Re: [PATCH v4 2/2] hwmon: (pmbus/d1u74t) Add Murata D1U74T PSU driver

[Guenter Roeck]

On Thu, May 14, 2026 at 08:03:26PM -0700, Abdurrahman Hussain wrote:
> Add PMBUS driver for Murata D1U74T power supplies.
> 
> Reported-by: kernel test robot <lkp@xxxxxxxxx>
> Closes: https://lore.kernel.org/oe-kbuild-all/202605122253.zInzmUeX-lkp@xxxxxxxxx/
> Signed-off-by: Abdurrahman Hussain <abdurrahman@xxxxxxxxxx>

Applied, after dropping the above Reported-by: and Closes: tags.
Those are inappropriate for new drivers.

I also added the missing include files.

Guenter

> ---
>  Documentation/hwmon/d1u74t.rst | 81 +++++++++++++++++++++++++++++++++++++++
>  Documentation/hwmon/index.rst  |  1 +
>  MAINTAINERS                    |  7 ++++
>  drivers/hwmon/pmbus/Kconfig    |  9 +++++
>  drivers/hwmon/pmbus/Makefile   |  1 +
>  drivers/hwmon/pmbus/d1u74t.c   | 86 ++++++++++++++++++++++++++++++++++++++++++
>  6 files changed, 185 insertions(+)
> 
> diff --git a/Documentation/hwmon/d1u74t.rst b/Documentation/hwmon/d1u74t.rst
> new file mode 100644
> index 000000000000..3a9eedbda483
> --- /dev/null
> +++ b/Documentation/hwmon/d1u74t.rst
> @@ -0,0 +1,81 @@
> +.. SPDX-License-Identifier: GPL-2.0-or-later
> +
> +Kernel driver d1u74t
> +====================
> +
> +Supported chips:
> +
> +  * Murata D1U74T
> +
> +    Prefix: 'd1u74t'
> +
> +    Addresses scanned: -
> +
> +    Datasheet: Publicly available at the Murata website
> +
> +Authors:
> +    Abdurrahman Hussain <abdurrahman@xxxxxxxxxx>
> +
> +
> +Description
> +-----------
> +
> +This driver implements support for Murata D1U74T 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 alarm
> +curr1_rated_max		Maximum rated input current
> +
> +curr2_label		"iout1"
> +curr2_input		Measured output current
> +curr2_max		Maximum output current
> +curr2_max_alarm		Output current high alarm
> +curr2_crit		Critical high output current
> +curr2_crit_alarm	Output current critical high alarm
> +curr2_rated_max		Maximum rated output current
> +
> +in1_label		"vin"
> +in1_input		Measured input voltage
> +in1_alarm		Input voltage alarm
> +in1_rated_min		Minimum rated input voltage
> +in1_rated_max		Maximum rated input voltage
> +
> +in2_label		"vout1"
> +in2_input		Measured output voltage
> +in2_alarm		Output voltage alarm
> +in2_rated_min		Minimum rated output voltage
> +in2_rated_max		Maximum rated output voltage
> +
> +power1_label		"pin"
> +power1_input		Measured input power
> +power1_alarm		Input power alarm
> +power1_rated_max	Maximum rated input power
> +
> +temp[1-3]_input		Measured temperature
> +temp[1-3]_max		Maximum temperature
> +temp[1-3]_max_alarm	Maximum temperature alarm
> +temp[1-3]_rated_max	Maximum rated temperature
> +
> +fan1_alarm		Fan 1 warning
> +fan1_fault		Fan 1 fault
> +fan1_input		Fan 1 speed in RPM
> +fan1_target		Fan 1 target
> +======================= ======================================================
> diff --git a/Documentation/hwmon/index.rst b/Documentation/hwmon/index.rst
> index 8b655e5d6b68..97b1ef65b1c1 100644
> --- a/Documentation/hwmon/index.rst
> +++ b/Documentation/hwmon/index.rst
> @@ -60,6 +60,7 @@ Hardware Monitoring Kernel Drivers
>     corsair-psu
>     cros_ec_hwmon
>     crps
> +   d1u74t
>     da9052
>     da9055
>     dell-smm-hwmon
> diff --git a/MAINTAINERS b/MAINTAINERS
> index b2040011a386..3106cf725dfc 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -18249,6 +18249,13 @@ F:	drivers/mux/
>  F:	include/dt-bindings/mux/
>  F:	include/linux/mux/
>  
> +MURATA D1U74T PSU DRIVER
> +M:	Abdurrahman Hussain <abdurrahman@xxxxxxxxxx>
> +L:	linux-hwmon@xxxxxxxxxxxxxxx
> +S:	Maintained
> +F:	Documentation/hwmon/d1u74t.rst
> +F:	drivers/hwmon/pmbus/d1u74t.c
> +
>  MUSB MULTIPOINT HIGH SPEED DUAL-ROLE CONTROLLER
>  M:	Bin Liu <b-liu@xxxxxx>
>  L:	linux-usb@xxxxxxxxxxxxxxx
> diff --git a/drivers/hwmon/pmbus/Kconfig b/drivers/hwmon/pmbus/Kconfig
> index 8f4bff375ecb..ee93b22d2887 100644
> --- a/drivers/hwmon/pmbus/Kconfig
> +++ b/drivers/hwmon/pmbus/Kconfig
> @@ -113,6 +113,15 @@ config SENSORS_CRPS
>  	  This driver can also be built as a module. If so, the module will
>  	  be called crps.
>  
> +config SENSORS_D1U74T
> +	tristate "Murata D1U74T Power Supply"
> +	help
> +	  If you say yes here you get hardware monitoring support for the Murata
> +	  D1U74T Power Supply.
> +
> +	  This driver can also be built as a module. If so, the module will
> +	  be called d1u74t.
> +
>  config SENSORS_DELTA_AHE50DC_FAN
>  	tristate "Delta AHE-50DC fan control module"
>  	help
> diff --git a/drivers/hwmon/pmbus/Makefile b/drivers/hwmon/pmbus/Makefile
> index 7129b62bc00f..8cf7d3075371 100644
> --- a/drivers/hwmon/pmbus/Makefile
> +++ b/drivers/hwmon/pmbus/Makefile
> @@ -76,3 +76,4 @@ obj-$(CONFIG_SENSORS_XDPE1A2G7B)	+= xdpe1a2g7b.o
>  obj-$(CONFIG_SENSORS_ZL6100)	+= zl6100.o
>  obj-$(CONFIG_SENSORS_PIM4328)	+= pim4328.o
>  obj-$(CONFIG_SENSORS_CRPS)	+= crps.o
> +obj-$(CONFIG_SENSORS_D1U74T)	+= d1u74t.o
> diff --git a/drivers/hwmon/pmbus/d1u74t.c b/drivers/hwmon/pmbus/d1u74t.c
> new file mode 100644
> index 000000000000..286ba492e336
> --- /dev/null
> +++ b/drivers/hwmon/pmbus/d1u74t.c
> @@ -0,0 +1,86 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Copyright 2026 Nexthop Systems.
> + */
> +
> +#include <linux/i2c.h>
> +#include <linux/of.h>
> +#include <linux/pmbus.h>
> +
> +#include "pmbus.h"
> +
> +static const struct i2c_device_id d1u74t_id[] = {
> +	{ "d1u74t" },
> +	{},
> +};
> +MODULE_DEVICE_TABLE(i2c, d1u74t_id);
> +
> +static struct pmbus_driver_info d1u74t_info = {
> +	.pages = 1,
> +	/* PSU uses default linear data format. */
> +	.func[0] = PMBUS_HAVE_PIN | PMBUS_HAVE_IOUT | PMBUS_HAVE_STATUS_IOUT |
> +		   PMBUS_HAVE_IIN | PMBUS_HAVE_VIN | PMBUS_HAVE_STATUS_INPUT |
> +		   PMBUS_HAVE_VOUT | PMBUS_HAVE_STATUS_VOUT | PMBUS_HAVE_TEMP |
> +		   PMBUS_HAVE_TEMP2 | PMBUS_HAVE_TEMP3 |
> +		   PMBUS_HAVE_STATUS_TEMP | PMBUS_HAVE_FAN12 |
> +		   PMBUS_HAVE_STATUS_FAN12,
> +};
> +
> +static int d1u74t_probe(struct i2c_client *client)
> +{
> +	char buf[I2C_SMBUS_BLOCK_MAX + 2] = { 0 };
> +	struct device *dev = &client->dev;
> +	int rc;
> +
> +	rc = i2c_smbus_read_block_data(client, PMBUS_MFR_ID, buf);
> +	if (rc < 0)
> +		return dev_err_probe(dev, rc, "Failed to read PMBUS_MFR_ID\n");
> +
> +	if (rc != 9 || strncmp(buf, "Murata-PS", 9)) {
> +		buf[rc] = '\0';
> +		return dev_err_probe(dev, -ENODEV,
> +				     "Unsupported Manufacturer ID '%s'\n",
> +				     buf);
> +	}
> +
> +	rc = i2c_smbus_read_block_data(client, PMBUS_MFR_MODEL, buf);
> +	if (rc < 0)
> +		return dev_err_probe(dev, rc,
> +				     "Failed to read PMBUS_MFR_MODEL\n");
> +
> +	if (rc < 8 || strncmp(buf, "D1U74T-W", 8)) {
> +		buf[rc] = '\0';
> +		return dev_err_probe(dev, -ENODEV, "Model '%s' not supported\n",
> +				     buf);
> +	}
> +
> +	rc = pmbus_do_probe(client, &d1u74t_info);
> +	if (rc)
> +		return dev_err_probe(dev, rc, "Failed to probe\n");
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id d1u74t_of_match[] = {
> +	{
> +		.compatible = "murata,d1u74t",
> +	},
> +	{},
> +};
> +MODULE_DEVICE_TABLE(of, d1u74t_of_match);
> +
> +static struct i2c_driver d1u74t_driver = {
> +	.driver = {
> +		.name = "d1u74t",
> +		.of_match_table = d1u74t_of_match,
> +	},
> +	.probe = d1u74t_probe,
> +	.id_table = d1u74t_id,
> +};
> +
> +module_i2c_driver(d1u74t_driver);
> +
> +MODULE_AUTHOR("Abdurrahman Hussain");
> +MODULE_DESCRIPTION("PMBus driver for Murata D1U74T-W power supplies");
> +MODULE_LICENSE("GPL");
> +MODULE_IMPORT_NS("PMBUS");