linux/drivers/regulator/of_regulator.c
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   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
  19static 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 */
  86struct 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}
 101EXPORT_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 */
 120int 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}
 167EXPORT_SYMBOL_GPL(of_regulator_match);
 168
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