root/drivers/of/property.c

DEFINITIONS

1. of_property_count_elems_of_size
2. of_find_property_value_of_size
3. of_property_read_u32_index
4. of_property_read_u64_index
5. of_property_read_variable_u8_array
6. of_property_read_variable_u16_array
7. of_property_read_variable_u32_array
8. of_property_read_u64
9. of_property_read_variable_u64_array
10. of_property_read_string
11. of_property_match_string
12. of_property_read_string_helper
13. of_prop_next_u32
14. of_prop_next_string
15. of_graph_parse_endpoint
16. of_graph_get_port_by_id
17. of_graph_get_next_endpoint
18. of_graph_get_endpoint_by_regs
19. of_graph_get_remote_endpoint
20. of_graph_get_port_parent
21. of_graph_get_remote_port_parent
22. of_graph_get_remote_port
23. of_graph_get_endpoint_count
24. of_graph_get_remote_node
25. of_fwnode_get
26. of_fwnode_put
27. of_fwnode_device_is_available
28. of_fwnode_property_present
29. of_fwnode_property_read_int_array
30. of_fwnode_property_read_string_array
31. of_fwnode_get_parent
32. of_fwnode_get_next_child_node
33. of_fwnode_get_named_child_node
34. of_fwnode_get_reference_args
35. of_fwnode_graph_get_next_endpoint
36. of_fwnode_graph_get_remote_endpoint
37. of_fwnode_graph_get_port_parent
38. of_fwnode_graph_parse_endpoint
39. of_fwnode_device_get_match_data

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * drivers/of/property.c - Procedures for accessing and interpreting
   4  *                         Devicetree properties and graphs.
   5  *
   6  * Initially created by copying procedures from drivers/of/base.c. This
   7  * file contains the OF property as well as the OF graph interface
   8  * functions.
   9  *
  10  * Paul Mackerras       August 1996.
  11  * Copyright (C) 1996-2005 Paul Mackerras.
  12  *
  13  *  Adapted for 64bit PowerPC by Dave Engebretsen and Peter Bergner.
  14  *    {engebret|bergner}@us.ibm.com
  15  *
  16  *  Adapted for sparc and sparc64 by David S. Miller davem@davemloft.net
  17  *
  18  *  Reconsolidated from arch/x/kernel/prom.c by Stephen Rothwell and
  19  *  Grant Likely.
  20  */
  21 
  22 #define pr_fmt(fmt)     "OF: " fmt
  23 
  24 #include <linux/of.h>
  25 #include <linux/of_device.h>
  26 #include <linux/of_graph.h>
  27 #include <linux/string.h>
  28 
  29 #include "of_private.h"
  30 
  31 /**
  32  * of_property_count_elems_of_size - Count the number of elements in a property
  33  *
  34  * @np:         device node from which the property value is to be read.
  35  * @propname:   name of the property to be searched.
  36  * @elem_size:  size of the individual element
  37  *
  38  * Search for a property in a device node and count the number of elements of
  39  * size elem_size in it. Returns number of elements on sucess, -EINVAL if the
  40  * property does not exist or its length does not match a multiple of elem_size
  41  * and -ENODATA if the property does not have a value.
  42  */
  43 int of_property_count_elems_of_size(const struct device_node *np,
  44                                 const char *propname, int elem_size)
  45 {
  46         struct property *prop = of_find_property(np, propname, NULL);
  47 
  48         if (!prop)
  49                 return -EINVAL;
  50         if (!prop->value)
  51                 return -ENODATA;
  52 
  53         if (prop->length % elem_size != 0) {
  54                 pr_err("size of %s in node %pOF is not a multiple of %d\n",
  55                        propname, np, elem_size);
  56                 return -EINVAL;
  57         }
  58 
  59         return prop->length / elem_size;
  60 }
  61 EXPORT_SYMBOL_GPL(of_property_count_elems_of_size);
  62 
  63 /**
  64  * of_find_property_value_of_size
  65  *
  66  * @np:         device node from which the property value is to be read.
  67  * @propname:   name of the property to be searched.
  68  * @min:        minimum allowed length of property value
  69  * @max:        maximum allowed length of property value (0 means unlimited)
  70  * @len:        if !=NULL, actual length is written to here
  71  *
  72  * Search for a property in a device node and valid the requested size.
  73  * Returns the property value on success, -EINVAL if the property does not
  74  *  exist, -ENODATA if property does not have a value, and -EOVERFLOW if the
  75  * property data is too small or too large.
  76  *
  77  */
  78 static void *of_find_property_value_of_size(const struct device_node *np,
  79                         const char *propname, u32 min, u32 max, size_t *len)
  80 {
  81         struct property *prop = of_find_property(np, propname, NULL);
  82 
  83         if (!prop)
  84                 return ERR_PTR(-EINVAL);
  85         if (!prop->value)
  86                 return ERR_PTR(-ENODATA);
  87         if (prop->length < min)
  88                 return ERR_PTR(-EOVERFLOW);
  89         if (max && prop->length > max)
  90                 return ERR_PTR(-EOVERFLOW);
  91 
  92         if (len)
  93                 *len = prop->length;
  94 
  95         return prop->value;
  96 }
  97 
  98 /**
  99  * of_property_read_u32_index - Find and read a u32 from a multi-value property.
 100  *
 101  * @np:         device node from which the property value is to be read.
 102  * @propname:   name of the property to be searched.
 103  * @index:      index of the u32 in the list of values
 104  * @out_value:  pointer to return value, modified only if no error.
 105  *
 106  * Search for a property in a device node and read nth 32-bit value from
 107  * it. Returns 0 on success, -EINVAL if the property does not exist,
 108  * -ENODATA if property does not have a value, and -EOVERFLOW if the
 109  * property data isn't large enough.
 110  *
 111  * The out_value is modified only if a valid u32 value can be decoded.
 112  */
 113 int of_property_read_u32_index(const struct device_node *np,
 114                                        const char *propname,
 115                                        u32 index, u32 *out_value)
 116 {
 117         const u32 *val = of_find_property_value_of_size(np, propname,
 118                                         ((index + 1) * sizeof(*out_value)),
 119                                         0,
 120                                         NULL);
 121 
 122         if (IS_ERR(val))
 123                 return PTR_ERR(val);
 124 
 125         *out_value = be32_to_cpup(((__be32 *)val) + index);
 126         return 0;
 127 }
 128 EXPORT_SYMBOL_GPL(of_property_read_u32_index);
 129 
 130 /**
 131  * of_property_read_u64_index - Find and read a u64 from a multi-value property.
 132  *
 133  * @np:         device node from which the property value is to be read.
 134  * @propname:   name of the property to be searched.
 135  * @index:      index of the u64 in the list of values
 136  * @out_value:  pointer to return value, modified only if no error.
 137  *
 138  * Search for a property in a device node and read nth 64-bit value from
 139  * it. Returns 0 on success, -EINVAL if the property does not exist,
 140  * -ENODATA if property does not have a value, and -EOVERFLOW if the
 141  * property data isn't large enough.
 142  *
 143  * The out_value is modified only if a valid u64 value can be decoded.
 144  */
 145 int of_property_read_u64_index(const struct device_node *np,
 146                                        const char *propname,
 147                                        u32 index, u64 *out_value)
 148 {
 149         const u64 *val = of_find_property_value_of_size(np, propname,
 150                                         ((index + 1) * sizeof(*out_value)),
 151                                         0, NULL);
 152 
 153         if (IS_ERR(val))
 154                 return PTR_ERR(val);
 155 
 156         *out_value = be64_to_cpup(((__be64 *)val) + index);
 157         return 0;
 158 }
 159 EXPORT_SYMBOL_GPL(of_property_read_u64_index);
 160 
 161 /**
 162  * of_property_read_variable_u8_array - Find and read an array of u8 from a
 163  * property, with bounds on the minimum and maximum array size.
 164  *
 165  * @np:         device node from which the property value is to be read.
 166  * @propname:   name of the property to be searched.
 167  * @out_values: pointer to return value, modified only if return value is 0.
 168  * @sz_min:     minimum number of array elements to read
 169  * @sz_max:     maximum number of array elements to read, if zero there is no
 170  *              upper limit on the number of elements in the dts entry but only
 171  *              sz_min will be read.
 172  *
 173  * Search for a property in a device node and read 8-bit value(s) from
 174  * it. Returns number of elements read on success, -EINVAL if the property
 175  * does not exist, -ENODATA if property does not have a value, and -EOVERFLOW
 176  * if the property data is smaller than sz_min or longer than sz_max.
 177  *
 178  * dts entry of array should be like:
 179  *      property = /bits/ 8 <0x50 0x60 0x70>;
 180  *
 181  * The out_values is modified only if a valid u8 value can be decoded.
 182  */
 183 int of_property_read_variable_u8_array(const struct device_node *np,
 184                                         const char *propname, u8 *out_values,
 185                                         size_t sz_min, size_t sz_max)
 186 {
 187         size_t sz, count;
 188         const u8 *val = of_find_property_value_of_size(np, propname,
 189                                                 (sz_min * sizeof(*out_values)),
 190                                                 (sz_max * sizeof(*out_values)),
 191                                                 &sz);
 192 
 193         if (IS_ERR(val))
 194                 return PTR_ERR(val);
 195 
 196         if (!sz_max)
 197                 sz = sz_min;
 198         else
 199                 sz /= sizeof(*out_values);
 200 
 201         count = sz;
 202         while (count--)
 203                 *out_values++ = *val++;
 204 
 205         return sz;
 206 }
 207 EXPORT_SYMBOL_GPL(of_property_read_variable_u8_array);
 208 
 209 /**
 210  * of_property_read_variable_u16_array - Find and read an array of u16 from a
 211  * property, with bounds on the minimum and maximum array size.
 212  *
 213  * @np:         device node from which the property value is to be read.
 214  * @propname:   name of the property to be searched.
 215  * @out_values: pointer to return value, modified only if return value is 0.
 216  * @sz_min:     minimum number of array elements to read
 217  * @sz_max:     maximum number of array elements to read, if zero there is no
 218  *              upper limit on the number of elements in the dts entry but only
 219  *              sz_min will be read.
 220  *
 221  * Search for a property in a device node and read 16-bit value(s) from
 222  * it. Returns number of elements read on success, -EINVAL if the property
 223  * does not exist, -ENODATA if property does not have a value, and -EOVERFLOW
 224  * if the property data is smaller than sz_min or longer than sz_max.
 225  *
 226  * dts entry of array should be like:
 227  *      property = /bits/ 16 <0x5000 0x6000 0x7000>;
 228  *
 229  * The out_values is modified only if a valid u16 value can be decoded.
 230  */
 231 int of_property_read_variable_u16_array(const struct device_node *np,
 232                                         const char *propname, u16 *out_values,
 233                                         size_t sz_min, size_t sz_max)
 234 {
 235         size_t sz, count;
 236         const __be16 *val = of_find_property_value_of_size(np, propname,
 237                                                 (sz_min * sizeof(*out_values)),
 238                                                 (sz_max * sizeof(*out_values)),
 239                                                 &sz);
 240 
 241         if (IS_ERR(val))
 242                 return PTR_ERR(val);
 243 
 244         if (!sz_max)
 245                 sz = sz_min;
 246         else
 247                 sz /= sizeof(*out_values);
 248 
 249         count = sz;
 250         while (count--)
 251                 *out_values++ = be16_to_cpup(val++);
 252 
 253         return sz;
 254 }
 255 EXPORT_SYMBOL_GPL(of_property_read_variable_u16_array);
 256 
 257 /**
 258  * of_property_read_variable_u32_array - Find and read an array of 32 bit
 259  * integers from a property, with bounds on the minimum and maximum array size.
 260  *
 261  * @np:         device node from which the property value is to be read.
 262  * @propname:   name of the property to be searched.
 263  * @out_values: pointer to return value, modified only if return value is 0.
 264  * @sz_min:     minimum number of array elements to read
 265  * @sz_max:     maximum number of array elements to read, if zero there is no
 266  *              upper limit on the number of elements in the dts entry but only
 267  *              sz_min will be read.
 268  *
 269  * Search for a property in a device node and read 32-bit value(s) from
 270  * it. Returns number of elements read on success, -EINVAL if the property
 271  * does not exist, -ENODATA if property does not have a value, and -EOVERFLOW
 272  * if the property data is smaller than sz_min or longer than sz_max.
 273  *
 274  * The out_values is modified only if a valid u32 value can be decoded.
 275  */
 276 int of_property_read_variable_u32_array(const struct device_node *np,
 277                                const char *propname, u32 *out_values,
 278                                size_t sz_min, size_t sz_max)
 279 {
 280         size_t sz, count;
 281         const __be32 *val = of_find_property_value_of_size(np, propname,
 282                                                 (sz_min * sizeof(*out_values)),
 283                                                 (sz_max * sizeof(*out_values)),
 284                                                 &sz);
 285 
 286         if (IS_ERR(val))
 287                 return PTR_ERR(val);
 288 
 289         if (!sz_max)
 290                 sz = sz_min;
 291         else
 292                 sz /= sizeof(*out_values);
 293 
 294         count = sz;
 295         while (count--)
 296                 *out_values++ = be32_to_cpup(val++);
 297 
 298         return sz;
 299 }
 300 EXPORT_SYMBOL_GPL(of_property_read_variable_u32_array);
 301 
 302 /**
 303  * of_property_read_u64 - Find and read a 64 bit integer from a property
 304  * @np:         device node from which the property value is to be read.
 305  * @propname:   name of the property to be searched.
 306  * @out_value:  pointer to return value, modified only if return value is 0.
 307  *
 308  * Search for a property in a device node and read a 64-bit value from
 309  * it. Returns 0 on success, -EINVAL if the property does not exist,
 310  * -ENODATA if property does not have a value, and -EOVERFLOW if the
 311  * property data isn't large enough.
 312  *
 313  * The out_value is modified only if a valid u64 value can be decoded.
 314  */
 315 int of_property_read_u64(const struct device_node *np, const char *propname,
 316                          u64 *out_value)
 317 {
 318         const __be32 *val = of_find_property_value_of_size(np, propname,
 319                                                 sizeof(*out_value),
 320                                                 0,
 321                                                 NULL);
 322 
 323         if (IS_ERR(val))
 324                 return PTR_ERR(val);
 325 
 326         *out_value = of_read_number(val, 2);
 327         return 0;
 328 }
 329 EXPORT_SYMBOL_GPL(of_property_read_u64);
 330 
 331 /**
 332  * of_property_read_variable_u64_array - Find and read an array of 64 bit
 333  * integers from a property, with bounds on the minimum and maximum array size.
 334  *
 335  * @np:         device node from which the property value is to be read.
 336  * @propname:   name of the property to be searched.
 337  * @out_values: pointer to return value, modified only if return value is 0.
 338  * @sz_min:     minimum number of array elements to read
 339  * @sz_max:     maximum number of array elements to read, if zero there is no
 340  *              upper limit on the number of elements in the dts entry but only
 341  *              sz_min will be read.
 342  *
 343  * Search for a property in a device node and read 64-bit value(s) from
 344  * it. Returns number of elements read on success, -EINVAL if the property
 345  * does not exist, -ENODATA if property does not have a value, and -EOVERFLOW
 346  * if the property data is smaller than sz_min or longer than sz_max.
 347  *
 348  * The out_values is modified only if a valid u64 value can be decoded.
 349  */
 350 int of_property_read_variable_u64_array(const struct device_node *np,
 351                                const char *propname, u64 *out_values,
 352                                size_t sz_min, size_t sz_max)
 353 {
 354         size_t sz, count;
 355         const __be32 *val = of_find_property_value_of_size(np, propname,
 356                                                 (sz_min * sizeof(*out_values)),
 357                                                 (sz_max * sizeof(*out_values)),
 358                                                 &sz);
 359 
 360         if (IS_ERR(val))
 361                 return PTR_ERR(val);
 362 
 363         if (!sz_max)
 364                 sz = sz_min;
 365         else
 366                 sz /= sizeof(*out_values);
 367 
 368         count = sz;
 369         while (count--) {
 370                 *out_values++ = of_read_number(val, 2);
 371                 val += 2;
 372         }
 373 
 374         return sz;
 375 }
 376 EXPORT_SYMBOL_GPL(of_property_read_variable_u64_array);
 377 
 378 /**
 379  * of_property_read_string - Find and read a string from a property
 380  * @np:         device node from which the property value is to be read.
 381  * @propname:   name of the property to be searched.
 382  * @out_string: pointer to null terminated return string, modified only if
 383  *              return value is 0.
 384  *
 385  * Search for a property in a device tree node and retrieve a null
 386  * terminated string value (pointer to data, not a copy). Returns 0 on
 387  * success, -EINVAL if the property does not exist, -ENODATA if property
 388  * does not have a value, and -EILSEQ if the string is not null-terminated
 389  * within the length of the property data.
 390  *
 391  * The out_string pointer is modified only if a valid string can be decoded.
 392  */
 393 int of_property_read_string(const struct device_node *np, const char *propname,
 394                                 const char **out_string)
 395 {
 396         const struct property *prop = of_find_property(np, propname, NULL);
 397         if (!prop)
 398                 return -EINVAL;
 399         if (!prop->value)
 400                 return -ENODATA;
 401         if (strnlen(prop->value, prop->length) >= prop->length)
 402                 return -EILSEQ;
 403         *out_string = prop->value;
 404         return 0;
 405 }
 406 EXPORT_SYMBOL_GPL(of_property_read_string);
 407 
 408 /**
 409  * of_property_match_string() - Find string in a list and return index
 410  * @np: pointer to node containing string list property
 411  * @propname: string list property name
 412  * @string: pointer to string to search for in string list
 413  *
 414  * This function searches a string list property and returns the index
 415  * of a specific string value.
 416  */
 417 int of_property_match_string(const struct device_node *np, const char *propname,
 418                              const char *string)
 419 {
 420         const struct property *prop = of_find_property(np, propname, NULL);
 421         size_t l;
 422         int i;
 423         const char *p, *end;
 424 
 425         if (!prop)
 426                 return -EINVAL;
 427         if (!prop->value)
 428                 return -ENODATA;
 429 
 430         p = prop->value;
 431         end = p + prop->length;
 432 
 433         for (i = 0; p < end; i++, p += l) {
 434                 l = strnlen(p, end - p) + 1;
 435                 if (p + l > end)
 436                         return -EILSEQ;
 437                 pr_debug("comparing %s with %s\n", string, p);
 438                 if (strcmp(string, p) == 0)
 439                         return i; /* Found it; return index */
 440         }
 441         return -ENODATA;
 442 }
 443 EXPORT_SYMBOL_GPL(of_property_match_string);
 444 
 445 /**
 446  * of_property_read_string_helper() - Utility helper for parsing string properties
 447  * @np:         device node from which the property value is to be read.
 448  * @propname:   name of the property to be searched.
 449  * @out_strs:   output array of string pointers.
 450  * @sz:         number of array elements to read.
 451  * @skip:       Number of strings to skip over at beginning of list.
 452  *
 453  * Don't call this function directly. It is a utility helper for the
 454  * of_property_read_string*() family of functions.
 455  */
 456 int of_property_read_string_helper(const struct device_node *np,
 457                                    const char *propname, const char **out_strs,
 458                                    size_t sz, int skip)
 459 {
 460         const struct property *prop = of_find_property(np, propname, NULL);
 461         int l = 0, i = 0;
 462         const char *p, *end;
 463 
 464         if (!prop)
 465                 return -EINVAL;
 466         if (!prop->value)
 467                 return -ENODATA;
 468         p = prop->value;
 469         end = p + prop->length;
 470 
 471         for (i = 0; p < end && (!out_strs || i < skip + sz); i++, p += l) {
 472                 l = strnlen(p, end - p) + 1;
 473                 if (p + l > end)
 474                         return -EILSEQ;
 475                 if (out_strs && i >= skip)
 476                         *out_strs++ = p;
 477         }
 478         i -= skip;
 479         return i <= 0 ? -ENODATA : i;
 480 }
 481 EXPORT_SYMBOL_GPL(of_property_read_string_helper);
 482 
 483 const __be32 *of_prop_next_u32(struct property *prop, const __be32 *cur,
 484                                u32 *pu)
 485 {
 486         const void *curv = cur;
 487 
 488         if (!prop)
 489                 return NULL;
 490 
 491         if (!cur) {
 492                 curv = prop->value;
 493                 goto out_val;
 494         }
 495 
 496         curv += sizeof(*cur);
 497         if (curv >= prop->value + prop->length)
 498                 return NULL;
 499 
 500 out_val:
 501         *pu = be32_to_cpup(curv);
 502         return curv;
 503 }
 504 EXPORT_SYMBOL_GPL(of_prop_next_u32);
 505 
 506 const char *of_prop_next_string(struct property *prop, const char *cur)
 507 {
 508         const void *curv = cur;
 509 
 510         if (!prop)
 511                 return NULL;
 512 
 513         if (!cur)
 514                 return prop->value;
 515 
 516         curv += strlen(cur) + 1;
 517         if (curv >= prop->value + prop->length)
 518                 return NULL;
 519 
 520         return curv;
 521 }
 522 EXPORT_SYMBOL_GPL(of_prop_next_string);
 523 
 524 /**
 525  * of_graph_parse_endpoint() - parse common endpoint node properties
 526  * @node: pointer to endpoint device_node
 527  * @endpoint: pointer to the OF endpoint data structure
 528  *
 529  * The caller should hold a reference to @node.
 530  */
 531 int of_graph_parse_endpoint(const struct device_node *node,
 532                             struct of_endpoint *endpoint)
 533 {
 534         struct device_node *port_node = of_get_parent(node);
 535 
 536         WARN_ONCE(!port_node, "%s(): endpoint %pOF has no parent node\n",
 537                   __func__, node);
 538 
 539         memset(endpoint, 0, sizeof(*endpoint));
 540 
 541         endpoint->local_node = node;
 542         /*
 543          * It doesn't matter whether the two calls below succeed.
 544          * If they don't then the default value 0 is used.
 545          */
 546         of_property_read_u32(port_node, "reg", &endpoint->port);
 547         of_property_read_u32(node, "reg", &endpoint->id);
 548 
 549         of_node_put(port_node);
 550 
 551         return 0;
 552 }
 553 EXPORT_SYMBOL(of_graph_parse_endpoint);
 554 
 555 /**
 556  * of_graph_get_port_by_id() - get the port matching a given id
 557  * @parent: pointer to the parent device node
 558  * @id: id of the port
 559  *
 560  * Return: A 'port' node pointer with refcount incremented. The caller
 561  * has to use of_node_put() on it when done.
 562  */
 563 struct device_node *of_graph_get_port_by_id(struct device_node *parent, u32 id)
 564 {
 565         struct device_node *node, *port;
 566 
 567         node = of_get_child_by_name(parent, "ports");
 568         if (node)
 569                 parent = node;
 570 
 571         for_each_child_of_node(parent, port) {
 572                 u32 port_id = 0;
 573 
 574                 if (!of_node_name_eq(port, "port"))
 575                         continue;
 576                 of_property_read_u32(port, "reg", &port_id);
 577                 if (id == port_id)
 578                         break;
 579         }
 580 
 581         of_node_put(node);
 582 
 583         return port;
 584 }
 585 EXPORT_SYMBOL(of_graph_get_port_by_id);
 586 
 587 /**
 588  * of_graph_get_next_endpoint() - get next endpoint node
 589  * @parent: pointer to the parent device node
 590  * @prev: previous endpoint node, or NULL to get first
 591  *
 592  * Return: An 'endpoint' node pointer with refcount incremented. Refcount
 593  * of the passed @prev node is decremented.
 594  */
 595 struct device_node *of_graph_get_next_endpoint(const struct device_node *parent,
 596                                         struct device_node *prev)
 597 {
 598         struct device_node *endpoint;
 599         struct device_node *port;
 600 
 601         if (!parent)
 602                 return NULL;
 603 
 604         /*
 605          * Start by locating the port node. If no previous endpoint is specified
 606          * search for the first port node, otherwise get the previous endpoint
 607          * parent port node.
 608          */
 609         if (!prev) {
 610                 struct device_node *node;
 611 
 612                 node = of_get_child_by_name(parent, "ports");
 613                 if (node)
 614                         parent = node;
 615 
 616                 port = of_get_child_by_name(parent, "port");
 617                 of_node_put(node);
 618 
 619                 if (!port) {
 620                         pr_err("graph: no port node found in %pOF\n", parent);
 621                         return NULL;
 622                 }
 623         } else {
 624                 port = of_get_parent(prev);
 625                 if (WARN_ONCE(!port, "%s(): endpoint %pOF has no parent node\n",
 626                               __func__, prev))
 627                         return NULL;
 628         }
 629 
 630         while (1) {
 631                 /*
 632                  * Now that we have a port node, get the next endpoint by
 633                  * getting the next child. If the previous endpoint is NULL this
 634                  * will return the first child.
 635                  */
 636                 endpoint = of_get_next_child(port, prev);
 637                 if (endpoint) {
 638                         of_node_put(port);
 639                         return endpoint;
 640                 }
 641 
 642                 /* No more endpoints under this port, try the next one. */
 643                 prev = NULL;
 644 
 645                 do {
 646                         port = of_get_next_child(parent, port);
 647                         if (!port)
 648                                 return NULL;
 649                 } while (!of_node_name_eq(port, "port"));
 650         }
 651 }
 652 EXPORT_SYMBOL(of_graph_get_next_endpoint);
 653 
 654 /**
 655  * of_graph_get_endpoint_by_regs() - get endpoint node of specific identifiers
 656  * @parent: pointer to the parent device node
 657  * @port_reg: identifier (value of reg property) of the parent port node
 658  * @reg: identifier (value of reg property) of the endpoint node
 659  *
 660  * Return: An 'endpoint' node pointer which is identified by reg and at the same
 661  * is the child of a port node identified by port_reg. reg and port_reg are
 662  * ignored when they are -1. Use of_node_put() on the pointer when done.
 663  */
 664 struct device_node *of_graph_get_endpoint_by_regs(
 665         const struct device_node *parent, int port_reg, int reg)
 666 {
 667         struct of_endpoint endpoint;
 668         struct device_node *node = NULL;
 669 
 670         for_each_endpoint_of_node(parent, node) {
 671                 of_graph_parse_endpoint(node, &endpoint);
 672                 if (((port_reg == -1) || (endpoint.port == port_reg)) &&
 673                         ((reg == -1) || (endpoint.id == reg)))
 674                         return node;
 675         }
 676 
 677         return NULL;
 678 }
 679 EXPORT_SYMBOL(of_graph_get_endpoint_by_regs);
 680 
 681 /**
 682  * of_graph_get_remote_endpoint() - get remote endpoint node
 683  * @node: pointer to a local endpoint device_node
 684  *
 685  * Return: Remote endpoint node associated with remote endpoint node linked
 686  *         to @node. Use of_node_put() on it when done.
 687  */
 688 struct device_node *of_graph_get_remote_endpoint(const struct device_node *node)
 689 {
 690         /* Get remote endpoint node. */
 691         return of_parse_phandle(node, "remote-endpoint", 0);
 692 }
 693 EXPORT_SYMBOL(of_graph_get_remote_endpoint);
 694 
 695 /**
 696  * of_graph_get_port_parent() - get port's parent node
 697  * @node: pointer to a local endpoint device_node
 698  *
 699  * Return: device node associated with endpoint node linked
 700  *         to @node. Use of_node_put() on it when done.
 701  */
 702 struct device_node *of_graph_get_port_parent(struct device_node *node)
 703 {
 704         unsigned int depth;
 705 
 706         if (!node)
 707                 return NULL;
 708 
 709         /*
 710          * Preserve usecount for passed in node as of_get_next_parent()
 711          * will do of_node_put() on it.
 712          */
 713         of_node_get(node);
 714 
 715         /* Walk 3 levels up only if there is 'ports' node. */
 716         for (depth = 3; depth && node; depth--) {
 717                 node = of_get_next_parent(node);
 718                 if (depth == 2 && !of_node_name_eq(node, "ports"))
 719                         break;
 720         }
 721         return node;
 722 }
 723 EXPORT_SYMBOL(of_graph_get_port_parent);
 724 
 725 /**
 726  * of_graph_get_remote_port_parent() - get remote port's parent node
 727  * @node: pointer to a local endpoint device_node
 728  *
 729  * Return: Remote device node associated with remote endpoint node linked
 730  *         to @node. Use of_node_put() on it when done.
 731  */
 732 struct device_node *of_graph_get_remote_port_parent(
 733                                const struct device_node *node)
 734 {
 735         struct device_node *np, *pp;
 736 
 737         /* Get remote endpoint node. */
 738         np = of_graph_get_remote_endpoint(node);
 739 
 740         pp = of_graph_get_port_parent(np);
 741 
 742         of_node_put(np);
 743 
 744         return pp;
 745 }
 746 EXPORT_SYMBOL(of_graph_get_remote_port_parent);
 747 
 748 /**
 749  * of_graph_get_remote_port() - get remote port node
 750  * @node: pointer to a local endpoint device_node
 751  *
 752  * Return: Remote port node associated with remote endpoint node linked
 753  *         to @node. Use of_node_put() on it when done.
 754  */
 755 struct device_node *of_graph_get_remote_port(const struct device_node *node)
 756 {
 757         struct device_node *np;
 758 
 759         /* Get remote endpoint node. */
 760         np = of_graph_get_remote_endpoint(node);
 761         if (!np)
 762                 return NULL;
 763         return of_get_next_parent(np);
 764 }
 765 EXPORT_SYMBOL(of_graph_get_remote_port);
 766 
 767 int of_graph_get_endpoint_count(const struct device_node *np)
 768 {
 769         struct device_node *endpoint;
 770         int num = 0;
 771 
 772         for_each_endpoint_of_node(np, endpoint)
 773                 num++;
 774 
 775         return num;
 776 }
 777 EXPORT_SYMBOL(of_graph_get_endpoint_count);
 778 
 779 /**
 780  * of_graph_get_remote_node() - get remote parent device_node for given port/endpoint
 781  * @node: pointer to parent device_node containing graph port/endpoint
 782  * @port: identifier (value of reg property) of the parent port node
 783  * @endpoint: identifier (value of reg property) of the endpoint node
 784  *
 785  * Return: Remote device node associated with remote endpoint node linked
 786  *         to @node. Use of_node_put() on it when done.
 787  */
 788 struct device_node *of_graph_get_remote_node(const struct device_node *node,
 789                                              u32 port, u32 endpoint)
 790 {
 791         struct device_node *endpoint_node, *remote;
 792 
 793         endpoint_node = of_graph_get_endpoint_by_regs(node, port, endpoint);
 794         if (!endpoint_node) {
 795                 pr_debug("no valid endpoint (%d, %d) for node %pOF\n",
 796                          port, endpoint, node);
 797                 return NULL;
 798         }
 799 
 800         remote = of_graph_get_remote_port_parent(endpoint_node);
 801         of_node_put(endpoint_node);
 802         if (!remote) {
 803                 pr_debug("no valid remote node\n");
 804                 return NULL;
 805         }
 806 
 807         if (!of_device_is_available(remote)) {
 808                 pr_debug("not available for remote node\n");
 809                 of_node_put(remote);
 810                 return NULL;
 811         }
 812 
 813         return remote;
 814 }
 815 EXPORT_SYMBOL(of_graph_get_remote_node);
 816 
 817 static struct fwnode_handle *of_fwnode_get(struct fwnode_handle *fwnode)
 818 {
 819         return of_fwnode_handle(of_node_get(to_of_node(fwnode)));
 820 }
 821 
 822 static void of_fwnode_put(struct fwnode_handle *fwnode)
 823 {
 824         of_node_put(to_of_node(fwnode));
 825 }
 826 
 827 static bool of_fwnode_device_is_available(const struct fwnode_handle *fwnode)
 828 {
 829         return of_device_is_available(to_of_node(fwnode));
 830 }
 831 
 832 static bool of_fwnode_property_present(const struct fwnode_handle *fwnode,
 833                                        const char *propname)
 834 {
 835         return of_property_read_bool(to_of_node(fwnode), propname);
 836 }
 837 
 838 static int of_fwnode_property_read_int_array(const struct fwnode_handle *fwnode,
 839                                              const char *propname,
 840                                              unsigned int elem_size, void *val,
 841                                              size_t nval)
 842 {
 843         const struct device_node *node = to_of_node(fwnode);
 844 
 845         if (!val)
 846                 return of_property_count_elems_of_size(node, propname,
 847                                                        elem_size);
 848 
 849         switch (elem_size) {
 850         case sizeof(u8):
 851                 return of_property_read_u8_array(node, propname, val, nval);
 852         case sizeof(u16):
 853                 return of_property_read_u16_array(node, propname, val, nval);
 854         case sizeof(u32):
 855                 return of_property_read_u32_array(node, propname, val, nval);
 856         case sizeof(u64):
 857                 return of_property_read_u64_array(node, propname, val, nval);
 858         }
 859 
 860         return -ENXIO;
 861 }
 862 
 863 static int
 864 of_fwnode_property_read_string_array(const struct fwnode_handle *fwnode,
 865                                      const char *propname, const char **val,
 866                                      size_t nval)
 867 {
 868         const struct device_node *node = to_of_node(fwnode);
 869 
 870         return val ?
 871                 of_property_read_string_array(node, propname, val, nval) :
 872                 of_property_count_strings(node, propname);
 873 }
 874 
 875 static struct fwnode_handle *
 876 of_fwnode_get_parent(const struct fwnode_handle *fwnode)
 877 {
 878         return of_fwnode_handle(of_get_parent(to_of_node(fwnode)));
 879 }
 880 
 881 static struct fwnode_handle *
 882 of_fwnode_get_next_child_node(const struct fwnode_handle *fwnode,
 883                               struct fwnode_handle *child)
 884 {
 885         return of_fwnode_handle(of_get_next_available_child(to_of_node(fwnode),
 886                                                             to_of_node(child)));
 887 }
 888 
 889 static struct fwnode_handle *
 890 of_fwnode_get_named_child_node(const struct fwnode_handle *fwnode,
 891                                const char *childname)
 892 {
 893         const struct device_node *node = to_of_node(fwnode);
 894         struct device_node *child;
 895 
 896         for_each_available_child_of_node(node, child)
 897                 if (of_node_name_eq(child, childname))
 898                         return of_fwnode_handle(child);
 899 
 900         return NULL;
 901 }
 902 
 903 static int
 904 of_fwnode_get_reference_args(const struct fwnode_handle *fwnode,
 905                              const char *prop, const char *nargs_prop,
 906                              unsigned int nargs, unsigned int index,
 907                              struct fwnode_reference_args *args)
 908 {
 909         struct of_phandle_args of_args;
 910         unsigned int i;
 911         int ret;
 912 
 913         if (nargs_prop)
 914                 ret = of_parse_phandle_with_args(to_of_node(fwnode), prop,
 915                                                  nargs_prop, index, &of_args);
 916         else
 917                 ret = of_parse_phandle_with_fixed_args(to_of_node(fwnode), prop,
 918                                                        nargs, index, &of_args);
 919         if (ret < 0)
 920                 return ret;
 921         if (!args)
 922                 return 0;
 923 
 924         args->nargs = of_args.args_count;
 925         args->fwnode = of_fwnode_handle(of_args.np);
 926 
 927         for (i = 0; i < NR_FWNODE_REFERENCE_ARGS; i++)
 928                 args->args[i] = i < of_args.args_count ? of_args.args[i] : 0;
 929 
 930         return 0;
 931 }
 932 
 933 static struct fwnode_handle *
 934 of_fwnode_graph_get_next_endpoint(const struct fwnode_handle *fwnode,
 935                                   struct fwnode_handle *prev)
 936 {
 937         return of_fwnode_handle(of_graph_get_next_endpoint(to_of_node(fwnode),
 938                                                            to_of_node(prev)));
 939 }
 940 
 941 static struct fwnode_handle *
 942 of_fwnode_graph_get_remote_endpoint(const struct fwnode_handle *fwnode)
 943 {
 944         return of_fwnode_handle(
 945                 of_graph_get_remote_endpoint(to_of_node(fwnode)));
 946 }
 947 
 948 static struct fwnode_handle *
 949 of_fwnode_graph_get_port_parent(struct fwnode_handle *fwnode)
 950 {
 951         struct device_node *np;
 952 
 953         /* Get the parent of the port */
 954         np = of_get_parent(to_of_node(fwnode));
 955         if (!np)
 956                 return NULL;
 957 
 958         /* Is this the "ports" node? If not, it's the port parent. */
 959         if (!of_node_name_eq(np, "ports"))
 960                 return of_fwnode_handle(np);
 961 
 962         return of_fwnode_handle(of_get_next_parent(np));
 963 }
 964 
 965 static int of_fwnode_graph_parse_endpoint(const struct fwnode_handle *fwnode,
 966                                           struct fwnode_endpoint *endpoint)
 967 {
 968         const struct device_node *node = to_of_node(fwnode);
 969         struct device_node *port_node = of_get_parent(node);
 970 
 971         endpoint->local_fwnode = fwnode;
 972 
 973         of_property_read_u32(port_node, "reg", &endpoint->port);
 974         of_property_read_u32(node, "reg", &endpoint->id);
 975 
 976         of_node_put(port_node);
 977 
 978         return 0;
 979 }
 980 
 981 static const void *
 982 of_fwnode_device_get_match_data(const struct fwnode_handle *fwnode,
 983                                 const struct device *dev)
 984 {
 985         return of_device_get_match_data(dev);
 986 }
 987 
 988 const struct fwnode_operations of_fwnode_ops = {
 989         .get = of_fwnode_get,
 990         .put = of_fwnode_put,
 991         .device_is_available = of_fwnode_device_is_available,
 992         .device_get_match_data = of_fwnode_device_get_match_data,
 993         .property_present = of_fwnode_property_present,
 994         .property_read_int_array = of_fwnode_property_read_int_array,
 995         .property_read_string_array = of_fwnode_property_read_string_array,
 996         .get_parent = of_fwnode_get_parent,
 997         .get_next_child_node = of_fwnode_get_next_child_node,
 998         .get_named_child_node = of_fwnode_get_named_child_node,
 999         .get_reference_args = of_fwnode_get_reference_args,
1000         .graph_get_next_endpoint = of_fwnode_graph_get_next_endpoint,
1001         .graph_get_remote_endpoint = of_fwnode_graph_get_remote_endpoint,
1002         .graph_get_port_parent = of_fwnode_graph_get_port_parent,
1003         .graph_parse_endpoint = of_fwnode_graph_parse_endpoint,
1004 };
1005 EXPORT_SYMBOL_GPL(of_fwnode_ops);