- /* Check if we have a device node, if yes, fallback to standard
- * device tree parsing
- */
- dn = pci_device_to_OF_node(pdev);
- if (dn) {
- rc = of_irq_map_one(dn, 0, out_irq);
- if (!rc)
- return rc;
- }
-
- /* Ok, we don't, time to have fun. Let's start by building up an
- * interrupt spec. we assume #interrupt-cells is 1, which is standard
- * for PCI. If you do different, then don't use that routine.
- */
- rc = pci_read_config_byte(pdev, PCI_INTERRUPT_PIN, &pin);
- if (rc != 0)
- return rc;
- /* No pin, exit */
- if (pin == 0)
- return -ENODEV;
-
- /* Now we walk up the PCI tree */
- lspec = pin;
- for (;;) {
- /* Get the pci_dev of our parent */
- ppdev = pdev->bus->self;
-
- /* Ouch, it's a host bridge... */
- if (ppdev == NULL) {
- ppnode = pci_bus_to_OF_node(pdev->bus);
-
- /* No node for host bridge ? give up */
- if (ppnode == NULL)
- return -EINVAL;
- } else {
- /* We found a P2P bridge, check if it has a node */
- ppnode = pci_device_to_OF_node(ppdev);
- }
-
- /* Ok, we have found a parent with a device-node, hand over to
- * the OF parsing code.
- * We build a unit address from the linux device to be used for
- * resolution. Note that we use the linux bus number which may
- * not match your firmware bus numbering.
- * Fortunately, in most cases, interrupt-map-mask doesn't
- * include the bus number as part of the matching.
- * You should still be careful about that though if you intend
- * to rely on this function (you ship a firmware that doesn't
- * create device nodes for all PCI devices).
- */
- if (ppnode)
- break;