drivers/regulator/max1586.c

   1 /*
   2  * max1586.c  --  Voltage and current regulation for the Maxim 1586
   3  *
   4  * Copyright (C) 2008 Robert Jarzmik
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  */
  20 #include <linux/module.h>
  21 #include <linux/err.h>
  22 #include <linux/i2c.h>
  23 #include <linux/platform_device.h>
  24 #include <linux/regulator/driver.h>
  25 #include <linux/slab.h>
  26 #include <linux/regulator/max1586.h>
  27
  28 #define MAX1586_V3_MAX_VSEL 31
  29 #define MAX1586_V6_MAX_VSEL 3
  30
  31 #define MAX1586_V3_MIN_UV   700000
  32 #define MAX1586_V3_MAX_UV  1475000
  33
  34 #define MAX1586_V6_MIN_UV        0
  35 #define MAX1586_V6_MAX_UV  3000000
  36
  37 #define I2C_V3_SELECT (0 << 5)
  38 #define I2C_V6_SELECT (1 << 5)
  39
  40 struct max1586_data {
  41         struct i2c_client *client;
  42
  43         /* min/max V3 voltage */
  44         unsigned int min_uV;
  45         unsigned int max_uV;
  46
  47         struct regulator_dev *rdev[0];
  48 };
  49
  50 /*
  51  * V6 voltage
  52  * On I2C bus, sending a "x" byte to the max1586 means :
  53  *   set V6 to either 0V, 1.8V, 2.5V, 3V depending on (x & 0x3)
  54  * As regulator framework doesn't accept voltages to be 0V, we use 1uV.
  55  */
  56 static int v6_voltages_uv[] = { 1, 1800000, 2500000, 3000000 };
  57
  58 /*
  59  * V3 voltage
  60  * On I2C bus, sending a "x" byte to the max1586 means :
  61  *   set V3 to 0.700V + (x & 0x1f) * 0.025V
  62  * This voltage can be increased by external resistors
  63  * R24 and R25=100kOhm as described in the data sheet.
  64  * The gain is approximately: 1 + R24/R25 + R24/185.5kOhm
  65  */
  66 static int max1586_v3_set_voltage_sel(struct regulator_dev *rdev,
  67                                       unsigned selector)
  68 {
  69         struct max1586_data *max1586 = rdev_get_drvdata(rdev);
  70         struct i2c_client *client = max1586->client;
  71         u8 v3_prog;
  72
  73         dev_dbg(&client->dev, "changing voltage v3 to %dmv\n",
  74                 regulator_list_voltage_linear(rdev, selector) / 1000);
  75
  76         v3_prog = I2C_V3_SELECT | (u8) selector;
  77         return i2c_smbus_write_byte(client, v3_prog);
  78 }
  79
  80 static int max1586_v6_set_voltage_sel(struct regulator_dev *rdev,
  81                                       unsigned int selector)
  82 {
  83         struct i2c_client *client = rdev_get_drvdata(rdev);
  84         u8 v6_prog;
  85
  86         dev_dbg(&client->dev, "changing voltage v6 to %dmv\n",
  87                 rdev->desc->volt_table[selector] / 1000);
  88
  89         v6_prog = I2C_V6_SELECT | (u8) selector;
  90         return i2c_smbus_write_byte(client, v6_prog);
  91 }
  92
  93 /*
  94  * The Maxim 1586 controls V3 and V6 voltages, but offers no way of reading back
  95  * the set up value.
  96  */
  97 static struct regulator_ops max1586_v3_ops = {
  98         .set_voltage_sel = max1586_v3_set_voltage_sel,
  99         .list_voltage = regulator_list_voltage_linear,
 100         .map_voltage = regulator_map_voltage_linear,
 101 };
 102
 103 static struct regulator_ops max1586_v6_ops = {
 104         .set_voltage_sel = max1586_v6_set_voltage_sel,
 105         .list_voltage = regulator_list_voltage_table,
 106 };
 107
 108 static struct regulator_desc max1586_reg[] = {
 109         {
 110                 .name = "Output_V3",
 111                 .id = MAX1586_V3,
 112                 .ops = &max1586_v3_ops,
 113                 .type = REGULATOR_VOLTAGE,
 114                 .n_voltages = MAX1586_V3_MAX_VSEL + 1,
 115                 .owner = THIS_MODULE,
 116         },
 117         {
 118                 .name = "Output_V6",
 119                 .id = MAX1586_V6,
 120                 .ops = &max1586_v6_ops,
 121                 .type = REGULATOR_VOLTAGE,
 122                 .n_voltages = MAX1586_V6_MAX_VSEL + 1,
 123                 .volt_table = v6_voltages_uv,
 124                 .owner = THIS_MODULE,
 125         },
 126 };
 127
 128 static int __devinit max1586_pmic_probe(struct i2c_client *client,
 129                                         const struct i2c_device_id *i2c_id)
 130 {
 131         struct regulator_dev **rdev;
 132         struct max1586_platform_data *pdata = client->dev.platform_data;
 133         struct regulator_config config = { };
 134         struct max1586_data *max1586;
 135         int i, id, ret = -ENOMEM;
 136
 137         max1586 = devm_kzalloc(&client->dev, sizeof(struct max1586_data) +
 138                         sizeof(struct regulator_dev *) * (MAX1586_V6 + 1),
 139                         GFP_KERNEL);
 140         if (!max1586)
 141                 return -ENOMEM;
 142
 143         max1586->client = client;
 144
 145         if (!pdata->v3_gain)
 146                 return -EINVAL;
 147
 148         max1586->min_uV = MAX1586_V3_MIN_UV / 1000 * pdata->v3_gain / 1000;
 149         max1586->max_uV = MAX1586_V3_MAX_UV / 1000 * pdata->v3_gain / 1000;
 150
 151         rdev = max1586->rdev;
 152         for (i = 0; i < pdata->num_subdevs && i <= MAX1586_V6; i++) {
 153                 id = pdata->subdevs[i].id;
 154                 if (!pdata->subdevs[i].platform_data)
 155                         continue;
 156                 if (id < MAX1586_V3 || id > MAX1586_V6) {
 157                         dev_err(&client->dev, "invalid regulator id %d\n", id);
 158                         goto err;
 159                 }
 160
 161                 if (id == MAX1586_V3) {
 162                         max1586_reg[id].min_uV = max1586->min_uV;
 163                         max1586_reg[id].uV_step =
 164                                         (max1586->max_uV - max1586->min_uV) /
 165                                         MAX1586_V3_MAX_VSEL;
 166                 }
 167
 168                 config.dev = &client->dev;
 169                 config.init_data = pdata->subdevs[i].platform_data;
 170                 config.driver_data = max1586;
 171
 172                 rdev[i] = regulator_register(&max1586_reg[id], &config);
 173                 if (IS_ERR(rdev[i])) {
 174                         ret = PTR_ERR(rdev[i]);
 175                         dev_err(&client->dev, "failed to register %s\n",
 176                                 max1586_reg[id].name);
 177                         goto err;
 178                 }
 179         }
 180
 181         i2c_set_clientdata(client, max1586);
 182         dev_info(&client->dev, "Maxim 1586 regulator driver loaded\n");
 183         return 0;
 184
 185 err:
 186         while (--i >= 0)
 187                 regulator_unregister(rdev[i]);
 188         return ret;
 189 }
 190
 191 static int __devexit max1586_pmic_remove(struct i2c_client *client)
 192 {
 193         struct max1586_data *max1586 = i2c_get_clientdata(client);
 194         int i;
 195
 196         for (i = 0; i <= MAX1586_V6; i++)
 197                 if (max1586->rdev[i])
 198                         regulator_unregister(max1586->rdev[i]);
 199         return 0;
 200 }
 201
 202 static const struct i2c_device_id max1586_id[] = {
 203         { "max1586", 0 },
 204         { }
 205 };
 206 MODULE_DEVICE_TABLE(i2c, max1586_id);
 207
 208 static struct i2c_driver max1586_pmic_driver = {
 209         .probe = max1586_pmic_probe,
 210         .remove = __devexit_p(max1586_pmic_remove),
 211         .driver         = {
 212                 .name   = "max1586",
 213                 .owner  = THIS_MODULE,
 214         },
 215         .id_table       = max1586_id,
 216 };
 217
 218 static int __init max1586_pmic_init(void)
 219 {
 220         return i2c_add_driver(&max1586_pmic_driver);
 221 }
 222 subsys_initcall(max1586_pmic_init);
 223
 224 static void __exit max1586_pmic_exit(void)
 225 {
 226         i2c_del_driver(&max1586_pmic_driver);
 227 }
 228 module_exit(max1586_pmic_exit);
 229
 230 /* Module information */
 231 MODULE_DESCRIPTION("MAXIM 1586 voltage regulator driver");
 232 MODULE_AUTHOR("Robert Jarzmik");
 233 MODULE_LICENSE("GPL");