79 lines
2.2 KiB
C
79 lines
2.2 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
#include <linux/kernel.h>
|
|
#include <linux/init.h>
|
|
#include <linux/pci.h>
|
|
#include <linux/types.h>
|
|
#include <cpu/irq.h>
|
|
#include "pci-sh5.h"
|
|
|
|
int pcibios_map_platform_irq(const struct pci_dev *dev, u8 slot, u8 pin)
|
|
{
|
|
int result = -1;
|
|
|
|
/* The complication here is that the PCI IRQ lines from the Cayman's 2
|
|
5V slots get into the CPU via a different path from the IRQ lines
|
|
from the 3 3.3V slots. Thus, we have to detect whether the card's
|
|
interrupts go via the 5V or 3.3V path, i.e. the 'bridge swizzling'
|
|
at the point where we cross from 5V to 3.3V is not the normal case.
|
|
|
|
The added complication is that we don't know that the 5V slots are
|
|
always bus 2, because a card containing a PCI-PCI bridge may be
|
|
plugged into a 3.3V slot, and this changes the bus numbering.
|
|
|
|
Also, the Cayman has an intermediate PCI bus that goes a custom
|
|
expansion board header (and to the secondary bridge). This bus has
|
|
never been used in practice.
|
|
|
|
The 1ary onboard PCI-PCI bridge is device 3 on bus 0
|
|
The 2ary onboard PCI-PCI bridge is device 0 on the 2ary bus of
|
|
the 1ary bridge.
|
|
*/
|
|
|
|
struct slot_pin {
|
|
int slot;
|
|
int pin;
|
|
} path[4];
|
|
int i=0;
|
|
|
|
while (dev->bus->number > 0) {
|
|
|
|
slot = path[i].slot = PCI_SLOT(dev->devfn);
|
|
pin = path[i].pin = pci_swizzle_interrupt_pin(dev, pin);
|
|
dev = dev->bus->self;
|
|
i++;
|
|
if (i > 3) panic("PCI path to root bus too long!\n");
|
|
}
|
|
|
|
slot = PCI_SLOT(dev->devfn);
|
|
/* This is the slot on bus 0 through which the device is eventually
|
|
reachable. */
|
|
|
|
/* Now work back up. */
|
|
if ((slot < 3) || (i == 0)) {
|
|
/* Bus 0 (incl. PCI-PCI bridge itself) : perform the final
|
|
swizzle now. */
|
|
result = IRQ_INTA + pci_swizzle_interrupt_pin(dev, pin) - 1;
|
|
} else {
|
|
i--;
|
|
slot = path[i].slot;
|
|
pin = path[i].pin;
|
|
if (slot > 0) {
|
|
panic("PCI expansion bus device found - not handled!\n");
|
|
} else {
|
|
if (i > 0) {
|
|
/* 5V slots */
|
|
i--;
|
|
slot = path[i].slot;
|
|
pin = path[i].pin;
|
|
/* 'pin' was swizzled earlier wrt slot, don't do it again. */
|
|
result = IRQ_P2INTA + (pin - 1);
|
|
} else {
|
|
/* IRQ for 2ary PCI-PCI bridge : unused */
|
|
result = -1;
|
|
}
|
|
}
|
|
}
|
|
|
|
return result;
|
|
}
|