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diff --git a/Documentation/devicetree/bindings/watchdog/aspeed-wdt.txt b/Documentation/devicetree/bindings/watchdog/aspeed-wdt.txt
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+Aspeed Watchdog Timer
+
+Required properties:
+ - compatible: must be one of:
+	- "aspeed,ast2400-wdt"
+	- "aspeed,ast2500-wdt"
+	- "aspeed,ast2600-wdt"
+
+ - reg: physical base address of the controller and length of memory mapped
+   region
+
+Optional properties:
+
+ - aspeed,reset-type = "cpu|soc|system|none"
+
+   Reset behavior - Whenever a timeout occurs the watchdog can be programmed
+   to generate one of three different, mutually exclusive, types of resets.
+
+   Type "none" can be specified to indicate that no resets are to be done.
+   This is useful in situations where another watchdog engine on chip is
+   to perform the reset.
+
+   If 'aspeed,reset-type=' is not specified the default is to enable system
+   reset.
+
+   Reset types:
+
+        - cpu: Reset CPU on watchdog timeout
+
+        - soc: Reset 'System on Chip' on watchdog timeout
+
+        - system: Reset system on watchdog timeout
+
+        - 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,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:
+
+	wdt1: watchdog@1e785000 {
+		compatible = "aspeed,ast2400-wdt";
+		reg = <0x1e785000 0x1c>;
+		aspeed,reset-type = "system";
+		aspeed,external-signal;
+	};