diff --git a/drivers/tty/serial/8250/8250_dwlib.c b/drivers/tty/serial/8250/8250_dwlib.c
index 622d3b0d89e7..08432e2fe511 100644
--- a/drivers/tty/serial/8250/8250_dwlib.c
+++ b/drivers/tty/serial/8250/8250_dwlib.c
@@ -2,19 +2,33 @@
 /* Synopsys DesignWare 8250 library. */
 
 #include <linux/bitops.h>
+#include <linux/bitfield.h>
 #include <linux/device.h>
 #include <linux/io.h>
 #include <linux/kernel.h>
+#include <linux/property.h>
 #include <linux/serial_8250.h>
 #include <linux/serial_core.h>
 
 #include "8250_dwlib.h"
 
 /* Offsets for the DesignWare specific registers */
+#define DW_UART_TCR	0xac /* Transceiver Control Register (RS485) */
+#define DW_UART_DE_EN	0xb0 /* Driver Output Enable Register */
+#define DW_UART_RE_EN	0xb4 /* Receiver Output Enable Register */
 #define DW_UART_DLF	0xc0 /* Divisor Latch Fraction Register */
 #define DW_UART_CPR	0xf4 /* Component Parameter Register */
 #define DW_UART_UCV	0xf8 /* UART Component Version */
 
+/* Transceiver Control Register bits */
+#define DW_UART_TCR_RS485_EN		BIT(0)
+#define DW_UART_TCR_RE_POL		BIT(1)
+#define DW_UART_TCR_DE_POL		BIT(2)
+#define DW_UART_TCR_XFER_MODE		GENMASK(4, 3)
+#define DW_UART_TCR_XFER_MODE_DE_DURING_RE	FIELD_PREP(DW_UART_TCR_XFER_MODE, 0)
+#define DW_UART_TCR_XFER_MODE_SW_DE_OR_RE	FIELD_PREP(DW_UART_TCR_XFER_MODE, 1)
+#define DW_UART_TCR_XFER_MODE_DE_OR_RE		FIELD_PREP(DW_UART_TCR_XFER_MODE, 2)
+
 /* Component Parameter Register bits */
 #define DW_UART_CPR_ABP_DATA_WIDTH	(3 << 0)
 #define DW_UART_CPR_AFCE_MODE		(1 << 4)
@@ -87,11 +101,80 @@ void dw8250_do_set_termios(struct uart_port *p, struct ktermios *termios, struct
 }
 EXPORT_SYMBOL_GPL(dw8250_do_set_termios);
 
+static int dw8250_rs485_config(struct uart_port *p, struct serial_rs485 *rs485)
+{
+	u32 tcr;
+
+	tcr = dw8250_readl_ext(p, DW_UART_TCR);
+	tcr &= ~DW_UART_TCR_XFER_MODE;
+
+	if (rs485->flags & SER_RS485_ENABLED) {
+		/* Clear unsupported flags. */
+		rs485->flags &= SER_RS485_ENABLED | SER_RS485_RX_DURING_TX |
+				SER_RS485_RTS_ON_SEND | SER_RS485_RTS_AFTER_SEND;
+		tcr |= DW_UART_TCR_RS485_EN;
+
+		if (rs485->flags & SER_RS485_RX_DURING_TX) {
+			tcr |= DW_UART_TCR_XFER_MODE_DE_DURING_RE;
+		} else {
+			/* HW does not support same DE level for tx and rx */
+			if (!(rs485->flags & SER_RS485_RTS_ON_SEND) ==
+			    !(rs485->flags & SER_RS485_RTS_AFTER_SEND))
+				return -EINVAL;
+
+			tcr |= DW_UART_TCR_XFER_MODE_DE_OR_RE;
+		}
+		dw8250_writel_ext(p, DW_UART_DE_EN, 1);
+		dw8250_writel_ext(p, DW_UART_RE_EN, 1);
+	} else {
+		rs485->flags = 0;
+
+		tcr &= ~DW_UART_TCR_RS485_EN;
+	}
+
+	/* Reset to default polarity */
+	tcr |= DW_UART_TCR_DE_POL;
+	tcr &= ~DW_UART_TCR_RE_POL;
+
+	if (!(rs485->flags & SER_RS485_RTS_ON_SEND))
+		tcr &= ~DW_UART_TCR_DE_POL;
+	if (device_property_read_bool(p->dev, "rs485-rx-active-high"))
+		tcr |= DW_UART_TCR_RE_POL;
+
+	dw8250_writel_ext(p, DW_UART_TCR, tcr);
+
+	rs485->delay_rts_before_send = 0;
+	rs485->delay_rts_after_send = 0;
+
+	p->rs485 = *rs485;
+
+	return 0;
+}
+
+/*
+ * Tests if RE_EN register can have non-zero value to see if RS-485 HW support
+ * is present.
+ */
+static bool dw8250_detect_rs485_hw(struct uart_port *p)
+{
+	u32 reg;
+
+	dw8250_writel_ext(p, DW_UART_RE_EN, 1);
+	reg = dw8250_readl_ext(p, DW_UART_RE_EN);
+	dw8250_writel_ext(p, DW_UART_RE_EN, 0);
+	return reg;
+}
+
 void dw8250_setup_port(struct uart_port *p)
 {
+	struct dw8250_port_data *d = p->private_data;
 	struct uart_8250_port *up = up_to_u8250p(p);
 	u32 reg;
 
+	d->hw_rs485_support = dw8250_detect_rs485_hw(p);
+	if (d->hw_rs485_support)
+		p->rs485_config = dw8250_rs485_config;
+
 	/*
 	 * If the Component Version Register returns zero, we know that
 	 * ADDITIONAL_FEATURES are not enabled. No need to go any further.
@@ -108,8 +191,6 @@ void dw8250_setup_port(struct uart_port *p)
 	dw8250_writel_ext(p, DW_UART_DLF, 0);
 
 	if (reg) {
-		struct dw8250_port_data *d = p->private_data;
-
 		d->dlf_size = fls(reg);
 		p->get_divisor = dw8250_get_divisor;
 		p->set_divisor = dw8250_set_divisor;
diff --git a/drivers/tty/serial/8250/8250_dwlib.h b/drivers/tty/serial/8250/8250_dwlib.h
index 83d528e5cc21..a8fa020ca544 100644
--- a/drivers/tty/serial/8250/8250_dwlib.h
+++ b/drivers/tty/serial/8250/8250_dwlib.h
@@ -14,6 +14,9 @@ struct dw8250_port_data {
 
 	/* Hardware configuration */
 	u8			dlf_size;
+
+	/* RS485 variables */
+	bool			hw_rs485_support;
 };
 
 void dw8250_do_set_termios(struct uart_port *p, struct ktermios *termios, struct ktermios *old);
