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>

1 files changed, 52 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/arm/samsung/interrupt-combiner.txt b/Documentation/devicetree/bindings/arm/samsung/interrupt-combiner.txt
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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>;
+	};