linux-kernel - Re: [PATCH v1] arm64: dts: sdm845: enable tsens thermal zones

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Message-ID: <20180726004738.GU129942@google.com>
Date:   Wed, 25 Jul 2018 17:47:38 -0700
From:   Matthias Kaehlcke <mka@...omium.org>
To:     Amit Kucheria <amit.kucheria@...aro.org>
Cc:     linux-kernel@...r.kernel.org, rnayak@...eaurora.org,
        linux-arm-msm@...r.kernel.org, bjorn.andersson@...aro.org,
        andy.gross@...aro.org, dianders@...omium.org, edubezval@...il.com,
        David Brown <david.brown@...aro.org>,
        Rob Herring <robh+dt@...nel.org>,
        Mark Rutland <mark.rutland@....com>,
        Catalin Marinas <catalin.marinas@....com>,
        Will Deacon <will.deacon@....com>, linux-soc@...r.kernel.org,
        devicetree@...r.kernel.org, linux-arm-kernel@...ts.infradead.org
Subject: Re: [PATCH v1] arm64: dts: sdm845: enable tsens thermal zones

Hi Amit,

On Wed, Jul 18, 2018 at 01:19:17PM +0530, Amit Kucheria wrote:
> One thermal zone per cpu is defined
> 
> Signed-off-by: Amit Kucheria <amit.kucheria@...aro.org>
> ---
>  arch/arm64/boot/dts/qcom/sdm845.dtsi | 170 +++++++++++++++++++++++++++++++++++
>  1 file changed, 170 insertions(+)
> 
> diff --git a/arch/arm64/boot/dts/qcom/sdm845.dtsi b/arch/arm64/boot/dts/qcom/sdm845.dtsi
> index 01ff146..a75be7c 100644
> --- a/arch/arm64/boot/dts/qcom/sdm845.dtsi
> +++ b/arch/arm64/boot/dts/qcom/sdm845.dtsi
> @@ -340,4 +340,174 @@
>  			};
>  		};
>  	};
> +
> +	thermal-zones {
> +		cpu0-thermal {
> +			polling-delay-passive = <250>;
> +			polling-delay = <1000>;

In the context of the TSENS patches you mentioned that you are working
on interrupt support. Can the polling delays be removed once that is merged?

> +			thermal-sensors = <&tsens0 1>;
> +
> +			trips {
> +				cpu_alert0: trip0 {
> +					temperature = <75000>;
> +					hysteresis = <2000>;
> +					type = "passive";
> +				};
> +
> +				cpu_crit0: trip1 {
> +					temperature = <110000>;
> +					hysteresis = <1000>;
> +					type = "critical";
> +				};
> +			};
> +		};
> +
> +		cpu1-thermal {
> +			polling-delay-passive = <250>;
> +			polling-delay = <1000>;
> +
> +			thermal-sensors = <&tsens0 2>;
> +
> +			trips {
> +				cpu_alert1: trip0 {
> +					temperature = <75000>;
> +					hysteresis = <2000>;
> +					type = "passive";
> +				};
> +
> +				cpu_crit1: trip1 {
> +					temperature = <110000>;
> +					hysteresis = <1000>;
> +					type = "critical";
> +				};
> +			};
> +		};
> +
> +		cpu2-thermal {
> +			polling-delay-passive = <250>;
> +			polling-delay = <1000>;
> +
> +			thermal-sensors = <&tsens0 3>;
> +
> +			trips {
> +				cpu_alert2: trip0 {
> +					temperature = <75000>;
> +					hysteresis = <2000>;
> +					type = "passive";
> +				};
> +
> +				cpu_crit2: trip1 {
> +					temperature = <110000>;
> +					hysteresis = <1000>;
> +					type = "critical";
> +				};
> +			};
> +		};
> +
> +		cpu3-thermal {
> +			polling-delay-passive = <250>;
> +			polling-delay = <1000>;
> +
> +			thermal-sensors = <&tsens0 4>;
> +
> +			trips {
> +				cpu_alert3: trip0 {
> +					temperature = <75000>;
> +					hysteresis = <2000>;
> +					type = "passive";
> +				};
> +
> +				cpu_crit3: trip1 {
> +					temperature = <110000>;
> +					hysteresis = <1000>;
> +					type = "critical";
> +				};
> +			};
> +		};
> +
> +		cpu4-thermal {
> +			polling-delay-passive = <250>;
> +			polling-delay = <1000>;
> +
> +			thermal-sensors = <&tsens0 7>;
> +
> +			trips {
> +				cpu_alert4: trip0 {
> +					temperature = <75000>;
> +					hysteresis = <2000>;
> +					type = "passive";
> +				};
> +
> +				cpu_crit4: trip1 {
> +					temperature = <110000>;
> +					hysteresis = <1000>;
> +					type = "critical";
> +				};
> +			};
> +		};
> +
> +		cpu5-thermal {
> +			polling-delay-passive = <250>;
> +			polling-delay = <1000>;
> +
> +			thermal-sensors = <&tsens0 8>;
> +
> +			trips {
> +				cpu_alert5: trip0 {
> +					temperature = <75000>;
> +					hysteresis = <2000>;
> +					type = "passive";
> +				};
> +
> +				cpu_crit5: trip1 {
> +					temperature = <110000>;
> +					hysteresis = <1000>;
> +					type = "critical";
> +				};
> +			};
> +		};
> +
> +		cpu6-thermal {
> +			polling-delay-passive = <250>;
> +			polling-delay = <1000>;
> +
> +			thermal-sensors = <&tsens0 9>;
> +
> +			trips {
> +				cpu_alert6: trip0 {
> +					temperature = <75000>;
> +					hysteresis = <2000>;
> +					type = "passive";
> +				};
> +
> +				cpu_crit6: trip1 {
> +					temperature = <110000>;
> +					hysteresis = <1000>;
> +					type = "critical";
> +				};
> +			};
> +		};
> +
> +		cpu7-thermal {
> +			polling-delay-passive = <250>;
> +			polling-delay = <1000>;
> +
> +			thermal-sensors = <&tsens0 10>;
> +
> +			trips {
> +				cpu_alert7: trip0 {
> +					temperature = <75000>;
> +					hysteresis = <2000>;
> +					type = "passive";
> +				};
> +
> +				cpu_crit7: trip1 {
> +					temperature = <110000>;
> +					hysteresis = <1000>;
> +					type = "critical";
> +				};
> +			};

Dumb DT question: the trip information is the same for all CPUs. Would
it be possible to have a single node and refer to it with a phandle?

I suppose the anwer is no and even if it was possible we probably
wouldn't want it, since it would complicate overriding settings for a
specific CPU (should that ever be needed ...) or cluster. Just wondering.

> +		};
> +	};
>  };

I don't have documentation to verify that the sensors and CPUs match,
but it is in line with what I've seen in some Android tree, so it
seems alright ;-)

Reviewed-by: Matthias Kaehlcke <mka@...omium.org>
Tested-by: Matthias Kaehlcke <mka@...omium.org>