--- /dev/null
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Hardware monitoring driver for MPS Multi-phase Digital VR Controllers(MP2993)
+ */
+
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include "pmbus.h"
+
+#define MP2993_VOUT_OVUV_UINT  125
+#define MP2993_VOUT_OVUV_DIV   64
+#define MP2993_VIN_LIMIT_UINT  1
+#define MP2993_VIN_LIMIT_DIV   8
+#define MP2993_READ_VIN_UINT   1
+#define MP2993_READ_VIN_DIV    32
+
+#define MP2993_PAGE_NUM        2
+
+#define MP2993_RAIL1_FUNC      (PMBUS_HAVE_VIN | PMBUS_HAVE_VOUT | \
+                                                       PMBUS_HAVE_IOUT | PMBUS_HAVE_POUT | \
+                                                       PMBUS_HAVE_TEMP | PMBUS_HAVE_PIN | \
+                                                       PMBUS_HAVE_IIN | \
+                                                       PMBUS_HAVE_STATUS_VOUT | \
+                                                       PMBUS_HAVE_STATUS_IOUT | \
+                                                       PMBUS_HAVE_STATUS_TEMP | \
+                                                       PMBUS_HAVE_STATUS_INPUT)
+
+#define MP2993_RAIL2_FUNC      (PMBUS_HAVE_VOUT | PMBUS_HAVE_IOUT | \
+                                                        PMBUS_HAVE_POUT | PMBUS_HAVE_TEMP | \
+                                                        PMBUS_HAVE_STATUS_VOUT | \
+                                                        PMBUS_HAVE_STATUS_IOUT | \
+                                                        PMBUS_HAVE_STATUS_TEMP | \
+                                                        PMBUS_HAVE_STATUS_INPUT)
+
+/* Converts a linear11 data exponent to a specified value */
+static u16 mp2993_linear11_exponent_transfer(u16 word, u16 expect_exponent)
+{
+       s16 exponent, mantissa, target_exponent;
+
+       exponent = ((s16)word) >> 11;
+       mantissa = ((s16)((word & 0x7ff) << 5)) >> 5;
+       target_exponent = (s16)((expect_exponent & 0x1f) << 11) >> 11;
+
+       if (exponent > target_exponent)
+               mantissa = mantissa << (exponent - target_exponent);
+       else
+               mantissa = mantissa >> (target_exponent - exponent);
+
+       return (mantissa & 0x7ff) | ((expect_exponent << 11) & 0xf800);
+}
+
+static int
+mp2993_set_vout_format(struct i2c_client *client, int page, int format)
+{
+       int ret;
+
+       ret = i2c_smbus_write_byte_data(client, PMBUS_PAGE, page);
+       if (ret < 0)
+               return ret;
+
+       return i2c_smbus_write_byte_data(client, PMBUS_VOUT_MODE, format);
+}
+
+static int mp2993_identify(struct i2c_client *client, struct pmbus_driver_info *info)
+{
+       int ret;
+
+       /* Set vout to direct format for rail1. */
+       ret = mp2993_set_vout_format(client, 0, PB_VOUT_MODE_DIRECT);
+       if (ret < 0)
+               return ret;
+
+       /* Set vout to direct format for rail2. */
+       return mp2993_set_vout_format(client, 1, PB_VOUT_MODE_DIRECT);
+}
+
+static int mp2993_read_word_data(struct i2c_client *client, int page, int phase,
+                                int reg)
+{
+       int ret;
+
+       switch (reg) {
+       case PMBUS_VOUT_OV_FAULT_LIMIT:
+       case PMBUS_VOUT_UV_FAULT_LIMIT:
+               ret = pmbus_read_word_data(client, page, phase, reg);
+               if (ret < 0)
+                       return ret;
+
+               ret = DIV_ROUND_CLOSEST(ret * MP2993_VOUT_OVUV_UINT, MP2993_VOUT_OVUV_DIV);
+               break;
+       case PMBUS_OT_FAULT_LIMIT:
+       case PMBUS_OT_WARN_LIMIT:
+               /*
+                * The MP2993 ot fault limit value and ot warn limit value
+                * per rail are always the same, so only PMBUS_OT_FAULT_LIMIT
+                * and PMBUS_OT_WARN_LIMIT register in page 0 are defined to
+                * indicates the limit value.
+                */
+               ret = pmbus_read_word_data(client, 0, phase, reg);
+               break;
+       case PMBUS_READ_VIN:
+               /* The MP2993 vin scale is (1/32V)/Lsb */
+               ret = pmbus_read_word_data(client, page, phase, reg);
+               if (ret < 0)
+                       return ret;
+
+               ret = DIV_ROUND_CLOSEST((ret & GENMASK(9, 0)) * MP2993_READ_VIN_UINT,
+                                       MP2993_READ_VIN_DIV);
+               break;
+       case PMBUS_VIN_OV_FAULT_LIMIT:
+       case PMBUS_VIN_OV_WARN_LIMIT:
+       case PMBUS_VIN_UV_WARN_LIMIT:
+       case PMBUS_VIN_UV_FAULT_LIMIT:
+               /* The MP2993 vin limit scale is (1/8V)/Lsb */
+               ret = pmbus_read_word_data(client, page, phase, reg);
+               if (ret < 0)
+                       return ret;
+
+               ret = DIV_ROUND_CLOSEST((ret & GENMASK(7, 0)) * MP2993_VIN_LIMIT_UINT,
+                                       MP2993_VIN_LIMIT_DIV);
+               break;
+       case PMBUS_READ_IOUT:
+       case PMBUS_READ_IIN:
+       case PMBUS_IIN_OC_WARN_LIMIT:
+       case PMBUS_IOUT_OC_FAULT_LIMIT:
+       case PMBUS_IOUT_OC_WARN_LIMIT:
+       case PMBUS_READ_VOUT:
+       case PMBUS_READ_PIN:
+       case PMBUS_READ_POUT:
+       case PMBUS_READ_TEMPERATURE_1:
+               ret = -ENODATA;
+               break;
+       default:
+               ret = -EINVAL;
+               break;
+       }
+
+       return ret;
+}
+
+static int mp2993_write_word_data(struct i2c_client *client, int page, int reg,
+                                 u16 word)
+{
+       int ret;
+
+       switch (reg) {
+       case PMBUS_VOUT_OV_FAULT_LIMIT:
+       case PMBUS_VOUT_UV_FAULT_LIMIT:
+               ret = DIV_ROUND_CLOSEST(word * MP2993_VOUT_OVUV_DIV, MP2993_VOUT_OVUV_UINT);
+               ret = pmbus_write_word_data(client, 0, reg, ret);
+               break;
+       case PMBUS_OT_FAULT_LIMIT:
+       case PMBUS_OT_WARN_LIMIT:
+               /*
+                * The MP2993 ot fault limit value and ot warn limit value
+                * per rail are always the same, so only PMBUS_OT_FAULT_LIMIT
+                * and PMBUS_OT_WARN_LIMIT register in page 0 are defined to
+                * config the ot limit value.
+                */
+               ret = pmbus_write_word_data(client, 0, reg, word);
+               break;
+       case PMBUS_VIN_OV_FAULT_LIMIT:
+       case PMBUS_VIN_OV_WARN_LIMIT:
+       case PMBUS_VIN_UV_WARN_LIMIT:
+       case PMBUS_VIN_UV_FAULT_LIMIT:
+               /* The MP2993 vin limit scale is (1/8V)/Lsb */
+               ret = pmbus_write_word_data(client, 0, reg,
+                                           DIV_ROUND_CLOSEST(word * MP2993_VIN_LIMIT_DIV,
+                                                             MP2993_VIN_LIMIT_UINT));
+               break;
+       case PMBUS_IIN_OC_WARN_LIMIT:
+               /*
+                * The PMBUS_IIN_OC_WARN_LIMIT of MP2993 is linear11 format,
+                * and the exponent is a constant value(5'b00000), so the
+                * exponent of word parameter should be converted to 5'b00000.
+                */
+               ret = pmbus_write_word_data(client, page, reg,
+                                           mp2993_linear11_exponent_transfer(word, 0x00));
+               break;
+               //
+       case PMBUS_IOUT_OC_FAULT_LIMIT:
+       case PMBUS_IOUT_OC_WARN_LIMIT:
+               /*
+                * The PMBUS_IOUT_OC_FAULT_LIMIT and PMBUS_IOUT_OC_WARN_LIMIT
+                * of MP2993 can be regarded as linear11 format, and the
+                * exponent is a 5'b00001 or 5'b00000. To ensure a larger
+                * range of limit value, so the exponent of word parameter
+                * should be converted to 5'b00001.
+                */
+               ret = pmbus_write_word_data(client, page, reg,
+                                           mp2993_linear11_exponent_transfer(word, 0x01));
+               break;
+       default:
+               ret = -EINVAL;
+               break;
+       }
+
+       return ret;
+}
+
+static struct pmbus_driver_info mp2993_info = {
+       .pages = MP2993_PAGE_NUM,
+       .format[PSC_VOLTAGE_IN] = direct,
+       .format[PSC_CURRENT_IN] = linear,
+       .format[PSC_CURRENT_OUT] = linear,
+       .format[PSC_TEMPERATURE] = direct,
+       .format[PSC_POWER] = linear,
+       .format[PSC_VOLTAGE_OUT] = direct,
+
+       .m[PSC_VOLTAGE_OUT] = 1,
+       .R[PSC_VOLTAGE_OUT] = 3,
+       .b[PSC_VOLTAGE_OUT] = 0,
+
+       .m[PSC_VOLTAGE_IN] = 1,
+       .R[PSC_VOLTAGE_IN] = 0,
+       .b[PSC_VOLTAGE_IN] = 0,
+
+       .m[PSC_TEMPERATURE] = 1,
+       .R[PSC_TEMPERATURE] = 0,
+       .b[PSC_TEMPERATURE] = 0,
+
+       .func[0] = MP2993_RAIL1_FUNC,
+       .func[1] = MP2993_RAIL2_FUNC,
+       .read_word_data = mp2993_read_word_data,
+       .write_word_data = mp2993_write_word_data,
+       .identify = mp2993_identify,
+};
+
+static int mp2993_probe(struct i2c_client *client)
+{
+       return pmbus_do_probe(client, &mp2993_info);
+}
+
+static const struct i2c_device_id mp2993_id[] = {
+       {"mp2993", 0},
+       {}
+};
+MODULE_DEVICE_TABLE(i2c, mp2993_id);
+
+static const struct of_device_id __maybe_unused mp2993_of_match[] = {
+       {.compatible = "mps,mp2993"},
+       {}
+};
+MODULE_DEVICE_TABLE(of, mp2993_of_match);
+
+static struct i2c_driver mp2993_driver = {
+       .driver = {
+               .name = "mp2993",
+               .of_match_table = mp2993_of_match,
+       },
+       .probe = mp2993_probe,
+       .id_table = mp2993_id,
+};
+
+module_i2c_driver(mp2993_driver);
+
+MODULE_AUTHOR("Noah Wang <noahwang.wang@outlook.com>");
+MODULE_DESCRIPTION("PMBus driver for MPS MP2993");
+MODULE_LICENSE("GPL");
+MODULE_IMPORT_NS(PMBUS);