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Date:   Tue, 19 Feb 2019 17:22:13 -0800
From:   Eduardo Valentin <edubezval@gmail.com>
To:     Wei Ni <wni@nvidia.com>
Cc:     Rob Herring <robh@kernel.org>, thierry.reding@gmail.com,
        daniel.lezcano@linaro.org, linux-tegra@vger.kernel.org,
        rui.zhang@intel.com, srikars@nvidia.com,
        linux-kernel@vger.kernel.org, devicetree@vger.kernel.org
Subject: Re: [PATCH v1 01/12] of: Add bindings of thermtrip for Tegra soctherm
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On Fri, Dec 28, 2018 at 11:28:42AM +0800, Wei Ni wrote:
> 
> 
> On 28/12/2018 7:06 AM, Rob Herring wrote:
> > On Tue, Dec 18, 2018 at 03:34:33PM +0800, Wei Ni wrote:
> >> Add optional property "nvidia,thermtrips".
> >> If present, these trips will be used as HW shutdown trips,
> >> and critical trips will be used as SW shutdown trips.
> >>
> >> Signed-off-by: Wei Ni <wni@nvidia.com>
> >> ---
> >>  .../bindings/thermal/nvidia,tegra124-soctherm.txt    | 20 +++++++++++++++++---
> >>  1 file changed, 17 insertions(+), 3 deletions(-)
> >>
> >> diff --git a/Documentation/devicetree/bindings/thermal/nvidia,tegra124-soctherm.txt b/Documentation/devicetree/bindings/thermal/nvidia,tegra124-soctherm.txt
> >> index b6c0ae53d4dc..ab66d6feab4b 100644
> >> --- a/Documentation/devicetree/bindings/thermal/nvidia,tegra124-soctherm.txt
> >> +++ b/Documentation/devicetree/bindings/thermal/nvidia,tegra124-soctherm.txt
> >> @@ -55,10 +55,21 @@ Required properties :
> >>        - #cooling-cells: Should be 1. This cooling device only support on/off state.
> >>          See ./thermal.txt for a description of this property.
> >>  
> >> +Optional properties:
> >> +- nvidia,thermtrips : When present, this property specifies the temperature at
> >> +  which the soctherm hardware will assert the thermal trigger signal to the
> >> +  Power Management IC, which can be configured to reset or shutdown the device.
> >> +  It is an array of pairs where each pair represents a tsensor id followed by a
> >> +  temperature in milli Celcius. In the absence of this property the critical
> >> +  trip point will be used for thermtrip temperature.
> >> +
> >>  Note:
> >> -- the "critical" type trip points will be set to SOC_THERM hardware as the
> >> -shut down temperature. Once the temperature of this thermal zone is higher
> >> -than it, the system will be shutdown or reset by hardware.
> >> +- the "critical" type trip points will be used to set the temperature at which
> >> +the SOC_THERM hardware will assert a thermal trigger if the "nvidia,thermtrips"
> >> +property is missing. When the thermtrips property is present, the breach of a
> >> +critical trip point is reported back to the thermal framework to implement
> >> +software shutdown.
> > 
> > This hardly seems like a NVidia specific concept. A h/w shutdown 
> > temperature... Come up with something common.
> 
> Hi Rob,
> In current thermal framework, it doesn't support to set h/w shutdown
> trips, the "critical" trip is used for s/w shutdown. I noticed that in
> rockchip-thermal driver, it also used "rockchip,hw-tshut-temp" to set
> h/w shutdown temperature.

Why a critical trip point cannot be used for your hw shutdown too?

> 
> > 
> > Also, we already have a temperature table. Why do we need temperatures 
> > in 2 places.
> 
> Sorry, what do you mean temperature table? Do you mean the trip nodes?
> 
> Thanks.
> Wei.
> 
> > 
> >> +
> >>  - the "hot" type trip points will be set to SOC_THERM hardware as the throttle
> >>  temperature. Once the the temperature of this thermal zone is higher
> >>  than it, it will trigger the HW throttle event.
> >> @@ -79,6 +90,9 @@ Example :
> >>  
> >>  		#thermal-sensor-cells = <1>;
> >>  
> >> +		nvidia,thermtrips = <TEGRA124_SOCTHERM_SENSOR_CPU 102500
> >> +				     TEGRA124_SOCTHERM_SENSOR_GPU 103000>;
> >> +
> >>  		throttle-cfgs {
> >>  			/*
> >>  			 * When the "heavy" cooling device triggered,
> >> -- 
> >> 2.7.4
> >>