1/* 2 * linux/arch/arm/mach-integrator/pci-integrator.c 3 * 4 * Copyright (C) 1999 ARM Limited 5 * Copyright (C) 2000 Deep Blue Solutions Ltd 6 * 7 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License as published by 9 * the Free Software Foundation; either version 2 of the License, or 10 * (at your option) any later version. 11 * 12 * This program is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 * GNU General Public License for more details. 16 * 17 * You should have received a copy of the GNU General Public License 18 * along with this program; if not, write to the Free Software 19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 20 * 21 * 22 * PCI functions for Integrator 23 */ 24#include <linux/kernel.h> 25#include <linux/pci.h> 26#include <linux/interrupt.h> 27#include <linux/init.h> 28 29#include <asm/irq.h> 30#include <asm/system.h> 31#include <asm/mach/pci.h> 32#include <asm/mach-types.h> 33 34/* 35 * A small note about bridges and interrupts. The DECchip 21050 (and 36 * later) adheres to the PCI-PCI bridge specification. This says that 37 * the interrupts on the other side of a bridge are swizzled in the 38 * following manner: 39 * 40 * Dev Interrupt Interrupt 41 * Pin on Pin on 42 * Device Connector 43 * 44 * 4 A A 45 * B B 46 * C C 47 * D D 48 * 49 * 5 A B 50 * B C 51 * C D 52 * D A 53 * 54 * 6 A C 55 * B D 56 * C A 57 * D B 58 * 59 * 7 A D 60 * B A 61 * C B 62 * D C 63 * 64 * Where A = pin 1, B = pin 2 and so on and pin=0 = default = A. 65 * Thus, each swizzle is ((pin-1) + (device#-4)) % 4 66 */ 67 68/* 69 * This routine handles multiple bridges. 70 */ 71static u8 __init integrator_swizzle(struct pci_dev *dev, u8 *pinp) 72{ 73 int pin = *pinp; 74 75 if (pin == 0) 76 pin = 1; 77 78 while (dev->bus->self) { 79 pin = pci_swizzle_interrupt_pin(dev, pin); 80 /* 81 * move up the chain of bridges, swizzling as we go. 82 */ 83 dev = dev->bus->self; 84 } 85 *pinp = pin; 86 87 return PCI_SLOT(dev->devfn); 88} 89 90static int irq_tab[4] __initdata = { 91 IRQ_AP_PCIINT0, IRQ_AP_PCIINT1, IRQ_AP_PCIINT2, IRQ_AP_PCIINT3 92}; 93 94/* 95 * map the specified device/slot/pin to an IRQ. This works out such 96 * that slot 9 pin 1 is INT0, pin 2 is INT1, and slot 10 pin 1 is INT1. 97 */ 98static int __init integrator_map_irq(struct pci_dev *dev, u8 slot, u8 pin) 99{ 100 int intnr = ((slot - 9) + (pin - 1)) & 3; 101 102 return irq_tab[intnr]; 103} 104 105extern void pci_v3_init(void *); 106 107static struct hw_pci integrator_pci __initdata = { 108 .swizzle = integrator_swizzle, 109 .map_irq = integrator_map_irq, 110 .setup = pci_v3_setup, 111 .nr_controllers = 1, 112 .scan = pci_v3_scan_bus, 113 .preinit = pci_v3_preinit, 114 .postinit = pci_v3_postinit, 115}; 116 117static int __init integrator_pci_init(void) 118{ 119 if (machine_is_integrator()) 120 pci_common_init(&integrator_pci); 121 return 0; 122} 123 124subsys_initcall(integrator_pci_init); 125