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 || !suspend_state)
 210                         continue;
 211
 212                 if (!of_property_read_u32(suspend_np, "regulator-mode",
 213                                           &pval)) {
 214                         if (desc && desc->of_map_mode) {
 215                                 mode = desc->of_map_mode(pval);
 216                                 if (mode == REGULATOR_MODE_INVALID)
 217                                         pr_err("%pOFn: invalid mode %u\n",
 218                                                np, pval);
 219                                 else
 220                                         suspend_state->mode = mode;
 221                         } else {
 222                                 pr_warn("%pOFn: mapping for mode %d not defined\n",
 223                                         np, pval);
 224                         }
 225                 }
 226
 227                 if (of_property_read_bool(suspend_np,
 228                                         "regulator-on-in-suspend"))
 229                         suspend_state->enabled = ENABLE_IN_SUSPEND;
 230                 else if (of_property_read_bool(suspend_np,
 231                                         "regulator-off-in-suspend"))
 232                         suspend_state->enabled = DISABLE_IN_SUSPEND;
 233
 234                 if (!of_property_read_u32(np, "regulator-suspend-min-microvolt",
 235                                           &pval))
 236                         suspend_state->min_uV = pval;
 237
 238                 if (!of_property_read_u32(np, "regulator-suspend-max-microvolt",
 239                                           &pval))
 240                         suspend_state->max_uV = pval;
 241
 242                 if (!of_property_read_u32(suspend_np,
 243                                         "regulator-suspend-microvolt", &pval))
 244                         suspend_state->uV = pval;
 245                 else /* otherwise use min_uV as default suspend voltage */
 246                         suspend_state->uV = suspend_state->min_uV;
 247
 248                 if (of_property_read_bool(suspend_np,
 249                                         "regulator-changeable-in-suspend"))
 250                         suspend_state->changeable = true;
 251
 252                 if (i == PM_SUSPEND_MEM)
 253                         constraints->initial_state = PM_SUSPEND_MEM;
 254
 255                 of_node_put(suspend_np);
 256                 suspend_state = NULL;
 257                 suspend_np = NULL;
 258         }
 259
 260         return 0;
 261 }
 262
 263 /**
 264  * of_get_regulator_init_data - extract regulator_init_data structure info
 265  * @dev: device requesting for regulator_init_data
 266  * @node: regulator device node
 267  * @desc: regulator description
 268  *
 269  * Populates regulator_init_data structure by extracting data from device
 270  * tree node, returns a pointer to the populated structure or NULL if memory
 271  * alloc fails.
 272  */
 273 struct regulator_init_data *of_get_regulator_init_data(struct device *dev,
 274                                           struct device_node *node,
 275                                           const struct regulator_desc *desc)
 276 {
 277         struct regulator_init_data *init_data;
 278
 279         if (!node)
 280                 return NULL;
 281
 282         init_data = devm_kzalloc(dev, sizeof(*init_data), GFP_KERNEL);
 283         if (!init_data)
 284                 return NULL; /* Out of memory? */
 285
 286         if (of_get_regulation_constraints(dev, node, &init_data, desc))
 287                 return NULL;
 288
 289         return init_data;
 290 }
 291 EXPORT_SYMBOL_GPL(of_get_regulator_init_data);
 292
 293 struct devm_of_regulator_matches {
 294         struct of_regulator_match *matches;
 295         unsigned int num_matches;
 296 };
 297
 298 static void devm_of_regulator_put_matches(struct device *dev, void *res)
 299 {
 300         struct devm_of_regulator_matches *devm_matches = res;
 301         int i;
 302
 303         for (i = 0; i < devm_matches->num_matches; i++)
 304                 of_node_put(devm_matches->matches[i].of_node);
 305 }
 306
 307 /**
 308  * of_regulator_match - extract multiple regulator init data from device tree.
 309  * @dev: device requesting the data
 310  * @node: parent device node of the regulators
 311  * @matches: match table for the regulators
 312  * @num_matches: number of entries in match table
 313  *
 314  * This function uses a match table specified by the regulator driver to
 315  * parse regulator init data from the device tree. @node is expected to
 316  * contain a set of child nodes, each providing the init data for one
 317  * regulator. The data parsed from a child node will be matched to a regulator
 318  * based on either the deprecated property regulator-compatible if present,
 319  * or otherwise the child node's name. Note that the match table is modified
 320  * in place and an additional of_node reference is taken for each matched
 321  * regulator.
 322  *
 323  * Returns the number of matches found or a negative error code on failure.
 324  */
 325 int of_regulator_match(struct device *dev, struct device_node *node,
 326                        struct of_regulator_match *matches,
 327                        unsigned int num_matches)
 328 {
 329         unsigned int count = 0;
 330         unsigned int i;
 331         const char *name;
 332         struct device_node *child;
 333         struct devm_of_regulator_matches *devm_matches;
 334
 335         if (!dev || !node)
 336                 return -EINVAL;
 337
 338         devm_matches = devres_alloc(devm_of_regulator_put_matches,
 339                                     sizeof(struct devm_of_regulator_matches),
 340                                     GFP_KERNEL);
 341         if (!devm_matches)
 342                 return -ENOMEM;
 343
 344         devm_matches->matches = matches;
 345         devm_matches->num_matches = num_matches;
 346
 347         devres_add(dev, devm_matches);
 348
 349         for (i = 0; i < num_matches; i++) {
 350                 struct of_regulator_match *match = &matches[i];
 351                 match->init_data = NULL;
 352                 match->of_node = NULL;
 353         }
 354
 355         for_each_child_of_node(node, child) {
 356                 name = of_get_property(child,
 357                                         "regulator-compatible", NULL);
 358                 if (!name)
 359                         name = child->name;
 360                 for (i = 0; i < num_matches; i++) {
 361                         struct of_regulator_match *match = &matches[i];
 362                         if (match->of_node)
 363                                 continue;
 364
 365                         if (strcmp(match->name, name))
 366                                 continue;
 367
 368                         match->init_data =
 369                                 of_get_regulator_init_data(dev, child,
 370                                                            match->desc);
 371                         if (!match->init_data) {
 372                                 dev_err(dev,
 373                                         "failed to parse DT for regulator %pOFn\n",
 374                                         child);
 375                                 of_node_put(child);
 376                                 return -EINVAL;
 377                         }
 378                         match->of_node = of_node_get(child);
 379                         count++;
 380                         break;
 381                 }
 382         }
 383
 384         return count;
 385 }
 386 EXPORT_SYMBOL_GPL(of_regulator_match);
 387
 388 static struct
 389 device_node *regulator_of_get_init_node(struct device *dev,
 390                                         const struct regulator_desc *desc)
 391 {
 392         struct device_node *search, *child;
 393         const char *name;
 394
 395         if (!dev->of_node || !desc->of_match)
 396                 return NULL;
 397
 398         if (desc->regulators_node) {
 399                 search = of_get_child_by_name(dev->of_node,
 400                                               desc->regulators_node);
 401         } else {
 402                 search = of_node_get(dev->of_node);
 403
 404                 if (!strcmp(desc->of_match, search->name))
 405                         return search;
 406         }
 407
 408         if (!search) {
 409                 dev_dbg(dev, "Failed to find regulator container node '%s'\n",
 410                         desc->regulators_node);
 411                 return NULL;
 412         }
 413
 414         for_each_available_child_of_node(search, child) {
 415                 name = of_get_property(child, "regulator-compatible", NULL);
 416                 if (!name)
 417                         name = child->name;
 418
 419                 if (!strcmp(desc->of_match, name)) {
 420                         of_node_put(search);
 421                         return of_node_get(child);
 422                 }
 423         }
 424
 425         of_node_put(search);
 426
 427         return NULL;
 428 }
 429
 430 struct regulator_init_data *regulator_of_get_init_data(struct device *dev,
 431                                             const struct regulator_desc *desc,
 432                                             struct regulator_config *config,
 433                                             struct device_node **node)
 434 {
 435         struct device_node *child;
 436         struct regulator_init_data *init_data = NULL;
 437
 438         child = regulator_of_get_init_node(dev, desc);
 439         if (!child)
 440                 return NULL;
 441
 442         init_data = of_get_regulator_init_data(dev, child, desc);
 443         if (!init_data) {
 444                 dev_err(dev, "failed to parse DT for regulator %pOFn\n", child);
 445                 goto error;
 446         }
 447
 448         if (desc->of_parse_cb && desc->of_parse_cb(child, desc, config)) {
 449                 dev_err(dev,
 450                         "driver callback failed to parse DT for regulator %pOFn\n",
 451                         child);
 452                 goto error;
 453         }
 454
 455         *node = child;
 456
 457         return init_data;
 458
 459 error:
 460         of_node_put(child);
 461
 462         return NULL;
 463 }
 464
 465 static int of_node_match(struct device *dev, const void *data)
 466 {
 467         return dev->of_node == data;
 468 }
 469
 470 struct regulator_dev *of_find_regulator_by_node(struct device_node *np)
 471 {
 472         struct device *dev;
 473
 474         dev = class_find_device(&regulator_class, NULL, np, of_node_match);
 475
 476         return dev ? dev_to_rdev(dev) : NULL;
 477 }
 478
 479 /*
 480  * Returns number of regulators coupled with rdev.
 481  */
 482 int of_get_n_coupled(struct regulator_dev *rdev)
 483 {
 484         struct device_node *node = rdev->dev.of_node;
 485         int n_phandles;
 486
 487         n_phandles = of_count_phandle_with_args(node,
 488                                                 "regulator-coupled-with",
 489                                                 NULL);
 490
 491         return (n_phandles > 0) ? n_phandles : 0;
 492 }
 493
 494 /* Looks for "to_find" device_node in src's "regulator-coupled-with" property */
 495 static bool of_coupling_find_node(struct device_node *src,
 496                                   struct device_node *to_find,
 497                                   int *index)
 498 {
 499         int n_phandles, i;
 500         bool found = false;
 501
 502         n_phandles = of_count_phandle_with_args(src,
 503                                                 "regulator-coupled-with",
 504                                                 NULL);
 505
 506         for (i = 0; i < n_phandles; i++) {
 507                 struct device_node *tmp = of_parse_phandle(src,
 508                                            "regulator-coupled-with", i);
 509
 510                 if (!tmp)
 511                         break;
 512
 513                 /* found */
 514                 if (tmp == to_find)
 515                         found = true;
 516
 517                 of_node_put(tmp);
 518
 519                 if (found) {
 520                         *index = i;
 521                         break;
 522                 }
 523         }
 524
 525         return found;
 526 }
 527
 528 /**
 529  * of_check_coupling_data - Parse rdev's coupling properties and check data
 530  *                          consistency
 531  * @rdev - pointer to regulator_dev whose data is checked
 532  *
 533  * Function checks if all the following conditions are met:
 534  * - rdev's max_spread is greater than 0
 535  * - all coupled regulators have the same max_spread
 536  * - all coupled regulators have the same number of regulator_dev phandles
 537  * - all regulators are linked to each other
 538  *
 539  * Returns true if all conditions are met.
 540  */
 541 bool of_check_coupling_data(struct regulator_dev *rdev)
 542 {
 543         struct device_node *node = rdev->dev.of_node;
 544         int n_phandles = of_get_n_coupled(rdev);
 545         struct device_node *c_node;
 546         int index;
 547         int i;
 548         bool ret = true;
 549
 550         /* iterate over rdev's phandles */
 551         for (i = 0; i < n_phandles; i++) {
 552                 int max_spread = rdev->constraints->max_spread[i];
 553                 int c_max_spread, c_n_phandles;
 554
 555                 if (max_spread <= 0) {
 556                         dev_err(&rdev->dev, "max_spread value invalid\n");
 557                         return false;
 558                 }
 559
 560                 c_node = of_parse_phandle(node,
 561                                           "regulator-coupled-with", i);
 562
 563                 if (!c_node)
 564                         ret = false;
 565
 566                 c_n_phandles = of_count_phandle_with_args(c_node,
 567                                                           "regulator-coupled-with",
 568                                                           NULL);
 569
 570                 if (c_n_phandles != n_phandles) {
 571                         dev_err(&rdev->dev, "number of coupled reg phandles mismatch\n");
 572                         ret = false;
 573                         goto clean;
 574                 }
 575
 576                 if (!of_coupling_find_node(c_node, node, &index)) {
 577                         dev_err(&rdev->dev, "missing 2-way linking for coupled regulators\n");
 578                         ret = false;
 579                         goto clean;
 580                 }
 581
 582                 if (of_property_read_u32_index(c_node, "regulator-coupled-max-spread",
 583                                                index, &c_max_spread)) {
 584                         ret = false;
 585                         goto clean;
 586                 }
 587
 588                 if (c_max_spread != max_spread) {
 589                         dev_err(&rdev->dev,
 590                                 "coupled regulators max_spread mismatch\n");
 591                         ret = false;
 592                         goto clean;
 593                 }
 594
 595 clean:
 596                 of_node_put(c_node);
 597                 if (!ret)
 598                         break;
 599         }
 600
 601         return ret;
 602 }
 603
 604 /**
 605  * of_parse_coupled regulator - Get regulator_dev pointer from rdev's property
 606  * @rdev: Pointer to regulator_dev, whose DTS is used as a source to parse
 607  *        "regulator-coupled-with" property
 608  * @index: Index in phandles array
 609  *
 610  * Returns the regulator_dev pointer parsed from DTS. If it has not been yet
 611  * registered, returns NULL
 612  */
 613 struct regulator_dev *of_parse_coupled_regulator(struct regulator_dev *rdev,
 614                                                  int index)
 615 {
 616         struct device_node *node = rdev->dev.of_node;
 617         struct device_node *c_node;
 618         struct regulator_dev *c_rdev;
 619
 620         c_node = of_parse_phandle(node, "regulator-coupled-with", index);
 621         if (!c_node)
 622                 return NULL;
 623
 624         c_rdev = of_find_regulator_by_node(c_node);
 625
 626         of_node_put(c_node);
 627
 628         return c_rdev;
 629 }