On maj 20, 2022 07:22, Guenter Roeck wrote:
> On 5/20/22 07:09, Krzysztof Kozlowski wrote:
> > On 20/05/2022 15:42, Guenter Roeck wrote:
> > > >
> > > > > + A descriptive name for this channel, like "ambient" or "psu".
> > > > > +
> > > > > + offset:
> > > > > + description: |
> > > >
> > > > This does not look like standard property, so you need vendor and unit
> > > > suffix.
> > > >
> > >
> > > Temperature offset is a standard property for temperature sensor
> >
> > The original description was strictly connected to registers, so that
> > one as not a standard. It seems it was just a wording...
> >
> > > chips with external channels, implemented by a diode or transistor.
> > > Making it non-standard will mean that we'll have lots of
> > > "vendor,offset" properties, one each for each vendor selling
> > > temperature sensor chips with external channels. This gets
> > > more complicated here because the lm90 driver does support chips
> > > from several different vendors. Almost all of them support
> > > this functionality. Which vendor do you select in this case ?
> > >
> > > I would suggest to use temperature-offset-milliseconds, though.
> >
> > Yes, this sounds good. Just not seconds but millicelsius, I guess?
> >
>
> Uuh, yes. Sorry, must be too early in the morning here.
Hello
I see that: *-millicelsius is defined as uint32-array:
"-millicelsius$":
$ref: "types.yaml#/definitions/uint32-array"
description: Degreee milli-Celsius
But it would be nice to have negative values as the prop value, for example <(-1000)>.
How should I approach that? Is change to this definition possible? If yes, how should it be
conducted? On github or via device-tree mailing list?
Or maybe there is a way to overwrite this (using $defs?) for this particular binding? I haven't
found any solution that will pass dt_binding_check.
> > > > > + The value (millidegree Celsius) to be programmed in the channel specific offset register
> > > > > + (if supported by device).
> > > >
> > > > You described programming model which should not be put in the bindings.
> > > > Please describe the hardware.
> > > >
> > >
> > > It is a configuration value, which is hardware dependent because
> > > it depends on the temperature diode or transistor connected to the chip.
> >
> > Sure, so this could be reworded "Offset against some base value for each
> > channel temperature", or something similar (you know better than me).
> > Referring to registers and where exactly this should be programmed in
> > the device is related to device programming model, not to bindings.
> >
>
> Maybe something like "Temperature offset to be added to or
> subtracted from remote temperature measurements".
--
Slawomir Stepien
