2 tda9840 - i2c-driver for the tda9840 by SGS Thomson
4 Copyright (C) 1998-2003 Michael Hunold <michael@mihu.de>
6 The tda9840 is a stereo/dual sound processor with digital
7 identification. It can be found at address 0x84 on the i2c-bus.
9 For detailed informations download the specifications directly
10 from SGS Thomson at http://www.st.com
12 This program is free software; you can redistribute it and/or modify
13 it under the terms of the GNU General Public License as published by
14 the Free Software Foundation; either version 2 of the License, or
15 (at your option) any later version.
17 This program is distributed in the hope that it will be useful,
18 but WITHOUT ANY WARRANTY; without even the implied warranty of
19 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 GNU General Public License for more details.
22 You should have received a copy of the GNU General Public License
23 along with this program; if not, write to the Free Software
24 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
28 #include <linux/module.h>
29 #include <linux/ioctl.h>
30 #include <linux/i2c.h>
34 static int debug; /* insmod parameter */
35 module_param(debug, int, 0644);
36 MODULE_PARM_DESC(debug, "Turn on/off device debugging (default:off).");
37 #define dprintk(args...) \
38 do { if (debug) { printk("%s: %s()[%d]: ", KBUILD_MODNAME, __func__, __LINE__); printk(args); } } while (0)
41 #define LEVEL_ADJUST 0x02
42 #define STEREO_ADJUST 0x03
45 /* addresses to scan, found only at 0x42 (7-Bit) */
46 static unsigned short normal_i2c[] = { I2C_ADDR_TDA9840, I2C_CLIENT_END };
48 /* magic definition of all other variables and things */
51 static struct i2c_driver driver;
52 static struct i2c_client client_template;
54 static int command(struct i2c_client *client, unsigned int cmd, void *arg)
57 int byte = *(int *)arg;
62 dprintk("TDA9840_SWITCH: 0x%02x\n", byte);
64 if (byte != TDA9840_SET_MONO
65 && byte != TDA9840_SET_MUTE
66 && byte != TDA9840_SET_STEREO
67 && byte != TDA9840_SET_LANG1
68 && byte != TDA9840_SET_LANG2
69 && byte != TDA9840_SET_BOTH
70 && byte != TDA9840_SET_BOTH_R
71 && byte != TDA9840_SET_EXTERNAL) {
75 result = i2c_smbus_write_byte_data(client, SWITCH, byte);
77 dprintk("i2c_smbus_write_byte() failed, ret:%d\n", result);
80 case TDA9840_LEVEL_ADJUST:
82 dprintk("TDA9840_LEVEL_ADJUST: %d\n", byte);
84 /* check for correct range */
85 if (byte > 25 || byte < -20)
88 /* calculate actual value to set, see specs, page 18 */
95 result = i2c_smbus_write_byte_data(client, LEVEL_ADJUST, byte);
97 dprintk("i2c_smbus_write_byte() failed, ret:%d\n", result);
100 case TDA9840_STEREO_ADJUST:
102 dprintk("TDA9840_STEREO_ADJUST: %d\n", byte);
104 /* check for correct range */
105 if (byte > 25 || byte < -24)
108 /* calculate actual value to set */
115 result = i2c_smbus_write_byte_data(client, STEREO_ADJUST, byte);
117 dprintk("i2c_smbus_write_byte() failed, ret:%d\n", result);
120 case TDA9840_DETECT: {
121 int *ret = (int *)arg;
123 byte = i2c_smbus_read_byte_data(client, STEREO_ADJUST);
125 dprintk("i2c_smbus_read_byte_data() failed\n");
129 if (0 != (byte & 0x80)) {
130 dprintk("TDA9840_DETECT: register contents invalid\n");
134 dprintk("TDA9840_DETECT: byte: 0x%02x\n", byte);
135 *ret = ((byte & 0x60) >> 5);
140 dprintk("TDA9840_TEST: 0x%02x\n", byte);
142 /* mask out irrelevant bits */
145 result = i2c_smbus_write_byte_data(client, TEST, byte);
147 dprintk("i2c_smbus_write_byte() failed, ret:%d\n", result);
159 static int detect(struct i2c_adapter *adapter, int address, int kind)
161 struct i2c_client *client;
166 /* let's see whether this adapter can support what we need */
167 if (0 == i2c_check_functionality(adapter,
168 I2C_FUNC_SMBUS_READ_BYTE_DATA |
169 I2C_FUNC_SMBUS_WRITE_BYTE_DATA)) {
173 /* allocate memory for client structure */
174 client = kmalloc(sizeof(struct i2c_client), GFP_KERNEL);
176 printk("not enough kernel memory\n");
180 /* fill client structure */
181 memcpy(client, &client_template, sizeof(struct i2c_client));
182 client->addr = address;
183 client->adapter = adapter;
185 /* tell the i2c layer a new client has arrived */
186 if (0 != (result = i2c_attach_client(client))) {
191 /* set initial values for level & stereo - adjustment, mode */
193 result = command(client, TDA9840_LEVEL_ADJUST, &byte);
194 result += command(client, TDA9840_STEREO_ADJUST, &byte);
195 byte = TDA9840_SET_MONO;
196 result = command(client, TDA9840_SWITCH, &byte);
198 dprintk("could not initialize tda9840\n");
202 printk("tda9840: detected @ 0x%02x on adapter %s\n", address, &client->adapter->name[0]);
206 static int attach(struct i2c_adapter *adapter)
208 /* let's see whether this is a know adapter we can attach to */
209 if (adapter->id != I2C_HW_SAA7146) {
210 dprintk("refusing to probe on unknown adapter [name='%s',id=0x%x]\n", adapter->name, adapter->id);
214 return i2c_probe(adapter, &addr_data, &detect);
217 static int detach(struct i2c_client *client)
219 int ret = i2c_detach_client(client);
224 static struct i2c_driver driver = {
228 .id = I2C_DRIVERID_TDA9840,
229 .attach_adapter = attach,
230 .detach_client = detach,
234 static struct i2c_client client_template = {
239 static int __init this_module_init(void)
241 return i2c_add_driver(&driver);
244 static void __exit this_module_exit(void)
246 i2c_del_driver(&driver);
249 module_init(this_module_init);
250 module_exit(this_module_exit);
252 MODULE_AUTHOR("Michael Hunold <michael@mihu.de>");
253 MODULE_DESCRIPTION("tda9840 driver");
254 MODULE_LICENSE("GPL");