drivers/regulator/of_regulator.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * OF helpers for regulator framework
   4  *
   5  * Copyright (C) 2011 Texas Instruments, Inc.
   6  * Rajendra Nayak <rnayak@ti.com>
   7  */
   8
   9 #include <linux/module.h>
  10 #include <linux/slab.h>
  11 #include <linux/of.h>
  12 #include <linux/regulator/machine.h>
  13 #include <linux/regulator/driver.h>
  14 #include <linux/regulator/of_regulator.h>
  15
  16 #include "internal.h"
  17
  18 static const char *const regulator_states[PM_SUSPEND_MAX + 1] = {
  19         [PM_SUSPEND_STANDBY]    = "regulator-state-standby",
  20         [PM_SUSPEND_MEM]        = "regulator-state-mem",
  21         [PM_SUSPEND_MAX]        = "regulator-state-disk",
  22 };
  23
  24 static void fill_limit(int *limit, int val)
  25 {
  26         if (val)
  27                 if (val == 1)
  28                         *limit = REGULATOR_NOTIF_LIMIT_ENABLE;
  29                 else
  30                         *limit = val;
  31         else
  32                 *limit = REGULATOR_NOTIF_LIMIT_DISABLE;
  33 }
  34
  35 static void of_get_regulator_prot_limits(struct device_node *np,
  36                                 struct regulation_constraints *constraints)
  37 {
  38         u32 pval;
  39         int i;
  40         static const char *const props[] = {
  41                 "regulator-oc-%s-microamp",
  42                 "regulator-ov-%s-microvolt",
  43                 "regulator-temp-%s-kelvin",
  44                 "regulator-uv-%s-microvolt",
  45         };
  46         struct notification_limit *limits[] = {
  47                 &constraints->over_curr_limits,
  48                 &constraints->over_voltage_limits,
  49                 &constraints->temp_limits,
  50                 &constraints->under_voltage_limits,
  51         };
  52         bool set[4] = {0};
  53
  54         /* Protection limits: */
  55         for (i = 0; i < ARRAY_SIZE(props); i++) {
  56                 char prop[255];
  57                 bool found;
  58                 int j;
  59                 static const char *const lvl[] = {
  60                         "protection", "error", "warn"
  61                 };
  62                 int *l[] = {
  63                         &limits[i]->prot, &limits[i]->err, &limits[i]->warn,
  64                 };
  65
  66                 for (j = 0; j < ARRAY_SIZE(lvl); j++) {
  67                         snprintf(prop, 255, props[i], lvl[j]);
  68                         found = !of_property_read_u32(np, prop, &pval);
  69                         if (found)
  70                                 fill_limit(l[j], pval);
  71                         set[i] |= found;
  72                 }
  73         }
  74         constraints->over_current_detection = set[0];
  75         constraints->over_voltage_detection = set[1];
  76         constraints->over_temp_detection = set[2];
  77         constraints->under_voltage_detection = set[3];
  78 }
  79
  80 static int of_get_regulation_constraints(struct device *dev,
  81                                         struct device_node *np,
  82                                         struct regulator_init_data **init_data,
  83                                         const struct regulator_desc *desc)
  84 {
  85         struct regulation_constraints *constraints = &(*init_data)->constraints;
  86         struct regulator_state *suspend_state;
  87         struct device_node *suspend_np;
  88         unsigned int mode;
  89         int ret, i, len;
  90         int n_phandles;
  91         u32 pval;
  92
  93         n_phandles = of_count_phandle_with_args(np, "regulator-coupled-with",
  94                                                 NULL);
  95         n_phandles = max(n_phandles, 0);
  96
  97         constraints->name = of_get_property(np, "regulator-name", NULL);
  98
  99         if (!of_property_read_u32(np, "regulator-min-microvolt", &pval))
 100                 constraints->min_uV = pval;
 101
 102         if (!of_property_read_u32(np, "regulator-max-microvolt", &pval))
 103                 constraints->max_uV = pval;
 104
 105         /* Voltage change possible? */
 106         if (constraints->min_uV != constraints->max_uV)
 107                 constraints->valid_ops_mask |= REGULATOR_CHANGE_VOLTAGE;
 108
 109         /* Do we have a voltage range, if so try to apply it? */
 110         if (constraints->min_uV && constraints->max_uV)
 111                 constraints->apply_uV = true;
 112
 113         if (!of_property_read_u32(np, "regulator-microvolt-offset", &pval))
 114                 constraints->uV_offset = pval;
 115         if (!of_property_read_u32(np, "regulator-min-microamp", &pval))
 116                 constraints->min_uA = pval;
 117         if (!of_property_read_u32(np, "regulator-max-microamp", &pval))
 118                 constraints->max_uA = pval;
 119
 120         if (!of_property_read_u32(np, "regulator-input-current-limit-microamp",
 121                                   &pval))
 122                 constraints->ilim_uA = pval;
 123
 124         /* Current change possible? */
 125         if (constraints->min_uA != constraints->max_uA)
 126                 constraints->valid_ops_mask |= REGULATOR_CHANGE_CURRENT;
 127
 128         constraints->boot_on = of_property_read_bool(np, "regulator-boot-on");
 129         constraints->always_on = of_property_read_bool(np, "regulator-always-on");
 130         if (!constraints->always_on) /* status change should be possible. */
 131                 constraints->valid_ops_mask |= REGULATOR_CHANGE_STATUS;
 132
 133         constraints->pull_down = of_property_read_bool(np, "regulator-pull-down");
 134         constraints->system_critical = of_property_read_bool(np,
 135                                                 "system-critical-regulator");
 136
 137         if (of_property_read_bool(np, "regulator-allow-bypass"))
 138                 constraints->valid_ops_mask |= REGULATOR_CHANGE_BYPASS;
 139
 140         if (of_property_read_bool(np, "regulator-allow-set-load"))
 141                 constraints->valid_ops_mask |= REGULATOR_CHANGE_DRMS;
 142
 143         ret = of_property_read_u32(np, "regulator-ramp-delay", &pval);
 144         if (!ret) {
 145                 if (pval)
 146                         constraints->ramp_delay = pval;
 147                 else
 148                         constraints->ramp_disable = true;
 149         }
 150
 151         ret = of_property_read_u32(np, "regulator-settling-time-us", &pval);
 152         if (!ret)
 153                 constraints->settling_time = pval;
 154
 155         ret = of_property_read_u32(np, "regulator-settling-time-up-us", &pval);
 156         if (!ret)
 157                 constraints->settling_time_up = pval;
 158         if (constraints->settling_time_up && constraints->settling_time) {
 159                 pr_warn("%pOFn: ambiguous configuration for settling time, ignoring 'regulator-settling-time-up-us'\n",
 160                         np);
 161                 constraints->settling_time_up = 0;
 162         }
 163
 164         ret = of_property_read_u32(np, "regulator-settling-time-down-us",
 165                                    &pval);
 166         if (!ret)
 167                 constraints->settling_time_down = pval;
 168         if (constraints->settling_time_down && constraints->settling_time) {
 169                 pr_warn("%pOFn: ambiguous configuration for settling time, ignoring 'regulator-settling-time-down-us'\n",
 170                         np);
 171                 constraints->settling_time_down = 0;
 172         }
 173
 174         ret = of_property_read_u32(np, "regulator-enable-ramp-delay", &pval);
 175         if (!ret)
 176                 constraints->enable_time = pval;
 177
 178         ret = of_property_read_u32(np, "regulator-uv-survival-time-ms", &pval);
 179         if (!ret)
 180                 constraints->uv_less_critical_window_ms = pval;
 181         else
 182                 constraints->uv_less_critical_window_ms =
 183                                 REGULATOR_DEF_UV_LESS_CRITICAL_WINDOW_MS;
 184
 185         constraints->soft_start = of_property_read_bool(np,
 186                                         "regulator-soft-start");
 187         ret = of_property_read_u32(np, "regulator-active-discharge", &pval);
 188         if (!ret) {
 189                 constraints->active_discharge =
 190                                 (pval) ? REGULATOR_ACTIVE_DISCHARGE_ENABLE :
 191                                         REGULATOR_ACTIVE_DISCHARGE_DISABLE;
 192         }
 193
 194         if (!of_property_read_u32(np, "regulator-initial-mode", &pval)) {
 195                 if (desc && desc->of_map_mode) {
 196                         mode = desc->of_map_mode(pval);
 197                         if (mode == REGULATOR_MODE_INVALID)
 198                                 pr_err("%pOFn: invalid mode %u\n", np, pval);
 199                         else
 200                                 constraints->initial_mode = mode;
 201                 } else {
 202                         pr_warn("%pOFn: mapping for mode %d not defined\n",
 203                                 np, pval);
 204                 }
 205         }
 206
 207         len = of_property_count_elems_of_size(np, "regulator-allowed-modes",
 208                                                 sizeof(u32));
 209         if (len > 0) {
 210                 if (desc && desc->of_map_mode) {
 211                         for (i = 0; i < len; i++) {
 212                                 ret = of_property_read_u32_index(np,
 213                                         "regulator-allowed-modes", i, &pval);
 214                                 if (ret) {
 215                                         pr_err("%pOFn: couldn't read allowed modes index %d, ret=%d\n",
 216                                                 np, i, ret);
 217                                         break;
 218                                 }
 219                                 mode = desc->of_map_mode(pval);
 220                                 if (mode == REGULATOR_MODE_INVALID)
 221                                         pr_err("%pOFn: invalid regulator-allowed-modes element %u\n",
 222                                                 np, pval);
 223                                 else
 224                                         constraints->valid_modes_mask |= mode;
 225                         }
 226                         if (constraints->valid_modes_mask)
 227                                 constraints->valid_ops_mask
 228                                         |= REGULATOR_CHANGE_MODE;
 229                 } else {
 230                         pr_warn("%pOFn: mode mapping not defined\n", np);
 231                 }
 232         }
 233
 234         if (!of_property_read_u32(np, "regulator-system-load", &pval))
 235                 constraints->system_load = pval;
 236
 237         if (n_phandles) {
 238                 constraints->max_spread = devm_kzalloc(dev,
 239                                 sizeof(*constraints->max_spread) * n_phandles,
 240                                 GFP_KERNEL);
 241
 242                 if (!constraints->max_spread)
 243                         return -ENOMEM;
 244
 245                 of_property_read_u32_array(np, "regulator-coupled-max-spread",
 246                                            constraints->max_spread, n_phandles);
 247         }
 248
 249         if (!of_property_read_u32(np, "regulator-max-step-microvolt",
 250                                   &pval))
 251                 constraints->max_uV_step = pval;
 252
 253         constraints->over_current_protection = of_property_read_bool(np,
 254                                         "regulator-over-current-protection");
 255
 256         of_get_regulator_prot_limits(np, constraints);
 257
 258         for (i = 0; i < ARRAY_SIZE(regulator_states); i++) {
 259                 switch (i) {
 260                 case PM_SUSPEND_MEM:
 261                         suspend_state = &constraints->state_mem;
 262                         break;
 263                 case PM_SUSPEND_MAX:
 264                         suspend_state = &constraints->state_disk;
 265                         break;
 266                 case PM_SUSPEND_STANDBY:
 267                         suspend_state = &constraints->state_standby;
 268                         break;
 269                 case PM_SUSPEND_ON:
 270                 case PM_SUSPEND_TO_IDLE:
 271                 default:
 272                         continue;
 273                 }
 274
 275                 suspend_np = of_get_child_by_name(np, regulator_states[i]);
 276                 if (!suspend_np)
 277                         continue;
 278                 if (!suspend_state) {
 279                         of_node_put(suspend_np);
 280                         continue;
 281                 }
 282
 283                 if (!of_property_read_u32(suspend_np, "regulator-mode",
 284                                           &pval)) {
 285                         if (desc && desc->of_map_mode) {
 286                                 mode = desc->of_map_mode(pval);
 287                                 if (mode == REGULATOR_MODE_INVALID)
 288                                         pr_err("%pOFn: invalid mode %u\n",
 289                                                np, pval);
 290                                 else
 291                                         suspend_state->mode = mode;
 292                         } else {
 293                                 pr_warn("%pOFn: mapping for mode %d not defined\n",
 294                                         np, pval);
 295                         }
 296                 }
 297
 298                 if (of_property_read_bool(suspend_np,
 299                                         "regulator-on-in-suspend"))
 300                         suspend_state->enabled = ENABLE_IN_SUSPEND;
 301                 else if (of_property_read_bool(suspend_np,
 302                                         "regulator-off-in-suspend"))
 303                         suspend_state->enabled = DISABLE_IN_SUSPEND;
 304
 305                 if (!of_property_read_u32(suspend_np,
 306                                 "regulator-suspend-min-microvolt", &pval))
 307                         suspend_state->min_uV = pval;
 308
 309                 if (!of_property_read_u32(suspend_np,
 310                                 "regulator-suspend-max-microvolt", &pval))
 311                         suspend_state->max_uV = pval;
 312
 313                 if (!of_property_read_u32(suspend_np,
 314                                         "regulator-suspend-microvolt", &pval))
 315                         suspend_state->uV = pval;
 316                 else /* otherwise use min_uV as default suspend voltage */
 317                         suspend_state->uV = suspend_state->min_uV;
 318
 319                 if (of_property_read_bool(suspend_np,
 320                                         "regulator-changeable-in-suspend"))
 321                         suspend_state->changeable = true;
 322
 323                 if (i == PM_SUSPEND_MEM)
 324                         constraints->initial_state = PM_SUSPEND_MEM;
 325
 326                 of_node_put(suspend_np);
 327                 suspend_state = NULL;
 328                 suspend_np = NULL;
 329         }
 330
 331         return 0;
 332 }
 333
 334 /**
 335  * of_get_regulator_init_data - extract regulator_init_data structure info
 336  * @dev: device requesting for regulator_init_data
 337  * @node: regulator device node
 338  * @desc: regulator description
 339  *
 340  * Populates regulator_init_data structure by extracting data from device
 341  * tree node, returns a pointer to the populated structure or NULL if memory
 342  * alloc fails.
 343  */
 344 struct regulator_init_data *of_get_regulator_init_data(struct device *dev,
 345                                           struct device_node *node,
 346                                           const struct regulator_desc *desc)
 347 {
 348         struct regulator_init_data *init_data;
 349
 350         if (!node)
 351                 return NULL;
 352
 353         init_data = devm_kzalloc(dev, sizeof(*init_data), GFP_KERNEL);
 354         if (!init_data)
 355                 return NULL; /* Out of memory? */
 356
 357         if (of_get_regulation_constraints(dev, node, &init_data, desc))
 358                 return NULL;
 359
 360         return init_data;
 361 }
 362 EXPORT_SYMBOL_GPL(of_get_regulator_init_data);
 363
 364 struct devm_of_regulator_matches {
 365         struct of_regulator_match *matches;
 366         unsigned int num_matches;
 367 };
 368
 369 static void devm_of_regulator_put_matches(struct device *dev, void *res)
 370 {
 371         struct devm_of_regulator_matches *devm_matches = res;
 372         int i;
 373
 374         for (i = 0; i < devm_matches->num_matches; i++)
 375                 of_node_put(devm_matches->matches[i].of_node);
 376 }
 377
 378 /**
 379  * of_regulator_match - extract multiple regulator init data from device tree.
 380  * @dev: device requesting the data
 381  * @node: parent device node of the regulators
 382  * @matches: match table for the regulators
 383  * @num_matches: number of entries in match table
 384  *
 385  * This function uses a match table specified by the regulator driver to
 386  * parse regulator init data from the device tree. @node is expected to
 387  * contain a set of child nodes, each providing the init data for one
 388  * regulator. The data parsed from a child node will be matched to a regulator
 389  * based on either the deprecated property regulator-compatible if present,
 390  * or otherwise the child node's name. Note that the match table is modified
 391  * in place and an additional of_node reference is taken for each matched
 392  * regulator.
 393  *
 394  * Returns the number of matches found or a negative error code on failure.
 395  */
 396 int of_regulator_match(struct device *dev, struct device_node *node,
 397                        struct of_regulator_match *matches,
 398                        unsigned int num_matches)
 399 {
 400         unsigned int count = 0;
 401         unsigned int i;
 402         const char *name;
 403         struct device_node *child;
 404         struct devm_of_regulator_matches *devm_matches;
 405
 406         if (!dev || !node)
 407                 return -EINVAL;
 408
 409         devm_matches = devres_alloc(devm_of_regulator_put_matches,
 410                                     sizeof(struct devm_of_regulator_matches),
 411                                     GFP_KERNEL);
 412         if (!devm_matches)
 413                 return -ENOMEM;
 414
 415         devm_matches->matches = matches;
 416         devm_matches->num_matches = num_matches;
 417
 418         devres_add(dev, devm_matches);
 419
 420         for (i = 0; i < num_matches; i++) {
 421                 struct of_regulator_match *match = &matches[i];
 422                 match->init_data = NULL;
 423                 match->of_node = NULL;
 424         }
 425
 426         for_each_child_of_node(node, child) {
 427                 name = of_get_property(child,
 428                                         "regulator-compatible", NULL);
 429                 if (!name)
 430                         name = child->name;
 431                 for (i = 0; i < num_matches; i++) {
 432                         struct of_regulator_match *match = &matches[i];
 433                         if (match->of_node)
 434                                 continue;
 435
 436                         if (strcmp(match->name, name))
 437                                 continue;
 438
 439                         match->init_data =
 440                                 of_get_regulator_init_data(dev, child,
 441                                                            match->desc);
 442                         if (!match->init_data) {
 443                                 dev_err(dev,
 444                                         "failed to parse DT for regulator %pOFn\n",
 445                                         child);
 446                                 of_node_put(child);
 447                                 return -EINVAL;
 448                         }
 449                         match->of_node = of_node_get(child);
 450                         count++;
 451                         break;
 452                 }
 453         }
 454
 455         return count;
 456 }
 457 EXPORT_SYMBOL_GPL(of_regulator_match);
 458
 459 static struct
 460 device_node *regulator_of_get_init_node(struct device *dev,
 461                                         const struct regulator_desc *desc)
 462 {
 463         struct device_node *search, *child;
 464         const char *name;
 465
 466         if (!dev->of_node || !desc->of_match)
 467                 return NULL;
 468
 469         if (desc->regulators_node) {
 470                 search = of_get_child_by_name(dev->of_node,
 471                                               desc->regulators_node);
 472         } else {
 473                 search = of_node_get(dev->of_node);
 474
 475                 if (!strcmp(desc->of_match, search->name))
 476                         return search;
 477         }
 478
 479         if (!search) {
 480                 dev_dbg(dev, "Failed to find regulator container node '%s'\n",
 481                         desc->regulators_node);
 482                 return NULL;
 483         }
 484
 485         for_each_available_child_of_node(search, child) {
 486                 name = of_get_property(child, "regulator-compatible", NULL);
 487                 if (!name) {
 488                         if (!desc->of_match_full_name)
 489                                 name = child->name;
 490                         else
 491                                 name = child->full_name;
 492                 }
 493
 494                 if (!strcmp(desc->of_match, name)) {
 495                         of_node_put(search);
 496                         /*
 497                          * 'of_node_get(child)' is already performed by the
 498                          * for_each loop.
 499                          */
 500                         return child;
 501                 }
 502         }
 503
 504         of_node_put(search);
 505
 506         return NULL;
 507 }
 508
 509 struct regulator_init_data *regulator_of_get_init_data(struct device *dev,
 510                                             const struct regulator_desc *desc,
 511                                             struct regulator_config *config,
 512                                             struct device_node **node)
 513 {
 514         struct device_node *child;
 515         struct regulator_init_data *init_data = NULL;
 516
 517         child = regulator_of_get_init_node(config->dev, desc);
 518         if (!child)
 519                 return NULL;
 520
 521         init_data = of_get_regulator_init_data(dev, child, desc);
 522         if (!init_data) {
 523                 dev_err(dev, "failed to parse DT for regulator %pOFn\n", child);
 524                 goto error;
 525         }
 526
 527         if (desc->of_parse_cb) {
 528                 int ret;
 529
 530                 ret = desc->of_parse_cb(child, desc, config);
 531                 if (ret) {
 532                         if (ret == -EPROBE_DEFER) {
 533                                 of_node_put(child);
 534                                 return ERR_PTR(-EPROBE_DEFER);
 535                         }
 536                         dev_err(dev,
 537                                 "driver callback failed to parse DT for regulator %pOFn\n",
 538                                 child);
 539                         goto error;
 540                 }
 541         }
 542
 543         *node = child;
 544
 545         return init_data;
 546
 547 error:
 548         of_node_put(child);
 549
 550         return NULL;
 551 }
 552
 553 struct regulator_dev *of_find_regulator_by_node(struct device_node *np)
 554 {
 555         struct device *dev;
 556
 557         dev = class_find_device_by_of_node(&regulator_class, np);
 558
 559         return dev ? dev_to_rdev(dev) : NULL;
 560 }
 561
 562 /*
 563  * Returns number of regulators coupled with rdev.
 564  */
 565 int of_get_n_coupled(struct regulator_dev *rdev)
 566 {
 567         struct device_node *node = rdev->dev.of_node;
 568         int n_phandles;
 569
 570         n_phandles = of_count_phandle_with_args(node,
 571                                                 "regulator-coupled-with",
 572                                                 NULL);
 573
 574         return (n_phandles > 0) ? n_phandles : 0;
 575 }
 576
 577 /* Looks for "to_find" device_node in src's "regulator-coupled-with" property */
 578 static bool of_coupling_find_node(struct device_node *src,
 579                                   struct device_node *to_find,
 580                                   int *index)
 581 {
 582         int n_phandles, i;
 583         bool found = false;
 584
 585         n_phandles = of_count_phandle_with_args(src,
 586                                                 "regulator-coupled-with",
 587                                                 NULL);
 588
 589         for (i = 0; i < n_phandles; i++) {
 590                 struct device_node *tmp = of_parse_phandle(src,
 591                                            "regulator-coupled-with", i);
 592
 593                 if (!tmp)
 594                         break;
 595
 596                 /* found */
 597                 if (tmp == to_find)
 598                         found = true;
 599
 600                 of_node_put(tmp);
 601
 602                 if (found) {
 603                         *index = i;
 604                         break;
 605                 }
 606         }
 607
 608         return found;
 609 }
 610
 611 /**
 612  * of_check_coupling_data - Parse rdev's coupling properties and check data
 613  *                          consistency
 614  * @rdev: pointer to regulator_dev whose data is checked
 615  *
 616  * Function checks if all the following conditions are met:
 617  * - rdev's max_spread is greater than 0
 618  * - all coupled regulators have the same max_spread
 619  * - all coupled regulators have the same number of regulator_dev phandles
 620  * - all regulators are linked to each other
 621  *
 622  * Returns true if all conditions are met.
 623  */
 624 bool of_check_coupling_data(struct regulator_dev *rdev)
 625 {
 626         struct device_node *node = rdev->dev.of_node;
 627         int n_phandles = of_get_n_coupled(rdev);
 628         struct device_node *c_node;
 629         int index;
 630         int i;
 631         bool ret = true;
 632
 633         /* iterate over rdev's phandles */
 634         for (i = 0; i < n_phandles; i++) {
 635                 int max_spread = rdev->constraints->max_spread[i];
 636                 int c_max_spread, c_n_phandles;
 637
 638                 if (max_spread <= 0) {
 639                         dev_err(&rdev->dev, "max_spread value invalid\n");
 640                         return false;
 641                 }
 642
 643                 c_node = of_parse_phandle(node,
 644                                           "regulator-coupled-with", i);
 645
 646                 if (!c_node)
 647                         ret = false;
 648
 649                 c_n_phandles = of_count_phandle_with_args(c_node,
 650                                                           "regulator-coupled-with",
 651                                                           NULL);
 652
 653                 if (c_n_phandles != n_phandles) {
 654                         dev_err(&rdev->dev, "number of coupled reg phandles mismatch\n");
 655                         ret = false;
 656                         goto clean;
 657                 }
 658
 659                 if (!of_coupling_find_node(c_node, node, &index)) {
 660                         dev_err(&rdev->dev, "missing 2-way linking for coupled regulators\n");
 661                         ret = false;
 662                         goto clean;
 663                 }
 664
 665                 if (of_property_read_u32_index(c_node, "regulator-coupled-max-spread",
 666                                                index, &c_max_spread)) {
 667                         ret = false;
 668                         goto clean;
 669                 }
 670
 671                 if (c_max_spread != max_spread) {
 672                         dev_err(&rdev->dev,
 673                                 "coupled regulators max_spread mismatch\n");
 674                         ret = false;
 675                         goto clean;
 676                 }
 677
 678 clean:
 679                 of_node_put(c_node);
 680                 if (!ret)
 681                         break;
 682         }
 683
 684         return ret;
 685 }
 686
 687 /**
 688  * of_parse_coupled_regulator() - Get regulator_dev pointer from rdev's property
 689  * @rdev: Pointer to regulator_dev, whose DTS is used as a source to parse
 690  *        "regulator-coupled-with" property
 691  * @index: Index in phandles array
 692  *
 693  * Returns the regulator_dev pointer parsed from DTS. If it has not been yet
 694  * registered, returns NULL
 695  */
 696 struct regulator_dev *of_parse_coupled_regulator(struct regulator_dev *rdev,
 697                                                  int index)
 698 {
 699         struct device_node *node = rdev->dev.of_node;
 700         struct device_node *c_node;
 701         struct regulator_dev *c_rdev;
 702
 703         c_node = of_parse_phandle(node, "regulator-coupled-with", index);
 704         if (!c_node)
 705                 return NULL;
 706
 707         c_rdev = of_find_regulator_by_node(c_node);
 708
 709         of_node_put(c_node);
 710
 711         return c_rdev;
 712 }
 713
 714 /*
 715  * Check if name is a supply name according to the '*-supply' pattern
 716  * return 0 if false
 717  * return length of supply name without the -supply
 718  */
 719 static int is_supply_name(const char *name)
 720 {
 721         int strs, i;
 722
 723         strs = strlen(name);
 724         /* string need to be at minimum len(x-supply) */
 725         if (strs < 8)
 726                 return 0;
 727         for (i = strs - 6; i > 0; i--) {
 728                 /* find first '-' and check if right part is supply */
 729                 if (name[i] != '-')
 730                         continue;
 731                 if (strcmp(name + i + 1, "supply") != 0)
 732                         return 0;
 733                 return i;
 734         }
 735         return 0;
 736 }
 737
 738 /*
 739  * of_regulator_bulk_get_all - get multiple regulator consumers
 740  *
 741  * @dev:        Device to supply
 742  * @np:         device node to search for consumers
 743  * @consumers:  Configuration of consumers; clients are stored here.
 744  *
 745  * @return number of regulators on success, an errno on failure.
 746  *
 747  * This helper function allows drivers to get several regulator
 748  * consumers in one operation.  If any of the regulators cannot be
 749  * acquired then any regulators that were allocated will be freed
 750  * before returning to the caller.
 751  */
 752 int of_regulator_bulk_get_all(struct device *dev, struct device_node *np,
 753                               struct regulator_bulk_data **consumers)
 754 {
 755         int num_consumers = 0;
 756         struct regulator *tmp;
 757         struct property *prop;
 758         int i, n = 0, ret;
 759         char name[64];
 760
 761         *consumers = NULL;
 762
 763         /*
 764          * first pass: get numbers of xxx-supply
 765          * second pass: fill consumers
 766          */
 767 restart:
 768         for_each_property_of_node(np, prop) {
 769                 i = is_supply_name(prop->name);
 770                 if (i == 0)
 771                         continue;
 772                 if (!*consumers) {
 773                         num_consumers++;
 774                         continue;
 775                 } else {
 776                         memcpy(name, prop->name, i);
 777                         name[i] = '\0';
 778                         tmp = regulator_get(dev, name);
 779                         if (IS_ERR(tmp)) {
 780                                 ret = -EINVAL;
 781                                 goto error;
 782                         }
 783                         (*consumers)[n].consumer = tmp;
 784                         n++;
 785                         continue;
 786                 }
 787         }
 788         if (*consumers)
 789                 return num_consumers;
 790         if (num_consumers == 0)
 791                 return 0;
 792         *consumers = kmalloc_array(num_consumers,
 793                                    sizeof(struct regulator_bulk_data),
 794                                    GFP_KERNEL);
 795         if (!*consumers)
 796                 return -ENOMEM;
 797         goto restart;
 798
 799 error:
 800         while (--n >= 0)
 801                 regulator_put(consumers[n]->consumer);
 802         return ret;
 803 }
 804 EXPORT_SYMBOL_GPL(of_regulator_bulk_get_all);