1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 tea6420 - i2c-driver for the tea6420 by SGS Thomson
4
5 Copyright (C) 1998-2003 Michael Hunold <michael@mihu.de>
6 Copyright (C) 2008 Hans Verkuil <hverkuil@xs4all.nl>
7
8 The tea6420 is a bus controlled audio-matrix with 5 stereo inputs,
9 4 stereo outputs and gain control for each output.
10 It is cascadable, i.e. it can be found at the addresses 0x98
11 and 0x9a on the i2c-bus.
12
13 For detailed information download the specifications directly
14 from SGS Thomson at http://www.st.com
15
16 */
17
18
19 #include <linux/module.h>
20 #include <linux/ioctl.h>
21 #include <linux/slab.h>
22 #include <linux/i2c.h>
23 #include <media/v4l2-device.h>
24 #include "tea6420.h"
25
26 MODULE_AUTHOR("Michael Hunold <michael@mihu.de>");
27 MODULE_DESCRIPTION("tea6420 driver");
28 MODULE_LICENSE("GPL");
29
30 static int debug;
31 module_param(debug, int, 0644);
32
33 MODULE_PARM_DESC(debug, "Debug level (0-1)");
34
35
36 /* make a connection between the input 'i' and the output 'o'
37 with gain 'g' (note: i = 6 means 'mute') */
tea6420_s_routing(struct v4l2_subdev * sd,u32 i,u32 o,u32 config)38 static int tea6420_s_routing(struct v4l2_subdev *sd,
39 u32 i, u32 o, u32 config)
40 {
41 struct i2c_client *client = v4l2_get_subdevdata(sd);
42 int g = (o >> 4) & 0xf;
43 u8 byte;
44 int ret;
45
46 o &= 0xf;
47 v4l2_dbg(1, debug, sd, "i=%d, o=%d, g=%d\n", i, o, g);
48
49 /* check if the parameters are valid */
50 if (i < 1 || i > 6 || o < 1 || o > 4 || g < 0 || g > 6 || g % 2 != 0)
51 return -EINVAL;
52
53 byte = ((o - 1) << 5);
54 byte |= (i - 1);
55
56 /* to understand this, have a look at the tea6420-specs (p.5) */
57 switch (g) {
58 case 0:
59 byte |= (3 << 3);
60 break;
61 case 2:
62 byte |= (2 << 3);
63 break;
64 case 4:
65 byte |= (1 << 3);
66 break;
67 case 6:
68 break;
69 }
70
71 ret = i2c_smbus_write_byte(client, byte);
72 if (ret) {
73 v4l2_dbg(1, debug, sd,
74 "i2c_smbus_write_byte() failed, ret:%d\n", ret);
75 return -EIO;
76 }
77 return 0;
78 }
79
80 /* ----------------------------------------------------------------------- */
81
82 static const struct v4l2_subdev_audio_ops tea6420_audio_ops = {
83 .s_routing = tea6420_s_routing,
84 };
85
86 static const struct v4l2_subdev_ops tea6420_ops = {
87 .audio = &tea6420_audio_ops,
88 };
89
tea6420_probe(struct i2c_client * client,const struct i2c_device_id * id)90 static int tea6420_probe(struct i2c_client *client,
91 const struct i2c_device_id *id)
92 {
93 struct v4l2_subdev *sd;
94 int err, i;
95
96 /* let's see whether this adapter can support what we need */
97 if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WRITE_BYTE))
98 return -EIO;
99
100 v4l_info(client, "chip found @ 0x%x (%s)\n",
101 client->addr << 1, client->adapter->name);
102
103 sd = devm_kzalloc(&client->dev, sizeof(*sd), GFP_KERNEL);
104 if (sd == NULL)
105 return -ENOMEM;
106 v4l2_i2c_subdev_init(sd, client, &tea6420_ops);
107
108 /* set initial values: set "mute"-input to all outputs at gain 0 */
109 err = 0;
110 for (i = 1; i < 5; i++)
111 err += tea6420_s_routing(sd, 6, i, 0);
112 if (err) {
113 v4l_dbg(1, debug, client, "could not initialize tea6420\n");
114 return -ENODEV;
115 }
116 return 0;
117 }
118
tea6420_remove(struct i2c_client * client)119 static int tea6420_remove(struct i2c_client *client)
120 {
121 struct v4l2_subdev *sd = i2c_get_clientdata(client);
122
123 v4l2_device_unregister_subdev(sd);
124 return 0;
125 }
126
127 static const struct i2c_device_id tea6420_id[] = {
128 { "tea6420", 0 },
129 { }
130 };
131 MODULE_DEVICE_TABLE(i2c, tea6420_id);
132
133 static struct i2c_driver tea6420_driver = {
134 .driver = {
135 .name = "tea6420",
136 },
137 .probe = tea6420_probe,
138 .remove = tea6420_remove,
139 .id_table = tea6420_id,
140 };
141
142 module_i2c_driver(tea6420_driver);
143
