From: Luke Wang <ziniu.wang_1@nxp.com>
Date: Tue, 8 Oct 2024 09:44:18 +0000 (+0800)
Subject: tty: serial: fsl_lpuart: add 7-bits format support on imx7ulp/imx8ulp/imx8qxp
X-Git-Tag: v6.13-rc1~25^2~27
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=fd29e1e4e6e6019a8e10a215280cab53590c8033;p=thirdparty%2Flinux.git

tty: serial: fsl_lpuart: add 7-bits format support on imx7ulp/imx8ulp/imx8qxp

imx7ulp/imx8ulp/imx8qxp lpuart IP support 7-bits format and have no
limitation on parity when CS7. Remove this limitation and add 7-bits
format support on imx7ulp/imx8ulp/imx8qxp.

Signed-off-by: Luke Wang <ziniu.wang_1@nxp.com>
Link: https://lore.kernel.org/r/20241008094418.439706-1-ziniu.wang_1@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c
index c14a83c86029a..57b0632a3db6f 100644
--- a/drivers/tty/serial/fsl_lpuart.c
+++ b/drivers/tty/serial/fsl_lpuart.c
@@ -184,6 +184,7 @@
 #define UARTCTRL_SBK		0x00010000
 #define UARTCTRL_MA1IE		0x00008000
 #define UARTCTRL_MA2IE		0x00004000
+#define UARTCTRL_M7		0x00000800
 #define UARTCTRL_IDLECFG	GENMASK(10, 8)
 #define UARTCTRL_LOOPS		0x00000080
 #define UARTCTRL_DOZEEN		0x00000040
@@ -2222,8 +2223,9 @@ lpuart32_set_termios(struct uart_port *port, struct ktermios *termios,
 	modem = lpuart32_read(&sport->port, UARTMODIR);
 	sport->is_cs7 = false;
 	/*
-	 * only support CS8 and CS7, and for CS7 must enable PE.
+	 * only support CS8 and CS7
 	 * supported mode:
+	 *  - (7,n,1) (imx only)
 	 *  - (7,e/o,1)
 	 *  - (8,n,1)
 	 *  - (8,m/s,1)
@@ -2238,7 +2240,7 @@ lpuart32_set_termios(struct uart_port *port, struct ktermios *termios,
 
 	if ((termios->c_cflag & CSIZE) == CS8 ||
 		(termios->c_cflag & CSIZE) == CS7)
-		ctrl = old_ctrl & ~UARTCTRL_M;
+		ctrl = old_ctrl & ~(UARTCTRL_M | UARTCTRL_M7);
 
 	if (termios->c_cflag & CMSPAR) {
 		if ((termios->c_cflag & CSIZE) != CS8) {
@@ -2265,9 +2267,18 @@ lpuart32_set_termios(struct uart_port *port, struct ktermios *termios,
 	else
 		bd &= ~UARTBAUD_SBNS;
 
-	/* parity must be enabled when CS7 to match 8-bits format */
-	if ((termios->c_cflag & CSIZE) == CS7)
-		termios->c_cflag |= PARENB;
+	/*
+	 * imx support 7-bits format, no limitation on parity when CS7
+	 * for layerscape, parity must be enabled when CS7 to match 8-bits format
+	 */
+	if ((termios->c_cflag & CSIZE) == CS7 && !(termios->c_cflag & PARENB)) {
+		if (is_imx7ulp_lpuart(sport) ||
+		    is_imx8ulp_lpuart(sport) ||
+		    is_imx8qxp_lpuart(sport))
+			ctrl |= UARTCTRL_M7;
+		else
+			termios->c_cflag |= PARENB;
+	}
 
 	if ((termios->c_cflag & PARENB)) {
 		if (termios->c_cflag & CMSPAR) {