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Linus Torvalds1da177e2005-04-16 15:20:36 -07001 /*
2 tea6420 - i2c-driver for the tea6420 by SGS Thomson
3
4 Copyright (C) 1998-2003 Michael Hunold <michael@mihu.de>
5
6 The tea6420 is a bus controlled audio-matrix with 5 stereo inputs,
7 4 stereo outputs and gain control for each output.
8 It is cascadable, i.e. it can be found at the adresses 0x98
9 and 0x9a on the i2c-bus.
10
11 For detailed informations download the specifications directly
12 from SGS Thomson at http://www.st.com
13
14 This program is free software; you can redistribute it and/or modify
15 it under the terms of the GNU General Public License as published by
16 the Free Software Foundation; either version 2 of the License, or
17 (at your option) any later version.
18
19 This program is distributed in the hope that it will be useful,
20 but WITHOUT ANY WARRANTY; without even the implied warranty of
21 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22 GNU General Public License for more details.
23
24 You should have received a copy of the GNU General Public License
25 along with this program; if not, write to the Free Software
26 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
27 */
28
Mauro Carvalho Chehaba8733ca2006-03-17 10:37:02 -030029
Linus Torvalds1da177e2005-04-16 15:20:36 -070030#include <linux/module.h>
31#include <linux/ioctl.h>
32#include <linux/i2c.h>
33
34#include "tea6420.h"
35
36static int debug = 0; /* insmod parameter */
37module_param(debug, int, 0644);
38MODULE_PARM_DESC(debug, "Turn on/off device debugging (default:off).");
39#define dprintk(args...) \
Mauro Carvalho Chehabd56410e2006-03-25 09:19:53 -030040 do { if (debug) { printk("%s: %s()[%d]: ", KBUILD_MODNAME, __FUNCTION__, __LINE__); printk(args); } } while (0)
Linus Torvalds1da177e2005-04-16 15:20:36 -070041
42/* addresses to scan, found only at 0x4c and/or 0x4d (7-Bit) */
Mauro Carvalho Chehab09df1c12006-03-18 08:31:34 -030043static unsigned short normal_i2c[] = { I2C_ADDR_TEA6420_1, I2C_ADDR_TEA6420_2, I2C_CLIENT_END };
Linus Torvalds1da177e2005-04-16 15:20:36 -070044
45/* magic definition of all other variables and things */
46I2C_CLIENT_INSMOD;
47
48static struct i2c_driver driver;
49static struct i2c_client client_template;
50
51/* make a connection between the input 'i' and the output 'o'
52 with gain 'g' for the tea6420-client 'client' (note: i = 6 means 'mute') */
53static int tea6420_switch(struct i2c_client *client, int i, int o, int g)
54{
55 u8 byte = 0;
56 int ret;
57
58 dprintk("adr:0x%02x, i:%d, o:%d, g:%d\n", client->addr, i, o, g);
59
Joe Perchesc84e6032008-02-03 17:18:59 +020060 /* check if the parameters are valid */
Linus Torvalds1da177e2005-04-16 15:20:36 -070061 if (i < 1 || i > 6 || o < 1 || o > 4 || g < 0 || g > 6 || g % 2 != 0)
62 return -1;
63
64 byte = ((o - 1) << 5);
65 byte |= (i - 1);
66
67 /* to understand this, have a look at the tea6420-specs (p.5) */
68 switch (g) {
69 case 0:
70 byte |= (3 << 3);
71 break;
72 case 2:
73 byte |= (2 << 3);
74 break;
75 case 4:
76 byte |= (1 << 3);
77 break;
78 case 6:
79 break;
80 }
81
82 ret = i2c_smbus_write_byte(client, byte);
83 if (ret) {
84 dprintk("i2c_smbus_write_byte() failed, ret:%d\n", ret);
85 return -EIO;
86 }
Mauro Carvalho Chehaba8733ca2006-03-17 10:37:02 -030087
Linus Torvalds1da177e2005-04-16 15:20:36 -070088 return 0;
89}
90
91/* this function is called by i2c_probe */
92static int tea6420_detect(struct i2c_adapter *adapter, int address, int kind)
93{
94 struct i2c_client *client;
95 int err = 0, i = 0;
96
97 /* let's see whether this adapter can support what we need */
98 if (0 == i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WRITE_BYTE)) {
99 return 0;
100 }
101
102 /* allocate memory for client structure */
Panagiotis Issaris74081872006-01-11 19:40:56 -0200103 client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL);
Al Viro5fa12472008-03-29 03:07:38 +0000104 if (!client) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700105 return -ENOMEM;
106 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700107
108 /* fill client structure */
109 memcpy(client, &client_template, sizeof(struct i2c_client));
110 client->addr = address;
111 client->adapter = adapter;
112
113 /* tell the i2c layer a new client has arrived */
114 if (0 != (err = i2c_attach_client(client))) {
115 kfree(client);
116 return err;
117 }
118
119 /* set initial values: set "mute"-input to all outputs at gain 0 */
120 err = 0;
121 for (i = 1; i < 5; i++) {
122 err += tea6420_switch(client, 6, i, 0);
123 }
124 if (err) {
125 dprintk("could not initialize tea6420\n");
126 kfree(client);
127 return -ENODEV;
128 }
129
130 printk("tea6420: detected @ 0x%02x on adapter %s\n", address, &client->adapter->name[0]);
131
132 return 0;
133}
134
135static int attach(struct i2c_adapter *adapter)
136{
137 /* let's see whether this is a know adapter we can attach to */
Jean Delvare1684a9842005-08-11 23:51:10 +0200138 if (adapter->id != I2C_HW_SAA7146) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139 dprintk("refusing to probe on unknown adapter [name='%s',id=0x%x]\n", adapter->name, adapter->id);
140 return -ENODEV;
141 }
142
143 return i2c_probe(adapter, &addr_data, &tea6420_detect);
144}
145
146static int detach(struct i2c_client *client)
147{
148 int ret = i2c_detach_client(client);
149 kfree(client);
150 return ret;
151}
152
153static int command(struct i2c_client *client, unsigned int cmd, void *arg)
154{
155 struct tea6420_multiplex *a = (struct tea6420_multiplex *)arg;
156 int result = 0;
157
158 switch (cmd) {
159 case TEA6420_SWITCH:
160 result = tea6420_switch(client, a->in, a->out, a->gain);
161 break;
162 default:
163 return -ENOIOCTLCMD;
164 }
165
166 return result;
167}
168
169static struct i2c_driver driver = {
Laurent Riffard604f28e2005-11-26 20:43:39 +0100170 .driver = {
Mauro Carvalho Chehaba8733ca2006-03-17 10:37:02 -0300171 .name = "tea6420",
Laurent Riffard604f28e2005-11-26 20:43:39 +0100172 },
Linus Torvalds1da177e2005-04-16 15:20:36 -0700173 .id = I2C_DRIVERID_TEA6420,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700174 .attach_adapter = attach,
175 .detach_client = detach,
176 .command = command,
177};
178
179static struct i2c_client client_template = {
Jean Delvarefae91e72005-08-15 19:57:04 +0200180 .name = "tea6420",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700181 .driver = &driver,
182};
183
184static int __init this_module_init(void)
185{
186 return i2c_add_driver(&driver);
187}
188
189static void __exit this_module_exit(void)
190{
191 i2c_del_driver(&driver);
192}
193
194module_init(this_module_init);
195module_exit(this_module_exit);
196
197MODULE_AUTHOR("Michael Hunold <michael@mihu.de>");
198MODULE_DESCRIPTION("tea6420 driver");
199MODULE_LICENSE("GPL");