diff --git a/Documentation/devicetree/bindings/watchdog/aspeed-wdt.txt b/Documentation/devicetree/bindings/watchdog/aspeed-wdt.txt
index 2b34ce9b60b9..c5077a1f5cb3 100644
--- a/Documentation/devicetree/bindings/watchdog/aspeed-wdt.txt
+++ b/Documentation/devicetree/bindings/watchdog/aspeed-wdt.txt
@@ -33,10 +33,18 @@ Optional properties:
         - none: No reset is performed on timeout. Assumes another watchdog
                 engine is responsible for this.
 
+ - aspeed,alt-boot:    If property is present then boot from alternate block.
  - aspeed,external-signal: If property is present then signal is sent to
 			external reset counter (only WDT1 and WDT2). If not
 			specified no external signal is sent.
- - aspeed,alt-boot:    If property is present then boot from alternate block.
+ - aspeed,ext-pulse-duration: External signal pulse duration in microseconds
+
+Optional properties for AST2500-compatible watchdogs:
+ - aspeed,ext-push-pull: If aspeed,external-signal is present, set the pin's
+			 drive type to push-pull. The default is open-drain.
+ - aspeed,ext-active-high: If aspeed,external-signal is present and and the pin
+			   is configured as push-pull, then set the pulse
+			   polarity to active-high. The default is active-low.
 
 Example: