1 /*
2  * arch/sh/drivers/pci/ops-dreamcast.c
3  *
4  * PCI operations for the Sega Dreamcast
5  *
6  * Copyright (C) 2001, 2002  M. R. Brown
7  * Copyright (C) 2002, 2003  Paul Mundt
8  *
9  * This file originally bore the message (with enclosed-$):
10  *	Id: pci.c,v 1.3 2003/05/04 19:29:46 lethal Exp
11  *	Dreamcast PCI: Supports SEGA Broadband Adaptor only.
12  *
13  * This file is subject to the terms and conditions of the GNU General Public
14  * License.  See the file "COPYING" in the main directory of this archive
15  * for more details.
16  */
17 
18 #include <linux/sched.h>
19 #include <linux/kernel.h>
20 #include <linux/param.h>
21 #include <linux/interrupt.h>
22 #include <linux/init.h>
23 #include <linux/irq.h>
24 #include <linux/pci.h>
25 #include <linux/module.h>
26 
27 #include <asm/io.h>
28 #include <asm/irq.h>
29 #include <mach/pci.h>
30 
31 static struct resource gapspci_io_resource = {
32 	.name	= "GAPSPCI IO",
33 	.start	= GAPSPCI_BBA_CONFIG,
34 	.end	= GAPSPCI_BBA_CONFIG + GAPSPCI_BBA_CONFIG_SIZE - 1,
35 	.flags	= IORESOURCE_IO,
36 };
37 
38 static struct resource gapspci_mem_resource = {
39 	.name	= "GAPSPCI mem",
40 	.start	= GAPSPCI_DMA_BASE,
41 	.end	= GAPSPCI_DMA_BASE + GAPSPCI_DMA_SIZE - 1,
42 	.flags	= IORESOURCE_MEM,
43 };
44 
45 static struct pci_ops gapspci_pci_ops;
46 
47 struct pci_channel board_pci_channels[] = {
48 	{ &gapspci_pci_ops, &gapspci_io_resource,
49 	  &gapspci_mem_resource, 0, 1 },
50 	{ 0, }
51 };
52 EXPORT_SYMBOL(board_pci_channels);
53 
54 /*
55  * The !gapspci_config_access case really shouldn't happen, ever, unless
56  * someone implicitly messes around with the last devfn value.. otherwise we
57  * only support a single device anyways, and if we didn't have a BBA, we
58  * wouldn't make it terribly far through the PCI setup anyways.
59  *
60  * Also, we could very easily support both Type 0 and Type 1 configurations
61  * here, but since it doesn't seem that there is any such implementation in
62  * existence, we don't bother.
63  *
64  * I suppose if someone actually gets around to ripping the chip out of
65  * the BBA and hanging some more devices off of it, then this might be
66  * something to take into consideration. However, due to the cost of the BBA,
67  * and the general lack of activity by DC hardware hackers, this doesn't seem
68  * likely to happen anytime soon.
69  */
70 static int gapspci_config_access(unsigned char bus, unsigned int devfn)
71 {
72 	return (bus == 0) && (devfn == 0);
73 }
74 
75 /*
76  * We can also actually read and write in b/w/l sizes! Thankfully this part
77  * was at least done right, and we don't have to do the stupid masking and
78  * shifting that we do on the 7751! Small wonders never cease to amaze.
79  */
80 static int gapspci_read(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 *val)
81 {
82 	*val = 0xffffffff;
83 
84 	if (!gapspci_config_access(bus->number, devfn))
85 		return PCIBIOS_DEVICE_NOT_FOUND;
86 
87 	switch (size) {
88 		case 1: *val = inb(GAPSPCI_BBA_CONFIG+where); break;
89 		case 2: *val = inw(GAPSPCI_BBA_CONFIG+where); break;
90 		case 4: *val = inl(GAPSPCI_BBA_CONFIG+where); break;
91 	}
92 
93         return PCIBIOS_SUCCESSFUL;
94 }
95 
96 static int gapspci_write(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 val)
97 {
98 	if (!gapspci_config_access(bus->number, devfn))
99 		return PCIBIOS_DEVICE_NOT_FOUND;
100 
101 	switch (size) {
102 		case 1: outb(( u8)val, GAPSPCI_BBA_CONFIG+where); break;
103 		case 2: outw((u16)val, GAPSPCI_BBA_CONFIG+where); break;
104 		case 4: outl((u32)val, GAPSPCI_BBA_CONFIG+where); break;
105 	}
106 
107         return PCIBIOS_SUCCESSFUL;
108 }
109 
110 static struct pci_ops gapspci_pci_ops = {
111 	.read	= gapspci_read,
112 	.write	= gapspci_write,
113 };
114 
115 /*
116  * gapspci init
117  */
118 
119 int __init gapspci_init(void)
120 {
121 	char idbuf[16];
122 	int i;
123 
124 	/*
125 	 * FIXME: All of this wants documenting to some degree,
126 	 * even some basic register definitions would be nice.
127 	 *
128 	 * I haven't seen anything this ugly since.. maple.
129 	 */
130 
131 	for (i=0; i<16; i++)
132 		idbuf[i] = inb(GAPSPCI_REGS+i);
133 
134 	if (strncmp(idbuf, "GAPSPCI_BRIDGE_2", 16))
135 		return -ENODEV;
136 
137 	outl(0x5a14a501, GAPSPCI_REGS+0x18);
138 
139 	for (i=0; i<1000000; i++)
140 		;
141 
142 	if (inl(GAPSPCI_REGS+0x18) != 1)
143 		return -EINVAL;
144 
145 	outl(0x01000000, GAPSPCI_REGS+0x20);
146 	outl(0x01000000, GAPSPCI_REGS+0x24);
147 
148 	outl(GAPSPCI_DMA_BASE, GAPSPCI_REGS+0x28);
149 	outl(GAPSPCI_DMA_BASE+GAPSPCI_DMA_SIZE, GAPSPCI_REGS+0x2c);
150 
151 	outl(1, GAPSPCI_REGS+0x14);
152 	outl(1, GAPSPCI_REGS+0x34);
153 
154 	/* Setting Broadband Adapter */
155 	outw(0xf900, GAPSPCI_BBA_CONFIG+0x06);
156 	outl(0x00000000, GAPSPCI_BBA_CONFIG+0x30);
157 	outb(0x00, GAPSPCI_BBA_CONFIG+0x3c);
158 	outb(0xf0, GAPSPCI_BBA_CONFIG+0x0d);
159 	outw(0x0006, GAPSPCI_BBA_CONFIG+0x04);
160 	outl(0x00002001, GAPSPCI_BBA_CONFIG+0x10);
161 	outl(0x01000000, GAPSPCI_BBA_CONFIG+0x14);
162 
163 	return 0;
164 }
165 
166 /* Haven't done anything here as yet */
167 char * __devinit pcibios_setup(char *str)
168 {
169 	return str;
170 }
171