From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Wed, 5 Aug 2015 17:04:01 -0300 Subject: Initial import --- .../devicetree/bindings/arm/spear/shirq.txt | 48 ++++++++++++++++++++++ 1 file changed, 48 insertions(+) create mode 100644 Documentation/devicetree/bindings/arm/spear/shirq.txt (limited to 'Documentation/devicetree/bindings/arm/spear') diff --git a/Documentation/devicetree/bindings/arm/spear/shirq.txt b/Documentation/devicetree/bindings/arm/spear/shirq.txt new file mode 100644 index 000000000..715a013ed --- /dev/null +++ b/Documentation/devicetree/bindings/arm/spear/shirq.txt @@ -0,0 +1,48 @@ +* SPEAr Shared IRQ layer (shirq) + +SPEAr3xx architecture includes shared/multiplexed irqs for certain set +of devices. The multiplexor provides a single interrupt to parent +interrupt controller (VIC) on behalf of a group of devices. + +There can be multiple groups available on SPEAr3xx variants but not +exceeding 4. The number of devices in a group can differ, further they +may share same set of status/mask registers spanning across different +bit masks. Also in some cases the group may not have enable or other +registers. This makes software little complex. + +A single node in the device tree is used to describe the shared +interrupt multiplexor (one node for all groups). A group in the +interrupt controller shares config/control registers with other groups. +For example, a 32-bit interrupt enable/disable config register can +accommodate up to 4 interrupt groups. + +Required properties: + - compatible: should be, either of + - "st,spear300-shirq" + - "st,spear310-shirq" + - "st,spear320-shirq" + - interrupt-controller: Identifies the node as an interrupt controller. + - #interrupt-cells: should be <1> which basically contains the offset + (starting from 0) of interrupts for all the groups. + - reg: Base address and size of shirq registers. + - interrupts: The list of interrupts generated by the groups which are + then connected to a parent interrupt controller. Each group is + associated with one of the interrupts, hence number of interrupts (to + parent) is equal to number of groups. The format of the interrupt + specifier depends in the interrupt parent controller. + + Optional properties: + - interrupt-parent: pHandle of the parent interrupt controller, if not + inherited from the parent node. + +Example: + +The following is an example from the SPEAr320 SoC dtsi file. + +shirq: interrupt-controller@0xb3000000 { + compatible = "st,spear320-shirq"; + reg = <0xb3000000 0x1000>; + interrupts = <28 29 30 1>; + #interrupt-cells = <1>; + interrupt-controller; +}; -- cgit v1.2.3-54-g00ecf