Re: [PATCH V4 07/11] of: Add bindings of hw-trip-points for soctherm

From: Wei Ni
Date: Tue Jan 26 2016 - 01:10:13 EST




On 2016å01æ26æ 10:41, Rob Herring wrote:
> On Mon, Jan 25, 2016 at 06:46:36PM +0800, Wei Ni wrote:
>> Add hw-trips sub-node for soctherm, which is
>> used to describe the hardware trip points for
>> each soctherm sensors.
>
> This seems like something that should be common. There was a hwmon
> binding just the other day with temperature set points.

I have checked the thermal_hwmon.c, but we can't use it. Because we use
of-thermal to register thermal zone, but it doesn't support to register to
hwmon. And it only support to show the critical temperature.
I think this sub-node is used for Tegra's soctherm specifically. And it's not
only for shutdown/reset, it also will be used to describe the hw-throttle
function in next serial patches (I'm preparing it, didn't send out yet).

BTW, I didn't find the hwmon binding to introduce the hw trips in TOT
kernel-next, could you show me it?

>
>> Signed-off-by: Wei Ni <wni@xxxxxxxxxx>
>> ---
>> .../devicetree/bindings/thermal/tegra-soctherm.txt | 24 ++++++++++++++++++++++
>> 1 file changed, 24 insertions(+)
>>
>> diff --git a/Documentation/devicetree/bindings/thermal/tegra-soctherm.txt b/Documentation/devicetree/bindings/thermal/tegra-soctherm.txt
>> index 6b68cd150405..75dc9dbe7e1a 100644
>> --- a/Documentation/devicetree/bindings/thermal/tegra-soctherm.txt
>> +++ b/Documentation/devicetree/bindings/thermal/tegra-soctherm.txt
>> @@ -26,6 +26,15 @@ Required properties :
>> of this property. See <dt-bindings/thermal/tegra124-soctherm.h> for a
>> list of valid values when referring to thermal sensors.
>>
>> +Optional properties:
>> +- hw-trip-points : A sub-node which is a container of hardware trip points
>> + for each sensors.
>> + * sensors: Sub-nodes which are used to describe the HW trip points info,
>> + must be named as "cpu", "gpu", "mem", "pll".
>> + Properties:
>> + - thermtrip-temperature : Shutdown or reset temperature in millicelsius,
>> + once the temperature of this sensor is higher than the
>> + thermtrip-temperature, the system will be shutdown or reset.
>
> Append units and temperature is a bit redundant. Something like
> thermtrip-mC or thermtrip-milliC

Hmm, got it, will change it in next version.

>
> You could easily have multiple levels of trip points, so perhaps the
> name needs to reflect the action (i.e. shutdown).

This temperature can trigger shutdown or reset, it depends on the platform
design, and the Tegra's SPEC call it as thermtrip, so I use this name. I prefer
to use "thermtgrip-mC".

>
> Rob
>