1/*
2 * PCI operations for the Sega Dreamcast
3 *
4 * Copyright (C) 2001, 2002  M. R. Brown
5 * Copyright (C) 2002, 2003  Paul Mundt
6 *
7 * This file is subject to the terms and conditions of the GNU General Public
8 * License.  See the file "COPYING" in the main directory of this archive
9 * for more details.
10 */
11
12#include <linux/sched.h>
13#include <linux/kernel.h>
14#include <linux/param.h>
15#include <linux/interrupt.h>
16#include <linux/init.h>
17#include <linux/irq.h>
18#include <linux/pci.h>
19#include <linux/module.h>
20#include <linux/io.h>
21#include <mach/pci.h>
22
23/*
24 * The !gapspci_config_access case really shouldn't happen, ever, unless
25 * someone implicitly messes around with the last devfn value.. otherwise we
26 * only support a single device anyways, and if we didn't have a BBA, we
27 * wouldn't make it terribly far through the PCI setup anyways.
28 *
29 * Also, we could very easily support both Type 0 and Type 1 configurations
30 * here, but since it doesn't seem that there is any such implementation in
31 * existence, we don't bother.
32 *
33 * I suppose if someone actually gets around to ripping the chip out of
34 * the BBA and hanging some more devices off of it, then this might be
35 * something to take into consideration. However, due to the cost of the BBA,
36 * and the general lack of activity by DC hardware hackers, this doesn't seem
37 * likely to happen anytime soon.
38 */
39static int gapspci_config_access(unsigned char bus, unsigned int devfn)
40{
41	return (bus == 0) && (devfn == 0);
42}
43
44/*
45 * We can also actually read and write in b/w/l sizes! Thankfully this part
46 * was at least done right, and we don't have to do the stupid masking and
47 * shifting that we do on the 7751! Small wonders never cease to amaze.
48 */
49static int gapspci_read(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 *val)
50{
51	*val = 0xffffffff;
52
53	if (!gapspci_config_access(bus->number, devfn))
54		return PCIBIOS_DEVICE_NOT_FOUND;
55
56	switch (size) {
57	case 1: *val = inb(GAPSPCI_BBA_CONFIG+where); break;
58	case 2: *val = inw(GAPSPCI_BBA_CONFIG+where); break;
59	case 4: *val = inl(GAPSPCI_BBA_CONFIG+where); break;
60	}
61
62        return PCIBIOS_SUCCESSFUL;
63}
64
65static int gapspci_write(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 val)
66{
67	if (!gapspci_config_access(bus->number, devfn))
68		return PCIBIOS_DEVICE_NOT_FOUND;
69
70	switch (size) {
71	case 1: outb(( u8)val, GAPSPCI_BBA_CONFIG+where); break;
72	case 2: outw((u16)val, GAPSPCI_BBA_CONFIG+where); break;
73	case 4: outl((u32)val, GAPSPCI_BBA_CONFIG+where); break;
74	}
75
76        return PCIBIOS_SUCCESSFUL;
77}
78
79struct pci_ops gapspci_pci_ops = {
80	.read	= gapspci_read,
81	.write	= gapspci_write,
82};
83