Re: [PATCH v2 2/2] hwmon: pmbus: Add ltc4286 driver

[Guenter Roeck <linux@xxxxxxxxxxxx>]

On 10/30/23 23:46, Delphine_CC_Chiu/WYHQ/Wiwynn wrote:
[ ... ]
> > > +
> > > +     ret = of_property_read_u32(client->dev.of_node,
> > > +                                "shunt-resistor-micro-ohms",
> > &rsense);
> > > +     if (ret < 0)
> > > +             return ret;
> > > +
> > > +     if (rsense == 0)
> > > +             return -EINVAL;
> > > +
> > > +     info = &ltc4286_info;
> > > +
> > > +     /* Default of VRANGE_SELECT = 1, 102.4V */
> > > +     if (device_property_read_bool(&client->dev,
> > "adi,vrange-select-25p6")) {
> >
> > What if the adi,vrange-select-25p6 property is not provided, but the chip
> > is programmed for this range ?
> The binding document tells programmers how to fill the dts.
> Thus, programmers must fill this property if their system is 25.6 volts voltage range.

Sure, but there is no else case, meaning VRANGE_SELECT is
unmodified in that case. There is no guarantee that the chip
is in its power-on state.

Guenter