CDNS_UART_IXR_BRK
writel(CDNS_UART_RX_IRQS | CDNS_UART_IXR_BRK,
port->read_status_mask |= CDNS_UART_IXR_BRK;
(port->read_status_mask & CDNS_UART_IXR_BRK)) {
port->read_status_mask &= ~CDNS_UART_IXR_BRK;