Re: DTS configuration of external interrupts on 8347

On Wed, 23 Jul 2008 15:58:38 +0100
"Richard Whitlock" [off-list ref] wrote:

I have a small problem with a port of linux 2.6.26 to a custom board.
Our board is almost identical to the Analogue & Micro asp 8347 board,
so I'm using Kumar Gala's excellent fsl tree (thank you Kumar) as it 
already has a defconfig for the asp.
Thanks also to Bryan O'Donoghue for pointing us in the direction of
the asp port in the first place.

The problem we have is I am unable to request an external interrupt.
We have an FPGA which has an interrupt line - HW IRQ_0, so thats
linux IRQ 48. I have added the following to the dts file:

fpgaKFAF@0xF8000000 {
                interrupts = <48 8>;
                interrupt-parent = <&ipic>;
}

but whenever I call request_irq() it returns -ENOSYS.

The driver loads fine, and the open function does very little - a
call to ioremap() - which works, and a call to request_irq() which
does not. Is there anything else I have to do to configure this
interrupt?

I don't think you have enough information in the dts. We do the same
thing on the warp (you can look at the warp.dts):

fpga@2,0 {
	compatible = "pika,fpga";
	reg = <0x00000002 0x00000000 0x00001000>;
	interrupts = <0x18 0x8>;
	interrupt-parent = <&UIC0>;
};

You need the compatible, maybe "kfaf,fpga", and I believe the reg entry
although you could try without it.

You then can use:

	of_find_compatible_node
	irq_of_parse_and_map
	request_irq

platforms/44x/warp.c shows an example using the ad7414. Just change the
ad7414 string to your compatible string.

Cheers,
   Sean