serial: fsl-lpuart: disable interrupt when suspend

For power management support, we should disable TX and
TX interrupt so that kernel can prepare for deep sleep.

Retain RX and RX interrupt for wakeup the kernel when
receive the input character.
Signed-off-by: Yuan Yao <yao.yuan@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/fsl_lpuart.c

@@ -1846,6 +1846,19 @@ static int lpuart_remove(struct platform_device *pdev)
 static int lpuart_suspend(struct device *dev)
 {
 	struct lpuart_port *sport = dev_get_drvdata(dev);
+	unsigned long temp;
+
+	if (sport->lpuart32) {
+		/* disable Rx/Tx and interrupts */
+		temp = lpuart32_read(sport->port.membase + UARTCTRL);
+		temp &= ~(UARTCTRL_TE | UARTCTRL_TIE | UARTCTRL_TCIE);
+		lpuart32_write(temp, sport->port.membase + UARTCTRL);
+	} else {
+		/* disable Rx/Tx and interrupts */
+		temp = readb(sport->port.membase + UARTCR2);
+		temp &= ~(UARTCR2_TE | UARTCR2_TIE | UARTCR2_TCIE);
+		writeb(temp, sport->port.membase + UARTCR2);
+	}
 
 	uart_suspend_port(&lpuart_reg, &sport->port);