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 1123) Interrupt wakeup parent 113-------------------------- 114 115Some interrupt controllers in a SoC, are always powered on and have a select 116interrupts routed to them, so that they can wakeup the SoC from suspend. These 117interrupt controllers do not fall into the category of a parent interrupt 118controller and can be specified by the "wakeup-parent" property and contain a 119single phandle referring to the wakeup capable interrupt controller. 120 121 Example: 122 wakeup-parent = <&pdc_intc>; 123