1 Specifying interrupt information for devices
2 ============================================
3
4 1) Interrupt client nodes
5 -------------------------
6
7 Nodes that describe devices which generate interrupts must contain an
8 "interrupts" property, an "interrupts-extended" property, or both. If both are
9 present, the latter should take precedence; the former may be provided simply
10 for compatibility with software that does not recognize the latter. These
11 properties contain a list of interrupt specifiers, one per output interrupt. The
12 format of the interrupt specifier is determined by the interrupt controller to
13 which the interrupts are routed; see section 2 below for details.
14
15 Example:
16 interrupt-parent = <&intc1>;
17 interrupts = <5 0>, <6 0>;
18
19 The "interrupt-parent" property is used to specify the controller to which
20 interrupts are routed and contains a single phandle referring to the interrupt
21 controller node. This property is inherited, so it may be specified in an
22 interrupt 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
25 The "interrupts-extended" property is a special form; useful when a node needs
26 to reference multiple interrupt parents or a different interrupt parent than
27 the inherited one. Each entry in this property contains both the parent phandle
28 and the interrupt specifier.
29
30 Example:
31 interrupts-extended = <&intc1 5 1>, <&intc2 1 0>;
32
33 2) Interrupt controller nodes
34 -----------------------------
35
36 A device is marked as an interrupt controller with the "interrupt-controller"
37 property. This is a empty, boolean property. An additional "#interrupt-cells"
38 property defines the number of cells needed to specify a single interrupt.
39
40 It is the responsibility of the interrupt controller's binding to define the
41 length and format of the interrupt specifier. The following two variants are
42 commonly 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
112 3) Interrupt wakeup parent
113 --------------------------
114
115 Some interrupt controllers in a SoC, are always powered on and have a select
116 interrupts routed to them, so that they can wakeup the SoC from suspend. These
117 interrupt controllers do not fall into the category of a parent interrupt
118 controller and can be specified by the "wakeup-parent" property and contain a
119 single phandle referring to the wakeup capable interrupt controller.
120
121 Example:
122 wakeup-parent = <&pdc_intc>;
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