diff --git a/Documentation/devicetree/bindings/mfd/mediatek,mt6397.yaml b/Documentation/devicetree/bindings/mfd/mediatek,mt6397.yaml
index bbd56e522a75..055625362951 100644
--- a/Documentation/devicetree/bindings/mfd/mediatek,mt6397.yaml
+++ b/Documentation/devicetree/bindings/mfd/mediatek,mt6397.yaml
@@ -84,6 +84,15 @@ properties:
 
       start-year: true
 
+      nvmem-layout:
+        $ref: /schemas/nvmem/layouts/nvmem-layout.yaml
+        description:
+          The RTC carries four bytes of storage that neither the clock nor the
+          alarm uses, in the high half of four of the alarm registers, and
+          offers them as a battery-backed nvmem provider. MediaTek's
+          documentation names them RTC_NEW_SPARE0 to RTC_NEW_SPARE3 and gives
+          the first to a fuel gauge.
+
     required:
       - compatible