isl6271a-regulator.c

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/*
 * isl6271a-regulator.c
 *
 * Support for Intersil ISL6271A voltage regulator
 *
 * Copyright (C) 2010 Marek Vasut <[email protected]>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation version 2.
 *
 * This program is distributed "as is" WITHOUT ANY WARRANTY of any kind,
 * whether express or implied; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/err.h>
#include <linux/platform_device.h>
#include <linux/regulator/driver.h>
#include <linux/i2c.h>
#include <linux/slab.h>

#define ISL6271A_VOLTAGE_MIN    850000
#define ISL6271A_VOLTAGE_MAX    1600000
#define ISL6271A_VOLTAGE_STEP   50000

/* PMIC details */
struct isl_pmic {
    struct i2c_client   *client;
    struct regulator_dev    *rdev[3];
    struct mutex        mtx;
};

static int isl6271a_get_voltage_sel(struct regulator_dev *dev)
{
    struct isl_pmic *pmic = rdev_get_drvdata(dev);
    int idx;

    mutex_lock(&pmic->mtx);

    idx = i2c_smbus_read_byte(pmic->client);
    if (idx < 0)
        dev_err(&pmic->client->dev, "Error getting voltage\n");

    mutex_unlock(&pmic->mtx);
    return idx;
}

static int isl6271a_set_voltage_sel(struct regulator_dev *dev,
                    unsigned selector)
{
    struct isl_pmic *pmic = rdev_get_drvdata(dev);
    int err;

    mutex_lock(&pmic->mtx);

    err = i2c_smbus_write_byte(pmic->client, selector);
    if (err < 0)
        dev_err(&pmic->client->dev, "Error setting voltage\n");

    mutex_unlock(&pmic->mtx);
    return err;
}

static struct regulator_ops isl_core_ops = {
    .get_voltage_sel = isl6271a_get_voltage_sel,
    .set_voltage_sel = isl6271a_set_voltage_sel,
    .list_voltage   = regulator_list_voltage_linear,
    .map_voltage    = regulator_map_voltage_linear,
};

static struct regulator_ops isl_fixed_ops = {
    .list_voltage   = regulator_list_voltage_linear,
};

static const struct regulator_desc isl_rd[] = {
    {
        .name       = "Core Buck",
        .id     = 0,
        .n_voltages = 16,
        .ops        = &isl_core_ops,
        .type       = REGULATOR_VOLTAGE,
        .owner      = THIS_MODULE,
        .min_uV     = ISL6271A_VOLTAGE_MIN,
        .uV_step    = ISL6271A_VOLTAGE_STEP,
    }, {
        .name       = "LDO1",
        .id     = 1,
        .n_voltages = 1,
        .ops        = &isl_fixed_ops,
        .type       = REGULATOR_VOLTAGE,
        .owner      = THIS_MODULE,
        .min_uV     = 1100000,
    }, {
        .name       = "LDO2",
        .id     = 2,
        .n_voltages = 1,
        .ops        = &isl_fixed_ops,
        .type       = REGULATOR_VOLTAGE,
        .owner      = THIS_MODULE,
        .min_uV     = 1300000,
    },
};

static int __devinit isl6271a_probe(struct i2c_client *i2c,
                     const struct i2c_device_id *id)
{
    struct regulator_config config = { };
    struct regulator_init_data *init_data   = i2c->dev.platform_data;
    struct isl_pmic *pmic;
    int err, i;

    if (!i2c_check_functionality(i2c->adapter, I2C_FUNC_SMBUS_BYTE_DATA))
        return -EIO;

    pmic = devm_kzalloc(&i2c->dev, sizeof(struct isl_pmic), GFP_KERNEL);
    if (!pmic)
        return -ENOMEM;

    pmic->client = i2c;

    mutex_init(&pmic->mtx);

    for (i = 0; i < 3; i++) {
        config.dev = &i2c->dev;
        if (i == 0)
            config.init_data = init_data;
        else
            config.init_data = 0;
        config.driver_data = pmic;

        pmic->rdev[i] = regulator_register(&isl_rd[i], &config);
        if (IS_ERR(pmic->rdev[i])) {
            dev_err(&i2c->dev, "failed to register %s\n", id->name);
            err = PTR_ERR(pmic->rdev[i]);
            goto error;
        }
    }

    i2c_set_clientdata(i2c, pmic);

    return 0;

error:
    while (--i >= 0)
        regulator_unregister(pmic->rdev[i]);
    return err;
}

static int __devexit isl6271a_remove(struct i2c_client *i2c)
{
    struct isl_pmic *pmic = i2c_get_clientdata(i2c);
    int i;

    for (i = 0; i < 3; i++)
        regulator_unregister(pmic->rdev[i]);
    return 0;
}

static const struct i2c_device_id isl6271a_id[] = {
    {.name = "isl6271a", 0 },
    { },
};

MODULE_DEVICE_TABLE(i2c, isl6271a_id);

static struct i2c_driver isl6271a_i2c_driver = {
    .driver = {
        .name = "isl6271a",
        .owner = THIS_MODULE,
    },
    .probe = isl6271a_probe,
    .remove = __devexit_p(isl6271a_remove),
    .id_table = isl6271a_id,
};

static int __init isl6271a_init(void)
{
    return i2c_add_driver(&isl6271a_i2c_driver);
}

static void __exit isl6271a_cleanup(void)
{
    i2c_del_driver(&isl6271a_i2c_driver);
}

subsys_initcall(isl6271a_init);
module_exit(isl6271a_cleanup);

MODULE_AUTHOR("Marek Vasut <[email protected]>");
MODULE_DESCRIPTION("Intersil ISL6271A voltage regulator driver");
MODULE_LICENSE("GPL v2");