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    Subject[PATCH v2 1/2] power: Charger-Manager: add initial Charger-Manager driver
    Date
    Because battery health monitoring should be done even when suspended,
    it needs to wake up and suspend periodically. Thus, userspace battery
    monitoring may incur too much overhead; every device and task is woken
    up periodically. Charger Manager uses suspend-again to provide
    in-suspend monitoring.

    This patch allows to monitor battery health in-suspend state.

    Signed-off-by: Donggeun Kim <dg77.kim@samsung.com>
    Signed-off-by: MyungJoo Ham <myungjoo.ham@samsung.com>
    Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
    ---
    Documentation/power/charger-manager.txt | 150 ++++++
    drivers/power/Kconfig | 9 +
    drivers/power/Makefile | 1 +
    drivers/power/charger-manager.c | 771 +++++++++++++++++++++++++++++++
    include/linux/power/charger-manager.h | 131 ++++++
    5 files changed, 1062 insertions(+), 0 deletions(-)
    create mode 100644 Documentation/power/charger-manager.txt
    create mode 100644 drivers/power/charger-manager.c
    create mode 100644 include/linux/power/charger-manager.h

    diff --git a/Documentation/power/charger-manager.txt b/Documentation/power/charger-manager.txt
    new file mode 100644
    index 0000000..99630e5
    --- /dev/null
    +++ b/Documentation/power/charger-manager.txt
    @@ -0,0 +1,150 @@
    +Charger Manager
    + (C) 2011 MyungJoo Ham <myungjoo.ham@samsung.com>, GPL
    +
    +Charger Manager provides in-kernel battery charger management that
    +requires temperature monitoring during suspend-to-RAM state
    +and where each battery may have multiple chargers attached and the userland
    +wants to look at the aggregated information of the multiple chargers.
    +
    +Charger Manager is a platform_driver with power-supply-class entries.
    +An instance of Charger Manager (a platform-device created with Charger-Manager)
    +represents an independent battery with chargers. If there are multiple
    +batteries with their own chargers acting independently in a system,
    +the system may need multiple instances of Charger Manager.
    +
    +1. Introduction
    +===============
    +
    +Charger Manager supports the following:
    +
    +* Support for multiple chargers (e.g., a device with USB, AC, and solar panels)
    + A system may have multiple chargers (or power sources) and some of
    + they may be activated at the same time. Each charger may have its
    + own power-supply-class and each power-supply-class can provide
    + different information about the battery status. This framework
    + aggregates charger-related information from multiple sources and
    + shows combined information as a single power-supply-class.
    +
    +* Support for in suspend-to-RAM polling (with suspend_again callback)
    + While the battery is being charged and the system is in suspend-to-RAM,
    + we may need to monitor the battery health by looking at the ambient or
    + battery temperature. We can accomplish this by waking up the system
    + periodically. However, such a method wakes up devices unncessary for
    + monitoring the battery health and tasks, and user processes that are
    + supposed to be kept suspended. That, in turn, incurs unnecessary power
    + consumption and slow down charging process. Or even, such peak power
    + consumption can stop chargers in the middle of charging
    + (external power input < device power consumption), which not
    + only affects the charging time, but the lifespan of the battery.
    +
    + Charger Manager provides a function "cm_suspend_again" that can be
    + used as suspend_again callback of platform_suspend_ops. If the platform
    + requires tasks other than cm_suspend_again, it may implement its own
    + suspend_again callback that calls cm_suspend_again in the middle.
    + Normally, the platform will need to resume and suspend some devices
    + that are used by Charger Manager.
    +
    +2. Global Charger-Manager Data related with suspend_again
    +========================================================
    +In order to setup Charger Manager with suspend-again feature
    +(in-suspend monitoring), the user should provide charger_global_desc
    +with setup_charger_manager(struct charger_global_desc *).
    +This charger_global_desc data for in-suspend monitoring is global
    +as the name suggests. Thus, the user needs to provide only once even
    +if there are multiple batteries. If there are multiple batteries, the
    +multiple instances of Charger Manager share the same charger_global_desc
    +and it will manage in-suspend monitoring for all instances of Charger Manager.
    +
    +The user needs to provide all the three entries properly in order to activate
    +in-suspend monitoring:
    +
    +struct charger_global_desc {
    +
    +char *rtc;
    + : The name of rtc (e.g., "rtc0") used to wakeup the system from
    + suspend for Charger Manager. The alarm interrupt (AIE) of the rtc
    + should be able to wake up the system from suspend. Charger Manager
    + saves and restores the alarm value and use the previously-defined
    + alarm if it is going to go off earlier than Charger Manager so that
    + Charger Manager does not interfere with previously-defined alarms.
    +
    +bool (*is_rtc_only_wakeup_reason)(void);
    + : This callback should let CM know whether
    + the wakeup-from-suspend is caused only by the alarm of "rtc" in the
    + same struct. If there is any other wakeup source triggered the
    + wakeup, it should return false. If the "rtc" is the only wakeup
    + reason, it should return true.
    +};
    +
    +3. How to setup suspend_again
    +=============================
    +Charger Manager provides a function "extern bool cm_suspend_again(void)".
    +When cm_suspend_again is called, it monitors every battery. The suspend_ops
    +callback of the system's platform_suspend_ops can call cm_suspend_again
    +function to know whether Charger Manager wants to suspend again or not.
    +If there are no other devices or tasks that want to use suspend_again
    +feature, the platform_suspend_ops may directly refer to cm_suspend_again
    +for its suspend_again callback.
    +
    +The cm_suspend_again() returns true (meaning "I want to suspend again")
    +if the system was woken up by Charger Manager and the polling
    +(in-suspend monitoring) results in "normal".
    +
    +4. Charger-Manager Data (struct charger_desc)
    +=============================================
    +For each battery charged independently from other batteries (if a series of
    +batteries are charged by a single charger, they are counted as one independent
    +battery), an instance of Charger Manager is attached to it.
    +
    +struct charger_desc {
    +
    +enum polling_modes polling_mode;
    + : CM_POLL_DISABLE: do not poll this battery.
    + CM_POLL_ALWAYS: always poll this battery.
    + CM_POLL_EXTERNAL_POWER_ONLY: poll this battery if and only if
    + an external power source is attached.
    + CM_POLL_CHARGING_ONLY: poll this battery if and only if the
    + battery is being charged.
    +
    +unsigned int polling_interval_ms;
    + : Required polling interval in ms. Charger Manager will poll
    + this battery every polling_interval_ms or more frequently.
    +
    +enum data_source battery_present;
    + CM_FUEL_GAUGE: get battery presence information from fuel gauge.
    + CM_CHARGER_STAT: get battery presence from chargers.
    +
    +char **psy_charger_stat;
    + : An array ending with NULL that has power-supply-class names of
    + chargers. Each power-supply-class should provide "PRESENT" (if
    + battery_present is "CM_CHARGER_STAT"), "ONLINE" (shows whether an
    + external power source is attached or not), and "STATUS" (shows whether
    + the battery is {"FULL" or not FULL} or {"FULL", "Charging",
    + "Discharging", "NotCharging"}).
    +
    +int num_charger_regulators;
    +struct regulator_bulk_data *charger_regulators;
    + : Regulators representing the chargers in the form for
    + regulator framework's bulk functions.
    +
    +char *psy_fuel_gauge;
    + : Power-supply-class name of the fuel gauge.
    +
    +int (*is_temperature_error)(int *mC);
    + : This callback returns 0 if the temperature is safe for charging,
    + a positive number if it is too hot to charge, and a negative number
    + if it is too cold to charge. With the variable mC, the callback returns
    + the temperature in 1/1000 of centigrade.
    +};
    +
    +5. Other Considerations
    +=======================
    +
    +At the charger/battery-related events such as battery-pulled-out,
    +charger-pulled-out, charger-inserted, DCIN-over/under-voltage, charger-stopped,
    +and others critical to chargers, the system should be configured to wake up.
    +At least the following should wake up the system from a suspend:
    +a) charger-on/off b) external-power-in/out c) battery-in/out (while charging)
    +
    +It is usually accomplished by configuring the PMIC as a wakeup source.
    +
    diff --git a/drivers/power/Kconfig b/drivers/power/Kconfig
    index 9f88641..92683b5 100644
    --- a/drivers/power/Kconfig
    +++ b/drivers/power/Kconfig
    @@ -236,6 +236,15 @@ config CHARGER_GPIO
    This driver can be build as a module. If so, the module will be
    called gpio-charger.

    +config CHARGER_MANAGER
    + bool "Battery charger manager for multiple chargers"
    + help
    + Say Y to enable charger-manager support, which allows multiple
    + chargers attached to a battery and multiple batteries attached to a
    + system. The charger-manager also can monitor charging status in
    + runtime and in suspend-to-RAM by waking up the system periodically
    + with help of suspend_again support.
    +
    config CHARGER_MAX8997
    tristate "Maxim MAX8997/MAX8966 PMIC battery charger driver"
    depends on MFD_MAX8997 && REGULATOR_MAX8997
    diff --git a/drivers/power/Makefile b/drivers/power/Makefile
    index b4af13d..d3b24e9 100644
    --- a/drivers/power/Makefile
    +++ b/drivers/power/Makefile
    @@ -36,5 +36,6 @@ obj-$(CONFIG_CHARGER_ISP1704) += isp1704_charger.o
    obj-$(CONFIG_CHARGER_MAX8903) += max8903_charger.o
    obj-$(CONFIG_CHARGER_TWL4030) += twl4030_charger.o
    obj-$(CONFIG_CHARGER_GPIO) += gpio-charger.o
    +obj-$(CONFIG_CHARGER_MANAGER) += charger-manager.o
    obj-$(CONFIG_CHARGER_MAX8997) += max8997_charger.o
    obj-$(CONFIG_CHARGER_MAX8998) += max8998_charger.o
    diff --git a/drivers/power/charger-manager.c b/drivers/power/charger-manager.c
    new file mode 100644
    index 0000000..5006756
    --- /dev/null
    +++ b/drivers/power/charger-manager.c
    @@ -0,0 +1,771 @@
    +/* linux/drivers/power/charger-manager.c
    + *
    + * 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;
    +static struct rtc_wkalrm rtc_wkalarm_save; /* Backup RTC alarm */
    +static unsigned long rtc_wkalarm_save_; /* 0 if not available */
    +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;
    +}
    +
    +/**
    + * 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->is_temperature_error(&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 already */
    + if (temp && cm->emergency_stop)
    + return false;
    +
    + /* It has been 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 |= _cm_monitor(cm);
    +
    + mutex_unlock(&cm_list_mtx);
    +
    + return stop;
    +}
    +
    +/**
    + * 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_ &&
    + rtc_wkalarm_save_ < time) {
    + if (rtc_wkalarm_save_ < now + CM_RTC_SMALL)
    + time = now + CM_RTC_SMALL;
    + else
    + time = rtc_wkalarm_save_;
    +
    + /* 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)
    + return false;
    + if (!g_desc->is_rtc_only_wakeup_reason)
    + return false;
    + if (!g_desc->is_rtc_only_wakeup_reason())
    + return false;
    + if (!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_ &&
    + now + CM_RTC_SMALL >= rtc_wkalarm_save_)
    + 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->is_rtc_only_wakeup_reason) {
    + pr_err("The callback is_wktimer_only_wkreason is not given.\n");
    + return -EINVAL;
    + }
    +
    + if (gd->rtc) {
    + rtc_dev = rtc_class_open(gd->rtc);
    + if (IS_ERR_OR_NULL(rtc_dev)) {
    + rtc_dev = NULL;
    + /* Retry at probe. RTC may be not registered yet */
    + }
    + } else {
    + pr_warn("No wktimer 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;
    +
    + if (g_desc && !rtc_dev && g_desc->rtc) {
    + rtc_dev = rtc_class_open(g_desc->rtc);
    + if (IS_ERR_OR_NULL(rtc_dev)) {
    + rtc_dev = NULL;
    + dev_err(&pdev->dev, "Cannot get RTC %s.\n",
    + g_desc->rtc);
    + 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 = 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;
    + }
    +
    + 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_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;
    + }
    +
    + for (i = 0; desc->psy_charger_stat[i]; i++)
    + /* Counting index only */ ;
    +
    + 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->is_temperature_error) {
    + dev_err(&pdev->dev, "there is no is_temperature_error\n");
    + ret = -EINVAL;
    + goto err_chg_stat;
    + }
    +
    + platform_set_drvdata(pdev, cm);
    +
    + ret = try_charger_enable(cm, true);
    + if (ret) {
    + dev_err(&pdev->dev, "Cannot enable charger regulators\n");
    + goto err_chg_stat;
    + }
    +
    + /* Add to the list */
    + mutex_lock(&cm_list_mtx);
    + list_add(&cm->entry, &cm_list);
    + mutex_unlock(&cm_list_mtx);
    +
    + return 0;
    +
    +err_chg_stat:
    + kfree(cm->charger_stat);
    +err_no_charger_stat:
    + if (desc->charger_regulators)
    + regulator_bulk_free(desc->num_charger_regulators,
    + desc->charger_regulators);
    +err_no_charger:
    + 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);
    +
    + kfree(cm->charger_stat);
    + if (desc->charger_regulators)
    + regulator_bulk_free(desc->num_charger_regulators,
    + desc->charger_regulators);
    + kfree(cm);
    + return 0;
    +}
    +
    +const struct platform_device_id charger_manager_id[] = {
    + { "charger-manager", 0 },
    + { },
    +};
    +
    +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_);
    + rtc_tm_to_time(&tmp, &now);
    + if (now > rtc_wkalarm_save_)
    + rtc_wkalarm_save_ = 0;
    + } else {
    + rtc_wkalarm_save_ = 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");
    +MODULE_ALIAS("charger-manager");
    diff --git a/include/linux/power/charger-manager.h b/include/linux/power/charger-manager.h
    new file mode 100644
    index 0000000..c91e208
    --- /dev/null
    +++ b/include/linux/power/charger-manager.h
    @@ -0,0 +1,131 @@
    +/* linux/include/linux/power/charger-manager.h
    + *
    + * Copyright (C) 2011 Samsung Electronics Co., Ltd.
    + * MyungJoo.Ham <myungjoo.ham@samsung.com>
    + *
    + * Charger Manager.
    + * This framework enables to control and multiple chargers and to
    + * monitor charging even in the context of suspend-to-RAM with
    + * an interface combining the chargers.
    + *
    + * 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.
    +**/
    +
    +#ifndef _CHARGER_MANAGER_H
    +#define _CHARGER_MANAGER_H
    +
    +#include <linux/power_supply.h>
    +
    +enum data_source {
    + CM_FUEL_GAUGE,
    + CM_CHARGER_STAT,
    +};
    +
    +enum polling_modes {
    + CM_POLL_DISABLE = 0,
    + CM_POLL_ALWAYS,
    + CM_POLL_EXTERNAL_POWER_ONLY,
    + CM_POLL_CHARGING_ONLY,
    +};
    +
    +/**
    + * struct charger_global_desc
    + * @rtc: the name of RTC used to wake up the system from suspend.
    + * @is_rtc_only_wakeup_reason:
    + * If the system is woken up by waekup-sources other than the RTC or
    + * callbacks, Charger Manager should recognize with
    + * is_rtc_only_wakeup_reason() returning false.
    + * If the RTC given to CM is the only wakeup reason,
    + * is_rtc_only_wakeup_reason should return true.
    + */
    +struct charger_global_desc {
    + char *rtc;
    +
    + bool (*is_rtc_only_wakeup_reason)(void);
    +};
    +
    +/**
    + * struct charger_desc
    + * @polling_mode:
    + * Determine which polling mode will be used
    + * @polling_interval_ms: interval in millisecond at which
    + * charger manager will monitor battery health
    + * @battery_present:
    + * Specify where information for existance of battery can be obtained
    + * @psy_charger_stat: the names of power-supply for chargers
    + * @num_charger_regulator: the number of entries in charger_regulators
    + * @charger_regulators: array of regulator_bulk_data for chargers
    + * @psy_fuel_gauge: the name of power-supply for fuel gauge
    + * @is_temperature_error:
    + * Determine whether the status is overheat or cold or normal.
    + * return_value > 0: overheat
    + * return_value == 0: normal
    + * return_value < 0: cold
    + */
    +struct charger_desc {
    + enum polling_modes polling_mode;
    + unsigned int polling_interval_ms;
    +
    + enum data_source battery_present;
    +
    + char **psy_charger_stat;
    +
    + int num_charger_regulators;
    + struct regulator_bulk_data *charger_regulators;
    +
    + char *psy_fuel_gauge;
    +
    + int (*is_temperature_error)(int *mC);
    +};
    +
    +#define PSY_NAME_MAX 30
    +
    +/**
    + * struct charger_manager
    + * @entry: entry for list
    + * @dev: device pointer
    + * @desc: instance of charger_desc
    + * @fuel_gauge: power_supply for fuel gauge
    + * @charger_stat: array of power_supply for chargers
    + * @charger_enabled: the state of charger
    + * @emergency_stop:
    + * When setting true, stop charging
    + * @last_temp_mC: the measured temperature in milli-Celsius
    + * @status_save_ext_pwr_inserted:
    + * saved status of external power before entering suspend-to-RAM
    + * @status_save_batt:
    + * saved status of battery before entering suspend-to-RAM
    + */
    +struct charger_manager {
    + struct list_head entry;
    + struct device *dev;
    + struct charger_desc *desc;
    +
    + struct power_supply *fuel_gauge;
    + struct power_supply **charger_stat;
    +
    + bool charger_enabled;
    +
    + int emergency_stop;
    + int last_temp_mC;
    +
    + bool status_save_ext_pwr_inserted;
    + bool status_save_batt;
    +};
    +
    +#ifdef CONFIG_CHARGER_MANAGER
    +extern int setup_charger_manager(struct charger_global_desc *gd);
    +extern bool cm_suspend_again(void);
    +#else
    +static void __maybe_unused setup_charger_manager(struct charger_global_desc *gd)
    +{ }
    +
    +static bool __maybe_unused cm_suspend_again(void)
    +{
    + return false;
    +}
    +#endif
    +
    +#endif /* _CHARGER_MANAGER_H */
    --
    1.7.4.1


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