Commit 7b7e8e8e authored Jan 07, 2017 by Fabio Estevam Committed by Greg Kroah-Hartman Jan 12, 2017

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 <fabio.estevam@nxp.com>
Tested-by: Clemens Gruber <clemens.gruber@pqgruber.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 3f080878

drivers/tty/serial/imx.c

+5 −1

Original line number	Diff line number	Diff line
		@@ -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

Admin message