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         int ret, i;
  35         u32 pval;
  36
  37         constraints->name = of_get_property(np, "regulator-name", NULL);
  38
  39         if (!of_property_read_u32(np, "regulator-min-microvolt", &pval))
  40                 constraints->min_uV = pval;
  41
  42         if (!of_property_read_u32(np, "regulator-max-microvolt", &pval))
  43                 constraints->max_uV = pval;
  44
  45         /* Voltage change possible? */
  46         if (constraints->min_uV != constraints->max_uV)
  47                 constraints->valid_ops_mask |= REGULATOR_CHANGE_VOLTAGE;
  48
  49         /* Do we have a voltage range, if so try to apply it? */
  50         if (constraints->min_uV && constraints->max_uV)
  51                 constraints->apply_uV = true;
  52
  53         if (!of_property_read_u32(np, "regulator-microvolt-offset", &pval))
  54                 constraints->uV_offset = pval;
  55         if (!of_property_read_u32(np, "regulator-min-microamp", &pval))
  56                 constraints->min_uA = pval;
  57         if (!of_property_read_u32(np, "regulator-max-microamp", &pval))
  58                 constraints->max_uA = pval;
  59
  60         if (!of_property_read_u32(np, "regulator-input-current-limit-microamp",
  61                                   &pval))
  62                 constraints->ilim_uA = pval;
  63
  64         /* Current change possible? */
  65         if (constraints->min_uA != constraints->max_uA)
  66                 constraints->valid_ops_mask |= REGULATOR_CHANGE_CURRENT;
  67
  68         constraints->boot_on = of_property_read_bool(np, "regulator-boot-on");
  69         constraints->always_on = of_property_read_bool(np, "regulator-always-on");
  70         if (!constraints->always_on) /* status change should be possible. */
  71                 constraints->valid_ops_mask |= REGULATOR_CHANGE_STATUS;
  72
  73         constraints->pull_down = of_property_read_bool(np, "regulator-pull-down");
  74
  75         if (of_property_read_bool(np, "regulator-allow-bypass"))
  76                 constraints->valid_ops_mask |= REGULATOR_CHANGE_BYPASS;
  77
  78         if (of_property_read_bool(np, "regulator-allow-set-load"))
  79                 constraints->valid_ops_mask |= REGULATOR_CHANGE_DRMS;
  80
  81         ret = of_property_read_u32(np, "regulator-ramp-delay", &pval);
  82         if (!ret) {
  83                 if (pval)
  84                         constraints->ramp_delay = pval;
  85                 else
  86                         constraints->ramp_disable = true;
  87         }
  88
  89         ret = of_property_read_u32(np, "regulator-settling-time-us", &pval);
  90         if (!ret)
  91                 constraints->settling_time = pval;
  92
  93         ret = of_property_read_u32(np, "regulator-settling-time-up-us", &pval);
  94         if (!ret)
  95                 constraints->settling_time_up = pval;
  96         if (constraints->settling_time_up && constraints->settling_time) {
  97                 pr_warn("%s: ambiguous configuration for settling time, ignoring 'regulator-settling-time-up-us'\n",
  98                         np->name);
  99                 constraints->settling_time_up = 0;
 100         }
 101
 102         ret = of_property_read_u32(np, "regulator-settling-time-down-us",
 103                                    &pval);
 104         if (!ret)
 105                 constraints->settling_time_down = pval;
 106         if (constraints->settling_time_down && constraints->settling_time) {
 107                 pr_warn("%s: ambiguous configuration for settling time, ignoring 'regulator-settling-time-down-us'\n",
 108                         np->name);
 109                 constraints->settling_time_down = 0;
 110         }
 111
 112         ret = of_property_read_u32(np, "regulator-enable-ramp-delay", &pval);
 113         if (!ret)
 114                 constraints->enable_time = pval;
 115
 116         constraints->soft_start = of_property_read_bool(np,
 117                                         "regulator-soft-start");
 118         ret = of_property_read_u32(np, "regulator-active-discharge", &pval);
 119         if (!ret) {
 120                 constraints->active_discharge =
 121                                 (pval) ? REGULATOR_ACTIVE_DISCHARGE_ENABLE :
 122                                         REGULATOR_ACTIVE_DISCHARGE_DISABLE;
 123         }
 124
 125         if (!of_property_read_u32(np, "regulator-initial-mode", &pval)) {
 126                 if (desc && desc->of_map_mode) {
 127                         ret = desc->of_map_mode(pval);
 128                         if (ret == -EINVAL)
 129                                 pr_err("%s: invalid mode %u\n", np->name, pval);
 130                         else
 131                                 constraints->initial_mode = ret;
 132                 } else {
 133                         pr_warn("%s: mapping for mode %d not defined\n",
 134                                 np->name, pval);
 135                 }
 136         }
 137
 138         if (!of_property_read_u32(np, "regulator-system-load", &pval))
 139                 constraints->system_load = pval;
 140
 141         constraints->over_current_protection = of_property_read_bool(np,
 142                                         "regulator-over-current-protection");
 143
 144         for (i = 0; i < ARRAY_SIZE(regulator_states); i++) {
 145                 switch (i) {
 146                 case PM_SUSPEND_MEM:
 147                         suspend_state = &constraints->state_mem;
 148                         break;
 149                 case PM_SUSPEND_MAX:
 150                         suspend_state = &constraints->state_disk;
 151                         break;
 152                 case PM_SUSPEND_ON:
 153                 case PM_SUSPEND_TO_IDLE:
 154                 case PM_SUSPEND_STANDBY:
 155                 default:
 156                         continue;
 157                 }
 158
 159                 suspend_np = of_get_child_by_name(np, regulator_states[i]);
 160                 if (!suspend_np || !suspend_state)
 161                         continue;
 162
 163                 if (!of_property_read_u32(suspend_np, "regulator-mode",
 164                                           &pval)) {
 165                         if (desc && desc->of_map_mode) {
 166                                 ret = desc->of_map_mode(pval);
 167                                 if (ret == -EINVAL)
 168                                         pr_err("%s: invalid mode %u\n",
 169                                                np->name, pval);
 170                                 else
 171                                         suspend_state->mode = ret;
 172                         } else {
 173                                 pr_warn("%s: mapping for mode %d not defined\n",
 174                                         np->name, pval);
 175                         }
 176                 }
 177
 178                 if (of_property_read_bool(suspend_np,
 179                                         "regulator-on-in-suspend"))
 180                         suspend_state->enabled = ENABLE_IN_SUSPEND;
 181                 else if (of_property_read_bool(suspend_np,
 182                                         "regulator-off-in-suspend"))
 183                         suspend_state->enabled = DISABLE_IN_SUSPEND;
 184                 else
 185                         suspend_state->enabled = DO_NOTHING_IN_SUSPEND;
 186
 187                 if (!of_property_read_u32(np, "regulator-suspend-min-microvolt",
 188                                           &pval))
 189                         suspend_state->min_uV = pval;
 190
 191                 if (!of_property_read_u32(np, "regulator-suspend-max-microvolt",
 192                                           &pval))
 193                         suspend_state->max_uV = pval;
 194
 195                 if (!of_property_read_u32(suspend_np,
 196                                         "regulator-suspend-microvolt", &pval))
 197                         suspend_state->uV = pval;
 198                 else /* otherwise use min_uV as default suspend voltage */
 199                         suspend_state->uV = suspend_state->min_uV;
 200
 201                 if (of_property_read_bool(suspend_np,
 202                                         "regulator-changeable-in-suspend"))
 203                         suspend_state->changeable = true;
 204
 205                 if (i == PM_SUSPEND_MEM)
 206                         constraints->initial_state = PM_SUSPEND_MEM;
 207
 208                 of_node_put(suspend_np);
 209                 suspend_state = NULL;
 210                 suspend_np = NULL;
 211         }
 212 }
 213
 214 /**
 215  * of_get_regulator_init_data - extract regulator_init_data structure info
 216  * @dev: device requesting for regulator_init_data
 217  * @node: regulator device node
 218  * @desc: regulator description
 219  *
 220  * Populates regulator_init_data structure by extracting data from device
 221  * tree node, returns a pointer to the populated struture or NULL if memory
 222  * alloc fails.
 223  */
 224 struct regulator_init_data *of_get_regulator_init_data(struct device *dev,
 225                                           struct device_node *node,
 226                                           const struct regulator_desc *desc)
 227 {
 228         struct regulator_init_data *init_data;
 229
 230         if (!node)
 231                 return NULL;
 232
 233         init_data = devm_kzalloc(dev, sizeof(*init_data), GFP_KERNEL);
 234         if (!init_data)
 235                 return NULL; /* Out of memory? */
 236
 237         of_get_regulation_constraints(node, &init_data, desc);
 238         return init_data;
 239 }
 240 EXPORT_SYMBOL_GPL(of_get_regulator_init_data);
 241
 242 struct devm_of_regulator_matches {
 243         struct of_regulator_match *matches;
 244         unsigned int num_matches;
 245 };
 246
 247 static void devm_of_regulator_put_matches(struct device *dev, void *res)
 248 {
 249         struct devm_of_regulator_matches *devm_matches = res;
 250         int i;
 251
 252         for (i = 0; i < devm_matches->num_matches; i++)
 253                 of_node_put(devm_matches->matches[i].of_node);
 254 }
 255
 256 /**
 257  * of_regulator_match - extract multiple regulator init data from device tree.
 258  * @dev: device requesting the data
 259  * @node: parent device node of the regulators
 260  * @matches: match table for the regulators
 261  * @num_matches: number of entries in match table
 262  *
 263  * This function uses a match table specified by the regulator driver to
 264  * parse regulator init data from the device tree. @node is expected to
 265  * contain a set of child nodes, each providing the init data for one
 266  * regulator. The data parsed from a child node will be matched to a regulator
 267  * based on either the deprecated property regulator-compatible if present,
 268  * or otherwise the child node's name. Note that the match table is modified
 269  * in place and an additional of_node reference is taken for each matched
 270  * regulator.
 271  *
 272  * Returns the number of matches found or a negative error code on failure.
 273  */
 274 int of_regulator_match(struct device *dev, struct device_node *node,
 275                        struct of_regulator_match *matches,
 276                        unsigned int num_matches)
 277 {
 278         unsigned int count = 0;
 279         unsigned int i;
 280         const char *name;
 281         struct device_node *child;
 282         struct devm_of_regulator_matches *devm_matches;
 283
 284         if (!dev || !node)
 285                 return -EINVAL;
 286
 287         devm_matches = devres_alloc(devm_of_regulator_put_matches,
 288                                     sizeof(struct devm_of_regulator_matches),
 289                                     GFP_KERNEL);
 290         if (!devm_matches)
 291                 return -ENOMEM;
 292
 293         devm_matches->matches = matches;
 294         devm_matches->num_matches = num_matches;
 295
 296         devres_add(dev, devm_matches);
 297
 298         for (i = 0; i < num_matches; i++) {
 299                 struct of_regulator_match *match = &matches[i];
 300                 match->init_data = NULL;
 301                 match->of_node = NULL;
 302         }
 303
 304         for_each_child_of_node(node, child) {
 305                 name = of_get_property(child,
 306                                         "regulator-compatible", NULL);
 307                 if (!name)
 308                         name = child->name;
 309                 for (i = 0; i < num_matches; i++) {
 310                         struct of_regulator_match *match = &matches[i];
 311                         if (match->of_node)
 312                                 continue;
 313
 314                         if (strcmp(match->name, name))
 315                                 continue;
 316
 317                         match->init_data =
 318                                 of_get_regulator_init_data(dev, child,
 319                                                            match->desc);
 320                         if (!match->init_data) {
 321                                 dev_err(dev,
 322                                         "failed to parse DT for regulator %s\n",
 323                                         child->name);
 324                                 return -EINVAL;
 325                         }
 326                         match->of_node = of_node_get(child);
 327                         count++;
 328                         break;
 329                 }
 330         }
 331
 332         return count;
 333 }
 334 EXPORT_SYMBOL_GPL(of_regulator_match);
 335
 336 struct regulator_init_data *regulator_of_get_init_data(struct device *dev,
 337                                             const struct regulator_desc *desc,
 338                                             struct regulator_config *config,
 339                                             struct device_node **node)
 340 {
 341         struct device_node *search, *child;
 342         struct regulator_init_data *init_data = NULL;
 343         const char *name;
 344
 345         if (!dev->of_node || !desc->of_match)
 346                 return NULL;
 347
 348         if (desc->regulators_node)
 349                 search = of_get_child_by_name(dev->of_node,
 350                                               desc->regulators_node);
 351         else
 352                 search = of_node_get(dev->of_node);
 353
 354         if (!search) {
 355                 dev_dbg(dev, "Failed to find regulator container node '%s'\n",
 356                         desc->regulators_node);
 357                 return NULL;
 358         }
 359
 360         for_each_available_child_of_node(search, child) {
 361                 name = of_get_property(child, "regulator-compatible", NULL);
 362                 if (!name)
 363                         name = child->name;
 364
 365                 if (strcmp(desc->of_match, name))
 366                         continue;
 367
 368                 init_data = of_get_regulator_init_data(dev, child, desc);
 369                 if (!init_data) {
 370                         dev_err(dev,
 371                                 "failed to parse DT for regulator %s\n",
 372                                 child->name);
 373                         break;
 374                 }
 375
 376                 if (desc->of_parse_cb) {
 377                         if (desc->of_parse_cb(child, desc, config)) {
 378                                 dev_err(dev,
 379                                         "driver callback failed to parse DT for regulator %s\n",
 380                                         child->name);
 381                                 init_data = NULL;
 382                                 break;
 383                         }
 384                 }
 385
 386                 of_node_get(child);
 387                 *node = child;
 388                 break;
 389         }
 390
 391         of_node_put(search);
 392
 393         return init_data;
 394 }
 395
 396 static int of_node_match(struct device *dev, const void *data)
 397 {
 398         return dev->of_node == data;
 399 }
 400
 401 struct regulator_dev *of_find_regulator_by_node(struct device_node *np)
 402 {
 403         struct device *dev;
 404
 405         dev = class_find_device(&regulator_class, NULL, np, of_node_match);
 406
 407         return dev ? dev_to_rdev(dev) : NULL;
 408 }