1// SPDX-License-Identifier: GPL-2.0
2/*
3 * PCI support for the Sega Dreamcast
4 *
5 * Copyright (C) 2001, 2002  M. R. Brown
6 * Copyright (C) 2002, 2003  Paul Mundt
7 *
8 * This file originally bore the message (with enclosed-$):
9 *	Id: pci.c,v 1.3 2003/05/04 19:29:46 lethal Exp
10 *	Dreamcast PCI: Supports SEGA Broadband Adaptor only.
11 */
12
13#include <linux/sched.h>
14#include <linux/kernel.h>
15#include <linux/param.h>
16#include <linux/interrupt.h>
17#include <linux/init.h>
18#include <linux/irq.h>
19#include <linux/pci.h>
20#include <linux/module.h>
21#include <asm/io.h>
22#include <asm/irq.h>
23#include <mach/pci.h>
24
25static struct resource gapspci_resources[] = {
26	{
27		.name	= "GAPSPCI IO",
28		.start	= GAPSPCI_BBA_CONFIG,
29		.end	= GAPSPCI_BBA_CONFIG + GAPSPCI_BBA_CONFIG_SIZE - 1,
30		.flags	= IORESOURCE_IO,
31	},  {
32		.name	= "GAPSPCI mem",
33		.start	= GAPSPCI_DMA_BASE,
34		.end	= GAPSPCI_DMA_BASE + GAPSPCI_DMA_SIZE - 1,
35		.flags	= IORESOURCE_MEM,
36	},
37};
38
39static struct pci_channel dreamcast_pci_controller = {
40	.pci_ops	= &gapspci_pci_ops,
41	.resources	= gapspci_resources,
42	.nr_resources	= ARRAY_SIZE(gapspci_resources),
43	.io_offset	= 0x00000000,
44	.mem_offset	= 0x00000000,
45};
46
47/*
48 * gapspci init
49 */
50
51static int __init gapspci_init(void)
52{
53	char idbuf[16];
54	int i;
55
56	/*
57	 * FIXME: All of this wants documenting to some degree,
58	 * even some basic register definitions would be nice.
59	 *
60	 * I haven't seen anything this ugly since.. maple.
61	 */
62
63	for (i=0; i<16; i++)
64		idbuf[i] = inb(GAPSPCI_REGS+i);
65
66	if (strncmp(idbuf, "GAPSPCI_BRIDGE_2", 16))
67		return -ENODEV;
68
69	outl(0x5a14a501, GAPSPCI_REGS+0x18);
70
71	for (i=0; i<1000000; i++)
72		cpu_relax();
73
74	if (inl(GAPSPCI_REGS+0x18) != 1)
75		return -EINVAL;
76
77	outl(0x01000000, GAPSPCI_REGS+0x20);
78	outl(0x01000000, GAPSPCI_REGS+0x24);
79
80	outl(GAPSPCI_DMA_BASE, GAPSPCI_REGS+0x28);
81	outl(GAPSPCI_DMA_BASE+GAPSPCI_DMA_SIZE, GAPSPCI_REGS+0x2c);
82
83	outl(1, GAPSPCI_REGS+0x14);
84	outl(1, GAPSPCI_REGS+0x34);
85
86	/* Setting Broadband Adapter */
87	outw(0xf900, GAPSPCI_BBA_CONFIG+0x06);
88	outl(0x00000000, GAPSPCI_BBA_CONFIG+0x30);
89	outb(0x00, GAPSPCI_BBA_CONFIG+0x3c);
90	outb(0xf0, GAPSPCI_BBA_CONFIG+0x0d);
91	outw(0x0006, GAPSPCI_BBA_CONFIG+0x04);
92	outl(0x00002001, GAPSPCI_BBA_CONFIG+0x10);
93	outl(0x01000000, GAPSPCI_BBA_CONFIG+0x14);
94
95	return register_pci_controller(&dreamcast_pci_controller);
96}
97arch_initcall(gapspci_init);
98