drivers/regulator/isl6271a-regulator.c

   1 /*
   2  * isl6271a-regulator.c
   3  *
   4  * Support for Intersil ISL6271A voltage regulator
   5  *
   6  * Copyright (C) 2010 Marek Vasut <marek.vasut@gmail.com>
   7  *
   8  * This program is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU General Public License as
  10  * published by the Free Software Foundation version 2.
  11  *
  12  * This program is distributed "as is" WITHOUT ANY WARRANTY of any kind,
  13  * whether express or implied; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * General Public License for more details.
  16  */
  17
  18 #include <linux/kernel.h>
  19 #include <linux/module.h>
  20 #include <linux/init.h>
  21 #include <linux/err.h>
  22 #include <linux/platform_device.h>
  23 #include <linux/regulator/driver.h>
  24 #include <linux/i2c.h>
  25 #include <linux/delay.h>
  26 #include <linux/slab.h>
  27
  28 #define ISL6271A_VOLTAGE_MIN    850000
  29 #define ISL6271A_VOLTAGE_MAX    1600000
  30 #define ISL6271A_VOLTAGE_STEP   50000
  31
  32 /* PMIC details */
  33 struct isl_pmic {
  34         struct i2c_client       *client;
  35         struct regulator_dev    *rdev[3];
  36         struct mutex            mtx;
  37 };
  38
  39 static int isl6271a_get_voltage(struct regulator_dev *dev)
  40 {
  41         struct isl_pmic *pmic = rdev_get_drvdata(dev);
  42         int idx, data;
  43
  44         mutex_lock(&pmic->mtx);
  45
  46         idx = i2c_smbus_read_byte(pmic->client);
  47         if (idx < 0) {
  48                 dev_err(&pmic->client->dev, "Error getting voltage\n");
  49                 data = idx;
  50                 goto out;
  51         }
  52
  53         /* Convert the data from chip to microvolts */
  54         data = ISL6271A_VOLTAGE_MIN + (ISL6271A_VOLTAGE_STEP * (idx & 0xf));
  55
  56 out:
  57         mutex_unlock(&pmic->mtx);
  58         return data;
  59 }
  60
  61 static int isl6271a_set_voltage(struct regulator_dev *dev,
  62                                 int minuV, int maxuV,
  63                                 unsigned *selector)
  64 {
  65         struct isl_pmic *pmic = rdev_get_drvdata(dev);
  66         int err, data;
  67
  68         if (minuV < ISL6271A_VOLTAGE_MIN || minuV > ISL6271A_VOLTAGE_MAX)
  69                 return -EINVAL;
  70         if (maxuV < ISL6271A_VOLTAGE_MIN || maxuV > ISL6271A_VOLTAGE_MAX)
  71                 return -EINVAL;
  72
  73         data = DIV_ROUND_UP(minuV - ISL6271A_VOLTAGE_MIN,
  74                             ISL6271A_VOLTAGE_STEP);
  75         *selector = data;
  76
  77         mutex_lock(&pmic->mtx);
  78
  79         err = i2c_smbus_write_byte(pmic->client, data);
  80         if (err < 0)
  81                 dev_err(&pmic->client->dev, "Error setting voltage\n");
  82
  83         mutex_unlock(&pmic->mtx);
  84         return err;
  85 }
  86
  87 static int isl6271a_list_voltage(struct regulator_dev *dev, unsigned selector)
  88 {
  89         return ISL6271A_VOLTAGE_MIN + (ISL6271A_VOLTAGE_STEP * selector);
  90 }
  91
  92 static struct regulator_ops isl_core_ops = {
  93         .get_voltage    = isl6271a_get_voltage,
  94         .set_voltage    = isl6271a_set_voltage,
  95         .list_voltage   = isl6271a_list_voltage,
  96 };
  97
  98 static int isl6271a_get_fixed_voltage(struct regulator_dev *dev)
  99 {
 100         int id = rdev_get_id(dev);
 101         return (id == 1) ? 1100000 : 1300000;
 102 }
 103
 104 static int isl6271a_list_fixed_voltage(struct regulator_dev *dev, unsigned selector)
 105 {
 106         int id = rdev_get_id(dev);
 107         return (id == 1) ? 1100000 : 1300000;
 108 }
 109
 110 static struct regulator_ops isl_fixed_ops = {
 111         .get_voltage    = isl6271a_get_fixed_voltage,
 112         .list_voltage   = isl6271a_list_fixed_voltage,
 113 };
 114
 115 static struct regulator_desc isl_rd[] = {
 116         {
 117                 .name           = "Core Buck",
 118                 .id             = 0,
 119                 .n_voltages     = 16,
 120                 .ops            = &isl_core_ops,
 121                 .type           = REGULATOR_VOLTAGE,
 122                 .owner          = THIS_MODULE,
 123         }, {
 124                 .name           = "LDO1",
 125                 .id             = 1,
 126                 .n_voltages     = 1,
 127                 .ops            = &isl_fixed_ops,
 128                 .type           = REGULATOR_VOLTAGE,
 129                 .owner          = THIS_MODULE,
 130         }, {
 131                 .name           = "LDO2",
 132                 .id             = 2,
 133                 .n_voltages     = 1,
 134                 .ops            = &isl_fixed_ops,
 135                 .type           = REGULATOR_VOLTAGE,
 136                 .owner          = THIS_MODULE,
 137         },
 138 };
 139
 140 static int __devinit isl6271a_probe(struct i2c_client *i2c,
 141                                      const struct i2c_device_id *id)
 142 {
 143         struct regulator_init_data *init_data   = i2c->dev.platform_data;
 144         struct isl_pmic *pmic;
 145         int err, i;
 146
 147         if (!i2c_check_functionality(i2c->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
 148                 return -EIO;
 149
 150         if (!init_data) {
 151                 dev_err(&i2c->dev, "no platform data supplied\n");
 152                 return -EIO;
 153         }
 154
 155         pmic = kzalloc(sizeof(struct isl_pmic), GFP_KERNEL);
 156         if (!pmic)
 157                 return -ENOMEM;
 158
 159         pmic->client = i2c;
 160
 161         mutex_init(&pmic->mtx);
 162
 163         for (i = 0; i < 3; i++) {
 164                 pmic->rdev[i] = regulator_register(&isl_rd[i], &i2c->dev,
 165                                                 init_data, pmic, NULL);
 166                 if (IS_ERR(pmic->rdev[i])) {
 167                         dev_err(&i2c->dev, "failed to register %s\n", id->name);
 168                         err = PTR_ERR(pmic->rdev[i]);
 169                         goto error;
 170                 }
 171         }
 172
 173         i2c_set_clientdata(i2c, pmic);
 174
 175         return 0;
 176
 177 error:
 178         while (--i >= 0)
 179                 regulator_unregister(pmic->rdev[i]);
 180
 181         kfree(pmic);
 182         return err;
 183 }
 184
 185 static int __devexit isl6271a_remove(struct i2c_client *i2c)
 186 {
 187         struct isl_pmic *pmic = i2c_get_clientdata(i2c);
 188         int i;
 189
 190         for (i = 0; i < 3; i++)
 191                 regulator_unregister(pmic->rdev[i]);
 192
 193         kfree(pmic);
 194
 195         return 0;
 196 }
 197
 198 static const struct i2c_device_id isl6271a_id[] = {
 199         {.name = "isl6271a", 0 },
 200         { },
 201 };
 202
 203 MODULE_DEVICE_TABLE(i2c, isl6271a_id);
 204
 205 static struct i2c_driver isl6271a_i2c_driver = {
 206         .driver = {
 207                 .name = "isl6271a",
 208                 .owner = THIS_MODULE,
 209         },
 210         .probe = isl6271a_probe,
 211         .remove = __devexit_p(isl6271a_remove),
 212         .id_table = isl6271a_id,
 213 };
 214
 215 static int __init isl6271a_init(void)
 216 {
 217         return i2c_add_driver(&isl6271a_i2c_driver);
 218 }
 219
 220 static void __exit isl6271a_cleanup(void)
 221 {
 222         i2c_del_driver(&isl6271a_i2c_driver);
 223 }
 224
 225 subsys_initcall(isl6271a_init);
 226 module_exit(isl6271a_cleanup);
 227
 228 MODULE_AUTHOR("Marek Vasut <marek.vasut@gmail.com>");
 229 MODULE_DESCRIPTION("Intersil ISL6271A voltage regulator driver");
 230 MODULE_LICENSE("GPL v2");