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
123
124
125
126
127
128
129
130
|
#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:
if (rc == -ENOENT) {
dev_warn(&pdev->dev,
"%s: no interrupt-map found, INTx interrupts not available\n",
__func__);
pr_warn_once("%s: possibly some PCI slots don't have level triggered interrupts capability\n",
__func__);
} else {
dev_err(&pdev->dev, "%s: failed with rc=%d\n", __func__, 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);
|
