1Specifying interrupt information for devices
2============================================
3
41) Interrupt client nodes
5-------------------------
6
7Nodes that describe devices which generate interrupts must contain an either an
8"interrupts" property or an "interrupts-extended" property. These properties
9contain a list of interrupt specifiers, one per output interrupt. The format of
10the interrupt specifier is determined by the interrupt controller to which the
11interrupts are routed; see section 2 below for details.
12
13  Example:
14	interrupt-parent = <&intc1>;
15	interrupts = <5 0>, <6 0>;
16
17The "interrupt-parent" property is used to specify the controller to which
18interrupts are routed and contains a single phandle referring to the interrupt
19controller node. This property is inherited, so it may be specified in an
20interrupt client node or in any of its parent nodes. Interrupts listed in the
21"interrupts" property are always in reference to the node's interrupt parent.
22
23The "interrupts-extended" property is a special form for use when a node needs
24to reference multiple interrupt parents. Each entry in this property contains
25both the parent phandle and the interrupt specifier. "interrupts-extended"
26should only be used when a device has multiple interrupt parents.
27
28  Example:
29	interrupts-extended = <&intc1 5 1>, <&intc2 1 0>;
30
31A device node may contain either "interrupts" or "interrupts-extended", but not
32both. If both properties are present, then the operating system should log an
33error and use only the data in "interrupts".
34
352) Interrupt controller nodes
36-----------------------------
37
38A device is marked as an interrupt controller with the "interrupt-controller"
39property. This is a empty, boolean property. An additional "#interrupt-cells"
40property defines the number of cells needed to specify a single interrupt.
41
42It is the responsibility of the interrupt controller's binding to define the
43length and format of the interrupt specifier. The following two variants are
44commonly used:
45
46  a) one cell
47  -----------
48  The #interrupt-cells property is set to 1 and the single cell defines the
49  index of the interrupt within the controller.
50
51  Example:
52
53	vic: intc@10140000 {
54		compatible = "arm,versatile-vic";
55		interrupt-controller;
56		#interrupt-cells = <1>;
57		reg = <0x10140000 0x1000>;
58	};
59
60	sic: intc@10003000 {
61		compatible = "arm,versatile-sic";
62		interrupt-controller;
63		#interrupt-cells = <1>;
64		reg = <0x10003000 0x1000>;
65		interrupt-parent = <&vic>;
66		interrupts = <31>; /* Cascaded to vic */
67	};
68
69  b) two cells
70  ------------
71  The #interrupt-cells property is set to 2 and the first cell defines the
72  index of the interrupt within the controller, while the second cell is used
73  to specify any of the following flags:
74    - bits[3:0] trigger type and level flags
75        1 = low-to-high edge triggered
76        2 = high-to-low edge triggered
77        4 = active high level-sensitive
78        8 = active low level-sensitive
79
80  Example:
81
82	i2c@7000c000 {
83		gpioext: gpio-adnp@41 {
84			compatible = "ad,gpio-adnp";
85			reg = <0x41>;
86
87			interrupt-parent = <&gpio>;
88			interrupts = <160 1>;
89
90			gpio-controller;
91			#gpio-cells = <1>;
92
93			interrupt-controller;
94			#interrupt-cells = <2>;
95
96			nr-gpios = <64>;
97		};
98
99		sx8634@2b {
100			compatible = "smtc,sx8634";
101			reg = <0x2b>;
102
103			interrupt-parent = <&gpioext>;
104			interrupts = <3 0x8>;
105
106			#address-cells = <1>;
107			#size-cells = <0>;
108
109			threshold = <0x40>;
110			sensitivity = <7>;
111		};
112	};
113