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   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
  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 DEFINE_MUTEX(w1_mlock);
  57 LIST_HEAD(w1_masters);
  58
  59 static int w1_attach_slave_device(struct w1_master *dev, struct w1_reg_num *rn);
  60
  61 static int w1_master_match(struct device *dev, struct device_driver *drv)
  62 {
  63         return 1;
  64 }
  65
  66 static int w1_master_probe(struct device *dev)
  67 {
  68         return -ENODEV;
  69 }
  70
  71 static 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
  80 static void w1_slave_release(struct device *dev)
  81 {
  82         struct w1_slave *sl = dev_to_w1_slave(dev);
  83
  84         printk("%s: Releasing %s.\n", __func__, sl->name);
  85
  86         while (atomic_read(&sl->refcnt)) {
  87                 printk("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
  99 static 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
 106 static ssize_t w1_slave_read_id(struct kobject *kobj,
 107                                 struct bin_attribute *bin_attr,
 108                                 char *buf, loff_t off, size_t count)
 109 {
 110         struct w1_slave *sl = kobj_to_w1_slave(kobj);
 111
 112         if (off > 8) {
 113                 count = 0;
 114         } else {
 115                 if (off + count > 8)
 116                         count = 8 - off;
 117
 118                 memcpy(buf, (u8 *)&sl->reg_num, count);
 119         }
 120
 121         return count;
 122 }
 123
 124 static struct device_attribute w1_slave_attr_name =
 125         __ATTR(name, S_IRUGO, w1_slave_read_name, NULL);
 126
 127 static struct bin_attribute w1_slave_attr_bin_id = {
 128       .attr = {
 129               .name = "id",
 130               .mode = S_IRUGO,
 131       },
 132       .size = 8,
 133       .read = w1_slave_read_id,
 134 };
 135
 136 /* Default family */
 137
 138 static ssize_t w1_default_write(struct kobject *kobj,
 139                                 struct bin_attribute *bin_attr,
 140                                 char *buf, loff_t off, size_t count)
 141 {
 142         struct w1_slave *sl = kobj_to_w1_slave(kobj);
 143
 144         mutex_lock(&sl->master->mutex);
 145         if (w1_reset_select_slave(sl)) {
 146                 count = 0;
 147                 goto out_up;
 148         }
 149
 150         w1_write_block(sl->master, buf, count);
 151
 152 out_up:
 153         mutex_unlock(&sl->master->mutex);
 154         return count;
 155 }
 156
 157 static ssize_t w1_default_read(struct kobject *kobj,
 158                                struct bin_attribute *bin_attr,
 159                                char *buf, loff_t off, size_t count)
 160 {
 161         struct w1_slave *sl = kobj_to_w1_slave(kobj);
 162
 163         mutex_lock(&sl->master->mutex);
 164         w1_read_block(sl->master, buf, count);
 165         mutex_unlock(&sl->master->mutex);
 166         return count;
 167 }
 168
 169 static struct bin_attribute w1_default_attr = {
 170       .attr = {
 171               .name = "rw",
 172               .mode = S_IRUGO | S_IWUSR,
 173       },
 174       .size = PAGE_SIZE,
 175       .read = w1_default_read,
 176       .write = w1_default_write,
 177 };
 178
 179 static int w1_default_add_slave(struct w1_slave *sl)
 180 {
 181         return sysfs_create_bin_file(&sl->dev.kobj, &w1_default_attr);
 182 }
 183
 184 static void w1_default_remove_slave(struct w1_slave *sl)
 185 {
 186         sysfs_remove_bin_file(&sl->dev.kobj, &w1_default_attr);
 187 }
 188
 189 static struct w1_family_ops w1_default_fops = {
 190         .add_slave      = w1_default_add_slave,
 191         .remove_slave   = w1_default_remove_slave,
 192 };
 193
 194 static struct w1_family w1_default_family = {
 195         .fops = &w1_default_fops,
 196 };
 197
 198 static int w1_uevent(struct device *dev, struct kobj_uevent_env *env);
 199
 200 static struct bus_type w1_bus_type = {
 201         .name = "w1",
 202         .match = w1_master_match,
 203         .uevent = w1_uevent,
 204 };
 205
 206 struct device_driver w1_master_driver = {
 207         .name = "w1_master_driver",
 208         .bus = &w1_bus_type,
 209         .probe = w1_master_probe,
 210 };
 211
 212 struct device w1_master_device = {
 213         .parent = NULL,
 214         .bus = &w1_bus_type,
 215         .bus_id = "w1 bus master",
 216         .driver = &w1_master_driver,
 217         .release = &w1_master_release
 218 };
 219
 220 static struct device_driver w1_slave_driver = {
 221         .name = "w1_slave_driver",
 222         .bus = &w1_bus_type,
 223 };
 224
 225 #if 0
 226 struct device w1_slave_device = {
 227         .parent = NULL,
 228         .bus = &w1_bus_type,
 229         .bus_id = "w1 bus slave",
 230         .driver = &w1_slave_driver,
 231         .release = &w1_slave_release
 232 };
 233 #endif  /*  0  */
 234
 235 static ssize_t w1_master_attribute_show_name(struct device *dev, struct device_attribute *attr, char *buf)
 236 {
 237         struct w1_master *md = dev_to_w1_master(dev);
 238         ssize_t count;
 239
 240         mutex_lock(&md->mutex);
 241         count = sprintf(buf, "%s\n", md->name);
 242         mutex_unlock(&md->mutex);
 243
 244         return count;
 245 }
 246
 247 static ssize_t w1_master_attribute_store_search(struct device * dev,
 248                                                 struct device_attribute *attr,
 249                                                 const char * buf, size_t count)
 250 {
 251         long tmp;
 252         struct w1_master *md = dev_to_w1_master(dev);
 253
 254         if (strict_strtol(buf, 0, &tmp) == -EINVAL)
 255                 return -EINVAL;
 256
 257         mutex_lock(&md->mutex);
 258         md->search_count = tmp;
 259         mutex_unlock(&md->mutex);
 260         wake_up_process(md->thread);
 261
 262         return count;
 263 }
 264
 265 static ssize_t w1_master_attribute_show_search(struct device *dev,
 266                                                struct device_attribute *attr,
 267                                                char *buf)
 268 {
 269         struct w1_master *md = dev_to_w1_master(dev);
 270         ssize_t count;
 271
 272         mutex_lock(&md->mutex);
 273         count = sprintf(buf, "%d\n", md->search_count);
 274         mutex_unlock(&md->mutex);
 275
 276         return count;
 277 }
 278
 279 static ssize_t w1_master_attribute_store_pullup(struct device *dev,
 280                                                 struct device_attribute *attr,
 281                                                 const char *buf, size_t count)
 282 {
 283         long tmp;
 284         struct w1_master *md = dev_to_w1_master(dev);
 285
 286         if (strict_strtol(buf, 0, &tmp) == -EINVAL)
 287                 return -EINVAL;
 288
 289         mutex_lock(&md->mutex);
 290         md->enable_pullup = tmp;
 291         mutex_unlock(&md->mutex);
 292         wake_up_process(md->thread);
 293
 294         return count;
 295 }
 296
 297 static ssize_t w1_master_attribute_show_pullup(struct device *dev,
 298                                                struct device_attribute *attr,
 299                                                char *buf)
 300 {
 301         struct w1_master *md = dev_to_w1_master(dev);
 302         ssize_t count;
 303
 304         mutex_lock(&md->mutex);
 305         count = sprintf(buf, "%d\n", md->enable_pullup);
 306         mutex_unlock(&md->mutex);
 307
 308         return count;
 309 }
 310
 311 static ssize_t w1_master_attribute_show_pointer(struct device *dev, struct device_attribute *attr, char *buf)
 312 {
 313         struct w1_master *md = dev_to_w1_master(dev);
 314         ssize_t count;
 315
 316         mutex_lock(&md->mutex);
 317         count = sprintf(buf, "0x%p\n", md->bus_master);
 318         mutex_unlock(&md->mutex);
 319         return count;
 320 }
 321
 322 static ssize_t w1_master_attribute_show_timeout(struct device *dev, struct device_attribute *attr, char *buf)
 323 {
 324         ssize_t count;
 325         count = sprintf(buf, "%d\n", w1_timeout);
 326         return count;
 327 }
 328
 329 static ssize_t w1_master_attribute_show_max_slave_count(struct device *dev, struct device_attribute *attr, char *buf)
 330 {
 331         struct w1_master *md = dev_to_w1_master(dev);
 332         ssize_t count;
 333
 334         mutex_lock(&md->mutex);
 335         count = sprintf(buf, "%d\n", md->max_slave_count);
 336         mutex_unlock(&md->mutex);
 337         return count;
 338 }
 339
 340 static ssize_t w1_master_attribute_show_attempts(struct device *dev, struct device_attribute *attr, char *buf)
 341 {
 342         struct w1_master *md = dev_to_w1_master(dev);
 343         ssize_t count;
 344
 345         mutex_lock(&md->mutex);
 346         count = sprintf(buf, "%lu\n", md->attempts);
 347         mutex_unlock(&md->mutex);
 348         return count;
 349 }
 350
 351 static ssize_t w1_master_attribute_show_slave_count(struct device *dev, struct device_attribute *attr, char *buf)
 352 {
 353         struct w1_master *md = dev_to_w1_master(dev);
 354         ssize_t count;
 355
 356         mutex_lock(&md->mutex);
 357         count = sprintf(buf, "%d\n", md->slave_count);
 358         mutex_unlock(&md->mutex);
 359         return count;
 360 }
 361
 362 static ssize_t w1_master_attribute_show_slaves(struct device *dev,
 363         struct device_attribute *attr, char *buf)
 364 {
 365         struct w1_master *md = dev_to_w1_master(dev);
 366         int c = PAGE_SIZE;
 367
 368         mutex_lock(&md->mutex);
 369
 370         if (md->slave_count == 0)
 371                 c -= snprintf(buf + PAGE_SIZE - c, c, "not found.\n");
 372         else {
 373                 struct list_head *ent, *n;
 374                 struct w1_slave *sl;
 375
 376                 list_for_each_safe(ent, n, &md->slist) {
 377                         sl = list_entry(ent, struct w1_slave, w1_slave_entry);
 378
 379                         c -= snprintf(buf + PAGE_SIZE - c, c, "%s\n", sl->name);
 380                 }
 381         }
 382
 383         mutex_unlock(&md->mutex);
 384
 385         return PAGE_SIZE - c;
 386 }
 387
 388 static ssize_t w1_master_attribute_show_add(struct device *dev,
 389         struct device_attribute *attr, char *buf)
 390 {
 391         int c = PAGE_SIZE;
 392         c -= snprintf(buf+PAGE_SIZE - c, c,
 393                 "write device id xx-xxxxxxxxxxxx to add slave\n");
 394         return PAGE_SIZE - c;
 395 }
 396
 397 static int w1_atoreg_num(struct device *dev, const char *buf, size_t count,
 398         struct w1_reg_num *rn)
 399 {
 400         unsigned int family;
 401         unsigned long long id;
 402         int i;
 403         u64 rn64_le;
 404
 405         /* The CRC value isn't read from the user because the sysfs directory
 406          * doesn't include it and most messages from the bus search don't
 407          * print it either.  It would be unreasonable for the user to then
 408          * provide it.
 409          */
 410         const char *error_msg = "bad slave string format, expecting "
 411                 "ff-dddddddddddd\n";
 412
 413         if (buf[2] != '-') {
 414                 dev_err(dev, "%s", error_msg);
 415                 return -EINVAL;
 416         }
 417         i = sscanf(buf, "%02x-%012llx", &family, &id);
 418         if (i != 2) {
 419                 dev_err(dev, "%s", error_msg);
 420                 return -EINVAL;
 421         }
 422         rn->family = family;
 423         rn->id = id;
 424
 425         rn64_le = cpu_to_le64(*(u64 *)rn);
 426         rn->crc = w1_calc_crc8((u8 *)&rn64_le, 7);
 427
 428 #if 0
 429         dev_info(dev, "With CRC device is %02x.%012llx.%02x.\n",
 430                   rn->family, (unsigned long long)rn->id, rn->crc);
 431 #endif
 432
 433         return 0;
 434 }
 435
 436 /* Searches the slaves in the w1_master and returns a pointer or NULL.
 437  * Note: must hold the mutex
 438  */
 439 static struct w1_slave *w1_slave_search_device(struct w1_master *dev,
 440         struct w1_reg_num *rn)
 441 {
 442         struct w1_slave *sl;
 443         list_for_each_entry(sl, &dev->slist, w1_slave_entry) {
 444                 if (sl->reg_num.family == rn->family &&
 445                                 sl->reg_num.id == rn->id &&
 446                                 sl->reg_num.crc == rn->crc) {
 447                         return sl;
 448                 }
 449         }
 450         return NULL;
 451 }
 452
 453 static ssize_t w1_master_attribute_store_add(struct device *dev,
 454                                                 struct device_attribute *attr,
 455                                                 const char *buf, size_t count)
 456 {
 457         struct w1_master *md = dev_to_w1_master(dev);
 458         struct w1_reg_num rn;
 459         struct w1_slave *sl;
 460         ssize_t result = count;
 461
 462         if (w1_atoreg_num(dev, buf, count, &rn))
 463                 return -EINVAL;
 464
 465         mutex_lock(&md->mutex);
 466         sl = w1_slave_search_device(md, &rn);
 467         /* It would be nice to do a targeted search one the one-wire bus
 468          * for the new device to see if it is out there or not.  But the
 469          * current search doesn't support that.
 470          */
 471         if (sl) {
 472                 dev_info(dev, "Device %s already exists\n", sl->name);
 473                 result = -EINVAL;
 474         } else {
 475                 w1_attach_slave_device(md, &rn);
 476         }
 477         mutex_unlock(&md->mutex);
 478
 479         return result;
 480 }
 481
 482 static ssize_t w1_master_attribute_show_remove(struct device *dev,
 483         struct device_attribute *attr, char *buf)
 484 {
 485         int c = PAGE_SIZE;
 486         c -= snprintf(buf+PAGE_SIZE - c, c,
 487                 "write device id xx-xxxxxxxxxxxx to remove slave\n");
 488         return PAGE_SIZE - c;
 489 }
 490
 491 static ssize_t w1_master_attribute_store_remove(struct device *dev,
 492                                                 struct device_attribute *attr,
 493                                                 const char *buf, size_t count)
 494 {
 495         struct w1_master *md = dev_to_w1_master(dev);
 496         struct w1_reg_num rn;
 497         struct w1_slave *sl;
 498         ssize_t result = count;
 499
 500         if (w1_atoreg_num(dev, buf, count, &rn))
 501                 return -EINVAL;
 502
 503         mutex_lock(&md->mutex);
 504         sl = w1_slave_search_device(md, &rn);
 505         if (sl) {
 506                 w1_slave_detach(sl);
 507         } else {
 508                 dev_info(dev, "Device %02x-%012llx doesn't exists\n", rn.family,
 509                         (unsigned long long)rn.id);
 510                 result = -EINVAL;
 511         }
 512         mutex_unlock(&md->mutex);
 513
 514         return result;
 515 }
 516
 517 #define W1_MASTER_ATTR_RO(_name, _mode)                         \
 518         struct device_attribute w1_master_attribute_##_name =   \
 519                 __ATTR(w1_master_##_name, _mode,                \
 520                        w1_master_attribute_show_##_name, NULL)
 521
 522 #define W1_MASTER_ATTR_RW(_name, _mode)                         \
 523         struct device_attribute w1_master_attribute_##_name =   \
 524                 __ATTR(w1_master_##_name, _mode,                \
 525                        w1_master_attribute_show_##_name,        \
 526                        w1_master_attribute_store_##_name)
 527
 528 static W1_MASTER_ATTR_RO(name, S_IRUGO);
 529 static W1_MASTER_ATTR_RO(slaves, S_IRUGO);
 530 static W1_MASTER_ATTR_RO(slave_count, S_IRUGO);
 531 static W1_MASTER_ATTR_RO(max_slave_count, S_IRUGO);
 532 static W1_MASTER_ATTR_RO(attempts, S_IRUGO);
 533 static W1_MASTER_ATTR_RO(timeout, S_IRUGO);
 534 static W1_MASTER_ATTR_RO(pointer, S_IRUGO);
 535 static W1_MASTER_ATTR_RW(search, S_IRUGO | S_IWUGO);
 536 static W1_MASTER_ATTR_RW(pullup, S_IRUGO | S_IWUGO);
 537 static W1_MASTER_ATTR_RW(add, S_IRUGO | S_IWUGO);
 538 static W1_MASTER_ATTR_RW(remove, S_IRUGO | S_IWUGO);
 539
 540 static struct attribute *w1_master_default_attrs[] = {
 541         &w1_master_attribute_name.attr,
 542         &w1_master_attribute_slaves.attr,
 543         &w1_master_attribute_slave_count.attr,
 544         &w1_master_attribute_max_slave_count.attr,
 545         &w1_master_attribute_attempts.attr,
 546         &w1_master_attribute_timeout.attr,
 547         &w1_master_attribute_pointer.attr,
 548         &w1_master_attribute_search.attr,
 549         &w1_master_attribute_pullup.attr,
 550         &w1_master_attribute_add.attr,
 551         &w1_master_attribute_remove.attr,
 552         NULL
 553 };
 554
 555 static struct attribute_group w1_master_defattr_group = {
 556         .attrs = w1_master_default_attrs,
 557 };
 558
 559 int w1_create_master_attributes(struct w1_master *master)
 560 {
 561         return sysfs_create_group(&master->dev.kobj, &w1_master_defattr_group);
 562 }
 563
 564 void w1_destroy_master_attributes(struct w1_master *master)
 565 {
 566         sysfs_remove_group(&master->dev.kobj, &w1_master_defattr_group);
 567 }
 568
 569 #ifdef CONFIG_HOTPLUG
 570 static int w1_uevent(struct device *dev, struct kobj_uevent_env *env)
 571 {
 572         struct w1_master *md = NULL;
 573         struct w1_slave *sl = NULL;
 574         char *event_owner, *name;
 575         int err;
 576
 577         if (dev->driver == &w1_master_driver) {
 578                 md = container_of(dev, struct w1_master, dev);
 579                 event_owner = "master";
 580                 name = md->name;
 581         } else if (dev->driver == &w1_slave_driver) {
 582                 sl = container_of(dev, struct w1_slave, dev);
 583                 event_owner = "slave";
 584                 name = sl->name;
 585         } else {
 586                 dev_dbg(dev, "Unknown event.\n");
 587                 return -EINVAL;
 588         }
 589
 590         dev_dbg(dev, "Hotplug event for %s %s, bus_id=%s.\n",
 591                         event_owner, name, dev->bus_id);
 592
 593         if (dev->driver != &w1_slave_driver || !sl)
 594                 return 0;
 595
 596         err = add_uevent_var(env, "W1_FID=%02X", sl->reg_num.family);
 597         if (err)
 598                 return err;
 599
 600         err = add_uevent_var(env, "W1_SLAVE_ID=%024LX",
 601                              (unsigned long long)sl->reg_num.id);
 602         if (err)
 603                 return err;
 604
 605         return 0;
 606 };
 607 #else
 608 static int w1_uevent(struct device *dev, struct kobj_uevent_env *env)
 609 {
 610         return 0;
 611 }
 612 #endif
 613
 614 static int __w1_attach_slave_device(struct w1_slave *sl)
 615 {
 616         int err;
 617
 618         sl->dev.parent = &sl->master->dev;
 619         sl->dev.driver = &w1_slave_driver;
 620         sl->dev.bus = &w1_bus_type;
 621         sl->dev.release = &w1_slave_release;
 622
 623         snprintf(&sl->dev.bus_id[0], sizeof(sl->dev.bus_id),
 624                  "%02x-%012llx",
 625                  (unsigned int) sl->reg_num.family,
 626                  (unsigned long long) sl->reg_num.id);
 627         snprintf(&sl->name[0], sizeof(sl->name),
 628                  "%02x-%012llx",
 629                  (unsigned int) sl->reg_num.family,
 630                  (unsigned long long) sl->reg_num.id);
 631
 632         dev_dbg(&sl->dev, "%s: registering %s as %p.\n", __func__,
 633                 &sl->dev.bus_id[0], sl);
 634
 635         err = device_register(&sl->dev);
 636         if (err < 0) {
 637                 dev_err(&sl->dev,
 638                         "Device registration [%s] failed. err=%d\n",
 639                         sl->dev.bus_id, err);
 640                 return err;
 641         }
 642
 643         /* Create "name" entry */
 644         err = device_create_file(&sl->dev, &w1_slave_attr_name);
 645         if (err < 0) {
 646                 dev_err(&sl->dev,
 647                         "sysfs file creation for [%s] failed. err=%d\n",
 648                         sl->dev.bus_id, err);
 649                 goto out_unreg;
 650         }
 651
 652         /* Create "id" entry */
 653         err = sysfs_create_bin_file(&sl->dev.kobj, &w1_slave_attr_bin_id);
 654         if (err < 0) {
 655                 dev_err(&sl->dev,
 656                         "sysfs file creation for [%s] failed. err=%d\n",
 657                         sl->dev.bus_id, err);
 658                 goto out_rem1;
 659         }
 660
 661         /* if the family driver needs to initialize something... */
 662         if (sl->family->fops && sl->family->fops->add_slave &&
 663             ((err = sl->family->fops->add_slave(sl)) < 0)) {
 664                 dev_err(&sl->dev,
 665                         "sysfs file creation for [%s] failed. err=%d\n",
 666                         sl->dev.bus_id, err);
 667                 goto out_rem2;
 668         }
 669
 670         list_add_tail(&sl->w1_slave_entry, &sl->master->slist);
 671
 672         return 0;
 673
 674 out_rem2:
 675         sysfs_remove_bin_file(&sl->dev.kobj, &w1_slave_attr_bin_id);
 676 out_rem1:
 677         device_remove_file(&sl->dev, &w1_slave_attr_name);
 678 out_unreg:
 679         device_unregister(&sl->dev);
 680         return err;
 681 }
 682
 683 static int w1_attach_slave_device(struct w1_master *dev, struct w1_reg_num *rn)
 684 {
 685         struct w1_slave *sl;
 686         struct w1_family *f;
 687         int err;
 688         struct w1_netlink_msg msg;
 689
 690         sl = kzalloc(sizeof(struct w1_slave), GFP_KERNEL);
 691         if (!sl) {
 692                 dev_err(&dev->dev,
 693                          "%s: failed to allocate new slave device.\n",
 694                          __func__);
 695                 return -ENOMEM;
 696         }
 697
 698
 699         sl->owner = THIS_MODULE;
 700         sl->master = dev;
 701         set_bit(W1_SLAVE_ACTIVE, (long *)&sl->flags);
 702
 703         memset(&msg, 0, sizeof(msg));
 704         memcpy(&sl->reg_num, rn, sizeof(sl->reg_num));
 705         atomic_set(&sl->refcnt, 0);
 706         init_completion(&sl->released);
 707
 708         spin_lock(&w1_flock);
 709         f = w1_family_registered(rn->family);
 710         if (!f) {
 711                 f= &w1_default_family;
 712                 dev_info(&dev->dev, "Family %x for %02x.%012llx.%02x is not registered.\n",
 713                           rn->family, rn->family,
 714                           (unsigned long long)rn->id, rn->crc);
 715         }
 716         __w1_family_get(f);
 717         spin_unlock(&w1_flock);
 718
 719         sl->family = f;
 720
 721
 722         err = __w1_attach_slave_device(sl);
 723         if (err < 0) {
 724                 dev_err(&dev->dev, "%s: Attaching %s failed.\n", __func__,
 725                          sl->name);
 726                 w1_family_put(sl->family);
 727                 kfree(sl);
 728                 return err;
 729         }
 730
 731         sl->ttl = dev->slave_ttl;
 732         dev->slave_count++;
 733
 734         memcpy(msg.id.id, rn, sizeof(msg.id));
 735         msg.type = W1_SLAVE_ADD;
 736         w1_netlink_send(dev, &msg);
 737
 738         return 0;
 739 }
 740
 741 void w1_slave_detach(struct w1_slave *sl)
 742 {
 743         struct w1_netlink_msg msg;
 744
 745         dev_dbg(&sl->dev, "%s: detaching %s [%p].\n", __func__, sl->name, sl);
 746
 747         list_del(&sl->w1_slave_entry);
 748
 749         if (sl->family->fops && sl->family->fops->remove_slave)
 750                 sl->family->fops->remove_slave(sl);
 751
 752         memset(&msg, 0, sizeof(msg));
 753         memcpy(msg.id.id, &sl->reg_num, sizeof(msg.id));
 754         msg.type = W1_SLAVE_REMOVE;
 755         w1_netlink_send(sl->master, &msg);
 756
 757         sysfs_remove_bin_file(&sl->dev.kobj, &w1_slave_attr_bin_id);
 758         device_remove_file(&sl->dev, &w1_slave_attr_name);
 759         device_unregister(&sl->dev);
 760
 761         wait_for_completion(&sl->released);
 762         kfree(sl);
 763 }
 764
 765 struct w1_master *w1_search_master_id(u32 id)
 766 {
 767         struct w1_master *dev;
 768         int found = 0;
 769
 770         mutex_lock(&w1_mlock);
 771         list_for_each_entry(dev, &w1_masters, w1_master_entry) {
 772                 if (dev->id == id) {
 773                         found = 1;
 774                         atomic_inc(&dev->refcnt);
 775                         break;
 776                 }
 777         }
 778         mutex_unlock(&w1_mlock);
 779
 780         return (found)?dev:NULL;
 781 }
 782
 783 struct w1_slave *w1_search_slave(struct w1_reg_num *id)
 784 {
 785         struct w1_master *dev;
 786         struct w1_slave *sl = NULL;
 787         int found = 0;
 788
 789         mutex_lock(&w1_mlock);
 790         list_for_each_entry(dev, &w1_masters, w1_master_entry) {
 791                 mutex_lock(&dev->mutex);
 792                 list_for_each_entry(sl, &dev->slist, w1_slave_entry) {
 793                         if (sl->reg_num.family == id->family &&
 794                                         sl->reg_num.id == id->id &&
 795                                         sl->reg_num.crc == id->crc) {
 796                                 found = 1;
 797                                 atomic_inc(&dev->refcnt);
 798                                 atomic_inc(&sl->refcnt);
 799                                 break;
 800                         }
 801                 }
 802                 mutex_unlock(&dev->mutex);
 803
 804                 if (found)
 805                         break;
 806         }
 807         mutex_unlock(&w1_mlock);
 808
 809         return (found)?sl:NULL;
 810 }
 811
 812 void w1_reconnect_slaves(struct w1_family *f, int attach)
 813 {
 814         struct w1_slave *sl, *sln;
 815         struct w1_master *dev;
 816
 817         mutex_lock(&w1_mlock);
 818         list_for_each_entry(dev, &w1_masters, w1_master_entry) {
 819                 dev_dbg(&dev->dev, "Reconnecting slaves in device %s "
 820                         "for family %02x.\n", dev->name, f->fid);
 821                 mutex_lock(&dev->mutex);
 822                 list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) {
 823                         /* If it is a new family, slaves with the default
 824                          * family driver and are that family will be
 825                          * connected.  If the family is going away, devices
 826                          * matching that family are reconneced.
 827                          */
 828                         if ((attach && sl->family->fid == W1_FAMILY_DEFAULT
 829                                 && sl->reg_num.family == f->fid) ||
 830                                 (!attach && sl->family->fid == f->fid)) {
 831                                 struct w1_reg_num rn;
 832
 833                                 memcpy(&rn, &sl->reg_num, sizeof(rn));
 834                                 w1_slave_detach(sl);
 835
 836                                 w1_attach_slave_device(dev, &rn);
 837                         }
 838                 }
 839                 dev_dbg(&dev->dev, "Reconnecting slaves in device %s "
 840                         "has been finished.\n", dev->name);
 841                 mutex_unlock(&dev->mutex);
 842         }
 843         mutex_unlock(&w1_mlock);
 844 }
 845
 846 static void w1_slave_found(struct w1_master *dev, u64 rn)
 847 {
 848         int slave_count;
 849         struct w1_slave *sl;
 850         struct list_head *ent;
 851         struct w1_reg_num *tmp;
 852         u64 rn_le = cpu_to_le64(rn);
 853
 854         atomic_inc(&dev->refcnt);
 855
 856         tmp = (struct w1_reg_num *) &rn;
 857
 858         slave_count = 0;
 859         list_for_each(ent, &dev->slist) {
 860
 861                 sl = list_entry(ent, struct w1_slave, w1_slave_entry);
 862
 863                 if (sl->reg_num.family == tmp->family &&
 864                     sl->reg_num.id == tmp->id &&
 865                     sl->reg_num.crc == tmp->crc) {
 866                         set_bit(W1_SLAVE_ACTIVE, (long *)&sl->flags);
 867                         break;
 868                 }
 869
 870                 slave_count++;
 871         }
 872
 873         if (slave_count == dev->slave_count &&
 874                 rn && ((rn >> 56) & 0xff) == w1_calc_crc8((u8 *)&rn_le, 7)) {
 875                 w1_attach_slave_device(dev, tmp);
 876         }
 877
 878         atomic_dec(&dev->refcnt);
 879 }
 880
 881 /**
 882  * Performs a ROM Search & registers any devices found.
 883  * The 1-wire search is a simple binary tree search.
 884  * For each bit of the address, we read two bits and write one bit.
 885  * The bit written will put to sleep all devies that don't match that bit.
 886  * When the two reads differ, the direction choice is obvious.
 887  * When both bits are 0, we must choose a path to take.
 888  * When we can scan all 64 bits without having to choose a path, we are done.
 889  *
 890  * See "Application note 187 1-wire search algorithm" at www.maxim-ic.com
 891  *
 892  * @dev        The master device to search
 893  * @cb         Function to call when a device is found
 894  */
 895 void w1_search(struct w1_master *dev, u8 search_type, w1_slave_found_callback cb)
 896 {
 897         u64 last_rn, rn, tmp64;
 898         int i, slave_count = 0;
 899         int last_zero, last_device;
 900         int search_bit, desc_bit;
 901         u8  triplet_ret = 0;
 902
 903         search_bit = 0;
 904         rn = last_rn = 0;
 905         last_device = 0;
 906         last_zero = -1;
 907
 908         desc_bit = 64;
 909
 910         while ( !last_device && (slave_count++ < dev->max_slave_count) ) {
 911                 last_rn = rn;
 912                 rn = 0;
 913
 914                 /*
 915                  * Reset bus and all 1-wire device state machines
 916                  * so they can respond to our requests.
 917                  *
 918                  * Return 0 - device(s) present, 1 - no devices present.
 919                  */
 920                 if (w1_reset_bus(dev)) {
 921                         dev_dbg(&dev->dev, "No devices present on the wire.\n");
 922                         break;
 923                 }
 924
 925                 /* Start the search */
 926                 w1_write_8(dev, search_type);
 927                 for (i = 0; i < 64; ++i) {
 928                         /* Determine the direction/search bit */
 929                         if (i == desc_bit)
 930                                 search_bit = 1;   /* took the 0 path last time, so take the 1 path */
 931                         else if (i > desc_bit)
 932                                 search_bit = 0;   /* take the 0 path on the next branch */
 933                         else
 934                                 search_bit = ((last_rn >> i) & 0x1);
 935
 936                         /** Read two bits and write one bit */
 937                         triplet_ret = w1_triplet(dev, search_bit);
 938
 939                         /* quit if no device responded */
 940                         if ( (triplet_ret & 0x03) == 0x03 )
 941                                 break;
 942
 943                         /* If both directions were valid, and we took the 0 path... */
 944                         if (triplet_ret == 0)
 945                                 last_zero = i;
 946
 947                         /* extract the direction taken & update the device number */
 948                         tmp64 = (triplet_ret >> 2);
 949                         rn |= (tmp64 << i);
 950
 951                         if (kthread_should_stop()) {
 952                                 printk(KERN_INFO "Abort w1_search (exiting)\n");
 953                                 return;
 954                         }
 955                 }
 956
 957                 if ( (triplet_ret & 0x03) != 0x03 ) {
 958                         if ( (desc_bit == last_zero) || (last_zero < 0))
 959                                 last_device = 1;
 960                         desc_bit = last_zero;
 961                         cb(dev, rn);
 962                 }
 963         }
 964 }
 965
 966 void w1_search_process(struct w1_master *dev, u8 search_type)
 967 {
 968         struct w1_slave *sl, *sln;
 969
 970         list_for_each_entry(sl, &dev->slist, w1_slave_entry)
 971                 clear_bit(W1_SLAVE_ACTIVE, (long *)&sl->flags);
 972
 973         w1_search_devices(dev, search_type, w1_slave_found);
 974
 975         list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) {
 976                 if (!test_bit(W1_SLAVE_ACTIVE, (unsigned long *)&sl->flags) && !--sl->ttl)
 977                         w1_slave_detach(sl);
 978                 else if (test_bit(W1_SLAVE_ACTIVE, (unsigned long *)&sl->flags))
 979                         sl->ttl = dev->slave_ttl;
 980         }
 981
 982         if (dev->search_count > 0)
 983                 dev->search_count--;
 984 }
 985
 986 int w1_process(void *data)
 987 {
 988         struct w1_master *dev = (struct w1_master *) data;
 989         /* As long as w1_timeout is only set by a module parameter the sleep
 990          * time can be calculated in jiffies once.
 991          */
 992         const unsigned long jtime = msecs_to_jiffies(w1_timeout * 1000);
 993
 994         while (!kthread_should_stop()) {
 995                 if (dev->search_count) {
 996                         mutex_lock(&dev->mutex);
 997                         w1_search_process(dev, W1_SEARCH);
 998                         mutex_unlock(&dev->mutex);
 999                 }
1000
1001                 try_to_freeze();
1002                 __set_current_state(TASK_INTERRUPTIBLE);
1003
1004                 if (kthread_should_stop())
1005                         break;
1006
1007                 /* Only sleep when the search is active. */
1008                 if (dev->search_count)
1009                         schedule_timeout(jtime);
1010                 else
1011                         schedule();
1012         }
1013
1014         atomic_dec(&dev->refcnt);
1015
1016         return 0;
1017 }
1018
1019 static int w1_init(void)
1020 {
1021         int retval;
1022
1023         printk(KERN_INFO "Driver for 1-wire Dallas network protocol.\n");
1024
1025         w1_init_netlink();
1026
1027         retval = bus_register(&w1_bus_type);
1028         if (retval) {
1029                 printk(KERN_ERR "Failed to register bus. err=%d.\n", retval);
1030                 goto err_out_exit_init;
1031         }
1032
1033         retval = driver_register(&w1_master_driver);
1034         if (retval) {
1035                 printk(KERN_ERR
1036                         "Failed to register master driver. err=%d.\n",
1037                         retval);
1038                 goto err_out_bus_unregister;
1039         }
1040
1041         retval = driver_register(&w1_slave_driver);
1042         if (retval) {
1043                 printk(KERN_ERR
1044                         "Failed to register master driver. err=%d.\n",
1045                         retval);
1046                 goto err_out_master_unregister;
1047         }
1048
1049         return 0;
1050
1051 #if 0
1052 /* For undoing the slave register if there was a step after it. */
1053 err_out_slave_unregister:
1054         driver_unregister(&w1_slave_driver);
1055 #endif
1056
1057 err_out_master_unregister:
1058         driver_unregister(&w1_master_driver);
1059
1060 err_out_bus_unregister:
1061         bus_unregister(&w1_bus_type);
1062
1063 err_out_exit_init:
1064         return retval;
1065 }
1066
1067 static void w1_fini(void)
1068 {
1069         struct w1_master *dev;
1070
1071         /* Set netlink removal messages and some cleanup */
1072         list_for_each_entry(dev, &w1_masters, w1_master_entry)
1073                 __w1_remove_master_device(dev);
1074
1075         w1_fini_netlink();
1076
1077         driver_unregister(&w1_slave_driver);
1078         driver_unregister(&w1_master_driver);
1079         bus_unregister(&w1_bus_type);
1080 }
1081
1082 module_init(w1_init);
1083 module_exit(w1_fini);