Add documentation for the virtual irq demuxer.
Signed-off-by: Boris Brezillon <boris.brezillon@xxxxxxxxxxxxxxxxxx>
Acked-by: Nicolas Ferre <nicolas.ferre@xxxxxxxxx>
---
.../bindings/interrupt-controller/dumb-demux.txt | 41 ++++++++++++++++++++++
1 file changed, 41 insertions(+)
create mode 100644 Documentation/devicetree/bindings/interrupt-controller/dumb-demux.txt
diff --git a/Documentation/devicetree/bindings/interrupt-controller/dumb-demux.txt b/Documentation/devicetree/bindings/interrupt-controller/dumb-demux.txt
new file mode 100644
index 0000000..b9a7830
--- /dev/null
+++ b/Documentation/devicetree/bindings/interrupt-controller/dumb-demux.txt
@@ -0,0 +1,41 @@
+* Virtual Interrupt Demultiplexer
+
+This virtual demultiplexer simply forward all incoming interrupts to its
+enabled/unmasked children.
+It is only intended to be used by hardware that do not provide a proper way
+to demultiplex a source interrupt, and thus have to wake all their children
+up so that they can possibly handle the interrupt (if needed).
+This can be seen as an alternative to shared interrupts when at least one
+of the interrupt children is a timer (and require the irq to stay enabled
+on suspend) while others are not. This will prevent calling irq handlers of
+non timer devices while they are suspended.
+
+Required properties:
+- compatible: Should be "virtual,irq-demux".
+- interrupt-controller: Identifies the node as an interrupt controller.
+- interrupts-extended or interrupt-parent and interrupts: Reference the source
+ interrupt connected to this dumb demuxer.
+- #interrupt-cells: The number of cells to define the interrupts (should be 1).
+ The only cell is the IRQ number.
+- irqs: u32 bitfield specifying the interrupts provided by the demuxer.
+
+Examples:
+ /*
+ * virtual demuxer controller
+ */
+ virt_irq1_demux: virt-irq-demux@1 {
+ compatible = "virtual,irq-demux";
+ interrupt-controller;
+ #interrupt-cells = <1>;
+ interrupts-extended = <&aic 1 IRQ_TYPE_LEVEL_HIGH 7>;
+ irqs = <0x3f>;
+ };
+
+ /*
+ * Device connected on this dumb demuxer
+ */
+ dma: dma-controller@ffffec00 {
+ compatible = "atmel,at91sam9g45-dma";
+ reg = <0xffffec00 0x200>;
+ interrupts-extended = <&virt_irq1_demux 0>;
+ };
--
1.9.1
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