Re: [PATCH v3 2/2] hwmon: (pmbus/max20860a) Add driver for Analog Devices MAX20860A

[Nuno Sá]

On Fri, May 29, 2026 at 12:19:21AM +0000, Pradhan, Sanman wrote:
> From: Syed Arif <arif.syed@xxxxxxx>
> 
> Add a PMBus driver for the Analog Devices MAX20860A step-down DC-DC
> switching regulator. The MAX20860A provides monitoring of input/output
> voltage, output current, and temperature via the PMBus interface using
> linear data format.
> 
> Signed-off-by: Syed Arif <arif.syed@xxxxxxx>
> Signed-off-by: Sanman Pradhan <psanman@xxxxxxxxxxx>
> ---
> v3:
>   - Removed "maxim,max20860a" from of_device_id
> v2:
>   - Removed WRITE_PROTECT write from probe
> 
>  Documentation/hwmon/index.rst     |  1 +
>  Documentation/hwmon/max20860a.rst | 57 +++++++++++++++++++++++++++++++
>  MAINTAINERS                       |  8 +++++
>  drivers/hwmon/pmbus/Kconfig       |  9 +++++
>  drivers/hwmon/pmbus/Makefile      |  1 +
>  drivers/hwmon/pmbus/max20860a.c   | 57 +++++++++++++++++++++++++++++++
>  6 files changed, 133 insertions(+)
>  create mode 100644 Documentation/hwmon/max20860a.rst
>  create mode 100644 drivers/hwmon/pmbus/max20860a.c
> 
> diff --git a/Documentation/hwmon/index.rst b/Documentation/hwmon/index.rst
> index e880c6ca84f0..ffaacda416e7 100644
> --- a/Documentation/hwmon/index.rst
> +++ b/Documentation/hwmon/index.rst
> @@ -163,6 +163,7 @@ Hardware Monitoring Kernel Drivers
>     max20730
>     max20751
>     max20830
> +   max20860a
>     max31722
>     max31730
>     max31760
> diff --git a/Documentation/hwmon/max20860a.rst b/Documentation/hwmon/max20860a.rst
> new file mode 100644
> index 000000000000..ea6d2228fafc
> --- /dev/null
> +++ b/Documentation/hwmon/max20860a.rst
> @@ -0,0 +1,57 @@
> +.. SPDX-License-Identifier: GPL-2.0
> +
> +Kernel driver max20860a
> +=======================
> +
> +Supported chips:
> +
> +  * Analog Devices MAX20860A
> +
> +    Prefix: 'max20860a'
> +
> +    Addresses scanned: -
> +
> +    Datasheet: https://www.analog.com/en/products/max20860a.html
> +
> +Author:
> +
> +  - Syed Arif <arif.syed@xxxxxxx>
> +  - Sanman Pradhan <psanman@xxxxxxxxxxx>
> +
> +
> +Description
> +-----------
> +
> +This driver supports hardware monitoring for Analog Devices MAX20860A
> +Step-Down Switching Regulator with PMBus Interface.
> +
> +The MAX20860A is a fully integrated step-down DC-DC switching regulator.
> +Through the PMBus interface, the device can monitor input/output voltages,
> +output current and temperature.
> +
> +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.
> +
> +Sysfs entries
> +-------------
> +
> +================= ========================================
> +in1_label         "vin"
> +in1_input         Measured input voltage
> +in1_alarm         Input voltage alarm
> +in2_label         "vout1"
> +in2_input         Measured output voltage
> +in2_alarm         Output voltage alarm
> +curr1_label       "iout1"
> +curr1_input       Measured output current
> +curr1_alarm       Output current alarm
> +temp1_input       Measured temperature
> +temp1_alarm       Chip temperature alarm
> +temp2_input       Measured temperature (secondary)
> +================= ========================================
> diff --git a/MAINTAINERS b/MAINTAINERS
> index b71acb130395..1d9651947ee3 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -15688,6 +15688,14 @@ F:	Documentation/devicetree/bindings/hwmon/pmbus/adi,max20830.yaml
>  F:	Documentation/hwmon/max20830.rst
>  F:	drivers/hwmon/pmbus/max20830.c
>  
> +MAX20860A HARDWARE MONITOR DRIVER
> +M:	Sanman Pradhan <psanman@xxxxxxxxxxx>
> +L:	linux-hwmon@xxxxxxxxxxxxxxx
> +S:	Maintained
> +F:	Documentation/devicetree/bindings/hwmon/pmbus/adi,max20860a.yaml
> +F:	Documentation/hwmon/max20860a.rst
> +F:	drivers/hwmon/pmbus/max20860a.c
> +
>  MAX2175 SDR TUNER DRIVER
>  M:	Ramesh Shanmugasundaram <rashanmu@xxxxxxxxx>
>  L:	linux-media@xxxxxxxxxxxxxxx
> diff --git a/drivers/hwmon/pmbus/Kconfig b/drivers/hwmon/pmbus/Kconfig
> index 64f38654f4e7..5825dda75f2c 100644
> --- a/drivers/hwmon/pmbus/Kconfig
> +++ b/drivers/hwmon/pmbus/Kconfig
> @@ -402,6 +402,15 @@ config SENSORS_MAX20830
>  	  This driver can also be built as a module. If so, the module will
>  	  be called max20830.
>  
> +config SENSORS_MAX20860A
> +	tristate "Analog Devices MAX20860A"
> +	help
> +	  If you say yes here you get hardware monitoring support for Analog
> +	  Devices MAX20860A step-down converter.
> +
> +	  This driver can also be built as a module. If so, the module will
> +	  be called max20860a.
> +
>  config SENSORS_MAX31785
>  	tristate "Maxim MAX31785 and compatibles"
>  	help
> diff --git a/drivers/hwmon/pmbus/Makefile b/drivers/hwmon/pmbus/Makefile
> index 1f2c73b71953..ffc05f493213 100644
> --- a/drivers/hwmon/pmbus/Makefile
> +++ b/drivers/hwmon/pmbus/Makefile
> @@ -39,6 +39,7 @@ obj-$(CONFIG_SENSORS_MAX17616)	+= max17616.o
>  obj-$(CONFIG_SENSORS_MAX20730)	+= max20730.o
>  obj-$(CONFIG_SENSORS_MAX20751)	+= max20751.o
>  obj-$(CONFIG_SENSORS_MAX20830)	+= max20830.o
> +obj-$(CONFIG_SENSORS_MAX20860A)	+= max20860a.o
>  obj-$(CONFIG_SENSORS_MAX31785)	+= max31785.o
>  obj-$(CONFIG_SENSORS_MAX34440)	+= max34440.o
>  obj-$(CONFIG_SENSORS_MAX8688)	+= max8688.o
> diff --git a/drivers/hwmon/pmbus/max20860a.c b/drivers/hwmon/pmbus/max20860a.c
> new file mode 100644
> index 000000000000..f5feefcbe407
> --- /dev/null
> +++ b/drivers/hwmon/pmbus/max20860a.c
> @@ -0,0 +1,57 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Hardware monitoring driver for Analog Devices MAX20860A
> + *
> + * SPDX-FileCopyrightText: Copyright Hewlett Packard Enterprise Development LP
> + */
> +
> +#include <linux/i2c.h>
> +#include <linux/module.h>
> +#include "pmbus.h"
> +
> +static struct pmbus_driver_info max20860a_info = {
> +	.pages = 1,
> +	.format[PSC_VOLTAGE_IN] = linear,
> +	.format[PSC_VOLTAGE_OUT] = linear,
> +	.format[PSC_CURRENT_OUT] = linear,
> +	.format[PSC_TEMPERATURE] = linear,
> +	.func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_VOUT |
> +		PMBUS_HAVE_STATUS_VOUT |
> +		PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT |
> +		PMBUS_HAVE_TEMP | PMBUS_HAVE_TEMP2 |
> +		PMBUS_HAVE_STATUS_TEMP | PMBUS_HAVE_STATUS_INPUT,
> +};

Any reason not to add regulator support? Given that the device seems to
be a regulator...

- Nuno Sá

> +
> +static int max20860a_probe(struct i2c_client *client)
> +{
> +	return pmbus_do_probe(client, &max20860a_info);
> +}
> +
> +static const struct i2c_device_id max20860a_id[] = {
> +	{"max20860a"},
> +	{}
> +};
> +MODULE_DEVICE_TABLE(i2c, max20860a_id);
> +
> +static const struct of_device_id max20860a_of_match[] = {
> +	{ .compatible = "adi,max20860a" },
> +	{}
> +};
> +MODULE_DEVICE_TABLE(of, max20860a_of_match);
> +
> +static struct i2c_driver max20860a_driver = {
> +	.driver = {
> +		.name = "max20860a",
> +		.of_match_table = max20860a_of_match,
> +	},
> +	.probe = max20860a_probe,
> +	.id_table = max20860a_id,
> +};
> +
> +module_i2c_driver(max20860a_driver);
> +
> +MODULE_AUTHOR("Syed Arif <arif.syed@xxxxxxx>");
> +MODULE_AUTHOR("Sanman Pradhan <psanman@xxxxxxxxxxx>");
> +MODULE_DESCRIPTION("PMBus driver for Analog Devices MAX20860A");
> +MODULE_LICENSE("GPL");
> +MODULE_IMPORT_NS("PMBUS");
> -- 
> 2.34.1
>