aboutsummaryrefslogtreecommitdiff
path: root/drivers/media/i2c/tea6420.c
blob: 712141b261ed63faf9466d619370477ea31212f9 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
// SPDX-License-Identifier: GPL-2.0-or-later
 /*
    tea6420 - i2c-driver for the tea6420 by SGS Thomson

    Copyright (C) 1998-2003 Michael Hunold <michael@mihu.de>
    Copyright (C) 2008 Hans Verkuil <hverkuil@xs4all.nl>

    The tea6420 is a bus controlled audio-matrix with 5 stereo inputs,
    4 stereo outputs and gain control for each output.
    It is cascadable, i.e. it can be found at the addresses 0x98
    and 0x9a on the i2c-bus.

    For detailed information download the specifications directly
    from SGS Thomson at http://www.st.com

  */


#include <linux/module.h>
#include <linux/ioctl.h>
#include <linux/slab.h>
#include <linux/i2c.h>
#include <media/v4l2-device.h>
#include "tea6420.h"

MODULE_AUTHOR("Michael Hunold <michael@mihu.de>");
MODULE_DESCRIPTION("tea6420 driver");
MODULE_LICENSE("GPL");

static int debug;
module_param(debug, int, 0644);

MODULE_PARM_DESC(debug, "Debug level (0-1)");


/* make a connection between the input 'i' and the output 'o'
   with gain 'g' (note: i = 6 means 'mute') */
static int tea6420_s_routing(struct v4l2_subdev *sd,
			     u32 i, u32 o, u32 config)
{
	struct i2c_client *client = v4l2_get_subdevdata(sd);
	int g = (o >> 4) & 0xf;
	u8 byte;
	int ret;

	o &= 0xf;
	v4l2_dbg(1, debug, sd, "i=%d, o=%d, g=%d\n", i, o, g);

	/* check if the parameters are valid */
	if (i < 1 || i > 6 || o < 1 || o > 4 || g < 0 || g > 6 || g % 2 != 0)
		return -EINVAL;

	byte = ((o - 1) << 5);
	byte |= (i - 1);

	/* to understand this, have a look at the tea6420-specs (p.5) */
	switch (g) {
	case 0:
		byte |= (3 << 3);
		break;
	case 2:
		byte |= (2 << 3);
		break;
	case 4:
		byte |= (1 << 3);
		break;
	case 6:
		break;
	}

	ret = i2c_smbus_write_byte(client, byte);
	if (ret) {
		v4l2_dbg(1, debug, sd,
			"i2c_smbus_write_byte() failed, ret:%d\n", ret);
		return -EIO;
	}
	return 0;
}

/* ----------------------------------------------------------------------- */

static const struct v4l2_subdev_audio_ops tea6420_audio_ops = {
	.s_routing = tea6420_s_routing,
};

static const struct v4l2_subdev_ops tea6420_ops = {
	.audio = &tea6420_audio_ops,
};

static int tea6420_probe(struct i2c_client *client,
			  const struct i2c_device_id *id)
{
	struct v4l2_subdev *sd;
	int err, i;

	/* let's see whether this adapter can support what we need */
	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WRITE_BYTE))
		return -EIO;

	v4l_info(client, "chip found @ 0x%x (%s)\n",
			client->addr << 1, client->adapter->name);

	sd = devm_kzalloc(&client->dev, sizeof(*sd), GFP_KERNEL);
	if (sd == NULL)
		return -ENOMEM;
	v4l2_i2c_subdev_init(sd, client, &tea6420_ops);

	/* set initial values: set "mute"-input to all outputs at gain 0 */
	err = 0;
	for (i = 1; i < 5; i++)
		err += tea6420_s_routing(sd, 6, i, 0);
	if (err) {
		v4l_dbg(1, debug, client, "could not initialize tea6420\n");
		return -ENODEV;
	}
	return 0;
}

static int tea6420_remove(struct i2c_client *client)
{
	struct v4l2_subdev *sd = i2c_get_clientdata(client);

	v4l2_device_unregister_subdev(sd);
	return 0;
}

static const struct i2c_device_id tea6420_id[] = {
	{ "tea6420", 0 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, tea6420_id);

static struct i2c_driver tea6420_driver = {
	.driver = {
		.name	= "tea6420",
	},
	.probe		= tea6420_probe,
	.remove		= tea6420_remove,
	.id_table	= tea6420_id,
};

module_i2c_driver(tea6420_driver);