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                 if (i == PM_SUSPEND_MEM)
 167                         constraints->initial_state = PM_SUSPEND_MEM;
 168
 169                 of_node_put(suspend_np);
 170                 suspend_state = NULL;
 171                 suspend_np = NULL;
 172         }
 173 }
 174
 175 /**
 176  * of_get_regulator_init_data - extract regulator_init_data structure info
 177  * @dev: device requesting for regulator_init_data
 178  * @node: regulator device node
 179  * @desc: regulator description
 180  *
 181  * Populates regulator_init_data structure by extracting data from device
 182  * tree node, returns a pointer to the populated struture or NULL if memory
 183  * alloc fails.
 184  */
 185 struct regulator_init_data *of_get_regulator_init_data(struct device *dev,
 186                                           struct device_node *node,
 187                                           const struct regulator_desc *desc)
 188 {
 189         struct regulator_init_data *init_data;
 190
 191         if (!node)
 192                 return NULL;
 193
 194         init_data = devm_kzalloc(dev, sizeof(*init_data), GFP_KERNEL);
 195         if (!init_data)
 196                 return NULL; /* Out of memory? */
 197
 198         of_get_regulation_constraints(node, &init_data, desc);
 199         return init_data;
 200 }
 201 EXPORT_SYMBOL_GPL(of_get_regulator_init_data);
 202
 203 struct devm_of_regulator_matches {
 204         struct of_regulator_match *matches;
 205         unsigned int num_matches;
 206 };
 207
 208 static void devm_of_regulator_put_matches(struct device *dev, void *res)
 209 {
 210         struct devm_of_regulator_matches *devm_matches = res;
 211         int i;
 212
 213         for (i = 0; i < devm_matches->num_matches; i++)
 214                 of_node_put(devm_matches->matches[i].of_node);
 215 }
 216
 217 /**
 218  * of_regulator_match - extract multiple regulator init data from device tree.
 219  * @dev: device requesting the data
 220  * @node: parent device node of the regulators
 221  * @matches: match table for the regulators
 222  * @num_matches: number of entries in match table
 223  *
 224  * This function uses a match table specified by the regulator driver to
 225  * parse regulator init data from the device tree. @node is expected to
 226  * contain a set of child nodes, each providing the init data for one
 227  * regulator. The data parsed from a child node will be matched to a regulator
 228  * based on either the deprecated property regulator-compatible if present,
 229  * or otherwise the child node's name. Note that the match table is modified
 230  * in place and an additional of_node reference is taken for each matched
 231  * regulator.
 232  *
 233  * Returns the number of matches found or a negative error code on failure.
 234  */
 235 int of_regulator_match(struct device *dev, struct device_node *node,
 236                        struct of_regulator_match *matches,
 237                        unsigned int num_matches)
 238 {
 239         unsigned int count = 0;
 240         unsigned int i;
 241         const char *name;
 242         struct device_node *child;
 243         struct devm_of_regulator_matches *devm_matches;
 244
 245         if (!dev || !node)
 246                 return -EINVAL;
 247
 248         devm_matches = devres_alloc(devm_of_regulator_put_matches,
 249                                     sizeof(struct devm_of_regulator_matches),
 250                                     GFP_KERNEL);
 251         if (!devm_matches)
 252                 return -ENOMEM;
 253
 254         devm_matches->matches = matches;
 255         devm_matches->num_matches = num_matches;
 256
 257         devres_add(dev, devm_matches);
 258
 259         for (i = 0; i < num_matches; i++) {
 260                 struct of_regulator_match *match = &matches[i];
 261                 match->init_data = NULL;
 262                 match->of_node = NULL;
 263         }
 264
 265         for_each_child_of_node(node, child) {
 266                 name = of_get_property(child,
 267                                         "regulator-compatible", NULL);
 268                 if (!name)
 269                         name = child->name;
 270                 for (i = 0; i < num_matches; i++) {
 271                         struct of_regulator_match *match = &matches[i];
 272                         if (match->of_node)
 273                                 continue;
 274
 275                         if (strcmp(match->name, name))
 276                                 continue;
 277
 278                         match->init_data =
 279                                 of_get_regulator_init_data(dev, child,
 280                                                            match->desc);
 281                         if (!match->init_data) {
 282                                 dev_err(dev,
 283                                         "failed to parse DT for regulator %s\n",
 284                                         child->name);
 285                                 return -EINVAL;
 286                         }
 287                         match->of_node = of_node_get(child);
 288                         count++;
 289                         break;
 290                 }
 291         }
 292
 293         return count;
 294 }
 295 EXPORT_SYMBOL_GPL(of_regulator_match);
 296
 297 struct regulator_init_data *regulator_of_get_init_data(struct device *dev,
 298                                             const struct regulator_desc *desc,
 299                                             struct regulator_config *config,
 300                                             struct device_node **node)
 301 {
 302         struct device_node *search, *child;
 303         struct regulator_init_data *init_data = NULL;
 304         const char *name;
 305
 306         if (!dev->of_node || !desc->of_match)
 307                 return NULL;
 308
 309         if (desc->regulators_node)
 310                 search = of_get_child_by_name(dev->of_node,
 311                                               desc->regulators_node);
 312         else
 313                 search = dev->of_node;
 314
 315         if (!search) {
 316                 dev_dbg(dev, "Failed to find regulator container node '%s'\n",
 317                         desc->regulators_node);
 318                 return NULL;
 319         }
 320
 321         for_each_available_child_of_node(search, child) {
 322                 name = of_get_property(child, "regulator-compatible", NULL);
 323                 if (!name)
 324                         name = child->name;
 325
 326                 if (strcmp(desc->of_match, name))
 327                         continue;
 328
 329                 init_data = of_get_regulator_init_data(dev, child, desc);
 330                 if (!init_data) {
 331                         dev_err(dev,
 332                                 "failed to parse DT for regulator %s\n",
 333                                 child->name);
 334                         break;
 335                 }
 336
 337                 if (desc->of_parse_cb) {
 338                         if (desc->of_parse_cb(child, desc, config)) {
 339                                 dev_err(dev,
 340                                         "driver callback failed to parse DT for regulator %s\n",
 341                                         child->name);
 342                                 init_data = NULL;
 343                                 break;
 344                         }
 345                 }
 346
 347                 of_node_get(child);
 348                 *node = child;
 349                 break;
 350         }
 351
 352         of_node_put(search);
 353
 354         return init_data;
 355 }