93 lines
2.7 KiB
C
93 lines
2.7 KiB
C
#include <linux/kernel.h>
|
|
#include <linux/of_pci.h>
|
|
#include <linux/of_irq.h>
|
|
#include <asm/prom.h>
|
|
|
|
/**
|
|
* of_irq_map_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_map_pci(struct pci_dev *pdev, struct of_irq *out_irq)
|
|
{
|
|
struct device_node *dn, *ppnode;
|
|
struct pci_dev *ppdev;
|
|
u32 lspec;
|
|
__be32 lspec_be;
|
|
__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_map_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)
|
|
return rc;
|
|
/* No pin, exit */
|
|
if (pin == 0)
|
|
return -ENODEV;
|
|
|
|
/* Now we walk up the PCI tree */
|
|
lspec = pin;
|
|
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)
|
|
return -EINVAL;
|
|
} 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
|
|
*/
|
|
lspec = pci_swizzle_interrupt_pin(pdev, lspec);
|
|
pdev = ppdev;
|
|
}
|
|
|
|
lspec_be = cpu_to_be32(lspec);
|
|
laddr[0] = cpu_to_be32((pdev->bus->number << 16) | (pdev->devfn << 8));
|
|
laddr[1] = laddr[2] = cpu_to_be32(0);
|
|
return of_irq_map_raw(ppnode, &lspec_be, 1, laddr, out_irq);
|
|
}
|
|
EXPORT_SYMBOL_GPL(of_irq_map_pci);
|