/*
 * 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 <johan.palsson@stericsson.com>
 *      Karl Komierowski <karl.komierowski@stericsson.com>
 *      Arun R Murthy <arun.murthy@stericsson.com>
 */

#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 - ab8500 fg interupts
 * @name:       name of the interrupt
 * @isr         function pointer to the isr
 */
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 - ab8500 FG device information
 * @dev:                Pointer to the structure device
 * @node:               a list of AB8500 FGs, hence prepared for reentrance
 * @irq                 holds the CCEOC interrupt number
 * @vbat:               Battery voltage in mV
 * @vbat_nom:           Nominal battery voltage in mV
 * @inst_curr:          Instantenous battery current in mA
 * @avg_curr:           Average battery current in mA
 * @bat_temp            battery temperature
 * @fg_samples:         Number of samples used in the FG accumulation
 * @accu_charge:        Accumulated charge from the last conversion
 * @recovery_cnt:       Counter for recovery mode
 * @high_curr_cnt:      Counter for high current mode
 * @init_cnt:           Counter for init mode
 * @recovery_needed:    Indicate if recovery is needed
 * @high_curr_mode:     Indicate if we're in high current mode
 * @init_capacity:      Indicate if initial capacity measuring should be done
 * @turn_off_fg:        True if fg was off before current measurement
 * @calib_state         State during offset calibration
 * @discharge_state:    Current discharge state
 * @charge_state:       Current charge state
 * @ab8500_fg_complete  Completion struct used for the instant current reading
 * @flags:              Structure for information about events triggered
 * @bat_cap:            Structure for battery capacity specific parameters
 * @avg_cap:            Average capacity filter
 * @parent:             Pointer to the struct ab8500
 * @gpadc:              Pointer to the struct gpadc
 * @pdata:              Pointer to the abx500_fg platform data
 * @bat:                Pointer to the abx500_bm platform data
 * @fg_psy:             Structure that holds the FG specific battery properties
 * @fg_wq:              Work queue for running the FG algorithm
 * @fg_periodic_work:   Work to run the FG algorithm periodically
 * @fg_low_bat_work:    Work to check low bat condition
 * @fg_reinit_work      Work used to reset and reinitialise the FG algorithm
 * @fg_work:            Work to run the FG algorithm instantly
 * @fg_acc_cur_work:    Work to read the FG accumulator
 * @fg_check_hw_failure_work:   Work for checking HW state
 * @cc_lock:            Mutex for locking the CC
 * @fg_kobject:         Structure of type kobject
 */
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);

/**
 * ab8500_fg_get() - returns a reference to the primary AB8500 fuel gauge
 * (i.e. the first fuel gauge in the instance 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;
}

/**
 * ab8500_fg_is_low_curr() - Low or high current mode
 * @di:         pointer to the ab8500_fg structure
 * @curr:       the current to base or our decision on
 *
 * Low current mode if the current consumption is below a certain threshold
 */
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;
}

/**
 * ab8500_fg_add_cap_sample() - Add capacity to average filter
 * @di:         pointer to the ab8500_fg structure
 * @sample:     the capacity in mAh to add to the filter
 *
 * A capacity is added to the filter and a new mean capacity is calculated and
 * returned
 */
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;
}

/**
 * ab8500_fg_clear_cap_samples() - Clear average filter
 * @di:         pointer to the ab8500_fg structure
 *
 * The capacity filter is is reset to zero.
 */
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;
        }
}

/**
 * ab8500_fg_fill_cap_sample() - Fill average filter
 * @di:         pointer to the ab8500_fg structure
 * @sample:     the capacity in mAh to fill the filter with
 *
 * The capacity filter is filled with a capacity in mAh
 */
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;
}

/**
 * ab8500_fg_coulomb_counter() - enable coulomb counter
 * @di:         pointer to the ab8500_fg structure
 * @enable:     enable/disable
 *
 * Enable/Disable coulomb counter.
 * On failure returns negative value.
 */
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;
}

/**
 * ab8500_fg_inst_curr_start() - start battery instantaneous current
 * @di:         pointer to the ab8500_fg structure
 *
 * Returns 0 or error code
 * Note: This is part "one" and has to be called before
 * ab8500_fg_inst_curr_finalize()
 */
 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;
}

/**
 * ab8500_fg_inst_curr_done() - check if fg conversion is done
 * @di:         pointer to the ab8500_fg structure
 *
 * Returns 1 if conversion done, 0 if still waiting
 */
int ab8500_fg_inst_curr_done(struct ab8500_fg *di)
{
        return completion_done(&di->ab8500_fg_complete);
}

/**
 * ab8500_fg_inst_curr_finalize() - battery instantaneous current
 * @di:         pointer to the ab8500_fg structure
 * @res:        battery instantenous current(on success)
 *
 * Returns 0 or an error code
 * Note: This is part "two" and has to be called at earliest 250 ms
 * after ab8500_fg_inst_curr_start()
 */
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;
}

/**
 * ab8500_fg_inst_curr_blocking() - battery instantaneous current
 * @di:         pointer to the ab8500_fg structure
 * @res:        battery instantenous current(on success)
 *
 * Returns 0 else error code
 */
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;
}

/**
 * ab8500_fg_acc_cur_work() - average battery current
 * @work:       pointer to the work_struct structure
 *
 * Updated the average battery current obtained from the
 * coulomb counter.
 */
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);
}

/**
 * ab8500_fg_bat_voltage() - get battery voltage
 * @di:         pointer to the ab8500_fg structure
 *
 * Returns battery voltage(on success) else error code
 */
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;
}

/**
 * ab8500_fg_volt_to_capacity() - Voltage based capacity
 * @di:         pointer to the ab8500_fg structure
 * @voltage:    The voltage to convert to a capacity
 *
 * Returns battery capacity in per mille based on voltage
 */
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;
}

/**
 * ab8500_fg_uncomp_volt_to_capacity() - Uncompensated voltage based capacity
 * @di:         pointer to the ab8500_fg structure
 *
 * Returns battery capacity based on battery voltage that is not compensated
 * for the voltage drop due to the load
 */
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);
}

/**
 * ab8500_fg_battery_resistance() - Returns the battery inner resistance
 * @di:         pointer to the ab8500_fg structure
 *
 * Returns battery inner resistance added with the fuel gauge resistor value
 * to get the total resistance in the whole link from gnd to bat+ node.
 */
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;
}

/**
 * ab8500_fg_load_comp_volt_to_capacity() - Load compensated voltage based capacity
 * @di:         pointer to the ab8500_fg structure
 *
 * Returns battery capacity based on battery voltage that is load compensated
 * for the voltage drop
 */
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);
}

/**
 * ab8500_fg_convert_mah_to_permille() - Capacity in mAh to permille
 * @di:         pointer to the ab8500_fg structure
 * @cap_mah:    capacity in mAh
 *
 * Converts capacity in mAh to capacity in permille
 */
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;
}

/**
 * ab8500_fg_convert_permille_to_mah() - Capacity in permille to mAh
 * @di:         pointer to the ab8500_fg structure
 * @cap_pm:     capacity in permille
 *
 * Converts capacity in permille to capacity in mAh
 */
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;
}

/**
 * ab8500_fg_convert_mah_to_uwh() - Capacity in mAh to uWh
 * @di:         pointer to the ab8500_fg structure
 * @cap_mah:    capacity in mAh
 *
 * Converts capacity in mAh to capacity in uWh
 */
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;
}

/**
 * ab8500_fg_calc_cap_charging() - Calculate remaining capacity while charging
 * @di:         pointer to the ab8500_fg structure
 *
 * Return the capacity in mAh based on previous calculated capcity and the FG
 * accumulator register value. The filter is filled with this capacity
 */
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;
}

/**
 * ab8500_fg_calc_cap_discharge_voltage() - Capacity in discharge with voltage
 * @di:         pointer to the ab8500_fg structure
 * @comp:       if voltage should be load compensated before capacity calc
 *
 * Return the capacity in mAh based on the battery voltage. The voltage can
 * either be load compensated or not. This value is added to the filter and a
 * new mean value is calculated and returned.
 */
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;
}

/**
 * ab8500_fg_calc_cap_discharge_fg() - Capacity in discharge with FG
 * @di:         pointer to the ab8500_fg structure
 *
 * Return the capacity in mAh based on previous calculated capcity and the FG
 * accumulator register value. This value is added to the filter and a
 * new mean value is calculated and returned.
 */
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;
}

/**
 * ab8500_fg_capacity_level() - Get the battery capacity level
 * @di:         pointer to the ab8500_fg structure
 *
 * Get the battery capacity level based on the capacity in percent
 */
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;
}

/**
 * ab8500_fg_check_capacity_limits() - Check if capacity has changed
 * @di:         pointer to the ab8500_fg structure
 * @init:       capacity is allowed to go up in init mode
 *
 * Check if capacity or capacity limit has changed and notify the system
 * about it using the power_supply framework
 */
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;
}

/**
 * ab8500_fg_algorithm_charging() - FG algorithm for when charging
 * @di:         pointer to the ab8500_fg structure
 *
 * Battery capacity calculation state machine for when we're charging
 */
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;
}

/**
 * ab8500_fg_algorithm_discharging() - FG algorithm for when discharging
 * @di:         pointer to the ab8500_fg structure
 *
 * Battery capacity calculation state machine for when we're discharging
 */
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;
        }
}

/**
 * ab8500_fg_algorithm_calibrate() - Internal columb counter offset calibration
 * @di:         pointer to the ab8500_fg structure
 *
 */
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);
}

/**
 * ab8500_fg_algorithm() - Entry point for the FG algorithm
 * @di:         pointer to the ab8500_fg structure
 *
 * Entry point for the battery capacity calculation state machine
 */
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);
}

/**
 * ab8500_fg_periodic_work() - Run the FG state machine periodically
 * @work:       pointer to the work_struct structure
 *
 * Work queue function for periodic work
 */
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);

}

/**
 * ab8500_fg_check_hw_failure_work() - Check OVV_BAT condition
 * @work:       pointer to the work_struct structure
 *
 * Work queue function for checking the OVV_BAT condition
 */
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));
        }
}

/**
 * ab8500_fg_low_bat_work() - Check LOW_BAT condition
 * @work:       pointer to the work_struct structure
 *
 * Work queue function for checking the LOW_BAT condition
 */
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;
}

/**
 * ab8500_fg_battok_calc - calculate the bit pattern corresponding
 * to the target voltage.
 * @di:       pointer to the ab8500_fg structure
 * @target    target voltage
 *
 * Returns bit pattern closest to the target voltage
 * valid return values are 0-14. (0-BATT_OK_MAX_NR_INCREMENTS)
 */

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;
}

/**
 * ab8500_fg_battok_init_hw_register - init battok levels
 * @di:       pointer to the ab8500_fg structure
 *
 */

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;
}

/**
 * ab8500_fg_instant_work() - Run the FG state machine instantly
 * @work:       pointer to the work_struct structure
 *
 * Work queue function for instant work
 */
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);
}

/**
 * ab8500_fg_cc_data_end_handler() - isr to get battery avg current.
 * @irq:       interrupt number
 * @_di:       pointer to the ab8500_fg structure
 *
 * Returns IRQ status(IRQ_HANDLED)
 */
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;
}

/**
 * ab8500_fg_cc_convend_handler() - isr to get battery avg current.
 * @irq:       interrupt number
 * @_di:       pointer to the ab8500_fg structure
 *
 * Returns IRQ status(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;
}

/**
 * ab8500_fg_cc_convend_handler() - isr to get battery avg current.
 * @irq:       interrupt number
 * @_di:       pointer to the ab8500_fg structure
 *
 * Returns IRQ status(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;
}

/**
 * ab8500_fg_batt_ovv_handler() - Battery OVV occured
 * @irq:       interrupt number
 * @_di:       pointer to the ab8500_fg structure
 *
 * Returns IRQ status(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;
}

/**
 * ab8500_fg_lowbatf_handler() - Battery voltage is below LOW threshold
 * @irq:       interrupt number
 * @_di:       pointer to the ab8500_fg structure
 *
 * Returns IRQ status(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;
}

/**
 * ab8500_fg_get_property() - get the fg properties
 * @psy:        pointer to the power_supply structure
 * @psp:        pointer to the power_supply_property structure
 * @val:        pointer to the power_supply_propval union
 *
 * This function gets called when an application tries to get the
 * fg properties by reading the sysfs files.
 * voltage_now:         battery voltage
 * current_now:         battery instant current
 * current_avg:         battery average current
 * charge_full_design:  capacity where battery is considered full
 * charge_now:          battery capacity in nAh
 * capacity:            capacity in percent
 * capacity_level:      capacity level
 *
 * Returns error code in case of failure else 0 on success
 */
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;
}

/**
 * ab8500_fg_init_hw_registers() - Set up FG related registers
 * @di:         pointer to the ab8500_fg structure
 *
 * Set up battery OVV, low battery voltage registers
 */
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;
}

/**
 * ab8500_fg_external_power_changed() - callback for power supply changes
 * @psy:       pointer to the structure power_supply
 *
 * This function is the entry point of the pointer external_power_changed
 * of the structure power_supply.
 * This function gets executed when there is a change in any external power
 * supply that this driver needs to be notified of.
 */
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);
}

/**
 * abab8500_fg_reinit_work() - work to reset the FG algorithm
 * @work:       pointer to the work_struct structure
 *
 * Used to reset the current battery capacity to be able to
 * retrigger a new voltage base capacity calculation. For
 * test and verification purpose.
 */
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));
        }
}

/**
 * ab8500_fg_reinit() - forces FG algorithm to reinitialize with current values
 *
 * This function can be used to force the FG algorithm to recalculate a new
 * voltage based battery capacity.
 */
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,
};

/**
 * ab8500_chargalg_sysfs_exit() - de-init of sysfs entry
 * @di:                pointer to the struct ab8500_chargalg
 *
 * This function removes the entry in sysfs.
 */
static void ab8500_fg_sysfs_exit(struct ab8500_fg *di)
{
        kobject_del(&di->fg_kobject);
}

/**
 * ab8500_chargalg_sysfs_init() - init of sysfs entry
 * @di:                pointer to the struct ab8500_chargalg
 *
 * This function adds an entry in sysfs.
 * Returns error code in case of failure else 0(on success)
 */
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");
                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_DELAYED_WORK_DEFERRABLE(&di->fg_reinit_work,
                ab8500_fg_reinit_work);

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

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

        /* Init work for HW failure check */
        INIT_DELAYED_WORK_DEFERRABLE(&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");