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