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, *uV_offset;
  23         const __be32 *min_uA, *max_uA, *ramp_delay;
  24         struct property *prop;
  25         struct regulation_constraints *constraints = &(*init_data)->constraints;
  26         int ret;
  27         u32 pval;
  28
  29         constraints->name = of_get_property(np, "regulator-name", NULL);
  30
  31         min_uV = of_get_property(np, "regulator-min-microvolt", NULL);
  32         if (min_uV)
  33                 constraints->min_uV = be32_to_cpu(*min_uV);
  34         max_uV = of_get_property(np, "regulator-max-microvolt", NULL);
  35         if (max_uV)
  36                 constraints->max_uV = be32_to_cpu(*max_uV);
  37
  38         /* Voltage change possible? */
  39         if (constraints->min_uV != constraints->max_uV)
  40                 constraints->valid_ops_mask |= REGULATOR_CHANGE_VOLTAGE;
  41         /* Only one voltage?  Then make sure it's set. */
  42         if (min_uV && max_uV && constraints->min_uV == constraints->max_uV)
  43                 constraints->apply_uV = true;
  44
  45         uV_offset = of_get_property(np, "regulator-microvolt-offset", NULL);
  46         if (uV_offset)
  47                 constraints->uV_offset = be32_to_cpu(*uV_offset);
  48         min_uA = of_get_property(np, "regulator-min-microamp", NULL);
  49         if (min_uA)
  50                 constraints->min_uA = be32_to_cpu(*min_uA);
  51         max_uA = of_get_property(np, "regulator-max-microamp", NULL);
  52         if (max_uA)
  53                 constraints->max_uA = be32_to_cpu(*max_uA);
  54
  55         /* Current change possible? */
  56         if (constraints->min_uA != constraints->max_uA)
  57                 constraints->valid_ops_mask |= REGULATOR_CHANGE_CURRENT;
  58
  59         if (of_find_property(np, "regulator-boot-on", NULL))
  60                 constraints->boot_on = true;
  61
  62         if (of_find_property(np, "regulator-always-on", NULL))
  63                 constraints->always_on = true;
  64         else /* status change should be possible if not always on. */
  65                 constraints->valid_ops_mask |= REGULATOR_CHANGE_STATUS;
  66
  67         if (of_property_read_bool(np, "regulator-allow-bypass"))
  68                 constraints->valid_ops_mask |= REGULATOR_CHANGE_BYPASS;
  69
  70         prop = of_find_property(np, "regulator-ramp-delay", NULL);
  71         if (prop && prop->value) {
  72                 ramp_delay = prop->value;
  73                 if (*ramp_delay)
  74                         constraints->ramp_delay = be32_to_cpu(*ramp_delay);
  75                 else
  76                         constraints->ramp_disable = true;
  77         }
  78
  79         ret = of_property_read_u32(np, "regulator-enable-ramp-delay", &pval);
  80         if (!ret)
  81                 constraints->enable_time = pval;
  82 }
  83
  84 /**
  85  * of_get_regulator_init_data - extract regulator_init_data structure info
  86  * @dev: device requesting for regulator_init_data
  87  *
  88  * Populates regulator_init_data structure by extracting data from device
  89  * tree node, returns a pointer to the populated struture or NULL if memory
  90  * alloc fails.
  91  */
  92 struct regulator_init_data *of_get_regulator_init_data(struct device *dev,
  93                                                 struct device_node *node)
  94 {
  95         struct regulator_init_data *init_data;
  96
  97         if (!node)
  98                 return NULL;
  99
 100         init_data = devm_kzalloc(dev, sizeof(*init_data), GFP_KERNEL);
 101         if (!init_data)
 102                 return NULL; /* Out of memory? */
 103
 104         of_get_regulation_constraints(node, &init_data);
 105         return init_data;
 106 }
 107 EXPORT_SYMBOL_GPL(of_get_regulator_init_data);
 108
 109 struct devm_of_regulator_matches {
 110         struct of_regulator_match *matches;
 111         unsigned int num_matches;
 112 };
 113
 114 static void devm_of_regulator_put_matches(struct device *dev, void *res)
 115 {
 116         struct devm_of_regulator_matches *devm_matches = res;
 117         int i;
 118
 119         for (i = 0; i < devm_matches->num_matches; i++)
 120                 of_node_put(devm_matches->matches[i].of_node);
 121 }
 122
 123 /**
 124  * of_regulator_match - extract multiple regulator init data from device tree.
 125  * @dev: device requesting the data
 126  * @node: parent device node of the regulators
 127  * @matches: match table for the regulators
 128  * @num_matches: number of entries in match table
 129  *
 130  * This function uses a match table specified by the regulator driver to
 131  * parse regulator init data from the device tree. @node is expected to
 132  * contain a set of child nodes, each providing the init data for one
 133  * regulator. The data parsed from a child node will be matched to a regulator
 134  * based on either the deprecated property regulator-compatible if present,
 135  * or otherwise the child node's name. Note that the match table is modified
 136  * in place and an additional of_node reference is taken for each matched
 137  * regulator.
 138  *
 139  * Returns the number of matches found or a negative error code on failure.
 140  */
 141 int of_regulator_match(struct device *dev, struct device_node *node,
 142                        struct of_regulator_match *matches,
 143                        unsigned int num_matches)
 144 {
 145         unsigned int count = 0;
 146         unsigned int i;
 147         const char *name;
 148         struct device_node *child;
 149         struct devm_of_regulator_matches *devm_matches;
 150
 151         if (!dev || !node)
 152                 return -EINVAL;
 153
 154         devm_matches = devres_alloc(devm_of_regulator_put_matches,
 155                                     sizeof(struct devm_of_regulator_matches),
 156                                     GFP_KERNEL);
 157         if (!devm_matches)
 158                 return -ENOMEM;
 159
 160         devm_matches->matches = matches;
 161         devm_matches->num_matches = num_matches;
 162
 163         devres_add(dev, devm_matches);
 164
 165         for (i = 0; i < num_matches; i++) {
 166                 struct of_regulator_match *match = &matches[i];
 167                 match->init_data = NULL;
 168                 match->of_node = NULL;
 169         }
 170
 171         for_each_child_of_node(node, child) {
 172                 name = of_get_property(child,
 173                                         "regulator-compatible", NULL);
 174                 if (!name)
 175                         name = child->name;
 176                 for (i = 0; i < num_matches; i++) {
 177                         struct of_regulator_match *match = &matches[i];
 178                         if (match->of_node)
 179                                 continue;
 180
 181                         if (strcmp(match->name, name))
 182                                 continue;
 183
 184                         match->init_data =
 185                                 of_get_regulator_init_data(dev, child);
 186                         if (!match->init_data) {
 187                                 dev_err(dev,
 188                                         "failed to parse DT for regulator %s\n",
 189                                         child->name);
 190                                 return -EINVAL;
 191                         }
 192                         match->of_node = of_node_get(child);
 193                         count++;
 194                         break;
 195                 }
 196         }
 197
 198         return count;
 199 }
 200 EXPORT_SYMBOL_GPL(of_regulator_match);