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From: Heiko Stuebner <heiko@sntech.de>
To: Rob Herring <robh+dt@kernel.org>,
 Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
 Conor Dooley <conor+dt@kernel.org>, Alexey Charkov <alchark@gmail.com>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>,
 Dragan Simic <dsimic@manjaro.org>, Viresh Kumar <viresh.kumar@linaro.org>,
 Chen-Yu Tsai <wens@kernel.org>, devicetree@vger.kernel.org,
 linux-arm-kernel@lists.infradead.org, linux-rockchip@lists.infradead.org,
 linux-kernel@vger.kernel.org, Alexey Charkov <alchark@gmail.com>
Subject:
 Re: [PATCH v3 1/5] arm64: dts: rockchip: enable built-in thermal monitoring
 on RK3588
Date: Sat, 02 Mar 2024 12:25:24 +0100
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In-Reply-To: <20240229-rk-dts-additions-v3-1-6afe8473a631@gmail.com>
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 <20240229-rk-dts-additions-v3-1-6afe8473a631@gmail.com>
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Am Donnerstag, 29. Februar 2024, 20:26:32 CET schrieb Alexey Charkov:
> Include thermal zones information in device tree for RK3588 variants.
> 
> This also enables the TSADC controller unconditionally on all boards
> to ensure that thermal protections are in place via throttling and
> emergency reset, once OPPs are added to enable CPU DVFS.
> 
> The default settings (using CRU as the emergency reset mechanism)
> should work on all boards regardless of their wiring, as CRU resets
> do not depend on any external components. Boards that have the TSHUT
> signal wired to the reset line of the PMIC may opt to switch to GPIO
> tshut mode instead (rockchip,hw-tshut-mode = <1>;)
> 
> It seems though that downstream kernels don't use that, even for
> those boards where the wiring allows for GPIO based tshut, such as
> Radxa Rock 5B [1], [2], [3]
> 
> [1] https://github.com/radxa/kernel/blob/stable-5.10-rock5/arch/arm64/boot/dts/rockchip/rk3588-rock-5b.dts#L540
> [2] https://github.com/radxa/kernel/blob/stable-5.10-rock5/arch/arm64/boot/dts/rockchip/rk3588s.dtsi#L5433
> [3] https://dl.radxa.com/rock5/5b/docs/hw/radxa_rock_5b_v1423_sch.pdf page 11 (TSADC_SHUT_H)
> 
> Signed-off-by: Alexey Charkov <alchark@gmail.com>
> ---
>  arch/arm64/boot/dts/rockchip/rk3588s.dtsi | 176 +++++++++++++++++++++++++++++-
>  1 file changed, 175 insertions(+), 1 deletion(-)
> 
> diff --git a/arch/arm64/boot/dts/rockchip/rk3588s.dtsi b/arch/arm64/boot/dts/rockchip/rk3588s.dtsi
> index 36b1b7acfe6a..9bf197358642 100644
> --- a/arch/arm64/boot/dts/rockchip/rk3588s.dtsi
> +++ b/arch/arm64/boot/dts/rockchip/rk3588s.dtsi
> @@ -10,6 +10,7 @@
>  #include <dt-bindings/reset/rockchip,rk3588-cru.h>
>  #include <dt-bindings/phy/phy.h>
>  #include <dt-bindings/ata/ahci.h>
> +#include <dt-bindings/thermal/thermal.h>
>  
>  / {
>  	compatible = "rockchip,rk3588";
> @@ -2225,7 +2226,180 @@ tsadc: tsadc@fec00000 {
>  		pinctrl-1 = <&tsadc_shut>;
>  		pinctrl-names = "gpio", "otpout";
>  		#thermal-sensor-cells = <1>;
> -		status = "disabled";
> +		status = "okay";
> +	};

so I've skimmed over the general discussion, though don't have a hard
opinion in either direction yet. Still there are some low-hanging fruit:

- having the thermal-zones addition in a separate patch would allow to
  merge the obvious stuff, while this discussion is still ongoing
- status=okay in a soc dtsi is wrong, because okay is the default status
  so if anything the status property should be removed

In general I'm not that much of a fan of things just working implicitly.
So somehow, when someone submits a board devicetree, I expect them to
having ensured stuff is enabled somewhat ok. So even seeing a simple

	&tsadc {
		status = "okay"
	};

suggests that they have at least noticed the existence of thermal stuff.


At least that is where my thought-process is at the moment ;-)


Heiko

> +	thermal_zones: thermal-zones {
> +		/* sensor near the center of the SoC */
> +		package_thermal: package-thermal {
> +			polling-delay-passive = <0>;
> +			polling-delay = <0>;
> +			thermal-sensors = <&tsadc 0>;
> +
> +			trips {
> +				package_crit: package-crit {
> +					temperature = <115000>;
> +					hysteresis = <0>;
> +					type = "critical";
> +				};
> +			};
> +		};
> +
> +		/* sensor between A76 cores 0 and 1 */
> +		bigcore0_thermal: bigcore0-thermal {
> +			polling-delay-passive = <100>;
> +			polling-delay = <0>;
> +			thermal-sensors = <&tsadc 1>;
> +
> +			trips {
> +				/* threshold to start collecting temperature
> +				 * statistics e.g. with the IPA governor
> +				 */
> +				bigcore0_alert0: bigcore0-alert0 {
> +					temperature = <75000>;
> +					hysteresis = <2000>;
> +					type = "passive";
> +				};
> +				/* actual control temperature */
> +				bigcore0_alert1: bigcore0-alert1 {
> +					temperature = <85000>;
> +					hysteresis = <2000>;
> +					type = "passive";
> +				};
> +				bigcore0_crit: bigcore0-crit {
> +					temperature = <115000>;
> +					hysteresis = <0>;
> +					type = "critical";
> +				};
> +			};
> +			cooling-maps {
> +				map0 {
> +					trip = <&bigcore0_alert1>;
> +					cooling-device =
> +						<&cpu_b0 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
> +						<&cpu_b1 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>;
> +				};
> +			};
> +		};
> +
> +		/* sensor between A76 cores 2 and 3 */
> +		bigcore2_thermal: bigcore2-thermal {
> +			polling-delay-passive = <100>;
> +			polling-delay = <0>;
> +			thermal-sensors = <&tsadc 2>;
> +
> +			trips {
> +				/* threshold to start collecting temperature
> +				 * statistics e.g. with the IPA governor
> +				 */
> +				bigcore2_alert0: bigcore2-alert0 {
> +					temperature = <75000>;
> +					hysteresis = <2000>;
> +					type = "passive";
> +				};
> +				/* actual control temperature */
> +				bigcore2_alert1: bigcore2-alert1 {
> +					temperature = <85000>;
> +					hysteresis = <2000>;
> +					type = "passive";
> +				};
> +				bigcore2_crit: bigcore2-crit {
> +					temperature = <115000>;
> +					hysteresis = <0>;
> +					type = "critical";
> +				};
> +			};
> +			cooling-maps {
> +				map0 {
> +					trip = <&bigcore2_alert1>;
> +					cooling-device =
> +						<&cpu_b2 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
> +						<&cpu_b3 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>;
> +				};
> +			};
> +		};
> +
> +		/* sensor between the four A55 cores */
> +		little_core_thermal: littlecore-thermal {
> +			polling-delay-passive = <100>;
> +			polling-delay = <0>;
> +			thermal-sensors = <&tsadc 3>;
> +
> +			trips {
> +				/* threshold to start collecting temperature
> +				 * statistics e.g. with the IPA governor
> +				 */
> +				littlecore_alert0: littlecore-alert0 {
> +					temperature = <75000>;
> +					hysteresis = <2000>;
> +					type = "passive";
> +				};
> +				/* actual control temperature */
> +				littlecore_alert1: littlecore-alert1 {
> +					temperature = <85000>;
> +					hysteresis = <2000>;
> +					type = "passive";
> +				};
> +				littlecore_crit: littlecore-crit {
> +					temperature = <115000>;
> +					hysteresis = <0>;
> +					type = "critical";
> +				};
> +			};
> +			cooling-maps {
> +				map0 {
> +					trip = <&littlecore_alert1>;
> +					cooling-device =
> +						<&cpu_l0 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
> +						<&cpu_l1 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
> +						<&cpu_l2 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>,
> +						<&cpu_l3 THERMAL_NO_LIMIT THERMAL_NO_LIMIT>;
> +				};
> +			};
> +		};
> +
> +		/* sensor near the PD_CENTER power domain */
> +		center_thermal: center-thermal {
> +			polling-delay-passive = <0>;
> +			polling-delay = <0>;
> +			thermal-sensors = <&tsadc 4>;
> +
> +			trips {
> +				center_crit: center-crit {
> +					temperature = <115000>;
> +					hysteresis = <0>;
> +					type = "critical";
> +				};
> +			};
> +		};
> +
> +		gpu_thermal: gpu-thermal {
> +			polling-delay-passive = <0>;
> +			polling-delay = <0>;
> +			thermal-sensors = <&tsadc 5>;
> +
> +			trips {
> +				gpu_crit: gpu-crit {
> +					temperature = <115000>;
> +					hysteresis = <0>;
> +					type = "critical";
> +				};
> +			};
> +		};
> +
> +		npu_thermal: npu-thermal {
> +			polling-delay-passive = <0>;
> +			polling-delay = <0>;
> +			thermal-sensors = <&tsadc 6>;
> +
> +			trips {
> +				npu_crit: npu-crit {
> +					temperature = <115000>;
> +					hysteresis = <0>;
> +					type = "critical";
> +				};
> +			};
> +		};
>  	};
>  
>  	saradc: adc@fec10000 {
> 
>