Re: [PATCH 1/2] dt-bindings: iio: magnetometer: add ti tmag5273 documentation file

[Jonathan Cameron <Jonathan.Cameron@huawei.com>]

On Thu, 17 Nov 2022 17:17:24 +0100
Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org> wrote:

> On 17/11/2022 17:12, Gerald Loacker wrote:
> >>  
> >>> +
> >>> +  compatible:
> >>> +    const: ti,tmag5273
> >>> +
> >>> +  reg:
> >>> +    maxItems: 1
> >>> +
> >>> +  "#io-channel-cells":
> >>> +    const: 1
> >>> +
> >>> +  ti,angle-enable:
> >>> +    description:
> >>> +      Enables angle measurement in the selected plane.
> >>> +      0 = OFF
> >>> +      1 = X-Y (default)
> >>> +      2 = Y-Z
> >>> +      3 = X-Z  
> >>
> >> This feels like something we should be configuring at runtime rather that
> >> DT, or is it driven by board design or similar?
> >>  
> > 
> > We use this sensor for a zoom wheel application, there is an EVM from TI
> > for this as well. So this is for setting the mounting position of the wheel.  
> 
> That's ok, but does not explain why choice of angle measurement should
> be a property of the hardware. I could imagine configuring device to
> measure sometimes X-Y and sometimes X-Z, depending on the use case. Use
> case can change runtime.

If it's part of a physical device mounting, may well not be changeable at runtime
(at least not with out a screw driver / hacksaw etc.  Not really different form
arguing someone might rewire a sensor at runtime.  In theory possible but if they
do they are on their own - mostly we don't bother supporting them doing that.

So I think this is probably valid as a DT property.


> 
> 
> Best regards,
> Krzysztof
>