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Diffstat (limited to 'Documentation/devicetree/bindings/interrupt-controller/brcm,bcm7120-l2-intc.txt')
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diff --git a/Documentation/devicetree/bindings/interrupt-controller/brcm,bcm7120-l2-intc.txt b/Documentation/devicetree/bindings/interrupt-controller/brcm,bcm7120-l2-intc.txt new file mode 100644 index 000000000000..bae1f2187226 --- /dev/null +++ b/Documentation/devicetree/bindings/interrupt-controller/brcm,bcm7120-l2-intc.txt @@ -0,0 +1,96 @@ +Broadcom BCM7120-style Level 2 interrupt controller + +This interrupt controller hardware is a second level interrupt controller that +is hooked to a parent interrupt controller: e.g: ARM GIC for ARM-based +platforms. It can be found on BCM7xxx products starting with BCM7120. + +Such an interrupt controller has the following hardware design: + +- outputs multiple interrupts signals towards its interrupt controller parent + +- controls how some of the interrupts will be flowing, whether they will + directly output an interrupt signal towards the interrupt controller parent, + or if they will output an interrupt signal at this 2nd level interrupt + controller, in particular for UARTs + +- typically has one 32-bit enable word and one 32-bit status word, but on + some hardware may have more than one enable/status pair + +- no atomic set/clear operations + +- not all bits within the interrupt controller actually map to an interrupt + +The typical hardware layout for this controller is represented below: + +2nd level interrupt line Outputs for the parent controller (e.g: ARM GIC) + +0 -----[ MUX ] ------------|==========> GIC interrupt 75 + \-----------\ + | +1 -----[ MUX ] --------)---|==========> GIC interrupt 76 + \------------| + | +2 -----[ MUX ] --------)---|==========> GIC interrupt 77 + \------------| + | +3 ---------------------| +4 ---------------------| +5 ---------------------| +7 ---------------------|---|===========> GIC interrupt 66 +9 ---------------------| +10 --------------------| +11 --------------------/ + +6 ------------------------\ + |===========> GIC interrupt 64 +8 ------------------------/ + +12 ........................ X +13 ........................ X (not connected) +.. +31 ........................ X + +Required properties: + +- compatible: should be "brcm,bcm7120-l2-intc" +- reg: specifies the base physical address and size of the registers; + multiple pairs may be specified, with the first pair handling IRQ offsets + 0..31 and the second pair handling 32..63 +- interrupt-controller: identifies the node as an interrupt controller +- #interrupt-cells: specifies the number of cells needed to encode an interrupt + source, should be 1. +- interrupt-parent: specifies the phandle to the parent interrupt controller + this one is cascaded from +- interrupts: specifies the interrupt line(s) in the interrupt-parent controller + node, valid values depend on the type of parent interrupt controller +- brcm,int-map-mask: 32-bits bit mask describing how many and which interrupts + are wired to this 2nd level interrupt controller, and how they match their + respective interrupt parents. Should match exactly the number of interrupts + specified in the 'interrupts' property, multiplied by the number of + enable/status register pairs implemented by this controller. For + multiple parent IRQs with multiple enable/status words, this looks like: + <irq0_w0 irq0_w1 irq1_w0 irq1_w1 ...> + +Optional properties: + +- brcm,irq-can-wake: if present, this means the L2 controller can be used as a + wakeup source for system suspend/resume. + +- brcm,int-fwd-mask: if present, a bit mask to configure the interrupts which + have a mux gate, typically UARTs. Setting these bits will make their + respective interrupt outputs bypass this 2nd level interrupt controller + completely; it is completely transparent for the interrupt controller + parent. This should have one 32-bit word per enable/status pair. + +Example: + +irq0_intc: interrupt-controller@f0406800 { + compatible = "brcm,bcm7120-l2-intc"; + interrupt-parent = <&intc>; + #interrupt-cells = <1>; + reg = <0xf0406800 0x8>; + interrupt-controller; + interrupts = <0x0 0x42 0x0>, <0x0 0x40 0x0>; + brcm,int-map-mask = <0xeb8>, <0x140>; + brcm,int-fwd-mask = <0x7>; +}; |