linux-arkmicro/linux/Documentation/devicetree/bindings/interrupt-controller/hisilicon,mbigen-v2.txt

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"

- reg: Specifies the base physical address and size of the Mbigen
  registers.

Mbigen sub node required properties:
------------------------------------------
- interrupt controller: Identifies the node as an interrupt controller

- msi-parent: Specifies the MSI controller this mbigen use.
  For more detail information,please refer to the generic msi-parent binding in
  Documentation/devicetree/bindings/interrupt-controller/msi.txt.

- num-pins: the total number of pins implemented in this Mbigen
  instance.

- #interrupt-cells : Specifies the number of cells needed to encode an
  interrupt source. The value must be 2.

  The 1st cell is hardware pin number of the interrupt.This number is local to
  each mbigen chip and in the range from 0 to the maximum interrupts number
  of the mbigen.

  The 2nd cell is the interrupt trigger type.
	The value of this cell should be:
	1: rising edge triggered
	or
	4: high level triggered

Examples:

	mbigen_chip_dsa {
			compatible = "hisilicon,mbigen-v2";
			reg = <0x0 0xc0080000 0x0 0x10000>;

			mbigen_gmac:intc_gmac {
				interrupt-controller;
				msi-parent = <&its_dsa 0x40b1c>;
				num-pins = <9>;
				#interrupt-cells = <2>;
			};

			mbigen_i2c:intc_i2c {
				interrupt-controller;
				msi-parent = <&its_dsa 0x40b0e>;
				num-pins = <2>;
				#interrupt-cells = <2>;
			};
	};

Devices connect to mbigen required properties:
----------------------------------------------------
-interrupts:Specifies the interrupt source.
 For the specific information of each cell in this property,please refer to
 the "interrupt-cells" description mentioned above.

Examples:
	gmac0: ethernet@c2080000 {
		#address-cells = <1>;
		#size-cells = <0>;
		reg = <0 0xc2080000 0 0x20000>,
		      <0 0xc0000000 0 0x1000>;
		interrupt-parent  = <&mbigen_device_gmac>;
		interrupts =	<656 1>,
				<657 1>;
	};