CDNS_UART_RX_IRQS
writel(CDNS_UART_RX_IRQS | CDNS_UART_IXR_BRK,
writel(CDNS_UART_RX_IRQS, port->membase + CDNS_UART_IER);
writel(CDNS_UART_RX_IRQS, port->membase + CDNS_UART_IDR);