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
|
/***************************************************************************
* __________ __ ___.
* Open \______ \ ____ ____ | | _\_ |__ _______ ___
* Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ /
* Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < <
* Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \
* \/ \/ \/ \/ \/
* $Id$
* Physical interface of the Philips TEA5767 in Archos Ondio
*
* Copyright (C) 2002 by Linus Nielsen Feltzing
*
* 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 distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
****************************************************************************/
#include "config.h"
#include "cpu.h"
#include "logf.h"
#include "system.h"
#if (CONFIG_TUNER & TEA5767)
/* cute little functions, atomic read-modify-write */
/* SDA is PB4 */
#define SDA_LO and_b(~0x10, &PBDRL)
#define SDA_HI or_b(0x10, &PBDRL)
#define SDA_INPUT and_b(~0x10, &PBIORL)
#define SDA_OUTPUT or_b(0x10, &PBIORL)
#define SDA (PBDR & 0x0010)
/* SCL is PB1 */
#define SCL_INPUT and_b(~0x02, &PBIORL)
#define SCL_OUTPUT or_b(0x02, &PBIORL)
#define SCL_LO and_b(~0x02, &PBDRL)
#define SCL_HI or_b(0x02, &PBDRL)
#define SCL (PBDR & 0x0002)
/* arbitrary delay loop */
#define DELAY do { int _x; for(_x=0;_x<20;_x++);} while (0)
static void fmradio_i2c_start(void)
{
SDA_OUTPUT;
SDA_HI;
SCL_HI;
SDA_LO;
DELAY;
SCL_LO;
}
static void fmradio_i2c_stop(void)
{
SDA_LO;
SCL_HI;
DELAY;
SDA_HI;
}
static void fmradio_i2c_ack(bool nack)
{
/* Here's the deal. The slave is slow, and sometimes needs to wait
before it can receive the acknowledge. Therefore it forces the clock
low until it is ready. We need to poll the clock line until it goes
high before we release the ack. */
SCL_LO; /* Set the clock low */
if (nack)
SDA_HI;
else
SDA_LO;
SCL_INPUT; /* Set the clock to input */
while(!SCL) /* and wait for the slave to release it */
sleep(0);
DELAY;
SCL_OUTPUT;
SCL_LO;
}
static int fmradio_i2c_getack(void)
{
int ret = 1;
/* Here's the deal. The slave is slow, and sometimes needs to wait
before it can send the acknowledge. Therefore it forces the clock
low until it is ready. We need to poll the clock line until it goes
high before we read the ack. */
SDA_INPUT; /* And set to input */
SCL_INPUT; /* Set the clock to input */
while(!SCL) /* and wait for the slave to release it */
sleep(0);
if (SDA)
/* ack failed */
ret = 0;
SCL_OUTPUT;
SCL_LO;
SDA_HI;
SDA_OUTPUT;
return ret;
}
static void fmradio_i2c_outb(unsigned char byte)
{
int i;
/* clock out each bit, MSB first */
for ( i=0x80; i; i>>=1 ) {
if ( i & byte )
{
SDA_HI;
}
else
{
SDA_LO;
}
SCL_HI;
SCL_LO;
}
SDA_HI;
}
static unsigned char fmradio_i2c_inb(void)
{
int i;
unsigned char byte = 0;
/* clock in each bit, MSB first */
for ( i=0x80; i; i>>=1 ) {
SDA_INPUT; /* And set to input */
SCL_HI;
if ( SDA )
byte |= i;
SCL_LO;
SDA_OUTPUT;
}
return byte;
}
int fmradio_i2c_write(int address, const unsigned char* buf, int count)
{
int i,x=0;
fmradio_i2c_start();
fmradio_i2c_outb(address & 0xfe);
if (fmradio_i2c_getack())
{
for (i=0; i<count; i++)
{
fmradio_i2c_outb(buf[i]);
if (!fmradio_i2c_getack())
{
x=-2;
break;
}
}
}
else
{
logf("fmradio_i2c_write() - no ack\n");
x=-1;
}
fmradio_i2c_stop();
return x;
}
int fmradio_i2c_read(int address, unsigned char* buf, int count)
{
int i,x=0;
fmradio_i2c_start();
fmradio_i2c_outb(address | 1);
if (fmradio_i2c_getack()) {
for (i=count; i>0; i--)
{
*buf++ = fmradio_i2c_inb();
fmradio_i2c_ack(i == 1);
}
}
else
x=-1;
fmradio_i2c_stop();
return x;
}
#endif
|
