[PATCH] arm64: dts: exynos850: Add syscon-poweroff node

[Alexey Klimov]

Without poweroff node Exynos850-based board continue to draw current
(around ~60 mA with my test setup) after poweroff. Kernel also reports
different lockup problems and RCU stalls warnings continuosly after
last kernel messages about hardware being switched off.
Turns out we missed a write to PMU's PS_HOLD_CONTROL (PMU + 0x30c)
register that actually switches the SoC off.

Add poweroff node that implements this.

With this change the current draw after power off is in range of few
milliampers and lockup messages are no more.

Signed-off-by: Alexey Klimov <alexey.klimov at linaro.org>
---
 arch/arm64/boot/dts/exynos/exynos850.dtsi | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/arch/arm64/boot/dts/exynos/exynos850.dtsi b/arch/arm64/boot/dts/exynos/exynos850.dtsi
index cb55015c8dce..3881f573ec08 100644
--- a/arch/arm64/boot/dts/exynos/exynos850.dtsi
+++ b/arch/arm64/boot/dts/exynos/exynos850.dtsi
@@ -215,6 +215,13 @@ pmu_system_controller: system-controller at 11860000 {
 			compatible = "samsung,exynos850-pmu", "syscon";
 			reg = <0x11860000 0x10000>;
 
+			poweroff: syscon-poweroff {
+				compatible = "syscon-poweroff";
+				offset = <0x30c>; /* PS_HOLD_CONTROL */
+				mask = <0x00000100>;
+				value = <0x0>;
+			};
+
 			reboot: syscon-reboot {
 				compatible = "syscon-reboot";
 				regmap = <&pmu_system_controller>;

---
base-commit: 85964cdcad0fac9a0eb7b87a0f9d88cc074b854c
change-id: 20260325-exynos850-poweroff-a6515334888a

Best regards,
-- 
Alexey Klimov <alexey.klimov at linaro.org>