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Diffstat (limited to 'Documentation/devicetree/bindings/timer/renesas,cmt.txt')
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diff --git a/Documentation/devicetree/bindings/timer/renesas,cmt.txt b/Documentation/devicetree/bindings/timer/renesas,cmt.txt new file mode 100644 index 0000000..a17418b --- /dev/null +++ b/Documentation/devicetree/bindings/timer/renesas,cmt.txt @@ -0,0 +1,47 @@ +* Renesas R-Car Compare Match Timer (CMT) + +The CMT is a multi-channel 16/32/48-bit timer/counter with configurable clock +inputs and programmable compare match. + +Channels share hardware resources but their counter and compare match value +are independent. A particular CMT instance can implement only a subset of the +channels supported by the CMT model. Channel indices represent the hardware +position of the channel in the CMT and don't match the channel numbers in the +datasheets. + +Required Properties: + + - compatible: must contain one of the following. + - "renesas,cmt-32" for the 32-bit CMT + (CMT0 on sh7372, sh73a0 and r8a7740) + - "renesas,cmt-32-fast" for the 32-bit CMT with fast clock support + (CMT[234] on sh7372, sh73a0 and r8a7740) + - "renesas,cmt-48" for the 48-bit CMT + (CMT1 on sh7372, sh73a0 and r8a7740) + - "renesas,cmt-48-gen2" for the second generation 48-bit CMT + (CMT[01] on r8a73a4, r8a7790 and r8a7791) + + - reg: base address and length of the registers block for the timer module. + - interrupts: interrupt-specifier for the timer, one per channel. + - clocks: a list of phandle + clock-specifier pairs, one for each entry + in clock-names. + - clock-names: must contain "fck" for the functional clock. + + - renesas,channels-mask: bitmask of the available channels. + + +Example: R8A7790 (R-Car H2) CMT0 node + + CMT0 on R8A7790 implements hardware channels 5 and 6 only and names + them channels 0 and 1 in the documentation. + + cmt0: timer@ffca0000 { + compatible = "renesas,cmt-48-gen2"; + reg = <0 0xffca0000 0 0x1004>; + interrupts = <0 142 IRQ_TYPE_LEVEL_HIGH>, + <0 142 IRQ_TYPE_LEVEL_HIGH>; + clocks = <&mstp1_clks R8A7790_CLK_CMT0>; + clock-names = "fck"; + + renesas,channels-mask = <0x60>; + }; |