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