[PATCH RFC 1/3] thermal: allow hwmon devices to be created for of-thermal zones

[Russell King - ARM Linux]

On Mon, Mar 20, 2017 at 12:15:52PM -0500, Rob Herring wrote:
> On Sun, Mar 12, 2017 at 07:07:40PM +0000, Russell King wrote:
> > Allow hwmon devices to be optionally created for of-thermal zones,
> > rather than permanently denying them "in case" there is a hwmon
> > driver duplicating the thermal driver.
> > 
> > Signed-off-by: Russell King <rmk+kernel at armlinux.org.uk>
> > ---
> > Without this, "sensors" is unable to report the temperature of the
> > Dove SoC when it supports thermal zones.
> > 
> >  Documentation/devicetree/bindings/thermal/thermal.txt | 3 +++
> >  arch/arm/boot/dts/dove.dtsi                           | 1 +
> >  drivers/thermal/of-thermal.c                          | 3 ++-
> >  3 files changed, 6 insertions(+), 1 deletion(-)
> > 
> > diff --git a/Documentation/devicetree/bindings/thermal/thermal.txt b/Documentation/devicetree/bindings/thermal/thermal.txt
> > index 88b6ea1ad290..1478735fff85 100644
> > --- a/Documentation/devicetree/bindings/thermal/thermal.txt
> > +++ b/Documentation/devicetree/bindings/thermal/thermal.txt
> > @@ -175,6 +175,9 @@ containing trip nodes and one sub-node containing all the zone cooling maps.
> >  			2000mW, while on a 10'' tablet is around
> >  			4500mW.
> >  
> > +- linux,hwmon:		Allow Linux to create hwmon devices for the thermal
> > +  Type: bool		zone.
> > +
> >  Note: The delay properties are bound to the maximum dT/dt (temperature
> >  derivative over time) in two situations for a thermal zone:
> >  (i)  - when passive cooling is activated (polling-delay-passive); and
> > diff --git a/arch/arm/boot/dts/dove.dtsi b/arch/arm/boot/dts/dove.dtsi
> > index 40fb98687230..00f5971cd039 100644
> > --- a/arch/arm/boot/dts/dove.dtsi
> > +++ b/arch/arm/boot/dts/dove.dtsi
> > @@ -804,6 +804,7 @@
> >  
> >  	thermal-zones {
> >  		soc-thermal {
> > +			linux,hwmon;
> 
> I'd prefer to see a black or white list of sensor compatibles here. Then 
> the dtb doesn't need to change if things move between hwmon and thermal 
> zones.

I'm not sure what you mean, and I can't see how that would be coded up.
The thermal layer doesn't give the option of individually selecting
which sensors have hwmon stuff created - it seems to be all or nothing.
I suspect what you're asking would require something of a rewrite of
the thermal code.  The sensors are registered completely independently
of parsing the thermal zone data.

-- 
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