drivers/w1/w1.c - maze/linux - Git at Google

 /*
  * 	w1.c
  *
  * Copyright (c) 2004 Evgeniy Polyakov <johnpol@2ka.mipt.ru>
  *
  *
  * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  */

 #include <linux/delay.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/moduleparam.h>
 #include <linux/list.h>
 #include <linux/interrupt.h>
 #include <linux/spinlock.h>
 #include <linux/timer.h>
 #include <linux/device.h>
 #include <linux/slab.h>
 #include <linux/sched.h>

 #include <asm/atomic.h>

 #include "w1.h"
 #include "w1_io.h"
 #include "w1_log.h"
 #include "w1_int.h"
 #include "w1_family.h"
 #include "w1_netlink.h"

 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Evgeniy Polyakov <johnpol@2ka.mipt.ru>");
 MODULE_DESCRIPTION("Driver for 1-wire Dallas network protocol.");

 static int w1_timeout = 10;
 int w1_max_slave_count = 10;
 int w1_max_slave_ttl = 10;

 module_param_named(timeout, w1_timeout, int, 0);
 module_param_named(max_slave_count, w1_max_slave_count, int, 0);
 module_param_named(slave_ttl, w1_max_slave_ttl, int, 0);

 DEFINE_SPINLOCK(w1_mlock);
 LIST_HEAD(w1_masters);

 static pid_t control_thread;
 static int control_needs_exit;
 static DECLARE_COMPLETION(w1_control_complete);

 static int w1_master_match(struct device *dev, struct device_driver *drv)
 {
 	return 1;
 }

 static int w1_master_probe(struct device *dev)
 {
 	return -ENODEV;
 }

 static int w1_master_remove(struct device *dev)
 {
 	return 0;
 }

 static void w1_master_release(struct device *dev)
 {
 	struct w1_master *md = container_of(dev, struct w1_master, dev);

 	complete(&md->dev_released);
 }

 static void w1_slave_release(struct device *dev)
 {
 	struct w1_slave *sl = container_of(dev, struct w1_slave, dev);

 	complete(&sl->dev_released);
 }

 static ssize_t w1_default_read_name(struct device *dev, struct device_attribute *attr, char *buf)
 {
 	return sprintf(buf, "No family registered.\n");
 }

 static ssize_t w1_default_read_bin(struct kobject *kobj, char *buf, loff_t off,
 		     size_t count)
 {
 	return sprintf(buf, "No family registered.\n");
 }

 static struct bus_type w1_bus_type = {
 	.name = "w1",
 	.match = w1_master_match,
 };

 struct device_driver w1_driver = {
 	.name = "w1_driver",
 	.bus = &w1_bus_type,
 	.probe = w1_master_probe,
 	.remove = w1_master_remove,
 };

 struct device w1_device = {
 	.parent = NULL,
 	.bus = &w1_bus_type,
 	.bus_id = "w1 bus master",
 	.driver = &w1_driver,
 	.release = &w1_master_release
 };

 static struct device_attribute w1_slave_attribute = {
 	.attr = {
 			.name = "name",
 			.mode = S_IRUGO,
 			.owner = THIS_MODULE
 	},
 	.show = &w1_default_read_name,
 };

 static struct device_attribute w1_slave_attribute_val = {
 	.attr = {
 			.name = "value",
 			.mode = S_IRUGO,
 			.owner = THIS_MODULE
 	},
 	.show = &w1_default_read_name,
 };

 static ssize_t w1_master_attribute_show_name(struct device *dev, struct device_attribute *attr, char *buf)
 {
 	struct w1_master *md = container_of (dev, struct w1_master, dev);
 	ssize_t count;

 	if (down_interruptible (&md->mutex))
 		return -EBUSY;

 	count = sprintf(buf, "%s\n", md->name);

 	up(&md->mutex);

 	return count;
 }

 static ssize_t w1_master_attribute_show_pointer(struct device *dev, struct device_attribute *attr, char *buf)
 {
 	struct w1_master *md = container_of(dev, struct w1_master, dev);
 	ssize_t count;

 	if (down_interruptible(&md->mutex))
 		return -EBUSY;

 	count = sprintf(buf, "0x%p\n", md->bus_master);

 	up(&md->mutex);
 	return count;
 }

 static ssize_t w1_master_attribute_show_timeout(struct device *dev, struct device_attribute *attr, char *buf)
 {
 	ssize_t count;
 	count = sprintf(buf, "%d\n", w1_timeout);
 	return count;
 }

 static ssize_t w1_master_attribute_show_max_slave_count(struct device *dev, struct device_attribute *attr, char *buf)
 {
 	struct w1_master *md = container_of(dev, struct w1_master, dev);
 	ssize_t count;

 	if (down_interruptible(&md->mutex))
 		return -EBUSY;

 	count = sprintf(buf, "%d\n", md->max_slave_count);

 	up(&md->mutex);
 	return count;
 }

 static ssize_t w1_master_attribute_show_attempts(struct device *dev, struct device_attribute *attr, char *buf)
 {
 	struct w1_master *md = container_of(dev, struct w1_master, dev);
 	ssize_t count;

 	if (down_interruptible(&md->mutex))
 		return -EBUSY;

 	count = sprintf(buf, "%lu\n", md->attempts);

 	up(&md->mutex);
 	return count;
 }

 static ssize_t w1_master_attribute_show_slave_count(struct device *dev, struct device_attribute *attr, char *buf)
 {
 	struct w1_master *md = container_of(dev, struct w1_master, dev);
 	ssize_t count;

 	if (down_interruptible(&md->mutex))
 		return -EBUSY;

 	count = sprintf(buf, "%d\n", md->slave_count);

 	up(&md->mutex);
 	return count;
 }

 static ssize_t w1_master_attribute_show_slaves(struct device *dev, struct device_attribute *attr, char *buf)

 {
 	struct w1_master *md = container_of(dev, struct w1_master, dev);
 	int c = PAGE_SIZE;

 	if (down_interruptible(&md->mutex))
 		return -EBUSY;

 	if (md->slave_count == 0)
 		c -= snprintf(buf + PAGE_SIZE - c, c, "not found.\n");
 	else {
 		struct list_head *ent, *n;
 		struct w1_slave *sl;

 		list_for_each_safe(ent, n, &md->slist) {
 			sl = list_entry(ent, struct w1_slave, w1_slave_entry);

  			c -= snprintf(buf + PAGE_SIZE - c, c, "%s\n", sl->name);
 		}
 	}

 	up(&md->mutex);

 	return PAGE_SIZE - c;
 }

 static struct device_attribute w1_master_attribute_slaves = {
 	.attr = {
  			.name = "w1_master_slaves",
 			.mode = S_IRUGO,
 			.owner = THIS_MODULE,
 	},
  	.show = &w1_master_attribute_show_slaves,
 };
 static struct device_attribute w1_master_attribute_slave_count = {
 	.attr = {
 			.name = "w1_master_slave_count",
 			.mode = S_IRUGO,
 			.owner = THIS_MODULE
 	},
 	.show = &w1_master_attribute_show_slave_count,
 };
 static struct device_attribute w1_master_attribute_attempts = {
 	.attr = {
 			.name = "w1_master_attempts",
 			.mode = S_IRUGO,
 			.owner = THIS_MODULE
 	},
 	.show = &w1_master_attribute_show_attempts,
 };
 static struct device_attribute w1_master_attribute_max_slave_count = {
 	.attr = {
 			.name = "w1_master_max_slave_count",
 			.mode = S_IRUGO,
 			.owner = THIS_MODULE
 	},
 	.show = &w1_master_attribute_show_max_slave_count,
 };
 static struct device_attribute w1_master_attribute_timeout = {
 	.attr = {
 			.name = "w1_master_timeout",
 			.mode = S_IRUGO,
 			.owner = THIS_MODULE
 	},
 	.show = &w1_master_attribute_show_timeout,
 };
 static struct device_attribute w1_master_attribute_pointer = {
 	.attr = {
 			.name = "w1_master_pointer",
 			.mode = S_IRUGO,
 			.owner = THIS_MODULE
 	},
 	.show = &w1_master_attribute_show_pointer,
 };
 static struct device_attribute w1_master_attribute_name = {
 	.attr = {
 			.name = "w1_master_name",
 			.mode = S_IRUGO,
 			.owner = THIS_MODULE
 	},
 	.show = &w1_master_attribute_show_name,
 };

 static struct bin_attribute w1_slave_bin_attribute = {
 	.attr = {
 		 	.name = "w1_slave",
 		 	.mode = S_IRUGO,
 			.owner = THIS_MODULE,
 	},
 	.size = W1_SLAVE_DATA_SIZE,
 	.read = &w1_default_read_bin,
 };

 static int __w1_attach_slave_device(struct w1_slave *sl)
 {
 	int err;

 	sl->dev.parent = &sl->master->dev;
 	sl->dev.driver = sl->master->driver;
 	sl->dev.bus = &w1_bus_type;
 	sl->dev.release = &w1_slave_release;

 	snprintf(&sl->dev.bus_id[0], sizeof(sl->dev.bus_id),
 		  "%02x-%012llx",
 		  (unsigned int) sl->reg_num.family,
 		  (unsigned long long) sl->reg_num.id);
 	snprintf (&sl->name[0], sizeof(sl->name),
 		  "%02x-%012llx",
 		  (unsigned int) sl->reg_num.family,
 		  (unsigned long long) sl->reg_num.id);

 	dev_dbg(&sl->dev, "%s: registering %s.\n", __func__,
 		&sl->dev.bus_id[0]);

 	err = device_register(&sl->dev);
 	if (err < 0) {
 		dev_err(&sl->dev,
 			 "Device registration [%s] failed. err=%d\n",
 			 sl->dev.bus_id, err);
 		return err;
 	}

 	memcpy(&sl->attr_bin, &w1_slave_bin_attribute, sizeof(sl->attr_bin));
 	memcpy(&sl->attr_name, &w1_slave_attribute, sizeof(sl->attr_name));
 	memcpy(&sl->attr_val, &w1_slave_attribute_val, sizeof(sl->attr_val));

 	sl->attr_bin.read = sl->family->fops->rbin;
 	sl->attr_name.show = sl->family->fops->rname;
 	sl->attr_val.show = sl->family->fops->rval;
 	sl->attr_val.attr.name = sl->family->fops->rvalname;

 	err = device_create_file(&sl->dev, &sl->attr_name);
 	if (err < 0) {
 		dev_err(&sl->dev,
 			 "sysfs file creation for [%s] failed. err=%d\n",
 			 sl->dev.bus_id, err);
 		device_unregister(&sl->dev);
 		return err;
 	}

 	err = device_create_file(&sl->dev, &sl->attr_val);
 	if (err < 0) {
 		dev_err(&sl->dev,
 			 "sysfs file creation for [%s] failed. err=%d\n",
 			 sl->dev.bus_id, err);
 		device_remove_file(&sl->dev, &sl->attr_name);
 		device_unregister(&sl->dev);
 		return err;
 	}

 	err = sysfs_create_bin_file(&sl->dev.kobj, &sl->attr_bin);
 	if (err < 0) {
 		dev_err(&sl->dev,
 			 "sysfs file creation for [%s] failed. err=%d\n",
 			 sl->dev.bus_id, err);
 		device_remove_file(&sl->dev, &sl->attr_name);
 		device_remove_file(&sl->dev, &sl->attr_val);
 		device_unregister(&sl->dev);
 		return err;
 	}

 	list_add_tail(&sl->w1_slave_entry, &sl->master->slist);

 	return 0;
 }

 static int w1_attach_slave_device(struct w1_master *dev, struct w1_reg_num *rn)
 {
 	struct w1_slave *sl;
 	struct w1_family *f;
 	int err;
 	struct w1_netlink_msg msg;

 	sl = kmalloc(sizeof(struct w1_slave), GFP_KERNEL);
 	if (!sl) {
 		dev_err(&dev->dev,
 			 "%s: failed to allocate new slave device.\n",
 			 __func__);
 		return -ENOMEM;
 	}

 	memset(sl, 0, sizeof(*sl));

 	sl->owner = THIS_MODULE;
 	sl->master = dev;
 	set_bit(W1_SLAVE_ACTIVE, (long *)&sl->flags);

 	memcpy(&sl->reg_num, rn, sizeof(sl->reg_num));
 	atomic_set(&sl->refcnt, 0);
 	init_completion(&sl->dev_released);

 	spin_lock(&w1_flock);
 	f = w1_family_registered(rn->family);
 	if (!f) {
 		spin_unlock(&w1_flock);
 		dev_info(&dev->dev, "Family %x for %02x.%012llx.%02x is not registered.\n",
 			  rn->family, rn->family,
 			  (unsigned long long)rn->id, rn->crc);
 		kfree(sl);
 		return -ENODEV;
 	}
 	__w1_family_get(f);
 	spin_unlock(&w1_flock);

 	sl->family = f;


 	err = __w1_attach_slave_device(sl);
 	if (err < 0) {
 		dev_err(&dev->dev, "%s: Attaching %s failed.\n", __func__,
 			 sl->name);
 		w1_family_put(sl->family);
 		kfree(sl);
 		return err;
 	}

 	sl->ttl = dev->slave_ttl;
 	dev->slave_count++;

 	memcpy(&msg.id.id, rn, sizeof(msg.id.id));
 	msg.type = W1_SLAVE_ADD;
 	w1_netlink_send(dev, &msg);

 	return 0;
 }

 static void w1_slave_detach(struct w1_slave *sl)
 {
 	struct w1_netlink_msg msg;

 	dev_info(&sl->dev, "%s: detaching %s.\n", __func__, sl->name);

 	while (atomic_read(&sl->refcnt)) {
 		printk(KERN_INFO "Waiting for %s to become free: refcnt=%d.\n",
 				sl->name, atomic_read(&sl->refcnt));

 		if (msleep_interruptible(1000))
 			flush_signals(current);
 	}

 	sysfs_remove_bin_file (&sl->dev.kobj, &sl->attr_bin);
 	device_remove_file(&sl->dev, &sl->attr_name);
 	device_remove_file(&sl->dev, &sl->attr_val);
 	device_unregister(&sl->dev);
 	w1_family_put(sl->family);

 	memcpy(&msg.id.id, &sl->reg_num, sizeof(msg.id.id));
 	msg.type = W1_SLAVE_REMOVE;
 	w1_netlink_send(sl->master, &msg);
 }

 static struct w1_master *w1_search_master(unsigned long data)
 {
 	struct w1_master *dev;
 	int found = 0;

 	spin_lock_irq(&w1_mlock);
 	list_for_each_entry(dev, &w1_masters, w1_master_entry) {
 		if (dev->bus_master->data == data) {
 			found = 1;
 			atomic_inc(&dev->refcnt);
 			break;
 		}
 	}
 	spin_unlock_irq(&w1_mlock);

 	return (found)?dev:NULL;
 }

 void w1_slave_found(unsigned long data, u64 rn)
 {
 	int slave_count;
 	struct w1_slave *sl;
 	struct list_head *ent;
 	struct w1_reg_num *tmp;
 	int family_found = 0;
 	struct w1_master *dev;

 	dev = w1_search_master(data);
 	if (!dev) {
 		printk(KERN_ERR "Failed to find w1 master device for data %08lx, it is impossible.\n",
 				data);
 		return;
 	}

 	tmp = (struct w1_reg_num *) &rn;

 	slave_count = 0;
 	list_for_each(ent, &dev->slist) {

 		sl = list_entry(ent, struct w1_slave, w1_slave_entry);

 		if (sl->reg_num.family == tmp->family &&
 		    sl->reg_num.id == tmp->id &&
 		    sl->reg_num.crc == tmp->crc) {
 			set_bit(W1_SLAVE_ACTIVE, (long *)&sl->flags);
 			break;
 		}
 		else if (sl->reg_num.family == tmp->family) {
 			family_found = 1;
 			break;
 		}

 		slave_count++;
 	}

 	rn = cpu_to_le64(rn);

 	if (slave_count == dev->slave_count &&
 		rn && ((le64_to_cpu(rn) >> 56) & 0xff) == w1_calc_crc8((u8 *)&rn, 7)) {
 		w1_attach_slave_device(dev, tmp);
 	}

 	atomic_dec(&dev->refcnt);
 }

 void w1_search(struct w1_master *dev)
 {
 	u64 last, rn, tmp;
 	int i, count = 0;
 	int last_family_desc, last_zero, last_device;
 	int search_bit, id_bit, comp_bit, desc_bit;

 	search_bit = id_bit = comp_bit = 0;
 	rn = tmp = last = 0;
 	last_device = last_zero = last_family_desc = 0;

 	desc_bit = 64;

 	while (!(id_bit && comp_bit) && !last_device
 		&& count++ < dev->max_slave_count) {
 		last = rn;
 		rn = 0;

 		last_family_desc = 0;

 		/*
 		 * Reset bus and all 1-wire device state machines
 		 * so they can respond to our requests.
 		 *
 		 * Return 0 - device(s) present, 1 - no devices present.
 		 */
 		if (w1_reset_bus(dev)) {
 			dev_info(&dev->dev, "No devices present on the wire.\n");
 			break;
 		}

 #if 1
 		w1_write_8(dev, W1_SEARCH);
 		for (i = 0; i < 64; ++i) {
 			/*
 			 * Read 2 bits from bus.
 			 * All who don't sleep must send ID bit and COMPLEMENT ID bit.
 			 * They actually are ANDed between all senders.
 			 */
 			id_bit = w1_touch_bit(dev, 1);
 			comp_bit = w1_touch_bit(dev, 1);

 			if (id_bit && comp_bit)
 				break;

 			if (id_bit == 0 && comp_bit == 0) {
 				if (i == desc_bit)
 					search_bit = 1;
 				else if (i > desc_bit)
 					search_bit = 0;
 				else
 					search_bit = ((last >> i) & 0x1);

 				if (search_bit == 0) {
 					last_zero = i;
 					if (last_zero < 9)
 						last_family_desc = last_zero;
 				}

 			}
 			else
 				search_bit = id_bit;

 			tmp = search_bit;
 			rn |= (tmp << i);

 			/*
 			 * Write 1 bit to bus
 			 * and make all who don't have "search_bit" in "i"'th position
 			 * in it's registration number sleep.
 			 */
 			if (dev->bus_master->touch_bit)
 				w1_touch_bit(dev, search_bit);
 			else
 				w1_write_bit(dev, search_bit);

 		}
 #endif

 		if (desc_bit == last_zero)
 			last_device = 1;

 		desc_bit = last_zero;

 		w1_slave_found(dev->bus_master->data, rn);
 	}
 }

 int w1_create_master_attributes(struct w1_master *dev)
 {
 	if (	device_create_file(&dev->dev, &w1_master_attribute_slaves) < 0 ||
 		device_create_file(&dev->dev, &w1_master_attribute_slave_count) < 0 ||
 		device_create_file(&dev->dev, &w1_master_attribute_attempts) < 0 ||
 		device_create_file(&dev->dev, &w1_master_attribute_max_slave_count) < 0 ||
 		device_create_file(&dev->dev, &w1_master_attribute_timeout) < 0||
 		device_create_file(&dev->dev, &w1_master_attribute_pointer) < 0||
 		device_create_file(&dev->dev, &w1_master_attribute_name) < 0)
 		return -EINVAL;

 	return 0;
 }

 void w1_destroy_master_attributes(struct w1_master *dev)
 {
 	device_remove_file(&dev->dev, &w1_master_attribute_slaves);
 	device_remove_file(&dev->dev, &w1_master_attribute_slave_count);
 	device_remove_file(&dev->dev, &w1_master_attribute_attempts);
 	device_remove_file(&dev->dev, &w1_master_attribute_max_slave_count);
 	device_remove_file(&dev->dev, &w1_master_attribute_timeout);
 	device_remove_file(&dev->dev, &w1_master_attribute_pointer);
 	device_remove_file(&dev->dev, &w1_master_attribute_name);
 }


 int w1_control(void *data)
 {
 	struct w1_slave *sl;
 	struct w1_master *dev;
 	struct list_head *ent, *ment, *n, *mn;
 	int err, have_to_wait = 0;

 	daemonize("w1_control");
 	allow_signal(SIGTERM);

 	while (!control_needs_exit || have_to_wait) {
 		have_to_wait = 0;

 		try_to_freeze(PF_FREEZE);
 		msleep_interruptible(w1_timeout * 1000);

 		if (signal_pending(current))
 			flush_signals(current);

 		list_for_each_safe(ment, mn, &w1_masters) {
 			dev = list_entry(ment, struct w1_master, w1_master_entry);

 			if (!control_needs_exit && !dev->need_exit)
 				continue;
 			/*
 			 * Little race: we can create thread but not set the flag.
 			 * Get a chance for external process to set flag up.
 			 */
 			if (!dev->initialized) {
 				have_to_wait = 1;
 				continue;
 			}

 			spin_lock(&w1_mlock);
 			list_del(&dev->w1_master_entry);
 			spin_unlock(&w1_mlock);

 			if (control_needs_exit) {
 				dev->need_exit = 1;

 				err = kill_proc(dev->kpid, SIGTERM, 1);
 				if (err)
 					dev_err(&dev->dev,
 						 "Failed to send signal to w1 kernel thread %d.\n",
 						 dev->kpid);
 			}

 			wait_for_completion(&dev->dev_exited);

 			list_for_each_safe(ent, n, &dev->slist) {
 				sl = list_entry(ent, struct w1_slave, w1_slave_entry);

 				if (!sl)
 					dev_warn(&dev->dev,
 						  "%s: slave entry is NULL.\n",
 						  __func__);
 				else {
 					list_del(&sl->w1_slave_entry);

 					w1_slave_detach(sl);
 					kfree(sl);
 				}
 			}
 			w1_destroy_master_attributes(dev);
 			atomic_dec(&dev->refcnt);
 		}
 	}

 	complete_and_exit(&w1_control_complete, 0);
 }

 int w1_process(void *data)
 {
 	struct w1_master *dev = (struct w1_master *) data;
 	struct list_head *ent, *n;
 	struct w1_slave *sl;

 	daemonize("%s", dev->name);
 	allow_signal(SIGTERM);

 	while (!dev->need_exit) {
 		try_to_freeze(PF_FREEZE);
 		msleep_interruptible(w1_timeout * 1000);

 		if (signal_pending(current))
 			flush_signals(current);

 		if (dev->need_exit)
 			break;

 		if (!dev->initialized)
 			continue;

 		if (down_interruptible(&dev->mutex))
 			continue;

 		list_for_each_safe(ent, n, &dev->slist) {
 			sl = list_entry(ent, struct w1_slave, w1_slave_entry);

 			if (sl)
 				clear_bit(W1_SLAVE_ACTIVE, (long *)&sl->flags);
 		}

 		w1_search_devices(dev, w1_slave_found);

 		list_for_each_safe(ent, n, &dev->slist) {
 			sl = list_entry(ent, struct w1_slave, w1_slave_entry);

 			if (sl && !test_bit(W1_SLAVE_ACTIVE, (unsigned long *)&sl->flags) && !--sl->ttl) {
 				list_del (&sl->w1_slave_entry);

 				w1_slave_detach (sl);
 				kfree (sl);

 				dev->slave_count--;
 			}
 			else if (test_bit(W1_SLAVE_ACTIVE, (unsigned long *)&sl->flags))
 				sl->ttl = dev->slave_ttl;
 		}
 		up(&dev->mutex);
 	}

 	atomic_dec(&dev->refcnt);
 	complete_and_exit(&dev->dev_exited, 0);

 	return 0;
 }

 int w1_init(void)
 {
 	int retval;

 	printk(KERN_INFO "Driver for 1-wire Dallas network protocol.\n");

 	retval = bus_register(&w1_bus_type);
 	if (retval) {
 		printk(KERN_ERR "Failed to register bus. err=%d.\n", retval);
 		goto err_out_exit_init;
 	}

 	retval = driver_register(&w1_driver);
 	if (retval) {
 		printk(KERN_ERR
 			"Failed to register master driver. err=%d.\n",
 			retval);
 		goto err_out_bus_unregister;
 	}

 	control_thread = kernel_thread(&w1_control, NULL, 0);
 	if (control_thread < 0) {
 		printk(KERN_ERR "Failed to create control thread. err=%d\n",
 			control_thread);
 		retval = control_thread;
 		goto err_out_driver_unregister;
 	}

 	return 0;

 err_out_driver_unregister:
 	driver_unregister(&w1_driver);

 err_out_bus_unregister:
 	bus_unregister(&w1_bus_type);

 err_out_exit_init:
 	return retval;
 }

 void w1_fini(void)
 {
 	struct w1_master *dev;
 	struct list_head *ent, *n;

 	list_for_each_safe(ent, n, &w1_masters) {
 		dev = list_entry(ent, struct w1_master, w1_master_entry);
 		__w1_remove_master_device(dev);
 	}

 	control_needs_exit = 1;

 	wait_for_completion(&w1_control_complete);

 	driver_unregister(&w1_driver);
 	bus_unregister(&w1_bus_type);
 }

 module_init(w1_init);
 module_exit(w1_fini);
	/*
	* w1.c
	*
	* Copyright (c) 2004 Evgeniy Polyakov <johnpol@2ka.mipt.ru>
	*
	*
	* 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	*/

	#include <linux/delay.h>
	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/moduleparam.h>
	#include <linux/list.h>
	#include <linux/interrupt.h>
	#include <linux/spinlock.h>
	#include <linux/timer.h>
	#include <linux/device.h>
	#include <linux/slab.h>
	#include <linux/sched.h>

	#include <asm/atomic.h>

	#include "w1.h"
	#include "w1_io.h"
	#include "w1_log.h"
	#include "w1_int.h"
	#include "w1_family.h"
	#include "w1_netlink.h"

	MODULE_LICENSE("GPL");
	MODULE_AUTHOR("Evgeniy Polyakov <johnpol@2ka.mipt.ru>");
	MODULE_DESCRIPTION("Driver for 1-wire Dallas network protocol.");

	static int w1_timeout = 10;
	int w1_max_slave_count = 10;
	int w1_max_slave_ttl = 10;

	module_param_named(timeout, w1_timeout, int, 0);
	module_param_named(max_slave_count, w1_max_slave_count, int, 0);
	module_param_named(slave_ttl, w1_max_slave_ttl, int, 0);

	DEFINE_SPINLOCK(w1_mlock);
	LIST_HEAD(w1_masters);

	static pid_t control_thread;
	static int control_needs_exit;
	static DECLARE_COMPLETION(w1_control_complete);

	static int w1_master_match(struct device dev, struct device_driver drv)
	{
	return 1;
	}

	static int w1_master_probe(struct device *dev)
	{
	return -ENODEV;
	}

	static int w1_master_remove(struct device *dev)
	{
	return 0;
	}

	static void w1_master_release(struct device *dev)
	{
	struct w1_master *md = container_of(dev, struct w1_master, dev);

	complete(&md->dev_released);
	}

	static void w1_slave_release(struct device *dev)
	{
	struct w1_slave *sl = container_of(dev, struct w1_slave, dev);

	complete(&sl->dev_released);
	}

	static ssize_t w1_default_read_name(struct device dev, struct device_attribute attr, char *buf)
	{
	return sprintf(buf, "No family registered.\n");
	}

	static ssize_t w1_default_read_bin(struct kobject kobj, char buf, loff_t off,
	size_t count)
	{
	return sprintf(buf, "No family registered.\n");
	}

	static struct bus_type w1_bus_type = {
	.name = "w1",
	.match = w1_master_match,
	};

	struct device_driver w1_driver = {
	.name = "w1_driver",
	.bus = &w1_bus_type,
	.probe = w1_master_probe,
	.remove = w1_master_remove,
	};

	struct device w1_device = {
	.parent = NULL,
	.bus = &w1_bus_type,
	.bus_id = "w1 bus master",
	.driver = &w1_driver,
	.release = &w1_master_release
	};

	static struct device_attribute w1_slave_attribute = {
	.attr = {
	.name = "name",
	.mode = S_IRUGO,
	.owner = THIS_MODULE
	},
	.show = &w1_default_read_name,
	};

	static struct device_attribute w1_slave_attribute_val = {
	.attr = {
	.name = "value",
	.mode = S_IRUGO,
	.owner = THIS_MODULE
	},
	.show = &w1_default_read_name,
	};

	static ssize_t w1_master_attribute_show_name(struct device dev, struct device_attribute attr, char *buf)
	{
	struct w1_master *md = container_of (dev, struct w1_master, dev);
	ssize_t count;

	if (down_interruptible (&md->mutex))
	return -EBUSY;

	count = sprintf(buf, "%s\n", md->name);

	up(&md->mutex);

	return count;
	}

	static ssize_t w1_master_attribute_show_pointer(struct device dev, struct device_attribute attr, char *buf)
	{
	struct w1_master *md = container_of(dev, struct w1_master, dev);
	ssize_t count;

	if (down_interruptible(&md->mutex))
	return -EBUSY;

	count = sprintf(buf, "0x%p\n", md->bus_master);

	up(&md->mutex);
	return count;
	}

	static ssize_t w1_master_attribute_show_timeout(struct device dev, struct device_attribute attr, char *buf)
	{
	ssize_t count;
	count = sprintf(buf, "%d\n", w1_timeout);
	return count;
	}

	static ssize_t w1_master_attribute_show_max_slave_count(struct device dev, struct device_attribute attr, char *buf)
	{
	struct w1_master *md = container_of(dev, struct w1_master, dev);
	ssize_t count;

	if (down_interruptible(&md->mutex))
	return -EBUSY;

	count = sprintf(buf, "%d\n", md->max_slave_count);

	up(&md->mutex);
	return count;
	}

	static ssize_t w1_master_attribute_show_attempts(struct device dev, struct device_attribute attr, char *buf)
	{
	struct w1_master *md = container_of(dev, struct w1_master, dev);
	ssize_t count;

	if (down_interruptible(&md->mutex))
	return -EBUSY;

	count = sprintf(buf, "%lu\n", md->attempts);

	up(&md->mutex);
	return count;
	}

	static ssize_t w1_master_attribute_show_slave_count(struct device dev, struct device_attribute attr, char *buf)
	{
	struct w1_master *md = container_of(dev, struct w1_master, dev);
	ssize_t count;

	if (down_interruptible(&md->mutex))
	return -EBUSY;

	count = sprintf(buf, "%d\n", md->slave_count);

	up(&md->mutex);
	return count;
	}

	static ssize_t w1_master_attribute_show_slaves(struct device dev, struct device_attribute attr, char *buf)

	{
	struct w1_master *md = container_of(dev, struct w1_master, dev);
	int c = PAGE_SIZE;

	if (down_interruptible(&md->mutex))
	return -EBUSY;

	if (md->slave_count == 0)
	c -= snprintf(buf + PAGE_SIZE - c, c, "not found.\n");
	else {
	struct list_head ent, n;
	struct w1_slave *sl;

	list_for_each_safe(ent, n, &md->slist) {
	sl = list_entry(ent, struct w1_slave, w1_slave_entry);

	c -= snprintf(buf + PAGE_SIZE - c, c, "%s\n", sl->name);
	}
	}

	up(&md->mutex);

	return PAGE_SIZE - c;
	}

	static struct device_attribute w1_master_attribute_slaves = {
	.attr = {
	.name = "w1_master_slaves",
	.mode = S_IRUGO,
	.owner = THIS_MODULE,
	},
	.show = &w1_master_attribute_show_slaves,
	};
	static struct device_attribute w1_master_attribute_slave_count = {
	.attr = {
	.name = "w1_master_slave_count",
	.mode = S_IRUGO,
	.owner = THIS_MODULE
	},
	.show = &w1_master_attribute_show_slave_count,
	};
	static struct device_attribute w1_master_attribute_attempts = {
	.attr = {
	.name = "w1_master_attempts",
	.mode = S_IRUGO,
	.owner = THIS_MODULE
	},
	.show = &w1_master_attribute_show_attempts,
	};
	static struct device_attribute w1_master_attribute_max_slave_count = {
	.attr = {
	.name = "w1_master_max_slave_count",
	.mode = S_IRUGO,
	.owner = THIS_MODULE
	},
	.show = &w1_master_attribute_show_max_slave_count,
	};
	static struct device_attribute w1_master_attribute_timeout = {
	.attr = {
	.name = "w1_master_timeout",
	.mode = S_IRUGO,
	.owner = THIS_MODULE
	},
	.show = &w1_master_attribute_show_timeout,
	};
	static struct device_attribute w1_master_attribute_pointer = {
	.attr = {
	.name = "w1_master_pointer",
	.mode = S_IRUGO,
	.owner = THIS_MODULE
	},
	.show = &w1_master_attribute_show_pointer,
	};
	static struct device_attribute w1_master_attribute_name = {
	.attr = {
	.name = "w1_master_name",
	.mode = S_IRUGO,
	.owner = THIS_MODULE
	},
	.show = &w1_master_attribute_show_name,
	};

	static struct bin_attribute w1_slave_bin_attribute = {
	.attr = {
	.name = "w1_slave",
	.mode = S_IRUGO,
	.owner = THIS_MODULE,
	},
	.size = W1_SLAVE_DATA_SIZE,
	.read = &w1_default_read_bin,
	};

	static int __w1_attach_slave_device(struct w1_slave *sl)
	{
	int err;

	sl->dev.parent = &sl->master->dev;
	sl->dev.driver = sl->master->driver;
	sl->dev.bus = &w1_bus_type;
	sl->dev.release = &w1_slave_release;

	snprintf(&sl->dev.bus_id[0], sizeof(sl->dev.bus_id),
	"%02x-%012llx",
	(unsigned int) sl->reg_num.family,
	(unsigned long long) sl->reg_num.id);
	snprintf (&sl->name[0], sizeof(sl->name),
	"%02x-%012llx",
	(unsigned int) sl->reg_num.family,
	(unsigned long long) sl->reg_num.id);

	dev_dbg(&sl->dev, "%s: registering %s.\n", __func__,
	&sl->dev.bus_id[0]);

	err = device_register(&sl->dev);
	if (err < 0) {
	dev_err(&sl->dev,
	"Device registration [%s] failed. err=%d\n",
	sl->dev.bus_id, err);
	return err;
	}

	memcpy(&sl->attr_bin, &w1_slave_bin_attribute, sizeof(sl->attr_bin));
	memcpy(&sl->attr_name, &w1_slave_attribute, sizeof(sl->attr_name));
	memcpy(&sl->attr_val, &w1_slave_attribute_val, sizeof(sl->attr_val));

	sl->attr_bin.read = sl->family->fops->rbin;
	sl->attr_name.show = sl->family->fops->rname;
	sl->attr_val.show = sl->family->fops->rval;
	sl->attr_val.attr.name = sl->family->fops->rvalname;

	err = device_create_file(&sl->dev, &sl->attr_name);
	if (err < 0) {
	dev_err(&sl->dev,
	"sysfs file creation for [%s] failed. err=%d\n",
	sl->dev.bus_id, err);
	device_unregister(&sl->dev);
	return err;
	}

	err = device_create_file(&sl->dev, &sl->attr_val);
	if (err < 0) {
	dev_err(&sl->dev,
	"sysfs file creation for [%s] failed. err=%d\n",
	sl->dev.bus_id, err);
	device_remove_file(&sl->dev, &sl->attr_name);
	device_unregister(&sl->dev);
	return err;
	}

	err = sysfs_create_bin_file(&sl->dev.kobj, &sl->attr_bin);
	if (err < 0) {
	dev_err(&sl->dev,
	"sysfs file creation for [%s] failed. err=%d\n",
	sl->dev.bus_id, err);
	device_remove_file(&sl->dev, &sl->attr_name);
	device_remove_file(&sl->dev, &sl->attr_val);
	device_unregister(&sl->dev);
	return err;
	}

	list_add_tail(&sl->w1_slave_entry, &sl->master->slist);

	return 0;
	}

	static int w1_attach_slave_device(struct w1_master dev, struct w1_reg_num rn)
	{
	struct w1_slave *sl;
	struct w1_family *f;
	int err;
	struct w1_netlink_msg msg;

	sl = kmalloc(sizeof(struct w1_slave), GFP_KERNEL);
	if (!sl) {
	dev_err(&dev->dev,
	"%s: failed to allocate new slave device.\n",
	__func__);
	return -ENOMEM;
	}

	memset(sl, 0, sizeof(*sl));

	sl->owner = THIS_MODULE;
	sl->master = dev;
	set_bit(W1_SLAVE_ACTIVE, (long *)&sl->flags);

	memcpy(&sl->reg_num, rn, sizeof(sl->reg_num));
	atomic_set(&sl->refcnt, 0);
	init_completion(&sl->dev_released);

	spin_lock(&w1_flock);
	f = w1_family_registered(rn->family);
	if (!f) {
	spin_unlock(&w1_flock);
	dev_info(&dev->dev, "Family %x for %02x.%012llx.%02x is not registered.\n",
	rn->family, rn->family,
	(unsigned long long)rn->id, rn->crc);
	kfree(sl);
	return -ENODEV;
	}
	__w1_family_get(f);
	spin_unlock(&w1_flock);

	sl->family = f;


	err = __w1_attach_slave_device(sl);
	if (err < 0) {
	dev_err(&dev->dev, "%s: Attaching %s failed.\n", __func__,
	sl->name);
	w1_family_put(sl->family);
	kfree(sl);
	return err;
	}

	sl->ttl = dev->slave_ttl;
	dev->slave_count++;

	memcpy(&msg.id.id, rn, sizeof(msg.id.id));
	msg.type = W1_SLAVE_ADD;
	w1_netlink_send(dev, &msg);

	return 0;
	}

	static void w1_slave_detach(struct w1_slave *sl)
	{
	struct w1_netlink_msg msg;

	dev_info(&sl->dev, "%s: detaching %s.\n", __func__, sl->name);

	while (atomic_read(&sl->refcnt)) {
	printk(KERN_INFO "Waiting for %s to become free: refcnt=%d.\n",
	sl->name, atomic_read(&sl->refcnt));

	if (msleep_interruptible(1000))
	flush_signals(current);
	}

	sysfs_remove_bin_file (&sl->dev.kobj, &sl->attr_bin);
	device_remove_file(&sl->dev, &sl->attr_name);
	device_remove_file(&sl->dev, &sl->attr_val);
	device_unregister(&sl->dev);
	w1_family_put(sl->family);

	memcpy(&msg.id.id, &sl->reg_num, sizeof(msg.id.id));
	msg.type = W1_SLAVE_REMOVE;
	w1_netlink_send(sl->master, &msg);
	}

	static struct w1_master *w1_search_master(unsigned long data)
	{
	struct w1_master *dev;
	int found = 0;

	spin_lock_irq(&w1_mlock);
	list_for_each_entry(dev, &w1_masters, w1_master_entry) {
	if (dev->bus_master->data == data) {
	found = 1;
	atomic_inc(&dev->refcnt);
	break;
	}
	}
	spin_unlock_irq(&w1_mlock);

	return (found)?dev:NULL;
	}

	void w1_slave_found(unsigned long data, u64 rn)
	{
	int slave_count;
	struct w1_slave *sl;
	struct list_head *ent;
	struct w1_reg_num *tmp;
	int family_found = 0;
	struct w1_master *dev;

	dev = w1_search_master(data);
	if (!dev) {
	printk(KERN_ERR "Failed to find w1 master device for data %08lx, it is impossible.\n",
	data);
	return;
	}

	tmp = (struct w1_reg_num *) &rn;

	slave_count = 0;
	list_for_each(ent, &dev->slist) {

	sl = list_entry(ent, struct w1_slave, w1_slave_entry);

	if (sl->reg_num.family == tmp->family &&
	sl->reg_num.id == tmp->id &&
	sl->reg_num.crc == tmp->crc) {
	set_bit(W1_SLAVE_ACTIVE, (long *)&sl->flags);
	break;
	}
	else if (sl->reg_num.family == tmp->family) {
	family_found = 1;
	break;
	}

	slave_count++;
	}

	rn = cpu_to_le64(rn);

	if (slave_count == dev->slave_count &&
	rn && ((le64_to_cpu(rn) >> 56) & 0xff) == w1_calc_crc8((u8 *)&rn, 7)) {
	w1_attach_slave_device(dev, tmp);
	}

	atomic_dec(&dev->refcnt);
	}

	void w1_search(struct w1_master *dev)
	{
	u64 last, rn, tmp;
	int i, count = 0;
	int last_family_desc, last_zero, last_device;
	int search_bit, id_bit, comp_bit, desc_bit;

	search_bit = id_bit = comp_bit = 0;
	rn = tmp = last = 0;
	last_device = last_zero = last_family_desc = 0;

	desc_bit = 64;

	while (!(id_bit && comp_bit) && !last_device
	&& count++ < dev->max_slave_count) {
	last = rn;
	rn = 0;

	last_family_desc = 0;

	/*
	* Reset bus and all 1-wire device state machines
	* so they can respond to our requests.
	*
	* Return 0 - device(s) present, 1 - no devices present.
	*/
	if (w1_reset_bus(dev)) {
	dev_info(&dev->dev, "No devices present on the wire.\n");
	break;
	}

	#if 1
	w1_write_8(dev, W1_SEARCH);
	for (i = 0; i < 64; ++i) {
	/*
	* Read 2 bits from bus.
	* All who don't sleep must send ID bit and COMPLEMENT ID bit.
	* They actually are ANDed between all senders.
	*/
	id_bit = w1_touch_bit(dev, 1);
	comp_bit = w1_touch_bit(dev, 1);

	if (id_bit && comp_bit)
	break;

	if (id_bit == 0 && comp_bit == 0) {
	if (i == desc_bit)
	search_bit = 1;
	else if (i > desc_bit)
	search_bit = 0;
	else
	search_bit = ((last >> i) & 0x1);

	if (search_bit == 0) {
	last_zero = i;
	if (last_zero < 9)
	last_family_desc = last_zero;
	}

	}
	else
	search_bit = id_bit;

	tmp = search_bit;
	rn \|= (tmp << i);

	/*
	* Write 1 bit to bus
	* and make all who don't have "search_bit" in "i"'th position
	* in it's registration number sleep.
	*/
	if (dev->bus_master->touch_bit)
	w1_touch_bit(dev, search_bit);
	else
	w1_write_bit(dev, search_bit);

	}
	#endif

	if (desc_bit == last_zero)
	last_device = 1;

	desc_bit = last_zero;

	w1_slave_found(dev->bus_master->data, rn);
	}
	}

	int w1_create_master_attributes(struct w1_master *dev)
	{
	if ( device_create_file(&dev->dev, &w1_master_attribute_slaves) < 0 \|\|
	device_create_file(&dev->dev, &w1_master_attribute_slave_count) < 0 \|\|
	device_create_file(&dev->dev, &w1_master_attribute_attempts) < 0 \|\|
	device_create_file(&dev->dev, &w1_master_attribute_max_slave_count) < 0 \|\|
	device_create_file(&dev->dev, &w1_master_attribute_timeout) < 0\|\|
	device_create_file(&dev->dev, &w1_master_attribute_pointer) < 0\|\|
	device_create_file(&dev->dev, &w1_master_attribute_name) < 0)
	return -EINVAL;

	return 0;
	}

	void w1_destroy_master_attributes(struct w1_master *dev)
	{
	device_remove_file(&dev->dev, &w1_master_attribute_slaves);
	device_remove_file(&dev->dev, &w1_master_attribute_slave_count);
	device_remove_file(&dev->dev, &w1_master_attribute_attempts);
	device_remove_file(&dev->dev, &w1_master_attribute_max_slave_count);
	device_remove_file(&dev->dev, &w1_master_attribute_timeout);
	device_remove_file(&dev->dev, &w1_master_attribute_pointer);
	device_remove_file(&dev->dev, &w1_master_attribute_name);
	}


	int w1_control(void *data)
	{
	struct w1_slave *sl;
	struct w1_master *dev;
	struct list_head ent, ment, n, mn;
	int err, have_to_wait = 0;

	daemonize("w1_control");
	allow_signal(SIGTERM);

	while (!control_needs_exit \|\| have_to_wait) {
	have_to_wait = 0;

	try_to_freeze(PF_FREEZE);
	msleep_interruptible(w1_timeout * 1000);

	if (signal_pending(current))
	flush_signals(current);

	list_for_each_safe(ment, mn, &w1_masters) {
	dev = list_entry(ment, struct w1_master, w1_master_entry);

	if (!control_needs_exit && !dev->need_exit)
	continue;
	/*
	* Little race: we can create thread but not set the flag.
	* Get a chance for external process to set flag up.
	*/
	if (!dev->initialized) {
	have_to_wait = 1;
	continue;
	}

	spin_lock(&w1_mlock);
	list_del(&dev->w1_master_entry);
	spin_unlock(&w1_mlock);

	if (control_needs_exit) {
	dev->need_exit = 1;

	err = kill_proc(dev->kpid, SIGTERM, 1);
	if (err)
	dev_err(&dev->dev,
	"Failed to send signal to w1 kernel thread %d.\n",
	dev->kpid);
	}

	wait_for_completion(&dev->dev_exited);

	list_for_each_safe(ent, n, &dev->slist) {
	sl = list_entry(ent, struct w1_slave, w1_slave_entry);

	if (!sl)
	dev_warn(&dev->dev,
	"%s: slave entry is NULL.\n",
	__func__);
	else {
	list_del(&sl->w1_slave_entry);

	w1_slave_detach(sl);
	kfree(sl);
	}
	}
	w1_destroy_master_attributes(dev);
	atomic_dec(&dev->refcnt);
	}
	}

	complete_and_exit(&w1_control_complete, 0);
	}

	int w1_process(void *data)
	{
	struct w1_master dev = (struct w1_master ) data;
	struct list_head ent, n;
	struct w1_slave *sl;

	daemonize("%s", dev->name);
	allow_signal(SIGTERM);

	while (!dev->need_exit) {
	try_to_freeze(PF_FREEZE);
	msleep_interruptible(w1_timeout * 1000);

	if (signal_pending(current))
	flush_signals(current);

	if (dev->need_exit)
	break;

	if (!dev->initialized)
	continue;

	if (down_interruptible(&dev->mutex))
	continue;

	list_for_each_safe(ent, n, &dev->slist) {
	sl = list_entry(ent, struct w1_slave, w1_slave_entry);

	if (sl)
	clear_bit(W1_SLAVE_ACTIVE, (long *)&sl->flags);
	}

	w1_search_devices(dev, w1_slave_found);

	list_for_each_safe(ent, n, &dev->slist) {
	sl = list_entry(ent, struct w1_slave, w1_slave_entry);

	if (sl && !test_bit(W1_SLAVE_ACTIVE, (unsigned long *)&sl->flags) && !--sl->ttl) {
	list_del (&sl->w1_slave_entry);

	w1_slave_detach (sl);
	kfree (sl);

	dev->slave_count--;
	}
	else if (test_bit(W1_SLAVE_ACTIVE, (unsigned long *)&sl->flags))
	sl->ttl = dev->slave_ttl;
	}
	up(&dev->mutex);
	}

	atomic_dec(&dev->refcnt);
	complete_and_exit(&dev->dev_exited, 0);

	return 0;
	}

	int w1_init(void)
	{
	int retval;

	printk(KERN_INFO "Driver for 1-wire Dallas network protocol.\n");

	retval = bus_register(&w1_bus_type);
	if (retval) {
	printk(KERN_ERR "Failed to register bus. err=%d.\n", retval);
	goto err_out_exit_init;
	}

	retval = driver_register(&w1_driver);
	if (retval) {
	printk(KERN_ERR
	"Failed to register master driver. err=%d.\n",
	retval);
	goto err_out_bus_unregister;
	}

	control_thread = kernel_thread(&w1_control, NULL, 0);
	if (control_thread < 0) {
	printk(KERN_ERR "Failed to create control thread. err=%d\n",
	control_thread);
	retval = control_thread;
	goto err_out_driver_unregister;
	}

	return 0;

	err_out_driver_unregister:
	driver_unregister(&w1_driver);

	err_out_bus_unregister:
	bus_unregister(&w1_bus_type);

	err_out_exit_init:
	return retval;
	}

	void w1_fini(void)
	{
	struct w1_master *dev;
	struct list_head ent, n;

	list_for_each_safe(ent, n, &w1_masters) {
	dev = list_entry(ent, struct w1_master, w1_master_entry);
	__w1_remove_master_device(dev);
	}

	control_needs_exit = 1;

	wait_for_completion(&w1_control_complete);

	driver_unregister(&w1_driver);
	bus_unregister(&w1_bus_type);
	}

	module_init(w1_init);
	module_exit(w1_fini);