From 4dc6f2b9d454099445b8bc3a4a6328761335ce4d Mon Sep 17 00:00:00 2001
From: Fugang Duan <fugang.duan@nxp.com>
Date: Wed, 11 Sep 2019 16:23:25 +0800
Subject: [PATCH] tty: serial: fsl_lpuart: enable loopback mode

Enable lpuart32 loopback mode.

Signed-off-by: Fugang Duan <fugang.duan@nxp.com>
---
 drivers/tty/serial/fsl_lpuart.c | 8 ++++++++
 1 file changed, 8 insertions(+)

--- a/drivers/tty/serial/fsl_lpuart.c
+++ b/drivers/tty/serial/fsl_lpuart.c
@@ -1474,6 +1474,14 @@ static void lpuart32_set_mctrl(struct ua
 		temp |= UARTMODIR_TXCTSE;
 
 	lpuart32_write(port, temp, UARTMODIR);
+
+	temp = lpuart32_read(port, UARTCTRL);
+	if (mctrl & TIOCM_LOOP)
+		temp |= UARTCTRL_LOOPS;
+	else
+		temp &= ~UARTCTRL_LOOPS;
+
+	lpuart32_write(port, temp, UARTCTRL);
 }
 
 static void lpuart_break_ctl(struct uart_port *port, int break_state)