drivers/base/property.c

   1 /*
   2  * property.c - Unified device property interface.
   3  *
   4  * Copyright (C) 2014, Intel Corporation
   5  * Authors: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
   6  *          Mika Westerberg <mika.westerberg@linux.intel.com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 as
  10  * published by the Free Software Foundation.
  11  */
  12
  13 #include <linux/acpi.h>
  14 #include <linux/export.h>
  15 #include <linux/kernel.h>
  16 #include <linux/of.h>
  17 #include <linux/of_address.h>
  18 #include <linux/property.h>
  19 #include <linux/etherdevice.h>
  20 #include <linux/phy.h>
  21
  22 /**
  23  * device_add_property_set - Add a collection of properties to a device object.
  24  * @dev: Device to add properties to.
  25  * @pset: Collection of properties to add.
  26  *
  27  * Associate a collection of device properties represented by @pset with @dev
  28  * as its secondary firmware node.
  29  */
  30 void device_add_property_set(struct device *dev, struct property_set *pset)
  31 {
  32         if (!pset)
  33                 return;
  34
  35         pset->fwnode.type = FWNODE_PDATA;
  36         set_secondary_fwnode(dev, &pset->fwnode);
  37 }
  38 EXPORT_SYMBOL_GPL(device_add_property_set);
  39
  40 static inline bool is_pset(struct fwnode_handle *fwnode)
  41 {
  42         return fwnode && fwnode->type == FWNODE_PDATA;
  43 }
  44
  45 static inline struct property_set *to_pset(struct fwnode_handle *fwnode)
  46 {
  47         return is_pset(fwnode) ?
  48                 container_of(fwnode, struct property_set, fwnode) : NULL;
  49 }
  50
  51 static struct property_entry *pset_prop_get(struct property_set *pset,
  52                                             const char *name)
  53 {
  54         struct property_entry *prop;
  55
  56         if (!pset || !pset->properties)
  57                 return NULL;
  58
  59         for (prop = pset->properties; prop->name; prop++)
  60                 if (!strcmp(name, prop->name))
  61                         return prop;
  62
  63         return NULL;
  64 }
  65
  66 static int pset_prop_read_array(struct property_set *pset, const char *name,
  67                                 enum dev_prop_type type, void *val, size_t nval)
  68 {
  69         struct property_entry *prop;
  70         unsigned int item_size;
  71
  72         prop = pset_prop_get(pset, name);
  73         if (!prop)
  74                 return -ENODATA;
  75
  76         if (prop->type != type)
  77                 return -EPROTO;
  78
  79         if (!val)
  80                 return prop->nval;
  81
  82         if (prop->nval < nval)
  83                 return -EOVERFLOW;
  84
  85         switch (type) {
  86         case DEV_PROP_U8:
  87                 item_size = sizeof(u8);
  88                 break;
  89         case DEV_PROP_U16:
  90                 item_size = sizeof(u16);
  91                 break;
  92         case DEV_PROP_U32:
  93                 item_size = sizeof(u32);
  94                 break;
  95         case DEV_PROP_U64:
  96                 item_size = sizeof(u64);
  97                 break;
  98         case DEV_PROP_STRING:
  99                 item_size = sizeof(const char *);
 100                 break;
 101         default:
 102                 return -EINVAL;
 103         }
 104         memcpy(val, prop->value.raw_data, nval * item_size);
 105         return 0;
 106 }
 107
 108 static inline struct fwnode_handle *dev_fwnode(struct device *dev)
 109 {
 110         return IS_ENABLED(CONFIG_OF) && dev->of_node ?
 111                 &dev->of_node->fwnode : dev->fwnode;
 112 }
 113
 114 /**
 115  * device_property_present - check if a property of a device is present
 116  * @dev: Device whose property is being checked
 117  * @propname: Name of the property
 118  *
 119  * Check if property @propname is present in the device firmware description.
 120  */
 121 bool device_property_present(struct device *dev, const char *propname)
 122 {
 123         return fwnode_property_present(dev_fwnode(dev), propname);
 124 }
 125 EXPORT_SYMBOL_GPL(device_property_present);
 126
 127 /**
 128  * fwnode_property_present - check if a property of a firmware node is present
 129  * @fwnode: Firmware node whose property to check
 130  * @propname: Name of the property
 131  */
 132 bool fwnode_property_present(struct fwnode_handle *fwnode, const char *propname)
 133 {
 134         if (is_of_node(fwnode))
 135                 return of_property_read_bool(to_of_node(fwnode), propname);
 136         else if (is_acpi_node(fwnode))
 137                 return !acpi_node_prop_get(fwnode, propname, NULL);
 138
 139         return !!pset_prop_get(to_pset(fwnode), propname);
 140 }
 141 EXPORT_SYMBOL_GPL(fwnode_property_present);
 142
 143 /**
 144  * device_property_read_u8_array - return a u8 array property of a device
 145  * @dev: Device to get the property of
 146  * @propname: Name of the property
 147  * @val: The values are stored here or %NULL to return the number of values
 148  * @nval: Size of the @val array
 149  *
 150  * Function reads an array of u8 properties with @propname from the device
 151  * firmware description and stores them to @val if found.
 152  *
 153  * Return: number of values if @val was %NULL,
 154  *         %0 if the property was found (success),
 155  *         %-EINVAL if given arguments are not valid,
 156  *         %-ENODATA if the property does not have a value,
 157  *         %-EPROTO if the property is not an array of numbers,
 158  *         %-EOVERFLOW if the size of the property is not as expected.
 159  *         %-ENXIO if no suitable firmware interface is present.
 160  */
 161 int device_property_read_u8_array(struct device *dev, const char *propname,
 162                                   u8 *val, size_t nval)
 163 {
 164         return fwnode_property_read_u8_array(dev_fwnode(dev), propname, val, nval);
 165 }
 166 EXPORT_SYMBOL_GPL(device_property_read_u8_array);
 167
 168 /**
 169  * device_property_read_u16_array - return a u16 array property of a device
 170  * @dev: Device to get the property of
 171  * @propname: Name of the property
 172  * @val: The values are stored here or %NULL to return the number of values
 173  * @nval: Size of the @val array
 174  *
 175  * Function reads an array of u16 properties with @propname from the device
 176  * firmware description and stores them to @val if found.
 177  *
 178  * Return: number of values if @val was %NULL,
 179  *         %0 if the property was found (success),
 180  *         %-EINVAL if given arguments are not valid,
 181  *         %-ENODATA if the property does not have a value,
 182  *         %-EPROTO if the property is not an array of numbers,
 183  *         %-EOVERFLOW if the size of the property is not as expected.
 184  *         %-ENXIO if no suitable firmware interface is present.
 185  */
 186 int device_property_read_u16_array(struct device *dev, const char *propname,
 187                                    u16 *val, size_t nval)
 188 {
 189         return fwnode_property_read_u16_array(dev_fwnode(dev), propname, val, nval);
 190 }
 191 EXPORT_SYMBOL_GPL(device_property_read_u16_array);
 192
 193 /**
 194  * device_property_read_u32_array - return a u32 array property of a device
 195  * @dev: Device to get the property of
 196  * @propname: Name of the property
 197  * @val: The values are stored here or %NULL to return the number of values
 198  * @nval: Size of the @val array
 199  *
 200  * Function reads an array of u32 properties with @propname from the device
 201  * firmware description and stores them to @val if found.
 202  *
 203  * Return: number of values if @val was %NULL,
 204  *         %0 if the property was found (success),
 205  *         %-EINVAL if given arguments are not valid,
 206  *         %-ENODATA if the property does not have a value,
 207  *         %-EPROTO if the property is not an array of numbers,
 208  *         %-EOVERFLOW if the size of the property is not as expected.
 209  *         %-ENXIO if no suitable firmware interface is present.
 210  */
 211 int device_property_read_u32_array(struct device *dev, const char *propname,
 212                                    u32 *val, size_t nval)
 213 {
 214         return fwnode_property_read_u32_array(dev_fwnode(dev), propname, val, nval);
 215 }
 216 EXPORT_SYMBOL_GPL(device_property_read_u32_array);
 217
 218 /**
 219  * device_property_read_u64_array - return a u64 array property of a device
 220  * @dev: Device to get the property of
 221  * @propname: Name of the property
 222  * @val: The values are stored here or %NULL to return the number of values
 223  * @nval: Size of the @val array
 224  *
 225  * Function reads an array of u64 properties with @propname from the device
 226  * firmware description and stores them to @val if found.
 227  *
 228  * Return: number of values if @val was %NULL,
 229  *         %0 if the property was found (success),
 230  *         %-EINVAL if given arguments are not valid,
 231  *         %-ENODATA if the property does not have a value,
 232  *         %-EPROTO if the property is not an array of numbers,
 233  *         %-EOVERFLOW if the size of the property is not as expected.
 234  *         %-ENXIO if no suitable firmware interface is present.
 235  */
 236 int device_property_read_u64_array(struct device *dev, const char *propname,
 237                                    u64 *val, size_t nval)
 238 {
 239         return fwnode_property_read_u64_array(dev_fwnode(dev), propname, val, nval);
 240 }
 241 EXPORT_SYMBOL_GPL(device_property_read_u64_array);
 242
 243 /**
 244  * device_property_read_string_array - return a string array property of device
 245  * @dev: Device to get the property of
 246  * @propname: Name of the property
 247  * @val: The values are stored here or %NULL to return the number of values
 248  * @nval: Size of the @val array
 249  *
 250  * Function reads an array of string properties with @propname from the device
 251  * firmware description and stores them to @val if found.
 252  *
 253  * Return: number of values if @val was %NULL,
 254  *         %0 if the property was found (success),
 255  *         %-EINVAL if given arguments are not valid,
 256  *         %-ENODATA if the property does not have a value,
 257  *         %-EPROTO or %-EILSEQ if the property is not an array of strings,
 258  *         %-EOVERFLOW if the size of the property is not as expected.
 259  *         %-ENXIO if no suitable firmware interface is present.
 260  */
 261 int device_property_read_string_array(struct device *dev, const char *propname,
 262                                       const char **val, size_t nval)
 263 {
 264         return fwnode_property_read_string_array(dev_fwnode(dev), propname, val, nval);
 265 }
 266 EXPORT_SYMBOL_GPL(device_property_read_string_array);
 267
 268 /**
 269  * device_property_read_string - return a string property of a device
 270  * @dev: Device to get the property of
 271  * @propname: Name of the property
 272  * @val: The value is stored here
 273  *
 274  * Function reads property @propname from the device firmware description and
 275  * stores the value into @val if found. The value is checked to be a string.
 276  *
 277  * Return: %0 if the property was found (success),
 278  *         %-EINVAL if given arguments are not valid,
 279  *         %-ENODATA if the property does not have a value,
 280  *         %-EPROTO or %-EILSEQ if the property type is not a string.
 281  *         %-ENXIO if no suitable firmware interface is present.
 282  */
 283 int device_property_read_string(struct device *dev, const char *propname,
 284                                 const char **val)
 285 {
 286         return fwnode_property_read_string(dev_fwnode(dev), propname, val);
 287 }
 288 EXPORT_SYMBOL_GPL(device_property_read_string);
 289
 290 /**
 291  * device_property_match_string - find a string in an array and return index
 292  * @dev: Device to get the property of
 293  * @propname: Name of the property holding the array
 294  * @string: String to look for
 295  *
 296  * Find a given string in a string array and if it is found return the
 297  * index back.
 298  *
 299  * Return: %0 if the property was found (success),
 300  *         %-EINVAL if given arguments are not valid,
 301  *         %-ENODATA if the property does not have a value,
 302  *         %-EPROTO if the property is not an array of strings,
 303  *         %-ENXIO if no suitable firmware interface is present.
 304  */
 305 int device_property_match_string(struct device *dev, const char *propname,
 306                                  const char *string)
 307 {
 308         return fwnode_property_match_string(dev_fwnode(dev), propname, string);
 309 }
 310 EXPORT_SYMBOL_GPL(device_property_match_string);
 311
 312 #define OF_DEV_PROP_READ_ARRAY(node, propname, type, val, nval) \
 313         (val) ? of_property_read_##type##_array((node), (propname), (val), (nval)) \
 314               : of_property_count_elems_of_size((node), (propname), sizeof(type))
 315
 316 #define FWNODE_PROP_READ_ARRAY(_fwnode_, _propname_, _type_, _proptype_, _val_, _nval_) \
 317 ({ \
 318         int _ret_; \
 319         if (is_of_node(_fwnode_)) \
 320                 _ret_ = OF_DEV_PROP_READ_ARRAY(to_of_node(_fwnode_), _propname_, \
 321                                                _type_, _val_, _nval_); \
 322         else if (is_acpi_node(_fwnode_)) \
 323                 _ret_ = acpi_node_prop_read(_fwnode_, _propname_, _proptype_, \
 324                                             _val_, _nval_); \
 325         else if (is_pset(_fwnode_)) \
 326                 _ret_ = pset_prop_read_array(to_pset(_fwnode_), _propname_, \
 327                                              _proptype_, _val_, _nval_); \
 328         else \
 329                 _ret_ = -ENXIO; \
 330         _ret_; \
 331 })
 332
 333 /**
 334  * fwnode_property_read_u8_array - return a u8 array property of firmware node
 335  * @fwnode: Firmware node to get the property of
 336  * @propname: Name of the property
 337  * @val: The values are stored here or %NULL to return the number of values
 338  * @nval: Size of the @val array
 339  *
 340  * Read an array of u8 properties with @propname from @fwnode and stores them to
 341  * @val if found.
 342  *
 343  * Return: number of values if @val was %NULL,
 344  *         %0 if the property was found (success),
 345  *         %-EINVAL if given arguments are not valid,
 346  *         %-ENODATA if the property does not have a value,
 347  *         %-EPROTO if the property is not an array of numbers,
 348  *         %-EOVERFLOW if the size of the property is not as expected,
 349  *         %-ENXIO if no suitable firmware interface is present.
 350  */
 351 int fwnode_property_read_u8_array(struct fwnode_handle *fwnode,
 352                                   const char *propname, u8 *val, size_t nval)
 353 {
 354         return FWNODE_PROP_READ_ARRAY(fwnode, propname, u8, DEV_PROP_U8,
 355                                       val, nval);
 356 }
 357 EXPORT_SYMBOL_GPL(fwnode_property_read_u8_array);
 358
 359 /**
 360  * fwnode_property_read_u16_array - return a u16 array property of firmware node
 361  * @fwnode: Firmware node to get the property of
 362  * @propname: Name of the property
 363  * @val: The values are stored here or %NULL to return the number of values
 364  * @nval: Size of the @val array
 365  *
 366  * Read an array of u16 properties with @propname from @fwnode and store them to
 367  * @val if found.
 368  *
 369  * Return: number of values if @val was %NULL,
 370  *         %0 if the property was found (success),
 371  *         %-EINVAL if given arguments are not valid,
 372  *         %-ENODATA if the property does not have a value,
 373  *         %-EPROTO if the property is not an array of numbers,
 374  *         %-EOVERFLOW if the size of the property is not as expected,
 375  *         %-ENXIO if no suitable firmware interface is present.
 376  */
 377 int fwnode_property_read_u16_array(struct fwnode_handle *fwnode,
 378                                    const char *propname, u16 *val, size_t nval)
 379 {
 380         return FWNODE_PROP_READ_ARRAY(fwnode, propname, u16, DEV_PROP_U16,
 381                                       val, nval);
 382 }
 383 EXPORT_SYMBOL_GPL(fwnode_property_read_u16_array);
 384
 385 /**
 386  * fwnode_property_read_u32_array - return a u32 array property of firmware node
 387  * @fwnode: Firmware node to get the property of
 388  * @propname: Name of the property
 389  * @val: The values are stored here or %NULL to return the number of values
 390  * @nval: Size of the @val array
 391  *
 392  * Read an array of u32 properties with @propname from @fwnode store them to
 393  * @val if found.
 394  *
 395  * Return: number of values if @val was %NULL,
 396  *         %0 if the property was found (success),
 397  *         %-EINVAL if given arguments are not valid,
 398  *         %-ENODATA if the property does not have a value,
 399  *         %-EPROTO if the property is not an array of numbers,
 400  *         %-EOVERFLOW if the size of the property is not as expected,
 401  *         %-ENXIO if no suitable firmware interface is present.
 402  */
 403 int fwnode_property_read_u32_array(struct fwnode_handle *fwnode,
 404                                    const char *propname, u32 *val, size_t nval)
 405 {
 406         return FWNODE_PROP_READ_ARRAY(fwnode, propname, u32, DEV_PROP_U32,
 407                                       val, nval);
 408 }
 409 EXPORT_SYMBOL_GPL(fwnode_property_read_u32_array);
 410
 411 /**
 412  * fwnode_property_read_u64_array - return a u64 array property firmware node
 413  * @fwnode: Firmware node to get the property of
 414  * @propname: Name of the property
 415  * @val: The values are stored here or %NULL to return the number of values
 416  * @nval: Size of the @val array
 417  *
 418  * Read an array of u64 properties with @propname from @fwnode and store them to
 419  * @val if found.
 420  *
 421  * Return: number of values if @val was %NULL,
 422  *         %0 if the property was found (success),
 423  *         %-EINVAL if given arguments are not valid,
 424  *         %-ENODATA if the property does not have a value,
 425  *         %-EPROTO if the property is not an array of numbers,
 426  *         %-EOVERFLOW if the size of the property is not as expected,
 427  *         %-ENXIO if no suitable firmware interface is present.
 428  */
 429 int fwnode_property_read_u64_array(struct fwnode_handle *fwnode,
 430                                    const char *propname, u64 *val, size_t nval)
 431 {
 432         return FWNODE_PROP_READ_ARRAY(fwnode, propname, u64, DEV_PROP_U64,
 433                                       val, nval);
 434 }
 435 EXPORT_SYMBOL_GPL(fwnode_property_read_u64_array);
 436
 437 /**
 438  * fwnode_property_read_string_array - return string array property of a node
 439  * @fwnode: Firmware node to get the property of
 440  * @propname: Name of the property
 441  * @val: The values are stored here or %NULL to return the number of values
 442  * @nval: Size of the @val array
 443  *
 444  * Read an string list property @propname from the given firmware node and store
 445  * them to @val if found.
 446  *
 447  * Return: number of values if @val was %NULL,
 448  *         %0 if the property was found (success),
 449  *         %-EINVAL if given arguments are not valid,
 450  *         %-ENODATA if the property does not have a value,
 451  *         %-EPROTO if the property is not an array of strings,
 452  *         %-EOVERFLOW if the size of the property is not as expected,
 453  *         %-ENXIO if no suitable firmware interface is present.
 454  */
 455 int fwnode_property_read_string_array(struct fwnode_handle *fwnode,
 456                                       const char *propname, const char **val,
 457                                       size_t nval)
 458 {
 459         if (is_of_node(fwnode))
 460                 return val ?
 461                         of_property_read_string_array(to_of_node(fwnode),
 462                                                       propname, val, nval) :
 463                         of_property_count_strings(to_of_node(fwnode), propname);
 464         else if (is_acpi_node(fwnode))
 465                 return acpi_node_prop_read(fwnode, propname, DEV_PROP_STRING,
 466                                            val, nval);
 467         else if (is_pset(fwnode))
 468                 return pset_prop_read_array(to_pset(fwnode), propname,
 469                                             DEV_PROP_STRING, val, nval);
 470         return -ENXIO;
 471 }
 472 EXPORT_SYMBOL_GPL(fwnode_property_read_string_array);
 473
 474 /**
 475  * fwnode_property_read_string - return a string property of a firmware node
 476  * @fwnode: Firmware node to get the property of
 477  * @propname: Name of the property
 478  * @val: The value is stored here
 479  *
 480  * Read property @propname from the given firmware node and store the value into
 481  * @val if found.  The value is checked to be a string.
 482  *
 483  * Return: %0 if the property was found (success),
 484  *         %-EINVAL if given arguments are not valid,
 485  *         %-ENODATA if the property does not have a value,
 486  *         %-EPROTO or %-EILSEQ if the property is not a string,
 487  *         %-ENXIO if no suitable firmware interface is present.
 488  */
 489 int fwnode_property_read_string(struct fwnode_handle *fwnode,
 490                                 const char *propname, const char **val)
 491 {
 492         if (is_of_node(fwnode))
 493                 return of_property_read_string(to_of_node(fwnode), propname, val);
 494         else if (is_acpi_node(fwnode))
 495                 return acpi_node_prop_read(fwnode, propname, DEV_PROP_STRING,
 496                                            val, 1);
 497
 498         return pset_prop_read_array(to_pset(fwnode), propname,
 499                                     DEV_PROP_STRING, val, 1);
 500 }
 501 EXPORT_SYMBOL_GPL(fwnode_property_read_string);
 502
 503 /**
 504  * fwnode_property_match_string - find a string in an array and return index
 505  * @fwnode: Firmware node to get the property of
 506  * @propname: Name of the property holding the array
 507  * @string: String to look for
 508  *
 509  * Find a given string in a string array and if it is found return the
 510  * index back.
 511  *
 512  * Return: %0 if the property was found (success),
 513  *         %-EINVAL if given arguments are not valid,
 514  *         %-ENODATA if the property does not have a value,
 515  *         %-EPROTO if the property is not an array of strings,
 516  *         %-ENXIO if no suitable firmware interface is present.
 517  */
 518 int fwnode_property_match_string(struct fwnode_handle *fwnode,
 519         const char *propname, const char *string)
 520 {
 521         const char **values;
 522         int nval, ret, i;
 523
 524         nval = fwnode_property_read_string_array(fwnode, propname, NULL, 0);
 525         if (nval < 0)
 526                 return nval;
 527
 528         values = kcalloc(nval, sizeof(*values), GFP_KERNEL);
 529         if (!values)
 530                 return -ENOMEM;
 531
 532         ret = fwnode_property_read_string_array(fwnode, propname, values, nval);
 533         if (ret < 0)
 534                 goto out;
 535
 536         ret = -ENODATA;
 537         for (i = 0; i < nval; i++) {
 538                 if (!strcmp(values[i], string)) {
 539                         ret = i;
 540                         break;
 541                 }
 542         }
 543 out:
 544         kfree(values);
 545         return ret;
 546 }
 547 EXPORT_SYMBOL_GPL(fwnode_property_match_string);
 548
 549 /**
 550  * device_get_next_child_node - Return the next child node handle for a device
 551  * @dev: Device to find the next child node for.
 552  * @child: Handle to one of the device's child nodes or a null handle.
 553  */
 554 struct fwnode_handle *device_get_next_child_node(struct device *dev,
 555                                                  struct fwnode_handle *child)
 556 {
 557         if (IS_ENABLED(CONFIG_OF) && dev->of_node) {
 558                 struct device_node *node;
 559
 560                 node = of_get_next_available_child(dev->of_node, to_of_node(child));
 561                 if (node)
 562                         return &node->fwnode;
 563         } else if (IS_ENABLED(CONFIG_ACPI)) {
 564                 return acpi_get_next_subnode(dev, child);
 565         }
 566         return NULL;
 567 }
 568 EXPORT_SYMBOL_GPL(device_get_next_child_node);
 569
 570 /**
 571  * fwnode_handle_put - Drop reference to a device node
 572  * @fwnode: Pointer to the device node to drop the reference to.
 573  *
 574  * This has to be used when terminating device_for_each_child_node() iteration
 575  * with break or return to prevent stale device node references from being left
 576  * behind.
 577  */
 578 void fwnode_handle_put(struct fwnode_handle *fwnode)
 579 {
 580         if (is_of_node(fwnode))
 581                 of_node_put(to_of_node(fwnode));
 582 }
 583 EXPORT_SYMBOL_GPL(fwnode_handle_put);
 584
 585 /**
 586  * device_get_child_node_count - return the number of child nodes for device
 587  * @dev: Device to cound the child nodes for
 588  */
 589 unsigned int device_get_child_node_count(struct device *dev)
 590 {
 591         struct fwnode_handle *child;
 592         unsigned int count = 0;
 593
 594         device_for_each_child_node(dev, child)
 595                 count++;
 596
 597         return count;
 598 }
 599 EXPORT_SYMBOL_GPL(device_get_child_node_count);
 600
 601 bool device_dma_supported(struct device *dev)
 602 {
 603         /* For DT, this is always supported.
 604          * For ACPI, this depends on CCA, which
 605          * is determined by the acpi_dma_supported().
 606          */
 607         if (IS_ENABLED(CONFIG_OF) && dev->of_node)
 608                 return true;
 609
 610         return acpi_dma_supported(ACPI_COMPANION(dev));
 611 }
 612 EXPORT_SYMBOL_GPL(device_dma_supported);
 613
 614 enum dev_dma_attr device_get_dma_attr(struct device *dev)
 615 {
 616         enum dev_dma_attr attr = DEV_DMA_NOT_SUPPORTED;
 617
 618         if (IS_ENABLED(CONFIG_OF) && dev->of_node) {
 619                 if (of_dma_is_coherent(dev->of_node))
 620                         attr = DEV_DMA_COHERENT;
 621                 else
 622                         attr = DEV_DMA_NON_COHERENT;
 623         } else
 624                 attr = acpi_get_dma_attr(ACPI_COMPANION(dev));
 625
 626         return attr;
 627 }
 628 EXPORT_SYMBOL_GPL(device_get_dma_attr);
 629
 630 /**
 631  * device_get_phy_mode - Get phy mode for given device
 632  * @dev:        Pointer to the given device
 633  *
 634  * The function gets phy interface string from property 'phy-mode' or
 635  * 'phy-connection-type', and return its index in phy_modes table, or errno in
 636  * error case.
 637  */
 638 int device_get_phy_mode(struct device *dev)
 639 {
 640         const char *pm;
 641         int err, i;
 642
 643         err = device_property_read_string(dev, "phy-mode", &pm);
 644         if (err < 0)
 645                 err = device_property_read_string(dev,
 646                                                   "phy-connection-type", &pm);
 647         if (err < 0)
 648                 return err;
 649
 650         for (i = 0; i < PHY_INTERFACE_MODE_MAX; i++)
 651                 if (!strcasecmp(pm, phy_modes(i)))
 652                         return i;
 653
 654         return -ENODEV;
 655 }
 656 EXPORT_SYMBOL_GPL(device_get_phy_mode);
 657
 658 static void *device_get_mac_addr(struct device *dev,
 659                                  const char *name, char *addr,
 660                                  int alen)
 661 {
 662         int ret = device_property_read_u8_array(dev, name, addr, alen);
 663
 664         if (ret == 0 && alen == ETH_ALEN && is_valid_ether_addr(addr))
 665                 return addr;
 666         return NULL;
 667 }
 668
 669 /**
 670  * device_get_mac_address - Get the MAC for a given device
 671  * @dev:        Pointer to the device
 672  * @addr:       Address of buffer to store the MAC in
 673  * @alen:       Length of the buffer pointed to by addr, should be ETH_ALEN
 674  *
 675  * Search the firmware node for the best MAC address to use.  'mac-address' is
 676  * checked first, because that is supposed to contain to "most recent" MAC
 677  * address. If that isn't set, then 'local-mac-address' is checked next,
 678  * because that is the default address.  If that isn't set, then the obsolete
 679  * 'address' is checked, just in case we're using an old device tree.
 680  *
 681  * Note that the 'address' property is supposed to contain a virtual address of
 682  * the register set, but some DTS files have redefined that property to be the
 683  * MAC address.
 684  *
 685  * All-zero MAC addresses are rejected, because those could be properties that
 686  * exist in the firmware tables, but were not updated by the firmware.  For
 687  * example, the DTS could define 'mac-address' and 'local-mac-address', with
 688  * zero MAC addresses.  Some older U-Boots only initialized 'local-mac-address'.
 689  * In this case, the real MAC is in 'local-mac-address', and 'mac-address'
 690  * exists but is all zeros.
 691 */
 692 void *device_get_mac_address(struct device *dev, char *addr, int alen)
 693 {
 694         char *res;
 695
 696         res = device_get_mac_addr(dev, "mac-address", addr, alen);
 697         if (res)
 698                 return res;
 699
 700         res = device_get_mac_addr(dev, "local-mac-address", addr, alen);
 701         if (res)
 702                 return res;
 703
 704         return device_get_mac_addr(dev, "address", addr, alen);
 705 }
 706 EXPORT_SYMBOL(device_get_mac_address);