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_size() - get address and size from a device property
 117  *
 118  * This does no address translation. It simply reads an property that contains
 119  * an address and a size value, one after the other.
 120  *
 121  * @dev: Device to read from
 122  * @propname: property to read
 123  * @sizep: place to put size value (on success)
 124  * @return address value, or FDT_ADDR_T_NONE on error
 125  */
 126 fdt_addr_t dev_read_addr_size(struct udevice *dev, const char *propname,
 127                                 fdt_size_t *sizep);
 128
 129 /**
 130  * dev_read_name() - get the name of a device's node
 131  *
 132  * @node: valid node to look up
 133  * @return name of node
 134  */
 135 const char *dev_read_name(struct udevice *dev);
 136
 137 /**
 138  * dev_read_stringlist_search() - find string in a string list and return index
 139  *
 140  * Note that it is possible for this function to succeed on property values
 141  * that are not NUL-terminated. That's because the function will stop after
 142  * finding the first occurrence of @string. This can for example happen with
 143  * small-valued cell properties, such as #address-cells, when searching for
 144  * the empty string.
 145  *
 146  * @dev: device to check
 147  * @propname: name of the property containing the string list
 148  * @string: string to look up in the string list
 149  *
 150  * @return:
 151  *   the index of the string in the list of strings
 152  *   -ENODATA if the property is not found
 153  *   -EINVAL on some other error
 154  */
 155 int dev_read_stringlist_search(struct udevice *dev, const char *property,
 156                           const char *string);
 157
 158 /**
 159  * dev_read_phandle_with_args() - Find a node pointed by phandle in a list
 160  *
 161  * This function is useful to parse lists of phandles and their arguments.
 162  * Returns 0 on success and fills out_args, on error returns appropriate
 163  * errno value.
 164  *
 165  * Caller is responsible to call of_node_put() on the returned out_args->np
 166  * pointer.
 167  *
 168  * Example:
 169  *
 170  * phandle1: node1 {
 171  *      #list-cells = <2>;
 172  * }
 173  *
 174  * phandle2: node2 {
 175  *      #list-cells = <1>;
 176  * }
 177  *
 178  * node3 {
 179  *      list = <&phandle1 1 2 &phandle2 3>;
 180  * }
 181  *
 182  * To get a device_node of the `node2' node you may call this:
 183  * dev_read_phandle_with_args(dev, "list", "#list-cells", 0, 1, &args);
 184  *
 185  * @dev:        device whose node containing a list
 186  * @list_name:  property name that contains a list
 187  * @cells_name: property name that specifies phandles' arguments count
 188  * @cells_count: Cell count to use if @cells_name is NULL
 189  * @index:      index of a phandle to parse out
 190  * @out_args:   optional pointer to output arguments structure (will be filled)
 191  * @return 0 on success (with @out_args filled out if not NULL), -ENOENT if
 192  *      @list_name does not exist, -EINVAL if a phandle was not found,
 193  *      @cells_name could not be found, the arguments were truncated or there
 194  *      were too many arguments.
 195  */
 196 int dev_read_phandle_with_args(struct udevice *dev, const char *list_name,
 197                                 const char *cells_name, int cell_count,
 198                                 int index,
 199                                 struct ofnode_phandle_args *out_args);
 200
 201 /**
 202  * dev_count_phandle_with_args() - Return phandle number in a list
 203  *
 204  * This function is usefull to get phandle number contained in a property list.
 205  * For example, this allows to allocate the right amount of memory to keep
 206  * clock's reference contained into the "clocks" property.
 207  *
 208  *
 209  * @dev:        device whose node containing a list
 210  * @list_name:  property name that contains a list
 211  * @cells_name: property name that specifies phandles' arguments count
 212  * @Returns number of phandle found on success, on error returns appropriate
 213  * errno value.
 214  */
 215
 216 int dev_count_phandle_with_args(struct udevice *dev, const char *list_name,
 217                                 const char *cells_name);
 218
 219 /**
 220  * dev_read_addr_cells() - Get the number of address cells for a device's node
 221  *
 222  * This walks back up the tree to find the closest #address-cells property
 223  * which controls the given node.
 224  *
 225  * @dev: devioe to check
 226  * @return number of address cells this node uses
 227  */
 228 int dev_read_addr_cells(struct udevice *dev);
 229
 230 /**
 231  * dev_read_size_cells() - Get the number of size cells for a device's node
 232  *
 233  * This walks back up the tree to find the closest #size-cells property
 234  * which controls the given node.
 235  *
 236  * @dev: devioe to check
 237  * @return number of size cells this node uses
 238  */
 239 int dev_read_size_cells(struct udevice *dev);
 240
 241 /**
 242  * dev_read_addr_cells() - Get the address cells property in a node
 243  *
 244  * This function matches fdt_address_cells().
 245  *
 246  * @dev: devioe to check
 247  * @return number of address cells this node uses
 248  */
 249 int dev_read_simple_addr_cells(struct udevice *dev);
 250
 251 /**
 252  * dev_read_size_cells() - Get the size cells property in a node
 253  *
 254  * This function matches fdt_size_cells().
 255  *
 256  * @dev: devioe to check
 257  * @return number of size cells this node uses
 258  */
 259 int dev_read_simple_size_cells(struct udevice *dev);
 260
 261 /**
 262  * dev_read_phandle() - Get the phandle from a device
 263  *
 264  * @dev: device to check
 265  * @return phandle (1 or greater), or 0 if no phandle or other error
 266  */
 267 int dev_read_phandle(struct udevice *dev);
 268
 269 /**
 270  * dev_read_prop()- - read a property from a device's node
 271  *
 272  * @dev: device to check
 273  * @propname: property to read
 274  * @lenp: place to put length on success
 275  * @return pointer to property, or NULL if not found
 276  */
 277 const void *dev_read_prop(struct udevice *dev, const char *propname, int *lenp);
 278
 279 /**
 280  * dev_read_alias_seq() - Get the alias sequence number of a node
 281  *
 282  * This works out whether a node is pointed to by an alias, and if so, the
 283  * sequence number of that alias. Aliases are of the form <base><num> where
 284  * <num> is the sequence number. For example spi2 would be sequence number 2.
 285  *
 286  * @dev: device to look up
 287  * @devnump: set to the sequence number if one is found
 288  * @return 0 if a sequence was found, -ve if not
 289  */
 290 int dev_read_alias_seq(struct udevice *dev, int *devnump);
 291
 292 /**
 293  * dev_read_u32_array() - Find and read an array of 32 bit integers
 294  *
 295  * Search for a property in a device node and read 32-bit value(s) from
 296  * it.
 297  *
 298  * The out_values is modified only if a valid u32 value can be decoded.
 299  *
 300  * @dev: device to look up
 301  * @propname:   name of the property to read
 302  * @out_values: pointer to return value, modified only if return value is 0
 303  * @sz:         number of array elements to read
 304  * @return 0 on success, -EINVAL if the property does not exist, -ENODATA if
 305  * property does not have a value, and -EOVERFLOW if the property data isn't
 306  * large enough.
 307  */
 308 int dev_read_u32_array(struct udevice *dev, const char *propname,
 309                        u32 *out_values, size_t sz);
 310
 311 /**
 312  * dev_read_first_subnode() - find the first subnode of a device's node
 313  *
 314  * @dev: device to look up
 315  * @return reference to the first subnode (which can be invalid if the device's
 316  * node has no subnodes)
 317  */
 318 ofnode dev_read_first_subnode(struct udevice *dev);
 319
 320 /**
 321  * ofnode_next_subnode() - find the next sibling of a subnode
 322  *
 323  * @node:       valid reference to previous node (sibling)
 324  * @return reference to the next subnode (which can be invalid if the node
 325  * has no more siblings)
 326  */
 327 ofnode dev_read_next_subnode(ofnode node);
 328
 329 /**
 330  * dev_read_u8_array_ptr() - find an 8-bit array
 331  *
 332  * Look up a device's node property and return a pointer to its contents as a
 333  * byte array of given length. The property must have at least enough data
 334  * for the array (count bytes). It may have more, but this will be ignored.
 335  * The data is not copied.
 336  *
 337  * @dev: device to look up
 338  * @propname: name of property to find
 339  * @sz: number of array elements
 340  * @return pointer to byte array if found, or NULL if the property is not
 341  *              found or there is not enough data
 342  */
 343 const uint8_t *dev_read_u8_array_ptr(struct udevice *dev, const char *propname,
 344                                      size_t sz);
 345
 346 /**
 347  * dev_read_enabled() - check whether a node is enabled
 348  *
 349  * This looks for a 'status' property. If this exists, then returns 1 if
 350  * the status is 'ok' and 0 otherwise. If there is no status property,
 351  * it returns 1 on the assumption that anything mentioned should be enabled
 352  * by default.
 353  *
 354  * @dev: device to examine
 355  * @return integer value 0 (not enabled) or 1 (enabled)
 356  */
 357 int dev_read_enabled(struct udevice *dev);
 358
 359 /**
 360  * dev_read_resource() - obtain an indexed resource from a device.
 361  *
 362  * @dev: devuce to examine
 363  * @index index of the resource to retrieve (0 = first)
 364  * @res returns the resource
 365  * @return 0 if ok, negative on error
 366  */
 367 int dev_read_resource(struct udevice *dev, uint index, struct resource *res);
 368
 369 #else /* CONFIG_DM_DEV_READ_INLINE is enabled */
 370
 371 static inline int dev_read_u32_default(struct udevice *dev,
 372                                        const char *propname, int def)
 373 {
 374         return ofnode_read_u32_default(dev_ofnode(dev), propname, def);
 375 }
 376
 377 static inline const char *dev_read_string(struct udevice *dev,
 378                                           const char *propname)
 379 {
 380         return ofnode_read_string(dev_ofnode(dev), propname);
 381 }
 382
 383 static inline bool dev_read_bool(struct udevice *dev, const char *propname)
 384 {
 385         return ofnode_read_bool(dev_ofnode(dev), propname);
 386 }
 387
 388 static inline ofnode dev_read_subnode(struct udevice *dev,
 389                                       const char *subbnode_name)
 390 {
 391         return ofnode_find_subnode(dev_ofnode(dev), subbnode_name);
 392 }
 393
 394 static inline int dev_read_size(struct udevice *dev, const char *propname)
 395 {
 396         return ofnode_read_size(dev_ofnode(dev), propname);
 397 }
 398
 399 static inline fdt_addr_t dev_read_addr_index(struct udevice *dev, int index)
 400 {
 401         return devfdt_get_addr_index(dev, index);
 402 }
 403
 404 static inline fdt_addr_t dev_read_addr(struct udevice *dev)
 405 {
 406         return devfdt_get_addr(dev);
 407 }
 408
 409 static inline fdt_addr_t dev_read_addr_size(struct udevice *dev,
 410                                             const char *propname,
 411                                             fdt_size_t *sizep)
 412 {
 413         return ofnode_get_addr_size(dev_ofnode(dev), propname, sizep);
 414 }
 415
 416 static inline const char *dev_read_name(struct udevice *dev)
 417 {
 418         return ofnode_get_name(dev_ofnode(dev));
 419 }
 420
 421 static inline int dev_read_stringlist_search(struct udevice *dev,
 422                                              const char *propname,
 423                                              const char *string)
 424 {
 425         return ofnode_stringlist_search(dev_ofnode(dev), propname, string);
 426 }
 427
 428 static inline int dev_read_phandle_with_args(struct udevice *dev,
 429                 const char *list_name, const char *cells_name, int cell_count,
 430                 int index, struct ofnode_phandle_args *out_args)
 431 {
 432         return ofnode_parse_phandle_with_args(dev_ofnode(dev), list_name,
 433                                               cells_name, cell_count, index,
 434                                               out_args);
 435 }
 436
 437 static inline int dev_count_phandle_with_args(struct udevice *dev,
 438                 const char *list_name, const char *cells_name)
 439 {
 440         return ofnode_count_phandle_with_args(dev_ofnode(dev), list_name,
 441                                               cells_name);
 442 }
 443
 444 static inline int dev_read_addr_cells(struct udevice *dev)
 445 {
 446         /* NOTE: this call should walk up the parent stack */
 447         return fdt_address_cells(gd->fdt_blob, dev_of_offset(dev));
 448 }
 449
 450 static inline int dev_read_size_cells(struct udevice *dev)
 451 {
 452         /* NOTE: this call should walk up the parent stack */
 453         return fdt_size_cells(gd->fdt_blob, dev_of_offset(dev));
 454 }
 455
 456 static inline int dev_read_simple_addr_cells(struct udevice *dev)
 457 {
 458         return fdt_address_cells(gd->fdt_blob, dev_of_offset(dev));
 459 }
 460
 461 static inline int dev_read_simple_size_cells(struct udevice *dev)
 462 {
 463         return fdt_size_cells(gd->fdt_blob, dev_of_offset(dev));
 464 }
 465
 466 static inline int dev_read_phandle(struct udevice *dev)
 467 {
 468         return fdt_get_phandle(gd->fdt_blob, dev_of_offset(dev));
 469 }
 470
 471 static inline const void *dev_read_prop(struct udevice *dev,
 472                                         const char *propname, int *lenp)
 473 {
 474         return ofnode_get_property(dev_ofnode(dev), propname, lenp);
 475 }
 476
 477 static inline int dev_read_alias_seq(struct udevice *dev, int *devnump)
 478 {
 479         return fdtdec_get_alias_seq(gd->fdt_blob, dev->uclass->uc_drv->name,
 480                                     dev_of_offset(dev), devnump);
 481 }
 482
 483 static inline int dev_read_u32_array(struct udevice *dev, const char *propname,
 484                                      u32 *out_values, size_t sz)
 485 {
 486         return ofnode_read_u32_array(dev_ofnode(dev), propname, out_values, sz);
 487 }
 488
 489 static inline ofnode dev_read_first_subnode(struct udevice *dev)
 490 {
 491         return ofnode_first_subnode(dev_ofnode(dev));
 492 }
 493
 494 static inline ofnode dev_read_next_subnode(ofnode node)
 495 {
 496         return ofnode_next_subnode(node);
 497 }
 498
 499 static inline const uint8_t *dev_read_u8_array_ptr(struct udevice *dev,
 500                                         const char *propname, size_t sz)
 501 {
 502         return ofnode_read_u8_array_ptr(dev_ofnode(dev), propname, sz);
 503 }
 504
 505 static inline int dev_read_enabled(struct udevice *dev)
 506 {
 507         return fdtdec_get_is_enabled(gd->fdt_blob, dev_of_offset(dev));
 508 }
 509
 510 static inline int dev_read_resource(struct udevice *dev, uint index,
 511                                     struct resource *res)
 512 {
 513         return ofnode_read_resource(dev_ofnode(dev), index, res);
 514 }
 515
 516 #endif /* CONFIG_DM_DEV_READ_INLINE */
 517
 518 /**
 519  * dev_for_each_subnode() - Helper function to iterate through subnodes
 520  *
 521  * This creates a for() loop which works through the subnodes in a device's
 522  * device-tree node.
 523  *
 524  * @subnode: ofnode holding the current subnode
 525  * @dev: device to use for interation (struct udevice *)
 526  */
 527 #define dev_for_each_subnode(subnode, dev) \
 528         for (subnode = dev_read_first_subnode(dev); \
 529              ofnode_valid(subnode); \
 530              subnode = ofnode_next_subnode(subnode))
 531
 532 #endif