2c3c8bea60
This allows bin_attr->read,write,mmap callbacks to check file specific data (such as inode owner) as part of any privilege validation. Signed-off-by: Chris Wright <chrisw@sous-sol.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
241 lines
5.0 KiB
C
241 lines
5.0 KiB
C
/*
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* 1-Wire implementation for the ds2760 chip
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*
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* Copyright © 2004-2005, Szabolcs Gyurko <szabolcs.gyurko@tlt.hu>
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*
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* Use consistent with the GNU GPL is permitted,
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* provided that this copyright notice is
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* preserved in its entirety in all copies and derived works.
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*
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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/device.h>
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#include <linux/types.h>
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#include <linux/platform_device.h>
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#include <linux/mutex.h>
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#include <linux/idr.h>
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#include <linux/gfp.h>
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#include "../w1.h"
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#include "../w1_int.h"
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#include "../w1_family.h"
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#include "w1_ds2760.h"
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static int w1_ds2760_io(struct device *dev, char *buf, int addr, size_t count,
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int io)
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{
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struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
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if (!dev)
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return 0;
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mutex_lock(&sl->master->mutex);
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if (addr > DS2760_DATA_SIZE || addr < 0) {
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count = 0;
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goto out;
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}
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if (addr + count > DS2760_DATA_SIZE)
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count = DS2760_DATA_SIZE - addr;
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if (!w1_reset_select_slave(sl)) {
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if (!io) {
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w1_write_8(sl->master, W1_DS2760_READ_DATA);
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w1_write_8(sl->master, addr);
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count = w1_read_block(sl->master, buf, count);
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} else {
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w1_write_8(sl->master, W1_DS2760_WRITE_DATA);
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w1_write_8(sl->master, addr);
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w1_write_block(sl->master, buf, count);
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/* XXX w1_write_block returns void, not n_written */
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}
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}
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out:
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mutex_unlock(&sl->master->mutex);
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return count;
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}
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int w1_ds2760_read(struct device *dev, char *buf, int addr, size_t count)
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{
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return w1_ds2760_io(dev, buf, addr, count, 0);
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}
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int w1_ds2760_write(struct device *dev, char *buf, int addr, size_t count)
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{
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return w1_ds2760_io(dev, buf, addr, count, 1);
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}
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static int w1_ds2760_eeprom_cmd(struct device *dev, int addr, int cmd)
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{
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struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
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if (!dev)
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return -EINVAL;
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mutex_lock(&sl->master->mutex);
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if (w1_reset_select_slave(sl) == 0) {
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w1_write_8(sl->master, cmd);
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w1_write_8(sl->master, addr);
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}
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mutex_unlock(&sl->master->mutex);
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return 0;
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}
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int w1_ds2760_store_eeprom(struct device *dev, int addr)
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{
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return w1_ds2760_eeprom_cmd(dev, addr, W1_DS2760_COPY_DATA);
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}
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int w1_ds2760_recall_eeprom(struct device *dev, int addr)
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{
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return w1_ds2760_eeprom_cmd(dev, addr, W1_DS2760_RECALL_DATA);
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}
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static ssize_t w1_ds2760_read_bin(struct file *filp, struct kobject *kobj,
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struct bin_attribute *bin_attr,
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char *buf, loff_t off, size_t count)
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{
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struct device *dev = container_of(kobj, struct device, kobj);
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return w1_ds2760_read(dev, buf, off, count);
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}
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static struct bin_attribute w1_ds2760_bin_attr = {
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.attr = {
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.name = "w1_slave",
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.mode = S_IRUGO,
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},
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.size = DS2760_DATA_SIZE,
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.read = w1_ds2760_read_bin,
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};
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static DEFINE_IDR(bat_idr);
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static DEFINE_MUTEX(bat_idr_lock);
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static int new_bat_id(void)
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{
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int ret;
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while (1) {
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int id;
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ret = idr_pre_get(&bat_idr, GFP_KERNEL);
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if (ret == 0)
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return -ENOMEM;
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mutex_lock(&bat_idr_lock);
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ret = idr_get_new(&bat_idr, NULL, &id);
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mutex_unlock(&bat_idr_lock);
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if (ret == 0) {
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ret = id & MAX_ID_MASK;
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break;
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} else if (ret == -EAGAIN) {
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continue;
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} else {
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break;
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}
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}
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return ret;
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}
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static void release_bat_id(int id)
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{
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mutex_lock(&bat_idr_lock);
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idr_remove(&bat_idr, id);
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mutex_unlock(&bat_idr_lock);
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}
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static int w1_ds2760_add_slave(struct w1_slave *sl)
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{
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int ret;
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int id;
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struct platform_device *pdev;
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id = new_bat_id();
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if (id < 0) {
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ret = id;
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goto noid;
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}
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pdev = platform_device_alloc("ds2760-battery", id);
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if (!pdev) {
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ret = -ENOMEM;
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goto pdev_alloc_failed;
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}
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pdev->dev.parent = &sl->dev;
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ret = platform_device_add(pdev);
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if (ret)
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goto pdev_add_failed;
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ret = sysfs_create_bin_file(&sl->dev.kobj, &w1_ds2760_bin_attr);
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if (ret)
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goto bin_attr_failed;
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dev_set_drvdata(&sl->dev, pdev);
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goto success;
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bin_attr_failed:
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pdev_add_failed:
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platform_device_unregister(pdev);
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pdev_alloc_failed:
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release_bat_id(id);
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noid:
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success:
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return ret;
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}
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static void w1_ds2760_remove_slave(struct w1_slave *sl)
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{
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struct platform_device *pdev = dev_get_drvdata(&sl->dev);
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int id = pdev->id;
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platform_device_unregister(pdev);
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release_bat_id(id);
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sysfs_remove_bin_file(&sl->dev.kobj, &w1_ds2760_bin_attr);
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}
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static struct w1_family_ops w1_ds2760_fops = {
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.add_slave = w1_ds2760_add_slave,
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.remove_slave = w1_ds2760_remove_slave,
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};
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static struct w1_family w1_ds2760_family = {
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.fid = W1_FAMILY_DS2760,
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.fops = &w1_ds2760_fops,
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};
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static int __init w1_ds2760_init(void)
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{
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printk(KERN_INFO "1-Wire driver for the DS2760 battery monitor "
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" chip - (c) 2004-2005, Szabolcs Gyurko\n");
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idr_init(&bat_idr);
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return w1_register_family(&w1_ds2760_family);
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}
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static void __exit w1_ds2760_exit(void)
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{
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w1_unregister_family(&w1_ds2760_family);
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idr_destroy(&bat_idr);
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}
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EXPORT_SYMBOL(w1_ds2760_read);
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EXPORT_SYMBOL(w1_ds2760_write);
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EXPORT_SYMBOL(w1_ds2760_store_eeprom);
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EXPORT_SYMBOL(w1_ds2760_recall_eeprom);
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module_init(w1_ds2760_init);
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module_exit(w1_ds2760_exit);
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MODULE_LICENSE("GPL");
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MODULE_AUTHOR("Szabolcs Gyurko <szabolcs.gyurko@tlt.hu>");
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MODULE_DESCRIPTION("1-wire Driver Dallas 2760 battery monitor chip");
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