Re: [PATCH 1/3] hwmon: (pmbus) Add driver for Delta DPS-920AB PSU

[Guenter Roeck <linux@roeck-us.net>]

On 5/21/21 4:56 AM, Robert Marko wrote:
> On Fri, May 21, 2021 at 12:56 PM Guenter Roeck <linux@roeck-us.net> wrote:
>>
>> On 5/21/21 1:36 AM, Robert Marko wrote:
>>> On Wed, May 19, 2021 at 3:19 PM Guenter Roeck <linux@roeck-us.net> wrote:
>>>>
>>>> On 5/19/21 5:38 AM, Robert Marko wrote:
>>>>> On Fri, Apr 30, 2021 at 3:48 PM Guenter Roeck <linux@roeck-us.net> wrote:
>>>>>>
>>>>>> On Fri, Apr 30, 2021 at 03:27:33PM +0200, Robert Marko wrote:
>>>>>>> This adds support for the Delta DPS-920AB PSU.
>>>>>>>
>>>>>>> Only missing feature is fan control which the PSU supports.
>>>>>>>
>>>>>>> Signed-off-by: Robert Marko <robert.marko@sartura.hr>
>>>>>>> ---
>>>>>>>     Documentation/hwmon/dps920ab.rst | 80 ++++++++++++++++++++++++++++++++
>>>>>>>     Documentation/hwmon/index.rst    |  1 +
>>>>>>>     drivers/hwmon/pmbus/Kconfig      |  9 ++++
>>>>>>>     drivers/hwmon/pmbus/Makefile     |  1 +
>>>>>>>     drivers/hwmon/pmbus/dps920ab.c   | 63 +++++++++++++++++++++++++
>>>>>>>     5 files changed, 154 insertions(+)
>>>>>>>     create mode 100644 Documentation/hwmon/dps920ab.rst
>>>>>>>     create mode 100644 drivers/hwmon/pmbus/dps920ab.c
>>>>>>>
>>>>>>> diff --git a/Documentation/hwmon/dps920ab.rst b/Documentation/hwmon/dps920ab.rst
>>>>>>> new file mode 100644
>>>>>>> index 000000000000..df0aef530c7e
>>>>>>> --- /dev/null
>>>>>>> +++ b/Documentation/hwmon/dps920ab.rst
>>>>>>> @@ -0,0 +1,80 @@
>>>>>>> +.. SPDX-License-Identifier: GPL-2.0-or-later
>>>>>>> +
>>>>>>> +Kernel driver dps920ab
>>>>>>> +========================
>>>>>>> +
>>>>>>> +Supported chips:
>>>>>>> +
>>>>>>> +  * Delta DPS920AB
>>>>>>> +
>>>>>>> +    Prefix: 'dps920ab'
>>>>>>> +
>>>>>>> +    Addresses scanned: -
>>>>>>> +
>>>>>>> +Authors:
>>>>>>> +    Robert Marko <robert.marko@sartura.hr>
>>>>>>> +
>>>>>>> +
>>>>>>> +Description
>>>>>>> +-----------
>>>>>>> +
>>>>>>> +This driver implements support for Delta DPS920AB 920W 54V DC single output
>>>>>>> +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_crit           Critical maximum current
>>>>>>> +curr1_crit_alarm     Current critical high alarm
>>>>>>> +
>>>>>>> +curr2_label          "iout1"
>>>>>>> +curr2_input          Measured output current
>>>>>>> +curr2_crit           Critical maximum current
>>>>>>> +curr2_crit_alarm     Current critical high alarm
>>>>>>> +
>>>>>>> +in1_label            "vin"
>>>>>>> +in1_input            Measured input voltage
>>>>>>> +in1_lcrit            Critical minimum input voltage
>>>>>>> +in1_lcrit_alarm              Input voltage critical low alarm
>>>>>>> +in1_crit             Critical maximum input voltage
>>>>>>> +in1_crit_alarm               Input voltage critical high alarm
>>>>>>> +
>>>>>>> +in2_label            "vout1"
>>>>>>> +in2_input            Measured output voltage
>>>>>>> +in2_lcrit            Critical minimum output voltage
>>>>>>> +in2_lcrit_alarm              Output voltage critical low alarm
>>>>>>> +in2_crit             Critical maximum output voltage
>>>>>>> +in2_crit_alarm               Output voltage critical high alarm
>>>>>>> +
>>>>>>> +power1_label         "pin"
>>>>>>> +power1_input         Measured input power
>>>>>>> +power1_alarm         Input power high alarm
>>>>>>> +
>>>>>>> +power2_label         "pout1"
>>>>>>> +power2_input         Measured output power
>>>>>>> +
>>>>>>> +temp[1-2]_input              Measured temperature
>>>>>>> +temp[1-2]_crit               Critical high temperature
>>>>>>> +temp[1-2]_crit_alarm Chip temperature critical high alarm
>>>>>>> +temp[1-2]_max                Maximum temperature
>>>>>>> +temp[1-2]_max_alarm  Chip temperature high alarm
>>>>>>> +
>>>>>>> +fan1_alarm           Fan 1 warning.
>>>>>>> +fan1_fault           Fan 1 fault.
>>>>>>> +fan1_input           Fan 1 speed in RPM.
>>>>>>> +======================= ======================================================
>>>>>>> diff --git a/Documentation/hwmon/index.rst b/Documentation/hwmon/index.rst
>>>>>>> index 8d5a2df1ecb6..b24436f22052 100644
>>>>>>> --- a/Documentation/hwmon/index.rst
>>>>>>> +++ b/Documentation/hwmon/index.rst
>>>>>>> @@ -54,6 +54,7 @@ Hardware Monitoring Kernel Drivers
>>>>>>>        dell-smm-hwmon
>>>>>>>        dme1737
>>>>>>>        drivetemp
>>>>>>> +   dps920ab
>>>>>>>        ds1621
>>>>>>>        ds620
>>>>>>>        emc1403
>>>>>>> diff --git a/drivers/hwmon/pmbus/Kconfig b/drivers/hwmon/pmbus/Kconfig
>>>>>>> index 32d2fc850621..865ade0aa205 100644
>>>>>>> --- a/drivers/hwmon/pmbus/Kconfig
>>>>>>> +++ b/drivers/hwmon/pmbus/Kconfig
>>>>>>> @@ -66,6 +66,15 @@ config SENSORS_IBM_CFFPS
>>>>>>>            This driver can also be built as a module. If so, the module will
>>>>>>>            be called ibm-cffps.
>>>>>>>
>>>>>>> +config SENSORS_DPS920AB
>>>>>>> +     tristate "Delta DPS920AB Power Supply"
>>>>>>> +     help
>>>>>>> +       If you say yes here you get hardware monitoring support for Delta
>>>>>>> +       DPS920AB Power Supplies.
>>>>>>> +
>>>>>>> +       This driver can also be built as a module. If so, the module will
>>>>>>> +       be called dps920ab.
>>>>>>> +
>>>>>>>     config SENSORS_INSPUR_IPSPS
>>>>>>>          tristate "INSPUR Power System Power Supply"
>>>>>>>          help
>>>>>>> diff --git a/drivers/hwmon/pmbus/Makefile b/drivers/hwmon/pmbus/Makefile
>>>>>>> index 6a4ba0fdc1db..f59ba0123d68 100644
>>>>>>> --- a/drivers/hwmon/pmbus/Makefile
>>>>>>> +++ b/drivers/hwmon/pmbus/Makefile
>>>>>>> @@ -9,6 +9,7 @@ obj-$(CONFIG_SENSORS_ADM1266) += adm1266.o
>>>>>>>     obj-$(CONFIG_SENSORS_ADM1275)        += adm1275.o
>>>>>>>     obj-$(CONFIG_SENSORS_BEL_PFE)        += bel-pfe.o
>>>>>>>     obj-$(CONFIG_SENSORS_IBM_CFFPS)      += ibm-cffps.o
>>>>>>> +obj-$(CONFIG_SENSORS_DPS920AB)       += dps920ab.o
>>>>>>>     obj-$(CONFIG_SENSORS_INSPUR_IPSPS) += inspur-ipsps.o
>>>>>>>     obj-$(CONFIG_SENSORS_IR35221)        += ir35221.o
>>>>>>>     obj-$(CONFIG_SENSORS_IR38064)        += ir38064.o
>>>>>>> diff --git a/drivers/hwmon/pmbus/dps920ab.c b/drivers/hwmon/pmbus/dps920ab.c
>>>>>>> new file mode 100644
>>>>>>> index 000000000000..d579ed9f879c
>>>>>>> --- /dev/null
>>>>>>> +++ b/drivers/hwmon/pmbus/dps920ab.c
>>>>>>> @@ -0,0 +1,63 @@
>>>>>>> +// SPDX-License-Identifier: GPL-2.0-or-later
>>>>>>> +/*
>>>>>>> + * Driver for Delta DPS920AB PSU
>>>>>>> + *
>>>>>>> + * Copyright (C) 2021 Delta Networks, Inc.
>>>>>>> + * Copyright (C) 2021 Sartura Ltd.
>>>>>>> + */
>>>>>>> +
>>>>>>> +#include <linux/i2c.h>
>>>>>>> +#include <linux/module.h>
>>>>>>> +#include <linux/of_device.h>
>>>>>>> +#include "pmbus.h"
>>>>>>> +
>>>>>>> +static struct pmbus_driver_info dps920ab_info = {
>>>>>>> +     .pages = 1,
>>>>>>> +
>>>>>>> +     .format[PSC_VOLTAGE_IN] = linear,
>>>>>>> +     .format[PSC_VOLTAGE_OUT] = linear,
>>>>>>> +     .format[PSC_CURRENT_IN] = linear,
>>>>>>> +     .format[PSC_CURRENT_OUT] = linear,
>>>>>>> +     .format[PSC_POWER] = linear,
>>>>>>> +     .format[PSC_FAN] = linear,
>>>>>>> +     .format[PSC_TEMPERATURE] = linear,
>>>>>>> +
>>>>>>> +     .func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_IIN  |
>>>>>>> +     PMBUS_HAVE_VOUT  | PMBUS_HAVE_STATUS_VOUT   |
>>>>>>> +     PMBUS_HAVE_IOUT  | PMBUS_HAVE_STATUS_IOUT   |
>>>>>>> +     PMBUS_HAVE_TEMP  | PMBUS_HAVE_TEMP2         |
>>>>>>> +     PMBUS_HAVE_PIN   | PMBUS_HAVE_POUT          |
>>>>>>> +     PMBUS_HAVE_FAN12 | PMBUS_HAVE_STATUS_FAN12  |
>>>>>>> +     PMBUS_HAVE_STATUS_INPUT | PMBUS_HAVE_STATUS_TEMP,
>>>>>>> +};
>>>>>>> +
>>>>>>> +static int dps920ab_probe(struct i2c_client *client)
>>>>>>> +{
>>>>>>> +     if (!i2c_check_functionality(client->adapter,
>>>>>>> +                                  I2C_FUNC_SMBUS_BYTE_DATA |
>>>>>>> +                                  I2C_FUNC_SMBUS_WORD_DATA))
>>>>>>> +             return -ENODEV;
>>>>>>
>>>>>> This check is done in pmbus_do_probe(), and repeating it here does not add
>>>>>> any value.
>>>>>
>>>>> Ok, makes sense.
>>>>>>
>>>>>> That makes me wonder: Is this driver needed in the first place, or could
>>>>>> it be added to drivers/hwmon/pmbus/pmbus.c ?
>>>>>
>>>>> It could be added as a generic driver, but that creates properties in
>>>>> the sysfs that this thing
>>>>> does not support like 3 voltage readings, 3 fans, and so on.
>>>>>
>>>>
>>>> Can you be more specific ? What additional unsupported attributes
>>>> are added, and why ? Are you saying the PSU reports registers as
>>>> existing which do not really exist ? If so, which registers are those ?
>>>
>>> Sure, when core does probing and autodiscovery, then the following
>>> sysfs attributes are created:
>>>>
>>>> curr1_crit         fan3_fault       in3_min_alarm      temp1_max
>>>> curr1_crit_alarm   fan3_input       in3_rated_max      temp1_max_alarm
>>>> curr1_input        fan3_target      in3_rated_min      temp1_min
>>>> curr1_label        in1_crit         name               temp1_min_alarm
>>>> curr1_max          in1_crit_alarm   of_node            temp1_rated_max
>>>> curr1_max_alarm    in1_input        power              temp2_crit
>>>> curr1_rated_max    in1_label        power1_alarm       temp2_crit_alarm
>>>> curr2_crit         in1_lcrit        power1_input       temp2_input
>>>> curr2_crit_alarm   in1_lcrit_alarm  power1_label       temp2_lcrit
>>>> curr2_input        in1_max          power1_max         temp2_lcrit_alarm
>>>> curr2_label        in1_max_alarm    power1_rated_max   temp2_max
>>>> curr2_lcrit        in1_min          power2_cap         temp2_max_alarm
>>>> curr2_lcrit_alarm  in1_min_alarm    power2_cap_alarm   temp2_min
>>>> curr2_max          in1_rated_max    power2_crit        temp2_min_alarm
>>>> curr2_max_alarm    in1_rated_min    power2_crit_alarm  temp2_rated_max
>>>> curr2_rated_max    in2_input        power2_input       temp3_crit
>>>> device             in2_label        power2_label       temp3_crit_alarm
>>>> fan1_alarm         in3_crit         power2_max         temp3_input
>>>> fan1_fault         in3_crit_alarm   power2_max_alarm   temp3_lcrit
>>>> fan1_input         in3_input        power2_rated_max   temp3_lcrit_alarm
>>>> fan1_target        in3_label        subsystem          temp3_max
>>>> fan2_alarm         in3_lcrit        temp1_crit         temp3_max_alarm
>>>> fan2_fault         in3_lcrit_alarm  temp1_crit_alarm   temp3_min
>>>> fan2_input         in3_max          temp1_input        temp3_min_alarm
>>>> fan2_target        in3_max_alarm    temp1_lcrit        temp3_rated_max
>>>> fan3_alarm         in3_min          temp1_lcrit_alarm  uevent
>>>
>>> The following return -1, or -500 so they are not supported.
>>> * fan2
>>> * in2
>>>
>>> Weirdly, with the external driver both fan2 and in2 are enabled and work fine,
>>> but when auto probing they are fan3 and in3.
>>>
>>> temp3 actually seems to return a valid temperature despite it not being used in
>>> the vendor driver that features were picked from.
>>>
>>
>> Can you run "grep . *" in the hwmon directory so I can see actual values ?
>>
> Sure:
>>
>> curr1_crit:-500
>> curr1_crit_alarm:0
>> curr1_input:195
>> curr1_label:iin
>> curr1_max:-500
>> curr1_max_alarm:0
>> curr1_rated_max:-500
>> curr2_crit:-500
>> curr2_crit_alarm:0
>> curr2_input:320
>> curr2_label:iout1
>> curr2_lcrit:-500
>> curr2_lcrit_alarm:0
>> curr2_max:18625
>> curr2_max_alarm:0
>> curr2_rated_max:16875
>> grep: device: Is a directory
>> fan1_alarm:0
>> fan1_fault:0
>> fan1_input:10000
>> fan1_target:0
>> fan2_alarm:1
>> fan2_fault:1
>> fan2_input:-1
>> fan2_target:-1
>> fan3_alarm:1
>> fan3_fault:1
>> fan3_input:-1
>> fan3_target:-1
>> in1_crit:-500
>> in1_crit_alarm:0
>> in1_input:245250
>> in1_label:vin
>> in1_lcrit:-500
>> in1_lcrit_alarm:0
>> in1_max:-500
>> in1_max_alarm:0
>> in1_min:-500
>> in1_min_alarm:0
>> in1_rated_max:-500
>> in1_rated_min:-500
>> in2_input:-500
>> in2_label:vcap
>> in3_crit:255996
>> in3_crit_alarm:0
>> in3_input:54511
>> in3_label:vout1
>> in3_lcrit:255996
>> in3_lcrit_alarm:0
>> in3_max:255996
>> in3_max_alarm:0
>> in3_min:255996
>> in3_min_alarm:0
>> in3_rated_max:56136
>> in3_rated_min:52863
>> name:dps920ab
>> grep: of_node: Is a directory
>> grep: power: Is a directory
>> power1_alarm:0
>> power1_input:33250000
>> power1_label:pin
>> power1_max:-500000
>> power1_rated_max:-500000
>> power2_cap:-500000
>> power2_cap_alarm:0
>> power2_crit:-500000
>> power2_crit_alarm:0
>> power2_input:17750000
>> power2_label:pout1
>> power2_max:-500000
>> power2_max_alarm:0
>> power2_rated_max:920000000
>> grep: subsystem: Is a directory
>> temp1_crit:-500
>> temp1_crit_alarm:0
>> temp1_input:23000
>> temp1_lcrit:-500
>> temp1_lcrit_alarm:0
>> temp1_max:-500
>> temp1_max_alarm:0
>> temp1_min:-500
>> temp1_min_alarm:0
>> temp1_rated_max:-500
>> temp2_crit:-500
>> temp2_crit_alarm:0
>> temp2_input:26000
>> temp2_lcrit:-500
>> temp2_lcrit_alarm:0
>> temp2_max:-500
>> temp2_max_alarm:0
>> temp2_min:-500
>> temp2_min_alarm:0
>> temp2_rated_max:-500
>> temp3_crit:-500
>> temp3_crit_alarm:0
>> temp3_input:30000
>> temp3_lcrit:-500
>> temp3_lcrit_alarm:0
>> temp3_max:-500
>> temp3_max_alarm:0
>> temp3_min:-500
>> temp3_min_alarm:0
>> temp3_rated_max:-500
>> uevent:OF_NAME=psu
>> uevent:OF_FULLNAME=/ap806/config-space@f0000000/i2c@511000/psu@5a
>> uevent:OF_COMPATIBLE_0=delta,dps920ab
>> uevent:OF_COMPATIBLE_N=1
> 
Ok, good enough. It looks like the PSU reports values for pretty much everything,
including registers which don't exist. With that in mind, please check
the attributes generated by your driver - I suspect that some of the limit
attributes are not really supported (maybe none of them is supported).

Thanks,
Guenter