drivers/w1/w1.c

   1 /*
   2  *      w1.c
   3  *
   4  * Copyright (c) 2004 Evgeniy Polyakov <johnpol@2ka.mipt.ru>
   5  *
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  20  */
  21
  22 #include <linux/delay.h>
  23 #include <linux/kernel.h>
  24 #include <linux/module.h>
  25 #include <linux/moduleparam.h>
  26 #include <linux/list.h>
  27 #include <linux/interrupt.h>
  28 #include <linux/spinlock.h>
  29 #include <linux/timer.h>
  30 #include <linux/device.h>
  31 #include <linux/slab.h>
  32 #include <linux/sched.h>
  33
  34 #include <asm/atomic.h>
  35
  36 #include "w1.h"
  37 #include "w1_io.h"
  38 #include "w1_log.h"
  39 #include "w1_int.h"
  40 #include "w1_family.h"
  41 #include "w1_netlink.h"
  42
  43 MODULE_LICENSE("GPL");
  44 MODULE_AUTHOR("Evgeniy Polyakov <johnpol@2ka.mipt.ru>");
  45 MODULE_DESCRIPTION("Driver for 1-wire Dallas network protocol.");
  46
  47 static int w1_timeout = 10;
  48 int w1_max_slave_count = 10;
  49 int w1_max_slave_ttl = 10;
  50
  51 module_param_named(timeout, w1_timeout, int, 0);
  52 module_param_named(max_slave_count, w1_max_slave_count, int, 0);
  53 module_param_named(slave_ttl, w1_max_slave_ttl, int, 0);
  54
  55 DEFINE_SPINLOCK(w1_mlock);
  56 LIST_HEAD(w1_masters);
  57
  58 static pid_t control_thread;
  59 static int control_needs_exit;
  60 static DECLARE_COMPLETION(w1_control_complete);
  61
  62 static int w1_master_match(struct device *dev, struct device_driver *drv)
  63 {
  64         return 1;
  65 }
  66
  67 static int w1_master_probe(struct device *dev)
  68 {
  69         return -ENODEV;
  70 }
  71
  72 static int w1_master_remove(struct device *dev)
  73 {
  74         return 0;
  75 }
  76
  77 static void w1_master_release(struct device *dev)
  78 {
  79         struct w1_master *md = container_of(dev, struct w1_master, dev);
  80
  81         complete(&md->dev_released);
  82 }
  83
  84 static void w1_slave_release(struct device *dev)
  85 {
  86         struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
  87
  88         complete(&sl->dev_released);
  89 }
  90
  91 static ssize_t w1_default_read_name(struct device *dev, struct device_attribute *attr, char *buf)
  92 {
  93         return sprintf(buf, "No family registered.\n");
  94 }
  95
  96 static ssize_t w1_default_read_bin(struct kobject *kobj, char *buf, loff_t off,
  97                      size_t count)
  98 {
  99         return sprintf(buf, "No family registered.\n");
 100 }
 101
 102 static struct device_attribute w1_slave_attribute =
 103         __ATTR(name, S_IRUGO, w1_default_read_name, NULL);
 104
 105 static struct device_attribute w1_slave_attribute_val =
 106         __ATTR(value, S_IRUGO, w1_default_read_name, NULL);
 107
 108 static struct bin_attribute w1_slave_bin_attribute = {
 109         .attr = {
 110                 .name = "w1_slave",
 111                 .mode = S_IRUGO,
 112                 .owner = THIS_MODULE,
 113         },
 114         .size = W1_SLAVE_DATA_SIZE,
 115         .read = &w1_default_read_bin,
 116 };
 117
 118
 119 static struct bus_type w1_bus_type = {
 120         .name = "w1",
 121         .match = w1_master_match,
 122 };
 123
 124 struct device_driver w1_driver = {
 125         .name = "w1_driver",
 126         .bus = &w1_bus_type,
 127         .probe = w1_master_probe,
 128         .remove = w1_master_remove,
 129 };
 130
 131 struct device w1_device = {
 132         .parent = NULL,
 133         .bus = &w1_bus_type,
 134         .bus_id = "w1 bus master",
 135         .driver = &w1_driver,
 136         .release = &w1_master_release
 137 };
 138
 139 static ssize_t w1_master_attribute_show_name(struct device *dev, struct device_attribute *attr, char *buf)
 140 {
 141         struct w1_master *md = container_of (dev, struct w1_master, dev);
 142         ssize_t count;
 143
 144         if (down_interruptible (&md->mutex))
 145                 return -EBUSY;
 146
 147         count = sprintf(buf, "%s\n", md->name);
 148
 149         up(&md->mutex);
 150
 151         return count;
 152 }
 153
 154 static ssize_t w1_master_attribute_show_pointer(struct device *dev, struct device_attribute *attr, char *buf)
 155 {
 156         struct w1_master *md = container_of(dev, struct w1_master, dev);
 157         ssize_t count;
 158
 159         if (down_interruptible(&md->mutex))
 160                 return -EBUSY;
 161
 162         count = sprintf(buf, "0x%p\n", md->bus_master);
 163
 164         up(&md->mutex);
 165         return count;
 166 }
 167
 168 static ssize_t w1_master_attribute_show_timeout(struct device *dev, struct device_attribute *attr, char *buf)
 169 {
 170         ssize_t count;
 171         count = sprintf(buf, "%d\n", w1_timeout);
 172         return count;
 173 }
 174
 175 static ssize_t w1_master_attribute_show_max_slave_count(struct device *dev, struct device_attribute *attr, char *buf)
 176 {
 177         struct w1_master *md = container_of(dev, struct w1_master, dev);
 178         ssize_t count;
 179
 180         if (down_interruptible(&md->mutex))
 181                 return -EBUSY;
 182
 183         count = sprintf(buf, "%d\n", md->max_slave_count);
 184
 185         up(&md->mutex);
 186         return count;
 187 }
 188
 189 static ssize_t w1_master_attribute_show_attempts(struct device *dev, struct device_attribute *attr, char *buf)
 190 {
 191         struct w1_master *md = container_of(dev, struct w1_master, dev);
 192         ssize_t count;
 193
 194         if (down_interruptible(&md->mutex))
 195                 return -EBUSY;
 196
 197         count = sprintf(buf, "%lu\n", md->attempts);
 198
 199         up(&md->mutex);
 200         return count;
 201 }
 202
 203 static ssize_t w1_master_attribute_show_slave_count(struct device *dev, struct device_attribute *attr, char *buf)
 204 {
 205         struct w1_master *md = container_of(dev, struct w1_master, dev);
 206         ssize_t count;
 207
 208         if (down_interruptible(&md->mutex))
 209                 return -EBUSY;
 210
 211         count = sprintf(buf, "%d\n", md->slave_count);
 212
 213         up(&md->mutex);
 214         return count;
 215 }
 216
 217 static ssize_t w1_master_attribute_show_slaves(struct device *dev, struct device_attribute *attr, char *buf)
 218
 219 {
 220         struct w1_master *md = container_of(dev, struct w1_master, dev);
 221         int c = PAGE_SIZE;
 222
 223         if (down_interruptible(&md->mutex))
 224                 return -EBUSY;
 225
 226         if (md->slave_count == 0)
 227                 c -= snprintf(buf + PAGE_SIZE - c, c, "not found.\n");
 228         else {
 229                 struct list_head *ent, *n;
 230                 struct w1_slave *sl;
 231
 232                 list_for_each_safe(ent, n, &md->slist) {
 233                         sl = list_entry(ent, struct w1_slave, w1_slave_entry);
 234
 235                         c -= snprintf(buf + PAGE_SIZE - c, c, "%s\n", sl->name);
 236                 }
 237         }
 238
 239         up(&md->mutex);
 240
 241         return PAGE_SIZE - c;
 242 }
 243
 244 #define W1_MASTER_ATTR_RO(_name, _mode)                         \
 245         struct device_attribute w1_master_attribute_##_name =   \
 246                 __ATTR(w1_master_##_name, _mode,                \
 247                        w1_master_attribute_show_##_name, NULL)
 248
 249 static W1_MASTER_ATTR_RO(name, S_IRUGO);
 250 static W1_MASTER_ATTR_RO(slaves, S_IRUGO);
 251 static W1_MASTER_ATTR_RO(slave_count, S_IRUGO);
 252 static W1_MASTER_ATTR_RO(max_slave_count, S_IRUGO);
 253 static W1_MASTER_ATTR_RO(attempts, S_IRUGO);
 254 static W1_MASTER_ATTR_RO(timeout, S_IRUGO);
 255 static W1_MASTER_ATTR_RO(pointer, S_IRUGO);
 256
 257 static struct attribute *w1_master_default_attrs[] = {
 258         &w1_master_attribute_name.attr,
 259         &w1_master_attribute_slaves.attr,
 260         &w1_master_attribute_slave_count.attr,
 261         &w1_master_attribute_max_slave_count.attr,
 262         &w1_master_attribute_attempts.attr,
 263         &w1_master_attribute_timeout.attr,
 264         &w1_master_attribute_pointer.attr,
 265         NULL
 266 };
 267
 268 static struct attribute_group w1_master_defattr_group = {
 269         .attrs = w1_master_default_attrs,
 270 };
 271
 272 int w1_create_master_attributes(struct w1_master *master)
 273 {
 274         return sysfs_create_group(&master->dev.kobj, &w1_master_defattr_group);
 275 }
 276
 277 void w1_destroy_master_attributes(struct w1_master *master)
 278 {
 279         sysfs_remove_group(&master->dev.kobj, &w1_master_defattr_group);
 280 }
 281
 282 static int __w1_attach_slave_device(struct w1_slave *sl)
 283 {
 284         int err;
 285
 286         sl->dev.parent = &sl->master->dev;
 287         sl->dev.driver = sl->master->driver;
 288         sl->dev.bus = &w1_bus_type;
 289         sl->dev.release = &w1_slave_release;
 290
 291         snprintf(&sl->dev.bus_id[0], sizeof(sl->dev.bus_id),
 292                   "%02x-%012llx",
 293                   (unsigned int) sl->reg_num.family,
 294                   (unsigned long long) sl->reg_num.id);
 295         snprintf (&sl->name[0], sizeof(sl->name),
 296                   "%02x-%012llx",
 297                   (unsigned int) sl->reg_num.family,
 298                   (unsigned long long) sl->reg_num.id);
 299
 300         dev_dbg(&sl->dev, "%s: registering %s.\n", __func__,
 301                 &sl->dev.bus_id[0]);
 302
 303         err = device_register(&sl->dev);
 304         if (err < 0) {
 305                 dev_err(&sl->dev,
 306                          "Device registration [%s] failed. err=%d\n",
 307                          sl->dev.bus_id, err);
 308                 return err;
 309         }
 310
 311         memcpy(&sl->attr_bin, &w1_slave_bin_attribute, sizeof(sl->attr_bin));
 312         memcpy(&sl->attr_name, &w1_slave_attribute, sizeof(sl->attr_name));
 313         memcpy(&sl->attr_val, &w1_slave_attribute_val, sizeof(sl->attr_val));
 314
 315         sl->attr_bin.read = sl->family->fops->rbin;
 316         sl->attr_name.show = sl->family->fops->rname;
 317         sl->attr_val.show = sl->family->fops->rval;
 318         sl->attr_val.attr.name = sl->family->fops->rvalname;
 319
 320         err = device_create_file(&sl->dev, &sl->attr_name);
 321         if (err < 0) {
 322                 dev_err(&sl->dev,
 323                          "sysfs file creation for [%s] failed. err=%d\n",
 324                          sl->dev.bus_id, err);
 325                 device_unregister(&sl->dev);
 326                 return err;
 327         }
 328
 329         err = device_create_file(&sl->dev, &sl->attr_val);
 330         if (err < 0) {
 331                 dev_err(&sl->dev,
 332                          "sysfs file creation for [%s] failed. err=%d\n",
 333                          sl->dev.bus_id, err);
 334                 device_remove_file(&sl->dev, &sl->attr_name);
 335                 device_unregister(&sl->dev);
 336                 return err;
 337         }
 338
 339         err = sysfs_create_bin_file(&sl->dev.kobj, &sl->attr_bin);
 340         if (err < 0) {
 341                 dev_err(&sl->dev,
 342                          "sysfs file creation for [%s] failed. err=%d\n",
 343                          sl->dev.bus_id, err);
 344                 device_remove_file(&sl->dev, &sl->attr_name);
 345                 device_remove_file(&sl->dev, &sl->attr_val);
 346                 device_unregister(&sl->dev);
 347                 return err;
 348         }
 349
 350         list_add_tail(&sl->w1_slave_entry, &sl->master->slist);
 351
 352         return 0;
 353 }
 354
 355 static int w1_attach_slave_device(struct w1_master *dev, struct w1_reg_num *rn)
 356 {
 357         struct w1_slave *sl;
 358         struct w1_family *f;
 359         int err;
 360         struct w1_netlink_msg msg;
 361
 362         sl = kmalloc(sizeof(struct w1_slave), GFP_KERNEL);
 363         if (!sl) {
 364                 dev_err(&dev->dev,
 365                          "%s: failed to allocate new slave device.\n",
 366                          __func__);
 367                 return -ENOMEM;
 368         }
 369
 370         memset(sl, 0, sizeof(*sl));
 371
 372         sl->owner = THIS_MODULE;
 373         sl->master = dev;
 374         set_bit(W1_SLAVE_ACTIVE, (long *)&sl->flags);
 375
 376         memcpy(&sl->reg_num, rn, sizeof(sl->reg_num));
 377         atomic_set(&sl->refcnt, 0);
 378         init_completion(&sl->dev_released);
 379
 380         spin_lock(&w1_flock);
 381         f = w1_family_registered(rn->family);
 382         if (!f) {
 383                 spin_unlock(&w1_flock);
 384                 dev_info(&dev->dev, "Family %x for %02x.%012llx.%02x is not registered.\n",
 385                           rn->family, rn->family,
 386                           (unsigned long long)rn->id, rn->crc);
 387                 kfree(sl);
 388                 return -ENODEV;
 389         }
 390         __w1_family_get(f);
 391         spin_unlock(&w1_flock);
 392
 393         sl->family = f;
 394
 395
 396         err = __w1_attach_slave_device(sl);
 397         if (err < 0) {
 398                 dev_err(&dev->dev, "%s: Attaching %s failed.\n", __func__,
 399                          sl->name);
 400                 w1_family_put(sl->family);
 401                 kfree(sl);
 402                 return err;
 403         }
 404
 405         sl->ttl = dev->slave_ttl;
 406         dev->slave_count++;
 407
 408         memcpy(&msg.id.id, rn, sizeof(msg.id.id));
 409         msg.type = W1_SLAVE_ADD;
 410         w1_netlink_send(dev, &msg);
 411
 412         return 0;
 413 }
 414
 415 static void w1_slave_detach(struct w1_slave *sl)
 416 {
 417         struct w1_netlink_msg msg;
 418
 419         dev_info(&sl->dev, "%s: detaching %s.\n", __func__, sl->name);
 420
 421         while (atomic_read(&sl->refcnt)) {
 422                 printk(KERN_INFO "Waiting for %s to become free: refcnt=%d.\n",
 423                                 sl->name, atomic_read(&sl->refcnt));
 424
 425                 if (msleep_interruptible(1000))
 426                         flush_signals(current);
 427         }
 428
 429         sysfs_remove_bin_file (&sl->dev.kobj, &sl->attr_bin);
 430         device_remove_file(&sl->dev, &sl->attr_name);
 431         device_remove_file(&sl->dev, &sl->attr_val);
 432         device_unregister(&sl->dev);
 433         w1_family_put(sl->family);
 434
 435         memcpy(&msg.id.id, &sl->reg_num, sizeof(msg.id.id));
 436         msg.type = W1_SLAVE_REMOVE;
 437         w1_netlink_send(sl->master, &msg);
 438 }
 439
 440 static struct w1_master *w1_search_master(unsigned long data)
 441 {
 442         struct w1_master *dev;
 443         int found = 0;
 444
 445         spin_lock_bh(&w1_mlock);
 446         list_for_each_entry(dev, &w1_masters, w1_master_entry) {
 447                 if (dev->bus_master->data == data) {
 448                         found = 1;
 449                         atomic_inc(&dev->refcnt);
 450                         break;
 451                 }
 452         }
 453         spin_unlock_bh(&w1_mlock);
 454
 455         return (found)?dev:NULL;
 456 }
 457
 458 static void w1_slave_found(unsigned long data, u64 rn)
 459 {
 460         int slave_count;
 461         struct w1_slave *sl;
 462         struct list_head *ent;
 463         struct w1_reg_num *tmp;
 464         int family_found = 0;
 465         struct w1_master *dev;
 466
 467         dev = w1_search_master(data);
 468         if (!dev) {
 469                 printk(KERN_ERR "Failed to find w1 master device for data %08lx, it is impossible.\n",
 470                                 data);
 471                 return;
 472         }
 473
 474         tmp = (struct w1_reg_num *) &rn;
 475
 476         slave_count = 0;
 477         list_for_each(ent, &dev->slist) {
 478
 479                 sl = list_entry(ent, struct w1_slave, w1_slave_entry);
 480
 481                 if (sl->reg_num.family == tmp->family &&
 482                     sl->reg_num.id == tmp->id &&
 483                     sl->reg_num.crc == tmp->crc) {
 484                         set_bit(W1_SLAVE_ACTIVE, (long *)&sl->flags);
 485                         break;
 486                 } else if (sl->reg_num.family == tmp->family) {
 487                         family_found = 1;
 488                         break;
 489                 }
 490
 491                 slave_count++;
 492         }
 493
 494         rn = cpu_to_le64(rn);
 495
 496         if (slave_count == dev->slave_count &&
 497                 rn && ((le64_to_cpu(rn) >> 56) & 0xff) == w1_calc_crc8((u8 *)&rn, 7)) {
 498                 w1_attach_slave_device(dev, tmp);
 499         }
 500
 501         atomic_dec(&dev->refcnt);
 502 }
 503
 504 void w1_search(struct w1_master *dev)
 505 {
 506         u64 last, rn, tmp;
 507         int i, count = 0;
 508         int last_family_desc, last_zero, last_device;
 509         int search_bit, id_bit, comp_bit, desc_bit;
 510
 511         search_bit = id_bit = comp_bit = 0;
 512         rn = tmp = last = 0;
 513         last_device = last_zero = last_family_desc = 0;
 514
 515         desc_bit = 64;
 516
 517         while (!(id_bit && comp_bit) && !last_device &&
 518                count++ < dev->max_slave_count) {
 519                 last = rn;
 520                 rn = 0;
 521
 522                 last_family_desc = 0;
 523
 524                 /*
 525                  * Reset bus and all 1-wire device state machines
 526                  * so they can respond to our requests.
 527                  *
 528                  * Return 0 - device(s) present, 1 - no devices present.
 529                  */
 530                 if (w1_reset_bus(dev)) {
 531                         dev_info(&dev->dev, "No devices present on the wire.\n");
 532                         break;
 533                 }
 534
 535 #if 1
 536                 w1_write_8(dev, W1_SEARCH);
 537                 for (i = 0; i < 64; ++i) {
 538                         /*
 539                          * Read 2 bits from bus.
 540                          * All who don't sleep must send ID bit and COMPLEMENT ID bit.
 541                          * They actually are ANDed between all senders.
 542                          */
 543                         id_bit = w1_touch_bit(dev, 1);
 544                         comp_bit = w1_touch_bit(dev, 1);
 545
 546                         if (id_bit && comp_bit)
 547                                 break;
 548
 549                         if (id_bit == 0 && comp_bit == 0) {
 550                                 if (i == desc_bit)
 551                                         search_bit = 1;
 552                                 else if (i > desc_bit)
 553                                         search_bit = 0;
 554                                 else
 555                                         search_bit = ((last >> i) & 0x1);
 556
 557                                 if (search_bit == 0) {
 558                                         last_zero = i;
 559                                         if (last_zero < 9)
 560                                                 last_family_desc = last_zero;
 561                                 }
 562
 563                         } else
 564                                 search_bit = id_bit;
 565
 566                         tmp = search_bit;
 567                         rn |= (tmp << i);
 568
 569                         /*
 570                          * Write 1 bit to bus
 571                          * and make all who don't have "search_bit" in "i"'th position
 572                          * in it's registration number sleep.
 573                          */
 574                         if (dev->bus_master->touch_bit)
 575                                 w1_touch_bit(dev, search_bit);
 576                         else
 577                                 w1_write_bit(dev, search_bit);
 578
 579                 }
 580 #endif
 581
 582                 if (desc_bit == last_zero)
 583                         last_device = 1;
 584
 585                 desc_bit = last_zero;
 586
 587                 w1_slave_found(dev->bus_master->data, rn);
 588         }
 589 }
 590
 591 static int w1_control(void *data)
 592 {
 593         struct w1_slave *sl, *sln;
 594         struct w1_master *dev, *n;
 595         int err, have_to_wait = 0;
 596
 597         daemonize("w1_control");
 598         allow_signal(SIGTERM);
 599
 600         while (!control_needs_exit || have_to_wait) {
 601                 have_to_wait = 0;
 602
 603                 try_to_freeze(PF_FREEZE);
 604                 msleep_interruptible(w1_timeout * 1000);
 605
 606                 if (signal_pending(current))
 607                         flush_signals(current);
 608
 609                 list_for_each_entry_safe(dev, n, &w1_masters, w1_master_entry) {
 610                         if (!control_needs_exit && !dev->need_exit)
 611                                 continue;
 612                         /*
 613                          * Little race: we can create thread but not set the flag.
 614                          * Get a chance for external process to set flag up.
 615                          */
 616                         if (!dev->initialized) {
 617                                 have_to_wait = 1;
 618                                 continue;
 619                         }
 620
 621                         spin_lock_bh(&w1_mlock);
 622                         list_del(&dev->w1_master_entry);
 623                         spin_unlock_bh(&w1_mlock);
 624
 625                         if (control_needs_exit) {
 626                                 dev->need_exit = 1;
 627
 628                                 err = kill_proc(dev->kpid, SIGTERM, 1);
 629                                 if (err)
 630                                         dev_err(&dev->dev,
 631                                                  "Failed to send signal to w1 kernel thread %d.\n",
 632                                                  dev->kpid);
 633                         }
 634
 635                         wait_for_completion(&dev->dev_exited);
 636
 637                         list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) {
 638                                 list_del(&sl->w1_slave_entry);
 639
 640                                 w1_slave_detach(sl);
 641                                 kfree(sl);
 642                         }
 643                         w1_destroy_master_attributes(dev);
 644                         atomic_dec(&dev->refcnt);
 645                 }
 646         }
 647
 648         complete_and_exit(&w1_control_complete, 0);
 649 }
 650
 651 int w1_process(void *data)
 652 {
 653         struct w1_master *dev = (struct w1_master *) data;
 654         struct w1_slave *sl, *sln;
 655
 656         daemonize("%s", dev->name);
 657         allow_signal(SIGTERM);
 658
 659         while (!dev->need_exit) {
 660                 try_to_freeze(PF_FREEZE);
 661                 msleep_interruptible(w1_timeout * 1000);
 662
 663                 if (signal_pending(current))
 664                         flush_signals(current);
 665
 666                 if (dev->need_exit)
 667                         break;
 668
 669                 if (!dev->initialized)
 670                         continue;
 671
 672                 if (down_interruptible(&dev->mutex))
 673                         continue;
 674
 675                 list_for_each_entry(sl, &dev->slist, w1_slave_entry)
 676                                 clear_bit(W1_SLAVE_ACTIVE, (long *)&sl->flags);
 677
 678                 w1_search_devices(dev, w1_slave_found);
 679
 680                 list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) {
 681                         if (!test_bit(W1_SLAVE_ACTIVE, (unsigned long *)&sl->flags) && !--sl->ttl) {
 682                                 list_del (&sl->w1_slave_entry);
 683
 684                                 w1_slave_detach (sl);
 685                                 kfree (sl);
 686
 687                                 dev->slave_count--;
 688                         } else if (test_bit(W1_SLAVE_ACTIVE, (unsigned long *)&sl->flags))
 689                                 sl->ttl = dev->slave_ttl;
 690                 }
 691                 up(&dev->mutex);
 692         }
 693
 694         atomic_dec(&dev->refcnt);
 695         complete_and_exit(&dev->dev_exited, 0);
 696
 697         return 0;
 698 }
 699
 700 static int w1_init(void)
 701 {
 702         int retval;
 703
 704         printk(KERN_INFO "Driver for 1-wire Dallas network protocol.\n");
 705
 706         retval = bus_register(&w1_bus_type);
 707         if (retval) {
 708                 printk(KERN_ERR "Failed to register bus. err=%d.\n", retval);
 709                 goto err_out_exit_init;
 710         }
 711
 712         retval = driver_register(&w1_driver);
 713         if (retval) {
 714                 printk(KERN_ERR
 715                         "Failed to register master driver. err=%d.\n",
 716                         retval);
 717                 goto err_out_bus_unregister;
 718         }
 719
 720         control_thread = kernel_thread(&w1_control, NULL, 0);
 721         if (control_thread < 0) {
 722                 printk(KERN_ERR "Failed to create control thread. err=%d\n",
 723                         control_thread);
 724                 retval = control_thread;
 725                 goto err_out_driver_unregister;
 726         }
 727
 728         return 0;
 729
 730 err_out_driver_unregister:
 731         driver_unregister(&w1_driver);
 732
 733 err_out_bus_unregister:
 734         bus_unregister(&w1_bus_type);
 735
 736 err_out_exit_init:
 737         return retval;
 738 }
 739
 740 static void w1_fini(void)
 741 {
 742         struct w1_master *dev;
 743
 744         list_for_each_entry(dev, &w1_masters, w1_master_entry)
 745                 __w1_remove_master_device(dev);
 746
 747         control_needs_exit = 1;
 748         wait_for_completion(&w1_control_complete);
 749
 750         driver_unregister(&w1_driver);
 751         bus_unregister(&w1_bus_type);
 752 }
 753
 754 module_init(w1_init);
 755 module_exit(w1_fini);