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

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

On Mon, May 24, 2021 at 3:47 PM Guenter Roeck <linux@roeck-us.net> wrote:
>
> On 5/24/21 5:21 AM, Robert Marko wrote:
> > 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?
> >
>
> Have the read_word function return -ENXIO for unsupported registers
> (and add a comment to the code explaining why you do that).
> See drivers/hwmon/pmbus/fsp-3y.c for an example.

Thanks, will implement that.
In the meantime I finally got the PMBus command list that
the PSU supports.
It implements PMBus 1.2, but it also claims that MFR_ID,
MFR_MODEL and MFR_REVISION are supported.

Block read returns what looks like a correct length, but the buffer
is empty.
>
> [  195.246464] dps920ab 0-005a: PMBUS_MFR_ID length: 5
> [  195.251495] dps920ab 0-005a: PMBUS_MFR_ID:
> [  195.300789] dps920ab 0-005b: PMBUS_MFR_ID length: 5
> [  195.305762] dps920ab 0-005b: PMBUS_MFR_ID:
> [  272.795222] dps920ab 0-005a: PMBUS_MFR_ID length: 5
> [  272.800190] dps920ab 0-005a: PMBUS_MFR_ID:
> [  272.804862] dps920ab 0-005a: PMBUS_MFR_MODEL length: 11
> [  272.810172] dps920ab 0-005a: PMBUS_MFR_MODEL:
> [  272.815098] dps920ab 0-005a: PMBUS_MFR_REVISION length: 2
> [  272.820600] dps920ab 0-005a: PMBUS_MFR_REVISION:
> [  272.874060] dps920ab 0-005b: PMBUS_MFR_ID length: 5
> [  272.879102] dps920ab 0-005b: PMBUS_MFR_ID:
> [  272.883833] dps920ab 0-005b: PMBUS_MFR_MODEL length: 11
> [  272.889151] dps920ab 0-005b: PMBUS_MFR_MODEL:
> [  272.894097] dps920ab 0-005b: PMBUS_MFR_REVISION length: 2
> [  272.899548] dps920ab 0-005b: PMBUS_MFR_REVISION:


However, manually reading using i2cget in word mode returns
something that looks ok.
i2cget -y 0 0x5a 0x9a w
0x440b

This would be D is ASCII, it looks like any kind of block read fails actually.

I am now a bit confused.
I tried applying the block support for mv64xx as well:
https://patchwork.ozlabs.org/project/linux-i2c/patch/20200118115820.9080-1-fuga@studiofuga.com/

But no luck.

Regards,
Robert
>
> Guenter



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