1Aspeed Watchdog Timer
2
3Required properties:
4 - compatible: must be one of:
5	- "aspeed,ast2400-wdt"
6	- "aspeed,ast2500-wdt"
7
8 - reg: physical base address of the controller and length of memory mapped
9   region
10
11Optional properties:
12
13 - aspeed,reset-type = "cpu|soc|system|none"
14
15   Reset behavior - Whenever a timeout occurs the watchdog can be programmed
16   to generate one of three different, mutually exclusive, types of resets.
17
18   Type "none" can be specified to indicate that no resets are to be done.
19   This is useful in situations where another watchdog engine on chip is
20   to perform the reset.
21
22   If 'aspeed,reset-type=' is not specfied the default is to enable system
23   reset.
24
25   Reset types:
26
27        - cpu: Reset CPU on watchdog timeout
28
29        - soc: Reset 'System on Chip' on watchdog timeout
30
31        - system: Reset system on watchdog timeout
32
33        - none: No reset is performed on timeout. Assumes another watchdog
34                engine is responsible for this.
35
36 - aspeed,alt-boot:    If property is present then boot from alternate block.
37 - aspeed,external-signal: If property is present then signal is sent to
38			external reset counter (only WDT1 and WDT2). If not
39			specified no external signal is sent.
40 - aspeed,ext-pulse-duration: External signal pulse duration in microseconds
41
42Optional properties for AST2500-compatible watchdogs:
43 - aspeed,ext-push-pull: If aspeed,external-signal is present, set the pin's
44			 drive type to push-pull. The default is open-drain.
45 - aspeed,ext-active-high: If aspeed,external-signal is present and and the pin
46			   is configured as push-pull, then set the pulse
47			   polarity to active-high. The default is active-low.
48
49Example:
50
51	wdt1: watchdog@1e785000 {
52		compatible = "aspeed,ast2400-wdt";
53		reg = <0x1e785000 0x1c>;
54		aspeed,reset-type = "system";
55		aspeed,external-signal;
56	};
57