254 lines
6.3 KiB
C
254 lines
6.3 KiB
C
/*
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tda9840 - i2c-driver for the tda9840 by SGS Thomson
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Copyright (C) 1998-2003 Michael Hunold <michael@mihu.de>
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The tda9840 is a stereo/dual sound processor with digital
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identification. It can be found at address 0x84 on the i2c-bus.
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For detailed informations download the specifications directly
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from SGS Thomson at http://www.st.com
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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#include <linux/module.h>
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#include <linux/ioctl.h>
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#include <linux/i2c.h>
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#include "tda9840.h"
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static int debug = 0; /* insmod parameter */
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module_param(debug, int, 0644);
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MODULE_PARM_DESC(debug, "Turn on/off device debugging (default:off).");
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#define dprintk(args...) \
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do { if (debug) { printk("%s: %s()[%d]: ", KBUILD_MODNAME, __FUNCTION__, __LINE__); printk(args); } } while (0)
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#define SWITCH 0x00
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#define LEVEL_ADJUST 0x02
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#define STEREO_ADJUST 0x03
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#define TEST 0x04
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/* addresses to scan, found only at 0x42 (7-Bit) */
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static unsigned short normal_i2c[] = { I2C_ADDR_TDA9840, I2C_CLIENT_END };
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/* magic definition of all other variables and things */
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I2C_CLIENT_INSMOD;
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static struct i2c_driver driver;
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static struct i2c_client client_template;
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static int command(struct i2c_client *client, unsigned int cmd, void *arg)
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{
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int result;
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int byte = *(int *)arg;
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switch (cmd) {
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case TDA9840_SWITCH:
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dprintk("TDA9840_SWITCH: 0x%02x\n", byte);
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if (byte != TDA9840_SET_MONO
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&& byte != TDA9840_SET_MUTE
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&& byte != TDA9840_SET_STEREO
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&& byte != TDA9840_SET_LANG1
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&& byte != TDA9840_SET_LANG2
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&& byte != TDA9840_SET_BOTH
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&& byte != TDA9840_SET_BOTH_R
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&& byte != TDA9840_SET_EXTERNAL) {
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return -EINVAL;
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}
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result = i2c_smbus_write_byte_data(client, SWITCH, byte);
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if (result)
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dprintk("i2c_smbus_write_byte() failed, ret:%d\n", result);
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break;
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case TDA9840_LEVEL_ADJUST:
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dprintk("TDA9840_LEVEL_ADJUST: %d\n", byte);
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/* check for correct range */
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if (byte > 25 || byte < -20)
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return -EINVAL;
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/* calculate actual value to set, see specs, page 18 */
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byte /= 5;
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if (0 < byte)
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byte += 0x8;
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else
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byte = -byte;
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result = i2c_smbus_write_byte_data(client, LEVEL_ADJUST, byte);
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if (result)
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dprintk("i2c_smbus_write_byte() failed, ret:%d\n", result);
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break;
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case TDA9840_STEREO_ADJUST:
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dprintk("TDA9840_STEREO_ADJUST: %d\n", byte);
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/* check for correct range */
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if (byte > 25 || byte < -24)
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return -EINVAL;
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/* calculate actual value to set */
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byte /= 5;
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if (0 < byte)
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byte += 0x20;
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else
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byte = -byte;
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result = i2c_smbus_write_byte_data(client, STEREO_ADJUST, byte);
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if (result)
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dprintk("i2c_smbus_write_byte() failed, ret:%d\n", result);
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break;
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case TDA9840_DETECT: {
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int *ret = (int *)arg;
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byte = i2c_smbus_read_byte_data(client, STEREO_ADJUST);
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if (byte == -1) {
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dprintk("i2c_smbus_read_byte_data() failed\n");
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return -EIO;
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}
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if (0 != (byte & 0x80)) {
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dprintk("TDA9840_DETECT: register contents invalid\n");
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return -EINVAL;
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}
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dprintk("TDA9840_DETECT: byte: 0x%02x\n", byte);
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*ret = ((byte & 0x60) >> 5);
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result = 0;
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break;
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}
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case TDA9840_TEST:
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dprintk("TDA9840_TEST: 0x%02x\n", byte);
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/* mask out irrelevant bits */
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byte &= 0x3;
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result = i2c_smbus_write_byte_data(client, TEST, byte);
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if (result)
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dprintk("i2c_smbus_write_byte() failed, ret:%d\n", result);
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break;
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default:
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return -ENOIOCTLCMD;
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}
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if (result)
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return -EIO;
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return 0;
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}
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static int detect(struct i2c_adapter *adapter, int address, int kind)
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{
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struct i2c_client *client;
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int result = 0;
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int byte = 0x0;
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/* let's see whether this adapter can support what we need */
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if (0 == i2c_check_functionality(adapter,
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I2C_FUNC_SMBUS_READ_BYTE_DATA |
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I2C_FUNC_SMBUS_WRITE_BYTE_DATA)) {
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return 0;
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}
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/* allocate memory for client structure */
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client = kmalloc(sizeof(struct i2c_client), GFP_KERNEL);
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if (0 == client) {
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printk("not enough kernel memory\n");
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return -ENOMEM;
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}
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/* fill client structure */
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memcpy(client, &client_template, sizeof(struct i2c_client));
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client->addr = address;
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client->adapter = adapter;
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/* tell the i2c layer a new client has arrived */
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if (0 != (result = i2c_attach_client(client))) {
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kfree(client);
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return result;
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}
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/* set initial values for level & stereo - adjustment, mode */
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byte = 0;
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result = command(client, TDA9840_LEVEL_ADJUST, &byte);
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result += command(client, TDA9840_STEREO_ADJUST, &byte);
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byte = TDA9840_SET_MONO;
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result = command(client, TDA9840_SWITCH, &byte);
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if (result) {
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dprintk("could not initialize tda9840\n");
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return -ENODEV;
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}
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printk("tda9840: detected @ 0x%02x on adapter %s\n", address, &client->adapter->name[0]);
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return 0;
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}
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static int attach(struct i2c_adapter *adapter)
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{
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/* let's see whether this is a know adapter we can attach to */
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if (adapter->id != I2C_HW_SAA7146) {
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dprintk("refusing to probe on unknown adapter [name='%s',id=0x%x]\n", adapter->name, adapter->id);
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return -ENODEV;
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}
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return i2c_probe(adapter, &addr_data, &detect);
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}
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static int detach(struct i2c_client *client)
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{
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int ret = i2c_detach_client(client);
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kfree(client);
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return ret;
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}
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static struct i2c_driver driver = {
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.driver = {
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.name = "tda9840",
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},
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.id = I2C_DRIVERID_TDA9840,
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.attach_adapter = attach,
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.detach_client = detach,
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.command = command,
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};
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static struct i2c_client client_template = {
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.name = "tda9840",
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.driver = &driver,
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};
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static int __init this_module_init(void)
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{
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return i2c_add_driver(&driver);
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}
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static void __exit this_module_exit(void)
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{
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i2c_del_driver(&driver);
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}
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module_init(this_module_init);
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module_exit(this_module_exit);
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MODULE_AUTHOR("Michael Hunold <michael@mihu.de>");
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MODULE_DESCRIPTION("tda9840 driver");
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MODULE_LICENSE("GPL");
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