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 int of_get_regulation_constraints(struct device *dev,
  25                                         struct device_node *np,
  26                                         struct regulator_init_data **init_data,
  27                                         const struct regulator_desc *desc)
  28 {
  29         struct regulation_constraints *constraints = &(*init_data)->constraints;
  30         struct regulator_state *suspend_state;
  31         struct device_node *suspend_np;
  32         unsigned int mode;
  33         int ret, i, len;
  34         int n_phandles;
  35         u32 pval;
  36
  37         n_phandles = of_count_phandle_with_args(np, "regulator-coupled-with",
  38                                                 NULL);
  39         n_phandles = max(n_phandles, 0);
  40
  41         constraints->name = of_get_property(np, "regulator-name", NULL);
  42
  43         if (!of_property_read_u32(np, "regulator-min-microvolt", &pval))
  44                 constraints->min_uV = pval;
  45
  46         if (!of_property_read_u32(np, "regulator-max-microvolt", &pval))
  47                 constraints->max_uV = pval;
  48
  49         /* Voltage change possible? */
  50         if (constraints->min_uV != constraints->max_uV)
  51                 constraints->valid_ops_mask |= REGULATOR_CHANGE_VOLTAGE;
  52
  53         /* Do we have a voltage range, if so try to apply it? */
  54         if (constraints->min_uV && constraints->max_uV)
  55                 constraints->apply_uV = true;
  56
  57         if (!of_property_read_u32(np, "regulator-microvolt-offset", &pval))
  58                 constraints->uV_offset = pval;
  59         if (!of_property_read_u32(np, "regulator-min-microamp", &pval))
  60                 constraints->min_uA = pval;
  61         if (!of_property_read_u32(np, "regulator-max-microamp", &pval))
  62                 constraints->max_uA = pval;
  63
  64         if (!of_property_read_u32(np, "regulator-input-current-limit-microamp",
  65                                   &pval))
  66                 constraints->ilim_uA = pval;
  67
  68         /* Current change possible? */
  69         if (constraints->min_uA != constraints->max_uA)
  70                 constraints->valid_ops_mask |= REGULATOR_CHANGE_CURRENT;
  71
  72         constraints->boot_on = of_property_read_bool(np, "regulator-boot-on");
  73         constraints->always_on = of_property_read_bool(np, "regulator-always-on");
  74         if (!constraints->always_on) /* status change should be possible. */
  75                 constraints->valid_ops_mask |= REGULATOR_CHANGE_STATUS;
  76
  77         constraints->pull_down = of_property_read_bool(np, "regulator-pull-down");
  78
  79         if (of_property_read_bool(np, "regulator-allow-bypass"))
  80                 constraints->valid_ops_mask |= REGULATOR_CHANGE_BYPASS;
  81
  82         if (of_property_read_bool(np, "regulator-allow-set-load"))
  83                 constraints->valid_ops_mask |= REGULATOR_CHANGE_DRMS;
  84
  85         ret = of_property_read_u32(np, "regulator-ramp-delay", &pval);
  86         if (!ret) {
  87                 if (pval)
  88                         constraints->ramp_delay = pval;
  89                 else
  90                         constraints->ramp_disable = true;
  91         }
  92
  93         ret = of_property_read_u32(np, "regulator-settling-time-us", &pval);
  94         if (!ret)
  95                 constraints->settling_time = pval;
  96
  97         ret = of_property_read_u32(np, "regulator-settling-time-up-us", &pval);
  98         if (!ret)
  99                 constraints->settling_time_up = pval;
 100         if (constraints->settling_time_up && constraints->settling_time) {
 101                 pr_warn("%pOFn: ambiguous configuration for settling time, ignoring 'regulator-settling-time-up-us'\n",
 102                         np);
 103                 constraints->settling_time_up = 0;
 104         }
 105
 106         ret = of_property_read_u32(np, "regulator-settling-time-down-us",
 107                                    &pval);
 108         if (!ret)
 109                 constraints->settling_time_down = pval;
 110         if (constraints->settling_time_down && constraints->settling_time) {
 111                 pr_warn("%pOFn: ambiguous configuration for settling time, ignoring 'regulator-settling-time-down-us'\n",
 112                         np);
 113                 constraints->settling_time_down = 0;
 114         }
 115
 116         ret = of_property_read_u32(np, "regulator-enable-ramp-delay", &pval);
 117         if (!ret)
 118                 constraints->enable_time = pval;
 119
 120         constraints->soft_start = of_property_read_bool(np,
 121                                         "regulator-soft-start");
 122         ret = of_property_read_u32(np, "regulator-active-discharge", &pval);
 123         if (!ret) {
 124                 constraints->active_discharge =
 125                                 (pval) ? REGULATOR_ACTIVE_DISCHARGE_ENABLE :
 126                                         REGULATOR_ACTIVE_DISCHARGE_DISABLE;
 127         }
 128
 129         if (!of_property_read_u32(np, "regulator-initial-mode", &pval)) {
 130                 if (desc && desc->of_map_mode) {
 131                         mode = desc->of_map_mode(pval);
 132                         if (mode == REGULATOR_MODE_INVALID)
 133                                 pr_err("%pOFn: invalid mode %u\n", np, pval);
 134                         else
 135                                 constraints->initial_mode = mode;
 136                 } else {
 137                         pr_warn("%pOFn: mapping for mode %d not defined\n",
 138                                 np, pval);
 139                 }
 140         }
 141
 142         len = of_property_count_elems_of_size(np, "regulator-allowed-modes",
 143                                                 sizeof(u32));
 144         if (len > 0) {
 145                 if (desc && desc->of_map_mode) {
 146                         for (i = 0; i < len; i++) {
 147                                 ret = of_property_read_u32_index(np,
 148                                         "regulator-allowed-modes", i, &pval);
 149                                 if (ret) {
 150                                         pr_err("%pOFn: couldn't read allowed modes index %d, ret=%d\n",
 151                                                 np, i, ret);
 152                                         break;
 153                                 }
 154                                 mode = desc->of_map_mode(pval);
 155                                 if (mode == REGULATOR_MODE_INVALID)
 156                                         pr_err("%pOFn: invalid regulator-allowed-modes element %u\n",
 157                                                 np, pval);
 158                                 else
 159                                         constraints->valid_modes_mask |= mode;
 160                         }
 161                         if (constraints->valid_modes_mask)
 162                                 constraints->valid_ops_mask
 163                                         |= REGULATOR_CHANGE_MODE;
 164                 } else {
 165                         pr_warn("%pOFn: mode mapping not defined\n", np);
 166                 }
 167         }
 168
 169         if (!of_property_read_u32(np, "regulator-system-load", &pval))
 170                 constraints->system_load = pval;
 171
 172         if (n_phandles) {
 173                 constraints->max_spread = devm_kzalloc(dev,
 174                                 sizeof(*constraints->max_spread) * n_phandles,
 175                                 GFP_KERNEL);
 176
 177                 if (!constraints->max_spread)
 178                         return -ENOMEM;
 179
 180                 of_property_read_u32_array(np, "regulator-coupled-max-spread",
 181                                            constraints->max_spread, n_phandles);
 182         }
 183
 184         if (!of_property_read_u32(np, "regulator-max-step-microvolt",
 185                                   &pval))
 186                 constraints->max_uV_step = pval;
 187
 188         constraints->over_current_protection = of_property_read_bool(np,
 189                                         "regulator-over-current-protection");
 190
 191         for (i = 0; i < ARRAY_SIZE(regulator_states); i++) {
 192                 switch (i) {
 193                 case PM_SUSPEND_MEM:
 194                         suspend_state = &constraints->state_mem;
 195                         break;
 196                 case PM_SUSPEND_MAX:
 197                         suspend_state = &constraints->state_disk;
 198                         break;
 199                 case PM_SUSPEND_STANDBY:
 200                         suspend_state = &constraints->state_standby;
 201                         break;
 202                 case PM_SUSPEND_ON:
 203                 case PM_SUSPEND_TO_IDLE:
 204                 default:
 205                         continue;
 206                 }
 207
 208                 suspend_np = of_get_child_by_name(np, regulator_states[i]);
 209                 if (!suspend_np)
 210                         continue;
 211                 if (!suspend_state) {
 212                         of_node_put(suspend_np);
 213                         continue;
 214                 }
 215
 216                 if (!of_property_read_u32(suspend_np, "regulator-mode",
 217                                           &pval)) {
 218                         if (desc && desc->of_map_mode) {
 219                                 mode = desc->of_map_mode(pval);
 220                                 if (mode == REGULATOR_MODE_INVALID)
 221                                         pr_err("%pOFn: invalid mode %u\n",
 222                                                np, pval);
 223                                 else
 224                                         suspend_state->mode = mode;
 225                         } else {
 226                                 pr_warn("%pOFn: mapping for mode %d not defined\n",
 227                                         np, pval);
 228                         }
 229                 }
 230
 231                 if (of_property_read_bool(suspend_np,
 232                                         "regulator-on-in-suspend"))
 233                         suspend_state->enabled = ENABLE_IN_SUSPEND;
 234                 else if (of_property_read_bool(suspend_np,
 235                                         "regulator-off-in-suspend"))
 236                         suspend_state->enabled = DISABLE_IN_SUSPEND;
 237
 238                 if (!of_property_read_u32(suspend_np,
 239                                 "regulator-suspend-min-microvolt", &pval))
 240                         suspend_state->min_uV = pval;
 241
 242                 if (!of_property_read_u32(suspend_np,
 243                                 "regulator-suspend-max-microvolt", &pval))
 244                         suspend_state->max_uV = pval;
 245
 246                 if (!of_property_read_u32(suspend_np,
 247                                         "regulator-suspend-microvolt", &pval))
 248                         suspend_state->uV = pval;
 249                 else /* otherwise use min_uV as default suspend voltage */
 250                         suspend_state->uV = suspend_state->min_uV;
 251
 252                 if (of_property_read_bool(suspend_np,
 253                                         "regulator-changeable-in-suspend"))
 254                         suspend_state->changeable = true;
 255
 256                 if (i == PM_SUSPEND_MEM)
 257                         constraints->initial_state = PM_SUSPEND_MEM;
 258
 259                 of_node_put(suspend_np);
 260                 suspend_state = NULL;
 261                 suspend_np = NULL;
 262         }
 263
 264         return 0;
 265 }
 266
 267 /**
 268  * of_get_regulator_init_data - extract regulator_init_data structure info
 269  * @dev: device requesting for regulator_init_data
 270  * @node: regulator device node
 271  * @desc: regulator description
 272  *
 273  * Populates regulator_init_data structure by extracting data from device
 274  * tree node, returns a pointer to the populated structure or NULL if memory
 275  * alloc fails.
 276  */
 277 struct regulator_init_data *of_get_regulator_init_data(struct device *dev,
 278                                           struct device_node *node,
 279                                           const struct regulator_desc *desc)
 280 {
 281         struct regulator_init_data *init_data;
 282
 283         if (!node)
 284                 return NULL;
 285
 286         init_data = devm_kzalloc(dev, sizeof(*init_data), GFP_KERNEL);
 287         if (!init_data)
 288                 return NULL; /* Out of memory? */
 289
 290         if (of_get_regulation_constraints(dev, node, &init_data, desc))
 291                 return NULL;
 292
 293         return init_data;
 294 }
 295 EXPORT_SYMBOL_GPL(of_get_regulator_init_data);
 296
 297 struct devm_of_regulator_matches {
 298         struct of_regulator_match *matches;
 299         unsigned int num_matches;
 300 };
 301
 302 static void devm_of_regulator_put_matches(struct device *dev, void *res)
 303 {
 304         struct devm_of_regulator_matches *devm_matches = res;
 305         int i;
 306
 307         for (i = 0; i < devm_matches->num_matches; i++)
 308                 of_node_put(devm_matches->matches[i].of_node);
 309 }
 310
 311 /**
 312  * of_regulator_match - extract multiple regulator init data from device tree.
 313  * @dev: device requesting the data
 314  * @node: parent device node of the regulators
 315  * @matches: match table for the regulators
 316  * @num_matches: number of entries in match table
 317  *
 318  * This function uses a match table specified by the regulator driver to
 319  * parse regulator init data from the device tree. @node is expected to
 320  * contain a set of child nodes, each providing the init data for one
 321  * regulator. The data parsed from a child node will be matched to a regulator
 322  * based on either the deprecated property regulator-compatible if present,
 323  * or otherwise the child node's name. Note that the match table is modified
 324  * in place and an additional of_node reference is taken for each matched
 325  * regulator.
 326  *
 327  * Returns the number of matches found or a negative error code on failure.
 328  */
 329 int of_regulator_match(struct device *dev, struct device_node *node,
 330                        struct of_regulator_match *matches,
 331                        unsigned int num_matches)
 332 {
 333         unsigned int count = 0;
 334         unsigned int i;
 335         const char *name;
 336         struct device_node *child;
 337         struct devm_of_regulator_matches *devm_matches;
 338
 339         if (!dev || !node)
 340                 return -EINVAL;
 341
 342         devm_matches = devres_alloc(devm_of_regulator_put_matches,
 343                                     sizeof(struct devm_of_regulator_matches),
 344                                     GFP_KERNEL);
 345         if (!devm_matches)
 346                 return -ENOMEM;
 347
 348         devm_matches->matches = matches;
 349         devm_matches->num_matches = num_matches;
 350
 351         devres_add(dev, devm_matches);
 352
 353         for (i = 0; i < num_matches; i++) {
 354                 struct of_regulator_match *match = &matches[i];
 355                 match->init_data = NULL;
 356                 match->of_node = NULL;
 357         }
 358
 359         for_each_child_of_node(node, child) {
 360                 name = of_get_property(child,
 361                                         "regulator-compatible", NULL);
 362                 if (!name)
 363                         name = child->name;
 364                 for (i = 0; i < num_matches; i++) {
 365                         struct of_regulator_match *match = &matches[i];
 366                         if (match->of_node)
 367                                 continue;
 368
 369                         if (strcmp(match->name, name))
 370                                 continue;
 371
 372                         match->init_data =
 373                                 of_get_regulator_init_data(dev, child,
 374                                                            match->desc);
 375                         if (!match->init_data) {
 376                                 dev_err(dev,
 377                                         "failed to parse DT for regulator %pOFn\n",
 378                                         child);
 379                                 of_node_put(child);
 380                                 return -EINVAL;
 381                         }
 382                         match->of_node = of_node_get(child);
 383                         count++;
 384                         break;
 385                 }
 386         }
 387
 388         return count;
 389 }
 390 EXPORT_SYMBOL_GPL(of_regulator_match);
 391
 392 static struct
 393 device_node *regulator_of_get_init_node(struct device *dev,
 394                                         const struct regulator_desc *desc)
 395 {
 396         struct device_node *search, *child;
 397         const char *name;
 398
 399         if (!dev->of_node || !desc->of_match)
 400                 return NULL;
 401
 402         if (desc->regulators_node) {
 403                 search = of_get_child_by_name(dev->of_node,
 404                                               desc->regulators_node);
 405         } else {
 406                 search = of_node_get(dev->of_node);
 407
 408                 if (!strcmp(desc->of_match, search->name))
 409                         return search;
 410         }
 411
 412         if (!search) {
 413                 dev_dbg(dev, "Failed to find regulator container node '%s'\n",
 414                         desc->regulators_node);
 415                 return NULL;
 416         }
 417
 418         for_each_available_child_of_node(search, child) {
 419                 name = of_get_property(child, "regulator-compatible", NULL);
 420                 if (!name)
 421                         name = child->name;
 422
 423                 if (!strcmp(desc->of_match, name)) {
 424                         of_node_put(search);
 425                         return of_node_get(child);
 426                 }
 427         }
 428
 429         of_node_put(search);
 430
 431         return NULL;
 432 }
 433
 434 struct regulator_init_data *regulator_of_get_init_data(struct device *dev,
 435                                             const struct regulator_desc *desc,
 436                                             struct regulator_config *config,
 437                                             struct device_node **node)
 438 {
 439         struct device_node *child;
 440         struct regulator_init_data *init_data = NULL;
 441
 442         child = regulator_of_get_init_node(dev, desc);
 443         if (!child)
 444                 return NULL;
 445
 446         init_data = of_get_regulator_init_data(dev, child, desc);
 447         if (!init_data) {
 448                 dev_err(dev, "failed to parse DT for regulator %pOFn\n", child);
 449                 goto error;
 450         }
 451
 452         if (desc->of_parse_cb) {
 453                 int ret;
 454
 455                 ret = desc->of_parse_cb(child, desc, config);
 456                 if (ret) {
 457                         if (ret == -EPROBE_DEFER) {
 458                                 of_node_put(child);
 459                                 return ERR_PTR(-EPROBE_DEFER);
 460                         }
 461                         dev_err(dev,
 462                                 "driver callback failed to parse DT for regulator %pOFn\n",
 463                                 child);
 464                         goto error;
 465                 }
 466         }
 467
 468         *node = child;
 469
 470         return init_data;
 471
 472 error:
 473         of_node_put(child);
 474
 475         return NULL;
 476 }
 477
 478 struct regulator_dev *of_find_regulator_by_node(struct device_node *np)
 479 {
 480         struct device *dev;
 481
 482         dev = class_find_device_by_of_node(&regulator_class, np);
 483
 484         return dev ? dev_to_rdev(dev) : NULL;
 485 }
 486
 487 /*
 488  * Returns number of regulators coupled with rdev.
 489  */
 490 int of_get_n_coupled(struct regulator_dev *rdev)
 491 {
 492         struct device_node *node = rdev->dev.of_node;
 493         int n_phandles;
 494
 495         n_phandles = of_count_phandle_with_args(node,
 496                                                 "regulator-coupled-with",
 497                                                 NULL);
 498
 499         return (n_phandles > 0) ? n_phandles : 0;
 500 }
 501
 502 /* Looks for "to_find" device_node in src's "regulator-coupled-with" property */
 503 static bool of_coupling_find_node(struct device_node *src,
 504                                   struct device_node *to_find,
 505                                   int *index)
 506 {
 507         int n_phandles, i;
 508         bool found = false;
 509
 510         n_phandles = of_count_phandle_with_args(src,
 511                                                 "regulator-coupled-with",
 512                                                 NULL);
 513
 514         for (i = 0; i < n_phandles; i++) {
 515                 struct device_node *tmp = of_parse_phandle(src,
 516                                            "regulator-coupled-with", i);
 517
 518                 if (!tmp)
 519                         break;
 520
 521                 /* found */
 522                 if (tmp == to_find)
 523                         found = true;
 524
 525                 of_node_put(tmp);
 526
 527                 if (found) {
 528                         *index = i;
 529                         break;
 530                 }
 531         }
 532
 533         return found;
 534 }
 535
 536 /**
 537  * of_check_coupling_data - Parse rdev's coupling properties and check data
 538  *                          consistency
 539  * @rdev: pointer to regulator_dev whose data is checked
 540  *
 541  * Function checks if all the following conditions are met:
 542  * - rdev's max_spread is greater than 0
 543  * - all coupled regulators have the same max_spread
 544  * - all coupled regulators have the same number of regulator_dev phandles
 545  * - all regulators are linked to each other
 546  *
 547  * Returns true if all conditions are met.
 548  */
 549 bool of_check_coupling_data(struct regulator_dev *rdev)
 550 {
 551         struct device_node *node = rdev->dev.of_node;
 552         int n_phandles = of_get_n_coupled(rdev);
 553         struct device_node *c_node;
 554         int index;
 555         int i;
 556         bool ret = true;
 557
 558         /* iterate over rdev's phandles */
 559         for (i = 0; i < n_phandles; i++) {
 560                 int max_spread = rdev->constraints->max_spread[i];
 561                 int c_max_spread, c_n_phandles;
 562
 563                 if (max_spread <= 0) {
 564                         dev_err(&rdev->dev, "max_spread value invalid\n");
 565                         return false;
 566                 }
 567
 568                 c_node = of_parse_phandle(node,
 569                                           "regulator-coupled-with", i);
 570
 571                 if (!c_node)
 572                         ret = false;
 573
 574                 c_n_phandles = of_count_phandle_with_args(c_node,
 575                                                           "regulator-coupled-with",
 576                                                           NULL);
 577
 578                 if (c_n_phandles != n_phandles) {
 579                         dev_err(&rdev->dev, "number of coupled reg phandles mismatch\n");
 580                         ret = false;
 581                         goto clean;
 582                 }
 583
 584                 if (!of_coupling_find_node(c_node, node, &index)) {
 585                         dev_err(&rdev->dev, "missing 2-way linking for coupled regulators\n");
 586                         ret = false;
 587                         goto clean;
 588                 }
 589
 590                 if (of_property_read_u32_index(c_node, "regulator-coupled-max-spread",
 591                                                index, &c_max_spread)) {
 592                         ret = false;
 593                         goto clean;
 594                 }
 595
 596                 if (c_max_spread != max_spread) {
 597                         dev_err(&rdev->dev,
 598                                 "coupled regulators max_spread mismatch\n");
 599                         ret = false;
 600                         goto clean;
 601                 }
 602
 603 clean:
 604                 of_node_put(c_node);
 605                 if (!ret)
 606                         break;
 607         }
 608
 609         return ret;
 610 }
 611
 612 /**
 613  * of_parse_coupled regulator - Get regulator_dev pointer from rdev's property
 614  * @rdev: Pointer to regulator_dev, whose DTS is used as a source to parse
 615  *        "regulator-coupled-with" property
 616  * @index: Index in phandles array
 617  *
 618  * Returns the regulator_dev pointer parsed from DTS. If it has not been yet
 619  * registered, returns NULL
 620  */
 621 struct regulator_dev *of_parse_coupled_regulator(struct regulator_dev *rdev,
 622                                                  int index)
 623 {
 624         struct device_node *node = rdev->dev.of_node;
 625         struct device_node *c_node;
 626         struct regulator_dev *c_rdev;
 627
 628         c_node = of_parse_phandle(node, "regulator-coupled-with", index);
 629         if (!c_node)
 630                 return NULL;
 631
 632         c_rdev = of_find_regulator_by_node(c_node);
 633
 634         of_node_put(c_node);
 635
 636         return c_rdev;
 637 }