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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 18:20:36 -0400
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /drivers/media/video/tea6420.c
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'drivers/media/video/tea6420.c')
-rw-r--r--drivers/media/video/tea6420.c200
1 files changed, 200 insertions, 0 deletions
diff --git a/drivers/media/video/tea6420.c b/drivers/media/video/tea6420.c
new file mode 100644
index 000000000000..bd10710fd909
--- /dev/null
+++ b/drivers/media/video/tea6420.c
@@ -0,0 +1,200 @@
1 /*
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
29#include <linux/module.h>
30#include <linux/ioctl.h>
31#include <linux/i2c.h>
32
33#include "tea6420.h"
34
35static int debug = 0; /* insmod parameter */
36module_param(debug, int, 0644);
37MODULE_PARM_DESC(debug, "Turn on/off device debugging (default:off).");
38#define dprintk(args...) \
39 do { if (debug) { printk("%s: %s()[%d]: ",__stringify(KBUILD_MODNAME), __FUNCTION__, __LINE__); printk(args); } } while (0)
40
41/* addresses to scan, found only at 0x4c and/or 0x4d (7-Bit) */
42static unsigned short normal_i2c[] = { I2C_TEA6420_1, I2C_TEA6420_2, I2C_CLIENT_END };
43static unsigned short normal_i2c_range[] = { I2C_CLIENT_END };
44
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
60 /* check if the paramters are valid */
61 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 }
87
88 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 */
103 client = kmalloc(sizeof(struct i2c_client), GFP_KERNEL);
104 if (0 == client) {
105 return -ENOMEM;
106 }
107 memset(client, 0x0, sizeof(struct i2c_client));
108
109 /* fill client structure */
110 memcpy(client, &client_template, sizeof(struct i2c_client));
111 client->addr = address;
112 client->adapter = adapter;
113
114 /* tell the i2c layer a new client has arrived */
115 if (0 != (err = i2c_attach_client(client))) {
116 kfree(client);
117 return err;
118 }
119
120 /* set initial values: set "mute"-input to all outputs at gain 0 */
121 err = 0;
122 for (i = 1; i < 5; i++) {
123 err += tea6420_switch(client, 6, i, 0);
124 }
125 if (err) {
126 dprintk("could not initialize tea6420\n");
127 kfree(client);
128 return -ENODEV;
129 }
130
131 printk("tea6420: detected @ 0x%02x on adapter %s\n", address, &client->adapter->name[0]);
132
133 return 0;
134}
135
136static int attach(struct i2c_adapter *adapter)
137{
138 /* let's see whether this is a know adapter we can attach to */
139 if (adapter->id != I2C_ALGO_SAA7146) {
140 dprintk("refusing to probe on unknown adapter [name='%s',id=0x%x]\n", adapter->name, adapter->id);
141 return -ENODEV;
142 }
143
144 return i2c_probe(adapter, &addr_data, &tea6420_detect);
145}
146
147static int detach(struct i2c_client *client)
148{
149 int ret = i2c_detach_client(client);
150 kfree(client);
151 return ret;
152}
153
154static int command(struct i2c_client *client, unsigned int cmd, void *arg)
155{
156 struct tea6420_multiplex *a = (struct tea6420_multiplex *)arg;
157 int result = 0;
158
159 switch (cmd) {
160 case TEA6420_SWITCH:
161 result = tea6420_switch(client, a->in, a->out, a->gain);
162 break;
163 default:
164 return -ENOIOCTLCMD;
165 }
166
167 return result;
168}
169
170static struct i2c_driver driver = {
171 .owner = THIS_MODULE,
172 .name = "tea6420",
173 .id = I2C_DRIVERID_TEA6420,
174 .flags = I2C_DF_NOTIFY,
175 .attach_adapter = attach,
176 .detach_client = detach,
177 .command = command,
178};
179
180static struct i2c_client client_template = {
181 I2C_DEVNAME("tea6420"),
182 .driver = &driver,
183};
184
185static int __init this_module_init(void)
186{
187 return i2c_add_driver(&driver);
188}
189
190static void __exit this_module_exit(void)
191{
192 i2c_del_driver(&driver);
193}
194
195module_init(this_module_init);
196module_exit(this_module_exit);
197
198MODULE_AUTHOR("Michael Hunold <michael@mihu.de>");
199MODULE_DESCRIPTION("tea6420 driver");
200MODULE_LICENSE("GPL");