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         unsigned int v3_curr_sel;
  48         unsigned int v6_curr_sel;
  49
  50         struct regulator_dev *rdev[0];
  51 };
  52
  53 /*
  54  * V6 voltage
  55  * On I2C bus, sending a "x" byte to the max1586 means :
  56  *   set V6 to either 0V, 1.8V, 2.5V, 3V depending on (x & 0x3)
  57  * As regulator framework doesn't accept voltages to be 0V, we use 1uV.
  58  */
  59 static const unsigned int v6_voltages_uv[] = { 1, 1800000, 2500000, 3000000 };
  60
  61 /*
  62  * V3 voltage
  63  * On I2C bus, sending a "x" byte to the max1586 means :
  64  *   set V3 to 0.700V + (x & 0x1f) * 0.025V
  65  * This voltage can be increased by external resistors
  66  * R24 and R25=100kOhm as described in the data sheet.
  67  * The gain is approximately: 1 + R24/R25 + R24/185.5kOhm
  68  */
  69 static int max1586_v3_get_voltage_sel(struct regulator_dev *rdev)
  70 {
  71         struct max1586_data *max1586 = rdev_get_drvdata(rdev);
  72
  73         return max1586->v3_curr_sel;
  74 }
  75
  76 static int max1586_v3_set_voltage_sel(struct regulator_dev *rdev,
  77                                       unsigned selector)
  78 {
  79         struct max1586_data *max1586 = rdev_get_drvdata(rdev);
  80         struct i2c_client *client = max1586->client;
  81         int ret;
  82         u8 v3_prog;
  83
  84         dev_dbg(&client->dev, "changing voltage v3 to %dmv\n",
  85                 regulator_list_voltage_linear(rdev, selector) / 1000);
  86
  87         v3_prog = I2C_V3_SELECT | (u8) selector;
  88         ret = i2c_smbus_write_byte(client, v3_prog);
  89         if (ret)
  90                 return ret;
  91
  92         max1586->v3_curr_sel = selector;
  93
  94         return 0;
  95 }
  96
  97 static int max1586_v6_get_voltage_sel(struct regulator_dev *rdev)
  98 {
  99         struct max1586_data *max1586 = rdev_get_drvdata(rdev);
 100
 101         return max1586->v6_curr_sel;
 102 }
 103
 104 static int max1586_v6_set_voltage_sel(struct regulator_dev *rdev,
 105                                       unsigned int selector)
 106 {
 107         struct max1586_data *max1586 = rdev_get_drvdata(rdev);
 108         struct i2c_client *client = max1586->client;
 109         u8 v6_prog;
 110         int ret;
 111
 112         dev_dbg(&client->dev, "changing voltage v6 to %dmv\n",
 113                 rdev->desc->volt_table[selector] / 1000);
 114
 115         v6_prog = I2C_V6_SELECT | (u8) selector;
 116         ret = i2c_smbus_write_byte(client, v6_prog);
 117         if (ret)
 118                 return ret;
 119
 120         max1586->v6_curr_sel = selector;
 121
 122         return 0;
 123 }
 124
 125 /*
 126  * The Maxim 1586 controls V3 and V6 voltages, but offers no way of reading back
 127  * the set up value.
 128  */
 129 static struct regulator_ops max1586_v3_ops = {
 130         .get_voltage_sel = max1586_v3_get_voltage_sel,
 131         .set_voltage_sel = max1586_v3_set_voltage_sel,
 132         .list_voltage = regulator_list_voltage_linear,
 133         .map_voltage = regulator_map_voltage_linear,
 134 };
 135
 136 static struct regulator_ops max1586_v6_ops = {
 137         .get_voltage_sel = max1586_v6_get_voltage_sel,
 138         .set_voltage_sel = max1586_v6_set_voltage_sel,
 139         .list_voltage = regulator_list_voltage_table,
 140 };
 141
 142 static struct regulator_desc max1586_reg[] = {
 143         {
 144                 .name = "Output_V3",
 145                 .id = MAX1586_V3,
 146                 .ops = &max1586_v3_ops,
 147                 .type = REGULATOR_VOLTAGE,
 148                 .n_voltages = MAX1586_V3_MAX_VSEL + 1,
 149                 .owner = THIS_MODULE,
 150         },
 151         {
 152                 .name = "Output_V6",
 153                 .id = MAX1586_V6,
 154                 .ops = &max1586_v6_ops,
 155                 .type = REGULATOR_VOLTAGE,
 156                 .n_voltages = MAX1586_V6_MAX_VSEL + 1,
 157                 .volt_table = v6_voltages_uv,
 158                 .owner = THIS_MODULE,
 159         },
 160 };
 161
 162 static int max1586_pmic_probe(struct i2c_client *client,
 163                                         const struct i2c_device_id *i2c_id)
 164 {
 165         struct regulator_dev **rdev;
 166         struct max1586_platform_data *pdata = dev_get_platdata(&client->dev);
 167         struct regulator_config config = { };
 168         struct max1586_data *max1586;
 169         int i, id, ret = -ENOMEM;
 170
 171         max1586 = devm_kzalloc(&client->dev, sizeof(struct max1586_data) +
 172                         sizeof(struct regulator_dev *) * (MAX1586_V6 + 1),
 173                         GFP_KERNEL);
 174         if (!max1586)
 175                 return -ENOMEM;
 176
 177         max1586->client = client;
 178
 179         if (!pdata->v3_gain)
 180                 return -EINVAL;
 181
 182         max1586->min_uV = MAX1586_V3_MIN_UV / 1000 * pdata->v3_gain / 1000;
 183         max1586->max_uV = MAX1586_V3_MAX_UV / 1000 * pdata->v3_gain / 1000;
 184
 185         /* Set curr_sel to default voltage on power-up */
 186         max1586->v3_curr_sel = 24; /* 1.3V */
 187         max1586->v6_curr_sel = 0;
 188
 189         rdev = max1586->rdev;
 190         for (i = 0; i < pdata->num_subdevs && i <= MAX1586_V6; i++) {
 191                 id = pdata->subdevs[i].id;
 192                 if (!pdata->subdevs[i].platform_data)
 193                         continue;
 194                 if (id < MAX1586_V3 || id > MAX1586_V6) {
 195                         dev_err(&client->dev, "invalid regulator id %d\n", id);
 196                         goto err;
 197                 }
 198
 199                 if (id == MAX1586_V3) {
 200                         max1586_reg[id].min_uV = max1586->min_uV;
 201                         max1586_reg[id].uV_step =
 202                                         (max1586->max_uV - max1586->min_uV) /
 203                                         MAX1586_V3_MAX_VSEL;
 204                 }
 205
 206                 config.dev = &client->dev;
 207                 config.init_data = pdata->subdevs[i].platform_data;
 208                 config.driver_data = max1586;
 209
 210                 rdev[i] = regulator_register(&max1586_reg[id], &config);
 211                 if (IS_ERR(rdev[i])) {
 212                         ret = PTR_ERR(rdev[i]);
 213                         dev_err(&client->dev, "failed to register %s\n",
 214                                 max1586_reg[id].name);
 215                         goto err;
 216                 }
 217         }
 218
 219         i2c_set_clientdata(client, max1586);
 220         dev_info(&client->dev, "Maxim 1586 regulator driver loaded\n");
 221         return 0;
 222
 223 err:
 224         while (--i >= 0)
 225                 regulator_unregister(rdev[i]);
 226         return ret;
 227 }
 228
 229 static int max1586_pmic_remove(struct i2c_client *client)
 230 {
 231         struct max1586_data *max1586 = i2c_get_clientdata(client);
 232         int i;
 233
 234         for (i = 0; i <= MAX1586_V6; i++)
 235                 regulator_unregister(max1586->rdev[i]);
 236         return 0;
 237 }
 238
 239 static const struct i2c_device_id max1586_id[] = {
 240         { "max1586", 0 },
 241         { }
 242 };
 243 MODULE_DEVICE_TABLE(i2c, max1586_id);
 244
 245 static struct i2c_driver max1586_pmic_driver = {
 246         .probe = max1586_pmic_probe,
 247         .remove = max1586_pmic_remove,
 248         .driver         = {
 249                 .name   = "max1586",
 250                 .owner  = THIS_MODULE,
 251         },
 252         .id_table       = max1586_id,
 253 };
 254
 255 static int __init max1586_pmic_init(void)
 256 {
 257         return i2c_add_driver(&max1586_pmic_driver);
 258 }
 259 subsys_initcall(max1586_pmic_init);
 260
 261 static void __exit max1586_pmic_exit(void)
 262 {
 263         i2c_del_driver(&max1586_pmic_driver);
 264 }
 265 module_exit(max1586_pmic_exit);
 266
 267 /* Module information */
 268 MODULE_DESCRIPTION("MAXIM 1586 voltage regulator driver");
 269 MODULE_AUTHOR("Robert Jarzmik");
 270 MODULE_LICENSE("GPL");