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/*
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 adresses 0x98
and 0x9a on the i2c-bus.
For detailed informations download the specifications directly
from SGS Thomson at http://www.st.com
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <linux/module.h>
#include <linux/ioctl.h>
#include <linux/i2c.h>
#include <media/v4l2-common.h>
#include <media/v4l2-i2c-drv-legacy.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)");
/* addresses to scan, found only at 0x4c and/or 0x4d (7-Bit) */
static unsigned short normal_i2c[] = { I2C_ADDR_TEA6420_1, I2C_ADDR_TEA6420_2, I2C_CLIENT_END };
/* magic definition of all other variables and things */
I2C_CLIENT_INSMOD;
/* make a connection between the input 'i' and the output 'o'
with gain 'g' for the tea6420-client 'client' (note: i = 6 means 'mute') */
static int tea6420_switch(struct i2c_client *client, int i, int o, int g)
{
u8 byte;
int ret;
v4l_dbg(1, debug, client, "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 -1;
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) {
v4l_dbg(1, debug, client,
"i2c_smbus_write_byte() failed, ret:%d\n", ret);
return -EIO;
}
return 0;
}
static int tea6420_command(struct i2c_client *client, unsigned cmd, void *arg)
{
struct tea6420_multiplex *a = (struct tea6420_multiplex *)arg;
int result = 0;
switch (cmd) {
case TEA6420_SWITCH:
result = tea6420_switch(client, a->in, a->out, a->gain);
break;
default:
return -ENOIOCTLCMD;
}
return result;
}
/* this function is called by i2c_probe */
static int tea6420_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
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);
/* set initial values: set "mute"-input to all outputs at gain 0 */
err = 0;
for (i = 1; i < 5; i++) {
err += tea6420_switch(client, 6, i, 0);
}
if (err) {
v4l_dbg(1, debug, client, "could not initialize tea6420\n");
kfree(client);
return -ENODEV;
}
return 0;
}
static int tea6420_legacy_probe(struct i2c_adapter *adapter)
{
/* Let's see whether this is a known adapter we can attach to.
Prevents conflicts with tvaudio.c. */
return adapter->id == I2C_HW_SAA7146;
}
static const struct i2c_device_id tea6420_id[] = {
{ "tea6420", 0 },
{ }
};
MODULE_DEVICE_TABLE(i2c, tea6420_id);
static struct v4l2_i2c_driver_data v4l2_i2c_data = {
.name = "tea6420",
.driverid = I2C_DRIVERID_TEA6420,
.command = tea6420_command,
.probe = tea6420_probe,
.legacy_probe = tea6420_legacy_probe,
.id_table = tea6420_id,
};
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