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