BCLASS_SET_INFORMATION_CALLBACK callback function (batclass.h)

Article
10/13/2021

BatteryMiniSetInformation requests that a battery enter the charging or discharging state, or sets a critical bias value for the battery.

Syntax

BCLASS_SET_INFORMATION_CALLBACK BclassSetInformationCallback;

NTSTATUS BclassSetInformationCallback(
  [in] PVOID Context,
  [in] ULONG BatteryTag,
  [in] BATTERY_SET_INFORMATION_LEVEL Level,
  [in] PVOID Buffer
)
{...}

Parameters

[in] Context

A pointer to the context area allocated by the miniclass driver for the battery device.

[in] BatteryTag

A battery tag value previously returned by BatteryMiniQueryTag.

[in] Level

One of the following values: BatteryCriticalBias, BatteryCharge, or BatteryDischarge.

[in] Buffer

The critical bias adjustment in milliwatts if Level is BatteryCriticalBias. Not used for other values of Level.

Return value

BatteryMiniSetInformation returns one of the following:

Return code	Description
STATUS_SUCCESS	The operation succeeded.
STATUS_NO_SUCH_DEVICE	No battery is present.
STATUS_NOT_SUPPORTED	The specified battery does not support the requested operation.
STATUS_UNSUCCESSFUL	The operation failed.

Remarks

The battery class driver calls BatteryMiniSetInformation to request that a battery start to charge or discharge. It can also call this routine to set a critical bias value.

With a smart battery charger/selector, the class driver specifies BatteryCharge to select a battery to charge, possibly discontinuing the charging of another battery.

The class driver specifies BatteryDischarge to indicate which battery should power the system.

The critical bias adjustment is analogous to the reserve capacity of the gas tank in an automobile. It represents the remaining charge when the battery capacity is reported as zero. Although the class driver does not change the critical bias value in normal use, this field is provided in the interface as a maintenance feature. Not all batteries can maintain a critical bias setting. Miniclass drivers for such batteries should return STATUS_NOT_SUPPORTED.

Requirements

Requirement	Value
Target Platform	Desktop
Header	batclass.h (include Batclass.h)
IRQL	PASSIVE_LEVEL

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