Re: [PATCH] arm64: dts: st: mark main supplies always-on on stm32mp257f-dk

[Patrick DELAUNAY <patrick.delaunay@foss.st.com>]

Hi,

On 10/4/26 13:24, Mateusz Nowicki wrote:
> The vddcore, v1v8 and v3v3 regulators have no consumer in Linux, so
> the regulator core disables them 30 seconds after boot. They supply
> the SoC digital logic, the SoC 1.8 V analog domain and the 3.3 V board
> peripherals, and must stay on while Linux runs.
>
> Mark them always-on.
>
> Signed-off-by: Mateusz Nowicki <mateusz.nowicki@posteo.net>
> ---
>   arch/arm64/boot/dts/st/stm32mp257f-dk.dts | 3 +++
>   1 file changed, 3 insertions(+)
>
> diff --git a/arch/arm64/boot/dts/st/stm32mp257f-dk.dts b/arch/arm64/boot/dts/st/stm32mp257f-dk.dts
> index a8f18508db3e..7a837e6fd578 100644
> --- a/arch/arm64/boot/dts/st/stm32mp257f-dk.dts
> +++ b/arch/arm64/boot/dts/st/stm32mp257f-dk.dts
> @@ -310,14 +310,17 @@ scmi_vddio1: regulator@0 {
>   	scmi_vddcore: regulator@11 {
>   		reg = <VOLTD_SCMI_STPMIC2_BUCK2>;
>   		regulator-name = "vddcore";
> +		regulator-always-on;
>   	};
>   	scmi_v1v8: regulator@14 {
>   		reg = <VOLTD_SCMI_STPMIC2_BUCK5>;
>   		regulator-name = "v1v8";
> +		regulator-always-on;
>   	};
>   	scmi_v3v3: regulator@16 {
>   		reg = <VOLTD_SCMI_STPMIC2_BUCK7>;
>   		regulator-name = "v3v3";
> +		regulator-always-on;
>   	};
>   	scmi_vdd_emmc: regulator@18 {
>   		reg = <VOLTD_SCMI_STPMIC2_LDO2>;
>
> base-commit: f831584128ac2a36fb4fa62fe106793d08c2dbf1


For STMicroelectronics boards, the STPMIC always-on regulator are 
managed on SCMI server side in OP-TEE.

So no need to manage this constraint in Linux device tree.

This always-on  regulator are exposed only for information or to be used 
are supply for some IP.


Regards

Patrick