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         const __be32 *min_uV, *max_uV;
  32         struct regulation_constraints *constraints = &(*init_data)->constraints;
  33         struct regulator_state *suspend_state;
  34         struct device_node *suspend_np;
  35         int ret, i;
  36         u32 pval;
  37
  38         constraints->name = of_get_property(np, "regulator-name", NULL);
  39
  40         min_uV = of_get_property(np, "regulator-min-microvolt", NULL);
  41         if (min_uV)
  42                 constraints->min_uV = be32_to_cpu(*min_uV);
  43         max_uV = of_get_property(np, "regulator-max-microvolt", NULL);
  44         if (max_uV)
  45                 constraints->max_uV = be32_to_cpu(*max_uV);
  46
  47         /* Voltage change possible? */
  48         if (constraints->min_uV != constraints->max_uV)
  49                 constraints->valid_ops_mask |= REGULATOR_CHANGE_VOLTAGE;
  50         /* Only one voltage?  Then make sure it's set. */
  51         if (min_uV && max_uV && 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-enable-ramp-delay", &pval);
  91         if (!ret)
  92                 constraints->enable_time = pval;
  93
  94         constraints->soft_start = of_property_read_bool(np,
  95                                         "regulator-soft-start");
  96         ret = of_property_read_u32(np, "regulator-active-discharge", &pval);
  97         if (!ret) {
  98                 constraints->active_discharge =
  99                                 (pval) ? REGULATOR_ACTIVE_DISCHARGE_ENABLE :
 100                                         REGULATOR_ACTIVE_DISCHARGE_DISABLE;
 101         }
 102
 103         if (!of_property_read_u32(np, "regulator-initial-mode", &pval)) {
 104                 if (desc && desc->of_map_mode) {
 105                         ret = desc->of_map_mode(pval);
 106                         if (ret == -EINVAL)
 107                                 pr_err("%s: invalid mode %u\n", np->name, pval);
 108                         else
 109                                 constraints->initial_mode = ret;
 110                 } else {
 111                         pr_warn("%s: mapping for mode %d not defined\n",
 112                                 np->name, pval);
 113                 }
 114         }
 115
 116         if (!of_property_read_u32(np, "regulator-system-load", &pval))
 117                 constraints->system_load = pval;
 118
 119         constraints->over_current_protection = of_property_read_bool(np,
 120                                         "regulator-over-current-protection");
 121
 122         for (i = 0; i < ARRAY_SIZE(regulator_states); i++) {
 123                 switch (i) {
 124                 case PM_SUSPEND_MEM:
 125                         suspend_state = &constraints->state_mem;
 126                         break;
 127                 case PM_SUSPEND_MAX:
 128                         suspend_state = &constraints->state_disk;
 129                         break;
 130                 case PM_SUSPEND_ON:
 131                 case PM_SUSPEND_FREEZE:
 132                 case PM_SUSPEND_STANDBY:
 133                 default:
 134                         continue;
 135                 }
 136
 137                 suspend_np = of_get_child_by_name(np, regulator_states[i]);
 138                 if (!suspend_np || !suspend_state)
 139                         continue;
 140
 141                 if (!of_property_read_u32(suspend_np, "regulator-mode",
 142                                           &pval)) {
 143                         if (desc && desc->of_map_mode) {
 144                                 ret = desc->of_map_mode(pval);
 145                                 if (ret == -EINVAL)
 146                                         pr_err("%s: invalid mode %u\n",
 147                                                np->name, pval);
 148                                 else
 149                                         suspend_state->mode = ret;
 150                         } else {
 151                                 pr_warn("%s: mapping for mode %d not defined\n",
 152                                         np->name, pval);
 153                         }
 154                 }
 155
 156                 if (of_property_read_bool(suspend_np,
 157                                         "regulator-on-in-suspend"))
 158                         suspend_state->enabled = true;
 159                 else if (of_property_read_bool(suspend_np,
 160                                         "regulator-off-in-suspend"))
 161                         suspend_state->disabled = true;
 162
 163                 if (!of_property_read_u32(suspend_np,
 164                                         "regulator-suspend-microvolt", &pval))
 165                         suspend_state->uV = pval;
 166
 167                 of_node_put(suspend_np);
 168                 suspend_state = NULL;
 169                 suspend_np = NULL;
 170         }
 171 }
 172
 173 /**
 174  * of_get_regulator_init_data - extract regulator_init_data structure info
 175  * @dev: device requesting for regulator_init_data
 176  * @node: regulator device node
 177  * @desc: regulator description
 178  *
 179  * Populates regulator_init_data structure by extracting data from device
 180  * tree node, returns a pointer to the populated struture or NULL if memory
 181  * alloc fails.
 182  */
 183 struct regulator_init_data *of_get_regulator_init_data(struct device *dev,
 184                                           struct device_node *node,
 185                                           const struct regulator_desc *desc)
 186 {
 187         struct regulator_init_data *init_data;
 188
 189         if (!node)
 190                 return NULL;
 191
 192         init_data = devm_kzalloc(dev, sizeof(*init_data), GFP_KERNEL);
 193         if (!init_data)
 194                 return NULL; /* Out of memory? */
 195
 196         of_get_regulation_constraints(node, &init_data, desc);
 197         return init_data;
 198 }
 199 EXPORT_SYMBOL_GPL(of_get_regulator_init_data);
 200
 201 struct devm_of_regulator_matches {
 202         struct of_regulator_match *matches;
 203         unsigned int num_matches;
 204 };
 205
 206 static void devm_of_regulator_put_matches(struct device *dev, void *res)
 207 {
 208         struct devm_of_regulator_matches *devm_matches = res;
 209         int i;
 210
 211         for (i = 0; i < devm_matches->num_matches; i++)
 212                 of_node_put(devm_matches->matches[i].of_node);
 213 }
 214
 215 /**
 216  * of_regulator_match - extract multiple regulator init data from device tree.
 217  * @dev: device requesting the data
 218  * @node: parent device node of the regulators
 219  * @matches: match table for the regulators
 220  * @num_matches: number of entries in match table
 221  *
 222  * This function uses a match table specified by the regulator driver to
 223  * parse regulator init data from the device tree. @node is expected to
 224  * contain a set of child nodes, each providing the init data for one
 225  * regulator. The data parsed from a child node will be matched to a regulator
 226  * based on either the deprecated property regulator-compatible if present,
 227  * or otherwise the child node's name. Note that the match table is modified
 228  * in place and an additional of_node reference is taken for each matched
 229  * regulator.
 230  *
 231  * Returns the number of matches found or a negative error code on failure.
 232  */
 233 int of_regulator_match(struct device *dev, struct device_node *node,
 234                        struct of_regulator_match *matches,
 235                        unsigned int num_matches)
 236 {
 237         unsigned int count = 0;
 238         unsigned int i;
 239         const char *name;
 240         struct device_node *child;
 241         struct devm_of_regulator_matches *devm_matches;
 242
 243         if (!dev || !node)
 244                 return -EINVAL;
 245
 246         devm_matches = devres_alloc(devm_of_regulator_put_matches,
 247                                     sizeof(struct devm_of_regulator_matches),
 248                                     GFP_KERNEL);
 249         if (!devm_matches)
 250                 return -ENOMEM;
 251
 252         devm_matches->matches = matches;
 253         devm_matches->num_matches = num_matches;
 254
 255         devres_add(dev, devm_matches);
 256
 257         for (i = 0; i < num_matches; i++) {
 258                 struct of_regulator_match *match = &matches[i];
 259                 match->init_data = NULL;
 260                 match->of_node = NULL;
 261         }
 262
 263         for_each_child_of_node(node, child) {
 264                 name = of_get_property(child,
 265                                         "regulator-compatible", NULL);
 266                 if (!name)
 267                         name = child->name;
 268                 for (i = 0; i < num_matches; i++) {
 269                         struct of_regulator_match *match = &matches[i];
 270                         if (match->of_node)
 271                                 continue;
 272
 273                         if (strcmp(match->name, name))
 274                                 continue;
 275
 276                         match->init_data =
 277                                 of_get_regulator_init_data(dev, child,
 278                                                            match->desc);
 279                         if (!match->init_data) {
 280                                 dev_err(dev,
 281                                         "failed to parse DT for regulator %s\n",
 282                                         child->name);
 283                                 return -EINVAL;
 284                         }
 285                         match->of_node = of_node_get(child);
 286                         count++;
 287                         break;
 288                 }
 289         }
 290
 291         return count;
 292 }
 293 EXPORT_SYMBOL_GPL(of_regulator_match);
 294
 295 struct regulator_init_data *regulator_of_get_init_data(struct device *dev,
 296                                             const struct regulator_desc *desc,
 297                                             struct regulator_config *config,
 298                                             struct device_node **node)
 299 {
 300         struct device_node *search, *child;
 301         struct regulator_init_data *init_data = NULL;
 302         const char *name;
 303
 304         if (!dev->of_node || !desc->of_match)
 305                 return NULL;
 306
 307         if (desc->regulators_node)
 308                 search = of_get_child_by_name(dev->of_node,
 309                                               desc->regulators_node);
 310         else
 311                 search = dev->of_node;
 312
 313         if (!search) {
 314                 dev_dbg(dev, "Failed to find regulator container node '%s'\n",
 315                         desc->regulators_node);
 316                 return NULL;
 317         }
 318
 319         for_each_available_child_of_node(search, child) {
 320                 name = of_get_property(child, "regulator-compatible", NULL);
 321                 if (!name)
 322                         name = child->name;
 323
 324                 if (strcmp(desc->of_match, name))
 325                         continue;
 326
 327                 init_data = of_get_regulator_init_data(dev, child, desc);
 328                 if (!init_data) {
 329                         dev_err(dev,
 330                                 "failed to parse DT for regulator %s\n",
 331                                 child->name);
 332                         break;
 333                 }
 334
 335                 if (desc->of_parse_cb) {
 336                         if (desc->of_parse_cb(child, desc, config)) {
 337                                 dev_err(dev,
 338                                         "driver callback failed to parse DT for regulator %s\n",
 339                                         child->name);
 340                                 init_data = NULL;
 341                                 break;
 342                         }
 343                 }
 344
 345                 of_node_get(child);
 346                 *node = child;
 347                 break;
 348         }
 349
 350         of_node_put(search);
 351
 352         return init_data;
 353 }