device tree parameter confusion

[aditya]

Hi,

      Following is the snippet from the device tree for the MicroZed Board.

ps7-scugic@f8f01000 {
            #address-cells = <0x2>;
            #interrupt-cells = <0x3>;
            #size-cells = <0x1>;
            compatible = "arm,cortex-a9-gic", "arm,gic";
            interrupt-controller;
            num_cpus = <0x2>;
            num_interrupts = <0x60>;
            reg = <0xf8f01000 0x1000 0xf8f00100 0x100>;
            xlnx,irq-f2p-mode = "REVERSE";
            linux,phandle = <0x3>;
            phandle = <0x3>;
        };

Mine particular interest is the line that is bold in above snippet.Actually i am working on the Zedboard and when i generated the device tree for mine Zedboard then following is the Snippet:-

ps7_scugic_0: ps7-scugic@f8f00100 {
            #address-cells = <2>;
            #interrupt-cells = <3>;
            #size-cells = <1>;
            compatible = "arm,cortex-a9-gic", "arm,gic";
            interrupt-controller ;
            num_cpus = <2>;
            num_interrupts = <96>;
            reg = <0xF8F00100 256 0xF8F00100 0x100>;
            xlnx,irq-f2p-mode = "DIRECT";
        } ;

So it has become "DIRECT".

So what is difference between "DIRECT" and "REVERSE",why for Microzed it is "REVERSE" and why for Zedboard it is "DIRECT".

Please reply me.

Regards

Aditya

[JColvin]

Hi Aditya,

I have asked some of our applications engineers about this; they will get back to you here on the Forum.

Thanks,
JColvin

[sbobrowicz]

I'm not sure what that node is supposed to mean, but it won't affect behavior in any way. "irq-f2p-mode" doesn't show up anywhere in the kernel source, which means no drivers are currently referencing it. You can remove it from your device tree if you like.