pBufIn

[in] Set to a pointer to POWER_RELATIONSHIP. This defines the target device for parent and bus drivers. Otherwise, set to NULL.

dwLenIn

[in] Size of the POWER_RELATIONSHIP structure.

pBufOut

[out] Set to a pointer to POWER_CAPABILITIES. This defines the devices power capabilities.

dwLenOut

[out] Size of the POWER_CAPABILITIES structure.

pdwActualOut

[out] Number of bytes passed back in the pBufOut buffer.

TRUE indicates success. FALSE indicates failure.

If a driver fails this I/O control, Power Manager assumes that the driver does not handle the remaining I/O controls and does not send them. As a minimum, the driver should complete the DeviceDx in POWER_CAPABILITIES.

During initialization, through this I/O control, the device driver should put the device into D0 and report device capabilities as accurately as possible when queried by Power Manager.

All drivers that support Power Manager must handle this I/O control.

Reference