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 regulation_constraints *constraints = &(*init_data)->constraints;
  25
  26         constraints->name = of_get_property(np, "regulator-name", NULL);
  27
  28         min_uV = of_get_property(np, "regulator-min-microvolt", NULL);
  29         if (min_uV)
  30                 constraints->min_uV = be32_to_cpu(*min_uV);
  31         max_uV = of_get_property(np, "regulator-max-microvolt", NULL);
  32         if (max_uV)
  33                 constraints->max_uV = be32_to_cpu(*max_uV);
  34
  35         /* Voltage change possible? */
  36         if (constraints->min_uV != constraints->max_uV)
  37                 constraints->valid_ops_mask |= REGULATOR_CHANGE_VOLTAGE;
  38         /* Only one voltage?  Then make sure it's set. */
  39         if (min_uV && max_uV && constraints->min_uV == constraints->max_uV)
  40                 constraints->apply_uV = true;
  41
  42         uV_offset = of_get_property(np, "regulator-microvolt-offset", NULL);
  43         if (uV_offset)
  44                 constraints->uV_offset = be32_to_cpu(*uV_offset);
  45         min_uA = of_get_property(np, "regulator-min-microamp", NULL);
  46         if (min_uA)
  47                 constraints->min_uA = be32_to_cpu(*min_uA);
  48         max_uA = of_get_property(np, "regulator-max-microamp", NULL);
  49         if (max_uA)
  50                 constraints->max_uA = be32_to_cpu(*max_uA);
  51
  52         /* Current change possible? */
  53         if (constraints->min_uA != constraints->max_uA)
  54                 constraints->valid_ops_mask |= REGULATOR_CHANGE_CURRENT;
  55
  56         if (of_find_property(np, "regulator-boot-on", NULL))
  57                 constraints->boot_on = true;
  58
  59         if (of_find_property(np, "regulator-always-on", NULL))
  60                 constraints->always_on = true;
  61         else /* status change should be possible if not always on. */
  62                 constraints->valid_ops_mask |= REGULATOR_CHANGE_STATUS;
  63
  64         ramp_delay = of_get_property(np, "regulator-ramp-delay", NULL);
  65         if (ramp_delay)
  66                 constraints->ramp_delay = be32_to_cpu(*ramp_delay);
  67 }
  68
  69 /**
  70  * of_get_regulator_init_data - extract regulator_init_data structure info
  71  * @dev: device requesting for regulator_init_data
  72  *
  73  * Populates regulator_init_data structure by extracting data from device
  74  * tree node, returns a pointer to the populated struture or NULL if memory
  75  * alloc fails.
  76  */
  77 struct regulator_init_data *of_get_regulator_init_data(struct device *dev,
  78                                                 struct device_node *node)
  79 {
  80         struct regulator_init_data *init_data;
  81
  82         if (!node)
  83                 return NULL;
  84
  85         init_data = devm_kzalloc(dev, sizeof(*init_data), GFP_KERNEL);
  86         if (!init_data)
  87                 return NULL; /* Out of memory? */
  88
  89         of_get_regulation_constraints(node, &init_data);
  90         return init_data;
  91 }
  92 EXPORT_SYMBOL_GPL(of_get_regulator_init_data);
  93
  94 /**
  95  * of_regulator_match - extract multiple regulator init data from device tree.
  96  * @dev: device requesting the data
  97  * @node: parent device node of the regulators
  98  * @matches: match table for the regulators
  99  * @num_matches: number of entries in match table
 100  *
 101  * This function uses a match table specified by the regulator driver to
 102  * parse regulator init data from the device tree. @node is expected to
 103  * contain a set of child nodes, each providing the init data for one
 104  * regulator. The data parsed from a child node will be matched to a regulator
 105  * based on either the deprecated property regulator-compatible if present,
 106  * or otherwise the child node's name. Note that the match table is modified
 107  * in place.
 108  *
 109  * Returns the number of matches found or a negative error code on failure.
 110  */
 111 int of_regulator_match(struct device *dev, struct device_node *node,
 112                        struct of_regulator_match *matches,
 113                        unsigned int num_matches)
 114 {
 115         unsigned int count = 0;
 116         unsigned int i;
 117         const char *name;
 118         struct device_node *child;
 119
 120         if (!dev || !node)
 121                 return -EINVAL;
 122
 123         for_each_child_of_node(node, child) {
 124                 name = of_get_property(child,
 125                                         "regulator-compatible", NULL);
 126                 if (!name)
 127                         name = child->name;
 128                 for (i = 0; i < num_matches; i++) {
 129                         struct of_regulator_match *match = &matches[i];
 130                         if (match->of_node)
 131                                 continue;
 132
 133                         if (strcmp(match->name, name))
 134                                 continue;
 135
 136                         match->init_data =
 137                                 of_get_regulator_init_data(dev, child);
 138                         if (!match->init_data) {
 139                                 dev_err(dev,
 140                                         "failed to parse DT for regulator %s\n",
 141                                         child->name);
 142                                 return -EINVAL;
 143                         }
 144                         match->of_node = child;
 145                         count++;
 146                         break;
 147                 }
 148         }
 149
 150         return count;
 151 }
 152 EXPORT_SYMBOL_GPL(of_regulator_match);