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