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

From: Dario Binacchi
Date: Wed Jan 07 2026 - 17:41:37 EST


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@xxxxxxxxxxxxxxxxxxxx>

---

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>;
--
2.43.0

base-commit: f0b9d8eb98dfee8d00419aa07543bdc2c1a44fb1
branch: stm32-tamp-nvram