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 void of_get_regulation_constraints(struct device_node *np,
  23                                         struct regulator_init_data **init_data)
  24 {
  25         const __be32 *min_uV, *max_uV;
  26         struct regulation_constraints *constraints = &(*init_data)->constraints;
  27         int ret;
  28         u32 pval;
  29
  30         constraints->name = of_get_property(np, "regulator-name", NULL);
  31
  32         min_uV = of_get_property(np, "regulator-min-microvolt", NULL);
  33         if (min_uV)
  34                 constraints->min_uV = be32_to_cpu(*min_uV);
  35         max_uV = of_get_property(np, "regulator-max-microvolt", NULL);
  36         if (max_uV)
  37                 constraints->max_uV = be32_to_cpu(*max_uV);
  38
  39         /* Voltage change possible? */
  40         if (constraints->min_uV != constraints->max_uV)
  41                 constraints->valid_ops_mask |= REGULATOR_CHANGE_VOLTAGE;
  42         /* Only one voltage?  Then make sure it's set. */
  43         if (min_uV && max_uV && constraints->min_uV == constraints->max_uV)
  44                 constraints->apply_uV = true;
  45
  46         if (!of_property_read_u32(np, "regulator-microvolt-offset", &pval))
  47                 constraints->uV_offset = pval;
  48         if (!of_property_read_u32(np, "regulator-min-microamp", &pval))
  49                 constraints->min_uA = pval;
  50         if (!of_property_read_u32(np, "regulator-max-microamp", &pval))
  51                 constraints->max_uA = pval;
  52
  53         /* Current change possible? */
  54         if (constraints->min_uA != constraints->max_uA)
  55                 constraints->valid_ops_mask |= REGULATOR_CHANGE_CURRENT;
  56
  57         constraints->boot_on = of_property_read_bool(np, "regulator-boot-on");
  58         constraints->always_on = of_property_read_bool(np, "regulator-always-on");
  59         if (!constraints->always_on) /* status change should be possible. */
  60                 constraints->valid_ops_mask |= REGULATOR_CHANGE_STATUS;
  61
  62         if (of_property_read_bool(np, "regulator-allow-bypass"))
  63                 constraints->valid_ops_mask |= REGULATOR_CHANGE_BYPASS;
  64
  65         ret = of_property_read_u32(np, "regulator-ramp-delay", &pval);
  66         if (!ret) {
  67                 if (pval)
  68                         constraints->ramp_delay = pval;
  69                 else
  70                         constraints->ramp_disable = true;
  71         }
  72
  73         ret = of_property_read_u32(np, "regulator-enable-ramp-delay", &pval);
  74         if (!ret)
  75                 constraints->enable_time = pval;
  76 }
  77
  78 /**
  79  * of_get_regulator_init_data - extract regulator_init_data structure info
  80  * @dev: device requesting for regulator_init_data
  81  *
  82  * Populates regulator_init_data structure by extracting data from device
  83  * tree node, returns a pointer to the populated struture or NULL if memory
  84  * alloc fails.
  85  */
  86 struct regulator_init_data *of_get_regulator_init_data(struct device *dev,
  87                                                 struct device_node *node)
  88 {
  89         struct regulator_init_data *init_data;
  90
  91         if (!node)
  92                 return NULL;
  93
  94         init_data = devm_kzalloc(dev, sizeof(*init_data), GFP_KERNEL);
  95         if (!init_data)
  96                 return NULL; /* Out of memory? */
  97
  98         of_get_regulation_constraints(node, &init_data);
  99         return init_data;
 100 }
 101 EXPORT_SYMBOL_GPL(of_get_regulator_init_data);
 102
 103 struct devm_of_regulator_matches {
 104         struct of_regulator_match *matches;
 105         unsigned int num_matches;
 106 };
 107
 108 static void devm_of_regulator_put_matches(struct device *dev, void *res)
 109 {
 110         struct devm_of_regulator_matches *devm_matches = res;
 111         int i;
 112
 113         for (i = 0; i < devm_matches->num_matches; i++)
 114                 of_node_put(devm_matches->matches[i].of_node);
 115 }
 116
 117 /**
 118  * of_regulator_match - extract multiple regulator init data from device tree.
 119  * @dev: device requesting the data
 120  * @node: parent device node of the regulators
 121  * @matches: match table for the regulators
 122  * @num_matches: number of entries in match table
 123  *
 124  * This function uses a match table specified by the regulator driver to
 125  * parse regulator init data from the device tree. @node is expected to
 126  * contain a set of child nodes, each providing the init data for one
 127  * regulator. The data parsed from a child node will be matched to a regulator
 128  * based on either the deprecated property regulator-compatible if present,
 129  * or otherwise the child node's name. Note that the match table is modified
 130  * in place and an additional of_node reference is taken for each matched
 131  * regulator.
 132  *
 133  * Returns the number of matches found or a negative error code on failure.
 134  */
 135 int of_regulator_match(struct device *dev, struct device_node *node,
 136                        struct of_regulator_match *matches,
 137                        unsigned int num_matches)
 138 {
 139         unsigned int count = 0;
 140         unsigned int i;
 141         const char *name;
 142         struct device_node *child;
 143         struct devm_of_regulator_matches *devm_matches;
 144
 145         if (!dev || !node)
 146                 return -EINVAL;
 147
 148         devm_matches = devres_alloc(devm_of_regulator_put_matches,
 149                                     sizeof(struct devm_of_regulator_matches),
 150                                     GFP_KERNEL);
 151         if (!devm_matches)
 152                 return -ENOMEM;
 153
 154         devm_matches->matches = matches;
 155         devm_matches->num_matches = num_matches;
 156
 157         devres_add(dev, devm_matches);
 158
 159         for (i = 0; i < num_matches; i++) {
 160                 struct of_regulator_match *match = &matches[i];
 161                 match->init_data = NULL;
 162                 match->of_node = NULL;
 163         }
 164
 165         for_each_child_of_node(node, child) {
 166                 name = of_get_property(child,
 167                                         "regulator-compatible", NULL);
 168                 if (!name)
 169                         name = child->name;
 170                 for (i = 0; i < num_matches; i++) {
 171                         struct of_regulator_match *match = &matches[i];
 172                         if (match->of_node)
 173                                 continue;
 174
 175                         if (strcmp(match->name, name))
 176                                 continue;
 177
 178                         match->init_data =
 179                                 of_get_regulator_init_data(dev, child);
 180                         if (!match->init_data) {
 181                                 dev_err(dev,
 182                                         "failed to parse DT for regulator %s\n",
 183                                         child->name);
 184                                 return -EINVAL;
 185                         }
 186                         match->of_node = of_node_get(child);
 187                         count++;
 188                         break;
 189                 }
 190         }
 191
 192         return count;
 193 }
 194 EXPORT_SYMBOL_GPL(of_regulator_match);
 195
 196 struct regulator_init_data *regulator_of_get_init_data(struct device *dev,
 197                                             const struct regulator_desc *desc,
 198                                             struct device_node **node)
 199 {
 200         struct device_node *search, *child;
 201         struct regulator_init_data *init_data = NULL;
 202         const char *name;
 203
 204         if (!dev->of_node || !desc->of_match)
 205                 return NULL;
 206
 207         if (desc->regulators_node)
 208                 search = of_get_child_by_name(dev->of_node,
 209                                               desc->regulators_node);
 210         else
 211                 search = dev->of_node;
 212
 213         if (!search) {
 214                 dev_err(dev, "Failed to find regulator container node\n");
 215                 return NULL;
 216         }
 217
 218         for_each_child_of_node(search, child) {
 219                 name = of_get_property(child, "regulator-compatible", NULL);
 220                 if (!name)
 221                         name = child->name;
 222
 223                 if (strcmp(desc->of_match, name))
 224                         continue;
 225
 226                 init_data = of_get_regulator_init_data(dev, child);
 227                 if (!init_data) {
 228                         dev_err(dev,
 229                                 "failed to parse DT for regulator %s\n",
 230                                 child->name);
 231                         break;
 232                 }
 233
 234                 of_node_get(child);
 235                 *node = child;
 236                 break;
 237         }
 238
 239         of_node_put(search);
 240
 241         return init_data;
 242 }