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diff --git a/Documentation/devicetree/bindings/interrupt-controller/interrupts.txt b/Documentation/devicetree/bindings/interrupt-controller/interrupts.txt new file mode 100644 index 0000000000..4ebfa00087 --- /dev/null +++ b/Documentation/devicetree/bindings/interrupt-controller/interrupts.txt @@ -0,0 +1,122 @@ +Specifying interrupt information for devices +============================================ + +1) Interrupt client nodes +------------------------- + +Nodes that describe devices which generate interrupts must contain an +"interrupts" property, an "interrupts-extended" property, or both. If both are +present, the latter should take precedence; the former may be provided simply +for compatibility with software that does not recognize the latter. These +properties contain a list of interrupt specifiers, one per output interrupt. The +format of the interrupt specifier is determined by the interrupt controller to +which the interrupts are routed; see section 2 below for details. + + Example: + interrupt-parent = <&intc1>; + interrupts = <5 0>, <6 0>; + +The "interrupt-parent" property is used to specify the controller to which +interrupts are routed and contains a single phandle referring to the interrupt +controller node. This property is inherited, so it may be specified in an +interrupt client node or in any of its parent nodes. Interrupts listed in the +"interrupts" property are always in reference to the node's interrupt parent. + +The "interrupts-extended" property is a special form; useful when a node needs +to reference multiple interrupt parents or a different interrupt parent than +the inherited one. Each entry in this property contains both the parent phandle +and the interrupt specifier. + + Example: + interrupts-extended = <&intc1 5 1>, <&intc2 1 0>; + +2) Interrupt controller nodes +----------------------------- + +A device is marked as an interrupt controller with the "interrupt-controller" +property. This is a empty, boolean property. An additional "#interrupt-cells" +property defines the number of cells needed to specify a single interrupt. + +It is the responsibility of the interrupt controller's binding to define the +length and format of the interrupt specifier. The following two variants are +commonly used: + + a) one cell + ----------- + The #interrupt-cells property is set to 1 and the single cell defines the + index of the interrupt within the controller. + + Example: + + vic: intc@10140000 { + compatible = "arm,versatile-vic"; + interrupt-controller; + #interrupt-cells = <1>; + reg = <0x10140000 0x1000>; + }; + + sic: intc@10003000 { + compatible = "arm,versatile-sic"; + interrupt-controller; + #interrupt-cells = <1>; + reg = <0x10003000 0x1000>; + interrupt-parent = <&vic>; + interrupts = <31>; /* Cascaded to vic */ + }; + + b) two cells + ------------ + The #interrupt-cells property is set to 2 and the first cell defines the + index of the interrupt within the controller, while the second cell is used + to specify any of the following flags: + - bits[3:0] trigger type and level flags + 1 = low-to-high edge triggered + 2 = high-to-low edge triggered + 4 = active high level-sensitive + 8 = active low level-sensitive + + Example: + + i2c@7000c000 { + gpioext: gpio-adnp@41 { + compatible = "ad,gpio-adnp"; + reg = <0x41>; + + interrupt-parent = <&gpio>; + interrupts = <160 1>; + + gpio-controller; + #gpio-cells = <1>; + + interrupt-controller; + #interrupt-cells = <2>; + + nr-gpios = <64>; + }; + + sx8634@2b { + compatible = "smtc,sx8634"; + reg = <0x2b>; + + interrupt-parent = <&gpioext>; + interrupts = <3 0x8>; + + #address-cells = <1>; + #size-cells = <0>; + + threshold = <0x40>; + sensitivity = <7>; + }; + }; + +3) Interrupt wakeup parent +-------------------------- + +Some interrupt controllers in a SoC, are always powered on and have a select +interrupts routed to them, so that they can wakeup the SoC from suspend. These +interrupt controllers do not fall into the category of a parent interrupt +controller and can be specified by the "wakeup-parent" property and contain a +single phandle referring to the wakeup capable interrupt controller. + + Example: + wakeup-parent = <&pdc_intc>; |