1 /*
2 * Copyright (C) 1999, 2000, 2004 MIPS Technologies, Inc.
3 * All rights reserved.
4 * Authors: Carsten Langgaard <carstenl@mips.com>
5 * Maciej W. Rozycki <macro@mips.com>
6 *
7 * This program is free software; you can distribute it and/or modify it
8 * under the terms of the GNU General Public License (Version 2) as
9 * published by the Free Software Foundation.
10 *
11 * This program is distributed in the hope it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * for more details.
15 *
16 * You should have received a copy of the GNU General Public License along
17 * with this program; if not, write to the Free Software Foundation, Inc.,
18 * 59 Temple Place - Suite 330, Boston MA 02111-1307, USA.
19 */
20 #include <linux/types.h>
21 #include <linux/pci.h>
22 #include <linux/kernel.h>
23
24 #include <asm/gt64120.h>
25
26 #define PCI_ACCESS_READ 0
27 #define PCI_ACCESS_WRITE 1
28
29 /*
30 * PCI configuration cycle AD bus definition
31 */
32 /* Type 0 */
33 #define PCI_CFG_TYPE0_REG_SHF 0
34 #define PCI_CFG_TYPE0_FUNC_SHF 8
35
36 /* Type 1 */
37 #define PCI_CFG_TYPE1_REG_SHF 0
38 #define PCI_CFG_TYPE1_FUNC_SHF 8
39 #define PCI_CFG_TYPE1_DEV_SHF 11
40 #define PCI_CFG_TYPE1_BUS_SHF 16
41
gt64xxx_pci0_pcibios_config_access(unsigned char access_type,struct pci_bus * bus,unsigned int devfn,int where,u32 * data)42 static int gt64xxx_pci0_pcibios_config_access(unsigned char access_type,
43 struct pci_bus *bus, unsigned int devfn, int where, u32 * data)
44 {
45 unsigned char busnum = bus->number;
46 u32 intr;
47
48 if ((busnum == 0) && (devfn >= PCI_DEVFN(31, 0)))
49 return -1; /* Because of a bug in the galileo (for slot 31). */
50
51 /* Clear cause register bits */
52 GT_WRITE(GT_INTRCAUSE_OFS, ~(GT_INTRCAUSE_MASABORT0_BIT |
53 GT_INTRCAUSE_TARABORT0_BIT));
54
55 /* Setup address */
56 GT_WRITE(GT_PCI0_CFGADDR_OFS,
57 (busnum << GT_PCI0_CFGADDR_BUSNUM_SHF) |
58 (devfn << GT_PCI0_CFGADDR_FUNCTNUM_SHF) |
59 ((where / 4) << GT_PCI0_CFGADDR_REGNUM_SHF) |
60 GT_PCI0_CFGADDR_CONFIGEN_BIT);
61
62 if (access_type == PCI_ACCESS_WRITE) {
63 if (busnum == 0 && PCI_SLOT(devfn) == 0) {
64 /*
65 * The Galileo system controller is acting
66 * differently than other devices.
67 */
68 GT_WRITE(GT_PCI0_CFGDATA_OFS, *data);
69 } else
70 __GT_WRITE(GT_PCI0_CFGDATA_OFS, *data);
71 } else {
72 if (busnum == 0 && PCI_SLOT(devfn) == 0) {
73 /*
74 * The Galileo system controller is acting
75 * differently than other devices.
76 */
77 *data = GT_READ(GT_PCI0_CFGDATA_OFS);
78 } else
79 *data = __GT_READ(GT_PCI0_CFGDATA_OFS);
80 }
81
82 /* Check for master or target abort */
83 intr = GT_READ(GT_INTRCAUSE_OFS);
84
85 if (intr & (GT_INTRCAUSE_MASABORT0_BIT | GT_INTRCAUSE_TARABORT0_BIT)) {
86 /* Error occurred */
87
88 /* Clear bits */
89 GT_WRITE(GT_INTRCAUSE_OFS, ~(GT_INTRCAUSE_MASABORT0_BIT |
90 GT_INTRCAUSE_TARABORT0_BIT));
91
92 return -1;
93 }
94
95 return 0;
96 }
97
98
99 /*
100 * We can't address 8 and 16 bit words directly. Instead we have to
101 * read/write a 32bit word and mask/modify the data we actually want.
102 */
gt64xxx_pci0_pcibios_read(struct pci_bus * bus,unsigned int devfn,int where,int size,u32 * val)103 static int gt64xxx_pci0_pcibios_read(struct pci_bus *bus, unsigned int devfn,
104 int where, int size, u32 * val)
105 {
106 u32 data = 0;
107
108 if (gt64xxx_pci0_pcibios_config_access(PCI_ACCESS_READ, bus, devfn,
109 where, &data))
110 return PCIBIOS_DEVICE_NOT_FOUND;
111
112 if (size == 1)
113 *val = (data >> ((where & 3) << 3)) & 0xff;
114 else if (size == 2)
115 *val = (data >> ((where & 3) << 3)) & 0xffff;
116 else
117 *val = data;
118
119 return PCIBIOS_SUCCESSFUL;
120 }
121
gt64xxx_pci0_pcibios_write(struct pci_bus * bus,unsigned int devfn,int where,int size,u32 val)122 static int gt64xxx_pci0_pcibios_write(struct pci_bus *bus, unsigned int devfn,
123 int where, int size, u32 val)
124 {
125 u32 data = 0;
126
127 if (size == 4)
128 data = val;
129 else {
130 if (gt64xxx_pci0_pcibios_config_access(PCI_ACCESS_READ, bus,
131 devfn, where, &data))
132 return PCIBIOS_DEVICE_NOT_FOUND;
133
134 if (size == 1)
135 data = (data & ~(0xff << ((where & 3) << 3))) |
136 (val << ((where & 3) << 3));
137 else if (size == 2)
138 data = (data & ~(0xffff << ((where & 3) << 3))) |
139 (val << ((where & 3) << 3));
140 }
141
142 if (gt64xxx_pci0_pcibios_config_access(PCI_ACCESS_WRITE, bus, devfn,
143 where, &data))
144 return PCIBIOS_DEVICE_NOT_FOUND;
145
146 return PCIBIOS_SUCCESSFUL;
147 }
148
149 struct pci_ops gt64xxx_pci0_ops = {
150 .read = gt64xxx_pci0_pcibios_read,
151 .write = gt64xxx_pci0_pcibios_write
152 };
153