Re: [PATCH v2 3/4] dt-bindings: hwmon: Add ti-max-expected-current-microamp property to ina2xx

[Guenter Roeck <linux@roeck-us.net>]

On Tue, Oct 17, 2017 at 03:36:31PM -0500, Rob Herring wrote:
> On Thu, Oct 12, 2017 at 02:36:04PM +0200, Maciej Purski wrote:
> > Add optional max expected current property which allows calibrating
> > the ina sensor in order to achieve requested measure scale. Document
> > the changes in Documentation/hwmon/ina2xx.
> > 
> > Signed-off-by: Maciej Purski <m.purski@samsung.com>
> > ---
> >  Documentation/devicetree/bindings/hwmon/ina2xx.txt | 4 +++-
> >  Documentation/hwmon/ina2xx                         | 3 +++
> >  2 files changed, 6 insertions(+), 1 deletion(-)
> > 
> > diff --git a/Documentation/devicetree/bindings/hwmon/ina2xx.txt b/Documentation/devicetree/bindings/hwmon/ina2xx.txt
> > index 02af0d9..49ef0be 100644
> > --- a/Documentation/devicetree/bindings/hwmon/ina2xx.txt
> > +++ b/Documentation/devicetree/bindings/hwmon/ina2xx.txt
> > @@ -14,11 +14,13 @@ Optional properties:
> >  
> >  - shunt-resistor
> >  	Shunt resistor value in micro-Ohm
> > -
> > +- ti-max-expected-current-microamp
> > +	Max expected current value in mA
> 
> ti,max-...
> 
> The property name is a bit long. Does "expected" add anything? Is there 
> a max unexpected current?
> 
I am not too happy with it either. To me it suggests that there _can_ be
an unexpected current (why specify a max _expected_ current otherwise ?),
and that unexpected current won't be measurable and thus not reported
because it is ... well, unexpected.

Guenter

> >  Example:
> >  
> >  ina220@44 {
> >  	compatible = "ti,ina220";
> >  	reg = <0x44>;
> >  	shunt-resistor = <1000>;
> > +	ti-max-expected-current-microamp = <3000>;
> >  };
> > diff --git a/Documentation/hwmon/ina2xx b/Documentation/hwmon/ina2xx
> > index cfd31d9..30620e8 100644
> > --- a/Documentation/hwmon/ina2xx
> > +++ b/Documentation/hwmon/ina2xx
> > @@ -55,6 +55,9 @@ The shunt value in micro-ohms can be set via platform data or device tree at
> >  compile-time or via the shunt_resistor attribute in sysfs at run-time. Please
> >  refer to the Documentation/devicetree/bindings/i2c/ina2xx.txt for bindings
> >  if the device tree is used.
> > +The max expected current value in miliamp can be set via platform data
> > +or device tree at compile-time or via currX_max attribute in sysfs
> > +at run-time.
> >  
> >  Additionally ina226 supports update_interval attribute as described in
> >  Documentation/hwmon/sysfs-interface. Internally the interval is the sum of
> > -- 
> > 2.7.4
> >