PCH_IC_INTR_MASK
write32(bus->registers + PCH_IC_INTR_MASK, 0);
write32(bus->registers + PCH_IC_INTR_MASK, PCH_IC_INTR_STAT_TX_EMPTY);
write32(bus->registers + PCH_IC_INTR_MASK,
write32(bus->registers + PCH_IC_INTR_MASK,
write32(bus->registers + PCH_IC_INTR_MASK, 0);