/*
   * 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.
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License version 2 as
   * published by the Free Software Foundation.
  **/

  #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 termperature 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\"
  ",
  					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\"
  ",
  					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\"
  ",
  					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
  ",
  				 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
  ",
  				 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)
  ",

  			 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
   * bacause 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 redundent 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
  ",
  					 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
  ",
  					 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
  ",
  					 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
  ", 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)
  ", __func__, err);

  		return;
  	}

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

  	dev_info(cm->dev, "VBATT dropped %duV after full-batt
  ", 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
  ",

  				 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->charging_max_duration_ms &&
  				is_ext_pwr_online(cm)) {

  			dev_info(cm->dev, "Discharging duration exceed %ums
  ",

  				 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 hazadous result. We have to handle it
  		 * depending on battery type.
  		 */
  		dev_err(cm->dev, "Failed to get battery temperature
  ");
  		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 discharing duration
  	 * after full-batt.
  	 */
  	} else if (!cm->emergency_stop && check_charging_duration(cm)) {
  		dev_dbg(cm->dev,

  			"Charging/Discharging duration is out of range
  ");

  	/*

  	 * 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
  ");

  		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
  ", __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
  ");

  	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!
  ");
  		uevent_notify(cm, default_event_names[CM_EVENT_BATT_OUT]);
  	} else {
  		uevent_notify(cm, "Battery Reinserted?");
  	}
  }
  
  /**
   * misc_event_handler - Handler for other evnets
   * @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
  ", 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)
  ",

  			       cable->charger->regulator_name, cable->name);

  			return;
  		}
  
  		pr_info("Set current limit of %s : %duA ~ %duA
  ",

  			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 = 0;
  
  	/*
  	 * 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)
  ",
  			cable->extcon_name, cable->name);

  		ret = -EINVAL;
  	}
  
  	return ret;
  }

  /**
   * charger_manager_register_extcon - Register extcon device to recevie 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 = 0;
  	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)
  ",
  				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)
  ",
  					charger->regulator_name);

  				goto err;
  			}
  			cable->charger = charger;
  			cable->cm = cm;
  		}
  	}
  
  err:
  	return ret;
  }

  /* 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
  ", 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
  ", 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
  ", 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
  ",
  			 charger->regulator_name);

  	}
  
  	return count;
  }

  /**
   * charger_manager_register_sysfs - Register 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_register_sysfs(struct charger_manager *cm)
  {
  	struct charger_desc *desc = cm->desc;
  	struct charger_regulator *charger;
  	int chargers_externally_control = 1;
  	char buf[11];
  	char *str;
  	int ret = 0;
  	int i;
  
  	/* Create sysfs entry to control charger(regulator) */
  	for (i = 0; i < desc->num_charger_regulators; i++) {
  		charger = &desc->charger_regulators[i];
  
  		snprintf(buf, 10, "charger.%d", i);

  		str = devm_kzalloc(cm->dev,
  				sizeof(char) * (strlen(buf) + 1), GFP_KERNEL);

  		if (!str) {

  			ret = -ENOMEM;
  			goto err;
  		}
  		strcpy(str, buf);
  
  		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_g.name = str;
  		charger->attr_g.attrs = charger->attrs;
  
  		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
  ",
  			 charger->regulator_name, charger->externally_control);

  		ret = sysfs_create_group(&cm->charger_psy->dev.kobj,

  					&charger->attr_g);
  		if (ret < 0) {

  			dev_err(cm->dev, "Cannot create sysfs entry of %s regulator
  ",
  				charger->regulator_name);

  			ret = -EINVAL;
  			goto err;
  		}
  	}
  
  	if (chargers_externally_control) {

  		dev_err(cm->dev, "Cannot register regulator because charger-manager must need at least one charger for charging battery
  ");

  		ret = -EINVAL;
  		goto err;
  	}
  
  err:
  	return ret;
  }

  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) {
  		/* Allocate empty bin at the tail of array */
  		desc->psy_charger_stat = devm_kzalloc(dev, sizeof(char *)
  						* (num_chgs + 1), GFP_KERNEL);
  		if (desc->psy_charger_stat) {
  			int i;
  			for (i = 0; i < num_chgs; i++)
  				of_property_read_string_index(np, "cm-chargers",
  						i, &desc->psy_charger_stat[i]);
  		} else {
  			return ERR_PTR(-ENOMEM);
  		}
  	}
  
  	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 regualtors */
  	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_kzalloc(dev, sizeof(*chg_regs)
  					* desc->num_charger_regulators,
  					GFP_KERNEL);
  		if (!chg_regs)
  			return ERR_PTR(-ENOMEM);
  
  		desc->charger_regulators = chg_regs;
  
  		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_kzalloc(dev, sizeof(*cables)
  						* chg_regs->num_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 = 0, 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
  ");

  		return -ENODEV;

  	}

  	cm = devm_kzalloc(&pdev->dev,
  			sizeof(struct charger_manager),	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);
  		alarm_init(cm_timer, ALARM_BOOTTIME, cm_timer_func);
  	}

  	/*
  	 * The following two do not need to be errors.
  	 * Users may intentionally ignore those two features.
  	 */
  	if (desc->fullbatt_uV == 0) {

  		dev_info(&pdev->dev, "Ignoring full-battery voltage threshold as it is not supplied
  ");

  	}
  	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
  ");

  		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
  ");

  	}
  	if (desc->fullbatt_full_capacity == 0) {

  		dev_info(&pdev->dev, "Ignoring full-battery full capacity threshold as it is not supplied
  ");

  	}

  	if (!desc->charger_regulators || desc->num_charger_regulators < 1) {

  		dev_err(&pdev->dev, "charger_regulators undefined
  ");

  		return -EINVAL;

  	}
  
  	if (!desc->psy_charger_stat || !desc->psy_charger_stat[0]) {

  		dev_err(&pdev->dev, "No power supply defined
  ");

  		return -EINVAL;

  	}

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

  	/* Counting index only */
  	while (desc->psy_charger_stat[i])
  		i++;

  	/* 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\"
  ",
  				desc->psy_charger_stat[i]);

  			return -ENODEV;

  		}

  		power_supply_put(psy);

  	}
  
  	if (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
  ");

  		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
  ");

  		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_kzalloc(&pdev->dev,

  				sizeof(enum power_supply_property)

  				* (ARRAY_SIZE(default_charger_props) +

  				NUM_CHARGER_PSY_OPTIONAL), 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\"
  ",
  			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
  ");
  		cm->desc->measure_battery_temp = false;

  	}

  	power_supply_put(fuel_gauge);

  	INIT_DELAYED_WORK(&cm->fullbatt_vchk_work, fullbatt_vchk);

  	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\"
  ",

  			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
  ");
  		goto err_reg_extcon;

  	}

  	/* Register sysfs entry for charger(regulator) */
  	ret = charger_manager_register_sysfs(cm);
  	if (ret < 0) {
  		dev_err(&pdev->dev,
  			"Cannot initialize sysfs entry of regulator
  ");
  		goto err_reg_sysfs;

  	}
  
  	/* 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 happend 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
  	 * tialization of charger-manager and then update current charging
  	 * state.
  	 */
  	cm_monitor();

  	schedule_work(&setup_polling);

  	return 0;

  err_reg_sysfs:

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

  		sysfs_remove_group(&cm->charger_psy->dev.kobj,

  				&charger->attr_g);

  	}

  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)
  {
  	int ret = 0;
  
  	if (device_may_wakeup(dev)) {
  		device_set_wakeup_capable(dev, false);
  		ret = -EAGAIN;
  	}
  
  	return ret;
  }

  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");
  	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 fuction
   */
  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
  ", __func__);

  		break;
  	}
  }
  EXPORT_SYMBOL_GPL(cm_notify_event);

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