MBOX5
in_ptr = sbus_readw(qpti->qregs + MBOX5);
sbus_writew(out_ptr, qpti->qregs + MBOX5);
case 6: sbus_writew(param[5], qpti->qregs + MBOX5);
case 6: param[5] = sbus_readw(qpti->qregs + MBOX5);