1 /*
2 tea6420 - i2c-driver for the tea6420 by SGS Thomson
3
4 Copyright (C) 1998-2003 Michael Hunold <michael@mihu.de>
5 Copyright (C) 2008 Hans Verkuil <hverkuil@xs4all.nl>
6
7 The tea6420 is a bus controlled audio-matrix with 5 stereo inputs,
8 4 stereo outputs and gain control for each output.
9 It is cascadable, i.e. it can be found at the adresses 0x98
10 and 0x9a on the i2c-bus.
11
12 For detailed informations download the specifications directly
13 from SGS Thomson at http://www.st.com
14
15 This program is free software; you can redistribute it and/or modify
16 it under the terms of the GNU General Public License as published by
17 the Free Software Foundation; either version 2 of the License, or
18 (at your option) any later version.
19
20 This program is distributed in the hope that it will be useful,
21 but WITHOUT ANY WARRANTY; without even the implied warranty of
22 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
23 GNU General Public License for more details.
24
25 You should have received a copy of the GNU General Public License
26 along with this program; if not, write to the Free Software
27 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
28 */
29
30
31 #include <linux/module.h>
32 #include <linux/ioctl.h>
33 #include <linux/i2c.h>
34 #include <media/v4l2-device.h>
35 #include <media/v4l2-i2c-drv-legacy.h>
36 #include "tea6420.h"
37
38 MODULE_AUTHOR("Michael Hunold <michael@mihu.de>");
39 MODULE_DESCRIPTION("tea6420 driver");
40 MODULE_LICENSE("GPL");
41
42 static int debug;
43 module_param(debug, int, 0644);
44
45 MODULE_PARM_DESC(debug, "Debug level (0-1)");
46
47 /* addresses to scan, found only at 0x4c and/or 0x4d (7-Bit) */
48 static unsigned short normal_i2c[] = { I2C_ADDR_TEA6420_1, I2C_ADDR_TEA6420_2, I2C_CLIENT_END };
49
50 /* magic definition of all other variables and things */
51 I2C_CLIENT_INSMOD;
52
53 /* make a connection between the input 'i' and the output 'o'
54 with gain 'g' for the tea6420-client 'client' (note: i = 6 means 'mute') */
tea6420_switch(struct i2c_client * client,int i,int o,int g)55 static int tea6420_switch(struct i2c_client *client, int i, int o, int g)
56 {
57 u8 byte;
58 int ret;
59
60 v4l_dbg(1, debug, client, "i=%d, o=%d, g=%d\n", i, o, g);
61
62 /* check if the parameters are valid */
63 if (i < 1 || i > 6 || o < 1 || o > 4 || g < 0 || g > 6 || g % 2 != 0)
64 return -1;
65
66 byte = ((o - 1) << 5);
67 byte |= (i - 1);
68
69 /* to understand this, have a look at the tea6420-specs (p.5) */
70 switch (g) {
71 case 0:
72 byte |= (3 << 3);
73 break;
74 case 2:
75 byte |= (2 << 3);
76 break;
77 case 4:
78 byte |= (1 << 3);
79 break;
80 case 6:
81 break;
82 }
83
84 ret = i2c_smbus_write_byte(client, byte);
85 if (ret) {
86 v4l_dbg(1, debug, client,
87 "i2c_smbus_write_byte() failed, ret:%d\n", ret);
88 return -EIO;
89 }
90 return 0;
91 }
92
tea6420_ioctl(struct v4l2_subdev * sd,unsigned cmd,void * arg)93 static long tea6420_ioctl(struct v4l2_subdev *sd, unsigned cmd, void *arg)
94 {
95 if (cmd == TEA6420_SWITCH) {
96 struct i2c_client *client = v4l2_get_subdevdata(sd);
97 struct tea6420_multiplex *a = (struct tea6420_multiplex *)arg;
98
99 return tea6420_switch(client, a->in, a->out, a->gain);
100 }
101 return -ENOIOCTLCMD;
102 }
103
tea6420_command(struct i2c_client * client,unsigned cmd,void * arg)104 static int tea6420_command(struct i2c_client *client, unsigned cmd, void *arg)
105 {
106 return v4l2_subdev_command(i2c_get_clientdata(client), cmd, arg);
107 }
108
109 /* ----------------------------------------------------------------------- */
110
111 static const struct v4l2_subdev_core_ops tea6420_core_ops = {
112 .ioctl = tea6420_ioctl,
113 };
114
115 static const struct v4l2_subdev_ops tea6420_ops = {
116 .core = &tea6420_core_ops,
117 };
118
119 /* this function is called by i2c_probe */
tea6420_probe(struct i2c_client * client,const struct i2c_device_id * id)120 static int tea6420_probe(struct i2c_client *client,
121 const struct i2c_device_id *id)
122 {
123 struct v4l2_subdev *sd;
124 int err, i;
125
126 /* let's see whether this adapter can support what we need */
127 if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WRITE_BYTE))
128 return -EIO;
129
130 v4l_info(client, "chip found @ 0x%x (%s)\n",
131 client->addr << 1, client->adapter->name);
132
133 /* set initial values: set "mute"-input to all outputs at gain 0 */
134 err = 0;
135 for (i = 1; i < 5; i++) {
136 err += tea6420_switch(client, 6, i, 0);
137 }
138 if (err) {
139 v4l_dbg(1, debug, client, "could not initialize tea6420\n");
140 return -ENODEV;
141 }
142
143 sd = kmalloc(sizeof(struct v4l2_subdev), GFP_KERNEL);
144 if (sd == NULL)
145 return -ENOMEM;
146 v4l2_i2c_subdev_init(sd, client, &tea6420_ops);
147 return 0;
148 }
149
tea6420_remove(struct i2c_client * client)150 static int tea6420_remove(struct i2c_client *client)
151 {
152 struct v4l2_subdev *sd = i2c_get_clientdata(client);
153
154 v4l2_device_unregister_subdev(sd);
155 kfree(sd);
156 return 0;
157 }
158
tea6420_legacy_probe(struct i2c_adapter * adapter)159 static int tea6420_legacy_probe(struct i2c_adapter *adapter)
160 {
161 /* Let's see whether this is a known adapter we can attach to.
162 Prevents conflicts with tvaudio.c. */
163 return adapter->id == I2C_HW_SAA7146;
164 }
165
166 static const struct i2c_device_id tea6420_id[] = {
167 { "tea6420", 0 },
168 { }
169 };
170 MODULE_DEVICE_TABLE(i2c, tea6420_id);
171
172 static struct v4l2_i2c_driver_data v4l2_i2c_data = {
173 .name = "tea6420",
174 .driverid = I2C_DRIVERID_TEA6420,
175 .command = tea6420_command,
176 .probe = tea6420_probe,
177 .remove = tea6420_remove,
178 .legacy_probe = tea6420_legacy_probe,
179 .id_table = tea6420_id,
180 };
181