diff --git a/drivers/serial/serial_mt7620.c b/drivers/serial/serial_mt7620.c
new file mode 100644
index 0000000..826a14b
--- /dev/null
+++ b/drivers/serial/serial_mt7620.c
@@ -0,0 +1,246 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * UART driver for MediaTek MT7620 and earlier SoCs
+ *
+ * Copyright (C) 2020 MediaTek Inc.
+ * Author: Weijie Gao <weijie.gao@mediatek.com>
+ */
+
+#include <clk.h>
+#include <div64.h>
+#include <dm.h>
+#include <errno.h>
+#include <log.h>
+#include <reset.h>
+#include <serial.h>
+#include <watchdog.h>
+#include <asm/io.h>
+#include <asm/types.h>
+#include <asm/addrspace.h>
+#include <dm/device_compat.h>
+#include <linux/err.h>
+
+#if CONFIG_IS_ENABLED(OF_PLATDATA)
+#include <dt-structs.h>
+#endif
+
+struct mt7620_serial_regs {
+	u32 rbr;
+	u32 thr;
+	u32 ier;
+	u32 iir;
+	u32 fcr;
+	u32 lcr;
+	u32 mcr;
+	u32 lsr;
+	u32 msr;
+	u32 scratch;
+	u32 dl;
+	u32 dll;
+	u32 dlm;
+	u32 ifctl;
+};
+
+#define UART_LCR_WLS_8		0x03	/* 8 bit character length */
+
+#define UART_LSR_DR		0x01	/* Data ready */
+#define UART_LSR_THRE		0x20	/* Xmit holding register empty */
+#define UART_LSR_TEMT		0x40	/* Xmitter empty */
+
+#define UART_MCR_DTR		0x01	/* DTR */
+#define UART_MCR_RTS		0x02	/* RTS */
+
+#define UART_FCR_FIFO_EN	0x01	/* Fifo enable */
+#define UART_FCR_RXSR		0x02	/* Receiver soft reset */
+#define UART_FCR_TXSR		0x04	/* Transmitter soft reset */
+
+#define UART_MCRVAL (UART_MCR_DTR | \
+		     UART_MCR_RTS)
+
+/* Clear & enable FIFOs */
+#define UART_FCRVAL (UART_FCR_FIFO_EN | \
+		     UART_FCR_RXSR |	\
+		     UART_FCR_TXSR)
+
+struct mt7620_serial_plat {
+#if CONFIG_IS_ENABLED(OF_PLATDATA)
+	struct dtd_serial_mt7620 dtplat;
+#endif
+
+	struct mt7620_serial_regs __iomem *regs;
+	u32 clock;
+};
+
+static void _mt7620_serial_setbrg(struct mt7620_serial_plat *plat, int baud)
+{
+	u32 quot;
+
+	/* set divisor */
+	quot = DIV_ROUND_CLOSEST(plat->clock, 16 * baud);
+	writel(quot, &plat->regs->dl);
+
+	/* set character length and stop bits */
+	writel(UART_LCR_WLS_8, &plat->regs->lcr);
+}
+
+static int mt7620_serial_setbrg(struct udevice *dev, int baudrate)
+{
+	struct mt7620_serial_plat *plat = dev_get_plat(dev);
+
+	_mt7620_serial_setbrg(plat, baudrate);
+
+	return 0;
+}
+
+static int mt7620_serial_putc(struct udevice *dev, const char ch)
+{
+	struct mt7620_serial_plat *plat = dev_get_plat(dev);
+
+	if (!(readl(&plat->regs->lsr) & UART_LSR_THRE))
+		return -EAGAIN;
+
+	writel(ch, &plat->regs->thr);
+
+	if (ch == '\n')
+		WATCHDOG_RESET();
+
+	return 0;
+}
+
+static int mt7620_serial_getc(struct udevice *dev)
+{
+	struct mt7620_serial_plat *plat = dev_get_plat(dev);
+
+	if (!(readl(&plat->regs->lsr) & UART_LSR_DR))
+		return -EAGAIN;
+
+	return readl(&plat->regs->rbr);
+}
+
+static int mt7620_serial_pending(struct udevice *dev, bool input)
+{
+	struct mt7620_serial_plat *plat = dev_get_plat(dev);
+
+	if (input)
+		return (readl(&plat->regs->lsr) & UART_LSR_DR) ? 1 : 0;
+
+	return (readl(&plat->regs->lsr) & UART_LSR_THRE) ? 0 : 1;
+}
+
+static int mt7620_serial_probe(struct udevice *dev)
+{
+	struct mt7620_serial_plat *plat = dev_get_plat(dev);
+
+#if CONFIG_IS_ENABLED(OF_PLATDATA)
+	plat->regs = (void __iomem *)KSEG1ADDR(plat->dtplat.reg[0]);
+	plat->clock = plat->dtplat.clock_frequency;
+#endif
+
+	/* Disable interrupt */
+	writel(0, &plat->regs->ier);
+
+	writel(UART_MCRVAL, &plat->regs->mcr);
+	writel(UART_FCRVAL, &plat->regs->fcr);
+
+	return 0;
+}
+
+#if !CONFIG_IS_ENABLED(OF_PLATDATA)
+static int mt7620_serial_of_to_plat(struct udevice *dev)
+{
+	struct mt7620_serial_plat *plat = dev_get_plat(dev);
+	struct reset_ctl reset_uart;
+	struct clk clk;
+	int err;
+
+	err = reset_get_by_index(dev, 0, &reset_uart);
+	if (!err)
+		reset_deassert(&reset_uart);
+
+	plat->regs = dev_remap_addr_index(dev, 0);
+	if (!plat->regs) {
+		dev_err(dev, "mt7620_serial: unable to map UART registers\n");
+		return -EINVAL;
+	}
+
+	err = clk_get_by_index(dev, 0, &clk);
+	if (!err) {
+		err = clk_get_rate(&clk);
+		if (!IS_ERR_VALUE(err))
+			plat->clock = err;
+	} else if (err != -ENOENT && err != -ENODEV && err != -ENOSYS) {
+		dev_err(dev, "mt7620_serial: failed to get clock\n");
+		return err;
+	}
+
+	if (!plat->clock)
+		plat->clock = dev_read_u32_default(dev, "clock-frequency", 0);
+
+	if (!plat->clock) {
+		dev_err(dev, "mt7620_serial: clock not defined\n");
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static const struct udevice_id mt7620_serial_ids[] = {
+	{ .compatible = "mediatek,mt7620-uart" },
+	{ }
+};
+#endif
+
+static const struct dm_serial_ops mt7620_serial_ops = {
+	.putc = mt7620_serial_putc,
+	.pending = mt7620_serial_pending,
+	.getc = mt7620_serial_getc,
+	.setbrg = mt7620_serial_setbrg,
+};
+
+U_BOOT_DRIVER(serial_mt7620) = {
+	.name = "serial_mt7620",
+	.id = UCLASS_SERIAL,
+#if !CONFIG_IS_ENABLED(OF_PLATDATA)
+	.of_match = mt7620_serial_ids,
+	.of_to_plat = mt7620_serial_of_to_plat,
+#endif
+	.plat_auto = sizeof(struct mt7620_serial_plat),
+	.probe = mt7620_serial_probe,
+	.ops = &mt7620_serial_ops,
+	.flags = DM_FLAG_PRE_RELOC,
+};
+
+DM_DRIVER_ALIAS(serial_mt7620, mediatek_mt7620_uart);
+
+#ifdef CONFIG_DEBUG_UART_MT7620
+
+#include <debug_uart.h>
+
+static inline void _debug_uart_init(void)
+{
+	struct mt7620_serial_plat plat;
+
+	plat.regs = (void *)CONFIG_DEBUG_UART_BASE;
+	plat.clock = CONFIG_DEBUG_UART_CLOCK;
+
+	writel(0, &plat.regs->ier);
+	writel(UART_MCRVAL, &plat.regs->mcr);
+	writel(UART_FCRVAL, &plat.regs->fcr);
+
+	_mt7620_serial_setbrg(&plat, CONFIG_BAUDRATE);
+}
+
+static inline void _debug_uart_putc(int ch)
+{
+	struct mt7620_serial_regs __iomem *regs =
+		(void *)CONFIG_DEBUG_UART_BASE;
+
+	while (!(readl(&regs->lsr) & UART_LSR_THRE))
+		;
+
+	writel(ch, &regs->thr);
+}
+
+DEBUG_UART_FUNCS
+
+#endif