forked from Minki/linux
5da69ba42a
Here is a simple path fixing an incorrect kfree in the m41t00 i2c chip driver. The current code happens to work by accident, but the freed pointer isn't the one which was allocated in the first place, which could cause problems later. Signed-off-by: Jean Delvare <khali@linux-fr.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
244 lines
5.3 KiB
C
244 lines
5.3 KiB
C
/*
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* drivers/i2c/chips/m41t00.c
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*
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* I2C client/driver for the ST M41T00 Real-Time Clock chip.
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*
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* Author: Mark A. Greer <mgreer@mvista.com>
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*
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* 2005 (c) MontaVista Software, Inc. This file is licensed under
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* the terms of the GNU General Public License version 2. This program
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* is licensed "as is" without any warranty of any kind, whether express
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* or implied.
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*/
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/*
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* This i2c client/driver wedges between the drivers/char/genrtc.c RTC
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* interface and the SMBus interface of the i2c subsystem.
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* It would be more efficient to use i2c msgs/i2c_transfer directly but, as
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* recommened in .../Documentation/i2c/writing-clients section
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* "Sending and receiving", using SMBus level communication is preferred.
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/interrupt.h>
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#include <linux/i2c.h>
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#include <linux/rtc.h>
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#include <linux/bcd.h>
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#include <asm/time.h>
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#include <asm/rtc.h>
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#define M41T00_DRV_NAME "m41t00"
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static DECLARE_MUTEX(m41t00_mutex);
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static struct i2c_driver m41t00_driver;
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static struct i2c_client *save_client;
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static unsigned short ignore[] = { I2C_CLIENT_END };
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static unsigned short normal_addr[] = { 0x68, I2C_CLIENT_END };
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static struct i2c_client_address_data addr_data = {
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.normal_i2c = normal_addr,
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.probe = ignore,
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.ignore = ignore,
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.force = ignore,
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};
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ulong
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m41t00_get_rtc_time(void)
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{
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s32 sec, min, hour, day, mon, year;
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s32 sec1, min1, hour1, day1, mon1, year1;
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ulong limit = 10;
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sec = min = hour = day = mon = year = 0;
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sec1 = min1 = hour1 = day1 = mon1 = year1 = 0;
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down(&m41t00_mutex);
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do {
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if (((sec = i2c_smbus_read_byte_data(save_client, 0)) >= 0)
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&& ((min = i2c_smbus_read_byte_data(save_client, 1))
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>= 0)
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&& ((hour = i2c_smbus_read_byte_data(save_client, 2))
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>= 0)
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&& ((day = i2c_smbus_read_byte_data(save_client, 4))
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>= 0)
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&& ((mon = i2c_smbus_read_byte_data(save_client, 5))
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>= 0)
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&& ((year = i2c_smbus_read_byte_data(save_client, 6))
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>= 0)
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&& ((sec == sec1) && (min == min1) && (hour == hour1)
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&& (day == day1) && (mon == mon1)
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&& (year == year1)))
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break;
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sec1 = sec;
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min1 = min;
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hour1 = hour;
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day1 = day;
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mon1 = mon;
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year1 = year;
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} while (--limit > 0);
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up(&m41t00_mutex);
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if (limit == 0) {
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dev_warn(&save_client->dev,
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"m41t00: can't read rtc chip\n");
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sec = min = hour = day = mon = year = 0;
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}
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sec &= 0x7f;
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min &= 0x7f;
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hour &= 0x3f;
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day &= 0x3f;
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mon &= 0x1f;
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year &= 0xff;
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BCD_TO_BIN(sec);
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BCD_TO_BIN(min);
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BCD_TO_BIN(hour);
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BCD_TO_BIN(day);
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BCD_TO_BIN(mon);
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BCD_TO_BIN(year);
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year += 1900;
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if (year < 1970)
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year += 100;
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return mktime(year, mon, day, hour, min, sec);
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}
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static void
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m41t00_set_tlet(ulong arg)
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{
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struct rtc_time tm;
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ulong nowtime = *(ulong *)arg;
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to_tm(nowtime, &tm);
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tm.tm_year = (tm.tm_year - 1900) % 100;
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BIN_TO_BCD(tm.tm_sec);
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BIN_TO_BCD(tm.tm_min);
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BIN_TO_BCD(tm.tm_hour);
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BIN_TO_BCD(tm.tm_mon);
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BIN_TO_BCD(tm.tm_mday);
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BIN_TO_BCD(tm.tm_year);
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down(&m41t00_mutex);
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if ((i2c_smbus_write_byte_data(save_client, 0, tm.tm_sec & 0x7f) < 0)
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|| (i2c_smbus_write_byte_data(save_client, 1, tm.tm_min & 0x7f)
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< 0)
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|| (i2c_smbus_write_byte_data(save_client, 2, tm.tm_hour & 0x7f)
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< 0)
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|| (i2c_smbus_write_byte_data(save_client, 4, tm.tm_mday & 0x7f)
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< 0)
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|| (i2c_smbus_write_byte_data(save_client, 5, tm.tm_mon & 0x7f)
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< 0)
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|| (i2c_smbus_write_byte_data(save_client, 6, tm.tm_year & 0x7f)
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< 0))
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dev_warn(&save_client->dev,"m41t00: can't write to rtc chip\n");
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up(&m41t00_mutex);
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return;
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}
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ulong new_time;
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DECLARE_TASKLET_DISABLED(m41t00_tasklet, m41t00_set_tlet, (ulong)&new_time);
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int
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m41t00_set_rtc_time(ulong nowtime)
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{
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new_time = nowtime;
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if (in_interrupt())
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tasklet_schedule(&m41t00_tasklet);
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else
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m41t00_set_tlet((ulong)&new_time);
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return 0;
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}
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/*
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*****************************************************************************
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*
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* Driver Interface
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*
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*****************************************************************************
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*/
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static int
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m41t00_probe(struct i2c_adapter *adap, int addr, int kind)
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{
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struct i2c_client *client;
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int rc;
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client = kmalloc(sizeof(struct i2c_client), GFP_KERNEL);
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if (!client)
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return -ENOMEM;
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memset(client, 0, sizeof(struct i2c_client));
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strncpy(client->name, M41T00_DRV_NAME, I2C_NAME_SIZE);
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client->flags = I2C_DF_NOTIFY;
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client->addr = addr;
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client->adapter = adap;
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client->driver = &m41t00_driver;
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if ((rc = i2c_attach_client(client)) != 0) {
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kfree(client);
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return rc;
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}
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save_client = client;
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return 0;
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}
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static int
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m41t00_attach(struct i2c_adapter *adap)
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{
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return i2c_probe(adap, &addr_data, m41t00_probe);
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}
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static int
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m41t00_detach(struct i2c_client *client)
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{
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int rc;
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if ((rc = i2c_detach_client(client)) == 0) {
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kfree(client);
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tasklet_kill(&m41t00_tasklet);
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}
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return rc;
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}
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static struct i2c_driver m41t00_driver = {
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.owner = THIS_MODULE,
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.name = M41T00_DRV_NAME,
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.id = I2C_DRIVERID_STM41T00,
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.flags = I2C_DF_NOTIFY,
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.attach_adapter = m41t00_attach,
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.detach_client = m41t00_detach,
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};
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static int __init
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m41t00_init(void)
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{
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return i2c_add_driver(&m41t00_driver);
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}
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static void __exit
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m41t00_exit(void)
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{
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i2c_del_driver(&m41t00_driver);
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return;
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}
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module_init(m41t00_init);
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module_exit(m41t00_exit);
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MODULE_AUTHOR("Mark A. Greer <mgreer@mvista.com>");
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MODULE_DESCRIPTION("ST Microelectronics M41T00 RTC I2C Client Driver");
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MODULE_LICENSE("GPL");
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