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
  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         uV_offset = of_get_property(np, "regulator-microvolt-offset", NULL);
  44         if (uV_offset)
  45                 constraints->uV_offset = be32_to_cpu(*uV_offset);
  46         min_uA = of_get_property(np, "regulator-min-microamp", NULL);
  47         if (min_uA)
  48                 constraints->min_uA = be32_to_cpu(*min_uA);
  49         max_uA = of_get_property(np, "regulator-max-microamp", NULL);
  50         if (max_uA)
  51                 constraints->max_uA = be32_to_cpu(*max_uA);
  52
  53         /* Current change possible? */
  54         if (constraints->min_uA != constraints->max_uA)
  55                 constraints->valid_ops_mask |= REGULATOR_CHANGE_CURRENT;
  56
  57         if (of_find_property(np, "regulator-boot-on", NULL))
  58                 constraints->boot_on = true;
  59
  60         if (of_find_property(np, "regulator-always-on", NULL))
  61                 constraints->always_on = true;
  62         else /* status change should be possible if not always on. */
  63                 constraints->valid_ops_mask |= REGULATOR_CHANGE_STATUS;
  64
  65         if (of_property_read_bool(np, "regulator-allow-bypass"))
  66                 constraints->valid_ops_mask |= REGULATOR_CHANGE_BYPASS;
  67
  68         prop = of_find_property(np, "regulator-ramp-delay", NULL);
  69         if (prop && prop->value) {
  70                 ramp_delay = prop->value;
  71                 if (*ramp_delay)
  72                         constraints->ramp_delay = be32_to_cpu(*ramp_delay);
  73                 else
  74                         constraints->ramp_disable = true;
  75         }
  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 /**
 104  * of_regulator_match - extract multiple regulator init data from device tree.
 105  * @dev: device requesting the data
 106  * @node: parent device node of the regulators
 107  * @matches: match table for the regulators
 108  * @num_matches: number of entries in match table
 109  *
 110  * This function uses a match table specified by the regulator driver to
 111  * parse regulator init data from the device tree. @node is expected to
 112  * contain a set of child nodes, each providing the init data for one
 113  * regulator. The data parsed from a child node will be matched to a regulator
 114  * based on either the deprecated property regulator-compatible if present,
 115  * or otherwise the child node's name. Note that the match table is modified
 116  * in place.
 117  *
 118  * Returns the number of matches found or a negative error code on failure.
 119  */
 120 int of_regulator_match(struct device *dev, struct device_node *node,
 121                        struct of_regulator_match *matches,
 122                        unsigned int num_matches)
 123 {
 124         unsigned int count = 0;
 125         unsigned int i;
 126         const char *name;
 127         struct device_node *child;
 128
 129         if (!dev || !node)
 130                 return -EINVAL;
 131
 132         for (i = 0; i < num_matches; i++) {
 133                 struct of_regulator_match *match = &matches[i];
 134                 match->init_data = NULL;
 135                 match->of_node = NULL;
 136         }
 137
 138         for_each_child_of_node(node, child) {
 139                 name = of_get_property(child,
 140                                         "regulator-compatible", NULL);
 141                 if (!name)
 142                         name = child->name;
 143                 for (i = 0; i < num_matches; i++) {
 144                         struct of_regulator_match *match = &matches[i];
 145                         if (match->of_node)
 146                                 continue;
 147
 148                         if (strcmp(match->name, name))
 149                                 continue;
 150
 151                         match->init_data =
 152                                 of_get_regulator_init_data(dev, child);
 153                         if (!match->init_data) {
 154                                 dev_err(dev,
 155                                         "failed to parse DT for regulator %s\n",
 156                                         child->name);
 157                                 return -EINVAL;
 158                         }
 159                         match->of_node = child;
 160                         count++;
 161                         break;
 162                 }
 163         }
 164
 165         return count;
 166 }
 167 EXPORT_SYMBOL_GPL(of_regulator_match);