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

From: Robert Marko
Date: Wed May 19 2021 - 08:38:52 EST

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.

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