interrupts.txt

  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>;