On 09/20/2012 07:16 AM, Thierry Reding wrote:
> In order to use a device as interrupt controller, it needs to be marked
> with the DT interrupt-controller property. This commit adds rudimentary
> documentation about the required standard properties and describes the
> most commonly used interrupt specifiers.
>
> Cc: Linus Walleij <linus.wall...@stericsson.com>
> Cc: Grant Likely <grant.lik...@secretlab.ca>
> Cc: Rob Herring <rob.herr...@calxeda.com>
> Cc: Stephen Warren <swar...@wwwdotorg.org>
> Cc: devicetree-disc...@lists.ozlabs.org
> Cc: linux-kernel@vger.kernel.org
> Signed-off-by: Thierry Reding <thierry.red...@avionic-design.de>
> ---
> Changes in v2:
> - update interrupt client description as per Stephen's suggestions
> - use an example for the two cell specifier where both the client and
> the parent use two cell specifiers, as suggested by Rob, to reduce
> the possibility for confusion
>
Applied.
Rob
> .../bindings/interrupt-controller/interrupts.txt | 95
> ++++++++++++++++++++++
> 1 file changed, 95 insertions(+)
> create mode 100644
> Documentation/devicetree/bindings/interrupt-controller/interrupts.txt
>
> diff --git
> a/Documentation/devicetree/bindings/interrupt-controller/interrupts.txt
> b/Documentation/devicetree/bindings/interrupt-controller/interrupts.txt
> new file mode 100644
> index 0000000..72a06c0
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/interrupt-controller/interrupts.txt
> @@ -0,0 +1,95 @@
> +Specifying interrupt information for devices
> +============================================
> +
> +1) Interrupt client nodes
> +-------------------------
> +
> +Nodes that describe devices which generate interrupts must contain an
> +"interrupts" property. This property must 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.
> +
> +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.
> +
> +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>;
> + };
> + };
>
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