1* ARM Generic Interrupt Controller 2 3ARM SMP cores are often associated with a GIC, providing per processor 4interrupts (PPI), shared processor interrupts (SPI) and software 5generated interrupts (SGI). 6 7Primary GIC is attached directly to the CPU and typically has PPIs and SGIs. 8Secondary GICs are cascaded into the upward interrupt controller and do not 9have PPIs or SGIs. 10 11Main node required properties: 12 13- compatible : should be one of: 14 "arm,cortex-a15-gic" 15 "arm,cortex-a9-gic" 16 "arm,cortex-a7-gic" 17 "arm,arm11mp-gic" 18- interrupt-controller : Identifies the node as an interrupt controller 19- #interrupt-cells : Specifies the number of cells needed to encode an 20 interrupt source. The type shall be a <u32> and the value shall be 3. 21 22 The 1st cell is the interrupt type; 0 for SPI interrupts, 1 for PPI 23 interrupts. 24 25 The 2nd cell contains the interrupt number for the interrupt type. 26 SPI interrupts are in the range [0-987]. PPI interrupts are in the 27 range [0-15]. 28 29 The 3rd cell is the flags, encoded as follows: 30 bits[3:0] trigger type and level flags. 31 1 = low-to-high edge triggered 32 2 = high-to-low edge triggered 33 4 = active high level-sensitive 34 8 = active low level-sensitive 35 bits[15:8] PPI interrupt cpu mask. Each bit corresponds to each of 36 the 8 possible cpus attached to the GIC. A bit set to '1' indicated 37 the interrupt is wired to that CPU. Only valid for PPI interrupts. 38 39- reg : Specifies base physical address(s) and size of the GIC registers. The 40 first region is the GIC distributor register base and size. The 2nd region is 41 the GIC cpu interface register base and size. 42 43Optional 44- interrupts : Interrupt source of the parent interrupt controller on 45 secondary GICs, or VGIC maintenance interrupt on primary GIC (see 46 below). 47 48- cpu-offset : per-cpu offset within the distributor and cpu interface 49 regions, used when the GIC doesn't have banked registers. The offset is 50 cpu-offset * cpu-nr. 51 52Example: 53 54 intc: interrupt-controller@fff11000 { 55 compatible = "arm,cortex-a9-gic"; 56 #interrupt-cells = <3>; 57 #address-cells = <1>; 58 interrupt-controller; 59 reg = <0xfff11000 0x1000>, 60 <0xfff10100 0x100>; 61 }; 62 63 64* GIC virtualization extensions (VGIC) 65 66For ARM cores that support the virtualization extensions, additional 67properties must be described (they only exist if the GIC is the 68primary interrupt controller). 69 70Required properties: 71 72- reg : Additional regions specifying the base physical address and 73 size of the VGIC registers. The first additional region is the GIC 74 virtual interface control register base and size. The 2nd additional 75 region is the GIC virtual cpu interface register base and size. 76 77- interrupts : VGIC maintenance interrupt. 78 79Example: 80 81 interrupt-controller@2c001000 { 82 compatible = "arm,cortex-a15-gic"; 83 #interrupt-cells = <3>; 84 interrupt-controller; 85 reg = <0x2c001000 0x1000>, 86 <0x2c002000 0x1000>, 87 <0x2c004000 0x2000>, 88 <0x2c006000 0x2000>; 89 interrupts = <1 9 0xf04>; 90 }; 91