arch/x86/pci/visws.c

   1 /*
   2  *      Low-Level PCI Support for SGI Visual Workstation
   3  *
   4  *      (c) 1999--2000 Martin Mares <mj@ucw.cz>
   5  */
   6
   7 #include <linux/kernel.h>
   8 #include <linux/pci.h>
   9 #include <linux/init.h>
  10
  11 #include <asm/setup.h>
  12 #include <asm/pci_x86.h>
  13 #include <asm/visws/cobalt.h>
  14 #include <asm/visws/lithium.h>
  15
  16 static int pci_visws_enable_irq(struct pci_dev *dev) { return 0; }
  17 static void pci_visws_disable_irq(struct pci_dev *dev) { }
  18
  19 /* int (*pcibios_enable_irq)(struct pci_dev *dev) = &pci_visws_enable_irq; */
  20 /* void (*pcibios_disable_irq)(struct pci_dev *dev) = &pci_visws_disable_irq; */
  21
  22 /* void __init pcibios_penalize_isa_irq(int irq, int active) {} */
  23
  24
  25 unsigned int pci_bus0, pci_bus1;
  26
  27 static int __init visws_map_irq(const struct pci_dev *dev, u8 slot, u8 pin)
  28 {
  29         int irq, bus = dev->bus->number;
  30
  31         pin--;
  32
  33         /* Nothing useful at PIIX4 pin 1 */
  34         if (bus == pci_bus0 && slot == 4 && pin == 0)
  35                 return -1;
  36
  37         /* PIIX4 USB is on Bus 0, Slot 4, Line 3 */
  38         if (bus == pci_bus0 && slot == 4 && pin == 3) {
  39                 irq = CO_IRQ(CO_APIC_PIIX4_USB);
  40                 goto out;
  41         }
  42
  43         /* First pin spread down 1 APIC entry per slot */
  44         if (pin == 0) {
  45                 irq = CO_IRQ((bus == pci_bus0 ? CO_APIC_PCIB_BASE0 :
  46                                                 CO_APIC_PCIA_BASE0) + slot);
  47                 goto out;
  48         }
  49
  50         /* lines 1,2,3 from any slot is shared in this twirly pattern */
  51         if (bus == pci_bus1) {
  52                 /* lines 1-3 from devices 0 1 rotate over 2 apic entries */
  53                 irq = CO_IRQ(CO_APIC_PCIA_BASE123 + ((slot + (pin - 1)) % 2));
  54         } else { /* bus == pci_bus0 */
  55                 /* lines 1-3 from devices 0-3 rotate over 3 apic entries */
  56                 if (slot == 0)
  57                         slot = 3; /* same pattern */
  58                 irq = CO_IRQ(CO_APIC_PCIA_BASE123 + ((3 - slot) + (pin - 1) % 3));
  59         }
  60 out:
  61         printk(KERN_DEBUG "PCI: Bus %d Slot %d Line %d -> IRQ %d\n", bus, slot, pin, irq);
  62         return irq;
  63 }
  64
  65 int __init pci_visws_init(void)
  66 {
  67         pcibios_enable_irq = &pci_visws_enable_irq;
  68         pcibios_disable_irq = &pci_visws_disable_irq;
  69
  70         /* The VISWS supports configuration access type 1 only */
  71         pci_probe = (pci_probe | PCI_PROBE_CONF1) &
  72                     ~(PCI_PROBE_BIOS | PCI_PROBE_CONF2);
  73
  74         pci_bus0 = li_pcib_read16(LI_PCI_BUSNUM) & 0xff;
  75         pci_bus1 = li_pcia_read16(LI_PCI_BUSNUM) & 0xff;
  76
  77         printk(KERN_INFO "PCI: Lithium bridge A bus: %u, "
  78                 "bridge B (PIIX4) bus: %u\n", pci_bus1, pci_bus0);
  79
  80         raw_pci_ops = &pci_direct_conf1;
  81         pci_scan_bus_with_sysdata(pci_bus0);
  82         pci_scan_bus_with_sysdata(pci_bus1);
  83         pci_fixup_irqs(pci_common_swizzle, visws_map_irq);
  84         pcibios_resource_survey();
  85         /* Request bus scan */
  86         return 1;
  87 }