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pci.c
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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/mach/pci.h>
30 #include <asm/mach-types.h>
31 
32 #include <mach/irqs.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  */
71 static u8 __init integrator_swizzle(struct pci_dev *dev, u8 *pinp)
72 {
73  if (*pinp == 0)
74  *pinp = 1;
75 
76  return pci_common_swizzle(dev, pinp);
77 }
78 
79 static int irq_tab[4] __initdata = {
81 };
82 
83 /*
84  * map the specified device/slot/pin to an IRQ. This works out such
85  * that slot 9 pin 1 is INT0, pin 2 is INT1, and slot 10 pin 1 is INT1.
86  */
87 static int __init integrator_map_irq(const struct pci_dev *dev, u8 slot, u8 pin)
88 {
89  int intnr = ((slot - 9) + (pin - 1)) & 3;
90 
91  return irq_tab[intnr];
92 }
93 
94 extern void pci_v3_init(void *);
95 
96 static struct hw_pci integrator_pci __initdata = {
97  .swizzle = integrator_swizzle,
98  .map_irq = integrator_map_irq,
99  .setup = pci_v3_setup,
100  .nr_controllers = 1,
101  .ops = &pci_v3_ops,
102  .preinit = pci_v3_preinit,
103  .postinit = pci_v3_postinit,
104 };
105 
106 static int __init integrator_pci_init(void)
107 {
108  if (machine_is_integrator())
109  pci_common_init(&integrator_pci);
110  return 0;
111 }
112 
113 subsys_initcall(integrator_pci_init);