APCI3501_AO_CTRL_STATUS_REG
status = inl(dev->iobase + APCI3501_AO_CTRL_STATUS_REG);
outl(0, dev->iobase + APCI3501_AO_CTRL_STATUS_REG);
dev->iobase + APCI3501_AO_CTRL_STATUS_REG);
dev->iobase + APCI3501_AO_CTRL_STATUS_REG);