path: root/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;
/*
 * 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-><