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 <asm/atomic.h>
  23
  24 #include <linux/delay.h>
  25 #include <linux/kernel.h>
  26 #include <linux/module.h>
  27 #include <linux/moduleparam.h>
  28 #include <linux/list.h>
  29 #include <linux/interrupt.h>
  30 #include <linux/spinlock.h>
  31 #include <linux/timer.h>
  32 #include <linux/device.h>
  33 #include <linux/slab.h>
  34 #include <linux/sched.h>
  35 #include <linux/suspend.h>
  36
  37 #include "w1.h"
  38 #include "w1_io.h"
  39 #include "w1_log.h"
  40 #include "w1_int.h"
  41 #include "w1_family.h"
  42 #include "w1_netlink.h"
  43
  44 MODULE_LICENSE("GPL");
  45 MODULE_AUTHOR("Evgeniy Polyakov <johnpol@2ka.mipt.ru>");
  46 MODULE_DESCRIPTION("Driver for 1-wire Dallas network protocol.");
  47
  48 static int w1_timeout = 10;
  49 int w1_max_slave_count = 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
  54 spinlock_t w1_mlock = SPIN_LOCK_UNLOCKED;
  55 LIST_HEAD(w1_masters);
  56
  57 static pid_t control_thread;
  58 static int control_needs_exit;
  59 static DECLARE_COMPLETION(w1_control_complete);
  60 static DECLARE_WAIT_QUEUE_HEAD(w1_control_wait);
  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, 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 struct bus_type w1_bus_type = {
 103         .name = "w1",
 104         .match = w1_master_match,
 105 };
 106
 107 struct device_driver w1_driver = {
 108         .name = "w1_driver",
 109         .bus = &w1_bus_type,
 110         .probe = w1_master_probe,
 111         .remove = w1_master_remove,
 112 };
 113
 114 struct device w1_device = {
 115         .parent = NULL,
 116         .bus = &w1_bus_type,
 117         .bus_id = "w1 bus master",
 118         .driver = &w1_driver,
 119         .release = &w1_master_release
 120 };
 121
 122 static struct device_attribute w1_slave_attribute = {
 123         .attr = {
 124                         .name = "name",
 125                         .mode = S_IRUGO,
 126                         .owner = THIS_MODULE
 127         },
 128         .show = &w1_default_read_name,
 129 };
 130
 131 static struct device_attribute w1_slave_attribute_val = {
 132         .attr = {
 133                         .name = "value",
 134                         .mode = S_IRUGO,
 135                         .owner = THIS_MODULE
 136         },
 137         .show = &w1_default_read_name,
 138 };
 139
 140 ssize_t w1_master_attribute_show_name(struct device *dev, char *buf)
 141 {
 142         struct w1_master *md = container_of (dev, struct w1_master, dev);
 143         ssize_t count;
 144
 145         if (down_interruptible (&md->mutex))
 146                 return -EBUSY;
 147
 148         count = sprintf(buf, "%s\n", md->name);
 149
 150         up(&md->mutex);
 151
 152         return count;
 153 }
 154
 155 ssize_t w1_master_attribute_show_pointer(struct device *dev, char *buf)
 156 {
 157         struct w1_master *md = container_of(dev, struct w1_master, dev);
 158         ssize_t count;
 159
 160         if (down_interruptible(&md->mutex))
 161                 return -EBUSY;
 162
 163         count = sprintf(buf, "0x%p\n", md->bus_master);
 164
 165         up(&md->mutex);
 166         return count;
 167 }
 168
 169 ssize_t w1_master_attribute_show_timeout(struct device *dev, char *buf)
 170 {
 171         ssize_t count;
 172         count = sprintf(buf, "%d\n", w1_timeout);
 173         return count;
 174 }
 175
 176 ssize_t w1_master_attribute_show_max_slave_count(struct device *dev, char *buf)
 177 {
 178         struct w1_master *md = container_of(dev, struct w1_master, dev);
 179         ssize_t count;
 180
 181         if (down_interruptible(&md->mutex))
 182                 return -EBUSY;
 183
 184         count = sprintf(buf, "%d\n", md->max_slave_count);
 185
 186         up(&md->mutex);
 187         return count;
 188 }
 189
 190 ssize_t w1_master_attribute_show_attempts(struct device *dev, char *buf)
 191 {
 192         struct w1_master *md = container_of(dev, struct w1_master, dev);
 193         ssize_t count;
 194
 195         if (down_interruptible(&md->mutex))
 196                 return -EBUSY;
 197
 198         count = sprintf(buf, "%lu\n", md->attempts);
 199
 200         up(&md->mutex);
 201         return count;
 202 }
 203
 204 ssize_t w1_master_attribute_show_slave_count(struct device *dev, char *buf)
 205 {
 206         struct w1_master *md = container_of(dev, struct w1_master, dev);
 207         ssize_t count;
 208
 209         if (down_interruptible(&md->mutex))
 210                 return -EBUSY;
 211
 212         count = sprintf(buf, "%d\n", md->slave_count);
 213
 214         up(&md->mutex);
 215         return count;
 216 }
 217
 218 ssize_t w1_master_attribute_show_slaves(struct device *dev, char *buf)
 219
 220 {
 221         struct w1_master *md = container_of(dev, struct w1_master, dev);
 222         int c = PAGE_SIZE;
 223
 224         if (down_interruptible(&md->mutex))
 225                 return -EBUSY;
 226
 227         if (md->slave_count == 0)
 228                 c -= snprintf(buf + PAGE_SIZE - c, c, "not found.\n");
 229         else {
 230                 struct list_head *ent, *n;
 231                 struct w1_slave *sl;
 232
 233                 list_for_each_safe(ent, n, &md->slist) {
 234                         sl = list_entry(ent, struct w1_slave, w1_slave_entry);
 235
 236                         c -= snprintf(buf + PAGE_SIZE - c, c, "%s\n", sl->name);
 237                 }
 238         }
 239
 240         up(&md->mutex);
 241
 242         return PAGE_SIZE - c;
 243 }
 244
 245 static struct device_attribute w1_master_attribute_slaves = {
 246         .attr = {
 247                         .name = "w1_master_slaves",
 248                         .mode = S_IRUGO,
 249                         .owner = THIS_MODULE,
 250         },
 251         .show = &w1_master_attribute_show_slaves,
 252 };
 253 static struct device_attribute w1_master_attribute_slave_count = {
 254         .attr = {
 255                         .name = "w1_master_slave_count",
 256                         .mode = S_IRUGO,
 257                         .owner = THIS_MODULE
 258         },
 259         .show = &w1_master_attribute_show_slave_count,
 260 };
 261 static struct device_attribute w1_master_attribute_attempts = {
 262         .attr = {
 263                         .name = "w1_master_attempts",
 264                         .mode = S_IRUGO,
 265                         .owner = THIS_MODULE
 266         },
 267         .show = &w1_master_attribute_show_attempts,
 268 };
 269 static struct device_attribute w1_master_attribute_max_slave_count = {
 270         .attr = {
 271                         .name = "w1_master_max_slave_count",
 272                         .mode = S_IRUGO,
 273                         .owner = THIS_MODULE
 274         },
 275         .show = &w1_master_attribute_show_max_slave_count,
 276 };
 277 static struct device_attribute w1_master_attribute_timeout = {
 278         .attr = {
 279                         .name = "w1_master_timeout",
 280                         .mode = S_IRUGO,
 281                         .owner = THIS_MODULE
 282         },
 283         .show = &w1_master_attribute_show_timeout,
 284 };
 285 static struct device_attribute w1_master_attribute_pointer = {
 286         .attr = {
 287                         .name = "w1_master_pointer",
 288                         .mode = S_IRUGO,
 289                         .owner = THIS_MODULE
 290         },
 291         .show = &w1_master_attribute_show_pointer,
 292 };
 293 static struct device_attribute w1_master_attribute_name = {
 294         .attr = {
 295                         .name = "w1_master_name",
 296                         .mode = S_IRUGO,
 297                         .owner = THIS_MODULE
 298         },
 299         .show = &w1_master_attribute_show_name,
 300 };
 301
 302 static struct bin_attribute w1_slave_bin_attribute = {
 303         .attr = {
 304                         .name = "w1_slave",
 305                         .mode = S_IRUGO,
 306                         .owner = THIS_MODULE,
 307         },
 308         .size = W1_SLAVE_DATA_SIZE,
 309         .read = &w1_default_read_bin,
 310 };
 311
 312 static int __w1_attach_slave_device(struct w1_slave *sl)
 313 {
 314         int err;
 315
 316         sl->dev.parent = &sl->master->dev;
 317         sl->dev.driver = sl->master->driver;
 318         sl->dev.bus = &w1_bus_type;
 319         sl->dev.release = &w1_slave_release;
 320
 321         snprintf(&sl->dev.bus_id[0], sizeof(sl->dev.bus_id),
 322                   "%02x-%012llx",
 323                   (unsigned int) sl->reg_num.family,
 324                   (unsigned long long) sl->reg_num.id);
 325         snprintf (&sl->name[0], sizeof(sl->name),
 326                   "%02x-%012llx",
 327                   (unsigned int) sl->reg_num.family,
 328                   (unsigned long long) sl->reg_num.id);
 329
 330         dev_dbg(&sl->dev, "%s: registering %s.\n", __func__,
 331                 &sl->dev.bus_id[0]);
 332
 333         err = device_register(&sl->dev);
 334         if (err < 0) {
 335                 dev_err(&sl->dev,
 336                          "Device registration [%s] failed. err=%d\n",
 337                          sl->dev.bus_id, err);
 338                 return err;
 339         }
 340
 341         memcpy(&sl->attr_bin, &w1_slave_bin_attribute, sizeof(sl->attr_bin));
 342         memcpy(&sl->attr_name, &w1_slave_attribute, sizeof(sl->attr_name));
 343         memcpy(&sl->attr_val, &w1_slave_attribute_val, sizeof(sl->attr_val));
 344
 345         sl->attr_bin.read = sl->family->fops->rbin;
 346         sl->attr_name.show = sl->family->fops->rname;
 347         sl->attr_val.show = sl->family->fops->rval;
 348         sl->attr_val.attr.name = sl->family->fops->rvalname;
 349
 350         err = device_create_file(&sl->dev, &sl->attr_name);
 351         if (err < 0) {
 352                 dev_err(&sl->dev,
 353                          "sysfs file creation for [%s] failed. err=%d\n",
 354                          sl->dev.bus_id, err);
 355                 device_unregister(&sl->dev);
 356                 return err;
 357         }
 358
 359         err = device_create_file(&sl->dev, &sl->attr_val);
 360         if (err < 0) {
 361                 dev_err(&sl->dev,
 362                          "sysfs file creation for [%s] failed. err=%d\n",
 363                          sl->dev.bus_id, err);
 364                 device_remove_file(&sl->dev, &sl->attr_name);
 365                 device_unregister(&sl->dev);
 366                 return err;
 367         }
 368
 369         err = sysfs_create_bin_file(&sl->dev.kobj, &sl->attr_bin);
 370         if (err < 0) {
 371                 dev_err(&sl->dev,
 372                          "sysfs file creation for [%s] failed. err=%d\n",
 373                          sl->dev.bus_id, err);
 374                 device_remove_file(&sl->dev, &sl->attr_name);
 375                 device_remove_file(&sl->dev, &sl->attr_val);
 376                 device_unregister(&sl->dev);
 377                 return err;
 378         }
 379
 380         list_add_tail(&sl->w1_slave_entry, &sl->master->slist);
 381
 382         return 0;
 383 }
 384
 385 static int w1_attach_slave_device(struct w1_master *dev, struct w1_reg_num *rn)
 386 {
 387         struct w1_slave *sl;
 388         struct w1_family *f;
 389         int err;
 390         struct w1_netlink_msg msg;
 391
 392         sl = kmalloc(sizeof(struct w1_slave), GFP_KERNEL);
 393         if (!sl) {
 394                 dev_err(&dev->dev,
 395                          "%s: failed to allocate new slave device.\n",
 396                          __func__);
 397                 return -ENOMEM;
 398         }
 399
 400         memset(sl, 0, sizeof(*sl));
 401
 402         sl->owner = THIS_MODULE;
 403         sl->master = dev;
 404         set_bit(W1_SLAVE_ACTIVE, (long *)&sl->flags);
 405
 406         memcpy(&sl->reg_num, rn, sizeof(sl->reg_num));
 407         atomic_set(&sl->refcnt, 0);
 408         init_completion(&sl->dev_released);
 409
 410         spin_lock(&w1_flock);
 411         f = w1_family_registered(rn->family);
 412         if (!f) {
 413                 spin_unlock(&w1_flock);
 414                 dev_info(&dev->dev, "Family %x for %02x.%012llx.%02x is not registered.\n",
 415                           rn->family, rn->family, rn->id, rn->crc);
 416                 kfree(sl);
 417                 return -ENODEV;
 418         }
 419         __w1_family_get(f);
 420         spin_unlock(&w1_flock);
 421
 422         sl->family = f;
 423
 424
 425         err = __w1_attach_slave_device(sl);
 426         if (err < 0) {
 427                 dev_err(&dev->dev, "%s: Attaching %s failed.\n", __func__,
 428                          sl->name);
 429                 w1_family_put(sl->family);
 430                 kfree(sl);
 431                 return err;
 432         }
 433
 434         dev->slave_count++;
 435
 436         memcpy(&msg.id.id, rn, sizeof(msg.id.id));
 437         msg.type = W1_SLAVE_ADD;
 438         w1_netlink_send(dev, &msg);
 439
 440         return 0;
 441 }
 442
 443 static void w1_slave_detach(struct w1_slave *sl)
 444 {
 445         struct w1_netlink_msg msg;
 446
 447         dev_info(&sl->dev, "%s: detaching %s.\n", __func__, sl->name);
 448
 449         while (atomic_read(&sl->refcnt))
 450                 schedule_timeout(10);
 451
 452         sysfs_remove_bin_file (&sl->dev.kobj, &sl->attr_bin);
 453         device_remove_file(&sl->dev, &sl->attr_name);
 454         device_remove_file(&sl->dev, &sl->attr_val);
 455         device_unregister(&sl->dev);
 456         w1_family_put(sl->family);
 457
 458         memcpy(&msg.id.id, &sl->reg_num, sizeof(msg.id.id));
 459         msg.type = W1_SLAVE_REMOVE;
 460         w1_netlink_send(sl->master, &msg);
 461 }
 462
 463 static void w1_search(struct w1_master *dev)
 464 {
 465         u64 last, rn, tmp;
 466         int i, count = 0, slave_count;
 467         int last_family_desc, last_zero, last_device;
 468         int search_bit, id_bit, comp_bit, desc_bit;
 469         struct list_head *ent;
 470         struct w1_slave *sl;
 471         int family_found = 0;
 472
 473         dev->attempts++;
 474
 475         search_bit = id_bit = comp_bit = 0;
 476         rn = tmp = last = 0;
 477         last_device = last_zero = last_family_desc = 0;
 478
 479         desc_bit = 64;
 480
 481         while (!(id_bit && comp_bit) && !last_device
 482                 && count++ < dev->max_slave_count) {
 483                 last = rn;
 484                 rn = 0;
 485
 486                 last_family_desc = 0;
 487
 488                 /*
 489                  * Reset bus and all 1-wire device state machines
 490                  * so they can respond to our requests.
 491                  *
 492                  * Return 0 - device(s) present, 1 - no devices present.
 493                  */
 494                 if (w1_reset_bus(dev)) {
 495                         dev_info(&dev->dev, "No devices present on the wire.\n");
 496                         break;
 497                 }
 498
 499 #if 1
 500                 w1_write_8(dev, W1_SEARCH);
 501                 for (i = 0; i < 64; ++i) {
 502                         /*
 503                          * Read 2 bits from bus.
 504                          * All who don't sleep must send ID bit and COMPLEMENT ID bit.
 505                          * They actually are ANDed between all senders.
 506                          */
 507                         id_bit = w1_read_bit(dev);
 508                         comp_bit = w1_read_bit(dev);
 509
 510                         if (id_bit && comp_bit)
 511                                 break;
 512
 513                         if (id_bit == 0 && comp_bit == 0) {
 514                                 if (i == desc_bit)
 515                                         search_bit = 1;
 516                                 else if (i > desc_bit)
 517                                         search_bit = 0;
 518                                 else
 519                                         search_bit = ((last >> i) & 0x1);
 520
 521                                 if (search_bit == 0) {
 522                                         last_zero = i;
 523                                         if (last_zero < 9)
 524                                                 last_family_desc = last_zero;
 525                                 }
 526
 527                         }
 528                         else
 529                                 search_bit = id_bit;
 530
 531                         tmp = search_bit;
 532                         rn |= (tmp << i);
 533
 534                         /*
 535                          * Write 1 bit to bus
 536                          * and make all who don't have "search_bit" in "i"'th position
 537                          * in it's registration number sleep.
 538                          */
 539                         w1_write_bit(dev, search_bit);
 540
 541                 }
 542 #endif
 543
 544                 if (desc_bit == last_zero)
 545                         last_device = 1;
 546
 547                 desc_bit = last_zero;
 548
 549                 slave_count = 0;
 550                 list_for_each(ent, &dev->slist) {
 551                         struct w1_reg_num *tmp;
 552
 553                         tmp = (struct w1_reg_num *) &rn;
 554
 555                         sl = list_entry(ent, struct w1_slave, w1_slave_entry);
 556
 557                         if (sl->reg_num.family == tmp->family &&
 558                             sl->reg_num.id == tmp->id &&
 559                             sl->reg_num.crc == tmp->crc) {
 560                                 set_bit(W1_SLAVE_ACTIVE, (long *)&sl->flags);
 561                                 break;
 562                         }
 563                         else if (sl->reg_num.family == tmp->family) {
 564                                 family_found = 1;
 565                                 break;
 566                         }
 567
 568                         slave_count++;
 569                 }
 570
 571                 if (slave_count == dev->slave_count &&
 572                     ((rn >> 56) & 0xff) == w1_calc_crc8((u8 *)&rn, 7)) {
 573                         w1_attach_slave_device(dev, (struct w1_reg_num *) &rn);
 574                 }
 575         }
 576 }
 577
 578 int w1_create_master_attributes(struct w1_master *dev)
 579 {
 580         if (    device_create_file(&dev->dev, &w1_master_attribute_slaves) < 0 ||
 581                 device_create_file(&dev->dev, &w1_master_attribute_slave_count) < 0 ||
 582                 device_create_file(&dev->dev, &w1_master_attribute_attempts) < 0 ||
 583                 device_create_file(&dev->dev, &w1_master_attribute_max_slave_count) < 0 ||
 584                 device_create_file(&dev->dev, &w1_master_attribute_timeout) < 0||
 585                 device_create_file(&dev->dev, &w1_master_attribute_pointer) < 0||
 586                 device_create_file(&dev->dev, &w1_master_attribute_name) < 0)
 587                 return -EINVAL;
 588
 589         return 0;
 590 }
 591
 592 void w1_destroy_master_attributes(struct w1_master *dev)
 593 {
 594         device_remove_file(&dev->dev, &w1_master_attribute_slaves);
 595         device_remove_file(&dev->dev, &w1_master_attribute_slave_count);
 596         device_remove_file(&dev->dev, &w1_master_attribute_attempts);
 597         device_remove_file(&dev->dev, &w1_master_attribute_max_slave_count);
 598         device_remove_file(&dev->dev, &w1_master_attribute_timeout);
 599         device_remove_file(&dev->dev, &w1_master_attribute_pointer);
 600         device_remove_file(&dev->dev, &w1_master_attribute_name);
 601 }
 602
 603
 604 int w1_control(void *data)
 605 {
 606         struct w1_slave *sl;
 607         struct w1_master *dev;
 608         struct list_head *ent, *ment, *n, *mn;
 609         int err, have_to_wait = 0, timeout;
 610
 611         daemonize("w1_control");
 612         allow_signal(SIGTERM);
 613
 614         while (!control_needs_exit || have_to_wait) {
 615                 have_to_wait = 0;
 616
 617                 timeout = w1_timeout*HZ;
 618                 do {
 619                         timeout = interruptible_sleep_on_timeout(&w1_control_wait, timeout);
 620                         if (current->flags & PF_FREEZE)
 621                                 refrigerator(PF_FREEZE);
 622                 } while (!signal_pending(current) && (timeout > 0));
 623
 624                 if (signal_pending(current))
 625                         flush_signals(current);
 626
 627                 list_for_each_safe(ment, mn, &w1_masters) {
 628                         dev = list_entry(ment, struct w1_master, w1_master_entry);
 629
 630                         if (!control_needs_exit && !dev->need_exit)
 631                                 continue;
 632                         /*
 633                          * Little race: we can create thread but not set the flag.
 634                          * Get a chance for external process to set flag up.
 635                          */
 636                         if (!dev->initialized) {
 637                                 have_to_wait = 1;
 638                                 continue;
 639                         }
 640
 641                         spin_lock(&w1_mlock);
 642                         list_del(&dev->w1_master_entry);
 643                         spin_unlock(&w1_mlock);
 644
 645                         if (control_needs_exit) {
 646                                 dev->need_exit = 1;
 647
 648                                 err = kill_proc(dev->kpid, SIGTERM, 1);
 649                                 if (err)
 650                                         dev_err(&dev->dev,
 651                                                  "Failed to send signal to w1 kernel thread %d.\n",
 652                                                  dev->kpid);
 653                         }
 654
 655                         wait_for_completion(&dev->dev_exited);
 656
 657                         list_for_each_safe(ent, n, &dev->slist) {
 658                                 sl = list_entry(ent, struct w1_slave, w1_slave_entry);
 659
 660                                 if (!sl)
 661                                         dev_warn(&dev->dev,
 662                                                   "%s: slave entry is NULL.\n",
 663                                                   __func__);
 664                                 else {
 665                                         list_del(&sl->w1_slave_entry);
 666
 667                                         w1_slave_detach(sl);
 668                                         kfree(sl);
 669                                 }
 670                         }
 671                         w1_destroy_master_attributes(dev);
 672                         atomic_dec(&dev->refcnt);
 673                 }
 674         }
 675
 676         complete_and_exit(&w1_control_complete, 0);
 677 }
 678
 679 int w1_process(void *data)
 680 {
 681         struct w1_master *dev = (struct w1_master *) data;
 682         unsigned long timeout;
 683         struct list_head *ent, *n;
 684         struct w1_slave *sl;
 685
 686         daemonize("%s", dev->name);
 687         allow_signal(SIGTERM);
 688
 689         while (!dev->need_exit) {
 690                 timeout = w1_timeout*HZ;
 691                 do {
 692                         timeout = interruptible_sleep_on_timeout(&dev->kwait, timeout);
 693                         if (current->flags & PF_FREEZE)
 694                                 refrigerator(PF_FREEZE);
 695                 } while (!signal_pending(current) && (timeout > 0));
 696
 697                 if (signal_pending(current))
 698                         flush_signals(current);
 699
 700                 if (dev->need_exit)
 701                         break;
 702
 703                 if (!dev->initialized)
 704                         continue;
 705
 706                 if (down_interruptible(&dev->mutex))
 707                         continue;
 708
 709                 list_for_each_safe(ent, n, &dev->slist) {
 710                         sl = list_entry(ent, struct w1_slave, w1_slave_entry);
 711
 712                         if (sl)
 713                                 clear_bit(W1_SLAVE_ACTIVE, (long *)&sl->flags);
 714                 }
 715
 716                 w1_search(dev);
 717
 718                 list_for_each_safe(ent, n, &dev->slist) {
 719                         sl = list_entry(ent, struct w1_slave, w1_slave_entry);
 720
 721                         if (sl && !test_bit(W1_SLAVE_ACTIVE, (unsigned long *)&sl->flags)) {
 722                                 list_del (&sl->w1_slave_entry);
 723
 724                                 w1_slave_detach (sl);
 725                                 kfree (sl);
 726
 727                                 dev->slave_count--;
 728                         }
 729                 }
 730                 up(&dev->mutex);
 731         }
 732
 733         atomic_dec(&dev->refcnt);
 734         complete_and_exit(&dev->dev_exited, 0);
 735
 736         return 0;
 737 }
 738
 739 int w1_init(void)
 740 {
 741         int retval;
 742
 743         printk(KERN_INFO "Driver for 1-wire Dallas network protocol.\n");
 744
 745         retval = bus_register(&w1_bus_type);
 746         if (retval) {
 747                 printk(KERN_ERR "Failed to register bus. err=%d.\n", retval);
 748                 goto err_out_exit_init;
 749         }
 750
 751         retval = driver_register(&w1_driver);
 752         if (retval) {
 753                 printk(KERN_ERR
 754                         "Failed to register master driver. err=%d.\n",
 755                         retval);
 756                 goto err_out_bus_unregister;
 757         }
 758
 759         control_thread = kernel_thread(&w1_control, NULL, 0);
 760         if (control_thread < 0) {
 761                 printk(KERN_ERR "Failed to create control thread. err=%d\n",
 762                         control_thread);
 763                 retval = control_thread;
 764                 goto err_out_driver_unregister;
 765         }
 766
 767         return 0;
 768
 769 err_out_driver_unregister:
 770         driver_unregister(&w1_driver);
 771
 772 err_out_bus_unregister:
 773         bus_unregister(&w1_bus_type);
 774
 775 err_out_exit_init:
 776         return retval;
 777 }
 778
 779 void w1_fini(void)
 780 {
 781         struct w1_master *dev;
 782         struct list_head *ent, *n;
 783
 784         list_for_each_safe(ent, n, &w1_masters) {
 785                 dev = list_entry(ent, struct w1_master, w1_master_entry);
 786                 __w1_remove_master_device(dev);
 787         }
 788
 789         control_needs_exit = 1;
 790
 791         wait_for_completion(&w1_control_complete);
 792
 793         driver_unregister(&w1_driver);
 794         bus_unregister(&w1_bus_type);
 795 }
 796
 797 module_init(w1_init);
 798 module_exit(w1_fini);
 799
 800 EXPORT_SYMBOL(w1_create_master_attributes);
 801 EXPORT_SYMBOL(w1_destroy_master_attributes);