Initial import

1 files changed, 1329 insertions, 0 deletions

diff --git a/drivers/acpi/battery.c b/drivers/acpi/battery.c
new file mode 100644
index 000000000..63d43677f
--- /dev/null
+++ b/drivers/acpi/battery.c
@@ -0,0 +1,1329 @@
+/*
+ *  battery.c - ACPI Battery Driver (Revision: 2.0)
+ *
+ *  Copyright (C) 2007 Alexey Starikovskiy <astarikovskiy@suse.de>
+ *  Copyright (C) 2004-2007 Vladimir Lebedev <vladimir.p.lebedev@intel.com>
+ *  Copyright (C) 2001, 2002 Andy Grover <andrew.grover@intel.com>
+ *  Copyright (C) 2001, 2002 Paul Diefenbaugh <paul.s.diefenbaugh@intel.com>
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or (at
+ *  your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful, but
+ *  WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *  General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+ *
+ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/types.h>
+#include <linux/jiffies.h>
+#include <linux/async.h>
+#include <linux/dmi.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include <linux/suspend.h>
+#include <asm/unaligned.h>
+
+#ifdef CONFIG_ACPI_PROCFS_POWER
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <asm/uaccess.h>
+#endif
+
+#include <linux/acpi.h>
+#include <linux/power_supply.h>
+
+#include "battery.h"
+
+#define PREFIX "ACPI: "
+
+#define ACPI_BATTERY_VALUE_UNKNOWN 0xFFFFFFFF
+
+#define ACPI_BATTERY_DEVICE_NAME	"Battery"
+
+/* Battery power unit: 0 means mW, 1 means mA */
+#define ACPI_BATTERY_POWER_UNIT_MA	1
+
+#define ACPI_BATTERY_STATE_DISCHARGING	0x1
+#define ACPI_BATTERY_STATE_CHARGING	0x2
+#define ACPI_BATTERY_STATE_CRITICAL	0x4
+
+#define _COMPONENT		ACPI_BATTERY_COMPONENT
+
+ACPI_MODULE_NAME("battery");
+
+MODULE_AUTHOR("Paul Diefenbaugh");
+MODULE_AUTHOR("Alexey Starikovskiy <astarikovskiy@suse.de>");
+MODULE_DESCRIPTION("ACPI Battery Driver");
+MODULE_LICENSE("GPL");
+
+static int battery_bix_broken_package;
+static int battery_notification_delay_ms;
+static unsigned int cache_time = 1000;
+module_param(cache_time, uint, 0644);
+MODULE_PARM_DESC(cache_time, "cache time in milliseconds");
+
+#ifdef CONFIG_ACPI_PROCFS_POWER
+extern struct proc_dir_entry *acpi_lock_battery_dir(void);
+extern void *acpi_unlock_battery_dir(struct proc_dir_entry *acpi_battery_dir);
+
+enum acpi_battery_files {
+	info_tag = 0,
+	state_tag,
+	alarm_tag,
+	ACPI_BATTERY_NUMFILES,
+};
+
+#endif
+
+static const struct acpi_device_id battery_device_ids[] = {
+	{"PNP0C0A", 0},
+	{"", 0},
+};
+
+MODULE_DEVICE_TABLE(acpi, battery_device_ids);
+
+enum {
+	ACPI_BATTERY_ALARM_PRESENT,
+	ACPI_BATTERY_XINFO_PRESENT,
+	ACPI_BATTERY_QUIRK_PERCENTAGE_CAPACITY,
+	/* On Lenovo Thinkpad models from 2010 and 2011, the power unit
+	   switches between mWh and mAh depending on whether the system
+	   is running on battery or not.  When mAh is the unit, most
+	   reported values are incorrect and need to be adjusted by
+	   10000/design_voltage.  Verified on x201, t410, t410s, and x220.
+	   Pre-2010 and 2012 models appear to always report in mWh and
+	   are thus unaffected (tested with t42, t61, t500, x200, x300,
+	   and x230).  Also, in mid-2012 Lenovo issued a BIOS update for
+	   the 2011 models that fixes the issue (tested on x220 with a
+	   post-1.29 BIOS), but as of Nov. 2012, no such update is
+	   available for the 2010 models.  */
+	ACPI_BATTERY_QUIRK_THINKPAD_MAH,
+};
+
+struct acpi_battery {
+	struct mutex lock;
+	struct mutex sysfs_lock;
+	struct power_supply *bat;
+	struct power_supply_desc bat_desc;
+	struct acpi_device *device;
+	struct notifier_block pm_nb;
+	unsigned long update_time;
+	int revision;
+	int rate_now;
+	int capacity_now;
+	int voltage_now;
+	int design_capacity;
+	int full_charge_capacity;
+	int technology;
+	int design_voltage;
+	int design_capacity_warning;
+	int design_capacity_low;
+	int cycle_count;
+	int measurement_accuracy;
+	int max_sampling_time;
+	int min_sampling_time;
+	int max_averaging_interval;
+	int min_averaging_interval;
+	int capacity_granularity_1;
+	int capacity_granularity_2;
+	int alarm;
+	char model_number[32];
+	char serial_number[32];
+	char type[32];
+	char oem_info[32];
+	int state;
+	int power_unit;
+	unsigned long flags;
+};
+
+#define to_acpi_battery(x) power_supply_get_drvdata(x)
+
+static inline int acpi_battery_present(struct acpi_battery *battery)
+{
+	return battery->device->status.battery_present;
+}
+
+static int acpi_battery_technology(struct acpi_battery *battery)
+{
+	if (!strcasecmp("NiCd", battery->type))
+		return POWER_SUPPLY_TECHNOLOGY_NiCd;
+	if (!strcasecmp("NiMH", battery->type))
+		return POWER_SUPPLY_TECHNOLOGY_NiMH;
+	if (!strcasecmp("LION", battery->type))
+		return POWER_SUPPLY_TECHNOLOGY_LION;
+	if (!strncasecmp("LI-ION", battery->type, 6))
+		return POWER_SUPPLY_TECHNOLOGY_LION;
+	if (!strcasecmp("LiP", battery->type))
+		return POWER_SUPPLY_TECHNOLOGY_LIPO;
+	return POWER_SUPPLY_TECHNOLOGY_UNKNOWN;
+}
+
+static int acpi_battery_get_state(struct acpi_battery *battery);
+
+static int acpi_battery_is_charged(struct acpi_battery *battery)
+{
+	/* charging, discharging or critical low */
+	if (battery->state != 0)
+		return 0;
+
+	/* battery not reporting charge */
+	if (battery->capacity_now == ACPI_BATTERY_VALUE_UNKNOWN ||
+	    battery->capacity_now == 0)
+		return 0;
+
+	/* good batteries update full_charge as the batteries degrade */
+	if (battery->full_charge_capacity == battery->capacity_now)
+		return 1;
+
+	/* fallback to using design values for broken batteries */
+	if (battery->design_capacity == battery->capacity_now)
+		return 1;
+
+	/* we don't do any sort of metric based on percentages */
+	return 0;
+}
+
+static int acpi_battery_get_property(struct power_supply *psy,
+				     enum power_supply_property psp,
+				     union power_supply_propval *val)
+{
+	int ret = 0;
+	struct acpi_battery *battery = to_acpi_battery(psy);
+
+	if (acpi_battery_present(battery)) {
+		/* run battery update only if it is present */
+		acpi_battery_get_state(battery);
+	} else if (psp != POWER_SUPPLY_PROP_PRESENT)
+		return -ENODEV;
+	switch (psp) {
+	case POWER_SUPPLY_PROP_STATUS:
+		if (battery->state & ACPI_BATTERY_STATE_DISCHARGING)
+			val->intval = POWER_SUPPLY_STATUS_DISCHARGING;
+		else if (battery->state & ACPI_BATTERY_STATE_CHARGING)
+			val->intval = POWER_SUPPLY_STATUS_CHARGING;
+		else if (acpi_battery_is_charged(battery))
+			val->intval = POWER_SUPPLY_STATUS_FULL;
+		else
+			val->intval = POWER_SUPPLY_STATUS_UNKNOWN;
+		break;
+	case POWER_SUPPLY_PROP_PRESENT:
+		val->intval = acpi_battery_present(battery);
+		break;
+	case POWER_SUPPLY_PROP_TECHNOLOGY:
+		val->intval = acpi_battery_technology(battery);
+		break;
+	case POWER_SUPPLY_PROP_CYCLE_COUNT:
+		val->intval = battery->cycle_count;
+		break;
+	case POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN:
+		if (battery->design_voltage == ACPI_BATTERY_VALUE_UNKNOWN)
+			ret = -ENODEV;
+		else
+			val->intval = battery->design_voltage * 1000;
+		break;
+	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
+		if (battery->voltage_now == ACPI_BATTERY_VALUE_UNKNOWN)
+			ret = -ENODEV;
+		else
+			val->intval = battery->voltage_now * 1000;
+		break;
+	case POWER_SUPPLY_PROP_CURRENT_NOW:
+	case POWER_SUPPLY_PROP_POWER_NOW:
+		if (battery->rate_now == ACPI_BATTERY_VALUE_UNKNOWN)
+			ret = -ENODEV;
+		else
+			val->intval = battery->rate_now * 1000;
+		break;
+	case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
+	case POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN:
+		if (battery->design_capacity == ACPI_BATTERY_VALUE_UNKNOWN)
+			ret = -ENODEV;
+		else
+			val->intval = battery->design_capacity * 1000;
+		break;
+	case POWER_SUPPLY_PROP_CHARGE_FULL:
+	case POWER_SUPPLY_PROP_ENERGY_FULL:
+		if (battery->full_charge_capacity == ACPI_BATTERY_VALUE_UNKNOWN)
+			ret = -ENODEV;
+		else
+			val->intval = battery->full_charge_capacity * 1000;
+		break;
+	case POWER_SUPPLY_PROP_CHARGE_NOW:
+	case POWER_SUPPLY_PROP_ENERGY_NOW:
+		if (battery->capacity_now == ACPI_BATTERY_VALUE_UNKNOWN)
+			ret = -ENODEV;
+		else
+			val->intval = battery->capacity_now * 1000;
+		break;
+	case POWER_SUPPLY_PROP_CAPACITY:
+		if (battery->capacity_now && battery->full_charge_capacity)
+			val->intval = battery->capacity_now * 100/
+					battery->full_charge_capacity;
+		else
+			val->intval = 0;
+		break;
+	case POWER_SUPPLY_PROP_CAPACITY_LEVEL:
+		if (battery->state & ACPI_BATTERY_STATE_CRITICAL)
+			val->intval = POWER_SUPPLY_CAPACITY_LEVEL_CRITICAL;
+		else if (test_bit(ACPI_BATTERY_ALARM_PRESENT, &battery->flags) &&
+			(battery->capacity_now <= battery->alarm))
+			val->intval = POWER_SUPPLY_CAPACITY_LEVEL_LOW;
+		else if (acpi_battery_is_charged(battery))
+			val->intval = POWER_SUPPLY_CAPACITY_LEVEL_FULL;
+		else
+			val->intval = POWER_SUPPLY_CAPACITY_LEVEL_NORMAL;
+		break;
+	case POWER_SUPPLY_PROP_MODEL_NAME:
+		val->strval = battery->model_number;
+		break;
+	case POWER_SUPPLY_PROP_MANUFACTURER:
+		val->strval = battery->oem_info;
+		break;
+	case POWER_SUPPLY_PROP_SERIAL_NUMBER:
+		val->strval = battery->serial_number;
+		break;
+	default:
+		ret = -EINVAL;
+	}
+	return ret;
+}
+
+static enum power_supply_property charge_battery_props[] = {
+	POWER_SUPPLY_PROP_STATUS,
+	POWER_SUPPLY_PROP_PRESENT,
+	POWER_SUPPLY_PROP_TECHNOLOGY,
+	POWER_SUPPLY_PROP_CYCLE_COUNT,
+	POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
+	POWER_SUPPLY_PROP_VOLTAGE_NOW,
+	POWER_SUPPLY_PROP_CURRENT_NOW,
+	POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
+	POWER_SUPPLY_PROP_CHARGE_FULL,
+	POWER_SUPPLY_PROP_CHARGE_NOW,
+	POWER_SUPPLY_PROP_CAPACITY,
+	POWER_SUPPLY_PROP_CAPACITY_LEVEL,
+	POWER_SUPPLY_PROP_MODEL_NAME,
+	POWER_SUPPLY_PROP_MANUFACTURER,
+	POWER_SUPPLY_PROP_SERIAL_NUMBER,
+};
+
+static enum power_supply_property energy_battery_props[] = {
+	POWER_SUPPLY_PROP_STATUS,
+	POWER_SUPPLY_PROP_PRESENT,
+	POWER_SUPPLY_PROP_TECHNOLOGY,
+	POWER_SUPPLY_PROP_CYCLE_COUNT,
+	POWER_SUPPLY_PROP_VOLTAGE_MIN_DESIGN,
+	POWER_SUPPLY_PROP_VOLTAGE_NOW,
+	POWER_SUPPLY_PROP_POWER_NOW,
+	POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN,
+	POWER_SUPPLY_PROP_ENERGY_FULL,
+	POWER_SUPPLY_PROP_ENERGY_NOW,
+	POWER_SUPPLY_PROP_CAPACITY,
+	POWER_SUPPLY_PROP_CAPACITY_LEVEL,
+	POWER_SUPPLY_PROP_MODEL_NAME,
+	POWER_SUPPLY_PROP_MANUFACTURER,
+	POWER_SUPPLY_PROP_SERIAL_NUMBER,
+};
+
+#ifdef CONFIG_ACPI_PROCFS_POWER
+inline char *acpi_battery_units(struct acpi_battery *battery)
+{
+	return (battery->power_unit == ACPI_BATTERY_POWER_UNIT_MA) ?
+		"mA" : "mW";
+}
+#endif
+
+/* --------------------------------------------------------------------------
+                               Battery Management
+   -------------------------------------------------------------------------- */
+struct acpi_offsets {
+	size_t offset;		/* offset inside struct acpi_sbs_battery */
+	u8 mode;		/* int or string? */
+};
+
+static struct acpi_offsets state_offsets[] = {
+	{offsetof(struct acpi_battery, state), 0},
+	{offsetof(struct acpi_battery, rate_now), 0},
+	{offsetof(struct acpi_battery, capacity_now), 0},
+	{offsetof(struct acpi_battery, voltage_now), 0},
+};
+
+static struct acpi_offsets info_offsets[] = {
+	{offsetof(struct acpi_battery, power_unit), 0},
+	{offsetof(struct acpi_battery, design_capacity), 0},
+	{offsetof(struct acpi_battery, full_charge_capacity), 0},
+	{offsetof(struct acpi_battery, technology), 0},
+	{offsetof(struct acpi_battery, design_voltage), 0},
+	{offsetof(struct acpi_battery, design_capacity_warning), 0},
+	{offsetof(struct acpi_battery, design_capacity_low), 0},
+	{offsetof(struct acpi_battery, capacity_granularity_1), 0},
+	{offsetof(struct acpi_battery, capacity_granularity_2), 0},
+	{offsetof(struct acpi_battery, model_number), 1},
+	{offsetof(struct acpi_battery, serial_number), 1},
+	{offsetof(struct acpi_battery, type), 1},
+	{offsetof(struct acpi_battery, oem_info), 1},
+};
+
+static struct acpi_offsets extended_info_offsets[] = {
+	{offsetof(struct acpi_battery, revision), 0},
+	{offsetof(struct acpi_battery, power_unit), 0},
+	{offsetof(struct acpi_battery, design_capacity), 0},
+	{offsetof(struct acpi_battery, full_charge_capacity), 0},
+	{offsetof(struct acpi_battery, technology), 0},
+	{offsetof(struct acpi_battery, design_voltage), 0},
+	{offsetof(struct acpi_battery, design_capacity_warning), 0},
+	{offsetof(struct acpi_battery, design_capacity_low), 0},
+	{offsetof(struct acpi_battery, cycle_count), 0},
+	{offsetof(struct acpi_battery, measurement_accuracy), 0},
+	{offsetof(struct acpi_battery, max_sampling_time), 0},
+	{offsetof(struct acpi_battery, min_sampling_time), 0},
+	{offsetof(struct acpi_battery, max_averaging_interval), 0},
+	{offsetof(struct acpi_battery, min_averaging_interval), 0},
+	{offsetof(struct acpi_battery, capacity_granularity_1), 0},
+	{offsetof(struct acpi_battery, capacity_granularity_2), 0},
+	{offsetof(struct acpi_battery, model_number), 1},
+	{offsetof(struct acpi_battery, serial_number), 1},
+	{offsetof(struct acpi_battery, type), 1},
+	{offsetof(struct acpi_battery, oem_info), 1},
+};
+
+static int extract_package(struct acpi_battery *battery,
+			   union acpi_object *package,
+			   struct acpi_offsets *offsets, int num)
+{
+	int i;
+	union acpi_object *element;
+	if (package->type != ACPI_TYPE_PACKAGE)
+		return -EFAULT;
+	for (i = 0; i < num; ++i) {
+		if (package->package.count <= i)
+			return -EFAULT;
+		element = &package->package.elements[i];
+		if (offsets[i].mode) {
+			u8 *ptr = (u8 *)battery + offsets[i].offset;
+			if (element->type == ACPI_TYPE_STRING ||
+			    element->type == ACPI_TYPE_BUFFER)
+				strncpy(ptr, element->string.pointer, 32);
+			else if (element->type == ACPI_TYPE_INTEGER) {
+				strncpy(ptr, (u8 *)&element->integer.value,
+					sizeof(u64));
+				ptr[sizeof(u64)] = 0;
+			} else
+				*ptr = 0; /* don't have value */
+		} else {
+			int *x = (int *)((u8 *)battery + offsets[i].offset);
+			*x = (element->type == ACPI_TYPE_INTEGER) ?
+				element->integer.value : -1;
+		}
+	}
+	return 0;
+}
+
+static int acpi_battery_get_status(struct acpi_battery *battery)
+{
+	if (acpi_bus_get_status(battery->device)) {
+		ACPI_EXCEPTION((AE_INFO, AE_ERROR, "Evaluating _STA"));
+		return -ENODEV;
+	}
+	return 0;
+}
+
+static int acpi_battery_get_info(struct acpi_battery *battery)
+{
+	int result = -EFAULT;
+	acpi_status status = 0;
+	char *name = test_bit(ACPI_BATTERY_XINFO_PRESENT, &battery->flags) ?
+			"_BIX" : "_BIF";
+
+	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+
+	if (!acpi_battery_present(battery))
+		return 0;
+	mutex_lock(&battery->lock);
+	status = acpi_evaluate_object(battery->device->handle, name,
+						NULL, &buffer);
+	mutex_unlock(&battery->lock);
+
+	if (ACPI_FAILURE(status)) {
+		ACPI_EXCEPTION((AE_INFO, status, "Evaluating %s", name));
+		return -ENODEV;
+	}
+
+	if (battery_bix_broken_package)
+		result = extract_package(battery, buffer.pointer,
+				extended_info_offsets + 1,
+				ARRAY_SIZE(extended_info_offsets) - 1);
+	else if (test_bit(ACPI_BATTERY_XINFO_PRESENT, &battery->flags))
+		result = extract_package(battery, buffer.pointer,
+				extended_info_offsets,
+				ARRAY_SIZE(extended_info_offsets));
+	else
+		result = extract_package(battery, buffer.pointer,
+				info_offsets, ARRAY_SIZE(info_offsets));
+	kfree(buffer.pointer);
+	if (test_bit(ACPI_BATTERY_QUIRK_PERCENTAGE_CAPACITY, &battery->flags))
+		battery->full_charge_capacity = battery->design_capacity;
+	if (test_bit(ACPI_BATTERY_QUIRK_THINKPAD_MAH, &battery->flags) &&
+	    battery->power_unit && battery->design_voltage) {
+		battery->design_capacity = battery->design_capacity *
+		    10000 / battery->design_voltage;
+		battery->full_charge_capacity = battery->full_charge_capacity *
+		    10000 / battery->design_voltage;
+		battery->design_capacity_warning =
+		    battery->design_capacity_warning *
+		    10000 / battery->design_voltage;
+		/* Curiously, design_capacity_low, unlike the rest of them,
+		   is correct.  */
+		/* capacity_granularity_* equal 1 on the systems tested, so
+		   it's impossible to tell if they would need an adjustment
+		   or not if their values were higher.  */
+	}
+	return result;
+}
+
+static int acpi_battery_get_state(struct acpi_battery *battery)
+{
+	int result = 0;
+	acpi_status status = 0;
+	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+
+	if (!acpi_battery_present(battery))
+		return 0;
+
+	if (battery->update_time &&
+	    time_before(jiffies, battery->update_time +
+			msecs_to_jiffies(cache_time)))
+		return 0;
+
+	mutex_lock(&battery->lock);
+	status = acpi_evaluate_object(battery->device->handle, "_BST",
+				      NULL, &buffer);
+	mutex_unlock(&battery->lock);
+
+	if (ACPI_FAILURE(status)) {
+		ACPI_EXCEPTION((AE_INFO, status, "Evaluating _BST"));
+		return -ENODEV;
+	}
+
+	result = extract_package(battery, buffer.pointer,
+				 state_offsets, ARRAY_SIZE(state_offsets));
+	battery->update_time = jiffies;
+	kfree(buffer.pointer);
+
+	/* For buggy DSDTs that report negative 16-bit values for either
+	 * charging or discharging current and/or report 0 as 65536
+	 * due to bad math.
+	 */
+	if (battery->power_unit == ACPI_BATTERY_POWER_UNIT_MA &&
+		battery->rate_now != ACPI_BATTERY_VALUE_UNKNOWN &&
+		(s16)(battery->rate_now) < 0) {
+		battery->rate_now = abs((s16)battery->rate_now);
+		printk_once(KERN_WARNING FW_BUG
+			    "battery: (dis)charge rate invalid.\n");
+	}
+
+	if (test_bit(ACPI_BATTERY_QUIRK_PERCENTAGE_CAPACITY, &battery->flags)
+	    && battery->capacity_now >= 0 && battery->capacity_now <= 100)
+		battery->capacity_now = (battery->capacity_now *
+				battery->full_charge_capacity) / 100;
+	if (test_bit(ACPI_BATTERY_QUIRK_THINKPAD_MAH, &battery->flags) &&
+	    battery->power_unit && battery->design_voltage) {
+		battery->capacity_now = battery->capacity_now *
+		    10000 / battery->design_voltage;
+	}
+	return result;
+}
+
+static int acpi_battery_set_alarm(struct acpi_battery *battery)
+{
+	acpi_status status = 0;
+
+	if (!acpi_battery_present(battery) ||
+	    !test_bit(ACPI_BATTERY_ALARM_PRESENT, &battery->flags))
+		return -ENODEV;
+
+	mutex_lock(&battery->lock);
+	status = acpi_execute_simple_method(battery->device->handle, "_BTP",
+					    battery->alarm);
+	mutex_unlock(&battery->lock);
+
+	if (ACPI_FAILURE(status))
+		return -ENODEV;
+
+	ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Alarm set to %d\n", battery->alarm));
+	return 0;
+}
+
+static int acpi_battery_init_alarm(struct acpi_battery *battery)
+{
+	/* See if alarms are supported, and if so, set default */
+	if (!acpi_has_method(battery->device->handle, "_BTP")) {
+		clear_bit(ACPI_BATTERY_ALARM_PRESENT, &battery->flags);
+		return 0;
+	}
+	set_bit(ACPI_BATTERY_ALARM_PRESENT, &battery->flags);
+	if (!battery->alarm)
+		battery->alarm = battery->design_capacity_warning;
+	return acpi_battery_set_alarm(battery);
+}
+
+static ssize_t acpi_battery_alarm_show(struct device *dev,
+					struct device_attribute *attr,
+					char *buf)
+{
+	struct acpi_battery *battery = to_acpi_battery(dev_get_drvdata(dev));
+	return sprintf(buf, "%d\n", battery->alarm * 1000);
+}
+
+static ssize_t acpi_battery_alarm_store(struct device *dev,
+					struct device_attribute *attr,
+					const char *buf, size_t count)
+{
+	unsigned long x;
+	struct acpi_battery *battery = to_acpi_battery(dev_get_drvdata(dev));
+	if (sscanf(buf, "%lu\n", &x) == 1)
+		battery->alarm = x/1000;
+	if (acpi_battery_present(battery))
+		acpi_battery_set_alarm(battery);
+	return count;
+}
+
+static struct device_attribute alarm_attr = {
+	.attr = {.name = "alarm", .mode = 0644},
+	.show = acpi_battery_alarm_show,
+	.store = acpi_battery_alarm_store,
+};
+
+static int sysfs_add_battery(struct acpi_battery *battery)
+{
+	struct power_supply_config psy_cfg = { .drv_data = battery, };
+
+	if (battery->power_unit == ACPI_BATTERY_POWER_UNIT_MA) {
+		battery->bat_desc.properties = charge_battery_props;
+		battery->bat_desc.num_properties =
+			ARRAY_SIZE(charge_battery_props);
+	} else {
+		battery->bat_desc.properties = energy_battery_props;
+		battery->bat_desc.num_properties =
+			ARRAY_SIZE(energy_battery_props);
+	}
+
+	battery->bat_desc.name = acpi_device_bid(battery->device);
+	battery->bat_desc.type = POWER_SUPPLY_TYPE_BATTERY;
+	battery->bat_desc.get_property = acpi_battery_get_property;
+
+	battery->bat = power_supply_register_no_ws(&battery->device->dev,
+				&battery->bat_desc, &psy_cfg);
+
+	if (IS_ERR(battery->bat)) {
+		int result = PTR_ERR(battery->bat);
+
+		battery->bat = NULL;
+		return result;
+	}
+	return device_create_file(&battery->bat->dev, &alarm_attr);
+}
+
+static void sysfs_remove_battery(struct acpi_battery *battery)
+{
+	mutex_lock(&battery->sysfs_lock);
+	if (!battery->bat) {
+		mutex_unlock(&battery->sysfs_lock);
+		return;
+	}
+
+	device_remove_file(&battery->bat->dev, &alarm_attr);
+	power_supply_unregister(battery->bat);
+	battery->bat = NULL;
+	mutex_unlock(&battery->sysfs_lock);
+}
+
+static void find_battery(const struct dmi_header *dm, void *private)
+{
+	struct acpi_battery *battery = (struct acpi_battery *)private;
+	/* Note: the hardcoded offsets below have been extracted from
+	   the source code of dmidecode.  */
+	if (dm->type == DMI_ENTRY_PORTABLE_BATTERY && dm->length >= 8) {
+		const u8 *dmi_data = (const u8 *)(dm + 1);
+		int dmi_capacity = get_unaligned((const u16 *)(dmi_data + 6));
+		if (dm->length >= 18)
+			dmi_capacity *= dmi_data[17];
+		if (battery->design_capacity * battery->design_voltage / 1000
+		    != dmi_capacity &&
+		    battery->design_capacity * 10 == dmi_capacity)
+			set_bit(ACPI_BATTERY_QUIRK_THINKPAD_MAH,
+				&battery->flags);
+	}
+}
+
+/*
+ * According to the ACPI spec, some kinds of primary batteries can
+ * report percentage battery remaining capacity directly to OS.
+ * In this case, it reports the Last Full Charged Capacity == 100
+ * and BatteryPresentRate == 0xFFFFFFFF.
+ *
+ * Now we found some battery reports percentage remaining capacity
+ * even if it's rechargeable.
+ * https://bugzilla.kernel.org/show_bug.cgi?id=15979
+ *
+ * Handle this correctly so that they won't break userspace.
+ */
+static void acpi_battery_quirks(struct acpi_battery *battery)
+{
+	if (test_bit(ACPI_BATTERY_QUIRK_PERCENTAGE_CAPACITY, &battery->flags))
+		return;
+
+	if (battery->full_charge_capacity == 100 &&
+		battery->rate_now == ACPI_BATTERY_VALUE_UNKNOWN &&
+		battery->capacity_now >= 0 && battery->capacity_now <= 100) {
+		set_bit(ACPI_BATTERY_QUIRK_PERCENTAGE_CAPACITY, &battery->flags);
+		battery->full_charge_capacity = battery->design_capacity;
+		battery->capacity_now = (battery->capacity_now *
+				battery->full_charge_capacity) / 100;
+	}
+
+	if (test_bit(ACPI_BATTERY_QUIRK_THINKPAD_MAH, &battery->flags))
+		return;
+
+	if (battery->power_unit && dmi_name_in_vendors("LENOVO")) {
+		const char *s;
+		s = dmi_get_system_info(DMI_PRODUCT_VERSION);
+		if (s && !strncasecmp(s, "ThinkPad", 8)) {
+			dmi_walk(find_battery, battery);
+			if (test_bit(ACPI_BATTERY_QUIRK_THINKPAD_MAH,
+				     &battery->flags) &&
+			    battery->design_voltage) {
+				battery->design_capacity =
+				    battery->design_capacity *
+				    10000 / battery->design_voltage;
+				battery->full_charge_capacity =
+				    battery->full_charge_capacity *
+				    10000 / battery->design_voltage;
+				battery->design_capacity_warning =
+				    battery->design_capacity_warning *
+				    10000 / battery->design_voltage;
+				battery->capacity_now = battery->capacity_now *
+				    10000 / battery->design_voltage;
+			}
+		}
+	}
+}
+
+static int acpi_battery_update(struct acpi_battery *battery, bool resume)
+{
+	int result, old_present = acpi_battery_present(battery);
+	result = acpi_battery_get_status(battery);
+	if (result)
+		return result;
+	if (!acpi_battery_present(battery)) {
+		sysfs_remove_battery(battery);
+		battery->update_time = 0;
+		return 0;
+	}
+
+	if (resume)
+		return 0;
+
+	if (!battery->update_time ||
+	    old_present != acpi_battery_present(battery)) {
+		result = acpi_battery_get_info(battery);
+		if (result)
+			return result;
+		acpi_battery_init_alarm(battery);
+	}
+	if (!battery->bat) {
+		result = sysfs_add_battery(battery);
+		if (result)
+			return result;
+	}
+	result = acpi_battery_get_state(battery);
+	if (result)
+		return result;
+	acpi_battery_quirks(battery);
+
+	/*
+	 * Wakeup the system if battery is critical low
+	 * or lower than the alarm level
+	 */
+	if ((battery->state & ACPI_BATTERY_STATE_CRITICAL) ||
+	    (test_bit(ACPI_BATTERY_ALARM_PRESENT, &battery->flags) &&
+            (battery->capacity_now <= battery->alarm)))
+		pm_wakeup_event(&battery->device->dev, 0);
+
+	return result;
+}
+
+static void acpi_battery_refresh(struct acpi_battery *battery)
+{
+	int power_unit;
+
+	if (!battery->bat)
+		return;
+
+	power_unit = battery->power_unit;
+
+	acpi_battery_get_info(battery);
+
+	if (power_unit == battery->power_unit)
+		return;
+
+	/* The battery has changed its reporting units. */
+	sysfs_remove_battery(battery);
+	sysfs_add_battery(battery);
+}
+
+/* --------------------------------------------------------------------------
+                              FS Interface (/proc)
+   -------------------------------------------------------------------------- */
+
+#ifdef CONFIG_ACPI_PROCFS_POWER
+static struct proc_dir_entry *acpi_battery_dir;
+
+static int acpi_battery_print_info(struct seq_file *seq, int result)
+{
+	struct acpi_battery *battery = seq->private;
+
+	if (result)
+		goto end;
+
+	seq_printf(seq, "present:                 %s\n",
+		   acpi_battery_present(battery) ? "yes" : "no");
+	if (!acpi_battery_present(battery))
+		goto end;
+	if (battery->design_capacity == ACPI_BATTERY_VALUE_UNKNOWN)
+		seq_printf(seq, "design capacity:         unknown\n");
+	else
+		seq_printf(seq, "design capacity:         %d %sh\n",
+			   battery->design_capacity,
+			   acpi_battery_units(battery));
+
+	if (battery->full_charge_capacity == ACPI_BATTERY_VALUE_UNKNOWN)
+		seq_printf(seq, "last full capacity:      unknown\n");
+	else
+		seq_printf(seq, "last full capacity:      %d %sh\n",
+			   battery->full_charge_capacity,
+			   acpi_battery_units(battery));
+
+	seq_printf(seq, "battery technology:      %srechargeable\n",
+		   (!battery->technology)?"non-":"");
+
+	if (battery->design_voltage == ACPI_BATTERY_VALUE_UNKNOWN)
+		seq_printf(seq, "design voltage:          unknown\n");
+	else
+		seq_printf(seq, "design voltage:          %d mV\n",
+			   battery->design_voltage);
+	seq_printf(seq, "design capacity warning: %d %sh\n",
+		   battery->design_capacity_warning,
+		   acpi_battery_units(battery));
+	seq_printf(seq, "design capacity low:     %d %sh\n",
+		   battery->design_capacity_low,
+		   acpi_battery_units(battery));
+	seq_printf(seq, "cycle count:		  %i\n", battery->cycle_count);
+	seq_printf(seq, "capacity granularity 1:  %d %sh\n",
+		   battery->capacity_granularity_1,
+		   acpi_battery_units(battery));
+	seq_printf(seq, "capacity granularity 2:  %d %sh\n",
+		   battery->capacity_granularity_2,
+		   acpi_battery_units(battery));
+	seq_printf(seq, "model number:            %s\n", battery->model_number);
+	seq_printf(seq, "serial number:           %s\n", battery->serial_number);
+	seq_printf(seq, "battery type:            %s\n", battery->type);
+	seq_printf(seq, "OEM info:                %s\n", battery->oem_info);
+      end:
+	if (result)
+		seq_printf(seq, "ERROR: Unable to read battery info\n");
+	return result;
+}
+
+static int acpi_battery_print_state(struct seq_file *seq, int result)
+{
+	struct acpi_battery *battery = seq->private;
+
+	if (result)
+		goto end;
+
+	seq_printf(seq, "present:                 %s\n",
+		   acpi_battery_present(battery) ? "yes" : "no");
+	if (!acpi_battery_present(battery))
+		goto end;
+
+	seq_printf(seq, "capacity state:          %s\n",
+			(battery->state & 0x04) ? "critical" : "ok");
+	if ((battery->state & 0x01) && (battery->state & 0x02))
+		seq_printf(seq,
+			   "charging state:          charging/discharging\n");
+	else if (battery->state & 0x01)
+		seq_printf(seq, "charging state:          discharging\n");
+	else if (battery->state & 0x02)
+		seq_printf(seq, "charging state:          charging\n");
+	else
+		seq_printf(seq, "charging state:          charged\n");
+
+	if (battery->rate_now == ACPI_BATTERY_VALUE_UNKNOWN)
+		seq_printf(seq, "present rate:            unknown\n");
+	else
+		seq_printf(seq, "present rate:            %d %s\n",
+			   battery->rate_now, acpi_battery_units(battery));
+
+	if (battery->capacity_now == ACPI_BATTERY_VALUE_UNKNOWN)
+		seq_printf(seq, "remaining capacity:      unknown\n");
+	else
+		seq_printf(seq, "remaining capacity:      %d %sh\n",
+			   battery->capacity_now, acpi_battery_units(battery));
+	if (battery->voltage_now == ACPI_BATTERY_VALUE_UNKNOWN)
+		seq_printf(seq, "present voltage:         unknown\n");
+	else
+		seq_printf(seq, "present voltage:         %d mV\n",
+			   battery->voltage_now);
+      end:
+	if (result)
+		seq_printf(seq, "ERROR: Unable to read battery state\n");
+
+	return result;
+}
+
+static int acpi_battery_print_alarm(struct seq_file *seq, int result)
+{
+	struct acpi_battery *battery = seq->private;
+
+	if (result)
+		goto end;
+
+	if (!acpi_battery_present(battery)) {
+		seq_printf(seq, "present:                 no\n");
+		goto end;
+	}
+	seq_printf(seq, "alarm:                   ");
+	if (!battery->alarm)
+		seq_printf(seq, "unsupported\n");
+	else
+		seq_printf(seq, "%u %sh\n", battery->alarm,
+				acpi_battery_units(battery));
+      end:
+	if (result)
+		seq_printf(seq, "ERROR: Unable to read battery alarm\n");
+	return result;
+}
+
+static ssize_t acpi_battery_write_alarm(struct file *file,
+					const char __user * buffer,
+					size_t count, loff_t * ppos)
+{
+	int result = 0;
+	char alarm_string[12] = { '\0' };
+	struct seq_file *m = file->private_data;
+	struct acpi_battery *battery = m->private;
+
+	if (!battery || (count > sizeof(alarm_string) - 1))
+		return -EINVAL;
+	if (!acpi_battery_present(battery)) {
+		result = -ENODEV;
+		goto end;
+	}
+	if (copy_from_user(alarm_string, buffer, count)) {
+		result = -EFAULT;
+		goto end;
+	}
+	alarm_string[count] = '\0';
+	if (kstrtoint(alarm_string, 0, &battery->alarm)) {
+		result = -EINVAL;
+		goto end;
+	}
+	result = acpi_battery_set_alarm(battery);
+      end:
+	if (!result)
+		return count;
+	return result;
+}
+
+typedef int(*print_func)(struct seq_file *seq, int result);
+
+static print_func acpi_print_funcs[ACPI_BATTERY_NUMFILES] = {
+	acpi_battery_print_info,
+	acpi_battery_print_state,
+	acpi_battery_print_alarm,
+};
+
+static int acpi_battery_read(int fid, struct seq_file *seq)
+{
+	struct acpi_battery *battery = seq->private;
+	int result = acpi_battery_update(battery, false);
+	return acpi_print_funcs[fid](seq, result);
+}
+
+#define DECLARE_FILE_FUNCTIONS(_name) \
+static int acpi_battery_read_##_name(struct seq_file *seq, void *offset) \
+{ \
+	return acpi_battery_read(_name##_tag, seq); \
+} \
+static int acpi_battery_##_name##_open_fs(struct inode *inode, struct file *file) \
+{ \
+	return single_open(file, acpi_battery_read_##_name, PDE_DATA(inode)); \
+}
+
+DECLARE_FILE_FUNCTIONS(info);
+DECLARE_FILE_FUNCTIONS(state);
+DECLARE_FILE_FUNCTIONS(alarm);
+
+#undef DECLARE_FILE_FUNCTIONS
+
+#define FILE_DESCRIPTION_RO(_name) \
+	{ \
+	.name = __stringify(_name), \
+	.mode = S_IRUGO, \
+	.ops = { \
+		.open = acpi_battery_##_name##_open_fs, \
+		.read = seq_read, \
+		.llseek = seq_lseek, \
+		.release = single_release, \
+		.owner = THIS_MODULE, \
+		}, \
+	}
+
+#define FILE_DESCRIPTION_RW(_name) \
+	{ \
+	.name = __stringify(_name), \
+	.mode = S_IFREG | S_IRUGO | S_IWUSR, \
+	.ops = { \
+		.open = acpi_battery_##_name##_open_fs, \
+		.read = seq_read, \
+		.llseek = seq_lseek, \
+		.write = acpi_battery_write_##_name, \
+		.release = single_release, \
+		.owner = THIS_MODULE, \
+		}, \
+	}
+
+static const struct battery_file {
+	struct file_operations ops;
+	umode_t mode;
+	const char *name;
+} acpi_battery_file[] = {
+	FILE_DESCRIPTION_RO(info),
+	FILE_DESCRIPTION_RO(state),
+	FILE_DESCRIPTION_RW(alarm),
+};
+
+#undef FILE_DESCRIPTION_RO
+#undef FILE_DESCRIPTION_RW
+
+static int acpi_battery_add_fs(struct acpi_device *device)
+{
+	struct proc_dir_entry *entry = NULL;
+	int i;
+
+	printk(KERN_WARNING PREFIX "Deprecated procfs I/F for battery is loaded,"
+			" please retry with CONFIG_ACPI_PROCFS_POWER cleared\n");
+	if (!acpi_device_dir(device)) {
+		acpi_device_dir(device) = proc_mkdir(acpi_device_bid(device),
+						     acpi_battery_dir);
+		if (!acpi_device_dir(device))
+			return -ENODEV;
+	}
+
+	for (i = 0; i < ACPI_BATTERY_NUMFILES; ++i) {
+		entry = proc_create_data(acpi_battery_file[i].name,
+					 acpi_battery_file[i].mode,
+					 acpi_device_dir(device),
+					 &acpi_battery_file[i].ops,
+					 acpi_driver_data(device));
+		if (!entry)
+			return -ENODEV;
+	}
+	return 0;
+}
+
+static void acpi_battery_remove_fs(struct acpi_device *device)
+{
+	int i;
+	if (!acpi_device_dir(device))
+		return;
+	for (i = 0; i < ACPI_BATTERY_NUMFILES; ++i)
+		remove_proc_entry(acpi_battery_file[i].name,
+				  acpi_device_dir(device));
+
+	remove_proc_entry(acpi_device_bid(device), acpi_battery_dir);
+	acpi_device_dir(device) = NULL;
+}
+
+#endif
+
+/* --------------------------------------------------------------------------
+                                 Driver Interface
+   -------------------------------------------------------------------------- */
+
+static void acpi_battery_notify(struct acpi_device *device, u32 event)
+{
+	struct acpi_battery *battery = acpi_driver_data(device);
+	struct power_supply *old;
+
+	if (!battery)
+		return;
+	old = battery->bat;
+	/*
+	* On Acer Aspire V5-573G notifications are sometimes triggered too
+	* early. For example, when AC is unplugged and notification is
+	* triggered, battery state is still reported as "Full", and changes to
+	* "Discharging" only after short delay, without any notification.
+	*/
+	if (battery_notification_delay_ms > 0)
+		msleep(battery_notification_delay_ms);
+	if (event == ACPI_BATTERY_NOTIFY_INFO)
+		acpi_battery_refresh(battery);
+	acpi_battery_update(battery, false);
+	acpi_bus_generate_netlink_event(device->pnp.device_class,
+					dev_name(&device->dev), event,
+					acpi_battery_present(battery));
+	acpi_notifier_call_chain(device, event, acpi_battery_present(battery));
+	/* acpi_battery_update could remove power_supply object */
+	if (old && battery->bat)
+		power_supply_changed(battery->bat);
+}
+
+static int battery_notify(struct notifier_block *nb,
+			       unsigned long mode, void *_unused)
+{
+	struct acpi_battery *battery = container_of(nb, struct acpi_battery,
+						    pm_nb);
+	int result;
+
+	switch (mode) {
+	case PM_POST_HIBERNATION:
+	case PM_POST_SUSPEND:
+		if (!acpi_battery_present(battery))
+			return 0;
+
+		if (!battery->bat) {
+			result = acpi_battery_get_info(battery);
+			if (result)
+				return result;
+
+			result = sysfs_add_battery(battery);
+			if (result)
+				return result;
+		} else
+			acpi_battery_refresh(battery);
+
+		acpi_battery_init_alarm(battery);
+		acpi_battery_get_state(battery);
+		break;
+	}
+
+	return 0;
+}
+
+static int battery_bix_broken_package_quirk(const struct dmi_system_id *d)
+{
+	battery_bix_broken_package = 1;
+	return 0;
+}
+
+static int battery_notification_delay_quirk(const struct dmi_system_id *d)
+{
+	battery_notification_delay_ms = 1000;
+	return 0;
+}
+
+static struct dmi_system_id bat_dmi_table[] = {
+	{
+		.callback = battery_bix_broken_package_quirk,
+		.ident = "NEC LZ750/LS",
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "NEC"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "PC-LZ750LS"),
+		},
+	},
+	{
+		.callback = battery_notification_delay_quirk,
+		.ident = "Acer Aspire V5-573G",
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "Aspire V5-573G"),
+		},
+	},
+	{},
+};
+
+/*
+ * Some machines'(E,G Lenovo Z480) ECs are not stable
+ * during boot up and this causes battery driver fails to be
+ * probed due to failure of getting battery information
+ * from EC sometimes. After several retries, the operation
+ * may work. So add retry code here and 20ms sleep between
+ * every retries.
+ */
+static int acpi_battery_update_retry(struct acpi_battery *battery)
+{
+	int retry, ret;
+
+	for (retry = 5; retry; retry--) {
+		ret = acpi_battery_update(battery, false);
+		if (!ret)
+			break;
+
+		msleep(20);
+	}
+	return ret;
+}
+
+static int acpi_battery_add(struct acpi_device *device)
+{
+	int result = 0;
+	struct acpi_battery *battery = NULL;
+
+	if (!device)
+		return -EINVAL;
+
+	if (device->dep_unmet)
+		return -EPROBE_DEFER;
+
+	battery = kzalloc(sizeof(struct acpi_battery), GFP_KERNEL);
+	if (!battery)
+		return -ENOMEM;
+	battery->device = device;
+	strcpy(acpi_device_name(device), ACPI_BATTERY_DEVICE_NAME);
+	strcpy(acpi_device_class(device), ACPI_BATTERY_CLASS);
+	device->driver_data = battery;
+	mutex_init(&battery->lock);
+	mutex_init(&battery->sysfs_lock);
+	if (acpi_has_method(battery->device->handle, "_BIX"))
+		set_bit(ACPI_BATTERY_XINFO_PRESENT, &battery->flags);
+
+	result = acpi_battery_update_retry(battery);
+	if (result)
+		goto fail;
+
+#ifdef CONFIG_ACPI_PROCFS_POWER
+	result = acpi_battery_add_fs(device);
+#endif
+	if (result) {
+#ifdef CONFIG_ACPI_PROCFS_POWER
+		acpi_battery_remove_fs(device);
+#endif
+		goto fail;
+	}
+
+	printk(KERN_INFO PREFIX "%s Slot [%s] (battery %s)\n",
+		ACPI_BATTERY_DEVICE_NAME, acpi_device_bid(device),
+		device->status.battery_present ? "present" : "absent");
+
+	battery->pm_nb.notifier_call = battery_notify;
+	register_pm_notifier(&battery->pm_nb);
+
+	device_init_wakeup(&device->dev, 1);
+
+	return result;
+
+fail:
+	sysfs_remove_battery(battery);
+	mutex_destroy(&battery->lock);
+	mutex_destroy(&battery->sysfs_lock);
+	kfree(battery);
+	return result;
+}
+
+static int acpi_battery_remove(struct acpi_device *device)
+{
+	struct acpi_battery *battery = NULL;
+
+	if (!device || !acpi_driver_data(device))
+		return -EINVAL;
+	device_init_wakeup(&device->dev, 0);
+	battery = acpi_driver_data(device);
+	unregister_pm_notifier(&battery->pm_nb);
+#ifdef CONFIG_ACPI_PROCFS_POWER
+	acpi_battery_remove_fs(device);
+#endif
+	sysfs_remove_battery(battery);
+	mutex_destroy(&battery->lock);
+	mutex_destroy(&battery->sysfs_lock);
+	kfree(battery);
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+/* this is needed to learn about changes made in suspended state */
+static int acpi_battery_resume(struct device *dev)
+{
+	struct acpi_battery *battery;
+
+	if (!dev)
+		return -EINVAL;
+
+	battery = acpi_driver_data(to_acpi_device(dev));
+	if (!battery)
+		return -EINVAL;
+
+	battery->update_time = 0;
+	acpi_battery_update(battery, true);
+	return 0;
+}
+#else
+#define acpi_battery_resume NULL
+#endif
+
+static SIMPLE_DEV_PM_OPS(acpi_battery_pm, NULL, acpi_battery_resume);
+
+static struct acpi_driver acpi_battery_driver = {
+	.name = "battery",
+	.class = ACPI_BATTERY_CLASS,
+	.ids = battery_device_ids,
+	.flags = ACPI_DRIVER_ALL_NOTIFY_EVENTS,
+	.ops = {
+		.add = acpi_battery_add,
+		.remove = acpi_battery_remove,
+		.notify = acpi_battery_notify,
+		},
+	.drv.pm = &acpi_battery_pm,
+};
+
+static void __init acpi_battery_init_async(void *unused, async_cookie_t cookie)
+{
+	if (acpi_disabled)
+		return;
+
+	dmi_check_system(bat_dmi_table);
+	
+#ifdef CONFIG_ACPI_PROCFS_POWER
+	acpi_battery_dir = acpi_lock_battery_dir();
+	if (!acpi_battery_dir)
+		return;
+#endif
+	if (acpi_bus_register_driver(&acpi_battery_driver) < 0) {
+#ifdef CONFIG_ACPI_PROCFS_POWER
+		acpi_unlock_battery_dir(acpi_battery_dir);
+#endif
+		return;
+	}
+	return;
+}
+
+static int __init acpi_battery_init(void)
+{
+	async_schedule(acpi_battery_init_async, NULL);
+	return 0;
+}
+
+static void __exit acpi_battery_exit(void)
+{
+	acpi_bus_unregister_driver(&acpi_battery_driver);
+#ifdef CONFIG_ACPI_PROCFS_POWER
+	acpi_unlock_battery_dir(acpi_battery_dir);
+#endif
+}
+
+module_init(acpi_battery_init);
+module_exit(acpi_battery_exit);