// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2011 Samsung Electronics Co., Ltd.
 * MyungJoo Ham <myungjoo.ham@samsung.com>
 *
 * This driver enables to monitor battery health and control charger
 * during suspend-to-mem.
 * Charger manager depends on other devices. Register this later than
 * the depending devices.
 *
**/

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/io.h>
#include <linux/module.h>
#include <linux/irq.h>
#include <linux/interrupt.h>
#include <linux/rtc.h>
#include <linux/slab.h>
#include <linux/workqueue.h>
#include <linux/platform_device.h>
#include <linux/power/charger-manager.h>
#include <linux/regulator/consumer.h>
#include <linux/sysfs.h>
#include <linux/of.h>
#include <linux/thermal.h>

/*
 * Default temperature threshold for charging.
 * Every temperature units are in tenth of centigrade.
 */
#define CM_DEFAULT_RECHARGE_TEMP_DIFF   50
#define CM_DEFAULT_CHARGE_TEMP_MAX      500

static const char * const default_event_names[] = {
        [CM_EVENT_UNKNOWN] = "Unknown",
        [CM_EVENT_BATT_FULL] = "Battery Full",
        [CM_EVENT_BATT_IN] = "Battery Inserted",
        [CM_EVENT_BATT_OUT] = "Battery Pulled Out",
        [CM_EVENT_BATT_OVERHEAT] = "Battery Overheat",
        [CM_EVENT_BATT_COLD] = "Battery Cold",
        [CM_EVENT_EXT_PWR_IN_OUT] = "External Power Attach/Detach",
        [CM_EVENT_CHG_START_STOP] = "Charging Start/Stop",
        [CM_EVENT_OTHERS] = "Other battery events"
};

/*
 * Regard CM_JIFFIES_SMALL jiffies is small enough to ignore for
 * delayed works so that we can run delayed works with CM_JIFFIES_SMALL
 * without any delays.
 */
#define CM_JIFFIES_SMALL        (2)

/* If y is valid (> 0) and smaller than x, do x = y */
#define CM_MIN_VALID(x, y)      x = (((y > 0) && ((x) > (y))) ? (y) : (x))

/*
 * Regard CM_RTC_SMALL (sec) is small enough to ignore error in invoking
 * rtc alarm. It should be 2 or larger
 */
#define CM_RTC_SMALL            (2)

#define UEVENT_BUF_SIZE         32

static LIST_HEAD(cm_list);
static DEFINE_MUTEX(cm_list_mtx);

/* About in-suspend (suspend-again) monitoring */
static struct alarm *cm_timer;

static bool cm_suspended;
static bool cm_timer_set;
static unsigned long cm_suspend_duration_ms;

/* About normal (not suspended) monitoring */
static unsigned long polling_jiffy = ULONG_MAX; /* ULONG_MAX: no polling */
static unsigned long next_polling; /* Next appointed polling time */
static struct workqueue_struct *cm_wq; /* init at driver add */
static struct delayed_work cm_monitor_work; /* init at driver add */

/**
 * is_batt_present - See if the battery presents in place.
 * @cm: the Charger Manager representing the battery.
 */
static bool is_batt_present(struct charger_manager *cm)
{
        union power_supply_propval val;
        struct power_supply *psy;
        bool present = false;
        int i, ret;

        switch (cm->desc->battery_present) {
        case CM_BATTERY_PRESENT:
                present = true;
                break;
        case CM_NO_BATTERY:
                break;
        case CM_FUEL_GAUGE:
                psy = power_supply_get_by_name(cm->desc->psy_fuel_gauge);
                if (!psy)
                        break;

                ret = power_supply_get_property(psy, POWER_SUPPLY_PROP_PRESENT,
                                &val);
                if (ret == 0 && val.intval)
                        present = true;
                power_supply_put(psy);
                break;
        case CM_CHARGER_STAT:
                for (i = 0; cm->desc->psy_charger_stat[i]; i++) {
                        psy = power_supply_get_by_name(
                                        cm->desc->psy_charger_stat[i]);
                        if (!psy) {
                                dev_err(cm->dev, "Cannot find power supply \"%s\"\n",
                                        cm->desc->psy_charger_stat[i]);
                                continue;
                        }

                        ret = power_supply_get_property(psy,
                                POWER_SUPPLY_PROP_PRESENT, &val);
                        power_supply_put(psy);
                        if (ret == 0 && val.intval) {
                                present = true;
                                break;
                        }
                }
                break;
        }

        return present;
}

/**
 * is_ext_pwr_online - See if an external power source is attached to charge
 * @cm: the Charger Manager representing the battery.
 *
 * Returns true if at least one of the chargers of the battery has an external
 * power source attached to charge the battery regardless of whether it is
 * actually charging or not.
 */
static bool is_ext_pwr_online(struct charger_manager *cm)
{
        union power_supply_propval val;
        struct power_supply *psy;
        bool online = false;
        int i, ret;

        /* If at least one of them has one, it's yes. */
        for (i = 0; cm->desc->psy_charger_stat[i]; i++) {
                psy = power_supply_get_by_name(cm->desc->psy_charger_stat[i]);
                if (!psy) {
                        dev_err(cm->dev, "Cannot find power supply \"%s\"\n",
                                        cm->desc->psy_charger_stat[i]);
                        continue;
                }

                ret = power_supply_get_property(psy, POWER_SUPPLY_PROP_ONLINE,
                                &val);
                power_supply_put(psy);
                if (ret == 0 && val.intval) {
                        online = true;
                        break;
                }
        }

        return online;
}

/**
 * get_batt_uV - Get the voltage level of the battery
 * @cm: the Charger Manager representing the battery.
 * @uV: the voltage level returned.
 *
 * Returns 0 if there is no error.
 * Returns a negative value on error.
 */
static int get_batt_uV(struct charger_manager *cm, int *uV)
{
        union power_supply_propval val;
        struct power_supply *fuel_gauge;
        int ret;

        fuel_gauge = power_supply_get_by_name(cm->desc->psy_fuel_gauge);
        if (!fuel_gauge)
                return -ENODEV;

        ret = power_supply_get_property(fuel_gauge,
                                POWER_SUPPLY_PROP_VOLTAGE_NOW, &val);
        power_supply_put(fuel_gauge);
        if (ret)
                return ret;

        *uV = val.intval;
        return 0;
}

/**
 * is_charging - Returns true if the battery is being charged.
 * @cm: the Charger Manager representing the battery.
 */
static bool is_charging(struct charger_manager *cm)
{
        int i, ret;
        bool charging = false;
        struct power_supply *psy;
        union power_supply_propval val;

        /* If there is no battery, it cannot be charged */
        if (!is_batt_present(cm))
                return false;

        /* If at least one of the charger is charging, return yes */
        for (i = 0; cm->desc->psy_charger_stat[i]; i++) {
                /* 1. The charger sholuld not be DISABLED */
                if (cm->emergency_stop)
                        continue;
                if (!cm->charger_enabled)
                        continue;

                psy = power_supply_get_by_name(cm->desc->psy_charger_stat[i]);
                if (!psy) {
                        dev_err(cm->dev, "Cannot find power supply \"%s\"\n",
                                        cm->desc->psy_charger_stat[i]);
                        continue;
                }

                /* 2. The charger should be online (ext-power) */
                ret = power_supply_get_property(psy, POWER_SUPPLY_PROP_ONLINE,
                                &val);
                if (ret) {
                        dev_warn(cm->dev, "Cannot read ONLINE value from %s\n",
                                 cm->desc->psy_charger_stat[i]);
                        power_supply_put(psy);
                        continue;
                }
                if (val.intval == 0) {
                        power_supply_put(psy);
                        continue;
                }

                /*
                 * 3. The charger should not be FULL, DISCHARGING,
                 * or NOT_CHARGING.
                 */
                ret = power_supply_get_property(psy, POWER_SUPPLY_PROP_STATUS,
                                &val);
                power_supply_put(psy);
                if (ret) {
                        dev_warn(cm->dev, "Cannot read STATUS value from %s\n",
                                 cm->desc->psy_charger_stat[i]);
                        continue;
                }
                if (val.intval == POWER_SUPPLY_STATUS_FULL ||
                                val.intval == POWER_SUPPLY_STATUS_DISCHARGING ||
                                val.intval == POWER_SUPPLY_STATUS_NOT_CHARGING)
                        continue;

                /* Then, this is charging. */
                charging = true;
                break;
        }

        return charging;
}

/**
 * is_full_charged - Returns true if the battery is fully charged.
 * @cm: the Charger Manager representing the battery.
 */
static bool is_full_charged(struct charger_manager *cm)
{
        struct charger_desc *desc = cm->desc;
        union power_supply_propval val;
        struct power_supply *fuel_gauge;
        bool is_full = false;
        int ret = 0;
        int uV;

        /* If there is no battery, it cannot be charged */
        if (!is_batt_present(cm))
                return false;

        fuel_gauge = power_supply_get_by_name(cm->desc->psy_fuel_gauge);
        if (!fuel_gauge)
                return false;

        if (desc->fullbatt_full_capacity > 0) {
                val.intval = 0;

                /* Not full if capacity of fuel gauge isn't full */
                ret = power_supply_get_property(fuel_gauge,
                                POWER_SUPPLY_PROP_CHARGE_FULL, &val);
                if (!ret && val.intval > desc->fullbatt_full_capacity) {
                        is_full = true;
                        goto out;
                }
        }

        /* Full, if it's over the fullbatt voltage */
        if (desc->fullbatt_uV > 0) {
                ret = get_batt_uV(cm, &uV);
                if (!ret && uV >= desc->fullbatt_uV) {
                        is_full = true;
                        goto out;
                }
        }

        /* Full, if the capacity is more than fullbatt_soc */
        if (desc->fullbatt_soc > 0) {
                val.intval = 0;

                ret = power_supply_get_property(fuel_gauge,
                                POWER_SUPPLY_PROP_CAPACITY, &val);
                if (!ret && val.intval >= desc->fullbatt_soc) {
                        is_full = true;
                        goto out;
                }
        }

out:
        power_supply_put(fuel_gauge);
        return is_full;
}

/**
 * is_polling_required - Return true if need to continue polling for this CM.
 * @cm: the Charger Manager representing the battery.
 */
static bool is_polling_required(struct charger_manager *cm)
{
        switch (cm->desc->polling_mode) {
        case CM_POLL_DISABLE:
                return false;
        case CM_POLL_ALWAYS:
                return true;
        case CM_POLL_EXTERNAL_POWER_ONLY:
                return is_ext_pwr_online(cm);
        case CM_POLL_CHARGING_ONLY:
                return is_charging(cm);
        default:
                dev_warn(cm->dev, "Incorrect polling_mode (%d)\n",
                         cm->desc->polling_mode);
        }

        return false;
}

/**
 * try_charger_enable - Enable/Disable chargers altogether
 * @cm: the Charger Manager representing the battery.
 * @enable: true: enable / false: disable
 *
 * Note that Charger Manager keeps the charger enabled regardless whether
 * the charger is charging or not (because battery is full or no external
 * power source exists) except when CM needs to disable chargers forcibly
 * because of emergency causes; when the battery is overheated or too cold.
 */
static int try_charger_enable(struct charger_manager *cm, bool enable)
{
        int err = 0, i;
        struct charger_desc *desc = cm->desc;

        /* Ignore if it's redundant command */
        if (enable == cm->charger_enabled)
                return 0;

        if (enable) {
                if (cm->emergency_stop)
                        return -EAGAIN;

                /*
                 * Save start time of charging to limit
                 * maximum possible charging time.
                 */
                cm->charging_start_time = ktime_to_ms(ktime_get());
                cm->charging_end_time = 0;

                for (i = 0 ; i < desc->num_charger_regulators ; i++) {
                        if (desc->charger_regulators[i].externally_control)
                                continue;

                        err = regulator_enable(desc->charger_regulators[i].consumer);
                        if (err < 0) {
                                dev_warn(cm->dev, "Cannot enable %s regulator\n",
                                         desc->charger_regulators[i].regulator_name);
                        }
                }
        } else {
                /*
                 * Save end time of charging to maintain fully charged state
                 * of battery after full-batt.
                 */
                cm->charging_start_time = 0;
                cm->charging_end_time = ktime_to_ms(ktime_get());

                for (i = 0 ; i < desc->num_charger_regulators ; i++) {
                        if (desc->charger_regulators[i].externally_control)
                                continue;

                        err = regulator_disable(desc->charger_regulators[i].consumer);
                        if (err < 0) {
                                dev_warn(cm->dev, "Cannot disable %s regulator\n",
                                         desc->charger_regulators[i].regulator_name);
                        }
                }

                /*
                 * Abnormal battery state - Stop charging forcibly,
                 * even if charger was enabled at the other places
                 */
                for (i = 0; i < desc->num_charger_regulators; i++) {
                        if (regulator_is_enabled(
                                    desc->charger_regulators[i].consumer)) {
                                regulator_force_disable(
                                        desc->charger_regulators[i].consumer);
                                dev_warn(cm->dev, "Disable regulator(%s) forcibly\n",
                                         desc->charger_regulators[i].regulator_name);
                        }
                }
        }

        if (!err)
                cm->charger_enabled = enable;

        return err;
}

/**
 * try_charger_restart - Restart charging.
 * @cm: the Charger Manager representing the battery.
 *
 * Restart charging by turning off and on the charger.
 */
static int try_charger_restart(struct charger_manager *cm)
{
        int err;

        if (cm->emergency_stop)
                return -EAGAIN;

        err = try_charger_enable(cm, false);
        if (err)
                return err;

        return try_charger_enable(cm, true);
}

/**
 * uevent_notify - Let users know something has changed.
 * @cm: the Charger Manager representing the battery.
 * @event: the event string.
 *
 * If @event is null, it implies that uevent_notify is called
 * by resume function. When called in the resume function, cm_suspended
 * should be already reset to false in order to let uevent_notify
 * notify the recent event during the suspend to users. While
 * suspended, uevent_notify does not notify users, but tracks
 * events so that uevent_notify can notify users later after resumed.
 */
static void uevent_notify(struct charger_manager *cm, const char *event)
{
        static char env_str[UEVENT_BUF_SIZE + 1] = "";
        static char env_str_save[UEVENT_BUF_SIZE + 1] = "";

        if (cm_suspended) {
                /* Nothing in suspended-event buffer */
                if (env_str_save[0] == 0) {
                        if (!strncmp(env_str, event, UEVENT_BUF_SIZE))
                                return; /* status not changed */
                        strncpy(env_str_save, event, UEVENT_BUF_SIZE);
                        return;
                }

                if (!strncmp(env_str_save, event, UEVENT_BUF_SIZE))
                        return; /* Duplicated. */
                strncpy(env_str_save, event, UEVENT_BUF_SIZE);
                return;
        }

        if (event == NULL) {
                /* No messages pending */
                if (!env_str_save[0])
                        return;

                strncpy(env_str, env_str_save, UEVENT_BUF_SIZE);
                kobject_uevent(&cm->dev->kobj, KOBJ_CHANGE);
                env_str_save[0] = 0;

                return;
        }

        /* status not changed */
        if (!strncmp(env_str, event, UEVENT_BUF_SIZE))
                return;

        /* save the status and notify the update */
        strncpy(env_str, event, UEVENT_BUF_SIZE);
        kobject_uevent(&cm->dev->kobj, KOBJ_CHANGE);

        dev_info(cm->dev, "%s\n", event);
}

/**
 * fullbatt_vchk - Check voltage drop some times after "FULL" event.
 * @work: the work_struct appointing the function
 *
 * If a user has designated "fullbatt_vchkdrop_ms/uV" values with
 * charger_desc, Charger Manager checks voltage drop after the battery
 * "FULL" event. It checks whether the voltage has dropped more than
 * fullbatt_vchkdrop_uV by calling this function after fullbatt_vchkrop_ms.
 */
static void fullbatt_vchk(struct work_struct *work)
{
        struct delayed_work *dwork = to_delayed_work(work);
        struct charger_manager *cm = container_of(dwork,
                        struct charger_manager, fullbatt_vchk_work);
        struct charger_desc *desc = cm->desc;
        int batt_uV, err, diff;

        /* remove the appointment for fullbatt_vchk */
        cm->fullbatt_vchk_jiffies_at = 0;

        if (!desc->fullbatt_vchkdrop_uV || !desc->fullbatt_vchkdrop_ms)
                return;

        err = get_batt_uV(cm, &batt_uV);
        if (err) {
                dev_err(cm->dev, "%s: get_batt_uV error(%d)\n", __func__, err);
                return;
        }

        diff = desc->fullbatt_uV - batt_uV;
        if (diff < 0)
                return;

        dev_info(cm->dev, "VBATT dropped %duV after full-batt\n", diff);

        if (diff > desc->fullbatt_vchkdrop_uV) {
                try_charger_restart(cm);
                uevent_notify(cm, "Recharging");
        }
}

/**
 * check_charging_duration - Monitor charging/discharging duration
 * @cm: the Charger Manager representing the battery.
 *
 * If whole charging duration exceed 'charging_max_duration_ms',
 * cm stop charging to prevent overcharge/overheat. If discharging
 * duration exceed 'discharging _max_duration_ms', charger cable is
 * attached, after full-batt, cm start charging to maintain fully
 * charged state for battery.
 */
static int check_charging_duration(struct charger_manager *cm)
{
        struct charger_desc *desc = cm->desc;
        u64 curr = ktime_to_ms(ktime_get());
        u64 duration;
        int ret = false;

        if (!desc->charging_max_duration_ms &&
                        !desc->discharging_max_duration_ms)
                return ret;

        if (cm->charger_enabled) {
                duration = curr - cm->charging_start_time;

                if (duration > desc->charging_max_duration_ms) {
                        dev_info(cm->dev, "Charging duration exceed %ums\n",
                                 desc->charging_max_duration_ms);
                        uevent_notify(cm, "Discharging");
                        try_charger_enable(cm, false);
                        ret = true;
                }
        } else if (is_ext_pwr_online(cm) && !cm->charger_enabled) {
                duration = curr - cm->charging_end_time;

                if (duration > desc->discharging_max_duration_ms &&
                                is_ext_pwr_online(cm)) {
                        dev_info(cm->dev, "Discharging duration exceed %ums\n",
                                 desc->discharging_max_duration_ms);
                        uevent_notify(cm, "Recharging");
                        try_charger_enable(cm, true);
                        ret = true;
                }
        }

        return ret;
}

static int cm_get_battery_temperature_by_psy(struct charger_manager *cm,
                                        int *temp)
{
        struct power_supply *fuel_gauge;
        int ret;

        fuel_gauge = power_supply_get_by_name(cm->desc->psy_fuel_gauge);
        if (!fuel_gauge)
                return -ENODEV;

        ret = power_supply_get_property(fuel_gauge,
                                POWER_SUPPLY_PROP_TEMP,
                                (union power_supply_propval *)temp);
        power_supply_put(fuel_gauge);

        return ret;
}

static int cm_get_battery_temperature(struct charger_manager *cm,
                                        int *temp)
{
        int ret;

        if (!cm->desc->measure_battery_temp)
                return -ENODEV;

#ifdef CONFIG_THERMAL
        if (cm->tzd_batt) {
                ret = thermal_zone_get_temp(cm->tzd_batt, temp);
                if (!ret)
                        /* Calibrate temperature unit */
                        *temp /= 100;
        } else
#endif
        {
                /* if-else continued from CONFIG_THERMAL */
                ret = cm_get_battery_temperature_by_psy(cm, temp);
        }

        return ret;
}

static int cm_check_thermal_status(struct charger_manager *cm)
{
        struct charger_desc *desc = cm->desc;
        int temp, upper_limit, lower_limit;
        int ret = 0;

        ret = cm_get_battery_temperature(cm, &temp);
        if (ret) {
                /* FIXME:
                 * No information of battery temperature might
                 * occur hazardous result. We have to handle it
                 * depending on battery type.
                 */
                dev_err(cm->dev, "Failed to get battery temperature\n");
                return 0;
        }

        upper_limit = desc->temp_max;
        lower_limit = desc->temp_min;

        if (cm->emergency_stop) {
                upper_limit -= desc->temp_diff;
                lower_limit += desc->temp_diff;
        }

        if (temp > upper_limit)
                ret = CM_EVENT_BATT_OVERHEAT;
        else if (temp < lower_limit)
                ret = CM_EVENT_BATT_COLD;

        return ret;
}

/**
 * _cm_monitor - Monitor the temperature and return true for exceptions.
 * @cm: the Charger Manager representing the battery.
 *
 * Returns true if there is an event to notify for the battery.
 * (True if the status of "emergency_stop" changes)
 */
static bool _cm_monitor(struct charger_manager *cm)
{
        int temp_alrt;

        temp_alrt = cm_check_thermal_status(cm);

        /* It has been stopped already */
        if (temp_alrt && cm->emergency_stop)
                return false;

        /*
         * Check temperature whether overheat or cold.
         * If temperature is out of range normal state, stop charging.
         */
        if (temp_alrt) {
                cm->emergency_stop = temp_alrt;
                if (!try_charger_enable(cm, false))
                        uevent_notify(cm, default_event_names[temp_alrt]);

        /*
         * Check whole charging duration and discharging duration
         * after full-batt.
         */
        } else if (!cm->emergency_stop && check_charging_duration(cm)) {
                dev_dbg(cm->dev,
                        "Charging/Discharging duration is out of range\n");
        /*
         * Check dropped voltage of battery. If battery voltage is more
         * dropped than fullbatt_vchkdrop_uV after fully charged state,
         * charger-manager have to recharge battery.
         */
        } else if (!cm->emergency_stop && is_ext_pwr_online(cm) &&
                        !cm->charger_enabled) {
                fullbatt_vchk(&cm->fullbatt_vchk_work.work);

        /*
         * Check whether fully charged state to protect overcharge
         * if charger-manager is charging for battery.
         */
        } else if (!cm->emergency_stop && is_full_charged(cm) &&
                        cm->charger_enabled) {
                dev_info(cm->dev, "EVENT_HANDLE: Battery Fully Charged\n");
                uevent_notify(cm, default_event_names[CM_EVENT_BATT_FULL]);

                try_charger_enable(cm, false);

                fullbatt_vchk(&cm->fullbatt_vchk_work.work);
        } else {
                cm->emergency_stop = 0;
                if (is_ext_pwr_online(cm)) {
                        if (!try_charger_enable(cm, true))
                                uevent_notify(cm, "CHARGING");
                }
        }

        return true;
}

/**
 * cm_monitor - Monitor every battery.
 *
 * Returns true if there is an event to notify from any of the batteries.
 * (True if the status of "emergency_stop" changes)
 */
static bool cm_monitor(void)
{
        bool stop = false;
        struct charger_manager *cm;

        mutex_lock(&cm_list_mtx);

        list_for_each_entry(cm, &cm_list, entry) {
                if (_cm_monitor(cm))
                        stop = true;
        }

        mutex_unlock(&cm_list_mtx);

        return stop;
}

/**
 * _setup_polling - Setup the next instance of polling.
 * @work: work_struct of the function _setup_polling.
 */
static void _setup_polling(struct work_struct *work)
{
        unsigned long min = ULONG_MAX;
        struct charger_manager *cm;
        bool keep_polling = false;
        unsigned long _next_polling;

        mutex_lock(&cm_list_mtx);

        list_for_each_entry(cm, &cm_list, entry) {
                if (is_polling_required(cm) && cm->desc->polling_interval_ms) {
                        keep_polling = true;

                        if (min > cm->desc->polling_interval_ms)
                                min = cm->desc->polling_interval_ms;
                }
        }

        polling_jiffy = msecs_to_jiffies(min);
        if (polling_jiffy <= CM_JIFFIES_SMALL)
                polling_jiffy = CM_JIFFIES_SMALL + 1;

        if (!keep_polling)
                polling_jiffy = ULONG_MAX;
        if (polling_jiffy == ULONG_MAX)
                goto out;

        WARN(cm_wq == NULL, "charger-manager: workqueue not initialized"
                            ". try it later. %s\n", __func__);

        /*
         * Use mod_delayed_work() iff the next polling interval should
         * occur before the currently scheduled one.  If @cm_monitor_work
         * isn't active, the end result is the same, so no need to worry
         * about stale @next_polling.
         */
        _next_polling = jiffies + polling_jiffy;

        if (time_before(_next_polling, next_polling)) {
                mod_delayed_work(cm_wq, &cm_monitor_work, polling_jiffy);
                next_polling = _next_polling;
        } else {
                if (queue_delayed_work(cm_wq, &cm_monitor_work, polling_jiffy))
                        next_polling = _next_polling;
        }
out:
        mutex_unlock(&cm_list_mtx);
}
static DECLARE_WORK(setup_polling, _setup_polling);

/**
 * cm_monitor_poller - The Monitor / Poller.
 * @work: work_struct of the function cm_monitor_poller
 *
 * During non-suspended state, cm_monitor_poller is used to poll and monitor
 * the batteries.
 */
static void cm_monitor_poller(struct work_struct *work)
{
        cm_monitor();
        schedule_work(&setup_polling);
}

/**
 * fullbatt_handler - Event handler for CM_EVENT_BATT_FULL
 * @cm: the Charger Manager representing the battery.
 */
static void fullbatt_handler(struct charger_manager *cm)
{
        struct charger_desc *desc = cm->desc;

        if (!desc->fullbatt_vchkdrop_uV || !desc->fullbatt_vchkdrop_ms)
                goto out;

        if (cm_suspended)
                device_set_wakeup_capable(cm->dev, true);

        mod_delayed_work(cm_wq, &cm->fullbatt_vchk_work,
                         msecs_to_jiffies(desc->fullbatt_vchkdrop_ms));
        cm->fullbatt_vchk_jiffies_at = jiffies + msecs_to_jiffies(
                                       desc->fullbatt_vchkdrop_ms);

        if (cm->fullbatt_vchk_jiffies_at == 0)
                cm->fullbatt_vchk_jiffies_at = 1;

out:
        dev_info(cm->dev, "EVENT_HANDLE: Battery Fully Charged\n");
        uevent_notify(cm, default_event_names[CM_EVENT_BATT_FULL]);
}

/**
 * battout_handler - Event handler for CM_EVENT_BATT_OUT
 * @cm: the Charger Manager representing the battery.
 */
static void battout_handler(struct charger_manager *cm)
{
        if (cm_suspended)
                device_set_wakeup_capable(cm->dev, true);

        if (!is_batt_present(cm)) {
                dev_emerg(cm->dev, "Battery Pulled Out!\n");
                uevent_notify(cm, default_event_names[CM_EVENT_BATT_OUT]);
        } else {
                uevent_notify(cm, "Battery Reinserted?");
        }
}

/**
 * misc_event_handler - Handler for other events
 * @cm: the Charger Manager representing the battery.
 * @type: the Charger Manager representing the battery.
 */
static void misc_event_handler(struct charger_manager *cm,
                        enum cm_event_types type)
{
        if (cm_suspended)
                device_set_wakeup_capable(cm->dev, true);

        if (is_polling_required(cm) && cm->desc->polling_interval_ms)
                schedule_work(&setup_polling);
        uevent_notify(cm, default_event_names[type]);
}

static int charger_get_property(struct power_supply *psy,
                enum power_supply_property psp,
                union power_supply_propval *val)
{
        struct charger_manager *cm = power_supply_get_drvdata(psy);
        struct charger_desc *desc = cm->desc;
        struct power_supply *fuel_gauge = NULL;
        int ret = 0;
        int uV;

        switch (psp) {
        case POWER_SUPPLY_PROP_STATUS:
                if (is_charging(cm))
                        val->intval = POWER_SUPPLY_STATUS_CHARGING;
                else if (is_ext_pwr_online(cm))
                        val->intval = POWER_SUPPLY_STATUS_NOT_CHARGING;
                else
                        val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
                break;
        case POWER_SUPPLY_PROP_HEALTH:
                if (cm->emergency_stop > 0)
                        val->intval = POWER_SUPPLY_HEALTH_OVERHEAT;
                else if (cm->emergency_stop < 0)
                        val->intval = POWER_SUPPLY_HEALTH_COLD;
                else
                        val->intval = POWER_SUPPLY_HEALTH_GOOD;
                break;
        case POWER_SUPPLY_PROP_PRESENT:
                if (is_batt_present(cm))
                        val->intval = 1;
                else
                        val->intval = 0;
                break;
        case POWER_SUPPLY_PROP_VOLTAGE_NOW:
                ret = get_batt_uV(cm, &val->intval);
                break;
        case POWER_SUPPLY_PROP_CURRENT_NOW:
                fuel_gauge = power_supply_get_by_name(cm->desc->psy_fuel_gauge);
                if (!fuel_gauge) {
                        ret = -ENODEV;
                        break;
                }
                ret = power_supply_get_property(fuel_gauge,
                                POWER_SUPPLY_PROP_CURRENT_NOW, val);
                break;
        case POWER_SUPPLY_PROP_TEMP:
        case POWER_SUPPLY_PROP_TEMP_AMBIENT:
                return cm_get_battery_temperature(cm, &val->intval);
        case POWER_SUPPLY_PROP_CAPACITY:
                if (!is_batt_present(cm)) {
                        /* There is no battery. Assume 100% */
                        val->intval = 100;
                        break;
                }

                fuel_gauge = power_supply_get_by_name(cm->desc->psy_fuel_gauge);
                if (!fuel_gauge) {
                        ret = -ENODEV;
                        break;
                }

                ret = power_supply_get_property(fuel_gauge,
                                        POWER_SUPPLY_PROP_CAPACITY, val);
                if (ret)
                        break;

                if (val->intval > 100) {
                        val->intval = 100;
                        break;
                }
                if (val->intval < 0)
                        val->intval = 0;

                /* Do not adjust SOC when charging: voltage is overrated */
                if (is_charging(cm))
                        break;

                /*
                 * If the capacity value is inconsistent, calibrate it base on
                 * the battery voltage values and the thresholds given as desc
                 */
                ret = get_batt_uV(cm, &uV);
                if (ret) {
                        /* Voltage information not available. No calibration */
                        ret = 0;
                        break;
                }

                if (desc->fullbatt_uV > 0 && uV >= desc->fullbatt_uV &&
                    !is_charging(cm)) {
                        val->intval = 100;
                        break;
                }

                break;
        case POWER_SUPPLY_PROP_ONLINE:
                if (is_ext_pwr_online(cm))
                        val->intval = 1;
                else
                        val->intval = 0;
                break;
        case POWER_SUPPLY_PROP_CHARGE_FULL:
                if (is_full_charged(cm))
                        val->intval = 1;
                else
                        val->intval = 0;
                ret = 0;
                break;
        case POWER_SUPPLY_PROP_CHARGE_NOW:
                if (is_charging(cm)) {
                        fuel_gauge = power_supply_get_by_name(
                                        cm->desc->psy_fuel_gauge);
                        if (!fuel_gauge) {
                                ret = -ENODEV;
                                break;
                        }

                        ret = power_supply_get_property(fuel_gauge,
                                                POWER_SUPPLY_PROP_CHARGE_NOW,

                                                val);
                        if (ret) {
                                val->intval = 1;
                                ret = 0;
                        } else {
                                /* If CHARGE_NOW is supplied, use it */
                                val->intval = (val->intval > 0) ?
                                                val->intval : 1;
                        }
                } else {
                        val->intval = 0;
                }
                break;
        default:
                return -EINVAL;
        }
        if (fuel_gauge)
                power_supply_put(fuel_gauge);
        return ret;
}

#define NUM_CHARGER_PSY_OPTIONAL        (4)
static enum power_supply_property default_charger_props[] = {
        /* Guaranteed to provide */
        POWER_SUPPLY_PROP_STATUS,
        POWER_SUPPLY_PROP_HEALTH,
        POWER_SUPPLY_PROP_PRESENT,
        POWER_SUPPLY_PROP_VOLTAGE_NOW,
        POWER_SUPPLY_PROP_CAPACITY,
        POWER_SUPPLY_PROP_ONLINE,
        POWER_SUPPLY_PROP_CHARGE_FULL,
        /*
         * Optional properties are:
         * POWER_SUPPLY_PROP_CHARGE_NOW,
         * POWER_SUPPLY_PROP_CURRENT_NOW,
         * POWER_SUPPLY_PROP_TEMP, and
         * POWER_SUPPLY_PROP_TEMP_AMBIENT,
         */
};

static const struct power_supply_desc psy_default = {
        .name = "battery",
        .type = POWER_SUPPLY_TYPE_BATTERY,
        .properties = default_charger_props,
        .num_properties = ARRAY_SIZE(default_charger_props),
        .get_property = charger_get_property,
        .no_thermal = true,
};

/**
 * cm_setup_timer - For in-suspend monitoring setup wakeup alarm
 *                  for suspend_again.
 *
 * Returns true if the alarm is set for Charger Manager to use.
 * Returns false if
 *      cm_setup_timer fails to set an alarm,
 *      cm_setup_timer does not need to set an alarm for Charger Manager,
 *      or an alarm previously configured is to be used.
 */
static bool cm_setup_timer(void)
{
        struct charger_manager *cm;
        unsigned int wakeup_ms = UINT_MAX;
        int timer_req = 0;

        if (time_after(next_polling, jiffies))
                CM_MIN_VALID(wakeup_ms,
                        jiffies_to_msecs(next_polling - jiffies));

        mutex_lock(&cm_list_mtx);
        list_for_each_entry(cm, &cm_list, entry) {
                unsigned int fbchk_ms = 0;

                /* fullbatt_vchk is required. setup timer for that */
                if (cm->fullbatt_vchk_jiffies_at) {
                        fbchk_ms = jiffies_to_msecs(cm->fullbatt_vchk_jiffies_at
                                                    - jiffies);
                        if (time_is_before_eq_jiffies(
                                cm->fullbatt_vchk_jiffies_at) ||
                                msecs_to_jiffies(fbchk_ms) < CM_JIFFIES_SMALL) {
                                fullbatt_vchk(&cm->fullbatt_vchk_work.work);
                                fbchk_ms = 0;
                        }
                }
                CM_MIN_VALID(wakeup_ms, fbchk_ms);

                /* Skip if polling is not required for this CM */
                if (!is_polling_required(cm) && !cm->emergency_stop)
                        continue;
                timer_req++;
                if (cm->desc->polling_interval_ms == 0)
                        continue;
                CM_MIN_VALID(wakeup_ms, cm->desc->polling_interval_ms);
        }
        mutex_unlock(&cm_list_mtx);

        if (timer_req && cm_timer) {
                ktime_t now, add;

                /*
                 * Set alarm with the polling interval (wakeup_ms)
                 * The alarm time should be NOW + CM_RTC_SMALL or later.
                 */
                if (wakeup_ms == UINT_MAX ||
                        wakeup_ms < CM_RTC_SMALL * MSEC_PER_SEC)
                        wakeup_ms = 2 * CM_RTC_SMALL * MSEC_PER_SEC;

                pr_info("Charger Manager wakeup timer: %u ms\n", wakeup_ms);

                now = ktime_get_boottime();
                add = ktime_set(wakeup_ms / MSEC_PER_SEC,
                                (wakeup_ms % MSEC_PER_SEC) * NSEC_PER_MSEC);
                alarm_start(cm_timer, ktime_add(now, add));

                cm_suspend_duration_ms = wakeup_ms;

                return true;
        }
        return false;
}

/**
 * charger_extcon_work - enable/diable charger according to the state
 *                      of charger cable
 *
 * @work: work_struct of the function charger_extcon_work.
 */
static void charger_extcon_work(struct work_struct *work)
{
        struct charger_cable *cable =
                        container_of(work, struct charger_cable, wq);
        int ret;

        if (cable->attached && cable->min_uA != 0 && cable->max_uA != 0) {
                ret = regulator_set_current_limit(cable->charger->consumer,
                                        cable->min_uA, cable->max_uA);
                if (ret < 0) {
                        pr_err("Cannot set current limit of %s (%s)\n",
                               cable->charger->regulator_name, cable->name);
                        return;
                }

                pr_info("Set current limit of %s : %duA ~ %duA\n",
                        cable->charger->regulator_name,
                        cable->min_uA, cable->max_uA);
        }

        try_charger_enable(cable->cm, cable->attached);
}

/**
 * charger_extcon_notifier - receive the state of charger cable
 *                      when registered cable is attached or detached.
 *
 * @self: the notifier block of the charger_extcon_notifier.
 * @event: the cable state.
 * @ptr: the data pointer of notifier block.
 */
static int charger_extcon_notifier(struct notifier_block *self,
                        unsigned long event, void *ptr)
{
        struct charger_cable *cable =
                container_of(self, struct charger_cable, nb);

        /*
         * The newly state of charger cable.
         * If cable is attached, cable->attached is true.
         */
        cable->attached = event;

        /*
         * Setup monitoring to check battery state
         * when charger cable is attached.
         */
        if (cable->attached && is_polling_required(cable->cm)) {
                cancel_work_sync(&setup_polling);
                schedule_work(&setup_polling);
        }

        /*
         * Setup work for controlling charger(regulator)
         * according to charger cable.
         */
        schedule_work(&cable->wq);

        return NOTIFY_DONE;
}

/**
 * charger_extcon_init - register external connector to use it
 *                      as the charger cable
 *
 * @cm: the Charger Manager representing the battery.
 * @cable: the Charger cable representing the external connector.
 */
static int charger_extcon_init(struct charger_manager *cm,
                struct charger_cable *cable)
{
        int ret;

        /*
         * Charger manager use Extcon framework to identify
         * the charger cable among various external connector
         * cable (e.g., TA, USB, MHL, Dock).
         */
        INIT_WORK(&cable->wq, charger_extcon_work);
        cable->nb.notifier_call = charger_extcon_notifier;
        ret = extcon_register_interest(&cable->extcon_dev,
                        cable->extcon_name, cable->name, &cable->nb);
        if (ret < 0) {
                pr_info("Cannot register extcon_dev for %s(cable: %s)\n",
                        cable->extcon_name, cable->name);
        }

        return ret;
}

/**
 * charger_manager_register_extcon - Register extcon device to receive state
 *                                   of charger cable.
 * @cm: the Charger Manager representing the battery.
 *
 * This function support EXTCON(External Connector) subsystem to detect the
 * state of charger cables for enabling or disabling charger(regulator) and
 * select the charger cable for charging among a number of external cable
 * according to policy of H/W board.
 */
static int charger_manager_register_extcon(struct charger_manager *cm)
{
        struct charger_desc *desc = cm->desc;
        struct charger_regulator *charger;
        int ret;
        int i;
        int j;

        for (i = 0; i < desc->num_charger_regulators; i++) {
                charger = &desc->charger_regulators[i];

                charger->consumer = regulator_get(cm->dev,
                                        charger->regulator_name);
                if (IS_ERR(charger->consumer)) {
                        dev_err(cm->dev, "Cannot find charger(%s)\n",
                                charger->regulator_name);
                        return PTR_ERR(charger->consumer);
                }
                charger->cm = cm;

                for (j = 0; j < charger->num_cables; j++) {
                        struct charger_cable *cable = &charger->cables[j];

                        ret = charger_extcon_init(cm, cable);
                        if (ret < 0) {
                                dev_err(cm->dev, "Cannot initialize charger(%s)\n",
                                        charger->regulator_name);
                                return ret;
                        }
                        cable->charger = charger;
                        cable->cm = cm;
                }
        }

        return 0;
}

/* help function of sysfs node to control charger(regulator) */
static ssize_t charger_name_show(struct device *dev,
                                struct device_attribute *attr, char *buf)
{
        struct charger_regulator *charger
                = container_of(attr, struct charger_regulator, attr_name);

        return sprintf(buf, "%s\n", charger->regulator_name);
}

static ssize_t charger_state_show(struct device *dev,
                                struct device_attribute *attr, char *buf)
{
        struct charger_regulator *charger
                = container_of(attr, struct charger_regulator, attr_state);
        int state = 0;

        if (!charger->externally_control)
                state = regulator_is_enabled(charger->consumer);

        return sprintf(buf, "%s\n", state ? "enabled" : "disabled");
}

static ssize_t charger_externally_control_show(struct device *dev,
                                struct device_attribute *attr, char *buf)
{
        struct charger_regulator *charger = container_of(attr,
                        struct charger_regulator, attr_externally_control);

        return sprintf(buf, "%d\n", charger->externally_control);
}

static ssize_t charger_externally_control_store(struct device *dev,
                                struct device_attribute *attr, const char *buf,
                                size_t count)
{
        struct charger_regulator *charger
                = container_of(attr, struct charger_regulator,
                                        attr_externally_control);
        struct charger_manager *cm = charger->cm;
        struct charger_desc *desc = cm->desc;
        int i;
        int ret;
        int externally_control;
        int chargers_externally_control = 1;

        ret = sscanf(buf, "%d", &externally_control);
        if (ret == 0) {
                ret = -EINVAL;
                return ret;
        }

        if (!externally_control) {
                charger->externally_control = 0;
                return count;
        }

        for (i = 0; i < desc->num_charger_regulators; i++) {
                if (&desc->charger_regulators[i] != charger &&
                        !desc->charger_regulators[i].externally_control) {
                        /*
                         * At least, one charger is controlled by
                         * charger-manager
                         */
                        chargers_externally_control = 0;
                        break;
                }
        }

        if (!chargers_externally_control) {
                if (cm->charger_enabled) {
                        try_charger_enable(charger->cm, false);
                        charger->externally_control = externally_control;
                        try_charger_enable(charger->cm, true);
                } else {
                        charger->externally_control = externally_control;
                }
        } else {
                dev_warn(cm->dev,
                         "'%s' regulator should be controlled in charger-manager because charger-manager must need at least one charger for charging\n",
                         charger->regulator_name);
        }

        return count;
}

/**
 * charger_manager_prepare_sysfs - Prepare sysfs entry for each charger
 * @cm: the Charger Manager representing the battery.
 *
 * This function add sysfs entry for charger(regulator) to control charger from
 * user-space. If some development board use one more chargers for charging
 * but only need one charger on specific case which is dependent on user
 * scenario or hardware restrictions, the user enter 1 or 0(zero) to '/sys/
 * class/power_supply/battery/charger.[index]/externally_control'. For example,
 * if user enter 1 to 'sys/class/power_supply/battery/charger.[index]/
 * externally_control, this charger isn't controlled from charger-manager and
 * always stay off state of regulator.
 */
static int charger_manager_prepare_sysfs(struct charger_manager *cm)
{
        struct charger_desc *desc = cm->desc;
        struct charger_regulator *charger;
        int chargers_externally_control = 1;
        char *name;
        int i;

        /* Create sysfs entry to control charger(regulator) */
        for (i = 0; i < desc->num_charger_regulators; i++) {
                charger = &desc->charger_regulators[i];

                name = devm_kasprintf(cm->dev, GFP_KERNEL, "charger.%d", i);
                if (!name)
                        return -ENOMEM;

                charger->attrs[0] = &charger->attr_name.attr;
                charger->attrs[1] = &charger->attr_state.attr;
                charger->attrs[2] = &charger->attr_externally_control.attr;
                charger->attrs[3] = NULL;

                charger->attr_grp.name = name;
                charger->attr_grp.attrs = charger->attrs;
                desc->sysfs_groups[i] = &charger->attr_grp;

                sysfs_attr_init(&charger->attr_name.attr);
                charger->attr_name.attr.name = "name";
                charger->attr_name.attr.mode = 0444;
                charger->attr_name.show = charger_name_show;

                sysfs_attr_init(&charger->attr_state.attr);
                charger->attr_state.attr.name = "state";
                charger->attr_state.attr.mode = 0444;
                charger->attr_state.show = charger_state_show;

                sysfs_attr_init(&charger->attr_externally_control.attr);
                charger->attr_externally_control.attr.name
                                = "externally_control";
                charger->attr_externally_control.attr.mode = 0644;
                charger->attr_externally_control.show
                                = charger_externally_control_show;
                charger->attr_externally_control.store
                                = charger_externally_control_store;

                if (!desc->charger_regulators[i].externally_control ||
                                !chargers_externally_control)
                        chargers_externally_control = 0;

                dev_info(cm->dev, "'%s' regulator's externally_control is %d\n",
                         charger->regulator_name, charger->externally_control);
        }

        if (chargers_externally_control) {
                dev_err(cm->dev, "Cannot register regulator because charger-manager must need at least one charger for charging battery\n");
                return -EINVAL;
        }

        return 0;
}

static int cm_init_thermal_data(struct charger_manager *cm,
                struct power_supply *fuel_gauge)
{
        struct charger_desc *desc = cm->desc;
        union power_supply_propval val;
        int ret;

        /* Verify whether fuel gauge provides battery temperature */
        ret = power_supply_get_property(fuel_gauge,
                                        POWER_SUPPLY_PROP_TEMP, &val);

        if (!ret) {
                cm->charger_psy_desc.properties[cm->charger_psy_desc.num_properties] =
                                POWER_SUPPLY_PROP_TEMP;
                cm->charger_psy_desc.num_properties++;
                cm->desc->measure_battery_temp = true;
        }
#ifdef CONFIG_THERMAL
        if (ret && desc->thermal_zone) {
                cm->tzd_batt =
                        thermal_zone_get_zone_by_name(desc->thermal_zone);
                if (IS_ERR(cm->tzd_batt))
                        return PTR_ERR(cm->tzd_batt);

                /* Use external thermometer */
                cm->charger_psy_desc.properties[cm->charger_psy_desc.num_properties] =
                                POWER_SUPPLY_PROP_TEMP_AMBIENT;
                cm->charger_psy_desc.num_properties++;
                cm->desc->measure_battery_temp = true;
                ret = 0;
        }
#endif
        if (cm->desc->measure_battery_temp) {
                /* NOTICE : Default allowable minimum charge temperature is 0 */
                if (!desc->temp_max)
                        desc->temp_max = CM_DEFAULT_CHARGE_TEMP_MAX;
                if (!desc->temp_diff)
                        desc->temp_diff = CM_DEFAULT_RECHARGE_TEMP_DIFF;
        }

        return ret;
}

static const struct of_device_id charger_manager_match[] = {
        {
                .compatible = "charger-manager",
        },
        {},
};

static struct charger_desc *of_cm_parse_desc(struct device *dev)
{
        struct charger_desc *desc;
        struct device_node *np = dev->of_node;
        u32 poll_mode = CM_POLL_DISABLE;
        u32 battery_stat = CM_NO_BATTERY;
        int num_chgs = 0;

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

        of_property_read_string(np, "cm-name", &desc->psy_name);

        of_property_read_u32(np, "cm-poll-mode", &poll_mode);
        desc->polling_mode = poll_mode;

        of_property_read_u32(np, "cm-poll-interval",
                                &desc->polling_interval_ms);

        of_property_read_u32(np, "cm-fullbatt-vchkdrop-ms",
                                        &desc->fullbatt_vchkdrop_ms);
        of_property_read_u32(np, "cm-fullbatt-vchkdrop-volt",
                                        &desc->fullbatt_vchkdrop_uV);
        of_property_read_u32(np, "cm-fullbatt-voltage", &desc->fullbatt_uV);
        of_property_read_u32(np, "cm-fullbatt-soc", &desc->fullbatt_soc);
        of_property_read_u32(np, "cm-fullbatt-capacity",
                                        &desc->fullbatt_full_capacity);

        of_property_read_u32(np, "cm-battery-stat", &battery_stat);
        desc->battery_present = battery_stat;

        /* chargers */
        of_property_read_u32(np, "cm-num-chargers", &num_chgs);
        if (num_chgs) {
                int i;

                /* Allocate empty bin at the tail of array */
                desc->psy_charger_stat = devm_kcalloc(dev,
                                                      num_chgs + 1,
                                                      sizeof(char *),
                                                      GFP_KERNEL);
                if (!desc->psy_charger_stat)
                        return ERR_PTR(-ENOMEM);

                for (i = 0; i < num_chgs; i++)
                        of_property_read_string_index(np, "cm-chargers",
                                                      i, &desc->psy_charger_stat[i]);
        }

        of_property_read_string(np, "cm-fuel-gauge", &desc->psy_fuel_gauge);

        of_property_read_string(np, "cm-thermal-zone", &desc->thermal_zone);

        of_property_read_u32(np, "cm-battery-cold", &desc->temp_min);
        if (of_get_property(np, "cm-battery-cold-in-minus", NULL))
                desc->temp_min *= -1;
        of_property_read_u32(np, "cm-battery-hot", &desc->temp_max);
        of_property_read_u32(np, "cm-battery-temp-diff", &desc->temp_diff);

        of_property_read_u32(np, "cm-charging-max",
                                &desc->charging_max_duration_ms);
        of_property_read_u32(np, "cm-discharging-max",
                                &desc->discharging_max_duration_ms);

        /* battery charger regulators */
        desc->num_charger_regulators = of_get_child_count(np);
        if (desc->num_charger_regulators) {
                struct charger_regulator *chg_regs;
                struct device_node *child;

                chg_regs = devm_kcalloc(dev,
                                        desc->num_charger_regulators,
                                        sizeof(*chg_regs),
                                        GFP_KERNEL);
                if (!chg_regs)
                        return ERR_PTR(-ENOMEM);

                desc->charger_regulators = chg_regs;

                desc->sysfs_groups = devm_kcalloc(dev,
                                        desc->num_charger_regulators + 1,
                                        sizeof(*desc->sysfs_groups),
                                        GFP_KERNEL);
                if (!desc->sysfs_groups)
                        return ERR_PTR(-ENOMEM);

                for_each_child_of_node(np, child) {
                        struct charger_cable *cables;
                        struct device_node *_child;

                        of_property_read_string(child, "cm-regulator-name",
                                        &chg_regs->regulator_name);

                        /* charger cables */
                        chg_regs->num_cables = of_get_child_count(child);
                        if (chg_regs->num_cables) {
                                cables = devm_kcalloc(dev,
                                                      chg_regs->num_cables,
                                                      sizeof(*cables),
                                                      GFP_KERNEL);
                                if (!cables) {
                                        of_node_put(child);
                                        return ERR_PTR(-ENOMEM);
                                }

                                chg_regs->cables = cables;

                                for_each_child_of_node(child, _child) {
                                        of_property_read_string(_child,
                                        "cm-cable-name", &cables->name);
                                        of_property_read_string(_child,
                                        "cm-cable-extcon",
                                        &cables->extcon_name);
                                        of_property_read_u32(_child,
                                        "cm-cable-min",
                                        &cables->min_uA);
                                        of_property_read_u32(_child,
                                        "cm-cable-max",
                                        &cables->max_uA);
                                        cables++;
                                }
                        }
                        chg_regs++;
                }
        }
        return desc;
}

static inline struct charger_desc *cm_get_drv_data(struct platform_device *pdev)
{
        if (pdev->dev.of_node)
                return of_cm_parse_desc(&pdev->dev);
        return dev_get_platdata(&pdev->dev);
}

static enum alarmtimer_restart cm_timer_func(struct alarm *alarm, ktime_t now)
{
        cm_timer_set = false;
        return ALARMTIMER_NORESTART;
}

static int charger_manager_probe(struct platform_device *pdev)
{
        struct charger_desc *desc = cm_get_drv_data(pdev);
        struct charger_manager *cm;
        int ret, i = 0;
        int j = 0;
        union power_supply_propval val;
        struct power_supply *fuel_gauge;
        struct power_supply_config psy_cfg = {};

        if (IS_ERR(desc)) {
                dev_err(&pdev->dev, "No platform data (desc) found\n");
                return PTR_ERR(desc);
        }

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

        /* Basic Values. Unspecified are Null or 0 */
        cm->dev = &pdev->dev;
        cm->desc = desc;
        psy_cfg.drv_data = cm;

        /* Initialize alarm timer */
        if (alarmtimer_get_rtcdev()) {
                cm_timer = devm_kzalloc(cm->dev, sizeof(*cm_timer), GFP_KERNEL);
                if (!cm_timer)
                        return -ENOMEM;
                alarm_init(cm_timer, ALARM_BOOTTIME, cm_timer_func);
        }

        /*
         * Some of the following do not need to be errors.
         * Users may intentionally ignore those features.
         */
        if (desc->fullbatt_uV == 0) {
                dev_info(&pdev->dev, "Ignoring full-battery voltage threshold as it is not supplied\n");
        }
        if (!desc->fullbatt_vchkdrop_ms || !desc->fullbatt_vchkdrop_uV) {
                dev_info(&pdev->dev, "Disabling full-battery voltage drop checking mechanism as it is not supplied\n");
                desc->fullbatt_vchkdrop_ms = 0;
                desc->fullbatt_vchkdrop_uV = 0;
        }
        if (desc->fullbatt_soc == 0) {
                dev_info(&pdev->dev, "Ignoring full-battery soc(state of charge) threshold as it is not supplied\n");
        }
        if (desc->fullbatt_full_capacity == 0) {
                dev_info(&pdev->dev, "Ignoring full-battery full capacity threshold as it is not supplied\n");
        }

        if (!desc->charger_regulators || desc->num_charger_regulators < 1) {
                dev_err(&pdev->dev, "charger_regulators undefined\n");
                return -EINVAL;
        }

        if (!desc->psy_charger_stat || !desc->psy_charger_stat[0]) {
                dev_err(&pdev->dev, "No power supply defined\n");
                return -EINVAL;
        }

        if (!desc->psy_fuel_gauge) {
                dev_err(&pdev->dev, "No fuel gauge power supply defined\n");
                return -EINVAL;
        }

        /* Check if charger's supplies are present at probe */
        for (i = 0; desc->psy_charger_stat[i]; i++) {
                struct power_supply *psy;

                psy = power_supply_get_by_name(desc->psy_charger_stat[i]);
                if (!psy) {
                        dev_err(&pdev->dev, "Cannot find power supply \"%s\"\n",
                                desc->psy_charger_stat[i]);
                        return -ENODEV;
                }
                power_supply_put(psy);
        }

        if (cm->desc->polling_mode != CM_POLL_DISABLE &&
            (desc->polling_interval_ms == 0 ||
             msecs_to_jiffies(desc->polling_interval_ms) <= CM_JIFFIES_SMALL)) {
                dev_err(&pdev->dev, "polling_interval_ms is too small\n");
                return -EINVAL;
        }

        if (!desc->charging_max_duration_ms ||
                        !desc->discharging_max_duration_ms) {
                dev_info(&pdev->dev, "Cannot limit charging duration checking mechanism to prevent overcharge/overheat and control discharging duration\n");
                desc->charging_max_duration_ms = 0;
                desc->discharging_max_duration_ms = 0;
        }

        platform_set_drvdata(pdev, cm);

        memcpy(&cm->charger_psy_desc, &psy_default, sizeof(psy_default));

        if (!desc->psy_name)
                strncpy(cm->psy_name_buf, psy_default.name, PSY_NAME_MAX);
        else
                strncpy(cm->psy_name_buf, desc->psy_name, PSY_NAME_MAX);
        cm->charger_psy_desc.name = cm->psy_name_buf;

        /* Allocate for psy properties because they may vary */
        cm->charger_psy_desc.properties =
                devm_kcalloc(&pdev->dev,
                             ARRAY_SIZE(default_charger_props) +
                                NUM_CHARGER_PSY_OPTIONAL,
                             sizeof(enum power_supply_property), GFP_KERNEL);
        if (!cm->charger_psy_desc.properties)
                return -ENOMEM;

        memcpy(cm->charger_psy_desc.properties, default_charger_props,
                sizeof(enum power_supply_property) *
                ARRAY_SIZE(default_charger_props));
        cm->charger_psy_desc.num_properties = psy_default.num_properties;

        /* Find which optional psy-properties are available */
        fuel_gauge = power_supply_get_by_name(desc->psy_fuel_gauge);
        if (!fuel_gauge) {
                dev_err(&pdev->dev, "Cannot find power supply \"%s\"\n",
                        desc->psy_fuel_gauge);
                return -ENODEV;
        }
        if (!power_supply_get_property(fuel_gauge,
                                          POWER_SUPPLY_PROP_CHARGE_NOW, &val)) {
                cm->charger_psy_desc.properties[cm->charger_psy_desc.num_properties] =
                                POWER_SUPPLY_PROP_CHARGE_NOW;
                cm->charger_psy_desc.num_properties++;
        }
        if (!power_supply_get_property(fuel_gauge,
                                          POWER_SUPPLY_PROP_CURRENT_NOW,
                                          &val)) {
                cm->charger_psy_desc.properties[cm->charger_psy_desc.num_properties] =
                                POWER_SUPPLY_PROP_CURRENT_NOW;
                cm->charger_psy_desc.num_properties++;
        }

        ret = cm_init_thermal_data(cm, fuel_gauge);
        if (ret) {
                dev_err(&pdev->dev, "Failed to initialize thermal data\n");
                cm->desc->measure_battery_temp = false;
        }
        power_supply_put(fuel_gauge);

        INIT_DELAYED_WORK(&cm->fullbatt_vchk_work, fullbatt_vchk);

        /* Register sysfs entry for charger(regulator) */
        ret = charger_manager_prepare_sysfs(cm);
        if (ret < 0) {
                dev_err(&pdev->dev,
                        "Cannot prepare sysfs entry of regulators\n");
                return ret;
        }
        psy_cfg.attr_grp = desc->sysfs_groups;

        cm->charger_psy = power_supply_register(&pdev->dev,
                                                &cm->charger_psy_desc,
                                                &psy_cfg);
        if (IS_ERR(cm->charger_psy)) {
                dev_err(&pdev->dev, "Cannot register charger-manager with name \"%s\"\n",
                        cm->charger_psy_desc.name);
                return PTR_ERR(cm->charger_psy);
        }

        /* Register extcon device for charger cable */
        ret = charger_manager_register_extcon(cm);
        if (ret < 0) {
                dev_err(&pdev->dev, "Cannot initialize extcon device\n");
                goto err_reg_extcon;
        }

        /* Add to the list */
        mutex_lock(&cm_list_mtx);
        list_add(&cm->entry, &cm_list);
        mutex_unlock(&cm_list_mtx);

        /*
         * Charger-manager is capable of waking up the systme from sleep
         * when event is happened through cm_notify_event()
         */
        device_init_wakeup(&pdev->dev, true);
        device_set_wakeup_capable(&pdev->dev, false);

        /*
         * Charger-manager have to check the charging state right after
         * initialization of charger-manager and then update current charging
         * state.
         */
        cm_monitor();

        schedule_work(&setup_polling);

        return 0;

err_reg_extcon:
        for (i = 0; i < desc->num_charger_regulators; i++) {
                struct charger_regulator *charger;

                charger = &desc->charger_regulators[i];
                for (j = 0; j < charger->num_cables; j++) {
                        struct charger_cable *cable = &charger->cables[j];
                        /* Remove notifier block if only edev exists */
                        if (cable->extcon_dev.edev)
                                extcon_unregister_interest(&cable->extcon_dev);
                }

                regulator_put(desc->charger_regulators[i].consumer);
        }

        power_supply_unregister(cm->charger_psy);

        return ret;
}

static int charger_manager_remove(struct platform_device *pdev)
{
        struct charger_manager *cm = platform_get_drvdata(pdev);
        struct charger_desc *desc = cm->desc;
        int i = 0;
        int j = 0;

        /* Remove from the list */
        mutex_lock(&cm_list_mtx);
        list_del(&cm->entry);
        mutex_unlock(&cm_list_mtx);

        cancel_work_sync(&setup_polling);
        cancel_delayed_work_sync(&cm_monitor_work);

        for (i = 0 ; i < desc->num_charger_regulators ; i++) {
                struct charger_regulator *charger
                                = &desc->charger_regulators[i];
                for (j = 0 ; j < charger->num_cables ; j++) {
                        struct charger_cable *cable = &charger->cables[j];
                        extcon_unregister_interest(&cable->extcon_dev);
                }
        }

        for (i = 0 ; i < desc->num_charger_regulators ; i++)
                regulator_put(desc->charger_regulators[i].consumer);

        power_supply_unregister(cm->charger_psy);

        try_charger_enable(cm, false);

        return 0;
}

static const struct platform_device_id charger_manager_id[] = {
        { "charger-manager", 0 },
        { },
};
MODULE_DEVICE_TABLE(platform, charger_manager_id);

static int cm_suspend_noirq(struct device *dev)
{
        if (device_may_wakeup(dev)) {
                device_set_wakeup_capable(dev, false);
                return -EAGAIN;
        }

        return 0;
}

static bool cm_need_to_awake(void)
{
        struct charger_manager *cm;

        if (cm_timer)
                return false;

        mutex_lock(&cm_list_mtx);
        list_for_each_entry(cm, &cm_list, entry) {
                if (is_charging(cm)) {
                        mutex_unlock(&cm_list_mtx);
                        return true;
                }
        }
        mutex_unlock(&cm_list_mtx);

        return false;
}

static int cm_suspend_prepare(struct device *dev)
{
        struct charger_manager *cm = dev_get_drvdata(dev);

        if (cm_need_to_awake())
                return -EBUSY;

        if (!cm_suspended)
                cm_suspended = true;

        cm_timer_set = cm_setup_timer();

        if (cm_timer_set) {
                cancel_work_sync(&setup_polling);
                cancel_delayed_work_sync(&cm_monitor_work);
                cancel_delayed_work(&cm->fullbatt_vchk_work);
        }

        return 0;
}

static void cm_suspend_complete(struct device *dev)
{
        struct charger_manager *cm = dev_get_drvdata(dev);

        if (cm_suspended)
                cm_suspended = false;

        if (cm_timer_set) {
                ktime_t remain;

                alarm_cancel(cm_timer);
                cm_timer_set = false;
                remain = alarm_expires_remaining(cm_timer);
                cm_suspend_duration_ms -= ktime_to_ms(remain);
                schedule_work(&setup_polling);
        }

        _cm_monitor(cm);

        /* Re-enqueue delayed work (fullbatt_vchk_work) */
        if (cm->fullbatt_vchk_jiffies_at) {
                unsigned long delay = 0;
                unsigned long now = jiffies + CM_JIFFIES_SMALL;

                if (time_after_eq(now, cm->fullbatt_vchk_jiffies_at)) {
                        delay = (unsigned long)((long)now
                                - (long)(cm->fullbatt_vchk_jiffies_at));
                        delay = jiffies_to_msecs(delay);
                } else {
                        delay = 0;
                }

                /*
                 * Account for cm_suspend_duration_ms with assuming that
                 * timer stops in suspend.
                 */
                if (delay > cm_suspend_duration_ms)
                        delay -= cm_suspend_duration_ms;
                else
                        delay = 0;

                queue_delayed_work(cm_wq, &cm->fullbatt_vchk_work,
                                   msecs_to_jiffies(delay));
        }
        device_set_wakeup_capable(cm->dev, false);
}

static const struct dev_pm_ops charger_manager_pm = {
        .prepare        = cm_suspend_prepare,
        .suspend_noirq  = cm_suspend_noirq,
        .complete       = cm_suspend_complete,
};

static struct platform_driver charger_manager_driver = {
        .driver = {
                .name = "charger-manager",
                .pm = &charger_manager_pm,
                .of_match_table = charger_manager_match,
        },
        .probe = charger_manager_probe,
        .remove = charger_manager_remove,
        .id_table = charger_manager_id,
};

static int __init charger_manager_init(void)
{
        cm_wq = create_freezable_workqueue("charger_manager");
        if (unlikely(!cm_wq))
                return -ENOMEM;

        INIT_DELAYED_WORK(&cm_monitor_work, cm_monitor_poller);

        return platform_driver_register(&charger_manager_driver);
}
late_initcall(charger_manager_init);

static void __exit charger_manager_cleanup(void)
{
        destroy_workqueue(cm_wq);
        cm_wq = NULL;

        platform_driver_unregister(&charger_manager_driver);
}
module_exit(charger_manager_cleanup);

/**
 * cm_notify_event - charger driver notify Charger Manager of charger event
 * @psy: pointer to instance of charger's power_supply
 * @type: type of charger event
 * @msg: optional message passed to uevent_notify function
 */
void cm_notify_event(struct power_supply *psy, enum cm_event_types type,
                     char *msg)
{
        struct charger_manager *cm;
        bool found_power_supply = false;

        if (psy == NULL)
                return;

        mutex_lock(&cm_list_mtx);
        list_for_each_entry(cm, &cm_list, entry) {
                if (match_string(cm->desc->psy_charger_stat, -1,
                                 psy->desc->name) >= 0) {
                        found_power_supply = true;
                        break;
                }
        }
        mutex_unlock(&cm_list_mtx);

        if (!found_power_supply)
                return;

        switch (type) {
        case CM_EVENT_BATT_FULL:
                fullbatt_handler(cm);
                break;
        case CM_EVENT_BATT_OUT:
                battout_handler(cm);
                break;
        case CM_EVENT_BATT_IN:
        case CM_EVENT_EXT_PWR_IN_OUT ... CM_EVENT_CHG_START_STOP:
                misc_event_handler(cm, type);
                break;
        case CM_EVENT_UNKNOWN:
        case CM_EVENT_OTHERS:
                uevent_notify(cm, msg ? msg : default_event_names[type]);
                break;
        default:
                dev_err(cm->dev, "%s: type not specified\n", __func__);
                break;
        }
}
EXPORT_SYMBOL_GPL(cm_notify_event);

MODULE_AUTHOR("MyungJoo Ham <myungjoo.ham@samsung.com>");
MODULE_DESCRIPTION("Charger Manager");
MODULE_LICENSE("GPL");