diff options
Diffstat (limited to 'Documentation/devicetree/bindings/arm/gic.txt')
-rw-r--r-- | Documentation/devicetree/bindings/arm/gic.txt | 152 |
1 files changed, 152 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/arm/gic.txt b/Documentation/devicetree/bindings/arm/gic.txt new file mode 100644 index 000000000..2da059a47 --- /dev/null +++ b/Documentation/devicetree/bindings/arm/gic.txt @@ -0,0 +1,152 @@ +* ARM Generic Interrupt Controller + +ARM SMP cores are often associated with a GIC, providing per processor +interrupts (PPI), shared processor interrupts (SPI) and software +generated interrupts (SGI). + +Primary GIC is attached directly to the CPU and typically has PPIs and SGIs. +Secondary GICs are cascaded into the upward interrupt controller and do not +have PPIs or SGIs. + +Main node required properties: + +- compatible : should be one of: + "arm,gic-400" + "arm,cortex-a15-gic" + "arm,cortex-a9-gic" + "arm,cortex-a7-gic" + "arm,arm11mp-gic" + "brcm,brahma-b15-gic" + "arm,arm1176jzf-devchip-gic" + "qcom,msm-8660-qgic" + "qcom,msm-qgic2" +- interrupt-controller : Identifies the node as an interrupt controller +- #interrupt-cells : Specifies the number of cells needed to encode an + interrupt source. The type shall be a <u32> and the value shall be 3. + + The 1st cell is the interrupt type; 0 for SPI interrupts, 1 for PPI + interrupts. + + The 2nd cell contains the interrupt number for the interrupt type. + SPI interrupts are in the range [0-987]. PPI interrupts are in the + range [0-15]. + + The 3rd cell is the flags, encoded as follows: + bits[3:0] trigger type and level flags. + 1 = low-to-high edge triggered + 2 = high-to-low edge triggered (invalid for SPIs) + 4 = active high level-sensitive + 8 = active low level-sensitive (invalid for SPIs). + bits[15:8] PPI interrupt cpu mask. Each bit corresponds to each of + the 8 possible cpus attached to the GIC. A bit set to '1' indicated + the interrupt is wired to that CPU. Only valid for PPI interrupts. + Also note that the configurability of PPI interrupts is IMPLEMENTATION + DEFINED and as such not guaranteed to be present (most SoC available + in 2014 seem to ignore the setting of this flag and use the hardware + default value). + +- reg : Specifies base physical address(s) and size of the GIC registers. The + first region is the GIC distributor register base and size. The 2nd region is + the GIC cpu interface register base and size. + +Optional +- interrupts : Interrupt source of the parent interrupt controller on + secondary GICs, or VGIC maintenance interrupt on primary GIC (see + below). + +- cpu-offset : per-cpu offset within the distributor and cpu interface + regions, used when the GIC doesn't have banked registers. The offset is + cpu-offset * cpu-nr. + +Example: + + intc: interrupt-controller@fff11000 { + compatible = "arm,cortex-a9-gic"; + #interrupt-cells = <3>; + #address-cells = <1>; + interrupt-controller; + reg = <0xfff11000 0x1000>, + <0xfff10100 0x100>; + }; + + +* GIC virtualization extensions (VGIC) + +For ARM cores that support the virtualization extensions, additional +properties must be described (they only exist if the GIC is the +primary interrupt controller). + +Required properties: + +- reg : Additional regions specifying the base physical address and + size of the VGIC registers. The first additional region is the GIC + virtual interface control register base and size. The 2nd additional + region is the GIC virtual cpu interface register base and size. + +- interrupts : VGIC maintenance interrupt. + +Example: + + interrupt-controller@2c001000 { + compatible = "arm,cortex-a15-gic"; + #interrupt-cells = <3>; + interrupt-controller; + reg = <0x2c001000 0x1000>, + <0x2c002000 0x1000>, + <0x2c004000 0x2000>, + <0x2c006000 0x2000>; + interrupts = <1 9 0xf04>; + }; + + +* GICv2m extension for MSI/MSI-x support (Optional) + +Certain revisions of GIC-400 supports MSI/MSI-x via V2M register frame(s). +This is enabled by specifying v2m sub-node(s). + +Required properties: + +- compatible : The value here should contain "arm,gic-v2m-frame". + +- msi-controller : Identifies the node as an MSI controller. + +- reg : GICv2m MSI interface register base and size + +Optional properties: + +- arm,msi-base-spi : When the MSI_TYPER register contains an incorrect + value, this property should contain the SPI base of + the MSI frame, overriding the HW value. + +- arm,msi-num-spis : When the MSI_TYPER register contains an incorrect + value, this property should contain the number of + SPIs assigned to the frame, overriding the HW value. + +Example: + + interrupt-controller@e1101000 { + compatible = "arm,gic-400"; + #interrupt-cells = <3>; + #address-cells = <2>; + #size-cells = <2>; + interrupt-controller; + interrupts = <1 8 0xf04>; + ranges = <0 0 0 0xe1100000 0 0x100000>; + reg = <0x0 0xe1110000 0 0x01000>, + <0x0 0xe112f000 0 0x02000>, + <0x0 0xe1140000 0 0x10000>, + <0x0 0xe1160000 0 0x10000>; + v2m0: v2m@0x8000 { + compatible = "arm,gic-v2m-frame"; + msi-controller; + reg = <0x0 0x80000 0 0x1000>; + }; + + .... + + v2mN: v2m@0x9000 { + compatible = "arm,gic-v2m-frame"; + msi-controller; + reg = <0x0 0x90000 0 0x1000>; + }; + }; |