/*
 * 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.
**/

#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>

/*
 * 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 rtc_device *rtc_dev;
/*
 * Backup RTC alarm
 * Save the wakeup alarm before entering suspend-to-RAM
 */
static struct rtc_wkalrm rtc_wkalarm_save;
/* Backup RTC alarm time in terms of seconds since 01-01-1970 00:00:00 */
static unsigned long rtc_wkalarm_save_time;
static bool cm_suspended;
static bool cm_rtc_set;
static unsigned long cm_suspend_duration_ms;

/* Global charger-manager description */
static struct charger_global_desc *g_desc; /* init with setup_charger_manager */

/**
 * 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;
        bool present = false;
        int i, ret;

        switch (cm->desc->battery_present) {
        case CM_FUEL_GAUGE:
                ret = cm->fuel_gauge->get_property(cm->fuel_gauge,
                                POWER_SUPPLY_PROP_PRESENT, &val);
                if (ret == 0 && val.intval)
                        present = true;
                break;
        case CM_CHARGER_STAT:
                for (i = 0; cm->charger_stat[i]; i++) {
                        ret = cm->charger_stat[i]->get_property(
                                        cm->charger_stat[i],
                                        POWER_SUPPLY_PROP_PRESENT, &val);
                        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;
        bool online = false;
        int i, ret;

        /* If at least one of them has one, it's yes. */
        for (i = 0; cm->charger_stat[i]; i++) {
                ret = cm->charger_stat[i]->get_property(
                                cm->charger_stat[i],
                                POWER_SUPPLY_PROP_ONLINE, &val);
                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;
        int ret;

        if (cm->fuel_gauge)
                ret = cm->fuel_gauge->get_property(cm->fuel_gauge,
                                POWER_SUPPLY_PROP_VOLTAGE_NOW, &val);
        else
                return -ENODEV;

        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;
        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->charger_stat[i]; i++) {
                /* 1. The charger sholuld not be DISABLED */
                if (cm->emergency_stop)
                        continue;
                if (!cm->charger_enabled)
                        continue;

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

                /*
                 * 3. The charger should not be FULL, DISCHARGING,
                 * or NOT_CHARGING.
                 */
                ret = cm->charger_stat[i]->get_property(
                                cm->charger_stat[i],
                                POWER_SUPPLY_PROP_STATUS, &val);
                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_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
 * 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 && !cm->charger_enabled)
                return 0;

        if (enable) {
                if (cm->emergency_stop)
                        return -EAGAIN;
                err = regulator_bulk_enable(desc->num_charger_regulators,
                                        desc->charger_regulators);
        } else {
                /*
                 * Abnormal battery state - Stop charging forcibly,
                 * even if charger was enabled at the other places
                 */
                err = regulator_bulk_disable(desc->num_charger_regulators,
                                        desc->charger_regulators);

                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].supply);
                        }
                }
        }

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

        return err;
}

/**
 * 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. */
                else
                        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, event);
}

/**
 * _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)
{
        struct charger_desc *desc = cm->desc;
        int temp = desc->temperature_out_of_range(&cm->last_temp_mC);

        dev_dbg(cm->dev, "monitoring (%2.2d.%3.3dC)\n",
                cm->last_temp_mC / 1000, cm->last_temp_mC % 1000);

        /* It has been stopped or charging already */
        if (!!temp == !!cm->emergency_stop)
                return false;

        if (temp) {
                cm->emergency_stop = temp;
                if (!try_charger_enable(cm, false)) {
                        if (temp > 0)
                                uevent_notify(cm, "OVERHEAT");
                        else
                                uevent_notify(cm, "COLD");
                }
        } else {
                cm->emergency_stop = 0;
                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)
                stop = stop || _cm_monitor(cm);

        mutex_unlock(&cm_list_mtx);

        return stop;
}

static int charger_get_property(struct power_supply *psy,
                enum power_supply_property psp,
                union power_supply_propval *val)
{
        struct charger_manager *cm = container_of(psy,
                        struct charger_manager, charger_psy);
        struct charger_desc *desc = cm->desc;
        int i, ret = 0, 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, &i);
                val->intval = i;
                break;
        case POWER_SUPPLY_PROP_CURRENT_NOW:
                ret = cm->fuel_gauge->get_property(cm->fuel_gauge,
                                POWER_SUPPLY_PROP_CURRENT_NOW, val);
                break;
        case POWER_SUPPLY_PROP_TEMP:
                /* in thenth of centigrade */
                if (cm->last_temp_mC == INT_MIN)
                        desc->temperature_out_of_range(&cm->last_temp_mC);
                val->intval = cm->last_temp_mC / 100;
                if (!desc->measure_battery_temp)
                        ret = -ENODEV;
                break;
        case POWER_SUPPLY_PROP_TEMP_AMBIENT:
                /* in thenth of centigrade */
                if (cm->last_temp_mC == INT_MIN)
                        desc->temperature_out_of_range(&cm->last_temp_mC);
                val->intval = cm->last_temp_mC / 100;
                if (desc->measure_battery_temp)
                        ret = -ENODEV;
                break;
        case POWER_SUPPLY_PROP_CAPACITY:
                if (!cm->fuel_gauge) {
                        ret = -ENODEV;
                        break;
                }

                if (!is_batt_present(cm)) {
                        /* There is no battery. Assume 100% */
                        val->intval = 100;
                        break;
                }

                ret = cm->fuel_gauge->get_property(cm->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 (cm->fuel_gauge) {
                        if (cm->fuel_gauge->get_property(cm->fuel_gauge,
                            POWER_SUPPLY_PROP_CHARGE_FULL, val) == 0)
                                break;
                }

                if (is_ext_pwr_online(cm)) {
                        /* Not full if it's charging. */
                        if (is_charging(cm)) {
                                val->intval = 0;
                                break;
                        }
                        /*
                         * Full if it's powered but not charging andi
                         * not forced stop by emergency
                         */
                        if (!cm->emergency_stop) {
                                val->intval = 1;
                                break;
                        }
                }

                /* Full if it's over the fullbatt voltage */
                ret = get_batt_uV(cm, &uV);
                if (!ret && desc->fullbatt_uV > 0 && uV >= desc->fullbatt_uV &&
                    !is_charging(cm)) {
                        val->intval = 1;
                        break;
                }

                /* Full if the cap is 100 */
                if (cm->fuel_gauge) {
                        ret = cm->fuel_gauge->get_property(cm->fuel_gauge,
                                        POWER_SUPPLY_PROP_CAPACITY, val);
                        if (!ret && val->intval >= 100 && !is_charging(cm)) {
                                val->intval = 1;
                                break;
                        }
                }

                val->intval = 0;
                ret = 0;
                break;
        case POWER_SUPPLY_PROP_CHARGE_NOW:
                if (is_charging(cm)) {
                        ret = cm->fuel_gauge->get_property(cm->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;
        }
        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 struct power_supply 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,
};

/**
 * 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;
        bool ret = false;

        mutex_lock(&cm_list_mtx);

        list_for_each_entry(cm, &cm_list, entry) {
                /* Skip if polling is not required for this CM */
                if (!is_polling_required(cm) && !cm->emergency_stop)
                        continue;
                if (cm->desc->polling_interval_ms == 0)
                        continue;
                CM_MIN_VALID(wakeup_ms, cm->desc->polling_interval_ms);
        }

        mutex_unlock(&cm_list_mtx);

        if (wakeup_ms < UINT_MAX && wakeup_ms > 0) {
                pr_info("Charger Manager wakeup timer: %u ms.\n", wakeup_ms);
                if (rtc_dev) {
                        struct rtc_wkalrm tmp;
                        unsigned long time, now;
                        unsigned long add = DIV_ROUND_UP(wakeup_ms, 1000);

                        /*
                         * Set alarm with the polling interval (wakeup_ms)
                         * except when rtc_wkalarm_save comes first.
                         * However, the alarm time should be NOW +
                         * CM_RTC_SMALL or later.
                         */
                        tmp.enabled = 1;
                        rtc_read_time(rtc_dev, &tmp.time);
                        rtc_tm_to_time(&tmp.time, &now);
                        if (add < CM_RTC_SMALL)
                                add = CM_RTC_SMALL;
                        time = now + add;

                        ret = true;

                        if (rtc_wkalarm_save.enabled &&
                            rtc_wkalarm_save_time &&
                            rtc_wkalarm_save_time < time) {
                                if (rtc_wkalarm_save_time < now + CM_RTC_SMALL)
                                        time = now + CM_RTC_SMALL;
                                else
                                        time = rtc_wkalarm_save_time;

                                /* The timer is not appointed by CM */
                                ret = false;
                        }

                        pr_info("Waking up after %lu secs.\n",
                                        time - now);

                        rtc_time_to_tm(time, &tmp.time);
                        rtc_set_alarm(rtc_dev, &tmp);
                        cm_suspend_duration_ms += wakeup_ms;
                        return ret;
                }
        }

        if (rtc_dev)
                rtc_set_alarm(rtc_dev, &rtc_wkalarm_save);
        return false;
}

/**
 * cm_suspend_again - Determine whether suspend again or not
 *
 * Returns true if the system should be suspended again
 * Returns false if the system should be woken up
 */
bool cm_suspend_again(void)
{
        struct charger_manager *cm;
        bool ret = false;

        if (!g_desc || !g_desc->rtc_only_wakeup || !g_desc->rtc_only_wakeup() ||
            !cm_rtc_set)
                return false;

        if (cm_monitor())
                goto out;

        ret = true;
        mutex_lock(&cm_list_mtx);
        list_for_each_entry(cm, &cm_list, entry) {
                if (cm->status_save_ext_pwr_inserted != is_ext_pwr_online(cm) ||
                    cm->status_save_batt != is_batt_present(cm))
                        ret = false;
        }
        mutex_unlock(&cm_list_mtx);

        cm_rtc_set = cm_setup_timer();
out:
        /* It's about the time when the non-CM appointed timer goes off */
        if (rtc_wkalarm_save.enabled) {
                unsigned long now;
                struct rtc_time tmp;

                rtc_read_time(rtc_dev, &tmp);
                rtc_tm_to_time(&tmp, &now);

                if (rtc_wkalarm_save_time &&
                    now + CM_RTC_SMALL >= rtc_wkalarm_save_time)
                        return false;
        }
        return ret;
}
EXPORT_SYMBOL_GPL(cm_suspend_again);

/**
 * setup_charger_manager - initialize charger_global_desc data
 * @gd: pointer to instance of charger_global_desc
 */
int setup_charger_manager(struct charger_global_desc *gd)
{
        if (!gd)
                return -EINVAL;

        if (rtc_dev)
                rtc_class_close(rtc_dev);
        rtc_dev = NULL;
        g_desc = NULL;

        if (!gd->rtc_only_wakeup) {
                pr_err("The callback rtc_only_wakeup is not given.\n");
                return -EINVAL;
        }

        if (gd->rtc_name) {
                rtc_dev = rtc_class_open(gd->rtc_name);
                if (IS_ERR_OR_NULL(rtc_dev)) {
                        rtc_dev = NULL;
                        /* Retry at probe. RTC may be not registered yet */
                }
        } else {
                pr_warn("No wakeup timer is given for charger manager."
                        "In-suspend monitoring won't work.\n");
        }

        g_desc = gd;
        return 0;
}
EXPORT_SYMBOL_GPL(setup_charger_manager);

static int charger_manager_probe(struct platform_device *pdev)
{
        struct charger_desc *desc = dev_get_platdata(&pdev->dev);
        struct charger_manager *cm;
        int ret = 0, i = 0;
        union power_supply_propval val;

        if (g_desc && !rtc_dev && g_desc->rtc_name) {
                rtc_dev = rtc_class_open(g_desc->rtc_name);
                if (IS_ERR_OR_NULL(rtc_dev)) {
                        rtc_dev = NULL;
                        dev_err(&pdev->dev, "Cannot get RTC %s.\n",
                                g_desc->rtc_name);
                        ret = -ENODEV;
                        goto err_alloc;
                }
        }

        if (!desc) {
                dev_err(&pdev->dev, "No platform data (desc) found.\n");
                ret = -ENODEV;
                goto err_alloc;
        }

        cm = kzalloc(sizeof(struct charger_manager), GFP_KERNEL);
        if (!cm) {
                dev_err(&pdev->dev, "Cannot allocate memory.\n");
                ret = -ENOMEM;
                goto err_alloc;
        }

        /* Basic Values. Unspecified are Null or 0 */
        cm->dev = &pdev->dev;
        cm->desc = kzalloc(sizeof(struct charger_desc), GFP_KERNEL);
        if (!cm->desc) {
                dev_err(&pdev->dev, "Cannot allocate memory.\n");
                ret = -ENOMEM;
                goto err_alloc_desc;
        }
        memcpy(cm->desc, desc, sizeof(struct charger_desc));
        cm->last_temp_mC = INT_MIN; /* denotes "unmeasured, yet" */

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

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

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

        cm->charger_stat = kzalloc(sizeof(struct power_supply *) * (i + 1),
                                   GFP_KERNEL);
        if (!cm->charger_stat) {
                ret = -ENOMEM;
                goto err_no_charger_stat;
        }

        for (i = 0; desc->psy_charger_stat[i]; i++) {
                cm->charger_stat[i] = power_supply_get_by_name(
                                        desc->psy_charger_stat[i]);
                if (!cm->charger_stat[i]) {
                        dev_err(&pdev->dev, "Cannot find power supply "
                                        "\"%s\"\n",
                                        desc->psy_charger_stat[i]);
                        ret = -ENODEV;
                        goto err_chg_stat;
                }
        }

        cm->fuel_gauge = power_supply_get_by_name(desc->psy_fuel_gauge);
        if (!cm->fuel_gauge) {
                dev_err(&pdev->dev, "Cannot find power supply \"%s\"\n",
                                desc->psy_fuel_gauge);
                ret = -ENODEV;
                goto err_chg_stat;
        }

        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\n");
                ret = -EINVAL;
                goto err_chg_stat;
        }

        if (!desc->temperature_out_of_range) {
                dev_err(&pdev->dev, "there is no temperature_out_of_range\n");
                ret = -EINVAL;
                goto err_chg_stat;
        }

        platform_set_drvdata(pdev, cm);

        memcpy(&cm->charger_psy, &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.name = cm->psy_name_buf;

        /* Allocate for psy properties because they may vary */
        cm->charger_psy.properties = kzalloc(sizeof(enum power_supply_property)
                                * (ARRAY_SIZE(default_charger_props) +
                                NUM_CHARGER_PSY_OPTIONAL),
                                GFP_KERNEL);
        if (!cm->charger_psy.properties) {
                dev_err(&pdev->dev, "Cannot allocate for psy properties.\n");
                ret = -ENOMEM;
                goto err_chg_stat;
        }
        memcpy(cm->charger_psy.properties, default_charger_props,
                sizeof(enum power_supply_property) *
                ARRAY_SIZE(default_charger_props));
        cm->charger_psy.num_properties = psy_default.num_properties;

        /* Find which optional psy-properties are available */
        if (!cm->fuel_gauge->get_property(cm->fuel_gauge,
                                          POWER_SUPPLY_PROP_CHARGE_NOW, &val)) {
                cm->charger_psy.properties[cm->charger_psy.num_properties] =
                                POWER_SUPPLY_PROP_CHARGE_NOW;
                cm->charger_psy.num_properties++;
        }
        if (!cm->fuel_gauge->get_property(cm->fuel_gauge,
                                          POWER_SUPPLY_PROP_CURRENT_NOW,
                                          &val)) {
                cm->charger_psy.properties[cm->charger_psy.num_properties] =
                                POWER_SUPPLY_PROP_CURRENT_NOW;
                cm->charger_psy.num_properties++;
        }
        if (!desc->measure_battery_temp) {
                cm->charger_psy.properties[cm->charger_psy.num_properties] =
                                POWER_SUPPLY_PROP_TEMP_AMBIENT;
                cm->charger_psy.num_properties++;
        }
        if (desc->measure_battery_temp) {
                cm->charger_psy.properties[cm->charger_psy.num_properties] =
                                POWER_SUPPLY_PROP_TEMP;
                cm->charger_psy.num_properties++;
        }

        ret = power_supply_register(NULL, &cm->charger_psy);
        if (ret) {
                dev_err(&pdev->dev, "Cannot register charger-manager with"
                                " name \"%s\".\n", cm->charger_psy.name);
                goto err_register;
        }

        ret = regulator_bulk_get(&pdev->dev, desc->num_charger_regulators,
                                 desc->charger_regulators);
        if (ret) {
                dev_err(&pdev->dev, "Cannot get charger regulators.\n");
                goto err_bulk_get;
        }

        ret = try_charger_enable(cm, true);
        if (ret) {
                dev_err(&pdev->dev, "Cannot enable charger regulators\n");
                goto err_chg_enable;
        }

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

        return 0;

err_chg_enable:
        if (desc->charger_regulators)
                regulator_bulk_free(desc->num_charger_regulators,
                                        desc->charger_regulators);
err_bulk_get:
        power_supply_unregister(&cm->charger_psy);
err_register:
        kfree(cm->charger_psy.properties);
err_chg_stat:
        kfree(cm->charger_stat);
err_no_charger_stat:
err_no_charger:
        kfree(cm->desc);
err_alloc_desc:
        kfree(cm);
err_alloc:
        return ret;
}

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

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

        if (desc->charger_regulators)
                regulator_bulk_free(desc->num_charger_regulators,
                                        desc->charger_regulators);

        power_supply_unregister(&cm->charger_psy);
        kfree(cm->charger_psy.properties);
        kfree(cm->charger_stat);
        kfree(cm->desc);
        kfree(cm);

        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_prepare(struct device *dev)
{
        struct platform_device *pdev = container_of(dev, struct platform_device,
                                                    dev);
        struct charger_manager *cm = platform_get_drvdata(pdev);

        if (!cm_suspended) {
                if (rtc_dev) {
                        struct rtc_time tmp;
                        unsigned long now;

                        rtc_read_alarm(rtc_dev, &rtc_wkalarm_save);
                        rtc_read_time(rtc_dev, &tmp);

                        if (rtc_wkalarm_save.enabled) {
                                rtc_tm_to_time(&rtc_wkalarm_save.time,
                                               &rtc_wkalarm_save_time);
                                rtc_tm_to_time(&tmp, &now);

                                if (now > rtc_wkalarm_save_time)
                                        rtc_wkalarm_save_time = 0;
                        } else {
                                rtc_wkalarm_save_time = 0;
                        }
                }
                cm_suspended = true;
        }

        cm->status_save_ext_pwr_inserted = is_ext_pwr_online(cm);
        cm->status_save_batt = is_batt_present(cm);

        if (!cm_rtc_set) {
                cm_suspend_duration_ms = 0;
                cm_rtc_set = cm_setup_timer();
        }

        return 0;
}

static void cm_suspend_complete(struct device *dev)
{
        struct platform_device *pdev = container_of(dev, struct platform_device,
                                                    dev);
        struct charger_manager *cm = platform_get_drvdata(pdev);

        if (cm_suspended) {
                if (rtc_dev) {
                        struct rtc_wkalrm tmp;

                        rtc_read_alarm(rtc_dev, &tmp);
                        rtc_wkalarm_save.pending = tmp.pending;
                        rtc_set_alarm(rtc_dev, &rtc_wkalarm_save);
                }
                cm_suspended = false;
                cm_rtc_set = false;
        }

        uevent_notify(cm, NULL);
}

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

static struct platform_driver charger_manager_driver = {
        .driver = {
                .name = "charger-manager",
                .owner = THIS_MODULE,
                .pm = &charger_manager_pm,
        },
        .probe = charger_manager_probe,
        .remove = __devexit_p(charger_manager_remove),
        .id_table = charger_manager_id,
};

static int __init charger_manager_init(void)
{
        return platform_driver_register(&charger_manager_driver);
}
late_initcall(charger_manager_init);

static void __exit charger_manager_cleanup(void)
{
        platform_driver_unregister(&charger_manager_driver);
}
module_exit(charger_manager_cleanup);

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