Thank you Benjamin!

Sorry for not using your qouting schema :(

Benjamin, you are right about the IRQ flags. Those interrupt.h flags seems =
to differ from my processor reference manual.

None the less. Antov, I saw that the code snippet I refer to below:

	ret =3D of_irq_to_resource(dn, 0, &irq_res);
	if (ret =3D=3D NO_IRQ)
		irq_res.start =3D irq_res.end =3D 0;
	else
		irq_res.flags =3D 0;

, originates from the first version of the file pata_of_platform.c and you =
are the creator :)
Could you explain the hardcoded ".flags =3D 0" part?=20
Looking amatuer-vise in the code it seems that the only thing one is able t=
o control (through Device Tree) regarding interrupts and pata, is the actua=
l IRQ number. Is this a correct assumption?

Thanks
BR
Robert


-----Original Message-----
From: Benjamin Herrenschmidt [mailto:benh@kernel.crashing.org]=20
Sent: den 24 februari 2011 21:47
To: Robert Thorhuus
Cc: linuxppc-dev@lists.ozlabs.org
Subject: Re: Open Firmware and interrupt trigger

On Wed, 2011-02-23 at 22:18 +0100, Robert Thorhuus wrote:

Hello!
=20
I'm quite new to linux and Open Firmware.
=20
I have a PPC processor. To this I have a Compact Flash connected. The Com=

pact Flash is using external interrupt 0 of the processor.

In my DTS file I have specified a Compact Flash node and within it I have=

 an interrupt element:

interrupt =3D <0 2 0 0>;
=20
Here I thought the first number was the ID of the interrupt and the secon=

d one should be a number indicating how the interrupt is triggered (high, l=
ow, raising, falling).

=20
The interrupt is active low.
=20
But I could not get it to work which ever value I chose.
=20
Looking in the code I found this in function __devinit pata_of_platform_p=

robe in file pata_of_platform.c:

=20
	ret =3D of_irq_to_resource(dn, 0, &irq_res);
	if (ret =3D=3D NO_IRQ)
		irq_res.start =3D irq_res.end =3D 0;
	else
		irq_res.flags =3D 0;
=20
Here "flags" will be zero whatever I do in the DTS. As far as I can under=

stand the flags are defined in interrupts.h:

#define IRQF_TRIGGER_NONE       0x00000000
#define IRQF_TRIGGER_RISING     0x00000001
#define IRQF_TRIGGER_FALLING    0x00000002
#define IRQF_TRIGGER_HIGH       0x00000004
#define IRQF_TRIGGER_LOW        0x00000008

Actually, the .dts flags depend on the specific interrupt controller you ar=
e using. For example, MPIC uses a different mapping scheme (for historical =
reasons). Check booting-without-of.txt.

So modifying the code to:
	else
		irq_res.flags =3D 2;
=20
I get it to work.
=20
Could someone please explain to me why the "flags" parameter is hardcoded=

 zero or just point in a good direction.

That does indeed look odd. Might be worth trying to figure out with the git=
 history who came up with that code in the first place and ask that person.=
 Without answer, I think it's valid to patch that out.

Cheers,
Ben.

Thank you
=20
BR
Robert
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