WdfDeviceInitRegisterPowerPolicyStateChangeCallback method

[Applies to KMDF only]

The WdfDeviceInitRegisterPowerPolicyStateChangeCallback method registers a driver-supplied event callback function that the framework calls when a device's power policy state machine changes state.

Syntax

C++


NTSTATUS WdfDeviceInitRegisterPowerPolicyStateChangeCallback(
  [in]  PWDFDEVICE_INIT DeviceInit,
  [in]  WDF_DEVICE_POWER_POLICY_STATE PowerPolicyState,
  [in]  PFN_WDF_DEVICE_POWER_POLICY_STATE_CHANGE_NOTIFICATION EvtDevicePowerPolicyStateChange,
  [in]  ULONG CallbackTypes
);

Parameters

DeviceInit [in]: A caller-supplied pointer to a WDFDEVICE_INIT structure.
PowerPolicyState [in]: A WDF_DEVICE_POWER_POLICY_STATE enumerator that identifies the power policy machine state for which the driver is requesting notification.
EvtDevicePowerPolicyStateChange [in]: A caller-supplied pointer to the driver's EvtDevicePowerPolicyStateChange event callback function.
CallbackTypes [in]: An ORed combination of WDF_STATE_NOTIFICATION_TYPE-typed enumerators.

Return value

If WdfDeviceInitRegisterPowerPolicyStateChangeCallback encounters no errors, it returns STATUS_SUCCESS. Additional return values include:

Return code	Description
STATUS_INVALID_PARAMETER	An invalid parameter was detected.
STATUS_INSUFFICIENT_RESOURCES	There is insufficient memory to complete the operation.

Remarks

If your driver calls WdfDeviceInitRegisterPowerPolicyStateChangeCallback, it must do so before it calls WdfDeviceCreate.

For more information about WdfDeviceInitRegisterPowerPolicyStateChangeCallback, see State Machines in the Framework.

Examples

The following code example registers an event callback function that the framework will call when the device's power policy state machine changes state.


status = WdfDeviceInitRegisterPowerPolicyStateChangeCallback(
                                 DeviceInit,
                                 WdfDevStatePwrPolCheckPowerPageable,
                                 PciDrvPowerPolicyStateChangeCallback,
                                 StateNotificationAllStates
                                 );

Requirements

Minimum KMDF version	1.0
Header	Wdfdevice.h (include Wdf.h)
Library	Wdf01000.sys (see Framework Library Versioning.)
IRQL	PASSIVE_LEVEL
DDI compliance rules	ChildDeviceInitAPI, DeviceInitAPI, DriverCreate, InitFreeDeviceCallback, InitFreeDeviceCreate, InitFreeNull, KmdfIrql, KmdfIrql2, PdoDeviceInitAPI, PdoInitFreeDeviceCallback, PdoInitFreeDeviceCreate

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