2 tea6420 - i2c-driver for the tea6420 by SGS Thomson
4 Copyright (C) 1998-2003 Michael Hunold <michael@mihu.de>
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.
11 For detailed informations download the specifications directly
12 from SGS Thomson at http://www.st.com
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.
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.
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.
29 #include <linux/module.h>
30 #include <linux/ioctl.h>
31 #include <linux/i2c.h>
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...) \
39 do { if (debug) { printk("%s: %s()[%d]: ",__stringify(KBUILD_MODNAME), __FUNCTION__, __LINE__); printk(args); } } while (0)
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
};
44 /* magic definition of all other variables and things */
47 static struct i2c_driver driver
;
48 static struct i2c_client client_template
;
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
)
57 dprintk("adr:0x%02x, i:%d, o:%d, g:%d\n", client
->addr
, i
, o
, g
);
59 /* check if the paramters are valid */
60 if (i
< 1 || i
> 6 || o
< 1 || o
> 4 || g
< 0 || g
> 6 || g
% 2 != 0)
63 byte
= ((o
- 1) << 5);
66 /* to understand this, have a look at the tea6420-specs (p.5) */
81 ret
= i2c_smbus_write_byte(client
, byte
);
83 dprintk("i2c_smbus_write_byte() failed, ret:%d\n", ret
);
90 /* this function is called by i2c_probe */
91 static int tea6420_detect(struct i2c_adapter
*adapter
, int address
, int kind
)
93 struct i2c_client
*client
;
96 /* let's see whether this adapter can support what we need */
97 if (0 == i2c_check_functionality(adapter
, I2C_FUNC_SMBUS_WRITE_BYTE
)) {
101 /* allocate memory for client structure */
102 client
= kmalloc(sizeof(struct i2c_client
), GFP_KERNEL
);
106 memset(client
, 0x0, sizeof(struct i2c_client
));
108 /* fill client structure */
109 memcpy(client
, &client_template
, sizeof(struct i2c_client
));
110 client
->addr
= address
;
111 client
->adapter
= adapter
;
113 /* tell the i2c layer a new client has arrived */
114 if (0 != (err
= i2c_attach_client(client
))) {
119 /* set initial values: set "mute"-input to all outputs at gain 0 */
121 for (i
= 1; i
< 5; i
++) {
122 err
+= tea6420_switch(client
, 6, i
, 0);
125 dprintk("could not initialize tea6420\n");
130 printk("tea6420: detected @ 0x%02x on adapter %s\n", address
, &client
->adapter
->name
[0]);
135 static int attach(struct i2c_adapter
*adapter
)
137 /* let's see whether this is a know adapter we can attach to */
138 if (adapter
->id
!= I2C_HW_SAA7146
) {
139 dprintk("refusing to probe on unknown adapter [name='%s',id=0x%x]\n", adapter
->name
, adapter
->id
);
143 return i2c_probe(adapter
, &addr_data
, &tea6420_detect
);
146 static int detach(struct i2c_client
*client
)
148 int ret
= i2c_detach_client(client
);
153 static int command(struct i2c_client
*client
, unsigned int cmd
, void *arg
)
155 struct tea6420_multiplex
*a
= (struct tea6420_multiplex
*)arg
;
160 result
= tea6420_switch(client
, a
->in
, a
->out
, a
->gain
);
169 static struct i2c_driver driver
= {
170 .owner
= THIS_MODULE
,
172 .id
= I2C_DRIVERID_TEA6420
,
173 .flags
= I2C_DF_NOTIFY
,
174 .attach_adapter
= attach
,
175 .detach_client
= detach
,
179 static struct i2c_client client_template
= {
184 static int __init
this_module_init(void)
186 return i2c_add_driver(&driver
);
189 static void __exit
this_module_exit(void)
191 i2c_del_driver(&driver
);
194 module_init(this_module_init
);
195 module_exit(this_module_exit
);
197 MODULE_AUTHOR("Michael Hunold <michael@mihu.de>");
198 MODULE_DESCRIPTION("tea6420 driver");
199 MODULE_LICENSE("GPL");