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

["majun (F)" <majun258@huawei.com>]

Hi Marc:

在 2015/9/22 2:09, Marc Zyngier 写道:
> On Wed, 19 Aug 2015 03:55:20 +0100
> MaJun <majun258@huawei.com> wrote:
> 
[...]
>> +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@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>;
>> +	};
>> +
> 
> I find the current split very confusing. In your example, the interrupt
> controller is the mbigen block, which forces you to encode the DevID as
> part of the interrupt specifier. This doesn't feel like an ideal
> design, because you end up duplicating the DevID information at both
> the "client" device and the mbi_device.
> 
> I'd be more inclined to have the mbi_device itself be the interrupt
> controller for the client device. This would eliminate information
> duplication, and reflect the hardware (or what I understand of the
> hardware) a bit more.

Do you mean make the dts likes below?


		mbigen_dsa: interrupt-controller@c0080000 {
			compatible = "hisilicon,mbigen-v2";
			interrupt-controller;
			#interrupt-cells = <5>;
			#mbigen-node-cells = <3>;
			reg = <0xc0080000 0x10000>;
			
			mbigen_client_device1 {
				msi-parent = <&its 0x40b1c>;
				nr-interrupts = <9>;
				interrupt-controller;
			}

			mbigen_client_device2{
				msi-parent = <&its 0x40b1d>;
				nr-interrupts = <3>;
				interrupt-controller;
			}
		};


	client_device1 {
		compatible = "arm,smmu-v3";
		reg = <0x0 0xc0040000 0x0 0x20000>;
		interrupt-parent  = <&mbigen_client_device1>;
		interrupts = <pin_offset 78 1>,
				<pin_offset 79 1>,
				<pin_offset 80 1>;
	};