0001 Specifying interrupt information for devices
0002 ============================================
0003
0004 1) Interrupt client nodes
0005 -------------------------
0006
0007 Nodes that describe devices which generate interrupts must contain an
0008 "interrupts" property, an "interrupts-extended" property, or both. If both are
0009 present, the latter should take precedence; the former may be provided simply
0010 for compatibility with software that does not recognize the latter. These
0011 properties contain a list of interrupt specifiers, one per output interrupt. The
0012 format of the interrupt specifier is determined by the interrupt controller to
0013 which the interrupts are routed; see section 2 below for details.
0014
0015 Example:
0016 interrupt-parent = <&intc1>;
0017 interrupts = <5 0>, <6 0>;
0018
0019 The "interrupt-parent" property is used to specify the controller to which
0020 interrupts are routed and contains a single phandle referring to the interrupt
0021 controller node. This property is inherited, so it may be specified in an
0022 interrupt client node or in any of its parent nodes. Interrupts listed in the
0023 "interrupts" property are always in reference to the node's interrupt parent.
0024
0025 The "interrupts-extended" property is a special form; useful when a node needs
0026 to reference multiple interrupt parents or a different interrupt parent than
0027 the inherited one. Each entry in this property contains both the parent phandle
0028 and the interrupt specifier.
0029
0030 Example:
0031 interrupts-extended = <&intc1 5 1>, <&intc2 1 0>;
0032
0033 2) Interrupt controller nodes
0034 -----------------------------
0035
0036 A device is marked as an interrupt controller with the "interrupt-controller"
0037 property. This is a empty, boolean property. An additional "#interrupt-cells"
0038 property defines the number of cells needed to specify a single interrupt.
0039
0040 It is the responsibility of the interrupt controller's binding to define the
0041 length and format of the interrupt specifier. The following two variants are
0042 commonly used:
0043
0044 a) one cell
0045 -----------
0046 The #interrupt-cells property is set to 1 and the single cell defines the
0047 index of the interrupt within the controller.
0048
0049 Example:
0050
0051 vic: intc@10140000 {
0052 compatible = "arm,versatile-vic";
0053 interrupt-controller;
0054 #interrupt-cells = <1>;
0055 reg = <0x10140000 0x1000>;
0056 };
0057
0058 sic: intc@10003000 {
0059 compatible = "arm,versatile-sic";
0060 interrupt-controller;
0061 #interrupt-cells = <1>;
0062 reg = <0x10003000 0x1000>;
0063 interrupt-parent = <&vic>;
0064 interrupts = <31>; /* Cascaded to vic */
0065 };
0066
0067 b) two cells
0068 ------------
0069 The #interrupt-cells property is set to 2 and the first cell defines the
0070 index of the interrupt within the controller, while the second cell is used
0071 to specify any of the following flags:
0072 - bits[3:0] trigger type and level flags
0073 1 = low-to-high edge triggered
0074 2 = high-to-low edge triggered
0075 4 = active high level-sensitive
0076 8 = active low level-sensitive
0077
0078 Example:
0079
0080 i2c@7000c000 {
0081 gpioext: gpio-adnp@41 {
0082 compatible = "ad,gpio-adnp";
0083 reg = <0x41>;
0084
0085 interrupt-parent = <&gpio>;
0086 interrupts = <160 1>;
0087
0088 gpio-controller;
0089 #gpio-cells = <1>;
0090
0091 interrupt-controller;
0092 #interrupt-cells = <2>;
0093
0094 nr-gpios = <64>;
0095 };
0096
0097 sx8634@2b {
0098 compatible = "smtc,sx8634";
0099 reg = <0x2b>;
0100
0101 interrupt-parent = <&gpioext>;
0102 interrupts = <3 0x8>;
0103
0104 #address-cells = <1>;
0105 #size-cells = <0>;
0106
0107 threshold = <0x40>;
0108 sensitivity = <7>;
0109 };
0110 };
0111
0112 3) Interrupt wakeup parent
0113 --------------------------
0114
0115 Some interrupt controllers in a SoC, are always powered on and have a select
0116 interrupts routed to them, so that they can wakeup the SoC from suspend. These
0117 interrupt controllers do not fall into the category of a parent interrupt
0118 controller and can be specified by the "wakeup-parent" property and contain a
0119 single phandle referring to the wakeup capable interrupt controller.
0120
0121 Example:
0122 wakeup-parent = <&pdc_intc>;
