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 */
integrator_swizzle(struct pci_dev * dev,u8 * pinp)71 static 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
90 static 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 */
integrator_map_irq(struct pci_dev * dev,u8 slot,u8 pin)98 static 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
105 extern void pci_v3_init(void *);
106
107 static 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
integrator_pci_init(void)117 static int __init integrator_pci_init(void)
118 {
119 if (machine_is_integrator())
120 pci_common_init(&integrator_pci);
121 return 0;
122 }
123
124 subsys_initcall(integrator_pci_init);
125