diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index 5c7f2b100191..0b0cf296aac4 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -1076,6 +1076,15 @@ config MFD_RDC321X
 	  southbridge which provides access to GPIOs and Watchdog using the
 	  southbridge PCI device configuration space.
 
+config MFD_RTL8231
+	tristate "Realtek RTL8231 GPIO and LED expander"
+	select MFD_CORE
+	select REGMAP
+	help
+	  Support for the Realtek RTL8231 GPIO and LED expander.
+	  Provides up to 37 GPIOs, 88 LEDs, and one PWM output.
+	  When built as a module, this module will be named rtl8231_expander.
+
 config MFD_RT5033
 	tristate "Richtek RT5033 Power Management IC"
 	depends on I2C
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index 4f6d2b8a5f76..4b27c2486ccc 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -234,6 +234,7 @@ obj-$(CONFIG_MFD_MENF21BMC)	+= menf21bmc.o
 obj-$(CONFIG_MFD_HI6421_PMIC)	+= hi6421-pmic-core.o
 obj-$(CONFIG_MFD_HI655X_PMIC)   += hi655x-pmic.o
 obj-$(CONFIG_MFD_DLN2)		+= dln2.o
+obj-$(CONFIG_MFD_RTL8231)	+= rtl8231.o
 obj-$(CONFIG_MFD_RT5033)	+= rt5033.o
 obj-$(CONFIG_MFD_SKY81452)	+= sky81452.o
 
diff --git a/drivers/mfd/rtl8231.c b/drivers/mfd/rtl8231.c
new file mode 100644
index 000000000000..4db3ad23d822
--- /dev/null
+++ b/drivers/mfd/rtl8231.c
@@ -0,0 +1,163 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <linux/bits.h>
+#include <linux/delay.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/rtl8231.h>
+#include <linux/mdio.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+static const struct reg_field RTL8231_FIELD_LED_START = REG_FIELD(RTL8231_REG_FUNC0, 1, 1);
+static const struct reg_field RTL8231_FIELD_READY_CODE = REG_FIELD(RTL8231_REG_FUNC1, 4, 9);
+static const struct reg_field RTL8231_FIELD_SOFT_RESET = REG_FIELD(RTL8231_REG_PIN_HI_CFG, 15, 15);
+
+static const struct mfd_cell rtl8231_cells[] = {
+	{
+		.name = "rtl8231-pinctrl",
+		.of_compatible = "realtek,rtl8231-pinctrl",
+	},
+	{
+		.name = "rtl8231-leds",
+		.of_compatible = "realtek,rtl8231-leds",
+	},
+};
+
+static int rtl8231_init(struct device *dev, struct regmap *map)
+{
+	struct regmap_field *field_ready_code;
+	struct regmap_field *field_soft_reset;
+	unsigned int v;
+	int err = 0;
+
+	field_ready_code = regmap_field_alloc(map, RTL8231_FIELD_READY_CODE);
+	if (IS_ERR(field_ready_code))
+		return PTR_ERR(field_ready_code);
+
+	field_soft_reset = regmap_field_alloc(map, RTL8231_FIELD_SOFT_RESET);
+	if (IS_ERR(field_soft_reset)) {
+		err = PTR_ERR(field_soft_reset);
+		goto init_out;
+	}
+
+	err = regmap_field_read(field_ready_code, &v);
+
+	if (err) {
+		dev_err(dev, "failed to read READY_CODE\n");
+		goto init_out;
+	} else if (v != RTL8231_FUNC1_READY_CODE_VALUE) {
+		dev_err(dev, "RTL8231 not present or ready 0x%x != 0x%x\n",
+			v, RTL8231_FUNC1_READY_CODE_VALUE);
+		err = -ENODEV;
+		goto init_out;
+	}
+
+	// TODO Implement reset-gpios
+	regmap_field_write(field_soft_reset, 1);
+	usleep_range(1000, 10000);
+
+	/* Do not write LED_START before configuring pins */
+	/* Select GPIO functionality for all pins and set to input */
+	regmap_write(map, RTL8231_REG_PIN_MODE0, 0xffff);
+	regmap_write(map, RTL8231_REG_GPIO_DIR0, 0xffff);
+	regmap_write(map, RTL8231_REG_PIN_MODE1, 0xffff);
+	regmap_write(map, RTL8231_REG_GPIO_DIR1, 0xffff);
+	regmap_write(map, RTL8231_REG_PIN_HI_CFG, GENMASK(4, 0) | GENMASK(9, 5));
+
+init_out:
+	regmap_field_free(field_ready_code);
+	regmap_field_free(field_soft_reset);
+	return err;
+}
+
+static int rtl8231_mdio_reg_read(void *ctx, unsigned int reg, unsigned int *val)
+{
+	struct mdio_device *mdiodev = ctx;
+	int ret;
+
+	ret = mdiobus_read(mdiodev->bus, mdiodev->addr, reg);
+	if (ret < 0)
+		return ret;
+
+	*val = ret & 0xffff;
+	return 0;
+}
+
+static int rtl8231_mdio_reg_write(void *ctx, unsigned int reg, unsigned int val)
+{
+	struct mdio_device *mdiodev = ctx;
+
+	return mdiobus_write(mdiodev->bus, mdiodev->addr, reg, val);
+}
+
+static const struct regmap_config rtl8231_regmap_config = {
+	.val_bits = 16,
+	.reg_bits = 5,
+	.max_register = RTL8231_REG_COUNT - 1,
+	.use_single_read = true,
+	.use_single_write = true,
+	.reg_format_endian = REGMAP_ENDIAN_BIG,
+	.val_format_endian = REGMAP_ENDIAN_BIG,
+	.reg_read = rtl8231_mdio_reg_read,
+	.reg_write = rtl8231_mdio_reg_write,
+};
+
+static int rtl8231_mdio_probe(struct mdio_device *mdiodev)
+{
+	struct device *dev = &mdiodev->dev;
+	struct regmap_field *led_start;
+	struct regmap *map;
+	int err;
+
+	map = devm_regmap_init(dev, NULL, mdiodev, &rtl8231_regmap_config);
+
+	if (IS_ERR(map)) {
+		dev_err(dev, "failed to init regmap\n");
+		return PTR_ERR(map);
+	}
+
+	led_start = devm_regmap_field_alloc(dev, map, RTL8231_FIELD_LED_START);
+	if (IS_ERR(led_start))
+		return PTR_ERR(led_start);
+
+	dev_set_drvdata(dev, led_start);
+
+	err = rtl8231_init(dev, map);
+	if (err)
+		return err;
+
+	/* LED_START enables power to output pins, and starts the LED engine */
+	regmap_field_write(led_start, 1);
+
+	return devm_mfd_add_devices(dev, PLATFORM_DEVID_AUTO, rtl8231_cells,
+		ARRAY_SIZE(rtl8231_cells), NULL, 0, NULL);
+}
+
+static void rtl8231_mdio_remove(struct mdio_device *mdiodev)
+{
+	struct regmap_field *led_start;
+
+	led_start = dev_get_drvdata(&mdiodev->dev);
+	regmap_field_write(led_start, 0);
+}
+
+static const struct of_device_id rtl8231_of_match[] = {
+	{ .compatible = "realtek,rtl8231" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, rtl8231_of_match);
+
+static struct mdio_driver rtl8231_mdio_driver = {
+	.mdiodrv.driver = {
+		.name = "rtl8231-expander",
+		.of_match_table	= rtl8231_of_match,
+	},
+	.probe = rtl8231_mdio_probe,
+	.remove = rtl8231_mdio_remove,
+};
+mdio_module_driver(rtl8231_mdio_driver);
+
+MODULE_AUTHOR("Sander Vanheule <sander@svanheule.net>");
+MODULE_DESCRIPTION("Realtek RTL8231 GPIO and LED expander");
+MODULE_LICENSE("GPL v2");
diff --git a/include/linux/mfd/rtl8231.h b/include/linux/mfd/rtl8231.h
new file mode 100644
index 000000000000..5af312adbf0b
--- /dev/null
+++ b/include/linux/mfd/rtl8231.h
@@ -0,0 +1,49 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Register definitions the RTL8231 GPIO and LED expander chip
+ */
+
+#ifndef __LINUX_MFD_RTL8231_H
+#define __LINUX_MFD_RTL8231_H
+
+/* Chip control */
+#define RTL8231_REG_FUNC0		0x00
+#define RTL8231_FUNC0_SCAN_MODE		BIT(0)
+#define RTL8231_FUNC0_SCAN_SINGLE	0
+#define RTL8231_FUNC0_SCAN_BICOLOR	BIT(0)
+
+#define RTL8231_REG_FUNC1		0x01
+#define RTL8231_FUNC1_READY_CODE_VALUE	0x37
+
+/* Pin control */
+#define RTL8231_REG_PIN_MODE0		0x02
+#define RTL8231_REG_PIN_MODE1		0x03
+
+#define RTL8231_PIN_MODE_LED		0
+#define RTL8231_PIN_MODE_GPIO		1
+
+/* Pin high config: pin and GPIO control for pins 32-26 */
+#define RTL8231_REG_PIN_HI_CFG		0x04
+
+/* GPIO control registers */
+#define RTL8231_REG_GPIO_DIR0		0x05
+#define RTL8231_REG_GPIO_DIR1		0x06
+#define RTL8231_REG_GPIO_INVERT0	0x07
+#define RTL8231_REG_GPIO_INVERT1	0x08
+
+#define RTL8231_GPIO_DIR_IN		1
+#define RTL8231_GPIO_DIR_OUT		0
+
+/* GPIO data registers */
+#define RTL8231_REG_GPIO_DATA0		0x1c
+#define RTL8231_REG_GPIO_DATA1		0x1d
+#define RTL8231_REG_GPIO_DATA2		0x1e
+
+/* LED control base registers */
+#define RTL8231_REG_LED0_BASE		0x09
+#define RTL8231_REG_LED1_BASE		0x10
+#define RTL8231_REG_LED2_BASE		0x17
+
+#define RTL8231_REG_COUNT		0x1f
+
+#endif /* __LINUX_MFD_RTL8231_H */
