This section describes how user-mode applications and kernel-mode drivers find and open a top-level HID collection.
Microsoft Windows provides device installation routines (SetupDiXxx functions) to find and identify the HIDClass devices. Windows provides other Win32 functions to initialize and connect to a HID collection.
After a user-mode application is loaded, it does the following sequence of operations:
Calls HidD_GetHidGuid to obtain the system-defined GUID for HIDClass devices.
Calls SetupDiGetClassDevs to obtain a handle to an opaque device information set that describes the device interfaces supported by all the HID collections currently installed in the system. The application should specify DIGCF_PRESENT and DIGCF_DEVICEINTERFACE in the Flags parameter that is passed to SetupDiGetClassDevs.
Calls SetupDiEnumDeviceInterfaces repeatedly to retrieve all the available interface information.
Calls SetupDiGetDeviceInterfaceDetail to format interface information for each collection as a SP_INTERFACE_DEVICE_DETAIL_DATA structure. The DevicePath member of this structure contains the user-mode name that the application uses with the Win32 function CreateFile to obtain a file handle to a HID collection.
Calls CreateFile to obtain a file handle to a HID collection.
If a kernel-mode driver is a function or filter driver, it has attached a device object to the HID collection's device stack. The driver has to only use a create request to open the device.
If the driver is not a function or filter driver, it typically uses Plug and Play notification to find a collection. After finding a collection, the driver uses a create request to open the collection.