diff options
Diffstat (limited to 'arch/sh/drivers/pci/fixups-cayman.c')
-rw-r--r-- | arch/sh/drivers/pci/fixups-cayman.c | 77 |
1 files changed, 77 insertions, 0 deletions
diff --git a/arch/sh/drivers/pci/fixups-cayman.c b/arch/sh/drivers/pci/fixups-cayman.c new file mode 100644 index 000000000000..b68b61d22c6c --- /dev/null +++ b/arch/sh/drivers/pci/fixups-cayman.c | |||
@@ -0,0 +1,77 @@ | |||
1 | #include <linux/kernel.h> | ||
2 | #include <linux/init.h> | ||
3 | #include <linux/pci.h> | ||
4 | #include <linux/types.h> | ||
5 | #include <cpu/irq.h> | ||
6 | #include "pci-sh5.h" | ||
7 | |||
8 | int __init pcibios_map_platform_irq(struct pci_dev *dev, u8 slot, u8 pin) | ||
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); | ||
40 | pin = path[i].pin = pci_swizzle_interrupt_pin(dev, pin); | ||
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. */ | ||
54 | result = IRQ_INTA + pci_swizzle_interrupt_pin(dev, pin) - 1; | ||
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 | } | ||