Legacy ISA registers/interrupts in PCI device tree node

Legacy ISA registers/interrupts in PCI device tree node

[Gerhard Pircher]

Hi,

I wonder, if there is a recommended way to specify ISA register addresses
and interrupts for a PCI device (unlike for a PCI2ISA bridge)?
The device in question is the integrated IDE controller of the VIA686B
southbridge, which works in compatible/legacy mode and thus uses interrupts
14 and 15 of the i8259 PIC. Should the fdt contain this information or
should I hardcode the values in the platform setup code?

Thanks!

Regards,

Gerhard
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Re: Legacy ISA registers/interrupts in PCI device tree node

[Matt Sealey]

Gerhard,

You could do a LOT worse than check the Pegasos.

-- 
Matt Sealey <matt@genesi-usa.com>
Genesi, Manager, Developer Relations

Gerhard Pircher wrote:
> Hi,
> 
> I wonder, if there is a recommended way to specify ISA register addresses
> and interrupts for a PCI device (unlike for a PCI2ISA bridge)?
> The device in question is the integrated IDE controller of the VIA686B
> southbridge, which works in compatible/legacy mode and thus uses interrupts
> 14 and 15 of the i8259 PIC. Should the fdt contain this information or
> should I hardcode the values in the platform setup code?
> 
> Thanks!
> 
> Regards,
> 
> Gerhard

Re: Legacy ISA registers/interrupts in PCI device tree node

[Benjamin Herrenschmidt]

On Mon, 2007-07-16 at 09:59 +0100, Matt Sealey wrote:
> You could do a LOT worse than check the Pegasos.

Yes, mimmicing the pegasos will probably work

> Matt Sealey <matt@genesi-usa.com>
> Genesi, Manager, Developer Relations
> 
> Gerhard Pircher wrote:
> > Hi,
> > 
> > I wonder, if there is a recommended way to specify ISA register
> addresses
> > and interrupts for a PCI device (unlike for a PCI2ISA bridge)?
> > The device in question is the integrated IDE controller of the
> VIA686B
> > southbridge, which works in compatible/legacy mode and thus uses
> interrupts
> > 14 and 15 of the i8259 PIC. Should the fdt contain this information
> or
> > should I hardcode the values in the platform setup code?

You may need a fixup like pegasos does because that chip seems to use
14/15 even when in native mode, which is somewhat out of spec.

Cheers,
Ben.

Re: Legacy ISA registers/interrupts in PCI device tree node

[Segher Boessenkool]

> I wonder, if there is a recommended way to specify ISA register  
> addresses
> and interrupts for a PCI device (unlike for a PCI2ISA bridge)?

The PCI binding describes the required way to do this.

> The device in question is the integrated IDE controller of the VIA686B
> southbridge, which works in compatible/legacy mode and thus uses  
> interrupts
> 14 and 15 of the i8259 PIC. Should the fdt contain this information

Yes, it should, even if you don't use this in the Linux
kernel yet.

> or should I hardcode the values in the platform setup code?

No.


Segher

Re: Legacy ISA registers/interrupts in PCI device tree node

[Gerhard Pircher]

-------- Original-Nachricht --------
Datum: Mon, 16 Jul 2007 14:40:48 +0200
Von: Segher Boessenkool <segher@kernel.crashing.org>
An: Gerhard Pircher <gerhard_pircher@gmx.net>
CC: linuxppc-dev@ozlabs.org
Betreff: Re: Legacy ISA registers/interrupts in PCI device tree node

> > I wonder, if there is a recommended way to specify ISA register  
> > addresses and interrupts for a PCI device (unlike for a PCI2ISA
> > bridge)?
> 
> The PCI binding describes the required way to do this.
Hmm, I must reread the PCI binding spec. It didn't seem to contain any
information about this.

> Yes, it should, even if you don't use this in the Linux
> kernel yet.
Well, I still have to wire up the IDE interrupts in the platform setup
code, right?

Gerhard
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Re: Legacy ISA registers/interrupts in PCI device tree node

[Segher Boessenkool]

>>> I wonder, if there is a recommended way to specify ISA register
>>> addresses and interrupts for a PCI device (unlike for a PCI2ISA
>>> bridge)?
>>
>> The PCI binding describes the required way to do this.
> Hmm, I must reread the PCI binding spec. It didn't seem to contain any
> information about this.

You can describe address regions in "reg" that aren't
corresponding to any PCI BAR.  There is also a facility
to describe subtractive decoding (though I don't think
you need this).

>> Yes, it should, even if you don't use this in the Linux
>> kernel yet.
> Well, I still have to wire up the IDE interrupts in the platform setup
> code, right?

Sure, if you want those interrupts to work, anyway ;-)


Segher