[PATCH v4 2/2] dt-binding:Documents of the mbigen bindings

[MaJun]

From: Ma Jun <majun258 at huawei.com>

Add the mbigen msi interrupt controller bindings document.

Change since v3:
--- Change the interrupt cells definition.
--- Change the mbigen node definition.
--- Add mbigen device node as sub node of mbigen.


Signed-off-by: Ma Jun <majun258 at huawei.com>
---
 Documentation/devicetree/bindings/arm/mbigen.txt |   97 ++++++++++++++++++++++
 1 files changed, 97 insertions(+), 0 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/arm/mbigen.txt

diff --git a/Documentation/devicetree/bindings/arm/mbigen.txt b/Documentation/devicetree/bindings/arm/mbigen.txt
new file mode 100644
index 0000000..8e1203b
--- /dev/null
+++ b/Documentation/devicetree/bindings/arm/mbigen.txt
@@ -0,0 +1,97 @@
+Hisilicon mbigen device tree bindings.
+=======================================
+
+Mbigen means: message based interrupt generator.
+
+MBI is kind of msi interrupt only used on Non-PCI devices.
+
+To reduce the wired interrupt number connected to GIC,
+Hisilicon designed mbigen to collect and generate interrupt.
+
+
+Non-pci devices can connect to mbigen and generate the
+interrupt by writing ITS register.
+
+The mbigen chip and devices connect to mbigen have the following properties:
+
+Mbigen main node required properties:
+-------------------------------------------
+- compatible: Should be "hisilicon,mbigen-v2"
+- interrupt controller: Identifies the node as an interrupt controller
+- #interrupt-cells : Specifies the number of cells needed to encode an
+  interrupt source. The value is 4 now.
+
+  The 1st cell is the device id.
+  The 2nd cell is the mbigen node number. This value should refer to the
+  vendor Soc specification.
+  The 3rd cell is the hardware pin number of the interrupt.
+  This value depends on the Soc design.
+  The 4th cell is the interrupt trigger type, encoded as follows:
+		1 = edge triggered
+		4 = level triggered
+
+- #mbigen-node-cells :Specifies the number of cells needed to encode an
+  mbigen node information. The value is 3 now.
+
+  The 1st cell is the mbigen node number.
+  The 2nd cell is the interrupt numbers connected to.
+  The 3rd cell is the start value of pin offset.
+
+- reg: Specifies the base physical address and size of the Mbigen
+  registers.
+
+Sub-nodes:
+
+Mbigen has one or more mbigen device nodes which represents the devices
+connected to this mbigen chip.
+
+These nodes must have the following properties:
+- msi-parent: This property has two cells.
+	The 1st cell specifies the ITS this device connected.
+	The 2nd cell specifies the device id.
+- nr-interrupts:Specifies the total number of interrupt this device has.
+- mbigen_node: Specifies the information of mbigen nodes this device
+  connected.Some devices with many interrupts maybe connects with several
+  mbigen nodes.
+
+Examples:
+
+		mbigen_dsa: interrupt-controller at c0080000 {
+			compatible = "hisilicon,mbigen-v2";
+			interrupt-controller;
+			#interrupt-cells = <5>;
+			#mbigen-node-cells = <3>;
+			reg = <0xc0080000 0x10000>;
+
+			mbigen_device_01 {
+				msi-parent = <&its 0x40b1c>;
+				nr-interrupts = <9>;
+				mbigen_node = <1 2 0>,
+							<3 2 4>,
+							<4 5 0>;
+			}
+
+			mbigen_device_02 {
+				msi-parent = <&its 0x40b1d>;
+				nr-interrupts = <3>;
+				mbigen_node = <6 3 0>;
+				interrupt-controller;
+			}
+		};
+
+Device connect to mbigen required properties:
+----------------------------------------------------
+-interrupt-parent: Specifies the mbigen node which device connected.
+-interrupts:specifies the interrupt source.The first cell is hwirq num, the
+  second number is trigger type.
+
+Examples:
+	smmu_dsa {
+		compatible = "arm,smmu-v3";
+		reg = <0x0 0xc0040000 0x0 0x20000>;
+		interrupt-parent  = <&mbigen_dsa>;
+		interrupts = <0x40b20 6 78 1>,
+				<0x40b20 6 79 1>,
+				<0x40b20 6 80 1>;
+	};
+
-- 
1.7.1