linux/drivers/regulator/da9210-regulator.c
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   1/*
   2 * da9210-regulator.c - Regulator device driver for DA9210
   3 * Copyright (C) 2013  Dialog Semiconductor Ltd.
   4 *
   5 * This library is free software; you can redistribute it and/or
   6 * modify it under the terms of the GNU Library General Public
   7 * License as published by the Free Software Foundation; either
   8 * version 2 of the License, or (at your option) any later version.
   9 *
  10 * This library is distributed in the hope that it will be useful,
  11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13 * Library General Public License for more details.
  14 *
  15 * You should have received a copy of the GNU Library General Public
  16 * License along with this library; if not, write to the
  17 * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
  18 * Boston, MA  02110-1301, USA.
  19 */
  20
  21#include <linux/err.h>
  22#include <linux/i2c.h>
  23#include <linux/module.h>
  24#include <linux/init.h>
  25#include <linux/slab.h>
  26#include <linux/regulator/driver.h>
  27#include <linux/regulator/machine.h>
  28#include <linux/regmap.h>
  29
  30#include "da9210-regulator.h"
  31
  32struct da9210 {
  33        struct regulator_dev *rdev;
  34        struct regmap *regmap;
  35};
  36
  37static const struct regmap_config da9210_regmap_config = {
  38        .reg_bits = 8,
  39        .val_bits = 8,
  40};
  41
  42static int da9210_set_current_limit(struct regulator_dev *rdev, int min_uA,
  43                                    int max_uA);
  44static int da9210_get_current_limit(struct regulator_dev *rdev);
  45
  46static struct regulator_ops da9210_buck_ops = {
  47        .enable = regulator_enable_regmap,
  48        .disable = regulator_disable_regmap,
  49        .is_enabled = regulator_is_enabled_regmap,
  50        .set_voltage_sel = regulator_set_voltage_sel_regmap,
  51        .get_voltage_sel = regulator_get_voltage_sel_regmap,
  52        .list_voltage = regulator_list_voltage_linear,
  53        .set_current_limit = da9210_set_current_limit,
  54        .get_current_limit = da9210_get_current_limit,
  55};
  56
  57/* Default limits measured in millivolts and milliamps */
  58#define DA9210_MIN_MV           300
  59#define DA9210_MAX_MV           1570
  60#define DA9210_STEP_MV          10
  61
  62/* Current limits for buck (uA) indices corresponds with register values */
  63static const int da9210_buck_limits[] = {
  64        1600000, 1800000, 2000000, 2200000, 2400000, 2600000, 2800000, 3000000,
  65        3200000, 3400000, 3600000, 3800000, 4000000, 4200000, 4400000, 4600000
  66};
  67
  68static const struct regulator_desc da9210_reg = {
  69        .name = "DA9210",
  70        .id = 0,
  71        .ops = &da9210_buck_ops,
  72        .type = REGULATOR_VOLTAGE,
  73        .n_voltages = ((DA9210_MAX_MV - DA9210_MIN_MV) / DA9210_STEP_MV) + 1,
  74        .min_uV = (DA9210_MIN_MV * 1000),
  75        .uV_step = (DA9210_STEP_MV * 1000),
  76        .vsel_reg = DA9210_REG_VBUCK_A,
  77        .vsel_mask = DA9210_VBUCK_MASK,
  78        .enable_reg = DA9210_REG_BUCK_CONT,
  79        .enable_mask = DA9210_BUCK_EN,
  80        .owner = THIS_MODULE,
  81};
  82
  83static int da9210_set_current_limit(struct regulator_dev *rdev, int min_uA,
  84                                    int max_uA)
  85{
  86        struct da9210 *chip = rdev_get_drvdata(rdev);
  87        unsigned int sel;
  88        int i;
  89
  90        /* search for closest to maximum */
  91        for (i = ARRAY_SIZE(da9210_buck_limits)-1; i >= 0; i--) {
  92                if (min_uA <= da9210_buck_limits[i] &&
  93                    max_uA >= da9210_buck_limits[i]) {
  94                        sel = i;
  95                        sel = sel << DA9210_BUCK_ILIM_SHIFT;
  96                        return regmap_update_bits(chip->regmap,
  97                                                  DA9210_REG_BUCK_ILIM,
  98                                                  DA9210_BUCK_ILIM_MASK, sel);
  99                }
 100        }
 101
 102        return -EINVAL;
 103}
 104
 105static int da9210_get_current_limit(struct regulator_dev *rdev)
 106{
 107        struct da9210 *chip = rdev_get_drvdata(rdev);
 108        unsigned int data;
 109        unsigned int sel;
 110        int ret;
 111
 112        ret = regmap_read(chip->regmap, DA9210_REG_BUCK_ILIM, &data);
 113        if (ret < 0)
 114                return ret;
 115
 116        /* select one of 16 values: 0000 (1600mA) to 1111 (4600mA) */
 117        sel = (data & DA9210_BUCK_ILIM_MASK) >> DA9210_BUCK_ILIM_SHIFT;
 118
 119        return da9210_buck_limits[sel];
 120}
 121
 122/*
 123 * I2C driver interface functions
 124 */
 125static int da9210_i2c_probe(struct i2c_client *i2c,
 126                            const struct i2c_device_id *id)
 127{
 128        struct da9210 *chip;
 129        struct da9210_pdata *pdata = i2c->dev.platform_data;
 130        struct regulator_dev *rdev = NULL;
 131        struct regulator_config config = { };
 132        int error;
 133
 134        chip = devm_kzalloc(&i2c->dev, sizeof(struct da9210), GFP_KERNEL);
 135        if (NULL == chip) {
 136                dev_err(&i2c->dev,
 137                        "Cannot kzalloc memory for regulator structure\n");
 138                return -ENOMEM;
 139        }
 140
 141        chip->regmap = devm_regmap_init_i2c(i2c, &da9210_regmap_config);
 142        if (IS_ERR(chip->regmap)) {
 143                error = PTR_ERR(chip->regmap);
 144                dev_err(&i2c->dev, "Failed to allocate register map: %d\n",
 145                        error);
 146                return error;
 147        }
 148
 149        config.dev = &i2c->dev;
 150        if (pdata)
 151                config.init_data = &pdata->da9210_constraints;
 152        config.driver_data = chip;
 153        config.regmap = chip->regmap;
 154
 155        rdev = regulator_register(&da9210_reg, &config);
 156        if (IS_ERR(rdev)) {
 157                dev_err(&i2c->dev, "Failed to register DA9210 regulator\n");
 158                return PTR_ERR(rdev);
 159        }
 160
 161        chip->rdev = rdev;
 162
 163        i2c_set_clientdata(i2c, chip);
 164
 165        return 0;
 166}
 167
 168static int da9210_i2c_remove(struct i2c_client *i2c)
 169{
 170        struct da9210 *chip = i2c_get_clientdata(i2c);
 171        regulator_unregister(chip->rdev);
 172        return 0;
 173}
 174
 175static const struct i2c_device_id da9210_i2c_id[] = {
 176        {"da9210", 0},
 177        {},
 178};
 179
 180MODULE_DEVICE_TABLE(i2c, da9210_i2c_id);
 181
 182static struct i2c_driver da9210_regulator_driver = {
 183        .driver = {
 184                .name = "da9210",
 185                .owner = THIS_MODULE,
 186        },
 187        .probe = da9210_i2c_probe,
 188        .remove = da9210_i2c_remove,
 189        .id_table = da9210_i2c_id,
 190};
 191
 192module_i2c_driver(da9210_regulator_driver);
 193
 194MODULE_AUTHOR("S Twiss <stwiss.opensource@diasemi.com>");
 195MODULE_DESCRIPTION("Regulator device driver for Dialog DA9210");
 196MODULE_LICENSE("GPL v2");
 197
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