1 * ARM architected timer
3 ARM cores may have a per-core architected timer, which provides per-cpu timers,
4 or a memory mapped architected timer, which provides up to 8 frames with a
5 physical and optional virtual timer per frame.
7 The per-core architected timer is attached to a GIC to deliver its
8 per-processor interrupts via PPIs. The memory mapped timer is attached to a GIC
9 to deliver its interrupts via SPIs.
11 ** CP15 Timer node properties:
13 - compatible : Should at least contain one of
17 - interrupts : Interrupt list for secure, non-secure, virtual and
18 hypervisor timers, in that order.
20 - clock-frequency : The frequency of the main counter, in Hz. Optional.
22 - always-on : a boolean property. If present, the timer is powered through an
23 always-on power domain, therefore it never loses context.
25 ** Optional properties:
27 - arm,cpu-registers-not-fw-configured : Firmware does not initialize
28 any of the generic timer CPU registers, which contain their
29 architecturally-defined reset values. Only supported for 32-bit
30 systems which follow the ARMv7 architected reset values.
36 compatible = "arm,cortex-a15-timer",
38 interrupts = <1 13 0xf08>,
42 clock-frequency = <100000000>;
45 ** Memory mapped timer node properties:
47 - compatible : Should at least contain "arm,armv7-timer-mem".
49 - clock-frequency : The frequency of the main counter, in Hz. Optional.
51 - reg : The control frame base address.
53 Note that #address-cells, #size-cells, and ranges shall be present to ensure
54 the CPU can address a frame's registers.
56 A timer node has up to 8 frame sub-nodes, each with the following properties:
58 - frame-number: 0 to 7.
60 - interrupts : Interrupt list for physical and virtual timers in that order.
61 The virtual timer interrupt is optional.
63 - reg : The first and second view base addresses in that order. The second view
64 base address is optional.
66 - status : "disabled" indicates the frame is not available for use. Optional.
71 compatible = "arm,armv7-timer-mem";
75 reg = <0xf0000000 0x1000>;
76 clock-frequency = <50000000>;
80 interrupts = <0 13 0x8>,
82 reg = <0xf0001000 0x1000>,
88 interrupts = <0 15 0x8>;
89 reg = <0xf0003000 0x1000>;