LTQ_ASC_IRNCR
__raw_writel(ASC_IRNCR_TIR, port->membase + LTQ_ASC_IRNCR);
__raw_writel(ASC_IRNCR_EIR, port->membase + LTQ_ASC_IRNCR);
__raw_writel(ASC_IRNCR_RIR, port->membase + LTQ_ASC_IRNCR);
stat = readl(port->membase + LTQ_ASC_IRNCR);