2 tda9840 - i2c-driver for the tda9840 by SGS Thomson
4 Copyright (C) 1998-2003 Michael Hunold <michael@mihu.de>
5 Copyright (C) 2008 Hans Verkuil <hverkuil@xs4all.nl>
7 The tda9840 is a stereo/dual sound processor with digital
8 identification. It can be found at address 0x84 on the i2c-bus.
10 For detailed informations download the specifications directly
11 from SGS Thomson at http://www.st.com
13 This program is free software; you can redistribute it and/or modify
14 it under the terms of the GNU General Public License as published by
15 the Free Software Foundation; either version 2 of the License, or
16 (at your option) any later version.
18 This program is distributed in the hope that it will be useful,
19 but WITHOUT ANY WARRANTY; without even the implied warranty of
20 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
21 GNU General Public License for more details.
23 You should have received a copy of the GNU General Public License
24 along with this program; if not, write to the Free Software
25 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
29 #include <linux/module.h>
30 #include <linux/ioctl.h>
31 #include <linux/i2c.h>
32 #include <media/v4l2-common.h>
33 #include <media/v4l2-i2c-drv-legacy.h>
36 MODULE_AUTHOR("Michael Hunold <michael@mihu.de>");
37 MODULE_DESCRIPTION("tda9840 driver");
38 MODULE_LICENSE("GPL");
41 module_param(debug, int, 0644);
43 MODULE_PARM_DESC(debug, "Debug level (0-1)");
46 #define LEVEL_ADJUST 0x02
47 #define STEREO_ADJUST 0x03
50 /* addresses to scan, found only at 0x42 (7-Bit) */
51 static unsigned short normal_i2c[] = { I2C_ADDR_TDA9840, I2C_CLIENT_END };
53 /* magic definition of all other variables and things */
56 static void tda9840_write(struct i2c_client *client, u8 reg, u8 val)
58 if (i2c_smbus_write_byte_data(client, reg, val))
59 v4l_dbg(1, debug, client, "error writing %02x to %02x\n",
63 static int tda9840_command(struct i2c_client *client, unsigned cmd, void *arg)
66 int byte = *(int *)arg;
70 v4l_dbg(1, debug, client, "TDA9840_SWITCH: 0x%02x\n", byte);
72 if (byte != TDA9840_SET_MONO
73 && byte != TDA9840_SET_MUTE
74 && byte != TDA9840_SET_STEREO
75 && byte != TDA9840_SET_LANG1
76 && byte != TDA9840_SET_LANG2
77 && byte != TDA9840_SET_BOTH
78 && byte != TDA9840_SET_BOTH_R
79 && byte != TDA9840_SET_EXTERNAL) {
83 tda9840_write(client, SWITCH, byte);
86 case TDA9840_LEVEL_ADJUST:
87 v4l_dbg(1, debug, client, "TDA9840_LEVEL_ADJUST: %d\n", byte);
89 /* check for correct range */
90 if (byte > 25 || byte < -20)
93 /* calculate actual value to set, see specs, page 18 */
99 tda9840_write(client, LEVEL_ADJUST, byte);
102 case TDA9840_STEREO_ADJUST:
103 v4l_dbg(1, debug, client, "TDA9840_STEREO_ADJUST: %d\n", byte);
105 /* check for correct range */
106 if (byte > 25 || byte < -24)
109 /* calculate actual value to set */
116 tda9840_write(client, STEREO_ADJUST, byte);
119 case TDA9840_DETECT: {
120 int *ret = (int *)arg;
122 byte = i2c_smbus_read_byte_data(client, STEREO_ADJUST);
124 v4l_dbg(1, debug, client,
125 "i2c_smbus_read_byte_data() failed\n");
130 v4l_dbg(1, debug, client,
131 "TDA9840_DETECT: register contents invalid\n");
135 v4l_dbg(1, debug, client, "TDA9840_DETECT: byte: 0x%02x\n", byte);
136 *ret = (byte & 0x60) >> 5;
141 v4l_dbg(1, debug, client, "TDA9840_TEST: 0x%02x\n", byte);
143 /* mask out irrelevant bits */
146 tda9840_write(client, TEST, byte);
158 static int tda9840_probe(struct i2c_client *client,
159 const struct i2c_device_id *id)
164 /* let's see whether this adapter can support what we need */
165 if (!i2c_check_functionality(client->adapter,
166 I2C_FUNC_SMBUS_READ_BYTE_DATA |
167 I2C_FUNC_SMBUS_WRITE_BYTE_DATA))
170 v4l_info(client, "chip found @ 0x%x (%s)\n",
171 client->addr << 1, client->adapter->name);
173 /* set initial values for level & stereo - adjustment, mode */
175 result = tda9840_command(client, TDA9840_LEVEL_ADJUST, &byte);
176 result += tda9840_command(client, TDA9840_STEREO_ADJUST, &byte);
177 byte = TDA9840_SET_MONO;
178 result = tda9840_command(client, TDA9840_SWITCH, &byte);
180 v4l_dbg(1, debug, client, "could not initialize tda9840\n");
186 static int tda9840_legacy_probe(struct i2c_adapter *adapter)
188 /* Let's see whether this is a known adapter we can attach to.
189 Prevents conflicts with tvaudio.c. */
190 return adapter->id == I2C_HW_SAA7146;
192 static const struct i2c_device_id tda9840_id[] = {
196 MODULE_DEVICE_TABLE(i2c, tda9840_id);
198 static struct v4l2_i2c_driver_data v4l2_i2c_data = {
200 .driverid = I2C_DRIVERID_TDA9840,
201 .command = tda9840_command,
202 .probe = tda9840_probe,
203 .legacy_probe = tda9840_legacy_probe,
204 .id_table = tda9840_id,