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