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1 | #include <linux/kernel.h> |
2 | #include <linux/init.h> | |
3 | #include <linux/pci.h> | |
4 | #include <linux/types.h> | |
f15cbe6f | 5 | #include <cpu/irq.h> |
b6d7b666 PM |
6 | #include "pci-sh5.h" |
7 | ||
d5341942 | 8 | int __init pcibios_map_platform_irq(const struct pci_dev *dev, u8 slot, u8 pin) |
b6d7b666 PM |
9 | { |
10 | int result = -1; | |
11 | ||
12 | /* The complication here is that the PCI IRQ lines from the Cayman's 2 | |
13 | 5V slots get into the CPU via a different path from the IRQ lines | |
14 | from the 3 3.3V slots. Thus, we have to detect whether the card's | |
15 | interrupts go via the 5V or 3.3V path, i.e. the 'bridge swizzling' | |
16 | at the point where we cross from 5V to 3.3V is not the normal case. | |
17 | ||
18 | The added complication is that we don't know that the 5V slots are | |
19 | always bus 2, because a card containing a PCI-PCI bridge may be | |
20 | plugged into a 3.3V slot, and this changes the bus numbering. | |
21 | ||
22 | Also, the Cayman has an intermediate PCI bus that goes a custom | |
23 | expansion board header (and to the secondary bridge). This bus has | |
24 | never been used in practice. | |
25 | ||
26 | The 1ary onboard PCI-PCI bridge is device 3 on bus 0 | |
27 | The 2ary onboard PCI-PCI bridge is device 0 on the 2ary bus of | |
28 | the 1ary bridge. | |
29 | */ | |
30 | ||
31 | struct slot_pin { | |
32 | int slot; | |
33 | int pin; | |
34 | } path[4]; | |
35 | int i=0; | |
36 | ||
37 | while (dev->bus->number > 0) { | |
38 | ||
39 | slot = path[i].slot = PCI_SLOT(dev->devfn); | |
6aa6e498 | 40 | pin = path[i].pin = pci_swizzle_interrupt_pin(dev, pin); |
b6d7b666 PM |
41 | dev = dev->bus->self; |
42 | i++; | |
43 | if (i > 3) panic("PCI path to root bus too long!\n"); | |
44 | } | |
45 | ||
46 | slot = PCI_SLOT(dev->devfn); | |
47 | /* This is the slot on bus 0 through which the device is eventually | |
48 | reachable. */ | |
49 | ||
50 | /* Now work back up. */ | |
51 | if ((slot < 3) || (i == 0)) { | |
52 | /* Bus 0 (incl. PCI-PCI bridge itself) : perform the final | |
53 | swizzle now. */ | |
6aa6e498 | 54 | result = IRQ_INTA + pci_swizzle_interrupt_pin(dev, pin) - 1; |
b6d7b666 PM |
55 | } else { |
56 | i--; | |
57 | slot = path[i].slot; | |
58 | pin = path[i].pin; | |
59 | if (slot > 0) { | |
60 | panic("PCI expansion bus device found - not handled!\n"); | |
61 | } else { | |
62 | if (i > 0) { | |
63 | /* 5V slots */ | |
64 | i--; | |
65 | slot = path[i].slot; | |
66 | pin = path[i].pin; | |
67 | /* 'pin' was swizzled earlier wrt slot, don't do it again. */ | |
68 | result = IRQ_P2INTA + (pin - 1); | |
69 | } else { | |
70 | /* IRQ for 2ary PCI-PCI bridge : unused */ | |
71 | result = -1; | |
72 | } | |
73 | } | |
74 | } | |
75 | ||
76 | return result; | |
77 | } |