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 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 */
  77struct 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}
  92EXPORT_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 */
 111int 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 (i = 0; i < num_matches; i++) {
 124                struct of_regulator_match *match = &matches[i];
 125                match->init_data = NULL;
 126                match->of_node = NULL;
 127        }
 128
 129        for_each_child_of_node(node, child) {
 130                name = of_get_property(child,
 131                                        "regulator-compatible", NULL);
 132                if (!name)
 133                        name = child->name;
 134                for (i = 0; i < num_matches; i++) {
 135                        struct of_regulator_match *match = &matches[i];
 136                        if (match->of_node)
 137                                continue;
 138
 139                        if (strcmp(match->name, name))
 140                                continue;
 141
 142                        match->init_data =
 143                                of_get_regulator_init_data(dev, child);
 144                        if (!match->init_data) {
 145                                dev_err(dev,
 146                                        "failed to parse DT for regulator %s\n",
 147                                        child->name);
 148                                return -EINVAL;
 149                        }
 150                        match->of_node = child;
 151                        count++;
 152                        break;
 153                }
 154        }
 155
 156        return count;
 157}
 158EXPORT_SYMBOL_GPL(of_regulator_match);
 159
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