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 static int w1_control_timeout = 1; 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(control_timeout, w1_control_timeout, int, 0); 54 module_param_named(max_slave_count, w1_max_slave_count, int, 0); 55 module_param_named(slave_ttl, w1_max_slave_ttl, int, 0); 56 57 DEFINE_SPINLOCK(w1_mlock); 58 LIST_HEAD(w1_masters); 59 60 static pid_t control_thread; 61 static int control_needs_exit; 62 static DECLARE_COMPLETION(w1_control_complete); 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 void w1_master_release(struct device *dev) 75 { 76 struct w1_master *md = dev_to_w1_master(dev); 77 78 dev_dbg(dev, "%s: Releasing %s.\n", __func__, md->name); 79 80 if (md->nls && md->nls->sk_socket) 81 sock_release(md->nls->sk_socket); 82 memset(md, 0, sizeof(struct w1_master) + sizeof(struct w1_bus_master)); 83 kfree(md); 84 } 85 86 static void w1_slave_release(struct device *dev) 87 { 88 struct w1_slave *sl = dev_to_w1_slave(dev); 89 90 dev_dbg(dev, "%s: Releasing %s.\n", __func__, sl->name); 91 92 while (atomic_read(&sl->refcnt)) { 93 dev_dbg(dev, "Waiting for %s to become free: refcnt=%d.\n", 94 sl->name, atomic_read(&sl->refcnt)); 95 if (msleep_interruptible(1000)) 96 flush_signals(current); 97 } 98 99 w1_family_put(sl->family); 100 sl->master->slave_count--; 101 102 complete(&sl->released); 103 } 104 105 static ssize_t w1_slave_read_name(struct device *dev, struct device_attribute *attr, char *buf) 106 { 107 struct w1_slave *sl = dev_to_w1_slave(dev); 108 109 return sprintf(buf, "%s\n", sl->name); 110 } 111 112 static ssize_t w1_slave_read_id(struct kobject *kobj, char *buf, loff_t off, size_t count) 113 { 114 struct w1_slave *sl = kobj_to_w1_slave(kobj); 115 116 atomic_inc(&sl->refcnt); 117 if (off > 8) { 118 count = 0; 119 } else { 120 if (off + count > 8) 121 count = 8 - off; 122 123 memcpy(buf, (u8 *)&sl->reg_num, count); 124 } 125 atomic_dec(&sl->refcnt); 126 127 return count; 128 } 129 130 static struct device_attribute w1_slave_attr_name = 131 __ATTR(name, S_IRUGO, w1_slave_read_name, NULL); 132 133 static struct bin_attribute w1_slave_attr_bin_id = { 134 .attr = { 135 .name = "id", 136 .mode = S_IRUGO, 137 .owner = THIS_MODULE, 138 }, 139 .size = 8, 140 .read = w1_slave_read_id, 141 }; 142 143 /* Default family */ 144 static struct w1_family w1_default_family; 145 146 static int w1_hotplug(struct device *dev, char **envp, int num_envp, char *buffer, int buffer_size); 147 148 static struct bus_type w1_bus_type = { 149 .name = "w1", 150 .match = w1_master_match, 151 .hotplug = w1_hotplug, 152 }; 153 154 struct device_driver w1_master_driver = { 155 .name = "w1_master_driver", 156 .bus = &w1_bus_type, 157 .probe = w1_master_probe, 158 }; 159 160 struct device w1_master_device = { 161 .parent = NULL, 162 .bus = &w1_bus_type, 163 .bus_id = "w1 bus master", 164 .driver = &w1_master_driver, 165 .release = &w1_master_release 166 }; 167 168 struct device_driver w1_slave_driver = { 169 .name = "w1_slave_driver", 170 .bus = &w1_bus_type, 171 }; 172 173 struct device w1_slave_device = { 174 .parent = NULL, 175 .bus = &w1_bus_type, 176 .bus_id = "w1 bus slave", 177 .driver = &w1_slave_driver, 178 .release = &w1_slave_release 179 }; 180 181 static ssize_t w1_master_attribute_show_name(struct device *dev, struct device_attribute *attr, char *buf) 182 { 183 struct w1_master *md = dev_to_w1_master(dev); 184 ssize_t count; 185 186 if (down_interruptible (&md->mutex)) 187 return -EBUSY; 188 189 count = sprintf(buf, "%s\n", md->name); 190 191 up(&md->mutex); 192 193 return count; 194 } 195 196 static ssize_t w1_master_attribute_store_search(struct device * dev, 197 struct device_attribute *attr, 198 const char * buf, size_t count) 199 { 200 struct w1_master *md = dev_to_w1_master(dev); 201 202 if (down_interruptible (&md->mutex)) 203 return -EBUSY; 204 205 md->search_count = simple_strtol(buf, NULL, 0); 206 207 up(&md->mutex); 208 209 return count; 210 } 211 212 static ssize_t w1_master_attribute_show_search(struct device *dev, 213 struct device_attribute *attr, 214 char *buf) 215 { 216 struct w1_master *md = dev_to_w1_master(dev); 217 ssize_t count; 218 219 if (down_interruptible (&md->mutex)) 220 return -EBUSY; 221 222 count = sprintf(buf, "%d\n", md->search_count); 223 224 up(&md->mutex); 225 226 return count; 227 } 228 229 static ssize_t w1_master_attribute_show_pointer(struct device *dev, struct device_attribute *attr, char *buf) 230 { 231 struct w1_master *md = dev_to_w1_master(dev); 232 ssize_t count; 233 234 if (down_interruptible(&md->mutex)) 235 return -EBUSY; 236 237 count = sprintf(buf, "0x%p\n", md->bus_master); 238 239 up(&md->mutex); 240 return count; 241 } 242 243 static ssize_t w1_master_attribute_show_timeout(struct device *dev, struct device_attribute *attr, char *buf) 244 { 245 ssize_t count; 246 count = sprintf(buf, "%d\n", w1_timeout); 247 return count; 248 } 249 250 static ssize_t w1_master_attribute_show_max_slave_count(struct device *dev, struct device_attribute *attr, char *buf) 251 { 252 struct w1_master *md = dev_to_w1_master(dev); 253 ssize_t count; 254 255 if (down_interruptible(&md->mutex)) 256 return -EBUSY; 257 258 count = sprintf(buf, "%d\n", md->max_slave_count); 259 260 up(&md->mutex); 261 return count; 262 } 263 264 static ssize_t w1_master_attribute_show_attempts(struct device *dev, struct device_attribute *attr, char *buf) 265 { 266 struct w1_master *md = dev_to_w1_master(dev); 267 ssize_t count; 268 269 if (down_interruptible(&md->mutex)) 270 return -EBUSY; 271 272 count = sprintf(buf, "%lu\n", md->attempts); 273 274 up(&md->mutex); 275 return count; 276 } 277 278 static ssize_t w1_master_attribute_show_slave_count(struct device *dev, struct device_attribute *attr, char *buf) 279 { 280 struct w1_master *md = dev_to_w1_master(dev); 281 ssize_t count; 282 283 if (down_interruptible(&md->mutex)) 284 return -EBUSY; 285 286 count = sprintf(buf, "%d\n", md->slave_count); 287 288 up(&md->mutex); 289 return count; 290 } 291 292 static ssize_t w1_master_attribute_show_slaves(struct device *dev, struct device_attribute *attr, char *buf) 293 { 294 struct w1_master *md = dev_to_w1_master(dev); 295 int c = PAGE_SIZE; 296 297 if (down_interruptible(&md->mutex)) 298 return -EBUSY; 299 300 if (md->slave_count == 0) 301 c -= snprintf(buf + PAGE_SIZE - c, c, "not found.\n"); 302 else { 303 struct list_head *ent, *n; 304 struct w1_slave *sl; 305 306 list_for_each_safe(ent, n, &md->slist) { 307 sl = list_entry(ent, struct w1_slave, w1_slave_entry); 308 309 c -= snprintf(buf + PAGE_SIZE - c, c, "%s\n", sl->name); 310 } 311 } 312 313 up(&md->mutex); 314 315 return PAGE_SIZE - c; 316 } 317 318 #define W1_MASTER_ATTR_RO(_name, _mode) \ 319 struct device_attribute w1_master_attribute_##_name = \ 320 __ATTR(w1_master_##_name, _mode, \ 321 w1_master_attribute_show_##_name, NULL) 322 323 #define W1_MASTER_ATTR_RW(_name, _mode) \ 324 struct device_attribute w1_master_attribute_##_name = \ 325 __ATTR(w1_master_##_name, _mode, \ 326 w1_master_attribute_show_##_name, \ 327 w1_master_attribute_store_##_name) 328 329 static W1_MASTER_ATTR_RO(name, S_IRUGO); 330 static W1_MASTER_ATTR_RO(slaves, S_IRUGO); 331 static W1_MASTER_ATTR_RO(slave_count, S_IRUGO); 332 static W1_MASTER_ATTR_RO(max_slave_count, S_IRUGO); 333 static W1_MASTER_ATTR_RO(attempts, S_IRUGO); 334 static W1_MASTER_ATTR_RO(timeout, S_IRUGO); 335 static W1_MASTER_ATTR_RO(pointer, S_IRUGO); 336 static W1_MASTER_ATTR_RW(search, S_IRUGO | S_IWUGO); 337 338 static struct attribute *w1_master_default_attrs[] = { 339 &w1_master_attribute_name.attr, 340 &w1_master_attribute_slaves.attr, 341 &w1_master_attribute_slave_count.attr, 342 &w1_master_attribute_max_slave_count.attr, 343 &w1_master_attribute_attempts.attr, 344 &w1_master_attribute_timeout.attr, 345 &w1_master_attribute_pointer.attr, 346 &w1_master_attribute_search.attr, 347 NULL 348 }; 349 350 static struct attribute_group w1_master_defattr_group = { 351 .attrs = w1_master_default_attrs, 352 }; 353 354 int w1_create_master_attributes(struct w1_master *master) 355 { 356 return sysfs_create_group(&master->dev.kobj, &w1_master_defattr_group); 357 } 358 359 void w1_destroy_master_attributes(struct w1_master *master) 360 { 361 sysfs_remove_group(&master->dev.kobj, &w1_master_defattr_group); 362 } 363 364 #ifdef CONFIG_HOTPLUG 365 static int w1_hotplug(struct device *dev, char **envp, int num_envp, char *buffer, int buffer_size) 366 { 367 struct w1_master *md = NULL; 368 struct w1_slave *sl = NULL; 369 char *event_owner, *name; 370 int err, cur_index=0, cur_len=0; 371 372 if (dev->driver == &w1_master_driver) { 373 md = container_of(dev, struct w1_master, dev); 374 event_owner = "master"; 375 name = md->name; 376 } else if (dev->driver == &w1_slave_driver) { 377 sl = container_of(dev, struct w1_slave, dev); 378 event_owner = "slave"; 379 name = sl->name; 380 } else { 381 dev_dbg(dev, "Unknown hotplug event.\n"); 382 return -EINVAL; 383 } 384 385 dev_dbg(dev, "Hotplug event for %s %s, bus_id=%s.\n", event_owner, name, dev->bus_id); 386 387 if (dev->driver != &w1_slave_driver || !sl) 388 return 0; 389 390 err = add_hotplug_env_var(envp, num_envp, &cur_index, buffer, buffer_size, &cur_len, "W1_FID=%02X", sl->reg_num.family); 391 if (err) 392 return err; 393 394 err = add_hotplug_env_var(envp, num_envp, &cur_index, buffer, buffer_size, &cur_len, "W1_SLAVE_ID=%024LX", (u64)sl->reg_num.id); 395 if (err) 396 return err; 397 398 return 0; 399 }; 400 #else 401 static int w1_hotplug(struct device *dev, char **envp, int num_envp, char *buffer, int buffer_size) 402 { 403 return 0; 404 } 405 #endif 406 407 static int __w1_attach_slave_device(struct w1_slave *sl) 408 { 409 int err; 410 411 sl->dev.parent = &sl->master->dev; 412 sl->dev.driver = &w1_slave_driver; 413 sl->dev.bus = &w1_bus_type; 414 sl->dev.release = &w1_slave_release; 415 416 snprintf(&sl->dev.bus_id[0], sizeof(sl->dev.bus_id), 417 "%02x-%012llx", 418 (unsigned int) sl->reg_num.family, 419 (unsigned long long) sl->reg_num.id); 420 snprintf(&sl->name[0], sizeof(sl->name), 421 "%02x-%012llx", 422 (unsigned int) sl->reg_num.family, 423 (unsigned long long) sl->reg_num.id); 424 425 dev_dbg(&sl->dev, "%s: registering %s as %p.\n", __func__, &sl->dev.bus_id[0]); 426 427 err = device_register(&sl->dev); 428 if (err < 0) { 429 dev_err(&sl->dev, 430 "Device registration [%s] failed. err=%d\n", 431 sl->dev.bus_id, err); 432 return err; 433 } 434 435 /* Create "name" entry */ 436 err = device_create_file(&sl->dev, &w1_slave_attr_name); 437 if (err < 0) { 438 dev_err(&sl->dev, 439 "sysfs file creation for [%s] failed. err=%d\n", 440 sl->dev.bus_id, err); 441 goto out_unreg; 442 } 443 444 /* Create "id" entry */ 445 err = sysfs_create_bin_file(&sl->dev.kobj, &w1_slave_attr_bin_id); 446 if (err < 0) { 447 dev_err(&sl->dev, 448 "sysfs file creation for [%s] failed. err=%d\n", 449 sl->dev.bus_id, err); 450 goto out_rem1; 451 } 452 453 /* if the family driver needs to initialize something... */ 454 if (sl->family->fops && sl->family->fops->add_slave && 455 ((err = sl->family->fops->add_slave(sl)) < 0)) { 456 dev_err(&sl->dev, 457 "sysfs file creation for [%s] failed. err=%d\n", 458 sl->dev.bus_id, err); 459 goto out_rem2; 460 } 461 462 list_add_tail(&sl->w1_slave_entry, &sl->master->slist); 463 464 return 0; 465 466 out_rem2: 467 sysfs_remove_bin_file(&sl->dev.kobj, &w1_slave_attr_bin_id); 468 out_rem1: 469 device_remove_file(&sl->dev, &w1_slave_attr_name); 470 out_unreg: 471 device_unregister(&sl->dev); 472 return err; 473 } 474 475 static int w1_attach_slave_device(struct w1_master *dev, struct w1_reg_num *rn) 476 { 477 struct w1_slave *sl; 478 struct w1_family *f; 479 int err; 480 struct w1_netlink_msg msg; 481 482 sl = kmalloc(sizeof(struct w1_slave), GFP_KERNEL); 483 if (!sl) { 484 dev_err(&dev->dev, 485 "%s: failed to allocate new slave device.\n", 486 __func__); 487 return -ENOMEM; 488 } 489 490 memset(sl, 0, sizeof(*sl)); 491 492 sl->owner = THIS_MODULE; 493 sl->master = dev; 494 set_bit(W1_SLAVE_ACTIVE, (long *)&sl->flags); 495 496 memcpy(&sl->reg_num, rn, sizeof(sl->reg_num)); 497 atomic_set(&sl->refcnt, 0); 498 init_completion(&sl->released); 499 500 spin_lock(&w1_flock); 501 f = w1_family_registered(rn->family); 502 if (!f) { 503 f= &w1_default_family; 504 dev_info(&dev->dev, "Family %x for %02x.%012llx.%02x is not registered.\n", 505 rn->family, rn->family, 506 (unsigned long long)rn->id, rn->crc); 507 } 508 __w1_family_get(f); 509 spin_unlock(&w1_flock); 510 511 sl->family = f; 512 513 514 err = __w1_attach_slave_device(sl); 515 if (err < 0) { 516 dev_err(&dev->dev, "%s: Attaching %s failed.\n", __func__, 517 sl->name); 518 w1_family_put(sl->family); 519 kfree(sl); 520 return err; 521 } 522 523 sl->ttl = dev->slave_ttl; 524 dev->slave_count++; 525 526 memcpy(&msg.id.id, rn, sizeof(msg.id.id)); 527 msg.type = W1_SLAVE_ADD; 528 w1_netlink_send(dev, &msg); 529 530 return 0; 531 } 532 533 static void w1_slave_detach(struct w1_slave *sl) 534 { 535 struct w1_netlink_msg msg; 536 537 dev_dbg(&sl->dev, "%s: detaching %s [%p].\n", __func__, sl->name, sl); 538 539 list_del(&sl->w1_slave_entry); 540 541 if (sl->family->fops && sl->family->fops->remove_slave) 542 sl->family->fops->remove_slave(sl); 543 544 memcpy(&msg.id.id, &sl->reg_num, sizeof(msg.id.id)); 545 msg.type = W1_SLAVE_REMOVE; 546 w1_netlink_send(sl->master, &msg); 547 548 sysfs_remove_bin_file(&sl->dev.kobj, &w1_slave_attr_bin_id); 549 device_remove_file(&sl->dev, &w1_slave_attr_name); 550 device_unregister(&sl->dev); 551 552 wait_for_completion(&sl->released); 553 kfree(sl); 554 } 555 556 static struct w1_master *w1_search_master(unsigned long data) 557 { 558 struct w1_master *dev; 559 int found = 0; 560 561 spin_lock_bh(&w1_mlock); 562 list_for_each_entry(dev, &w1_masters, w1_master_entry) { 563 if (dev->bus_master->data == data) { 564 found = 1; 565 atomic_inc(&dev->refcnt); 566 break; 567 } 568 } 569 spin_unlock_bh(&w1_mlock); 570 571 return (found)?dev:NULL; 572 } 573 574 void w1_reconnect_slaves(struct w1_family *f) 575 { 576 struct w1_master *dev; 577 578 spin_lock_bh(&w1_mlock); 579 list_for_each_entry(dev, &w1_masters, w1_master_entry) { 580 dev_dbg(&dev->dev, "Reconnecting slaves in %s into new family %02x.\n", 581 dev->name, f->fid); 582 set_bit(W1_MASTER_NEED_RECONNECT, &dev->flags); 583 } 584 spin_unlock_bh(&w1_mlock); 585 } 586 587 static void w1_slave_found(unsigned long data, u64 rn) 588 { 589 int slave_count; 590 struct w1_slave *sl; 591 struct list_head *ent; 592 struct w1_reg_num *tmp; 593 int family_found = 0; 594 struct w1_master *dev; 595 u64 rn_le = cpu_to_le64(rn); 596 597 dev = w1_search_master(data); 598 if (!dev) { 599 printk(KERN_ERR "Failed to find w1 master device for data %08lx, it is impossible.\n", 600 data); 601 return; 602 } 603 604 tmp = (struct w1_reg_num *) &rn; 605 606 slave_count = 0; 607 list_for_each(ent, &dev->slist) { 608 609 sl = list_entry(ent, struct w1_slave, w1_slave_entry); 610 611 if (sl->reg_num.family == tmp->family && 612 sl->reg_num.id == tmp->id && 613 sl->reg_num.crc == tmp->crc) { 614 set_bit(W1_SLAVE_ACTIVE, (long *)&sl->flags); 615 break; 616 } else if (sl->reg_num.family == tmp->family) { 617 family_found = 1; 618 break; 619 } 620 621 slave_count++; 622 } 623 624 if (slave_count == dev->slave_count && 625 rn && ((rn >> 56) & 0xff) == w1_calc_crc8((u8 *)&rn_le, 7)) { 626 w1_attach_slave_device(dev, tmp); 627 } 628 629 atomic_dec(&dev->refcnt); 630 } 631 632 /** 633 * Performs a ROM Search & registers any devices found. 634 * The 1-wire search is a simple binary tree search. 635 * For each bit of the address, we read two bits and write one bit. 636 * The bit written will put to sleep all devies that don't match that bit. 637 * When the two reads differ, the direction choice is obvious. 638 * When both bits are 0, we must choose a path to take. 639 * When we can scan all 64 bits without having to choose a path, we are done. 640 * 641 * See "Application note 187 1-wire search algorithm" at www.maxim-ic.com 642 * 643 * @dev The master device to search 644 * @cb Function to call when a device is found 645 */ 646 void w1_search(struct w1_master *dev, w1_slave_found_callback cb) 647 { 648 u64 last_rn, rn, tmp64; 649 int i, slave_count = 0; 650 int last_zero, last_device; 651 int search_bit, desc_bit; 652 u8 triplet_ret = 0; 653 654 search_bit = 0; 655 rn = last_rn = 0; 656 last_device = 0; 657 last_zero = -1; 658 659 desc_bit = 64; 660 661 while ( !last_device && (slave_count++ < dev->max_slave_count) ) { 662 last_rn = rn; 663 rn = 0; 664 665 /* 666 * Reset bus and all 1-wire device state machines 667 * so they can respond to our requests. 668 * 669 * Return 0 - device(s) present, 1 - no devices present. 670 */ 671 if (w1_reset_bus(dev)) { 672 dev_dbg(&dev->dev, "No devices present on the wire.\n"); 673 break; 674 } 675 676 /* Start the search */ 677 w1_write_8(dev, W1_SEARCH); 678 for (i = 0; i < 64; ++i) { 679 /* Determine the direction/search bit */ 680 if (i == desc_bit) 681 search_bit = 1; /* took the 0 path last time, so take the 1 path */ 682 else if (i > desc_bit) 683 search_bit = 0; /* take the 0 path on the next branch */ 684 else 685 search_bit = ((last_rn >> i) & 0x1); 686 687 /** Read two bits and write one bit */ 688 triplet_ret = w1_triplet(dev, search_bit); 689 690 /* quit if no device responded */ 691 if ( (triplet_ret & 0x03) == 0x03 ) 692 break; 693 694 /* If both directions were valid, and we took the 0 path... */ 695 if (triplet_ret == 0) 696 last_zero = i; 697 698 /* extract the direction taken & update the device number */ 699 tmp64 = (triplet_ret >> 2); 700 rn |= (tmp64 << i); 701 } 702 703 if ( (triplet_ret & 0x03) != 0x03 ) { 704 if ( (desc_bit == last_zero) || (last_zero < 0)) 705 last_device = 1; 706 desc_bit = last_zero; 707 cb(dev->bus_master->data, rn); 708 } 709 } 710 } 711 712 static int w1_control(void *data) 713 { 714 struct w1_slave *sl, *sln; 715 struct w1_master *dev, *n; 716 int err, have_to_wait = 0; 717 718 daemonize("w1_control"); 719 allow_signal(SIGTERM); 720 721 while (!control_needs_exit || have_to_wait) { 722 have_to_wait = 0; 723 724 try_to_freeze(); 725 msleep_interruptible(w1_control_timeout * 1000); 726 727 if (signal_pending(current)) 728 flush_signals(current); 729 730 list_for_each_entry_safe(dev, n, &w1_masters, w1_master_entry) { 731 if (!control_needs_exit && !dev->flags) 732 continue; 733 /* 734 * Little race: we can create thread but not set the flag. 735 * Get a chance for external process to set flag up. 736 */ 737 if (!dev->initialized) { 738 have_to_wait = 1; 739 continue; 740 } 741 742 if (control_needs_exit) { 743 set_bit(W1_MASTER_NEED_EXIT, &dev->flags); 744 745 err = kill_proc(dev->kpid, SIGTERM, 1); 746 if (err) 747 dev_err(&dev->dev, 748 "Failed to send signal to w1 kernel thread %d.\n", 749 dev->kpid); 750 } 751 752 if (test_bit(W1_MASTER_NEED_EXIT, &dev->flags)) { 753 wait_for_completion(&dev->dev_exited); 754 spin_lock_bh(&w1_mlock); 755 list_del(&dev->w1_master_entry); 756 spin_unlock_bh(&w1_mlock); 757 758 down(&dev->mutex); 759 list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) { 760 w1_slave_detach(sl); 761 } 762 w1_destroy_master_attributes(dev); 763 up(&dev->mutex); 764 atomic_dec(&dev->refcnt); 765 continue; 766 } 767 768 if (test_bit(W1_MASTER_NEED_RECONNECT, &dev->flags)) { 769 dev_dbg(&dev->dev, "Reconnecting slaves in device %s.\n", dev->name); 770 down(&dev->mutex); 771 list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) { 772 if (sl->family->fid == W1_FAMILY_DEFAULT) { 773 struct w1_reg_num rn; 774 775 memcpy(&rn, &sl->reg_num, sizeof(rn)); 776 w1_slave_detach(sl); 777 778 w1_attach_slave_device(dev, &rn); 779 } 780 } 781 dev_dbg(&dev->dev, "Reconnecting slaves in device %s has been finished.\n", dev->name); 782 clear_bit(W1_MASTER_NEED_RECONNECT, &dev->flags); 783 up(&dev->mutex); 784 } 785 } 786 } 787 788 complete_and_exit(&w1_control_complete, 0); 789 } 790 791 int w1_process(void *data) 792 { 793 struct w1_master *dev = (struct w1_master *) data; 794 struct w1_slave *sl, *sln; 795 796 daemonize("%s", dev->name); 797 allow_signal(SIGTERM); 798 799 while (!test_bit(W1_MASTER_NEED_EXIT, &dev->flags)) { 800 try_to_freeze(); 801 msleep_interruptible(w1_timeout * 1000); 802 803 if (signal_pending(current)) 804 flush_signals(current); 805 806 if (test_bit(W1_MASTER_NEED_EXIT, &dev->flags)) 807 break; 808 809 if (!dev->initialized) 810 continue; 811 812 if (dev->search_count == 0) 813 continue; 814 815 if (down_interruptible(&dev->mutex)) 816 continue; 817 818 list_for_each_entry(sl, &dev->slist, w1_slave_entry) 819 clear_bit(W1_SLAVE_ACTIVE, (long *)&sl->flags); 820 821 w1_search_devices(dev, w1_slave_found); 822 823 list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) { 824 if (!test_bit(W1_SLAVE_ACTIVE, (unsigned long *)&sl->flags) && !--sl->ttl) { 825 w1_slave_detach(sl); 826 827 dev->slave_count--; 828 } else if (test_bit(W1_SLAVE_ACTIVE, (unsigned long *)&sl->flags)) 829 sl->ttl = dev->slave_ttl; 830 } 831 832 if (dev->search_count > 0) 833 dev->search_count--; 834 835 up(&dev->mutex); 836 } 837 838 atomic_dec(&dev->refcnt); 839 complete_and_exit(&dev->dev_exited, 0); 840 841 return 0; 842 } 843 844 static int w1_init(void) 845 { 846 int retval; 847 848 printk(KERN_INFO "Driver for 1-wire Dallas network protocol.\n"); 849 850 retval = bus_register(&w1_bus_type); 851 if (retval) { 852 printk(KERN_ERR "Failed to register bus. err=%d.\n", retval); 853 goto err_out_exit_init; 854 } 855 856 retval = driver_register(&w1_master_driver); 857 if (retval) { 858 printk(KERN_ERR 859 "Failed to register master driver. err=%d.\n", 860 retval); 861 goto err_out_bus_unregister; 862 } 863 864 retval = driver_register(&w1_slave_driver); 865 if (retval) { 866 printk(KERN_ERR 867 "Failed to register master driver. err=%d.\n", 868 retval); 869 goto err_out_master_unregister; 870 } 871 872 control_thread = kernel_thread(&w1_control, NULL, 0); 873 if (control_thread < 0) { 874 printk(KERN_ERR "Failed to create control thread. err=%d\n", 875 control_thread); 876 retval = control_thread; 877 goto err_out_slave_unregister; 878 } 879 880 return 0; 881 882 err_out_slave_unregister: 883 driver_unregister(&w1_slave_driver); 884 885 err_out_master_unregister: 886 driver_unregister(&w1_master_driver); 887 888 err_out_bus_unregister: 889 bus_unregister(&w1_bus_type); 890 891 err_out_exit_init: 892 return retval; 893 } 894 895 static void w1_fini(void) 896 { 897 struct w1_master *dev; 898 899 list_for_each_entry(dev, &w1_masters, w1_master_entry) 900 __w1_remove_master_device(dev); 901 902 control_needs_exit = 1; 903 wait_for_completion(&w1_control_complete); 904 905 driver_unregister(&w1_slave_driver); 906 driver_unregister(&w1_master_driver); 907 bus_unregister(&w1_bus_type); 908 } 909 910 module_init(w1_init); 911 module_exit(w1_fini); 912