/*
 * Battery driver for Marvell 88PM860x PMIC
 *
 * Copyright (c) 2012 Marvell International Ltd.
 * Author:      Jett Zhou <jtzhou@marvell.com>
 *              Haojian Zhuang <haojian.zhuang@marvell.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/mutex.h>
#include <linux/string.h>
#include <linux/power_supply.h>
#include <linux/mfd/88pm860x.h>
#include <linux/delay.h>

/* bit definitions of Status Query Interface 2 */
#define STATUS2_CHG                     (1 << 2)
#define STATUS2_BAT                     (1 << 3)
#define STATUS2_VBUS                    (1 << 4)

/* bit definitions of Measurement Enable 1 Register */
#define MEAS1_TINT                      (1 << 3)
#define MEAS1_GP1                       (1 << 5)

/* bit definitions of Measurement Enable 3 Register */
#define MEAS3_IBAT                      (1 << 0)
#define MEAS3_BAT_DET                   (1 << 1)
#define MEAS3_CC                        (1 << 2)

/* bit definitions of Measurement Off Time Register */
#define MEAS_OFF_SLEEP_EN               (1 << 1)

/* bit definitions of GPADC Bias Current 2 Register */
#define GPBIAS2_GPADC1_SET              (2 << 4)
/* GPADC1 Bias Current value in uA unit */
#define GPBIAS2_GPADC1_UA               ((GPBIAS2_GPADC1_SET >> 4) * 5 + 1)

/* bit definitions of GPADC Misc 1 Register */
#define GPMISC1_GPADC_EN                (1 << 0)

/* bit definitions of Charger Control 6 Register */
#define CC6_BAT_DET_GPADC1              1

/* bit definitions of Coulomb Counter Reading Register */
#define CCNT_AVG_SEL                    (4 << 3)

/* bit definitions of RTC miscellaneous Register1 */
#define RTC_SOC_5LSB            (0x1F << 3)

/* bit definitions of RTC Register1 */
#define RTC_SOC_3MSB            (0x7)

/* bit definitions of Power up Log register */
#define BAT_WU_LOG                      (1<<6)

/* coulomb counter index */
#define CCNT_POS1                       0
#define CCNT_POS2                       1
#define CCNT_NEG1                       2
#define CCNT_NEG2                       3
#define CCNT_SPOS                       4
#define CCNT_SNEG                       5

/* OCV -- Open Circuit Voltage */
#define OCV_MODE_ACTIVE                 0
#define OCV_MODE_SLEEP                  1

/* Vbat range of CC for measuring Rbat */
#define LOW_BAT_THRESHOLD               3600
#define VBATT_RESISTOR_MIN              3800
#define VBATT_RESISTOR_MAX              4100

/* TBAT for batt, TINT for chip itself */
#define PM860X_TEMP_TINT                (0)
#define PM860X_TEMP_TBAT                (1)

/*
 * Battery temperature based on NTC resistor, defined
 * corresponding resistor value  -- Ohm / C degeree.
 */
#define TBAT_NEG_25D            127773  /* -25 */
#define TBAT_NEG_10D            54564   /* -10 */
#define TBAT_0D                 32330   /* 0 */
#define TBAT_10D                19785   /* 10 */
#define TBAT_20D                12468   /* 20 */
#define TBAT_30D                8072    /* 30 */
#define TBAT_40D                5356    /* 40 */

struct pm860x_battery_info {
        struct pm860x_chip *chip;
        struct i2c_client *i2c;
        struct device *dev;

        struct power_supply battery;
        struct mutex lock;
        int status;
        int irq_cc;
        int irq_batt;
        int max_capacity;
        int resistor;           /* Battery Internal Resistor */
        int last_capacity;
        int start_soc;
        unsigned present:1;
        unsigned temp_type:1;   /* TINT or TBAT */
};

struct ccnt {
        unsigned long long int pos;
        unsigned long long int neg;
        unsigned int spos;
        unsigned int sneg;

        int total_chg;          /* mAh(3.6C) */
        int total_dischg;       /* mAh(3.6C) */
};

/*
 * State of Charge.
 * The first number is mAh(=3.6C), and the second number is percent point.
 */
static int array_soc[][2] = {
        {4170, 100}, {4154, 99}, {4136, 98}, {4122, 97}, {4107, 96},
        {4102, 95}, {4088, 94}, {4081, 93}, {4070, 92}, {4060, 91},
        {4053, 90}, {4044, 89}, {4035, 88}, {4028, 87}, {4019, 86},
        {4013, 85}, {4006, 84}, {3995, 83}, {3987, 82}, {3982, 81},
        {3976, 80}, {3968, 79}, {3962, 78}, {3954, 77}, {3946, 76},
        {3941, 75}, {3934, 74}, {3929, 73}, {3922, 72}, {3916, 71},
        {3910, 70}, {3904, 69}, {3898, 68}, {3892, 67}, {3887, 66},
        {3880, 65}, {3874, 64}, {3868, 63}, {3862, 62}, {3854, 61},
        {3849, 60}, {3843, 59}, {3840, 58}, {3833, 57}, {3829, 56},
        {3824, 55}, {3818, 54}, {3815, 53}, {3810, 52}, {3808, 51},
        {3804, 50}, {3801, 49}, {3798, 48}, {3796, 47}, {3792, 46},
        {3789, 45}, {3785, 44}, {3784, 43}, {3782, 42}, {3780, 41},
        {3777, 40}, {3776, 39}, {3774, 38}, {3772, 37}, {3771, 36},
        {3769, 35}, {3768, 34}, {3764, 33}, {3763, 32}, {3760, 31},
        {3760, 30}, {3754, 29}, {3750, 28}, {3749, 27}, {3744, 26},
        {3740, 25}, {3734, 24}, {3732, 23}, {3728, 22}, {3726, 21},
        {3720, 20}, {3716, 19}, {3709, 18}, {3703, 17}, {3698, 16},
        {3692, 15}, {3683, 14}, {3675, 13}, {3670, 12}, {3665, 11},
        {3661, 10}, {3649, 9}, {3637, 8}, {3622, 7}, {3609, 6},
        {3580, 5}, {3558, 4}, {3540, 3}, {3510, 2}, {3429, 1},
};

static struct ccnt ccnt_data;

/*
 * register 1 bit[7:0] -- bit[11:4] of measured value of voltage
 * register 0 bit[3:0] -- bit[3:0] of measured value of voltage
 */
static int measure_12bit_voltage(struct pm860x_battery_info *info,
                                 int offset, int *data)
{
        unsigned char buf[2];
        int ret;

        ret = pm860x_bulk_read(info->i2c, offset, 2, buf);
        if (ret < 0)
                return ret;

        *data = ((buf[0] & 0xff) << 4) | (buf[1] & 0x0f);
        /* V_MEAS(mV) = data * 1.8 * 1000 / (2^12) */
        *data = ((*data & 0xfff) * 9 * 25) >> 9;
        return 0;
}

static int measure_vbatt(struct pm860x_battery_info *info, int state,
                         int *data)
{
        unsigned char buf[5];
        int ret;

        switch (state) {
        case OCV_MODE_ACTIVE:
                ret = measure_12bit_voltage(info, PM8607_VBAT_MEAS1, data);
                if (ret)
                        return ret;
                /* V_BATT_MEAS(mV) = value * 3 * 1.8 * 1000 / (2^12) */
                *data *= 3;
                break;
        case OCV_MODE_SLEEP:
                /*
                 * voltage value of VBATT in sleep mode is saved in different
                 * registers.
                 * bit[11:10] -- bit[7:6] of LDO9(0x18)
                 * bit[9:8] -- bit[7:6] of LDO8(0x17)
                 * bit[7:6] -- bit[7:6] of LDO7(0x16)
                 * bit[5:4] -- bit[7:6] of LDO6(0x15)
                 * bit[3:0] -- bit[7:4] of LDO5(0x14)
                 */
                ret = pm860x_bulk_read(info->i2c, PM8607_LDO5, 5, buf);
                if (ret < 0)
                        return ret;
                ret = ((buf[4] >> 6) << 10) | ((buf[3] >> 6) << 8)
                    | ((buf[2] >> 6) << 6) | ((buf[1] >> 6) << 4)
                    | (buf[0] >> 4);
                /* V_BATT_MEAS(mV) = data * 3 * 1.8 * 1000 / (2^12) */
                *data = ((*data & 0xff) * 27 * 25) >> 9;
                break;
        default:
                return -EINVAL;
        }
        return 0;
}

/*
 * Return value is signed data.
 * Negative value means discharging, and positive value means charging.
 */
static int measure_current(struct pm860x_battery_info *info, int *data)
{
        unsigned char buf[2];
        short s;
        int ret;

        ret = pm860x_bulk_read(info->i2c, PM8607_IBAT_MEAS1, 2, buf);
        if (ret < 0)
                return ret;

        s = ((buf[0] & 0xff) << 8) | (buf[1] & 0xff);
        /* current(mA) = value * 0.125 */
        *data = s >> 3;
        return 0;
}

static int set_charger_current(struct pm860x_battery_info *info, int data,
                               int *old)
{
        int ret;

        if (data < 50 || data > 1600 || !old)
                return -EINVAL;

        data = ((data - 50) / 50) & 0x1f;
        *old = pm860x_reg_read(info->i2c, PM8607_CHG_CTRL2);
        *old = (*old & 0x1f) * 50 + 50;
        ret = pm860x_set_bits(info->i2c, PM8607_CHG_CTRL2, 0x1f, data);
        if (ret < 0)
                return ret;
        return 0;
}

static int read_ccnt(struct pm860x_battery_info *info, int offset,
                     int *ccnt)
{
        unsigned char buf[2];
        int ret;

        ret = pm860x_set_bits(info->i2c, PM8607_CCNT, 7, offset & 7);
        if (ret < 0)
                goto out;
        ret = pm860x_bulk_read(info->i2c, PM8607_CCNT_MEAS1, 2, buf);
        if (ret < 0)
                goto out;
        *ccnt = ((buf[0] & 0xff) << 8) | (buf[1] & 0xff);
        return 0;
out:
        return ret;
}

static int calc_ccnt(struct pm860x_battery_info *info, struct ccnt *ccnt)
{
        unsigned int sum;
        int ret;
        int data;

        ret = read_ccnt(info, CCNT_POS1, &data);
        if (ret)
                goto out;
        sum = data & 0xffff;
        ret = read_ccnt(info, CCNT_POS2, &data);
        if (ret)
                goto out;
        sum |= (data & 0xffff) << 16;
        ccnt->pos += sum;

        ret = read_ccnt(info, CCNT_NEG1, &data);
        if (ret)
                goto out;
        sum = data & 0xffff;
        ret = read_ccnt(info, CCNT_NEG2, &data);
        if (ret)
                goto out;
        sum |= (data & 0xffff) << 16;
        sum = ~sum + 1;         /* since it's negative */
        ccnt->neg += sum;

        ret = read_ccnt(info, CCNT_SPOS, &data);
        if (ret)
                goto out;
        ccnt->spos += data;
        ret = read_ccnt(info, CCNT_SNEG, &data);
        if (ret)
                goto out;

        /*
         * charge(mAh)  = count * 1.6984 * 1e(-8)
         *              = count * 16984 * 1.024 * 1.024 * 1.024 / (2 ^ 40)
         *              = count * 18236 / (2 ^ 40)
         */
        ccnt->total_chg = (int) ((ccnt->pos * 18236) >> 40);
        ccnt->total_dischg = (int) ((ccnt->neg * 18236) >> 40);
        return 0;
out:
        return ret;
}

static int clear_ccnt(struct pm860x_battery_info *info, struct ccnt *ccnt)
{
        int data;

        memset(ccnt, 0, sizeof(*ccnt));
        /* read to clear ccnt */
        read_ccnt(info, CCNT_POS1, &data);
        read_ccnt(info, CCNT_POS2, &data);
        read_ccnt(info, CCNT_NEG1, &data);
        read_ccnt(info, CCNT_NEG2, &data);
        read_ccnt(info, CCNT_SPOS, &data);
        read_ccnt(info, CCNT_SNEG, &data);
        return 0;
}

/* Calculate Open Circuit Voltage */
static int calc_ocv(struct pm860x_battery_info *info, int *ocv)
{
        int ret;
        int i;
        int data;
        int vbatt_avg;
        int vbatt_sum;
        int ibatt_avg;
        int ibatt_sum;

        if (!ocv)
                return -EINVAL;

        for (i = 0, ibatt_sum = 0, vbatt_sum = 0; i < 10; i++) {
                ret = measure_vbatt(info, OCV_MODE_ACTIVE, &data);
                if (ret)
                        goto out;
                vbatt_sum += data;
                ret = measure_current(info, &data);
                if (ret)
                        goto out;
                ibatt_sum += data;
        }
        vbatt_avg = vbatt_sum / 10;
        ibatt_avg = ibatt_sum / 10;

        mutex_lock(&info->lock);
        if (info->present)
                *ocv = vbatt_avg - ibatt_avg * info->resistor / 1000;
        else
                *ocv = vbatt_avg;
        mutex_unlock(&info->lock);
        dev_dbg(info->dev, "VBAT average:%d, OCV:%d\n", vbatt_avg, *ocv);
        return 0;
out:
        return ret;
}

/* Calculate State of Charge (percent points) */
static int calc_soc(struct pm860x_battery_info *info, int state, int *soc)
{
        int i;
        int ocv;
        int count;
        int ret = -EINVAL;

        if (!soc)
                return -EINVAL;

        switch (state) {
        case OCV_MODE_ACTIVE:
                ret = calc_ocv(info, &ocv);
                break;
        case OCV_MODE_SLEEP:
                ret = measure_vbatt(info, OCV_MODE_SLEEP, &ocv);
                break;
        }
        if (ret)
                return ret;

        count = ARRAY_SIZE(array_soc);
        if (ocv < array_soc[count - 1][0]) {
                *soc = 0;
                return 0;
        }

        for (i = 0; i < count; i++) {
                if (ocv >= array_soc[i][0]) {
                        *soc = array_soc[i][1];
                        break;
                }
        }
        return 0;
}

static irqreturn_t pm860x_coulomb_handler(int irq, void *data)
{
        struct pm860x_battery_info *info = data;

        calc_ccnt(info, &ccnt_data);
        return IRQ_HANDLED;
}

static irqreturn_t pm860x_batt_handler(int irq, void *data)
{
        struct pm860x_battery_info *info = data;
        int ret;

        mutex_lock(&info->lock);
        ret = pm860x_reg_read(info->i2c, PM8607_STATUS_2);
        if (ret & STATUS2_BAT) {
                info->present = 1;
                info->temp_type = PM860X_TEMP_TBAT;
        } else {
                info->present = 0;
                info->temp_type = PM860X_TEMP_TINT;
        }
        mutex_unlock(&info->lock);
        /* clear ccnt since battery is attached or dettached */
        clear_ccnt(info, &ccnt_data);
        return IRQ_HANDLED;
}

static void pm860x_init_battery(struct pm860x_battery_info *info)
{
        unsigned char buf[2];
        int ret;
        int data;
        int bat_remove;
        int soc;

        /* measure enable on GPADC1 */
        data = MEAS1_GP1;
        if (info->temp_type == PM860X_TEMP_TINT)
                data |= MEAS1_TINT;
        ret = pm860x_set_bits(info->i2c, PM8607_MEAS_EN1, data, data);
        if (ret)
                goto out;

        /* measure enable on IBAT, BAT_DET, CC. IBAT is depend on CC. */
        data = MEAS3_IBAT | MEAS3_BAT_DET | MEAS3_CC;
        ret = pm860x_set_bits(info->i2c, PM8607_MEAS_EN3, data, data);
        if (ret)
                goto out;

        /* measure disable CC in sleep time  */
        ret = pm860x_reg_write(info->i2c, PM8607_MEAS_OFF_TIME1, 0x82);
        if (ret)
                goto out;
        ret = pm860x_reg_write(info->i2c, PM8607_MEAS_OFF_TIME2, 0x6c);
        if (ret)
                goto out;

        /* enable GPADC */
        ret = pm860x_set_bits(info->i2c, PM8607_GPADC_MISC1,
                            GPMISC1_GPADC_EN, GPMISC1_GPADC_EN);
        if (ret < 0)
                goto out;

        /* detect battery via GPADC1 */
        ret = pm860x_set_bits(info->i2c, PM8607_CHG_CTRL6,
                            CC6_BAT_DET_GPADC1, CC6_BAT_DET_GPADC1);
        if (ret < 0)
                goto out;

        ret = pm860x_set_bits(info->i2c, PM8607_CCNT, 7 << 3,
                              CCNT_AVG_SEL);
        if (ret < 0)
                goto out;

        /* set GPADC1 bias */
        ret = pm860x_set_bits(info->i2c, PM8607_GP_BIAS2, 0xF << 4,
                              GPBIAS2_GPADC1_SET);
        if (ret < 0)
                goto out;

        /* check whether battery present) */
        mutex_lock(&info->lock);
        ret = pm860x_reg_read(info->i2c, PM8607_STATUS_2);
        if (ret < 0) {
                mutex_unlock(&info->lock);
                goto out;
        }
        if (ret & STATUS2_BAT) {
                info->present = 1;
                info->temp_type = PM860X_TEMP_TBAT;
        } else {
                info->present = 0;
                info->temp_type = PM860X_TEMP_TINT;
        }
        mutex_unlock(&info->lock);

        calc_soc(info, OCV_MODE_ACTIVE, &soc);

        data = pm860x_reg_read(info->i2c, PM8607_POWER_UP_LOG);
        bat_remove = data & BAT_WU_LOG;

        dev_dbg(info->dev, "battery wake up? %s\n",
                bat_remove != 0 ? "yes" : "no");

        /* restore SOC from RTC domain register */
        if (bat_remove == 0) {
                buf[0] = pm860x_reg_read(info->i2c, PM8607_RTC_MISC2);
                buf[1] = pm860x_reg_read(info->i2c, PM8607_RTC1);
                data = ((buf[1] & 0x3) << 5) | ((buf[0] >> 3) & 0x1F);
                if (data > soc + 15)
                        info->start_soc = soc;
                else if (data < soc - 15)
                        info->start_soc = soc;
                else
                        info->start_soc = data;
                dev_dbg(info->dev, "soc_rtc %d, soc_ocv :%d\n", data, soc);
        } else {
                pm860x_set_bits(info->i2c, PM8607_POWER_UP_LOG,
                                BAT_WU_LOG, BAT_WU_LOG);
                info->start_soc = soc;
        }
        info->last_capacity = info->start_soc;
        dev_dbg(info->dev, "init soc : %d\n", info->last_capacity);
out:
        return;
}

static void set_temp_threshold(struct pm860x_battery_info *info,
                               int min, int max)
{
        int data;

        /* (tmp << 8) / 1800 */
        if (min <= 0)
                data = 0;
        else
                data = (min << 8) / 1800;
        pm860x_reg_write(info->i2c, PM8607_GPADC1_HIGHTH, data);
        dev_dbg(info->dev, "TEMP_HIGHTH : min: %d, 0x%x\n", min, data);

        if (max <= 0)
                data = 0xff;
        else
                data = (max << 8) / 1800;
        pm860x_reg_write(info->i2c, PM8607_GPADC1_LOWTH, data);
        dev_dbg(info->dev, "TEMP_LOWTH:max : %d, 0x%x\n", max, data);
}

static int measure_temp(struct pm860x_battery_info *info, int *data)
{
        int ret;
        int temp;
        int min;
        int max;

        if (info->temp_type == PM860X_TEMP_TINT) {
                ret = measure_12bit_voltage(info, PM8607_TINT_MEAS1, data);
                if (ret)
                        return ret;
                *data = (*data - 884) * 1000 / 3611;
        } else {
                ret = measure_12bit_voltage(info, PM8607_GPADC1_MEAS1, data);
                if (ret)
                        return ret;
                /* meausered Vtbat(mV) / Ibias_current(11uA)*/
                *data = (*data * 1000) / GPBIAS2_GPADC1_UA;

                if (*data > TBAT_NEG_25D) {
                        temp = -30;     /* over cold , suppose -30 roughly */
                        max = TBAT_NEG_10D * GPBIAS2_GPADC1_UA / 1000;
                        set_temp_threshold(info, 0, max);
                } else if (*data > TBAT_NEG_10D) {
                        temp = -15;     /* -15 degree, code */
                        max = TBAT_NEG_10D * GPBIAS2_GPADC1_UA / 1000;
                        set_temp_threshold(info, 0, max);
                } else if (*data > TBAT_0D) {
                        temp = -5;      /* -5 degree */
                        min = TBAT_NEG_10D * GPBIAS2_GPADC1_UA / 1000;
                        max = TBAT_40D * GPBIAS2_GPADC1_UA / 1000;
                        set_temp_threshold(info, min, max);
                } else if (*data > TBAT_10D) {
                        temp = 5;       /* in range of (0, 10) */
                        min = TBAT_NEG_10D * GPBIAS2_GPADC1_UA / 1000;
                        max = TBAT_40D * GPBIAS2_GPADC1_UA / 1000;
                        set_temp_threshold(info, min, max);
                } else if (*data > TBAT_20D) {
                        temp = 15;      /* in range of (10, 20) */
                        min = TBAT_NEG_10D * GPBIAS2_GPADC1_UA / 1000;
                        max = TBAT_40D * GPBIAS2_GPADC1_UA / 1000;
                        set_temp_threshold(info, min, max);
                } else if (*data > TBAT_30D) {
                        temp = 25;      /* in range of (20, 30) */
                        min = TBAT_NEG_10D * GPBIAS2_GPADC1_UA / 1000;
                        max = TBAT_40D * GPBIAS2_GPADC1_UA / 1000;
                        set_temp_threshold(info, min, max);
                } else if (*data > TBAT_40D) {
                        temp = 35;      /* in range of (30, 40) */
                        min = TBAT_NEG_10D * GPBIAS2_GPADC1_UA / 1000;
                        max = TBAT_40D * GPBIAS2_GPADC1_UA / 1000;
                        set_temp_threshold(info, min, max);
                } else {
                        min = TBAT_40D * GPBIAS2_GPADC1_UA / 1000;
                        set_temp_threshold(info, min, 0);
                        temp = 45;      /* over heat ,suppose 45 roughly */
                }

                dev_dbg(info->dev, "temp_C:%d C,temp_mv:%d mv\n", temp, *data);
                *data = temp;
        }
        return 0;
}

static int calc_resistor(struct pm860x_battery_info *info)
{
        int vbatt_sum1;
        int vbatt_sum2;
        int chg_current;
        int ibatt_sum1;
        int ibatt_sum2;
        int data;
        int ret;
        int i;

        ret = measure_current(info, &data);
        /* make sure that charging is launched by data > 0 */
        if (ret || data < 0)
                goto out;

        ret = measure_vbatt(info, OCV_MODE_ACTIVE, &data);
        if (ret)
                goto out;
        /* calculate resistor only in CC charge mode */
        if (data < VBATT_RESISTOR_MIN || data > VBATT_RESISTOR_MAX)
                goto out;

        /* current is saved */
        if (set_charger_current(info, 500, &chg_current))
                goto out;

        /*
         * set charge current as 500mA, wait about 500ms till charging
         * process is launched and stable with the newer charging current.
         */
        msleep(500);

        for (i = 0, vbatt_sum1 = 0, ibatt_sum1 = 0; i < 10; i++) {
                ret = measure_vbatt(info, OCV_MODE_ACTIVE, &data);
                if (ret)
                        goto out_meas;
                vbatt_sum1 += data;
                ret = measure_current(info, &data);
                if (ret)
                        goto out_meas;

                if (data < 0)
                        ibatt_sum1 = ibatt_sum1 - data; /* discharging */
                else
                        ibatt_sum1 = ibatt_sum1 + data; /* charging */
        }

        if (set_charger_current(info, 100, &ret))
                goto out_meas;
        /*
         * set charge current as 100mA, wait about 500ms till charging
         * process is launched and stable with the newer charging current.
         */
        msleep(500);

        for (i = 0, vbatt_sum2 = 0, ibatt_sum2 = 0; i < 10; i++) {
                ret = measure_vbatt(info, OCV_MODE_ACTIVE, &data);
                if (ret)
                        goto out_meas;
                vbatt_sum2 += data;
                ret = measure_current(info, &data);
                if (ret)
                        goto out_meas;

                if (data < 0)
                        ibatt_sum2 = ibatt_sum2 - data; /* discharging */
                else
                        ibatt_sum2 = ibatt_sum2 + data; /* charging */
        }

        /* restore current setting */
        if (set_charger_current(info, chg_current, &ret))
                goto out_meas;

        if ((vbatt_sum1 > vbatt_sum2) && (ibatt_sum1 > ibatt_sum2) &&
                        (ibatt_sum2 > 0)) {
                /* calculate resistor in discharging case */
                data = 1000 * (vbatt_sum1 - vbatt_sum2)
                    / (ibatt_sum1 - ibatt_sum2);
                if ((data - info->resistor > 0) &&
                                (data - info->resistor < info->resistor))
                        info->resistor = data;
                if ((info->resistor - data > 0) &&
                                (info->resistor - data < data))
                        info->resistor = data;
        }
        return 0;

out_meas:
        set_charger_current(info, chg_current, &ret);
out:
        return -EINVAL;
}

static int calc_capacity(struct pm860x_battery_info *info, int *cap)
{
        int ret;
        int data;
        int ibat;
        int cap_ocv = 0;
        int cap_cc = 0;

        ret = calc_ccnt(info, &ccnt_data);
        if (ret)
                goto out;
soc:
        data = info->max_capacity * info->start_soc / 100;
        if (ccnt_data.total_dischg - ccnt_data.total_chg <= data) {
                cap_cc =
                    data + ccnt_data.total_chg - ccnt_data.total_dischg;
        } else {
                clear_ccnt(info, &ccnt_data);
                calc_soc(info, OCV_MODE_ACTIVE, &info->start_soc);
                dev_dbg(info->dev, "restart soc = %d !\n",
                        info->start_soc);
                goto soc;
        }

        cap_cc = cap_cc * 100 / info->max_capacity;
        if (cap_cc < 0)
                cap_cc = 0;
        else if (cap_cc > 100)
                cap_cc = 100;

        dev_dbg(info->dev, "%s, last cap : %d", __func__,
                info->last_capacity);

        ret = measure_current(info, &ibat);
        if (ret)
                goto out;
        /* Calculate the capacity when discharging(ibat < 0) */
        if (ibat < 0) {
                ret = calc_soc(info, OCV_MODE_ACTIVE, &cap_ocv);
                if (ret)
                        cap_ocv = info->last_capacity;
                ret = measure_vbatt(info, OCV_MODE_ACTIVE, &data);
                if (ret)
                        goto out;
                if (data <= LOW_BAT_THRESHOLD) {
                        /* choose the lower capacity value to report
                         * between vbat and CC when vbat < 3.6v;
                         * than 3.6v;
                         */
                        *cap = min(cap_ocv, cap_cc);
                } else {
                        /* when detect vbat > 3.6v, but cap_cc < 15,and
                         * cap_ocv is 10% larger than cap_cc, we can think
                         * CC have some accumulation error, switch to OCV
                         * to estimate capacity;
                         * */
                        if (cap_cc < 15 && cap_ocv - cap_cc > 10)
                                *cap = cap_ocv;
                        else
                                *cap = cap_cc;
                }
                /* when discharging, make sure current capacity
                 * is lower than last*/
                if (*cap > info->last_capacity)
                        *cap = info->last_capacity;
        } else {
                *cap = cap_cc;
        }
        info->last_capacity = *cap;

        dev_dbg(info->dev, "%s, cap_ocv:%d cap_cc:%d, cap:%d\n",
                (ibat < 0) ? "discharging" : "charging",
                 cap_ocv, cap_cc, *cap);
        /*
         * store the current capacity to RTC domain register,
         * after next power up , it will be restored.
         */
        pm860x_set_bits(info->i2c, PM8607_RTC_MISC2, RTC_SOC_5LSB,
                        (*cap & 0x1F) << 3);
        pm860x_set_bits(info->i2c, PM8607_RTC1, RTC_SOC_3MSB,
                        ((*cap >> 5) & 0x3));
        return 0;
out:
        return ret;
}

static void pm860x_external_power_changed(struct power_supply *psy)
{
        struct pm860x_battery_info *info;

        info = container_of(psy, struct pm860x_battery_info, battery);
        calc_resistor(info);
}

static int pm860x_batt_get_prop(struct power_supply *psy,
                                enum power_supply_property psp,
                                union power_supply_propval *val)
{
        struct pm860x_battery_info *info = dev_get_drvdata(psy->dev->parent);
        int data;
        int ret;

        switch (psp) {
        case POWER_SUPPLY_PROP_PRESENT:
                val->intval = info->present;
                break;
        case POWER_SUPPLY_PROP_CAPACITY:
                ret = calc_capacity(info, &data);
                if (ret)
                        return ret;
                if (data < 0)
                        data = 0;
                else if (data > 100)
                        data = 100;
                /* return 100 if battery is not attached */
                if (!info->present)
                        data = 100;
                val->intval = data;
                break;
        case POWER_SUPPLY_PROP_TECHNOLOGY:
                val->intval = POWER_SUPPLY_TECHNOLOGY_LION;
                break;
        case POWER_SUPPLY_PROP_VOLTAGE_NOW:
                /* return real vbatt Voltage */
                ret = measure_vbatt(info, OCV_MODE_ACTIVE, &data);
                if (ret)
                        return ret;
                val->intval = data * 1000;
                break;
        case POWER_SUPPLY_PROP_VOLTAGE_AVG:
                /* return Open Circuit Voltage (not measured voltage) */
                ret = calc_ocv(info, &data);
                if (ret)
                        return ret;
                val->intval = data * 1000;
                break;
        case POWER_SUPPLY_PROP_CURRENT_NOW:
                ret = measure_current(info, &data);
                if (ret)
                        return ret;
                val->intval = data;
                break;
        case POWER_SUPPLY_PROP_TEMP:
                if (info->present) {
                        ret = measure_temp(info, &data);
                        if (ret)
                                return ret;
                        data *= 10;
                } else {
                        /* Fake Temp 25C Without Battery */
                        data = 250;
                }
                val->intval = data;
                break;
        default:
                return -ENODEV;
        }
        return 0;
}

static int pm860x_batt_set_prop(struct power_supply *psy,
                                       enum power_supply_property psp,
                                       const union power_supply_propval *val)
{
        struct pm860x_battery_info *info = dev_get_drvdata(psy->dev->parent);

        switch (psp) {
        case POWER_SUPPLY_PROP_CHARGE_FULL:
                clear_ccnt(info, &ccnt_data);
                info->start_soc = 100;
                dev_dbg(info->dev, "chg done, update soc = %d\n",
                        info->start_soc);
                break;
        default:
                return -EPERM;
        }

        return 0;
}


static enum power_supply_property pm860x_batt_props[] = {
        POWER_SUPPLY_PROP_PRESENT,
        POWER_SUPPLY_PROP_CAPACITY,
        POWER_SUPPLY_PROP_TECHNOLOGY,
        POWER_SUPPLY_PROP_VOLTAGE_NOW,
        POWER_SUPPLY_PROP_VOLTAGE_AVG,
        POWER_SUPPLY_PROP_CURRENT_NOW,
        POWER_SUPPLY_PROP_TEMP,
};

static int pm860x_battery_probe(struct platform_device *pdev)
{
        struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent);
        struct pm860x_battery_info *info;
        struct pm860x_power_pdata *pdata;
        int ret;

        info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
        if (!info)
                return -ENOMEM;

        info->irq_cc = platform_get_irq(pdev, 0);
        if (info->irq_cc <= 0) {
                dev_err(&pdev->dev, "No IRQ resource!\n");
                return -EINVAL;
        }

        info->irq_batt = platform_get_irq(pdev, 1);
        if (info->irq_batt <= 0) {
                dev_err(&pdev->dev, "No IRQ resource!\n");
                return -EINVAL;
        }

        info->chip = chip;
        info->i2c =
            (chip->id == CHIP_PM8607) ? chip->client : chip->companion;
        info->dev = &pdev->dev;
        info->status = POWER_SUPPLY_STATUS_UNKNOWN;
        pdata = pdev->dev.platform_data;

        mutex_init(&info->lock);
        platform_set_drvdata(pdev, info);

        pm860x_init_battery(info);

        info->battery.name = "battery-monitor";
        info->battery.type = POWER_SUPPLY_TYPE_BATTERY;
        info->battery.properties = pm860x_batt_props;
        info->battery.num_properties = ARRAY_SIZE(pm860x_batt_props);
        info->battery.get_property = pm860x_batt_get_prop;
        info->battery.set_property = pm860x_batt_set_prop;
        info->battery.external_power_changed = pm860x_external_power_changed;

        if (pdata && pdata->max_capacity)
                info->max_capacity = pdata->max_capacity;
        else
                info->max_capacity = 1500;      /* set default capacity */
        if (pdata && pdata->resistor)
                info->resistor = pdata->resistor;
        else
                info->resistor = 300;   /* set default internal resistor */

        ret = power_supply_register(&pdev->dev, &info->battery);
        if (ret)
                return ret;
        info->battery.dev->parent = &pdev->dev;

        ret = request_threaded_irq(info->irq_cc, NULL,
                                pm860x_coulomb_handler, IRQF_ONESHOT,
                                "coulomb", info);
        if (ret < 0) {
                dev_err(chip->dev, "Failed to request IRQ: #%d: %d\n",
                        info->irq_cc, ret);
                goto out_reg;
        }

        ret = request_threaded_irq(info->irq_batt, NULL, pm860x_batt_handler,
                                IRQF_ONESHOT, "battery", info);
        if (ret < 0) {
                dev_err(chip->dev, "Failed to request IRQ: #%d: %d\n",
                        info->irq_batt, ret);
                goto out_coulomb;
        }


        return 0;

out_coulomb:
        free_irq(info->irq_cc, info);
out_reg:
        power_supply_unregister(&info->battery);
        return ret;
}

static int pm860x_battery_remove(struct platform_device *pdev)
{
        struct pm860x_battery_info *info = platform_get_drvdata(pdev);

        free_irq(info->irq_batt, info);
        free_irq(info->irq_cc, info);
        power_supply_unregister(&info->battery);
        platform_set_drvdata(pdev, NULL);
        return 0;
}

#ifdef CONFIG_PM_SLEEP
static int pm860x_battery_suspend(struct device *dev)

{
        struct platform_device *pdev = to_platform_device(dev);
        struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent);

        if (device_may_wakeup(dev))
                chip->wakeup_flag |= 1 << PM8607_IRQ_CC;
        return 0;
}

static int pm860x_battery_resume(struct device *dev)
{
        struct platform_device *pdev = to_platform_device(dev);
        struct pm860x_chip *chip = dev_get_drvdata(pdev->dev.parent);

        if (device_may_wakeup(dev))
                chip->wakeup_flag &= ~(1 << PM8607_IRQ_CC);
        return 0;
}
#endif

static SIMPLE_DEV_PM_OPS(pm860x_battery_pm_ops,
                        pm860x_battery_suspend, pm860x_battery_resume);

static struct platform_driver pm860x_battery_driver = {
        .driver = {
                   .name = "88pm860x-battery",
                   .owner = THIS_MODULE,
                   .pm = &pm860x_battery_pm_ops,
        },
        .probe = pm860x_battery_probe,
        .remove = pm860x_battery_remove,
};
module_platform_driver(pm860x_battery_driver);

MODULE_DESCRIPTION("Marvell 88PM860x Battery driver");
MODULE_LICENSE("GPL");