @lenp: place to put length on success
 308  * @return pointer to property, or NULL if not found
 309  */
 310 const void *dev_read_prop(struct udevice *dev, const char *propname, int *lenp);
 311
 312 /**
 313  * dev_read_alias_seq() - Get the alias sequence number of a node
 314  *
 315  * This works out whether a node is pointed to by an alias, and if so, the
 316  * sequence number of that alias. Aliases are of the form <base><num> where
 317  * <num> is the sequence number. For example spi2 would be sequence number 2.
 318  *
 319  * @dev: device to look up
 320  * @devnump: set to the sequence number if one is found
 321  * @return 0 if a sequence was found, -ve if not
 322  */
 323 int dev_read_alias_seq(struct udevice *dev, int *devnump);
 324
 325 /**
 326  * dev_read_u32_array() - Find and read an array of 32 bit integers
 327  *
 328  * Search for a property in a device node and read 32-bit value(s) from
 329  * it.
 330  *
 331  * The out_values is modified only if a valid u32 value can be decoded.
 332  *
 333  * @dev: device to look up
 334  * @propname:   name of the property to read
 335  * @out_values: pointer to return value, modified only if return value is 0
 336  * @sz:         number of array elements to read
 337  * @return 0 on success, -EINVAL if the property does not exist, -ENODATA if
 338  * property does not have a value, and -EOVERFLOW if the property data isn't
 339  * large enough.
 340  */
 341 int dev_read_u32_array(struct udevice *dev, const char *propname,
 342                        u32 *out_values, size_t sz);
 343
 344 /**
 345  * dev_read_first_subnode() - find the first subnode of a device's node
 346  *
 347  * @dev: device to look up
 348  * @return reference to the first subnode (which can be invalid if the device's
 349  * node has no subnodes)
 350  */
 351 ofnode dev_read_first_subnode(struct udevice *dev);
 352
 353 /**
 354  * ofnode_next_subnode() - find the next sibling of a subnode
 355  *
 356  * @node:       valid reference to previous node (sibling)
 357  * @return reference to the next subnode (which can be invalid if the node
 358  * has no more siblings)
 359  */
 360 ofnode dev_read_next_subnode(ofnode node);
 361
 362 /**
 363  * dev_read_u8_array_ptr() - find an 8-bit array
 364  *
 365  * Look up a device's node property and return a pointer to its contents as a
 366  * byte array of given length. The property must have at least enough data
 367  * for the array (count bytes). It may have more, but this will be ignored.
 368  * The data is not copied.
 369  *
 370  * @dev: device to look up
 371  * @propname: name of property to find
 372  * @sz: number of array elements
 373  * @return pointer to byte array if found, or NULL if the property is not
 374  *              found or there is not enough data
 375  */
 376 const uint8_t *dev_read_u8_array_ptr(struct udevice *dev, const char *propname,
 377                                      size_t sz);
 378
 379 /**
 380  * dev_read_enabled() - check whether a node is enabled
 381  *
 382  * This looks for a 'status' property. If this exists, then returns 1 if
 383  * the status is 'ok' and 0 otherwise. If there is no status property,
 384  * it returns 1 on the assumption that anything mentioned should be enabled
 385  * by default.
 386  *
 387  * @dev: device to examine
 388  * @return integer value 0 (not enabled) or 1 (enabled)
 389  */
 390 int dev_read_enabled(struct udevice *dev);
 391
 392 /**
 393  * dev_read_resource() - obtain an indexed resource from a device.
 394  *
 395  * @dev: device to examine
 396  * @index index of the resource to retrieve (0 = first)
 397  * @res returns the resource
 398  * @return 0 if ok, negative on error
 399  */
 400 int dev_read_resource(struct udevice *dev, uint index, struct resource *res);
 401
 402 /**
 403  * dev_read_resource_byname() - obtain a named resource from a device.
 404  *
 405  * @dev: device to examine
 406  * @name: name of the resource to retrieve
 407  * @res: returns the resource
 408  * @return 0 if ok, negative on error
 409  */
 410 int dev_read_resource_byname(struct udevice *dev, const char *name,
 411                              struct resource *res);
 412
 413 #else /* CONFIG_DM_DEV_READ_INLINE is enabled */
 414
 415 static inline int dev_read_u32_default(struct udevice *dev,
 416                                        const char *propname, int def)
 417 {
 418         return ofnode_read_u32_default(dev_ofnode(dev), propname, def);
 419 }
 420
 421 static inline const char *dev_read_string(struct udevice *dev,
 422                                           const char *propname)
 423 {
 424         return ofnode_read_string(dev_ofnode(dev), propname);
 425 }
 426
 427 static inline bool dev_read_bool(struct udevice *dev, const char *propname)
 428 {
 429         return ofnode_read_bool(dev_ofnode(dev), propname);
 430 }
 431
 432 static inline ofnode dev_read_subnode(struct udevice *dev,
 433                                       const char *subbnode_name)
 434 {
 435         return ofnode_find_subnode(dev_ofnode(dev), subbnode_name);
 436 }
 437
 438 static inline int dev_read_size(struct udevice *dev, const char *propname)
 439 {
 440         return ofnode_read_size(dev_ofnode(dev), propname);
 441 }
 442
 443 static inline fdt_addr_t dev_read_addr_index(struct udevice *dev, int index)
 444 {
 445         return devfdt_get_addr_index(dev, index);
 446 }
 447
 448 static inline fdt_addr_t dev_read_addr(struct udevice *dev)
 449 {
 450         return devfdt_get_addr(dev);
 451 }
 452
 453 static inline void *dev_read_addr_ptr(struct udevice *dev)
 454 {
 455         return devfdt_get_addr_ptr(dev);
 456 }
 457
 458 static inline fdt_addr_t dev_read_addr_size(struct udevice *dev,
 459                                             const char *propname,
 460                                             fdt_size_t *sizep)
 461 {
 462         return ofnode_get_addr_size(dev_ofnode(dev), propname, sizep);
 463 }
 464
 465 static inline const char *dev_read_name(struct udevice *dev)
 466 {
 467         return ofnode_get_name(dev_ofnode(dev));
 468 }
 469
 470 static inline int dev_read_stringlist_search(struct udevice *dev,
 471                                              const char *propname,
 472                                              const char *string)
 473 {
 474         return ofnode_stringlist_search(dev_ofnode(dev), propname, string);
 475 }
 476
 477 static inline int dev_read_string_index(struct udevice *dev,
 478                                         const char *propname, int index,
 479                                         const char **outp)
 480 {
 481         return ofnode_read_string_index(dev_ofnode(dev), propname, index, outp);
 482 }
 483
 484 static inline int dev_read_string_count(struct udevice *dev,
 485                                         const char *propname)
 486 {
 487         return ofnode_read_string_count(dev_ofnode(dev), propname);
 488 }
 489
 490 static inline int dev_read_phandle_with_args(struct udevice *dev,
 491                 const char *list_name, const char *cells_name, int cell_count,
 492                 int index, struct ofnode_phandle_args *out_args)
 493 {
 494         return ofnode_parse_phandle_with_args(dev_ofnode(dev), list_name,
 495                                               cells_name, cell_count, index,
 496                                               out_args);
 497 }
 498
 499 static inline int dev_count_phandle_with_args(struct udevice *dev,
 500                 const char *list_name, const char *cells_name)
 501 {
 502         return ofnode_count_phandle_with_args(dev_ofnode(dev), list_name,
 503                                               cells_name);
 504 }
 505
 506 static inline int dev_read_addr_cells(struct udevice *dev)
 507 {
 508         /* NOTE: this call should walk up the parent stack */
 509         return fdt_address_cells(gd->fdt_blob, dev_of_offset(dev));
 510 }
 511
 512 static inline int dev_read_size_cells(struct udevice *dev)
 513 {
 514         /* NOTE: this call should walk up the parent stack */
 515         return fdt_size_cells(gd->fdt_blob, dev_of_offset(dev));
 516 }
 517
 518 static inline int dev_read_simple_addr_cells(struct udevice *dev)
 519 {
 520         return fdt_address_cells(gd->fdt_blob, dev_of_offset(dev));
 521 }
 522
 523 static inline int dev_read_simple_size_cells(struct udevice *dev)
 524 {
 525         return fdt_size_cells(gd->fdt_blob, dev_of_offset(dev));
 526 }
 527
 528 static inline int dev_read_phandle(struct udevice *dev)
 529 {
 530         return fdt_get_phandle(gd->fdt_blob, dev_of_offset(dev));
 531 }
 532
 533 static inline const void *dev_read_prop(struct udevice *dev,
 534                                         const char *propname, int *lenp)
 535 {
 536         return ofnode_get_property(dev_ofnode(dev), propname, lenp);
 537 }
 538
 539 static inline int dev_read_alias_seq(struct udevice *dev, int *devnump)
 540 {
 541         return fdtdec_get_alias_seq(gd->fdt_blob, dev->uclass->uc_drv->name,
 542                                     dev_of_offset(dev), devnump);
 543 }
 544
 545 static inline int dev_read_u32_array(struct udevice *dev, const char *propname,
 546                                      u32 *out_values, size_t sz)
 547 {
 548         return ofnode_read_u32_array(dev_ofnode(dev), propname, out_values, sz);
 549 }
 550
 551 static inline ofnode dev_read_first_subnode(struct udevice *dev)
 552 {
 553         return ofnode_first_subnode(dev_ofnode(dev));
 554 }
 555
 556 static inline ofnode dev_read_next_subnode(ofnode node)
 557 {
 558         return ofnode_next_subnode(node);
 559 }
 560
 561 static inline const uint8_t *dev_read_u8_array_ptr(struct udevice *dev,
 562                                         const char *propname, size_t sz)
 563 {
 564         return ofnode_read_u8_array_ptr(dev_ofnode(dev), propname, sz);
 565 }
 566
 567 static inline int dev_read_enabled(struct udevice *dev)
 568 {
 569         return fdtdec_get_is_enabled(gd->fdt_blob, dev_of_offset(dev));
 570 }
 571
 572 static inline int dev_read_resource(struct udevice *dev, uint index,
 573                                     struct resource *res)
 574 {
 575         return ofnode_read_resource(dev_ofnode(dev), index, res);
 576 }
 577
 578 static inline int dev_read_resource_byname(struct udevice *dev,
 579                                            const char *name,
 580                                            struct resource *res)
 581 {
 582         return ofnode_read_resource_byname(dev_ofnode(dev), name, res);
 583 }
 584
 585 #endif /* CONFIG_DM_DEV_READ_INLINE */
 586
 587 /**
 588  * dev_for_each_subnode() - Helper function to iterate through subnodes
 589  *
 590  * This creates a for() loop which works through the subnodes in a device's
 591  * device-tree node.
 592  *
 593  * @subnode: ofnode holding the current subnode
 594  * @dev: device to use for interation (struct udevice *)
 595  */
 596 #define dev_for_each_subnode(subnode, dev) \
 597         for (subnode = dev_read_first_subnode(dev); \
 598              ofnode_valid(subnode); \
 599              subnode = ofnode_next_subnode(subnode))
 600
 601 #endif