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

[Robert Marko <robert.marko@sartura.hr>]

On Fri, May 21, 2021 at 4:46 PM Guenter Roeck <linux@roeck-us.net> wrote:
>
> 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).

Yeah, I also think that none of those limits are actually supported.
Does the core expose a way to not register those?

Regards,
Robert
>
> Thanks,
> Guenter



-- 
Robert Marko
Staff Embedded Linux Engineer
Sartura Ltd.
Lendavska ulica 16a
10000 Zagreb, Croatia
Email: robert.marko@sartura.hr
Web: www.sartura.hr