serial: imx: add support for loopback mode.

Add the loopback mode support for imx uart driver.

Signed-off-by: Huang Shijie <b32955@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
index b2cfdb6..d799140 100644 (file)
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -806,6 +806,9 @@ static unsigned int imx_get_mctrl(struct uart_port *port)
        if (readl(sport->port.membase + UCR2) & UCR2_CTS)
                tmp |= TIOCM_RTS;
 
+       if (readl(sport->port.membase + uts_reg(sport)) & UTS_LOOP)
+               tmp |= TIOCM_LOOP;
+
        return tmp;
 }
 
@@ -821,6 +824,11 @@ static void imx_set_mctrl(struct uart_port *port, unsigned int mctrl)
                        temp |= UCR2_CTS;
 
        writel(temp, sport->port.membase + UCR2);
+
+       temp = readl(sport->port.membase + uts_reg(sport)) & ~UTS_LOOP;
+       if (mctrl & TIOCM_LOOP)
+               temp |= UTS_LOOP;
+       writel(temp, sport->port.membase + uts_reg(sport));
 }
 
 /*