Re: [PATCH] arm64: dts: st: add thermal zones on stm32mp251

[Patrick DELAUNAY]

Hi,

in rules established by STMicroelectronics:
    -Tcritical = Tj - (sensor tolerance). With Tj the function temperature.
    -Tlimitation = 90% of Tcritical.

On STM32MP25, Tj=125C even if the overdrive is used. So we have:
    - STM32MP2xxA/C/D/F, Tcritical = 125-3 = 122C
    - STM32MP2xxA/C/D/F, Tlimitation = 110C

So critical value need to be adjusted to
                    temperature = <122000>;
                    hysteresis = <1000>;

On 10/4/26 14:12, Mateusz Nowicki wrote:
> Add a CPU and a SoC thermal zone for the two DTS sensors, each with a
> critical trip point at 120 degrees Celsius, below the 125 degrees
> Celsius max junction temperature of the STM32MP25.
>
> Signed-off-by: Mateusz Nowicki <mateusz.nowicki@xxxxxxxxxx>
> ---
>   arch/arm64/boot/dts/st/stm32mp251.dtsi | 28 ++++++++++++++++++++++++++
>   1 file changed, 28 insertions(+)
>
> diff --git a/arch/arm64/boot/dts/st/stm32mp251.dtsi b/arch/arm64/boot/dts/st/stm32mp251.dtsi
> index b624f998b87c..fd174c88b26d 100644
> --- a/arch/arm64/boot/dts/st/stm32mp251.dtsi
> +++ b/arch/arm64/boot/dts/st/stm32mp251.dtsi
> @@ -158,6 +158,34 @@ RET_PD: power-domain-retention {
>   		};
>   	};
>   
> +	thermal-zones {
> +		cpu-thermal {
            polling-delay-passive = <250>;

because the DTS  sensors have no interrupts support

> +			polling-delay = <1000>;
> +			thermal-sensors = <&dts 1>;
> +
> +			trips {
> +				cpu-crit {
> +					temperature = <120000>;
> +					hysteresis = <2000>;


                    temperature = <122000>;
                    hysteresis = <1000>;

> +					type = "critical";
> +				};
> +			};
> +		};
> +
> +		soc-thermal {
            polling-delay-passive = <250>;
> +			polling-delay = <1000>;
> +			thermal-sensors = <&dts 0>;
> +
> +			trips {
> +				soc-crit {
> +					temperature = <120000>;
> +					hysteresis = <2000>;

                    temperature = <122000>;
                    hysteresis = <1000>;
> +					type = "critical";
> +				};
> +			};
> +		};
> +	};
> +
>   	timer {
>   		compatible = "arm,armv8-timer";
>   		interrupt-parent = <&intc>;
>
> base-commit: f831584128ac2a36fb4fa62fe106793d08c2dbf1


Regards

Patrick