Re: [PATCH v5 1/2] dt-bindings: hwmon: Add ina3221 documentation

[Nicolin Chen <nicoleotsuka@gmail.com>]

Hello Guenter,

On Tue, Sep 25, 2018 at 06:52:29PM -0700, Guenter Roeck wrote:

> > +2) child nodes
> > +  Required properties:
> > +  - reg: Must be 0, 1 or 2, corresponding to IN1, IN2 or IN3 port of INA3221
> > +
> > +  Optional properties:
> > +  - label: Name of the input source
> > +  - shunt-resistor-micro-ohms: Shunt resistor value in micro-Ohm
> > +  - status: Should be "disabled" if no input source
> > +
> > +  Example:
> > +
> > +  input@0 {
> > +          reg = <0x0>;
> > +          status = "disabled";
> 
> I kind of feel embarrassed that I asked for the reg change ... especially while
> saying at the same time that I would like to see this work for other chips
> as well.

Well, though I didn't mention it, yet I changed it to "reg" is more
likely an agreement than a compromise: I searched in the mail list
and then found this mail (a year ago though):
    https://www.spinics.net/lists/kernel/msg2455439.html

I feel it very similar to my case. So rather than betting Rob won't
tell me the same, changing to "reg" may reduce a turnaround time :)

> Other chips have different kinds of sensors. Voltage, current, power, temperature,
> and others. Whatever we come up with should support that.
> 
> I see two possibilities right now. We can stick with reg and add a "type" property,
> or we can make the index something like
> 	{voltage,current,power,temperature,humidity}-{id,index}

One small concern is a case of being multi-type. For example, I saw
ina2xx driver having voltage, current and power at the same time...

> I personally prefer "type", but I don't really have a strong opinion.
> What do you think ?

I also like this over "reg" -- "reg" requires two extra properties,
and itself sounds slightly unnatural to me for situations like this
one where we don't use it as a register address, although I know it
is convenient and common to use.

> Or maybe we should really wait for feedback from Rob.

Personally I don't mind it all to change the doc and code and then
send a v6. But eventually we'll still need the final Acked-by from
Rob right? Then I guess it's the only option.

By the way, I have two ina3221 hwmon patches that rebase upon this
binding series. And I'd like to send them out to go through review
first, but I am not sure if you'd be okay for it -- I don't really
like to change their rebase order as it might mess up something.

Thanks
Nicolin