aboutsummaryrefslogtreecommitdiff
path: root/arch/mips/pci/ops-rc32434.c
blob: 874ed6df97683ad1d6dbce7b49c72c091e64488c (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
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
/*
 *  BRIEF MODULE DESCRIPTION
 *     pci_ops for IDT EB434 board
 *
 *  Copyright 2004 IDT Inc. (rischelp@idt.com)
 *  Copyright 2006 Felix Fietkau <nbd@openwrt.org>
 *
 *  This program is free software; you can redistribute  it and/or modify it
 *  under  the terms of  the GNU General  Public License as published by the
 *  Free Software Foundation;  either version 2 of the  License, or (at your
 *  option) any later version.
 *
 *  THIS  SOFTWARE  IS PROVIDED   ``AS  IS'' AND   ANY  EXPRESS OR IMPLIED
 *  WARRANTIES,   INCLUDING, BUT NOT  LIMITED  TO, THE IMPLIED WARRANTIES OF
 *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  IN
 *  NO  EVENT  SHALL   THE AUTHOR  BE    LIABLE FOR ANY   DIRECT, INDIRECT,
 *  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 *  NOT LIMITED   TO, PROCUREMENT OF  SUBSTITUTE GOODS  OR SERVICES; LOSS OF
 *  USE, DATA,  OR PROFITS; OR  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
 *  ANY THEORY OF LIABILITY, WHETHER IN  CONTRACT, STRICT LIABILITY, OR TORT
 *  (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 *  THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 *  You should have received a copy of the  GNU General Public License along
 *  with this program; if not, write  to the Free Software Foundation, Inc.,
 *  675 Mass Ave, Cambridge, MA 02139, USA.
 */
#include <linux/delay.h>
#include <linux/io.h>
#include <linux/pci.h>
#include <linux/types.h>

#include <asm/cpu.h>
#include <asm/mach-rc32434/rc32434.h>
#include <asm/mach-rc32434/pci.h>

#define PCI_ACCESS_READ	 0
#define PCI_ACCESS_WRITE 1


#define PCI_CFG_SET(bus, slot, func, off) \
	(rc32434_pci->pcicfga = (0x80000000 | \
				((bus) << 16) | ((slot)<<11) | \
				((func)<<8) | (off)))

static inline int config_access(unsigned char access_type,
				struct pci_bus *bus, unsigned int devfn,
				unsigned char where, u32 *data)
{
	unsigned int slot = PCI_SLOT(devfn);
	u8 func = PCI_FUNC(devfn);

	/* Setup address */
	PCI_CFG_SET(bus->number, slot, func, where);
	rc32434_sync();

	if (access_type == PCI_ACCESS_WRITE)
		rc32434_pci->pcicfgd = *data;
	else
		*data = rc32434_pci->pcicfgd;

	rc32434_sync();

	return 0;
}


/*
 * We can't address 8 and 16 bit words directly.  Instead we have to
 * read/write a 32bit word and mask/modify the data we actually want.
 */
static int read_config_byte(struct pci_bus *bus, unsigned int devfn,
			    int where, u8 *val)
{
	u32 data;
	int ret;

	ret = config_access(PCI_ACCESS_READ, bus, devfn, where, &data);
	*val = (data >> ((where & 3) << 3)) & 0xff;
	return ret;
}

static int read_config_word(struct pci_bus *bus, unsigned int devfn,
			    int where, u16 *val)
{
	u32 data;
	int ret;

	ret = config_access(PCI_ACCESS_READ, bus, devfn, where, &data);
	*val = (data >> ((where & 3) << 3)) & 0xffff;
	return ret;
}

static int read_config_dword(struct pci_bus *bus, unsigned int devfn,
			     int where, u32 *val)
{
	int ret;
	int delay = 1;

	/*
	 * Don't scan too far, else there will be errors with plugged in
	 * daughterboard (rb564).
	 */
	if (bus->number == 0 && PCI_SLOT(devfn) > 21)
		return 0;

retry:
	ret = config_access(PCI_ACCESS_READ, bus, devfn, where, val);

	/*
	 * Certain devices react delayed at device scan time, this
	 * gives them time to settle
	 */
	if (where == PCI_VENDOR_ID) {
		if (ret == 0xffffffff || ret == 0x00000000 ||
		    ret == 0x0000ffff || ret == 0xffff0000) {
			if (delay > 4)
				return 0;
			delay *= 2;
			msleep(delay);
			goto retry;
		}
	}

	return ret;
}

static int
write_config_byte(struct pci_bus *bus, unsigned int devfn, int where,
		  u8 val)
{
	u32 data = 0;

	if (config_access(PCI_ACCESS_READ, bus, devfn, where, &data))
		return -1;

	data = (data & ~(0xff << ((where & 3) << 3))) |
	    (val << ((where & 3) << 3));

	if (config_access(PCI_ACCESS_WRITE, bus, devfn, where, &data))
		return -1;

	return PCIBIOS_SUCCESSFUL;
}


static int
write_config_word(struct pci_bus *bus, unsigned int devfn, int where,
		  u16 val)
{
	u32 data = 0;

	if (config_access(PCI_ACCESS_READ, bus, devfn, where, &data))
		return -1;

	data = (data & ~(0xffff << ((where & 3) << 3))) |
	    (val << ((where & 3) << 3));

	if (config_access(PCI_ACCESS_WRITE, bus, devfn, where, &data))
		return -1;


	return PCIBIOS_SUCCESSFUL;
}


static int
write_config_dword(struct pci_bus *bus, unsigned int devfn, int where,
		   u32 val)
{
	if (config_access(PCI_ACCESS_WRITE, bus, devfn, where, &val))
		return -1;

	return PCIBIOS_SUCCESSFUL;
}

static int pci_config_read(struct pci_bus *bus, unsigned int devfn,
			   int where, int size, u32 *val)
{
	switch (size) {
	case 1:
		return read_config_byte(bus, devfn, where, (u8 *) val);
	case 2:
		return read_config_word(bus, devfn, where, (u16 *) val);
	default:
		return read_config_dword(bus, devfn, where, val);
	}
}

static int pci_config_write(struct pci_bus *bus, unsigned int devfn,
			    int where, int size, u32 val)
{
	switch (size) {
	case 1:
		return write_config_byte(bus, devfn, where, (u8) val);
	case 2:
		return write_config_word(bus, devfn, where, (u16) val);
	default:
		return write_config_dword(bus, devfn, where, val);
	}
}

struct pci_ops rc32434_pci_ops = {
	.read = pci_config_read,
	.write = pci_config_write,
};