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
|
/*
tea6420 - i2c-driver for the tea6420 by SGS Thomson
Copyright (C) 1998-2003 Michael Hunold <michael@mihu.de>
The tea6420 is a bus controlled audio-matrix with 5 stereo inputs,
4 stereo outputs and gain control for each output.
It is cascadable, i.e. it can be found at the adresses 0x98
and 0x9a on the i2c-bus.
For detailed informations download the specifications directly
from SGS Thomson at http://www.st.com
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., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <linux/module.h>
#include <linux/ioctl.h>
#include <linux/i2c.h>
#include "tea6420.h"
static int debug = 0; /* insmod parameter */
module_param(debug, int, 0644);
MODULE_PARM_DESC(debug, "Turn on/off device debugging (default:off).");
#define dprintk(args...) \
do { if (debug) { printk("%s: %s()[%d]: ", KBUILD_MODNAME, __FUNCTION__, __LINE__); printk(args); } } while (0)
/* addresses to scan, found only at 0x4c and/or 0x4d (7-Bit) */
static unsigned short normal_i2c[] = { I2C_ADDR_TEA6420_1, I2C_ADDR_TEA6420_2, I2C_CLIENT_END };
/* magic definition of all other variables and things */
I2C_CLIENT_INSMOD;
static struct i2c_driver driver;
static struct i2c_client client_template;
/* make a connection between the input 'i' and the output 'o'
with gain 'g' for the tea6420-client 'client' (note: i = 6 means 'mute') */
static int tea6420_switch(struct i2c_client *client, int i, int o, int g)
{
u8 byte = 0;
int ret;
dprintk("adr:0x%02x, i:%d, o:%d, g:%d\n", client->addr, i, o, g);
/* check if the paramters are valid */
if (i < 1 || i > 6 || o < 1 || o > 4 || g < 0 || g > 6 || g % 2 != 0)
return -1;
byte = ((o - 1) << 5);
byte |= (i - 1);
/* to understand this, have a look at the tea6420-specs (p.5) */
switch (g) {
case 0:
byte |= (3 << 3);
break;
case 2:
byte |= (2 << 3);
break;
case 4:
byte |= (1 << 3);
break;
case 6:
break;
}
ret = i2c_smbus_write_byte(client, byte);
if (ret) {
dprintk("i2c_smbus_write_byte() failed, ret:%d\n", ret);
return -EIO;
}
return 0;
}
/* this function is called by i2c_probe */
static int tea6420_detect(struct i2c_adapter *adapter, int address, int kind)
{
struct i2c_client *client;
int err = 0, i = 0;
/* let's see whether this adapter can support what we need */
if (0 == i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WRITE_BYTE)) {
return 0;
}
/* allocate memory for client structure */
client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL);
if (0 == client) {
return -ENOMEM;
}
/* fill client structure */
memcpy(client, &client_template, sizeof(struct i2c_client));
client->addr = address;
client->adapter = adapter;
/* tell the i2c layer a new client has arrived */
if (0 != (err = i2c_attach_client(client))) {
kfree(client);
return err;
}
/* set initial values: set "mute"-input to all outputs at gain 0 */
err = 0;
for (i = 1; i < 5; i++) {
err += tea6420_switch(client, 6, i, 0);
}
if (err) {
dprintk("could not initialize tea6420\n");
kfree(client);
return -ENODEV;
}
printk("tea6420: detected @ 0x%02x on adapter %s\n", address, &client->adapter->name[0]);
return 0;
}
static int attach(struct i2c_adapter *adapter)
{
/* let's see whether this is a know adapter we can attach to */
if (adapter->id != I2C_HW_SAA7146) {
dprintk("refusing to probe on unknown adapter [name='%s',id=0x%x]\n", adapter->name, adapter->id);
return -ENODEV;
}
return i2c_probe(adapter, &addr_data, &tea6420_detect);
}
static int detach(struct i2c_client *client)
{
int ret = i2c_detach_client(client);
kfree(client);
return ret;
}
static int command(struct i2c_client *client, unsigned int cmd, void *arg)
{
struct tea6420_multiplex *a = (struct tea6420_multiplex *)arg;
int result = 0;
switch (cmd) {
case TEA6420_SWITCH:
result = tea6420_switch(client, a->in, a->out, a->gain);
break;
default:
return -ENOIOCTLCMD;
}
return result;
}
static struct i2c_driver driver = {
.driver = {
.name = "tea6420",
},
.id = I2C_DRIVERID_TEA6420,
.attach_adapter = attach,
.detach_client = detach,
.command = command,
};
static struct i2c_client client_template = {
.name = "tea6420",
.driver = &driver,
};
static int __init this_module_init(void)
{
return i2c_add_driver(&driver);
}
static void __exit this_module_exit(void)
{
i2c_del_driver(&driver);
}
module_init(this_module_init);
module_exit(this_module_exit);
MODULE_AUTHOR("Michael Hunold <michael@mihu.de>");
MODULE_DESCRIPTION("tea6420 driver");
MODULE_LICENSE("GPL");
|
