fan53555.c

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/*
 * FAN53555 Fairchild Digitally Programmable TinyBuck Regulator Driver.
 *
 * Supported Part Numbers:
 * FAN53555UC00X/01X/03X/04X/05X
 *
 * Copyright (c) 2012 Marvell Technology Ltd.
 * Yunfan Zhang <[email protected]>
 *
 * This package 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/module.h>
#include <linux/param.h>
#include <linux/err.h>
#include <linux/platform_device.h>
#include <linux/regulator/driver.h>
#include <linux/regulator/machine.h>
#include <linux/i2c.h>
#include <linux/slab.h>
#include <linux/regmap.h>
#include <linux/regulator/fan53555.h>

/* Voltage setting */
#define FAN53555_VSEL0      0x00
#define FAN53555_VSEL1      0x01
/* Control register */
#define FAN53555_CONTROL    0x02
/* IC Type */
#define FAN53555_ID1        0x03
/* IC mask version */
#define FAN53555_ID2        0x04
/* Monitor register */
#define FAN53555_MONITOR    0x05

/* VSEL bit definitions */
#define VSEL_BUCK_EN    (1 << 7)
#define VSEL_MODE       (1 << 6)
#define VSEL_NSEL_MASK  0x3F
/* Chip ID and Verison */
#define DIE_ID      0x0F    /* ID1 */
#define DIE_REV     0x0F    /* ID2 */
/* Control bit definitions */
#define CTL_OUTPUT_DISCHG   (1 << 7)
#define CTL_SLEW_MASK       (0x7 << 4)
#define CTL_SLEW_SHIFT      4
#define CTL_RESET           (1 << 2)

#define FAN53555_NVOLTAGES  64  /* Numbers of voltages */

/* IC Type */
enum {
    FAN53555_CHIP_ID_00 = 0,
    FAN53555_CHIP_ID_01,
    FAN53555_CHIP_ID_02,
    FAN53555_CHIP_ID_03,
    FAN53555_CHIP_ID_04,
    FAN53555_CHIP_ID_05,
};

struct fan53555_device_info {
    struct regmap *regmap;
    struct device *dev;
    struct regulator_desc desc;
    struct regulator_dev *rdev;
    struct regulator_init_data *regulator;
    /* IC Type and Rev */
    int chip_id;
    int chip_rev;
    /* Voltage setting register */
    unsigned int vol_reg;
    unsigned int sleep_reg;
    /* Voltage range and step(linear) */
    unsigned int vsel_min;
    unsigned int vsel_step;
    /* Voltage slew rate limiting */
    unsigned int slew_rate;
    /* Sleep voltage cache */
    unsigned int sleep_vol_cache;
};

static int fan53555_set_suspend_voltage(struct regulator_dev *rdev, int uV)
{
    struct fan53555_device_info *di = rdev_get_drvdata(rdev);
    int ret;

    if (di->sleep_vol_cache == uV)
        return 0;
    ret = regulator_map_voltage_linear(rdev, uV, uV);
    if (ret < 0)
        return -EINVAL;
    ret = regmap_update_bits(di->regmap, di->sleep_reg,
                    VSEL_NSEL_MASK, ret);
    if (ret < 0)
        return -EINVAL;
    /* Cache the sleep voltage setting.
     * Might not be the real voltage which is rounded */
    di->sleep_vol_cache = uV;

    return 0;
}

static int fan53555_set_mode(struct regulator_dev *rdev, unsigned int mode)
{
    struct fan53555_device_info *di = rdev_get_drvdata(rdev);

    switch (mode) {
    case REGULATOR_MODE_FAST:
        regmap_update_bits(di->regmap, di->vol_reg,
                VSEL_MODE, VSEL_MODE);
        break;
    case REGULATOR_MODE_NORMAL:
        regmap_update_bits(di->regmap, di->vol_reg, VSEL_MODE, 0);
        break;
    default:
        return -EINVAL;
    }
    return 0;
}

static unsigned int fan53555_get_mode(struct regulator_dev *rdev)
{
    struct fan53555_device_info *di = rdev_get_drvdata(rdev);
    unsigned int val;
    int ret = 0;

    ret = regmap_read(di->regmap, di->vol_reg, &val);
    if (ret < 0)
        return ret;
    if (val & VSEL_MODE)
        return REGULATOR_MODE_FAST;
    else
        return REGULATOR_MODE_NORMAL;
}

static struct regulator_ops fan53555_regulator_ops = {
    .set_voltage_sel = regulator_set_voltage_sel_regmap,
    .get_voltage_sel = regulator_get_voltage_sel_regmap,
    .map_voltage = regulator_map_voltage_linear,
    .list_voltage = regulator_list_voltage_linear,
    .set_suspend_voltage = fan53555_set_suspend_voltage,
    .enable = regulator_enable_regmap,
    .disable = regulator_disable_regmap,
    .is_enabled = regulator_is_enabled_regmap,
    .set_mode = fan53555_set_mode,
    .get_mode = fan53555_get_mode,
};

/* For 00,01,03,05 options:
 * VOUT = 0.60V + NSELx * 10mV, from 0.60 to 1.23V.
 * For 04 option:
 * VOUT = 0.603V + NSELx * 12.826mV, from 0.603 to 1.411V.
 * */
static int fan53555_device_setup(struct fan53555_device_info *di,
                struct fan53555_platform_data *pdata)
{
    unsigned int reg, data, mask;

    /* Setup voltage control register */
    switch (pdata->sleep_vsel_id) {
    case FAN53555_VSEL_ID_0:
        di->sleep_reg = FAN53555_VSEL0;
        di->vol_reg = FAN53555_VSEL1;
        break;
    case FAN53555_VSEL_ID_1:
        di->sleep_reg = FAN53555_VSEL1;
        di->vol_reg = FAN53555_VSEL0;
        break;
    default:
        dev_err(di->dev, "Invalid VSEL ID!\n");
        return -EINVAL;
    }
    /* Init voltage range and step */
    switch (di->chip_id) {
    case FAN53555_CHIP_ID_00:
    case FAN53555_CHIP_ID_01:
    case FAN53555_CHIP_ID_03:
    case FAN53555_CHIP_ID_05:
        di->vsel_min = 600000;
        di->vsel_step = 10000;
        break;
    case FAN53555_CHIP_ID_04:
        di->vsel_min = 603000;
        di->vsel_step = 12826;
        break;
    default:
        dev_err(di->dev,
            "Chip ID[%d]\n not supported!\n", di->chip_id);
        return -EINVAL;
    }
    /* Init slew rate */
    if (pdata->slew_rate & 0x7)
        di->slew_rate = pdata->slew_rate;
    else
        di->slew_rate = FAN53555_SLEW_RATE_64MV;
    reg = FAN53555_CONTROL;
    data = di->slew_rate << CTL_SLEW_SHIFT;
    mask = CTL_SLEW_MASK;
    return regmap_update_bits(di->regmap, reg, mask, data);
}

static int fan53555_regulator_register(struct fan53555_device_info *di,
            struct regulator_config *config)
{
    struct regulator_desc *rdesc = &di->desc;

    rdesc->name = "fan53555-reg";
    rdesc->ops = &fan53555_regulator_ops;
    rdesc->type = REGULATOR_VOLTAGE;
    rdesc->n_voltages = FAN53555_NVOLTAGES;
    rdesc->enable_reg = di->vol_reg;
    rdesc->enable_mask = VSEL_BUCK_EN;
    rdesc->min_uV = di->vsel_min;
    rdesc->uV_step = di->vsel_step;
    rdesc->vsel_reg = di->vol_reg;
    rdesc->vsel_mask = VSEL_NSEL_MASK;
    rdesc->owner = THIS_MODULE;

    di->rdev = regulator_register(&di->desc, config);
    if (IS_ERR(di->rdev))
        return PTR_ERR(di->rdev);
    return 0;

}

static struct regmap_config fan53555_regmap_config = {
    .reg_bits = 8,
    .val_bits = 8,
};

static int __devinit fan53555_regulator_probe(struct i2c_client *client,
                const struct i2c_device_id *id)
{
    struct fan53555_device_info *di;
    struct fan53555_platform_data *pdata;
    struct regulator_config config = { };
    unsigned int val;
    int ret;

    pdata = client->dev.platform_data;
    if (!pdata || !pdata->regulator) {
        dev_err(&client->dev, "Platform data not found!\n");
        return -ENODEV;
    }

    di = devm_kzalloc(&client->dev, sizeof(struct fan53555_device_info),
                    GFP_KERNEL);
    if (!di) {
        dev_err(&client->dev, "Failed to allocate device info data!\n");
        return -ENOMEM;
    }
    di->regmap = devm_regmap_init_i2c(client, &fan53555_regmap_config);
    if (IS_ERR(di->regmap)) {
        dev_err(&client->dev, "Failed to allocate regmap!\n");
        return PTR_ERR(di->regmap);
    }
    di->dev = &client->dev;
    di->regulator = pdata->regulator;
    i2c_set_clientdata(client, di);
    /* Get chip ID */
    ret = regmap_read(di->regmap, FAN53555_ID1, &val);
    if (ret < 0) {
        dev_err(&client->dev, "Failed to get chip ID!\n");
        return -ENODEV;
    }
    di->chip_id = val & DIE_ID;
    /* Get chip revision */
    ret = regmap_read(di->regmap, FAN53555_ID2, &val);
    if (ret < 0) {
        dev_err(&client->dev, "Failed to get chip Rev!\n");
        return -ENODEV;
    }
    di->chip_rev = val & DIE_REV;
    dev_info(&client->dev, "FAN53555 Option[%d] Rev[%d] Detected!\n",
                di->chip_id, di->chip_rev);
    /* Device init */
    ret = fan53555_device_setup(di, pdata);
    if (ret < 0) {
        dev_err(&client->dev, "Failed to setup device!\n");
        return ret;
    }
    /* Register regulator */
    config.dev = di->dev;
    config.init_data = di->regulator;
    config.regmap = di->regmap;
    config.driver_data = di;
    ret = fan53555_regulator_register(di, &config);
    if (ret < 0)
        dev_err(&client->dev, "Failed to register regulator!\n");
    return ret;

}

static int __devexit fan53555_regulator_remove(struct i2c_client *client)
{
    struct fan53555_device_info *di = i2c_get_clientdata(client);

    regulator_unregister(di->rdev);
    return 0;
}

static const struct i2c_device_id fan53555_id[] = {
    {"fan53555", -1},
    { },
};

static struct i2c_driver fan53555_regulator_driver = {
    .driver = {
        .name = "fan53555-regulator",
    },
    .probe = fan53555_regulator_probe,
    .remove = __devexit_p(fan53555_regulator_remove),
    .id_table = fan53555_id,
};

module_i2c_driver(fan53555_regulator_driver);

MODULE_AUTHOR("Yunfan Zhang <[email protected]>");
MODULE_DESCRIPTION("FAN53555 regulator driver");
MODULE_LICENSE("GPL v2");