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') */ |
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, value: 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 | |
90 | static int tea6420_probe(struct i2c_client *client) |
91 | { |
92 | struct v4l2_subdev *sd; |
93 | int err, i; |
94 | |
95 | /* let's see whether this adapter can support what we need */ |
96 | if (!i2c_check_functionality(adap: client->adapter, I2C_FUNC_SMBUS_WRITE_BYTE)) |
97 | return -EIO; |
98 | |
99 | v4l_info(client, "chip found @ 0x%x (%s)\n" , |
100 | client->addr << 1, client->adapter->name); |
101 | |
102 | sd = devm_kzalloc(dev: &client->dev, size: sizeof(*sd), GFP_KERNEL); |
103 | if (sd == NULL) |
104 | return -ENOMEM; |
105 | v4l2_i2c_subdev_init(sd, client, ops: &tea6420_ops); |
106 | |
107 | /* set initial values: set "mute"-input to all outputs at gain 0 */ |
108 | err = 0; |
109 | for (i = 1; i < 5; i++) |
110 | err += tea6420_s_routing(sd, i: 6, o: i, config: 0); |
111 | if (err) { |
112 | v4l_dbg(1, debug, client, "could not initialize tea6420\n" ); |
113 | return -ENODEV; |
114 | } |
115 | return 0; |
116 | } |
117 | |
118 | static void tea6420_remove(struct i2c_client *client) |
119 | { |
120 | struct v4l2_subdev *sd = i2c_get_clientdata(client); |
121 | |
122 | v4l2_device_unregister_subdev(sd); |
123 | } |
124 | |
125 | static const struct i2c_device_id tea6420_id[] = { |
126 | { "tea6420" , 0 }, |
127 | { } |
128 | }; |
129 | MODULE_DEVICE_TABLE(i2c, tea6420_id); |
130 | |
131 | static struct i2c_driver tea6420_driver = { |
132 | .driver = { |
133 | .name = "tea6420" , |
134 | }, |
135 | .probe = tea6420_probe, |
136 | .remove = tea6420_remove, |
137 | .id_table = tea6420_id, |
138 | }; |
139 | |
140 | module_i2c_driver(tea6420_driver); |
141 | |