Hello Jacek,
> There is currently no support for tda9840 in bttv, and AFAIK there is no
> bttv version which support mono/stereo switching with this chip. I read
> sources and modified it - so now I can listen mono or stereo sound
> with my AVerMedia TV Phone 98.
I have written a full-featured i2c-client-driver for the tda9840
because this chipset is used for my non-bt8x8-based tv-card.
Because of the fact that it is very small I attached it to this mail,
but I don�t know how it fits into bttv's architecture.
(I remember bttv to be a monolithic block, not using any external
i2c-drivers.)
Btw: I have written full-featured drivers for the following
chipsets:
- tda9840: dual sound processor
- tea6420: audio-matrix switch
- tea6415c: video-matrix switch
More informations can be found at http://www.mihu.de/linux/
Good luck,
Michael.
#include <linux/module.h>
#include <linux/malloc.h>
#include <linux/init.h>
#include <linux/i2c.h>
#include "tda9840.h"
#define DATE "20000707"
#define VERSION "1.2"
#ifdef MODULE
MODULE_PARM(debug,"i");
#endif
int debug = 0; /* insmod parameter */
#define dprintk if (debug) printk
#define SWITCH 0x00
#define LEVEL_ADJUST 0x02
#define STEREO_ADJUST 0x03
#define TEST 0x04
/* addresses to scan, found only at 0x42 (7-Bit) */
unsigned short normal_i2c[] = {I2C_TDA9840, I2C_CLIENT_END};
unsigned short normal_i2c_range[] = {I2C_CLIENT_END};
/* magic definition of all other variables and things */
I2C_CLIENT_INSMOD;
/* unique ID allocation */
int tda9840_id = 0;
struct i2c_driver driver;
int tda9840_command(struct i2c_client *client, unsigned int cmd, void* arg)
{
int result = 0;
switch (cmd) {
case TDA9840_SWITCH:
{
int byte = *(int*)arg;
dprintk("tda9840.o: 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;
}
if ( 0 != (result = i2c_smbus_write_byte_data(client, SWITCH,
byte))) {
printk("tda9840.o: TDA9840_SWITCH error.\n");
return -EFAULT;
}
return 0;
}
case TDA9840_LEVEL_ADJUST:
{
int byte = *(int*)arg;
dprintk("tda9840.o: TDA9840_LEVEL_ADJUST: 0x%02x\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;
if ( 0 != (result = i2c_smbus_write_byte_data(client,
LEVEL_ADJUST, byte))) {
printk("tda9840.o: TDA9840_LEVEL_ADJUST error.\n");
return -EFAULT;
}
return 0;
}
case TDA9840_STEREO_ADJUST:
{
int byte = *(int*)arg;
dprintk("tda9840.o: TDA9840_STEREO_ADJUST: 0x%02x\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;
if ( 0 != (result = i2c_smbus_write_byte_data(client,
STEREO_ADJUST, byte))) {
printk("tda9840.o: TDA9840_STEREO_ADJUST error.\n");
return -EFAULT;
}
return 0;
}
case TDA9840_DETECT:
{
int byte = 0x0;
if ( -1 == (byte = i2c_smbus_read_byte_data(client,
STEREO_ADJUST))) {
printk("tda9840.o: TDA9840_DETECT error while
reading.\n");
return -EFAULT;
}
if( 0 != (byte & 0x80)) {
dprintk("tda9840.o: TDA9840_DETECT, register contents
invalid.\n");
return -EFAULT;
}
dprintk("tda9840.o: TDA9840_DETECT, result: 0x%02x (original
byte)\n",byte);
return ((byte & 0x60) >> 5);
}
case TDA9840_TEST:
{
int byte = *(int*)arg;
dprintk("tda9840.o: TDA9840_TEST: 0x%02x\n",byte);
/* mask out irrelevant bits */
byte &= 0x3;
if ( 0 != (result = i2c_smbus_write_byte_data(client, TEST,
byte))) {
printk("tda9840.o: TDA9840_TEST error.\n");
return -EFAULT;
}
return 0;
}
default:
return -ENOIOCTLCMD;
}
return 0;
}
int tda9840_detect(struct i2c_adapter *adapter, int address, unsigned short flags, 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 (0 == client) {
printk("tda9840.o: not enough kernel memory.\n");
return -ENOMEM;
}
/* fill client structure */
sprintf(client->name,"tda9840 (0x%02x)", address);
client->id = tda9840_id++;
client->flags = 0;
client->addr = address;
client->adapter = adapter;
client->driver = &driver;
client->data = NULL;
/* 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;
if ( 0 != (result = tda9840_command(client, TDA9840_LEVEL_ADJUST, &byte))) {
printk("tda9840.o: could not initialize ic #1. continuing anyway.
(result:%d)\n",result);
}
if ( 0 != (result = tda9840_command(client, TDA9840_STEREO_ADJUST, &byte))) {
printk("tda9840.o: could not initialize ic #2. continuing anyway.
(result:%d)\n",result);
}
byte = TDA9840_SET_MONO;
if ( 0 != (result = tda9840_command(client, TDA9840_SWITCH, &byte))) {
printk("tda9840.o: could not initialize ic #3. continuing anyway.
(result:%d)\n",result);
}
printk("tda9840.o: detected @ 0x%02x on adapter
%s\n",2*address,&client->adapter->name[0]);
return 0;
}
int tda9840_attach(struct i2c_adapter *adapter)
{
return i2c_probe(adapter,&addr_data,&tda9840_detect);
}
int tda9840_detach(struct i2c_client *client)
{
int err = 0;
if ( 0 != (err = i2c_detach_client(client))) {
printk("tda9840.o: Client deregistration failed, client not
detached.\n");
return err;
}
kfree(client);
return 0;
}
void tda9840_inc_use(struct i2c_client *client)
{
#ifdef MODULE
MOD_INC_USE_COUNT;
#endif
}
void tda9840_dec_use(struct i2c_client *client)
{
#ifdef MODULE
MOD_DEC_USE_COUNT;
#endif
}
struct i2c_driver driver = {
"tda9840 driver",
I2C_DRIVERID_TDA9840,
I2C_DF_NOTIFY,
tda9840_attach,
tda9840_detach,
tda9840_command,
tda9840_inc_use,
tda9840_dec_use
};
EXPORT_NO_SYMBOLS;
#ifndef MODULE
extern
#endif
int __init tda9840_init(void)
{
int res = 0;
printk("tda9840.o version %s (%s)\n",VERSION,DATE);
if( 0 != (res = i2c_add_driver(&driver))) {
printk("tda9840.o: Driver registration failed, module not
inserted.\n");
return res;
}
return 0;
}
int __init tda9840_cleanup(void)
{
int res = 0;
if ( 0 != (res = i2c_del_driver(&driver))) {
printk("tda9840.o: Driver deregistration failed, module not
removed.\n");
return res;
}
return 0;
}
#ifdef MODULE
MODULE_AUTHOR("Michael Hunold <[EMAIL PROTECTED]>");
MODULE_DESCRIPTION("tda9840 driver");
int init_module(void)
{
return tda9840_init();
}
void cleanup_module(void)
{
tda9840_cleanup();
}
#endif
/*
tda9840.h - definitions for the i2c-driver
for the tda9840 by SGS Thomson
Copyright (C) 1998,1999,2000 Michael Hunold <[EMAIL PROTECTED]>
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.
*/
#ifndef __INCLUDED_TDA9840__
#define __INCLUDED_TDA9840__
#define I2C_TDA9840 0x42
/* I'm using the currently unused letter 'd' for
identifying. perhaps this will be changed in the
future.
(see /usr/src/linux/Documentation/ioctl-number.txt
for further details.) */
#define TDA9840_DETECT _IOR('d',1,int)
/* return values for TDA9840_DETCT */
#define TDA9840_MONO_DETECT 0x0
#define TDA9840_DUAL_DETECT 0x1
#define TDA9840_STEREO_DETECT 0x2
#define TDA9840_INCORRECT_DETECT 0x3
#define TDA9840_SWITCH _IOW('d',2,int)
/* modes than can be set with TDA9840_SWITCH */
#define TDA9840_SET_MUTE 0x00
#define TDA9840_SET_MONO 0x10
#define TDA9840_SET_STEREO 0x2a
#define TDA9840_SET_LANG1 0x12
#define TDA9840_SET_LANG2 0x1e
#define TDA9840_SET_BOTH 0x1a
#define TDA9840_SET_BOTH_R 0x16
#define TDA9840_SET_EXTERNAL 0x7a
/* values may range between +2.5 and -2.0;
the value has to be multiplied with 10 */
#define TDA9840_LEVEL_ADJUST _IOW('d',3,int)
/* values may range between +2.5 and -2.4;
the value has to be multiplied with 10 */
#define TDA9840_STEREO_ADJUST _IOW('d',4,int)
/* currently not implemented */
#define TDA9840_TEST _IOW('d',5,int)
#endif
