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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 | #include <linux/kernel.h> #include <linux/of_pci.h> #include <linux/of_irq.h> #include <linux/export.h> /** * of_irq_parse_pci - Resolve the interrupt for a PCI device * @pdev: the device whose interrupt is to be resolved * @out_irq: structure of_irq filled by this function * * This function resolves the PCI interrupt for a given PCI device. If a * device-node exists for a given pci_dev, it will use normal OF tree * walking. If not, it will implement standard swizzling and walk up the * PCI tree until an device-node is found, at which point it will finish * resolving using the OF tree walking. */ int of_irq_parse_pci(const struct pci_dev *pdev, struct of_phandle_args *out_irq) { struct device_node *dn, *ppnode; struct pci_dev *ppdev; __be32 laddr[3]; u8 pin; int rc; /* 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_parse_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) goto err; /* No pin, exit with no error message. */ if (pin == 0) return -ENODEV; /* Now we walk up the PCI tree */ 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) { rc = -EINVAL; goto err; } } 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; /* We can only get here if we hit a P2P bridge with no node, * let's do standard swizzling and try again */ pin = pci_swizzle_interrupt_pin(pdev, pin); pdev = ppdev; } out_irq->np = ppnode; out_irq->args_count = 1; out_irq->args[0] = pin; laddr[0] = cpu_to_be32((pdev->bus->number << 16) | (pdev->devfn << 8)); laddr[1] = laddr[2] = cpu_to_be32(0); rc = of_irq_parse_raw(laddr, out_irq); if (rc) goto err; return 0; err: dev_err(&pdev->dev, "of_irq_parse_pci() failed with rc=%d\n", rc); return rc; } EXPORT_SYMBOL_GPL(of_irq_parse_pci); /** * of_irq_parse_and_map_pci() - Decode a PCI irq from the device tree and map to a virq * @dev: The pci device needing an irq * @slot: PCI slot number; passed when used as map_irq callback. Unused * @pin: PCI irq pin number; passed when used as map_irq callback. Unused * * @slot and @pin are unused, but included in the function so that this * function can be used directly as the map_irq callback to pci_fixup_irqs(). */ int of_irq_parse_and_map_pci(const struct pci_dev *dev, u8 slot, u8 pin) { struct of_phandle_args oirq; int ret; ret = of_irq_parse_pci(dev, &oirq); if (ret) return 0; /* Proper return code 0 == NO_IRQ */ return irq_create_of_mapping(&oirq); } EXPORT_SYMBOL_GPL(of_irq_parse_and_map_pci); |