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 vsel, 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         /* Align to 50000 mV */
  74         vsel = minuV - (minuV % ISL6271A_VOLTAGE_STEP);
  75
  76         /* If the result fell out of [minuV,maxuV] range, put it back */
  77         if (vsel < minuV)
  78                 vsel += ISL6271A_VOLTAGE_STEP;
  79
  80         /* Convert the microvolts to data for the chip */
  81         data = (vsel - ISL6271A_VOLTAGE_MIN) / ISL6271A_VOLTAGE_STEP;
  82
  83         *selector = data;
  84
  85         mutex_lock(&pmic->mtx);
  86
  87         err = i2c_smbus_write_byte(pmic->client, data);
  88         if (err < 0)
  89                 dev_err(&pmic->client->dev, "Error setting voltage\n");
  90
  91         mutex_unlock(&pmic->mtx);
  92         return err;
  93 }
  94
  95 static int isl6271a_list_voltage(struct regulator_dev *dev, unsigned selector)
  96 {
  97         return ISL6271A_VOLTAGE_MIN + (ISL6271A_VOLTAGE_STEP * selector);
  98 }
  99
 100 static struct regulator_ops isl_core_ops = {
 101         .get_voltage    = isl6271a_get_voltage,
 102         .set_voltage    = isl6271a_set_voltage,
 103         .list_voltage   = isl6271a_list_voltage,
 104 };
 105
 106 static int isl6271a_get_fixed_voltage(struct regulator_dev *dev)
 107 {
 108         int id = rdev_get_id(dev);
 109         return (id == 1) ? 1100000 : 1300000;
 110 }
 111
 112 static int isl6271a_list_fixed_voltage(struct regulator_dev *dev, unsigned selector)
 113 {
 114         int id = rdev_get_id(dev);
 115         return (id == 1) ? 1100000 : 1300000;
 116 }
 117
 118 static struct regulator_ops isl_fixed_ops = {
 119         .get_voltage    = isl6271a_get_fixed_voltage,
 120         .list_voltage   = isl6271a_list_fixed_voltage,
 121 };
 122
 123 static struct regulator_desc isl_rd[] = {
 124         {
 125                 .name           = "Core Buck",
 126                 .id             = 0,
 127                 .n_voltages     = 16,
 128                 .ops            = &isl_core_ops,
 129                 .type           = REGULATOR_VOLTAGE,
 130                 .owner          = THIS_MODULE,
 131         }, {
 132                 .name           = "LDO1",
 133                 .id             = 1,
 134                 .n_voltages     = 1,
 135                 .ops            = &isl_fixed_ops,
 136                 .type           = REGULATOR_VOLTAGE,
 137                 .owner          = THIS_MODULE,
 138         }, {
 139                 .name           = "LDO2",
 140                 .id             = 2,
 141                 .n_voltages     = 1,
 142                 .ops            = &isl_fixed_ops,
 143                 .type           = REGULATOR_VOLTAGE,
 144                 .owner          = THIS_MODULE,
 145         },
 146 };
 147
 148 static int __devinit isl6271a_probe(struct i2c_client *i2c,
 149                                      const struct i2c_device_id *id)
 150 {
 151         struct regulator_init_data *init_data   = i2c->dev.platform_data;
 152         struct isl_pmic *pmic;
 153         int err, i;
 154
 155         if (!i2c_check_functionality(i2c->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
 156                 return -EIO;
 157
 158         if (!init_data) {
 159                 dev_err(&i2c->dev, "no platform data supplied\n");
 160                 return -EIO;
 161         }
 162
 163         pmic = kzalloc(sizeof(struct isl_pmic), GFP_KERNEL);
 164         if (!pmic)
 165                 return -ENOMEM;
 166
 167         pmic->client = i2c;
 168
 169         mutex_init(&pmic->mtx);
 170
 171         for (i = 0; i < 3; i++) {
 172                 pmic->rdev[i] = regulator_register(&isl_rd[i], &i2c->dev,
 173                                                 init_data, pmic, NULL);
 174                 if (IS_ERR(pmic->rdev[i])) {
 175                         dev_err(&i2c->dev, "failed to register %s\n", id->name);
 176                         err = PTR_ERR(pmic->rdev[i]);
 177                         goto error;
 178                 }
 179         }
 180
 181         i2c_set_clientdata(i2c, pmic);
 182
 183         return 0;
 184
 185 error:
 186         while (--i >= 0)
 187                 regulator_unregister(pmic->rdev[i]);
 188
 189         kfree(pmic);
 190         return err;
 191 }
 192
 193 static int __devexit isl6271a_remove(struct i2c_client *i2c)
 194 {
 195         struct isl_pmic *pmic = i2c_get_clientdata(i2c);
 196         int i;
 197
 198         for (i = 0; i < 3; i++)
 199                 regulator_unregister(pmic->rdev[i]);
 200
 201         kfree(pmic);
 202
 203         return 0;
 204 }
 205
 206 static const struct i2c_device_id isl6271a_id[] = {
 207         {.name = "isl6271a", 0 },
 208         { },
 209 };
 210
 211 MODULE_DEVICE_TABLE(i2c, isl6271a_id);
 212
 213 static struct i2c_driver isl6271a_i2c_driver = {
 214         .driver = {
 215                 .name = "isl6271a",
 216                 .owner = THIS_MODULE,
 217         },
 218         .probe = isl6271a_probe,
 219         .remove = __devexit_p(isl6271a_remove),
 220         .id_table = isl6271a_id,
 221 };
 222
 223 static int __init isl6271a_init(void)
 224 {
 225         return i2c_add_driver(&isl6271a_i2c_driver);
 226 }
 227
 228 static void __exit isl6271a_cleanup(void)
 229 {
 230         i2c_del_driver(&isl6271a_i2c_driver);
 231 }
 232
 233 subsys_initcall(isl6271a_init);
 234 module_exit(isl6271a_cleanup);
 235
 236 MODULE_AUTHOR("Marek Vasut <marek.vasut@gmail.com>");
 237 MODULE_DESCRIPTION("Intersil ISL6271A voltage regulator driver");
 238 MODULE_LICENSE("GPL v2");