openwrt/target/linux/layerscape/patches-5.4/819-uart-0011-serial-fsl_lpuart-enable-two-stop-bits.patch

From 5f1a35c3f5c17cc6229873248a56784fcd03db1c Mon Sep 17 00:00:00 2001
From: Fugang Duan <fugang.duan@nxp.com>
Date: Fri, 27 Sep 2019 15:18:41 +0800
Subject: [PATCH] serial: fsl_lpuart: enable two stop bits

Add two stop bits support.
User can run the command to enable two stop bits
for test: stty  cstopb  -F /dev/ttyLPx

Signed-off-by: Fugang Duan <fugang.duan@nxp.com>
---
 drivers/tty/serial/fsl_lpuart.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

--- a/drivers/tty/serial/fsl_lpuart.c
+++ b/drivers/tty/serial/fsl_lpuart.c
@@ -2135,11 +2135,12 @@ lpuart32_set_termios(struct uart_port *p
 {
 	struct lpuart_port *sport = container_of(port, struct lpuart_port, port);
 	unsigned long flags;
-	unsigned long ctrl, old_ctrl, modem;
+	unsigned long ctrl, old_ctrl, bd, modem;
 	unsigned int  baud;
 	unsigned int old_csize = old ? old->c_cflag & CSIZE : CS8;
 
 	ctrl = old_ctrl = lpuart32_read(&sport->port, UARTCTRL);
+	bd = lpuart32_read(&sport->port, UARTBAUD);
 	modem = lpuart32_read(&sport->port, UARTMODIR);
 	/*
 	 * only support CS8 and CS7, and for CS7 must enable PE.
@@ -2176,7 +2177,9 @@ lpuart32_set_termios(struct uart_port *p
 	}
 
 	if (termios->c_cflag & CSTOPB)
-		termios->c_cflag &= ~CSTOPB;
+		bd |= UARTBAUD_SBNS;
+	else
+		bd &= ~UARTBAUD_SBNS;
 
 	/* parity must be enabled when CS7 to match 8-bits format */
 	if ((termios->c_cflag & CSIZE) == CS7)
@@ -2246,6 +2249,7 @@ lpuart32_set_termios(struct uart_port *p
 	lpuart32_write(&sport->port, old_ctrl & ~(UARTCTRL_TE | UARTCTRL_RE),
 		       UARTCTRL);
 
+	lpuart32_write(&sport->port, bd, UARTBAUD);
 	lpuart32_serial_setbrg(sport, baud);
 	lpuart32_write(&sport->port, modem, UARTMODIR);
 	lpuart32_write(&sport->port, ctrl, UARTCTRL);