UART_OSAMP
osamp = readl(port->membase + UART_OSAMP);
writel(osamp, port->membase + UART_OSAMP);
mvuart->pm_regs.osamp = readl(port->membase + UART_OSAMP);
writel(mvuart->pm_regs.osamp, port->membase + UART_OSAMP);