Re: [PATCH 2/2] hwmon: pmbus: Add support for Sony APS-379

[Guenter Roeck]

On 3/31/26 17:26, Chris Packham wrote:
> On 01/04/2026 12:56, Guenter Roeck wrote:
> > Hi Chris,
> >
> > On 3/31/26 16:19, Chris Packham wrote:
> > > Add pmbus support for Sony APS-379 power supplies. There are a few PMBUS
> > > commands that return data that is undocumented/invalid so these need to
> > > be rejected with -ENXIO. The READ_VOUT command returns data in linear11
> > > format instead of linear16 so we need to workaround this.
> > >
> > > Signed-off-by: Chris Packham <chris.packham@xxxxxxxxxxxxxxxxxxx>
> >
> > Feedback inline.
> >
> > Thanks,
> > Guenter
> >
> > > ---
> > >    drivers/hwmon/pmbus/Kconfig   |   6 ++
> > >    drivers/hwmon/pmbus/Makefile  |   1 +
> > >    drivers/hwmon/pmbus/aps-379.c | 196 ++++++++++++++++++++++++++++++++++
> > >    3 files changed, 203 insertions(+)
> > >    create mode 100644 drivers/hwmon/pmbus/aps-379.c
> > >
> > > diff --git a/drivers/hwmon/pmbus/Kconfig b/drivers/hwmon/pmbus/Kconfig
> > > index fc1273abe357..29076921e330 100644
> > > --- a/drivers/hwmon/pmbus/Kconfig
> > > +++ b/drivers/hwmon/pmbus/Kconfig
> > > @@ -77,6 +77,12 @@ config SENSORS_ADP1050_REGULATOR
> > >          µModule regulators that can provide microprocessor power from
> > > 54V
> > >          power distribution architecture.
> > >    +config SENSORS_APS_379
> > > +    tristate "Sony APS-379 Power Supplies"
> > > +    help
> > > +      If you say yes here you get hardware monitoring support for Sony
> > > +      APS-379 Power Supplies.
> > > +
> > >    config SENSORS_BEL_PFE
> > >        tristate "Bel PFE Compatible Power Supplies"
> > >        help
> > > diff --git a/drivers/hwmon/pmbus/Makefile b/drivers/hwmon/pmbus/Makefile
> > > index d6c86924f887..94f36c7069ec 100644
> > > --- a/drivers/hwmon/pmbus/Makefile
> > > +++ b/drivers/hwmon/pmbus/Makefile
> > > @@ -9,6 +9,7 @@ obj-$(CONFIG_SENSORS_ACBEL_FSG032) += acbel-fsg032.o
> > >    obj-$(CONFIG_SENSORS_ADM1266)    += adm1266.o
> > >    obj-$(CONFIG_SENSORS_ADM1275)    += adm1275.o
> > >    obj-$(CONFIG_SENSORS_ADP1050)    += adp1050.o
> > > +obj-$(CONFIG_SENSORS_APS_379)    += aps-379.o
> > >    obj-$(CONFIG_SENSORS_BEL_PFE)    += bel-pfe.o
> > >    obj-$(CONFIG_SENSORS_BPA_RS600)    += bpa-rs600.o
> > >    obj-$(CONFIG_SENSORS_DELTA_AHE50DC_FAN) += delta-ahe50dc-fan.o
> > > diff --git a/drivers/hwmon/pmbus/aps-379.c
> > > b/drivers/hwmon/pmbus/aps-379.c
> > > new file mode 100644
> > > index 000000000000..e4c4c2d12bc9
> > > --- /dev/null
> > > +++ b/drivers/hwmon/pmbus/aps-379.c
> >
> > Driver documentation is missing.
> >
> > This power supply does not seem to be documented anywhere, so this is
> > actually quite
> > important.
>
> I'll see what I can add. I do have a list of the actual supported PMBus
> commands so that would be helpful to share.
>
> >   Having said this, the behavior seems quite similar to BluTek
> > BPA-RS600. Are those
> > power supplies from the same OEM ?
>
> The BPA-RS600 is a smaller form factor. BluTek do make PSUs in the same
> from factor (there's a DC input one we use that I might get around to
> upstreaming one day), but they are genuinely different suppliers and the
> definitely don't interop electrically. Part of the reason for us using
> the APS-379 is manufactured by a Japanese company which lets us sell it
> into markets that have country of origin restrictions (that's as much
> politics as I care to discuss). They all have different
> quirks/deviations from the PMBus spec.
>
> I did of course refer to the bpa-rs600 driver as I was familiar with it.
> I pulled the linear11 vout workaround from mp5990 and adapted it for my
> needs.

I asked the AI version of Google search if they use the same OEM. It suggested
that they probably use the same or a similar controller chip and use the
firmware provided from that manufacturer as base for their firmware
implementation. Guess that makes sense.

Guenter