/*
 * Copyright (C) ST-Ericsson SA 2012
 *
 * Charging algorithm driver for abx500 variants
 *
 * License Terms: GNU General Public License v2
 * Authors:
 *      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/delay.h>
#include <linux/slab.h>
#include <linux/platform_device.h>
#include <linux/power_supply.h>
#include <linux/completion.h>
#include <linux/workqueue.h>
#include <linux/kobject.h>
#include <linux/of.h>
#include <linux/mfd/core.h>
#include <linux/mfd/abx500.h>
#include <linux/mfd/abx500/ux500_chargalg.h>
#include <linux/mfd/abx500/ab8500-bm.h>

/* Watchdog kick interval */
#define CHG_WD_INTERVAL                 (6 * HZ)

/* End-of-charge criteria counter */
#define EOC_COND_CNT                    10

#define to_abx500_chargalg_device_info(x) container_of((x), \
        struct abx500_chargalg, chargalg_psy);

enum abx500_chargers {
        NO_CHG,
        AC_CHG,
        USB_CHG,
};

struct abx500_chargalg_charger_info {
        enum abx500_chargers conn_chg;
        enum abx500_chargers prev_conn_chg;
        enum abx500_chargers online_chg;
        enum abx500_chargers prev_online_chg;
        enum abx500_chargers charger_type;
        bool usb_chg_ok;
        bool ac_chg_ok;
        int usb_volt;
        int usb_curr;
        int ac_volt;
        int ac_curr;
        int usb_vset;
        int usb_iset;
        int ac_vset;
        int ac_iset;
};

struct abx500_chargalg_suspension_status {
        bool suspended_change;
        bool ac_suspended;
        bool usb_suspended;
};

struct abx500_chargalg_battery_data {
        int temp;
        int volt;
        int avg_curr;
        int inst_curr;
        int percent;
};

enum abx500_chargalg_states {
        STATE_HANDHELD_INIT,
        STATE_HANDHELD,
        STATE_CHG_NOT_OK_INIT,
        STATE_CHG_NOT_OK,
        STATE_HW_TEMP_PROTECT_INIT,
        STATE_HW_TEMP_PROTECT,
        STATE_NORMAL_INIT,
        STATE_NORMAL,
        STATE_WAIT_FOR_RECHARGE_INIT,
        STATE_WAIT_FOR_RECHARGE,
        STATE_MAINTENANCE_A_INIT,
        STATE_MAINTENANCE_A,
        STATE_MAINTENANCE_B_INIT,
        STATE_MAINTENANCE_B,
        STATE_TEMP_UNDEROVER_INIT,
        STATE_TEMP_UNDEROVER,
        STATE_TEMP_LOWHIGH_INIT,
        STATE_TEMP_LOWHIGH,
        STATE_SUSPENDED_INIT,
        STATE_SUSPENDED,
        STATE_OVV_PROTECT_INIT,
        STATE_OVV_PROTECT,
        STATE_SAFETY_TIMER_EXPIRED_INIT,
        STATE_SAFETY_TIMER_EXPIRED,
        STATE_BATT_REMOVED_INIT,
        STATE_BATT_REMOVED,
        STATE_WD_EXPIRED_INIT,
        STATE_WD_EXPIRED,
};

static const char *states[] = {
        "HANDHELD_INIT",
        "HANDHELD",
        "CHG_NOT_OK_INIT",
        "CHG_NOT_OK",
        "HW_TEMP_PROTECT_INIT",
        "HW_TEMP_PROTECT",
        "NORMAL_INIT",
        "NORMAL",
        "WAIT_FOR_RECHARGE_INIT",
        "WAIT_FOR_RECHARGE",
        "MAINTENANCE_A_INIT",
        "MAINTENANCE_A",
        "MAINTENANCE_B_INIT",
        "MAINTENANCE_B",
        "TEMP_UNDEROVER_INIT",
        "TEMP_UNDEROVER",
        "TEMP_LOWHIGH_INIT",
        "TEMP_LOWHIGH",
        "SUSPENDED_INIT",
        "SUSPENDED",
        "OVV_PROTECT_INIT",
        "OVV_PROTECT",
        "SAFETY_TIMER_EXPIRED_INIT",
        "SAFETY_TIMER_EXPIRED",
        "BATT_REMOVED_INIT",
        "BATT_REMOVED",
        "WD_EXPIRED_INIT",
        "WD_EXPIRED",
};

struct abx500_chargalg_events {
        bool batt_unknown;
        bool mainextchnotok;
        bool batt_ovv;
        bool batt_rem;
        bool btemp_underover;
        bool btemp_lowhigh;
        bool main_thermal_prot;
        bool usb_thermal_prot;
        bool main_ovv;
        bool vbus_ovv;
        bool usbchargernotok;
        bool safety_timer_expired;
        bool maintenance_timer_expired;
        bool ac_wd_expired;
        bool usb_wd_expired;
        bool ac_cv_active;
        bool usb_cv_active;
        bool vbus_collapsed;
};

/**
 * struct abx500_charge_curr_maximization - Charger maximization parameters
 * @original_iset:      the non optimized/maximised charger current
 * @current_iset:       the charging current used at this moment
 * @test_delta_i:       the delta between the current we want to charge and the
                        current that is really going into the battery
 * @condition_cnt:      number of iterations needed before a new charger current
                        is set
 * @max_current:        maximum charger current
 * @wait_cnt:           to avoid too fast current step down in case of charger
 *                      voltage collapse, we insert this delay between step
 *                      down
 * @level:              tells in how many steps the charging current has been
                        increased
 */
struct abx500_charge_curr_maximization {
        int original_iset;
        int current_iset;
        int test_delta_i;
        int condition_cnt;
        int max_current;
        int wait_cnt;
        u8 level;
};

enum maxim_ret {
        MAXIM_RET_NOACTION,
        MAXIM_RET_CHANGE,
        MAXIM_RET_IBAT_TOO_HIGH,
};

/**
 * struct abx500_chargalg - abx500 Charging algorithm device information
 * @dev:                pointer to the structure device
 * @charge_status:      battery operating status
 * @eoc_cnt:            counter used to determine end-of_charge
 * @maintenance_chg:    indicate if maintenance charge is active
 * @t_hyst_norm         temperature hysteresis when the temperature has been
 *                      over or under normal limits
 * @t_hyst_lowhigh      temperature hysteresis when the temperature has been
 *                      over or under the high or low limits
 * @charge_state:       current state of the charging algorithm
 * @ccm                 charging current maximization parameters
 * @chg_info:           information about connected charger types
 * @batt_data:          data of the battery
 * @susp_status:        current charger suspension status
 * @bm:                 Platform specific battery management information
 * @chargalg_psy:       structure that holds the battery properties exposed by
 *                      the charging algorithm
 * @events:             structure for information about events triggered
 * @chargalg_wq:                work queue for running the charging algorithm
 * @chargalg_periodic_work:     work to run the charging algorithm periodically
 * @chargalg_wd_work:           work to kick the charger watchdog periodically
 * @chargalg_work:              work to run the charging algorithm instantly
 * @safety_timer:               charging safety timer
 * @maintenance_timer:          maintenance charging timer
 * @chargalg_kobject:           structure of type kobject
 */
struct abx500_chargalg {
        struct device *dev;
        int charge_status;
        int eoc_cnt;
        bool maintenance_chg;
        int t_hyst_norm;
        int t_hyst_lowhigh;
        enum abx500_chargalg_states charge_state;
        struct abx500_charge_curr_maximization ccm;
        struct abx500_chargalg_charger_info chg_info;
        struct abx500_chargalg_battery_data batt_data;
        struct abx500_chargalg_suspension_status susp_status;
        struct abx500_bm_data *bm;
        struct power_supply chargalg_psy;
        struct ux500_charger *ac_chg;
        struct ux500_charger *usb_chg;
        struct abx500_chargalg_events events;
        struct workqueue_struct *chargalg_wq;
        struct delayed_work chargalg_periodic_work;
        struct delayed_work chargalg_wd_work;
        struct work_struct chargalg_work;
        struct timer_list safety_timer;
        struct timer_list maintenance_timer;
        struct kobject chargalg_kobject;
};

/* Main battery properties */
static enum power_supply_property abx500_chargalg_props[] = {
        POWER_SUPPLY_PROP_STATUS,
        POWER_SUPPLY_PROP_HEALTH,
};

/**
 * abx500_chargalg_safety_timer_expired() - Expiration of the safety timer
 * @data:       pointer to the abx500_chargalg structure
 *
 * This function gets called when the safety timer for the charger
 * expires
 */
static void abx500_chargalg_safety_timer_expired(unsigned long data)
{
        struct abx500_chargalg *di = (struct abx500_chargalg *) data;
        dev_err(di->dev, "Safety timer expired\n");
        di->events.safety_timer_expired = true;

        /* Trigger execution of the algorithm instantly */
        queue_work(di->chargalg_wq, &di->chargalg_work);
}

/**
 * abx500_chargalg_maintenance_timer_expired() - Expiration of
 * the maintenance timer
 * @i:          pointer to the abx500_chargalg structure
 *
 * This function gets called when the maintenence timer
 * expires
 */
static void abx500_chargalg_maintenance_timer_expired(unsigned long data)
{

        struct abx500_chargalg *di = (struct abx500_chargalg *) data;
        dev_dbg(di->dev, "Maintenance timer expired\n");
        di->events.maintenance_timer_expired = true;

        /* Trigger execution of the algorithm instantly */
        queue_work(di->chargalg_wq, &di->chargalg_work);
}

/**
 * abx500_chargalg_state_to() - Change charge state
 * @di:         pointer to the abx500_chargalg structure
 *
 * This function gets called when a charge state change should occur
 */
static void abx500_chargalg_state_to(struct abx500_chargalg *di,
        enum abx500_chargalg_states state)
{
        dev_dbg(di->dev,
                "State changed: %s (From state: [%d] %s =to=> [%d] %s )\n",
                di->charge_state == state ? "NO" : "YES",
                di->charge_state,
                states[di->charge_state],
                state,
                states[state]);

        di->charge_state = state;
}

/**
 * abx500_chargalg_check_charger_connection() - Check charger connection change
 * @di:         pointer to the abx500_chargalg structure
 *
 * This function will check if there is a change in the charger connection
 * and change charge state accordingly. AC has precedence over USB.
 */
static int abx500_chargalg_check_charger_connection(struct abx500_chargalg *di)
{
        if (di->chg_info.conn_chg != di->chg_info.prev_conn_chg ||
                di->susp_status.suspended_change) {
                /*
                 * Charger state changed or suspension
                 * has changed since last update
                 */
                if ((di->chg_info.conn_chg & AC_CHG) &&
                        !di->susp_status.ac_suspended) {
                        dev_dbg(di->dev, "Charging source is AC\n");
                        if (di->chg_info.charger_type != AC_CHG) {
                                di->chg_info.charger_type = AC_CHG;
                                abx500_chargalg_state_to(di, STATE_NORMAL_INIT);
                        }
                } else if ((di->chg_info.conn_chg & USB_CHG) &&
                        !di->susp_status.usb_suspended) {
                        dev_dbg(di->dev, "Charging source is USB\n");
                        di->chg_info.charger_type = USB_CHG;
                        abx500_chargalg_state_to(di, STATE_NORMAL_INIT);
                } else if (di->chg_info.conn_chg &&
                        (di->susp_status.ac_suspended ||
                        di->susp_status.usb_suspended)) {
                        dev_dbg(di->dev, "Charging is suspended\n");
                        di->chg_info.charger_type = NO_CHG;
                        abx500_chargalg_state_to(di, STATE_SUSPENDED_INIT);
                } else {
                        dev_dbg(di->dev, "Charging source is OFF\n");
                        di->chg_info.charger_type = NO_CHG;
                        abx500_chargalg_state_to(di, STATE_HANDHELD_INIT);
                }
                di->chg_info.prev_conn_chg = di->chg_info.conn_chg;
                di->susp_status.suspended_change = false;
        }
        return di->chg_info.conn_chg;
}

/**
 * abx500_chargalg_start_safety_timer() - Start charging safety timer
 * @di:         pointer to the abx500_chargalg structure
 *
 * The safety timer is used to avoid overcharging of old or bad batteries.
 * There are different timers for AC and USB
 */
static void abx500_chargalg_start_safety_timer(struct abx500_chargalg *di)
{
        unsigned long timer_expiration = 0;

        switch (di->chg_info.charger_type) {
        case AC_CHG:
                timer_expiration =
                round_jiffies(jiffies +
                        (di->bm->main_safety_tmr_h * 3600 * HZ));
                break;

        case USB_CHG:
                timer_expiration =
                round_jiffies(jiffies +
                        (di->bm->usb_safety_tmr_h * 3600 * HZ));
                break;

        default:
                dev_err(di->dev, "Unknown charger to charge from\n");
                break;
        }

        di->events.safety_timer_expired = false;
        di->safety_timer.expires = timer_expiration;
        if (!timer_pending(&di->safety_timer))
                add_timer(&di->safety_timer);
        else
                mod_timer(&di->safety_timer, timer_expiration);
}

/**
 * abx500_chargalg_stop_safety_timer() - Stop charging safety timer
 * @di:         pointer to the abx500_chargalg structure
 *
 * The safety timer is stopped whenever the NORMAL state is exited
 */
static void abx500_chargalg_stop_safety_timer(struct abx500_chargalg *di)
{
        di->events.safety_timer_expired = false;
        del_timer(&di->safety_timer);
}

/**
 * abx500_chargalg_start_maintenance_timer() - Start charging maintenance timer
 * @di:         pointer to the abx500_chargalg structure
 * @duration:   duration of ther maintenance timer in hours
 *
 * The maintenance timer is used to maintain the charge in the battery once
 * the battery is considered full. These timers are chosen to match the
 * discharge curve of the battery
 */
static void abx500_chargalg_start_maintenance_timer(struct abx500_chargalg *di,
        int duration)
{
        unsigned long timer_expiration;

        /* Convert from hours to jiffies */
        timer_expiration = round_jiffies(jiffies + (duration * 3600 * HZ));

        di->events.maintenance_timer_expired = false;
        di->maintenance_timer.expires = timer_expiration;
        if (!timer_pending(&di->maintenance_timer))
                add_timer(&di->maintenance_timer);
        else
                mod_timer(&di->maintenance_timer, timer_expiration);
}

/**
 * abx500_chargalg_stop_maintenance_timer() - Stop maintenance timer
 * @di:         pointer to the abx500_chargalg structure
 *
 * The maintenance timer is stopped whenever maintenance ends or when another
 * state is entered
 */
static void abx500_chargalg_stop_maintenance_timer(struct abx500_chargalg *di)
{
        di->events.maintenance_timer_expired = false;
        del_timer(&di->maintenance_timer);
}

/**
 * abx500_chargalg_kick_watchdog() - Kick charger watchdog
 * @di:         pointer to the abx500_chargalg structure
 *
 * The charger watchdog have to be kicked periodically whenever the charger is
 * on, else the ABB will reset the system
 */
static int abx500_chargalg_kick_watchdog(struct abx500_chargalg *di)
{
        /* Check if charger exists and kick watchdog if charging */
        if (di->ac_chg && di->ac_chg->ops.kick_wd &&
            di->chg_info.online_chg & AC_CHG) {
                /*
                 * If AB charger watchdog expired, pm2xxx charging
                 * gets disabled. To be safe, kick both AB charger watchdog
                 * and pm2xxx watchdog.
                 */
                if (di->ac_chg->external &&
                    di->usb_chg && di->usb_chg->ops.kick_wd)
                        di->usb_chg->ops.kick_wd(di->usb_chg);

                return di->ac_chg->ops.kick_wd(di->ac_chg);
        }
        else if (di->usb_chg && di->usb_chg->ops.kick_wd &&
                        di->chg_info.online_chg & USB_CHG)
                return di->usb_chg->ops.kick_wd(di->usb_chg);

        return -ENXIO;
}

/**
 * abx500_chargalg_ac_en() - Turn on/off the AC charger
 * @di:         pointer to the abx500_chargalg structure
 * @enable:     charger on/off
 * @vset:       requested charger output voltage
 * @iset:       requested charger output current
 *
 * The AC charger will be turned on/off with the requested charge voltage and
 * current
 */
static int abx500_chargalg_ac_en(struct abx500_chargalg *di, int enable,
        int vset, int iset)
{
        if (!di->ac_chg || !di->ac_chg->ops.enable)
                return -ENXIO;

        /* Select maximum of what both the charger and the battery supports */
        if (di->ac_chg->max_out_volt)
                vset = min(vset, di->ac_chg->max_out_volt);
        if (di->ac_chg->max_out_curr)
                iset = min(iset, di->ac_chg->max_out_curr);

        di->chg_info.ac_iset = iset;
        di->chg_info.ac_vset = vset;

        return di->ac_chg->ops.enable(di->ac_chg, enable, vset, iset);
}

/**
 * abx500_chargalg_usb_en() - Turn on/off the USB charger
 * @di:         pointer to the abx500_chargalg structure
 * @enable:     charger on/off
 * @vset:       requested charger output voltage
 * @iset:       requested charger output current
 *
 * The USB charger will be turned on/off with the requested charge voltage and
 * current
 */
static int abx500_chargalg_usb_en(struct abx500_chargalg *di, int enable,
        int vset, int iset)
{
        if (!di->usb_chg || !di->usb_chg->ops.enable)
                return -ENXIO;

        /* Select maximum of what both the charger and the battery supports */
        if (di->usb_chg->max_out_volt)
                vset = min(vset, di->usb_chg->max_out_volt);
        if (di->usb_chg->max_out_curr)
                iset = min(iset, di->usb_chg->max_out_curr);

        di->chg_info.usb_iset = iset;
        di->chg_info.usb_vset = vset;

        return di->usb_chg->ops.enable(di->usb_chg, enable, vset, iset);
}

/**
 * abx500_chargalg_update_chg_curr() - Update charger current
 * @di:         pointer to the abx500_chargalg structure
 * @iset:       requested charger output current
 *
 * The charger output current will be updated for the charger
 * that is currently in use
 */
static int abx500_chargalg_update_chg_curr(struct abx500_chargalg *di,
                int iset)
{
        /* Check if charger exists and update current if charging */
        if (di->ac_chg && di->ac_chg->ops.update_curr &&
                        di->chg_info.charger_type & AC_CHG) {
                /*
                 * Select maximum of what both the charger
                 * and the battery supports
                 */
                if (di->ac_chg->max_out_curr)
                        iset = min(iset, di->ac_chg->max_out_curr);

                di->chg_info.ac_iset = iset;

                return di->ac_chg->ops.update_curr(di->ac_chg, iset);
        } else if (di->usb_chg && di->usb_chg->ops.update_curr &&
                        di->chg_info.charger_type & USB_CHG) {
                /*
                 * Select maximum of what both the charger
                 * and the battery supports
                 */
                if (di->usb_chg->max_out_curr)
                        iset = min(iset, di->usb_chg->max_out_curr);

                di->chg_info.usb_iset = iset;

                return di->usb_chg->ops.update_curr(di->usb_chg, iset);
        }

        return -ENXIO;
}

/**
 * abx500_chargalg_stop_charging() - Stop charging
 * @di:         pointer to the abx500_chargalg structure
 *
 * This function is called from any state where charging should be stopped.
 * All charging is disabled and all status parameters and timers are changed
 * accordingly
 */
static void abx500_chargalg_stop_charging(struct abx500_chargalg *di)
{
        abx500_chargalg_ac_en(di, false, 0, 0);
        abx500_chargalg_usb_en(di, false, 0, 0);
        abx500_chargalg_stop_safety_timer(di);
        abx500_chargalg_stop_maintenance_timer(di);
        di->charge_status = POWER_SUPPLY_STATUS_NOT_CHARGING;
        di->maintenance_chg = false;
        cancel_delayed_work(&di->chargalg_wd_work);
        power_supply_changed(&di->chargalg_psy);
}

/**
 * abx500_chargalg_hold_charging() - Pauses charging
 * @di:         pointer to the abx500_chargalg structure
 *
 * This function is called in the case where maintenance charging has been
 * disabled and instead a battery voltage mode is entered to check when the
 * battery voltage has reached a certain recharge voltage
 */
static void abx500_chargalg_hold_charging(struct abx500_chargalg *di)
{
        abx500_chargalg_ac_en(di, false, 0, 0);
        abx500_chargalg_usb_en(di, false, 0, 0);
        abx500_chargalg_stop_safety_timer(di);
        abx500_chargalg_stop_maintenance_timer(di);
        di->charge_status = POWER_SUPPLY_STATUS_CHARGING;
        di->maintenance_chg = false;
        cancel_delayed_work(&di->chargalg_wd_work);
        power_supply_changed(&di->chargalg_psy);
}

/**
 * abx500_chargalg_start_charging() - Start the charger
 * @di:         pointer to the abx500_chargalg structure
 * @vset:       requested charger output voltage
 * @iset:       requested charger output current
 *
 * A charger will be enabled depending on the requested charger type that was
 * detected previously.
 */
static void abx500_chargalg_start_charging(struct abx500_chargalg *di,
        int vset, int iset)
{
        bool start_chargalg_wd = true;

        switch (di->chg_info.charger_type) {
        case AC_CHG:
                dev_dbg(di->dev,
                        "AC parameters: Vset %d, Ich %d\n", vset, iset);
                abx500_chargalg_usb_en(di, false, 0, 0);
                abx500_chargalg_ac_en(di, true, vset, iset);
                break;

        case USB_CHG:
                dev_dbg(di->dev,
                        "USB parameters: Vset %d, Ich %d\n", vset, iset);
                abx500_chargalg_ac_en(di, false, 0, 0);
                abx500_chargalg_usb_en(di, true, vset, iset);
                break;

        default:
                dev_err(di->dev, "Unknown charger to charge from\n");
                start_chargalg_wd = false;
                break;
        }

        if (start_chargalg_wd && !delayed_work_pending(&di->chargalg_wd_work))
                queue_delayed_work(di->chargalg_wq, &di->chargalg_wd_work, 0);
}

/**
 * abx500_chargalg_check_temp() - Check battery temperature ranges
 * @di:         pointer to the abx500_chargalg structure
 *
 * The battery temperature is checked against the predefined limits and the
 * charge state is changed accordingly
 */
static void abx500_chargalg_check_temp(struct abx500_chargalg *di)
{
        if (di->batt_data.temp > (di->bm->temp_low + di->t_hyst_norm) &&
                di->batt_data.temp < (di->bm->temp_high - di->t_hyst_norm)) {
                /* Temp OK! */
                di->events.btemp_underover = false;
                di->events.btemp_lowhigh = false;
                di->t_hyst_norm = 0;
                di->t_hyst_lowhigh = 0;
        } else {
                if (((di->batt_data.temp >= di->bm->temp_high) &&
                        (di->batt_data.temp <
                                (di->bm->temp_over - di->t_hyst_lowhigh))) ||
                        ((di->batt_data.temp >
                                (di->bm->temp_under + di->t_hyst_lowhigh)) &&
                        (di->batt_data.temp <= di->bm->temp_low))) {
                        /* TEMP minor!!!!! */
                        di->events.btemp_underover = false;
                        di->events.btemp_lowhigh = true;
                        di->t_hyst_norm = di->bm->temp_hysteresis;
                        di->t_hyst_lowhigh = 0;
                } else if (di->batt_data.temp <= di->bm->temp_under ||
                        di->batt_data.temp >= di->bm->temp_over) {
                        /* TEMP major!!!!! */
                        di->events.btemp_underover = true;
                        di->events.btemp_lowhigh = false;
                        di->t_hyst_norm = 0;
                        di->t_hyst_lowhigh = di->bm->temp_hysteresis;
                } else {
                /* Within hysteresis */
                dev_dbg(di->dev, "Within hysteresis limit temp: %d "
                                "hyst_lowhigh %d, hyst normal %d\n",
                                di->batt_data.temp, di->t_hyst_lowhigh,
                                di->t_hyst_norm);
                }
        }
}

/**
 * abx500_chargalg_check_charger_voltage() - Check charger voltage
 * @di:         pointer to the abx500_chargalg structure
 *
 * Charger voltage is checked against maximum limit
 */
static void abx500_chargalg_check_charger_voltage(struct abx500_chargalg *di)
{
        if (di->chg_info.usb_volt > di->bm->chg_params->usb_volt_max)
                di->chg_info.usb_chg_ok = false;
        else
                di->chg_info.usb_chg_ok = true;

        if (di->chg_info.ac_volt > di->bm->chg_params->ac_volt_max)
                di->chg_info.ac_chg_ok = false;
        else
                di->chg_info.ac_chg_ok = true;

}

/**
 * abx500_chargalg_end_of_charge() - Check if end-of-charge criteria is fulfilled
 * @di:         pointer to the abx500_chargalg structure
 *
 * End-of-charge criteria is fulfilled when the battery voltage is above a
 * certain limit and the battery current is below a certain limit for a
 * predefined number of consecutive seconds. If true, the battery is full
 */
static void abx500_chargalg_end_of_charge(struct abx500_chargalg *di)
{
        if (di->charge_status == POWER_SUPPLY_STATUS_CHARGING &&
                di->charge_state == STATE_NORMAL &&
                !di->maintenance_chg && (di->batt_data.volt >=
                di->bm->bat_type[di->bm->batt_id].termination_vol ||
                di->events.usb_cv_active || di->events.ac_cv_active) &&
                di->batt_data.avg_curr <
                di->bm->bat_type[di->bm->batt_id].termination_curr &&
                di->batt_data.avg_curr > 0) {
                if (++di->eoc_cnt >= EOC_COND_CNT) {
                        di->eoc_cnt = 0;
                        di->charge_status = POWER_SUPPLY_STATUS_FULL;
                        di->maintenance_chg = true;
                        dev_dbg(di->dev, "EOC reached!\n");
                        power_supply_changed(&di->chargalg_psy);
                } else {
                        dev_dbg(di->dev,
                                " EOC limit reached for the %d"
                                " time, out of %d before EOC\n",
                                di->eoc_cnt,
                                EOC_COND_CNT);
                }
        } else {
                di->eoc_cnt = 0;
        }
}

static void init_maxim_chg_curr(struct abx500_chargalg *di)
{
        di->ccm.original_iset =
                di->bm->bat_type[di->bm->batt_id].normal_cur_lvl;
        di->ccm.current_iset =
                di->bm->bat_type[di->bm->batt_id].normal_cur_lvl;
        di->ccm.test_delta_i = di->bm->maxi->charger_curr_step;
        di->ccm.max_current = di->bm->maxi->chg_curr;
        di->ccm.condition_cnt = di->bm->maxi->wait_cycles;
        di->ccm.level = 0;
}

/**
 * abx500_chargalg_chg_curr_maxim - increases the charger current to
 *                      compensate for the system load
 * @di          pointer to the abx500_chargalg structure
 *
 * This maximization function is used to raise the charger current to get the
 * battery current as close to the optimal value as possible. The battery
 * current during charging is affected by the system load
 */
static enum maxim_ret abx500_chargalg_chg_curr_maxim(struct abx500_chargalg *di)
{
        int delta_i;

        if (!di->bm->maxi->ena_maxi)
                return MAXIM_RET_NOACTION;

        delta_i = di->ccm.original_iset - di->batt_data.inst_curr;

        if (di->events.vbus_collapsed) {
                dev_dbg(di->dev, "Charger voltage has collapsed %d\n",
                                di->ccm.wait_cnt);
                if (di->ccm.wait_cnt == 0) {
                        dev_dbg(di->dev, "lowering current\n");
                        di->ccm.wait_cnt++;
                        di->ccm.condition_cnt = di->bm->maxi->wait_cycles;
                        di->ccm.max_current =
                                di->ccm.current_iset - di->ccm.test_delta_i;
                        di->ccm.current_iset = di->ccm.max_current;
                        di->ccm.level--;
                        return MAXIM_RET_CHANGE;
                } else {
                        dev_dbg(di->dev, "waiting\n");
                        /* Let's go in here twice before lowering curr again */
                        di->ccm.wait_cnt = (di->ccm.wait_cnt + 1) % 3;
                        return MAXIM_RET_NOACTION;
                }
        }

        di->ccm.wait_cnt = 0;

        if ((di->batt_data.inst_curr > di->ccm.original_iset)) {
                dev_dbg(di->dev, " Maximization Ibat (%dmA) too high"
                        " (limit %dmA) (current iset: %dmA)!\n",
                        di->batt_data.inst_curr, di->ccm.original_iset,
                        di->ccm.current_iset);

                if (di->ccm.current_iset == di->ccm.original_iset)
                        return MAXIM_RET_NOACTION;

                di->ccm.condition_cnt = di->bm->maxi->wait_cycles;
                di->ccm.current_iset = di->ccm.original_iset;
                di->ccm.level = 0;

                return MAXIM_RET_IBAT_TOO_HIGH;
        }

        if (delta_i > di->ccm.test_delta_i &&
                (di->ccm.current_iset + di->ccm.test_delta_i) <
                di->ccm.max_current) {
                if (di->ccm.condition_cnt-- == 0) {
                        /* Increse the iset with cco.test_delta_i */
                        di->ccm.condition_cnt = di->bm->maxi->wait_cycles;
                        di->ccm.current_iset += di->ccm.test_delta_i;
                        di->ccm.level++;
                        dev_dbg(di->dev, " Maximization needed, increase"
                                " with %d mA to %dmA (Optimal ibat: %d)"
                                " Level %d\n",
                                di->ccm.test_delta_i,
                                di->ccm.current_iset,
                                di->ccm.original_iset,
                                di->ccm.level);
                        return MAXIM_RET_CHANGE;
                } else {
                        return MAXIM_RET_NOACTION;
                }
        }  else {
                di->ccm.condition_cnt = di->bm->maxi->wait_cycles;
                return MAXIM_RET_NOACTION;
        }
}

static void handle_maxim_chg_curr(struct abx500_chargalg *di)
{
        enum maxim_ret ret;
        int result;

        ret = abx500_chargalg_chg_curr_maxim(di);
        switch (ret) {
        case MAXIM_RET_CHANGE:
                result = abx500_chargalg_update_chg_curr(di,
                        di->ccm.current_iset);
                if (result)
                        dev_err(di->dev, "failed to set chg curr\n");
                break;
        case MAXIM_RET_IBAT_TOO_HIGH:
                result = abx500_chargalg_update_chg_curr(di,
                        di->bm->bat_type[di->bm->batt_id].normal_cur_lvl);
                if (result)
                        dev_err(di->dev, "failed to set chg curr\n");
                break;

        case MAXIM_RET_NOACTION:
        default:
                /* Do nothing..*/
                break;
        }
}

static int abx500_chargalg_get_ext_psy_data(struct device *dev, void *data)
{
        struct power_supply *psy;
        struct power_supply *ext;
        struct abx500_chargalg *di;
        union power_supply_propval ret;
        int i, j;
        bool psy_found = false;
        bool capacity_updated = false;

        psy = (struct power_supply *)data;
        ext = dev_get_drvdata(dev);
        di = to_abx500_chargalg_device_info(psy);
        /* For all psy where the driver name 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;

        /*
         *  If external is not registering 'POWER_SUPPLY_PROP_CAPACITY' to its
         * property because of handling that sysfs entry on its own, this is
         * the place to get the battery capacity.
         */
        if (!ext->get_property(ext, POWER_SUPPLY_PROP_CAPACITY, &ret)) {
                di->batt_data.percent = ret.intval;
                capacity_updated = true;
        }

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

                /* Initialize chargers if not already done */
                if (!di->ac_chg &&
                        ext->type == POWER_SUPPLY_TYPE_MAINS)
                        di->ac_chg = psy_to_ux500_charger(ext);
                else if (!di->usb_chg &&
                        ext->type == POWER_SUPPLY_TYPE_USB)
                        di->usb_chg = psy_to_ux500_charger(ext);

                if (ext->get_property(ext, prop, &ret))
                        continue;
                switch (prop) {
                case POWER_SUPPLY_PROP_PRESENT:
                        switch (ext->type) {
                        case POWER_SUPPLY_TYPE_BATTERY:
                                /* Battery present */
                                if (ret.intval)
                                        di->events.batt_rem = false;
                                /* Battery removed */
                                else
                                        di->events.batt_rem = true;
                                break;
                        case POWER_SUPPLY_TYPE_MAINS:
                                /* AC disconnected */
                                if (!ret.intval &&
                                        (di->chg_info.conn_chg & AC_CHG)) {
                                        di->chg_info.prev_conn_chg =
                                                di->chg_info.conn_chg;
                                        di->chg_info.conn_chg &= ~AC_CHG;
                                }
                                /* AC connected */
                                else if (ret.intval &&
                                        !(di->chg_info.conn_chg & AC_CHG)) {
                                        di->chg_info.prev_conn_chg =
                                                di->chg_info.conn_chg;
                                        di->chg_info.conn_chg |= AC_CHG;
                                }
                                break;
                        case POWER_SUPPLY_TYPE_USB:
                                /* USB disconnected */
                                if (!ret.intval &&
                                        (di->chg_info.conn_chg & USB_CHG)) {
                                        di->chg_info.prev_conn_chg =
                                                di->chg_info.conn_chg;
                                        di->chg_info.conn_chg &= ~USB_CHG;
                                }
                                /* USB connected */
                                else if (ret.intval &&
                                        !(di->chg_info.conn_chg & USB_CHG)) {
                                        di->chg_info.prev_conn_chg =
                                                di->chg_info.conn_chg;
                                        di->chg_info.conn_chg |= USB_CHG;
                                }
                                break;
                        default:
                                break;
                        }
                        break;

                case POWER_SUPPLY_PROP_ONLINE:
                        switch (ext->type) {
                        case POWER_SUPPLY_TYPE_BATTERY:
                                break;
                        case POWER_SUPPLY_TYPE_MAINS:
                                /* AC offline */
                                if (!ret.intval &&
                                        (di->chg_info.online_chg & AC_CHG)) {
                                        di->chg_info.prev_online_chg =
                                                di->chg_info.online_chg;
                                        di->chg_info.online_chg &= ~AC_CHG;
                                }
                                /* AC online */
                                else if (ret.intval &&
                                        !(di->chg_info.online_chg & AC_CHG)) {
                                        di->chg_info.prev_online_chg =
                                                di->chg_info.online_chg;
                                        di->chg_info.online_chg |= AC_CHG;
                                        queue_delayed_work(di->chargalg_wq,
                                                &di->chargalg_wd_work, 0);
                                }
                                break;
                        case POWER_SUPPLY_TYPE_USB:
                                /* USB offline */
                                if (!ret.intval &&
                                        (di->chg_info.online_chg & USB_CHG)) {
                                        di->chg_info.prev_online_chg =
                                                di->chg_info.online_chg;
                                        di->chg_info.online_chg &= ~USB_CHG;
                                }
                                /* USB online */
                                else if (ret.intval &&
                                        !(di->chg_info.online_chg & USB_CHG)) {
                                        di->chg_info.prev_online_chg =
                                                di->chg_info.online_chg;
                                        di->chg_info.online_chg |= USB_CHG;
                                        queue_delayed_work(di->chargalg_wq,
                                                &di->chargalg_wd_work, 0);
                                }
                                break;
                        default:
                                break;
                        }

                        break;

                case POWER_SUPPLY_PROP_HEALTH:
                        switch (ext->type) {
                        case POWER_SUPPLY_TYPE_BATTERY:
                                break;
                        case POWER_SUPPLY_TYPE_MAINS:
                                switch (ret.intval) {
                                case POWER_SUPPLY_HEALTH_UNSPEC_FAILURE:
                                        di->events.mainextchnotok = true;
                                        di->events.main_thermal_prot = false;
                                        di->events.main_ovv = false;
                                        di->events.ac_wd_expired = false;
                                        break;
                                case POWER_SUPPLY_HEALTH_DEAD:
                                        di->events.ac_wd_expired = true;
                                        di->events.mainextchnotok = false;
                                        di->events.main_ovv = false;
                                        di->events.main_thermal_prot = false;
                                        break;
                                case POWER_SUPPLY_HEALTH_COLD:
                                case POWER_SUPPLY_HEALTH_OVERHEAT:
                                        di->events.main_thermal_prot = true;
                                        di->events.mainextchnotok = false;
                                        di->events.main_ovv = false;
                                        di->events.ac_wd_expired = false;
                                        break;
                                case POWER_SUPPLY_HEALTH_OVERVOLTAGE:
                                        di->events.main_ovv = true;
                                        di->events.mainextchnotok = false;
                                        di->events.main_thermal_prot = false;
                                        di->events.ac_wd_expired = false;
                                        break;
                                case POWER_SUPPLY_HEALTH_GOOD:
                                        di->events.main_thermal_prot = false;
                                        di->events.mainextchnotok = false;
                                        di->events.main_ovv = false;
                                        di->events.ac_wd_expired = false;
                                        break;
                                default:
                                        break;
                                }
                                break;

                        case POWER_SUPPLY_TYPE_USB:
                                switch (ret.intval) {
                                case POWER_SUPPLY_HEALTH_UNSPEC_FAILURE:
                                        di->events.usbchargernotok = true;
                                        di->events.usb_thermal_prot = false;
                                        di->events.vbus_ovv = false;
                                        di->events.usb_wd_expired = false;
                                        break;
                                case POWER_SUPPLY_HEALTH_DEAD:
                                        di->events.usb_wd_expired = true;
                                        di->events.usbchargernotok = false;
                                        di->events.usb_thermal_prot = false;
                                        di->events.vbus_ovv = false;
                                        break;
                                case POWER_SUPPLY_HEALTH_COLD:
                                case POWER_SUPPLY_HEALTH_OVERHEAT:
                                        di->events.usb_thermal_prot = true;
                                        di->events.usbchargernotok = false;
                                        di->events.vbus_ovv = false;
                                        di->events.usb_wd_expired = false;
                                        break;
                                case POWER_SUPPLY_HEALTH_OVERVOLTAGE:
                                        di->events.vbus_ovv = true;
                                        di->events.usbchargernotok = false;
                                        di->events.usb_thermal_prot = false;
                                        di->events.usb_wd_expired = false;
                                        break;
                                case POWER_SUPPLY_HEALTH_GOOD:
                                        di->events.usbchargernotok = false;
                                        di->events.usb_thermal_prot = false;
                                        di->events.vbus_ovv = false;
                                        di->events.usb_wd_expired = false;
                                        break;
                                default:
                                        break;
                                }
                        default:
                                break;
                        }
                        break;

                case POWER_SUPPLY_PROP_VOLTAGE_NOW:
                        switch (ext->type) {
                        case POWER_SUPPLY_TYPE_BATTERY:
                                di->batt_data.volt = ret.intval / 1000;
                                break;
                        case POWER_SUPPLY_TYPE_MAINS:
                                di->chg_info.ac_volt = ret.intval / 1000;
                                break;
                        case POWER_SUPPLY_TYPE_USB:
                                di->chg_info.usb_volt = ret.intval / 1000;
                                break;
                        default:
                                break;
                        }
                        break;

                case POWER_SUPPLY_PROP_VOLTAGE_AVG:
                        switch (ext->type) {
                        case POWER_SUPPLY_TYPE_MAINS:
                                /* AVG is used to indicate when we are
                                 * in CV mode */
                                if (ret.intval)
                                        di->events.ac_cv_active = true;
                                else
                                        di->events.ac_cv_active = false;

                                break;
                        case POWER_SUPPLY_TYPE_USB:
                                /* AVG is used to indicate when we are
                                 * in CV mode */
                                if (ret.intval)
                                        di->events.usb_cv_active = true;
                                else
                                        di->events.usb_cv_active = false;

                                break;
                        default:
                                break;
                        }
                        break;

                case POWER_SUPPLY_PROP_TECHNOLOGY:
                        switch (ext->type) {
                        case POWER_SUPPLY_TYPE_BATTERY:
                                if (ret.intval)
                                        di->events.batt_unknown = false;
                                else
                                        di->events.batt_unknown = true;

                                break;
                        default:
                                break;
                        }
                        break;

                case POWER_SUPPLY_PROP_TEMP:
                        di->batt_data.temp = ret.intval / 10;
                        break;

                case POWER_SUPPLY_PROP_CURRENT_NOW:
                        switch (ext->type) {
                        case POWER_SUPPLY_TYPE_MAINS:
                                        di->chg_info.ac_curr =
                                                ret.intval / 1000;
                                        break;
                        case POWER_SUPPLY_TYPE_USB:
                                        di->chg_info.usb_curr =
                                                ret.intval / 1000;
                                break;
                        case POWER_SUPPLY_TYPE_BATTERY:
                                di->batt_data.inst_curr = ret.intval / 1000;
                                break;
                        default:
                                break;
                        }
                        break;

                case POWER_SUPPLY_PROP_CURRENT_AVG:
                        switch (ext->type) {
                        case POWER_SUPPLY_TYPE_BATTERY:
                                di->batt_data.avg_curr = ret.intval / 1000;
                                break;
                        case POWER_SUPPLY_TYPE_USB:
                                if (ret.intval)
                                        di->events.vbus_collapsed = true;
                                else
                                        di->events.vbus_collapsed = false;
                                break;
                        default:
                                break;
                        }
                        break;
                case POWER_SUPPLY_PROP_CAPACITY:
                        if (!capacity_updated)
                                di->batt_data.percent = ret.intval;
                        break;
                default:
                        break;
                }
        }
        return 0;
}

/**
 * abx500_chargalg_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 abx500_chargalg_external_power_changed(struct power_supply *psy)
{
        struct abx500_chargalg *di = to_abx500_chargalg_device_info(psy);

        /*
         * Trigger execution of the algorithm instantly and read
         * all power_supply properties there instead
         */
        queue_work(di->chargalg_wq, &di->chargalg_work);
}

/**
 * abx500_chargalg_algorithm() - Main function for the algorithm
 * @di:         pointer to the abx500_chargalg structure
 *
 * This is the main control function for the charging algorithm.
 * It is called periodically or when something happens that will
 * trigger a state change
 */
static void abx500_chargalg_algorithm(struct abx500_chargalg *di)
{
        int charger_status;

        /* Collect data from all power_supply class devices */
        class_for_each_device(power_supply_class, NULL,
                &di->chargalg_psy, abx500_chargalg_get_ext_psy_data);

        abx500_chargalg_end_of_charge(di);
        abx500_chargalg_check_temp(di);
        abx500_chargalg_check_charger_voltage(di);

        charger_status = abx500_chargalg_check_charger_connection(di);
        /*
         * First check if we have a charger connected.
         * Also we don't allow charging of unknown batteries if configured
         * this way
         */
        if (!charger_status ||
                (di->events.batt_unknown && !di->bm->chg_unknown_bat)) {
                if (di->charge_state != STATE_HANDHELD) {
                        di->events.safety_timer_expired = false;
                        abx500_chargalg_state_to(di, STATE_HANDHELD_INIT);
                }
        }

        /* If suspended, we should not continue checking the flags */
        else if (di->charge_state == STATE_SUSPENDED_INIT ||
                di->charge_state == STATE_SUSPENDED) {
                /* We don't do anything here, just don,t continue */
        }

        /* Safety timer expiration */
        else if (di->events.safety_timer_expired) {
                if (di->charge_state != STATE_SAFETY_TIMER_EXPIRED)
                        abx500_chargalg_state_to(di,
                                STATE_SAFETY_TIMER_EXPIRED_INIT);
        }
        /*
         * Check if any interrupts has occured
         * that will prevent us from charging
         */

        /* Battery removed */
        else if (di->events.batt_rem) {
                if (di->charge_state != STATE_BATT_REMOVED)
                        abx500_chargalg_state_to(di, STATE_BATT_REMOVED_INIT);
        }
        /* Main or USB charger not ok. */
        else if (di->events.mainextchnotok || di->events.usbchargernotok) {
                /*
                 * If vbus_collapsed is set, we have to lower the charger
                 * current, which is done in the normal state below
                 */
                if (di->charge_state != STATE_CHG_NOT_OK &&
                                !di->events.vbus_collapsed)
                        abx500_chargalg_state_to(di, STATE_CHG_NOT_OK_INIT);
        }
        /* VBUS, Main or VBAT OVV. */
        else if (di->events.vbus_ovv ||
                        di->events.main_ovv ||
                        di->events.batt_ovv ||
                        !di->chg_info.usb_chg_ok ||
                        !di->chg_info.ac_chg_ok) {
                if (di->charge_state != STATE_OVV_PROTECT)
                        abx500_chargalg_state_to(di, STATE_OVV_PROTECT_INIT);
        }
        /* USB Thermal, stop charging */
        else if (di->events.main_thermal_prot ||
                di->events.usb_thermal_prot) {
                if (di->charge_state != STATE_HW_TEMP_PROTECT)
                        abx500_chargalg_state_to(di,
                                STATE_HW_TEMP_PROTECT_INIT);
        }
        /* Battery temp over/under */
        else if (di->events.btemp_underover) {
                if (di->charge_state != STATE_TEMP_UNDEROVER)
                        abx500_chargalg_state_to(di,
                                STATE_TEMP_UNDEROVER_INIT);
        }
        /* Watchdog expired */
        else if (di->events.ac_wd_expired ||
                di->events.usb_wd_expired) {
                if (di->charge_state != STATE_WD_EXPIRED)
                        abx500_chargalg_state_to(di, STATE_WD_EXPIRED_INIT);
        }
        /* Battery temp high/low */
        else if (di->events.btemp_lowhigh) {
                if (di->charge_state != STATE_TEMP_LOWHIGH)
                        abx500_chargalg_state_to(di, STATE_TEMP_LOWHIGH_INIT);
        }

        dev_dbg(di->dev,
                "[CHARGALG] Vb %d Ib_avg %d Ib_inst %d Tb %d Cap %d Maint %d "
                "State %s Active_chg %d Chg_status %d AC %d USB %d "
                "AC_online %d USB_online %d AC_CV %d USB_CV %d AC_I %d "
                "USB_I %d AC_Vset %d AC_Iset %d USB_Vset %d USB_Iset %d\n",
                di->batt_data.volt,
                di->batt_data.avg_curr,
                di->batt_data.inst_curr,
                di->batt_data.temp,
                di->batt_data.percent,
                di->maintenance_chg,
                states[di->charge_state],
                di->chg_info.charger_type,
                di->charge_status,
                di->chg_info.conn_chg & AC_CHG,
                di->chg_info.conn_chg & USB_CHG,
                di->chg_info.online_chg & AC_CHG,
                di->chg_info.online_chg & USB_CHG,
                di->events.ac_cv_active,
                di->events.usb_cv_active,
                di->chg_info.ac_curr,
                di->chg_info.usb_curr,
                di->chg_info.ac_vset,
                di->chg_info.ac_iset,
                di->chg_info.usb_vset,
                di->chg_info.usb_iset);

        switch (di->charge_state) {
        case STATE_HANDHELD_INIT:
                abx500_chargalg_stop_charging(di);
                di->charge_status = POWER_SUPPLY_STATUS_DISCHARGING;
                abx500_chargalg_state_to(di, STATE_HANDHELD);
                /* Intentional fallthrough */

        case STATE_HANDHELD:
                break;

        case STATE_SUSPENDED_INIT:
                if (di->susp_status.ac_suspended)
                        abx500_chargalg_ac_en(di, false, 0, 0);
                if (di->susp_status.usb_suspended)
                        abx500_chargalg_usb_en(di, false, 0, 0);
                abx500_chargalg_stop_safety_timer(di);
                abx500_chargalg_stop_maintenance_timer(di);
                di->charge_status = POWER_SUPPLY_STATUS_NOT_CHARGING;
                di->maintenance_chg = false;
                abx500_chargalg_state_to(di, STATE_SUSPENDED);
                power_supply_changed(&di->chargalg_psy);
                /* Intentional fallthrough */

        case STATE_SUSPENDED:
                /* CHARGING is suspended */
                break;

        case STATE_BATT_REMOVED_INIT:
                abx500_chargalg_stop_charging(di);
                abx500_chargalg_state_to(di, STATE_BATT_REMOVED);
                /* Intentional fallthrough */

        case STATE_BATT_REMOVED:
                if (!di->events.batt_rem)
                        abx500_chargalg_state_to(di, STATE_NORMAL_INIT);
                break;

        case STATE_HW_TEMP_PROTECT_INIT:
                abx500_chargalg_stop_charging(di);
                abx500_chargalg_state_to(di, STATE_HW_TEMP_PROTECT);
                /* Intentional fallthrough */

        case STATE_HW_TEMP_PROTECT:
                if (!di->events.main_thermal_prot &&
                                !di->events.usb_thermal_prot)
                        abx500_chargalg_state_to(di, STATE_NORMAL_INIT);
                break;

        case STATE_OVV_PROTECT_INIT:
                abx500_chargalg_stop_charging(di);
                abx500_chargalg_state_to(di, STATE_OVV_PROTECT);
                /* Intentional fallthrough */

        case STATE_OVV_PROTECT:
                if (!di->events.vbus_ovv &&
                                !di->events.main_ovv &&
                                !di->events.batt_ovv &&
                                di->chg_info.usb_chg_ok &&
                                di->chg_info.ac_chg_ok)
                        abx500_chargalg_state_to(di, STATE_NORMAL_INIT);
                break;

        case STATE_CHG_NOT_OK_INIT:
                abx500_chargalg_stop_charging(di);
                abx500_chargalg_state_to(di, STATE_CHG_NOT_OK);
                /* Intentional fallthrough */

        case STATE_CHG_NOT_OK:
                if (!di->events.mainextchnotok &&
                                !di->events.usbchargernotok)
                        abx500_chargalg_state_to(di, STATE_NORMAL_INIT);
                break;

        case STATE_SAFETY_TIMER_EXPIRED_INIT:
                abx500_chargalg_stop_charging(di);
                abx500_chargalg_state_to(di, STATE_SAFETY_TIMER_EXPIRED);
                /* Intentional fallthrough */

        case STATE_SAFETY_TIMER_EXPIRED:
                /* We exit this state when charger is removed */
                break;

        case STATE_NORMAL_INIT:
                abx500_chargalg_start_charging(di,
                        di->bm->bat_type[di->bm->batt_id].normal_vol_lvl,
                        di->bm->bat_type[di->bm->batt_id].normal_cur_lvl);
                abx500_chargalg_state_to(di, STATE_NORMAL);
                abx500_chargalg_start_safety_timer(di);
                abx500_chargalg_stop_maintenance_timer(di);
                init_maxim_chg_curr(di);
                di->charge_status = POWER_SUPPLY_STATUS_CHARGING;
                di->eoc_cnt = 0;
                di->maintenance_chg = false;
                power_supply_changed(&di->chargalg_psy);

                break;

        case STATE_NORMAL:
                handle_maxim_chg_curr(di);
                if (di->charge_status == POWER_SUPPLY_STATUS_FULL &&
                        di->maintenance_chg) {
                        if (di->bm->no_maintenance)
                                abx500_chargalg_state_to(di,
                                        STATE_WAIT_FOR_RECHARGE_INIT);
                        else
                                abx500_chargalg_state_to(di,
                                        STATE_MAINTENANCE_A_INIT);
                }
                break;

        /* This state will be used when the maintenance state is disabled */
        case STATE_WAIT_FOR_RECHARGE_INIT:
                abx500_chargalg_hold_charging(di);
                abx500_chargalg_state_to(di, STATE_WAIT_FOR_RECHARGE);
                /* Intentional fallthrough */

        case STATE_WAIT_FOR_RECHARGE:
                if (di->batt_data.percent <=
                    di->bm->bat_type[di->bm->batt_id].
                    recharge_cap)
                        abx500_chargalg_state_to(di, STATE_NORMAL_INIT);
                break;

        case STATE_MAINTENANCE_A_INIT:
                abx500_chargalg_stop_safety_timer(di);
                abx500_chargalg_start_maintenance_timer(di,
                        di->bm->bat_type[
                                di->bm->batt_id].maint_a_chg_timer_h);
                abx500_chargalg_start_charging(di,
                        di->bm->bat_type[
                                di->bm->batt_id].maint_a_vol_lvl,
                        di->bm->bat_type[
                                di->bm->batt_id].maint_a_cur_lvl);
                abx500_chargalg_state_to(di, STATE_MAINTENANCE_A);
                power_supply_changed(&di->chargalg_psy);
                /* Intentional fallthrough*/

        case STATE_MAINTENANCE_A:
                if (di->events.maintenance_timer_expired) {
                        abx500_chargalg_stop_maintenance_timer(di);
                        abx500_chargalg_state_to(di, STATE_MAINTENANCE_B_INIT);
                }
                break;

        case STATE_MAINTENANCE_B_INIT:
                abx500_chargalg_start_maintenance_timer(di,
                        di->bm->bat_type[
                                di->bm->batt_id].maint_b_chg_timer_h);
                abx500_chargalg_start_charging(di,
                        di->bm->bat_type[
                                di->bm->batt_id].maint_b_vol_lvl,
                        di->bm->bat_type[
                                di->bm->batt_id].maint_b_cur_lvl);
                abx500_chargalg_state_to(di, STATE_MAINTENANCE_B);
                power_supply_changed(&di->chargalg_psy);
                /* Intentional fallthrough*/

        case STATE_MAINTENANCE_B:
                if (di->events.maintenance_timer_expired) {
                        abx500_chargalg_stop_maintenance_timer(di);
                        abx500_chargalg_state_to(di, STATE_NORMAL_INIT);
                }
                break;

        case STATE_TEMP_LOWHIGH_INIT:
                abx500_chargalg_start_charging(di,
                        di->bm->bat_type[
                                di->bm->batt_id].low_high_vol_lvl,
                        di->bm->bat_type[
                                di->bm->batt_id].low_high_cur_lvl);
                abx500_chargalg_stop_maintenance_timer(di);
                di->charge_status = POWER_SUPPLY_STATUS_CHARGING;
                abx500_chargalg_state_to(di, STATE_TEMP_LOWHIGH);
                power_supply_changed(&di->chargalg_psy);
                /* Intentional fallthrough */

        case STATE_TEMP_LOWHIGH:
                if (!di->events.btemp_lowhigh)
                        abx500_chargalg_state_to(di, STATE_NORMAL_INIT);
                break;

        case STATE_WD_EXPIRED_INIT:
                abx500_chargalg_stop_charging(di);
                abx500_chargalg_state_to(di, STATE_WD_EXPIRED);
                /* Intentional fallthrough */

        case STATE_WD_EXPIRED:
                if (!di->events.ac_wd_expired &&
                                !di->events.usb_wd_expired)
                        abx500_chargalg_state_to(di, STATE_NORMAL_INIT);
                break;

        case STATE_TEMP_UNDEROVER_INIT:
                abx500_chargalg_stop_charging(di);
                abx500_chargalg_state_to(di, STATE_TEMP_UNDEROVER);
                /* Intentional fallthrough */

        case STATE_TEMP_UNDEROVER:
                if (!di->events.btemp_underover)
                        abx500_chargalg_state_to(di, STATE_NORMAL_INIT);
                break;
        }

        /* Start charging directly if the new state is a charge state */
        if (di->charge_state == STATE_NORMAL_INIT ||
                        di->charge_state == STATE_MAINTENANCE_A_INIT ||
                        di->charge_state == STATE_MAINTENANCE_B_INIT)
                queue_work(di->chargalg_wq, &di->chargalg_work);
}

/**
 * abx500_chargalg_periodic_work() - Periodic work for the algorithm
 * @work:       pointer to the work_struct structure
 *
 * Work queue function for the charging algorithm
 */
static void abx500_chargalg_periodic_work(struct work_struct *work)
{
        struct abx500_chargalg *di = container_of(work,
                struct abx500_chargalg, chargalg_periodic_work.work);

        abx500_chargalg_algorithm(di);

        /*
         * If a charger is connected then the battery has to be monitored
         * frequently, else the work can be delayed.
         */
        if (di->chg_info.conn_chg)
                queue_delayed_work(di->chargalg_wq,
                        &di->chargalg_periodic_work,
                        di->bm->interval_charging * HZ);
        else
                queue_delayed_work(di->chargalg_wq,
                        &di->chargalg_periodic_work,
                        di->bm->interval_not_charging * HZ);
}

/**
 * abx500_chargalg_wd_work() - periodic work to kick the charger watchdog
 * @work:       pointer to the work_struct structure
 *
 * Work queue function for kicking the charger watchdog
 */
static void abx500_chargalg_wd_work(struct work_struct *work)
{
        int ret;
        struct abx500_chargalg *di = container_of(work,
                struct abx500_chargalg, chargalg_wd_work.work);

        dev_dbg(di->dev, "abx500_chargalg_wd_work\n");

        ret = abx500_chargalg_kick_watchdog(di);
        if (ret < 0)
                dev_err(di->dev, "failed to kick watchdog\n");

        queue_delayed_work(di->chargalg_wq,
                &di->chargalg_wd_work, CHG_WD_INTERVAL);
}

/**
 * abx500_chargalg_work() - Work to run the charging algorithm instantly
 * @work:       pointer to the work_struct structure
 *
 * Work queue function for calling the charging algorithm
 */
static void abx500_chargalg_work(struct work_struct *work)
{
        struct abx500_chargalg *di = container_of(work,
                struct abx500_chargalg, chargalg_work);

        abx500_chargalg_algorithm(di);
}

/**
 * abx500_chargalg_get_property() - get the chargalg 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
 * chargalg properties by reading the sysfs files.
 * status:     charging/discharging/full/unknown
 * health:     health of the battery
 * Returns error code in case of failure else 0 on success
 */
static int abx500_chargalg_get_property(struct power_supply *psy,
        enum power_supply_property psp,
        union power_supply_propval *val)
{
        struct abx500_chargalg *di;

        di = to_abx500_chargalg_device_info(psy);

        switch (psp) {
        case POWER_SUPPLY_PROP_STATUS:
                val->intval = di->charge_status;
                break;
        case POWER_SUPPLY_PROP_HEALTH:
                if (di->events.batt_ovv) {
                        val->intval = POWER_SUPPLY_HEALTH_OVERVOLTAGE;
                } else if (di->events.btemp_underover) {
                        if (di->batt_data.temp <= di->bm->temp_under)
                                val->intval = POWER_SUPPLY_HEALTH_COLD;
                        else
                                val->intval = POWER_SUPPLY_HEALTH_OVERHEAT;
                } else if (di->charge_state == STATE_SAFETY_TIMER_EXPIRED ||
                           di->charge_state == STATE_SAFETY_TIMER_EXPIRED_INIT) {
                        val->intval = POWER_SUPPLY_HEALTH_UNSPEC_FAILURE;
                } else {
                        val->intval = POWER_SUPPLY_HEALTH_GOOD;
                }
                break;
        default:
                return -EINVAL;
        }
        return 0;
}

/* Exposure to the sysfs interface */

/**
 * abx500_chargalg_sysfs_show() - sysfs show operations
 * @kobj:      pointer to the struct kobject
 * @attr:      pointer to the struct attribute
 * @buf:       buffer that holds the parameter to send to userspace
 *
 * Returns a buffer to be displayed in user space
 */
static ssize_t abx500_chargalg_sysfs_show(struct kobject *kobj,
                                          struct attribute *attr, char *buf)
{
        struct abx500_chargalg *di = container_of(kobj,
               struct abx500_chargalg, chargalg_kobject);

        return sprintf(buf, "%d\n",
                       di->susp_status.ac_suspended &&
                       di->susp_status.usb_suspended);
}

/**
 * abx500_chargalg_sysfs_charger() - sysfs store operations
 * @kobj:      pointer to the struct kobject
 * @attr:      pointer to the struct attribute
 * @buf:       buffer that holds the parameter passed from userspace
 * @length:    length of the parameter passed
 *
 * Returns length of the buffer(input taken from user space) on success
 * else error code on failure
 * The operation to be performed on passing the parameters from the user space.
 */
static ssize_t abx500_chargalg_sysfs_charger(struct kobject *kobj,
        struct attribute *attr, const char *buf, size_t length)
{
        struct abx500_chargalg *di = container_of(kobj,
                struct abx500_chargalg, chargalg_kobject);
        long int param;
        int ac_usb;
        int ret;
        char entry = *attr->name;

        switch (entry) {
        case 'c':
                ret = strict_strtol(buf, 10, &param);
                if (ret < 0)
                        return ret;

                ac_usb = param;
                switch (ac_usb) {
                case 0:
                        /* Disable charging */
                        di->susp_status.ac_suspended = true;
                        di->susp_status.usb_suspended = true;
                        di->susp_status.suspended_change = true;
                        /* Trigger a state change */
                        queue_work(di->chargalg_wq,
                                &di->chargalg_work);
                        break;
                case 1:
                        /* Enable AC Charging */
                        di->susp_status.ac_suspended = false;
                        di->susp_status.suspended_change = true;
                        /* Trigger a state change */
                        queue_work(di->chargalg_wq,
                                &di->chargalg_work);
                        break;
                case 2:
                        /* Enable USB charging */
                        di->susp_status.usb_suspended = false;
                        di->susp_status.suspended_change = true;
                        /* Trigger a state change */
                        queue_work(di->chargalg_wq,
                                &di->chargalg_work);
                        break;
                default:
                        dev_info(di->dev, "Wrong input\n"
                                "Enter 0. Disable AC/USB Charging\n"
                                "1. Enable AC charging\n"
                                "2. Enable USB Charging\n");
                };
                break;
        };
        return strlen(buf);
}

static struct attribute abx500_chargalg_en_charger = \
{
        .name = "chargalg",
        .mode = S_IRUGO | S_IWUSR,
};

static struct attribute *abx500_chargalg_chg[] = {
        &abx500_chargalg_en_charger,
        NULL
};

static const struct sysfs_ops abx500_chargalg_sysfs_ops = {
        .show = abx500_chargalg_sysfs_show,
        .store = abx500_chargalg_sysfs_charger,
};

static struct kobj_type abx500_chargalg_ktype = {
        .sysfs_ops = &abx500_chargalg_sysfs_ops,
        .default_attrs = abx500_chargalg_chg,
};

/**
 * abx500_chargalg_sysfs_exit() - de-init of sysfs entry
 * @di:                pointer to the struct abx500_chargalg
 *
 * This function removes the entry in sysfs.
 */
static void abx500_chargalg_sysfs_exit(struct abx500_chargalg *di)
{
        kobject_del(&di->chargalg_kobject);
}

/**
 * abx500_chargalg_sysfs_init() - init of sysfs entry
 * @di:                pointer to the struct abx500_chargalg
 *
 * This function adds an entry in sysfs.
 * Returns error code in case of failure else 0(on success)
 */
static int abx500_chargalg_sysfs_init(struct abx500_chargalg *di)
{
        int ret = 0;

        ret = kobject_init_and_add(&di->chargalg_kobject,
                &abx500_chargalg_ktype,
                NULL, "abx500_chargalg");
        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 abx500_chargalg_resume(struct platform_device *pdev)
{
        struct abx500_chargalg *di = platform_get_drvdata(pdev);

        /* Kick charger watchdog if charging (any charger online) */
        if (di->chg_info.online_chg)
                queue_delayed_work(di->chargalg_wq, &di->chargalg_wd_work, 0);

        /*
         * Run the charging algorithm directly to be sure we don't
         * do it too seldom
         */
        queue_delayed_work(di->chargalg_wq, &di->chargalg_periodic_work, 0);

        return 0;
}

static int abx500_chargalg_suspend(struct platform_device *pdev,
        pm_message_t state)
{
        struct abx500_chargalg *di = platform_get_drvdata(pdev);

        if (di->chg_info.online_chg)
                cancel_delayed_work_sync(&di->chargalg_wd_work);

        cancel_delayed_work_sync(&di->chargalg_periodic_work);

        return 0;
}
#else
#define abx500_chargalg_suspend      NULL
#define abx500_chargalg_resume       NULL
#endif

static int abx500_chargalg_remove(struct platform_device *pdev)
{
        struct abx500_chargalg *di = platform_get_drvdata(pdev);

        /* sysfs interface to enable/disbale charging from user space */
        abx500_chargalg_sysfs_exit(di);

        /* Delete the work queue */
        destroy_workqueue(di->chargalg_wq);

        flush_scheduled_work();
        power_supply_unregister(&di->chargalg_psy);
        platform_set_drvdata(pdev, NULL);

        return 0;
}

static char *supply_interface[] = {
        "ab8500_fg",
};

static int abx500_chargalg_probe(struct platform_device *pdev)
{
        struct device_node *np = pdev->dev.of_node;
        struct abx500_bm_data *plat = pdev->dev.platform_data;
        struct abx500_chargalg *di;
        int ret = 0;

        di = devm_kzalloc(&pdev->dev, sizeof(*di), GFP_KERNEL);
        if (!di) {
                dev_err(&pdev->dev, "%s no mem for ab8500_chargalg\n", __func__);
                return -ENOMEM;
        }

        if (!plat) {
                dev_err(&pdev->dev, "no battery management data supplied\n");
                return -EINVAL;
        }
        di->bm = plat;

        if (np) {
                ret = ab8500_bm_of_probe(&pdev->dev, np, di->bm);
                if (ret) {
                        dev_err(&pdev->dev, "failed to get battery information\n");
                        return ret;
                }
        }

        /* get device struct */
        di->dev = &pdev->dev;

        /* chargalg supply */
        di->chargalg_psy.name = "abx500_chargalg";
        di->chargalg_psy.type = POWER_SUPPLY_TYPE_BATTERY;
        di->chargalg_psy.properties = abx500_chargalg_props;
        di->chargalg_psy.num_properties = ARRAY_SIZE(abx500_chargalg_props);
        di->chargalg_psy.get_property = abx500_chargalg_get_property;
        di->chargalg_psy.supplied_to = supply_interface;
        di->chargalg_psy.num_supplicants = ARRAY_SIZE(supply_interface),
        di->chargalg_psy.external_power_changed =
                abx500_chargalg_external_power_changed;

        /* Initilialize safety timer */
        init_timer(&di->safety_timer);
        di->safety_timer.function = abx500_chargalg_safety_timer_expired;
        di->safety_timer.data = (unsigned long) di;

        /* Initilialize maintenance timer */
        init_timer(&di->maintenance_timer);
        di->maintenance_timer.function =
                abx500_chargalg_maintenance_timer_expired;
        di->maintenance_timer.data = (unsigned long) di;

        /* Create a work queue for the chargalg */
        di->chargalg_wq =
                create_singlethread_workqueue("abx500_chargalg_wq");
        if (di->chargalg_wq == NULL) {
                dev_err(di->dev, "failed to create work queue\n");
                return -ENOMEM;
        }

        /* Init work for chargalg */
        INIT_DEFERRABLE_WORK(&di->chargalg_periodic_work,
                abx500_chargalg_periodic_work);
        INIT_DEFERRABLE_WORK(&di->chargalg_wd_work,
                abx500_chargalg_wd_work);

        /* Init work for chargalg */
        INIT_WORK(&di->chargalg_work, abx500_chargalg_work);

        /* To detect charger at startup */
        di->chg_info.prev_conn_chg = -1;

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

        platform_set_drvdata(pdev, di);

        /* sysfs interface to enable/disable charging from user space */
        ret = abx500_chargalg_sysfs_init(di);
        if (ret) {
                dev_err(di->dev, "failed to create sysfs entry\n");
                goto free_psy;
        }

        /* Run the charging algorithm */
        queue_delayed_work(di->chargalg_wq, &di->chargalg_periodic_work, 0);

        dev_info(di->dev, "probe success\n");
        return ret;

free_psy:
        power_supply_unregister(&di->chargalg_psy);
free_chargalg_wq:
        destroy_workqueue(di->chargalg_wq);
        return ret;
}

static const struct of_device_id ab8500_chargalg_match[] = {
        { .compatible = "stericsson,ab8500-chargalg", },
        { },
};

static struct platform_driver abx500_chargalg_driver = {
        .probe = abx500_chargalg_probe,
        .remove = abx500_chargalg_remove,
        .suspend = abx500_chargalg_suspend,
        .resume = abx500_chargalg_resume,
        .driver = {
                .name = "ab8500-chargalg",
                .owner = THIS_MODULE,
                .of_match_table = ab8500_chargalg_match,
        },
};

static int __init abx500_chargalg_init(void)
{
        return platform_driver_register(&abx500_chargalg_driver);
}

static void __exit abx500_chargalg_exit(void)
{
        platform_driver_unregister(&abx500_chargalg_driver);
}

module_init(abx500_chargalg_init);
module_exit(abx500_chargalg_exit);

MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Johan Palsson, Karl Komierowski");
MODULE_ALIAS("platform:abx500-chargalg");
MODULE_DESCRIPTION("abx500 battery charging algorithm");