The USB HID Host Mouse Driver interacts with the USB Host HID Client Driver to control the attached HID device. The USB Host Layer attaches the USB HID Host Client Driver to the HID device when it meets the matching criteria specified in the USB Host TPL table. 

The USB HID Host Client driver notifies the mouse driver of device attach and detach information and with report receive events with relevant event data. On a report receive event, the USB Host HID Mouse Driver obtains all of the field information present in the Report Descriptor of the mouse device and uses that field information and the INTERRUPT IN data received to understand mouse parameter values.