UART_BRDV
brdv = readl(port->membase + UART_BRDV);
writel(brdv, port->membase + UART_BRDV);
mvuart->pm_regs.brdv = readl(port->membase + UART_BRDV);
writel(mvuart->pm_regs.brdv, port->membase + UART_BRDV);