root/drivers/regulator/max8997-regulator.c
// SPDX-License-Identifier: GPL-2.0+
//
// max8997.c - Regulator driver for the Maxim 8997/8966
//
// Copyright (C) 2011 Samsung Electronics
// MyungJoo Ham <myungjoo.ham@samsung.com>
//
// This driver is based on max8998.c

#include <linux/bug.h>
#include <linux/cleanup.h>
#include <linux/err.h>
#include <linux/gpio/consumer.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/regulator/driver.h>
#include <linux/regulator/machine.h>
#include <linux/mfd/max8997.h>
#include <linux/mfd/max8997-private.h>
#include <linux/regulator/of_regulator.h>

struct max8997_data {
        struct device *dev;
        struct max8997_dev *iodev;
        int num_regulators;
        int ramp_delay; /* in mV/us */

        bool buck1_gpiodvs;
        bool buck2_gpiodvs;
        bool buck5_gpiodvs;
        u8 buck1_vol[8];
        u8 buck2_vol[8];
        u8 buck5_vol[8];
        struct gpio_desc *buck125_gpiods[3];
        int buck125_gpioindex;
        bool ignore_gpiodvs_side_effect;

        u8 saved_states[MAX8997_REG_MAX];
};

static const unsigned int safeoutvolt[] = {
        4850000,
        4900000,
        4950000,
        3300000,
};

static inline void max8997_set_gpio(struct max8997_data *max8997)
{
        int set3 = (max8997->buck125_gpioindex) & 0x1;
        int set2 = ((max8997->buck125_gpioindex) >> 1) & 0x1;
        int set1 = ((max8997->buck125_gpioindex) >> 2) & 0x1;

        gpiod_set_value(max8997->buck125_gpiods[0], set1);
        gpiod_set_value(max8997->buck125_gpiods[1], set2);
        gpiod_set_value(max8997->buck125_gpiods[2], set3);
}

struct voltage_map_desc {
        int min;
        int max;
        int step;
};

/* Voltage maps in uV */
static const struct voltage_map_desc ldo_voltage_map_desc = {
        .min = 800000,  .max = 3950000, .step = 50000,
}; /* LDO1 ~ 18, 21 all */

static const struct voltage_map_desc buck1245_voltage_map_desc = {
        .min = 650000,  .max = 2225000, .step = 25000,
}; /* Buck1, 2, 4, 5 */

static const struct voltage_map_desc buck37_voltage_map_desc = {
        .min = 750000,  .max = 3900000, .step = 50000,
}; /* Buck3, 7 */

/* current map in uA */
static const struct voltage_map_desc charger_current_map_desc = {
        .min = 200000,  .max = 950000,  .step = 50000,
};

static const struct voltage_map_desc topoff_current_map_desc = {
        .min = 50000,   .max = 200000,  .step = 10000,
};

static const struct voltage_map_desc *reg_voltage_map[] = {
        [MAX8997_LDO1] = &ldo_voltage_map_desc,
        [MAX8997_LDO2] = &ldo_voltage_map_desc,
        [MAX8997_LDO3] = &ldo_voltage_map_desc,
        [MAX8997_LDO4] = &ldo_voltage_map_desc,
        [MAX8997_LDO5] = &ldo_voltage_map_desc,
        [MAX8997_LDO6] = &ldo_voltage_map_desc,
        [MAX8997_LDO7] = &ldo_voltage_map_desc,
        [MAX8997_LDO8] = &ldo_voltage_map_desc,
        [MAX8997_LDO9] = &ldo_voltage_map_desc,
        [MAX8997_LDO10] = &ldo_voltage_map_desc,
        [MAX8997_LDO11] = &ldo_voltage_map_desc,
        [MAX8997_LDO12] = &ldo_voltage_map_desc,
        [MAX8997_LDO13] = &ldo_voltage_map_desc,
        [MAX8997_LDO14] = &ldo_voltage_map_desc,
        [MAX8997_LDO15] = &ldo_voltage_map_desc,
        [MAX8997_LDO16] = &ldo_voltage_map_desc,
        [MAX8997_LDO17] = &ldo_voltage_map_desc,
        [MAX8997_LDO18] = &ldo_voltage_map_desc,
        [MAX8997_LDO21] = &ldo_voltage_map_desc,
        [MAX8997_BUCK1] = &buck1245_voltage_map_desc,
        [MAX8997_BUCK2] = &buck1245_voltage_map_desc,
        [MAX8997_BUCK3] = &buck37_voltage_map_desc,
        [MAX8997_BUCK4] = &buck1245_voltage_map_desc,
        [MAX8997_BUCK5] = &buck1245_voltage_map_desc,
        [MAX8997_BUCK6] = NULL,
        [MAX8997_BUCK7] = &buck37_voltage_map_desc,
        [MAX8997_EN32KHZ_AP] = NULL,
        [MAX8997_EN32KHZ_CP] = NULL,
        [MAX8997_ENVICHG] = NULL,
        [MAX8997_ESAFEOUT1] = NULL,
        [MAX8997_ESAFEOUT2] = NULL,
        [MAX8997_CHARGER_CV] = NULL,
        [MAX8997_CHARGER] = &charger_current_map_desc,
        [MAX8997_CHARGER_TOPOFF] = &topoff_current_map_desc,
};

static int max8997_list_voltage_charger_cv(struct regulator_dev *rdev,
                unsigned int selector)
{
        int rid = rdev_get_id(rdev);

        if (rid != MAX8997_CHARGER_CV)
                goto err;

        switch (selector) {
        case 0x00:
                return 4200000;
        case 0x01 ... 0x0E:
                return 4000000 + 20000 * (selector - 0x01);
        case 0x0F:
                return 4350000;
        default:
                return -EINVAL;
        }
err:
        return -EINVAL;
}

static int max8997_list_voltage(struct regulator_dev *rdev,
                unsigned int selector)
{
        const struct voltage_map_desc *desc;
        int rid = rdev_get_id(rdev);
        int val;

        if (rid < 0 || rid >= ARRAY_SIZE(reg_voltage_map))
                return -EINVAL;

        desc = reg_voltage_map[rid];
        if (desc == NULL)
                return -EINVAL;

        val = desc->min + desc->step * selector;
        if (val > desc->max)
                return -EINVAL;

        return val;
}

static int max8997_get_enable_register(struct regulator_dev *rdev,
                int *reg, int *mask, int *pattern)
{
        int rid = rdev_get_id(rdev);

        switch (rid) {
        case MAX8997_LDO1 ... MAX8997_LDO21:
                *reg = MAX8997_REG_LDO1CTRL + (rid - MAX8997_LDO1);
                *mask = 0xC0;
                *pattern = 0xC0;
                break;
        case MAX8997_BUCK1:
                *reg = MAX8997_REG_BUCK1CTRL;
                *mask = 0x01;
                *pattern = 0x01;
                break;
        case MAX8997_BUCK2:
                *reg = MAX8997_REG_BUCK2CTRL;
                *mask = 0x01;
                *pattern = 0x01;
                break;
        case MAX8997_BUCK3:
                *reg = MAX8997_REG_BUCK3CTRL;
                *mask = 0x01;
                *pattern = 0x01;
                break;
        case MAX8997_BUCK4:
                *reg = MAX8997_REG_BUCK4CTRL;
                *mask = 0x01;
                *pattern = 0x01;
                break;
        case MAX8997_BUCK5:
                *reg = MAX8997_REG_BUCK5CTRL;
                *mask = 0x01;
                *pattern = 0x01;
                break;
        case MAX8997_BUCK6:
                *reg = MAX8997_REG_BUCK6CTRL;
                *mask = 0x01;
                *pattern = 0x01;
                break;
        case MAX8997_BUCK7:
                *reg = MAX8997_REG_BUCK7CTRL;
                *mask = 0x01;
                *pattern = 0x01;
                break;
        case MAX8997_EN32KHZ_AP ... MAX8997_EN32KHZ_CP:
                *reg = MAX8997_REG_MAINCON1;
                *mask = 0x01 << (rid - MAX8997_EN32KHZ_AP);
                *pattern = 0x01 << (rid - MAX8997_EN32KHZ_AP);
                break;
        case MAX8997_ENVICHG:
                *reg = MAX8997_REG_MBCCTRL1;
                *mask = 0x80;
                *pattern = 0x80;
                break;
        case MAX8997_ESAFEOUT1 ... MAX8997_ESAFEOUT2:
                *reg = MAX8997_REG_SAFEOUTCTRL;
                *mask = 0x40 << (rid - MAX8997_ESAFEOUT1);
                *pattern = 0x40 << (rid - MAX8997_ESAFEOUT1);
                break;
        case MAX8997_CHARGER:
                *reg = MAX8997_REG_MBCCTRL2;
                *mask = 0x40;
                *pattern = 0x40;
                break;
        default:
                /* Not controllable or not exists */
                return -EINVAL;
        }

        return 0;
}

static int max8997_reg_is_enabled(struct regulator_dev *rdev)
{
        struct max8997_data *max8997 = rdev_get_drvdata(rdev);
        struct i2c_client *i2c = max8997->iodev->i2c;
        int ret, reg, mask, pattern;
        u8 val;

        ret = max8997_get_enable_register(rdev, &reg, &mask, &pattern);
        if (ret)
                return ret;

        ret = max8997_read_reg(i2c, reg, &val);
        if (ret)
                return ret;

        return (val & mask) == pattern;
}

static int max8997_reg_enable(struct regulator_dev *rdev)
{
        struct max8997_data *max8997 = rdev_get_drvdata(rdev);
        struct i2c_client *i2c = max8997->iodev->i2c;
        int ret, reg, mask, pattern;

        ret = max8997_get_enable_register(rdev, &reg, &mask, &pattern);
        if (ret)
                return ret;

        return max8997_update_reg(i2c, reg, pattern, mask);
}

static int max8997_reg_disable(struct regulator_dev *rdev)
{
        struct max8997_data *max8997 = rdev_get_drvdata(rdev);
        struct i2c_client *i2c = max8997->iodev->i2c;
        int ret, reg, mask, pattern;

        ret = max8997_get_enable_register(rdev, &reg, &mask, &pattern);
        if (ret)
                return ret;

        return max8997_update_reg(i2c, reg, ~pattern, mask);
}

static int max8997_get_voltage_register(struct regulator_dev *rdev,
                int *_reg, int *_shift, int *_mask)
{
        struct max8997_data *max8997 = rdev_get_drvdata(rdev);
        int rid = rdev_get_id(rdev);
        int reg, shift = 0, mask = 0x3f;

        switch (rid) {
        case MAX8997_LDO1 ... MAX8997_LDO21:
                reg = MAX8997_REG_LDO1CTRL + (rid - MAX8997_LDO1);
                break;
        case MAX8997_BUCK1:
                reg = MAX8997_REG_BUCK1DVS1;
                if (max8997->buck1_gpiodvs)
                        reg += max8997->buck125_gpioindex;
                break;
        case MAX8997_BUCK2:
                reg = MAX8997_REG_BUCK2DVS1;
                if (max8997->buck2_gpiodvs)
                        reg += max8997->buck125_gpioindex;
                break;
        case MAX8997_BUCK3:
                reg = MAX8997_REG_BUCK3DVS;
                break;
        case MAX8997_BUCK4:
                reg = MAX8997_REG_BUCK4DVS;
                break;
        case MAX8997_BUCK5:
                reg = MAX8997_REG_BUCK5DVS1;
                if (max8997->buck5_gpiodvs)
                        reg += max8997->buck125_gpioindex;
                break;
        case MAX8997_BUCK7:
                reg = MAX8997_REG_BUCK7DVS;
                break;
        case MAX8997_ESAFEOUT1 ...  MAX8997_ESAFEOUT2:
                reg = MAX8997_REG_SAFEOUTCTRL;
                shift = (rid == MAX8997_ESAFEOUT2) ? 2 : 0;
                mask = 0x3;
                break;
        case MAX8997_CHARGER_CV:
                reg = MAX8997_REG_MBCCTRL3;
                shift = 0;
                mask = 0xf;
                break;
        case MAX8997_CHARGER:
                reg = MAX8997_REG_MBCCTRL4;
                shift = 0;
                mask = 0xf;
                break;
        case MAX8997_CHARGER_TOPOFF:
                reg = MAX8997_REG_MBCCTRL5;
                shift = 0;
                mask = 0xf;
                break;
        default:
                return -EINVAL;
        }

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

        return 0;
}

static int max8997_get_voltage_sel(struct regulator_dev *rdev)
{
        struct max8997_data *max8997 = rdev_get_drvdata(rdev);
        struct i2c_client *i2c = max8997->iodev->i2c;
        int reg, shift, mask, ret;
        u8 val;

        ret = max8997_get_voltage_register(rdev, &reg, &shift, &mask);
        if (ret)
                return ret;

        ret = max8997_read_reg(i2c, reg, &val);
        if (ret)
                return ret;

        val >>= shift;
        val &= mask;

        return val;
}

static inline int max8997_get_voltage_proper_val(
                const struct voltage_map_desc *desc,
                int min_vol, int max_vol)
{
        int i;

        if (desc == NULL)
                return -EINVAL;

        if (max_vol < desc->min || min_vol > desc->max)
                return -EINVAL;

        if (min_vol < desc->min)
                min_vol = desc->min;

        i = DIV_ROUND_UP(min_vol - desc->min, desc->step);

        if (desc->min + desc->step * i > max_vol)
                return -EINVAL;

        return i;
}

static int max8997_set_voltage_charger_cv(struct regulator_dev *rdev,
                int min_uV, int max_uV, unsigned *selector)
{
        struct max8997_data *max8997 = rdev_get_drvdata(rdev);
        struct i2c_client *i2c = max8997->iodev->i2c;
        int rid = rdev_get_id(rdev);
        int lb, ub;
        int reg, shift = 0, mask, ret = 0;
        u8 val = 0x0;

        if (rid != MAX8997_CHARGER_CV)
                return -EINVAL;

        ret = max8997_get_voltage_register(rdev, &reg, &shift, &mask);
        if (ret)
                return ret;

        if (max_uV < 4000000 || min_uV > 4350000)
                return -EINVAL;

        if (min_uV <= 4000000)
                val = 0x1;
        else if (min_uV <= 4200000 && max_uV >= 4200000)
                val = 0x0;
        else {
                lb = (min_uV - 4000001) / 20000 + 2;
                ub = (max_uV - 4000000) / 20000 + 1;

                if (lb > ub)
                        return -EINVAL;

                if (lb < 0xf)
                        val = lb;
                else {
                        if (ub >= 0xf)
                                val = 0xf;
                        else
                                return -EINVAL;
                }
        }

        *selector = val;

        ret = max8997_update_reg(i2c, reg, val << shift, mask);

        return ret;
}

/*
 * For LDO1 ~ LDO21, BUCK1~5, BUCK7, CHARGER, CHARGER_TOPOFF
 * BUCK1, 2, and 5 are available if they are not controlled by gpio
 */
static int max8997_set_voltage_ldobuck(struct regulator_dev *rdev,
                int min_uV, int max_uV, unsigned *selector)
{
        struct max8997_data *max8997 = rdev_get_drvdata(rdev);
        struct i2c_client *i2c = max8997->iodev->i2c;
        const struct voltage_map_desc *desc;
        int rid = rdev_get_id(rdev);
        int i, reg, shift, mask, ret;

        switch (rid) {
        case MAX8997_LDO1 ... MAX8997_LDO21:
                break;
        case MAX8997_BUCK1 ... MAX8997_BUCK5:
                break;
        case MAX8997_BUCK6:
                return -EINVAL;
        case MAX8997_BUCK7:
                break;
        case MAX8997_CHARGER:
                break;
        case MAX8997_CHARGER_TOPOFF:
                break;
        default:
                return -EINVAL;
        }

        desc = reg_voltage_map[rid];

        i = max8997_get_voltage_proper_val(desc, min_uV, max_uV);
        if (i < 0)
                return i;

        ret = max8997_get_voltage_register(rdev, &reg, &shift, &mask);
        if (ret)
                return ret;

        ret = max8997_update_reg(i2c, reg, i << shift, mask << shift);
        *selector = i;

        return ret;
}

static int max8997_set_voltage_buck_time_sel(struct regulator_dev *rdev,
                                                unsigned int old_selector,
                                                unsigned int new_selector)
{
        struct max8997_data *max8997 = rdev_get_drvdata(rdev);
        int rid = rdev_get_id(rdev);
        const struct voltage_map_desc *desc = reg_voltage_map[rid];

        /* Delay is required only if the voltage is increasing */
        if (old_selector >= new_selector)
                return 0;

        /* No need to delay if gpio_dvs_mode */
        switch (rid) {
        case MAX8997_BUCK1:
                if (max8997->buck1_gpiodvs)
                        return 0;
                break;
        case MAX8997_BUCK2:
                if (max8997->buck2_gpiodvs)
                        return 0;
                break;
        case MAX8997_BUCK5:
                if (max8997->buck5_gpiodvs)
                        return 0;
                break;
        }

        switch (rid) {
        case MAX8997_BUCK1:
        case MAX8997_BUCK2:
        case MAX8997_BUCK4:
        case MAX8997_BUCK5:
                return DIV_ROUND_UP(desc->step * (new_selector - old_selector),
                                    max8997->ramp_delay * 1000);
        }

        return 0;
}

/*
 * Assess the damage on the voltage setting of BUCK1,2,5 by the change.
 *
 * When GPIO-DVS mode is used for multiple bucks, changing the voltage value
 * of one of the bucks may affect that of another buck, which is the side
 * effect of the change (set_voltage). This function examines the GPIO-DVS
 * configurations and checks whether such side-effect exists.
 */
static int max8997_assess_side_effect(struct regulator_dev *rdev,
                u8 new_val, int *best)
{
        struct max8997_data *max8997 = rdev_get_drvdata(rdev);
        int rid = rdev_get_id(rdev);
        u8 *buckx_val[3];
        bool buckx_gpiodvs[3];
        int side_effect[8];
        int min_side_effect = INT_MAX;
        int i;

        *best = -1;

        switch (rid) {
        case MAX8997_BUCK1:
                rid = 0;
                break;
        case MAX8997_BUCK2:
                rid = 1;
                break;
        case MAX8997_BUCK5:
                rid = 2;
                break;
        default:
                return -EINVAL;
        }

        buckx_val[0] = max8997->buck1_vol;
        buckx_val[1] = max8997->buck2_vol;
        buckx_val[2] = max8997->buck5_vol;
        buckx_gpiodvs[0] = max8997->buck1_gpiodvs;
        buckx_gpiodvs[1] = max8997->buck2_gpiodvs;
        buckx_gpiodvs[2] = max8997->buck5_gpiodvs;

        for (i = 0; i < 8; i++) {
                int others;

                if (new_val != (buckx_val[rid])[i]) {
                        side_effect[i] = -1;
                        continue;
                }

                side_effect[i] = 0;
                for (others = 0; others < 3; others++) {
                        int diff;

                        if (others == rid)
                                continue;
                        if (buckx_gpiodvs[others] == false)
                                continue; /* Not affected */
                        diff = (buckx_val[others])[i] -
                                (buckx_val[others])[max8997->buck125_gpioindex];
                        if (diff > 0)
                                side_effect[i] += diff;
                        else if (diff < 0)
                                side_effect[i] -= diff;
                }
                if (side_effect[i] == 0) {
                        *best = i;
                        return 0; /* NO SIDE EFFECT! Use This! */
                }
                if (side_effect[i] < min_side_effect) {
                        min_side_effect = side_effect[i];
                        *best = i;
                }
        }

        if (*best == -1)
                return -EINVAL;

        return side_effect[*best];
}

/*
 * For Buck 1 ~ 5 and 7. If it is not controlled by GPIO, this calls
 * max8997_set_voltage_ldobuck to do the job.
 */
static int max8997_set_voltage_buck(struct regulator_dev *rdev,
                int min_uV, int max_uV, unsigned *selector)
{
        struct max8997_data *max8997 = rdev_get_drvdata(rdev);
        int rid = rdev_get_id(rdev);
        const struct voltage_map_desc *desc;
        int new_val, new_idx, damage, tmp_val, tmp_idx, tmp_dmg;
        bool gpio_dvs_mode = false;

        if (rid < MAX8997_BUCK1 || rid > MAX8997_BUCK7)
                return -EINVAL;

        switch (rid) {
        case MAX8997_BUCK1:
                if (max8997->buck1_gpiodvs)
                        gpio_dvs_mode = true;
                break;
        case MAX8997_BUCK2:
                if (max8997->buck2_gpiodvs)
                        gpio_dvs_mode = true;
                break;
        case MAX8997_BUCK5:
                if (max8997->buck5_gpiodvs)
                        gpio_dvs_mode = true;
                break;
        }

        if (!gpio_dvs_mode)
                return max8997_set_voltage_ldobuck(rdev, min_uV, max_uV,
                                                selector);

        desc = reg_voltage_map[rid];
        new_val = max8997_get_voltage_proper_val(desc, min_uV, max_uV);
        if (new_val < 0)
                return new_val;

        tmp_dmg = INT_MAX;
        tmp_idx = -1;
        tmp_val = -1;
        do {
                damage = max8997_assess_side_effect(rdev, new_val, &new_idx);
                if (damage == 0)
                        goto out;

                if (tmp_dmg > damage) {
                        tmp_idx = new_idx;
                        tmp_val = new_val;
                        tmp_dmg = damage;
                }

                new_val++;
        } while (desc->min + desc->step * new_val <= desc->max);

        new_idx = tmp_idx;
        new_val = tmp_val;

        if (max8997->ignore_gpiodvs_side_effect == false)
                return -EINVAL;

        dev_warn(&rdev->dev,
                "MAX8997 GPIO-DVS Side Effect Warning: GPIO SET:  %d -> %d\n",
                max8997->buck125_gpioindex, tmp_idx);

out:
        if (new_idx < 0 || new_val < 0)
                return -EINVAL;

        max8997->buck125_gpioindex = new_idx;
        max8997_set_gpio(max8997);
        *selector = new_val;

        return 0;
}

/* For SAFEOUT1 and SAFEOUT2 */
static int max8997_set_voltage_safeout_sel(struct regulator_dev *rdev,
                                           unsigned selector)
{
        struct max8997_data *max8997 = rdev_get_drvdata(rdev);
        struct i2c_client *i2c = max8997->iodev->i2c;
        int rid = rdev_get_id(rdev);
        int reg, shift = 0, mask, ret;

        if (rid != MAX8997_ESAFEOUT1 && rid != MAX8997_ESAFEOUT2)
                return -EINVAL;

        ret = max8997_get_voltage_register(rdev, &reg, &shift, &mask);
        if (ret)
                return ret;

        return max8997_update_reg(i2c, reg, selector << shift, mask << shift);
}

static int max8997_reg_disable_suspend(struct regulator_dev *rdev)
{
        struct max8997_data *max8997 = rdev_get_drvdata(rdev);
        struct i2c_client *i2c = max8997->iodev->i2c;
        int ret, reg, mask, pattern;
        int rid = rdev_get_id(rdev);

        ret = max8997_get_enable_register(rdev, &reg, &mask, &pattern);
        if (ret)
                return ret;

        max8997_read_reg(i2c, reg, &max8997->saved_states[rid]);

        if (rid == MAX8997_LDO1 ||
                        rid == MAX8997_LDO10 ||
                        rid == MAX8997_LDO21) {
                dev_dbg(&rdev->dev, "Conditional Power-Off for %s\n",
                                rdev->desc->name);
                return max8997_update_reg(i2c, reg, 0x40, mask);
        }

        dev_dbg(&rdev->dev, "Full Power-Off for %s (%xh -> %xh)\n",
                        rdev->desc->name, max8997->saved_states[rid] & mask,
                        (~pattern) & mask);
        return max8997_update_reg(i2c, reg, ~pattern, mask);
}

static const struct regulator_ops max8997_ldo_ops = {
        .list_voltage           = max8997_list_voltage,
        .is_enabled             = max8997_reg_is_enabled,
        .enable                 = max8997_reg_enable,
        .disable                = max8997_reg_disable,
        .get_voltage_sel        = max8997_get_voltage_sel,
        .set_voltage            = max8997_set_voltage_ldobuck,
        .set_suspend_disable    = max8997_reg_disable_suspend,
};

static const struct regulator_ops max8997_buck_ops = {
        .list_voltage           = max8997_list_voltage,
        .is_enabled             = max8997_reg_is_enabled,
        .enable                 = max8997_reg_enable,
        .disable                = max8997_reg_disable,
        .get_voltage_sel        = max8997_get_voltage_sel,
        .set_voltage            = max8997_set_voltage_buck,
        .set_voltage_time_sel   = max8997_set_voltage_buck_time_sel,
        .set_suspend_disable    = max8997_reg_disable_suspend,
};

static const struct regulator_ops max8997_fixedvolt_ops = {
        .list_voltage           = max8997_list_voltage,
        .is_enabled             = max8997_reg_is_enabled,
        .enable                 = max8997_reg_enable,
        .disable                = max8997_reg_disable,
        .set_suspend_disable    = max8997_reg_disable_suspend,
};

static const struct regulator_ops max8997_safeout_ops = {
        .list_voltage           = regulator_list_voltage_table,
        .is_enabled             = max8997_reg_is_enabled,
        .enable                 = max8997_reg_enable,
        .disable                = max8997_reg_disable,
        .get_voltage_sel        = max8997_get_voltage_sel,
        .set_voltage_sel        = max8997_set_voltage_safeout_sel,
        .set_suspend_disable    = max8997_reg_disable_suspend,
};

static const struct regulator_ops max8997_fixedstate_ops = {
        .list_voltage           = max8997_list_voltage_charger_cv,
        .get_voltage_sel        = max8997_get_voltage_sel,
        .set_voltage            = max8997_set_voltage_charger_cv,
};

static int max8997_set_current_limit(struct regulator_dev *rdev,
                                     int min_uA, int max_uA)
{
        unsigned dummy;
        int rid = rdev_get_id(rdev);

        if (rid != MAX8997_CHARGER && rid != MAX8997_CHARGER_TOPOFF)
                return -EINVAL;

        /* Reuse max8997_set_voltage_ldobuck to set current_limit. */
        return max8997_set_voltage_ldobuck(rdev, min_uA, max_uA, &dummy);
}

static int max8997_get_current_limit(struct regulator_dev *rdev)
{
        int sel, rid = rdev_get_id(rdev);

        if (rid != MAX8997_CHARGER && rid != MAX8997_CHARGER_TOPOFF)
                return -EINVAL;

        sel = max8997_get_voltage_sel(rdev);
        if (sel < 0)
                return sel;

        /* Reuse max8997_list_voltage to get current_limit. */
        return max8997_list_voltage(rdev, sel);
}

static const struct regulator_ops max8997_charger_ops = {
        .is_enabled             = max8997_reg_is_enabled,
        .enable                 = max8997_reg_enable,
        .disable                = max8997_reg_disable,
        .get_current_limit      = max8997_get_current_limit,
        .set_current_limit      = max8997_set_current_limit,
};

static const struct regulator_ops max8997_charger_fixedstate_ops = {
        .get_current_limit      = max8997_get_current_limit,
        .set_current_limit      = max8997_set_current_limit,
};

#define MAX8997_VOLTAGE_REGULATOR(_name, _ops) {\
        .name           = #_name,               \
        .id             = MAX8997_##_name,      \
        .ops            = &_ops,                \
        .type           = REGULATOR_VOLTAGE,    \
        .owner          = THIS_MODULE,          \
}

#define MAX8997_CURRENT_REGULATOR(_name, _ops) {\
        .name           = #_name,               \
        .id             = MAX8997_##_name,      \
        .ops            = &_ops,                \
        .type           = REGULATOR_CURRENT,    \
        .owner          = THIS_MODULE,          \
}

static struct regulator_desc regulators[] = {
        MAX8997_VOLTAGE_REGULATOR(LDO1, max8997_ldo_ops),
        MAX8997_VOLTAGE_REGULATOR(LDO2, max8997_ldo_ops),
        MAX8997_VOLTAGE_REGULATOR(LDO3, max8997_ldo_ops),
        MAX8997_VOLTAGE_REGULATOR(LDO4, max8997_ldo_ops),
        MAX8997_VOLTAGE_REGULATOR(LDO5, max8997_ldo_ops),
        MAX8997_VOLTAGE_REGULATOR(LDO6, max8997_ldo_ops),
        MAX8997_VOLTAGE_REGULATOR(LDO7, max8997_ldo_ops),
        MAX8997_VOLTAGE_REGULATOR(LDO8, max8997_ldo_ops),
        MAX8997_VOLTAGE_REGULATOR(LDO9, max8997_ldo_ops),
        MAX8997_VOLTAGE_REGULATOR(LDO10, max8997_ldo_ops),
        MAX8997_VOLTAGE_REGULATOR(LDO11, max8997_ldo_ops),
        MAX8997_VOLTAGE_REGULATOR(LDO12, max8997_ldo_ops),
        MAX8997_VOLTAGE_REGULATOR(LDO13, max8997_ldo_ops),
        MAX8997_VOLTAGE_REGULATOR(LDO14, max8997_ldo_ops),
        MAX8997_VOLTAGE_REGULATOR(LDO15, max8997_ldo_ops),
        MAX8997_VOLTAGE_REGULATOR(LDO16, max8997_ldo_ops),
        MAX8997_VOLTAGE_REGULATOR(LDO17, max8997_ldo_ops),
        MAX8997_VOLTAGE_REGULATOR(LDO18, max8997_ldo_ops),
        MAX8997_VOLTAGE_REGULATOR(LDO21, max8997_ldo_ops),
        MAX8997_VOLTAGE_REGULATOR(BUCK1, max8997_buck_ops),
        MAX8997_VOLTAGE_REGULATOR(BUCK2, max8997_buck_ops),
        MAX8997_VOLTAGE_REGULATOR(BUCK3, max8997_buck_ops),
        MAX8997_VOLTAGE_REGULATOR(BUCK4, max8997_buck_ops),
        MAX8997_VOLTAGE_REGULATOR(BUCK5, max8997_buck_ops),
        MAX8997_VOLTAGE_REGULATOR(BUCK6, max8997_fixedvolt_ops),
        MAX8997_VOLTAGE_REGULATOR(BUCK7, max8997_buck_ops),
        MAX8997_VOLTAGE_REGULATOR(EN32KHZ_AP, max8997_fixedvolt_ops),
        MAX8997_VOLTAGE_REGULATOR(EN32KHZ_CP, max8997_fixedvolt_ops),
        MAX8997_VOLTAGE_REGULATOR(ENVICHG, max8997_fixedvolt_ops),
        MAX8997_VOLTAGE_REGULATOR(ESAFEOUT1, max8997_safeout_ops),
        MAX8997_VOLTAGE_REGULATOR(ESAFEOUT2, max8997_safeout_ops),
        MAX8997_VOLTAGE_REGULATOR(CHARGER_CV, max8997_fixedstate_ops),
        MAX8997_CURRENT_REGULATOR(CHARGER, max8997_charger_ops),
        MAX8997_CURRENT_REGULATOR(CHARGER_TOPOFF,
                                  max8997_charger_fixedstate_ops),
};

#ifdef CONFIG_OF
static int max8997_pmic_dt_parse_pdata(struct platform_device *pdev,
                                        struct max8997_platform_data *pdata)
{
        struct max8997_dev *iodev = dev_get_drvdata(pdev->dev.parent);
        struct device_node *pmic_np, *reg_np;
        struct max8997_regulator_data *rdata;
        unsigned int i, dvs_voltage_nr = 1;

        pmic_np = iodev->dev->of_node;
        if (!pmic_np) {
                dev_err(&pdev->dev, "could not find pmic sub-node\n");
                return -ENODEV;
        }

        struct device_node *regulators_np __free(device_node) = of_get_child_by_name(pmic_np,
                                                                                     "regulators");
        if (!regulators_np) {
                dev_err(&pdev->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(&pdev->dev,
                             pdata->num_regulators, sizeof(*rdata),
                             GFP_KERNEL);
        if (!rdata)
                return -ENOMEM;

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

                if (i == ARRAY_SIZE(regulators)) {
                        dev_warn(&pdev->dev, "don't know how to configure regulator %pOFn\n",
                                 reg_np);
                        continue;
                }

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

        pdata->buck1_gpiodvs = of_property_read_bool(pmic_np, "max8997,pmic-buck1-uses-gpio-dvs");
        pdata->buck2_gpiodvs = of_property_read_bool(pmic_np, "max8997,pmic-buck2-uses-gpio-dvs");
        pdata->buck5_gpiodvs = of_property_read_bool(pmic_np, "max8997,pmic-buck5-uses-gpio-dvs");

        if (pdata->buck1_gpiodvs || pdata->buck2_gpiodvs ||
                                                pdata->buck5_gpiodvs) {
                if (of_property_read_u32(pmic_np,
                                "max8997,pmic-buck125-default-dvs-idx",
                                &pdata->buck125_default_idx)) {
                        pdata->buck125_default_idx = 0;
                } else {
                        if (pdata->buck125_default_idx >= 8) {
                                pdata->buck125_default_idx = 0;
                                dev_info(&pdev->dev, "invalid value for default dvs index, using 0 instead\n");
                        }
                }

                pdata->ignore_gpiodvs_side_effect = of_property_read_bool(pmic_np,
                        "max8997,pmic-ignore-gpiodvs-side-effect");

                dvs_voltage_nr = 8;
        }

        if (of_property_read_u32_array(pmic_np,
                                "max8997,pmic-buck1-dvs-voltage",
                                pdata->buck1_voltage, dvs_voltage_nr)) {
                dev_err(&pdev->dev, "buck1 voltages not specified\n");
                return -EINVAL;
        }

        if (of_property_read_u32_array(pmic_np,
                                "max8997,pmic-buck2-dvs-voltage",
                                pdata->buck2_voltage, dvs_voltage_nr)) {
                dev_err(&pdev->dev, "buck2 voltages not specified\n");
                return -EINVAL;
        }

        if (of_property_read_u32_array(pmic_np,
                                "max8997,pmic-buck5-dvs-voltage",
                                pdata->buck5_voltage, dvs_voltage_nr)) {
                dev_err(&pdev->dev, "buck5 voltages not specified\n");
                return -EINVAL;
        }

        return 0;
}
#else
static int max8997_pmic_dt_parse_pdata(struct platform_device *pdev,
                                        struct max8997_platform_data *pdata)
{
        return 0;
}
#endif /* CONFIG_OF */

static int max8997_pmic_probe(struct platform_device *pdev)
{
        struct max8997_dev *iodev = dev_get_drvdata(pdev->dev.parent);
        struct max8997_platform_data *pdata = iodev->pdata;
        struct regulator_config config = { };
        struct regulator_dev *rdev;
        struct max8997_data *max8997;
        struct i2c_client *i2c;
        int i, ret, nr_dvs;
        u8 max_buck1 = 0, max_buck2 = 0, max_buck5 = 0;

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

        if (iodev->dev->of_node) {
                ret = max8997_pmic_dt_parse_pdata(pdev, pdata);
                if (ret)
                        return ret;
        }

        max8997 = devm_kzalloc(&pdev->dev, sizeof(struct max8997_data),
                               GFP_KERNEL);
        if (!max8997)
                return -ENOMEM;

        max8997->dev = &pdev->dev;
        max8997->iodev = iodev;
        max8997->num_regulators = pdata->num_regulators;
        platform_set_drvdata(pdev, max8997);
        i2c = max8997->iodev->i2c;

        max8997->buck125_gpioindex = pdata->buck125_default_idx;
        max8997->buck1_gpiodvs = pdata->buck1_gpiodvs;
        max8997->buck2_gpiodvs = pdata->buck2_gpiodvs;
        max8997->buck5_gpiodvs = pdata->buck5_gpiodvs;
        max8997->ignore_gpiodvs_side_effect = pdata->ignore_gpiodvs_side_effect;

        nr_dvs = (pdata->buck1_gpiodvs || pdata->buck2_gpiodvs ||
                        pdata->buck5_gpiodvs) ? 8 : 1;

        for (i = 0; i < nr_dvs; i++) {
                max8997->buck1_vol[i] = ret =
                        max8997_get_voltage_proper_val(
                                        &buck1245_voltage_map_desc,
                                        pdata->buck1_voltage[i],
                                        pdata->buck1_voltage[i] +
                                        buck1245_voltage_map_desc.step);
                if (ret < 0)
                        return ret;

                max8997->buck2_vol[i] = ret =
                        max8997_get_voltage_proper_val(
                                        &buck1245_voltage_map_desc,
                                        pdata->buck2_voltage[i],
                                        pdata->buck2_voltage[i] +
                                        buck1245_voltage_map_desc.step);
                if (ret < 0)
                        return ret;

                max8997->buck5_vol[i] = ret =
                        max8997_get_voltage_proper_val(
                                        &buck1245_voltage_map_desc,
                                        pdata->buck5_voltage[i],
                                        pdata->buck5_voltage[i] +
                                        buck1245_voltage_map_desc.step);
                if (ret < 0)
                        return ret;

                if (max_buck1 < max8997->buck1_vol[i])
                        max_buck1 = max8997->buck1_vol[i];
                if (max_buck2 < max8997->buck2_vol[i])
                        max_buck2 = max8997->buck2_vol[i];
                if (max_buck5 < max8997->buck5_vol[i])
                        max_buck5 = max8997->buck5_vol[i];
        }

        /* For the safety, set max voltage before setting up */
        for (i = 0; i < 8; i++) {
                max8997_update_reg(i2c, MAX8997_REG_BUCK1DVS1 + i,
                                max_buck1, 0x3f);
                max8997_update_reg(i2c, MAX8997_REG_BUCK2DVS1 + i,
                                max_buck2, 0x3f);
                max8997_update_reg(i2c, MAX8997_REG_BUCK5DVS1 + i,
                                max_buck5, 0x3f);
        }

        /* Initialize all the DVS related BUCK registers */
        for (i = 0; i < nr_dvs; i++) {
                max8997_update_reg(i2c, MAX8997_REG_BUCK1DVS1 + i,
                                max8997->buck1_vol[i],
                                0x3f);
                max8997_update_reg(i2c, MAX8997_REG_BUCK2DVS1 + i,
                                max8997->buck2_vol[i],
                                0x3f);
                max8997_update_reg(i2c, MAX8997_REG_BUCK5DVS1 + i,
                                max8997->buck5_vol[i],
                                0x3f);
        }

        /*
         * If buck 1, 2, and 5 do not care DVS GPIO settings, ignore them.
         * If at least one of them cares, set gpios.
         */
        if (pdata->buck1_gpiodvs || pdata->buck2_gpiodvs ||
                        pdata->buck5_gpiodvs) {
                const char *gpio_names[3] = {"MAX8997 SET1", "MAX8997 SET2", "MAX8997 SET3"};

                for (i = 0; i < 3; i++) {
                        enum gpiod_flags flags;

                        if (max8997->buck125_gpioindex & BIT(2 - i))
                                flags = GPIOD_OUT_HIGH;
                        else
                                flags = GPIOD_OUT_LOW;

                        max8997->buck125_gpiods[i] = devm_gpiod_get_index(iodev->dev,
                                                                          "max8997,pmic-buck125-dvs",
                                                                          i,
                                                                          flags);
                        if (IS_ERR(max8997->buck125_gpiods[i])) {
                                ret = PTR_ERR(max8997->buck125_gpiods[i]);
                                return dev_err_probe(iodev->dev, ret, "cant get GPIO %d (%d)\n",
                                                     i, ret);
                        }
                        gpiod_set_consumer_name(max8997->buck125_gpiods[i], gpio_names[i]);
                }
        }

        /* DVS-GPIO disabled */
        max8997_update_reg(i2c, MAX8997_REG_BUCK1CTRL, (pdata->buck1_gpiodvs) ?
                        (1 << 1) : (0 << 1), 1 << 1);
        max8997_update_reg(i2c, MAX8997_REG_BUCK2CTRL, (pdata->buck2_gpiodvs) ?
                        (1 << 1) : (0 << 1), 1 << 1);
        max8997_update_reg(i2c, MAX8997_REG_BUCK5CTRL, (pdata->buck5_gpiodvs) ?
                        (1 << 1) : (0 << 1), 1 << 1);

        /* Misc Settings */
        max8997->ramp_delay = 10; /* set 10mV/us, which is the default */
        max8997_write_reg(i2c, MAX8997_REG_BUCKRAMP, (0xf << 4) | 0x9);

        for (i = 0; i < pdata->num_regulators; i++) {
                const struct voltage_map_desc *desc;
                int id = pdata->regulators[i].id;

                desc = reg_voltage_map[id];
                if (desc) {
                        regulators[id].n_voltages =
                                (desc->max - desc->min) / desc->step + 1;
                } else if (id == MAX8997_ESAFEOUT1 || id == MAX8997_ESAFEOUT2) {
                        regulators[id].volt_table = safeoutvolt;
                        regulators[id].n_voltages = ARRAY_SIZE(safeoutvolt);
                } else if (id == MAX8997_CHARGER_CV) {
                        regulators[id].n_voltages = 16;
                }

                config.dev = max8997->dev;
                config.init_data = pdata->regulators[i].initdata;
                config.driver_data = max8997;
                config.of_node = pdata->regulators[i].reg_node;

                rdev = devm_regulator_register(&pdev->dev, &regulators[id],
                                               &config);
                if (IS_ERR(rdev)) {
                        dev_err(max8997->dev, "regulator init failed for %d\n",
                                        id);
                        return PTR_ERR(rdev);
                }
        }

        return 0;
}

static const struct platform_device_id max8997_pmic_id[] = {
        { "max8997-pmic", 0},
        { },
};
MODULE_DEVICE_TABLE(platform, max8997_pmic_id);

static struct platform_driver max8997_pmic_driver = {
        .driver = {
                .name = "max8997-pmic",
                .probe_type = PROBE_PREFER_ASYNCHRONOUS,
        },
        .probe = max8997_pmic_probe,
        .id_table = max8997_pmic_id,
};

static int __init max8997_pmic_init(void)
{
        return platform_driver_register(&max8997_pmic_driver);
}
subsys_initcall(max8997_pmic_init);

static void __exit max8997_pmic_cleanup(void)
{
        platform_driver_unregister(&max8997_pmic_driver);
}
module_exit(max8997_pmic_cleanup);

MODULE_DESCRIPTION("MAXIM 8997/8966 Regulator Driver");
MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
MODULE_LICENSE("GPL");