[v1,2/2] hwmon: (pmbus) Add support for MPS Multi-phase mp5990

Message ID 20231103080128.1204218-3-peteryin.openbmc@gmail.com
State New
Headers
Series hwmon: (pmbus) Add support for MPS Multi-phase mp5990 |

Commit Message

Peter Yin Nov. 3, 2023, 8:01 a.m. UTC
  Add support for mp5990 device from Monolithic Power Systems, Inc. (MPS)
vendor. This is a Hot-Swap Controller.

Signed-off-by: Peter Yin <peteryin.openbmc@gmail.com>
---
 Documentation/hwmon/index.rst  |  1 +
 Documentation/hwmon/mp5990.rst | 84 +++++++++++++++++++++++++++++++
 drivers/hwmon/pmbus/Kconfig    |  9 ++++
 drivers/hwmon/pmbus/Makefile   |  1 +
 drivers/hwmon/pmbus/mp5990.c   | 90 ++++++++++++++++++++++++++++++++++
 5 files changed, 185 insertions(+)
 create mode 100644 Documentation/hwmon/mp5990.rst
 create mode 100644 drivers/hwmon/pmbus/mp5990.c
  

Comments

Guenter Roeck Nov. 3, 2023, 2:35 p.m. UTC | #1
On 11/3/23 01:01, Peter Yin wrote:
> Add support for mp5990 device from Monolithic Power Systems, Inc. (MPS)
> vendor. This is a Hot-Swap Controller.
> 
> Signed-off-by: Peter Yin <peteryin.openbmc@gmail.com>
> ---
>   Documentation/hwmon/index.rst  |  1 +
>   Documentation/hwmon/mp5990.rst | 84 +++++++++++++++++++++++++++++++
>   drivers/hwmon/pmbus/Kconfig    |  9 ++++
>   drivers/hwmon/pmbus/Makefile   |  1 +
>   drivers/hwmon/pmbus/mp5990.c   | 90 ++++++++++++++++++++++++++++++++++
>   5 files changed, 185 insertions(+)
>   create mode 100644 Documentation/hwmon/mp5990.rst
>   create mode 100644 drivers/hwmon/pmbus/mp5990.c
> 
> diff --git a/Documentation/hwmon/index.rst b/Documentation/hwmon/index.rst
> index 042e1cf9501b..8c70e10fc795 100644
> --- a/Documentation/hwmon/index.rst
> +++ b/Documentation/hwmon/index.rst
> @@ -157,6 +157,7 @@ Hardware Monitoring Kernel Drivers
>      mp2888
>      mp2975
>      mp5023
> +   mp5990
>      nct6683
>      nct6775
>      nct7802
> diff --git a/Documentation/hwmon/mp5990.rst b/Documentation/hwmon/mp5990.rst
> new file mode 100644
> index 000000000000..8fc4e388ff7b
> --- /dev/null
> +++ b/Documentation/hwmon/mp5990.rst
> @@ -0,0 +1,84 @@
> +.. SPDX-License-Identifier: GPL-2.0
> +
> +Kernel driver mp5990
> +====================
> +
> +Supported chips:
> +
> +  * MPS MP5990
> +
> +    Prefix: 'mp5990'
> +
> +  * Datasheet
> +
> +    Publicly available at the MPS website : https://www.monolithicpower.com/en/mp5990.html
> +
> +Author:
> +
> +	Peter Yin <peteryin.openbmc@gmail.com>
> +
> +Description
> +-----------
> +
> +This driver implements support for Monolithic Power Systems, Inc. (MPS)
> +MP5990 Hot-Swap Controller.
> +
> +Device complaint with:

compliant

> +
> +- PMBus rev 1.3 interface.
> +
> +Device supports direct 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_max**
> +
> +**in1_max_alarm**
> +
> +**in1_min**
> +
> +**in1_min_alarm**
> +
> +The driver provides the following attributes for output voltage:
> +
> +**in2_input**
> +
> +**in2_label**
> +
> +**in2_alarm**
> +
> +The driver provides the following attributes for output current:
> +
> +**curr1_input**
> +
> +**curr1_label**
> +
> +**curr1_alarm**
> +
> +**curr1_max**
> +
> +The driver provides the following attributes for input power:
> +
> +**power1_input**
> +
> +**power1_label**
> +
> +**power1_alarm**
> +
> +The driver provides the following attributes for temperature:
> +
> +**temp1_input**
> +
> +**temp1_max**
> +
> +**temp1_max_alarm**
> +
> +**temp1_crit**
> +
> +**temp1_crit_alarm**
> diff --git a/drivers/hwmon/pmbus/Kconfig b/drivers/hwmon/pmbus/Kconfig
> index 270b6336b76d..65a116f7744d 100644
> --- a/drivers/hwmon/pmbus/Kconfig
> +++ b/drivers/hwmon/pmbus/Kconfig
> @@ -326,6 +326,15 @@ config SENSORS_MP5023
>   	  This driver can also be built as a module. If so, the module will
>   	  be called mp5023.
>   
> +config SENSORS_MP5990
> +	tristate "MPS MP5990"
> +	help
> +	  If you say yes here you get hardware monitoring support for MPS
> +	  MP5990.
> +
> +	  This driver can also be built as a module. If so, the module will
> +	  be called mp5990.
> +
>   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 84ee960a6c2d..212d9ca0acc9 100644
> --- a/drivers/hwmon/pmbus/Makefile
> +++ b/drivers/hwmon/pmbus/Makefile
> @@ -35,6 +35,7 @@ obj-$(CONFIG_SENSORS_MAX8688)	+= max8688.o
>   obj-$(CONFIG_SENSORS_MP2888)	+= mp2888.o
>   obj-$(CONFIG_SENSORS_MP2975)	+= mp2975.o
>   obj-$(CONFIG_SENSORS_MP5023)	+= mp5023.o
> +obj-$(CONFIG_SENSORS_MP5990)	+= mp5990.o
>   obj-$(CONFIG_SENSORS_MPQ7932)	+= mpq7932.o
>   obj-$(CONFIG_SENSORS_PLI1209BC)	+= pli1209bc.o
>   obj-$(CONFIG_SENSORS_PM6764TR)	+= pm6764tr.o
> diff --git a/drivers/hwmon/pmbus/mp5990.c b/drivers/hwmon/pmbus/mp5990.c
> new file mode 100644
> index 000000000000..c3b31af9f750
> --- /dev/null
> +++ b/drivers/hwmon/pmbus/mp5990.c
> @@ -0,0 +1,90 @@
> +// SPDX-License-Identifier: GPL-2.0-or-later
> +/*
> + * Driver for MPS MP5990 Hot-Swap Controller
> + */
> +
> +#include <linux/i2c.h>
> +#include <linux/module.h>
> +#include <linux/of_device.h>
> +#include <linux/pmbus.h>
> +#include "pmbus.h"
> +
> +static int mp5990_read_byte_data(struct i2c_client *client, int page, int reg)
> +{
> +	switch (reg) {
> +	case PMBUS_VOUT_MODE:
> +		/*
> +		  Enforce VOUT direct format, C4h reg BIT9
> +		  default val is not match vout format
> +		 */

/*
  * Please use proper multi-line comments. Also, the problem here is that the
  * chip does not support the VOUT_MODE command, which should be mentioned.
  *
  * On top of that, overwriting PMBUS_VOUT_MODE result from the chip is only
  * necessary if the chip does not return an error when reading the value.
  * If that is the case, it should be mentioned in the comment. The above
  * does not explain why this would be needed, even if the command is not
  * (officially) supported by the chip. What does it return that requires
  * an overwrite ?
  */

> +		return PB_VOUT_MODE_DIRECT;
> +	default:
> +		return -ENODATA;
> +	}
> +}
> +
> +static struct pmbus_driver_info mp5990_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] = 32,
> +	.b[PSC_VOLTAGE_IN] = 0,
> +	.R[PSC_VOLTAGE_IN] = 0,
> +	.m[PSC_VOLTAGE_OUT] = 32,
> +	.b[PSC_VOLTAGE_OUT] = 0,
> +	.R[PSC_VOLTAGE_OUT] = 0,
> +	.m[PSC_CURRENT_OUT] = 16,
> +	.b[PSC_CURRENT_OUT] = 0,
> +	.R[PSC_CURRENT_OUT] = 0,
> +	.m[PSC_POWER] = 1,
> +	.b[PSC_POWER] = 0,
> +	.R[PSC_POWER] = 0,
> +	.m[PSC_TEMPERATURE] = 1,
> +	.b[PSC_TEMPERATURE] = 0,
> +	.R[PSC_TEMPERATURE] = 0,
> +	.func[0] =
> +		PMBUS_HAVE_VIN | PMBUS_HAVE_VOUT | PMBUS_HAVE_PIN |
> +		PMBUS_HAVE_TEMP | PMBUS_HAVE_IOUT |
> +		PMBUS_HAVE_STATUS_INPUT | PMBUS_HAVE_STATUS_TEMP,
> +	.read_byte_data = mp5990_read_byte_data,
> +};
> +
> +static int mp5990_probe(struct i2c_client *client)
> +{
> +	int ret;
> +
> +	ret = i2c_smbus_write_byte_data(client, PMBUS_VOUT_MODE,
> +					PB_VOUT_MODE_DIRECT);

According to the datasheet, the chip does not support the VOUT_MODE
command. Supposedly, direct vs. linear mode is selected with bit 9
of EFUSE_CFG. Even if the chip happens to "silently" support the command,
the official command should be used to select the chip mode.

Next question: Why use direct mode ? Linear mode is supported and would
be much more flexible.

> +	if (ret < 0)
> +		return ret;
> +	return pmbus_do_probe(client, &mp5990_info);
> +}
> +
> +static const struct of_device_id mp5990_of_match[] = {
> +	{ .compatible = "mps,mp5990" },
> +	{}
> +};
> +
> +static const struct i2c_device_id mp5990_id[] = {
> +	{"mp5990", 0},
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(i2c, mp5990_id);
> +
> +static struct i2c_driver mp5990_driver = {
> +	.driver = {
> +		   .name = "mp5990",
> +		   .of_match_table = of_match_ptr(mp5990_of_match),

Using of_match_ptr() will result in a build failure if CONFIG_OF=n.

> +	},
> +	.probe = mp5990_probe,
> +	.id_table = mp5990_id,
> +};
> +module_i2c_driver(mp5990_driver);
> +
> +MODULE_AUTHOR("Peter Yin <peter.yin@quantatw.com>");
> +MODULE_DESCRIPTION("PMBus driver for MP5990 HSC");
> +MODULE_LICENSE("GPL");
> +MODULE_IMPORT_NS(PMBUS);
  
Peter Yin Nov. 6, 2023, 8:02 a.m. UTC | #2
Guenter Roeck 於 11/3/23 22:35 寫道:
> On 11/3/23 01:01, Peter Yin wrote:
>> Add support for mp5990 device from Monolithic Power Systems, Inc. (MPS)
>> vendor. This is a Hot-Swap Controller.
>>
>> Signed-off-by: Peter Yin <peteryin.openbmc@gmail.com>
>> ---
>>   Documentation/hwmon/index.rst  |  1 +
>>   Documentation/hwmon/mp5990.rst | 84 +++++++++++++++++++++++++++++++
>>   drivers/hwmon/pmbus/Kconfig    |  9 ++++
>>   drivers/hwmon/pmbus/Makefile   |  1 +
>>   drivers/hwmon/pmbus/mp5990.c   | 90 ++++++++++++++++++++++++++++++++++
>>   5 files changed, 185 insertions(+)
>>   create mode 100644 Documentation/hwmon/mp5990.rst
>>   create mode 100644 drivers/hwmon/pmbus/mp5990.c
>>
>> diff --git a/Documentation/hwmon/index.rst 
>> b/Documentation/hwmon/index.rst
>> index 042e1cf9501b..8c70e10fc795 100644
>> --- a/Documentation/hwmon/index.rst
>> +++ b/Documentation/hwmon/index.rst
>> @@ -157,6 +157,7 @@ Hardware Monitoring Kernel Drivers
>>      mp2888
>>      mp2975
>>      mp5023
>> +   mp5990
>>      nct6683
>>      nct6775
>>      nct7802
>> diff --git a/Documentation/hwmon/mp5990.rst 
>> b/Documentation/hwmon/mp5990.rst
>> new file mode 100644
>> index 000000000000..8fc4e388ff7b
>> --- /dev/null
>> +++ b/Documentation/hwmon/mp5990.rst
>> @@ -0,0 +1,84 @@
>> +.. SPDX-License-Identifier: GPL-2.0
>> +
>> +Kernel driver mp5990
>> +====================
>> +
>> +Supported chips:
>> +
>> +  * MPS MP5990
>> +
>> +    Prefix: 'mp5990'
>> +
>> +  * Datasheet
>> +
>> +    Publicly available at the MPS website : 
>> https://www.monolithicpower.com/en/mp5990.html
>> +
>> +Author:
>> +
>> +    Peter Yin <peteryin.openbmc@gmail.com>
>> +
>> +Description
>> +-----------
>> +
>> +This driver implements support for Monolithic Power Systems, Inc. (MPS)
>> +MP5990 Hot-Swap Controller.
>> +
>> +Device complaint with:
> 
> compliant
> 
Thanks, I will fix it.
>> +
>> +- PMBus rev 1.3 interface.
>> +
>> +Device supports direct 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_max**
>> +
>> +**in1_max_alarm**
>> +
>> +**in1_min**
>> +
>> +**in1_min_alarm**
>> +
>> +The driver provides the following attributes for output voltage:
>> +
>> +**in2_input**
>> +
>> +**in2_label**
>> +
>> +**in2_alarm**
>> +
>> +The driver provides the following attributes for output current:
>> +
>> +**curr1_input**
>> +
>> +**curr1_label**
>> +
>> +**curr1_alarm**
>> +
>> +**curr1_max**
>> +
>> +The driver provides the following attributes for input power:
>> +
>> +**power1_input**
>> +
>> +**power1_label**
>> +
>> +**power1_alarm**
>> +
>> +The driver provides the following attributes for temperature:
>> +
>> +**temp1_input**
>> +
>> +**temp1_max**
>> +
>> +**temp1_max_alarm**
>> +
>> +**temp1_crit**
>> +
>> +**temp1_crit_alarm**
>> diff --git a/drivers/hwmon/pmbus/Kconfig b/drivers/hwmon/pmbus/Kconfig
>> index 270b6336b76d..65a116f7744d 100644
>> --- a/drivers/hwmon/pmbus/Kconfig
>> +++ b/drivers/hwmon/pmbus/Kconfig
>> @@ -326,6 +326,15 @@ config SENSORS_MP5023
>>         This driver can also be built as a module. If so, the module will
>>         be called mp5023.
>> +config SENSORS_MP5990
>> +    tristate "MPS MP5990"
>> +    help
>> +      If you say yes here you get hardware monitoring support for MPS
>> +      MP5990.
>> +
>> +      This driver can also be built as a module. If so, the module will
>> +      be called mp5990.
>> +
>>   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 84ee960a6c2d..212d9ca0acc9 100644
>> --- a/drivers/hwmon/pmbus/Makefile
>> +++ b/drivers/hwmon/pmbus/Makefile
>> @@ -35,6 +35,7 @@ obj-$(CONFIG_SENSORS_MAX8688)    += max8688.o
>>   obj-$(CONFIG_SENSORS_MP2888)    += mp2888.o
>>   obj-$(CONFIG_SENSORS_MP2975)    += mp2975.o
>>   obj-$(CONFIG_SENSORS_MP5023)    += mp5023.o
>> +obj-$(CONFIG_SENSORS_MP5990)    += mp5990.o
>>   obj-$(CONFIG_SENSORS_MPQ7932)    += mpq7932.o
>>   obj-$(CONFIG_SENSORS_PLI1209BC)    += pli1209bc.o
>>   obj-$(CONFIG_SENSORS_PM6764TR)    += pm6764tr.o
>> diff --git a/drivers/hwmon/pmbus/mp5990.c b/drivers/hwmon/pmbus/mp5990.c
>> new file mode 100644
>> index 000000000000..c3b31af9f750
>> --- /dev/null
>> +++ b/drivers/hwmon/pmbus/mp5990.c
>> @@ -0,0 +1,90 @@
>> +// SPDX-License-Identifier: GPL-2.0-or-later
>> +/*
>> + * Driver for MPS MP5990 Hot-Swap Controller
>> + */
>> +
>> +#include <linux/i2c.h>
>> +#include <linux/module.h>
>> +#include <linux/of_device.h>
>> +#include <linux/pmbus.h>
>> +#include "pmbus.h"
>> +
>> +static int mp5990_read_byte_data(struct i2c_client *client, int page, 
>> int reg)
>> +{
>> +    switch (reg) {
>> +    case PMBUS_VOUT_MODE:
>> +        /*
>> +          Enforce VOUT direct format, C4h reg BIT9
>> +          default val is not match vout format
>> +         */
> 
> /*
>   * Please use proper multi-line comments. Also, the problem here is 
> that the
>   * chip does not support the VOUT_MODE command, which should be mentioned.
>   *
>   * On top of that, overwriting PMBUS_VOUT_MODE result from the chip is 
> only
>   * necessary if the chip does not return an error when reading the value.
>   * If that is the case, it should be mentioned in the comment. The above
>   * does not explain why this would be needed, even if the command is not
>   * (officially) supported by the chip. What does it return that requires
>   * an overwrite ?
>   */
>
The datasheet does not support the VOUT command, but the device responds 
with a default value of 0x17. In the standard, 0x17 represents linear mode.
>> +        return PB_VOUT_MODE_DIRECT;
>> +    default:
>> +        return -ENODATA;
>> +    }
>> +}
>> +
>> +static struct pmbus_driver_info mp5990_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] = 32,
>> +    .b[PSC_VOLTAGE_IN] = 0,
>> +    .R[PSC_VOLTAGE_IN] = 0,
>> +    .m[PSC_VOLTAGE_OUT] = 32,
>> +    .b[PSC_VOLTAGE_OUT] = 0,
>> +    .R[PSC_VOLTAGE_OUT] = 0,
>> +    .m[PSC_CURRENT_OUT] = 16,
>> +    .b[PSC_CURRENT_OUT] = 0,
>> +    .R[PSC_CURRENT_OUT] = 0,
>> +    .m[PSC_POWER] = 1,
>> +    .b[PSC_POWER] = 0,
>> +    .R[PSC_POWER] = 0,
>> +    .m[PSC_TEMPERATURE] = 1,
>> +    .b[PSC_TEMPERATURE] = 0,
>> +    .R[PSC_TEMPERATURE] = 0,
>> +    .func[0] =
>> +        PMBUS_HAVE_VIN | PMBUS_HAVE_VOUT | PMBUS_HAVE_PIN |
>> +        PMBUS_HAVE_TEMP | PMBUS_HAVE_IOUT |
>> +        PMBUS_HAVE_STATUS_INPUT | PMBUS_HAVE_STATUS_TEMP,
>> +    .read_byte_data = mp5990_read_byte_data,
>> +};
>> +
>> +static int mp5990_probe(struct i2c_client *client)
>> +{
>> +    int ret;
>> +
>> +    ret = i2c_smbus_write_byte_data(client, PMBUS_VOUT_MODE,
>> +                    PB_VOUT_MODE_DIRECT);
> 
> According to the datasheet, the chip does not support the VOUT_MODE
> command. Supposedly, direct vs. linear mode is selected with bit 9
> of EFUSE_CFG. Even if the chip happens to "silently" support the command,
> the official command should be used to select the chip mode.
> 
> Next question: Why use direct mode ? Linear mode is supported and would
> be much more flexible.
>
The MP5990, the VOUT linear mode is linear11, not linear16. Therefore, 
we should enforce the VOUT in the direct format.

>> +    if (ret < 0)
>> +        return ret;
>> +    return pmbus_do_probe(client, &mp5990_info);
>> +}
>> +
>> +static const struct of_device_id mp5990_of_match[] = {
>> +    { .compatible = "mps,mp5990" },
>> +    {}
>> +};
>> +
>> +static const struct i2c_device_id mp5990_id[] = {
>> +    {"mp5990", 0},
>> +    { }
>> +};
>> +MODULE_DEVICE_TABLE(i2c, mp5990_id);
>> +
>> +static struct i2c_driver mp5990_driver = {
>> +    .driver = {
>> +           .name = "mp5990",
>> +           .of_match_table = of_match_ptr(mp5990_of_match),
> 
> Using of_match_ptr() will result in a build failure if CONFIG_OF=n.
>
Should I use .of_match_table = mp5990_of_match, ?

>> +    },
>> +    .probe = mp5990_probe,
>> +    .id_table = mp5990_id,
>> +};
>> +module_i2c_driver(mp5990_driver);
>> +
>> +MODULE_AUTHOR("Peter Yin <peter.yin@quantatw.com>");
>> +MODULE_DESCRIPTION("PMBus driver for MP5990 HSC");
>> +MODULE_LICENSE("GPL");
>> +MODULE_IMPORT_NS(PMBUS);
>
  
Guenter Roeck Nov. 6, 2023, 7:11 p.m. UTC | #3
On 11/6/23 00:02, PeterYin wrote:
> 
[ ... ]
>>> +
>>> +static const struct of_device_id mp5990_of_match[] = {
>>> +    { .compatible = "mps,mp5990" },
>>> +    {}
>>> +};
>>> +
>>> +static const struct i2c_device_id mp5990_id[] = {
>>> +    {"mp5990", 0},
>>> +    { }
>>> +};
>>> +MODULE_DEVICE_TABLE(i2c, mp5990_id);
>>> +
>>> +static struct i2c_driver mp5990_driver = {
>>> +    .driver = {
>>> +           .name = "mp5990",
>>> +           .of_match_table = of_match_ptr(mp5990_of_match),
>>
>> Using of_match_ptr() will result in a build failure if CONFIG_OF=n.
>>
> Should I use .of_match_table = mp5990_of_match, ?
> 

Yes.

Thanks,
Guenter
  
kernel test robot Nov. 7, 2023, 1:27 a.m. UTC | #4
Hi Peter,

kernel test robot noticed the following build warnings:

[auto build test WARNING on groeck-staging/hwmon-next]
[also build test WARNING on linus/master v6.6 next-20231106]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Peter-Yin/dt-bindings-hwmon-Add-mps-mp5990-driver-bindings/20231103-160759
base:   https://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging.git hwmon-next
patch link:    https://lore.kernel.org/r/20231103080128.1204218-3-peteryin.openbmc%40gmail.com
patch subject: [PATCH v1 2/2] hwmon: (pmbus) Add support for MPS Multi-phase mp5990
config: xtensa-randconfig-001-20231107 (https://download.01.org/0day-ci/archive/20231107/202311070822.cgjfXGD7-lkp@intel.com/config)
compiler: xtensa-linux-gcc (GCC) 13.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231107/202311070822.cgjfXGD7-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202311070822.cgjfXGD7-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> drivers/hwmon/pmbus/mp5990.c:66:34: warning: 'mp5990_of_match' defined but not used [-Wunused-const-variable=]
      66 | static const struct of_device_id mp5990_of_match[] = {
         |                                  ^~~~~~~~~~~~~~~


vim +/mp5990_of_match +66 drivers/hwmon/pmbus/mp5990.c

    65	
  > 66	static const struct of_device_id mp5990_of_match[] = {
    67		{ .compatible = "mps,mp5990" },
    68		{}
    69	};
    70
  

Patch

diff --git a/Documentation/hwmon/index.rst b/Documentation/hwmon/index.rst
index 042e1cf9501b..8c70e10fc795 100644
--- a/Documentation/hwmon/index.rst
+++ b/Documentation/hwmon/index.rst
@@ -157,6 +157,7 @@  Hardware Monitoring Kernel Drivers
    mp2888
    mp2975
    mp5023
+   mp5990
    nct6683
    nct6775
    nct7802
diff --git a/Documentation/hwmon/mp5990.rst b/Documentation/hwmon/mp5990.rst
new file mode 100644
index 000000000000..8fc4e388ff7b
--- /dev/null
+++ b/Documentation/hwmon/mp5990.rst
@@ -0,0 +1,84 @@ 
+.. SPDX-License-Identifier: GPL-2.0
+
+Kernel driver mp5990
+====================
+
+Supported chips:
+
+  * MPS MP5990
+
+    Prefix: 'mp5990'
+
+  * Datasheet
+
+    Publicly available at the MPS website : https://www.monolithicpower.com/en/mp5990.html
+
+Author:
+
+	Peter Yin <peteryin.openbmc@gmail.com>
+
+Description
+-----------
+
+This driver implements support for Monolithic Power Systems, Inc. (MPS)
+MP5990 Hot-Swap Controller.
+
+Device complaint with:
+
+- PMBus rev 1.3 interface.
+
+Device supports direct 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_max**
+
+**in1_max_alarm**
+
+**in1_min**
+
+**in1_min_alarm**
+
+The driver provides the following attributes for output voltage:
+
+**in2_input**
+
+**in2_label**
+
+**in2_alarm**
+
+The driver provides the following attributes for output current:
+
+**curr1_input**
+
+**curr1_label**
+
+**curr1_alarm**
+
+**curr1_max**
+
+The driver provides the following attributes for input power:
+
+**power1_input**
+
+**power1_label**
+
+**power1_alarm**
+
+The driver provides the following attributes for temperature:
+
+**temp1_input**
+
+**temp1_max**
+
+**temp1_max_alarm**
+
+**temp1_crit**
+
+**temp1_crit_alarm**
diff --git a/drivers/hwmon/pmbus/Kconfig b/drivers/hwmon/pmbus/Kconfig
index 270b6336b76d..65a116f7744d 100644
--- a/drivers/hwmon/pmbus/Kconfig
+++ b/drivers/hwmon/pmbus/Kconfig
@@ -326,6 +326,15 @@  config SENSORS_MP5023
 	  This driver can also be built as a module. If so, the module will
 	  be called mp5023.
 
+config SENSORS_MP5990
+	tristate "MPS MP5990"
+	help
+	  If you say yes here you get hardware monitoring support for MPS
+	  MP5990.
+
+	  This driver can also be built as a module. If so, the module will
+	  be called mp5990.
+
 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 84ee960a6c2d..212d9ca0acc9 100644
--- a/drivers/hwmon/pmbus/Makefile
+++ b/drivers/hwmon/pmbus/Makefile
@@ -35,6 +35,7 @@  obj-$(CONFIG_SENSORS_MAX8688)	+= max8688.o
 obj-$(CONFIG_SENSORS_MP2888)	+= mp2888.o
 obj-$(CONFIG_SENSORS_MP2975)	+= mp2975.o
 obj-$(CONFIG_SENSORS_MP5023)	+= mp5023.o
+obj-$(CONFIG_SENSORS_MP5990)	+= mp5990.o
 obj-$(CONFIG_SENSORS_MPQ7932)	+= mpq7932.o
 obj-$(CONFIG_SENSORS_PLI1209BC)	+= pli1209bc.o
 obj-$(CONFIG_SENSORS_PM6764TR)	+= pm6764tr.o
diff --git a/drivers/hwmon/pmbus/mp5990.c b/drivers/hwmon/pmbus/mp5990.c
new file mode 100644
index 000000000000..c3b31af9f750
--- /dev/null
+++ b/drivers/hwmon/pmbus/mp5990.c
@@ -0,0 +1,90 @@ 
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Driver for MPS MP5990 Hot-Swap Controller
+ */
+
+#include <linux/i2c.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/pmbus.h>
+#include "pmbus.h"
+
+static int mp5990_read_byte_data(struct i2c_client *client, int page, int reg)
+{
+	switch (reg) {
+	case PMBUS_VOUT_MODE:
+		/*
+		  Enforce VOUT direct format, C4h reg BIT9
+		  default val is not match vout format
+		 */
+		return PB_VOUT_MODE_DIRECT;
+	default:
+		return -ENODATA;
+	}
+}
+
+static struct pmbus_driver_info mp5990_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] = 32,
+	.b[PSC_VOLTAGE_IN] = 0,
+	.R[PSC_VOLTAGE_IN] = 0,
+	.m[PSC_VOLTAGE_OUT] = 32,
+	.b[PSC_VOLTAGE_OUT] = 0,
+	.R[PSC_VOLTAGE_OUT] = 0,
+	.m[PSC_CURRENT_OUT] = 16,
+	.b[PSC_CURRENT_OUT] = 0,
+	.R[PSC_CURRENT_OUT] = 0,
+	.m[PSC_POWER] = 1,
+	.b[PSC_POWER] = 0,
+	.R[PSC_POWER] = 0,
+	.m[PSC_TEMPERATURE] = 1,
+	.b[PSC_TEMPERATURE] = 0,
+	.R[PSC_TEMPERATURE] = 0,
+	.func[0] =
+		PMBUS_HAVE_VIN | PMBUS_HAVE_VOUT | PMBUS_HAVE_PIN |
+		PMBUS_HAVE_TEMP | PMBUS_HAVE_IOUT |
+		PMBUS_HAVE_STATUS_INPUT | PMBUS_HAVE_STATUS_TEMP,
+	.read_byte_data = mp5990_read_byte_data,
+};
+
+static int mp5990_probe(struct i2c_client *client)
+{
+	int ret;
+
+	ret = i2c_smbus_write_byte_data(client, PMBUS_VOUT_MODE,
+					PB_VOUT_MODE_DIRECT);
+	if (ret < 0)
+		return ret;
+	return pmbus_do_probe(client, &mp5990_info);
+}
+
+static const struct of_device_id mp5990_of_match[] = {
+	{ .compatible = "mps,mp5990" },
+	{}
+};
+
+static const struct i2c_device_id mp5990_id[] = {
+	{"mp5990", 0},
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, mp5990_id);
+
+static struct i2c_driver mp5990_driver = {
+	.driver = {
+		   .name = "mp5990",
+		   .of_match_table = of_match_ptr(mp5990_of_match),
+	},
+	.probe = mp5990_probe,
+	.id_table = mp5990_id,
+};
+module_i2c_driver(mp5990_driver);
+
+MODULE_AUTHOR("Peter Yin <peter.yin@quantatw.com>");
+MODULE_DESCRIPTION("PMBus driver for MP5990 HSC");
+MODULE_LICENSE("GPL");
+MODULE_IMPORT_NS(PMBUS);