diff --git a/include/dt-bindings/mfd/st-lpc.h b/include/dt-bindings/mfd/st-lpc.h
index e3e6c75d8822..d05894afa7e7 100644
--- a/include/dt-bindings/mfd/st-lpc.h
+++ b/include/dt-bindings/mfd/st-lpc.h
@@ -11,5 +11,6 @@
 
 #define ST_LPC_MODE_RTC		0
 #define ST_LPC_MODE_WDT		1
+#define ST_LPC_MODE_CLKSRC	2
 
 #endif /* __DT_BINDINGS_ST_LPC_H__ */