--- /dev/null
+.. SPDX-License-Identifier: GPL-2.0-or-later
+
+Kernel driver dps920ab
+========================
+
+Supported chips:
+
+  * Delta DPS920AB
+
+    Prefix: 'dps920ab'
+
+    Addresses scanned: -
+
+Authors:
+    Robert Marko <robert.marko@sartura.hr>
+
+
+Description
+-----------
+
+This driver implements support for Delta DPS920AB 920W 54V DC single output
+power supply with PMBus support.
+
+The driver is a client driver to the core PMBus driver.
+Please see Documentation/hwmon/pmbus.rst for details on PMBus client drivers.
+
+
+Usage Notes
+-----------
+
+This driver does not auto-detect devices. You will have to instantiate the
+devices explicitly. Please see Documentation/i2c/instantiating-devices.rst for
+details.
+
+
+Sysfs entries
+-------------
+
+======================= ======================================================
+curr1_label            "iin"
+curr1_input            Measured input current
+curr1_alarm            Input current high alarm
+
+curr2_label            "iout1"
+curr2_input            Measured output current
+curr2_max              Maximum output current
+curr2_rated_max                Maximum rated output current
+
+in1_label              "vin"
+in1_input              Measured input voltage
+in1_alarm              Input voltage alarm
+
+in2_label              "vout1"
+in2_input              Measured output voltage
+in2_rated_min          Minimum rated output voltage
+in2_rated_max          Maximum rated output voltage
+in2_alarm              Output voltage alarm
+
+power1_label           "pin"
+power1_input           Measured input power
+power1_alarm           Input power high alarm
+
+power2_label           "pout1"
+power2_input           Measured output power
+power2_rated_max       Maximum rated output power
+
+temp[1-3]_input                Measured temperature
+temp[1-3]_alarm                Temperature alarm
+
+fan1_alarm             Fan 1 warning.
+fan1_fault             Fan 1 fault.
+fan1_input             Fan 1 speed in RPM.
+======================= ======================================================
 
--- /dev/null
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Driver for Delta DPS920AB PSU
+ *
+ * Copyright (C) 2021 Delta Networks, Inc.
+ * Copyright (C) 2021 Sartura Ltd.
+ */
+
+#include <linux/debugfs.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include "pmbus.h"
+
+struct dps920ab_data {
+       char *mfr_model;
+       char *mfr_id;
+};
+
+static int dps920ab_read_word_data(struct i2c_client *client, int page, int phase, int reg)
+{
+       /*
+        * This masks commands which are not supported.
+        * PSU advertises that all features are supported,
+        * in reality that unfortunately is not true.
+        * So enable only those that the datasheet confirms.
+        */
+       switch (reg) {
+       case PMBUS_FAN_COMMAND_1:
+       case PMBUS_IOUT_OC_WARN_LIMIT:
+       case PMBUS_STATUS_WORD:
+       case PMBUS_READ_VIN:
+       case PMBUS_READ_IIN:
+       case PMBUS_READ_VOUT:
+       case PMBUS_READ_IOUT:
+       case PMBUS_READ_TEMPERATURE_1:
+       case PMBUS_READ_TEMPERATURE_2:
+       case PMBUS_READ_TEMPERATURE_3:
+       case PMBUS_READ_FAN_SPEED_1:
+       case PMBUS_READ_POUT:
+       case PMBUS_READ_PIN:
+       case PMBUS_MFR_VOUT_MIN:
+       case PMBUS_MFR_VOUT_MAX:
+       case PMBUS_MFR_IOUT_MAX:
+       case PMBUS_MFR_POUT_MAX:
+               return pmbus_read_word_data(client, page, phase, reg);
+       default:
+               return -ENXIO;
+       }
+}
+
+static int dps920ab_write_word_data(struct i2c_client *client, int page, int reg,
+                                   u16 word)
+{
+       /*
+        * This masks commands which are not supported.
+        * PSU only has one R/W register and that is
+        * for the fan.
+        */
+       switch (reg) {
+       case PMBUS_FAN_COMMAND_1:
+               return pmbus_write_word_data(client, page, reg, word);
+       default:
+               return -EACCES;
+       }
+}
+
+static struct pmbus_driver_info dps920ab_info = {
+       .pages = 1,
+
+       .format[PSC_VOLTAGE_IN] = linear,
+       .format[PSC_VOLTAGE_OUT] = linear,
+       .format[PSC_CURRENT_IN] = linear,
+       .format[PSC_CURRENT_OUT] = linear,
+       .format[PSC_POWER] = linear,
+       .format[PSC_FAN] = linear,
+       .format[PSC_TEMPERATURE] = linear,
+
+       .func[0] =
+               PMBUS_HAVE_VIN | PMBUS_HAVE_IIN | PMBUS_HAVE_PIN |
+               PMBUS_HAVE_VOUT | PMBUS_HAVE_IOUT | PMBUS_HAVE_POUT |
+               PMBUS_HAVE_TEMP  | PMBUS_HAVE_TEMP2 | PMBUS_HAVE_TEMP3 |
+               PMBUS_HAVE_FAN12 | PMBUS_HAVE_STATUS_FAN12 |
+               PMBUS_HAVE_STATUS_VOUT | PMBUS_HAVE_STATUS_IOUT |
+               PMBUS_HAVE_STATUS_INPUT | PMBUS_HAVE_STATUS_TEMP,
+       .read_word_data = dps920ab_read_word_data,
+       .write_word_data = dps920ab_write_word_data,
+};
+
+static int dps920ab_mfr_id_show(struct seq_file *s, void *data)
+{
+       struct dps920ab_data *priv = s->private;
+
+       seq_printf(s, "%s\n", priv->mfr_id);
+
+       return 0;
+}
+
+DEFINE_SHOW_ATTRIBUTE(dps920ab_mfr_id);
+
+static int dps920ab_mfr_model_show(struct seq_file *s, void *data)
+{
+       struct dps920ab_data *priv = s->private;
+
+       seq_printf(s, "%s\n", priv->mfr_model);
+
+       return 0;
+}
+
+DEFINE_SHOW_ATTRIBUTE(dps920ab_mfr_model);
+
+static void dps920ab_init_debugfs(struct dps920ab_data *data, struct i2c_client *client)
+{
+       struct dentry *debugfs_dir;
+       struct dentry *root;
+
+       root = pmbus_get_debugfs_dir(client);
+       if (!root)
+               return;
+
+       debugfs_dir = debugfs_create_dir(client->name, root);
+       if (!debugfs_dir)
+               return;
+
+       debugfs_create_file("mfr_id",
+                           0400,
+                           debugfs_dir,
+                           data,
+                           &dps920ab_mfr_id_fops);
+
+       debugfs_create_file("mfr_model",
+                           0400,
+                           debugfs_dir,
+                           data,
+                           &dps920ab_mfr_model_fops);
+}
+
+static int dps920ab_probe(struct i2c_client *client)
+{
+       u8 buf[I2C_SMBUS_BLOCK_MAX + 1];
+       struct dps920ab_data *data;
+       int ret;
+
+       data = devm_kzalloc(&client->dev, sizeof(*data), GFP_KERNEL);
+       if (!data)
+               return -ENOMEM;
+
+       ret = i2c_smbus_read_block_data(client, PMBUS_MFR_ID, buf);
+       if (ret < 0) {
+               dev_err(&client->dev, "Failed to read Manufacturer ID\n");
+               return ret;
+       }
+
+       buf[ret] = '\0';
+       if (ret != 5 || strncmp(buf, "DELTA", 5)) {
+               buf[ret] = '\0';
+               dev_err(&client->dev, "Unsupported Manufacturer ID '%s'\n", buf);
+               return -ENODEV;
+       }
+       data->mfr_id = devm_kstrdup(&client->dev, buf, GFP_KERNEL);
+       if (!data->mfr_id)
+               return -ENOMEM;
+
+       ret = i2c_smbus_read_block_data(client, PMBUS_MFR_MODEL, buf);
+       if (ret < 0) {
+               dev_err(&client->dev, "Failed to read Manufacturer Model\n");
+               return ret;
+       }
+
+       buf[ret] = '\0';
+       if (ret != 11 || strncmp(buf, "DPS-920AB", 9)) {
+               dev_err(&client->dev, "Unsupported Manufacturer Model '%s'\n", buf);
+               return -ENODEV;
+       }
+       data->mfr_model = devm_kstrdup(&client->dev, buf, GFP_KERNEL);
+       if (!data->mfr_model)
+               return -ENOMEM;
+
+       ret = pmbus_do_probe(client, &dps920ab_info);
+       if (ret)
+               return ret;
+
+       dps920ab_init_debugfs(data, client);
+
+       return 0;
+}
+
+static const struct of_device_id __maybe_unused dps920ab_of_match[] = {
+       { .compatible = "delta,dps920ab", },
+       {}
+};
+
+MODULE_DEVICE_TABLE(of, dps920ab_of_match);
+
+static struct i2c_driver dps920ab_driver = {
+       .driver = {
+                  .name = "dps920ab",
+                  .of_match_table = of_match_ptr(dps920ab_of_match),
+       },
+       .probe_new = dps920ab_probe,
+};
+
+module_i2c_driver(dps920ab_driver);
+
+MODULE_AUTHOR("Robert Marko <robert.marko@sartura.hr>");
+MODULE_DESCRIPTION("PMBus driver for Delta DPS920AB PSU");
+MODULE_LICENSE("GPL");
+MODULE_IMPORT_NS(PMBUS);