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("%pOFn: ambiguous configuration for settling time, ignoring 'regulator-settling-time-up-us'\n",
  99                         np);
 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("%pOFn: ambiguous configuration for settling time, ignoring 'regulator-settling-time-down-us'\n",
 109                         np);
 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("%pOFn: invalid mode %u\n", np, pval);
 131                         else
 132                                 constraints->initial_mode = mode;
 133                 } else {
 134                         pr_warn("%pOFn: mapping for mode %d not defined\n",
 135                                 np, 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("%pOFn: couldn't read allowed modes index %d, ret=%d\n",
 148                                                 np, i, ret);
 149                                         break;
 150                                 }
 151                                 mode = desc->of_map_mode(pval);
 152                                 if (mode == REGULATOR_MODE_INVALID)
 153                                         pr_err("%pOFn: invalid regulator-allowed-modes element %u\n",
 154                                                 np, 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("%pOFn: mode mapping not defined\n", np);
 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("%pOFn: invalid mode %u\n",
 201                                                np, pval);
 202                                 else
 203                                         suspend_state->mode = mode;
 204                         } else {
 205                                 pr_warn("%pOFn: mapping for mode %d not defined\n",
 206                                         np, 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
 217                 if (!of_property_read_u32(np, "regulator-suspend-min-microvolt",
 218                                           &pval))
 219                         suspend_state->min_uV = pval;
 220
 221                 if (!of_property_read_u32(np, "regulator-suspend-max-microvolt",
 222                                           &pval))
 223                         suspend_state->max_uV = pval;
 224
 225                 if (!of_property_read_u32(suspend_np,
 226                                         "regulator-suspend-microvolt", &pval))
 227                         suspend_state->uV = pval;
 228                 else /* otherwise use min_uV as default suspend voltage */
 229                         suspend_state->uV = suspend_state->min_uV;
 230
 231                 if (of_property_read_bool(suspend_np,
 232                                         "regulator-changeable-in-suspend"))
 233                         suspend_state->changeable = true;
 234
 235                 if (i == PM_SUSPEND_MEM)
 236                         constraints->initial_state = PM_SUSPEND_MEM;
 237
 238                 of_node_put(suspend_np);
 239                 suspend_state = NULL;
 240                 suspend_np = NULL;
 241         }
 242 }
 243
 244 /**
 245  * of_get_regulator_init_data - extract regulator_init_data structure info
 246  * @dev: device requesting for regulator_init_data
 247  * @node: regulator device node
 248  * @desc: regulator description
 249  *
 250  * Populates regulator_init_data structure by extracting data from device
 251  * tree node, returns a pointer to the populated struture or NULL if memory
 252  * alloc fails.
 253  */
 254 struct regulator_init_data *of_get_regulator_init_data(struct device *dev,
 255                                           struct device_node *node,
 256                                           const struct regulator_desc *desc)
 257 {
 258         struct regulator_init_data *init_data;
 259
 260         if (!node)
 261                 return NULL;
 262
 263         init_data = devm_kzalloc(dev, sizeof(*init_data), GFP_KERNEL);
 264         if (!init_data)
 265                 return NULL; /* Out of memory? */
 266
 267         of_get_regulation_constraints(node, &init_data, desc);
 268         return init_data;
 269 }
 270 EXPORT_SYMBOL_GPL(of_get_regulator_init_data);
 271
 272 struct devm_of_regulator_matches {
 273         struct of_regulator_match *matches;
 274         unsigned int num_matches;
 275 };
 276
 277 static void devm_of_regulator_put_matches(struct device *dev, void *res)
 278 {
 279         struct devm_of_regulator_matches *devm_matches = res;
 280         int i;
 281
 282         for (i = 0; i < devm_matches->num_matches; i++)
 283                 of_node_put(devm_matches->matches[i].of_node);
 284 }
 285
 286 /**
 287  * of_regulator_match - extract multiple regulator init data from device tree.
 288  * @dev: device requesting the data
 289  * @node: parent device node of the regulators
 290  * @matches: match table for the regulators
 291  * @num_matches: number of entries in match table
 292  *
 293  * This function uses a match table specified by the regulator driver to
 294  * parse regulator init data from the device tree. @node is expected to
 295  * contain a set of child nodes, each providing the init data for one
 296  * regulator. The data parsed from a child node will be matched to a regulator
 297  * based on either the deprecated property regulator-compatible if present,
 298  * or otherwise the child node's name. Note that the match table is modified
 299  * in place and an additional of_node reference is taken for each matched
 300  * regulator.
 301  *
 302  * Returns the number of matches found or a negative error code on failure.
 303  */
 304 int of_regulator_match(struct device *dev, struct device_node *node,
 305                        struct of_regulator_match *matches,
 306                        unsigned int num_matches)
 307 {
 308         unsigned int count = 0;
 309         unsigned int i;
 310         const char *name;
 311         struct device_node *child;
 312         struct devm_of_regulator_matches *devm_matches;
 313
 314         if (!dev || !node)
 315                 return -EINVAL;
 316
 317         devm_matches = devres_alloc(devm_of_regulator_put_matches,
 318                                     sizeof(struct devm_of_regulator_matches),
 319                                     GFP_KERNEL);
 320         if (!devm_matches)
 321                 return -ENOMEM;
 322
 323         devm_matches->matches = matches;
 324         devm_matches->num_matches = num_matches;
 325
 326         devres_add(dev, devm_matches);
 327
 328         for (i = 0; i < num_matches; i++) {
 329                 struct of_regulator_match *match = &matches[i];
 330                 match->init_data = NULL;
 331                 match->of_node = NULL;
 332         }
 333
 334         for_each_child_of_node(node, child) {
 335                 name = of_get_property(child,
 336                                         "regulator-compatible", NULL);
 337                 if (!name)
 338                         name = child->name;
 339                 for (i = 0; i < num_matches; i++) {
 340                         struct of_regulator_match *match = &matches[i];
 341                         if (match->of_node)
 342                                 continue;
 343
 344                         if (strcmp(match->name, name))
 345                                 continue;
 346
 347                         match->init_data =
 348                                 of_get_regulator_init_data(dev, child,
 349                                                            match->desc);
 350                         if (!match->init_data) {
 351                                 dev_err(dev,
 352                                         "failed to parse DT for regulator %pOFn\n",
 353                                         child);
 354                                 of_node_put(child);
 355                                 return -EINVAL;
 356                         }
 357                         match->of_node = of_node_get(child);
 358                         count++;
 359                         break;
 360                 }
 361         }
 362
 363         return count;
 364 }
 365 EXPORT_SYMBOL_GPL(of_regulator_match);
 366
 367 struct regulator_init_data *regulator_of_get_init_data(struct device *dev,
 368                                             const struct regulator_desc *desc,
 369                                             struct regulator_config *config,
 370                                             struct device_node **node)
 371 {
 372         struct device_node *search, *child;
 373         struct regulator_init_data *init_data = NULL;
 374         const char *name;
 375
 376         if (!dev->of_node || !desc->of_match)
 377                 return NULL;
 378
 379         if (desc->regulators_node)
 380                 search = of_get_child_by_name(dev->of_node,
 381                                               desc->regulators_node);
 382         else
 383                 search = of_node_get(dev->of_node);
 384
 385         if (!search) {
 386                 dev_dbg(dev, "Failed to find regulator container node '%s'\n",
 387                         desc->regulators_node);
 388                 return NULL;
 389         }
 390
 391         for_each_available_child_of_node(search, child) {
 392                 name = of_get_property(child, "regulator-compatible", NULL);
 393                 if (!name)
 394                         name = child->name;
 395
 396                 if (strcmp(desc->of_match, name))
 397                         continue;
 398
 399                 init_data = of_get_regulator_init_data(dev, child, desc);
 400                 if (!init_data) {
 401                         dev_err(dev,
 402                                 "failed to parse DT for regulator %pOFn\n",
 403                                 child);
 404                         break;
 405                 }
 406
 407                 if (desc->of_parse_cb) {
 408                         if (desc->of_parse_cb(child, desc, config)) {
 409                                 dev_err(dev,
 410                                         "driver callback failed to parse DT for regulator %pOFn\n",
 411                                         child);
 412                                 init_data = NULL;
 413                                 break;
 414                         }
 415                 }
 416
 417                 of_node_get(child);
 418                 *node = child;
 419                 break;
 420         }
 421
 422         of_node_put(search);
 423
 424         return init_data;
 425 }
 426
 427 static int of_node_match(struct device *dev, const void *data)
 428 {
 429         return dev->of_node == data;
 430 }
 431
 432 struct regulator_dev *of_find_regulator_by_node(struct device_node *np)
 433 {
 434         struct device *dev;
 435
 436         dev = class_find_device(&regulator_class, NULL, np, of_node_match);
 437
 438         return dev ? dev_to_rdev(dev) : NULL;
 439 }
 440
 441 /*
 442  * Returns number of regulators coupled with rdev.
 443  */
 444 int of_get_n_coupled(struct regulator_dev *rdev)
 445 {
 446         struct device_node *node = rdev->dev.of_node;
 447         int n_phandles;
 448
 449         n_phandles = of_count_phandle_with_args(node,
 450                                                 "regulator-coupled-with",
 451                                                 NULL);
 452
 453         return (n_phandles > 0) ? n_phandles : 0;
 454 }
 455
 456 /* Looks for "to_find" device_node in src's "regulator-coupled-with" property */
 457 static bool of_coupling_find_node(struct device_node *src,
 458                                   struct device_node *to_find)
 459 {
 460         int n_phandles, i;
 461         bool found = false;
 462
 463         n_phandles = of_count_phandle_with_args(src,
 464                                                 "regulator-coupled-with",
 465                                                 NULL);
 466
 467         for (i = 0; i < n_phandles; i++) {
 468                 struct device_node *tmp = of_parse_phandle(src,
 469                                            "regulator-coupled-with", i);
 470
 471                 if (!tmp)
 472                         break;
 473
 474                 /* found */
 475                 if (tmp == to_find)
 476                         found = true;
 477
 478                 of_node_put(tmp);
 479
 480                 if (found)
 481                         break;
 482         }
 483
 484         return found;
 485 }
 486
 487 /**
 488  * of_check_coupling_data - Parse rdev's coupling properties and check data
 489  *                          consistency
 490  * @rdev - pointer to regulator_dev whose data is checked
 491  *
 492  * Function checks if all the following conditions are met:
 493  * - rdev's max_spread is greater than 0
 494  * - all coupled regulators have the same max_spread
 495  * - all coupled regulators have the same number of regulator_dev phandles
 496  * - all regulators are linked to each other
 497  *
 498  * Returns true if all conditions are met.
 499  */
 500 bool of_check_coupling_data(struct regulator_dev *rdev)
 501 {
 502         int max_spread = rdev->constraints->max_spread;
 503         struct device_node *node = rdev->dev.of_node;
 504         int n_phandles = of_get_n_coupled(rdev);
 505         struct device_node *c_node;
 506         int i;
 507         bool ret = true;
 508
 509         if (max_spread <= 0) {
 510                 dev_err(&rdev->dev, "max_spread value invalid\n");
 511                 return false;
 512         }
 513
 514         /* iterate over rdev's phandles */
 515         for (i = 0; i < n_phandles; i++) {
 516                 int c_max_spread, c_n_phandles;
 517
 518                 c_node = of_parse_phandle(node,
 519                                           "regulator-coupled-with", i);
 520
 521                 if (!c_node)
 522                         ret = false;
 523
 524                 c_n_phandles = of_count_phandle_with_args(c_node,
 525                                                           "regulator-coupled-with",
 526                                                           NULL);
 527
 528                 if (c_n_phandles != n_phandles) {
 529                         dev_err(&rdev->dev, "number of couped reg phandles mismatch\n");
 530                         ret = false;
 531                         goto clean;
 532                 }
 533
 534                 if (of_property_read_u32(c_node, "regulator-coupled-max-spread",
 535                                          &c_max_spread)) {
 536                         ret = false;
 537                         goto clean;
 538                 }
 539
 540                 if (c_max_spread != max_spread) {
 541                         dev_err(&rdev->dev,
 542                                 "coupled regulators max_spread mismatch\n");
 543                         ret = false;
 544                         goto clean;
 545                 }
 546
 547                 if (!of_coupling_find_node(c_node, node)) {
 548                         dev_err(&rdev->dev, "missing 2-way linking for coupled regulators\n");
 549                         ret = false;
 550                 }
 551
 552 clean:
 553                 of_node_put(c_node);
 554                 if (!ret)
 555                         break;
 556         }
 557
 558         return ret;
 559 }
 560
 561 /**
 562  * of_parse_coupled regulator - Get regulator_dev pointer from rdev's property
 563  * @rdev: Pointer to regulator_dev, whose DTS is used as a source to parse
 564  *        "regulator-coupled-with" property
 565  * @index: Index in phandles array
 566  *
 567  * Returns the regulator_dev pointer parsed from DTS. If it has not been yet
 568  * registered, returns NULL
 569  */
 570 struct regulator_dev *of_parse_coupled_regulator(struct regulator_dev *rdev,
 571                                                  int index)
 572 {
 573         struct device_node *node = rdev->dev.of_node;
 574         struct device_node *c_node;
 575         struct regulator_dev *c_rdev;
 576
 577         c_node = of_parse_phandle(node, "regulator-coupled-with", index);
 578         if (!c_node)
 579                 return NULL;
 580
 581         c_rdev = of_find_regulator_by_node(c_node);
 582
 583         of_node_put(c_node);
 584
 585         return c_rdev;
 586 }