linux/drivers/regulator/of_regulator.c
<<
>>
Prefs
   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        if (of_property_read_bool(np, "regulator-allow-bypass"))
  65                constraints->valid_ops_mask |= REGULATOR_CHANGE_BYPASS;
  66
  67        ramp_delay = of_get_property(np, "regulator-ramp-delay", NULL);
  68        if (ramp_delay)
  69                constraints->ramp_delay = be32_to_cpu(*ramp_delay);
  70}
  71
  72/**
  73 * of_get_regulator_init_data - extract regulator_init_data structure info
  74 * @dev: device requesting for regulator_init_data
  75 *
  76 * Populates regulator_init_data structure by extracting data from device
  77 * tree node, returns a pointer to the populated struture or NULL if memory
  78 * alloc fails.
  79 */
  80struct regulator_init_data *of_get_regulator_init_data(struct device *dev,
  81                                                struct device_node *node)
  82{
  83        struct regulator_init_data *init_data;
  84
  85        if (!node)
  86                return NULL;
  87
  88        init_data = devm_kzalloc(dev, sizeof(*init_data), GFP_KERNEL);
  89        if (!init_data)
  90                return NULL; /* Out of memory? */
  91
  92        of_get_regulation_constraints(node, &init_data);
  93        return init_data;
  94}
  95EXPORT_SYMBOL_GPL(of_get_regulator_init_data);
  96
  97/**
  98 * of_regulator_match - extract multiple regulator init data from device tree.
  99 * @dev: device requesting the data
 100 * @node: parent device node of the regulators
 101 * @matches: match table for the regulators
 102 * @num_matches: number of entries in match table
 103 *
 104 * This function uses a match table specified by the regulator driver to
 105 * parse regulator init data from the device tree. @node is expected to
 106 * contain a set of child nodes, each providing the init data for one
 107 * regulator. The data parsed from a child node will be matched to a regulator
 108 * based on either the deprecated property regulator-compatible if present,
 109 * or otherwise the child node's name. Note that the match table is modified
 110 * in place.
 111 *
 112 * Returns the number of matches found or a negative error code on failure.
 113 */
 114int of_regulator_match(struct device *dev, struct device_node *node,
 115                       struct of_regulator_match *matches,
 116                       unsigned int num_matches)
 117{
 118        unsigned int count = 0;
 119        unsigned int i;
 120        const char *name;
 121        struct device_node *child;
 122
 123        if (!dev || !node)
 124                return -EINVAL;
 125
 126        for (i = 0; i < num_matches; i++) {
 127                struct of_regulator_match *match = &matches[i];
 128                match->init_data = NULL;
 129                match->of_node = NULL;
 130        }
 131
 132        for_each_child_of_node(node, child) {
 133                name = of_get_property(child,
 134                                        "regulator-compatible", NULL);
 135                if (!name)
 136                        name = child->name;
 137                for (i = 0; i < num_matches; i++) {
 138                        struct of_regulator_match *match = &matches[i];
 139                        if (match->of_node)
 140                                continue;
 141
 142                        if (strcmp(match->name, name))
 143                                continue;
 144
 145                        match->init_data =
 146                                of_get_regulator_init_data(dev, child);
 147                        if (!match->init_data) {
 148                                dev_err(dev,
 149                                        "failed to parse DT for regulator %s\n",
 150                                        child->name);
 151                                return -EINVAL;
 152                        }
 153                        match->of_node = child;
 154                        count++;
 155                        break;
 156                }
 157        }
 158
 159        return count;
 160}
 161EXPORT_SYMBOL_GPL(of_regulator_match);
 162
lxr.linux.no kindly hosted by Redpill Linpro AS, provider of Linux consulting and operations services since 1995.