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#include <linux/freezer.h> 35 36#include <asm/atomic.h> 37 38#include "w1.h" 39#include "w1_log.h" 40#include "w1_int.h" 41#include "w1_family.h" 42#include "w1_netlink.h" 43 44MODULE_LICENSE("GPL"); 45MODULE_AUTHOR("Evgeniy Polyakov <johnpol@2ka.mipt.ru>"); 46MODULE_DESCRIPTION("Driver for 1-wire Dallas network protocol."); 47 48static int w1_timeout = 10; 49int w1_max_slave_count = 10; 50int w1_max_slave_ttl = 10; 51 52module_param_named(timeout, w1_timeout, int, 0); 53module_param_named(max_slave_count, w1_max_slave_count, int, 0); 54module_param_named(slave_ttl, w1_max_slave_ttl, int, 0); 55 56DEFINE_MUTEX(w1_mlock); 57LIST_HEAD(w1_masters); 58 59static int w1_attach_slave_device(struct w1_master *dev, struct w1_reg_num *rn); 60 61static int w1_master_match(struct device *dev, struct device_driver *drv) 62{ 63 return 1; 64} 65 66static int w1_master_probe(struct device *dev) 67{ 68 return -ENODEV; 69} 70 71static void w1_master_release(struct device *dev) 72{ 73 struct w1_master *md = dev_to_w1_master(dev); 74 75 dev_dbg(dev, "%s: Releasing %s.\n", __func__, md->name); 76 memset(md, 0, sizeof(struct w1_master) + sizeof(struct w1_bus_master)); 77 kfree(md); 78} 79 80static void w1_slave_release(struct device *dev) 81{ 82 struct w1_slave *sl = dev_to_w1_slave(dev); 83 84 dev_dbg(dev, "%s: Releasing %s.\n", __func__, sl->name); 85 86 while (atomic_read(&sl->refcnt)) { 87 dev_dbg(dev, "Waiting for %s to become free: refcnt=%d.\n", 88 sl->name, atomic_read(&sl->refcnt)); 89 if (msleep_interruptible(1000)) 90 flush_signals(current); 91 } 92 93 w1_family_put(sl->family); 94 sl->master->slave_count--; 95 96 complete(&sl->released); 97} 98 99static ssize_t w1_slave_read_name(struct device *dev, struct device_attribute *attr, char *buf) 100{ 101 struct w1_slave *sl = dev_to_w1_slave(dev); 102 103 return sprintf(buf, "%s\n", sl->name); 104} 105 106static ssize_t w1_slave_read_id(struct device *dev, 107 struct device_attribute *attr, char *buf) 108{ 109 struct w1_slave *sl = dev_to_w1_slave(dev); 110 ssize_t count = sizeof(sl->reg_num); 111 112 memcpy(buf, (u8 *)&sl->reg_num, count); 113 return count; 114} 115 116static struct device_attribute w1_slave_attr_name = 117 __ATTR(name, S_IRUGO, w1_slave_read_name, NULL); 118static struct device_attribute w1_slave_attr_id = 119 __ATTR(id, S_IRUGO, w1_slave_read_id, NULL); 120 121/* Default family */ 122 123static ssize_t w1_default_write(struct file *filp, struct kobject *kobj, 124 struct bin_attribute *bin_attr, 125 char *buf, loff_t off, size_t count) 126{ 127 struct w1_slave *sl = kobj_to_w1_slave(kobj); 128 129 mutex_lock(&sl->master->mutex); 130 if (w1_reset_select_slave(sl)) { 131 count = 0; 132 goto out_up; 133 } 134 135 w1_write_block(sl->master, buf, count); 136 137out_up: 138 mutex_unlock(&sl->master->mutex); 139 return count; 140} 141 142static ssize_t w1_default_read(struct file *filp, struct kobject *kobj, 143 struct bin_attribute *bin_attr, 144 char *buf, loff_t off, size_t count) 145{ 146 struct w1_slave *sl = kobj_to_w1_slave(kobj); 147 148 mutex_lock(&sl->master->mutex); 149 w1_read_block(sl->master, buf, count); 150 mutex_unlock(&sl->master->mutex); 151 return count; 152} 153 154static struct bin_attribute w1_default_attr = { 155 .attr = { 156 .name = "rw", 157 .mode = S_IRUGO | S_IWUSR, 158 }, 159 .size = PAGE_SIZE, 160 .read = w1_default_read, 161 .write = w1_default_write, 162}; 163 164static int w1_default_add_slave(struct w1_slave *sl) 165{ 166 return sysfs_create_bin_file(&sl->dev.kobj, &w1_default_attr); 167} 168 169static void w1_default_remove_slave(struct w1_slave *sl) 170{ 171 sysfs_remove_bin_file(&sl->dev.kobj, &w1_default_attr); 172} 173 174static struct w1_family_ops w1_default_fops = { 175 .add_slave = w1_default_add_slave, 176 .remove_slave = w1_default_remove_slave, 177}; 178 179static struct w1_family w1_default_family = { 180 .fops = &w1_default_fops, 181}; 182 183static int w1_uevent(struct device *dev, struct kobj_uevent_env *env); 184 185static struct bus_type w1_bus_type = { 186 .name = "w1", 187 .match = w1_master_match, 188 .uevent = w1_uevent, 189}; 190 191struct device_driver w1_master_driver = { 192 .name = "w1_master_driver", 193 .bus = &w1_bus_type, 194 .probe = w1_master_probe, 195}; 196 197struct device w1_master_device = { 198 .parent = NULL, 199 .bus = &w1_bus_type, 200 .init_name = "w1 bus master", 201 .driver = &w1_master_driver, 202 .release = &w1_master_release 203}; 204 205static struct device_driver w1_slave_driver = { 206 .name = "w1_slave_driver", 207 .bus = &w1_bus_type, 208}; 209 210 211static ssize_t w1_master_attribute_show_name(struct device *dev, struct device_attribute *attr, char *buf) 212{ 213 struct w1_master *md = dev_to_w1_master(dev); 214 ssize_t count; 215 216 mutex_lock(&md->mutex); 217 count = sprintf(buf, "%s\n", md->name); 218 mutex_unlock(&md->mutex); 219 220 return count; 221} 222 223static ssize_t w1_master_attribute_store_search(struct device * dev, 224 struct device_attribute *attr, 225 const char * buf, size_t count) 226{ 227 long tmp; 228 struct w1_master *md = dev_to_w1_master(dev); 229 230 if (strict_strtol(buf, 0, &tmp) == -EINVAL) 231 return -EINVAL; 232 233 mutex_lock(&md->mutex); 234 md->search_count = tmp; 235 mutex_unlock(&md->mutex); 236 wake_up_process(md->thread); 237 238 return count; 239} 240 241static ssize_t w1_master_attribute_show_search(struct device *dev, 242 struct device_attribute *attr, 243 char *buf) 244{ 245 struct w1_master *md = dev_to_w1_master(dev); 246 ssize_t count; 247 248 mutex_lock(&md->mutex); 249 count = sprintf(buf, "%d\n", md->search_count); 250 mutex_unlock(&md->mutex); 251 252 return count; 253} 254 255static ssize_t w1_master_attribute_store_pullup(struct device *dev, 256 struct device_attribute *attr, 257 const char *buf, size_t count) 258{ 259 long tmp; 260 struct w1_master *md = dev_to_w1_master(dev); 261 262 if (strict_strtol(buf, 0, &tmp) == -EINVAL) 263 return -EINVAL; 264 265 mutex_lock(&md->mutex); 266 md->enable_pullup = tmp; 267 mutex_unlock(&md->mutex); 268 wake_up_process(md->thread); 269 270 return count; 271} 272 273static ssize_t w1_master_attribute_show_pullup(struct device *dev, 274 struct device_attribute *attr, 275 char *buf) 276{ 277 struct w1_master *md = dev_to_w1_master(dev); 278 ssize_t count; 279 280 mutex_lock(&md->mutex); 281 count = sprintf(buf, "%d\n", md->enable_pullup); 282 mutex_unlock(&md->mutex); 283 284 return count; 285} 286 287static ssize_t w1_master_attribute_show_pointer(struct device *dev, struct device_attribute *attr, char *buf) 288{ 289 struct w1_master *md = dev_to_w1_master(dev); 290 ssize_t count; 291 292 mutex_lock(&md->mutex); 293 count = sprintf(buf, "0x%p\n", md->bus_master); 294 mutex_unlock(&md->mutex); 295 return count; 296} 297 298static ssize_t w1_master_attribute_show_timeout(struct device *dev, struct device_attribute *attr, char *buf) 299{ 300 ssize_t count; 301 count = sprintf(buf, "%d\n", w1_timeout); 302 return count; 303} 304 305static ssize_t w1_master_attribute_show_max_slave_count(struct device *dev, struct device_attribute *attr, char *buf) 306{ 307 struct w1_master *md = dev_to_w1_master(dev); 308 ssize_t count; 309 310 mutex_lock(&md->mutex); 311 count = sprintf(buf, "%d\n", md->max_slave_count); 312 mutex_unlock(&md->mutex); 313 return count; 314} 315 316static ssize_t w1_master_attribute_show_attempts(struct device *dev, struct device_attribute *attr, char *buf) 317{ 318 struct w1_master *md = dev_to_w1_master(dev); 319 ssize_t count; 320 321 mutex_lock(&md->mutex); 322 count = sprintf(buf, "%lu\n", md->attempts); 323 mutex_unlock(&md->mutex); 324 return count; 325} 326 327static ssize_t w1_master_attribute_show_slave_count(struct device *dev, struct device_attribute *attr, char *buf) 328{ 329 struct w1_master *md = dev_to_w1_master(dev); 330 ssize_t count; 331 332 mutex_lock(&md->mutex); 333 count = sprintf(buf, "%d\n", md->slave_count); 334 mutex_unlock(&md->mutex); 335 return count; 336} 337 338static ssize_t w1_master_attribute_show_slaves(struct device *dev, 339 struct device_attribute *attr, char *buf) 340{ 341 struct w1_master *md = dev_to_w1_master(dev); 342 int c = PAGE_SIZE; 343 344 mutex_lock(&md->mutex); 345 346 if (md->slave_count == 0) 347 c -= snprintf(buf + PAGE_SIZE - c, c, "not found.\n"); 348 else { 349 struct list_head *ent, *n; 350 struct w1_slave *sl; 351 352 list_for_each_safe(ent, n, &md->slist) { 353 sl = list_entry(ent, struct w1_slave, w1_slave_entry); 354 355 c -= snprintf(buf + PAGE_SIZE - c, c, "%s\n", sl->name); 356 } 357 } 358 359 mutex_unlock(&md->mutex); 360 361 return PAGE_SIZE - c; 362} 363 364static ssize_t w1_master_attribute_show_add(struct device *dev, 365 struct device_attribute *attr, char *buf) 366{ 367 int c = PAGE_SIZE; 368 c -= snprintf(buf+PAGE_SIZE - c, c, 369 "write device id xx-xxxxxxxxxxxx to add slave\n"); 370 return PAGE_SIZE - c; 371} 372 373static int w1_atoreg_num(struct device *dev, const char *buf, size_t count, 374 struct w1_reg_num *rn) 375{ 376 unsigned int family; 377 unsigned long long id; 378 int i; 379 u64 rn64_le; 380 381 /* The CRC value isn't read from the user because the sysfs directory 382 * doesn't include it and most messages from the bus search don't 383 * print it either. It would be unreasonable for the user to then 384 * provide it. 385 */ 386 const char *error_msg = "bad slave string format, expecting " 387 "ff-dddddddddddd\n"; 388 389 if (buf[2] != '-') { 390 dev_err(dev, "%s", error_msg); 391 return -EINVAL; 392 } 393 i = sscanf(buf, "%02x-%012llx", &family, &id); 394 if (i != 2) { 395 dev_err(dev, "%s", error_msg); 396 return -EINVAL; 397 } 398 rn->family = family; 399 rn->id = id; 400 401 rn64_le = cpu_to_le64(*(u64 *)rn); 402 rn->crc = w1_calc_crc8((u8 *)&rn64_le, 7); 403 404 405 return 0; 406} 407 408/* Searches the slaves in the w1_master and returns a pointer or NULL. 409 * Note: must hold the mutex 410 */ 411static struct w1_slave *w1_slave_search_device(struct w1_master *dev, 412 struct w1_reg_num *rn) 413{ 414 struct w1_slave *sl; 415 list_for_each_entry(sl, &dev->slist, w1_slave_entry) { 416 if (sl->reg_num.family == rn->family && 417 sl->reg_num.id == rn->id && 418 sl->reg_num.crc == rn->crc) { 419 return sl; 420 } 421 } 422 return NULL; 423} 424 425static ssize_t w1_master_attribute_store_add(struct device *dev, 426 struct device_attribute *attr, 427 const char *buf, size_t count) 428{ 429 struct w1_master *md = dev_to_w1_master(dev); 430 struct w1_reg_num rn; 431 struct w1_slave *sl; 432 ssize_t result = count; 433 434 if (w1_atoreg_num(dev, buf, count, &rn)) 435 return -EINVAL; 436 437 mutex_lock(&md->mutex); 438 sl = w1_slave_search_device(md, &rn); 439 /* It would be nice to do a targeted search one the one-wire bus 440 * for the new device to see if it is out there or not. But the 441 * current search doesn't support that. 442 */ 443 if (sl) { 444 dev_info(dev, "Device %s already exists\n", sl->name); 445 result = -EINVAL; 446 } else { 447 w1_attach_slave_device(md, &rn); 448 } 449 mutex_unlock(&md->mutex); 450 451 return result; 452} 453 454static ssize_t w1_master_attribute_show_remove(struct device *dev, 455 struct device_attribute *attr, char *buf) 456{ 457 int c = PAGE_SIZE; 458 c -= snprintf(buf+PAGE_SIZE - c, c, 459 "write device id xx-xxxxxxxxxxxx to remove slave\n"); 460 return PAGE_SIZE - c; 461} 462 463static ssize_t w1_master_attribute_store_remove(struct device *dev, 464 struct device_attribute *attr, 465 const char *buf, size_t count) 466{ 467 struct w1_master *md = dev_to_w1_master(dev); 468 struct w1_reg_num rn; 469 struct w1_slave *sl; 470 ssize_t result = count; 471 472 if (w1_atoreg_num(dev, buf, count, &rn)) 473 return -EINVAL; 474 475 mutex_lock(&md->mutex); 476 sl = w1_slave_search_device(md, &rn); 477 if (sl) { 478 w1_slave_detach(sl); 479 } else { 480 dev_info(dev, "Device %02x-%012llx doesn't exists\n", rn.family, 481 (unsigned long long)rn.id); 482 result = -EINVAL; 483 } 484 mutex_unlock(&md->mutex); 485 486 return result; 487} 488 489#define W1_MASTER_ATTR_RO(_name, _mode) \ 490 struct device_attribute w1_master_attribute_##_name = \ 491 __ATTR(w1_master_##_name, _mode, \ 492 w1_master_attribute_show_##_name, NULL) 493 494#define W1_MASTER_ATTR_RW(_name, _mode) \ 495 struct device_attribute w1_master_attribute_##_name = \ 496 __ATTR(w1_master_##_name, _mode, \ 497 w1_master_attribute_show_##_name, \ 498 w1_master_attribute_store_##_name) 499 500static W1_MASTER_ATTR_RO(name, S_IRUGO); 501static W1_MASTER_ATTR_RO(slaves, S_IRUGO); 502static W1_MASTER_ATTR_RO(slave_count, S_IRUGO); 503static W1_MASTER_ATTR_RO(max_slave_count, S_IRUGO); 504static W1_MASTER_ATTR_RO(attempts, S_IRUGO); 505static W1_MASTER_ATTR_RO(timeout, S_IRUGO); 506static W1_MASTER_ATTR_RO(pointer, S_IRUGO); 507static W1_MASTER_ATTR_RW(search, S_IRUGO | S_IWUGO); 508static W1_MASTER_ATTR_RW(pullup, S_IRUGO | S_IWUGO); 509static W1_MASTER_ATTR_RW(add, S_IRUGO | S_IWUGO); 510static W1_MASTER_ATTR_RW(remove, S_IRUGO | S_IWUGO); 511 512static struct attribute *w1_master_default_attrs[] = { 513 &w1_master_attribute_name.attr, 514 &w1_master_attribute_slaves.attr, 515 &w1_master_attribute_slave_count.attr, 516 &w1_master_attribute_max_slave_count.attr, 517 &w1_master_attribute_attempts.attr, 518 &w1_master_attribute_timeout.attr, 519 &w1_master_attribute_pointer.attr, 520 &w1_master_attribute_search.attr, 521 &w1_master_attribute_pullup.attr, 522 &w1_master_attribute_add.attr, 523 &w1_master_attribute_remove.attr, 524 NULL 525}; 526 527static struct attribute_group w1_master_defattr_group = { 528 .attrs = w1_master_default_attrs, 529}; 530 531int w1_create_master_attributes(struct w1_master *master) 532{ 533 return sysfs_create_group(&master->dev.kobj, &w1_master_defattr_group); 534} 535 536void w1_destroy_master_attributes(struct w1_master *master) 537{ 538 sysfs_remove_group(&master->dev.kobj, &w1_master_defattr_group); 539} 540 541#ifdef CONFIG_HOTPLUG 542static int w1_uevent(struct device *dev, struct kobj_uevent_env *env) 543{ 544 struct w1_master *md = NULL; 545 struct w1_slave *sl = NULL; 546 char *event_owner, *name; 547 int err; 548 549 if (dev->driver == &w1_master_driver) { 550 md = container_of(dev, struct w1_master, dev); 551 event_owner = "master"; 552 name = md->name; 553 } else if (dev->driver == &w1_slave_driver) { 554 sl = container_of(dev, struct w1_slave, dev); 555 event_owner = "slave"; 556 name = sl->name; 557 } else { 558 dev_dbg(dev, "Unknown event.\n"); 559 return -EINVAL; 560 } 561 562 dev_dbg(dev, "Hotplug event for %s %s, bus_id=%s.\n", 563 event_owner, name, dev_name(dev)); 564 565 if (dev->driver != &w1_slave_driver || !sl) 566 return 0; 567 568 err = add_uevent_var(env, "W1_FID=%02X", sl->reg_num.family); 569 if (err) 570 return err; 571 572 err = add_uevent_var(env, "W1_SLAVE_ID=%024LX", 573 (unsigned long long)sl->reg_num.id); 574 if (err) 575 return err; 576 577 return 0; 578}; 579#else 580static int w1_uevent(struct device *dev, struct kobj_uevent_env *env) 581{ 582 return 0; 583} 584#endif 585 586static int __w1_attach_slave_device(struct w1_slave *sl) 587{ 588 int err; 589 590 sl->dev.parent = &sl->master->dev; 591 sl->dev.driver = &w1_slave_driver; 592 sl->dev.bus = &w1_bus_type; 593 sl->dev.release = &w1_slave_release; 594 595 dev_set_name(&sl->dev, "%02x-%012llx", 596 (unsigned int) sl->reg_num.family, 597 (unsigned long long) sl->reg_num.id); 598 snprintf(&sl->name[0], sizeof(sl->name), 599 "%02x-%012llx", 600 (unsigned int) sl->reg_num.family, 601 (unsigned long long) sl->reg_num.id); 602 603 dev_dbg(&sl->dev, "%s: registering %s as %p.\n", __func__, 604 dev_name(&sl->dev), sl); 605 606 err = device_register(&sl->dev); 607 if (err < 0) { 608 dev_err(&sl->dev, 609 "Device registration [%s] failed. err=%d\n", 610 dev_name(&sl->dev), err); 611 return err; 612 } 613 614 /* Create "name" entry */ 615 err = device_create_file(&sl->dev, &w1_slave_attr_name); 616 if (err < 0) { 617 dev_err(&sl->dev, 618 "sysfs file creation for [%s] failed. err=%d\n", 619 dev_name(&sl->dev), err); 620 goto out_unreg; 621 } 622 623 /* Create "id" entry */ 624 err = device_create_file(&sl->dev, &w1_slave_attr_id); 625 if (err < 0) { 626 dev_err(&sl->dev, 627 "sysfs file creation for [%s] failed. err=%d\n", 628 dev_name(&sl->dev), err); 629 goto out_rem1; 630 } 631 632 /* if the family driver needs to initialize something... */ 633 if (sl->family->fops && sl->family->fops->add_slave && 634 ((err = sl->family->fops->add_slave(sl)) < 0)) { 635 dev_err(&sl->dev, 636 "sysfs file creation for [%s] failed. err=%d\n", 637 dev_name(&sl->dev), err); 638 goto out_rem2; 639 } 640 641 list_add_tail(&sl->w1_slave_entry, &sl->master->slist); 642 643 return 0; 644 645out_rem2: 646 device_remove_file(&sl->dev, &w1_slave_attr_id); 647out_rem1: 648 device_remove_file(&sl->dev, &w1_slave_attr_name); 649out_unreg: 650 device_unregister(&sl->dev); 651 return err; 652} 653 654static int w1_attach_slave_device(struct w1_master *dev, struct w1_reg_num *rn) 655{ 656 struct w1_slave *sl; 657 struct w1_family *f; 658 int err; 659 struct w1_netlink_msg msg; 660 661 sl = kzalloc(sizeof(struct w1_slave), GFP_KERNEL); 662 if (!sl) { 663 dev_err(&dev->dev, 664 "%s: failed to allocate new slave device.\n", 665 __func__); 666 return -ENOMEM; 667 } 668 669 670 sl->owner = THIS_MODULE; 671 sl->master = dev; 672 set_bit(W1_SLAVE_ACTIVE, (long *)&sl->flags); 673 674 memset(&msg, 0, sizeof(msg)); 675 memcpy(&sl->reg_num, rn, sizeof(sl->reg_num)); 676 atomic_set(&sl->refcnt, 0); 677 init_completion(&sl->released); 678 679 spin_lock(&w1_flock); 680 f = w1_family_registered(rn->family); 681 if (!f) { 682 f= &w1_default_family; 683 dev_info(&dev->dev, "Family %x for %02x.%012llx.%02x is not registered.\n", 684 rn->family, rn->family, 685 (unsigned long long)rn->id, rn->crc); 686 } 687 __w1_family_get(f); 688 spin_unlock(&w1_flock); 689 690 sl->family = f; 691 692 693 err = __w1_attach_slave_device(sl); 694 if (err < 0) { 695 dev_err(&dev->dev, "%s: Attaching %s failed.\n", __func__, 696 sl->name); 697 w1_family_put(sl->family); 698 kfree(sl); 699 return err; 700 } 701 702 sl->ttl = dev->slave_ttl; 703 dev->slave_count++; 704 705 memcpy(msg.id.id, rn, sizeof(msg.id)); 706 msg.type = W1_SLAVE_ADD; 707 w1_netlink_send(dev, &msg); 708 709 return 0; 710} 711 712void w1_slave_detach(struct w1_slave *sl) 713{ 714 struct w1_netlink_msg msg; 715 716 dev_dbg(&sl->dev, "%s: detaching %s [%p].\n", __func__, sl->name, sl); 717 718 list_del(&sl->w1_slave_entry); 719 720 if (sl->family->fops && sl->family->fops->remove_slave) 721 sl->family->fops->remove_slave(sl); 722 723 memset(&msg, 0, sizeof(msg)); 724 memcpy(msg.id.id, &sl->reg_num, sizeof(msg.id)); 725 msg.type = W1_SLAVE_REMOVE; 726 w1_netlink_send(sl->master, &msg); 727 728 device_remove_file(&sl->dev, &w1_slave_attr_id); 729 device_remove_file(&sl->dev, &w1_slave_attr_name); 730 device_unregister(&sl->dev); 731 732 wait_for_completion(&sl->released); 733 kfree(sl); 734} 735 736struct w1_master *w1_search_master_id(u32 id) 737{ 738 struct w1_master *dev; 739 int found = 0; 740 741 mutex_lock(&w1_mlock); 742 list_for_each_entry(dev, &w1_masters, w1_master_entry) { 743 if (dev->id == id) { 744 found = 1; 745 atomic_inc(&dev->refcnt); 746 break; 747 } 748 } 749 mutex_unlock(&w1_mlock); 750 751 return (found)?dev:NULL; 752} 753 754struct w1_slave *w1_search_slave(struct w1_reg_num *id) 755{ 756 struct w1_master *dev; 757 struct w1_slave *sl = NULL; 758 int found = 0; 759 760 mutex_lock(&w1_mlock); 761 list_for_each_entry(dev, &w1_masters, w1_master_entry) { 762 mutex_lock(&dev->mutex); 763 list_for_each_entry(sl, &dev->slist, w1_slave_entry) { 764 if (sl->reg_num.family == id->family && 765 sl->reg_num.id == id->id && 766 sl->reg_num.crc == id->crc) { 767 found = 1; 768 atomic_inc(&dev->refcnt); 769 atomic_inc(&sl->refcnt); 770 break; 771 } 772 } 773 mutex_unlock(&dev->mutex); 774 775 if (found) 776 break; 777 } 778 mutex_unlock(&w1_mlock); 779 780 return (found)?sl:NULL; 781} 782 783void w1_reconnect_slaves(struct w1_family *f, int attach) 784{ 785 struct w1_slave *sl, *sln; 786 struct w1_master *dev; 787 788 mutex_lock(&w1_mlock); 789 list_for_each_entry(dev, &w1_masters, w1_master_entry) { 790 dev_dbg(&dev->dev, "Reconnecting slaves in device %s " 791 "for family %02x.\n", dev->name, f->fid); 792 mutex_lock(&dev->mutex); 793 list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) { 794 /* If it is a new family, slaves with the default 795 * family driver and are that family will be 796 * connected. If the family is going away, devices 797 * matching that family are reconneced. 798 */ 799 if ((attach && sl->family->fid == W1_FAMILY_DEFAULT 800 && sl->reg_num.family == f->fid) || 801 (!attach && sl->family->fid == f->fid)) { 802 struct w1_reg_num rn; 803 804 memcpy(&rn, &sl->reg_num, sizeof(rn)); 805 w1_slave_detach(sl); 806 807 w1_attach_slave_device(dev, &rn); 808 } 809 } 810 dev_dbg(&dev->dev, "Reconnecting slaves in device %s " 811 "has been finished.\n", dev->name); 812 mutex_unlock(&dev->mutex); 813 } 814 mutex_unlock(&w1_mlock); 815} 816 817static void w1_slave_found(struct w1_master *dev, u64 rn) 818{ 819 struct w1_slave *sl; 820 struct w1_reg_num *tmp; 821 u64 rn_le = cpu_to_le64(rn); 822 823 atomic_inc(&dev->refcnt); 824 825 tmp = (struct w1_reg_num *) &rn; 826 827 sl = w1_slave_search_device(dev, tmp); 828 if (sl) { 829 set_bit(W1_SLAVE_ACTIVE, (long *)&sl->flags); 830 } else { 831 if (rn && tmp->crc == w1_calc_crc8((u8 *)&rn_le, 7)) 832 w1_attach_slave_device(dev, tmp); 833 } 834 835 atomic_dec(&dev->refcnt); 836} 837 838/** 839 * Performs a ROM Search & registers any devices found. 840 * The 1-wire search is a simple binary tree search. 841 * For each bit of the address, we read two bits and write one bit. 842 * The bit written will put to sleep all devies that don't match that bit. 843 * When the two reads differ, the direction choice is obvious. 844 * When both bits are 0, we must choose a path to take. 845 * When we can scan all 64 bits without having to choose a path, we are done. 846 * 847 * See "Application note 187 1-wire search algorithm" at www.maxim-ic.com 848 * 849 * @dev The master device to search 850 * @cb Function to call when a device is found 851 */ 852void w1_search(struct w1_master *dev, u8 search_type, w1_slave_found_callback cb) 853{ 854 u64 last_rn, rn, tmp64; 855 int i, slave_count = 0; 856 int last_zero, last_device; 857 int search_bit, desc_bit; 858 u8 triplet_ret = 0; 859 860 search_bit = 0; 861 rn = last_rn = 0; 862 last_device = 0; 863 last_zero = -1; 864 865 desc_bit = 64; 866 867 while ( !last_device && (slave_count++ < dev->max_slave_count) ) { 868 last_rn = rn; 869 rn = 0; 870 871 /* 872 * Reset bus and all 1-wire device state machines 873 * so they can respond to our requests. 874 * 875 * Return 0 - device(s) present, 1 - no devices present. 876 */ 877 if (w1_reset_bus(dev)) { 878 dev_dbg(&dev->dev, "No devices present on the wire.\n"); 879 break; 880 } 881 882 /* Start the search */ 883 w1_write_8(dev, search_type); 884 for (i = 0; i < 64; ++i) { 885 /* Determine the direction/search bit */ 886 if (i == desc_bit) 887 search_bit = 1; /* took the 0 path last time, so take the 1 path */ 888 else if (i > desc_bit) 889 search_bit = 0; /* take the 0 path on the next branch */ 890 else 891 search_bit = ((last_rn >> i) & 0x1); 892 893 /** Read two bits and write one bit */ 894 triplet_ret = w1_triplet(dev, search_bit); 895 896 /* quit if no device responded */ 897 if ( (triplet_ret & 0x03) == 0x03 ) 898 break; 899 900 /* If both directions were valid, and we took the 0 path... */ 901 if (triplet_ret == 0) 902 last_zero = i; 903 904 /* extract the direction taken & update the device number */ 905 tmp64 = (triplet_ret >> 2); 906 rn |= (tmp64 << i); 907 908 if (kthread_should_stop()) { 909 dev_dbg(&dev->dev, "Abort w1_search\n"); 910 return; 911 } 912 } 913 914 if ( (triplet_ret & 0x03) != 0x03 ) { 915 if ( (desc_bit == last_zero) || (last_zero < 0)) 916 last_device = 1; 917 desc_bit = last_zero; 918 cb(dev, rn); 919 } 920 } 921} 922 923void w1_search_process(struct w1_master *dev, u8 search_type) 924{ 925 struct w1_slave *sl, *sln; 926 927 list_for_each_entry(sl, &dev->slist, w1_slave_entry) 928 clear_bit(W1_SLAVE_ACTIVE, (long *)&sl->flags); 929 930 w1_search_devices(dev, search_type, w1_slave_found); 931 932 list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) { 933 if (!test_bit(W1_SLAVE_ACTIVE, (unsigned long *)&sl->flags) && !--sl->ttl) 934 w1_slave_detach(sl); 935 else if (test_bit(W1_SLAVE_ACTIVE, (unsigned long *)&sl->flags)) 936 sl->ttl = dev->slave_ttl; 937 } 938 939 if (dev->search_count > 0) 940 dev->search_count--; 941} 942 943int w1_process(void *data) 944{ 945 struct w1_master *dev = (struct w1_master *) data; 946 /* As long as w1_timeout is only set by a module parameter the sleep 947 * time can be calculated in jiffies once. 948 */ 949 const unsigned long jtime = msecs_to_jiffies(w1_timeout * 1000); 950 951 while (!kthread_should_stop()) { 952 if (dev->search_count) { 953 mutex_lock(&dev->mutex); 954 w1_search_process(dev, W1_SEARCH); 955 mutex_unlock(&dev->mutex); 956 } 957 958 try_to_freeze(); 959 __set_current_state(TASK_INTERRUPTIBLE); 960 961 if (kthread_should_stop()) 962 break; 963 964 /* Only sleep when the search is active. */ 965 if (dev->search_count) 966 schedule_timeout(jtime); 967 else 968 schedule(); 969 } 970 971 atomic_dec(&dev->refcnt); 972 973 return 0; 974} 975 976static int __init w1_init(void) 977{ 978 int retval; 979 980 printk(KERN_INFO "Driver for 1-wire Dallas network protocol.\n"); 981 982 w1_init_netlink(); 983 984 retval = bus_register(&w1_bus_type); 985 if (retval) { 986 printk(KERN_ERR "Failed to register bus. err=%d.\n", retval); 987 goto err_out_exit_init; 988 } 989 990 retval = driver_register(&w1_master_driver); 991 if (retval) { 992 printk(KERN_ERR 993 "Failed to register master driver. err=%d.\n", 994 retval); 995 goto err_out_bus_unregister; 996 } 997 998 retval = driver_register(&w1_slave_driver); 999 if (retval) { 1000 printk(KERN_ERR 1001 "Failed to register master driver. err=%d.\n", 1002 retval); 1003 goto err_out_master_unregister; 1004 } 1005 1006 return 0; 1007 1008 1009err_out_master_unregister: 1010 driver_unregister(&w1_master_driver); 1011 1012err_out_bus_unregister: 1013 bus_unregister(&w1_bus_type); 1014 1015err_out_exit_init: 1016 return retval; 1017} 1018 1019static void __exit w1_fini(void) 1020{ 1021 struct w1_master *dev; 1022 1023 /* Set netlink removal messages and some cleanup */ 1024 list_for_each_entry(dev, &w1_masters, w1_master_entry) 1025 __w1_remove_master_device(dev); 1026 1027 w1_fini_netlink(); 1028 1029 driver_unregister(&w1_slave_driver); 1030 driver_unregister(&w1_master_driver); 1031 bus_unregister(&w1_bus_type); 1032} 1033 1034module_init(w1_init); 1035module_exit(w1_fini); 1036