diff options
Diffstat (limited to 'Documentation/devicetree/bindings/arm/arch_timer.txt')
-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 @@ | |||
1 | * ARM architected timer | 1 | * ARM architected timer |
2 | 2 | ||
3 | ARM cores may have a per-core architected timer, which provides per-cpu timers. | 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. | ||
4 | 6 | ||
5 | The timer is attached to a GIC to deliver its per-processor interrupts. | 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. | ||
6 | 10 | ||
7 | ** Timer node properties: | 11 | ** CP15 Timer node properties: |
8 | 12 | ||
9 | - compatible : Should at least contain one of | 13 | - compatible : Should at least contain one of |
10 | "arm,armv7-timer" | 14 | "arm,armv7-timer" |
@@ -26,3 +30,52 @@ Example: | |||
26 | <1 10 0xf08>; | 30 | <1 10 0xf08>; |
27 | clock-frequency = <100000000>; | 31 | clock-frequency = <100000000>; |
28 | }; | 32 | }; |
33 | |||
34 | ** Memory mapped timer node properties: | ||
35 | |||
36 | - compatible : Should at least contain "arm,armv7-timer-mem". | ||
37 | |||
38 | - clock-frequency : The frequency of the main counter, in Hz. Optional. | ||
39 | |||
40 | - reg : The control frame base address. | ||
41 | |||
42 | Note that #address-cells, #size-cells, and ranges shall be present to ensure | ||
43 | the CPU can address a frame's registers. | ||
44 | |||
45 | A timer node has up to 8 frame sub-nodes, each with the following properties: | ||
46 | |||
47 | - frame-number: 0 to 7. | ||
48 | |||
49 | - interrupts : Interrupt list for physical and virtual timers in that order. | ||
50 | The virtual timer interrupt is optional. | ||
51 | |||
52 | - reg : The first and second view base addresses in that order. The second view | ||
53 | base address is optional. | ||
54 | |||
55 | - status : "disabled" indicates the frame is not available for use. Optional. | ||
56 | |||
57 | Example: | ||
58 | |||
59 | timer@f0000000 { | ||
60 | compatible = "arm,armv7-timer-mem"; | ||
61 | #address-cells = <1>; | ||
62 | #size-cells = <1>; | ||
63 | ranges; | ||
64 | reg = <0xf0000000 0x1000>; | ||
65 | clock-frequency = <50000000>; | ||
66 | |||
67 | frame@f0001000 { | ||
68 | frame-number = <0> | ||
69 | interrupts = <0 13 0x8>, | ||
70 | <0 14 0x8>; | ||
71 | reg = <0xf0001000 0x1000>, | ||
72 | <0xf0002000 0x1000>; | ||
73 | }; | ||
74 | |||
75 | frame@f0003000 { | ||
76 | frame-number = <1> | ||
77 | interrupts = <0 15 0x8>; | ||
78 | reg = <0xf0003000 0x1000>; | ||
79 | status = "disabled"; | ||
80 | }; | ||
81 | }; | ||