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