serial: fsl-lpuart: disable interrupt when suspend
authorYuan Yao <yao.yuan@freescale.com>
Fri, 23 Jan 2015 09:48:54 +0000 (17:48 +0800)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Mon, 2 Feb 2015 18:09:55 +0000 (10:09 -0800)
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

index 914f9a2a01576612684f2fd6eaeaa7f3ecda0070..f196a33e619b5e48138e89c8441e0edd00c66e07 100644 (file)
@@ -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);