aboutsummaryrefslogtreecommitdiffstats
path: root/arch/mips/pci/ops-sni.c
blob: 97ed25b92edfbee1414425ea217351c60c28e115 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * SNI specific PCI support for RM200/RM300.
 *
 * Copyright (C) 1997 - 2000, 2003 Ralf Baechle <ralf@linux-mips.org>
 */
#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/types.h>
#include <asm/sni.h>

/*
 * It seems that on the RM200 only lower 3 bits of the 5 bit PCI device
 * address are decoded.  We therefore manually have to reject attempts at
 * reading outside this range.  Being on the paranoid side we only do this
 * test for bus 0 and hope forwarding and decoding work properly for any
 * subordinated busses.
 *
 * ASIC PCI only supports type 1 config cycles.
 */
static int set_config_address(unsigned int busno, unsigned int devfn, int reg)
{
	if ((devfn > 255) || (reg > 255))
		return PCIBIOS_BAD_REGISTER_NUMBER;

	if (busno == 0 && devfn >= PCI_DEVFN(8, 0))
		return PCIBIOS_DEVICE_NOT_FOUND;

	*(volatile u32 *)PCIMT_CONFIG_ADDRESS =
		 ((busno    & 0xff) << 16) |
	         ((devfn    & 0xff) <<  8) |
	          (reg      & 0xfc);

	return PCIBIOS_SUCCESSFUL;
}

static int pcimt_read(struct pci_bus *bus, unsigned int devfn, int reg,
		      int size, u32 * val)
{
	int res;

	if ((res = set_config_address(bus->number, devfn, reg)))
		return res;

	switch (size) {
	case 1:
		*val = inb(PCIMT_CONFIG_DATA + (reg & 3));
		break;
	case 2:
		*val = inw(PCIMT_CONFIG_DATA + (reg & 2));
		break;
	case 4:
		*val = inl(PCIMT_CONFIG_DATA);
		break;
	}

	return 0;
}

static int pcimt_write(struct pci_bus *bus, unsigned int devfn, int reg,
		       int size, u32 val)
{
	int res;

	if ((res = set_config_address(bus->number, devfn, reg)))
		return res;

	switch (size) {
	case 1:
		outb(val, PCIMT_CONFIG_DATA + (reg & 3));
		break;
	case 2:
		outw(val, PCIMT_CONFIG_DATA + (reg & 2));
		break;
	case 4:
		outl(val, PCIMT_CONFIG_DATA);
		break;
	}

	return 0;
}

struct pci_ops sni_pcimt_ops = {
	.read = pcimt_read,
	.write = pcimt_write,
};

static int pcit_set_config_address(unsigned int busno, unsigned int devfn, int reg)
{
	if ((devfn > 255) || (reg > 255) || (busno > 255))
		return PCIBIOS_BAD_REGISTER_NUMBER;

	outl((1 << 31) | ((busno & 0xff) << 16) | ((devfn & 0xff) << 8) | (reg & 0xfc), 0xcf8);
	return PCIBIOS_SUCCESSFUL;
}

static int pcit_read(struct pci_bus *bus, unsigned int devfn, int reg,
		      int size, u32 * val)
{
	int res;

	/*
	 * on bus 0 we need to check, whether there is a device answering
	 * for the devfn by doing a config write and checking the result. If
	 * we don't do it, we will get a data bus error
	 */
	if (bus->number == 0) {
		pcit_set_config_address(0, 0, 0x68);
		outl(inl(0xcfc) | 0xc0000000, 0xcfc);
		if ((res = pcit_set_config_address(0, devfn, 0)))
			return res;
		outl(0xffffffff, 0xcfc);
		pcit_set_config_address(0, 0, 0x68);
		if (inl(0xcfc) & 0x100000)
			return PCIBIOS_DEVICE_NOT_FOUND;
	}
	if ((res = pcit_set_config_address(bus->number, devfn, reg)))
		return res;

	switch (size) {
	case 1:
		*val = inb(PCIMT_CONFIG_DATA + (reg & 3));
		break;
	case 2:
		*val = inw(PCIMT_CONFIG_DATA + (reg & 2));
		break;
	case 4:
		*val = inl(PCIMT_CONFIG_DATA);
		break;
	}
	return 0;
}

static int pcit_write(struct pci_bus *bus, unsigned int devfn, int reg,
		       int size, u32 val)
{
	int res;

	if ((res = pcit_set_config_address(bus->number, devfn, reg)))
		return res;

	switch (size) {
	case 1:
		outb(val, PCIMT_CONFIG_DATA + (reg & 3));
		break;
	case 2:
		outw(val, PCIMT_CONFIG_DATA + (reg & 2));
		break;
	case 4:
		outl(val, PCIMT_CONFIG_DATA);
		break;
	}

	return 0;
}


struct pci_ops sni_pcit_ops = {
	.read = pcit_read,
	.write = pcit_write,
};