1Specifying interrupt information for devices
2============================================
3
41) Interrupt client nodes
5-------------------------
6
7Nodes that describe devices which generate interrupts must contain an
8"interrupts" property, an "interrupts-extended" property, or both. If both are
9present, the latter should take precedence; the former may be provided simply
10for compatibility with software that does not recognize the latter. These
11properties contain a list of interrupt specifiers, one per output interrupt. The
12format of the interrupt specifier is determined by the interrupt controller to
13which the interrupts are routed; see section 2 below for details.
14
15  Example:
16	interrupt-parent = <&intc1>;
17	interrupts = <5 0>, <6 0>;
18
19The "interrupt-parent" property is used to specify the controller to which
20interrupts are routed and contains a single phandle referring to the interrupt
21controller node. This property is inherited, so it may be specified in an
22interrupt client node or in any of its parent nodes. Interrupts listed in the
23"interrupts" property are always in reference to the node's interrupt parent.
24
25The "interrupts-extended" property is a special form; useful when a node needs
26to reference multiple interrupt parents or a different interrupt parent than
27the inherited one. Each entry in this property contains both the parent phandle
28and the interrupt specifier.
29
30  Example:
31	interrupts-extended = <&intc1 5 1>, <&intc2 1 0>;
32
332) Interrupt controller nodes
34-----------------------------
35
36A device is marked as an interrupt controller with the "interrupt-controller"
37property. This is a empty, boolean property. An additional "#interrupt-cells"
38property defines the number of cells needed to specify a single interrupt.
39
40It is the responsibility of the interrupt controller's binding to define the
41length and format of the interrupt specifier. The following two variants are
42commonly used:
43
44  a) one cell
45  -----------
46  The #interrupt-cells property is set to 1 and the single cell defines the
47  index of the interrupt within the controller.
48
49  Example:
50
51	vic: intc@10140000 {
52		compatible = "arm,versatile-vic";
53		interrupt-controller;
54		#interrupt-cells = <1>;
55		reg = <0x10140000 0x1000>;
56	};
57
58	sic: intc@10003000 {
59		compatible = "arm,versatile-sic";
60		interrupt-controller;
61		#interrupt-cells = <1>;
62		reg = <0x10003000 0x1000>;
63		interrupt-parent = <&vic>;
64		interrupts = <31>; /* Cascaded to vic */
65	};
66
67  b) two cells
68  ------------
69  The #interrupt-cells property is set to 2 and the first cell defines the
70  index of the interrupt within the controller, while the second cell is used
71  to specify any of the following flags:
72    - bits[3:0] trigger type and level flags
73        1 = low-to-high edge triggered
74        2 = high-to-low edge triggered
75        4 = active high level-sensitive
76        8 = active low level-sensitive
77
78  Example:
79
80	i2c@7000c000 {
81		gpioext: gpio-adnp@41 {
82			compatible = "ad,gpio-adnp";
83			reg = <0x41>;
84
85			interrupt-parent = <&gpio>;
86			interrupts = <160 1>;
87
88			gpio-controller;
89			#gpio-cells = <1>;
90
91			interrupt-controller;
92			#interrupt-cells = <2>;
93
94			nr-gpios = <64>;
95		};
96
97		sx8634@2b {
98			compatible = "smtc,sx8634";
99			reg = <0x2b>;
100
101			interrupt-parent = <&gpioext>;
102			interrupts = <3 0x8>;
103
104			#address-cells = <1>;
105			#size-cells = <0>;
106
107			threshold = <0x40>;
108			sensitivity = <7>;
109		};
110	};
111