release/src-rt-6.x.4708/linux/linux-2.6.36/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, int minuV, int maxuV)
  62 {
  63         struct isl_pmic *pmic = rdev_get_drvdata(dev);
  64         int vsel, err, data;
  65
  66         if (minuV < ISL6271A_VOLTAGE_MIN || minuV > ISL6271A_VOLTAGE_MAX)
  67                 return -EINVAL;
  68         if (maxuV < ISL6271A_VOLTAGE_MIN || maxuV > ISL6271A_VOLTAGE_MAX)
  69                 return -EINVAL;
  70
  71         /* Align to 50000 mV */
  72         vsel = minuV - (minuV % ISL6271A_VOLTAGE_STEP);
  73
  74         /* If the result fell out of [minuV,maxuV] range, put it back */
  75         if (vsel < minuV)
  76                 vsel += ISL6271A_VOLTAGE_STEP;
  77
  78         /* Convert the microvolts to data for the chip */
  79         data = (vsel - ISL6271A_VOLTAGE_MIN) / ISL6271A_VOLTAGE_STEP;
  80
  81         mutex_lock(&pmic->mtx);
  82
  83         err = i2c_smbus_write_byte(pmic->client, data);
  84         if (err < 0)
  85                 dev_err(&pmic->client->dev, "Error setting voltage\n");
  86
  87         mutex_unlock(&pmic->mtx);
  88         return err;
  89 }
  90
  91 static int isl6271a_list_voltage(struct regulator_dev *dev, unsigned selector)
  92 {
  93         return ISL6271A_VOLTAGE_MIN + (ISL6271A_VOLTAGE_STEP * selector);
  94 }
  95
  96 static struct regulator_ops isl_core_ops = {
  97         .get_voltage    = isl6271a_get_voltage,
  98         .set_voltage    = isl6271a_set_voltage,
  99         .list_voltage   = isl6271a_list_voltage,
 100 };
 101
 102 static int isl6271a_get_fixed_voltage(struct regulator_dev *dev)
 103 {
 104         int id = rdev_get_id(dev);
 105         return (id == 1) ? 1100000 : 1300000;
 106 }
 107
 108 static int isl6271a_list_fixed_voltage(struct regulator_dev *dev, unsigned selector)
 109 {
 110         int id = rdev_get_id(dev);
 111         return (id == 1) ? 1100000 : 1300000;
 112 }
 113
 114 static struct regulator_ops isl_fixed_ops = {
 115         .get_voltage    = isl6271a_get_fixed_voltage,
 116         .list_voltage   = isl6271a_list_fixed_voltage,
 117 };
 118
 119 static struct regulator_desc isl_rd[] = {
 120         {
 121                 .name           = "Core Buck",
 122                 .id             = 0,
 123                 .n_voltages     = 16,
 124                 .ops            = &isl_core_ops,
 125                 .type           = REGULATOR_VOLTAGE,
 126                 .owner          = THIS_MODULE,
 127         }, {
 128                 .name           = "LDO1",
 129                 .id             = 1,
 130                 .n_voltages     = 1,
 131                 .ops            = &isl_fixed_ops,
 132                 .type           = REGULATOR_VOLTAGE,
 133                 .owner          = THIS_MODULE,
 134         }, {
 135                 .name           = "LDO2",
 136                 .id             = 2,
 137                 .n_voltages     = 1,
 138                 .ops            = &isl_fixed_ops,
 139                 .type           = REGULATOR_VOLTAGE,
 140                 .owner          = THIS_MODULE,
 141         },
 142 };
 143
 144 static int __devinit isl6271a_probe(struct i2c_client *i2c,
 145                                      const struct i2c_device_id *id)
 146 {
 147         struct regulator_init_data *init_data   = i2c->dev.platform_data;
 148         struct isl_pmic *pmic;
 149         int err, i;
 150
 151         if (!i2c_check_functionality(i2c->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
 152                 return -EIO;
 153
 154         if (!init_data) {
 155                 dev_err(&i2c->dev, "no platform data supplied\n");
 156                 return -EIO;
 157         }
 158
 159         pmic = kzalloc(sizeof(struct isl_pmic), GFP_KERNEL);
 160         if (!pmic)
 161                 return -ENOMEM;
 162
 163         pmic->client = i2c;
 164
 165         mutex_init(&pmic->mtx);
 166
 167         for (i = 0; i < 3; i++) {
 168                 pmic->rdev[i] = regulator_register(&isl_rd[i], &i2c->dev,
 169                                                 init_data, pmic);
 170                 if (IS_ERR(pmic->rdev[i])) {
 171                         dev_err(&i2c->dev, "failed to register %s\n", id->name);
 172                         err = PTR_ERR(pmic->rdev);
 173                         goto error;
 174                 }
 175         }
 176
 177         i2c_set_clientdata(i2c, pmic);
 178
 179         return 0;
 180
 181 error:
 182         while (--i >= 0)
 183                 regulator_unregister(pmic->rdev[i]);
 184
 185         kfree(pmic);
 186         return err;
 187 }
 188
 189 static int __devexit isl6271a_remove(struct i2c_client *i2c)
 190 {
 191         struct isl_pmic *pmic = i2c_get_clientdata(i2c);
 192         int i;
 193
 194         for (i = 0; i < 3; i++)
 195                 regulator_unregister(pmic->rdev[i]);
 196
 197         kfree(pmic);
 198
 199         return 0;
 200 }
 201
 202 static const struct i2c_device_id isl6271a_id[] = {
 203         {.name = "isl6271a", 0 },
 204         { },
 205 };
 206
 207 MODULE_DEVICE_TABLE(i2c, isl6271a_id);
 208
 209 static struct i2c_driver isl6271a_i2c_driver = {
 210         .driver = {
 211                 .name = "isl6271a",
 212                 .owner = THIS_MODULE,
 213         },
 214         .probe = isl6271a_probe,
 215         .remove = __devexit_p(isl6271a_remove),
 216         .id_table = isl6271a_id,
 217 };
 218
 219 static int __init isl6271a_init(void)
 220 {
 221         return i2c_add_driver(&isl6271a_i2c_driver);
 222 }
 223
 224 static void __exit isl6271a_cleanup(void)
 225 {
 226         i2c_del_driver(&isl6271a_i2c_driver);
 227 }
 228
 229 subsys_initcall(isl6271a_init);
 230 module_exit(isl6271a_cleanup);
 231
 232 MODULE_AUTHOR("Marek Vasut <marek.vasut@gmail.com>");
 233 MODULE_DESCRIPTION("Intersil ISL6271A voltage regulator driver");
 234 MODULE_LICENSE("GPL v2");