serial: imx: add support for DTE mode

The uart works in the DCE mode by default, but sometime we need it
works at the DTE mode.

This patch adds the support for the DTE mode.

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

1 files changed, 6 insertions, 0 deletions

diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
index 72bc1dbcd055..381a2d79593c 100644
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -201,6 +201,7 @@ struct imx_port {
         unsigned int            old_status;
         int                     txirq, rxirq, rtsirq;
         unsigned int            have_rtscts:1;
+        unsigned int            dte_mode:1;
         unsigned int            use_irda:1;
         unsigned int            irda_inv_rx:1;
         unsigned int            irda_inv_tx:1;
@@ -1020,6 +1021,8 @@ imx_set_termios(struct uart_port *port, struct ktermios *termios,
 
         ufcr = readl(sport->port.membase + UFCR);
         ufcr = (ufcr & (~UFCR_RFDIV)) | UFCR_RFDIV_REG(div);
+        if (sport->dte_mode)
+                ufcr |= UFCR_DCEDTE;
         writel(ufcr, sport->port.membase + UFCR);
 
         writel(num, sport->port.membase + UBIR);
@@ -1444,6 +1447,9 @@ static int serial_imx_probe_dt(struct imx_port *sport,
         if (of_get_property(np, "fsl,irda-mode", NULL))
                 sport->use_irda = 1;
 
+        if (of_get_property(np, "fsl,dte-mode", NULL))
+                sport->dte_mode = 1;
+
         sport->devdata = of_id->data;
 
         return 0;