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
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
|
/*
* (C) Copyright 2003,Motorola Inc.
* Xianghua Xiao <x.xiao@motorola.com>
* Adapted for Motorola 85xx chip.
*
* (C) Copyright 2003
* Gleb Natapov <gnatapov@mrv.com>
* Some bits are taken from linux driver writen by adrian@humboldt.co.uk
*
* Hardware I2C driver for MPC107 PCI bridge.
*
* See file CREDITS for list of people who contributed to this
* project.
*
* 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 program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* 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., 59 Temple Place, Suite 330, Boston,
* MA 02111-1307 USA
*/
#include <common.h>
#include <command.h>
#include <asm/io.h>
#ifdef CONFIG_HARD_I2C
#include <i2c.h>
#define TIMEOUT (CFG_HZ/4)
#define I2C_Addr ((u8 *)(CFG_CCSRBAR + 0x3000))
#define I2CADR &I2C_Addr[0]
#define I2CFDR &I2C_Addr[4]
#define I2CCCR &I2C_Addr[8]
#define I2CCSR &I2C_Addr[12]
#define I2CCDR &I2C_Addr[16]
#define I2CDFSRR &I2C_Addr[20]
#define I2C_READ 1
#define I2C_WRITE 0
void
i2c_init(int speed, int slaveadd)
{
/* stop I2C controller */
writeb(0x0, I2CCCR);
/* set clock */
writeb(0x3f, I2CFDR);
/* set default filter */
writeb(0x10,I2CDFSRR);
/* write slave address */
writeb(slaveadd, I2CADR);
/* clear status register */
writeb(0x0, I2CCSR);
/* start I2C controller */
writeb(MPC85xx_I2CCR_MEN, I2CCCR);
}
static __inline__ int
i2c_wait4bus (void)
{
ulong timeval = get_timer (0);
while (readb(I2CCSR) & MPC85xx_I2CSR_MBB) {
if (get_timer (timeval) > TIMEOUT) {
return -1;
}
}
return 0;
}
static __inline__ int
i2c_wait (int write)
{
u32 csr;
ulong timeval = get_timer (0);
do {
csr = readb(I2CCSR);
if (!(csr & MPC85xx_I2CSR_MIF))
continue;
writeb(0x0, I2CCSR);
if (csr & MPC85xx_I2CSR_MAL) {
debug("i2c_wait: MAL\n");
return -1;
}
if (!(csr & MPC85xx_I2CSR_MCF)) {
debug("i2c_wait: unfinished\n");
return -1;
}
if (write == I2C_WRITE && (csr & MPC85xx_I2CSR_RXAK)) {
debug("i2c_wait: No RXACK\n");
return -1;
}
return 0;
} while (get_timer (timeval) < TIMEOUT);
debug("i2c_wait: timed out\n");
return -1;
}
static __inline__ int
i2c_write_addr (u8 dev, u8 dir, int rsta)
{
writeb(MPC85xx_I2CCR_MEN | MPC85xx_I2CCR_MSTA | MPC85xx_I2CCR_MTX |
(rsta?MPC85xx_I2CCR_RSTA:0),
I2CCCR);
writeb((dev << 1) | dir, I2CCDR);
if (i2c_wait (I2C_WRITE) < 0)
return 0;
return 1;
}
static __inline__ int
__i2c_write (u8 *data, int length)
{
int i;
writeb(MPC85xx_I2CCR_MEN | MPC85xx_I2CCR_MSTA | MPC85xx_I2CCR_MTX,
I2CCCR);
for (i=0; i < length; i++) {
writeb(data[i], I2CCDR);
if (i2c_wait (I2C_WRITE) < 0)
break;
}
return i;
}
static __inline__ int
__i2c_read (u8 *data, int length)
{
int i;
writeb(MPC85xx_I2CCR_MEN | MPC85xx_I2CCR_MSTA |
((length == 1) ? MPC85xx_I2CCR_TXAK : 0),
I2CCCR);
/* dummy read */
readb(I2CCDR);
for (i=0; i < length; i++) {
if (i2c_wait (I2C_READ) < 0)
break;
/* Generate ack on last next to last byte */
if (i == length - 2)
writeb(MPC85xx_I2CCR_MEN | MPC85xx_I2CCR_MSTA |
MPC85xx_I2CCR_TXAK,
I2CCCR);
/* Generate stop on last byte */
if (i == length - 1)
writeb(MPC85xx_I2CCR_MEN | MPC85xx_I2CCR_TXAK, I2CCCR);
data[i] = readb(I2CCDR);
}
return i;
}
int
i2c_read (u8 dev, uint addr, int alen, u8 *data, int length)
{
int i = 0;
u8 *a = (u8*)&addr;
if (i2c_wait4bus () < 0)
goto exit;
if (i2c_write_addr (dev, I2C_WRITE, 0) == 0)
goto exit;
if (__i2c_write (&a[4 - alen], alen) != alen)
goto exit;
if (i2c_write_addr (dev, I2C_READ, 1) == 0)
goto exit;
i = __i2c_read (data, length);
exit:
writeb(MPC85xx_I2CCR_MEN, I2CCCR);
return !(i == length);
}
int
i2c_write (u8 dev, uint addr, int alen, u8 *data, int length)
{
int i = 0;
u8 *a = (u8*)&addr;
if (i2c_wait4bus () < 0)
goto exit;
if (i2c_write_addr (dev, I2C_WRITE, 0) == 0)
goto exit;
if (__i2c_write (&a[4 - alen], alen) != alen)
goto exit;
i = __i2c_write (data, length);
exit:
writeb(MPC85xx_I2CCR_MEN, I2CCCR);
return !(i == length);
}
int i2c_probe (uchar chip)
{
int tmp;
/*
* Try to read the first location of the chip. The underlying
* driver doesn't appear to support sending just the chip address
* and looking for an <ACK> back.
*/
udelay(10000);
return i2c_read (chip, 0, 1, (uchar *)&tmp, 1);
}
uchar i2c_reg_read (uchar i2c_addr, uchar reg)
{
uchar buf[1];
i2c_read (i2c_addr, reg, 1, buf, 1);
return (buf[0]);
}
void i2c_reg_write (uchar i2c_addr, uchar reg, uchar val)
{
i2c_write (i2c_addr, reg, 1, &val, 1);
}
#endif /* CONFIG_HARD_I2C */
|
