// SPDX-License-Identifier: GPL-2.0+
//
// Fuel gauge driver for Maxim 17042 / 8966 / 8997
//  Note that Maxim 8966 and 8997 are mfd and this is its subdevice.
//
// Copyright (C) 2011 Samsung Electronics
// MyungJoo Ham <myungjoo.ham@samsung.com>
//
// This driver is based on max17040_battery.c

#include <linux/acpi.h>
#include <linux/devm-helpers.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/i2c.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/pm.h>
#include <linux/mod_devicetable.h>
#include <linux/power_supply.h>
#include <linux/power/max17042_battery.h>
#include <linux/of.h>
#include <linux/regmap.h>

/* Status register bits */
#define STATUS_POR_BIT         (1 << 1)
#define STATUS_BST_BIT         (1 << 3)
#define STATUS_VMN_BIT         (1 << 8)
#define STATUS_TMN_BIT         (1 << 9)
#define STATUS_SMN_BIT         (1 << 10)
#define STATUS_BI_BIT          (1 << 11)
#define STATUS_VMX_BIT         (1 << 12)
#define STATUS_TMX_BIT         (1 << 13)
#define STATUS_SMX_BIT         (1 << 14)
#define STATUS_BR_BIT          (1 << 15)

/* Interrupt mask bits */
#define CFG_ALRT_BIT_ENBL       (1 << 2)

#define VFSOC0_LOCK             0x0000
#define VFSOC0_UNLOCK           0x0080
#define MODEL_UNLOCK1   0X0059
#define MODEL_UNLOCK2   0X00C4
#define MODEL_LOCK1             0X0000
#define MODEL_LOCK2             0X0000

#define dQ_ACC_DIV      0x4
#define dP_ACC_100      0x1900
#define dP_ACC_200      0x3200

#define MAX17042_VMAX_TOLERANCE         50 /* 50 mV */

struct max17042_chip {
        struct device *dev;
        struct regmap *regmap;
        struct power_supply *battery;
        enum max170xx_chip_type chip_type;
        struct max17042_platform_data *pdata;
        struct work_struct work;
        int    init_complete;
        int    irq;
};

static enum power_supply_property max17042_battery_props[] = {
        POWER_SUPPLY_PROP_STATUS,
        POWER_SUPPLY_PROP_PRESENT,
        POWER_SUPPLY_PROP_TECHNOLOGY,
        POWER_SUPPLY_PROP_CYCLE_COUNT,
        POWER_SUPPLY_PROP_VOLTAGE_MAX,
        POWER_SUPPLY_PROP_VOLTAGE_MIN,
        POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
        POWER_SUPPLY_PROP_VOLTAGE_NOW,
        POWER_SUPPLY_PROP_VOLTAGE_AVG,
        POWER_SUPPLY_PROP_VOLTAGE_OCV,
        POWER_SUPPLY_PROP_CAPACITY,
        POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
        POWER_SUPPLY_PROP_CHARGE_FULL,
        POWER_SUPPLY_PROP_CHARGE_NOW,
        POWER_SUPPLY_PROP_CHARGE_COUNTER,
        POWER_SUPPLY_PROP_CHARGE_TERM_CURRENT,
        POWER_SUPPLY_PROP_TEMP,
        POWER_SUPPLY_PROP_TEMP_ALERT_MIN,
        POWER_SUPPLY_PROP_TEMP_ALERT_MAX,
        POWER_SUPPLY_PROP_TEMP_MIN,
        POWER_SUPPLY_PROP_TEMP_MAX,
        POWER_SUPPLY_PROP_HEALTH,
        POWER_SUPPLY_PROP_SCOPE,
        POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW,
        // these two have to be at the end on the list
        POWER_SUPPLY_PROP_CURRENT_NOW,
        POWER_SUPPLY_PROP_CURRENT_AVG,
};

static int max17042_get_temperature(struct max17042_chip *chip, int *temp)
{
        int ret;
        u32 data;
        struct regmap *map = chip->regmap;

        ret = regmap_read(map, MAX17042_TEMP, &data);
        if (ret < 0)
                return ret;

        *temp = sign_extend32(data, 15);
        /* The value is converted into deci-centigrade scale */
        /* Units of LSB = 1 / 256 degree Celsius */
        *temp = *temp * 10 / 256;
        return 0;
}

static int max17042_get_status(struct max17042_chip *chip, int *status)
{
        int ret, charge_full, charge_now;
        int avg_current;
        u32 data;

        ret = power_supply_am_i_supplied(chip->battery);
        if (ret < 0) {
                *status = POWER_SUPPLY_STATUS_UNKNOWN;
                return 0;
        }
        if (ret == 0) {
                *status = POWER_SUPPLY_STATUS_DISCHARGING;
                return 0;
        }

        /*
         * The MAX170xx has builtin end-of-charge detection and will update
         * FullCAP to match RepCap when it detects end of charging.
         *
         * When this cycle the battery gets charged to a higher (calculated)
         * capacity then the previous cycle then FullCAP will get updated
         * continuously once end-of-charge detection kicks in, so allow the
         * 2 to differ a bit.
         */

        ret = regmap_read(chip->regmap, MAX17042_FullCAP, &charge_full);
        if (ret < 0)
                return ret;

        ret = regmap_read(chip->regmap, MAX17042_RepCap, &charge_now);
        if (ret < 0)
                return ret;

        if ((charge_full - charge_now) <= MAX17042_FULL_THRESHOLD) {
                *status = POWER_SUPPLY_STATUS_FULL;
                return 0;
        }

        /*
         * Even though we are supplied, we may still be discharging if the
         * supply is e.g. only delivering 5V 0.5A. Check current if available.
         */
        if (!chip->pdata->enable_current_sense) {
                *status = POWER_SUPPLY_STATUS_CHARGING;
                return 0;
        }

        ret = regmap_read(chip->regmap, MAX17042_AvgCurrent, &data);
        if (ret < 0)
                return ret;

        avg_current = sign_extend32(data, 15);
        avg_current *= 1562500 / chip->pdata->r_sns;

        if (avg_current > 0)
                *status = POWER_SUPPLY_STATUS_CHARGING;
        else
                *status = POWER_SUPPLY_STATUS_DISCHARGING;

        return 0;
}

static int max17042_get_battery_health(struct max17042_chip *chip, int *health)
{
        int temp, vavg, vbatt, ret;
        u32 val;

        ret = regmap_read(chip->regmap, MAX17042_AvgVCELL, &val);
        if (ret < 0)
                goto health_error;

        /* bits [0-3] unused */
        vavg = val * 625 / 8;
        /* Convert to millivolts */
        vavg /= 1000;

        ret = regmap_read(chip->regmap, MAX17042_VCELL, &val);
        if (ret < 0)
                goto health_error;

        /* bits [0-3] unused */
        vbatt = val * 625 / 8;
        /* Convert to millivolts */
        vbatt /= 1000;

        if (vavg < chip->pdata->vmin) {
                *health = POWER_SUPPLY_HEALTH_DEAD;
                goto out;
        }

        if (vbatt > chip->pdata->vmax + MAX17042_VMAX_TOLERANCE) {
                *health = POWER_SUPPLY_HEALTH_OVERVOLTAGE;
                goto out;
        }

        ret = max17042_get_temperature(chip, &temp);
        if (ret < 0)
                goto health_error;

        if (temp < chip->pdata->temp_min) {
                *health = POWER_SUPPLY_HEALTH_COLD;
                goto out;
        }

        if (temp > chip->pdata->temp_max) {
                *health = POWER_SUPPLY_HEALTH_OVERHEAT;
                goto out;
        }

        *health = POWER_SUPPLY_HEALTH_GOOD;

out:
        return 0;

health_error:
        return ret;
}

static int max17042_get_property(struct power_supply *psy,
                            enum power_supply_property psp,
                            union power_supply_propval *val)
{
        struct max17042_chip *chip = power_supply_get_drvdata(psy);
        struct regmap *map = chip->regmap;
        int ret;
        u32 data;
        u64 data64;

        if (!chip->init_complete)
                return -EAGAIN;

        switch (psp) {
        case POWER_SUPPLY_PROP_STATUS:
                ret = max17042_get_status(chip, &val->intval);
                if (ret < 0)
                        return ret;
                break;
        case POWER_SUPPLY_PROP_PRESENT:
                ret = regmap_read(map, MAX17042_STATUS, &data);
                if (ret < 0)
                        return ret;

                if (data & MAX17042_STATUS_BattAbsent)
                        val->intval = 0;
                else
                        val->intval = 1;
                break;
        case POWER_SUPPLY_PROP_TECHNOLOGY:
                val->intval = POWER_SUPPLY_TECHNOLOGY_LION;
                break;
        case POWER_SUPPLY_PROP_CYCLE_COUNT:
                ret = regmap_read(map, MAX17042_Cycles, &data);
                if (ret < 0)
                        return ret;

                val->intval = data;
                break;
        case POWER_SUPPLY_PROP_VOLTAGE_MAX:
                ret = regmap_read(map, MAX17042_MinMaxVolt, &data);
                if (ret < 0)
                        return ret;

                val->intval = data >> 8;
                val->intval *= 20000; /* Units of LSB = 20mV */
                break;
        case POWER_SUPPLY_PROP_VOLTAGE_MIN:
                ret = regmap_read(map, MAX17042_MinMaxVolt, &data);
                if (ret < 0)
                        return ret;

                val->intval = (data & 0xff) * 20000; /* Units of 20mV */
                break;
        case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
                if (chip->chip_type == MAXIM_DEVICE_TYPE_MAX17042)
                        ret = regmap_read(map, MAX17042_V_empty, &data);
                else
                        ret = regmap_read(map, MAX17047_V_empty, &data);
                if (ret < 0)
                        return ret;

                val->intval = data >> 7;
                val->intval *= 10000; /* Units of LSB = 10mV */
                break;
        case POWER_SUPPLY_PROP_VOLTAGE_NOW:
                ret = regmap_read(map, MAX17042_VCELL, &data);
                if (ret < 0)
                        return ret;

                val->intval = data * 625 / 8;
                break;
        case POWER_SUPPLY_PROP_VOLTAGE_AVG:
                ret = regmap_read(map, MAX17042_AvgVCELL, &data);
                if (ret < 0)
                        return ret;

                val->intval = data * 625 / 8;
                break;
        case POWER_SUPPLY_PROP_VOLTAGE_OCV:
                ret = regmap_read(map, MAX17042_OCVInternal, &data);
                if (ret < 0)
                        return ret;

                val->intval = data * 625 / 8;
                break;
        case POWER_SUPPLY_PROP_CAPACITY:
                if (chip->pdata->enable_current_sense)
                        ret = regmap_read(map, MAX17042_RepSOC, &data);
                else
                        ret = regmap_read(map, MAX17042_VFSOC, &data);
                if (ret < 0)
                        return ret;

                val->intval = data >> 8;
                break;
        case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
                ret = regmap_read(map, MAX17042_DesignCap, &data);
                if (ret < 0)
                        return ret;

                data64 = data * 5000000ll;
                do_div(data64, chip->pdata->r_sns);
                val->intval = data64;
                break;
        case POWER_SUPPLY_PROP_CHARGE_FULL:
                ret = regmap_read(map, MAX17042_FullCAP, &data);
                if (ret < 0)
                        return ret;

                data64 = data * 5000000ll;
                do_div(data64, chip->pdata->r_sns);
                val->intval = data64;
                break;
        case POWER_SUPPLY_PROP_CHARGE_NOW:
                ret = regmap_read(map, MAX17042_RepCap, &data);
                if (ret < 0)
                        return ret;

                data64 = data * 5000000ll;
                do_div(data64, chip->pdata->r_sns);
                val->intval = data64;
                break;
        case POWER_SUPPLY_PROP_CHARGE_COUNTER:
                ret = regmap_read(map, MAX17042_QH, &data);
                if (ret < 0)
                        return ret;

                data64 = sign_extend64(data, 15) * 5000000ll;
                val->intval = div_s64(data64, chip->pdata->r_sns);
                break;
        case POWER_SUPPLY_PROP_TEMP:
                ret = max17042_get_temperature(chip, &val->intval);
                if (ret < 0)
                        return ret;
                break;
        case POWER_SUPPLY_PROP_TEMP_ALERT_MIN:
                ret = regmap_read(map, MAX17042_TALRT_Th, &data);
                if (ret < 0)
                        return ret;
                /* LSB is Alert Minimum. In deci-centigrade */
                val->intval = sign_extend32(data & 0xff, 7) * 10;
                break;
        case POWER_SUPPLY_PROP_TEMP_ALERT_MAX:
                ret = regmap_read(map, MAX17042_TALRT_Th, &data);
                if (ret < 0)
                        return ret;
                /* MSB is Alert Maximum. In deci-centigrade */
                val->intval = sign_extend32(data >> 8, 7) * 10;
                break;
        case POWER_SUPPLY_PROP_TEMP_MIN:
                val->intval = chip->pdata->temp_min;
                break;
        case POWER_SUPPLY_PROP_TEMP_MAX:
                val->intval = chip->pdata->temp_max;
                break;
        case POWER_SUPPLY_PROP_HEALTH:
                ret = max17042_get_battery_health(chip, &val->intval);
                if (ret < 0)
                        return ret;
                break;
        case POWER_SUPPLY_PROP_SCOPE:
                val->intval = POWER_SUPPLY_SCOPE_SYSTEM;
                break;
        case POWER_SUPPLY_PROP_CURRENT_NOW:
                if (chip->pdata->enable_current_sense) {
                        ret = regmap_read(map, MAX17042_Current, &data);
                        if (ret < 0)
                                return ret;

                        data64 = sign_extend64(data, 15) * 1562500ll;
                        val->intval = div_s64(data64, chip->pdata->r_sns);
                } else {
                        return -EINVAL;
                }
                break;
        case POWER_SUPPLY_PROP_CURRENT_AVG:
                if (chip->pdata->enable_current_sense) {
                        ret = regmap_read(map, MAX17042_AvgCurrent, &data);
                        if (ret < 0)
                                return ret;

                        data64 = sign_extend64(data, 15) * 1562500ll;
                        val->intval = div_s64(data64, chip->pdata->r_sns);
                } else {
                        return -EINVAL;
                }
                break;
        case POWER_SUPPLY_PROP_CHARGE_TERM_CURRENT:
                ret = regmap_read(map, MAX17042_ICHGTerm, &data);
                if (ret < 0)
                        return ret;

                data64 = data * 1562500ll;
                val->intval = div_s64(data64, chip->pdata->r_sns);
                break;
        case POWER_SUPPLY_PROP_TIME_TO_EMPTY_NOW:
                ret = regmap_read(map, MAX17042_TTE, &data);
                if (ret < 0)
                        return ret;

                val->intval = data * 5625 / 1000;
                break;
        default:
                return -EINVAL;
        }
        return 0;
}

static int max17042_set_property(struct power_supply *psy,
                            enum power_supply_property psp,
                            const union power_supply_propval *val)
{
        struct max17042_chip *chip = power_supply_get_drvdata(psy);
        struct regmap *map = chip->regmap;
        int ret = 0;
        u32 data;
        int8_t temp;

        switch (psp) {
        case POWER_SUPPLY_PROP_TEMP_ALERT_MIN:
                ret = regmap_read(map, MAX17042_TALRT_Th, &data);
                if (ret < 0)
                        return ret;

                /* Input in deci-centigrade, convert to centigrade */
                temp = val->intval / 10;
                /* force min < max */
                if (temp >= (int8_t)(data >> 8))
                        temp = (int8_t)(data >> 8) - 1;
                /* Write both MAX and MIN ALERT */
                data = (data & 0xff00) + temp;
                ret = regmap_write(map, MAX17042_TALRT_Th, data);
                break;
        case POWER_SUPPLY_PROP_TEMP_ALERT_MAX:
                ret = regmap_read(map, MAX17042_TALRT_Th, &data);
                if (ret < 0)
                        return ret;

                /* Input in Deci-Centigrade, convert to centigrade */
                temp = val->intval / 10;
                /* force max > min */
                if (temp <= (int8_t)(data & 0xff))
                        temp = (int8_t)(data & 0xff) + 1;
                /* Write both MAX and MIN ALERT */
                data = (data & 0xff) + (temp << 8);
                ret = regmap_write(map, MAX17042_TALRT_Th, data);
                break;
        default:
                ret = -EINVAL;
        }

        return ret;
}

static int max17042_property_is_writeable(struct power_supply *psy,
                enum power_supply_property psp)
{
        int ret;

        switch (psp) {
        case POWER_SUPPLY_PROP_TEMP_ALERT_MIN:
        case POWER_SUPPLY_PROP_TEMP_ALERT_MAX:
                ret = 1;
                break;
        default:
                ret = 0;
        }

        return ret;
}

static int max17042_write_verify_reg(struct regmap *map, u8 reg, u32 value)
{
        int retries = 8;
        int ret;
        u32 read_value;

        do {
                ret = regmap_write(map, reg, value);
                regmap_read(map, reg, &read_value);
                if (read_value != value) {
                        ret = -EIO;
                        retries--;
                }
        } while (retries && read_value != value);

        if (ret < 0)
                pr_err("%s: err %d\n", __func__, ret);

        return ret;
}

static inline void max17042_override_por(struct regmap *map,
                                         u8 reg, u16 value)
{
        if (value)
                regmap_write(map, reg, value);
}

static inline void max17042_unlock_model(struct max17042_chip *chip)
{
        struct regmap *map = chip->regmap;

        regmap_write(map, MAX17042_MLOCKReg1, MODEL_UNLOCK1);
        regmap_write(map, MAX17042_MLOCKReg2, MODEL_UNLOCK2);
}

static inline void max17042_lock_model(struct max17042_chip *chip)
{
        struct regmap *map = chip->regmap;

        regmap_write(map, MAX17042_MLOCKReg1, MODEL_LOCK1);
        regmap_write(map, MAX17042_MLOCKReg2, MODEL_LOCK2);
}

static inline void max17042_write_model_data(struct max17042_chip *chip,
                                        u8 addr, int size)
{
        struct regmap *map = chip->regmap;
        int i;

        for (i = 0; i < size; i++)
                regmap_write(map, addr + i,
                        chip->pdata->config_data->cell_char_tbl[i]);
}

static inline void max17042_read_model_data(struct max17042_chip *chip,
                                        u8 addr, u16 *data, int size)
{
        struct regmap *map = chip->regmap;
        int i;
        u32 tmp;

        for (i = 0; i < size; i++) {
                regmap_read(map, addr + i, &tmp);
                data[i] = (u16)tmp;
        }
}

static inline int max17042_model_data_compare(struct max17042_chip *chip,
                                        u16 *data1, u16 *data2, int size)
{
        int i;

        if (memcmp(data1, data2, size)) {
                dev_err(chip->dev, "%s compare failed\n", __func__);
                for (i = 0; i < size; i++)
                        dev_info(chip->dev, "0x%x, 0x%x",
                                data1[i], data2[i]);
                dev_info(chip->dev, "\n");
                return -EINVAL;
        }
        return 0;
}

static int max17042_init_model(struct max17042_chip *chip)
{
        int ret;
        int table_size = ARRAY_SIZE(chip->pdata->config_data->cell_char_tbl);
        u16 *temp_data;

        temp_data = kcalloc(table_size, sizeof(*temp_data), GFP_KERNEL);
        if (!temp_data)
                return -ENOMEM;

        max17042_unlock_model(chip);
        max17042_write_model_data(chip, MAX17042_MODELChrTbl,
                                table_size);
        max17042_read_model_data(chip, MAX17042_MODELChrTbl, temp_data,
                                table_size);

        ret = max17042_model_data_compare(
                chip,
                chip->pdata->config_data->cell_char_tbl,
                temp_data,
                table_size);

        max17042_lock_model(chip);
        kfree(temp_data);

        return ret;
}

static int max17042_verify_model_lock(struct max17042_chip *chip)
{
        int i;
        int table_size = ARRAY_SIZE(chip->pdata->config_data->cell_char_tbl);
        u16 *temp_data;
        int ret = 0;

        temp_data = kcalloc(table_size, sizeof(*temp_data), GFP_KERNEL);
        if (!temp_data)
                return -ENOMEM;

        max17042_read_model_data(chip, MAX17042_MODELChrTbl, temp_data,
                                table_size);
        for (i = 0; i < table_size; i++)
                if (temp_data[i])
                        ret = -EINVAL;

        kfree(temp_data);
        return ret;
}

static void max17042_write_config_regs(struct max17042_chip *chip)
{
        struct max17042_config_data *config = chip->pdata->config_data;
        struct regmap *map = chip->regmap;

        regmap_write(map, MAX17042_CONFIG, config->config);
        regmap_write(map, MAX17042_LearnCFG, config->learn_cfg);
        regmap_write(map, MAX17042_FilterCFG,
                        config->filter_cfg);
        regmap_write(map, MAX17042_RelaxCFG, config->relax_cfg);
        if (chip->chip_type == MAXIM_DEVICE_TYPE_MAX17047 ||
                        chip->chip_type == MAXIM_DEVICE_TYPE_MAX17050 ||
                        chip->chip_type == MAXIM_DEVICE_TYPE_MAX17055)
                regmap_write(map, MAX17047_FullSOCThr,
                                                config->full_soc_thresh);
}

static void  max17042_write_custom_regs(struct max17042_chip *chip)
{
        struct max17042_config_data *config = chip->pdata->config_data;
        struct regmap *map = chip->regmap;

        max17042_write_verify_reg(map, MAX17042_RCOMP0, config->rcomp0);
        max17042_write_verify_reg(map, MAX17042_TempCo, config->tcompc0);
        max17042_write_verify_reg(map, MAX17042_ICHGTerm, config->ichgt_term);
        if (chip->chip_type == MAXIM_DEVICE_TYPE_MAX17042) {
                regmap_write(map, MAX17042_EmptyTempCo, config->empty_tempco);
                max17042_write_verify_reg(map, MAX17042_K_empty0,
                                        config->kempty0);
        } else {
                max17042_write_verify_reg(map, MAX17047_QRTbl00,
                                                config->qrtbl00);
                max17042_write_verify_reg(map, MAX17047_QRTbl10,
                                                config->qrtbl10);
                max17042_write_verify_reg(map, MAX17047_QRTbl20,
                                                config->qrtbl20);
                max17042_write_verify_reg(map, MAX17047_QRTbl30,
                                                config->qrtbl30);
        }
}

static void max17042_update_capacity_regs(struct max17042_chip *chip)
{
        struct max17042_config_data *config = chip->pdata->config_data;
        struct regmap *map = chip->regmap;

        max17042_write_verify_reg(map, MAX17042_FullCAP,
                                config->fullcap);
        regmap_write(map, MAX17042_DesignCap, config->design_cap);
        max17042_write_verify_reg(map, MAX17042_FullCAPNom,
                                config->fullcapnom);
}

static void max17042_reset_vfsoc0_reg(struct max17042_chip *chip)
{
        unsigned int vfSoc;
        struct regmap *map = chip->regmap;

        regmap_read(map, MAX17042_VFSOC, &vfSoc);
        regmap_write(map, MAX17042_VFSOC0Enable, VFSOC0_UNLOCK);
        max17042_write_verify_reg(map, MAX17042_VFSOC0, vfSoc);
        regmap_write(map, MAX17042_VFSOC0Enable, VFSOC0_LOCK);
}

static void max17042_load_new_capacity_params(struct max17042_chip *chip)
{
        u32 full_cap0, rep_cap, dq_acc, vfSoc;
        u32 rem_cap;

        struct max17042_config_data *config = chip->pdata->config_data;
        struct regmap *map = chip->regmap;

        regmap_read(map, MAX17042_FullCAP0, &full_cap0);
        regmap_read(map, MAX17042_VFSOC, &vfSoc);

        /* fg_vfSoc needs to shifted by 8 bits to get the
         * perc in 1% accuracy, to get the right rem_cap multiply
         * full_cap0, fg_vfSoc and devide by 100
         */
        rem_cap = ((vfSoc >> 8) * full_cap0) / 100;
        max17042_write_verify_reg(map, MAX17042_RemCap, rem_cap);

        rep_cap = rem_cap;
        max17042_write_verify_reg(map, MAX17042_RepCap, rep_cap);

        /* Write dQ_acc to 200% of Capacity and dP_acc to 200% */
        dq_acc = config->fullcap / dQ_ACC_DIV;
        max17042_write_verify_reg(map, MAX17042_dQacc, dq_acc);
        max17042_write_verify_reg(map, MAX17042_dPacc, dP_ACC_200);

        max17042_write_verify_reg(map, MAX17042_FullCAP,
                        config->fullcap);
        regmap_write(map, MAX17042_DesignCap,
                        config->design_cap);
        max17042_write_verify_reg(map, MAX17042_FullCAPNom,
                        config->fullcapnom);
        /* Update SOC register with new SOC */
        regmap_write(map, MAX17042_RepSOC, vfSoc);
}

/*
 * Block write all the override values coming from platform data.
 * This function MUST be called before the POR initialization procedure
 * specified by maxim.
 */
static inline void max17042_override_por_values(struct max17042_chip *chip)
{
        struct regmap *map = chip->regmap;
        struct max17042_config_data *config = chip->pdata->config_data;

        max17042_override_por(map, MAX17042_TGAIN, config->tgain);
        max17042_override_por(map, MAX17042_TOFF, config->toff);
        max17042_override_por(map, MAX17042_CGAIN, config->cgain);
        max17042_override_por(map, MAX17042_COFF, config->coff);

        max17042_override_por(map, MAX17042_VALRT_Th, config->valrt_thresh);
        max17042_override_por(map, MAX17042_TALRT_Th, config->talrt_thresh);
        max17042_override_por(map, MAX17042_SALRT_Th,
                                                config->soc_alrt_thresh);
        max17042_override_por(map, MAX17042_CONFIG, config->config);
        max17042_override_por(map, MAX17042_SHDNTIMER, config->shdntimer);

        max17042_override_por(map, MAX17042_DesignCap, config->design_cap);
        max17042_override_por(map, MAX17042_ICHGTerm, config->ichgt_term);

        max17042_override_por(map, MAX17042_AtRate, config->at_rate);
        max17042_override_por(map, MAX17042_LearnCFG, config->learn_cfg);
        max17042_override_por(map, MAX17042_FilterCFG, config->filter_cfg);
        max17042_override_por(map, MAX17042_RelaxCFG, config->relax_cfg);
        max17042_override_por(map, MAX17042_MiscCFG, config->misc_cfg);

        max17042_override_por(map, MAX17042_FullCAP, config->fullcap);
        max17042_override_por(map, MAX17042_FullCAPNom, config->fullcapnom);
        max17042_override_por(map, MAX17042_dQacc, config->dqacc);
        max17042_override_por(map, MAX17042_dPacc, config->dpacc);

        max17042_override_por(map, MAX17042_RCOMP0, config->rcomp0);
        max17042_override_por(map, MAX17042_TempCo, config->tcompc0);

        if (chip->chip_type == MAXIM_DEVICE_TYPE_MAX17042) {
                max17042_override_por(map, MAX17042_MaskSOC, config->masksoc);
                max17042_override_por(map, MAX17042_SOC_empty, config->socempty);
                max17042_override_por(map, MAX17042_V_empty, config->vempty);
                max17042_override_por(map, MAX17042_EmptyTempCo, config->empty_tempco);
                max17042_override_por(map, MAX17042_K_empty0, config->kempty0);
        }

        if ((chip->chip_type == MAXIM_DEVICE_TYPE_MAX17042) ||
            (chip->chip_type == MAXIM_DEVICE_TYPE_MAX17047) ||
            (chip->chip_type == MAXIM_DEVICE_TYPE_MAX17050)) {
                max17042_override_por(map, MAX17042_IAvg_empty, config->iavg_empty);
                max17042_override_por(map, MAX17042_TempNom, config->temp_nom);
                max17042_override_por(map, MAX17042_TempLim, config->temp_lim);
                max17042_override_por(map, MAX17042_FCTC, config->fctc);
        }

        if ((chip->chip_type == MAXIM_DEVICE_TYPE_MAX17047) ||
            (chip->chip_type == MAXIM_DEVICE_TYPE_MAX17050) ||
            (chip->chip_type == MAXIM_DEVICE_TYPE_MAX17055)) {
                max17042_override_por(map, MAX17047_V_empty, config->vempty);
        }
}

static int max17042_init_chip(struct max17042_chip *chip)
{
        struct regmap *map = chip->regmap;
        int ret;

        max17042_override_por_values(chip);
        /* After Power up, the MAX17042 requires 500mS in order
         * to perform signal debouncing and initial SOC reporting
         */
        msleep(500);

        /* Initialize configuration */
        max17042_write_config_regs(chip);

        /* write cell characterization data */
        ret = max17042_init_model(chip);
        if (ret) {
                dev_err(chip->dev, "%s init failed\n",
                        __func__);
                return -EIO;
        }

        ret = max17042_verify_model_lock(chip);
        if (ret) {
                dev_err(chip->dev, "%s lock verify failed\n",
                        __func__);
                return -EIO;
        }
        /* write custom parameters */
        max17042_write_custom_regs(chip);

        /* update capacity params */
        max17042_update_capacity_regs(chip);

        /* delay must be atleast 350mS to allow VFSOC
         * to be calculated from the new configuration
         */
        msleep(350);

        /* reset vfsoc0 reg */
        max17042_reset_vfsoc0_reg(chip);

        /* load new capacity params */
        max17042_load_new_capacity_params(chip);

        /* Init complete, Clear the POR bit */
        regmap_update_bits(map, MAX17042_STATUS, STATUS_POR_BIT, 0x0);
        return 0;
}

static void max17042_set_soc_threshold(struct max17042_chip *chip, u16 off)
{
        struct regmap *map = chip->regmap;
        u32 soc, soc_tr;

        /* program interrupt thresholds such that we should
         * get interrupt for every 'off' perc change in the soc
         */
        if (chip->pdata->enable_current_sense)
                regmap_read(map, MAX17042_RepSOC, &soc);
        else
                regmap_read(map, MAX17042_VFSOC, &soc);
        soc >>= 8;
        soc_tr = (soc + off) << 8;
        if (off < soc)
                soc_tr |= soc - off;
        regmap_write(map, MAX17042_SALRT_Th, soc_tr);
}

static irqreturn_t max17042_thread_handler(int id, void *dev)
{
        struct max17042_chip *chip = dev;
        u32 val;
        int ret;

        ret = regmap_read(chip->regmap, MAX17042_STATUS, &val);
        if (ret)
                return IRQ_HANDLED;

        if ((val & STATUS_SMN_BIT) || (val & STATUS_SMX_BIT)) {
                dev_dbg(chip->dev, "SOC threshold INTR\n");
                max17042_set_soc_threshold(chip, 1);
        }

        /* we implicitly handle all alerts via power_supply_changed */
        regmap_clear_bits(chip->regmap, MAX17042_STATUS,
                          0xFFFF & ~(STATUS_POR_BIT | STATUS_BST_BIT));

        power_supply_changed(chip->battery);
        return IRQ_HANDLED;
}

static void max17042_init_worker(struct work_struct *work)
{
        struct max17042_chip *chip = container_of(work,
                                struct max17042_chip, work);
        int ret;

        /* Initialize registers according to values from the platform data */
        if (chip->pdata->enable_por_init && chip->pdata->config_data) {
                ret = max17042_init_chip(chip);
                if (ret)
                        return;
        }

        chip->init_complete = 1;
}

#ifdef CONFIG_OF
static struct max17042_platform_data *
max17042_get_of_pdata(struct max17042_chip *chip)
{
        struct device *dev = chip->dev;
        struct device_node *np = dev->of_node;
        u32 prop;
        struct max17042_platform_data *pdata;

        pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
        if (!pdata)
                return NULL;

        /*
         * Require current sense resistor value to be specified for
         * current-sense functionality to be enabled at all.
         */
        if (of_property_read_u32(np, "maxim,rsns-microohm", &prop) == 0) {
                pdata->r_sns = prop;
                pdata->enable_current_sense = true;
        }

        if (of_property_read_s32(np, "maxim,cold-temp", &pdata->temp_min))
                pdata->temp_min = INT_MIN;
        if (of_property_read_s32(np, "maxim,over-heat-temp", &pdata->temp_max))
                pdata->temp_max = INT_MAX;
        if (of_property_read_s32(np, "maxim,dead-volt", &pdata->vmin))
                pdata->vmin = INT_MIN;
        if (of_property_read_s32(np, "maxim,over-volt", &pdata->vmax))
                pdata->vmax = INT_MAX;

        return pdata;
}
#endif

static struct max17042_reg_data max17047_default_pdata_init_regs[] = {
        /*
         * Some firmwares do not set FullSOCThr, Enable End-of-Charge Detection
         * when the voltage FG reports 95%, as recommended in the datasheet.
         */
        { MAX17047_FullSOCThr, MAX17042_BATTERY_FULL << 8 },
};

static struct max17042_platform_data *
max17042_get_default_pdata(struct max17042_chip *chip)
{
        struct device *dev = chip->dev;
        struct max17042_platform_data *pdata;
        int ret, misc_cfg;

        /*
         * The MAX17047 gets used on x86 where we might not have pdata, assume
         * the firmware will already have initialized the fuel-gauge and provide
         * default values for the non init bits to make things work.
         */
        pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
        if (!pdata)
                return pdata;

        if ((chip->chip_type == MAXIM_DEVICE_TYPE_MAX17047) ||
            (chip->chip_type == MAXIM_DEVICE_TYPE_MAX17050)) {
                pdata->init_data = max17047_default_pdata_init_regs;
                pdata->num_init_data =
                        ARRAY_SIZE(max17047_default_pdata_init_regs);
        }

        ret = regmap_read(chip->regmap, MAX17042_MiscCFG, &misc_cfg);
        if (ret < 0)
                return NULL;

        /* If bits 0-1 are set to 3 then only Voltage readings are used */
        if ((misc_cfg & 0x3) == 0x3)
                pdata->enable_current_sense = false;
        else
                pdata->enable_current_sense = true;

        pdata->vmin = MAX17042_DEFAULT_VMIN;
        pdata->vmax = MAX17042_DEFAULT_VMAX;
        pdata->temp_min = MAX17042_DEFAULT_TEMP_MIN;
        pdata->temp_max = MAX17042_DEFAULT_TEMP_MAX;

        return pdata;
}

static struct max17042_platform_data *
max17042_get_pdata(struct max17042_chip *chip)
{
        struct device *dev = chip->dev;

#ifdef CONFIG_OF
        if (dev->of_node)
                return max17042_get_of_pdata(chip);
#endif
        if (dev->platform_data)
                return dev->platform_data;

        return max17042_get_default_pdata(chip);
}

static const struct regmap_config max17042_regmap_config = {
        .name = "max17042",
        .reg_bits = 8,
        .val_bits = 16,
        .val_format_endian = REGMAP_ENDIAN_NATIVE,
};

static const struct power_supply_desc max17042_psy_desc = {
        .name           = "max170xx_battery",
        .type           = POWER_SUPPLY_TYPE_BATTERY,
        .get_property   = max17042_get_property,
        .set_property   = max17042_set_property,
        .property_is_writeable  = max17042_property_is_writeable,
        .external_power_changed = power_supply_changed,
        .properties     = max17042_battery_props,
        .num_properties = ARRAY_SIZE(max17042_battery_props),
};

static const struct power_supply_desc max17042_no_current_sense_psy_desc = {
        .name           = "max170xx_battery",
        .type           = POWER_SUPPLY_TYPE_BATTERY,
        .get_property   = max17042_get_property,
        .set_property   = max17042_set_property,
        .property_is_writeable  = max17042_property_is_writeable,
        .properties     = max17042_battery_props,
        .num_properties = ARRAY_SIZE(max17042_battery_props) - 2,
};

static int max17042_probe(struct i2c_client *client, struct device *dev, int irq,
                          enum max170xx_chip_type chip_type)
{
        struct i2c_adapter *adapter = client->adapter;
        const struct power_supply_desc *max17042_desc = &max17042_psy_desc;
        struct power_supply_config psy_cfg = {};
        struct max17042_chip *chip;
        int ret;
        int i;
        u32 val;

        if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WORD_DATA))
                return -EIO;

        chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
        if (!chip)
                return -ENOMEM;

        chip->dev = dev;
        chip->chip_type = chip_type;
        chip->regmap = devm_regmap_init_i2c(client, &max17042_regmap_config);
        if (IS_ERR(chip->regmap)) {
                dev_err(dev, "Failed to initialize regmap\n");
                return -EINVAL;
        }

        chip->pdata = max17042_get_pdata(chip);
        if (!chip->pdata) {
                dev_err(dev, "no platform data provided\n");
                return -EINVAL;
        }

        dev_set_drvdata(dev, chip);
        psy_cfg.drv_data = chip;
        psy_cfg.fwnode = dev_fwnode(dev);

        /* When current is not measured,
         * CURRENT_NOW and CURRENT_AVG properties should be invisible. */
        if (!chip->pdata->enable_current_sense)
                max17042_desc = &max17042_no_current_sense_psy_desc;

        if (chip->pdata->r_sns == 0)
                chip->pdata->r_sns = MAX17042_DEFAULT_SNS_RESISTOR;

        if (chip->pdata->init_data)
                for (i = 0; i < chip->pdata->num_init_data; i++)
                        regmap_write(chip->regmap,
                                        chip->pdata->init_data[i].addr,
                                        chip->pdata->init_data[i].data);

        if (!chip->pdata->enable_current_sense) {
                regmap_write(chip->regmap, MAX17042_CGAIN, 0x0000);
                regmap_write(chip->regmap, MAX17042_MiscCFG, 0x0003);
                regmap_write(chip->regmap, MAX17042_LearnCFG, 0x0007);
        }

        chip->battery = devm_power_supply_register(dev, max17042_desc,
                                                   &psy_cfg);
        if (IS_ERR(chip->battery)) {
                dev_err(dev, "failed: power supply register\n");
                return PTR_ERR(chip->battery);
        }

        if (irq) {
                unsigned int flags = IRQF_ONESHOT | IRQF_SHARED | IRQF_PROBE_SHARED;

                ret = devm_request_threaded_irq(dev, irq,
                                                NULL,
                                                max17042_thread_handler, flags,
                                                chip->battery->desc->name,
                                                chip);
                if (!ret) {
                        regmap_update_bits(chip->regmap, MAX17042_CONFIG,
                                        CFG_ALRT_BIT_ENBL,
                                        CFG_ALRT_BIT_ENBL);
                        max17042_set_soc_threshold(chip, 1);
                } else {
                        irq = 0;
                        if (ret != -EBUSY)
                                dev_err(dev, "Failed to get IRQ\n");
                }
        }
        /* Not able to update the charge threshold when exceeded? -> disable */
        if (!irq)
                regmap_write(chip->regmap, MAX17042_SALRT_Th, 0xff00);

        chip->irq = irq;

        regmap_read(chip->regmap, MAX17042_STATUS, &val);
        if (val & STATUS_POR_BIT) {
                ret = devm_work_autocancel(dev, &chip->work,
                                           max17042_init_worker);
                if (ret)
                        return ret;
                schedule_work(&chip->work);
        } else {
                chip->init_complete = 1;
        }

        return 0;
}

static int max17042_i2c_probe(struct i2c_client *client)
{
        const struct i2c_device_id *id = i2c_client_get_device_id(client);
        const struct acpi_device_id *acpi_id = NULL;
        struct device *dev = &client->dev;
        enum max170xx_chip_type chip_type;

        if (id) {
                chip_type = id->driver_data;
        } else {
                acpi_id = acpi_match_device(dev->driver->acpi_match_table, dev);
                if (!acpi_id)
                        return -ENODEV;

                chip_type = acpi_id->driver_data;
        }

        return max17042_probe(client, dev, client->irq, chip_type);
}

static int max17042_platform_probe(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        struct i2c_client *i2c;
        const struct platform_device_id *id;
        int irq;

        i2c = to_i2c_client(pdev->dev.parent);
        if (!i2c)
                return -EINVAL;

        dev->of_node = dev->parent->of_node;
        id = platform_get_device_id(pdev);
        irq = platform_get_irq(pdev, 0);

        return max17042_probe(i2c, dev, irq, id->driver_data);
}

#ifdef CONFIG_PM_SLEEP
static int max17042_suspend(struct device *dev)
{
        struct max17042_chip *chip = dev_get_drvdata(dev);

        /*
         * disable the irq and enable irq_wake
         * capability to the interrupt line.
         */
        if (chip->irq) {
                disable_irq(chip->irq);
                enable_irq_wake(chip->irq);
        }

        return 0;
}

static int max17042_resume(struct device *dev)
{
        struct max17042_chip *chip = dev_get_drvdata(dev);

        if (chip->irq) {
                disable_irq_wake(chip->irq);
                enable_irq(chip->irq);
                /* re-program the SOC thresholds to 1% change */
                max17042_set_soc_threshold(chip, 1);
        }

        return 0;
}
#endif

static SIMPLE_DEV_PM_OPS(max17042_pm_ops, max17042_suspend,
                        max17042_resume);

#ifdef CONFIG_ACPI
static const struct acpi_device_id max17042_acpi_match[] = {
        { "MAX17047", MAXIM_DEVICE_TYPE_MAX17047 },
        { }
};
MODULE_DEVICE_TABLE(acpi, max17042_acpi_match);
#endif

#ifdef CONFIG_OF
/*
 * Device may be instantiated through parent MFD device and device matching is done
 * through platform_device_id.
 *
 * However if device's DT node contains proper clock compatible and driver is
 * built as a module, then the *module* matching will be done trough DT aliases.
 * This requires of_device_id table.  In the same time this will not change the
 * actual *device* matching so do not add .of_match_table.
 */
static const struct of_device_id max17042_dt_match[] __used = {
        { .compatible = "maxim,max17042",
                .data = (void *) MAXIM_DEVICE_TYPE_MAX17042 },
        { .compatible = "maxim,max17047",
                .data = (void *) MAXIM_DEVICE_TYPE_MAX17047 },
        { .compatible = "maxim,max17050",
                .data = (void *) MAXIM_DEVICE_TYPE_MAX17050 },
        { .compatible = "maxim,max17055",
                .data = (void *) MAXIM_DEVICE_TYPE_MAX17055 },
        { .compatible = "maxim,max77705-battery",
                .data = (void *) MAXIM_DEVICE_TYPE_MAX17047 },
        { .compatible = "maxim,max77849-battery",
                .data = (void *) MAXIM_DEVICE_TYPE_MAX17047 },
        { },
};
MODULE_DEVICE_TABLE(of, max17042_dt_match);
#endif

static const struct i2c_device_id max17042_id[] = {
        { "max17042", MAXIM_DEVICE_TYPE_MAX17042 },
        { "max17047", MAXIM_DEVICE_TYPE_MAX17047 },
        { "max17050", MAXIM_DEVICE_TYPE_MAX17050 },
        { "max17055", MAXIM_DEVICE_TYPE_MAX17055 },
        { "max77849-battery", MAXIM_DEVICE_TYPE_MAX17047 },
        { }
};
MODULE_DEVICE_TABLE(i2c, max17042_id);

static const struct platform_device_id max17042_platform_id[] = {
        { "max17042", MAXIM_DEVICE_TYPE_MAX17042 },
        { "max17047", MAXIM_DEVICE_TYPE_MAX17047 },
        { "max17050", MAXIM_DEVICE_TYPE_MAX17050 },
        { "max17055", MAXIM_DEVICE_TYPE_MAX17055 },
        { "max77705-battery", MAXIM_DEVICE_TYPE_MAX17047 },
        { "max77849-battery", MAXIM_DEVICE_TYPE_MAX17047 },
        { }
};
MODULE_DEVICE_TABLE(platform, max17042_platform_id);

static struct i2c_driver max17042_i2c_driver = {
        .driver = {
                .name   = "max17042",
                .acpi_match_table = ACPI_PTR(max17042_acpi_match),
                .of_match_table = of_match_ptr(max17042_dt_match),
                .pm     = &max17042_pm_ops,
        },
        .probe          = max17042_i2c_probe,
        .id_table       = max17042_id,
};

static struct platform_driver max17042_platform_driver = {
        .driver = {
                .name   = "max17042",
                .acpi_match_table = ACPI_PTR(max17042_acpi_match),
                .pm     = &max17042_pm_ops,
        },
        .probe          = max17042_platform_probe,
        .id_table       = max17042_platform_id,
};

static int __init max17042_init(void)
{
        int ret;

        ret = platform_driver_register(&max17042_platform_driver);
        if (ret)
                return ret;

        ret = i2c_add_driver(&max17042_i2c_driver);
        if (ret) {
                platform_driver_unregister(&max17042_platform_driver);
                return ret;
        }

        return 0;
}
module_init(max17042_init);

static void __exit max17042_exit(void)
{
        i2c_del_driver(&max17042_i2c_driver);
        platform_driver_unregister(&max17042_platform_driver);
}
module_exit(max17042_exit);

MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
MODULE_DESCRIPTION("MAX17042 Fuel Gauge");
MODULE_LICENSE("GPL");