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| -rw-r--r-- | Documentation/devicetree/bindings/arm/arch_timer.txt | 59 |
1 files changed, 56 insertions, 3 deletions
diff --git a/Documentation/devicetree/bindings/arm/arch_timer.txt b/Documentation/devicetree/bindings/arm/arch_timer.txt index 20746e5abe6f..06fc7602593a 100644 --- a/Documentation/devicetree/bindings/arm/arch_timer.txt +++ b/Documentation/devicetree/bindings/arm/arch_timer.txt @@ -1,10 +1,14 @@ * ARM architected timer -ARM cores may have a per-core architected timer, which provides per-cpu timers. +ARM cores may have a per-core architected timer, which provides per-cpu timers, +or a memory mapped architected timer, which provides up to 8 frames with a +physical and optional virtual timer per frame. -The timer is attached to a GIC to deliver its per-processor interrupts. +The per-core architected timer is attached to a GIC to deliver its +per-processor interrupts via PPIs. The memory mapped timer is attached to a GIC +to deliver its interrupts via SPIs. -** Timer node properties: +** CP15 Timer node properties: - compatible : Should at least contain one of "arm,armv7-timer" @@ -26,3 +30,52 @@ Example: <1 10 0xf08>; clock-frequency = <100000000>; }; + +** Memory mapped timer node properties: + +- compatible : Should at least contain "arm,armv7-timer-mem". + +- clock-frequency : The frequency of the main counter, in Hz. Optional. + +- reg : The control frame base address. + +Note that #address-cells, #size-cells, and ranges shall be present to ensure +the CPU can address a frame's registers. + +A timer node has up to 8 frame sub-nodes, each with the following properties: + +- frame-number: 0 to 7. + +- interrupts : Interrupt list for physical and virtual timers in that order. + The virtual timer interrupt is optional. + +- reg : The first and second view base addresses in that order. The second view + base address is optional. + +- status : "disabled" indicates the frame is not available for use. Optional. + +Example: + + timer@f0000000 { + compatible = "arm,armv7-timer-mem"; + #address-cells = <1>; + #size-cells = <1>; + ranges; + reg = <0xf0000000 0x1000>; + clock-frequency = <50000000>; + + frame@f0001000 { + frame-number = <0> + interrupts = <0 13 0x8>, + <0 14 0x8>; + reg = <0xf0001000 0x1000>, + <0xf0002000 0x1000>; + }; + + frame@f0003000 { + frame-number = <1> + interrupts = <0 15 0x8>; + reg = <0xf0003000 0x1000>; + status = "disabled"; + }; + }; |