From 7b7e8e8e8fc6a9f1f0372d1ffb271ecfdaf0285a Mon Sep 17 00:00:00 2001 From: Fabio Estevam Date: Sat, 7 Jan 2017 19:29:13 -0200 Subject: [PATCH] serial: imx: Allow passing 'rst-gpios' for rs485 mode According to Documentation/devicetree/bindings/serial/serial.txt the generic 'rts-gpios' property can be used to specify the GPIO for RTS functionality. Currently it is not possible to use the imx UART port in rs485 mode when the 'rts-gpios' property is passed in the device tree. The imx uart driver only checks for the presence of the built-in RTS pin, via 'uart-has-rtscts' property and disable the rs485 flag if this property is absent. So fix this logic by also checking if RTS pin has been passed via GPIO. Tested on a imx6dl based board. Signed-off-by: Fabio Estevam Tested-by: Clemens Gruber Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/imx.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c index a70356dad1b7..33fcc84e756b 100644 --- a/drivers/tty/serial/imx.c +++ b/drivers/tty/serial/imx.c @@ -205,6 +205,7 @@ struct imx_port { struct timer_list timer; unsigned int old_status; unsigned int have_rtscts:1; + unsigned int have_rtsgpio:1; unsigned int dte_mode:1; unsigned int irda_inv_rx:1; unsigned int irda_inv_tx:1; @@ -1725,7 +1726,7 @@ static int imx_rs485_config(struct uart_port *port, rs485conf->delay_rts_after_send = 0; /* RTS is required to control the transmitter */ - if (!sport->have_rtscts) + if (!sport->have_rtscts && !sport->have_rtsgpio) rs485conf->flags &= ~SER_RS485_ENABLED; if (rs485conf->flags & SER_RS485_ENABLED) { @@ -2048,6 +2049,9 @@ static int serial_imx_probe_dt(struct imx_port *sport, if (of_get_property(np, "fsl,dte-mode", NULL)) sport->dte_mode = 1; + if (of_get_property(np, "rts-gpios", NULL)) + sport->have_rtsgpio = 1; + return 0; } #else