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(const 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);