- Atmel Watchdog Timers
** at91sam9-wdt
Required properties:
- compatible: must be “atmel,at91sam9260-wdt”.
- reg: physical base address of the controller and length of memory mapped
region. - clocks: phandle to input clock.
Optional properties:
- timeout-sec: contains the watchdog timeout in seconds.
- interrupts : Should contain WDT interrupt.
- atmel,max-heartbeat-sec : Should contain the maximum heartbeat value in
seconds. This value should be less or equal to 16. It is used to
compute the WDV field. - atmel,min-heartbeat-sec : Should contain the minimum heartbeat value in
seconds. This value must be smaller than the max-heartbeat-sec value.
It is used to compute the WDD field. - atmel,watchdog-type : Should be “hardware” or “software”. Hardware watchdog
use the at91 watchdog reset. Software watchdog use the watchdog
interrupt to trigger a software reset. - atmel,reset-type : Should be “proc” or “all”.
“all” : assert peripherals and processor reset signals
“proc” : assert the processor reset signal
This is valid only when using “hardware” watchdog. - atmel,disable : Should be present if you want to disable the watchdog.
- atmel,idle-halt : Should be present if you want to stop the watchdog when
entering idle state.
CAUTION: This property should be used with care, it actually makes the
watchdog not counting when the CPU is in idle state, therefore the
watchdog reset time depends on mean CPU usage and will not reset at all
if the CPU stop working while it is in idle state, which is probably
not what you want. - atmel,dbg-halt : Should be present if you want to stop the watchdog when
entering debug state.
Example:
watchdog@fffffd40 {
compatible = “atmel,at91sam9260-wdt”;
reg = <0xfffffd40 0x10>;
interrupts = <1 IRQ_TYPE_LEVEL_HIGH 7>;
clocks = <&clk32k>;
timeout-sec = <15>;
atmel,watchdog-type = “hardware”;
atmel,reset-type = “all”;
atmel,dbg-halt;
atmel,idle-halt;
atmel,max-heartbeat-sec = <16>;
atmel,min-heartbeat-sec = <0>;
};
