/*
tda9840 - i2c-driver for the tda9840 by SGS Thomson
Copyright (C) 1998-2003 Michael Hunold <michael@mihu.de>
Copyright (C) 2008 Hans Verkuil <hverkuil@xs4all.nl>
The tda9840 is a stereo/dual sound processor with digital
identification. It can be found at address 0x84 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 "tda9840.h"
MODULE_AUTHOR("Michael Hunold <michael@mihu.de>");
MODULE_DESCRIPTION("tda9840 driver");
MODULE_LICENSE("GPL");
static int debug;
module_param(debug, int, 0644);
MODULE_PARM_DESC(debug, "Debug level (0-1)");
#define SWITCH 0x00
#define LEVEL_ADJUST 0x02
#define STEREO_ADJUST 0x03
#define TEST 0x04
/* addresses to scan, found only at 0x42 (7-Bit) */
static unsigned short normal_i2c[] = { I2C_ADDR_TDA9840, I2C_CLIENT_END };
/* magic definition of all other variables and things */
I2C_CLIENT_INSMOD;
static void tda9840_write(struct i2c_client *client, u8 reg, u8 val)
{
if (i2c_smbus_write_byte_data(client, reg, val))
v4l_dbg(1, debug, client, "error writing %02x to %02x\n",
val, reg);
}
static int tda9840_command(struct i2c_client *client, unsigned cmd, void *arg)
{
int result;
int byte = *(int *)arg;
switch (cmd) {
case TDA9840_SWITCH:
v4l_dbg(1, debug, client, "TDA9840_SWITCH: 0x%02x\n", byte);
if (byte != TDA9840_SET_MONO
&& byte != TDA9840_SET_MUTE
&& byte != TDA9840_SET_STEREO
&& byte != TDA9840_SET_LANG1
&& byte != TDA9840_SET_LANG2
&& byte != TDA9840_SET_BOTH
&& byte != TDA9840_SET_BOTH_R
&& byte != TDA9840_SET_EXTERNAL) {
return -EINVAL;
}
tda9840_write(client, SWITCH, byte);
break;
case TDA9840_LEVEL_ADJUST:
v4l_dbg(1, debug, client, "TDA9840_LEVEL_ADJUST: %d\n", byte);
/* check for correct range */
if (byte > 25 || byte < -20)
return -EINVAL;
/* calculate actual value to set, see specs, page 18 */
byte /= 5;
if (0 < byte)
byte += 0x8;
else
byte = -byte;
tda9840_write(client, LEVEL_ADJUST, byte);
break;
case TDA9840_STEREO_ADJUST:
v4l_dbg(1, debug, client, "TDA9840_STEREO_ADJUST: %d\n", byte);
/* check for correct range */
if (byte > 25 || byte < -24)
return -EINVAL;
/* calculate actual value to set */
byte /= 5;
if (0 < byte)
byte += 0x20;
else
byte = -byte;
tda9840_write(client, STEREO_ADJUST, byte);
break;
case TDA9840_DETECT: {
int *ret = (int *)arg;
byte = i2c_smbus_read_byte_data(client, STEREO_ADJUST);
if (byte == -1) {
v4l_dbg(1, debug, client,
"i2c_smbus_read_byte_data() failed\n");
return -EIO;
}
if (byte & 0x80) {
v4l_dbg(1, debug, client,
"TDA9840_DETECT: register contents invalid\n");
return -EINVAL;
}
v4l_dbg(1, debug, client, "TDA9840_DETECT: byte: 0x%02x\n", byte);
*ret = (byte & 0x60) >> 5;
result = 0;
break;
}
case TDA9840_TEST:
v4l_dbg(1, debug, client, "TDA9840_TEST: 0x%02x\n", byte);
/* mask out irrelevant bits */
byte &= 0x3;
tda9840_write(client, TEST, byte);
break;
default:
return -ENOIOCTLCMD;
}
if (result)
return -EIO;
return 0;
}
static int tda9840_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
int result;
int byte;
/* let's see whether this adapter can support what we need */
if (!i2c_check_functionality(client->adapter,
I2C_FUNC_SMBUS_READ_BYTE_DATA |
I2C_FUNC_SMBUS_WRITE_BYTE_DATA))
return 0;
v4l_info(client, "chip found @ 0x%x (%s)\n",
client->addr << 1, client->adapter->name);
/* set initial values for level & stereo - adjustment, mode */
byte = 0;
result = tda9840_command(client, TDA9840_LEVEL_ADJUST, &byte);
result += tda9840_command(client, TDA9840_STEREO_ADJUST, &byte);
byte = TDA9840_SET_MONO;
result = tda9840_command(client, TDA9840_SWITCH, &byte);
if (result) {
v4l_dbg(1, debug, client, "could not initialize tda9840\n");
return -ENODEV;
}
return 0;
}
static int tda9840_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 tda9840_id[] = {
{ "tda9840", 0 },
{ }
};
MODULE_DEVICE_TABLE(i2c, tda9840_id);
static struct v4l2_i2c_driver_data v4l2_i2c_data = {
.name = "tda9840",
.driverid = I2C_DRIVERID_TDA9840,
.command = tda9840_command,
.probe = tda9840_probe,
.legacy_probe = tda9840_legacy_probe,
.id_table = tda9840_id,
};