diff --git a/drivers/tty/serial/st-asc.c b/drivers/tty/serial/st-asc.c
index 69e62326723d..397df507579e 100644
--- a/drivers/tty/serial/st-asc.c
+++ b/drivers/tty/serial/st-asc.c
@@ -30,6 +30,7 @@
 #include <linux/of_platform.h>
 #include <linux/serial_core.h>
 #include <linux/clk.h>
+#include <linux/gpio/consumer.h>
 
 #define DRIVER_NAME "st-asc"
 #define ASC_SERIAL_NAME "ttyAS"
@@ -38,6 +39,7 @@
 
 struct asc_port {
 	struct uart_port port;
+	struct gpio_desc *rts;
 	struct clk *clk;
 	unsigned int hw_flow_control:1;
 	unsigned int force_m1:1;
@@ -391,12 +393,27 @@ static unsigned int asc_tx_empty(struct uart_port *port)
 
 static void asc_set_mctrl(struct uart_port *port, unsigned int mctrl)
 {
+	struct asc_port *ascport = to_asc_port(port);
+
 	/*
-	 * This routine is used for seting signals of: DTR, DCD, CTS/RTS
-	 * We use ASC's hardware for CTS/RTS, so don't need any for that.
-	 * Some boards have DTR and DCD implemented using PIO pins,
-	 * code to do this should be hooked in here.
+	 * This routine is used for seting signals of: DTR, DCD, CTS and RTS.
+	 * We use ASC's hardware for CTS/RTS when hardware flow-control is
+	 * enabled, however if the RTS line is required for another purpose,
+	 * commonly controlled using HUP from userspace, then we need to toggle
+	 * it manually, using GPIO.
+	 *
+	 * Some boards also have DTR and DCD implemented using PIO pins, code to
+	 * do this should be hooked in here.
 	 */
+
+	if (!ascport->rts)
+		return;
+
+	/* If HW flow-control is enabled, we can't fiddle with the RTS line */
+	if (asc_in(port, ASC_CTL) & ASC_CTL_CTSENABLE)
+		return;
+
+	gpiod_set_value(ascport->rts, mctrl & TIOCM_RTS);
 }
 
 static unsigned int asc_get_mctrl(struct uart_port *port)
@@ -726,6 +743,8 @@ static struct asc_port *asc_of_get_asc_port(struct platform_device *pdev)
 							"st,hw-flow-control");
 	asc_ports[id].force_m1 =  of_property_read_bool(np, "st,force_m1");
 	asc_ports[id].port.line = id;
+	asc_ports[id].rts = NULL;
+
 	return &asc_ports[id];
 }