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 #include <linux/kthread.h> 34 35 #include <asm/atomic.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 static int w1_control_timeout = 1; 50 int w1_max_slave_count = 10; 51 int w1_max_slave_ttl = 10; 52 53 module_param_named(timeout, w1_timeout, int, 0); 54 module_param_named(control_timeout, w1_control_timeout, int, 0); 55 module_param_named(max_slave_count, w1_max_slave_count, int, 0); 56 module_param_named(slave_ttl, w1_max_slave_ttl, int, 0); 57 58 DEFINE_SPINLOCK(w1_mlock); 59 LIST_HEAD(w1_masters); 60 61 static struct task_struct *w1_control_thread; 62 63 static int w1_master_match(struct device *dev, struct device_driver *drv) 64 { 65 return 1; 66 } 67 68 static int w1_master_probe(struct device *dev) 69 { 70 return -ENODEV; 71 } 72 73 static void w1_master_release(struct device *dev) 74 { 75 struct w1_master *md = dev_to_w1_master(dev); 76 77 dev_dbg(dev, "%s: Releasing %s.\n", __func__, md->name); 78 79 dev_fini_netlink(md); 80 memset(md, 0, sizeof(struct w1_master) + sizeof(struct w1_bus_master)); 81 kfree(md); 82 } 83 84 static void w1_slave_release(struct device *dev) 85 { 86 struct w1_slave *sl = dev_to_w1_slave(dev); 87 88 dev_dbg(dev, "%s: Releasing %s.\n", __func__, sl->name); 89 90 while (atomic_read(&sl->refcnt)) { 91 dev_dbg(dev, "Waiting for %s to become free: refcnt=%d.\n", 92 sl->name, atomic_read(&sl->refcnt)); 93 if (msleep_interruptible(1000)) 94 flush_signals(current); 95 } 96 97 w1_family_put(sl->family); 98 sl->master->slave_count--; 99 100 complete(&sl->released); 101 } 102 103 static ssize_t w1_slave_read_name(struct device *dev, struct device_attribute *attr, char *buf) 104 { 105 struct w1_slave *sl = dev_to_w1_slave(dev); 106 107 return sprintf(buf, "%s\n", sl->name); 108 } 109 110 static ssize_t w1_slave_read_id(struct kobject *kobj, char *buf, loff_t off, size_t count) 111 { 112 struct w1_slave *sl = kobj_to_w1_slave(kobj); 113 114 atomic_inc(&sl->refcnt); 115 if (off > 8) { 116 count = 0; 117 } else { 118 if (off + count > 8) 119 count = 8 - off; 120 121 memcpy(buf, (u8 *)&sl->reg_num, count); 122 } 123 atomic_dec(&sl->refcnt); 124 125 return count; 126 } 127 128 static struct device_attribute w1_slave_attr_name = 129 __ATTR(name, S_IRUGO, w1_slave_read_name, NULL); 130 131 static struct bin_attribute w1_slave_attr_bin_id = { 132 .attr = { 133 .name = "id", 134 .mode = S_IRUGO, 135 .owner = THIS_MODULE, 136 }, 137 .size = 8, 138 .read = w1_slave_read_id, 139 }; 140 141 /* Default family */ 142 static struct w1_family w1_default_family; 143 144 static int w1_uevent(struct device *dev, char **envp, int num_envp, char *buffer, int buffer_size); 145 146 static struct bus_type w1_bus_type = { 147 .name = "w1", 148 .match = w1_master_match, 149 .uevent = w1_uevent, 150 }; 151 152 struct device_driver w1_master_driver = { 153 .name = "w1_master_driver", 154 .bus = &w1_bus_type, 155 .probe = w1_master_probe, 156 }; 157 158 struct device w1_master_device = { 159 .parent = NULL, 160 .bus = &w1_bus_type, 161 .bus_id = "w1 bus master", 162 .driver = &w1_master_driver, 163 .release = &w1_master_release 164 }; 165 166 static struct device_driver w1_slave_driver = { 167 .name = "w1_slave_driver", 168 .bus = &w1_bus_type, 169 }; 170 171 #if 0 172 struct device w1_slave_device = { 173 .parent = NULL, 174 .bus = &w1_bus_type, 175 .bus_id = "w1 bus slave", 176 .driver = &w1_slave_driver, 177 .release = &w1_slave_release 178 }; 179 #endif /* 0 */ 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 static 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_uevent(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 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_uevent_var(envp, num_envp, &cur_index, buffer, buffer_size, 391 &cur_len, "W1_FID=%02X", sl->reg_num.family); 392 if (err) 393 return err; 394 395 err = add_uevent_var(envp, num_envp, &cur_index, buffer, buffer_size, 396 &cur_len, "W1_SLAVE_ID=%024LX", 397 (unsigned long long)sl->reg_num.id); 398 if (err) 399 return err; 400 401 return 0; 402 }; 403 #else 404 static int w1_uevent(struct device *dev, char **envp, int num_envp, char *buffer, int buffer_size) 405 { 406 return 0; 407 } 408 #endif 409 410 static int __w1_attach_slave_device(struct w1_slave *sl) 411 { 412 int err; 413 414 sl->dev.parent = &sl->master->dev; 415 sl->dev.driver = &w1_slave_driver; 416 sl->dev.bus = &w1_bus_type; 417 sl->dev.release = &w1_slave_release; 418 419 snprintf(&sl->dev.bus_id[0], sizeof(sl->dev.bus_id), 420 "%02x-%012llx", 421 (unsigned int) sl->reg_num.family, 422 (unsigned long long) sl->reg_num.id); 423 snprintf(&sl->name[0], sizeof(sl->name), 424 "%02x-%012llx", 425 (unsigned int) sl->reg_num.family, 426 (unsigned long long) sl->reg_num.id); 427 428 dev_dbg(&sl->dev, "%s: registering %s as %p.\n", __func__, &sl->dev.bus_id[0]); 429 430 err = device_register(&sl->dev); 431 if (err < 0) { 432 dev_err(&sl->dev, 433 "Device registration [%s] failed. err=%d\n", 434 sl->dev.bus_id, err); 435 return err; 436 } 437 438 /* Create "name" entry */ 439 err = device_create_file(&sl->dev, &w1_slave_attr_name); 440 if (err < 0) { 441 dev_err(&sl->dev, 442 "sysfs file creation for [%s] failed. err=%d\n", 443 sl->dev.bus_id, err); 444 goto out_unreg; 445 } 446 447 /* Create "id" entry */ 448 err = sysfs_create_bin_file(&sl->dev.kobj, &w1_slave_attr_bin_id); 449 if (err < 0) { 450 dev_err(&sl->dev, 451 "sysfs file creation for [%s] failed. err=%d\n", 452 sl->dev.bus_id, err); 453 goto out_rem1; 454 } 455 456 /* if the family driver needs to initialize something... */ 457 if (sl->family->fops && sl->family->fops->add_slave && 458 ((err = sl->family->fops->add_slave(sl)) < 0)) { 459 dev_err(&sl->dev, 460 "sysfs file creation for [%s] failed. err=%d\n", 461 sl->dev.bus_id, err); 462 goto out_rem2; 463 } 464 465 list_add_tail(&sl->w1_slave_entry, &sl->master->slist); 466 467 return 0; 468 469 out_rem2: 470 sysfs_remove_bin_file(&sl->dev.kobj, &w1_slave_attr_bin_id); 471 out_rem1: 472 device_remove_file(&sl->dev, &w1_slave_attr_name); 473 out_unreg: 474 device_unregister(&sl->dev); 475 return err; 476 } 477 478 static int w1_attach_slave_device(struct w1_master *dev, struct w1_reg_num *rn) 479 { 480 struct w1_slave *sl; 481 struct w1_family *f; 482 int err; 483 struct w1_netlink_msg msg; 484 485 sl = kmalloc(sizeof(struct w1_slave), GFP_KERNEL); 486 if (!sl) { 487 dev_err(&dev->dev, 488 "%s: failed to allocate new slave device.\n", 489 __func__); 490 return -ENOMEM; 491 } 492 493 memset(sl, 0, sizeof(*sl)); 494 495 sl->owner = THIS_MODULE; 496 sl->master = dev; 497 set_bit(W1_SLAVE_ACTIVE, (long *)&sl->flags); 498 499 memcpy(&sl->reg_num, rn, sizeof(sl->reg_num)); 500 atomic_set(&sl->refcnt, 0); 501 init_completion(&sl->released); 502 503 spin_lock(&w1_flock); 504 f = w1_family_registered(rn->family); 505 if (!f) { 506 f= &w1_default_family; 507 dev_info(&dev->dev, "Family %x for %02x.%012llx.%02x is not registered.\n", 508 rn->family, rn->family, 509 (unsigned long long)rn->id, rn->crc); 510 } 511 __w1_family_get(f); 512 spin_unlock(&w1_flock); 513 514 sl->family = f; 515 516 517 err = __w1_attach_slave_device(sl); 518 if (err < 0) { 519 dev_err(&dev->dev, "%s: Attaching %s failed.\n", __func__, 520 sl->name); 521 w1_family_put(sl->family); 522 kfree(sl); 523 return err; 524 } 525 526 sl->ttl = dev->slave_ttl; 527 dev->slave_count++; 528 529 memcpy(&msg.id.id, rn, sizeof(msg.id.id)); 530 msg.type = W1_SLAVE_ADD; 531 w1_netlink_send(dev, &msg); 532 533 return 0; 534 } 535 536 static void w1_slave_detach(struct w1_slave *sl) 537 { 538 struct w1_netlink_msg msg; 539 540 dev_dbg(&sl->dev, "%s: detaching %s [%p].\n", __func__, sl->name, sl); 541 542 list_del(&sl->w1_slave_entry); 543 544 if (sl->family->fops && sl->family->fops->remove_slave) 545 sl->family->fops->remove_slave(sl); 546 547 memcpy(&msg.id.id, &sl->reg_num, sizeof(msg.id.id)); 548 msg.type = W1_SLAVE_REMOVE; 549 w1_netlink_send(sl->master, &msg); 550 551 sysfs_remove_bin_file(&sl->dev.kobj, &w1_slave_attr_bin_id); 552 device_remove_file(&sl->dev, &w1_slave_attr_name); 553 device_unregister(&sl->dev); 554 555 wait_for_completion(&sl->released); 556 kfree(sl); 557 } 558 559 static struct w1_master *w1_search_master(void *data) 560 { 561 struct w1_master *dev; 562 int found = 0; 563 564 spin_lock_bh(&w1_mlock); 565 list_for_each_entry(dev, &w1_masters, w1_master_entry) { 566 if (dev->bus_master->data == data) { 567 found = 1; 568 atomic_inc(&dev->refcnt); 569 break; 570 } 571 } 572 spin_unlock_bh(&w1_mlock); 573 574 return (found)?dev:NULL; 575 } 576 577 void w1_reconnect_slaves(struct w1_family *f) 578 { 579 struct w1_master *dev; 580 581 spin_lock_bh(&w1_mlock); 582 list_for_each_entry(dev, &w1_masters, w1_master_entry) { 583 dev_dbg(&dev->dev, "Reconnecting slaves in %s into new family %02x.\n", 584 dev->name, f->fid); 585 set_bit(W1_MASTER_NEED_RECONNECT, &dev->flags); 586 } 587 spin_unlock_bh(&w1_mlock); 588 } 589 590 static void w1_slave_found(void *data, u64 rn) 591 { 592 int slave_count; 593 struct w1_slave *sl; 594 struct list_head *ent; 595 struct w1_reg_num *tmp; 596 int family_found = 0; 597 struct w1_master *dev; 598 u64 rn_le = cpu_to_le64(rn); 599 600 dev = w1_search_master(data); 601 if (!dev) { 602 printk(KERN_ERR "Failed to find w1 master device for data %p, " 603 "it is impossible.\n", data); 604 return; 605 } 606 607 tmp = (struct w1_reg_num *) &rn; 608 609 slave_count = 0; 610 list_for_each(ent, &dev->slist) { 611 612 sl = list_entry(ent, struct w1_slave, w1_slave_entry); 613 614 if (sl->reg_num.family == tmp->family && 615 sl->reg_num.id == tmp->id && 616 sl->reg_num.crc == tmp->crc) { 617 set_bit(W1_SLAVE_ACTIVE, (long *)&sl->flags); 618 break; 619 } else if (sl->reg_num.family == tmp->family) { 620 family_found = 1; 621 break; 622 } 623 624 slave_count++; 625 } 626 627 if (slave_count == dev->slave_count && 628 rn && ((rn >> 56) & 0xff) == w1_calc_crc8((u8 *)&rn_le, 7)) { 629 w1_attach_slave_device(dev, tmp); 630 } 631 632 atomic_dec(&dev->refcnt); 633 } 634 635 /** 636 * Performs a ROM Search & registers any devices found. 637 * The 1-wire search is a simple binary tree search. 638 * For each bit of the address, we read two bits and write one bit. 639 * The bit written will put to sleep all devies that don't match that bit. 640 * When the two reads differ, the direction choice is obvious. 641 * When both bits are 0, we must choose a path to take. 642 * When we can scan all 64 bits without having to choose a path, we are done. 643 * 644 * See "Application note 187 1-wire search algorithm" at www.maxim-ic.com 645 * 646 * @dev The master device to search 647 * @cb Function to call when a device is found 648 */ 649 void w1_search(struct w1_master *dev, w1_slave_found_callback cb) 650 { 651 u64 last_rn, rn, tmp64; 652 int i, slave_count = 0; 653 int last_zero, last_device; 654 int search_bit, desc_bit; 655 u8 triplet_ret = 0; 656 657 search_bit = 0; 658 rn = last_rn = 0; 659 last_device = 0; 660 last_zero = -1; 661 662 desc_bit = 64; 663 664 while ( !last_device && (slave_count++ < dev->max_slave_count) ) { 665 last_rn = rn; 666 rn = 0; 667 668 /* 669 * Reset bus and all 1-wire device state machines 670 * so they can respond to our requests. 671 * 672 * Return 0 - device(s) present, 1 - no devices present. 673 */ 674 if (w1_reset_bus(dev)) { 675 dev_dbg(&dev->dev, "No devices present on the wire.\n"); 676 break; 677 } 678 679 /* Start the search */ 680 w1_write_8(dev, W1_SEARCH); 681 for (i = 0; i < 64; ++i) { 682 /* Determine the direction/search bit */ 683 if (i == desc_bit) 684 search_bit = 1; /* took the 0 path last time, so take the 1 path */ 685 else if (i > desc_bit) 686 search_bit = 0; /* take the 0 path on the next branch */ 687 else 688 search_bit = ((last_rn >> i) & 0x1); 689 690 /** Read two bits and write one bit */ 691 triplet_ret = w1_triplet(dev, search_bit); 692 693 /* quit if no device responded */ 694 if ( (triplet_ret & 0x03) == 0x03 ) 695 break; 696 697 /* If both directions were valid, and we took the 0 path... */ 698 if (triplet_ret == 0) 699 last_zero = i; 700 701 /* extract the direction taken & update the device number */ 702 tmp64 = (triplet_ret >> 2); 703 rn |= (tmp64 << i); 704 } 705 706 if ( (triplet_ret & 0x03) != 0x03 ) { 707 if ( (desc_bit == last_zero) || (last_zero < 0)) 708 last_device = 1; 709 desc_bit = last_zero; 710 cb(dev->bus_master->data, rn); 711 } 712 } 713 } 714 715 static int w1_control(void *data) 716 { 717 struct w1_slave *sl, *sln; 718 struct w1_master *dev, *n; 719 int have_to_wait = 0; 720 721 while (!kthread_should_stop() || have_to_wait) { 722 have_to_wait = 0; 723 724 try_to_freeze(); 725 msleep_interruptible(w1_control_timeout * 1000); 726 727 list_for_each_entry_safe(dev, n, &w1_masters, w1_master_entry) { 728 if (!kthread_should_stop() && !dev->flags) 729 continue; 730 /* 731 * Little race: we can create thread but not set the flag. 732 * Get a chance for external process to set flag up. 733 */ 734 if (!dev->initialized) { 735 have_to_wait = 1; 736 continue; 737 } 738 739 if (kthread_should_stop() || test_bit(W1_MASTER_NEED_EXIT, &dev->flags)) { 740 set_bit(W1_MASTER_NEED_EXIT, &dev->flags); 741 742 spin_lock(&w1_mlock); 743 list_del(&dev->w1_master_entry); 744 spin_unlock(&w1_mlock); 745 746 down(&dev->mutex); 747 list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) { 748 w1_slave_detach(sl); 749 } 750 w1_destroy_master_attributes(dev); 751 up(&dev->mutex); 752 atomic_dec(&dev->refcnt); 753 continue; 754 } 755 756 if (test_bit(W1_MASTER_NEED_RECONNECT, &dev->flags)) { 757 dev_dbg(&dev->dev, "Reconnecting slaves in device %s.\n", dev->name); 758 down(&dev->mutex); 759 list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) { 760 if (sl->family->fid == W1_FAMILY_DEFAULT) { 761 struct w1_reg_num rn; 762 763 memcpy(&rn, &sl->reg_num, sizeof(rn)); 764 w1_slave_detach(sl); 765 766 w1_attach_slave_device(dev, &rn); 767 } 768 } 769 dev_dbg(&dev->dev, "Reconnecting slaves in device %s has been finished.\n", dev->name); 770 clear_bit(W1_MASTER_NEED_RECONNECT, &dev->flags); 771 up(&dev->mutex); 772 } 773 } 774 } 775 776 return 0; 777 } 778 779 int w1_process(void *data) 780 { 781 struct w1_master *dev = (struct w1_master *) data; 782 struct w1_slave *sl, *sln; 783 784 while (!kthread_should_stop() && !test_bit(W1_MASTER_NEED_EXIT, &dev->flags)) { 785 try_to_freeze(); 786 msleep_interruptible(w1_timeout * 1000); 787 788 if (kthread_should_stop() || test_bit(W1_MASTER_NEED_EXIT, &dev->flags)) 789 break; 790 791 if (!dev->initialized) 792 continue; 793 794 if (dev->search_count == 0) 795 continue; 796 797 if (down_interruptible(&dev->mutex)) 798 continue; 799 800 list_for_each_entry(sl, &dev->slist, w1_slave_entry) 801 clear_bit(W1_SLAVE_ACTIVE, (long *)&sl->flags); 802 803 w1_search_devices(dev, w1_slave_found); 804 805 list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) { 806 if (!test_bit(W1_SLAVE_ACTIVE, (unsigned long *)&sl->flags) && !--sl->ttl) { 807 w1_slave_detach(sl); 808 809 dev->slave_count--; 810 } else if (test_bit(W1_SLAVE_ACTIVE, (unsigned long *)&sl->flags)) 811 sl->ttl = dev->slave_ttl; 812 } 813 814 if (dev->search_count > 0) 815 dev->search_count--; 816 817 up(&dev->mutex); 818 } 819 820 atomic_dec(&dev->refcnt); 821 822 return 0; 823 } 824 825 static int w1_init(void) 826 { 827 int retval; 828 829 printk(KERN_INFO "Driver for 1-wire Dallas network protocol.\n"); 830 831 retval = bus_register(&w1_bus_type); 832 if (retval) { 833 printk(KERN_ERR "Failed to register bus. err=%d.\n", retval); 834 goto err_out_exit_init; 835 } 836 837 retval = driver_register(&w1_master_driver); 838 if (retval) { 839 printk(KERN_ERR 840 "Failed to register master driver. err=%d.\n", 841 retval); 842 goto err_out_bus_unregister; 843 } 844 845 retval = driver_register(&w1_slave_driver); 846 if (retval) { 847 printk(KERN_ERR 848 "Failed to register master driver. err=%d.\n", 849 retval); 850 goto err_out_master_unregister; 851 } 852 853 w1_control_thread = kthread_run(w1_control, NULL, "w1_control"); 854 if (IS_ERR(w1_control_thread)) { 855 retval = PTR_ERR(w1_control_thread); 856 printk(KERN_ERR "Failed to create control thread. err=%d\n", 857 retval); 858 goto err_out_slave_unregister; 859 } 860 861 return 0; 862 863 err_out_slave_unregister: 864 driver_unregister(&w1_slave_driver); 865 866 err_out_master_unregister: 867 driver_unregister(&w1_master_driver); 868 869 err_out_bus_unregister: 870 bus_unregister(&w1_bus_type); 871 872 err_out_exit_init: 873 return retval; 874 } 875 876 static void w1_fini(void) 877 { 878 struct w1_master *dev; 879 880 list_for_each_entry(dev, &w1_masters, w1_master_entry) 881 __w1_remove_master_device(dev); 882 883 kthread_stop(w1_control_thread); 884 885 driver_unregister(&w1_slave_driver); 886 driver_unregister(&w1_master_driver); 887 bus_unregister(&w1_bus_type); 888 } 889 890 module_init(w1_init); 891 module_exit(w1_fini); 892