tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * BRIEF MODULE DESCRIPTION
3 * pci_ops for IDT EB434 board
4 *
5 * Copyright 2004 IDT Inc. (rischelp@idt.com)
6 * Copyright 2006 Felix Fietkau <nbd@openwrt.org>
7 *
8 * This program is free software; you can redistribute it and/or modify it
9 * under the terms of the GNU General Public License as published by the
10 * Free Software Foundation; either version 2 of the License, or (at your
11 * option) any later version.
12 *
13 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
14 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
15 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN
16 * NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
17 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
18 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
19 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
20 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
21 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
22 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
23 *
24 * You should have received a copy of the GNU General Public License along
25 * with this program; if not, write to the Free Software Foundation, Inc.,
26 * 675 Mass Ave, Cambridge, MA 02139, USA.
27 */
28#include <linux/delay.h>
29#include <linux/init.h>
30#include <linux/io.h>
31#include <linux/pci.h>
32#include <linux/types.h>
33
34#include <asm/cpu.h>
35#include <asm/mach-rc32434/rc32434.h>
36#include <asm/mach-rc32434/pci.h>
37
38#define PCI_ACCESS_READ 0
39#define PCI_ACCESS_WRITE 1
40
41
42#define PCI_CFG_SET(bus, slot, func, off) \
43 (rc32434_pci->pcicfga = (0x80000000 | \
44 ((bus) << 16) | ((slot)<<11) | \
45 ((func)<<8) | (off)))
46
47static inline int config_access(unsigned char access_type,
48 struct pci_bus *bus, unsigned int devfn,
49 unsigned char where, u32 *data)
50{
51 unsigned int slot = PCI_SLOT(devfn);
52 u8 func = PCI_FUNC(devfn);
53
54 /* Setup address */
55 PCI_CFG_SET(bus->number, slot, func, where);
56 rc32434_sync();
57
58 if (access_type == PCI_ACCESS_WRITE)
59 rc32434_pci->pcicfgd = *data;
60 else
61 *data = rc32434_pci->pcicfgd;
62
63 rc32434_sync();
64
65 return 0;
66}
67
68
69/*
70 * We can't address 8 and 16 bit words directly. Instead we have to
71 * read/write a 32bit word and mask/modify the data we actually want.
72 */
73static int read_config_byte(struct pci_bus *bus, unsigned int devfn,
74 int where, u8 *val)
75{
76 u32 data;
77 int ret;
78
79 ret = config_access(PCI_ACCESS_READ, bus, devfn, where, &data);
80 *val = (data >> ((where & 3) << 3)) & 0xff;
81 return ret;
82}
83
84static int read_config_word(struct pci_bus *bus, unsigned int devfn,
85 int where, u16 *val)
86{
87 u32 data;
88 int ret;
89
90 ret = config_access(PCI_ACCESS_READ, bus, devfn, where, &data);
91 *val = (data >> ((where & 3) << 3)) & 0xffff;
92 return ret;
93}
94
95static int read_config_dword(struct pci_bus *bus, unsigned int devfn,
96 int where, u32 *val)
97{
98 int ret;
99 int delay = 1;
100
101 /*
102 * Don't scan too far, else there will be errors with plugged in
103 * daughterboard (rb564).
104 */
105 if (bus->number == 0 && PCI_SLOT(devfn) > 21)
106 return 0;
107
108retry:
109 ret = config_access(PCI_ACCESS_READ, bus, devfn, where, val);
110
111 /*
112 * Certain devices react delayed at device scan time, this
113 * gives them time to settle
114 */
115 if (where == PCI_VENDOR_ID) {
116 if (ret == 0xffffffff || ret == 0x00000000 ||
117 ret == 0x0000ffff || ret == 0xffff0000) {
118 if (delay > 4)
119 return 0;
120 delay *= 2;
121 msleep(delay);
122 goto retry;
123 }
124 }
125
126 return ret;
127}
128
129static int
130write_config_byte(struct pci_bus *bus, unsigned int devfn, int where,
131 u8 val)
132{
133 u32 data = 0;
134
135 if (config_access(PCI_ACCESS_READ, bus, devfn, where, &data))
136 return -1;
137
138 data = (data & ~(0xff << ((where & 3) << 3))) |
139 (val << ((where & 3) << 3));
140
141 if (config_access(PCI_ACCESS_WRITE, bus, devfn, where, &data))
142 return -1;
143
144 return PCIBIOS_SUCCESSFUL;
145}
146
147
148static int
149write_config_word(struct pci_bus *bus, unsigned int devfn, int where,
150 u16 val)
151{
152 u32 data = 0;
153
154 if (config_access(PCI_ACCESS_READ, bus, devfn, where, &data))
155 return -1;
156
157 data = (data & ~(0xffff << ((where & 3) << 3))) |
158 (val << ((where & 3) << 3));
159
160 if (config_access(PCI_ACCESS_WRITE, bus, devfn, where, &data))
161 return -1;
162
163
164 return PCIBIOS_SUCCESSFUL;
165}
166
167
168static int
169write_config_dword(struct pci_bus *bus, unsigned int devfn, int where,
170 u32 val)
171{
172 if (config_access(PCI_ACCESS_WRITE, bus, devfn, where, &val))
173 return -1;
174
175 return PCIBIOS_SUCCESSFUL;
176}
177
178static int pci_config_read(struct pci_bus *bus, unsigned int devfn,
179 int where, int size, u32 *val)
180{
181 switch (size) {
182 case 1:
183 return read_config_byte(bus, devfn, where, (u8 *) val);
184 case 2:
185 return read_config_word(bus, devfn, where, (u16 *) val);
186 default:
187 return read_config_dword(bus, devfn, where, val);
188 }
189}
190
191static int pci_config_write(struct pci_bus *bus, unsigned int devfn,
192 int where, int size, u32 val)
193{
194 switch (size) {
195 case 1:
196 return write_config_byte(bus, devfn, where, (u8) val);
197 case 2:
198 return write_config_word(bus, devfn, where, (u16) val);
199 default:
200 return write_config_dword(bus, devfn, where, val);
201 }
202}
203
204struct pci_ops rc32434_pci_ops = {
205 .read = pci_config_read,
206 .write = pci_config_write,
207};