Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6
[linux-2.6.git] / drivers / w1 / w1.c
1 /*
2  *      w1.c
3  *
4  * Copyright (c) 2004 Evgeniy Polyakov <johnpol@2ka.mipt.ru>
5  *
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License as published by
9  * the Free Software Foundation; either version 2 of the License, or
10  * (at your option) any later version.
11  *
12  * This program is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  * GNU General Public License for more details.
16  *
17  * You should have received a copy of the GNU General Public License
18  * along with this program; if not, write to the Free Software
19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20  */
21
22 #include <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         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
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 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
116 static struct device_attribute w1_slave_attr_name =
117         __ATTR(name, S_IRUGO, w1_slave_read_name, NULL);
118 static struct device_attribute w1_slave_attr_id =
119         __ATTR(id, S_IRUGO, w1_slave_read_id, NULL);
120
121 /* Default family */
122
123 static ssize_t w1_default_write(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
137 out_up:
138         mutex_unlock(&sl->master->mutex);
139         return count;
140 }
141
142 static ssize_t w1_default_read(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
154 static 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
164 static int w1_default_add_slave(struct w1_slave *sl)
165 {
166         return sysfs_create_bin_file(&sl->dev.kobj, &w1_default_attr);
167 }
168
169 static void w1_default_remove_slave(struct w1_slave *sl)
170 {
171         sysfs_remove_bin_file(&sl->dev.kobj, &w1_default_attr);
172 }
173
174 static struct w1_family_ops w1_default_fops = {
175         .add_slave      = w1_default_add_slave,
176         .remove_slave   = w1_default_remove_slave,
177 };
178
179 static struct w1_family w1_default_family = {
180         .fops = &w1_default_fops,
181 };
182
183 static int w1_uevent(struct device *dev, struct kobj_uevent_env *env);
184
185 static struct bus_type w1_bus_type = {
186         .name = "w1",
187         .match = w1_master_match,
188         .uevent = w1_uevent,
189 };
190
191 struct device_driver w1_master_driver = {
192         .name = "w1_master_driver",
193         .bus = &w1_bus_type,
194         .probe = w1_master_probe,
195 };
196
197 struct 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
205 static struct device_driver w1_slave_driver = {
206         .name = "w1_slave_driver",
207         .bus = &w1_bus_type,
208 };
209
210 #if 0
211 struct device w1_slave_device = {
212         .parent = NULL,
213         .bus = &w1_bus_type,
214         .init_name = "w1 bus slave",
215         .driver = &w1_slave_driver,
216         .release = &w1_slave_release
217 };
218 #endif  /*  0  */
219
220 static ssize_t w1_master_attribute_show_name(struct device *dev, struct device_attribute *attr, char *buf)
221 {
222         struct w1_master *md = dev_to_w1_master(dev);
223         ssize_t count;
224
225         mutex_lock(&md->mutex);
226         count = sprintf(buf, "%s\n", md->name);
227         mutex_unlock(&md->mutex);
228
229         return count;
230 }
231
232 static ssize_t w1_master_attribute_store_search(struct device * dev,
233                                                 struct device_attribute *attr,
234                                                 const char * buf, size_t count)
235 {
236         long tmp;
237         struct w1_master *md = dev_to_w1_master(dev);
238
239         if (strict_strtol(buf, 0, &tmp) == -EINVAL)
240                 return -EINVAL;
241
242         mutex_lock(&md->mutex);
243         md->search_count = tmp;
244         mutex_unlock(&md->mutex);
245         wake_up_process(md->thread);
246
247         return count;
248 }
249
250 static ssize_t w1_master_attribute_show_search(struct device *dev,
251                                                struct device_attribute *attr,
252                                                char *buf)
253 {
254         struct w1_master *md = dev_to_w1_master(dev);
255         ssize_t count;
256
257         mutex_lock(&md->mutex);
258         count = sprintf(buf, "%d\n", md->search_count);
259         mutex_unlock(&md->mutex);
260
261         return count;
262 }
263
264 static ssize_t w1_master_attribute_store_pullup(struct device *dev,
265                                                 struct device_attribute *attr,
266                                                 const char *buf, size_t count)
267 {
268         long tmp;
269         struct w1_master *md = dev_to_w1_master(dev);
270
271         if (strict_strtol(buf, 0, &tmp) == -EINVAL)
272                 return -EINVAL;
273
274         mutex_lock(&md->mutex);
275         md->enable_pullup = tmp;
276         mutex_unlock(&md->mutex);
277         wake_up_process(md->thread);
278
279         return count;
280 }
281
282 static ssize_t w1_master_attribute_show_pullup(struct device *dev,
283                                                struct device_attribute *attr,
284                                                char *buf)
285 {
286         struct w1_master *md = dev_to_w1_master(dev);
287         ssize_t count;
288
289         mutex_lock(&md->mutex);
290         count = sprintf(buf, "%d\n", md->enable_pullup);
291         mutex_unlock(&md->mutex);
292
293         return count;
294 }
295
296 static ssize_t w1_master_attribute_show_pointer(struct device *dev, struct device_attribute *attr, char *buf)
297 {
298         struct w1_master *md = dev_to_w1_master(dev);
299         ssize_t count;
300
301         mutex_lock(&md->mutex);
302         count = sprintf(buf, "0x%p\n", md->bus_master);
303         mutex_unlock(&md->mutex);
304         return count;
305 }
306
307 static ssize_t w1_master_attribute_show_timeout(struct device *dev, struct device_attribute *attr, char *buf)
308 {
309         ssize_t count;
310         count = sprintf(buf, "%d\n", w1_timeout);
311         return count;
312 }
313
314 static ssize_t w1_master_attribute_show_max_slave_count(struct device *dev, struct device_attribute *attr, char *buf)
315 {
316         struct w1_master *md = dev_to_w1_master(dev);
317         ssize_t count;
318
319         mutex_lock(&md->mutex);
320         count = sprintf(buf, "%d\n", md->max_slave_count);
321         mutex_unlock(&md->mutex);
322         return count;
323 }
324
325 static ssize_t w1_master_attribute_show_attempts(struct device *dev, struct device_attribute *attr, char *buf)
326 {
327         struct w1_master *md = dev_to_w1_master(dev);
328         ssize_t count;
329
330         mutex_lock(&md->mutex);
331         count = sprintf(buf, "%lu\n", md->attempts);
332         mutex_unlock(&md->mutex);
333         return count;
334 }
335
336 static ssize_t w1_master_attribute_show_slave_count(struct device *dev, struct device_attribute *attr, char *buf)
337 {
338         struct w1_master *md = dev_to_w1_master(dev);
339         ssize_t count;
340
341         mutex_lock(&md->mutex);
342         count = sprintf(buf, "%d\n", md->slave_count);
343         mutex_unlock(&md->mutex);
344         return count;
345 }
346
347 static ssize_t w1_master_attribute_show_slaves(struct device *dev,
348         struct device_attribute *attr, char *buf)
349 {
350         struct w1_master *md = dev_to_w1_master(dev);
351         int c = PAGE_SIZE;
352
353         mutex_lock(&md->mutex);
354
355         if (md->slave_count == 0)
356                 c -= snprintf(buf + PAGE_SIZE - c, c, "not found.\n");
357         else {
358                 struct list_head *ent, *n;
359                 struct w1_slave *sl;
360
361                 list_for_each_safe(ent, n, &md->slist) {
362                         sl = list_entry(ent, struct w1_slave, w1_slave_entry);
363
364                         c -= snprintf(buf + PAGE_SIZE - c, c, "%s\n", sl->name);
365                 }
366         }
367
368         mutex_unlock(&md->mutex);
369
370         return PAGE_SIZE - c;
371 }
372
373 static ssize_t w1_master_attribute_show_add(struct device *dev,
374         struct device_attribute *attr, char *buf)
375 {
376         int c = PAGE_SIZE;
377         c -= snprintf(buf+PAGE_SIZE - c, c,
378                 "write device id xx-xxxxxxxxxxxx to add slave\n");
379         return PAGE_SIZE - c;
380 }
381
382 static int w1_atoreg_num(struct device *dev, const char *buf, size_t count,
383         struct w1_reg_num *rn)
384 {
385         unsigned int family;
386         unsigned long long id;
387         int i;
388         u64 rn64_le;
389
390         /* The CRC value isn't read from the user because the sysfs directory
391          * doesn't include it and most messages from the bus search don't
392          * print it either.  It would be unreasonable for the user to then
393          * provide it.
394          */
395         const char *error_msg = "bad slave string format, expecting "
396                 "ff-dddddddddddd\n";
397
398         if (buf[2] != '-') {
399                 dev_err(dev, "%s", error_msg);
400                 return -EINVAL;
401         }
402         i = sscanf(buf, "%02x-%012llx", &family, &id);
403         if (i != 2) {
404                 dev_err(dev, "%s", error_msg);
405                 return -EINVAL;
406         }
407         rn->family = family;
408         rn->id = id;
409
410         rn64_le = cpu_to_le64(*(u64 *)rn);
411         rn->crc = w1_calc_crc8((u8 *)&rn64_le, 7);
412
413 #if 0
414         dev_info(dev, "With CRC device is %02x.%012llx.%02x.\n",
415                   rn->family, (unsigned long long)rn->id, rn->crc);
416 #endif
417
418         return 0;
419 }
420
421 /* Searches the slaves in the w1_master and returns a pointer or NULL.
422  * Note: must hold the mutex
423  */
424 static struct w1_slave *w1_slave_search_device(struct w1_master *dev,
425         struct w1_reg_num *rn)
426 {
427         struct w1_slave *sl;
428         list_for_each_entry(sl, &dev->slist, w1_slave_entry) {
429                 if (sl->reg_num.family == rn->family &&
430                                 sl->reg_num.id == rn->id &&
431                                 sl->reg_num.crc == rn->crc) {
432                         return sl;
433                 }
434         }
435         return NULL;
436 }
437
438 static ssize_t w1_master_attribute_store_add(struct device *dev,
439                                                 struct device_attribute *attr,
440                                                 const char *buf, size_t count)
441 {
442         struct w1_master *md = dev_to_w1_master(dev);
443         struct w1_reg_num rn;
444         struct w1_slave *sl;
445         ssize_t result = count;
446
447         if (w1_atoreg_num(dev, buf, count, &rn))
448                 return -EINVAL;
449
450         mutex_lock(&md->mutex);
451         sl = w1_slave_search_device(md, &rn);
452         /* It would be nice to do a targeted search one the one-wire bus
453          * for the new device to see if it is out there or not.  But the
454          * current search doesn't support that.
455          */
456         if (sl) {
457                 dev_info(dev, "Device %s already exists\n", sl->name);
458                 result = -EINVAL;
459         } else {
460                 w1_attach_slave_device(md, &rn);
461         }
462         mutex_unlock(&md->mutex);
463
464         return result;
465 }
466
467 static ssize_t w1_master_attribute_show_remove(struct device *dev,
468         struct device_attribute *attr, char *buf)
469 {
470         int c = PAGE_SIZE;
471         c -= snprintf(buf+PAGE_SIZE - c, c,
472                 "write device id xx-xxxxxxxxxxxx to remove slave\n");
473         return PAGE_SIZE - c;
474 }
475
476 static ssize_t w1_master_attribute_store_remove(struct device *dev,
477                                                 struct device_attribute *attr,
478                                                 const char *buf, size_t count)
479 {
480         struct w1_master *md = dev_to_w1_master(dev);
481         struct w1_reg_num rn;
482         struct w1_slave *sl;
483         ssize_t result = count;
484
485         if (w1_atoreg_num(dev, buf, count, &rn))
486                 return -EINVAL;
487
488         mutex_lock(&md->mutex);
489         sl = w1_slave_search_device(md, &rn);
490         if (sl) {
491                 w1_slave_detach(sl);
492         } else {
493                 dev_info(dev, "Device %02x-%012llx doesn't exists\n", rn.family,
494                         (unsigned long long)rn.id);
495                 result = -EINVAL;
496         }
497         mutex_unlock(&md->mutex);
498
499         return result;
500 }
501
502 #define W1_MASTER_ATTR_RO(_name, _mode)                         \
503         struct device_attribute w1_master_attribute_##_name =   \
504                 __ATTR(w1_master_##_name, _mode,                \
505                        w1_master_attribute_show_##_name, NULL)
506
507 #define W1_MASTER_ATTR_RW(_name, _mode)                         \
508         struct device_attribute w1_master_attribute_##_name =   \
509                 __ATTR(w1_master_##_name, _mode,                \
510                        w1_master_attribute_show_##_name,        \
511                        w1_master_attribute_store_##_name)
512
513 static W1_MASTER_ATTR_RO(name, S_IRUGO);
514 static W1_MASTER_ATTR_RO(slaves, S_IRUGO);
515 static W1_MASTER_ATTR_RO(slave_count, S_IRUGO);
516 static W1_MASTER_ATTR_RO(max_slave_count, S_IRUGO);
517 static W1_MASTER_ATTR_RO(attempts, S_IRUGO);
518 static W1_MASTER_ATTR_RO(timeout, S_IRUGO);
519 static W1_MASTER_ATTR_RO(pointer, S_IRUGO);
520 static W1_MASTER_ATTR_RW(search, S_IRUGO | S_IWUGO);
521 static W1_MASTER_ATTR_RW(pullup, S_IRUGO | S_IWUGO);
522 static W1_MASTER_ATTR_RW(add, S_IRUGO | S_IWUGO);
523 static W1_MASTER_ATTR_RW(remove, S_IRUGO | S_IWUGO);
524
525 static struct attribute *w1_master_default_attrs[] = {
526         &w1_master_attribute_name.attr,
527         &w1_master_attribute_slaves.attr,
528         &w1_master_attribute_slave_count.attr,
529         &w1_master_attribute_max_slave_count.attr,
530         &w1_master_attribute_attempts.attr,
531         &w1_master_attribute_timeout.attr,
532         &w1_master_attribute_pointer.attr,
533         &w1_master_attribute_search.attr,
534         &w1_master_attribute_pullup.attr,
535         &w1_master_attribute_add.attr,
536         &w1_master_attribute_remove.attr,
537         NULL
538 };
539
540 static struct attribute_group w1_master_defattr_group = {
541         .attrs = w1_master_default_attrs,
542 };
543
544 int w1_create_master_attributes(struct w1_master *master)
545 {
546         return sysfs_create_group(&master->dev.kobj, &w1_master_defattr_group);
547 }
548
549 void w1_destroy_master_attributes(struct w1_master *master)
550 {
551         sysfs_remove_group(&master->dev.kobj, &w1_master_defattr_group);
552 }
553
554 #ifdef CONFIG_HOTPLUG
555 static int w1_uevent(struct device *dev, struct kobj_uevent_env *env)
556 {
557         struct w1_master *md = NULL;
558         struct w1_slave *sl = NULL;
559         char *event_owner, *name;
560         int err;
561
562         if (dev->driver == &w1_master_driver) {
563                 md = container_of(dev, struct w1_master, dev);
564                 event_owner = "master";
565                 name = md->name;
566         } else if (dev->driver == &w1_slave_driver) {
567                 sl = container_of(dev, struct w1_slave, dev);
568                 event_owner = "slave";
569                 name = sl->name;
570         } else {
571                 dev_dbg(dev, "Unknown event.\n");
572                 return -EINVAL;
573         }
574
575         dev_dbg(dev, "Hotplug event for %s %s, bus_id=%s.\n",
576                         event_owner, name, dev_name(dev));
577
578         if (dev->driver != &w1_slave_driver || !sl)
579                 return 0;
580
581         err = add_uevent_var(env, "W1_FID=%02X", sl->reg_num.family);
582         if (err)
583                 return err;
584
585         err = add_uevent_var(env, "W1_SLAVE_ID=%024LX",
586                              (unsigned long long)sl->reg_num.id);
587         if (err)
588                 return err;
589
590         return 0;
591 };
592 #else
593 static int w1_uevent(struct device *dev, struct kobj_uevent_env *env)
594 {
595         return 0;
596 }
597 #endif
598
599 static int __w1_attach_slave_device(struct w1_slave *sl)
600 {
601         int err;
602
603         sl->dev.parent = &sl->master->dev;
604         sl->dev.driver = &w1_slave_driver;
605         sl->dev.bus = &w1_bus_type;
606         sl->dev.release = &w1_slave_release;
607
608         dev_set_name(&sl->dev, "%02x-%012llx",
609                  (unsigned int) sl->reg_num.family,
610                  (unsigned long long) sl->reg_num.id);
611         snprintf(&sl->name[0], sizeof(sl->name),
612                  "%02x-%012llx",
613                  (unsigned int) sl->reg_num.family,
614                  (unsigned long long) sl->reg_num.id);
615
616         dev_dbg(&sl->dev, "%s: registering %s as %p.\n", __func__,
617                 dev_name(&sl->dev), sl);
618
619         err = device_register(&sl->dev);
620         if (err < 0) {
621                 dev_err(&sl->dev,
622                         "Device registration [%s] failed. err=%d\n",
623                         dev_name(&sl->dev), err);
624                 return err;
625         }
626
627         /* Create "name" entry */
628         err = device_create_file(&sl->dev, &w1_slave_attr_name);
629         if (err < 0) {
630                 dev_err(&sl->dev,
631                         "sysfs file creation for [%s] failed. err=%d\n",
632                         dev_name(&sl->dev), err);
633                 goto out_unreg;
634         }
635
636         /* Create "id" entry */
637         err = device_create_file(&sl->dev, &w1_slave_attr_id);
638         if (err < 0) {
639                 dev_err(&sl->dev,
640                         "sysfs file creation for [%s] failed. err=%d\n",
641                         dev_name(&sl->dev), err);
642                 goto out_rem1;
643         }
644
645         /* if the family driver needs to initialize something... */
646         if (sl->family->fops && sl->family->fops->add_slave &&
647             ((err = sl->family->fops->add_slave(sl)) < 0)) {
648                 dev_err(&sl->dev,
649                         "sysfs file creation for [%s] failed. err=%d\n",
650                         dev_name(&sl->dev), err);
651                 goto out_rem2;
652         }
653
654         list_add_tail(&sl->w1_slave_entry, &sl->master->slist);
655
656         return 0;
657
658 out_rem2:
659         device_remove_file(&sl->dev, &w1_slave_attr_id);
660 out_rem1:
661         device_remove_file(&sl->dev, &w1_slave_attr_name);
662 out_unreg:
663         device_unregister(&sl->dev);
664         return err;
665 }
666
667 static int w1_attach_slave_device(struct w1_master *dev, struct w1_reg_num *rn)
668 {
669         struct w1_slave *sl;
670         struct w1_family *f;
671         int err;
672         struct w1_netlink_msg msg;
673
674         sl = kzalloc(sizeof(struct w1_slave), GFP_KERNEL);
675         if (!sl) {
676                 dev_err(&dev->dev,
677                          "%s: failed to allocate new slave device.\n",
678                          __func__);
679                 return -ENOMEM;
680         }
681
682
683         sl->owner = THIS_MODULE;
684         sl->master = dev;
685         set_bit(W1_SLAVE_ACTIVE, (long *)&sl->flags);
686
687         memset(&msg, 0, sizeof(msg));
688         memcpy(&sl->reg_num, rn, sizeof(sl->reg_num));
689         atomic_set(&sl->refcnt, 0);
690         init_completion(&sl->released);
691
692         spin_lock(&w1_flock);
693         f = w1_family_registered(rn->family);
694         if (!f) {
695                 f= &w1_default_family;
696                 dev_info(&dev->dev, "Family %x for %02x.%012llx.%02x is not registered.\n",
697                           rn->family, rn->family,
698                           (unsigned long long)rn->id, rn->crc);
699         }
700         __w1_family_get(f);
701         spin_unlock(&w1_flock);
702
703         sl->family = f;
704
705
706         err = __w1_attach_slave_device(sl);
707         if (err < 0) {
708                 dev_err(&dev->dev, "%s: Attaching %s failed.\n", __func__,
709                          sl->name);
710                 w1_family_put(sl->family);
711                 kfree(sl);
712                 return err;
713         }
714
715         sl->ttl = dev->slave_ttl;
716         dev->slave_count++;
717
718         memcpy(msg.id.id, rn, sizeof(msg.id));
719         msg.type = W1_SLAVE_ADD;
720         w1_netlink_send(dev, &msg);
721
722         return 0;
723 }
724
725 void w1_slave_detach(struct w1_slave *sl)
726 {
727         struct w1_netlink_msg msg;
728
729         dev_dbg(&sl->dev, "%s: detaching %s [%p].\n", __func__, sl->name, sl);
730
731         list_del(&sl->w1_slave_entry);
732
733         if (sl->family->fops && sl->family->fops->remove_slave)
734                 sl->family->fops->remove_slave(sl);
735
736         memset(&msg, 0, sizeof(msg));
737         memcpy(msg.id.id, &sl->reg_num, sizeof(msg.id));
738         msg.type = W1_SLAVE_REMOVE;
739         w1_netlink_send(sl->master, &msg);
740
741         device_remove_file(&sl->dev, &w1_slave_attr_id);
742         device_remove_file(&sl->dev, &w1_slave_attr_name);
743         device_unregister(&sl->dev);
744
745         wait_for_completion(&sl->released);
746         kfree(sl);
747 }
748
749 struct w1_master *w1_search_master_id(u32 id)
750 {
751         struct w1_master *dev;
752         int found = 0;
753
754         mutex_lock(&w1_mlock);
755         list_for_each_entry(dev, &w1_masters, w1_master_entry) {
756                 if (dev->id == id) {
757                         found = 1;
758                         atomic_inc(&dev->refcnt);
759                         break;
760                 }
761         }
762         mutex_unlock(&w1_mlock);
763
764         return (found)?dev:NULL;
765 }
766
767 struct w1_slave *w1_search_slave(struct w1_reg_num *id)
768 {
769         struct w1_master *dev;
770         struct w1_slave *sl = NULL;
771         int found = 0;
772
773         mutex_lock(&w1_mlock);
774         list_for_each_entry(dev, &w1_masters, w1_master_entry) {
775                 mutex_lock(&dev->mutex);
776                 list_for_each_entry(sl, &dev->slist, w1_slave_entry) {
777                         if (sl->reg_num.family == id->family &&
778                                         sl->reg_num.id == id->id &&
779                                         sl->reg_num.crc == id->crc) {
780                                 found = 1;
781                                 atomic_inc(&dev->refcnt);
782                                 atomic_inc(&sl->refcnt);
783                                 break;
784                         }
785                 }
786                 mutex_unlock(&dev->mutex);
787
788                 if (found)
789                         break;
790         }
791         mutex_unlock(&w1_mlock);
792
793         return (found)?sl:NULL;
794 }
795
796 void w1_reconnect_slaves(struct w1_family *f, int attach)
797 {
798         struct w1_slave *sl, *sln;
799         struct w1_master *dev;
800
801         mutex_lock(&w1_mlock);
802         list_for_each_entry(dev, &w1_masters, w1_master_entry) {
803                 dev_dbg(&dev->dev, "Reconnecting slaves in device %s "
804                         "for family %02x.\n", dev->name, f->fid);
805                 mutex_lock(&dev->mutex);
806                 list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) {
807                         /* If it is a new family, slaves with the default
808                          * family driver and are that family will be
809                          * connected.  If the family is going away, devices
810                          * matching that family are reconneced.
811                          */
812                         if ((attach && sl->family->fid == W1_FAMILY_DEFAULT
813                                 && sl->reg_num.family == f->fid) ||
814                                 (!attach && sl->family->fid == f->fid)) {
815                                 struct w1_reg_num rn;
816
817                                 memcpy(&rn, &sl->reg_num, sizeof(rn));
818                                 w1_slave_detach(sl);
819
820                                 w1_attach_slave_device(dev, &rn);
821                         }
822                 }
823                 dev_dbg(&dev->dev, "Reconnecting slaves in device %s "
824                         "has been finished.\n", dev->name);
825                 mutex_unlock(&dev->mutex);
826         }
827         mutex_unlock(&w1_mlock);
828 }
829
830 static void w1_slave_found(struct w1_master *dev, u64 rn)
831 {
832         struct w1_slave *sl;
833         struct w1_reg_num *tmp;
834         u64 rn_le = cpu_to_le64(rn);
835
836         atomic_inc(&dev->refcnt);
837
838         tmp = (struct w1_reg_num *) &rn;
839
840         sl = w1_slave_search_device(dev, tmp);
841         if (sl) {
842                 set_bit(W1_SLAVE_ACTIVE, (long *)&sl->flags);
843         } else {
844                 if (rn && tmp->crc == w1_calc_crc8((u8 *)&rn_le, 7))
845                         w1_attach_slave_device(dev, tmp);
846         }
847
848         atomic_dec(&dev->refcnt);
849 }
850
851 /**
852  * Performs a ROM Search & registers any devices found.
853  * The 1-wire search is a simple binary tree search.
854  * For each bit of the address, we read two bits and write one bit.
855  * The bit written will put to sleep all devies that don't match that bit.
856  * When the two reads differ, the direction choice is obvious.
857  * When both bits are 0, we must choose a path to take.
858  * When we can scan all 64 bits without having to choose a path, we are done.
859  *
860  * See "Application note 187 1-wire search algorithm" at www.maxim-ic.com
861  *
862  * @dev        The master device to search
863  * @cb         Function to call when a device is found
864  */
865 void w1_search(struct w1_master *dev, u8 search_type, w1_slave_found_callback cb)
866 {
867         u64 last_rn, rn, tmp64;
868         int i, slave_count = 0;
869         int last_zero, last_device;
870         int search_bit, desc_bit;
871         u8  triplet_ret = 0;
872
873         search_bit = 0;
874         rn = last_rn = 0;
875         last_device = 0;
876         last_zero = -1;
877
878         desc_bit = 64;
879
880         while ( !last_device && (slave_count++ < dev->max_slave_count) ) {
881                 last_rn = rn;
882                 rn = 0;
883
884                 /*
885                  * Reset bus and all 1-wire device state machines
886                  * so they can respond to our requests.
887                  *
888                  * Return 0 - device(s) present, 1 - no devices present.
889                  */
890                 if (w1_reset_bus(dev)) {
891                         dev_dbg(&dev->dev, "No devices present on the wire.\n");
892                         break;
893                 }
894
895                 /* Start the search */
896                 w1_write_8(dev, search_type);
897                 for (i = 0; i < 64; ++i) {
898                         /* Determine the direction/search bit */
899                         if (i == desc_bit)
900                                 search_bit = 1;   /* took the 0 path last time, so take the 1 path */
901                         else if (i > desc_bit)
902                                 search_bit = 0;   /* take the 0 path on the next branch */
903                         else
904                                 search_bit = ((last_rn >> i) & 0x1);
905
906                         /** Read two bits and write one bit */
907                         triplet_ret = w1_triplet(dev, search_bit);
908
909                         /* quit if no device responded */
910                         if ( (triplet_ret & 0x03) == 0x03 )
911                                 break;
912
913                         /* If both directions were valid, and we took the 0 path... */
914                         if (triplet_ret == 0)
915                                 last_zero = i;
916
917                         /* extract the direction taken & update the device number */
918                         tmp64 = (triplet_ret >> 2);
919                         rn |= (tmp64 << i);
920
921                         if (kthread_should_stop()) {
922                                 dev_dbg(&dev->dev, "Abort w1_search\n");
923                                 return;
924                         }
925                 }
926
927                 if ( (triplet_ret & 0x03) != 0x03 ) {
928                         if ( (desc_bit == last_zero) || (last_zero < 0))
929                                 last_device = 1;
930                         desc_bit = last_zero;
931                         cb(dev, rn);
932                 }
933         }
934 }
935
936 void w1_search_process(struct w1_master *dev, u8 search_type)
937 {
938         struct w1_slave *sl, *sln;
939
940         list_for_each_entry(sl, &dev->slist, w1_slave_entry)
941                 clear_bit(W1_SLAVE_ACTIVE, (long *)&sl->flags);
942
943         w1_search_devices(dev, search_type, w1_slave_found);
944
945         list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) {
946                 if (!test_bit(W1_SLAVE_ACTIVE, (unsigned long *)&sl->flags) && !--sl->ttl)
947                         w1_slave_detach(sl);
948                 else if (test_bit(W1_SLAVE_ACTIVE, (unsigned long *)&sl->flags))
949                         sl->ttl = dev->slave_ttl;
950         }
951
952         if (dev->search_count > 0)
953                 dev->search_count--;
954 }
955
956 int w1_process(void *data)
957 {
958         struct w1_master *dev = (struct w1_master *) data;
959         /* As long as w1_timeout is only set by a module parameter the sleep
960          * time can be calculated in jiffies once.
961          */
962         const unsigned long jtime = msecs_to_jiffies(w1_timeout * 1000);
963
964         while (!kthread_should_stop()) {
965                 if (dev->search_count) {
966                         mutex_lock(&dev->mutex);
967                         w1_search_process(dev, W1_SEARCH);
968                         mutex_unlock(&dev->mutex);
969                 }
970
971                 try_to_freeze();
972                 __set_current_state(TASK_INTERRUPTIBLE);
973
974                 if (kthread_should_stop())
975                         break;
976
977                 /* Only sleep when the search is active. */
978                 if (dev->search_count)
979                         schedule_timeout(jtime);
980                 else
981                         schedule();
982         }
983
984         atomic_dec(&dev->refcnt);
985
986         return 0;
987 }
988
989 static int __init w1_init(void)
990 {
991         int retval;
992
993         printk(KERN_INFO "Driver for 1-wire Dallas network protocol.\n");
994
995         w1_init_netlink();
996
997         retval = bus_register(&w1_bus_type);
998         if (retval) {
999                 printk(KERN_ERR "Failed to register bus. err=%d.\n", retval);
1000                 goto err_out_exit_init;
1001         }
1002
1003         retval = driver_register(&w1_master_driver);
1004         if (retval) {
1005                 printk(KERN_ERR
1006                         "Failed to register master driver. err=%d.\n",
1007                         retval);
1008                 goto err_out_bus_unregister;
1009         }
1010
1011         retval = driver_register(&w1_slave_driver);
1012         if (retval) {
1013                 printk(KERN_ERR
1014                         "Failed to register master driver. err=%d.\n",
1015                         retval);
1016                 goto err_out_master_unregister;
1017         }
1018
1019         return 0;
1020
1021 #if 0
1022 /* For undoing the slave register if there was a step after it. */
1023 err_out_slave_unregister:
1024         driver_unregister(&w1_slave_driver);
1025 #endif
1026
1027 err_out_master_unregister:
1028         driver_unregister(&w1_master_driver);
1029
1030 err_out_bus_unregister:
1031         bus_unregister(&w1_bus_type);
1032
1033 err_out_exit_init:
1034         return retval;
1035 }
1036
1037 static void __exit w1_fini(void)
1038 {
1039         struct w1_master *dev;
1040
1041         /* Set netlink removal messages and some cleanup */
1042         list_for_each_entry(dev, &w1_masters, w1_master_entry)
1043                 __w1_remove_master_device(dev);
1044
1045         w1_fini_netlink();
1046
1047         driver_unregister(&w1_slave_driver);
1048         driver_unregister(&w1_master_driver);
1049         bus_unregister(&w1_bus_type);
1050 }
1051
1052 module_init(w1_init);
1053 module_exit(w1_fini);