serial: imx: Support common rs485 binding for RTS polarity

l1k · gregkh · commit b8f3bff057b0 · 2017-11-28T16:05:20.000+01:00
Invoke the -&gt;rs485_config callback on probe to adjust the initial RTS
polarity based on the UART's device properties.

This implicitly fixes a bug:  If RTS control is not available, rs485
should be disabled even if it was enabled through a device property.
Log an error when that occurs.

Cc: Sascha Hauer &lt;s.hauer@pengutronix.de&gt;
Signed-off-by: Lukas Wunner &lt;lukas@wunner.de&gt;
Acked-by: Uwe Kleine-König &lt;u.kleine-koenig@pengutronix.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
@@ -2092,6 +2092,12 @@ static int serial_imx_probe(struct platform_device *pdev)
 
 	uart_get_rs485_mode(&pdev->dev, &sport->port.rs485);
 
+	if (sport->port.rs485.flags & SER_RS485_ENABLED &&
+	    (!sport->have_rtscts || !sport->have_rtsgpio))
+		dev_err(&pdev->dev, "no RTS control, disabling rs485\n");
+
+	imx_rs485_config(&sport->port, &sport->port.rs485);
+
 	/* Disable interrupts before requesting them */
 	reg = readl_relaxed(sport->port.membase + UCR1);
 	reg &= ~(UCR1_ADEN | UCR1_TRDYEN | UCR1_IDEN | UCR1_RRDYEN |
