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-enable-ramp-delay", &pval);
  90         if (!ret)
  91                 constraints->enable_time = pval;
  92
  93         constraints->soft_start = of_property_read_bool(np,
  94                                         "regulator-soft-start");
  95         ret = of_property_read_u32(np, "regulator-active-discharge", &pval);
  96         if (!ret) {
  97                 constraints->active_discharge =
  98                                 (pval) ? REGULATOR_ACTIVE_DISCHARGE_ENABLE :
  99                                         REGULATOR_ACTIVE_DISCHARGE_DISABLE;
 100         }
 101
 102         if (!of_property_read_u32(np, "regulator-initial-mode", &pval)) {
 103                 if (desc && desc->of_map_mode) {
 104                         ret = desc->of_map_mode(pval);
 105                         if (ret == -EINVAL)
 106                                 pr_err("%s: invalid mode %u\n", np->name, pval);
 107                         else
 108                                 constraints->initial_mode = ret;
 109                 } else {
 110                         pr_warn("%s: mapping for mode %d not defined\n",
 111                                 np->name, pval);
 112                 }
 113         }
 114
 115         if (!of_property_read_u32(np, "regulator-system-load", &pval))
 116                 constraints->system_load = pval;
 117
 118         constraints->over_current_protection = of_property_read_bool(np,
 119                                         "regulator-over-current-protection");
 120
 121         for (i = 0; i < ARRAY_SIZE(regulator_states); i++) {
 122                 switch (i) {
 123                 case PM_SUSPEND_MEM:
 124                         suspend_state = &constraints->state_mem;
 125                         break;
 126                 case PM_SUSPEND_MAX:
 127                         suspend_state = &constraints->state_disk;
 128                         break;
 129                 case PM_SUSPEND_ON:
 130                 case PM_SUSPEND_FREEZE:
 131                 case PM_SUSPEND_STANDBY:
 132                 default:
 133                         continue;
 134                 }
 135
 136                 suspend_np = of_get_child_by_name(np, regulator_states[i]);
 137                 if (!suspend_np || !suspend_state)
 138                         continue;
 139
 140                 if (!of_property_read_u32(suspend_np, "regulator-mode",
 141                                           &pval)) {
 142                         if (desc && desc->of_map_mode) {
 143                                 ret = desc->of_map_mode(pval);
 144                                 if (ret == -EINVAL)
 145                                         pr_err("%s: invalid mode %u\n",
 146                                                np->name, pval);
 147                                 else
 148                                         suspend_state->mode = ret;
 149                         } else {
 150                                 pr_warn("%s: mapping for mode %d not defined\n",
 151                                         np->name, pval);
 152                         }
 153                 }
 154
 155                 if (of_property_read_bool(suspend_np,
 156                                         "regulator-on-in-suspend"))
 157                         suspend_state->enabled = true;
 158                 else if (of_property_read_bool(suspend_np,
 159                                         "regulator-off-in-suspend"))
 160                         suspend_state->disabled = true;
 161
 162                 if (!of_property_read_u32(suspend_np,
 163                                         "regulator-suspend-microvolt", &pval))
 164                         suspend_state->uV = pval;
 165
 166                 of_node_put(suspend_np);
 167                 suspend_state = NULL;
 168                 suspend_np = NULL;
 169         }
 170 }
 171
 172 /**
 173  * of_get_regulator_init_data - extract regulator_init_data structure info
 174  * @dev: device requesting for regulator_init_data
 175  * @node: regulator device node
 176  * @desc: regulator description
 177  *
 178  * Populates regulator_init_data structure by extracting data from device
 179  * tree node, returns a pointer to the populated struture or NULL if memory
 180  * alloc fails.
 181  */
 182 struct regulator_init_data *of_get_regulator_init_data(struct device *dev,
 183                                           struct device_node *node,
 184                                           const struct regulator_desc *desc)
 185 {
 186         struct regulator_init_data *init_data;
 187
 188         if (!node)
 189                 return NULL;
 190
 191         init_data = devm_kzalloc(dev, sizeof(*init_data), GFP_KERNEL);
 192         if (!init_data)
 193                 return NULL; /* Out of memory? */
 194
 195         of_get_regulation_constraints(node, &init_data, desc);
 196         return init_data;
 197 }
 198 EXPORT_SYMBOL_GPL(of_get_regulator_init_data);
 199
 200 struct devm_of_regulator_matches {
 201         struct of_regulator_match *matches;
 202         unsigned int num_matches;
 203 };
 204
 205 static void devm_of_regulator_put_matches(struct device *dev, void *res)
 206 {
 207         struct devm_of_regulator_matches *devm_matches = res;
 208         int i;
 209
 210         for (i = 0; i < devm_matches->num_matches; i++)
 211                 of_node_put(devm_matches->matches[i].of_node);
 212 }
 213
 214 /**
 215  * of_regulator_match - extract multiple regulator init data from device tree.
 216  * @dev: device requesting the data
 217  * @node: parent device node of the regulators
 218  * @matches: match table for the regulators
 219  * @num_matches: number of entries in match table
 220  *
 221  * This function uses a match table specified by the regulator driver to
 222  * parse regulator init data from the device tree. @node is expected to
 223  * contain a set of child nodes, each providing the init data for one
 224  * regulator. The data parsed from a child node will be matched to a regulator
 225  * based on either the deprecated property regulator-compatible if present,
 226  * or otherwise the child node's name. Note that the match table is modified
 227  * in place and an additional of_node reference is taken for each matched
 228  * regulator.
 229  *
 230  * Returns the number of matches found or a negative error code on failure.
 231  */
 232 int of_regulator_match(struct device *dev, struct device_node *node,
 233                        struct of_regulator_match *matches,
 234                        unsigned int num_matches)
 235 {
 236         unsigned int count = 0;
 237         unsigned int i;
 238         const char *name;
 239         struct device_node *child;
 240         struct devm_of_regulator_matches *devm_matches;
 241
 242         if (!dev || !node)
 243                 return -EINVAL;
 244
 245         devm_matches = devres_alloc(devm_of_regulator_put_matches,
 246                                     sizeof(struct devm_of_regulator_matches),
 247                                     GFP_KERNEL);
 248         if (!devm_matches)
 249                 return -ENOMEM;
 250
 251         devm_matches->matches = matches;
 252         devm_matches->num_matches = num_matches;
 253
 254         devres_add(dev, devm_matches);
 255
 256         for (i = 0; i < num_matches; i++) {
 257                 struct of_regulator_match *match = &matches[i];
 258                 match->init_data = NULL;
 259                 match->of_node = NULL;
 260         }
 261
 262         for_each_child_of_node(node, child) {
 263                 name = of_get_property(child,
 264                                         "regulator-compatible", NULL);
 265                 if (!name)
 266                         name = child->name;
 267                 for (i = 0; i < num_matches; i++) {
 268                         struct of_regulator_match *match = &matches[i];
 269                         if (match->of_node)
 270                                 continue;
 271
 272                         if (strcmp(match->name, name))
 273                                 continue;
 274
 275                         match->init_data =
 276                                 of_get_regulator_init_data(dev, child,
 277                                                            match->desc);
 278                         if (!match->init_data) {
 279                                 dev_err(dev,
 280                                         "failed to parse DT for regulator %s\n",
 281                                         child->name);
 282                                 return -EINVAL;
 283                         }
 284                         match->of_node = of_node_get(child);
 285                         count++;
 286                         break;
 287                 }
 288         }
 289
 290         return count;
 291 }
 292 EXPORT_SYMBOL_GPL(of_regulator_match);
 293
 294 struct regulator_init_data *regulator_of_get_init_data(struct device *dev,
 295                                             const struct regulator_desc *desc,
 296                                             struct regulator_config *config,
 297                                             struct device_node **node)
 298 {
 299         struct device_node *search, *child;
 300         struct regulator_init_data *init_data = NULL;
 301         const char *name;
 302
 303         if (!dev->of_node || !desc->of_match)
 304                 return NULL;
 305
 306         if (desc->regulators_node)
 307                 search = of_get_child_by_name(dev->of_node,
 308                                               desc->regulators_node);
 309         else
 310                 search = dev->of_node;
 311
 312         if (!search) {
 313                 dev_dbg(dev, "Failed to find regulator container node '%s'\n",
 314                         desc->regulators_node);
 315                 return NULL;
 316         }
 317
 318         for_each_available_child_of_node(search, child) {
 319                 name = of_get_property(child, "regulator-compatible", NULL);
 320                 if (!name)
 321                         name = child->name;
 322
 323                 if (strcmp(desc->of_match, name))
 324                         continue;
 325
 326                 init_data = of_get_regulator_init_data(dev, child, desc);
 327                 if (!init_data) {
 328                         dev_err(dev,
 329                                 "failed to parse DT for regulator %s\n",
 330                                 child->name);
 331                         break;
 332                 }
 333
 334                 if (desc->of_parse_cb) {
 335                         if (desc->of_parse_cb(child, desc, config)) {
 336                                 dev_err(dev,
 337                                         "driver callback failed to parse DT for regulator %s\n",
 338                                         child->name);
 339                                 init_data = NULL;
 340                                 break;
 341                         }
 342                 }
 343
 344                 of_node_get(child);
 345                 *node = child;
 346                 break;
 347         }
 348
 349         of_node_put(search);
 350
 351         return init_data;
 352 }