linux/drivers/regulator/max1586.c
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   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
  40struct 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 */
  56static 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 */
  66static 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
  80static 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 */
  97static 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
 103static struct regulator_ops max1586_v6_ops = {
 104        .set_voltage_sel = max1586_v6_set_voltage_sel,
 105        .list_voltage = regulator_list_voltage_table,
 106};
 107
 108static 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
 128static 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
 185err:
 186        while (--i >= 0)
 187                regulator_unregister(rdev[i]);
 188        return ret;
 189}
 190
 191static 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
 202static const struct i2c_device_id max1586_id[] = {
 203        { "max1586", 0 },
 204        { }
 205};
 206MODULE_DEVICE_TABLE(i2c, max1586_id);
 207
 208static 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
 218static int __init max1586_pmic_init(void)
 219{
 220        return i2c_add_driver(&max1586_pmic_driver);
 221}
 222subsys_initcall(max1586_pmic_init);
 223
 224static void __exit max1586_pmic_exit(void)
 225{
 226        i2c_del_driver(&max1586_pmic_driver);
 227}
 228module_exit(max1586_pmic_exit);
 229
 230/* Module information */
 231MODULE_DESCRIPTION("MAXIM 1586 voltage regulator driver");
 232MODULE_AUTHOR("Robert Jarzmik");
 233MODULE_LICENSE("GPL");
 234
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