CDNS_UART_IER
port->membase + CDNS_UART_IER);
writel(CDNS_UART_RX_IRQS, port->membase + CDNS_UART_IER);
writel(imr, port->membase + CDNS_UART_IER);
writel(CDNS_UART_IXR_TOUT, port->membase + CDNS_UART_IER);
writel(CDNS_UART_IXR_TXEMPTY, cdns_uart->port->membase + CDNS_UART_IER);