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1da177e4 LT |
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 | ||
35 | static int debug = 0; /* insmod parameter */ | |
36 | module_param(debug, int, 0644); | |
37 | MODULE_PARM_DESC(debug, "Turn on/off device debugging (default:off)."); | |
38 | #define dprintk(args...) \ | |
367cb704 | 39 | do { if (debug) { printk("%s: %s()[%d]: ", KBUILD_MODNAME, __FUNCTION__, __LINE__); printk(args); } } while (0) |
1da177e4 LT |
40 | |
41 | /* addresses to scan, found only at 0x4c and/or 0x4d (7-Bit) */ | |
42 | static unsigned short normal_i2c[] = { I2C_TEA6420_1, I2C_TEA6420_2, I2C_CLIENT_END }; | |
1da177e4 LT |
43 | |
44 | /* magic definition of all other variables and things */ | |
45 | I2C_CLIENT_INSMOD; | |
46 | ||
47 | static struct i2c_driver driver; | |
48 | static struct i2c_client client_template; | |
49 | ||
50 | /* make a connection between the input 'i' and the output 'o' | |
51 | with gain 'g' for the tea6420-client 'client' (note: i = 6 means 'mute') */ | |
52 | static int tea6420_switch(struct i2c_client *client, int i, int o, int g) | |
53 | { | |
54 | u8 byte = 0; | |
55 | int ret; | |
56 | ||
57 | dprintk("adr:0x%02x, i:%d, o:%d, g:%d\n", client->addr, i, o, g); | |
58 | ||
59 | /* check if the paramters are valid */ | |
60 | if (i < 1 || i > 6 || o < 1 || o > 4 || g < 0 || g > 6 || g % 2 != 0) | |
61 | return -1; | |
62 | ||
63 | byte = ((o - 1) << 5); | |
64 | byte |= (i - 1); | |
65 | ||
66 | /* to understand this, have a look at the tea6420-specs (p.5) */ | |
67 | switch (g) { | |
68 | case 0: | |
69 | byte |= (3 << 3); | |
70 | break; | |
71 | case 2: | |
72 | byte |= (2 << 3); | |
73 | break; | |
74 | case 4: | |
75 | byte |= (1 << 3); | |
76 | break; | |
77 | case 6: | |
78 | break; | |
79 | } | |
80 | ||
81 | ret = i2c_smbus_write_byte(client, byte); | |
82 | if (ret) { | |
83 | dprintk("i2c_smbus_write_byte() failed, ret:%d\n", ret); | |
84 | return -EIO; | |
85 | } | |
86 | ||
87 | return 0; | |
88 | } | |
89 | ||
90 | /* this function is called by i2c_probe */ | |
91 | static int tea6420_detect(struct i2c_adapter *adapter, int address, int kind) | |
92 | { | |
93 | struct i2c_client *client; | |
94 | int err = 0, i = 0; | |
95 | ||
96 | /* let's see whether this adapter can support what we need */ | |
97 | if (0 == i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WRITE_BYTE)) { | |
98 | return 0; | |
99 | } | |
100 | ||
101 | /* allocate memory for client structure */ | |
7408187d | 102 | client = kzalloc(sizeof(struct i2c_client), GFP_KERNEL); |
1da177e4 LT |
103 | if (0 == client) { |
104 | return -ENOMEM; | |
105 | } | |
1da177e4 LT |
106 | |
107 | /* fill client structure */ | |
108 | memcpy(client, &client_template, sizeof(struct i2c_client)); | |
109 | client->addr = address; | |
110 | client->adapter = adapter; | |
111 | ||
112 | /* tell the i2c layer a new client has arrived */ | |
113 | if (0 != (err = i2c_attach_client(client))) { | |
114 | kfree(client); | |
115 | return err; | |
116 | } | |
117 | ||
118 | /* set initial values: set "mute"-input to all outputs at gain 0 */ | |
119 | err = 0; | |
120 | for (i = 1; i < 5; i++) { | |
121 | err += tea6420_switch(client, 6, i, 0); | |
122 | } | |
123 | if (err) { | |
124 | dprintk("could not initialize tea6420\n"); | |
125 | kfree(client); | |
126 | return -ENODEV; | |
127 | } | |
128 | ||
129 | printk("tea6420: detected @ 0x%02x on adapter %s\n", address, &client->adapter->name[0]); | |
130 | ||
131 | return 0; | |
132 | } | |
133 | ||
134 | static int attach(struct i2c_adapter *adapter) | |
135 | { | |
136 | /* let's see whether this is a know adapter we can attach to */ | |
1684a984 | 137 | if (adapter->id != I2C_HW_SAA7146) { |
1da177e4 LT |
138 | dprintk("refusing to probe on unknown adapter [name='%s',id=0x%x]\n", adapter->name, adapter->id); |
139 | return -ENODEV; | |
140 | } | |
141 | ||
142 | return i2c_probe(adapter, &addr_data, &tea6420_detect); | |
143 | } | |
144 | ||
145 | static int detach(struct i2c_client *client) | |
146 | { | |
147 | int ret = i2c_detach_client(client); | |
148 | kfree(client); | |
149 | return ret; | |
150 | } | |
151 | ||
152 | static int command(struct i2c_client *client, unsigned int cmd, void *arg) | |
153 | { | |
154 | struct tea6420_multiplex *a = (struct tea6420_multiplex *)arg; | |
155 | int result = 0; | |
156 | ||
157 | switch (cmd) { | |
158 | case TEA6420_SWITCH: | |
159 | result = tea6420_switch(client, a->in, a->out, a->gain); | |
160 | break; | |
161 | default: | |
162 | return -ENOIOCTLCMD; | |
163 | } | |
164 | ||
165 | return result; | |
166 | } | |
167 | ||
168 | static struct i2c_driver driver = { | |
604f28e2 | 169 | .driver = { |
604f28e2 LR |
170 | .name = "tea6420", |
171 | }, | |
1da177e4 | 172 | .id = I2C_DRIVERID_TEA6420, |
1da177e4 LT |
173 | .attach_adapter = attach, |
174 | .detach_client = detach, | |
175 | .command = command, | |
176 | }; | |
177 | ||
178 | static struct i2c_client client_template = { | |
fae91e72 | 179 | .name = "tea6420", |
1da177e4 LT |
180 | .driver = &driver, |
181 | }; | |
182 | ||
183 | static int __init this_module_init(void) | |
184 | { | |
185 | return i2c_add_driver(&driver); | |
186 | } | |
187 | ||
188 | static void __exit this_module_exit(void) | |
189 | { | |
190 | i2c_del_driver(&driver); | |
191 | } | |
192 | ||
193 | module_init(this_module_init); | |
194 | module_exit(this_module_exit); | |
195 | ||
196 | MODULE_AUTHOR("Michael Hunold <michael@mihu.de>"); | |
197 | MODULE_DESCRIPTION("tea6420 driver"); | |
198 | MODULE_LICENSE("GPL"); |