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 addresses 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/slab.h>
34#include <linux/i2c.h>
35#include <media/v4l2-device.h>
36#include <media/v4l2-chip-ident.h>
37#include "tea6420.h"
38
39MODULE_AUTHOR("Michael Hunold <michael@mihu.de>");
40MODULE_DESCRIPTION("tea6420 driver");
41MODULE_LICENSE("GPL");
42
43static int debug;
44module_param(debug, int, 0644);
45
46MODULE_PARM_DESC(debug, "Debug level (0-1)");
47
48
49/* make a connection between the input 'i' and the output 'o'
50   with gain 'g' (note: i = 6 means 'mute') */
51static int tea6420_s_routing(struct v4l2_subdev *sd,
52			     u32 i, u32 o, u32 config)
53{
54	struct i2c_client *client = v4l2_get_subdevdata(sd);
55	int g = (o >> 4) & 0xf;
56	u8 byte;
57	int ret;
58
59	o &= 0xf;
60	v4l2_dbg(1, debug, sd, "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 -EINVAL;
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		v4l2_dbg(1, debug, sd,
87			"i2c_smbus_write_byte() failed, ret:%d\n", ret);
88		return -EIO;
89	}
90	return 0;
91}
92
93static int tea6420_g_chip_ident(struct v4l2_subdev *sd, struct v4l2_dbg_chip_ident *chip)
94{
95	struct i2c_client *client = v4l2_get_subdevdata(sd);
96
97	return v4l2_chip_ident_i2c_client(client, chip, V4L2_IDENT_TEA6420, 0);
98}
99
100/* ----------------------------------------------------------------------- */
101
102static const struct v4l2_subdev_core_ops tea6420_core_ops = {
103	.g_chip_ident = tea6420_g_chip_ident,
104};
105
106static const struct v4l2_subdev_audio_ops tea6420_audio_ops = {
107	.s_routing = tea6420_s_routing,
108};
109
110static const struct v4l2_subdev_ops tea6420_ops = {
111	.core = &tea6420_core_ops,
112	.audio = &tea6420_audio_ops,
113};
114
115static int tea6420_probe(struct i2c_client *client,
116			  const struct i2c_device_id *id)
117{
118	struct v4l2_subdev *sd;
119	int err, i;
120
121	/* let's see whether this adapter can support what we need */
122	if (!i2c_check_functionality(client->adapter, I2C_FUNC_SMBUS_WRITE_BYTE))
123		return -EIO;
124
125	v4l_info(client, "chip found @ 0x%x (%s)\n",
126			client->addr << 1, client->adapter->name);
127
128	sd = kzalloc(sizeof(struct v4l2_subdev), GFP_KERNEL);
129	if (sd == NULL)
130		return -ENOMEM;
131	v4l2_i2c_subdev_init(sd, client, &tea6420_ops);
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_s_routing(sd, 6, i, 0);
137	if (err) {
138		v4l_dbg(1, debug, client, "could not initialize tea6420\n");
139		return -ENODEV;
140	}
141	return 0;
142}
143
144static int tea6420_remove(struct i2c_client *client)
145{
146	struct v4l2_subdev *sd = i2c_get_clientdata(client);
147
148	v4l2_device_unregister_subdev(sd);
149	kfree(sd);
150	return 0;
151}
152
153static const struct i2c_device_id tea6420_id[] = {
154	{ "tea6420", 0 },
155	{ }
156};
157MODULE_DEVICE_TABLE(i2c, tea6420_id);
158
159static struct i2c_driver tea6420_driver = {
160	.driver = {
161		.owner	= THIS_MODULE,
162		.name	= "tea6420",
163	},
164	.probe		= tea6420_probe,
165	.remove		= tea6420_remove,
166	.id_table	= tea6420_id,
167};
168
169static __init int init_tea6420(void)
170{
171	return i2c_add_driver(&tea6420_driver);
172}
173
174static __exit void exit_tea6420(void)
175{
176	i2c_del_driver(&tea6420_driver);
177}
178
179module_init(init_tea6420);
180module_exit(exit_tea6420);
181