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| -rw-r--r-- | Documentation/devicetree/bindings/timer/samsung,exynos4210-mct.txt | 88 |
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diff --git a/Documentation/devicetree/bindings/timer/samsung,exynos4210-mct.txt b/Documentation/devicetree/bindings/timer/samsung,exynos4210-mct.txt new file mode 100644 index 000000000..8f78640ad --- /dev/null +++ b/Documentation/devicetree/bindings/timer/samsung,exynos4210-mct.txt @@ -0,0 +1,88 @@ +Samsung's Multi Core Timer (MCT) + +The Samsung's Multi Core Timer (MCT) module includes two main blocks, the +global timer and CPU local timers. The global timer is a 64-bit free running +up-counter and can generate 4 interrupts when the counter reaches one of the +four preset counter values. The CPU local timers are 32-bit free running +down-counters and generate an interrupt when the counter expires. There is +one CPU local timer instantiated in MCT for every CPU in the system. + +Required properties: + +- compatible: should be "samsung,exynos4210-mct". + (a) "samsung,exynos4210-mct", for mct compatible with Exynos4210 mct. + (b) "samsung,exynos4412-mct", for mct compatible with Exynos4412 mct. + +- reg: base address of the mct controller and length of the address space + it occupies. + +- interrupts: the list of interrupts generated by the controller. The following + should be the order of the interrupts specified. The local timer interrupts + should be specified after the four global timer interrupts have been + specified. + + 0: Global Timer Interrupt 0 + 1: Global Timer Interrupt 1 + 2: Global Timer Interrupt 2 + 3: Global Timer Interrupt 3 + 4: Local Timer Interrupt 0 + 5: Local Timer Interrupt 1 + 6: .. + 7: .. + i: Local Timer Interrupt n + + For MCT block that uses a per-processor interrupt for local timers, such + as ones compatible with "samsung,exynos4412-mct", only one local timer + interrupt might be specified, meaning that all local timers use the same + per processor interrupt. + +Example 1: In this example, the IP contains two local timers, using separate + interrupts, so two local timer interrupts have been specified, + in addition to four global timer interrupts. + + mct@10050000 { + compatible = "samsung,exynos4210-mct"; + reg = <0x10050000 0x800>; + interrupts = <0 57 0>, <0 69 0>, <0 70 0>, <0 71 0>, + <0 42 0>, <0 48 0>; + }; + +Example 2: In this example, the timer interrupts are connected to two separate + interrupt controllers. Hence, an interrupt-map is created to map + the interrupts to the respective interrupt controllers. + + mct@101c0000 { + compatible = "samsung,exynos4210-mct"; + reg = <0x101C0000 0x800>; + interrupt-parent = <&mct_map>; + interrupts = <0>, <1>, <2>, <3>, <4>, <5>; + + mct_map: mct-map { + #interrupt-cells = <1>; + #address-cells = <0>; + #size-cells = <0>; + interrupt-map = <0 &gic 0 57 0>, + <1 &gic 0 69 0>, + <2 &combiner 12 6>, + <3 &combiner 12 7>, + <4 &gic 0 42 0>, + <5 &gic 0 48 0>; + }; + }; + +Example 3: In this example, the IP contains four local timers, but using + a per-processor interrupt to handle them. Either all the local + timer interrupts can be specified, with the same interrupt specifier + value or just the first one. + + mct@10050000 { + compatible = "samsung,exynos4412-mct"; + reg = <0x10050000 0x800>; + + /* Both ways are possible in this case. Either: */ + interrupts = <0 57 0>, <0 69 0>, <0 70 0>, <0 71 0>, + <0 42 0>; + /* or: */ + interrupts = <0 57 0>, <0 69 0>, <0 70 0>, <0 71 0>, + <0 42 0>, <0 42 0>, <0 42 0>, <0 42 0>; + }; |