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

From: Robert Marko
Date: Fri May 21 2021 - 04:36:21 EST

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In reply to: Guenter Roeck: "Re: [PATCH 1/3] hwmon: (pmbus) Add driver for Delta DPS-920AB PSU"
Next in thread: Guenter Roeck: "Re: [PATCH 1/3] hwmon: (pmbus) Add driver for Delta DPS-920AB PSU"
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On Wed, May 19, 2021 at 3:19 PM Guenter Roeck <linux@xxxxxxxxxxxx> wrote:
>
> On 5/19/21 5:38 AM, Robert Marko wrote:
> > On Fri, Apr 30, 2021 at 3:48 PM Guenter Roeck <linux@xxxxxxxxxxxx> 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@xxxxxxxxxx>
> >>> ---
> >>> 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@xxxxxxxxxx>
> >>> +
> >>> +
> >>> +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.

>
> In this context, I have a hard time finding a reference for
> this power supply. Do you have a datasheet or some other documents
> you can share ?

Unfortunately, I don't have a datasheet as that would have made this way easier.
It was all based on the vendor "driver" from DENT:
https://github.com/dentproject/dentOS/blob/main/packages/platforms/delta/arm64/tn48m/tn48m-poe/modules/builds/src/arm64-delta-tn48m-poe-psu.c

I will try asking Delta for the datasheet.
Regards,
Robert

>
> Thanks,
> Guenter
>
> > Is it okay to keep it as a separate driver then?
> >
> > Regards,
> > Robert
> >>
> >> Thanks,
> >> Guenter
> >>
> >>> +
> >>> + return pmbus_do_probe(client, &dps920ab_info);
> >>> +}
> >>> +
> >>> +static const struct of_device_id __maybe_unused dps920ab_of_match[] = {
> >>> + { .compatible = "delta,dps920ab", },
> >>> + {}
> >>> +};
> >>> +
> >>> +MODULE_DEVICE_TABLE(of, dps920ab_of_match);
> >>> +
> >>> +static struct i2c_driver dps920ab_driver = {
> >>> + .driver = {
> >>> + .name = "dps920ab",
> >>> + .of_match_table = of_match_ptr(dps920ab_of_match),
> >>> + },
> >>> + .probe_new = dps920ab_probe,
> >>> +};
> >>> +
> >>> +module_i2c_driver(dps920ab_driver);
> >>> +
> >>> +MODULE_AUTHOR("Robert Marko <robert.marko@xxxxxxxxxx>");
> >>> +MODULE_DESCRIPTION("PMBus driver for Delta DPS920AB PSU");
> >>> +MODULE_LICENSE("GPL");
> >>> --
> >>> 2.31.1
> >>>
> >
> >
> >
>

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

Next message: Herman: "[PATCH] drivers/media/usb/gspca/cpia1.c : fix spelling typo"
Previous message: kernel test robot: "WARNING: modpost: vmlinux.o(.text.unlikely+0xa5c): Section mismatch in reference from the function top_trace_array() to the variable .init.data:initcall_level_names"
In reply to: Guenter Roeck: "Re: [PATCH 1/3] hwmon: (pmbus) Add driver for Delta DPS-920AB PSU"
Next in thread: Guenter Roeck: "Re: [PATCH 1/3] hwmon: (pmbus) Add driver for Delta DPS-920AB PSU"
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