EVENT_BUT
ms->ms_eventstate = EVENT_BUT(usbmsp->usbms_num_buttons);
ms->ms_eventstate = EVENT_BUT(nbutt);
} while (ms->ms_eventstate != EVENT_BUT(nbutt));
button_number = nbutt - (EVENT_BUT(nbutt) - ms->ms_eventstate) - 1;
hwbit = USBMS_BUT(nbutt) >> (EVENT_BUT(nbutt) -