From: Fabio Estevam <fabio.estevam@xxxxxxx>
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 <fabio.estevam@xxxxxxx>
---
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 a70356d..33fcc84 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
--
2.7.4
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