Re: [PATCH v4 2/4] dt-bindings: iio: dac: add adi,ad5710r.yaml

[Jonathan Cameron]

Hi Conor,

> > +  adi,range-double:
> > +    description:
> > +      Configure the output range for all channels. If the property is present,
> > +      the output will range from 0V to 2 x Vref. If the property is not present,
> > +      the output will range from 0V to Vref.  
> 
> What was the rationale provided for this not being a userspace control?
> 
Jumping in as I happen to read this...

For DACs we often do it in kernel as potentially there is a circuit dependent aspect.
In extreme case leading to the bad kind of smoke. Normally it is covered by an
output-range pair, but can't do that here as it is relative to vref (which
we have no way of knowing in the binding). 

For input devices it is always a userspace thing to control.

> > +    type: boolean