Re: [PATCH 1/5] hwmon: ina2xx: bail-out from ina2xx_probe() in case of configuration errors

[Guenter Roeck]

On 11/26/2014 01:38 AM, Benoit Cousson wrote:
> Hi Guenter,
>
> On 26/11/2014 04:05, Guenter Roeck wrote:
>
> [...]
>
> > Looking into the available documents, I am quite sure that the resistor
> > is changed by replacing the probe, in other words by pulling the board
> > with the ina226 and replacing it with another one. Given that, configuring
> > the shunt resistor value with a sysfs attribute is really the wrong way
> > to do it; you should use probe specific devicetree overlays instead.
>
> Unfortunately, that's not dynamic enough for all the use cases we need to support with the probes.
> In fact, most customers will rather put the shunts on their board and thus use a shunt-less version of the probe to do the measurement. In that case, there is no way we can hard code, even in a DTS, the shunt value.
>
> That's for that kind of usage that we do need to be able to set the shunt value at runtime. The probe in that case can be pluged dynamically on different board jumpers to do the measurement.
>
> Later, thanks to the web UI, the user will be able to configure the shunt value based on the way they were plugged to its boards.
>
> sysfs seems to be the easiest way to do that. I don't think DT overlay can handle that, since it is depend of the targeted system and not on the measurement system.

I just noticed that you did not copy the lm-sensors mailing list.

I am not really happy with this, and want to get some more feedback
from the list before I accept more or less arbitrary attributes.
Jean, any comments ?

Thanks,
Guenter

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