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/io.h>
30 #include <linux/pci.h>
31 #include <linux/types.h>
32
33 #include <asm/cpu.h>
34 #include <asm/mach-rc32434/rc32434.h>
35 #include <asm/mach-rc32434/pci.h>
36
37 #define PCI_ACCESS_READ 0
38 #define PCI_ACCESS_WRITE 1
39
40
41 #define PCI_CFG_SET(bus, slot, func, off) \
42 (rc32434_pci->pcicfga = (0x80000000 | \
43 ((bus) << 16) | ((slot)<<11) | \
44 ((func)<<8) | (off)))
45
config_access(unsigned char access_type,struct pci_bus * bus,unsigned int devfn,unsigned char where,u32 * data)46 static inline int config_access(unsigned char access_type,
47 struct pci_bus *bus, unsigned int devfn,
48 unsigned char where, u32 *data)
49 {
50 unsigned int slot = PCI_SLOT(devfn);
51 u8 func = PCI_FUNC(devfn);
52
53 /* Setup address */
54 PCI_CFG_SET(bus->number, slot, func, where);
55 rc32434_sync();
56
57 if (access_type == PCI_ACCESS_WRITE)
58 rc32434_pci->pcicfgd = *data;
59 else
60 *data = rc32434_pci->pcicfgd;
61
62 rc32434_sync();
63
64 return 0;
65 }
66
67
68 /*
69 * We can't address 8 and 16 bit words directly. Instead we have to
70 * read/write a 32bit word and mask/modify the data we actually want.
71 */
read_config_byte(struct pci_bus * bus,unsigned int devfn,int where,u8 * val)72 static int read_config_byte(struct pci_bus *bus, unsigned int devfn,
73 int where, u8 *val)
74 {
75 u32 data;
76 int ret;
77
78 ret = config_access(PCI_ACCESS_READ, bus, devfn, where, &data);
79 *val = (data >> ((where & 3) << 3)) & 0xff;
80 return ret;
81 }
82
read_config_word(struct pci_bus * bus,unsigned int devfn,int where,u16 * val)83 static int read_config_word(struct pci_bus *bus, unsigned int devfn,
84 int where, u16 *val)
85 {
86 u32 data;
87 int ret;
88
89 ret = config_access(PCI_ACCESS_READ, bus, devfn, where, &data);
90 *val = (data >> ((where & 3) << 3)) & 0xffff;
91 return ret;
92 }
93
read_config_dword(struct pci_bus * bus,unsigned int devfn,int where,u32 * val)94 static int read_config_dword(struct pci_bus *bus, unsigned int devfn,
95 int where, u32 *val)
96 {
97 int ret;
98 int delay = 1;
99
100 /*
101 * Don't scan too far, else there will be errors with plugged in
102 * daughterboard (rb564).
103 */
104 if (bus->number == 0 && PCI_SLOT(devfn) > 21)
105 return 0;
106
107 retry:
108 ret = config_access(PCI_ACCESS_READ, bus, devfn, where, val);
109
110 /*
111 * Certain devices react delayed at device scan time, this
112 * gives them time to settle
113 */
114 if (where == PCI_VENDOR_ID) {
115 if (ret == 0xffffffff || ret == 0x00000000 ||
116 ret == 0x0000ffff || ret == 0xffff0000) {
117 if (delay > 4)
118 return 0;
119 delay *= 2;
120 msleep(delay);
121 goto retry;
122 }
123 }
124
125 return ret;
126 }
127
128 static int
write_config_byte(struct pci_bus * bus,unsigned int devfn,int where,u8 val)129 write_config_byte(struct pci_bus *bus, unsigned int devfn, int where,
130 u8 val)
131 {
132 u32 data = 0;
133
134 if (config_access(PCI_ACCESS_READ, bus, devfn, where, &data))
135 return -1;
136
137 data = (data & ~(0xff << ((where & 3) << 3))) |
138 (val << ((where & 3) << 3));
139
140 if (config_access(PCI_ACCESS_WRITE, bus, devfn, where, &data))
141 return -1;
142
143 return PCIBIOS_SUCCESSFUL;
144 }
145
146
147 static int
write_config_word(struct pci_bus * bus,unsigned int devfn,int where,u16 val)148 write_config_word(struct pci_bus *bus, unsigned int devfn, int where,
149 u16 val)
150 {
151 u32 data = 0;
152
153 if (config_access(PCI_ACCESS_READ, bus, devfn, where, &data))
154 return -1;
155
156 data = (data & ~(0xffff << ((where & 3) << 3))) |
157 (val << ((where & 3) << 3));
158
159 if (config_access(PCI_ACCESS_WRITE, bus, devfn, where, &data))
160 return -1;
161
162
163 return PCIBIOS_SUCCESSFUL;
164 }
165
166
167 static int
write_config_dword(struct pci_bus * bus,unsigned int devfn,int where,u32 val)168 write_config_dword(struct pci_bus *bus, unsigned int devfn, int where,
169 u32 val)
170 {
171 if (config_access(PCI_ACCESS_WRITE, bus, devfn, where, &val))
172 return -1;
173
174 return PCIBIOS_SUCCESSFUL;
175 }
176
pci_config_read(struct pci_bus * bus,unsigned int devfn,int where,int size,u32 * val)177 static int pci_config_read(struct pci_bus *bus, unsigned int devfn,
178 int where, int size, u32 *val)
179 {
180 switch (size) {
181 case 1:
182 return read_config_byte(bus, devfn, where, (u8 *) val);
183 case 2:
184 return read_config_word(bus, devfn, where, (u16 *) val);
185 default:
186 return read_config_dword(bus, devfn, where, val);
187 }
188 }
189
pci_config_write(struct pci_bus * bus,unsigned int devfn,int where,int size,u32 val)190 static int pci_config_write(struct pci_bus *bus, unsigned int devfn,
191 int where, int size, u32 val)
192 {
193 switch (size) {
194 case 1:
195 return write_config_byte(bus, devfn, where, (u8) val);
196 case 2:
197 return write_config_word(bus, devfn, where, (u16) val);
198 default:
199 return write_config_dword(bus, devfn, where, val);
200 }
201 }
202
203 struct pci_ops rc32434_pci_ops = {
204 .read = pci_config_read,
205 .write = pci_config_write,
206 };
207