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/*
* Low-Level PCI Support for SGI Visual Workstation
*
* (c) 1999--2000 Martin Mares <mj@ucw.cz>
*/
#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/init.h>
#include "cobalt.h"
#include "lithium.h"
#include "pci.h"
static int pci_visws_enable_irq(struct pci_dev *dev) { return 0; }
static void pci_visws_disable_irq(struct pci_dev *dev) { }
int (*pcibios_enable_irq)(struct pci_dev *dev) = &pci_visws_enable_irq;
void (*pcibios_disable_irq)(struct pci_dev *dev) = &pci_visws_disable_irq;
void __init pcibios_penalize_isa_irq(int irq, int active) {}
unsigned int pci_bus0, pci_bus1;
static inline u8 bridge_swizzle(u8 pin, u8 slot)
{
return (((pin - 1) + slot) % 4) + 1;
}
static u8 __init visws_swizzle(struct pci_dev *dev, u8 *pinp)
{
u8 pin = *pinp;
while (dev->bus->self) { /* Move up the chain of bridges. */
pin = bridge_swizzle(pin, PCI_SLOT(dev->devfn));
dev = dev->bus->self;
}
*pinp = pin;
return PCI_SLOT(dev->devfn);
}
static int __init visws_map_irq(struct pci_dev *dev, u8 slot, u8 pin)
{
int irq, bus = dev->bus->number;
pin--;
/* Nothing useful at PIIX4 pin 1 */
if (bus == pci_bus0 && slot == 4 && pin == 0)
return -1;
/* PIIX4 USB is on Bus 0, Slot 4, Line 3 */
if (bus == pci_bus0 && slot == 4 && pin == 3) {
irq = CO_IRQ(CO_APIC_PIIX4_USB);
goto out;
}
/* First pin spread down 1 APIC entry per slot */
if (pin == 0) {
irq = CO_IRQ((bus == pci_bus0 ? CO_APIC_PCIB_BASE0 :
CO_APIC_PCIA_BASE0) + slot);
goto out;
}
/* lines 1,2,3 from any slot is shared in this twirly pattern */
if (bus == pci_bus1) {
/* lines 1-3 from devices 0 1 rotate over 2 apic entries */
irq = CO_IRQ(CO_APIC_PCIA_BASE123 + ((slot + (pin - 1)) % 2));
} else { /* bus == pci_bus0 */
/* lines 1-3 from devices 0-3 rotate over 3 apic entries */
if (slot == 0)
slot = 3; /* same pattern */
irq = CO_IRQ(CO_APIC_PCIA_BASE123 + ((3 - slot) + (pin - 1) % 3));
}
out:
printk(KERN_DEBUG "PCI: Bus %d Slot %d Line %d -> IRQ %d\n", bus, slot, pin, irq);
return irq;
}
void __init pcibios_update_irq(struct pci_dev *dev, int irq)
{
pci_write_config_byte(dev, PCI_INTERRUPT_LINE, irq);
}
static int __init pci_visws_init(void)
{
/* The VISWS supports configuration access type 1 only */
pci_probe = (pci_probe | PCI_PROBE_CONF1) &
~(PCI_PROBE_BIOS | PCI_PROBE_CONF2);
pci_bus0 = li_pcib_read16(LI_PCI_BUSNUM) & 0xff;
pci_bus1 = li_pcia_read16(LI_PCI_BUSNUM) & 0xff;
printk(KERN_INFO "PCI: Lithium bridge A bus: %u, "
"bridge B (PIIX4) bus: %u\n", pci_bus1, pci_bus0);
raw_pci_ops = &pci_direct_conf1;
pci_scan_bus_with_sysdata(pci_bus0);
pci_scan_bus_with_sysdata(pci_bus1);
pci_fixup_irqs(visws_swizzle, visws_map_irq);
pcibios_resource_survey();
return 0;
}
subsys_initcall(pci_visws_init);
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