Re: [PATCH 2/2] hwmon: add mpm369x driver

From: Guenter Roeck

Date: Wed Mar 18 2026 - 04:00:11 EST

On 3/18/26 00:02, Yuxi Wang wrote:

Add support for mps mpm369x chip family,
which includes mpm3695-20 and mpm3690S-15.

mpm3695 is already supported by the mpq8785 driver, and mpm3690 can
and should be added to the same driver.

Any register adjustments besides the temperature register, if needed,
that can easily be added to that driver.

Thanks,
Guenter

Signed-off-by: Yuxi Wang <Yuxi.Wang@xxxxxxxxxxxxxxxxxxx>
---
Documentation/hwmon/index.rst | 1 +
Documentation/hwmon/mpm369x.rst | 75 +++++++++++++++++++++
MAINTAINERS | 7 ++
drivers/hwmon/pmbus/Kconfig | 9 +++
drivers/hwmon/pmbus/Makefile | 1 +
drivers/hwmon/pmbus/mpm369x.c | 115 ++++++++++++++++++++++++++++++++
6 files changed, 208 insertions(+)
create mode 100644 Documentation/hwmon/mpm369x.rst
create mode 100644 drivers/hwmon/pmbus/mpm369x.c

diff --git a/Documentation/hwmon/index.rst b/Documentation/hwmon/index.rst
index b2ca8513cfcd..340df0ccc9f1 100644
--- a/Documentation/hwmon/index.rst
+++ b/Documentation/hwmon/index.rst
@@ -190,6 +190,7 @@ Hardware Monitoring Kernel Drivers
mp5990
mp9941
mp9945
+ mpm369x
mpq8785
nct6683
nct6775
diff --git a/Documentation/hwmon/mpm369x.rst b/Documentation/hwmon/mpm369x.rst
new file mode 100644
index 000000000000..df15eb1f81c3
--- /dev/null
+++ b/Documentation/hwmon/mpm369x.rst
@@ -0,0 +1,75 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+Kernel driver mpm369x
+====================
+
+Supported chips:
+
+ * MPS mpm3695-20
+
+ Prefix: 'mpm3695-20'
+
+ * MPS mpm3690S-15
+
+ Prefix: 'mpm3690S-15'
+
+Author:
+
+ Yuxi Wang <Yuxi.Wang@xxxxxxxxxxxxxxxxxxx>
+
+Description
+-----------
+
+This driver implements support for Monolithic Power Systems, Inc. (MPS)
+MPM3695-20 and MPM3690S-15 Controller.
+
+Device compliant with:
+
+- PMBus rev 1.3 interface.
+
+The driver exports the following attributes via the 'sysfs' files
+for input voltage:
+
+**in1_input**
+
+**in1_label**
+
+**in1_crit**
+
+**in1_crit_alarm**
+
+The driver provides the following attributes for output voltage:
+
+**in2_input**
+
+**in2_label**
+
+**in2_lcrit**
+
+**in2_lcrit_alarm**
+
+**in2_rated_max**
+
+**in2_rated_min**
+
+The driver provides the following attributes for output current:
+
+**curr1_input**
+
+**curr1_label**
+
+**curr1_max**
+
+**curr1_max_alarm**
+
+The driver provides the following attributes for temperature:
+
+**temp1_input**
+
+**temp1_crit**
+
+**temp1_crit_alarm**
+
+**temp1_max**
+
+**temp1_max_alarm**
diff --git a/MAINTAINERS b/MAINTAINERS
index 96ea84948d76..26b2949b2dd6 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -17948,6 +17948,13 @@ S: Maintained
F: Documentation/hwmon/mp9945.rst
F: drivers/hwmon/pmbus/mp9945.c
+MPS MPM369X DRIVER
+M: Yuxi Wang <Yuxi.Wang@xxxxxxxxxxxxxxxxxxx>
+L: linux-hwmon@xxxxxxxxxxxxxxx
+S: Maintained
+F: Documentation/hwmon/mpm369x.rst
+F: drivers/hwmon/pmbus/mpm369x.c
+
MR800 AVERMEDIA USB FM RADIO DRIVER
M: Alexey Klimov <alexey.klimov@xxxxxxxxxx>
L: linux-media@xxxxxxxxxxxxxxx
diff --git a/drivers/hwmon/pmbus/Kconfig b/drivers/hwmon/pmbus/Kconfig
index fc1273abe357..4aadecd49209 100644
--- a/drivers/hwmon/pmbus/Kconfig
+++ b/drivers/hwmon/pmbus/Kconfig
@@ -517,6 +517,15 @@ config SENSORS_MP9945
This driver can also be built as a module. If so, the module will
be called mp9945.
+config SENSORS_MPM369X
+ tristate "MPS MPM369X"
+ help
+ If you say yes here you get hardware monitoring support for MPS
+ MPM369X chip family.
+
+ This driver can also be built as a module. If so, the module will
+ be called mpm369x.
+
config SENSORS_MPQ7932_REGULATOR
bool "Regulator support for MPQ7932"
depends on SENSORS_MPQ7932 && REGULATOR
diff --git a/drivers/hwmon/pmbus/Makefile b/drivers/hwmon/pmbus/Makefile
index d6c86924f887..58f38f2013b0 100644
--- a/drivers/hwmon/pmbus/Makefile
+++ b/drivers/hwmon/pmbus/Makefile
@@ -52,6 +52,7 @@ obj-$(CONFIG_SENSORS_MP5926) += mp5926.o
obj-$(CONFIG_SENSORS_MP5990) += mp5990.o
obj-$(CONFIG_SENSORS_MP9941) += mp9941.o
obj-$(CONFIG_SENSORS_MP9945) += mp9945.o
+obj-$(CONFIG_SENSORS_MPM369X) += mpm369x.o
obj-$(CONFIG_SENSORS_MPQ7932) += mpq7932.o
obj-$(CONFIG_SENSORS_MPQ8785) += mpq8785.o
obj-$(CONFIG_SENSORS_PLI1209BC) += pli1209bc.o
diff --git a/drivers/hwmon/pmbus/mpm369x.c b/drivers/hwmon/pmbus/mpm369x.c
new file mode 100644
index 000000000000..3f1fe9c28ca7
--- /dev/null
+++ b/drivers/hwmon/pmbus/mpm369x.c
@@ -0,0 +1,115 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * mpm369x.c - pmbus driver for mps mpm369x
+ *
+ * Copyright 2026 Monolithic Power Systems, Inc
+ *
+ * Author: Yuxi Wang <Yuxi.Wang@xxxxxxxxxxxxxxxxxxx>
+ */
+
+#include <linux/bitfield.h>
+#include <linux/bits.h>
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/pmbus.h>
+#include "pmbus.h"
+
+#define PAGE 0x01
+#define MPM369x_FUNC (PMBUS_HAVE_VIN | PMBUS_HAVE_VOUT | \
+ PMBUS_HAVE_IOUT | PMBUS_HAVE_TEMP | \
+ PMBUS_HAVE_STATUS_VOUT | PMBUS_HAVE_STATUS_IOUT | \
+ PMBUS_HAVE_STATUS_INPUT | PMBUS_HAVE_STATUS_TEMP)
+
+static int mpm369x_read_byte_data(struct i2c_client *client, int page,
+ int reg)
+{
+ return -ENODATA;
+}
+
+static int mpm369x_read_word_data(struct i2c_client *client, int page, int phase,
+ int reg)
+{
+ int ret;
+
+ switch (reg) {
+ case PMBUS_READ_TEMPERATURE_1:
+ ret = pmbus_read_word_data(client, page, phase, reg);
+ if (ret < 0)
+ return ret;
+ /*
+ * Because the Temperature format used by the chip is a 2-byte,
+ * twos complement integer and the sign bit is bits[9].
+ * Report that signed short integer.
+ */
+ if (ret & 0x200)
+ ret = (ret & 0x1ff) | 0xfe00;
+ break;
+ default:
+ ret = -ENODATA;
+ break;
+ }
+ return ret;
+}
+
+static struct pmbus_driver_info mpm369x_info = {
+ .pages = PAGE,
+ .format[PSC_VOLTAGE_IN] = direct,
+ .format[PSC_CURRENT_OUT] = direct,
+ .format[PSC_VOLTAGE_OUT] = direct,
+ .format[PSC_TEMPERATURE] = direct,
+
+ .m[PSC_VOLTAGE_IN] = 40,
+ .b[PSC_VOLTAGE_IN] = 0,
+ .R[PSC_VOLTAGE_IN] = 0,
+
+ .m[PSC_CURRENT_OUT] = 16,
+ .b[PSC_CURRENT_OUT] = 0,
+ .R[PSC_CURRENT_OUT] = 0,
+
+ .m[PSC_VOLTAGE_OUT] = 800,
+ .b[PSC_VOLTAGE_OUT] = 0,
+ .R[PSC_VOLTAGE_OUT] = 0,
+
+ .m[PSC_TEMPERATURE] = 1,
+ .b[PSC_TEMPERATURE] = 0,
+ .R[PSC_TEMPERATURE] = 3,
+
+ .read_word_data = mpm369x_read_word_data,
+ .read_byte_data = mpm369x_read_byte_data,
+ .func[0] = MPM369x_FUNC,
+};
+
+static int mpm369x_probe(struct i2c_client *client)
+{
+ return pmbus_do_probe(client, &mpm369x_info);
+}
+
+static const struct i2c_device_id mpm369x_id[] = {
+ { "MPM3695-20", 0 },
+ { "MPM3690S-15", 1 },
+ {}
+};
+MODULE_DEVICE_TABLE(i2c, mpm369x_id);
+
+static const struct of_device_id mpm369x_of_match[] = {
+ { .compatible = "mps,mpm3695-20" },
+ { .compatible = "mps,mpm3690S-15" },
+ {}
+};
+MODULE_DEVICE_TABLE(of, mpm369x_of_match);
+
+static struct i2c_driver mpm369x_driver = {
+ .probe = mpm369x_probe,
+ .driver = {
+ .name = "mpm369x",
+ .of_match_table = mpm369x_of_match,
+ },
+ .id_table = mpm369x_id,
+};
+
+module_i2c_driver(mpm369x_driver);
+MODULE_AUTHOR("Yuxi Wang <Yuxi.Wang@xxxxxxxxxxxxxxxxxxx>");
+MODULE_DESCRIPTION("MPS MPM369x pmbus driver");
+MODULE_LICENSE("GPL");
+MODULE_IMPORT_NS("PMBUS");