diff --git a/Documentation/devicetree/bindings/serial/8250.txt b/Documentation/devicetree/bindings/serial/8250.txt
index 936ab5b..f5561ac 100644
--- a/Documentation/devicetree/bindings/serial/8250.txt
+++ b/Documentation/devicetree/bindings/serial/8250.txt
@@ -42,6 +42,9 @@ Optional properties:
 - auto-flow-control: one way to enable automatic flow control support. The
   driver is allowed to detect support for the capability even without this
   property.
+- {rts,cts,dtr,dsr,rng,dcd}-gpios: specify a GPIO for RTS/CTS/DTR/DSR/RI/DCD
+  line respectively. It will use specified GPIO instead of the peripheral
+  function pin for the UART feature. If unsure, don't specify this property.
 
 Note:
 * fsl,ns16550:
@@ -63,3 +66,19 @@ Example:
 		interrupts = <10>;
 		reg-shift = <2>;
 	};
+
+Example for OMAP UART using GPIO-based modem control signals:
+
+	uart4: serial@49042000 {
+		compatible = "ti,omap3-uart";
+		reg = <0x49042000 0x400>;
+		interrupts = <80>;
+		ti,hwmods = "uart4";
+		clock-frequency = <48000000>;
+		cts-gpios = <&gpio3 5 GPIO_ACTIVE_LOW>;
+		rts-gpios = <&gpio3 6 GPIO_ACTIVE_LOW>;
+		dtr-gpios = <&gpio1 12 GPIO_ACTIVE_LOW>;
+		dsr-gpios = <&gpio1 13 GPIO_ACTIVE_LOW>;
+		dcd-gpios = <&gpio1 14 GPIO_ACTIVE_LOW>;
+		rng-gpios = <&gpio1 15 GPIO_ACTIVE_LOW>;
+	};
diff --git a/drivers/tty/serial/8250/8250.h b/drivers/tty/serial/8250/8250.h
index 73bf57d..8e92baf 100644
--- a/drivers/tty/serial/8250/8250.h
+++ b/drivers/tty/serial/8250/8250.h
@@ -15,6 +15,8 @@
 #include <linux/serial_reg.h>
 #include <linux/dmaengine.h>
 
+#include "../serial_mctrl_gpio.h"
+
 struct uart_8250_dma {
 	int (*tx_dma)(struct uart_8250_port *p);
 	int (*rx_dma)(struct uart_8250_port *p, unsigned int iir);
@@ -134,12 +136,51 @@ void serial8250_em485_destroy(struct uart_8250_port *p);
 
 static inline void serial8250_out_MCR(struct uart_8250_port *up, int value)
 {
+	int mctrl_gpio = 0;
+
 	serial_out(up, UART_MCR, value);
+
+	if (value & UART_MCR_RTS)
+		mctrl_gpio |= TIOCM_RTS;
+	if (value & UART_MCR_DTR)
+		mctrl_gpio |= TIOCM_DTR;
+	if (value & UART_MCR_OUT1)
+		mctrl_gpio |= TIOCM_OUT1;
+	if (value & UART_MCR_OUT2)
+		mctrl_gpio |= TIOCM_OUT2;
+
+	mctrl_gpio_set(up->gpios, mctrl_gpio);
 }
 
 static inline int serial8250_in_MCR(struct uart_8250_port *up)
 {
-	return serial_in(up, UART_MCR);
+	int mctrl, mctrl_gpio = 0;
+
+	mctrl = serial_in(up, UART_MCR);
+
+	mctrl_gpio = mctrl_gpio_get_outputs(up->gpios, &mctrl_gpio);
+
+	if (mctrl_gpio & TIOCM_RTS)
+		mctrl |= UART_MCR_RTS;
+	else
+		mctrl &= ~UART_MCR_RTS;
+
+	if (mctrl_gpio & TIOCM_DTR)
+		mctrl |= UART_MCR_DTR;
+	else
+		mctrl &= ~UART_MCR_DTR;
+
+	if (mctrl_gpio & TIOCM_OUT1)
+		mctrl |= UART_MCR_OUT1;
+	else
+		mctrl &= ~UART_MCR_OUT1;
+
+	if (mctrl_gpio & TIOCM_OUT2)
+		mctrl |= UART_MCR_OUT2;
+	else
+		mctrl &= ~UART_MCR_OUT2;
+
+	return mctrl;
 }
 
 #if defined(__alpha__) && !defined(CONFIG_PCI)
diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c
index 2f4f5ee..bfde589 100644
--- a/drivers/tty/serial/8250/8250_core.c
+++ b/drivers/tty/serial/8250/8250_core.c
@@ -1010,6 +1010,10 @@ int serial8250_register_8250_port(struct uart_8250_port *up)
 		if (up->port.flags & UPF_FIXED_TYPE)
 			uart->port.type = up->port.type;
 
+		uart->gpios = mctrl_gpio_init(&uart->port, 0);
+		if (IS_ERR(uart->gpios))
+			dev_dbg(uart->port.dev, "Failed to init mctrl_gpio\n");
+
 		serial8250_set_defaults(uart);
 
 		/* Possibly override default I/O functions.  */
diff --git a/drivers/tty/serial/8250/8250_omap.c b/drivers/tty/serial/8250/8250_omap.c
index d8bd8ce..d4e7663 100644
--- a/drivers/tty/serial/8250/8250_omap.c
+++ b/drivers/tty/serial/8250/8250_omap.c
@@ -128,18 +128,21 @@ static void omap8250_set_mctrl(struct uart_port *port, unsigned int mctrl)
 
 	serial8250_do_set_mctrl(port, mctrl);
 
-	/*
-	 * Turn off autoRTS if RTS is lowered and restore autoRTS setting
-	 * if RTS is raised
-	 */
-	lcr = serial_in(up, UART_LCR);
-	serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
-	if ((mctrl & TIOCM_RTS) && (port->status & UPSTAT_AUTORTS))
-		priv->efr |= UART_EFR_RTS;
-	else
-		priv->efr &= ~UART_EFR_RTS;
-	serial_out(up, UART_EFR, priv->efr);
-	serial_out(up, UART_LCR, lcr);
+	if (IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(up->gpios,
+						UART_GPIO_RTS))) {
+		/*
+		 * Turn off autoRTS if RTS is lowered and restore autoRTS
+		 * setting if RTS is raised
+		 */
+		lcr = serial_in(up, UART_LCR);
+		serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B);
+		if ((mctrl & TIOCM_RTS) && (port->status & UPSTAT_AUTORTS))
+			priv->efr |= UART_EFR_RTS;
+		else
+			priv->efr &= ~UART_EFR_RTS;
+		serial_out(up, UART_EFR, priv->efr);
+		serial_out(up, UART_LCR, lcr);
+	}
 }
 
 /*
@@ -440,7 +443,9 @@ static void omap_8250_set_termios(struct uart_port *port,
 	priv->efr = 0;
 	up->port.status &= ~(UPSTAT_AUTOCTS | UPSTAT_AUTORTS | UPSTAT_AUTOXOFF);
 
-	if (termios->c_cflag & CRTSCTS && up->port.flags & UPF_HARD_FLOW) {
+	if (termios->c_cflag & CRTSCTS && up->port.flags & UPF_HARD_FLOW
+		&& IS_ERR_OR_NULL(mctrl_gpio_to_gpiod(up->gpios,
+							UART_GPIO_RTS))) {
 		/* Enable AUTOCTS (autoRTS is enabled when RTS is raised) */
 		up->port.status |= UPSTAT_AUTOCTS | UPSTAT_AUTORTS;
 		priv->efr |= UART_EFR_CTS;
diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c
index 094763b..bdf2dc4 100644
--- a/drivers/tty/serial/8250/8250_port.c
+++ b/drivers/tty/serial/8250/8250_port.c
@@ -1611,6 +1611,8 @@ static void serial8250_disable_ms(struct uart_port *port)
 	if (up->bugs & UART_BUG_NOMSR)
 		return;
 
+	mctrl_gpio_disable_ms(up->gpios);
+
 	up->ier &= ~UART_IER_MSI;
 	serial_port_out(port, UART_IER, up->ier);
 }
@@ -1623,6 +1625,8 @@ static void serial8250_enable_ms(struct uart_port *port)
 	if (up->bugs & UART_BUG_NOMSR)
 		return;
 
+	mctrl_gpio_enable_ms(up->gpios);
+
 	up->ier |= UART_IER_MSI;
 
 	serial8250_rpm_get(up);
@@ -1900,7 +1904,8 @@ static unsigned int serial8250_get_mctrl(struct uart_port *port)
 		ret |= TIOCM_DSR;
 	if (status & UART_MSR_CTS)
 		ret |= TIOCM_CTS;
-	return ret;
+
+	return mctrl_gpio_get(up->gpios, &ret);
 }
 
 void serial8250_do_set_mctrl(struct uart_port *port, unsigned int mctrl)
diff --git a/drivers/tty/serial/8250/Kconfig b/drivers/tty/serial/8250/Kconfig
index 64742a0..74cf227 100644
--- a/drivers/tty/serial/8250/Kconfig
+++ b/drivers/tty/serial/8250/Kconfig
@@ -6,6 +6,7 @@
 config SERIAL_8250
 	tristate "8250/16550 and compatible serial support"
 	select SERIAL_CORE
+	select SERIAL_MCTRL_GPIO if GPIOLIB
 	---help---
 	  This selects whether you want to include the driver for the standard
 	  serial ports.  The standard answer is Y.  People who might say N
diff --git a/include/linux/serial_8250.h b/include/linux/serial_8250.h
index 4348797..3148d6d 100644
--- a/include/linux/serial_8250.h
+++ b/include/linux/serial_8250.h
@@ -110,6 +110,7 @@ struct uart_8250_port {
 						 *   if no_console_suspend
 						 */
 	unsigned char		probe;
+	struct mctrl_gpios	*gpios;
 #define UART_PROBE_RSA	(1 << 0)
 
 	/*
