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/regulator/max1586.h>
  26
  27 #define MAX1586_V3_MAX_VSEL 31
  28 #define MAX1586_V6_MAX_VSEL 3
  29
  30 #define MAX1586_V3_MIN_UV   700000
  31 #define MAX1586_V3_MAX_UV  1475000
  32
  33 #define MAX1586_V6_MIN_UV        0
  34 #define MAX1586_V6_MAX_UV  3000000
  35
  36 #define I2C_V3_SELECT (0 << 5)
  37 #define I2C_V6_SELECT (1 << 5)
  38
  39 struct max1586_data {
  40         struct i2c_client *client;
  41
  42         /* min/max V3 voltage */
  43         unsigned int min_uV;
  44         unsigned int max_uV;
  45
  46         struct regulator_dev *rdev[0];
  47 };
  48
  49 /*
  50  * V3 voltage
  51  * On I2C bus, sending a "x" byte to the max1586 means :
  52  *   set V3 to 0.700V + (x & 0x1f) * 0.025V
  53  * This voltage can be increased by external resistors
  54  * R24 and R25=100kOhm as described in the data sheet.
  55  * The gain is approximately: 1 + R24/R25 + R24/185.5kOhm
  56  */
  57 static int max1586_v3_calc_voltage(struct max1586_data *max1586,
  58         unsigned selector)
  59 {
  60         unsigned range_uV = max1586->max_uV - max1586->min_uV;
  61
  62         return max1586->min_uV + (selector * range_uV / MAX1586_V3_MAX_VSEL);
  63 }
  64
  65 static int max1586_v3_set(struct regulator_dev *rdev, int min_uV, int max_uV)
  66 {
  67         struct max1586_data *max1586 = rdev_get_drvdata(rdev);
  68         struct i2c_client *client = max1586->client;
  69         unsigned range_uV = max1586->max_uV - max1586->min_uV;
  70         unsigned selector;
  71         u8 v3_prog;
  72
  73         if (min_uV > max1586->max_uV || max_uV < max1586->min_uV)
  74                 return -EINVAL;
  75         if (min_uV < max1586->min_uV)
  76                 min_uV = max1586->min_uV;
  77
  78         selector = ((min_uV - max1586->min_uV) * MAX1586_V3_MAX_VSEL +
  79                         range_uV - 1) / range_uV;
  80         if (max1586_v3_calc_voltage(max1586, selector) > max_uV)
  81                 return -EINVAL;
  82
  83         dev_dbg(&client->dev, "changing voltage v3 to %dmv\n",
  84                 max1586_v3_calc_voltage(max1586, selector) / 1000);
  85
  86         v3_prog = I2C_V3_SELECT | (u8) selector;
  87         return i2c_smbus_write_byte(client, v3_prog);
  88 }
  89
  90 static int max1586_v3_list(struct regulator_dev *rdev, unsigned selector)
  91 {
  92         struct max1586_data *max1586 = rdev_get_drvdata(rdev);
  93
  94         if (selector > MAX1586_V3_MAX_VSEL)
  95                 return -EINVAL;
  96         return max1586_v3_calc_voltage(max1586, selector);
  97 }
  98
  99 /*
 100  * V6 voltage
 101  * On I2C bus, sending a "x" byte to the max1586 means :
 102  *   set V6 to either 0V, 1.8V, 2.5V, 3V depending on (x & 0x3)
 103  * As regulator framework doesn't accept voltages to be 0V, we use 1uV.
 104  */
 105 static int max1586_v6_calc_voltage(unsigned selector)
 106 {
 107         static int voltages_uv[] = { 1, 1800000, 2500000, 3000000 };
 108
 109         return voltages_uv[selector];
 110 }
 111
 112 static int max1586_v6_set(struct regulator_dev *rdev, int min_uV, int max_uV)
 113 {
 114         struct i2c_client *client = rdev_get_drvdata(rdev);
 115         unsigned selector;
 116         u8 v6_prog;
 117
 118         if (min_uV < MAX1586_V6_MIN_UV || min_uV > MAX1586_V6_MAX_UV)
 119                 return -EINVAL;
 120         if (max_uV < MAX1586_V6_MIN_UV || max_uV > MAX1586_V6_MAX_UV)
 121                 return -EINVAL;
 122
 123         if (min_uV >= 3000000)
 124                 selector = 3;
 125         if (min_uV < 3000000)
 126                 selector = 2;
 127         if (min_uV < 2500000)
 128                 selector = 1;
 129         if (min_uV < 1800000)
 130                 selector = 0;
 131
 132         if (max1586_v6_calc_voltage(selector) > max_uV)
 133                 return -EINVAL;
 134
 135         dev_dbg(&client->dev, "changing voltage v6 to %dmv\n",
 136                 max1586_v6_calc_voltage(selector) / 1000);
 137
 138         v6_prog = I2C_V6_SELECT | (u8) selector;
 139         return i2c_smbus_write_byte(client, v6_prog);
 140 }
 141
 142 static int max1586_v6_list(struct regulator_dev *rdev, unsigned selector)
 143 {
 144         if (selector > MAX1586_V6_MAX_VSEL)
 145                 return -EINVAL;
 146         return max1586_v6_calc_voltage(selector);
 147 }
 148
 149 /*
 150  * The Maxim 1586 controls V3 and V6 voltages, but offers no way of reading back
 151  * the set up value.
 152  */
 153 static struct regulator_ops max1586_v3_ops = {
 154         .set_voltage = max1586_v3_set,
 155         .list_voltage = max1586_v3_list,
 156 };
 157
 158 static struct regulator_ops max1586_v6_ops = {
 159         .set_voltage = max1586_v6_set,
 160         .list_voltage = max1586_v6_list,
 161 };
 162
 163 static struct regulator_desc max1586_reg[] = {
 164         {
 165                 .name = "Output_V3",
 166                 .id = MAX1586_V3,
 167                 .ops = &max1586_v3_ops,
 168                 .type = REGULATOR_VOLTAGE,
 169                 .n_voltages = MAX1586_V3_MAX_VSEL + 1,
 170                 .owner = THIS_MODULE,
 171         },
 172         {
 173                 .name = "Output_V6",
 174                 .id = MAX1586_V6,
 175                 .ops = &max1586_v6_ops,
 176                 .type = REGULATOR_VOLTAGE,
 177                 .n_voltages = MAX1586_V6_MAX_VSEL + 1,
 178                 .owner = THIS_MODULE,
 179         },
 180 };
 181
 182 static int max1586_pmic_probe(struct i2c_client *client,
 183                               const struct i2c_device_id *i2c_id)
 184 {
 185         struct regulator_dev **rdev;
 186         struct max1586_platform_data *pdata = client->dev.platform_data;
 187         struct max1586_data *max1586;
 188         int i, id, ret = -ENOMEM;
 189
 190         max1586 = kzalloc(sizeof(struct max1586_data) +
 191                         sizeof(struct regulator_dev *) * (MAX1586_V6 + 1),
 192                         GFP_KERNEL);
 193         if (!max1586)
 194                 goto out;
 195
 196         max1586->client = client;
 197
 198         if (!pdata->v3_gain) {
 199                 ret = -EINVAL;
 200                 goto out_unmap;
 201         }
 202         max1586->min_uV = MAX1586_V3_MIN_UV / 1000 * pdata->v3_gain / 1000;
 203         max1586->max_uV = MAX1586_V3_MAX_UV / 1000 * pdata->v3_gain / 1000;
 204
 205         rdev = max1586->rdev;
 206         for (i = 0; i < pdata->num_subdevs && i <= MAX1586_V6; i++) {
 207                 id = pdata->subdevs[i].id;
 208                 if (!pdata->subdevs[i].platform_data)
 209                         continue;
 210                 if (id < MAX1586_V3 || id > MAX1586_V6) {
 211                         dev_err(&client->dev, "invalid regulator id %d\n", id);
 212                         goto err;
 213                 }
 214                 rdev[i] = regulator_register(&max1586_reg[id], &client->dev,
 215                                              pdata->subdevs[i].platform_data,
 216                                              max1586);
 217                 if (IS_ERR(rdev[i])) {
 218                         ret = PTR_ERR(rdev[i]);
 219                         dev_err(&client->dev, "failed to register %s\n",
 220                                 max1586_reg[id].name);
 221                         goto err;
 222                 }
 223         }
 224
 225         i2c_set_clientdata(client, rdev);
 226         dev_info(&client->dev, "Maxim 1586 regulator driver loaded\n");
 227         return 0;
 228
 229 err:
 230         while (--i >= 0)
 231                 regulator_unregister(rdev[i]);
 232 out_unmap:
 233         kfree(max1586);
 234 out:
 235         return ret;
 236 }
 237
 238 static int max1586_pmic_remove(struct i2c_client *client)
 239 {
 240         struct regulator_dev **rdev = i2c_get_clientdata(client);
 241         int i;
 242
 243         for (i = 0; i <= MAX1586_V6; i++)
 244                 if (rdev[i])
 245                         regulator_unregister(rdev[i]);
 246         kfree(rdev);
 247         i2c_set_clientdata(client, NULL);
 248
 249         return 0;
 250 }
 251
 252 static const struct i2c_device_id max1586_id[] = {
 253         { "max1586", 0 },
 254         { }
 255 };
 256 MODULE_DEVICE_TABLE(i2c, max1586_id);
 257
 258 static struct i2c_driver max1586_pmic_driver = {
 259         .probe = max1586_pmic_probe,
 260         .remove = max1586_pmic_remove,
 261         .driver         = {
 262                 .name   = "max1586",
 263         },
 264         .id_table       = max1586_id,
 265 };
 266
 267 static int __init max1586_pmic_init(void)
 268 {
 269         return i2c_add_driver(&max1586_pmic_driver);
 270 }
 271 subsys_initcall(max1586_pmic_init);
 272
 273 static void __exit max1586_pmic_exit(void)
 274 {
 275         i2c_del_driver(&max1586_pmic_driver);
 276 }
 277 module_exit(max1586_pmic_exit);
 278
 279 /* Module information */
 280 MODULE_DESCRIPTION("MAXIM 1586 voltage regulator driver");
 281 MODULE_AUTHOR("Robert Jarzmik");
 282 MODULE_LICENSE("GPL");