drivers/regulator/of_regulator.c

   1 /*
   2  * OF helpers for regulator framework
   3  *
   4  * Copyright (C) 2011 Texas Instruments, Inc.
   5  * Rajendra Nayak <rnayak@ti.com>
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  */
  12
  13 #include <linux/module.h>
  14 #include <linux/slab.h>
  15 #include <linux/of.h>
  16 #include <linux/regulator/machine.h>
  17 #include <linux/regulator/driver.h>
  18 #include <linux/regulator/of_regulator.h>
  19
  20 #include "internal.h"
  21
  22 static const char *const regulator_states[PM_SUSPEND_MAX + 1] = {
  23         [PM_SUSPEND_STANDBY]    = "regulator-state-standby",
  24         [PM_SUSPEND_MEM]        = "regulator-state-mem",
  25         [PM_SUSPEND_MAX]        = "regulator-state-disk",
  26 };
  27
  28 static void of_get_regulation_constraints(struct device_node *np,
  29                                         struct regulator_init_data **init_data,
  30                                         const struct regulator_desc *desc)
  31 {
  32         struct regulation_constraints *constraints = &(*init_data)->constraints;
  33         struct regulator_state *suspend_state;
  34         struct device_node *suspend_np;
  35         unsigned int mode;
  36         int ret, i, len;
  37         u32 pval;
  38
  39         constraints->name = of_get_property(np, "regulator-name", NULL);
  40
  41         if (!of_property_read_u32(np, "regulator-min-microvolt", &pval))
  42                 constraints->min_uV = pval;
  43
  44         if (!of_property_read_u32(np, "regulator-max-microvolt", &pval))
  45                 constraints->max_uV = pval;
  46
  47         /* Voltage change possible? */
  48         if (constraints->min_uV != constraints->max_uV)
  49                 constraints->valid_ops_mask |= REGULATOR_CHANGE_VOLTAGE;
  50
  51         /* Do we have a voltage range, if so try to apply it? */
  52         if (constraints->min_uV && constraints->max_uV)
  53                 constraints->apply_uV = true;
  54
  55         if (!of_property_read_u32(np, "regulator-microvolt-offset", &pval))
  56                 constraints->uV_offset = pval;
  57         if (!of_property_read_u32(np, "regulator-min-microamp", &pval))
  58                 constraints->min_uA = pval;
  59         if (!of_property_read_u32(np, "regulator-max-microamp", &pval))
  60                 constraints->max_uA = pval;
  61
  62         if (!of_property_read_u32(np, "regulator-input-current-limit-microamp",
  63                                   &pval))
  64                 constraints->ilim_uA = pval;
  65
  66         /* Current change possible? */
  67         if (constraints->min_uA != constraints->max_uA)
  68                 constraints->valid_ops_mask |= REGULATOR_CHANGE_CURRENT;
  69
  70         constraints->boot_on = of_property_read_bool(np, "regulator-boot-on");
  71         constraints->always_on = of_property_read_bool(np, "regulator-always-on");
  72         if (!constraints->always_on) /* status change should be possible. */
  73                 constraints->valid_ops_mask |= REGULATOR_CHANGE_STATUS;
  74
  75         constraints->pull_down = of_property_read_bool(np, "regulator-pull-down");
  76
  77         if (of_property_read_bool(np, "regulator-allow-bypass"))
  78                 constraints->valid_ops_mask |= REGULATOR_CHANGE_BYPASS;
  79
  80         if (of_property_read_bool(np, "regulator-allow-set-load"))
  81                 constraints->valid_ops_mask |= REGULATOR_CHANGE_DRMS;
  82
  83         ret = of_property_read_u32(np, "regulator-ramp-delay", &pval);
  84         if (!ret) {
  85                 if (pval)
  86                         constraints->ramp_delay = pval;
  87                 else
  88                         constraints->ramp_disable = true;
  89         }
  90
  91         ret = of_property_read_u32(np, "regulator-settling-time-us", &pval);
  92         if (!ret)
  93                 constraints->settling_time = pval;
  94
  95         ret = of_property_read_u32(np, "regulator-settling-time-up-us", &pval);
  96         if (!ret)
  97                 constraints->settling_time_up = pval;
  98         if (constraints->settling_time_up && constraints->settling_time) {
  99                 pr_warn("%pOFn: ambiguous configuration for settling time, ignoring 'regulator-settling-time-up-us'\n",
 100                         np);
 101                 constraints->settling_time_up = 0;
 102         }
 103
 104         ret = of_property_read_u32(np, "regulator-settling-time-down-us",
 105                                    &pval);
 106         if (!ret)
 107                 constraints->settling_time_down = pval;
 108         if (constraints->settling_time_down && constraints->settling_time) {
 109                 pr_warn("%pOFn: ambiguous configuration for settling time, ignoring 'regulator-settling-time-down-us'\n",
 110                         np);
 111                 constraints->settling_time_down = 0;
 112         }
 113
 114         ret = of_property_read_u32(np, "regulator-enable-ramp-delay", &pval);
 115         if (!ret)
 116                 constraints->enable_time = pval;
 117
 118         constraints->soft_start = of_property_read_bool(np,
 119                                         "regulator-soft-start");
 120         ret = of_property_read_u32(np, "regulator-active-discharge", &pval);
 121         if (!ret) {
 122                 constraints->active_discharge =
 123                                 (pval) ? REGULATOR_ACTIVE_DISCHARGE_ENABLE :
 124                                         REGULATOR_ACTIVE_DISCHARGE_DISABLE;
 125         }
 126
 127         if (!of_property_read_u32(np, "regulator-initial-mode", &pval)) {
 128                 if (desc && desc->of_map_mode) {
 129                         mode = desc->of_map_mode(pval);
 130                         if (mode == REGULATOR_MODE_INVALID)
 131                                 pr_err("%pOFn: invalid mode %u\n", np, pval);
 132                         else
 133                                 constraints->initial_mode = mode;
 134                 } else {
 135                         pr_warn("%pOFn: mapping for mode %d not defined\n",
 136                                 np, pval);
 137                 }
 138         }
 139
 140         len = of_property_count_elems_of_size(np, "regulator-allowed-modes",
 141                                                 sizeof(u32));
 142         if (len > 0) {
 143                 if (desc && desc->of_map_mode) {
 144                         for (i = 0; i < len; i++) {
 145                                 ret = of_property_read_u32_index(np,
 146                                         "regulator-allowed-modes", i, &pval);
 147                                 if (ret) {
 148                                         pr_err("%pOFn: couldn't read allowed modes index %d, ret=%d\n",
 149                                                 np, i, ret);
 150                                         break;
 151                                 }
 152                                 mode = desc->of_map_mode(pval);
 153                                 if (mode == REGULATOR_MODE_INVALID)
 154                                         pr_err("%pOFn: invalid regulator-allowed-modes element %u\n",
 155                                                 np, pval);
 156                                 else
 157                                         constraints->valid_modes_mask |= mode;
 158                         }
 159                         if (constraints->valid_modes_mask)
 160                                 constraints->valid_ops_mask
 161                                         |= REGULATOR_CHANGE_MODE;
 162                 } else {
 163                         pr_warn("%pOFn: mode mapping not defined\n", np);
 164                 }
 165         }
 166
 167         if (!of_property_read_u32(np, "regulator-system-load", &pval))
 168                 constraints->system_load = pval;
 169
 170         if (!of_property_read_u32(np, "regulator-coupled-max-spread",
 171                                   &pval))
 172                 constraints->max_spread = pval;
 173
 174         if (!of_property_read_u32(np, "regulator-max-step-microvolt",
 175                                   &pval))
 176                 constraints->max_uV_step = pval;
 177
 178         constraints->over_current_protection = of_property_read_bool(np,
 179                                         "regulator-over-current-protection");
 180
 181         for (i = 0; i < ARRAY_SIZE(regulator_states); i++) {
 182                 switch (i) {
 183                 case PM_SUSPEND_MEM:
 184                         suspend_state = &constraints->state_mem;
 185                         break;
 186                 case PM_SUSPEND_MAX:
 187                         suspend_state = &constraints->state_disk;
 188                         break;
 189                 case PM_SUSPEND_STANDBY:
 190                         suspend_state = &constraints->state_standby;
 191                         break;
 192                 case PM_SUSPEND_ON:
 193                 case PM_SUSPEND_TO_IDLE:
 194                 default:
 195                         continue;
 196                 }
 197
 198                 suspend_np = of_get_child_by_name(np, regulator_states[i]);
 199                 if (!suspend_np || !suspend_state)
 200                         continue;
 201
 202                 if (!of_property_read_u32(suspend_np, "regulator-mode",
 203                                           &pval)) {
 204                         if (desc && desc->of_map_mode) {
 205                                 mode = desc->of_map_mode(pval);
 206                                 if (mode == REGULATOR_MODE_INVALID)
 207                                         pr_err("%pOFn: invalid mode %u\n",
 208                                                np, pval);
 209                                 else
 210                                         suspend_state->mode = mode;
 211                         } else {
 212                                 pr_warn("%pOFn: mapping for mode %d not defined\n",
 213                                         np, pval);
 214                         }
 215                 }
 216
 217                 if (of_property_read_bool(suspend_np,
 218                                         "regulator-on-in-suspend"))
 219                         suspend_state->enabled = ENABLE_IN_SUSPEND;
 220                 else if (of_property_read_bool(suspend_np,
 221                                         "regulator-off-in-suspend"))
 222                         suspend_state->enabled = DISABLE_IN_SUSPEND;
 223
 224                 if (!of_property_read_u32(np, "regulator-suspend-min-microvolt",
 225                                           &pval))
 226                         suspend_state->min_uV = pval;
 227
 228                 if (!of_property_read_u32(np, "regulator-suspend-max-microvolt",
 229                                           &pval))
 230                         suspend_state->max_uV = pval;
 231
 232                 if (!of_property_read_u32(suspend_np,
 233                                         "regulator-suspend-microvolt", &pval))
 234                         suspend_state->uV = pval;
 235                 else /* otherwise use min_uV as default suspend voltage */
 236                         suspend_state->uV = suspend_state->min_uV;
 237
 238                 if (of_property_read_bool(suspend_np,
 239                                         "regulator-changeable-in-suspend"))
 240                         suspend_state->changeable = true;
 241
 242                 if (i == PM_SUSPEND_MEM)
 243                         constraints->initial_state = PM_SUSPEND_MEM;
 244
 245                 of_node_put(suspend_np);
 246                 suspend_state = NULL;
 247                 suspend_np = NULL;
 248         }
 249 }
 250
 251 /**
 252  * of_get_regulator_init_data - extract regulator_init_data structure info
 253  * @dev: device requesting for regulator_init_data
 254  * @node: regulator device node
 255  * @desc: regulator description
 256  *
 257  * Populates regulator_init_data structure by extracting data from device
 258  * tree node, returns a pointer to the populated structure or NULL if memory
 259  * alloc fails.
 260  */
 261 struct regulator_init_data *of_get_regulator_init_data(struct device *dev,
 262                                           struct device_node *node,
 263                                           const struct regulator_desc *desc)
 264 {
 265         struct regulator_init_data *init_data;
 266
 267         if (!node)
 268                 return NULL;
 269
 270         init_data = devm_kzalloc(dev, sizeof(*init_data), GFP_KERNEL);
 271         if (!init_data)
 272                 return NULL; /* Out of memory? */
 273
 274         of_get_regulation_constraints(node, &init_data, desc);
 275         return init_data;
 276 }
 277 EXPORT_SYMBOL_GPL(of_get_regulator_init_data);
 278
 279 struct devm_of_regulator_matches {
 280         struct of_regulator_match *matches;
 281         unsigned int num_matches;
 282 };
 283
 284 static void devm_of_regulator_put_matches(struct device *dev, void *res)
 285 {
 286         struct devm_of_regulator_matches *devm_matches = res;
 287         int i;
 288
 289         for (i = 0; i < devm_matches->num_matches; i++)
 290                 of_node_put(devm_matches->matches[i].of_node);
 291 }
 292
 293 /**
 294  * of_regulator_match - extract multiple regulator init data from device tree.
 295  * @dev: device requesting the data
 296  * @node: parent device node of the regulators
 297  * @matches: match table for the regulators
 298  * @num_matches: number of entries in match table
 299  *
 300  * This function uses a match table specified by the regulator driver to
 301  * parse regulator init data from the device tree. @node is expected to
 302  * contain a set of child nodes, each providing the init data for one
 303  * regulator. The data parsed from a child node will be matched to a regulator
 304  * based on either the deprecated property regulator-compatible if present,
 305  * or otherwise the child node's name. Note that the match table is modified
 306  * in place and an additional of_node reference is taken for each matched
 307  * regulator.
 308  *
 309  * Returns the number of matches found or a negative error code on failure.
 310  */
 311 int of_regulator_match(struct device *dev, struct device_node *node,
 312                        struct of_regulator_match *matches,
 313                        unsigned int num_matches)
 314 {
 315         unsigned int count = 0;
 316         unsigned int i;
 317         const char *name;
 318         struct device_node *child;
 319         struct devm_of_regulator_matches *devm_matches;
 320
 321         if (!dev || !node)
 322                 return -EINVAL;
 323
 324         devm_matches = devres_alloc(devm_of_regulator_put_matches,
 325                                     sizeof(struct devm_of_regulator_matches),
 326                                     GFP_KERNEL);
 327         if (!devm_matches)
 328                 return -ENOMEM;
 329
 330         devm_matches->matches = matches;
 331         devm_matches->num_matches = num_matches;
 332
 333         devres_add(dev, devm_matches);
 334
 335         for (i = 0; i < num_matches; i++) {
 336                 struct of_regulator_match *match = &matches[i];
 337                 match->init_data = NULL;
 338                 match->of_node = NULL;
 339         }
 340
 341         for_each_child_of_node(node, child) {
 342                 name = of_get_property(child,
 343                                         "regulator-compatible", NULL);
 344                 if (!name)
 345                         name = child->name;
 346                 for (i = 0; i < num_matches; i++) {
 347                         struct of_regulator_match *match = &matches[i];
 348                         if (match->of_node)
 349                                 continue;
 350
 351                         if (strcmp(match->name, name))
 352                                 continue;
 353
 354                         match->init_data =
 355                                 of_get_regulator_init_data(dev, child,
 356                                                            match->desc);
 357                         if (!match->init_data) {
 358                                 dev_err(dev,
 359                                         "failed to parse DT for regulator %pOFn\n",
 360                                         child);
 361                                 of_node_put(child);
 362                                 return -EINVAL;
 363                         }
 364                         match->of_node = of_node_get(child);
 365                         count++;
 366                         break;
 367                 }
 368         }
 369
 370         return count;
 371 }
 372 EXPORT_SYMBOL_GPL(of_regulator_match);
 373
 374 struct device_node *regulator_of_get_init_node(struct device *dev,
 375                                                const struct regulator_desc *desc)
 376 {
 377         struct device_node *search, *child;
 378         const char *name;
 379
 380         if (!dev->of_node || !desc->of_match)
 381                 return NULL;
 382
 383         if (desc->regulators_node) {
 384                 search = of_get_child_by_name(dev->of_node,
 385                                               desc->regulators_node);
 386         } else {
 387                 search = of_node_get(dev->of_node);
 388
 389                 if (!strcmp(desc->of_match, search->name))
 390                         return search;
 391         }
 392
 393         if (!search) {
 394                 dev_dbg(dev, "Failed to find regulator container node '%s'\n",
 395                         desc->regulators_node);
 396                 return NULL;
 397         }
 398
 399         for_each_available_child_of_node(search, child) {
 400                 name = of_get_property(child, "regulator-compatible", NULL);
 401                 if (!name)
 402                         name = child->name;
 403
 404                 if (!strcmp(desc->of_match, name))
 405                         return of_node_get(child);
 406         }
 407
 408         of_node_put(search);
 409
 410         return NULL;
 411 }
 412
 413 struct regulator_init_data *regulator_of_get_init_data(struct device *dev,
 414                                             const struct regulator_desc *desc,
 415                                             struct regulator_config *config,
 416                                             struct device_node **node)
 417 {
 418         struct device_node *child;
 419         struct regulator_init_data *init_data = NULL;
 420
 421         child = regulator_of_get_init_node(dev, desc);
 422         if (!child)
 423                 return NULL;
 424
 425         init_data = of_get_regulator_init_data(dev, child, desc);
 426         if (!init_data) {
 427                 dev_err(dev, "failed to parse DT for regulator %pOFn\n", child);
 428                 goto error;
 429         }
 430
 431         if (desc->of_parse_cb && desc->of_parse_cb(child, desc, config)) {
 432                 dev_err(dev,
 433                         "driver callback failed to parse DT for regulator %pOFn\n",
 434                         child);
 435                 goto error;
 436         }
 437
 438         *node = child;
 439
 440         return init_data;
 441
 442 error:
 443         of_node_put(child);
 444
 445         return NULL;
 446 }
 447
 448 static int of_node_match(struct device *dev, const void *data)
 449 {
 450         return dev->of_node == data;
 451 }
 452
 453 struct regulator_dev *of_find_regulator_by_node(struct device_node *np)
 454 {
 455         struct device *dev;
 456
 457         dev = class_find_device(&regulator_class, NULL, np, of_node_match);
 458
 459         return dev ? dev_to_rdev(dev) : NULL;
 460 }
 461
 462 /*
 463  * Returns number of regulators coupled with rdev.
 464  */
 465 int of_get_n_coupled(struct regulator_dev *rdev)
 466 {
 467         struct device_node *node = rdev->dev.of_node;
 468         int n_phandles;
 469
 470         n_phandles = of_count_phandle_with_args(node,
 471                                                 "regulator-coupled-with",
 472                                                 NULL);
 473
 474         return (n_phandles > 0) ? n_phandles : 0;
 475 }
 476
 477 /* Looks for "to_find" device_node in src's "regulator-coupled-with" property */
 478 static bool of_coupling_find_node(struct device_node *src,
 479                                   struct device_node *to_find)
 480 {
 481         int n_phandles, i;
 482         bool found = false;
 483
 484         n_phandles = of_count_phandle_with_args(src,
 485                                                 "regulator-coupled-with",
 486                                                 NULL);
 487
 488         for (i = 0; i < n_phandles; i++) {
 489                 struct device_node *tmp = of_parse_phandle(src,
 490                                            "regulator-coupled-with", i);
 491
 492                 if (!tmp)
 493                         break;
 494
 495                 /* found */
 496                 if (tmp == to_find)
 497                         found = true;
 498
 499                 of_node_put(tmp);
 500
 501                 if (found)
 502                         break;
 503         }
 504
 505         return found;
 506 }
 507
 508 /**
 509  * of_check_coupling_data - Parse rdev's coupling properties and check data
 510  *                          consistency
 511  * @rdev - pointer to regulator_dev whose data is checked
 512  *
 513  * Function checks if all the following conditions are met:
 514  * - rdev's max_spread is greater than 0
 515  * - all coupled regulators have the same max_spread
 516  * - all coupled regulators have the same number of regulator_dev phandles
 517  * - all regulators are linked to each other
 518  *
 519  * Returns true if all conditions are met.
 520  */
 521 bool of_check_coupling_data(struct regulator_dev *rdev)
 522 {
 523         int max_spread = rdev->constraints->max_spread;
 524         struct device_node *node = rdev->dev.of_node;
 525         int n_phandles = of_get_n_coupled(rdev);
 526         struct device_node *c_node;
 527         int i;
 528         bool ret = true;
 529
 530         if (max_spread <= 0) {
 531                 dev_err(&rdev->dev, "max_spread value invalid\n");
 532                 return false;
 533         }
 534
 535         /* iterate over rdev's phandles */
 536         for (i = 0; i < n_phandles; i++) {
 537                 int c_max_spread, c_n_phandles;
 538
 539                 c_node = of_parse_phandle(node,
 540                                           "regulator-coupled-with", i);
 541
 542                 if (!c_node)
 543                         ret = false;
 544
 545                 c_n_phandles = of_count_phandle_with_args(c_node,
 546                                                           "regulator-coupled-with",
 547                                                           NULL);
 548
 549                 if (c_n_phandles != n_phandles) {
 550                         dev_err(&rdev->dev, "number of coupled reg phandles mismatch\n");
 551                         ret = false;
 552                         goto clean;
 553                 }
 554
 555                 if (of_property_read_u32(c_node, "regulator-coupled-max-spread",
 556                                          &c_max_spread)) {
 557                         ret = false;
 558                         goto clean;
 559                 }
 560
 561                 if (c_max_spread != max_spread) {
 562                         dev_err(&rdev->dev,
 563                                 "coupled regulators max_spread mismatch\n");
 564                         ret = false;
 565                         goto clean;
 566                 }
 567
 568                 if (!of_coupling_find_node(c_node, node)) {
 569                         dev_err(&rdev->dev, "missing 2-way linking for coupled regulators\n");
 570                         ret = false;
 571                 }
 572
 573 clean:
 574                 of_node_put(c_node);
 575                 if (!ret)
 576                         break;
 577         }
 578
 579         return ret;
 580 }
 581
 582 /**
 583  * of_parse_coupled regulator - Get regulator_dev pointer from rdev's property
 584  * @rdev: Pointer to regulator_dev, whose DTS is used as a source to parse
 585  *        "regulator-coupled-with" property
 586  * @index: Index in phandles array
 587  *
 588  * Returns the regulator_dev pointer parsed from DTS. If it has not been yet
 589  * registered, returns NULL
 590  */
 591 struct regulator_dev *of_parse_coupled_regulator(struct regulator_dev *rdev,
 592                                                  int index)
 593 {
 594         struct device_node *node = rdev->dev.of_node;
 595         struct device_node *c_node;
 596         struct regulator_dev *c_rdev;
 597
 598         c_node = of_parse_phandle(node, "regulator-coupled-with", index);
 599         if (!c_node)
 600                 return NULL;
 601
 602         c_rdev = of_find_regulator_by_node(c_node);
 603
 604         of_node_put(c_node);
 605
 606         return c_rdev;
 607 }