Re: [Linux-stm32] [PATCH 2/2] arm64: dts: st: add TAMP-NVRAM support for STM32MP25

[Patrice CHOTARD <patrice.chotard@foss.st.com>]

On 1/7/26 20:45, Dario Binacchi wrote:
> Add the TAMP node along with its NVRAM child node and define the
> fixed-layout for fwu_info and boot_mode registers.
> 
> The TAMP (Tamper and backup registers) block is a system controller that
> provides access to backup registers as NVMEM storage that persists across
> reboots.
> 
> Signed-off-by: Dario Binacchi <dario.binacchi@amarulasolutions.com>
> 
> ---
> 
>  arch/arm64/boot/dts/st/stm32mp251.dtsi | 26 ++++++++++++++++++++++++++
>  1 file changed, 26 insertions(+)
> 
> diff --git a/arch/arm64/boot/dts/st/stm32mp251.dtsi b/arch/arm64/boot/dts/st/stm32mp251.dtsi
> index a8e6e0f77b83..c7839e732f31 100644
> --- a/arch/arm64/boot/dts/st/stm32mp251.dtsi
> +++ b/arch/arm64/boot/dts/st/stm32mp251.dtsi
> @@ -2084,6 +2084,32 @@ rtc: rtc@46000000 {
>  			status = "disabled";
>  		};
>  
> +		tamp: tamp@46010000 {
> +			compatible = "st,stm32-tamp", "syscon", "simple-mfd";
> +			#address-cells = <1>;
> +			#size-cells = <1>;
> +			reg = <0x46010000 0x400>;
> +			ranges;
> +
> +			nvram: nvram@46010100 {
> +				compatible = "st,stm32mp25-tamp-nvram";
> +				reg = <0x46010100 0x200>;
> +				nvmem-layout {
> +					compatible = "fixed-layout";
> +					#address-cells = <1>;
> +					#size-cells = <1>;
> +
> +					fwu_info: tamp-bkp@c0 {
> +						reg = <0xc0 0x4>;
> +					};
> +
> +					boot_mode: tamp-bkp@180 {
> +						reg = <0x180 0x4>;
> +					};
> +				};
> +			};
> +		};
> +
>  		pinctrl_z: pinctrl@46200000 {
>  			#address-cells = <1>;
>  			#size-cells = <1>;
Hi Dario

At STMicroelectronics we intend to upstream tamp-vram driver for STM32MP series.
If you don't see any objection, we prefer to manage it in our side.

Thanks
Patrice