Bluetooth HFP DDI Reference
Windows 8 has introduced the GUID_DEVINTERFACE_BLUETOOTH_HFP_SCO_HCIBYPASS class, with interfaces that implement I/O control codes (IOCTLs) and structures for the Hands-free profile (HFP) bypass audio driver.
For each HFP on a paired Bluetooth device the HFP driver registers an interface in this class. The interface is registered and enabled after the device is paired and the HFP driver is running. When the driver stops, the interface is disabled and unregistered.
When you develop a driver for bypass audio connections on a Bluetooth controller, your driver can use these interfaces to fully implement Bluetooth audio support. The HFP device allows only a single file object on the GUID_DEVINTERFACE_BLUETOOTH_HFP_SCO_HCIBYPASS device interface.
The following topics describe the structures and IOCTLs that are defined for this class.