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// 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)
{
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 void tea6420_remove(struct i2c_client *client)
{
struct v4l2_subdev *sd = i2c_get_clientdata(client);
v4l2_device_unregister_subdev(sd);
}
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);
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