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1 | #include <linux/kernel.h> |
2 | #include <linux/of_pci.h> | |
3 | #include <linux/of_irq.h> | |
2c8d667a | 4 | #include <linux/export.h> |
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5 | |
6 | /** | |
0c02c800 | 7 | * of_irq_parse_pci - Resolve the interrupt for a PCI device |
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8 | * @pdev: the device whose interrupt is to be resolved |
9 | * @out_irq: structure of_irq filled by this function | |
10 | * | |
11 | * This function resolves the PCI interrupt for a given PCI device. If a | |
12 | * device-node exists for a given pci_dev, it will use normal OF tree | |
13 | * walking. If not, it will implement standard swizzling and walk up the | |
14 | * PCI tree until an device-node is found, at which point it will finish | |
15 | * resolving using the OF tree walking. | |
16 | */ | |
530210c7 | 17 | int of_irq_parse_pci(const struct pci_dev *pdev, struct of_phandle_args *out_irq) |
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18 | { |
19 | struct device_node *dn, *ppnode; | |
20 | struct pci_dev *ppdev; | |
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21 | __be32 laddr[3]; |
22 | u8 pin; | |
23 | int rc; | |
24 | ||
25 | /* Check if we have a device node, if yes, fallback to standard | |
26 | * device tree parsing | |
27 | */ | |
28 | dn = pci_device_to_OF_node(pdev); | |
29 | if (dn) { | |
0c02c800 | 30 | rc = of_irq_parse_one(dn, 0, out_irq); |
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31 | if (!rc) |
32 | return rc; | |
33 | } | |
34 | ||
35 | /* Ok, we don't, time to have fun. Let's start by building up an | |
36 | * interrupt spec. we assume #interrupt-cells is 1, which is standard | |
37 | * for PCI. If you do different, then don't use that routine. | |
38 | */ | |
39 | rc = pci_read_config_byte(pdev, PCI_INTERRUPT_PIN, &pin); | |
40 | if (rc != 0) | |
41 | return rc; | |
42 | /* No pin, exit */ | |
43 | if (pin == 0) | |
44 | return -ENODEV; | |
45 | ||
46 | /* Now we walk up the PCI tree */ | |
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47 | for (;;) { |
48 | /* Get the pci_dev of our parent */ | |
49 | ppdev = pdev->bus->self; | |
50 | ||
51 | /* Ouch, it's a host bridge... */ | |
52 | if (ppdev == NULL) { | |
53 | ppnode = pci_bus_to_OF_node(pdev->bus); | |
54 | ||
55 | /* No node for host bridge ? give up */ | |
56 | if (ppnode == NULL) | |
57 | return -EINVAL; | |
58 | } else { | |
59 | /* We found a P2P bridge, check if it has a node */ | |
60 | ppnode = pci_device_to_OF_node(ppdev); | |
61 | } | |
62 | ||
63 | /* Ok, we have found a parent with a device-node, hand over to | |
64 | * the OF parsing code. | |
65 | * We build a unit address from the linux device to be used for | |
66 | * resolution. Note that we use the linux bus number which may | |
67 | * not match your firmware bus numbering. | |
68 | * Fortunately, in most cases, interrupt-map-mask doesn't | |
69 | * include the bus number as part of the matching. | |
70 | * You should still be careful about that though if you intend | |
71 | * to rely on this function (you ship a firmware that doesn't | |
72 | * create device nodes for all PCI devices). | |
73 | */ | |
74 | if (ppnode) | |
75 | break; | |
76 | ||
77 | /* We can only get here if we hit a P2P bridge with no node, | |
78 | * let's do standard swizzling and try again | |
79 | */ | |
08cf78ed | 80 | pin = pci_swizzle_interrupt_pin(pdev, pin); |
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81 | pdev = ppdev; |
82 | } | |
83 | ||
23616132 GL |
84 | out_irq->np = ppnode; |
85 | out_irq->args_count = 1; | |
08cf78ed | 86 | out_irq->args[0] = pin; |
98d9f30c | 87 | laddr[0] = cpu_to_be32((pdev->bus->number << 16) | (pdev->devfn << 8)); |
23616132 GL |
88 | laddr[1] = laddr[2] = cpu_to_be32(0); |
89 | return of_irq_parse_raw(laddr, out_irq); | |
98d9f30c | 90 | } |
0c02c800 | 91 | EXPORT_SYMBOL_GPL(of_irq_parse_pci); |
16b84e5a GL |
92 | |
93 | /** | |
94 | * of_irq_parse_and_map_pci() - Decode a PCI irq from the device tree and map to a virq | |
95 | * @dev: The pci device needing an irq | |
96 | * @slot: PCI slot number; passed when used as map_irq callback. Unused | |
97 | * @pin: PCI irq pin number; passed when used as map_irq callback. Unused | |
98 | * | |
99 | * @slot and @pin are unused, but included in the function so that this | |
100 | * function can be used directly as the map_irq callback to pci_fixup_irqs(). | |
101 | */ | |
102 | int of_irq_parse_and_map_pci(const struct pci_dev *dev, u8 slot, u8 pin) | |
103 | { | |
104 | struct of_phandle_args oirq; | |
105 | int ret; | |
106 | ||
107 | ret = of_irq_parse_pci(dev, &oirq); | |
108 | if (ret) { | |
109 | dev_err(&dev->dev, "of_irq_parse_pci() failed with rc=%d\n", ret); | |
110 | return 0; /* Proper return code 0 == NO_IRQ */ | |
111 | } | |
112 | ||
113 | return irq_create_of_mapping(&oirq); | |
114 | } | |
115 | EXPORT_SYMBOL_GPL(of_irq_parse_and_map_pci); | |
116 |