/*
tda9840 - i2c-driver for the tda9840 by SGS Thomson
Copyright (C) 1998-2003 Michael Hunold <michael@mihu.de>
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 "tda9840.h"
static int debug; /* insmod parameter */
module_param(debug, int, 0644);
MODULE_PARM_DESC(debug, "Turn on/off device debugging (default:off).");
#define dprintk(args...) \
do { if (debug) { printk("%s: %s()[%d]: ", KBUILD_MODNAME, __func__, __LINE__); printk(args); } } while (0)
#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 struct i2c_driver driver;
static struct i2c_client client_template;
static int command(struct i2c_client *client, unsigned int cmd, void *arg)
{
int result;
int byte = *(int *)arg;
switch (cmd) {
case TDA9840_SWITCH:
dprintk("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;
}
result = i2c_smbus_write_byte_data(client, SWITCH, byte);
if (result)
dprintk("i2c_smbus_write_byte() failed, ret:%d\n", result);
break;
case TDA9840_LEVEL_ADJUST:
dprintk("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;
result = i2c_smbus_write_byte_data(client, LEVEL_ADJUST, byte);
if (result)
dprintk("i2c_smbus_write_byte() failed, ret:%d\n", result);
break;
case TDA9840_STEREO_ADJUST:
dprintk("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;
result = i2c_smbus_write_byte_data(client, STEREO_ADJUST, byte);
if (result)
dprintk("i2c_smbus_write_byte() failed, ret:%d\n", result);
break;
case TDA9840_DETECT: {
int *ret = (int *)arg;
byte = i2c_smbus_read_byte_data(client, STEREO_ADJUST);
if (byte == -1) {
dprintk("i2c_smbus_read_byte_data() failed\n");
return -EIO;
}
if (0 != (byte & 0x80)) {
dprintk("TDA9840_DETECT: register contents invalid\n");
return -EINVAL;
}
dprintk("TDA9840_DETECT: byte: 0x%02x\n", byte);
*ret = ((byte & 0x60) >> 5);
result = 0;
break;
}
case TDA9840_TEST:
dprintk("TDA9840_TEST: 0x%02x\n", byte);
/* mask out irrelevant bits */
byte &= 0x3;
result = i2c_smbus_write_byte_data(client, TEST, byte);
if (result)
dprintk("i2c_smbus_write_byte() failed, ret:%d\n", result);
break;
default:
return -ENOIOCTLCMD;
}
if (result)
return -EIO;
return 0;
}
static int detect(struct i2c_adapter *adapter, int address, int kind)
{
struct i2c_client *client;
int result = 0;
int byte = 0x0;
/* let's see whether this adapter can support what we need */
if (0 == i2c_check_functionality(adapter,
I2C_FUNC_SMBUS_READ_BYTE_DATA |
I2C_FUNC_SMBUS_WRITE_BYTE_DATA)) {
return 0;
}
/* allocate memory for client structure */
client = kmalloc(sizeof(struct i2c_client), GFP_KERNEL);
if (!client) {
printk("not enough kernel memory\n");
return -ENOMEM;
}
/* fill client structure */
memcpy(client, &client_template, sizeof(struct i2c_client));
client->addr = address;
client->adapter = adapter;
/* tell the i2c layer a new client has arrived */
if (0 != (result = i2c_attach_client(client))) {
kfree(client);
return result;
}
/* set initial values for level & stereo - adjustment, mode */
byte = 0;
result = command(client, TDA9840_LEVEL_ADJUST, &byte);
result += command(client, TDA9840_STEREO_ADJUST, &byte);
byte = TDA9840_SET_MONO;
result = command(client, TDA9840_SWITCH, &byte);
if (result) {
dprintk("could not initialize tda9840\n");
return -ENODEV;
}
printk("tda9840: detected @ 0x%02x on adapter %s\n", address, &client->adapter->name[0]);
return 0;
}
static int attach(struct i2c_adapter *adapter)
{
/* let's see whether this is a know adapter we can attach to */
if (adapter->id != I2C_HW_SAA7146) {
dprintk("refusing to probe on unknown adapter [name='%s',id=0x%x]\n", adapter->name, adapter->id);
return -ENODEV;
}
return i2c_probe(adapter, &addr_data, &detect);
}
static int detach(struct i2c_client *client)
{
int ret = i2c_detach_client(client);
kfree(client);
return ret;
}
static struct i2c_driver driver = {
.driver = {
.name = "tda9840",
},
.id = I2C_DRIVERID_TDA9840,
.attach_adapter = attach,
.detach_client = detach,
.command = command,
};
static struct i2c_client client_template = {
.name = "tda9840",
.driver = &driver,
};
static int __init this_module_init(void)
{
return i2c_add_driver(&driver);
}
static void __exit this_module_exit(void)
{
i2c_del_driver(&driver);
}
module_init(this_module_init);
module_exit(this_module_exit);
MODULE_AUTHOR("Michael Hunold <michael@mihu.de>");
MODULE_DESCRIPTION("tda9840 driver");
MODULE_LICENSE("GPL");
