lp3971.c

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/*
 * Regulator driver for National Semiconductors LP3971 PMIC chip
 *
 *  Copyright (C) 2009 Samsung Electronics
 *  Author: Marek Szyprowski <[email protected]>
 *
 * Based on wm8350.c
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 */

#include <linux/bug.h>
#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/regulator/driver.h>
#include <linux/regulator/lp3971.h>
#include <linux/slab.h>

struct lp3971 {
    struct device *dev;
    struct mutex io_lock;
    struct i2c_client *i2c;
    int num_regulators;
    struct regulator_dev **rdev;
};

static u8 lp3971_reg_read(struct lp3971 *lp3971, u8 reg);
static int lp3971_set_bits(struct lp3971 *lp3971, u8 reg, u16 mask, u16 val);

#define LP3971_SYS_CONTROL1_REG 0x07

/* System control register 1 initial value,
   bits 4 and 5 are EPROM programmable */
#define SYS_CONTROL1_INIT_VAL 0x40
#define SYS_CONTROL1_INIT_MASK 0xCF

#define LP3971_BUCK_VOL_ENABLE_REG 0x10
#define LP3971_BUCK_VOL_CHANGE_REG 0x20

/*  Voltage control registers shift:
    LP3971_BUCK1 -> 0
    LP3971_BUCK2 -> 4
    LP3971_BUCK3 -> 6
*/
#define BUCK_VOL_CHANGE_SHIFT(x) (((!!x) << 2) | (x & ~0x01))
#define BUCK_VOL_CHANGE_FLAG_GO 0x01
#define BUCK_VOL_CHANGE_FLAG_TARGET 0x02
#define BUCK_VOL_CHANGE_FLAG_MASK 0x03

#define LP3971_BUCK1_BASE 0x23
#define LP3971_BUCK2_BASE 0x29
#define LP3971_BUCK3_BASE 0x32

static const int buck_base_addr[] = {
    LP3971_BUCK1_BASE,
    LP3971_BUCK2_BASE,
    LP3971_BUCK3_BASE,
};

#define LP3971_BUCK_TARGET_VOL1_REG(x) (buck_base_addr[x])
#define LP3971_BUCK_TARGET_VOL2_REG(x) (buck_base_addr[x]+1)

static const unsigned int buck_voltage_map[] = {
          0,  800000,  850000,  900000,  950000, 1000000, 1050000, 1100000,
    1150000, 1200000, 1250000, 1300000, 1350000, 1400000, 1450000, 1500000,
    1550000, 1600000, 1650000, 1700000, 1800000, 1900000, 2500000, 2800000,
    3000000, 3300000,
};

#define BUCK_TARGET_VOL_MASK 0x3f
#define BUCK_TARGET_VOL_MIN_IDX 0x01
#define BUCK_TARGET_VOL_MAX_IDX 0x19

#define LP3971_BUCK_RAMP_REG(x) (buck_base_addr[x]+2)

#define LP3971_LDO_ENABLE_REG 0x12
#define LP3971_LDO_VOL_CONTR_BASE 0x39

/*  Voltage control registers:
    LP3971_LDO1 -> LP3971_LDO_VOL_CONTR_BASE + 0
    LP3971_LDO2 -> LP3971_LDO_VOL_CONTR_BASE + 0
    LP3971_LDO3 -> LP3971_LDO_VOL_CONTR_BASE + 1
    LP3971_LDO4 -> LP3971_LDO_VOL_CONTR_BASE + 1
    LP3971_LDO5 -> LP3971_LDO_VOL_CONTR_BASE + 2
*/
#define LP3971_LDO_VOL_CONTR_REG(x) (LP3971_LDO_VOL_CONTR_BASE + (x >> 1))

/*  Voltage control registers shift:
    LP3971_LDO1 -> 0, LP3971_LDO2 -> 4
    LP3971_LDO3 -> 0, LP3971_LDO4 -> 4
    LP3971_LDO5 -> 0
*/
#define LDO_VOL_CONTR_SHIFT(x) ((x & 1) << 2)
#define LDO_VOL_CONTR_MASK 0x0f

static const unsigned int ldo45_voltage_map[] = {
    1000000, 1050000, 1100000, 1150000, 1200000, 1250000, 1300000, 1350000,
    1400000, 1500000, 1800000, 1900000, 2500000, 2800000, 3000000, 3300000,
};

static const unsigned int ldo123_voltage_map[] = {
    1800000, 1900000, 2000000, 2100000, 2200000, 2300000, 2400000, 2500000,
    2600000, 2700000, 2800000, 2900000, 3000000, 3100000, 3200000, 3300000,
};

#define LDO_VOL_MIN_IDX 0x00
#define LDO_VOL_MAX_IDX 0x0f

static int lp3971_ldo_is_enabled(struct regulator_dev *dev)
{
    struct lp3971 *lp3971 = rdev_get_drvdata(dev);
    int ldo = rdev_get_id(dev) - LP3971_LDO1;
    u16 mask = 1 << (1 + ldo);
    u16 val;

    val = lp3971_reg_read(lp3971, LP3971_LDO_ENABLE_REG);
    return (val & mask) != 0;
}

static int lp3971_ldo_enable(struct regulator_dev *dev)
{
    struct lp3971 *lp3971 = rdev_get_drvdata(dev);
    int ldo = rdev_get_id(dev) - LP3971_LDO1;
    u16 mask = 1 << (1 + ldo);

    return lp3971_set_bits(lp3971, LP3971_LDO_ENABLE_REG, mask, mask);
}

static int lp3971_ldo_disable(struct regulator_dev *dev)
{
    struct lp3971 *lp3971 = rdev_get_drvdata(dev);
    int ldo = rdev_get_id(dev) - LP3971_LDO1;
    u16 mask = 1 << (1 + ldo);

    return lp3971_set_bits(lp3971, LP3971_LDO_ENABLE_REG, mask, 0);
}

static int lp3971_ldo_get_voltage(struct regulator_dev *dev)
{
    struct lp3971 *lp3971 = rdev_get_drvdata(dev);
    int ldo = rdev_get_id(dev) - LP3971_LDO1;
    u16 val, reg;

    reg = lp3971_reg_read(lp3971, LP3971_LDO_VOL_CONTR_REG(ldo));
    val = (reg >> LDO_VOL_CONTR_SHIFT(ldo)) & LDO_VOL_CONTR_MASK;

    return dev->desc->volt_table[val];
}

static int lp3971_ldo_set_voltage_sel(struct regulator_dev *dev,
                      unsigned int selector)
{
    struct lp3971 *lp3971 = rdev_get_drvdata(dev);
    int ldo = rdev_get_id(dev) - LP3971_LDO1;

    return lp3971_set_bits(lp3971, LP3971_LDO_VOL_CONTR_REG(ldo),
            LDO_VOL_CONTR_MASK << LDO_VOL_CONTR_SHIFT(ldo),
            selector << LDO_VOL_CONTR_SHIFT(ldo));
}

static struct regulator_ops lp3971_ldo_ops = {
    .list_voltage = regulator_list_voltage_table,
    .is_enabled = lp3971_ldo_is_enabled,
    .enable = lp3971_ldo_enable,
    .disable = lp3971_ldo_disable,
    .get_voltage = lp3971_ldo_get_voltage,
    .set_voltage_sel = lp3971_ldo_set_voltage_sel,
};

static int lp3971_dcdc_is_enabled(struct regulator_dev *dev)
{
    struct lp3971 *lp3971 = rdev_get_drvdata(dev);
    int buck = rdev_get_id(dev) - LP3971_DCDC1;
    u16 mask = 1 << (buck * 2);
    u16 val;

    val = lp3971_reg_read(lp3971, LP3971_BUCK_VOL_ENABLE_REG);
    return (val & mask) != 0;
}

static int lp3971_dcdc_enable(struct regulator_dev *dev)
{
    struct lp3971 *lp3971 = rdev_get_drvdata(dev);
    int buck = rdev_get_id(dev) - LP3971_DCDC1;
    u16 mask = 1 << (buck * 2);

    return lp3971_set_bits(lp3971, LP3971_BUCK_VOL_ENABLE_REG, mask, mask);
}

static int lp3971_dcdc_disable(struct regulator_dev *dev)
{
    struct lp3971 *lp3971 = rdev_get_drvdata(dev);
    int buck = rdev_get_id(dev) - LP3971_DCDC1;
    u16 mask = 1 << (buck * 2);

    return lp3971_set_bits(lp3971, LP3971_BUCK_VOL_ENABLE_REG, mask, 0);
}

static int lp3971_dcdc_get_voltage(struct regulator_dev *dev)
{
    struct lp3971 *lp3971 = rdev_get_drvdata(dev);
    int buck = rdev_get_id(dev) - LP3971_DCDC1;
    u16 reg;
    int val;

    reg = lp3971_reg_read(lp3971, LP3971_BUCK_TARGET_VOL1_REG(buck));
    reg &= BUCK_TARGET_VOL_MASK;

    if (reg <= BUCK_TARGET_VOL_MAX_IDX)
        val = buck_voltage_map[reg];
    else {
        val = 0;
        dev_warn(&dev->dev, "chip reported incorrect voltage value.\n");
    }

    return val;
}

static int lp3971_dcdc_set_voltage_sel(struct regulator_dev *dev,
                       unsigned int selector)
{
    struct lp3971 *lp3971 = rdev_get_drvdata(dev);
    int buck = rdev_get_id(dev) - LP3971_DCDC1;
    int ret;

    ret = lp3971_set_bits(lp3971, LP3971_BUCK_TARGET_VOL1_REG(buck),
           BUCK_TARGET_VOL_MASK, selector);
    if (ret)
        return ret;

    ret = lp3971_set_bits(lp3971, LP3971_BUCK_VOL_CHANGE_REG,
           BUCK_VOL_CHANGE_FLAG_MASK << BUCK_VOL_CHANGE_SHIFT(buck),
           BUCK_VOL_CHANGE_FLAG_GO << BUCK_VOL_CHANGE_SHIFT(buck));
    if (ret)
        return ret;

    return lp3971_set_bits(lp3971, LP3971_BUCK_VOL_CHANGE_REG,
           BUCK_VOL_CHANGE_FLAG_MASK << BUCK_VOL_CHANGE_SHIFT(buck),
           0 << BUCK_VOL_CHANGE_SHIFT(buck));
}

static struct regulator_ops lp3971_dcdc_ops = {
    .list_voltage = regulator_list_voltage_table,
    .is_enabled = lp3971_dcdc_is_enabled,
    .enable = lp3971_dcdc_enable,
    .disable = lp3971_dcdc_disable,
    .get_voltage = lp3971_dcdc_get_voltage,
    .set_voltage_sel = lp3971_dcdc_set_voltage_sel,
};

static const struct regulator_desc regulators[] = {
    {
        .name = "LDO1",
        .id = LP3971_LDO1,
        .ops = &lp3971_ldo_ops,
        .n_voltages = ARRAY_SIZE(ldo123_voltage_map),
        .volt_table = ldo123_voltage_map,
        .type = REGULATOR_VOLTAGE,
        .owner = THIS_MODULE,
    },
    {
        .name = "LDO2",
        .id = LP3971_LDO2,
        .ops = &lp3971_ldo_ops,
        .n_voltages = ARRAY_SIZE(ldo123_voltage_map),
        .volt_table = ldo123_voltage_map,
        .type = REGULATOR_VOLTAGE,
        .owner = THIS_MODULE,
    },
    {
        .name = "LDO3",
        .id = LP3971_LDO3,
        .ops = &lp3971_ldo_ops,
        .n_voltages = ARRAY_SIZE(ldo123_voltage_map),
        .volt_table = ldo123_voltage_map,
        .type = REGULATOR_VOLTAGE,
        .owner = THIS_MODULE,
    },
    {
        .name = "LDO4",
        .id = LP3971_LDO4,
        .ops = &lp3971_ldo_ops,
        .n_voltages = ARRAY_SIZE(ldo45_voltage_map),
        .volt_table = ldo45_voltage_map,
        .type = REGULATOR_VOLTAGE,
        .owner = THIS_MODULE,
    },
    {
        .name = "LDO5",
        .id = LP3971_LDO5,
        .ops = &lp3971_ldo_ops,
        .n_voltages = ARRAY_SIZE(ldo45_voltage_map),
        .volt_table = ldo45_voltage_map,
        .type = REGULATOR_VOLTAGE,
        .owner = THIS_MODULE,
    },
    {
        .name = "DCDC1",
        .id = LP3971_DCDC1,
        .ops = &lp3971_dcdc_ops,
        .n_voltages = ARRAY_SIZE(buck_voltage_map),
        .volt_table = buck_voltage_map,
        .type = REGULATOR_VOLTAGE,
        .owner = THIS_MODULE,
    },
    {
        .name = "DCDC2",
        .id = LP3971_DCDC2,
        .ops = &lp3971_dcdc_ops,
        .n_voltages = ARRAY_SIZE(buck_voltage_map),
        .volt_table = buck_voltage_map,
        .type = REGULATOR_VOLTAGE,
        .owner = THIS_MODULE,
    },
    {
        .name = "DCDC3",
        .id = LP3971_DCDC3,
        .ops = &lp3971_dcdc_ops,
        .n_voltages = ARRAY_SIZE(buck_voltage_map),
        .volt_table = buck_voltage_map,
        .type = REGULATOR_VOLTAGE,
        .owner = THIS_MODULE,
    },
};

static int lp3971_i2c_read(struct i2c_client *i2c, char reg, int count,
    u16 *dest)
{
    int ret;

    if (count != 1)
        return -EIO;
    ret = i2c_smbus_read_byte_data(i2c, reg);
    if (ret < 0)
        return -EIO;

    *dest = ret;
    return 0;
}

static int lp3971_i2c_write(struct i2c_client *i2c, char reg, int count,
    const u16 *src)
{
    if (count != 1)
        return -EIO;
    return i2c_smbus_write_byte_data(i2c, reg, *src);
}

static u8 lp3971_reg_read(struct lp3971 *lp3971, u8 reg)
{
    u16 val = 0;

    mutex_lock(&lp3971->io_lock);

    lp3971_i2c_read(lp3971->i2c, reg, 1, &val);

    dev_dbg(lp3971->dev, "reg read 0x%02x -> 0x%02x\n", (int)reg,
        (unsigned)val&0xff);

    mutex_unlock(&lp3971->io_lock);

    return val & 0xff;
}

static int lp3971_set_bits(struct lp3971 *lp3971, u8 reg, u16 mask, u16 val)
{
    u16 tmp;
    int ret;

    mutex_lock(&lp3971->io_lock);

    ret = lp3971_i2c_read(lp3971->i2c, reg, 1, &tmp);
    tmp = (tmp & ~mask) | val;
    if (ret == 0) {
        ret = lp3971_i2c_write(lp3971->i2c, reg, 1, &tmp);
        dev_dbg(lp3971->dev, "reg write 0x%02x -> 0x%02x\n", (int)reg,
            (unsigned)val&0xff);
    }
    mutex_unlock(&lp3971->io_lock);

    return ret;
}

static int __devinit setup_regulators(struct lp3971 *lp3971,
                      struct lp3971_platform_data *pdata)
{
    int i, err;

    lp3971->num_regulators = pdata->num_regulators;
    lp3971->rdev = kcalloc(pdata->num_regulators,
                sizeof(struct regulator_dev *), GFP_KERNEL);
    if (!lp3971->rdev) {
        err = -ENOMEM;
        goto err_nomem;
    }

    /* Instantiate the regulators */
    for (i = 0; i < pdata->num_regulators; i++) {
        struct regulator_config config = { };
        struct lp3971_regulator_subdev *reg = &pdata->regulators[i];

        config.dev = lp3971->dev;
        config.init_data = reg->initdata;
        config.driver_data = lp3971;

        lp3971->rdev[i] = regulator_register(&regulators[reg->id],
                             &config);
        if (IS_ERR(lp3971->rdev[i])) {
            err = PTR_ERR(lp3971->rdev[i]);
            dev_err(lp3971->dev, "regulator init failed: %d\n",
                err);
            goto error;
        }
    }

    return 0;

error:
    while (--i >= 0)
        regulator_unregister(lp3971->rdev[i]);
    kfree(lp3971->rdev);
    lp3971->rdev = NULL;
err_nomem:
    return err;
}

static int __devinit lp3971_i2c_probe(struct i2c_client *i2c,
                const struct i2c_device_id *id)
{
    struct lp3971 *lp3971;
    struct lp3971_platform_data *pdata = i2c->dev.platform_data;
    int ret;
    u16 val;

    if (!pdata) {
        dev_dbg(&i2c->dev, "No platform init data supplied\n");
        return -ENODEV;
    }

    lp3971 = kzalloc(sizeof(struct lp3971), GFP_KERNEL);
    if (lp3971 == NULL)
        return -ENOMEM;

    lp3971->i2c = i2c;
    lp3971->dev = &i2c->dev;

    mutex_init(&lp3971->io_lock);

    /* Detect LP3971 */
    ret = lp3971_i2c_read(i2c, LP3971_SYS_CONTROL1_REG, 1, &val);
    if (ret == 0 && (val & SYS_CONTROL1_INIT_MASK) != SYS_CONTROL1_INIT_VAL)
        ret = -ENODEV;
    if (ret < 0) {
        dev_err(&i2c->dev, "failed to detect device\n");
        goto err_detect;
    }

    ret = setup_regulators(lp3971, pdata);
    if (ret < 0)
        goto err_detect;

    i2c_set_clientdata(i2c, lp3971);
    return 0;

err_detect:
    kfree(lp3971);
    return ret;
}

static int __devexit lp3971_i2c_remove(struct i2c_client *i2c)
{
    struct lp3971 *lp3971 = i2c_get_clientdata(i2c);
    int i;

    for (i = 0; i < lp3971->num_regulators; i++)
        regulator_unregister(lp3971->rdev[i]);

    kfree(lp3971->rdev);
    kfree(lp3971);

    return 0;
}

static const struct i2c_device_id lp3971_i2c_id[] = {
       { "lp3971", 0 },
       { }
};
MODULE_DEVICE_TABLE(i2c, lp3971_i2c_id);

static struct i2c_driver lp3971_i2c_driver = {
    .driver = {
        .name = "LP3971",
        .owner = THIS_MODULE,
    },
    .probe    = lp3971_i2c_probe,
    .remove   = __devexit_p(lp3971_i2c_remove),
    .id_table = lp3971_i2c_id,
};

module_i2c_driver(lp3971_i2c_driver);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Marek Szyprowski <[email protected]>");
MODULE_DESCRIPTION("LP3971 PMIC driver");