From bc2be239feef9ac9fc8ad17adf7c03b353f6546f Mon Sep 17 00:00:00 2001 From: Fabio Estevam Date: Mon, 30 Jan 2017 09:12:12 -0200 Subject: [PATCH] serial: imx: Fix the CTS_B polarity in RS485 mode When userspace passes the SER_RS485_RTS_ON_SEND flag it means that the CTS_B pin should go to logic level high before the transmission begins. CTS_B goes to logic level high when both CTSC and CTS bits are cleared. When userspace passes the SER_RS485_RTS_AFTER_SEND flag it means that the CTS_B pin should go to logic level low after the transmission finishes. CTS_B goes to logic level low when CTSC bit is cleared and CTS bit is set. So fix the CTS_B polarity logic. Signed-off-by: Fabio Estevam Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/imx.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c index 29dd57c51706..e3e152cbc75e 100644 --- a/drivers/tty/serial/imx.c +++ b/drivers/tty/serial/imx.c @@ -336,15 +336,15 @@ static void imx_port_ucrs_restore(struct uart_port *port, static void imx_port_rts_active(struct imx_port *sport, unsigned long *ucr2) { - *ucr2 &= ~UCR2_CTSC; - *ucr2 |= UCR2_CTS; + *ucr2 &= ~(UCR2_CTSC | UCR2_CTS); mctrl_gpio_set(sport->gpios, sport->port.mctrl | TIOCM_RTS); } static void imx_port_rts_inactive(struct imx_port *sport, unsigned long *ucr2) { - *ucr2 &= ~(UCR2_CTSC | UCR2_CTS); + *ucr2 &= ~UCR2_CTSC; + *ucr2 |= UCR2_CTS; mctrl_gpio_set(sport->gpios, sport->port.mctrl & ~TIOCM_RTS); } -- 2.20.1