Re: [PATCH RFT RFC 1/3] arm64: dts: qcom: sc8280xp: Add lower cluster idle states

[Konrad Dybcio <konrad.dybcio@linaro.org>]

On 19.06.2023 18:18, Konrad Dybcio wrote:
> Apart from a total LLCC + APSS power collapse, SC8280XP can also put
> either the DSU rail (CPU + L3), or VDD_CX in power collapse.
> 
> Add support for these lower idle states to allow more flexibility.
> 
> Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
> ---
>  arch/arm64/boot/dts/qcom/sc8280xp.dtsi | 20 ++++++++++++++++++--
>  1 file changed, 18 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/arm64/boot/dts/qcom/sc8280xp.dtsi b/arch/arm64/boot/dts/qcom/sc8280xp.dtsi
> index ac0596dfdbc4..d524f851cb53 100644
> --- a/arch/arm64/boot/dts/qcom/sc8280xp.dtsi
> +++ b/arch/arm64/boot/dts/qcom/sc8280xp.dtsi
> @@ -285,7 +285,23 @@ BIG_CPU_SLEEP_0: cpu-sleep-1-0 {
>  		};
>  
>  		domain-idle-states {
> -			CLUSTER_SLEEP_0: cluster-sleep-0 {
> +			CLUSTER_SLEEP_L3_PC: cluster-sleep-0 {
I guess this is misleading.

cluster-sleep-0 would be APSS_OFF (cores and caches have no power)
cluster-sleep-1 is ok (the CX rail is 0.0W)
cluster-sleep-2 would be AOSS_SLEEP (a.k.a. we've entered the SLEEP
state within RPMh and the system needs to be woken up by PDC)

Konrad
> +				compatible = "domain-idle-state";
> +				arm,psci-suspend-param = <0x41000044>;
> +				entry-latency-us = <2752>;
> +				exit-latency-us = <3048>;
> +				min-residency-us = <6118>;
> +			};
> +
> +			CLUSTER_SLEEP_CX_OFF: cluster-sleep-1 {
> +				compatible = "domain-idle-state";
> +				arm,psci-suspend-param = <0x41002344>;
> +				entry-latency-us = <3263>;
> +				exit-latency-us = <4562>;
> +				min-residency-us = <8467>;
> +			};
> +
> +			CLUSTER_SLEEP_APSS_OFF: cluster-sleep-2 {
>  				compatible = "domain-idle-state";
>  				arm,psci-suspend-param = <0x4100c344>;
>  				entry-latency-us = <3263>;
> @@ -632,7 +648,7 @@ CPU_PD7: power-domain-cpu7 {
>  
>  		CLUSTER_PD: power-domain-cpu-cluster0 {
>  			#power-domain-cells = <0>;
> -			domain-idle-states = <&CLUSTER_SLEEP_0>;
> +			domain-idle-states = <&CLUSTER_SLEEP_L3_PC &CLUSTER_SLEEP_CX_OFF &CLUSTER_SLEEP_APSS_OFF>;
>  		};
>  	};
>  
>