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