ab8500_fg.c

Go to the documentation of this file.

/*
 * Copyright (C) ST-Ericsson AB 2012
 *
 * Main and Back-up battery management driver.
 *
 * Note: Backup battery management is required in case of Li-Ion battery and not
 * for capacitive battery. HREF boards have capacitive battery and hence backup
 * battery management is not used and the supported code is available in this
 * driver.
 *
 * License Terms: GNU General Public License v2
 * Author:
 *  Johan Palsson <[email protected]>
 *  Karl Komierowski <[email protected]>
 *  Arun R Murthy <[email protected]>
 */

#include <linux/init.h>
#include <linux/module.h>
#include <linux/device.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/power_supply.h>
#include <linux/kobject.h>
#include <linux/mfd/abx500/ab8500.h>
#include <linux/mfd/abx500.h>
#include <linux/slab.h>
#include <linux/mfd/abx500/ab8500-bm.h>
#include <linux/delay.h>
#include <linux/mfd/abx500/ab8500-gpadc.h>
#include <linux/mfd/abx500.h>
#include <linux/time.h>
#include <linux/completion.h>

#define MILLI_TO_MICRO          1000
#define FG_LSB_IN_MA            1627
#define QLSB_NANO_AMP_HOURS_X10     1129
#define INS_CURR_TIMEOUT        (3 * HZ)

#define SEC_TO_SAMPLE(S)        (S * 4)

#define NBR_AVG_SAMPLES         20

#define LOW_BAT_CHECK_INTERVAL      (2 * HZ)

#define VALID_CAPACITY_SEC      (45 * 60) /* 45 minutes */
#define BATT_OK_MIN         2360 /* mV */
#define BATT_OK_INCREMENT       50 /* mV */
#define BATT_OK_MAX_NR_INCREMENTS   0xE

/* FG constants */
#define BATT_OVV            0x01

#define interpolate(x, x1, y1, x2, y2) \
    ((y1) + ((((y2) - (y1)) * ((x) - (x1))) / ((x2) - (x1))));

#define to_ab8500_fg_device_info(x) container_of((x), \
    struct ab8500_fg, fg_psy);

struct ab8500_fg_interrupts {
    char *name;
    irqreturn_t (*isr)(int irq, void *data);
};

enum ab8500_fg_discharge_state {
    AB8500_FG_DISCHARGE_INIT,
    AB8500_FG_DISCHARGE_INITMEASURING,
    AB8500_FG_DISCHARGE_INIT_RECOVERY,
    AB8500_FG_DISCHARGE_RECOVERY,
    AB8500_FG_DISCHARGE_READOUT_INIT,
    AB8500_FG_DISCHARGE_READOUT,
    AB8500_FG_DISCHARGE_WAKEUP,
};

static char *discharge_state[] = {
    "DISCHARGE_INIT",
    "DISCHARGE_INITMEASURING",
    "DISCHARGE_INIT_RECOVERY",
    "DISCHARGE_RECOVERY",
    "DISCHARGE_READOUT_INIT",
    "DISCHARGE_READOUT",
    "DISCHARGE_WAKEUP",
};

enum ab8500_fg_charge_state {
    AB8500_FG_CHARGE_INIT,
    AB8500_FG_CHARGE_READOUT,
};

static char *charge_state[] = {
    "CHARGE_INIT",
    "CHARGE_READOUT",
};

enum ab8500_fg_calibration_state {
    AB8500_FG_CALIB_INIT,
    AB8500_FG_CALIB_WAIT,
    AB8500_FG_CALIB_END,
};

struct ab8500_fg_avg_cap {
    int avg;
    int samples[NBR_AVG_SAMPLES];
    __kernel_time_t time_stamps[NBR_AVG_SAMPLES];
    int pos;
    int nbr_samples;
    int sum;
};

struct ab8500_fg_battery_capacity {
    int max_mah_design;
    int max_mah;
    int mah;
    int permille;
    int level;
    int prev_mah;
    int prev_percent;
    int prev_level;
    int user_mah;
};

struct ab8500_fg_flags {
    bool fg_enabled;
    bool conv_done;
    bool charging;
    bool fully_charged;
    bool force_full;
    bool low_bat_delay;
    bool low_bat;
    bool bat_ovv;
    bool batt_unknown;
    bool calibrate;
    bool user_cap;
    bool batt_id_received;
};

struct inst_curr_result_list {
    struct list_head list;
    int *result;
};

struct ab8500_fg {
    struct device *dev;
    struct list_head node;
    int irq;
    int vbat;
    int vbat_nom;
    int inst_curr;
    int avg_curr;
    int bat_temp;
    int fg_samples;
    int accu_charge;
    int recovery_cnt;
    int high_curr_cnt;
    int init_cnt;
    bool recovery_needed;
    bool high_curr_mode;
    bool init_capacity;
    bool turn_off_fg;
    enum ab8500_fg_calibration_state calib_state;
    enum ab8500_fg_discharge_state discharge_state;
    enum ab8500_fg_charge_state charge_state;
    struct completion ab8500_fg_complete;
    struct ab8500_fg_flags flags;
    struct ab8500_fg_battery_capacity bat_cap;
    struct ab8500_fg_avg_cap avg_cap;
    struct ab8500 *parent;
    struct ab8500_gpadc *gpadc;
    struct abx500_fg_platform_data *pdata;
    struct abx500_bm_data *bat;
    struct power_supply fg_psy;
    struct workqueue_struct *fg_wq;
    struct delayed_work fg_periodic_work;
    struct delayed_work fg_low_bat_work;
    struct delayed_work fg_reinit_work;
    struct work_struct fg_work;
    struct work_struct fg_acc_cur_work;
    struct delayed_work fg_check_hw_failure_work;
    struct mutex cc_lock;
    struct kobject fg_kobject;
};
static LIST_HEAD(ab8500_fg_list);

struct ab8500_fg *ab8500_fg_get(void)
{
    struct ab8500_fg *fg;

    if (list_empty(&ab8500_fg_list))
        return NULL;

    fg = list_first_entry(&ab8500_fg_list, struct ab8500_fg, node);
    return fg;
}

/* Main battery properties */
static enum power_supply_property ab8500_fg_props[] = {
    POWER_SUPPLY_PROP_VOLTAGE_NOW,
    POWER_SUPPLY_PROP_CURRENT_NOW,
    POWER_SUPPLY_PROP_CURRENT_AVG,
    POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN,
    POWER_SUPPLY_PROP_ENERGY_FULL,
    POWER_SUPPLY_PROP_ENERGY_NOW,
    POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
    POWER_SUPPLY_PROP_CHARGE_FULL,
    POWER_SUPPLY_PROP_CHARGE_NOW,
    POWER_SUPPLY_PROP_CAPACITY,
    POWER_SUPPLY_PROP_CAPACITY_LEVEL,
};

/*
 * This array maps the raw hex value to lowbat voltage used by the AB8500
 * Values taken from the UM0836
 */
static int ab8500_fg_lowbat_voltage_map[] = {
    2300 ,
    2325 ,
    2350 ,
    2375 ,
    2400 ,
    2425 ,
    2450 ,
    2475 ,
    2500 ,
    2525 ,
    2550 ,
    2575 ,
    2600 ,
    2625 ,
    2650 ,
    2675 ,
    2700 ,
    2725 ,
    2750 ,
    2775 ,
    2800 ,
    2825 ,
    2850 ,
    2875 ,
    2900 ,
    2925 ,
    2950 ,
    2975 ,
    3000 ,
    3025 ,
    3050 ,
    3075 ,
    3100 ,
    3125 ,
    3150 ,
    3175 ,
    3200 ,
    3225 ,
    3250 ,
    3275 ,
    3300 ,
    3325 ,
    3350 ,
    3375 ,
    3400 ,
    3425 ,
    3450 ,
    3475 ,
    3500 ,
    3525 ,
    3550 ,
    3575 ,
    3600 ,
    3625 ,
    3650 ,
    3675 ,
    3700 ,
    3725 ,
    3750 ,
    3775 ,
    3800 ,
    3825 ,
    3850 ,
    3850 ,
};

static u8 ab8500_volt_to_regval(int voltage)
{
    int i;

    if (voltage < ab8500_fg_lowbat_voltage_map[0])
        return 0;

    for (i = 0; i < ARRAY_SIZE(ab8500_fg_lowbat_voltage_map); i++) {
        if (voltage < ab8500_fg_lowbat_voltage_map[i])
            return (u8) i - 1;
    }

    /* If not captured above, return index of last element */
    return (u8) ARRAY_SIZE(ab8500_fg_lowbat_voltage_map) - 1;
}

static int ab8500_fg_is_low_curr(struct ab8500_fg *di, int curr)
{
    /*
     * We want to know if we're in low current mode
     */
    if (curr > -di->bat->fg_params->high_curr_threshold)
        return true;
    else
        return false;
}

static int ab8500_fg_add_cap_sample(struct ab8500_fg *di, int sample)
{
    struct timespec ts;
    struct ab8500_fg_avg_cap *avg = &di->avg_cap;

    getnstimeofday(&ts);

    do {
        avg->sum += sample - avg->samples[avg->pos];
        avg->samples[avg->pos] = sample;
        avg->time_stamps[avg->pos] = ts.tv_sec;
        avg->pos++;

        if (avg->pos == NBR_AVG_SAMPLES)
            avg->pos = 0;

        if (avg->nbr_samples < NBR_AVG_SAMPLES)
            avg->nbr_samples++;

        /*
         * Check the time stamp for each sample. If too old,
         * replace with latest sample
         */
    } while (ts.tv_sec - VALID_CAPACITY_SEC > avg->time_stamps[avg->pos]);

    avg->avg = avg->sum / avg->nbr_samples;

    return avg->avg;
}

static void ab8500_fg_clear_cap_samples(struct ab8500_fg *di)
{
    int i;
    struct ab8500_fg_avg_cap *avg = &di->avg_cap;

    avg->pos = 0;
    avg->nbr_samples = 0;
    avg->sum = 0;
    avg->avg = 0;

    for (i = 0; i < NBR_AVG_SAMPLES; i++) {
        avg->samples[i] = 0;
        avg->time_stamps[i] = 0;
    }
}

static void ab8500_fg_fill_cap_sample(struct ab8500_fg *di, int sample)
{
    int i;
    struct timespec ts;
    struct ab8500_fg_avg_cap *avg = &di->avg_cap;

    getnstimeofday(&ts);

    for (i = 0; i < NBR_AVG_SAMPLES; i++) {
        avg->samples[i] = sample;
        avg->time_stamps[i] = ts.tv_sec;
    }

    avg->pos = 0;
    avg->nbr_samples = NBR_AVG_SAMPLES;
    avg->sum = sample * NBR_AVG_SAMPLES;
    avg->avg = sample;
}

static int ab8500_fg_coulomb_counter(struct ab8500_fg *di, bool enable)
{
    int ret = 0;
    mutex_lock(&di->cc_lock);
    if (enable) {
        /* To be able to reprogram the number of samples, we have to
         * first stop the CC and then enable it again */
        ret = abx500_set_register_interruptible(di->dev, AB8500_RTC,
            AB8500_RTC_CC_CONF_REG, 0x00);
        if (ret)
            goto cc_err;

        /* Program the samples */
        ret = abx500_set_register_interruptible(di->dev,
            AB8500_GAS_GAUGE, AB8500_GASG_CC_NCOV_ACCU,
            di->fg_samples);
        if (ret)
            goto cc_err;

        /* Start the CC */
        ret = abx500_set_register_interruptible(di->dev, AB8500_RTC,
            AB8500_RTC_CC_CONF_REG,
            (CC_DEEP_SLEEP_ENA | CC_PWR_UP_ENA));
        if (ret)
            goto cc_err;

        di->flags.fg_enabled = true;
    } else {
        /* Clear any pending read requests */
        ret = abx500_set_register_interruptible(di->dev,
            AB8500_GAS_GAUGE, AB8500_GASG_CC_CTRL_REG, 0);
        if (ret)
            goto cc_err;

        ret = abx500_set_register_interruptible(di->dev,
            AB8500_GAS_GAUGE, AB8500_GASG_CC_NCOV_ACCU_CTRL, 0);
        if (ret)
            goto cc_err;

        /* Stop the CC */
        ret = abx500_set_register_interruptible(di->dev, AB8500_RTC,
            AB8500_RTC_CC_CONF_REG, 0);
        if (ret)
            goto cc_err;

        di->flags.fg_enabled = false;

    }
    dev_dbg(di->dev, " CC enabled: %d Samples: %d\n",
        enable, di->fg_samples);

    mutex_unlock(&di->cc_lock);

    return ret;
cc_err:
    dev_err(di->dev, "%s Enabling coulomb counter failed\n", __func__);
    mutex_unlock(&di->cc_lock);
    return ret;
}

 int ab8500_fg_inst_curr_start(struct ab8500_fg *di)
{
    u8 reg_val;
    int ret;

    mutex_lock(&di->cc_lock);

    ret = abx500_get_register_interruptible(di->dev, AB8500_RTC,
        AB8500_RTC_CC_CONF_REG, &reg_val);
    if (ret < 0)
        goto fail;

    if (!(reg_val & CC_PWR_UP_ENA)) {
        dev_dbg(di->dev, "%s Enable FG\n", __func__);
        di->turn_off_fg = true;

        /* Program the samples */
        ret = abx500_set_register_interruptible(di->dev,
            AB8500_GAS_GAUGE, AB8500_GASG_CC_NCOV_ACCU,
            SEC_TO_SAMPLE(10));
        if (ret)
            goto fail;

        /* Start the CC */
        ret = abx500_set_register_interruptible(di->dev, AB8500_RTC,
            AB8500_RTC_CC_CONF_REG,
            (CC_DEEP_SLEEP_ENA | CC_PWR_UP_ENA));
        if (ret)
            goto fail;
    } else {
        di->turn_off_fg = false;
    }

    /* Return and WFI */
    INIT_COMPLETION(di->ab8500_fg_complete);
    enable_irq(di->irq);

    /* Note: cc_lock is still locked */
    return 0;
fail:
    mutex_unlock(&di->cc_lock);
    return ret;
}

int ab8500_fg_inst_curr_done(struct ab8500_fg *di)
{
    return completion_done(&di->ab8500_fg_complete);
}

int ab8500_fg_inst_curr_finalize(struct ab8500_fg *di, int *res)
{
    u8 low, high;
    int val;
    int ret;
    int timeout;

    if (!completion_done(&di->ab8500_fg_complete)) {
        timeout = wait_for_completion_timeout(&di->ab8500_fg_complete,
            INS_CURR_TIMEOUT);
        dev_dbg(di->dev, "Finalize time: %d ms\n",
            ((INS_CURR_TIMEOUT - timeout) * 1000) / HZ);
        if (!timeout) {
            ret = -ETIME;
            disable_irq(di->irq);
            dev_err(di->dev, "completion timed out [%d]\n",
                __LINE__);
            goto fail;
        }
    }

    disable_irq(di->irq);

    ret = abx500_mask_and_set_register_interruptible(di->dev,
            AB8500_GAS_GAUGE, AB8500_GASG_CC_CTRL_REG,
            READ_REQ, READ_REQ);

    /* 100uS between read request and read is needed */
    usleep_range(100, 100);

    /* Read CC Sample conversion value Low and high */
    ret = abx500_get_register_interruptible(di->dev, AB8500_GAS_GAUGE,
        AB8500_GASG_CC_SMPL_CNVL_REG,  &low);
    if (ret < 0)
        goto fail;

    ret = abx500_get_register_interruptible(di->dev, AB8500_GAS_GAUGE,
        AB8500_GASG_CC_SMPL_CNVH_REG,  &high);
    if (ret < 0)
        goto fail;

    /*
     * negative value for Discharging
     * convert 2's compliment into decimal
     */
    if (high & 0x10)
        val = (low | (high << 8) | 0xFFFFE000);
    else
        val = (low | (high << 8));

    /*
     * Convert to unit value in mA
     * Full scale input voltage is
     * 66.660mV => LSB = 66.660mV/(4096*res) = 1.627mA
     * Given a 250ms conversion cycle time the LSB corresponds
     * to 112.9 nAh. Convert to current by dividing by the conversion
     * time in hours (250ms = 1 / (3600 * 4)h)
     * 112.9nAh assumes 10mOhm, but fg_res is in 0.1mOhm
     */
    val = (val * QLSB_NANO_AMP_HOURS_X10 * 36 * 4) /
        (1000 * di->bat->fg_res);

    if (di->turn_off_fg) {
        dev_dbg(di->dev, "%s Disable FG\n", __func__);

        /* Clear any pending read requests */
        ret = abx500_set_register_interruptible(di->dev,
            AB8500_GAS_GAUGE, AB8500_GASG_CC_CTRL_REG, 0);
        if (ret)
            goto fail;

        /* Stop the CC */
        ret = abx500_set_register_interruptible(di->dev, AB8500_RTC,
            AB8500_RTC_CC_CONF_REG, 0);
        if (ret)
            goto fail;
    }
    mutex_unlock(&di->cc_lock);
    (*res) = val;

    return 0;
fail:
    mutex_unlock(&di->cc_lock);
    return ret;
}

int ab8500_fg_inst_curr_blocking(struct ab8500_fg *di)
{
    int ret;
    int res = 0;

    ret = ab8500_fg_inst_curr_start(di);
    if (ret) {
        dev_err(di->dev, "Failed to initialize fg_inst\n");
        return 0;
    }

    ret = ab8500_fg_inst_curr_finalize(di, &res);
    if (ret) {
        dev_err(di->dev, "Failed to finalize fg_inst\n");
        return 0;
    }

    return res;
}

static void ab8500_fg_acc_cur_work(struct work_struct *work)
{
    int val;
    int ret;
    u8 low, med, high;

    struct ab8500_fg *di = container_of(work,
        struct ab8500_fg, fg_acc_cur_work);

    mutex_lock(&di->cc_lock);
    ret = abx500_set_register_interruptible(di->dev, AB8500_GAS_GAUGE,
        AB8500_GASG_CC_NCOV_ACCU_CTRL, RD_NCONV_ACCU_REQ);
    if (ret)
        goto exit;

    ret = abx500_get_register_interruptible(di->dev, AB8500_GAS_GAUGE,
        AB8500_GASG_CC_NCOV_ACCU_LOW,  &low);
    if (ret < 0)
        goto exit;

    ret = abx500_get_register_interruptible(di->dev, AB8500_GAS_GAUGE,
        AB8500_GASG_CC_NCOV_ACCU_MED,  &med);
    if (ret < 0)
        goto exit;

    ret = abx500_get_register_interruptible(di->dev, AB8500_GAS_GAUGE,
        AB8500_GASG_CC_NCOV_ACCU_HIGH, &high);
    if (ret < 0)
        goto exit;

    /* Check for sign bit in case of negative value, 2's compliment */
    if (high & 0x10)
        val = (low | (med << 8) | (high << 16) | 0xFFE00000);
    else
        val = (low | (med << 8) | (high << 16));

    /*
     * Convert to uAh
     * Given a 250ms conversion cycle time the LSB corresponds
     * to 112.9 nAh.
     * 112.9nAh assumes 10mOhm, but fg_res is in 0.1mOhm
     */
    di->accu_charge = (val * QLSB_NANO_AMP_HOURS_X10) /
        (100 * di->bat->fg_res);

    /*
     * Convert to unit value in mA
     * Full scale input voltage is
     * 66.660mV => LSB = 66.660mV/(4096*res) = 1.627mA
     * Given a 250ms conversion cycle time the LSB corresponds
     * to 112.9 nAh. Convert to current by dividing by the conversion
     * time in hours (= samples / (3600 * 4)h)
     * 112.9nAh assumes 10mOhm, but fg_res is in 0.1mOhm
     */
    di->avg_curr = (val * QLSB_NANO_AMP_HOURS_X10 * 36) /
        (1000 * di->bat->fg_res * (di->fg_samples / 4));

    di->flags.conv_done = true;

    mutex_unlock(&di->cc_lock);

    queue_work(di->fg_wq, &di->fg_work);

    return;
exit:
    dev_err(di->dev,
        "Failed to read or write gas gauge registers\n");
    mutex_unlock(&di->cc_lock);
    queue_work(di->fg_wq, &di->fg_work);
}

static int ab8500_fg_bat_voltage(struct ab8500_fg *di)
{
    int vbat;
    static int prev;

    vbat = ab8500_gpadc_convert(di->gpadc, MAIN_BAT_V);
    if (vbat < 0) {
        dev_err(di->dev,
            "%s gpadc conversion failed, using previous value\n",
            __func__);
        return prev;
    }

    prev = vbat;
    return vbat;
}

static int ab8500_fg_volt_to_capacity(struct ab8500_fg *di, int voltage)
{
    int i, tbl_size;
    struct abx500_v_to_cap *tbl;
    int cap = 0;

    tbl = di->bat->bat_type[di->bat->batt_id].v_to_cap_tbl,
    tbl_size = di->bat->bat_type[di->bat->batt_id].n_v_cap_tbl_elements;

    for (i = 0; i < tbl_size; ++i) {
        if (voltage > tbl[i].voltage)
            break;
    }

    if ((i > 0) && (i < tbl_size)) {
        cap = interpolate(voltage,
            tbl[i].voltage,
            tbl[i].capacity * 10,
            tbl[i-1].voltage,
            tbl[i-1].capacity * 10);
    } else if (i == 0) {
        cap = 1000;
    } else {
        cap = 0;
    }

    dev_dbg(di->dev, "%s Vbat: %d, Cap: %d per mille",
        __func__, voltage, cap);

    return cap;
}

static int ab8500_fg_uncomp_volt_to_capacity(struct ab8500_fg *di)
{
    di->vbat = ab8500_fg_bat_voltage(di);
    return ab8500_fg_volt_to_capacity(di, di->vbat);
}

static int ab8500_fg_battery_resistance(struct ab8500_fg *di)
{
    int i, tbl_size;
    struct batres_vs_temp *tbl;
    int resist = 0;

    tbl = di->bat->bat_type[di->bat->batt_id].batres_tbl;
    tbl_size = di->bat->bat_type[di->bat->batt_id].n_batres_tbl_elements;

    for (i = 0; i < tbl_size; ++i) {
        if (di->bat_temp / 10 > tbl[i].temp)
            break;
    }

    if ((i > 0) && (i < tbl_size)) {
        resist = interpolate(di->bat_temp / 10,
            tbl[i].temp,
            tbl[i].resist,
            tbl[i-1].temp,
            tbl[i-1].resist);
    } else if (i == 0) {
        resist = tbl[0].resist;
    } else {
        resist = tbl[tbl_size - 1].resist;
    }

    dev_dbg(di->dev, "%s Temp: %d battery internal resistance: %d"
        " fg resistance %d, total: %d (mOhm)\n",
        __func__, di->bat_temp, resist, di->bat->fg_res / 10,
        (di->bat->fg_res / 10) + resist);

    /* fg_res variable is in 0.1mOhm */
    resist += di->bat->fg_res / 10;

    return resist;
}

static int ab8500_fg_load_comp_volt_to_capacity(struct ab8500_fg *di)
{
    int vbat_comp, res;
    int i = 0;
    int vbat = 0;

    ab8500_fg_inst_curr_start(di);

    do {
        vbat += ab8500_fg_bat_voltage(di);
        i++;
        msleep(5);
    } while (!ab8500_fg_inst_curr_done(di));

    ab8500_fg_inst_curr_finalize(di, &di->inst_curr);

    di->vbat = vbat / i;
    res = ab8500_fg_battery_resistance(di);

    /* Use Ohms law to get the load compensated voltage */
    vbat_comp = di->vbat - (di->inst_curr * res) / 1000;

    dev_dbg(di->dev, "%s Measured Vbat: %dmV,Compensated Vbat %dmV, "
        "R: %dmOhm, Current: %dmA Vbat Samples: %d\n",
        __func__, di->vbat, vbat_comp, res, di->inst_curr, i);

    return ab8500_fg_volt_to_capacity(di, vbat_comp);
}

static int ab8500_fg_convert_mah_to_permille(struct ab8500_fg *di, int cap_mah)
{
    return (cap_mah * 1000) / di->bat_cap.max_mah_design;
}

static int ab8500_fg_convert_permille_to_mah(struct ab8500_fg *di, int cap_pm)
{
    return cap_pm * di->bat_cap.max_mah_design / 1000;
}

static int ab8500_fg_convert_mah_to_uwh(struct ab8500_fg *di, int cap_mah)
{
    u64 div_res;
    u32 div_rem;

    div_res = ((u64) cap_mah) * ((u64) di->vbat_nom);
    div_rem = do_div(div_res, 1000);

    /* Make sure to round upwards if necessary */
    if (div_rem >= 1000 / 2)
        div_res++;

    return (int) div_res;
}

static int ab8500_fg_calc_cap_charging(struct ab8500_fg *di)
{
    dev_dbg(di->dev, "%s cap_mah %d accu_charge %d\n",
        __func__,
        di->bat_cap.mah,
        di->accu_charge);

    /* Capacity should not be less than 0 */
    if (di->bat_cap.mah + di->accu_charge > 0)
        di->bat_cap.mah += di->accu_charge;
    else
        di->bat_cap.mah = 0;
    /*
     * We force capacity to 100% once when the algorithm
     * reports that it's full.
     */
    if (di->bat_cap.mah >= di->bat_cap.max_mah_design ||
        di->flags.force_full) {
        di->bat_cap.mah = di->bat_cap.max_mah_design;
    }

    ab8500_fg_fill_cap_sample(di, di->bat_cap.mah);
    di->bat_cap.permille =
        ab8500_fg_convert_mah_to_permille(di, di->bat_cap.mah);

    /* We need to update battery voltage and inst current when charging */
    di->vbat = ab8500_fg_bat_voltage(di);
    di->inst_curr = ab8500_fg_inst_curr_blocking(di);

    return di->bat_cap.mah;
}

static int ab8500_fg_calc_cap_discharge_voltage(struct ab8500_fg *di, bool comp)
{
    int permille, mah;

    if (comp)
        permille = ab8500_fg_load_comp_volt_to_capacity(di);
    else
        permille = ab8500_fg_uncomp_volt_to_capacity(di);

    mah = ab8500_fg_convert_permille_to_mah(di, permille);

    di->bat_cap.mah = ab8500_fg_add_cap_sample(di, mah);
    di->bat_cap.permille =
        ab8500_fg_convert_mah_to_permille(di, di->bat_cap.mah);

    return di->bat_cap.mah;
}

static int ab8500_fg_calc_cap_discharge_fg(struct ab8500_fg *di)
{
    int permille_volt, permille;

    dev_dbg(di->dev, "%s cap_mah %d accu_charge %d\n",
        __func__,
        di->bat_cap.mah,
        di->accu_charge);

    /* Capacity should not be less than 0 */
    if (di->bat_cap.mah + di->accu_charge > 0)
        di->bat_cap.mah += di->accu_charge;
    else
        di->bat_cap.mah = 0;

    if (di->bat_cap.mah >= di->bat_cap.max_mah_design)
        di->bat_cap.mah = di->bat_cap.max_mah_design;

    /*
     * Check against voltage based capacity. It can not be lower
     * than what the uncompensated voltage says
     */
    permille = ab8500_fg_convert_mah_to_permille(di, di->bat_cap.mah);
    permille_volt = ab8500_fg_uncomp_volt_to_capacity(di);

    if (permille < permille_volt) {
        di->bat_cap.permille = permille_volt;
        di->bat_cap.mah = ab8500_fg_convert_permille_to_mah(di,
            di->bat_cap.permille);

        dev_dbg(di->dev, "%s voltage based: perm %d perm_volt %d\n",
            __func__,
            permille,
            permille_volt);

        ab8500_fg_fill_cap_sample(di, di->bat_cap.mah);
    } else {
        ab8500_fg_fill_cap_sample(di, di->bat_cap.mah);
        di->bat_cap.permille =
            ab8500_fg_convert_mah_to_permille(di, di->bat_cap.mah);
    }

    return di->bat_cap.mah;
}

static int ab8500_fg_capacity_level(struct ab8500_fg *di)
{
    int ret, percent;

    percent = di->bat_cap.permille / 10;

    if (percent <= di->bat->cap_levels->critical ||
        di->flags.low_bat)
        ret = POWER_SUPPLY_CAPACITY_LEVEL_CRITICAL;
    else if (percent <= di->bat->cap_levels->low)
        ret = POWER_SUPPLY_CAPACITY_LEVEL_LOW;
    else if (percent <= di->bat->cap_levels->normal)
        ret = POWER_SUPPLY_CAPACITY_LEVEL_NORMAL;
    else if (percent <= di->bat->cap_levels->high)
        ret = POWER_SUPPLY_CAPACITY_LEVEL_HIGH;
    else
        ret = POWER_SUPPLY_CAPACITY_LEVEL_FULL;

    return ret;
}

static void ab8500_fg_check_capacity_limits(struct ab8500_fg *di, bool init)
{
    bool changed = false;

    di->bat_cap.level = ab8500_fg_capacity_level(di);

    if (di->bat_cap.level != di->bat_cap.prev_level) {
        /*
         * We do not allow reported capacity level to go up
         * unless we're charging or if we're in init
         */
        if (!(!di->flags.charging && di->bat_cap.level >
            di->bat_cap.prev_level) || init) {
            dev_dbg(di->dev, "level changed from %d to %d\n",
                di->bat_cap.prev_level,
                di->bat_cap.level);
            di->bat_cap.prev_level = di->bat_cap.level;
            changed = true;
        } else {
            dev_dbg(di->dev, "level not allowed to go up "
                "since no charger is connected: %d to %d\n",
                di->bat_cap.prev_level,
                di->bat_cap.level);
        }
    }

    /*
     * If we have received the LOW_BAT IRQ, set capacity to 0 to initiate
     * shutdown
     */
    if (di->flags.low_bat) {
        dev_dbg(di->dev, "Battery low, set capacity to 0\n");
        di->bat_cap.prev_percent = 0;
        di->bat_cap.permille = 0;
        di->bat_cap.prev_mah = 0;
        di->bat_cap.mah = 0;
        changed = true;
    } else if (di->flags.fully_charged) {
        /*
         * We report 100% if algorithm reported fully charged
         * unless capacity drops too much
         */
        if (di->flags.force_full) {
            di->bat_cap.prev_percent = di->bat_cap.permille / 10;
            di->bat_cap.prev_mah = di->bat_cap.mah;
        } else if (!di->flags.force_full &&
            di->bat_cap.prev_percent !=
            (di->bat_cap.permille) / 10 &&
            (di->bat_cap.permille / 10) <
            di->bat->fg_params->maint_thres) {
            dev_dbg(di->dev,
                "battery reported full "
                "but capacity dropping: %d\n",
                di->bat_cap.permille / 10);
            di->bat_cap.prev_percent = di->bat_cap.permille / 10;
            di->bat_cap.prev_mah = di->bat_cap.mah;

            changed = true;
        }
    } else if (di->bat_cap.prev_percent != di->bat_cap.permille / 10) {
        if (di->bat_cap.permille / 10 == 0) {
            /*
             * We will not report 0% unless we've got
             * the LOW_BAT IRQ, no matter what the FG
             * algorithm says.
             */
            di->bat_cap.prev_percent = 1;
            di->bat_cap.permille = 1;
            di->bat_cap.prev_mah = 1;
            di->bat_cap.mah = 1;

            changed = true;
        } else if (!(!di->flags.charging &&
            (di->bat_cap.permille / 10) >
            di->bat_cap.prev_percent) || init) {
            /*
             * We do not allow reported capacity to go up
             * unless we're charging or if we're in init
             */
            dev_dbg(di->dev,
                "capacity changed from %d to %d (%d)\n",
                di->bat_cap.prev_percent,
                di->bat_cap.permille / 10,
                di->bat_cap.permille);
            di->bat_cap.prev_percent = di->bat_cap.permille / 10;
            di->bat_cap.prev_mah = di->bat_cap.mah;

            changed = true;
        } else {
            dev_dbg(di->dev, "capacity not allowed to go up since "
                "no charger is connected: %d to %d (%d)\n",
                di->bat_cap.prev_percent,
                di->bat_cap.permille / 10,
                di->bat_cap.permille);
        }
    }

    if (changed) {
        power_supply_changed(&di->fg_psy);
        if (di->flags.fully_charged && di->flags.force_full) {
            dev_dbg(di->dev, "Battery full, notifying.\n");
            di->flags.force_full = false;
            sysfs_notify(&di->fg_kobject, NULL, "charge_full");
        }
        sysfs_notify(&di->fg_kobject, NULL, "charge_now");
    }
}

static void ab8500_fg_charge_state_to(struct ab8500_fg *di,
    enum ab8500_fg_charge_state new_state)
{
    dev_dbg(di->dev, "Charge state from %d [%s] to %d [%s]\n",
        di->charge_state,
        charge_state[di->charge_state],
        new_state,
        charge_state[new_state]);

    di->charge_state = new_state;
}

static void ab8500_fg_discharge_state_to(struct ab8500_fg *di,
    enum ab8500_fg_discharge_state new_state)
{
    dev_dbg(di->dev, "Disharge state from %d [%s] to %d [%s]\n",
        di->discharge_state,
        discharge_state[di->discharge_state],
        new_state,
        discharge_state[new_state]);

    di->discharge_state = new_state;
}

static void ab8500_fg_algorithm_charging(struct ab8500_fg *di)
{
    /*
     * If we change to discharge mode
     * we should start with recovery
     */
    if (di->discharge_state != AB8500_FG_DISCHARGE_INIT_RECOVERY)
        ab8500_fg_discharge_state_to(di,
            AB8500_FG_DISCHARGE_INIT_RECOVERY);

    switch (di->charge_state) {
    case AB8500_FG_CHARGE_INIT:
        di->fg_samples = SEC_TO_SAMPLE(
            di->bat->fg_params->accu_charging);

        ab8500_fg_coulomb_counter(di, true);
        ab8500_fg_charge_state_to(di, AB8500_FG_CHARGE_READOUT);

        break;

    case AB8500_FG_CHARGE_READOUT:
        /*
         * Read the FG and calculate the new capacity
         */
        mutex_lock(&di->cc_lock);
        if (!di->flags.conv_done) {
            /* Wasn't the CC IRQ that got us here */
            mutex_unlock(&di->cc_lock);
            dev_dbg(di->dev, "%s CC conv not done\n",
                __func__);

            break;
        }
        di->flags.conv_done = false;
        mutex_unlock(&di->cc_lock);

        ab8500_fg_calc_cap_charging(di);

        break;

    default:
        break;
    }

    /* Check capacity limits */
    ab8500_fg_check_capacity_limits(di, false);
}

static void force_capacity(struct ab8500_fg *di)
{
    int cap;

    ab8500_fg_clear_cap_samples(di);
    cap = di->bat_cap.user_mah;
    if (cap > di->bat_cap.max_mah_design) {
        dev_dbg(di->dev, "Remaining cap %d can't be bigger than total"
            " %d\n", cap, di->bat_cap.max_mah_design);
        cap = di->bat_cap.max_mah_design;
    }
    ab8500_fg_fill_cap_sample(di, di->bat_cap.user_mah);
    di->bat_cap.permille = ab8500_fg_convert_mah_to_permille(di, cap);
    di->bat_cap.mah = cap;
    ab8500_fg_check_capacity_limits(di, true);
}

static bool check_sysfs_capacity(struct ab8500_fg *di)
{
    int cap, lower, upper;
    int cap_permille;

    cap = di->bat_cap.user_mah;

    cap_permille = ab8500_fg_convert_mah_to_permille(di,
        di->bat_cap.user_mah);

    lower = di->bat_cap.permille - di->bat->fg_params->user_cap_limit * 10;
    upper = di->bat_cap.permille + di->bat->fg_params->user_cap_limit * 10;

    if (lower < 0)
        lower = 0;
    /* 1000 is permille, -> 100 percent */
    if (upper > 1000)
        upper = 1000;

    dev_dbg(di->dev, "Capacity limits:"
        " (Lower: %d User: %d Upper: %d) [user: %d, was: %d]\n",
        lower, cap_permille, upper, cap, di->bat_cap.mah);

    /* If within limits, use the saved capacity and exit estimation...*/
    if (cap_permille > lower && cap_permille < upper) {
        dev_dbg(di->dev, "OK! Using users cap %d uAh now\n", cap);
        force_capacity(di);
        return true;
    }
    dev_dbg(di->dev, "Capacity from user out of limits, ignoring");
    return false;
}

static void ab8500_fg_algorithm_discharging(struct ab8500_fg *di)
{
    int sleep_time;

    /* If we change to charge mode we should start with init */
    if (di->charge_state != AB8500_FG_CHARGE_INIT)
        ab8500_fg_charge_state_to(di, AB8500_FG_CHARGE_INIT);

    switch (di->discharge_state) {
    case AB8500_FG_DISCHARGE_INIT:
        /* We use the FG IRQ to work on */
        di->init_cnt = 0;
        di->fg_samples = SEC_TO_SAMPLE(di->bat->fg_params->init_timer);
        ab8500_fg_coulomb_counter(di, true);
        ab8500_fg_discharge_state_to(di,
            AB8500_FG_DISCHARGE_INITMEASURING);

        /* Intentional fallthrough */
    case AB8500_FG_DISCHARGE_INITMEASURING:
        /*
         * Discard a number of samples during startup.
         * After that, use compensated voltage for a few
         * samples to get an initial capacity.
         * Then go to READOUT
         */
        sleep_time = di->bat->fg_params->init_timer;

        /* Discard the first [x] seconds */
        if (di->init_cnt >
            di->bat->fg_params->init_discard_time) {
            ab8500_fg_calc_cap_discharge_voltage(di, true);

            ab8500_fg_check_capacity_limits(di, true);
        }

        di->init_cnt += sleep_time;
        if (di->init_cnt > di->bat->fg_params->init_total_time)
            ab8500_fg_discharge_state_to(di,
                AB8500_FG_DISCHARGE_READOUT_INIT);

        break;

    case AB8500_FG_DISCHARGE_INIT_RECOVERY:
        di->recovery_cnt = 0;
        di->recovery_needed = true;
        ab8500_fg_discharge_state_to(di,
            AB8500_FG_DISCHARGE_RECOVERY);

        /* Intentional fallthrough */

    case AB8500_FG_DISCHARGE_RECOVERY:
        sleep_time = di->bat->fg_params->recovery_sleep_timer;

        /*
         * We should check the power consumption
         * If low, go to READOUT (after x min) or
         * RECOVERY_SLEEP if time left.
         * If high, go to READOUT
         */
        di->inst_curr = ab8500_fg_inst_curr_blocking(di);

        if (ab8500_fg_is_low_curr(di, di->inst_curr)) {
            if (di->recovery_cnt >
                di->bat->fg_params->recovery_total_time) {
                di->fg_samples = SEC_TO_SAMPLE(
                    di->bat->fg_params->accu_high_curr);
                ab8500_fg_coulomb_counter(di, true);
                ab8500_fg_discharge_state_to(di,
                    AB8500_FG_DISCHARGE_READOUT);
                di->recovery_needed = false;
            } else {
                queue_delayed_work(di->fg_wq,
                    &di->fg_periodic_work,
                    sleep_time * HZ);
            }
            di->recovery_cnt += sleep_time;
        } else {
            di->fg_samples = SEC_TO_SAMPLE(
                di->bat->fg_params->accu_high_curr);
            ab8500_fg_coulomb_counter(di, true);
            ab8500_fg_discharge_state_to(di,
                AB8500_FG_DISCHARGE_READOUT);
        }
        break;

    case AB8500_FG_DISCHARGE_READOUT_INIT:
        di->fg_samples = SEC_TO_SAMPLE(
            di->bat->fg_params->accu_high_curr);
        ab8500_fg_coulomb_counter(di, true);
        ab8500_fg_discharge_state_to(di,
                AB8500_FG_DISCHARGE_READOUT);
        break;

    case AB8500_FG_DISCHARGE_READOUT:
        di->inst_curr = ab8500_fg_inst_curr_blocking(di);

        if (ab8500_fg_is_low_curr(di, di->inst_curr)) {
            /* Detect mode change */
            if (di->high_curr_mode) {
                di->high_curr_mode = false;
                di->high_curr_cnt = 0;
            }

            if (di->recovery_needed) {
                ab8500_fg_discharge_state_to(di,
                    AB8500_FG_DISCHARGE_RECOVERY);

                queue_delayed_work(di->fg_wq,
                    &di->fg_periodic_work, 0);

                break;
            }

            ab8500_fg_calc_cap_discharge_voltage(di, true);
        } else {
            mutex_lock(&di->cc_lock);
            if (!di->flags.conv_done) {
                /* Wasn't the CC IRQ that got us here */
                mutex_unlock(&di->cc_lock);
                dev_dbg(di->dev, "%s CC conv not done\n",
                    __func__);

                break;
            }
            di->flags.conv_done = false;
            mutex_unlock(&di->cc_lock);

            /* Detect mode change */
            if (!di->high_curr_mode) {
                di->high_curr_mode = true;
                di->high_curr_cnt = 0;
            }

            di->high_curr_cnt +=
                di->bat->fg_params->accu_high_curr;
            if (di->high_curr_cnt >
                di->bat->fg_params->high_curr_time)
                di->recovery_needed = true;

            ab8500_fg_calc_cap_discharge_fg(di);
        }

        ab8500_fg_check_capacity_limits(di, false);

        break;

    case AB8500_FG_DISCHARGE_WAKEUP:
        ab8500_fg_coulomb_counter(di, true);
        di->inst_curr = ab8500_fg_inst_curr_blocking(di);

        ab8500_fg_calc_cap_discharge_voltage(di, true);

        di->fg_samples = SEC_TO_SAMPLE(
            di->bat->fg_params->accu_high_curr);
        ab8500_fg_coulomb_counter(di, true);
        ab8500_fg_discharge_state_to(di,
                AB8500_FG_DISCHARGE_READOUT);

        ab8500_fg_check_capacity_limits(di, false);

        break;

    default:
        break;
    }
}

static void ab8500_fg_algorithm_calibrate(struct ab8500_fg *di)
{
    int ret;

    switch (di->calib_state) {
    case AB8500_FG_CALIB_INIT:
        dev_dbg(di->dev, "Calibration ongoing...\n");

        ret = abx500_mask_and_set_register_interruptible(di->dev,
            AB8500_GAS_GAUGE, AB8500_GASG_CC_CTRL_REG,
            CC_INT_CAL_N_AVG_MASK, CC_INT_CAL_SAMPLES_8);
        if (ret < 0)
            goto err;

        ret = abx500_mask_and_set_register_interruptible(di->dev,
            AB8500_GAS_GAUGE, AB8500_GASG_CC_CTRL_REG,
            CC_INTAVGOFFSET_ENA, CC_INTAVGOFFSET_ENA);
        if (ret < 0)
            goto err;
        di->calib_state = AB8500_FG_CALIB_WAIT;
        break;
    case AB8500_FG_CALIB_END:
        ret = abx500_mask_and_set_register_interruptible(di->dev,
            AB8500_GAS_GAUGE, AB8500_GASG_CC_CTRL_REG,
            CC_MUXOFFSET, CC_MUXOFFSET);
        if (ret < 0)
            goto err;
        di->flags.calibrate = false;
        dev_dbg(di->dev, "Calibration done...\n");
        queue_delayed_work(di->fg_wq, &di->fg_periodic_work, 0);
        break;
    case AB8500_FG_CALIB_WAIT:
        dev_dbg(di->dev, "Calibration WFI\n");
    default:
        break;
    }
    return;
err:
    /* Something went wrong, don't calibrate then */
    dev_err(di->dev, "failed to calibrate the CC\n");
    di->flags.calibrate = false;
    di->calib_state = AB8500_FG_CALIB_INIT;
    queue_delayed_work(di->fg_wq, &di->fg_periodic_work, 0);
}

static void ab8500_fg_algorithm(struct ab8500_fg *di)
{
    if (di->flags.calibrate)
        ab8500_fg_algorithm_calibrate(di);
    else {
        if (di->flags.charging)
            ab8500_fg_algorithm_charging(di);
        else
            ab8500_fg_algorithm_discharging(di);
    }

    dev_dbg(di->dev, "[FG_DATA] %d %d %d %d %d %d %d %d %d "
        "%d %d %d %d %d %d %d\n",
        di->bat_cap.max_mah_design,
        di->bat_cap.mah,
        di->bat_cap.permille,
        di->bat_cap.level,
        di->bat_cap.prev_mah,
        di->bat_cap.prev_percent,
        di->bat_cap.prev_level,
        di->vbat,
        di->inst_curr,
        di->avg_curr,
        di->accu_charge,
        di->flags.charging,
        di->charge_state,
        di->discharge_state,
        di->high_curr_mode,
        di->recovery_needed);
}

static void ab8500_fg_periodic_work(struct work_struct *work)
{
    struct ab8500_fg *di = container_of(work, struct ab8500_fg,
        fg_periodic_work.work);

    if (di->init_capacity) {
        /* A dummy read that will return 0 */
        di->inst_curr = ab8500_fg_inst_curr_blocking(di);
        /* Get an initial capacity calculation */
        ab8500_fg_calc_cap_discharge_voltage(di, true);
        ab8500_fg_check_capacity_limits(di, true);
        di->init_capacity = false;

        queue_delayed_work(di->fg_wq, &di->fg_periodic_work, 0);
    } else if (di->flags.user_cap) {
        if (check_sysfs_capacity(di)) {
            ab8500_fg_check_capacity_limits(di, true);
            if (di->flags.charging)
                ab8500_fg_charge_state_to(di,
                    AB8500_FG_CHARGE_INIT);
            else
                ab8500_fg_discharge_state_to(di,
                    AB8500_FG_DISCHARGE_READOUT_INIT);
        }
        di->flags.user_cap = false;
        queue_delayed_work(di->fg_wq, &di->fg_periodic_work, 0);
    } else
        ab8500_fg_algorithm(di);

}

static void ab8500_fg_check_hw_failure_work(struct work_struct *work)
{
    int ret;
    u8 reg_value;

    struct ab8500_fg *di = container_of(work, struct ab8500_fg,
        fg_check_hw_failure_work.work);

    /*
     * If we have had a battery over-voltage situation,
     * check ovv-bit to see if it should be reset.
     */
    if (di->flags.bat_ovv) {
        ret = abx500_get_register_interruptible(di->dev,
            AB8500_CHARGER, AB8500_CH_STAT_REG,
            &reg_value);
        if (ret < 0) {
            dev_err(di->dev, "%s ab8500 read failed\n", __func__);
            return;
        }
        if ((reg_value & BATT_OVV) != BATT_OVV) {
            dev_dbg(di->dev, "Battery recovered from OVV\n");
            di->flags.bat_ovv = false;
            power_supply_changed(&di->fg_psy);
            return;
        }

        /* Not yet recovered from ovv, reschedule this test */
        queue_delayed_work(di->fg_wq, &di->fg_check_hw_failure_work,
                   round_jiffies(HZ));
    }
}

static void ab8500_fg_low_bat_work(struct work_struct *work)
{
    int vbat;

    struct ab8500_fg *di = container_of(work, struct ab8500_fg,
        fg_low_bat_work.work);

    vbat = ab8500_fg_bat_voltage(di);

    /* Check if LOW_BAT still fulfilled */
    if (vbat < di->bat->fg_params->lowbat_threshold) {
        di->flags.low_bat = true;
        dev_warn(di->dev, "Battery voltage still LOW\n");

        /*
         * We need to re-schedule this check to be able to detect
         * if the voltage increases again during charging
         */
        queue_delayed_work(di->fg_wq, &di->fg_low_bat_work,
            round_jiffies(LOW_BAT_CHECK_INTERVAL));
    } else {
        di->flags.low_bat = false;
        dev_warn(di->dev, "Battery voltage OK again\n");
    }

    /* This is needed to dispatch LOW_BAT */
    ab8500_fg_check_capacity_limits(di, false);

    /* Set this flag to check if LOW_BAT IRQ still occurs */
    di->flags.low_bat_delay = false;
}

static int ab8500_fg_battok_calc(struct ab8500_fg *di, int target)
{
    if (target > BATT_OK_MIN +
        (BATT_OK_INCREMENT * BATT_OK_MAX_NR_INCREMENTS))
        return BATT_OK_MAX_NR_INCREMENTS;
    if (target < BATT_OK_MIN)
        return 0;
    return (target - BATT_OK_MIN) / BATT_OK_INCREMENT;
}

static int ab8500_fg_battok_init_hw_register(struct ab8500_fg *di)
{
    int selected;
    int sel0;
    int sel1;
    int cbp_sel0;
    int cbp_sel1;
    int ret;
    int new_val;

    sel0 = di->bat->fg_params->battok_falling_th_sel0;
    sel1 = di->bat->fg_params->battok_raising_th_sel1;

    cbp_sel0 = ab8500_fg_battok_calc(di, sel0);
    cbp_sel1 = ab8500_fg_battok_calc(di, sel1);

    selected = BATT_OK_MIN + cbp_sel0 * BATT_OK_INCREMENT;

    if (selected != sel0)
        dev_warn(di->dev, "Invalid voltage step:%d, using %d %d\n",
            sel0, selected, cbp_sel0);

    selected = BATT_OK_MIN + cbp_sel1 * BATT_OK_INCREMENT;

    if (selected != sel1)
        dev_warn(di->dev, "Invalid voltage step:%d, using %d %d\n",
            sel1, selected, cbp_sel1);

    new_val = cbp_sel0 | (cbp_sel1 << 4);

    dev_dbg(di->dev, "using: %x %d %d\n", new_val, cbp_sel0, cbp_sel1);
    ret = abx500_set_register_interruptible(di->dev, AB8500_SYS_CTRL2_BLOCK,
        AB8500_BATT_OK_REG, new_val);
    return ret;
}

static void ab8500_fg_instant_work(struct work_struct *work)
{
    struct ab8500_fg *di = container_of(work, struct ab8500_fg, fg_work);

    ab8500_fg_algorithm(di);
}

static irqreturn_t ab8500_fg_cc_data_end_handler(int irq, void *_di)
{
    struct ab8500_fg *di = _di;
    complete(&di->ab8500_fg_complete);
    return IRQ_HANDLED;
}

static irqreturn_t ab8500_fg_cc_int_calib_handler(int irq, void *_di)
{
    struct ab8500_fg *di = _di;
    di->calib_state = AB8500_FG_CALIB_END;
    queue_delayed_work(di->fg_wq, &di->fg_periodic_work, 0);
    return IRQ_HANDLED;
}

static irqreturn_t ab8500_fg_cc_convend_handler(int irq, void *_di)
{
    struct ab8500_fg *di = _di;

    queue_work(di->fg_wq, &di->fg_acc_cur_work);

    return IRQ_HANDLED;
}

static irqreturn_t ab8500_fg_batt_ovv_handler(int irq, void *_di)
{
    struct ab8500_fg *di = _di;

    dev_dbg(di->dev, "Battery OVV\n");
    di->flags.bat_ovv = true;
    power_supply_changed(&di->fg_psy);

    /* Schedule a new HW failure check */
    queue_delayed_work(di->fg_wq, &di->fg_check_hw_failure_work, 0);

    return IRQ_HANDLED;
}

static irqreturn_t ab8500_fg_lowbatf_handler(int irq, void *_di)
{
    struct ab8500_fg *di = _di;

    if (!di->flags.low_bat_delay) {
        dev_warn(di->dev, "Battery voltage is below LOW threshold\n");
        di->flags.low_bat_delay = true;
        /*
         * Start a timer to check LOW_BAT again after some time
         * This is done to avoid shutdown on single voltage dips
         */
        queue_delayed_work(di->fg_wq, &di->fg_low_bat_work,
            round_jiffies(LOW_BAT_CHECK_INTERVAL));
    }
    return IRQ_HANDLED;
}

static int ab8500_fg_get_property(struct power_supply *psy,
    enum power_supply_property psp,
    union power_supply_propval *val)
{
    struct ab8500_fg *di;

    di = to_ab8500_fg_device_info(psy);

    /*
     * If battery is identified as unknown and charging of unknown
     * batteries is disabled, we always report 100% capacity and
     * capacity level UNKNOWN, since we can't calculate
     * remaining capacity
     */

    switch (psp) {
    case POWER_SUPPLY_PROP_VOLTAGE_NOW:
        if (di->flags.bat_ovv)
            val->intval = BATT_OVV_VALUE * 1000;
        else
            val->intval = di->vbat * 1000;
        break;
    case POWER_SUPPLY_PROP_CURRENT_NOW:
        val->intval = di->inst_curr * 1000;
        break;
    case POWER_SUPPLY_PROP_CURRENT_AVG:
        val->intval = di->avg_curr * 1000;
        break;
    case POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN:
        val->intval = ab8500_fg_convert_mah_to_uwh(di,
                di->bat_cap.max_mah_design);
        break;
    case POWER_SUPPLY_PROP_ENERGY_FULL:
        val->intval = ab8500_fg_convert_mah_to_uwh(di,
                di->bat_cap.max_mah);
        break;
    case POWER_SUPPLY_PROP_ENERGY_NOW:
        if (di->flags.batt_unknown && !di->bat->chg_unknown_bat &&
                di->flags.batt_id_received)
            val->intval = ab8500_fg_convert_mah_to_uwh(di,
                    di->bat_cap.max_mah);
        else
            val->intval = ab8500_fg_convert_mah_to_uwh(di,
                    di->bat_cap.prev_mah);
        break;
    case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
        val->intval = di->bat_cap.max_mah_design;
        break;
    case POWER_SUPPLY_PROP_CHARGE_FULL:
        val->intval = di->bat_cap.max_mah;
        break;
    case POWER_SUPPLY_PROP_CHARGE_NOW:
        if (di->flags.batt_unknown && !di->bat->chg_unknown_bat &&
                di->flags.batt_id_received)
            val->intval = di->bat_cap.max_mah;
        else
            val->intval = di->bat_cap.prev_mah;
        break;
    case POWER_SUPPLY_PROP_CAPACITY:
        if (di->flags.batt_unknown && !di->bat->chg_unknown_bat &&
                di->flags.batt_id_received)
            val->intval = 100;
        else
            val->intval = di->bat_cap.prev_percent;
        break;
    case POWER_SUPPLY_PROP_CAPACITY_LEVEL:
        if (di->flags.batt_unknown && !di->bat->chg_unknown_bat &&
                di->flags.batt_id_received)
            val->intval = POWER_SUPPLY_CAPACITY_LEVEL_UNKNOWN;
        else
            val->intval = di->bat_cap.prev_level;
        break;
    default:
        return -EINVAL;
    }
    return 0;
}

static int ab8500_fg_get_ext_psy_data(struct device *dev, void *data)
{
    struct power_supply *psy;
    struct power_supply *ext;
    struct ab8500_fg *di;
    union power_supply_propval ret;
    int i, j;
    bool psy_found = false;

    psy = (struct power_supply *)data;
    ext = dev_get_drvdata(dev);
    di = to_ab8500_fg_device_info(psy);

    /*
     * For all psy where the name of your driver
     * appears in any supplied_to
     */
    for (i = 0; i < ext->num_supplicants; i++) {
        if (!strcmp(ext->supplied_to[i], psy->name))
            psy_found = true;
    }

    if (!psy_found)
        return 0;

    /* Go through all properties for the psy */
    for (j = 0; j < ext->num_properties; j++) {
        enum power_supply_property prop;
        prop = ext->properties[j];

        if (ext->get_property(ext, prop, &ret))
            continue;

        switch (prop) {
        case POWER_SUPPLY_PROP_STATUS:
            switch (ext->type) {
            case POWER_SUPPLY_TYPE_BATTERY:
                switch (ret.intval) {
                case POWER_SUPPLY_STATUS_UNKNOWN:
                case POWER_SUPPLY_STATUS_DISCHARGING:
                case POWER_SUPPLY_STATUS_NOT_CHARGING:
                    if (!di->flags.charging)
                        break;
                    di->flags.charging = false;
                    di->flags.fully_charged = false;
                    queue_work(di->fg_wq, &di->fg_work);
                    break;
                case POWER_SUPPLY_STATUS_FULL:
                    if (di->flags.fully_charged)
                        break;
                    di->flags.fully_charged = true;
                    di->flags.force_full = true;
                    /* Save current capacity as maximum */
                    di->bat_cap.max_mah = di->bat_cap.mah;
                    queue_work(di->fg_wq, &di->fg_work);
                    break;
                case POWER_SUPPLY_STATUS_CHARGING:
                    if (di->flags.charging)
                        break;
                    di->flags.charging = true;
                    di->flags.fully_charged = false;
                    queue_work(di->fg_wq, &di->fg_work);
                    break;
                };
            default:
                break;
            };
            break;
        case POWER_SUPPLY_PROP_TECHNOLOGY:
            switch (ext->type) {
            case POWER_SUPPLY_TYPE_BATTERY:
                if (!di->flags.batt_id_received) {
                    const struct abx500_battery_type *b;

                    b = &(di->bat->bat_type[di->bat->batt_id]);

                    di->flags.batt_id_received = true;

                    di->bat_cap.max_mah_design =
                        MILLI_TO_MICRO *
                        b->charge_full_design;

                    di->bat_cap.max_mah =
                        di->bat_cap.max_mah_design;

                    di->vbat_nom = b->nominal_voltage;
                }

                if (ret.intval)
                    di->flags.batt_unknown = false;
                else
                    di->flags.batt_unknown = true;
                break;
            default:
                break;
            }
            break;
        case POWER_SUPPLY_PROP_TEMP:
            switch (ext->type) {
            case POWER_SUPPLY_TYPE_BATTERY:
                if (di->flags.batt_id_received)
                di->bat_temp = ret.intval;
                break;
            default:
                break;
            }
            break;
        default:
            break;
        }
    }
    return 0;
}

static int ab8500_fg_init_hw_registers(struct ab8500_fg *di)
{
    int ret;

    /* Set VBAT OVV threshold */
    ret = abx500_mask_and_set_register_interruptible(di->dev,
        AB8500_CHARGER,
        AB8500_BATT_OVV,
        BATT_OVV_TH_4P75,
        BATT_OVV_TH_4P75);
    if (ret) {
        dev_err(di->dev, "failed to set BATT_OVV\n");
        goto out;
    }

    /* Enable VBAT OVV detection */
    ret = abx500_mask_and_set_register_interruptible(di->dev,
        AB8500_CHARGER,
        AB8500_BATT_OVV,
        BATT_OVV_ENA,
        BATT_OVV_ENA);
    if (ret) {
        dev_err(di->dev, "failed to enable BATT_OVV\n");
        goto out;
    }

    /* Low Battery Voltage */
    ret = abx500_set_register_interruptible(di->dev,
        AB8500_SYS_CTRL2_BLOCK,
        AB8500_LOW_BAT_REG,
        ab8500_volt_to_regval(
            di->bat->fg_params->lowbat_threshold) << 1 |
        LOW_BAT_ENABLE);
    if (ret) {
        dev_err(di->dev, "%s write failed\n", __func__);
        goto out;
    }

    /* Battery OK threshold */
    ret = ab8500_fg_battok_init_hw_register(di);
    if (ret) {
        dev_err(di->dev, "BattOk init write failed.\n");
        goto out;
    }
out:
    return ret;
}

static void ab8500_fg_external_power_changed(struct power_supply *psy)
{
    struct ab8500_fg *di = to_ab8500_fg_device_info(psy);

    class_for_each_device(power_supply_class, NULL,
        &di->fg_psy, ab8500_fg_get_ext_psy_data);
}

static void ab8500_fg_reinit_work(struct work_struct *work)
{
    struct ab8500_fg *di = container_of(work, struct ab8500_fg,
        fg_reinit_work.work);

    if (di->flags.calibrate == false) {
        dev_dbg(di->dev, "Resetting FG state machine to init.\n");
        ab8500_fg_clear_cap_samples(di);
        ab8500_fg_calc_cap_discharge_voltage(di, true);
        ab8500_fg_charge_state_to(di, AB8500_FG_CHARGE_INIT);
        ab8500_fg_discharge_state_to(di, AB8500_FG_DISCHARGE_INIT);
        queue_delayed_work(di->fg_wq, &di->fg_periodic_work, 0);

    } else {
        dev_err(di->dev, "Residual offset calibration ongoing "
            "retrying..\n");
        /* Wait one second until next try*/
        queue_delayed_work(di->fg_wq, &di->fg_reinit_work,
            round_jiffies(1));
    }
}

void ab8500_fg_reinit(void)
{
    struct ab8500_fg *di = ab8500_fg_get();
    /* User won't be notified if a null pointer returned. */
    if (di != NULL)
        queue_delayed_work(di->fg_wq, &di->fg_reinit_work, 0);
}

/* Exposure to the sysfs interface */

struct ab8500_fg_sysfs_entry {
    struct attribute attr;
    ssize_t (*show)(struct ab8500_fg *, char *);
    ssize_t (*store)(struct ab8500_fg *, const char *, size_t);
};

static ssize_t charge_full_show(struct ab8500_fg *di, char *buf)
{
    return sprintf(buf, "%d\n", di->bat_cap.max_mah);
}

static ssize_t charge_full_store(struct ab8500_fg *di, const char *buf,
                 size_t count)
{
    unsigned long charge_full;
    ssize_t ret = -EINVAL;

    ret = strict_strtoul(buf, 10, &charge_full);

    dev_dbg(di->dev, "Ret %zd charge_full %lu", ret, charge_full);

    if (!ret) {
        di->bat_cap.max_mah = (int) charge_full;
        ret = count;
    }
    return ret;
}

static ssize_t charge_now_show(struct ab8500_fg *di, char *buf)
{
    return sprintf(buf, "%d\n", di->bat_cap.prev_mah);
}

static ssize_t charge_now_store(struct ab8500_fg *di, const char *buf,
                 size_t count)
{
    unsigned long charge_now;
    ssize_t ret;

    ret = strict_strtoul(buf, 10, &charge_now);

    dev_dbg(di->dev, "Ret %zd charge_now %lu was %d",
        ret, charge_now, di->bat_cap.prev_mah);

    if (!ret) {
        di->bat_cap.user_mah = (int) charge_now;
        di->flags.user_cap = true;
        ret = count;
        queue_delayed_work(di->fg_wq, &di->fg_periodic_work, 0);
    }
    return ret;
}

static struct ab8500_fg_sysfs_entry charge_full_attr =
    __ATTR(charge_full, 0644, charge_full_show, charge_full_store);

static struct ab8500_fg_sysfs_entry charge_now_attr =
    __ATTR(charge_now, 0644, charge_now_show, charge_now_store);

static ssize_t
ab8500_fg_show(struct kobject *kobj, struct attribute *attr, char *buf)
{
    struct ab8500_fg_sysfs_entry *entry;
    struct ab8500_fg *di;

    entry = container_of(attr, struct ab8500_fg_sysfs_entry, attr);
    di = container_of(kobj, struct ab8500_fg, fg_kobject);

    if (!entry->show)
        return -EIO;

    return entry->show(di, buf);
}
static ssize_t
ab8500_fg_store(struct kobject *kobj, struct attribute *attr, const char *buf,
        size_t count)
{
    struct ab8500_fg_sysfs_entry *entry;
    struct ab8500_fg *di;

    entry = container_of(attr, struct ab8500_fg_sysfs_entry, attr);
    di = container_of(kobj, struct ab8500_fg, fg_kobject);

    if (!entry->store)
        return -EIO;

    return entry->store(di, buf, count);
}

static const struct sysfs_ops ab8500_fg_sysfs_ops = {
    .show = ab8500_fg_show,
    .store = ab8500_fg_store,
};

static struct attribute *ab8500_fg_attrs[] = {
    &charge_full_attr.attr,
    &charge_now_attr.attr,
    NULL,
};

static struct kobj_type ab8500_fg_ktype = {
    .sysfs_ops = &ab8500_fg_sysfs_ops,
    .default_attrs = ab8500_fg_attrs,
};

static void ab8500_fg_sysfs_exit(struct ab8500_fg *di)
{
    kobject_del(&di->fg_kobject);
}

static int ab8500_fg_sysfs_init(struct ab8500_fg *di)
{
    int ret = 0;

    ret = kobject_init_and_add(&di->fg_kobject,
        &ab8500_fg_ktype,
        NULL, "battery");
    if (ret < 0)
        dev_err(di->dev, "failed to create sysfs entry\n");

    return ret;
}
/* Exposure to the sysfs interface <<END>> */

#if defined(CONFIG_PM)
static int ab8500_fg_resume(struct platform_device *pdev)
{
    struct ab8500_fg *di = platform_get_drvdata(pdev);

    /*
     * Change state if we're not charging. If we're charging we will wake
     * up on the FG IRQ
     */
    if (!di->flags.charging) {
        ab8500_fg_discharge_state_to(di, AB8500_FG_DISCHARGE_WAKEUP);
        queue_work(di->fg_wq, &di->fg_work);
    }

    return 0;
}

static int ab8500_fg_suspend(struct platform_device *pdev,
    pm_message_t state)
{
    struct ab8500_fg *di = platform_get_drvdata(pdev);

    flush_delayed_work(&di->fg_periodic_work);

    /*
     * If the FG is enabled we will disable it before going to suspend
     * only if we're not charging
     */
    if (di->flags.fg_enabled && !di->flags.charging)
        ab8500_fg_coulomb_counter(di, false);

    return 0;
}
#else
#define ab8500_fg_suspend      NULL
#define ab8500_fg_resume       NULL
#endif

static int __devexit ab8500_fg_remove(struct platform_device *pdev)
{
    int ret = 0;
    struct ab8500_fg *di = platform_get_drvdata(pdev);

    list_del(&di->node);

    /* Disable coulomb counter */
    ret = ab8500_fg_coulomb_counter(di, false);
    if (ret)
        dev_err(di->dev, "failed to disable coulomb counter\n");

    destroy_workqueue(di->fg_wq);
    ab8500_fg_sysfs_exit(di);

    flush_scheduled_work();
    power_supply_unregister(&di->fg_psy);
    platform_set_drvdata(pdev, NULL);
    kfree(di);
    return ret;
}

/* ab8500 fg driver interrupts and their respective isr */
static struct ab8500_fg_interrupts ab8500_fg_irq[] = {
    {"NCONV_ACCU", ab8500_fg_cc_convend_handler},
    {"BATT_OVV", ab8500_fg_batt_ovv_handler},
    {"LOW_BAT_F", ab8500_fg_lowbatf_handler},
    {"CC_INT_CALIB", ab8500_fg_cc_int_calib_handler},
    {"CCEOC", ab8500_fg_cc_data_end_handler},
};

static int __devinit ab8500_fg_probe(struct platform_device *pdev)
{
    int i, irq;
    int ret = 0;
    struct abx500_bm_plat_data *plat_data = pdev->dev.platform_data;
    struct ab8500_fg *di;

    if (!plat_data) {
        dev_err(&pdev->dev, "No platform data\n");
        return -EINVAL;
    }

    di = kzalloc(sizeof(*di), GFP_KERNEL);
    if (!di)
        return -ENOMEM;

    mutex_init(&di->cc_lock);

    /* get parent data */
    di->dev = &pdev->dev;
    di->parent = dev_get_drvdata(pdev->dev.parent);
    di->gpadc = ab8500_gpadc_get("ab8500-gpadc.0");

    /* get fg specific platform data */
    di->pdata = plat_data->fg;
    if (!di->pdata) {
        dev_err(di->dev, "no fg platform data supplied\n");
        ret = -EINVAL;
        goto free_device_info;
    }

    /* get battery specific platform data */
    di->bat = plat_data->battery;
    if (!di->bat) {
        dev_err(di->dev, "no battery platform data supplied\n");
        ret = -EINVAL;
        goto free_device_info;
    }

    di->fg_psy.name = "ab8500_fg";
    di->fg_psy.type = POWER_SUPPLY_TYPE_BATTERY;
    di->fg_psy.properties = ab8500_fg_props;
    di->fg_psy.num_properties = ARRAY_SIZE(ab8500_fg_props);
    di->fg_psy.get_property = ab8500_fg_get_property;
    di->fg_psy.supplied_to = di->pdata->supplied_to;
    di->fg_psy.num_supplicants = di->pdata->num_supplicants;
    di->fg_psy.external_power_changed = ab8500_fg_external_power_changed;

    di->bat_cap.max_mah_design = MILLI_TO_MICRO *
        di->bat->bat_type[di->bat->batt_id].charge_full_design;

    di->bat_cap.max_mah = di->bat_cap.max_mah_design;

    di->vbat_nom = di->bat->bat_type[di->bat->batt_id].nominal_voltage;

    di->init_capacity = true;

    ab8500_fg_charge_state_to(di, AB8500_FG_CHARGE_INIT);
    ab8500_fg_discharge_state_to(di, AB8500_FG_DISCHARGE_INIT);

    /* Create a work queue for running the FG algorithm */
    di->fg_wq = create_singlethread_workqueue("ab8500_fg_wq");
    if (di->fg_wq == NULL) {
        dev_err(di->dev, "failed to create work queue\n");
        ret = -ENOMEM;
        goto free_device_info;
    }

    /* Init work for running the fg algorithm instantly */
    INIT_WORK(&di->fg_work, ab8500_fg_instant_work);

    /* Init work for getting the battery accumulated current */
    INIT_WORK(&di->fg_acc_cur_work, ab8500_fg_acc_cur_work);

    /* Init work for reinitialising the fg algorithm */
    INIT_DEFERRABLE_WORK(&di->fg_reinit_work,
        ab8500_fg_reinit_work);

    /* Work delayed Queue to run the state machine */
    INIT_DEFERRABLE_WORK(&di->fg_periodic_work,
        ab8500_fg_periodic_work);

    /* Work to check low battery condition */
    INIT_DEFERRABLE_WORK(&di->fg_low_bat_work,
        ab8500_fg_low_bat_work);

    /* Init work for HW failure check */
    INIT_DEFERRABLE_WORK(&di->fg_check_hw_failure_work,
        ab8500_fg_check_hw_failure_work);

    /* Initialize OVV, and other registers */
    ret = ab8500_fg_init_hw_registers(di);
    if (ret) {
        dev_err(di->dev, "failed to initialize registers\n");
        goto free_inst_curr_wq;
    }

    /* Consider battery unknown until we're informed otherwise */
    di->flags.batt_unknown = true;
    di->flags.batt_id_received = false;

    /* Register FG power supply class */
    ret = power_supply_register(di->dev, &di->fg_psy);
    if (ret) {
        dev_err(di->dev, "failed to register FG psy\n");
        goto free_inst_curr_wq;
    }

    di->fg_samples = SEC_TO_SAMPLE(di->bat->fg_params->init_timer);
    ab8500_fg_coulomb_counter(di, true);

    /* Initialize completion used to notify completion of inst current */
    init_completion(&di->ab8500_fg_complete);

    /* Register interrupts */
    for (i = 0; i < ARRAY_SIZE(ab8500_fg_irq); i++) {
        irq = platform_get_irq_byname(pdev, ab8500_fg_irq[i].name);
        ret = request_threaded_irq(irq, NULL, ab8500_fg_irq[i].isr,
            IRQF_SHARED | IRQF_NO_SUSPEND,
            ab8500_fg_irq[i].name, di);

        if (ret != 0) {
            dev_err(di->dev, "failed to request %s IRQ %d: %d\n"
                , ab8500_fg_irq[i].name, irq, ret);
            goto free_irq;
        }
        dev_dbg(di->dev, "Requested %s IRQ %d: %d\n",
            ab8500_fg_irq[i].name, irq, ret);
    }
    di->irq = platform_get_irq_byname(pdev, "CCEOC");
    disable_irq(di->irq);

    platform_set_drvdata(pdev, di);

    ret = ab8500_fg_sysfs_init(di);
    if (ret) {
        dev_err(di->dev, "failed to create sysfs entry\n");
        goto free_irq;
    }

    /* Calibrate the fg first time */
    di->flags.calibrate = true;
    di->calib_state = AB8500_FG_CALIB_INIT;

    /* Use room temp as default value until we get an update from driver. */
    di->bat_temp = 210;

    /* Run the FG algorithm */
    queue_delayed_work(di->fg_wq, &di->fg_periodic_work, 0);

    list_add_tail(&di->node, &ab8500_fg_list);

    return ret;

free_irq:
    power_supply_unregister(&di->fg_psy);

    /* We also have to free all successfully registered irqs */
    for (i = i - 1; i >= 0; i--) {
        irq = platform_get_irq_byname(pdev, ab8500_fg_irq[i].name);
        free_irq(irq, di);
    }
free_inst_curr_wq:
    destroy_workqueue(di->fg_wq);
free_device_info:
    kfree(di);

    return ret;
}

static struct platform_driver ab8500_fg_driver = {
    .probe = ab8500_fg_probe,
    .remove = __devexit_p(ab8500_fg_remove),
    .suspend = ab8500_fg_suspend,
    .resume = ab8500_fg_resume,
    .driver = {
        .name = "ab8500-fg",
        .owner = THIS_MODULE,
    },
};

static int __init ab8500_fg_init(void)
{
    return platform_driver_register(&ab8500_fg_driver);
}

static void __exit ab8500_fg_exit(void)
{
    platform_driver_unregister(&ab8500_fg_driver);
}

subsys_initcall_sync(ab8500_fg_init);
module_exit(ab8500_fg_exit);

MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Johan Palsson, Karl Komierowski");
MODULE_ALIAS("platform:ab8500-fg");
MODULE_DESCRIPTION("AB8500 Fuel Gauge driver");