1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (C) 1999, 2000, 2004 MIPS Technologies, Inc.
4 * All rights reserved.
5 * Authors: Carsten Langgaard <carstenl@mips.com>
6 * Maciej W. Rozycki <macro@mips.com>
7 *
8 * MIPS boards specific PCI support.
9 */
10 #include <linux/types.h>
11 #include <linux/pci.h>
12 #include <linux/kernel.h>
13
14 #include <asm/mips-boards/bonito64.h>
15
16 #define PCI_ACCESS_READ 0
17 #define PCI_ACCESS_WRITE 1
18
19 #define CFG_SPACE_REG(offset) (void *)CKSEG1ADDR(_pcictrl_bonito_pcicfg + (offset))
20 #define ID_SEL_BEGIN 10
21 #define MAX_DEV_NUM (31 - ID_SEL_BEGIN)
22
23
24 static int bonito64_pcibios_config_access(unsigned char access_type,
25 struct pci_bus *bus,
26 unsigned int devfn, int where,
27 u32 * data)
28 {
29 u32 busnum = bus->number;
30 u32 addr, type;
31 u32 dummy;
32 void *addrp;
33 int device = PCI_SLOT(devfn);
34 int function = PCI_FUNC(devfn);
35 int reg = where & ~3;
36
37 if (busnum == 0) {
38 /* Type 0 configuration for onboard PCI bus */
39 if (device > MAX_DEV_NUM)
40 return -1;
41
42 addr = (1 << (device + ID_SEL_BEGIN)) | (function << 8) | reg;
43 type = 0;
44 } else {
45 /* Type 1 configuration for offboard PCI bus */
46 addr = (busnum << 16) | (device << 11) | (function << 8) | reg;
47 type = 0x10000;
48 }
49
50 /* Clear aborts */
51 BONITO_PCICMD |= BONITO_PCICMD_MABORT_CLR | BONITO_PCICMD_MTABORT_CLR;
52
53 BONITO_PCIMAP_CFG = (addr >> 16) | type;
54
55 /* Flush Bonito register block */
56 dummy = BONITO_PCIMAP_CFG;
57 mmiowb();
58
59 addrp = CFG_SPACE_REG(addr & 0xffff);
60 if (access_type == PCI_ACCESS_WRITE) {
61 writel(cpu_to_le32(*data), addrp);
62 /* Wait till done */
63 while (BONITO_PCIMSTAT & 0xF);
64 } else {
65 *data = le32_to_cpu(readl(addrp));
66 }
67
68 /* Detect Master/Target abort */
69 if (BONITO_PCICMD & (BONITO_PCICMD_MABORT_CLR |
70 BONITO_PCICMD_MTABORT_CLR)) {
71 /* Error occurred */
72
73 /* Clear bits */
74 BONITO_PCICMD |= (BONITO_PCICMD_MABORT_CLR |
75 BONITO_PCICMD_MTABORT_CLR);
76
77 return -1;
78 }
79
80 return 0;
81
82 }
83
84
85 /*
86 * We can't address 8 and 16 bit words directly. Instead we have to
87 * read/write a 32bit word and mask/modify the data we actually want.
88 */
89 static int bonito64_pcibios_read(struct pci_bus *bus, unsigned int devfn,
90 int where, int size, u32 * val)
91 {
92 u32 data = 0;
93
94 if ((size == 2) && (where & 1))
95 return PCIBIOS_BAD_REGISTER_NUMBER;
96 else if ((size == 4) && (where & 3))
97 return PCIBIOS_BAD_REGISTER_NUMBER;
98
99 if (bonito64_pcibios_config_access(PCI_ACCESS_READ, bus, devfn, where,
100 &data))
101 return -1;
102
103 if (size == 1)
104 *val = (data >> ((where & 3) << 3)) & 0xff;
105 else if (size == 2)
106 *val = (data >> ((where & 3) << 3)) & 0xffff;
107 else
108 *val = data;
109
110 return PCIBIOS_SUCCESSFUL;
111 }
112
113 static int bonito64_pcibios_write(struct pci_bus *bus, unsigned int devfn,
114 int where, int size, u32 val)
115 {
116 u32 data = 0;
117
118 if ((size == 2) && (where & 1))
119 return PCIBIOS_BAD_REGISTER_NUMBER;
120 else if ((size == 4) && (where & 3))
121 return PCIBIOS_BAD_REGISTER_NUMBER;
122
123 if (size == 4)
124 data = val;
125 else {
126 if (bonito64_pcibios_config_access(PCI_ACCESS_READ, bus, devfn,
127 where, &data))
128 return -1;
129
130 if (size == 1)
131 data = (data & ~(0xff << ((where & 3) << 3))) |
132 (val << ((where & 3) << 3));
133 else if (size == 2)
134 data = (data & ~(0xffff << ((where & 3) << 3))) |
135 (val << ((where & 3) << 3));
136 }
137
138 if (bonito64_pcibios_config_access(PCI_ACCESS_WRITE, bus, devfn, where,
139 &data))
140 return -1;
141
142 return PCIBIOS_SUCCESSFUL;
143 }
144
145 struct pci_ops bonito64_pci_ops = {
146 .read = bonito64_pcibios_read,
147 .write = bonito64_pcibios_write
148 };
149
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.