[PATCH v3 2/2] hwmon: add MP5920 driver

[Alex Vdovydchenko <keromvp@gmail.com>]

Add support for MPS Hot-Swap controller mp5920. This driver exposes
telemetry and limit value readings and writings.

Signed-off-by: Alex Vdovydchenko <xzeol@yahoo.com>
---
 Documentation/hwmon/index.rst  |  1 +
 Documentation/hwmon/mp5920.rst | 91 +++++++++++++++++++++++++++++++++
 drivers/hwmon/pmbus/Kconfig    |  9 ++++
 drivers/hwmon/pmbus/Makefile   |  1 +
 drivers/hwmon/pmbus/mp5920.c   | 93 ++++++++++++++++++++++++++++++++++
 5 files changed, 195 insertions(+)
 create mode 100644 Documentation/hwmon/mp5920.rst
 create mode 100644 drivers/hwmon/pmbus/mp5920.c

diff --git a/Documentation/hwmon/index.rst b/Documentation/hwmon/index.rst
index e92a3d5c7..9eba7e402 100644
--- a/Documentation/hwmon/index.rst
+++ b/Documentation/hwmon/index.rst
@@ -168,6 +168,7 @@ Hardware Monitoring Kernel Drivers
    mp2975
    mp2993
    mp5023
+   mp5920
    mp5990
    mp9941
    mpq8785
--- /dev/null
+++ b/Documentation/hwmon/mp5920.rst
@@ -0,0 +1,91 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+Kernel driver mp5920
+====================
+
+Supported chips:
+
+  * MPS MP5920
+
+    Prefix: 'mp5920'
+
+  * Datasheet
+
+    Publicly available at the MPS website : https://www.monolithicpower.com/en/mp5920.html
+
+Authors:
+
+	Tony Ao <tony_ao@wiwynn.com>
+	Alex Vdovydchenko <xzeol@yahoo.com>
+
+Description
+-----------
+
+This driver implements support for Monolithic Power Systems, Inc. (MPS)
+MP5920 Hot-Swap Controller.
+
+Device compliant with:
+
+- PMBus rev 1.3 interface.
+
+Device supports direct and linear format for reading input voltage,
+output voltage, output current, input power and temperature.
+
+The driver exports the following attributes via the 'sysfs' files
+for input voltage:
+
+**in1_input**
+
+**in1_label**
+
+**in1_rated_max**
+
+**in1_rated_min**
+
+**in1_crit**
+
+**in1_alarm**
+
+The driver provides the following attributes for output voltage:
+
+**in2_input**
+
+**in2_label**
+
+**in2_rated_max**
+
+**in2_rated_min**
+
+**in2_alarm**
+
+The driver provides the following attributes for output current:
+
+**curr1_input**
+
+**curr1_label**
+
+**curr1_crit**
+
+**curr1_alarm**
+
+**curr1_rated_max**
+
+The driver provides the following attributes for input power:
+
+**power1_input**
+
+**power1_label**
+
+**power1_max**
+
+**power1_rated_max**
+
+The driver provides the following attributes for temperature:
+
+**temp1_input**
+
+**temp1_max**
+
+**temp1_crit**
+
+**temp1_alarm**
--- a/drivers/hwmon/pmbus/Kconfig
+++ b/drivers/hwmon/pmbus/Kconfig
@@ -371,6 +371,15 @@ config SENSORS_MP5023
 	  This driver can also be built as a module. If so, the module will
 	  be called mp5023.
 
+config SENSORS_MP5920
+	tristate "MPS MP5920"
+	help
+	  If you say yes here you get hardware monitoring support for Monolithic
+	  MP5920.
+
+	  This driver can also be built as a module. If so, the module will
+	  be called mp5920.
+
 config SENSORS_MP5990
 	tristate "MPS MP5990"
 	help
--- a/drivers/hwmon/pmbus/Makefile
+++ b/drivers/hwmon/pmbus/Makefile
@@ -39,6 +39,7 @@ obj-$(CONFIG_SENSORS_MP2888)	+= mp2888.o
 obj-$(CONFIG_SENSORS_MP2975)	+= mp2975.o
 obj-$(CONFIG_SENSORS_MP2993)	+= mp2993.o
 obj-$(CONFIG_SENSORS_MP5023)	+= mp5023.o
+obj-$(CONFIG_SENSORS_MP5920)	+= mp5920.o
 obj-$(CONFIG_SENSORS_MP5990)	+= mp5990.o
 obj-$(CONFIG_SENSORS_MP9941)	+= mp9941.o
 obj-$(CONFIG_SENSORS_MPQ7932)	+= mpq7932.o
--- /dev/null
+++ b/drivers/hwmon/pmbus/mp5920.c
@@ -0,0 +1,82 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include "pmbus.h"
+
+static struct pmbus_driver_info mp5920_info = {
+	.pages = 1,
+	.format[PSC_VOLTAGE_IN] = direct,
+	.format[PSC_VOLTAGE_OUT] = direct,
+	.format[PSC_CURRENT_OUT] = direct,
+	.format[PSC_POWER] = direct,
+	.format[PSC_TEMPERATURE] = direct,
+	.m[PSC_VOLTAGE_IN] = 2266,
+	.b[PSC_VOLTAGE_IN] = 0,
+	.R[PSC_VOLTAGE_IN] = -1,
+	.m[PSC_VOLTAGE_OUT] = 2266,
+	.b[PSC_VOLTAGE_OUT] = 0,
+	.R[PSC_VOLTAGE_OUT] = -1,
+	.m[PSC_CURRENT_OUT] = 546,
+	.b[PSC_CURRENT_OUT] = 0,
+	.R[PSC_CURRENT_OUT] = -2,
+	.m[PSC_POWER] = 5840,
+	.b[PSC_POWER] = 0,
+	.R[PSC_POWER] = -3,
+	.m[PSC_TEMPERATURE] = 1067,
+	.b[PSC_TEMPERATURE] = 20500,
+	.R[PSC_TEMPERATURE] = -2,
+	.func[0] = PMBUS_HAVE_VIN  | PMBUS_HAVE_VOUT |
+		PMBUS_HAVE_IOUT | PMBUS_HAVE_POUT |
+		PMBUS_HAVE_TEMP,
+};
+
+static int mp5920_probe(struct i2c_client *client)
+{
+	struct device *dev =  &client->dev;
+	int ret;
+	u8 buf[I2C_SMBUS_BLOCK_MAX + 1];
+
+	ret = i2c_smbus_read_block_data(client, PMBUS_MFR_MODEL, buf);
+	if (ret < 0) {
+		dev_err(dev, "Failed to read PMBUS_MFR_MODEL\n");
+		return ret;
+	}
+	if (ret != 6 || strncmp(buf, "MP5920", 6)) {
+		buf[ret] = '\0';
+		dev_err(dev, "Model '%s' not supported\n", buf);
+		return -ENODEV;
+	}
+
+	return pmbus_do_probe(client, &mp5920_info);
+}
+
+static const struct of_device_id mp5920_of_match[] = {
+	{ .compatible = "mps,mp5920" },
+	{ }
+};
+
+MODULE_DEVICE_TABLE(of, mp5920_of_match);
+
+static const struct i2c_device_id mp5920_id[] = {
+	{ "mp5920" },
+	{ }
+};
+
+MODULE_DEVICE_TABLE(i2c, mp5920_id);
+
+static struct i2c_driver mp5920_driver = {
+	.driver = {
+			.name = "mp5920",
+			},
+	.probe = mp5920_probe,
+	.id_table = mp5920_id,
+};
+
+module_i2c_driver(mp5920_driver);
+
+MODULE_AUTHOR("Tony Ao <tony_ao@wiwynn.com>");
+MODULE_AUTHOR("Alex Vdovydchenko <xzeol@yahoo.com>");
+MODULE_DESCRIPTION("PMBus driver for MP5920 HSC");
+MODULE_LICENSE("GPL");
+MODULE_IMPORT_NS(PMBUS);
-- 
2.43.0