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authorThomas Abraham <thomas.abraham@linaro.org>2012-05-15 09:25:23 +0200
committerKukjin Kim <kgene.kim@samsung.com>2012-05-16 00:03:44 +0200
commite873a47c4ef3fbb2e439a6b674e73b0c40dd8248 (patch)
tree245b58e5d007f998ca6e9be39d25bec80818c12f /Documentation/devicetree
parentARM: EXYNOS: Add irq_domain support for interrupt combiner (diff)
downloadlinux-e873a47c4ef3fbb2e439a6b674e73b0c40dd8248.tar.xz
linux-e873a47c4ef3fbb2e439a6b674e73b0c40dd8248.zip
ARM: EXYNOS: Add device tree support for interrupt combiner
Add device tree based instantiation of the interrupt combiner controller. Signed-off-by: Thomas Abraham <thomas.abraham@linaro.org> Acked-by: Rob Herring <rob.herring@calxeda.com> Acked-by: Grant Likely <grant.likely@secretlab.ca> Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
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+* Samsung Exynos Interrupt Combiner Controller
+
+Samsung's Exynos4 architecture includes a interrupt combiner controller which
+can combine interrupt sources as a group and provide a single interrupt request
+for the group. The interrupt request from each group are connected to a parent
+interrupt controller, such as GIC in case of Exynos4210.
+
+The interrupt combiner controller consists of multiple combiners. Upto eight
+interrupt sources can be connected to a combiner. The combiner outputs one
+combined interrupt for its eight interrupt sources. The combined interrupt
+is usually connected to a parent interrupt controller.
+
+A single node in the device tree is used to describe the interrupt combiner
+controller module (which includes multiple combiners). A combiner in the
+interrupt controller module shares config/control registers with other
+combiners. For example, a 32-bit interrupt enable/disable config register
+can accommodate upto 4 interrupt combiners (with each combiner supporting
+upto 8 interrupt sources).
+
+Required properties:
+- compatible: should be "samsung,exynos4210-combiner".
+- interrupt-controller: Identifies the node as an interrupt controller.
+- #interrupt-cells: should be <2>. The meaning of the cells are
+ * First Cell: Combiner Group Number.
+ * Second Cell: Interrupt number within the group.
+- reg: Base address and size of interrupt combiner registers.
+- interrupts: The list of interrupts generated by the combiners which are then
+ connected to a parent interrupt controller. The format of the interrupt
+ specifier depends in the interrupt parent controller.
+
+Optional properties:
+- samsung,combiner-nr: The number of interrupt combiners supported. If this
+ property is not specified, the default number of combiners is assumed
+ to be 16.
+- interrupt-parent: pHandle of the parent interrupt controller, if not
+ inherited from the parent node.
+
+
+Example:
+
+ The following is a an example from the Exynos4210 SoC dtsi file.
+
+ combiner:interrupt-controller@10440000 {
+ compatible = "samsung,exynos4210-combiner";
+ interrupt-controller;
+ #interrupt-cells = <2>;
+ reg = <0x10440000 0x1000>;
+ interrupts = <0 0 0>, <0 1 0>, <0 2 0>, <0 3 0>,
+ <0 4 0>, <0 5 0>, <0 6 0>, <0 7 0>,
+ <0 8 0>, <0 9 0>, <0 10 0>, <0 11 0>,
+ <0 12 0>, <0 13 0>, <0 14 0>, <0 15 0>;
+ };