--- /dev/null
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2023 Richtek Technology Corp.
+ *
+ * Author: ChiYuan Huang <cy_huang@richtek.com>
+ */
+
+#include <linux/i2c.h>
+#include <linux/kernel.h>
+#include <linux/mod_devicetable.h>
+#include <linux/module.h>
+#include <linux/property.h>
+#include <linux/regmap.h>
+#include <linux/regulator/driver.h>
+#include <linux/regulator/of_regulator.h>
+
+#define RT4803_AUTO_MODE       1
+#define RT4803_FPWM_MODE       2
+
+#define RT4803_REG_CONFIG      0x01
+#define RT4803_REG_VSELL       0x02
+#define RT4803_REG_VSELH       0x03
+#define RT4803_REG_ILIM                0x04
+#define RT4803_REG_STAT                0x05
+
+#define RT4803_MODE_MASK       GENMASK(1, 0)
+#define RT4803_VSEL_MASK       GENMASK(4, 0)
+#define RT4803_ILIM_MASK       GENMASK(3, 0)
+#define RT4803_TSD_MASK                BIT(7)
+#define RT4803_HOTDIE_MASK     BIT(6)
+#define RT4803_FAULT_MASK      BIT(1)
+#define RT4803_PGOOD_MASK      BIT(0)
+
+#define RT4803_VOUT_MINUV      2850000
+#define RT4803_VOUT_STEPUV     50000
+#define RT4803_VOUT_NUM                32
+
+static int rt4803_set_mode(struct regulator_dev *rdev, unsigned int mode)
+{
+       struct regmap *regmap = rdev_get_regmap(rdev);
+       unsigned int modeval;
+
+       switch (mode) {
+       case REGULATOR_MODE_NORMAL:
+               modeval = RT4803_AUTO_MODE;
+               break;
+       case REGULATOR_MODE_FAST:
+               modeval = RT4803_FPWM_MODE;
+               break;
+       default:
+               return -EINVAL;
+       }
+
+       modeval <<= ffs(RT4803_MODE_MASK) - 1;
+
+       return regmap_update_bits(regmap, RT4803_REG_CONFIG, RT4803_MODE_MASK, modeval);
+}
+
+static unsigned int rt4803_get_mode(struct regulator_dev *rdev)
+{
+       struct regmap *regmap = rdev_get_regmap(rdev);
+       unsigned int modeval;
+       int ret;
+
+       ret = regmap_read(regmap, RT4803_REG_CONFIG, &modeval);
+       if (ret)
+               return REGULATOR_MODE_INVALID;
+
+       modeval >>= ffs(RT4803_MODE_MASK) - 1;
+
+       switch (modeval) {
+       case RT4803_AUTO_MODE:
+               return REGULATOR_MODE_NORMAL;
+       case RT4803_FPWM_MODE:
+               return REGULATOR_MODE_FAST;
+       default:
+               return REGULATOR_MODE_INVALID;
+       }
+}
+
+static int rt4803_get_error_flags(struct regulator_dev *rdev, unsigned int *flags)
+{
+       struct regmap *regmap = rdev_get_regmap(rdev);
+       unsigned int state, events = 0;
+       int ret;
+
+       ret = regmap_read(regmap, RT4803_REG_STAT, &state);
+       if (ret)
+               return ret;
+
+       if (state & RT4803_PGOOD_MASK)
+               goto out_error_flag;
+
+       if (state & RT4803_FAULT_MASK)
+               events |= REGULATOR_ERROR_FAIL;
+
+       if (state & RT4803_HOTDIE_MASK)
+               events |= REGULATOR_ERROR_OVER_TEMP_WARN;
+
+       if (state & RT4803_TSD_MASK)
+               events |= REGULATOR_ERROR_OVER_TEMP;
+
+out_error_flag:
+       *flags = events;
+       return 0;
+}
+
+static int rt4803_set_suspend_voltage(struct regulator_dev *rdev, int uV)
+{
+       struct regmap *regmap = rdev_get_regmap(rdev);
+       unsigned int reg, vsel;
+
+       if (rdev->desc->vsel_reg == RT4803_REG_VSELL)
+               reg = RT4803_REG_VSELH;
+       else
+               reg = RT4803_REG_VSELL;
+
+       vsel = (uV - rdev->desc->min_uV) / rdev->desc->uV_step;
+       vsel <<= ffs(RT4803_VSEL_MASK) - 1;
+
+       return regmap_update_bits(regmap, reg, RT4803_VSEL_MASK, vsel);
+}
+
+static const struct regulator_ops rt4803_regulator_ops = {
+       .list_voltage = regulator_list_voltage_linear,
+       .set_voltage_sel = regulator_set_voltage_sel_regmap,
+       .get_voltage_sel = regulator_get_voltage_sel_regmap,
+       .set_mode = rt4803_set_mode,
+       .get_mode = rt4803_get_mode,
+       .get_error_flags = rt4803_get_error_flags,
+       .set_suspend_voltage = rt4803_set_suspend_voltage,
+};
+
+static unsigned int rt4803_of_map_mode(unsigned int mode)
+{
+       switch (mode) {
+       case RT4803_AUTO_MODE:
+               return REGULATOR_MODE_NORMAL;
+       case RT4803_FPWM_MODE:
+               return REGULATOR_MODE_FAST;
+       default:
+               return REGULATOR_MODE_INVALID;
+       }
+}
+
+static const struct regmap_config rt4803_regmap_config = {
+       .reg_bits = 8,
+       .val_bits = 8,
+       .max_register = RT4803_REG_STAT,
+};
+
+static int rt4803_probe(struct i2c_client *i2c)
+{
+       struct device *dev = &i2c->dev;
+       struct regmap *regmap;
+       struct regulator_desc *desc;
+       struct regulator_config cfg = {};
+       struct regulator_dev *rdev;
+       bool vsel_act_high;
+       int ret;
+
+       desc = devm_kzalloc(dev, sizeof(*desc), GFP_KERNEL);
+       if (!desc)
+               return -ENOMEM;
+
+       regmap = devm_regmap_init_i2c(i2c, &rt4803_regmap_config);
+       if (IS_ERR(regmap))
+               return dev_err_probe(dev, PTR_ERR(regmap), "Failed to init regmap\n");
+
+       /* Always configure the input current limit to max 5A at initial */
+       ret = regmap_update_bits(regmap, RT4803_REG_ILIM, RT4803_ILIM_MASK, 0xff);
+       if (ret)
+               return dev_err_probe(dev, ret, "Failed to config ILIM to max\n");
+
+       vsel_act_high = device_property_read_bool(dev, "richtek,vsel-active-high");
+
+       desc->name = "rt4803-regulator";
+       desc->type = REGULATOR_VOLTAGE;
+       desc->owner = THIS_MODULE;
+       desc->ops = &rt4803_regulator_ops;
+       desc->min_uV = RT4803_VOUT_MINUV;
+       desc->uV_step = RT4803_VOUT_STEPUV;
+       desc->n_voltages = RT4803_VOUT_NUM;
+       desc->vsel_mask = RT4803_VSEL_MASK;
+       desc->of_map_mode = rt4803_of_map_mode;
+       if (vsel_act_high)
+               desc->vsel_reg = RT4803_REG_VSELH;
+       else
+               desc->vsel_reg = RT4803_REG_VSELL;
+
+       cfg.dev = dev;
+       cfg.of_node = dev_of_node(dev);
+       cfg.init_data = of_get_regulator_init_data(dev, dev_of_node(dev), desc);
+
+       rdev = devm_regulator_register(dev, desc, &cfg);
+       return PTR_ERR_OR_ZERO(rdev);
+}
+
+static const struct of_device_id rt4803_device_match_table[] = {
+       { .compatible = "richtek,rt4803" },
+       {}
+};
+MODULE_DEVICE_TABLE(of, rt4803_device_match_table);
+
+static struct i2c_driver rt4803_driver = {
+       .driver = {
+               .name = "rt4803",
+               .of_match_table = rt4803_device_match_table,
+       },
+       .probe = rt4803_probe,
+};
+module_i2c_driver(rt4803_driver);
+
+MODULE_DESCRIPTION("Richtek RT4803 voltage regulator driver");
+MODULE_AUTHOR("ChiYuan Huang <cy_huang@richtek.com>");
+MODULE_LICENSE("GPL");