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#include <linux/version.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/poll.h>
#include <linux/slab.h>
#include <linux/i2c.h>
#include <linux/init.h>
#include "tea6420.h"
static int debug = 0; /* insmod parameter */
MODULE_PARM(debug,"i");
#define dprintk if (debug) printk
/* addresses to scan, found only at 0x4c and/or 0x4d (7-Bit) */
static unsigned short normal_i2c[] = {I2C_TEA6420_1, I2C_TEA6420_2, I2C_CLIENT_END};
static unsigned short normal_i2c_range[] = {I2C_CLIENT_END};
/* magic definition of all other variables and things */
I2C_CLIENT_INSMOD;
static struct i2c_driver driver;
/* unique ID allocation */
static int tea6420_id = 0;
/* 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 = 0;
int result = 0;
dprintk("tea6420.o: tea6420_switch: adr:0x%02x, i:%d, o:%d, g:%d\n",client->addr,i,o,g);
/* check if the paramters 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;
}
/* fixme?: 1 != ... => 0 != */
if ( 0 != (result = i2c_smbus_write_byte(client,byte))) {
printk("tea6402:%d\n",result);
dprintk(KERN_ERR "tea6420.o: could not switch, result:%d\n",result);
return -EFAULT;
}
return 0;
}
/* this function is called by i2c_probe */
static int tea6420_detect(struct i2c_adapter *adapter, int address, unsigned short flags, int kind)
{
struct i2c_client *client;
int err = 0, i = 0;
/* let's see whether this adapter can support what we need */
if ( 0 == i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WRITE_BYTE)) {
return 0;
}
/* allocate memory for client structure */
client = kmalloc(sizeof(struct i2c_client), GFP_KERNEL);
if (0 == client) {
return -ENOMEM;
}
/* fill client structure */
sprintf(client->name,"tea6420 (0x%02x)", address);
client->id = tea6420_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 != (err = i2c_attach_client(client))) {
kfree(client);
return err;
}
/* 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( 0 != err) {
printk("tea6420.o: could not initialize chipset. continuing anyway.\n");
}
printk("tea6420.o: detected @ 0x%02x on adapter %s\n",2*address,&client->adapter->name[0]);
return 0;
}
static int tea6420_attach(struct i2c_adapter *adapter)
{
return i2c_probe(adapter,&addr_data,&tea6420_detect);
}
static int tea6420_detach(struct i2c_client *client)
{
int err = 0;
if ( 0 != (err = i2c_detach_client(client))) {
printk("tea6420.o: Client deregistration failed, client not detached.\n");
return err;
}
kfree(client);
return 0;
}
static int tea6420_command(struct i2c_client *client, unsigned int cmd, void* arg)
{
struct audio_multiplex *a = (struct audio_multiplex*)arg;
int result = 0;
switch (cmd) {
case TEA6420_SWITCH: {
result = tea6420_switch(client,a->in,a->out,a->gain);
break;
}
default: {
return -ENOIOCTLCMD;
}
}
if ( 0 != result )
return result;
return 0;
}
static struct i2c_driver driver = {
#if LINUX_VERSION_CODE > KERNEL_VERSION(2,5,54)
.owner = THIS_MODULE,
#endif
.name = "tea6420 driver",
.id = I2C_DRIVERID_TEA6420,
.flags = I2C_DF_NOTIFY,
.attach_adapter = tea6420_attach,
.detach_client = tea6420_detach,
.command = tea6420_command,
};
static int tea6420_init_module(void)
{
i2c_add_driver(&driver);
return 0;
}
static void tea6420_cleanup_module(void)
{
i2c_del_driver(&driver);
}
module_init(tea6420_init_module);
module_exit(tea6420_cleanup_module);
MODULE_AUTHOR("Michael Hunold <michael@mihu.de>");
MODULE_DESCRIPTION("tea6420 driver");
MODULE_LICENSE("GPL");
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