diff --git a/Documentation/devicetree/bindings/timer/renesas,tmu.txt b/Documentation/devicetree/bindings/timer/renesas,tmu.txt
index 4ae7910af09ffcb4caafe221f008f88b32b97ff8..cd5f20bf2582e742c426018d91d31c652767d7fd 100644
--- a/Documentation/devicetree/bindings/timer/renesas,tmu.txt
+++ b/Documentation/devicetree/bindings/timer/renesas,tmu.txt
@@ -10,6 +10,7 @@ Required Properties:
 
   - compatible: must contain one or more of the following:
     - "renesas,tmu-r8a7740" for the r8a7740 TMU
+    - "renesas,tmu-r8a7778" for the r8a7778 TMU
     - "renesas,tmu-r8a7779" for the r8a7779 TMU
     - "renesas,tmu" for any TMU.
       This is a fallback for the above renesas,tmu-* entries