Re: [PATCH 4/6] hwmon: (pmbus/max20830): add VOUT feedback resistor scaling support

[Guenter Roeck]

On 6/30/26 01:07, Torreno, Alexis Czezar wrote:
> > [External]
> >
> > On 6/29/26 19:46, Alexis Czezar Torreno wrote:
> > > Implement support for external voltage divider scaling using the
> > > adi,vout-rfb1-ohms and adi,vout-rfb2-ohms device tree properties.
> > >
> > > When the desired output voltage exceeds VREF, a resistor divider
> > > (RFB1 and RFB2) is used to scale down the feedback voltage. The driver
> > > reads these resistor values from device tree and applies the scaling
> > > formula: VOUT_actual = VOUT_measured × (1 + RFB1/RFB2)
> > >
> > > The properties are optional. If not specified, the driver assumes no
> > > voltage divider is present and reports the raw VOUT reading.
> >
> > This will require a detailed explanation why only PMBUS_READ_VOUT would
> > require scaling but not any of the other vout related commands.
> >
> > Guenter
>
> Will add it.
> For reference, the device only has 3 vout related commands. The other 2
> is referred to a feedback/reference voltage rather than a scaled output value.
> Hence only read_vout has scaling.

The other two commands are VOUT_COMMAND and VOUT_MAX. While they are currently
not used, VOUT_COMMAND _would_ be used if someone adds regulator support to the
driver in the future. Thus, even though those two commands are currently not
used, you have to at least add a note into the driver that the register values
will have to be adjusted if regulator support is added to the driver in the
future.

Thanks,
Guenter