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-rw-r--r--drivers/acpi/battery.c1295
1 files changed, 1295 insertions, 0 deletions
diff --git a/drivers/acpi/battery.c b/drivers/acpi/battery.c
new file mode 100644
index 000000000..084f156bd
--- /dev/null
+++ b/drivers/acpi/battery.c
@@ -0,0 +1,1295 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * 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>
+ */
+
+#define pr_fmt(fmt) "ACPI: battery: " fmt
+
+#include <linux/async.h>
+#include <linux/delay.h>
+#include <linux/dmi.h>
+#include <linux/jiffies.h>
+#include <linux/kernel.h>
+#include <linux/list.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/slab.h>
+#include <linux/suspend.h>
+#include <linux/types.h>
+
+#include <asm/unaligned.h>
+
+#include <linux/acpi.h>
+#include <linux/power_supply.h>
+
+#include <acpi/battery.h>
+
+#define ACPI_BATTERY_VALUE_UNKNOWN 0xFFFFFFFF
+#define ACPI_BATTERY_CAPACITY_VALID(capacity) \
+ ((capacity) != 0 && (capacity) != ACPI_BATTERY_VALUE_UNKNOWN)
+
+#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
+
+MODULE_AUTHOR("Paul Diefenbaugh");
+MODULE_AUTHOR("Alexey Starikovskiy <astarikovskiy@suse.de>");
+MODULE_DESCRIPTION("ACPI Battery Driver");
+MODULE_LICENSE("GPL");
+
+static async_cookie_t async_cookie;
+static bool battery_driver_registered;
+static int battery_bix_broken_package;
+static int battery_notification_delay_ms;
+static int battery_ac_is_broken;
+static unsigned int cache_time = 1000;
+module_param(cache_time, uint, 0644);
+MODULE_PARM_DESC(cache_time, "cache time in milliseconds");
+
+static const struct acpi_device_id battery_device_ids[] = {
+ {"PNP0C0A", 0},
+
+ /* Microsoft Surface Go 3 */
+ {"MSHW0146", 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,
+ /* for batteries reporting current capacity with design capacity
+ * on a full charge, but showing degradation in full charge cap.
+ */
+ ACPI_BATTERY_QUIRK_DEGRADED_FULL_CHARGE,
+};
+
+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;
+ struct list_head list;
+ 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 bool acpi_battery_is_degraded(struct acpi_battery *battery)
+{
+ return ACPI_BATTERY_CAPACITY_VALID(battery->full_charge_capacity) &&
+ ACPI_BATTERY_CAPACITY_VALID(battery->design_capacity) &&
+ battery->full_charge_capacity < battery->design_capacity;
+}
+
+static int acpi_battery_handle_discharging(struct acpi_battery *battery)
+{
+ /*
+ * Some devices wrongly report discharging if the battery's charge level
+ * was above the device's start charging threshold atm the AC adapter
+ * was plugged in and the device thus did not start a new charge cycle.
+ */
+ if ((battery_ac_is_broken || power_supply_is_system_supplied()) &&
+ battery->rate_now == 0)
+ return POWER_SUPPLY_STATUS_NOT_CHARGING;
+
+ return POWER_SUPPLY_STATUS_DISCHARGING;
+}
+
+static int acpi_battery_get_property(struct power_supply *psy,
+ enum power_supply_property psp,
+ union power_supply_propval *val)
+{
+ int full_capacity = ACPI_BATTERY_VALUE_UNKNOWN, 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 = acpi_battery_handle_discharging(battery);
+ 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_NOT_CHARGING;
+ 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 (!ACPI_BATTERY_CAPACITY_VALID(battery->design_capacity))
+ ret = -ENODEV;
+ else
+ val->intval = battery->design_capacity * 1000;
+ break;
+ case POWER_SUPPLY_PROP_CHARGE_FULL:
+ case POWER_SUPPLY_PROP_ENERGY_FULL:
+ if (!ACPI_BATTERY_CAPACITY_VALID(battery->full_charge_capacity))
+ 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 (ACPI_BATTERY_CAPACITY_VALID(battery->full_charge_capacity))
+ full_capacity = battery->full_charge_capacity;
+ else if (ACPI_BATTERY_CAPACITY_VALID(battery->design_capacity))
+ full_capacity = battery->design_capacity;
+
+ if (battery->capacity_now == ACPI_BATTERY_VALUE_UNKNOWN ||
+ full_capacity == ACPI_BATTERY_VALUE_UNKNOWN)
+ ret = -ENODEV;
+ else
+ val->intval = battery->capacity_now * 100/
+ full_capacity;
+ 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 charge_battery_full_cap_broken_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_NOW,
+ 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,
+};
+
+static enum power_supply_property energy_battery_full_cap_broken_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_NOW,
+ POWER_SUPPLY_PROP_MODEL_NAME,
+ POWER_SUPPLY_PROP_MANUFACTURER,
+ POWER_SUPPLY_PROP_SERIAL_NUMBER,
+};
+
+/* Battery Management */
+struct acpi_offsets {
+ size_t offset; /* offset inside struct acpi_sbs_battery */
+ u8 mode; /* int or string? */
+};
+
+static const 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 const 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 const 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,
+ const 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)
+ strscpy(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_handle_info(battery->device->handle,
+ "_STA evaluation failed\n");
+ return -ENODEV;
+ }
+ return 0;
+}
+
+
+static int extract_battery_info(const int use_bix,
+ struct acpi_battery *battery,
+ const struct acpi_buffer *buffer)
+{
+ int result = -EFAULT;
+
+ if (use_bix && battery_bix_broken_package)
+ result = extract_package(battery, buffer->pointer,
+ extended_info_offsets + 1,
+ ARRAY_SIZE(extended_info_offsets) - 1);
+ else if (use_bix)
+ 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));
+ 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.
+ */
+ }
+ if (test_bit(ACPI_BATTERY_QUIRK_DEGRADED_FULL_CHARGE, &battery->flags) &&
+ battery->capacity_now > battery->full_charge_capacity)
+ battery->capacity_now = battery->full_charge_capacity;
+
+ return result;
+}
+
+static int acpi_battery_get_info(struct acpi_battery *battery)
+{
+ const int xinfo = test_bit(ACPI_BATTERY_XINFO_PRESENT, &battery->flags);
+ int use_bix;
+ int result = -ENODEV;
+
+ if (!acpi_battery_present(battery))
+ return 0;
+
+
+ for (use_bix = xinfo ? 1 : 0; use_bix >= 0; use_bix--) {
+ struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+ acpi_status status = AE_ERROR;
+
+ mutex_lock(&battery->lock);
+ status = acpi_evaluate_object(battery->device->handle,
+ use_bix ? "_BIX":"_BIF",
+ NULL, &buffer);
+ mutex_unlock(&battery->lock);
+
+ if (ACPI_FAILURE(status)) {
+ acpi_handle_info(battery->device->handle,
+ "%s evaluation failed: %s\n",
+ use_bix ? "_BIX":"_BIF",
+ acpi_format_exception(status));
+ } else {
+ result = extract_battery_info(use_bix,
+ battery,
+ &buffer);
+
+ kfree(buffer.pointer);
+ break;
+ }
+ }
+
+ if (!result && !use_bix && xinfo)
+ pr_warn(FW_BUG "The _BIX method is broken, using _BIF.\n");
+
+ 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_handle_info(battery->device->handle,
+ "_BST evaluation failed: %s",
+ acpi_format_exception(status));
+ 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);
+ pr_warn_once(FW_BUG "(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;
+ }
+ if (test_bit(ACPI_BATTERY_QUIRK_DEGRADED_FULL_CHARGE, &battery->flags) &&
+ battery->capacity_now > battery->full_charge_capacity)
+ battery->capacity_now = battery->full_charge_capacity;
+
+ 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_handle_debug(battery->device->handle, "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 const struct device_attribute alarm_attr = {
+ .attr = {.name = "alarm", .mode = 0644},
+ .show = acpi_battery_alarm_show,
+ .store = acpi_battery_alarm_store,
+};
+
+/*
+ * The Battery Hooking API
+ *
+ * This API is used inside other drivers that need to expose
+ * platform-specific behaviour within the generic driver in a
+ * generic way.
+ *
+ */
+
+static LIST_HEAD(acpi_battery_list);
+static LIST_HEAD(battery_hook_list);
+static DEFINE_MUTEX(hook_mutex);
+
+static void __battery_hook_unregister(struct acpi_battery_hook *hook, int lock)
+{
+ struct acpi_battery *battery;
+ /*
+ * In order to remove a hook, we first need to
+ * de-register all the batteries that are registered.
+ */
+ if (lock)
+ mutex_lock(&hook_mutex);
+ list_for_each_entry(battery, &acpi_battery_list, list) {
+ hook->remove_battery(battery->bat);
+ }
+ list_del(&hook->list);
+ if (lock)
+ mutex_unlock(&hook_mutex);
+ pr_info("extension unregistered: %s\n", hook->name);
+}
+
+void battery_hook_unregister(struct acpi_battery_hook *hook)
+{
+ __battery_hook_unregister(hook, 1);
+}
+EXPORT_SYMBOL_GPL(battery_hook_unregister);
+
+void battery_hook_register(struct acpi_battery_hook *hook)
+{
+ struct acpi_battery *battery;
+
+ mutex_lock(&hook_mutex);
+ INIT_LIST_HEAD(&hook->list);
+ list_add(&hook->list, &battery_hook_list);
+ /*
+ * Now that the driver is registered, we need
+ * to notify the hook that a battery is available
+ * for each battery, so that the driver may add
+ * its attributes.
+ */
+ list_for_each_entry(battery, &acpi_battery_list, list) {
+ if (hook->add_battery(battery->bat)) {
+ /*
+ * If a add-battery returns non-zero,
+ * the registration of the extension has failed,
+ * and we will not add it to the list of loaded
+ * hooks.
+ */
+ pr_err("extension failed to load: %s", hook->name);
+ __battery_hook_unregister(hook, 0);
+ goto end;
+ }
+ }
+ pr_info("new extension: %s\n", hook->name);
+end:
+ mutex_unlock(&hook_mutex);
+}
+EXPORT_SYMBOL_GPL(battery_hook_register);
+
+/*
+ * This function gets called right after the battery sysfs
+ * attributes have been added, so that the drivers that
+ * define custom sysfs attributes can add their own.
+ */
+static void battery_hook_add_battery(struct acpi_battery *battery)
+{
+ struct acpi_battery_hook *hook_node, *tmp;
+
+ mutex_lock(&hook_mutex);
+ INIT_LIST_HEAD(&battery->list);
+ list_add(&battery->list, &acpi_battery_list);
+ /*
+ * Since we added a new battery to the list, we need to
+ * iterate over the hooks and call add_battery for each
+ * hook that was registered. This usually happens
+ * when a battery gets hotplugged or initialized
+ * during the battery module initialization.
+ */
+ list_for_each_entry_safe(hook_node, tmp, &battery_hook_list, list) {
+ if (hook_node->add_battery(battery->bat)) {
+ /*
+ * The notification of the extensions has failed, to
+ * prevent further errors we will unload the extension.
+ */
+ pr_err("error in extension, unloading: %s",
+ hook_node->name);
+ __battery_hook_unregister(hook_node, 0);
+ }
+ }
+ mutex_unlock(&hook_mutex);
+}
+
+static void battery_hook_remove_battery(struct acpi_battery *battery)
+{
+ struct acpi_battery_hook *hook;
+
+ mutex_lock(&hook_mutex);
+ /*
+ * Before removing the hook, we need to remove all
+ * custom attributes from the battery.
+ */
+ list_for_each_entry(hook, &battery_hook_list, list) {
+ hook->remove_battery(battery->bat);
+ }
+ /* Then, just remove the battery from the list */
+ list_del(&battery->list);
+ mutex_unlock(&hook_mutex);
+}
+
+static void __exit battery_hook_exit(void)
+{
+ struct acpi_battery_hook *hook;
+ struct acpi_battery_hook *ptr;
+ /*
+ * At this point, the acpi_bus_unregister_driver()
+ * has called remove for all batteries. We just
+ * need to remove the hooks.
+ */
+ list_for_each_entry_safe(hook, ptr, &battery_hook_list, list) {
+ __battery_hook_unregister(hook, 1);
+ }
+ mutex_destroy(&hook_mutex);
+}
+
+static int sysfs_add_battery(struct acpi_battery *battery)
+{
+ struct power_supply_config psy_cfg = { .drv_data = battery, };
+ bool full_cap_broken = false;
+
+ if (!ACPI_BATTERY_CAPACITY_VALID(battery->full_charge_capacity) &&
+ !ACPI_BATTERY_CAPACITY_VALID(battery->design_capacity))
+ full_cap_broken = true;
+
+ if (battery->power_unit == ACPI_BATTERY_POWER_UNIT_MA) {
+ if (full_cap_broken) {
+ battery->bat_desc.properties =
+ charge_battery_full_cap_broken_props;
+ battery->bat_desc.num_properties =
+ ARRAY_SIZE(charge_battery_full_cap_broken_props);
+ } else {
+ battery->bat_desc.properties = charge_battery_props;
+ battery->bat_desc.num_properties =
+ ARRAY_SIZE(charge_battery_props);
+ }
+ } else {
+ if (full_cap_broken) {
+ battery->bat_desc.properties =
+ energy_battery_full_cap_broken_props;
+ battery->bat_desc.num_properties =
+ ARRAY_SIZE(energy_battery_full_cap_broken_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;
+ }
+ battery_hook_add_battery(battery);
+ 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;
+ }
+ battery_hook_remove_battery(battery);
+ 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;
+ }
+ }
+ }
+
+ if (test_bit(ACPI_BATTERY_QUIRK_DEGRADED_FULL_CHARGE, &battery->flags))
+ return;
+
+ if (acpi_battery_is_degraded(battery) &&
+ battery->capacity_now > battery->full_charge_capacity) {
+ set_bit(ACPI_BATTERY_QUIRK_DEGRADED_FULL_CHARGE, &battery->flags);
+ battery->capacity_now = battery->full_charge_capacity;
+ }
+}
+
+static int acpi_battery_update(struct acpi_battery *battery, bool resume)
+{
+ int 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) {
+ result = acpi_battery_get_info(battery);
+ if (result)
+ return result;
+ acpi_battery_init_alarm(battery);
+ }
+
+ result = acpi_battery_get_state(battery);
+ if (result)
+ return result;
+ acpi_battery_quirks(battery);
+
+ if (!battery->bat) {
+ result = sysfs_add_battery(battery);
+ if (result)
+ return result;
+ }
+
+ /*
+ * 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)))
+ acpi_pm_wakeup_event(&battery->device->dev);
+
+ 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);
+}
+
+/* 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) {
+ acpi_battery_refresh(battery);
+ } else {
+ result = acpi_battery_get_info(battery);
+ if (result)
+ return result;
+
+ result = sysfs_add_battery(battery);
+ if (result)
+ return result;
+ }
+
+ acpi_battery_init_alarm(battery);
+ acpi_battery_get_state(battery);
+ break;
+ }
+
+ return 0;
+}
+
+static int __init
+battery_bix_broken_package_quirk(const struct dmi_system_id *d)
+{
+ battery_bix_broken_package = 1;
+ return 0;
+}
+
+static int __init
+battery_notification_delay_quirk(const struct dmi_system_id *d)
+{
+ battery_notification_delay_ms = 1000;
+ return 0;
+}
+
+static int __init
+battery_ac_is_broken_quirk(const struct dmi_system_id *d)
+{
+ battery_ac_is_broken = 1;
+ return 0;
+}
+
+static const struct dmi_system_id bat_dmi_table[] __initconst = {
+ {
+ /* NEC LZ750/LS */
+ .callback = battery_bix_broken_package_quirk,
+ .matches = {
+ DMI_MATCH(DMI_SYS_VENDOR, "NEC"),
+ DMI_MATCH(DMI_PRODUCT_NAME, "PC-LZ750LS"),
+ },
+ },
+ {
+ /* Acer Aspire V5-573G */
+ .callback = battery_notification_delay_quirk,
+ .matches = {
+ DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
+ DMI_MATCH(DMI_PRODUCT_NAME, "Aspire V5-573G"),
+ },
+ },
+ {
+ /* Point of View mobii wintab p800w */
+ .callback = battery_ac_is_broken_quirk,
+ .matches = {
+ DMI_MATCH(DMI_BOARD_VENDOR, "AMI Corporation"),
+ DMI_MATCH(DMI_BOARD_NAME, "Aptio CRB"),
+ DMI_MATCH(DMI_BIOS_VERSION, "3BAIR1013"),
+ /* Above matches are too generic, add bios-date match */
+ DMI_MATCH(DMI_BIOS_DATE, "08/22/2014"),
+ },
+ },
+ {
+ /* Microsoft Surface Go 3 */
+ .callback = battery_notification_delay_quirk,
+ .matches = {
+ DMI_MATCH(DMI_SYS_VENDOR, "Microsoft Corporation"),
+ DMI_MATCH(DMI_PRODUCT_NAME, "Surface Go 3"),
+ },
+ },
+ {},
+};
+
+/*
+ * 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;
+
+ pr_info("Slot [%s] (battery %s)\n", 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);
+ 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)
+{
+ int result;
+
+ if (acpi_quirk_skip_acpi_ac_and_battery())
+ return;
+
+ dmi_check_system(bat_dmi_table);
+
+ result = acpi_bus_register_driver(&acpi_battery_driver);
+ battery_driver_registered = (result == 0);
+}
+
+static int __init acpi_battery_init(void)
+{
+ if (acpi_disabled)
+ return -ENODEV;
+
+ async_cookie = async_schedule(acpi_battery_init_async, NULL);
+ return 0;
+}
+
+static void __exit acpi_battery_exit(void)
+{
+ async_synchronize_cookie(async_cookie + 1);
+ if (battery_driver_registered) {
+ acpi_bus_unregister_driver(&acpi_battery_driver);
+ battery_hook_exit();
+ }
+}
+
+module_init(acpi_battery_init);
+module_exit(acpi_battery_exit);