xref: /freebsd/sys/contrib/device-tree/Bindings/interrupt-controller/mips-gic.txt (revision c66ec88fed842fbaad62c30d510644ceb7bd2d71)
1MIPS Global Interrupt Controller (GIC)
2
3The MIPS GIC routes external interrupts to individual VPEs and IRQ pins.
4It also supports local (per-processor) interrupts and software-generated
5interrupts which can be used as IPIs.  The GIC also includes a free-running
6global timer, per-CPU count/compare timers, and a watchdog.
7
8Required properties:
9- compatible : Should be "mti,gic".
10- interrupt-controller : Identifies the node as an interrupt controller
11- #interrupt-cells : Specifies the number of cells needed to encode an
12  interrupt specifier.  Should be 3.
13  - The first cell is the type of interrupt, local or shared.
14    See <include/dt-bindings/interrupt-controller/mips-gic.h>.
15  - The second cell is the GIC interrupt number.
16  - The third cell encodes the interrupt flags.
17    See <include/dt-bindings/interrupt-controller/irq.h> for a list of valid
18    flags.
19
20Optional properties:
21- reg : Base address and length of the GIC registers.  If not present,
22  the base address reported by the hardware GCR_GIC_BASE will be used.
23- mti,reserved-cpu-vectors : Specifies the list of CPU interrupt vectors
24  to which the GIC may not route interrupts.  Valid values are 2 - 7.
25  This property is ignored if the CPU is started in EIC mode.
26- mti,reserved-ipi-vectors : Specifies the range of GIC interrupts that are
27  reserved for IPIs.
28  It accepts 2 values, the 1st is the starting interrupt and the 2nd is the size
29  of the reserved range.
30  If not specified, the driver will allocate the last 2 * number of VPEs in the
31  system.
32
33Required properties for timer sub-node:
34- compatible : Should be "mti,gic-timer".
35- interrupts : Interrupt for the GIC local timer.
36
37Optional properties for timer sub-node:
38- clocks : GIC timer operating clock.
39- clock-frequency : Clock frequency at which the GIC timers operate.
40
41Note that one of clocks or clock-frequency must be specified.
42
43Example:
44
45	gic: interrupt-controller@1bdc0000 {
46		compatible = "mti,gic";
47		reg = <0x1bdc0000 0x20000>;
48
49		interrupt-controller;
50		#interrupt-cells = <3>;
51
52		mti,reserved-cpu-vectors = <7>;
53		mti,reserved-ipi-vectors = <40 8>;
54
55		timer {
56			compatible = "mti,gic-timer";
57			interrupts = <GIC_LOCAL 1 IRQ_TYPE_NONE>;
58			clock-frequency = <50000000>;
59		};
60	};
61
62	uart@18101400 {
63		...
64		interrupt-parent = <&gic>;
65		interrupts = <GIC_SHARED 24 IRQ_TYPE_LEVEL_HIGH>;
66		...
67	};
68