USB Device HID Function Driver Device Layer callback function pointer group 

This is a pointer to a group of HID Function Driver callback function pointers. The application must use this pointer while registering an instance of the HID function driver with the Device Layer via the function driver registration table i.e. the driver member of the function driver registration object in the device layer function driver registration table should be set to this value.

#define USB_DEVICE_HID_FUNCTION_DRIVER 

None.