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