IRQCONTROL
nsp_write(base, IRQCONTROL, IRQCONTROL_TIMER_CLEAR);
nsp_write(base, IRQCONTROL, IRQCONTROL_TIMER_CLEAR | IRQCONTROL_FIFO_CLEAR);
nsp_write(base, IRQCONTROL, IRQCONTROL_RESELECT_CLEAR);
nsp_write(base, IRQCONTROL, IRQCONTROL_ALLMASK);
nsp_write(base, IRQCONTROL, IRQCONTROL_ALLCLEAR);
nsp_write(base, IRQCONTROL, IRQCONTROL_ALLMASK);
nsp_write(base, IRQCONTROL, IRQCONTROL_ALLCLEAR);
nsp_write(base, IRQCONTROL, IRQCONTROL_IRQDISABLE);
nsp_write(base, IRQCONTROL, 0);
outb(0xf0, SLIO_REG(chip, IRQCONTROL));
outb(0x00, SLIO_REG(chip, IRQCONTROL)); /* disable irqs */
outb(0x00, SLIO_REG(chip, IRQCONTROL));
status = inb(SLIO_REG(chip, IRQCONTROL));