root/drivers/regulator/max8998.c
// SPDX-License-Identifier: GPL-2.0+
//
// max8998.c - Voltage regulator driver for the Maxim 8998
//
//  Copyright (C) 2009-2010 Samsung Electronics
//  Kyungmin Park <kyungmin.park@samsung.com>
//  Marek Szyprowski <m.szyprowski@samsung.com>

#include <linux/module.h>
#include <linux/init.h>
#include <linux/i2c.h>
#include <linux/err.h>
#include <linux/bits.h>
#include <linux/gpio/consumer.h>
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/mutex.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/regulator/driver.h>
#include <linux/regulator/of_regulator.h>
#include <linux/mfd/max8998.h>
#include <linux/mfd/max8998-private.h>

struct max8998_data {
        struct device           *dev;
        struct max8998_dev      *iodev;
        int                     num_regulators;
        u8                      buck1_vol[4]; /* voltages for selection */
        u8                      buck2_vol[2];
        unsigned int            buck1_idx; /* index to last changed voltage */
                                           /* value in a set */
        unsigned int            buck2_idx;
        struct gpio_desc        *buck1_gpio1;
        struct gpio_desc        *buck1_gpio2;
        struct gpio_desc        *buck2_gpio;
};

static const unsigned int charger_current_table[] = {
        90000, 380000, 475000, 550000, 570000, 600000, 700000, 800000,
};

static int max8998_get_enable_register(struct regulator_dev *rdev,
                                        int *reg, int *shift)
{
        int ldo = rdev_get_id(rdev);

        switch (ldo) {
        case MAX8998_LDO2 ... MAX8998_LDO5:
                *reg = MAX8998_REG_ONOFF1;
                *shift = 3 - (ldo - MAX8998_LDO2);
                break;
        case MAX8998_LDO6 ... MAX8998_LDO13:
                *reg = MAX8998_REG_ONOFF2;
                *shift = 7 - (ldo - MAX8998_LDO6);
                break;
        case MAX8998_LDO14 ... MAX8998_LDO17:
                *reg = MAX8998_REG_ONOFF3;
                *shift = 7 - (ldo - MAX8998_LDO14);
                break;
        case MAX8998_BUCK1 ... MAX8998_BUCK4:
                *reg = MAX8998_REG_ONOFF1;
                *shift = 7 - (ldo - MAX8998_BUCK1);
                break;
        case MAX8998_EN32KHZ_AP ... MAX8998_ENVICHG:
                *reg = MAX8998_REG_ONOFF4;
                *shift = 7 - (ldo - MAX8998_EN32KHZ_AP);
                break;
        case MAX8998_ESAFEOUT1 ... MAX8998_ESAFEOUT2:
                *reg = MAX8998_REG_CHGR2;
                *shift = 7 - (ldo - MAX8998_ESAFEOUT1);
                break;
        case MAX8998_CHARGER:
                *reg = MAX8998_REG_CHGR2;
                *shift = 0;
                break;
        default:
                return -EINVAL;
        }

        return 0;
}

static int max8998_ldo_is_enabled(struct regulator_dev *rdev)
{
        struct max8998_data *max8998 = rdev_get_drvdata(rdev);
        struct i2c_client *i2c = max8998->iodev->i2c;
        int ret, reg, shift = 8;
        u8 val;

        ret = max8998_get_enable_register(rdev, &reg, &shift);
        if (ret)
                return ret;

        ret = max8998_read_reg(i2c, reg, &val);
        if (ret)
                return ret;

        return val & (1 << shift);
}

static int max8998_ldo_is_enabled_inverted(struct regulator_dev *rdev)
{
        return (!max8998_ldo_is_enabled(rdev));
}

static int max8998_ldo_enable(struct regulator_dev *rdev)
{
        struct max8998_data *max8998 = rdev_get_drvdata(rdev);
        struct i2c_client *i2c = max8998->iodev->i2c;
        int reg, shift = 8, ret;

        ret = max8998_get_enable_register(rdev, &reg, &shift);
        if (ret)
                return ret;

        return max8998_update_reg(i2c, reg, 1<<shift, 1<<shift);
}

static int max8998_ldo_disable(struct regulator_dev *rdev)
{
        struct max8998_data *max8998 = rdev_get_drvdata(rdev);
        struct i2c_client *i2c = max8998->iodev->i2c;
        int reg, shift = 8, ret;

        ret = max8998_get_enable_register(rdev, &reg, &shift);
        if (ret)
                return ret;

        return max8998_update_reg(i2c, reg, 0, 1<<shift);
}

static int max8998_get_voltage_register(struct regulator_dev *rdev,
                                int *_reg, int *_shift, int *_mask)
{
        int ldo = rdev_get_id(rdev);
        struct max8998_data *max8998 = rdev_get_drvdata(rdev);
        int reg, shift = 0, mask = 0xff;

        switch (ldo) {
        case MAX8998_LDO2 ... MAX8998_LDO3:
                reg = MAX8998_REG_LDO2_LDO3;
                mask = 0xf;
                if (ldo == MAX8998_LDO2)
                        shift = 4;
                else
                        shift = 0;
                break;
        case MAX8998_LDO4 ... MAX8998_LDO7:
                reg = MAX8998_REG_LDO4 + (ldo - MAX8998_LDO4);
                break;
        case MAX8998_LDO8 ... MAX8998_LDO9:
                reg = MAX8998_REG_LDO8_LDO9;
                mask = 0xf;
                if (ldo == MAX8998_LDO8)
                        shift = 4;
                else
                        shift = 0;
                break;
        case MAX8998_LDO10 ... MAX8998_LDO11:
                reg = MAX8998_REG_LDO10_LDO11;
                if (ldo == MAX8998_LDO10) {
                        shift = 5;
                        mask = 0x7;
                } else {
                        shift = 0;
                        mask = 0x1f;
                }
                break;
        case MAX8998_LDO12 ... MAX8998_LDO17:
                reg = MAX8998_REG_LDO12 + (ldo - MAX8998_LDO12);
                break;
        case MAX8998_BUCK1:
                reg = MAX8998_REG_BUCK1_VOLTAGE1 + max8998->buck1_idx;
                break;
        case MAX8998_BUCK2:
                reg = MAX8998_REG_BUCK2_VOLTAGE1 + max8998->buck2_idx;
                break;
        case MAX8998_BUCK3:
                reg = MAX8998_REG_BUCK3;
                break;
        case MAX8998_BUCK4:
                reg = MAX8998_REG_BUCK4;
                break;
        default:
                return -EINVAL;
        }

        *_reg = reg;
        *_shift = shift;
        *_mask = mask;

        return 0;
}

static int max8998_get_voltage_sel(struct regulator_dev *rdev)
{
        struct max8998_data *max8998 = rdev_get_drvdata(rdev);
        struct i2c_client *i2c = max8998->iodev->i2c;
        int reg, shift = 0, mask, ret;
        u8 val;

        ret = max8998_get_voltage_register(rdev, &reg, &shift, &mask);
        if (ret)
                return ret;

        ret = max8998_read_reg(i2c, reg, &val);
        if (ret)
                return ret;

        val >>= shift;
        val &= mask;

        return val;
}

static int max8998_set_voltage_ldo_sel(struct regulator_dev *rdev,
                                       unsigned selector)
{
        struct max8998_data *max8998 = rdev_get_drvdata(rdev);
        struct i2c_client *i2c = max8998->iodev->i2c;
        int reg, shift = 0, mask, ret;

        ret = max8998_get_voltage_register(rdev, &reg, &shift, &mask);
        if (ret)
                return ret;

        ret = max8998_update_reg(i2c, reg, selector<<shift, mask<<shift);

        return ret;
}

static inline void buck1_gpio_set(struct gpio_desc *gpio1, struct gpio_desc *gpio2, int v)
{
        gpiod_set_value(gpio1, v & 0x1);
        gpiod_set_value(gpio2, (v >> 1) & 0x1);
}

static inline void buck2_gpio_set(struct gpio_desc *gpio, int v)
{
        gpiod_set_value(gpio, v & 0x1);
}

static int max8998_set_voltage_buck_sel(struct regulator_dev *rdev,
                                        unsigned selector)
{
        struct max8998_data *max8998 = rdev_get_drvdata(rdev);
        struct max8998_platform_data *pdata = max8998->iodev->pdata;
        struct i2c_client *i2c = max8998->iodev->i2c;
        int buck = rdev_get_id(rdev);
        int reg, shift = 0, mask, ret, j;
        static u8 buck1_last_val;

        ret = max8998_get_voltage_register(rdev, &reg, &shift, &mask);
        if (ret)
                return ret;

        switch (buck) {
        case MAX8998_BUCK1:
                dev_dbg(max8998->dev,
                        "BUCK1, selector:%d, buck1_vol1:%d, buck1_vol2:%d\n"
                        "buck1_vol3:%d, buck1_vol4:%d\n",
                        selector, max8998->buck1_vol[0], max8998->buck1_vol[1],
                        max8998->buck1_vol[2], max8998->buck1_vol[3]);

                if (max8998->buck1_gpio1 && max8998->buck1_gpio2) {

                        /* check if requested voltage */
                        /* value is already defined */
                        for (j = 0; j < ARRAY_SIZE(max8998->buck1_vol); j++) {
                                if (max8998->buck1_vol[j] == selector) {
                                        max8998->buck1_idx = j;
                                        buck1_gpio_set(max8998->buck1_gpio1,
                                                       max8998->buck1_gpio2, j);
                                        goto buck1_exit;
                                }
                        }

                        if (pdata->buck_voltage_lock)
                                return -EINVAL;

                        /* no predefine regulator found */
                        max8998->buck1_idx = (buck1_last_val % 2) + 2;
                        dev_dbg(max8998->dev, "max8998->buck1_idx:%d\n",
                                max8998->buck1_idx);
                        max8998->buck1_vol[max8998->buck1_idx] = selector;
                        ret = max8998_get_voltage_register(rdev, &reg,
                                                           &shift,
                                                           &mask);
                        ret = max8998_write_reg(i2c, reg, selector);
                        buck1_gpio_set(max8998->buck1_gpio1,
                                       max8998->buck1_gpio2, max8998->buck1_idx);
                        buck1_last_val++;
buck1_exit:
                        dev_dbg(max8998->dev, "%s: SET1:%d, SET2:%d\n",
                                i2c->name, gpiod_get_value(max8998->buck1_gpio1),
                                gpiod_get_value(max8998->buck1_gpio2));
                        break;
                } else {
                        ret = max8998_write_reg(i2c, reg, selector);
                }
                break;

        case MAX8998_BUCK2:
                dev_dbg(max8998->dev,
                        "BUCK2, selector:%d buck2_vol1:%d, buck2_vol2:%d\n",
                        selector, max8998->buck2_vol[0], max8998->buck2_vol[1]);
                if (max8998->buck2_gpio) {
                        /* check if requested voltage */
                        /* value is already defined */
                        for (j = 0; j < ARRAY_SIZE(max8998->buck2_vol); j++) {
                                if (max8998->buck2_vol[j] == selector) {
                                        max8998->buck2_idx = j;
                                        buck2_gpio_set(max8998->buck2_gpio, j);
                                        goto buck2_exit;
                                }
                        }

                        if (pdata->buck_voltage_lock)
                                return -EINVAL;

                        max8998_get_voltage_register(rdev,
                                        &reg, &shift, &mask);
                        ret = max8998_write_reg(i2c, reg, selector);
                        max8998->buck2_vol[max8998->buck2_idx] = selector;
                        buck2_gpio_set(max8998->buck2_gpio, max8998->buck2_idx);
buck2_exit:
                        dev_dbg(max8998->dev, "%s: SET3:%d\n", i2c->name,
                                gpiod_get_value(max8998->buck2_gpio));
                } else {
                        ret = max8998_write_reg(i2c, reg, selector);
                }
                break;

        case MAX8998_BUCK3:
        case MAX8998_BUCK4:
                ret = max8998_update_reg(i2c, reg, selector<<shift,
                                         mask<<shift);
                break;
        }

        return ret;
}

static int max8998_set_voltage_buck_time_sel(struct regulator_dev *rdev,
                                             unsigned int old_selector,
                                             unsigned int new_selector)
{
        struct max8998_data *max8998 = rdev_get_drvdata(rdev);
        struct i2c_client *i2c = max8998->iodev->i2c;
        int buck = rdev_get_id(rdev);
        u8 val = 0;
        int difference, ret;

        if (buck < MAX8998_BUCK1 || buck > MAX8998_BUCK4)
                return -EINVAL;

        /* Voltage stabilization */
        ret = max8998_read_reg(i2c, MAX8998_REG_ONOFF4, &val);
        if (ret)
                return ret;

        /* lp3974 hasn't got ENRAMP bit - ramp is assumed as true */
        /* MAX8998 has ENRAMP bit implemented, so test it*/
        if (max8998->iodev->type == TYPE_MAX8998 && !(val & MAX8998_ENRAMP))
                return 0;

        difference = (new_selector - old_selector) * rdev->desc->uV_step / 1000;
        if (difference > 0)
                return DIV_ROUND_UP(difference, (val & 0x0f) + 1);

        return 0;
}

static int max8998_set_current_limit(struct regulator_dev *rdev,
                                     int min_uA, int max_uA)
{
        struct max8998_data *max8998 = rdev_get_drvdata(rdev);
        struct i2c_client *i2c = max8998->iodev->i2c;
        unsigned int n_currents = rdev->desc->n_current_limits;
        int i, sel = -1;

        if (n_currents == 0)
                return -EINVAL;

        if (rdev->desc->curr_table) {
                const unsigned int *curr_table = rdev->desc->curr_table;
                bool ascend = curr_table[n_currents - 1] > curr_table[0];

                /* search for closest to maximum */
                if (ascend) {
                        for (i = n_currents - 1; i >= 0; i--) {
                                if (min_uA <= curr_table[i] &&
                                    curr_table[i] <= max_uA) {
                                        sel = i;
                                        break;
                                }
                        }
                } else {
                        for (i = 0; i < n_currents; i++) {
                                if (min_uA <= curr_table[i] &&
                                    curr_table[i] <= max_uA) {
                                        sel = i;
                                        break;
                                }
                        }
                }
        }

        if (sel < 0)
                return -EINVAL;

        sel <<= ffs(rdev->desc->csel_mask) - 1;

        return max8998_update_reg(i2c, rdev->desc->csel_reg,
                                  sel, rdev->desc->csel_mask);
}

static int max8998_get_current_limit(struct regulator_dev *rdev)
{
        struct max8998_data *max8998 = rdev_get_drvdata(rdev);
        struct i2c_client *i2c = max8998->iodev->i2c;
        u8 val;
        int ret;

        ret = max8998_read_reg(i2c, rdev->desc->csel_reg, &val);
        if (ret != 0)
                return ret;

        val &= rdev->desc->csel_mask;
        val >>= ffs(rdev->desc->csel_mask) - 1;

        if (rdev->desc->curr_table) {
                if (val >= rdev->desc->n_current_limits)
                        return -EINVAL;

                return rdev->desc->curr_table[val];
        }

        return -EINVAL;
}

static const struct regulator_ops max8998_ldo_ops = {
        .list_voltage           = regulator_list_voltage_linear,
        .map_voltage            = regulator_map_voltage_linear,
        .is_enabled             = max8998_ldo_is_enabled,
        .enable                 = max8998_ldo_enable,
        .disable                = max8998_ldo_disable,
        .get_voltage_sel        = max8998_get_voltage_sel,
        .set_voltage_sel        = max8998_set_voltage_ldo_sel,
};

static const struct regulator_ops max8998_buck_ops = {
        .list_voltage           = regulator_list_voltage_linear,
        .map_voltage            = regulator_map_voltage_linear,
        .is_enabled             = max8998_ldo_is_enabled,
        .enable                 = max8998_ldo_enable,
        .disable                = max8998_ldo_disable,
        .get_voltage_sel        = max8998_get_voltage_sel,
        .set_voltage_sel        = max8998_set_voltage_buck_sel,
        .set_voltage_time_sel   = max8998_set_voltage_buck_time_sel,
};

static const struct regulator_ops max8998_charger_ops = {
        .set_current_limit      = max8998_set_current_limit,
        .get_current_limit      = max8998_get_current_limit,
        .is_enabled             = max8998_ldo_is_enabled_inverted,
        /* Swapped as register is inverted */
        .enable                 = max8998_ldo_disable,
        .disable                = max8998_ldo_enable,
};

static const struct regulator_ops max8998_others_ops = {
        .is_enabled             = max8998_ldo_is_enabled,
        .enable                 = max8998_ldo_enable,
        .disable                = max8998_ldo_disable,
};

#define MAX8998_LINEAR_REG(_name, _ops, _min, _step, _max) \
        { \
                .name = #_name, \
                .id = MAX8998_##_name, \
                .ops = _ops, \
                .min_uV = (_min), \
                .uV_step = (_step), \
                .n_voltages = ((_max) - (_min)) / (_step) + 1, \
                .type = REGULATOR_VOLTAGE, \
                .owner = THIS_MODULE, \
        }

#define MAX8998_CURRENT_REG(_name, _ops, _table, _reg, _mask) \
        { \
                .name = #_name, \
                .id = MAX8998_##_name, \
                .ops = _ops, \
                .curr_table = _table, \
                .n_current_limits = ARRAY_SIZE(_table), \
                .csel_reg = _reg, \
                .csel_mask = _mask, \
                .type = REGULATOR_CURRENT, \
                .owner = THIS_MODULE, \
        }

#define MAX8998_OTHERS_REG(_name, _id) \
        { \
                .name = #_name, \
                .id = _id, \
                .ops = &max8998_others_ops, \
                .type = REGULATOR_VOLTAGE, \
                .owner = THIS_MODULE, \
        }

static const struct regulator_desc regulators[] = {
        MAX8998_LINEAR_REG(LDO2, &max8998_ldo_ops, 800000, 50000, 1300000),
        MAX8998_LINEAR_REG(LDO3, &max8998_ldo_ops, 800000, 50000, 1300000),
        MAX8998_LINEAR_REG(LDO4, &max8998_ldo_ops, 1600000, 100000, 3600000),
        MAX8998_LINEAR_REG(LDO5, &max8998_ldo_ops, 1600000, 100000, 3600000),
        MAX8998_LINEAR_REG(LDO6, &max8998_ldo_ops, 1600000, 100000, 3600000),
        MAX8998_LINEAR_REG(LDO7, &max8998_ldo_ops, 1600000, 100000, 3600000),
        MAX8998_LINEAR_REG(LDO8, &max8998_ldo_ops, 3000000, 100000, 3600000),
        MAX8998_LINEAR_REG(LDO9, &max8998_ldo_ops, 2800000, 100000, 3100000),
        MAX8998_LINEAR_REG(LDO10, &max8998_ldo_ops, 950000, 50000, 1300000),
        MAX8998_LINEAR_REG(LDO11, &max8998_ldo_ops, 1600000, 100000, 3600000),
        MAX8998_LINEAR_REG(LDO12, &max8998_ldo_ops, 800000, 100000, 3300000),
        MAX8998_LINEAR_REG(LDO13, &max8998_ldo_ops, 800000, 100000, 3300000),
        MAX8998_LINEAR_REG(LDO14, &max8998_ldo_ops, 1200000, 100000, 3300000),
        MAX8998_LINEAR_REG(LDO15, &max8998_ldo_ops, 1200000, 100000, 3300000),
        MAX8998_LINEAR_REG(LDO16, &max8998_ldo_ops, 1600000, 100000, 3600000),
        MAX8998_LINEAR_REG(LDO17, &max8998_ldo_ops, 1600000, 100000, 3600000),
        MAX8998_LINEAR_REG(BUCK1, &max8998_buck_ops, 750000, 25000, 1525000),
        MAX8998_LINEAR_REG(BUCK2, &max8998_buck_ops, 750000, 25000, 1525000),
        MAX8998_LINEAR_REG(BUCK3, &max8998_buck_ops, 1600000, 100000, 3600000),
        MAX8998_LINEAR_REG(BUCK4, &max8998_buck_ops, 800000, 100000, 2300000),
        MAX8998_OTHERS_REG(EN32KHz-AP, MAX8998_EN32KHZ_AP),
        MAX8998_OTHERS_REG(EN32KHz-CP, MAX8998_EN32KHZ_CP),
        MAX8998_OTHERS_REG(ENVICHG, MAX8998_ENVICHG),
        MAX8998_OTHERS_REG(ESAFEOUT1, MAX8998_ESAFEOUT1),
        MAX8998_OTHERS_REG(ESAFEOUT2, MAX8998_ESAFEOUT2),
        MAX8998_CURRENT_REG(CHARGER, &max8998_charger_ops,
                            charger_current_table, MAX8998_REG_CHGR1, 0x7),
};

static int max8998_pmic_dt_parse_pdata(struct max8998_dev *iodev,
                                        struct max8998_platform_data *pdata)
{
        struct device_node *pmic_np = iodev->dev->of_node;
        struct device_node *regulators_np, *reg_np;
        struct max8998_regulator_data *rdata;
        unsigned int i;
        int ret;

        regulators_np = of_get_child_by_name(pmic_np, "regulators");
        if (!regulators_np) {
                dev_err(iodev->dev, "could not find regulators sub-node\n");
                return -EINVAL;
        }

        /* count the number of regulators to be supported in pmic */
        pdata->num_regulators = of_get_child_count(regulators_np);

        rdata = devm_kcalloc(iodev->dev,
                             pdata->num_regulators, sizeof(*rdata),
                             GFP_KERNEL);
        if (!rdata) {
                of_node_put(regulators_np);
                return -ENOMEM;
        }

        pdata->regulators = rdata;
        for (i = 0; i < ARRAY_SIZE(regulators); ++i) {
                reg_np = of_get_child_by_name(regulators_np,
                                                        regulators[i].name);
                if (!reg_np)
                        continue;

                rdata->id = regulators[i].id;
                rdata->initdata = of_get_regulator_init_data(iodev->dev,
                                                             reg_np,
                                                             &regulators[i]);
                rdata->reg_node = reg_np;
                ++rdata;
        }
        pdata->num_regulators = rdata - pdata->regulators;

        of_node_put(reg_np);
        of_node_put(regulators_np);

        pdata->buck_voltage_lock = of_property_read_bool(pmic_np, "max8998,pmic-buck-voltage-lock");

        ret = of_property_read_u32(pmic_np,
                                        "max8998,pmic-buck1-default-dvs-idx",
                                        &pdata->buck1_default_idx);
        if (!ret && pdata->buck1_default_idx >= 4) {
                pdata->buck1_default_idx = 0;
                dev_warn(iodev->dev, "invalid value for default dvs index, using 0 instead\n");
        }

        ret = of_property_read_u32(pmic_np,
                                        "max8998,pmic-buck2-default-dvs-idx",
                                        &pdata->buck2_default_idx);
        if (!ret && pdata->buck2_default_idx >= 2) {
                pdata->buck2_default_idx = 0;
                dev_warn(iodev->dev, "invalid value for default dvs index, using 0 instead\n");
        }

        ret = of_property_read_u32_array(pmic_np,
                                        "max8998,pmic-buck1-dvs-voltage",
                                        pdata->buck1_voltage,
                                        ARRAY_SIZE(pdata->buck1_voltage));
        if (ret) {
                dev_err(iodev->dev, "buck1 voltages not specified\n");
                return -EINVAL;
        }

        ret = of_property_read_u32_array(pmic_np,
                                        "max8998,pmic-buck2-dvs-voltage",
                                        pdata->buck2_voltage,
                                        ARRAY_SIZE(pdata->buck2_voltage));
        if (ret) {
                dev_err(iodev->dev, "buck2 voltages not specified\n");
                return -EINVAL;
        }

        return 0;
}

static int max8998_pmic_probe(struct platform_device *pdev)
{
        struct max8998_dev *iodev = dev_get_drvdata(pdev->dev.parent);
        struct max8998_platform_data *pdata = iodev->pdata;
        struct regulator_config config = { };
        struct regulator_dev *rdev;
        struct max8998_data *max8998;
        struct i2c_client *i2c;
        enum gpiod_flags flags;
        int i, ret;
        unsigned int v;

        if (!pdata) {
                dev_err(pdev->dev.parent, "No platform init data supplied\n");
                return -ENODEV;
        }

        if (IS_ENABLED(CONFIG_OF) && iodev->dev->of_node) {
                ret = max8998_pmic_dt_parse_pdata(iodev, pdata);
                if (ret)
                        return ret;
        }

        max8998 = devm_kzalloc(&pdev->dev, sizeof(struct max8998_data),
                               GFP_KERNEL);
        if (!max8998)
                return -ENOMEM;

        max8998->dev = &pdev->dev;
        max8998->iodev = iodev;
        max8998->num_regulators = pdata->num_regulators;
        platform_set_drvdata(pdev, max8998);
        i2c = max8998->iodev->i2c;

        max8998->buck1_idx = pdata->buck1_default_idx;
        max8998->buck2_idx = pdata->buck2_default_idx;

        /* Check if MAX8998 voltage selection GPIOs are defined */
        flags = (max8998->buck1_idx & BIT(0)) ? GPIOD_OUT_HIGH : GPIOD_OUT_LOW;
        max8998->buck1_gpio1 = devm_gpiod_get_index_optional(iodev->dev,
                                                             "max8998,pmic-buck1-dvs",
                                                             0,
                                                             flags);
        if (IS_ERR(max8998->buck1_gpio1))
                return dev_err_probe(&pdev->dev, PTR_ERR(max8998->buck1_gpio1),
                                     "could not get BUCK1 GPIO1\n");
        gpiod_set_consumer_name(max8998->buck1_gpio1, "MAX8998 BUCK1_SET1");

        flags = (max8998->buck1_idx & BIT(1)) ? GPIOD_OUT_HIGH : GPIOD_OUT_LOW;
        max8998->buck1_gpio2 = devm_gpiod_get_index_optional(iodev->dev,
                                                             "max8998,pmic-buck1-dvs",
                                                             1,
                                                             flags);
        if (IS_ERR(max8998->buck1_gpio2))
                return dev_err_probe(&pdev->dev, PTR_ERR(max8998->buck1_gpio2),
                                     "could not get BUCK1 GPIO2\n");
        gpiod_set_consumer_name(max8998->buck1_gpio1, "MAX8998 BUCK1_SET2");

        flags = (max8998->buck2_idx & BIT(0)) ? GPIOD_OUT_HIGH : GPIOD_OUT_LOW;
        max8998->buck2_gpio = devm_gpiod_get_index_optional(iodev->dev,
                                                             "max8998,pmic-buck2-dvs",
                                                             0,
                                                             flags);
        if (IS_ERR(max8998->buck2_gpio))
                return dev_err_probe(&pdev->dev, PTR_ERR(max8998->buck2_gpio),
                                     "could not get BUCK2 GPIO\n");
        gpiod_set_consumer_name(max8998->buck1_gpio1, "MAX8998 BUCK2_SET3");

        if (max8998->buck1_gpio1 && max8998->buck1_gpio2) {
                /* Set predefined values for BUCK1 registers */
                for (v = 0; v < ARRAY_SIZE(pdata->buck1_voltage); ++v) {
                        int index = MAX8998_BUCK1 - MAX8998_LDO2;

                        i = 0;
                        while (regulators[index].min_uV +
                               regulators[index].uV_step * i
                               < pdata->buck1_voltage[v])
                                i++;

                        max8998->buck1_vol[v] = i;
                        ret = max8998_write_reg(i2c,
                                        MAX8998_REG_BUCK1_VOLTAGE1 + v, i);
                        if (ret)
                                return ret;
                }
        }

        if (max8998->buck2_gpio) {
                /* Set predefined values for BUCK2 registers */
                for (v = 0; v < ARRAY_SIZE(pdata->buck2_voltage); ++v) {
                        int index = MAX8998_BUCK2 - MAX8998_LDO2;

                        i = 0;
                        while (regulators[index].min_uV +
                               regulators[index].uV_step * i
                               < pdata->buck2_voltage[v])
                                i++;

                        max8998->buck2_vol[v] = i;
                        ret = max8998_write_reg(i2c,
                                        MAX8998_REG_BUCK2_VOLTAGE1 + v, i);
                        if (ret)
                                return ret;
                }
        }

        for (i = 0; i < pdata->num_regulators; i++) {
                int index = pdata->regulators[i].id - MAX8998_LDO2;

                config.dev = max8998->dev;
                config.of_node = pdata->regulators[i].reg_node;
                config.init_data = pdata->regulators[i].initdata;
                config.driver_data = max8998;

                rdev = devm_regulator_register(&pdev->dev, &regulators[index],
                                               &config);
                if (IS_ERR(rdev)) {
                        ret = PTR_ERR(rdev);
                        dev_err(max8998->dev, "regulator %s init failed (%d)\n",
                                                regulators[index].name, ret);
                        return ret;
                }
        }

        return 0;
}

static const struct platform_device_id max8998_pmic_id[] = {
        { "max8998-pmic", TYPE_MAX8998 },
        { "lp3974-pmic", TYPE_LP3974 },
        { }
};
MODULE_DEVICE_TABLE(platform, max8998_pmic_id);

static struct platform_driver max8998_pmic_driver = {
        .driver = {
                .name = "max8998-pmic",
                .probe_type = PROBE_PREFER_ASYNCHRONOUS,
        },
        .probe = max8998_pmic_probe,
        .id_table = max8998_pmic_id,
};

static int __init max8998_pmic_init(void)
{
        return platform_driver_register(&max8998_pmic_driver);
}
subsys_initcall(max8998_pmic_init);

static void __exit max8998_pmic_cleanup(void)
{
        platform_driver_unregister(&max8998_pmic_driver);
}
module_exit(max8998_pmic_cleanup);

MODULE_DESCRIPTION("MAXIM 8998 voltage regulator driver");
MODULE_AUTHOR("Kyungmin Park <kyungmin.park@samsung.com>");
MODULE_LICENSE("GPL");