atmel-wdt.txt 2.0 KB

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