atmel-wdt.txt (2011B)
1* Atmel Watchdog Timers 2 3** at91sam9-wdt 4 5Required properties: 6- compatible: must be "atmel,at91sam9260-wdt". 7- reg: physical base address of the controller and length of memory mapped 8 region. 9- clocks: phandle to input clock. 10 11Optional properties: 12- timeout-sec: contains the watchdog timeout in seconds. 13- interrupts : Should contain WDT interrupt. 14- atmel,max-heartbeat-sec : Should contain the maximum heartbeat value in 15 seconds. This value should be less or equal to 16. It is used to 16 compute the WDV field. 17- atmel,min-heartbeat-sec : Should contain the minimum heartbeat value in 18 seconds. This value must be smaller than the max-heartbeat-sec value. 19 It is used to compute the WDD field. 20- atmel,watchdog-type : Should be "hardware" or "software". Hardware watchdog 21 use the at91 watchdog reset. Software watchdog use the watchdog 22 interrupt to trigger a software reset. 23- atmel,reset-type : Should be "proc" or "all". 24 "all" : assert peripherals and processor reset signals 25 "proc" : assert the processor reset signal 26 This is valid only when using "hardware" watchdog. 27- atmel,disable : Should be present if you want to disable the watchdog. 28- atmel,idle-halt : Should be present if you want to stop the watchdog when 29 entering idle state. 30 CAUTION: This property should be used with care, it actually makes the 31 watchdog not counting when the CPU is in idle state, therefore the 32 watchdog reset time depends on mean CPU usage and will not reset at all 33 if the CPU stop working while it is in idle state, which is probably 34 not what you want. 35- atmel,dbg-halt : Should be present if you want to stop the watchdog when 36 entering debug state. 37 38Example: 39 watchdog@fffffd40 { 40 compatible = "atmel,at91sam9260-wdt"; 41 reg = <0xfffffd40 0x10>; 42 interrupts = <1 IRQ_TYPE_LEVEL_HIGH 7>; 43 clocks = <&clk32k>; 44 timeout-sec = <15>; 45 atmel,watchdog-type = "hardware"; 46 atmel,reset-type = "all"; 47 atmel,dbg-halt; 48 atmel,idle-halt; 49 atmel,max-heartbeat-sec = <16>; 50 atmel,min-heartbeat-sec = <0>; 51 };