diff mbox series

[RFC,v1,4/7] serial: imx: set_termios(): preserve RTS state

Message ID 1561042073-617-5-git-send-email-sorganov@gmail.com (mailing list archive)
State RFC
Headers show
Series serial: imx: fix RTS and RTS/CTS handling | expand

Commit Message

Sergey Organov June 20, 2019, 2:47 p.m. UTC 
imx_set_termios() cleared RTS on every call, now fixed.

Signed-off-by: Sergey Organov <sorganov@gmail.com>
---
 drivers/tty/serial/imx.c | 14 +++++++++-----
 1 file changed, 9 insertions(+), 5 deletions(-)
diff mbox series

Patch

diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
index 17e2322..e0f5365 100644
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -1563,7 +1563,14 @@  imx_uart_set_termios(struct uart_port *port, struct ktermios *termios,
 
 	spin_lock_irqsave(&sport->port.lock, flags);
 
-	ucr2 = UCR2_SRST | UCR2_IRTS;
+	/*
+	 * Read current UCR2 and save it for future use, then clear all the bits
+	 * except those we will or may need to preserve.
+	 */
+	old_ucr2 = imx_uart_readl(sport, UCR2);
+	ucr2 = old_ucr2 & (UCR2_TXEN | UCR2_RXEN | UCR2_ATEN | UCR2_CTS);
+
+	ucr2 |= UCR2_SRST | UCR2_IRTS;
 	if ((termios->c_cflag & CSIZE) == CS8)
 		ucr2 |= UCR2_WS;
 
@@ -1632,7 +1639,6 @@  imx_uart_set_termios(struct uart_port *port, struct ktermios *termios,
 	imx_uart_writel(sport,
 			old_ucr1 & ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN),
 			UCR1);
-	old_ucr2 = imx_uart_readl(sport, UCR2);
 	imx_uart_writel(sport, old_ucr2 & ~UCR2_ATEN, UCR2);
 
 	while (!(imx_uart_readl(sport, USR2) & USR2_TXDC))
@@ -1640,7 +1646,6 @@  imx_uart_set_termios(struct uart_port *port, struct ktermios *termios,
 
 	/* then, disable everything */
 	imx_uart_writel(sport, old_ucr2 & ~(UCR2_TXEN | UCR2_RXEN | UCR2_ATEN), UCR2);
-	old_ucr2 &= (UCR2_TXEN | UCR2_RXEN | UCR2_ATEN);
 
 	/* custom-baudrate handling */
 	div = sport->port.uartclk / (baud * 16);
@@ -1678,8 +1683,7 @@  imx_uart_set_termios(struct uart_port *port, struct ktermios *termios,
 
 	imx_uart_writel(sport, old_ucr1, UCR1);
 
-	/* set the parity, stop bits and data size */
-	imx_uart_writel(sport, ucr2 | old_ucr2, UCR2);
+	imx_uart_writel(sport, ucr2, UCR2);
 
 	if (UART_ENABLE_MS(&sport->port, termios->c_cflag))
 		imx_uart_enable_ms(&sport->port);