irqchip: add DesignWare APB ICTL interrupt controller

This adds an irqchip driver and corresponding devicetree binding for the
secondary interrupt controllers based on Synopsys DesignWare IP dw_apb_ictl.

Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Jisheng Zhang <jszhang@marvell.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 32 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/interrupt-controller/snps,dw-apb-ictl.txt b/Documentation/devicetree/bindings/interrupt-controller/snps,dw-apb-ictl.txt
new file mode 100644
index 000000000000..492911744ca3
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+++ b/Documentation/devicetree/bindings/interrupt-controller/snps,dw-apb-ictl.txt
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+Synopsys DesignWare APB interrupt controller (dw_apb_ictl)
+
+Synopsys DesignWare provides interrupt controller IP for APB known as
+dw_apb_ictl. The IP is used as secondary interrupt controller in some SoCs with
+APB bus, e.g. Marvell Armada 1500.
+
+Required properties:
+- compatible: shall be "snps,dw-apb-ictl"
+- reg: physical base address of the controller and length of memory mapped
+  region starting with ENABLE_LOW register
+- interrupt-controller: identifies the node as an interrupt controller
+- #interrupt-cells: number of cells to encode an interrupt-specifier, shall be 1
+- interrupts: interrupt reference to primary interrupt controller
+- interrupt-parent: (optional) reference specific primary interrupt controller
+
+The interrupt sources map to the corresponding bits in the interrupt
+registers, i.e.
+- 0 maps to bit 0 of low interrupts,
+- 1 maps to bit 1 of low interrupts,
+- 32 maps to bit 0 of high interrupts,
+- 33 maps to bit 1 of high interrupts,
+- (optional) fast interrupts start at 64.
+
+Example:
+	aic: interrupt-controller@3000 {
+		compatible = "snps,dw-apb-ictl";
+		reg = <0x3000 0xc00>;
+		interrupt-controller;
+		#interrupt-cells = <1>;
+		interrupt-parent = <&gic>;
+		interrupts = <GIC_SPI 3 IRQ_TYPE_LEVEL_HIGH>;
+	};