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/regmap.h>
  29
  30 #include "da9210-regulator.h"
  31
  32 struct da9210 {
  33         struct regulator_dev *rdev;
  34         struct regmap *regmap;
  35 };
  36
  37 static const struct regmap_config da9210_regmap_config = {
  38         .reg_bits = 8,
  39         .val_bits = 8,
  40 };
  41
  42 static int da9210_set_current_limit(struct regulator_dev *rdev, int min_uA,
  43                                     int max_uA);
  44 static int da9210_get_current_limit(struct regulator_dev *rdev);
  45
  46 static 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 */
  63 static 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
  68 static 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
  83 static 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
 105 static 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  */
 125 static 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
 168 static 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
 175 static const struct i2c_device_id da9210_i2c_id[] = {
 176         {"da9210", 0},
 177         {},
 178 };
 179
 180 MODULE_DEVICE_TABLE(i2c, da9210_i2c_id);
 181
 182 static 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
 192 module_i2c_driver(da9210_regulator_driver);
 193
 194 MODULE_AUTHOR("S Twiss <stwiss.opensource@diasemi.com>");
 195 MODULE_DESCRIPTION("Regulator device driver for Dialog DA9210");
 196 MODULE_LICENSE("GPL v2");