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/of_regulator.h>
  18
  19 static void of_get_regulation_constraints(struct device_node *np,
  20                                         struct regulator_init_data **init_data)
  21 {
  22         const __be32 *min_uV, *max_uV;
  23         struct regulation_constraints *constraints = &(*init_data)->constraints;
  24         int ret;
  25         u32 pval;
  26
  27         constraints->name = of_get_property(np, "regulator-name", NULL);
  28
  29         min_uV = of_get_property(np, "regulator-min-microvolt", NULL);
  30         if (min_uV)
  31                 constraints->min_uV = be32_to_cpu(*min_uV);
  32         max_uV = of_get_property(np, "regulator-max-microvolt", NULL);
  33         if (max_uV)
  34                 constraints->max_uV = be32_to_cpu(*max_uV);
  35
  36         /* Voltage change possible? */
  37         if (constraints->min_uV != constraints->max_uV)
  38                 constraints->valid_ops_mask |= REGULATOR_CHANGE_VOLTAGE;
  39         /* Only one voltage?  Then make sure it's set. */
  40         if (min_uV && max_uV && constraints->min_uV == constraints->max_uV)
  41                 constraints->apply_uV = true;
  42
  43         if (!of_property_read_u32(np, "regulator-microvolt-offset", &pval))
  44                 constraints->uV_offset = pval;
  45         if (!of_property_read_u32(np, "regulator-min-microamp", &pval))
  46                 constraints->min_uA = pval;
  47         if (!of_property_read_u32(np, "regulator-max-microamp", &pval))
  48                 constraints->max_uA = pval;
  49
  50         /* Current change possible? */
  51         if (constraints->min_uA != constraints->max_uA)
  52                 constraints->valid_ops_mask |= REGULATOR_CHANGE_CURRENT;
  53
  54         constraints->boot_on = of_property_read_bool(np, "regulator-boot-on");
  55         constraints->always_on = of_property_read_bool(np, "regulator-always-on");
  56         if (!constraints->always_on) /* status change should be possible. */
  57                 constraints->valid_ops_mask |= REGULATOR_CHANGE_STATUS;
  58
  59         if (of_property_read_bool(np, "regulator-allow-bypass"))
  60                 constraints->valid_ops_mask |= REGULATOR_CHANGE_BYPASS;
  61
  62         ret = of_property_read_u32(np, "regulator-ramp-delay", &pval);
  63         if (!ret) {
  64                 if (pval)
  65                         constraints->ramp_delay = pval;
  66                 else
  67                         constraints->ramp_disable = true;
  68         }
  69
  70         ret = of_property_read_u32(np, "regulator-enable-ramp-delay", &pval);
  71         if (!ret)
  72                 constraints->enable_time = pval;
  73 }
  74
  75 /**
  76  * of_get_regulator_init_data - extract regulator_init_data structure info
  77  * @dev: device requesting for regulator_init_data
  78  *
  79  * Populates regulator_init_data structure by extracting data from device
  80  * tree node, returns a pointer to the populated struture or NULL if memory
  81  * alloc fails.
  82  */
  83 struct regulator_init_data *of_get_regulator_init_data(struct device *dev,
  84                                                 struct device_node *node)
  85 {
  86         struct regulator_init_data *init_data;
  87
  88         if (!node)
  89                 return NULL;
  90
  91         init_data = devm_kzalloc(dev, sizeof(*init_data), GFP_KERNEL);
  92         if (!init_data)
  93                 return NULL; /* Out of memory? */
  94
  95         of_get_regulation_constraints(node, &init_data);
  96         return init_data;
  97 }
  98 EXPORT_SYMBOL_GPL(of_get_regulator_init_data);
  99
 100 struct devm_of_regulator_matches {
 101         struct of_regulator_match *matches;
 102         unsigned int num_matches;
 103 };
 104
 105 static void devm_of_regulator_put_matches(struct device *dev, void *res)
 106 {
 107         struct devm_of_regulator_matches *devm_matches = res;
 108         int i;
 109
 110         for (i = 0; i < devm_matches->num_matches; i++)
 111                 of_node_put(devm_matches->matches[i].of_node);
 112 }
 113
 114 /**
 115  * of_regulator_match - extract multiple regulator init data from device tree.
 116  * @dev: device requesting the data
 117  * @node: parent device node of the regulators
 118  * @matches: match table for the regulators
 119  * @num_matches: number of entries in match table
 120  *
 121  * This function uses a match table specified by the regulator driver to
 122  * parse regulator init data from the device tree. @node is expected to
 123  * contain a set of child nodes, each providing the init data for one
 124  * regulator. The data parsed from a child node will be matched to a regulator
 125  * based on either the deprecated property regulator-compatible if present,
 126  * or otherwise the child node's name. Note that the match table is modified
 127  * in place and an additional of_node reference is taken for each matched
 128  * regulator.
 129  *
 130  * Returns the number of matches found or a negative error code on failure.
 131  */
 132 int of_regulator_match(struct device *dev, struct device_node *node,
 133                        struct of_regulator_match *matches,
 134                        unsigned int num_matches)
 135 {
 136         unsigned int count = 0;
 137         unsigned int i;
 138         const char *name;
 139         struct device_node *child;
 140         struct devm_of_regulator_matches *devm_matches;
 141
 142         if (!dev || !node)
 143                 return -EINVAL;
 144
 145         devm_matches = devres_alloc(devm_of_regulator_put_matches,
 146                                     sizeof(struct devm_of_regulator_matches),
 147                                     GFP_KERNEL);
 148         if (!devm_matches)
 149                 return -ENOMEM;
 150
 151         devm_matches->matches = matches;
 152         devm_matches->num_matches = num_matches;
 153
 154         devres_add(dev, devm_matches);
 155
 156         for (i = 0; i < num_matches; i++) {
 157                 struct of_regulator_match *match = &matches[i];
 158                 match->init_data = NULL;
 159                 match->of_node = NULL;
 160         }
 161
 162         for_each_child_of_node(node, child) {
 163                 name = of_get_property(child,
 164                                         "regulator-compatible", NULL);
 165                 if (!name)
 166                         name = child->name;
 167                 for (i = 0; i < num_matches; i++) {
 168                         struct of_regulator_match *match = &matches[i];
 169                         if (match->of_node)
 170                                 continue;
 171
 172                         if (strcmp(match->name, name))
 173                                 continue;
 174
 175                         match->init_data =
 176                                 of_get_regulator_init_data(dev, child);
 177                         if (!match->init_data) {
 178                                 dev_err(dev,
 179                                         "failed to parse DT for regulator %s\n",
 180                                         child->name);
 181                                 return -EINVAL;
 182                         }
 183                         match->of_node = of_node_get(child);
 184                         count++;
 185                         break;
 186                 }
 187         }
 188
 189         return count;
 190 }
 191 EXPORT_SYMBOL_GPL(of_regulator_match);