diff --git a/Documentation/devicetree/bindings/arm/firmware/linaro,optee-tz.yaml b/Documentation/devicetree/bindings/arm/firmware/linaro,optee-tz.yaml
index c24047c1fdd5..9a426110a14a 100644
--- a/Documentation/devicetree/bindings/arm/firmware/linaro,optee-tz.yaml
+++ b/Documentation/devicetree/bindings/arm/firmware/linaro,optee-tz.yaml
@@ -24,6 +24,12 @@ properties:
   compatible:
     const: linaro,optee-tz
 
+  interrupts:
+    maxItems: 1
+    description: |
+      This interrupt which is used to signal an event by the secure world
+      software is expected to be edge-triggered.
+
   method:
     enum: [smc, hvc]
     description: |
@@ -42,10 +48,12 @@ additionalProperties: false
 
 examples:
   - |
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
     firmware  {
         optee  {
             compatible = "linaro,optee-tz";
             method = "smc";
+            interrupts = <GIC_SPI 187 IRQ_TYPE_EDGE_RISING>;
         };
     };