tty: serial: fsl_lpuart: enable two stop bits for lpuart32

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>
Signed-off-by: Sherry Sun <sherry.sun@nxp.com>
Link: https://lore.kernel.org/r/20210823081733.31941-1-sherry.sun@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 117e011..55097e0 100644 (file)
--- a/drivers/tty/serial/fsl_lpuart.c
+++ b/drivers/tty/serial/fsl_lpuart.c
@@ -2049,11 +2049,12 @@ lpuart32_set_termios(struct uart_port *port, struct ktermios *termios,
 {
        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.
@@ -2097,7 +2098,9 @@ lpuart32_set_termios(struct uart_port *port, struct ktermios *termios,
        }
 
        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)
@@ -2167,6 +2170,7 @@ lpuart32_set_termios(struct uart_port *port, struct ktermios *termios,
        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);