mirror of https://gitee.com/openkylin/linux.git
58 lines
1.8 KiB
Plaintext
58 lines
1.8 KiB
Plaintext
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 specfied 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;
|
|
};
|