Re: [PATCH v5 1/1] platform/x86: add Acer battery control driver

Am 05.08.26 um 20:46 schrieb Jelle van der Waa:

> Some Acer laptops can configure battery related features through Acer
> Care Center on Windows. This driver uses the power supply extension to
> set a battery charge limit and exposes the battery
> temperature.
>
> This driver is based on the existing acer-wmi-battery project on GitHub
> and was tested on an Acer Aspire A315-510P.
>
> Signed-off-by: Jelle van der Waa <[email protected]>
>
> ---
> v5:
> - Add Acer WMI Battery Interface documentation
> - Drop unneeded wmi_buffer output initialisation
> - Drop get_unaligned_le32, as wmi core returns aligned data
> - Derive temperature divider contsant from <linux/units.h> defines
> - Add trailing commas to any non-terminating entry in DMI match table
> - Remove duplicate DMI entry from DMI match table
> - Update set_battery_health_control_output members to be __le16 not u8
>    as WMI data suggests
> - Replace sizeof(u32) with sizeof(*result)
> - Add an empty line between if statements in POWER_SUPPLY_PROP_TEMP case
> - Drop unneeded .set_property callback in acer_wmi_battery_extension_v1
> - Introduce a force module parameter for easier testing of new notebook
>    models
> - Use "ret" instead of "r"
> - Check the "uReturn" value of SetBatteryHealthControl
> v4:
> - Add additional DMI ids from https://github.com/frederik-h/acer-wmi-battery/blob/main/MODELS.md
>    cross checked with DMI ids found in https://github.com/linuxhw/DMI
> - Move DMI matching to __init and make the DMI table __initconst
> - Port to the new wmidev_invoke_* API
> v3:
> - Add depends on DMI
> - Rename CamelCase struct member names
> - Simplify returning errors
> - Add comma to non-terminating entries
> - Simplified acer_wmi_battery_set_battery_health_control to acer_wmi_set_battery_health_control
> - Use sizeof for acpi_object buffer
> - Drop POWER_SUPPLY_EXTENSION macro
> v2:
> - Alphabetically sort linux headers
> - Include headers for types / _packed
> - Use cleanup.h instead of goto + label
> - Add missing prefix for set_battery_health_control
> - General code formatting fixes
> - Remove HWMON dependency in Kconfig
> - Use wmidev_evaluate_method()
> - Accept oversized ACPI buffers
> - Use DRIVER_NAME for battery extension name
> - Set no_singleton = true
> - Implement DMI matching to support laptops with only battery
>    temperature support.
> ---
>   .../wmi/devices/acer-wmi-battery.rst          |  70 +++
>   drivers/platform/x86/Kconfig                  |  12 +
>   drivers/platform/x86/Makefile                 |   1 +
>   drivers/platform/x86/acer-wmi-battery.c       | 449 ++++++++++++++++++
>   4 files changed, 532 insertions(+)
>   create mode 100644 Documentation/wmi/devices/acer-wmi-battery.rst
>   create mode 100644 drivers/platform/x86/acer-wmi-battery.c
>
> diff --git a/Documentation/wmi/devices/acer-wmi-battery.rst b/Documentation/wmi/devices/acer-wmi-battery.rst
> new file mode 100644
> index 000000000000..8aa3e1334490
> --- /dev/null
> +++ b/Documentation/wmi/devices/acer-wmi-battery.rst
> @@ -0,0 +1,70 @@
> +.. SPDX-License-Identifier: GPL-2.0-or-later
> +
> +====================================================
> +Acer WMI Battery interface driver (acer-wmi-battery)
> +====================================================
> +
> +Introduction
> +============
> +
> +Some Acer laptops support setting battery charge control limits and allow a
> +user to calibrate their battery.
> +
> +WMI interface description
> +=========================
> +
> +The WMI interface description can be decoded from the embedded binary MOF (bmof)
> +data using the `bmfdec <https://github.com/pali/bmfdec>`_ utility:
> +
> +::
> +
> +  [WMI, Dynamic, Provider("WmiProv"), Locale("MS\\0x409"), Description("Class used to control smart battery, Version 2.88"), guid("{79772EC5-04B1-4bfd-843C-61E7F77B6CC9}")]
> +  class BatteryControl {
> +    [key, read] string InstanceName;
> +    [read] boolean Active;
> +
> +    [WmiMethodId(19), Implemented, read, write, Description("Get battery Information Interface.")] void GetBattInfoInterface([in] uint32 uBatteryInfoIndex, [in] uint32 uBatteryNo, [out] uint32 uReturn);
> +    [WmiMethodId(20), Implemented, read, write, Description("Get Battery Health Control Status.")] void GetBatteryHealthControlStatus([in] uint8 uBatteryNo, [in] uint8 uFunctionQuery, [in] uint8 uReserved[2], [out] uint8 uFunctionList, [out] uint8 uReturn[2], [out] uint8 uFunctionStatus[5]);
> +    [WmiMethodId(21), Implemented, read, write, Description("Set Battery Health Control.")] void SetBatteryHealthControl([in] uint8 uBatteryNo, [in] uint8 uFunctionMask, [in] uint8 uFunctionStatus, [in] uint8 uReservedIn[5], [out] uint16 uReturn, [out] uint16 uReservedOut);
> +    [WmiMethodId(22), Implemented, read, write, Description("Get Battery Function Data.")] void GetBatteryFunctionData([in] uint8 uFunctionMask, [in] uint8 uReservedIn[3], [out] uint8 uReturnCode[2], [out] uint8 uBACStartTime[2], [out] uint8 uBACStopTime[2], [out] uint8 uBACStatus, [out] uint8 uReservedOut[9]);
> +    [WmiMethodId(23), Implemented, read, write, Description("Set Battery Function Data.")] void SetBatteryFunctionData([in] uint8 uFunctionMask, [in] uint8 uBACSwitch, [in] uint8 uReservedIn[6], [out] uint16 uReturnCode, [out] uint8 uReservedOut[2]);
> +  };
> +
> +For all methods the ``uBatteryNo`` is always ``0x1``, there are no known Acer
> +laptop models with two batteries.
> +
> +WMI method GetBatteryInfoInterface()
> +------------------------------------
> +
> +Returns additional battery information, the data seems to be based on the
> +"Smart Battery Data Specification". The only known value for
> +``uBatteryInfoIndex`` is ``0x8``, the battery temperature.
> +
> +WMI method GetBatteryHealthControlStatus()
> +------------------------------------------
> +
> +This interface does not exist on all Acer laptops, it returns whether battery
> +charge limiting or calibration mode is enabled.
> +
> +When calling this method, ``uFunctionList`` is a bitmask with known values:
> +
> ++--------------------+------------------------------------+
> +| Value              | Description                        |
> ++====================+====================================+
> +| 0x01               | Health mode supported              |
> ++--------------------+------------------------------------+
> +| 0x02               | Calibration mode supported         |
> ++--------------------+------------------------------------+
> +
> +``uFunctionStatus`` is a 5 byte array known elements are ``0`` for health mode
> +and ``1`` for calibration mode. A non-zero value means the mode is enabled.
> +
> +WMI method SetBatteryHealthControl()
> +------------------------------------
> +
> +This interface does not exist on all Acer laptops, it enables battery
> +charge limiting or battery calibration.
> +
> +The argument ``uFunctionMask`` is known to accept either ``0x01`` for setting
> +health mode or ``0x02`` for calibration mode; other values are unknown.
> +``uFunctionStatus`` is an uint8 value, a non-zero value enables the given mode.
> diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig
> index b54b5212b204..d4a8294df5e1 100644
> --- a/drivers/platform/x86/Kconfig
> +++ b/drivers/platform/x86/Kconfig
> @@ -189,6 +189,18 @@ config ACER_WMI
>   	  If you have an ACPI-WMI compatible Acer/ Wistron laptop, say Y or M
>   	  here.
>   
> +config ACER_WMI_BATTERY
> +	tristate "Acer WMI Battery"
> +	depends on ACPI_WMI
> +	depends on ACPI_BATTERY
> +	depends on DMI
> +	help
> +	  This is a driver for Acer laptops with battery health control. It
> +	  adds charge limit control and battery temperature reporting.
> +
> +	  If you have an ACPI-WMI Battery compatible Acer laptop, say Y or M
> +	  here.
> +
>   source "drivers/platform/x86/amd/Kconfig"
>   
>   config ADV_SWBUTTON
> diff --git a/drivers/platform/x86/Makefile b/drivers/platform/x86/Makefile
> index 872ac3842391..a877acd937cd 100644
> --- a/drivers/platform/x86/Makefile
> +++ b/drivers/platform/x86/Makefile
> @@ -20,6 +20,7 @@ obj-$(CONFIG_BITLAND_MIFS_WMI)		+= bitland-mifs-wmi.o
>   obj-$(CONFIG_ACERHDF)		+= acerhdf.o
>   obj-$(CONFIG_ACER_WIRELESS)	+= acer-wireless.o
>   obj-$(CONFIG_ACER_WMI)		+= acer-wmi.o
> +obj-$(CONFIG_ACER_WMI_BATTERY)	+= acer-wmi-battery.o
>   
>   # AMD
>   obj-y				+= amd/
> diff --git a/drivers/platform/x86/acer-wmi-battery.c b/drivers/platform/x86/acer-wmi-battery.c
> new file mode 100644
> index 000000000000..6163ee021ffb
> --- /dev/null
> +++ b/drivers/platform/x86/acer-wmi-battery.c
> @@ -0,0 +1,449 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * acer-wmi-battery.c: Acer battery health control driver
> + *
> + * This is a driver for the WMI battery health control interface found
> + * on some Acer laptops.  This interface allows to enable/disable a
> + * battery charge limit ("health mode") and exposes the battery temperature.
> + *
> + * Based on acer-wmi-battery https://github.com/frederik-h/acer-wmi-battery/
> + *
> + * Copyright (C) 2022-2025  Frederik Harwath <[email protected]>
> + */
> +
> +#include <linux/acpi.h>
> +#include <linux/cleanup.h>
> +#include <linux/compiler_attributes.h>
> +#include <linux/dmi.h>
> +#include <linux/init.h>
> +#include <linux/kernel.h>
> +#include <linux/limits.h>
> +#include <linux/module.h>
> +#include <linux/power_supply.h>
> +#include <linux/types.h>
> +#include <linux/units.h>
> +#include <linux/version.h>
> +#include <linux/wmi.h>

Hi,

please also add a include of linux/byteorder/generic.h

> +
> +#include <acpi/battery.h>
> +
> +#define DRIVER_NAME	"acer-wmi-battery"
> +
> +#define ACER_BATTERY_GUID "79772EC5-04B1-4BFD-843C-61E7F77B6CC9"
> +
> +/*
> + * The Acer OEM software seems to always use this battery index,
> + * so we emulate this behaviour to not confuse the underlying firmware.
> + *
> + * However this also means that we only fully support devices with a
> + * single battery for now.
> + */
> +#define ACER_BATTERY_INDEX	0x1
> +
> +static bool force;
> +module_param_unsafe(force, bool, 0);
> +MODULE_PARM_DESC(force, "Enable health mode control without checking for supported devices\n");
> +
> +struct get_battery_health_control_status_input {
> +	u8 battery_no;
> +	u8 function_query;
> +	u8 reserved[2];
> +} __packed;
> +
> +struct get_battery_health_control_status_output {
> +	u8 function_list;
> +	u8 ret[2];
> +	u8 function_status[5];
> +} __packed;
> +
> +struct set_battery_health_control_input {
> +	u8 battery_no;
> +	u8 function_mask;
> +	u8 function_status;
> +	u8 reserved_in[5];
> +} __packed;
> +
> +struct set_battery_health_control_output {
> +	__le16 ret;
> +	__le16 reserved_out;
> +} __packed;
> +
> +enum battery_mode {
> +	HEALTH_MODE = 1,
> +	CALIBRATION_MODE = 2,
> +};
> +
> +struct acer_wmi_battery_data {
> +	struct acpi_battery_hook hook;
> +	struct wmi_device *wdev;
> +	const struct power_supply_ext *battery_ext;
> +};
> +
> +bool health_mode;

This variable should be made static and marked as __ro_after_init.

> +
> +static int acer_wmi_battery_get_information(struct acer_wmi_battery_data *data,
> +					    u32 index, u32 battery, u32 *result)
> +{
> +	u32 args[2] = { index, battery };
> +	struct wmi_buffer input = { .length = sizeof(args), .data = args };
> +	struct wmi_buffer output;
> +	int ret;
> +
> +	ret = wmidev_invoke_method(data->wdev, 0, 19, &input, &output, sizeof(*result));
> +	if (ret)
> +		return ret;
> +
> +	*result = *(u32 *)output.data;

Please use __le32 here and convert the output data to u32 using le32_to_cpup().

> +	kfree(output.data);
> +
> +	return 0;
> +}
> +
> +static int acer_wmi_battery_get_health_control_status(struct acer_wmi_battery_data *data,
> +						      bool *health_mode)
> +{
> +	/*
> +	 * Acer Care Center seems to always call the WMI method
> +	 * with fixed parameters. This yields information about
> +	 * the availability and state of both health and
> +	 * calibration mode. The modes probably apply to
> +	 * all batteries of the system.
> +	 */
> +	struct get_battery_health_control_status_input args = {
> +		.battery_no = ACER_BATTERY_INDEX,
> +		.function_query = 0x1,
> +		.reserved = { 0x0, 0x0 },
> +	};
> +	struct wmi_buffer input = { .length = sizeof(args), .data = &args };
> +	struct wmi_buffer output;
> +	int ret;
> +
> +	ret = wmidev_invoke_method(data->wdev, 0, 20, &input, &output,
> +				   sizeof(struct get_battery_health_control_status_output));
> +	if (ret)
> +		return ret;
> +
> +	struct get_battery_health_control_status_output *status_output __free(kfree) = output.data;
> +
> +	if (health_mode) {

health_mode is always non-NULL, so please remove this unnecessary if-statement.

> +		if (!(status_output->function_list & HEALTH_MODE))
> +			return -EINVAL;
> +
> +		*health_mode = status_output->function_status[0] > 0;
> +	}
> +
> +	return 0;
> +}
> +
> +static int acer_wmi_battery_set_health_control(struct acer_wmi_battery_data *data,
> +					       u8 function, bool function_status)
> +{
> +	struct set_battery_health_control_input args = {
> +		.battery_no = ACER_BATTERY_INDEX,
> +		.function_mask = function,
> +		.function_status = function_status ? 1 : 0,
> +		.reserved_in = { 0x0, 0x0, 0x0, 0x0, 0x0 },
> +	};
> +	struct wmi_buffer input = { .length = sizeof(args), .data = &args };
> +	struct wmi_buffer output;
> +	int ret;
> +
> +	ret = wmidev_invoke_method(data->wdev, 0, 21, &input, &output,
> +				   sizeof(struct set_battery_health_control_output));
> +	if (ret)
> +		return ret;
> +
> +	struct set_battery_health_control_output *status_output __free(kfree) = output.data;
> +	if (le16_to_cpu(status_output->ret) != 0)
> +		return -EIO;
> +
> +	return 0;
> +}
> +
> +static int acer_battery_ext_property_get(struct power_supply *psy,
> +					 const struct power_supply_ext *ext,
> +					 void *ext_data,
> +					 enum power_supply_property psp,
> +					 union power_supply_propval *val)
> +{
> +	struct acer_wmi_battery_data *data = ext_data;
> +	bool health_mode;
> +	u32 value;
> +	int ret;
> +
> +	switch (psp) {
> +	case POWER_SUPPLY_PROP_CHARGE_TYPES:
> +		ret = acer_wmi_battery_get_health_control_status(data, &health_mode);
> +		if (ret)
> +			return ret;
> +
> +		val->intval = health_mode ? POWER_SUPPLY_CHARGE_TYPE_LONGLIFE
> +					  : POWER_SUPPLY_CHARGE_TYPE_STANDARD;
> +		break;
> +	case POWER_SUPPLY_PROP_TEMP:
> +		ret = acer_wmi_battery_get_information(data, 0x8, ACER_BATTERY_INDEX, &value);
> +		if (ret)
> +			return ret;
> +
> +		if (value > U16_MAX)
> +			return -ERANGE;
> +
> +		val->intval = value + ABSOLUTE_ZERO_MILLICELSIUS / MILLIDEGREE_PER_DECIDEGREE;
> +		break;
> +	default:
> +		return -EINVAL;
> +	}
> +
> +	return 0;
> +}
> +
> +static int acer_battery_ext_property_set(struct power_supply *psy,
> +					 const struct power_supply_ext *ext,
> +					 void *ext_data,
> +					 enum power_supply_property psp,
> +					 const union power_supply_propval *val)
> +{
> +	struct acer_wmi_battery_data *data = ext_data;
> +
> +	switch (psp) {
> +	case POWER_SUPPLY_PROP_CHARGE_TYPES:
> +		return acer_wmi_battery_set_health_control(data, HEALTH_MODE,
> +				val->intval == POWER_SUPPLY_CHARGE_TYPE_LONGLIFE);
> +	default:
> +		return -EINVAL;
> +	}
> +}
> +
> +static int acer_battery_ext_property_is_writeable(struct power_supply *psy,
> +						  const struct power_supply_ext *ext,
> +						  void *ext_data,
> +						  enum power_supply_property psp)
> +{
> +	switch (psp) {
> +	case POWER_SUPPLY_PROP_CHARGE_TYPES:
> +		return true;
> +	default:
> +		return false;
> +	}
> +}
> +
> +static const struct dmi_system_id acer_wmi_battery_health_mode_table[] __initconst = {
> +	{
> +		.matches = {
> +			DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
> +			DMI_MATCH(DMI_PRODUCT_NAME, "Aspire A315-510P"),
> +		},
> +	},
> +	{
> +		.matches = {
> +			DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
> +			DMI_MATCH(DMI_PRODUCT_NAME, "Aspire A315-24PT"),
> +		},
> +	},
> +	{
> +		.matches = {
> +			DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
> +			DMI_MATCH(DMI_PRODUCT_NAME, "Aspire A315-44P"),
> +		},
> +	},
> +	{
> +		.matches = {
> +			DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
> +			DMI_MATCH(DMI_PRODUCT_NAME, "Aspire A315-59"),
> +		},
> +	},
> +	{
> +		.matches = {
> +			DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
> +			DMI_MATCH(DMI_PRODUCT_NAME, "Aspire A315-59"),
> +		},
> +	},
> +	{
> +		.matches = {
> +			DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
> +			DMI_MATCH(DMI_PRODUCT_NAME, "Aspire A715-42G"),
> +		},
> +	},
> +	{
> +		.matches = {
> +			DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
> +			DMI_MATCH(DMI_PRODUCT_NAME, "Nitro ANV15-51"),
> +		},
> +	},
> +	{
> +		.matches = {
> +			DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
> +			DMI_MATCH(DMI_PRODUCT_NAME, "Nitro AN515-57"),
> +		},
> +	},
> +	{
> +		.matches = {
> +			DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
> +			DMI_MATCH(DMI_PRODUCT_NAME, "Nitro AN515-58"),
> +		},
> +	},
> +	{
> +		.matches = {
> +			DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
> +			DMI_MATCH(DMI_PRODUCT_NAME, "Nitro AN517-54"),
> +		},
> +	},
> +	{
> +		.matches = {
> +			DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
> +			DMI_MATCH(DMI_PRODUCT_NAME, "Nitro AN517-54"),
> +		},
> +	},
> +	{
> +		.matches = {
> +			DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
> +			DMI_MATCH(DMI_PRODUCT_NAME, "Predator PHN16-71"),
> +		},
> +	},
> +	{
> +		.matches = {
> +			DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
> +			DMI_MATCH(DMI_PRODUCT_NAME, "Swift SF314-34"),
> +		},
> +	},
> +	{
> +		.matches = {
> +			DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
> +			DMI_MATCH(DMI_PRODUCT_NAME, "Swift SF314-43"),
> +		},
> +	},
> +	{
> +		.matches = {
> +			DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
> +			DMI_MATCH(DMI_PRODUCT_NAME, "Swift SFE16-44"),
> +		},
> +	},
> +	{
> +		.matches = {
> +			DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
> +			DMI_MATCH(DMI_PRODUCT_NAME, "Swift SFG16-72"),
> +		},
> +	},
> +	{
> +		.matches = {
> +			DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
> +			DMI_MATCH(DMI_PRODUCT_NAME, "Swift SFX14-71G"),
> +		},
> +	},
> +	{
> +		.matches = {
> +			DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
> +			DMI_MATCH(DMI_PRODUCT_NAME, "Swift SFX16-61G"),
> +		},
> +	},
> +	{}
> +};

Maybe you could move this whitelist a bit further down, just below acer_wmi_battery_module_init()?

Otherwise, the driver looks good to me.

Thanks,
Armin Wolf

> +
> +static const enum power_supply_property acer_battery_properties_v1[] = {
> +	POWER_SUPPLY_PROP_TEMP,
> +};
> +
> +static const enum power_supply_property acer_battery_properties_v2[] = {
> +	POWER_SUPPLY_PROP_TEMP,
> +	POWER_SUPPLY_PROP_CHARGE_TYPES,
> +};
> +
> +static const struct power_supply_ext acer_wmi_battery_extension_v1 = {
> +	.name			= DRIVER_NAME,
> +	.properties		= acer_battery_properties_v1,
> +	.num_properties		= ARRAY_SIZE(acer_battery_properties_v1),
> +	.get_property		= acer_battery_ext_property_get,
> +	.property_is_writeable	= acer_battery_ext_property_is_writeable,

Please remove this line, as there exist no writable properties in the v1 extension.
The power supply core should then automatically fall back to read-only.

With those issues being addressed:

Reviewed-by: Armin Wolf <[email protected]>

> +};
> +
> +static const struct power_supply_ext acer_wmi_battery_extension_v2 = {
> +	.name			= DRIVER_NAME,
> +	.properties		= acer_battery_properties_v2,
> +	.num_properties		= ARRAY_SIZE(acer_battery_properties_v2),
> +	.charge_types           = BIT(POWER_SUPPLY_CHARGE_TYPE_STANDARD) |
> +				  BIT(POWER_SUPPLY_CHARGE_TYPE_LONGLIFE),
> +	.get_property		= acer_battery_ext_property_get,
> +	.set_property		= acer_battery_ext_property_set,
> +	.property_is_writeable	= acer_battery_ext_property_is_writeable,
> +};
> +
> +static int acer_battery_add(struct power_supply *battery, struct acpi_battery_hook *hook)
> +{
> +	struct acer_wmi_battery_data *data = container_of(hook, struct acer_wmi_battery_data, hook);
> +
> +	return power_supply_register_extension(battery, data->battery_ext,
> +					       &data->wdev->dev, data);
> +}
> +
> +static int acer_battery_remove(struct power_supply *battery, struct acpi_battery_hook *hook)
> +{
> +	struct acer_wmi_battery_data *data = container_of(hook, struct acer_wmi_battery_data, hook);
> +
> +	power_supply_unregister_extension(battery, data->battery_ext);
> +
> +	return 0;
> +}
> +
> +static int acer_wmi_battery_probe(struct wmi_device *wdev, const void *context)
> +{
> +	struct acer_wmi_battery_data *data;
> +
> +	data = devm_kzalloc(&wdev->dev, sizeof(*data), GFP_KERNEL);
> +	if (!data)
> +		return -ENOMEM;
> +
> +	dev_set_drvdata(&wdev->dev, data);
> +	data->wdev = wdev;
> +	data->battery_ext = health_mode ? &acer_wmi_battery_extension_v2
> +					: &acer_wmi_battery_extension_v1;
> +	data->hook.name = "Acer Battery Extension";
> +	data->hook.add_battery = acer_battery_add;
> +	data->hook.remove_battery = acer_battery_remove;
> +
> +	return devm_battery_hook_register(&data->wdev->dev, &data->hook);
> +}
> +
> +static const struct wmi_device_id acer_wmi_battery_id_table[] = {
> +	{ ACER_BATTERY_GUID, NULL },
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(wmi, acer_wmi_battery_id_table);
> +
> +static struct wmi_driver acer_wmi_battery_driver = {
> +	.driver = {
> +		.name = DRIVER_NAME,
> +		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
> +	},
> +	.id_table = acer_wmi_battery_id_table,
> +	.probe = acer_wmi_battery_probe,
> +	.no_singleton = true,
> +};
> +
> +static int __init acer_wmi_battery_module_init(void)
> +{
> +	int ret;
> +
> +	if (dmi_check_system(acer_wmi_battery_health_mode_table) || force)
> +		health_mode = true;
> +	else
> +		health_mode = false;
> +
> +	ret = wmi_driver_register(&acer_wmi_battery_driver);
> +	if (ret)
> +		return ret;
> +
> +	return ret;
> +}
> +
> +static void __exit acer_wmi_battery_module_exit(void)
> +{
> +	wmi_driver_unregister(&acer_wmi_battery_driver);
> +}
> +
> +module_init(acer_wmi_battery_module_init);
> +module_exit(acer_wmi_battery_module_exit);
> +
> +MODULE_AUTHOR("Frederik Harwath <[email protected]>");
> +MODULE_AUTHOR("Jelle van der Waa <[email protected]>");
> +MODULE_DESCRIPTION("Acer battery health control WMI driver");
> +MODULE_LICENSE("GPL");