drivers/regulator/da9210-regulator.c

   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/regulator/of_regulator.h>
  29 #include <linux/regmap.h>
  30
  31 #include "da9210-regulator.h"
  32
  33 struct da9210 {
  34         struct regulator_dev *rdev;
  35         struct regmap *regmap;
  36 };
  37
  38 static const struct regmap_config da9210_regmap_config = {
  39         .reg_bits = 8,
  40         .val_bits = 8,
  41 };
  42
  43 static int da9210_set_current_limit(struct regulator_dev *rdev, int min_uA,
  44                                     int max_uA);
  45 static int da9210_get_current_limit(struct regulator_dev *rdev);
  46
  47 static struct regulator_ops da9210_buck_ops = {
  48         .enable = regulator_enable_regmap,
  49         .disable = regulator_disable_regmap,
  50         .is_enabled = regulator_is_enabled_regmap,
  51         .set_voltage_sel = regulator_set_voltage_sel_regmap,
  52         .get_voltage_sel = regulator_get_voltage_sel_regmap,
  53         .list_voltage = regulator_list_voltage_linear,
  54         .set_current_limit = da9210_set_current_limit,
  55         .get_current_limit = da9210_get_current_limit,
  56 };
  57
  58 /* Default limits measured in millivolts and milliamps */
  59 #define DA9210_MIN_MV           300
  60 #define DA9210_MAX_MV           1570
  61 #define DA9210_STEP_MV          10
  62
  63 /* Current limits for buck (uA) indices corresponds with register values */
  64 static const int da9210_buck_limits[] = {
  65         1600000, 1800000, 2000000, 2200000, 2400000, 2600000, 2800000, 3000000,
  66         3200000, 3400000, 3600000, 3800000, 4000000, 4200000, 4400000, 4600000
  67 };
  68
  69 static const struct regulator_desc da9210_reg = {
  70         .name = "DA9210",
  71         .id = 0,
  72         .ops = &da9210_buck_ops,
  73         .type = REGULATOR_VOLTAGE,
  74         .n_voltages = ((DA9210_MAX_MV - DA9210_MIN_MV) / DA9210_STEP_MV) + 1,
  75         .min_uV = (DA9210_MIN_MV * 1000),
  76         .uV_step = (DA9210_STEP_MV * 1000),
  77         .vsel_reg = DA9210_REG_VBUCK_A,
  78         .vsel_mask = DA9210_VBUCK_MASK,
  79         .enable_reg = DA9210_REG_BUCK_CONT,
  80         .enable_mask = DA9210_BUCK_EN,
  81         .owner = THIS_MODULE,
  82 };
  83
  84 static int da9210_set_current_limit(struct regulator_dev *rdev, int min_uA,
  85                                     int max_uA)
  86 {
  87         struct da9210 *chip = rdev_get_drvdata(rdev);
  88         unsigned int sel;
  89         int i;
  90
  91         /* search for closest to maximum */
  92         for (i = ARRAY_SIZE(da9210_buck_limits)-1; i >= 0; i--) {
  93                 if (min_uA <= da9210_buck_limits[i] &&
  94                     max_uA >= da9210_buck_limits[i]) {
  95                         sel = i;
  96                         sel = sel << DA9210_BUCK_ILIM_SHIFT;
  97                         return regmap_update_bits(chip->regmap,
  98                                                   DA9210_REG_BUCK_ILIM,
  99                                                   DA9210_BUCK_ILIM_MASK, sel);
 100                 }
 101         }
 102
 103         return -EINVAL;
 104 }
 105
 106 static int da9210_get_current_limit(struct regulator_dev *rdev)
 107 {
 108         struct da9210 *chip = rdev_get_drvdata(rdev);
 109         unsigned int data;
 110         unsigned int sel;
 111         int ret;
 112
 113         ret = regmap_read(chip->regmap, DA9210_REG_BUCK_ILIM, &data);
 114         if (ret < 0)
 115                 return ret;
 116
 117         /* select one of 16 values: 0000 (1600mA) to 1111 (4600mA) */
 118         sel = (data & DA9210_BUCK_ILIM_MASK) >> DA9210_BUCK_ILIM_SHIFT;
 119
 120         return da9210_buck_limits[sel];
 121 }
 122
 123 /*
 124  * I2C driver interface functions
 125  */
 126 static int da9210_i2c_probe(struct i2c_client *i2c,
 127                             const struct i2c_device_id *id)
 128 {
 129         struct da9210 *chip;
 130         struct device *dev = &i2c->dev;
 131         struct da9210_pdata *pdata = dev_get_platdata(dev);
 132         struct regulator_dev *rdev = NULL;
 133         struct regulator_config config = { };
 134         int error;
 135
 136         chip = devm_kzalloc(&i2c->dev, sizeof(struct da9210), GFP_KERNEL);
 137         if (!chip)
 138                 return -ENOMEM;
 139
 140         chip->regmap = devm_regmap_init_i2c(i2c, &da9210_regmap_config);
 141         if (IS_ERR(chip->regmap)) {
 142                 error = PTR_ERR(chip->regmap);
 143                 dev_err(&i2c->dev, "Failed to allocate register map: %d\n",
 144                         error);
 145                 return error;
 146         }
 147
 148         config.dev = &i2c->dev;
 149         config.init_data = pdata ? &pdata->da9210_constraints :
 150                 of_get_regulator_init_data(dev, dev->of_node);
 151         config.driver_data = chip;
 152         config.regmap = chip->regmap;
 153         config.of_node = dev->of_node;
 154
 155         rdev = devm_regulator_register(&i2c->dev, &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
 168 static const struct i2c_device_id da9210_i2c_id[] = {
 169         {"da9210", 0},
 170         {},
 171 };
 172
 173 MODULE_DEVICE_TABLE(i2c, da9210_i2c_id);
 174
 175 static struct i2c_driver da9210_regulator_driver = {
 176         .driver = {
 177                 .name = "da9210",
 178                 .owner = THIS_MODULE,
 179         },
 180         .probe = da9210_i2c_probe,
 181         .id_table = da9210_i2c_id,
 182 };
 183
 184 module_i2c_driver(da9210_regulator_driver);
 185
 186 MODULE_AUTHOR("S Twiss <stwiss.opensource@diasemi.com>");
 187 MODULE_DESCRIPTION("Regulator device driver for Dialog DA9210");
 188 MODULE_LICENSE("GPL v2");