arch_timer.txt 1.8 KB

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  1. * ARM architected timer
  2. ARM Cortex-A7 and Cortex-A15 have a per-core architected timer, which
  3. provides a per-cpu local timer.
  4. The timer is attached to a GIC to deliver its two per-processor
  5. interrupts (one for the secure mode, one for the non-secure mode).
  6. ** CP15 Timer node properties:
  7. - compatible : Should be "arm,armv7-timer"
  8. - interrupts : One or two interrupts for secure and non-secure mode
  9. - clock-frequency : The frequency of the main counter, in Hz. Optional.
  10. Example:
  11. timer {
  12. compatible = "arm,armv7-timer"";
  13. interrupts = <1 13 0xf08 1 14 0xf08>;
  14. clock-frequency = <100000000>;
  15. };
  16. ** Memory mapped timer node properties:
  17. - compatible : Should at least contain "arm,armv7-timer-mem".
  18. - clock-frequency : The frequency of the main counter, in Hz. Optional.
  19. - reg : The control frame base address.
  20. Note that #address-cells, #size-cells, and ranges shall be present to ensure
  21. the CPU can address the frame's registers.
  22. Each timer node has up to 8 frame sub-nodes with the following properties:
  23. - frame-number: 0 to 7.
  24. - interrupts : Interrupt list for physical and virtual timers in that order.
  25. The virtual timer interrupt is optional.
  26. - reg : The first and second view base addresses in that order. The second view
  27. base address is optional.
  28. - status : "disabled" indicates the frame is not available for use. Optional.
  29. Example:
  30. timer@f0000000 {
  31. compatible = "arm,armv7-timer-mem";
  32. #address-cells = <1>;
  33. #size-cells = <1>;
  34. ranges;
  35. reg = <0xf0000000 0x1000>;
  36. clock-frequency = <50000000>;
  37. frame0@f0001000 {
  38. frame-number = <0>
  39. interrupts = <0 13 0x8>,
  40. <0 14 0x8>;
  41. reg = <0xf0001000 0x1000>,
  42. <0xf0002000 0x1000>;
  43. };
  44. frame1@f0003000 {
  45. frame-number = <1>
  46. interrupts = <0 15 0x8>;
  47. reg = <0xf0003000 0x1000>;
  48. status = "disabled";
  49. };
  50. };