440SP External Interrupt IRQ

440SP External Interrupt IRQ

[Jeff Stevens]

I am trying to figure out the PCI IRQ mapping on a
440SP processor in linux-2.6.17.9.  I have a board
that is based off of the Luan development board, and I
am not sure which IRQ corresponds to each external
IRQ[0:5] pins on the processor.  Where can I find this
information?

Thanks,
   Jeff Stevens

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Re: 440SP External Interrupt IRQ

[Stefan Roese]

Jeff,

On Friday 06 October 2006 05:49, Jeff Stevens wrote:
> I am trying to figure out the PCI IRQ mapping on a
> 440SP processor in linux-2.6.17.9.  I have a board
> that is based off of the Luan development board, and I
> am not sure which IRQ corresponds to each external
> IRQ[0:5] pins on the processor.  Where can I find this
> information?

In your schematics. Sorry but it's that simple.

Best regards,
Stefan

Re: 440SP External Interrupt IRQ

[Jeff Stevens]

I'm sorry if this is an easy question, but how do my
schematics tell me that pint IRQ0 uses IRQ 48 in my
board specific PCI IRQ lookup table, where it is
matching up the idsel lines to an irq number?  For
instance, in arch/ppc/platforms/4xx/luan.c it maps PCI
interrupts like:

static inline int
luan_map_irq(struct pci_dev *dev, unsigned char idsel,
unsigned char pin)
{
	struct pci_controller *hose =
pci_bus_to_hose(dev->bus->number);

	/* PCIX0 in adapter mode, no host interrupt routing
*/

	/* PCIX1 */
	if (hose->index == 0) {
		static char pci_irq_table[][4] =
		/*
		 *	PCI IDSEL/INTPIN->INTLINE
		 *	  A   B   C   D
		 */
		{
			{ 49, 49, 49, 49 },	/* IDSEL 1 - PCIX1 Slot 0 */
			{ 49, 49, 49, 49 },	/* IDSEL 2 - PCIX1 Slot 1 */
			{ 49, 49, 49, 49 },	/* IDSEL 3 - PCIX1 Slot 2 */
			{ 49, 49, 49, 49 },	/* IDSEL 4 - PCIX1 Slot 3 */
		};
		const long min_idsel = 1, max_idsel = 4,
irqs_per_slot = 4;
		return PCI_IRQ_TABLE_LOOKUP;
	/* PCIX2 */
	} else if (hose->index == 1) {
		static char pci_irq_table[][4] =
		/*
		 *	PCI IDSEL/INTPIN->INTLINE
		 *	  A   B   C   D
		 */
		{
			{ 50, 50, 50, 50 },	/* IDSEL 1 - PCIX2 Slot 0 */
			{ 50, 50, 50, 50 },	/* IDSEL 2 - PCIX2 Slot 1 */
			{ 50, 50, 50, 50 },	/* IDSEL 3 - PCIX2 Slot 2 */
			{ 50, 50, 50, 50 },	/* IDSEL 4 - PCIX2 Slot 3 */
		};
		const long min_idsel = 1, max_idsel = 4,
irqs_per_slot = 4;
		return PCI_IRQ_TABLE_LOOKUP;
	}
	return -1;
}

Based on their schematics, I assume:
IRQ Line      IRQ#
  IRQ0        48
  IRQ1        49
  IRQ2        50
  IRQ3        51
  IRQ4        52
  IRQ5        53

I just hate assuming, and would like to understand how
they come up with the IRQ offset for the external
interrups.

-Jeff

--- Stefan Roese <sr@denx.de> wrote:

> Jeff,
> 
> On Friday 06 October 2006 05:49, Jeff Stevens wrote:
> > I am trying to figure out the PCI IRQ mapping on a
> > 440SP processor in linux-2.6.17.9.  I have a board
> > that is based off of the Luan development board,
> and I
> > am not sure which IRQ corresponds to each external
> > IRQ[0:5] pins on the processor.  Where can I find
> this
> > information?
> 
> In your schematics. Sorry but it's that simple.
> 
> Best regards,
> Stefan
> 


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Re: 440SP External Interrupt IRQ

[Eugene Surovegin]

On Fri, Oct 06, 2006 at 03:27:38AM -0700, Jeff Stevens wrote:

[snip]

> Based on their schematics, I assume:
> IRQ Line      IRQ#
>   IRQ0        48
>   IRQ1        49
>   IRQ2        50
>   IRQ3        51
>   IRQ4        52
>   IRQ5        53

No, this mapping doesn't depend on board shematics. This is fixed, see 
"Universal Interrupt controller" chapter in user manual.

What is not fixed is mapping between IDSEL line which selects your PCI 
device and INTx# line from that PCI device to IRQx line in 440SP.

-- 
Eugene