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 int w1_max_slave_ttl = 10;
  51
  52 module_param_named(timeout, w1_timeout, int, 0);
  53 module_param_named(max_slave_count, w1_max_slave_count, int, 0);
  54 module_param_named(slave_ttl, w1_max_slave_ttl, int, 0);
  55
  56 spinlock_t w1_mlock = SPIN_LOCK_UNLOCKED;
  57 LIST_HEAD(w1_masters);
  58
  59 static pid_t control_thread;
  60 static int control_needs_exit;
  61 static DECLARE_COMPLETION(w1_control_complete);
  62 static DECLARE_WAIT_QUEUE_HEAD(w1_control_wait);
  63
  64 static int w1_master_match(struct device *dev, struct device_driver *drv)
  65 {
  66         return 1;
  67 }
  68
  69 static int w1_master_probe(struct device *dev)
  70 {
  71         return -ENODEV;
  72 }
  73
  74 static int w1_master_remove(struct device *dev)
  75 {
  76         return 0;
  77 }
  78
  79 static void w1_master_release(struct device *dev)
  80 {
  81         struct w1_master *md = container_of(dev, struct w1_master, dev);
  82
  83         complete(&md->dev_released);
  84 }
  85
  86 static void w1_slave_release(struct device *dev)
  87 {
  88         struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
  89
  90         complete(&sl->dev_released);
  91 }
  92
  93 static ssize_t w1_default_read_name(struct device *dev, char *buf)
  94 {
  95         return sprintf(buf, "No family registered.\n");
  96 }
  97
  98 static ssize_t w1_default_read_bin(struct kobject *kobj, char *buf, loff_t off,
  99                      size_t count)
 100 {
 101         return sprintf(buf, "No family registered.\n");
 102 }
 103
 104 struct bus_type w1_bus_type = {
 105         .name = "w1",
 106         .match = w1_master_match,
 107 };
 108
 109 struct device_driver w1_driver = {
 110         .name = "w1_driver",
 111         .bus = &w1_bus_type,
 112         .probe = w1_master_probe,
 113         .remove = w1_master_remove,
 114 };
 115
 116 struct device w1_device = {
 117         .parent = NULL,
 118         .bus = &w1_bus_type,
 119         .bus_id = "w1 bus master",
 120         .driver = &w1_driver,
 121         .release = &w1_master_release
 122 };
 123
 124 static struct device_attribute w1_slave_attribute = {
 125         .attr = {
 126                         .name = "name",
 127                         .mode = S_IRUGO,
 128                         .owner = THIS_MODULE
 129         },
 130         .show = &w1_default_read_name,
 131 };
 132
 133 static struct device_attribute w1_slave_attribute_val = {
 134         .attr = {
 135                         .name = "value",
 136                         .mode = S_IRUGO,
 137                         .owner = THIS_MODULE
 138         },
 139         .show = &w1_default_read_name,
 140 };
 141
 142 ssize_t w1_master_attribute_show_name(struct device *dev, char *buf)
 143 {
 144         struct w1_master *md = container_of (dev, struct w1_master, dev);
 145         ssize_t count;
 146
 147         if (down_interruptible (&md->mutex))
 148                 return -EBUSY;
 149
 150         count = sprintf(buf, "%s\n", md->name);
 151
 152         up(&md->mutex);
 153
 154         return count;
 155 }
 156
 157 ssize_t w1_master_attribute_show_pointer(struct device *dev, char *buf)
 158 {
 159         struct w1_master *md = container_of(dev, struct w1_master, dev);
 160         ssize_t count;
 161
 162         if (down_interruptible(&md->mutex))
 163                 return -EBUSY;
 164
 165         count = sprintf(buf, "0x%p\n", md->bus_master);
 166
 167         up(&md->mutex);
 168         return count;
 169 }
 170
 171 ssize_t w1_master_attribute_show_timeout(struct device *dev, char *buf)
 172 {
 173         ssize_t count;
 174         count = sprintf(buf, "%d\n", w1_timeout);
 175         return count;
 176 }
 177
 178 ssize_t w1_master_attribute_show_max_slave_count(struct device *dev, char *buf)
 179 {
 180         struct w1_master *md = container_of(dev, struct w1_master, dev);
 181         ssize_t count;
 182
 183         if (down_interruptible(&md->mutex))
 184                 return -EBUSY;
 185
 186         count = sprintf(buf, "%d\n", md->max_slave_count);
 187
 188         up(&md->mutex);
 189         return count;
 190 }
 191
 192 ssize_t w1_master_attribute_show_attempts(struct device *dev, char *buf)
 193 {
 194         struct w1_master *md = container_of(dev, struct w1_master, dev);
 195         ssize_t count;
 196
 197         if (down_interruptible(&md->mutex))
 198                 return -EBUSY;
 199
 200         count = sprintf(buf, "%lu\n", md->attempts);
 201
 202         up(&md->mutex);
 203         return count;
 204 }
 205
 206 ssize_t w1_master_attribute_show_slave_count(struct device *dev, char *buf)
 207 {
 208         struct w1_master *md = container_of(dev, struct w1_master, dev);
 209         ssize_t count;
 210
 211         if (down_interruptible(&md->mutex))
 212                 return -EBUSY;
 213
 214         count = sprintf(buf, "%d\n", md->slave_count);
 215
 216         up(&md->mutex);
 217         return count;
 218 }
 219
 220 ssize_t w1_master_attribute_show_slaves(struct device *dev, char *buf)
 221
 222 {
 223         struct w1_master *md = container_of(dev, struct w1_master, dev);
 224         int c = PAGE_SIZE;
 225
 226         if (down_interruptible(&md->mutex))
 227                 return -EBUSY;
 228
 229         if (md->slave_count == 0)
 230                 c -= snprintf(buf + PAGE_SIZE - c, c, "not found.\n");
 231         else {
 232                 struct list_head *ent, *n;
 233                 struct w1_slave *sl;
 234
 235                 list_for_each_safe(ent, n, &md->slist) {
 236                         sl = list_entry(ent, struct w1_slave, w1_slave_entry);
 237
 238                         c -= snprintf(buf + PAGE_SIZE - c, c, "%s\n", sl->name);
 239                 }
 240         }
 241
 242         up(&md->mutex);
 243
 244         return PAGE_SIZE - c;
 245 }
 246
 247 static struct device_attribute w1_master_attribute_slaves = {
 248         .attr = {
 249                         .name = "w1_master_slaves",
 250                         .mode = S_IRUGO,
 251                         .owner = THIS_MODULE,
 252         },
 253         .show = &w1_master_attribute_show_slaves,
 254 };
 255 static struct device_attribute w1_master_attribute_slave_count = {
 256         .attr = {
 257                         .name = "w1_master_slave_count",
 258                         .mode = S_IRUGO,
 259                         .owner = THIS_MODULE
 260         },
 261         .show = &w1_master_attribute_show_slave_count,
 262 };
 263 static struct device_attribute w1_master_attribute_attempts = {
 264         .attr = {
 265                         .name = "w1_master_attempts",
 266                         .mode = S_IRUGO,
 267                         .owner = THIS_MODULE
 268         },
 269         .show = &w1_master_attribute_show_attempts,
 270 };
 271 static struct device_attribute w1_master_attribute_max_slave_count = {
 272         .attr = {
 273                         .name = "w1_master_max_slave_count",
 274                         .mode = S_IRUGO,
 275                         .owner = THIS_MODULE
 276         },
 277         .show = &w1_master_attribute_show_max_slave_count,
 278 };
 279 static struct device_attribute w1_master_attribute_timeout = {
 280         .attr = {
 281                         .name = "w1_master_timeout",
 282                         .mode = S_IRUGO,
 283                         .owner = THIS_MODULE
 284         },
 285         .show = &w1_master_attribute_show_timeout,
 286 };
 287 static struct device_attribute w1_master_attribute_pointer = {
 288         .attr = {
 289                         .name = "w1_master_pointer",
 290                         .mode = S_IRUGO,
 291                         .owner = THIS_MODULE
 292         },
 293         .show = &w1_master_attribute_show_pointer,
 294 };
 295 static struct device_attribute w1_master_attribute_name = {
 296         .attr = {
 297                         .name = "w1_master_name",
 298                         .mode = S_IRUGO,
 299                         .owner = THIS_MODULE
 300         },
 301         .show = &w1_master_attribute_show_name,
 302 };
 303
 304 static struct bin_attribute w1_slave_bin_attribute = {
 305         .attr = {
 306                         .name = "w1_slave",
 307                         .mode = S_IRUGO,
 308                         .owner = THIS_MODULE,
 309         },
 310         .size = W1_SLAVE_DATA_SIZE,
 311         .read = &w1_default_read_bin,
 312 };
 313
 314 static int __w1_attach_slave_device(struct w1_slave *sl)
 315 {
 316         int err;
 317
 318         sl->dev.parent = &sl->master->dev;
 319         sl->dev.driver = sl->master->driver;
 320         sl->dev.bus = &w1_bus_type;
 321         sl->dev.release = &w1_slave_release;
 322
 323         snprintf(&sl->dev.bus_id[0], sizeof(sl->dev.bus_id),
 324                   "%02x-%012llx",
 325                   (unsigned int) sl->reg_num.family,
 326                   (unsigned long long) sl->reg_num.id);
 327         snprintf (&sl->name[0], sizeof(sl->name),
 328                   "%02x-%012llx",
 329                   (unsigned int) sl->reg_num.family,
 330                   (unsigned long long) sl->reg_num.id);
 331
 332         dev_dbg(&sl->dev, "%s: registering %s.\n", __func__,
 333                 &sl->dev.bus_id[0]);
 334
 335         err = device_register(&sl->dev);
 336         if (err < 0) {
 337                 dev_err(&sl->dev,
 338                          "Device registration [%s] failed. err=%d\n",
 339                          sl->dev.bus_id, err);
 340                 return err;
 341         }
 342
 343         memcpy(&sl->attr_bin, &w1_slave_bin_attribute, sizeof(sl->attr_bin));
 344         memcpy(&sl->attr_name, &w1_slave_attribute, sizeof(sl->attr_name));
 345         memcpy(&sl->attr_val, &w1_slave_attribute_val, sizeof(sl->attr_val));
 346
 347         sl->attr_bin.read = sl->family->fops->rbin;
 348         sl->attr_name.show = sl->family->fops->rname;
 349         sl->attr_val.show = sl->family->fops->rval;
 350         sl->attr_val.attr.name = sl->family->fops->rvalname;
 351
 352         err = device_create_file(&sl->dev, &sl->attr_name);
 353         if (err < 0) {
 354                 dev_err(&sl->dev,
 355                          "sysfs file creation for [%s] failed. err=%d\n",
 356                          sl->dev.bus_id, err);
 357                 device_unregister(&sl->dev);
 358                 return err;
 359         }
 360
 361         err = device_create_file(&sl->dev, &sl->attr_val);
 362         if (err < 0) {
 363                 dev_err(&sl->dev,
 364                          "sysfs file creation for [%s] failed. err=%d\n",
 365                          sl->dev.bus_id, err);
 366                 device_remove_file(&sl->dev, &sl->attr_name);
 367                 device_unregister(&sl->dev);
 368                 return err;
 369         }
 370
 371         err = sysfs_create_bin_file(&sl->dev.kobj, &sl->attr_bin);
 372         if (err < 0) {
 373                 dev_err(&sl->dev,
 374                          "sysfs file creation for [%s] failed. err=%d\n",
 375                          sl->dev.bus_id, err);
 376                 device_remove_file(&sl->dev, &sl->attr_name);
 377                 device_remove_file(&sl->dev, &sl->attr_val);
 378                 device_unregister(&sl->dev);
 379                 return err;
 380         }
 381
 382         list_add_tail(&sl->w1_slave_entry, &sl->master->slist);
 383
 384         return 0;
 385 }
 386
 387 static int w1_attach_slave_device(struct w1_master *dev, struct w1_reg_num *rn)
 388 {
 389         struct w1_slave *sl;
 390         struct w1_family *f;
 391         int err;
 392         struct w1_netlink_msg msg;
 393
 394         sl = kmalloc(sizeof(struct w1_slave), GFP_KERNEL);
 395         if (!sl) {
 396                 dev_err(&dev->dev,
 397                          "%s: failed to allocate new slave device.\n",
 398                          __func__);
 399                 return -ENOMEM;
 400         }
 401
 402         memset(sl, 0, sizeof(*sl));
 403
 404         sl->owner = THIS_MODULE;
 405         sl->master = dev;
 406         set_bit(W1_SLAVE_ACTIVE, (long *)&sl->flags);
 407
 408         memcpy(&sl->reg_num, rn, sizeof(sl->reg_num));
 409         atomic_set(&sl->refcnt, 0);
 410         init_completion(&sl->dev_released);
 411
 412         spin_lock(&w1_flock);
 413         f = w1_family_registered(rn->family);
 414         if (!f) {
 415                 spin_unlock(&w1_flock);
 416                 dev_info(&dev->dev, "Family %x for %02x.%012llx.%02x is not registered.\n",
 417                           rn->family, rn->family, rn->id, rn->crc);
 418                 kfree(sl);
 419                 return -ENODEV;
 420         }
 421         __w1_family_get(f);
 422         spin_unlock(&w1_flock);
 423
 424         sl->family = f;
 425
 426
 427         err = __w1_attach_slave_device(sl);
 428         if (err < 0) {
 429                 dev_err(&dev->dev, "%s: Attaching %s failed.\n", __func__,
 430                          sl->name);
 431                 w1_family_put(sl->family);
 432                 kfree(sl);
 433                 return err;
 434         }
 435
 436         sl->ttl = dev->slave_ttl;
 437         dev->slave_count++;
 438
 439         memcpy(&msg.id.id, rn, sizeof(msg.id.id));
 440         msg.type = W1_SLAVE_ADD;
 441         w1_netlink_send(dev, &msg);
 442
 443         return 0;
 444 }
 445
 446 static void w1_slave_detach(struct w1_slave *sl)
 447 {
 448         struct w1_netlink_msg msg;
 449
 450         dev_info(&sl->dev, "%s: detaching %s.\n", __func__, sl->name);
 451
 452         while (atomic_read(&sl->refcnt)) {
 453                 printk(KERN_INFO "Waiting for %s to become free: refcnt=%d.\n",
 454                                 sl->name, atomic_read(&sl->refcnt));
 455
 456                 if (msleep_interruptible(1000))
 457                         flush_signals(current);
 458         }
 459
 460         sysfs_remove_bin_file (&sl->dev.kobj, &sl->attr_bin);
 461         device_remove_file(&sl->dev, &sl->attr_name);
 462         device_remove_file(&sl->dev, &sl->attr_val);
 463         device_unregister(&sl->dev);
 464         w1_family_put(sl->family);
 465
 466         memcpy(&msg.id.id, &sl->reg_num, sizeof(msg.id.id));
 467         msg.type = W1_SLAVE_REMOVE;
 468         w1_netlink_send(sl->master, &msg);
 469 }
 470
 471 static void w1_search(struct w1_master *dev)
 472 {
 473         u64 last, rn, tmp;
 474         int i, count = 0, slave_count;
 475         int last_family_desc, last_zero, last_device;
 476         int search_bit, id_bit, comp_bit, desc_bit;
 477         struct list_head *ent;
 478         struct w1_slave *sl;
 479         int family_found = 0;
 480
 481         dev->attempts++;
 482
 483         search_bit = id_bit = comp_bit = 0;
 484         rn = tmp = last = 0;
 485         last_device = last_zero = last_family_desc = 0;
 486
 487         desc_bit = 64;
 488
 489         while (!(id_bit && comp_bit) && !last_device
 490                 && count++ < dev->max_slave_count) {
 491                 last = rn;
 492                 rn = 0;
 493
 494                 last_family_desc = 0;
 495
 496                 /*
 497                  * Reset bus and all 1-wire device state machines
 498                  * so they can respond to our requests.
 499                  *
 500                  * Return 0 - device(s) present, 1 - no devices present.
 501                  */
 502                 if (w1_reset_bus(dev)) {
 503                         dev_info(&dev->dev, "No devices present on the wire.\n");
 504                         break;
 505                 }
 506
 507 #if 1
 508                 w1_write_8(dev, W1_SEARCH);
 509                 for (i = 0; i < 64; ++i) {
 510                         /*
 511                          * Read 2 bits from bus.
 512                          * All who don't sleep must send ID bit and COMPLEMENT ID bit.
 513                          * They actually are ANDed between all senders.
 514                          */
 515                         id_bit = w1_touch_bit(dev, 1);
 516                         comp_bit = w1_touch_bit(dev, 1);
 517
 518                         if (id_bit && comp_bit)
 519                                 break;
 520
 521                         if (id_bit == 0 && comp_bit == 0) {
 522                                 if (i == desc_bit)
 523                                         search_bit = 1;
 524                                 else if (i > desc_bit)
 525                                         search_bit = 0;
 526                                 else
 527                                         search_bit = ((last >> i) & 0x1);
 528
 529                                 if (search_bit == 0) {
 530                                         last_zero = i;
 531                                         if (last_zero < 9)
 532                                                 last_family_desc = last_zero;
 533                                 }
 534
 535                         }
 536                         else
 537                                 search_bit = id_bit;
 538
 539                         tmp = search_bit;
 540                         rn |= (tmp << i);
 541
 542                         /*
 543                          * Write 1 bit to bus
 544                          * and make all who don't have "search_bit" in "i"'th position
 545                          * in it's registration number sleep.
 546                          */
 547                         if (dev->bus_master->touch_bit)
 548                                 w1_touch_bit(dev, search_bit);
 549                         else
 550                                 w1_write_bit(dev, search_bit);
 551
 552                 }
 553 #endif
 554
 555                 if (desc_bit == last_zero)
 556                         last_device = 1;
 557
 558                 desc_bit = last_zero;
 559
 560                 slave_count = 0;
 561                 list_for_each(ent, &dev->slist) {
 562                         struct w1_reg_num *tmp;
 563
 564                         tmp = (struct w1_reg_num *) &rn;
 565
 566                         sl = list_entry(ent, struct w1_slave, w1_slave_entry);
 567
 568                         if (sl->reg_num.family == tmp->family &&
 569                             sl->reg_num.id == tmp->id &&
 570                             sl->reg_num.crc == tmp->crc) {
 571                                 set_bit(W1_SLAVE_ACTIVE, (long *)&sl->flags);
 572                                 break;
 573                         }
 574                         else if (sl->reg_num.family == tmp->family) {
 575                                 family_found = 1;
 576                                 break;
 577                         }
 578
 579                         slave_count++;
 580                 }
 581
 582                 if (slave_count == dev->slave_count &&
 583                         rn && ((rn >> 56) & 0xff) == w1_calc_crc8((u8 *)&rn, 7)) {
 584                         w1_attach_slave_device(dev, (struct w1_reg_num *) &rn);
 585                 }
 586         }
 587 }
 588
 589 int w1_create_master_attributes(struct w1_master *dev)
 590 {
 591         if (    device_create_file(&dev->dev, &w1_master_attribute_slaves) < 0 ||
 592                 device_create_file(&dev->dev, &w1_master_attribute_slave_count) < 0 ||
 593                 device_create_file(&dev->dev, &w1_master_attribute_attempts) < 0 ||
 594                 device_create_file(&dev->dev, &w1_master_attribute_max_slave_count) < 0 ||
 595                 device_create_file(&dev->dev, &w1_master_attribute_timeout) < 0||
 596                 device_create_file(&dev->dev, &w1_master_attribute_pointer) < 0||
 597                 device_create_file(&dev->dev, &w1_master_attribute_name) < 0)
 598                 return -EINVAL;
 599
 600         return 0;
 601 }
 602
 603 void w1_destroy_master_attributes(struct w1_master *dev)
 604 {
 605         device_remove_file(&dev->dev, &w1_master_attribute_slaves);
 606         device_remove_file(&dev->dev, &w1_master_attribute_slave_count);
 607         device_remove_file(&dev->dev, &w1_master_attribute_attempts);
 608         device_remove_file(&dev->dev, &w1_master_attribute_max_slave_count);
 609         device_remove_file(&dev->dev, &w1_master_attribute_timeout);
 610         device_remove_file(&dev->dev, &w1_master_attribute_pointer);
 611         device_remove_file(&dev->dev, &w1_master_attribute_name);
 612 }
 613
 614
 615 int w1_control(void *data)
 616 {
 617         struct w1_slave *sl;
 618         struct w1_master *dev;
 619         struct list_head *ent, *ment, *n, *mn;
 620         int err, have_to_wait = 0, timeout;
 621
 622         daemonize("w1_control");
 623         allow_signal(SIGTERM);
 624
 625         while (!control_needs_exit || have_to_wait) {
 626                 have_to_wait = 0;
 627
 628                 timeout = w1_timeout*HZ;
 629                 do {
 630                         timeout = interruptible_sleep_on_timeout(&w1_control_wait, timeout);
 631                         if (current->flags & PF_FREEZE)
 632                                 refrigerator(PF_FREEZE);
 633                 } while (!signal_pending(current) && (timeout > 0));
 634
 635                 if (signal_pending(current))
 636                         flush_signals(current);
 637
 638                 list_for_each_safe(ment, mn, &w1_masters) {
 639                         dev = list_entry(ment, struct w1_master, w1_master_entry);
 640
 641                         if (!control_needs_exit && !dev->need_exit)
 642                                 continue;
 643                         /*
 644                          * Little race: we can create thread but not set the flag.
 645                          * Get a chance for external process to set flag up.
 646                          */
 647                         if (!dev->initialized) {
 648                                 have_to_wait = 1;
 649                                 continue;
 650                         }
 651
 652                         spin_lock(&w1_mlock);
 653                         list_del(&dev->w1_master_entry);
 654                         spin_unlock(&w1_mlock);
 655
 656                         if (control_needs_exit) {
 657                                 dev->need_exit = 1;
 658
 659                                 err = kill_proc(dev->kpid, SIGTERM, 1);
 660                                 if (err)
 661                                         dev_err(&dev->dev,
 662                                                  "Failed to send signal to w1 kernel thread %d.\n",
 663                                                  dev->kpid);
 664                         }
 665
 666                         wait_for_completion(&dev->dev_exited);
 667
 668                         list_for_each_safe(ent, n, &dev->slist) {
 669                                 sl = list_entry(ent, struct w1_slave, w1_slave_entry);
 670
 671                                 if (!sl)
 672                                         dev_warn(&dev->dev,
 673                                                   "%s: slave entry is NULL.\n",
 674                                                   __func__);
 675                                 else {
 676                                         list_del(&sl->w1_slave_entry);
 677
 678                                         w1_slave_detach(sl);
 679                                         kfree(sl);
 680                                 }
 681                         }
 682                         w1_destroy_master_attributes(dev);
 683                         atomic_dec(&dev->refcnt);
 684                 }
 685         }
 686
 687         complete_and_exit(&w1_control_complete, 0);
 688 }
 689
 690 int w1_process(void *data)
 691 {
 692         struct w1_master *dev = (struct w1_master *) data;
 693         unsigned long timeout;
 694         struct list_head *ent, *n;
 695         struct w1_slave *sl;
 696
 697         daemonize("%s", dev->name);
 698         allow_signal(SIGTERM);
 699
 700         while (!dev->need_exit) {
 701                 timeout = w1_timeout*HZ;
 702                 do {
 703                         timeout = interruptible_sleep_on_timeout(&dev->kwait, timeout);
 704                         if (current->flags & PF_FREEZE)
 705                                 refrigerator(PF_FREEZE);
 706                 } while (!signal_pending(current) && (timeout > 0));
 707
 708                 if (signal_pending(current))
 709                         flush_signals(current);
 710
 711                 if (dev->need_exit)
 712                         break;
 713
 714                 if (!dev->initialized)
 715                         continue;
 716
 717                 if (down_interruptible(&dev->mutex))
 718                         continue;
 719
 720                 list_for_each_safe(ent, n, &dev->slist) {
 721                         sl = list_entry(ent, struct w1_slave, w1_slave_entry);
 722
 723                         if (sl)
 724                                 clear_bit(W1_SLAVE_ACTIVE, (long *)&sl->flags);
 725                 }
 726
 727                 w1_search(dev);
 728
 729                 list_for_each_safe(ent, n, &dev->slist) {
 730                         sl = list_entry(ent, struct w1_slave, w1_slave_entry);
 731
 732                         if (sl && !test_bit(W1_SLAVE_ACTIVE, (unsigned long *)&sl->flags) && !--sl->ttl) {
 733                                 list_del (&sl->w1_slave_entry);
 734
 735                                 w1_slave_detach (sl);
 736                                 kfree (sl);
 737
 738                                 dev->slave_count--;
 739                         }
 740                         else if (test_bit(W1_SLAVE_ACTIVE, (unsigned long *)&sl->flags))
 741                                 sl->ttl = dev->slave_ttl;
 742                 }
 743                 up(&dev->mutex);
 744         }
 745
 746         atomic_dec(&dev->refcnt);
 747         complete_and_exit(&dev->dev_exited, 0);
 748
 749         return 0;
 750 }
 751
 752 int w1_init(void)
 753 {
 754         int retval;
 755
 756         printk(KERN_INFO "Driver for 1-wire Dallas network protocol.\n");
 757
 758         retval = bus_register(&w1_bus_type);
 759         if (retval) {
 760                 printk(KERN_ERR "Failed to register bus. err=%d.\n", retval);
 761                 goto err_out_exit_init;
 762         }
 763
 764         retval = driver_register(&w1_driver);
 765         if (retval) {
 766                 printk(KERN_ERR
 767                         "Failed to register master driver. err=%d.\n",
 768                         retval);
 769                 goto err_out_bus_unregister;
 770         }
 771
 772         control_thread = kernel_thread(&w1_control, NULL, 0);
 773         if (control_thread < 0) {
 774                 printk(KERN_ERR "Failed to create control thread. err=%d\n",
 775                         control_thread);
 776                 retval = control_thread;
 777                 goto err_out_driver_unregister;
 778         }
 779
 780         return 0;
 781
 782 err_out_driver_unregister:
 783         driver_unregister(&w1_driver);
 784
 785 err_out_bus_unregister:
 786         bus_unregister(&w1_bus_type);
 787
 788 err_out_exit_init:
 789         return retval;
 790 }
 791
 792 void w1_fini(void)
 793 {
 794         struct w1_master *dev;
 795         struct list_head *ent, *n;
 796
 797         list_for_each_safe(ent, n, &w1_masters) {
 798                 dev = list_entry(ent, struct w1_master, w1_master_entry);
 799                 __w1_remove_master_device(dev);
 800         }
 801
 802         control_needs_exit = 1;
 803
 804         wait_for_completion(&w1_control_complete);
 805
 806         driver_unregister(&w1_driver);
 807         bus_unregister(&w1_bus_type);
 808 }
 809
 810 module_init(w1_init);
 811 module_exit(w1_fini);
 812
 813 EXPORT_SYMBOL(w1_create_master_attributes);
 814 EXPORT_SYMBOL(w1_destroy_master_attributes);