W1: abort search early on on exit
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / w1 / w1.c
CommitLineData
1da177e4 1/*
7785925d 2 * w1.c
1da177e4
LT
3 *
4 * Copyright (c) 2004 Evgeniy Polyakov <johnpol@2ka.mipt.ru>
7785925d 5 *
1da177e4
LT
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>
674a396c 33#include <linux/kthread.h>
7dfb7103 34#include <linux/freezer.h>
1da177e4
LT
35
36#include <asm/atomic.h>
37
38#include "w1.h"
1da177e4
LT
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
abd52a13 56DEFINE_MUTEX(w1_mlock);
1da177e4
LT
57LIST_HEAD(w1_masters);
58
1da177e4
LT
59static int w1_master_match(struct device *dev, struct device_driver *drv)
60{
61 return 1;
62}
63
64static int w1_master_probe(struct device *dev)
65{
66 return -ENODEV;
67}
68
1da177e4
LT
69static void w1_master_release(struct device *dev)
70{
db2d0008 71 struct w1_master *md = dev_to_w1_master(dev);
3aca692d
EP
72
73 dev_dbg(dev, "%s: Releasing %s.\n", __func__, md->name);
3aca692d
EP
74 memset(md, 0, sizeof(struct w1_master) + sizeof(struct w1_bus_master));
75 kfree(md);
1da177e4
LT
76}
77
78static void w1_slave_release(struct device *dev)
79{
db2d0008 80 struct w1_slave *sl = dev_to_w1_slave(dev);
3aca692d 81
12003375 82 printk("%s: Releasing %s.\n", __func__, sl->name);
3aca692d
EP
83
84 while (atomic_read(&sl->refcnt)) {
12003375 85 printk("Waiting for %s to become free: refcnt=%d.\n",
3aca692d
EP
86 sl->name, atomic_read(&sl->refcnt));
87 if (msleep_interruptible(1000))
88 flush_signals(current);
89 }
90
91 w1_family_put(sl->family);
92 sl->master->slave_count--;
93
94 complete(&sl->released);
1da177e4
LT
95}
96
d2a4ef6a 97static ssize_t w1_slave_read_name(struct device *dev, struct device_attribute *attr, char *buf)
1da177e4 98{
3aca692d 99 struct w1_slave *sl = dev_to_w1_slave(dev);
d2a4ef6a 100
3aca692d 101 return sprintf(buf, "%s\n", sl->name);
1da177e4
LT
102}
103
91a69029
ZR
104static ssize_t w1_slave_read_id(struct kobject *kobj,
105 struct bin_attribute *bin_attr,
106 char *buf, loff_t off, size_t count)
1da177e4 107{
3aca692d 108 struct w1_slave *sl = kobj_to_w1_slave(kobj);
1da177e4 109
3aca692d
EP
110 if (off > 8) {
111 count = 0;
d2a4ef6a
EP
112 } else {
113 if (off + count > 8)
114 count = 8 - off;
115
116 memcpy(buf, (u8 *)&sl->reg_num, count);
117 }
d2a4ef6a
EP
118
119 return count;
3aca692d 120}
d2a4ef6a
EP
121
122static struct device_attribute w1_slave_attr_name =
123 __ATTR(name, S_IRUGO, w1_slave_read_name, NULL);
124
125static struct bin_attribute w1_slave_attr_bin_id = {
126 .attr = {
127 .name = "id",
128 .mode = S_IRUGO,
d2a4ef6a
EP
129 },
130 .size = 8,
131 .read = w1_slave_read_id,
7785925d
EP
132};
133
d2a4ef6a 134/* Default family */
f522d239 135
91a69029
ZR
136static ssize_t w1_default_write(struct kobject *kobj,
137 struct bin_attribute *bin_attr,
138 char *buf, loff_t off, size_t count)
f522d239
EP
139{
140 struct w1_slave *sl = kobj_to_w1_slave(kobj);
141
abd52a13 142 mutex_lock(&sl->master->mutex);
f522d239
EP
143 if (w1_reset_select_slave(sl)) {
144 count = 0;
145 goto out_up;
146 }
147
148 w1_write_block(sl->master, buf, count);
149
150out_up:
abd52a13 151 mutex_unlock(&sl->master->mutex);
f522d239
EP
152 return count;
153}
154
91a69029
ZR
155static ssize_t w1_default_read(struct kobject *kobj,
156 struct bin_attribute *bin_attr,
157 char *buf, loff_t off, size_t count)
f522d239
EP
158{
159 struct w1_slave *sl = kobj_to_w1_slave(kobj);
160
abd52a13 161 mutex_lock(&sl->master->mutex);
f522d239 162 w1_read_block(sl->master, buf, count);
abd52a13 163 mutex_unlock(&sl->master->mutex);
f522d239
EP
164 return count;
165}
166
167static struct bin_attribute w1_default_attr = {
168 .attr = {
169 .name = "rw",
170 .mode = S_IRUGO | S_IWUSR,
f522d239
EP
171 },
172 .size = PAGE_SIZE,
173 .read = w1_default_read,
174 .write = w1_default_write,
175};
176
177static int w1_default_add_slave(struct w1_slave *sl)
178{
179 return sysfs_create_bin_file(&sl->dev.kobj, &w1_default_attr);
180}
181
182static void w1_default_remove_slave(struct w1_slave *sl)
183{
184 sysfs_remove_bin_file(&sl->dev.kobj, &w1_default_attr);
185}
186
187static struct w1_family_ops w1_default_fops = {
188 .add_slave = w1_default_add_slave,
189 .remove_slave = w1_default_remove_slave,
190};
191
192static struct w1_family w1_default_family = {
193 .fops = &w1_default_fops,
194};
d2a4ef6a 195
7eff2e7a 196static int w1_uevent(struct device *dev, struct kobj_uevent_env *env);
7785925d 197
1da177e4
LT
198static struct bus_type w1_bus_type = {
199 .name = "w1",
200 .match = w1_master_match,
312c004d 201 .uevent = w1_uevent,
1da177e4
LT
202};
203
7f772ed8
EP
204struct device_driver w1_master_driver = {
205 .name = "w1_master_driver",
1da177e4
LT
206 .bus = &w1_bus_type,
207 .probe = w1_master_probe,
1da177e4
LT
208};
209
7f772ed8 210struct device w1_master_device = {
1da177e4
LT
211 .parent = NULL,
212 .bus = &w1_bus_type,
213 .bus_id = "w1 bus master",
7f772ed8 214 .driver = &w1_master_driver,
1da177e4
LT
215 .release = &w1_master_release
216};
217
2c5bfdac 218static struct device_driver w1_slave_driver = {
7f772ed8
EP
219 .name = "w1_slave_driver",
220 .bus = &w1_bus_type,
221};
222
2c5bfdac 223#if 0
7f772ed8
EP
224struct device w1_slave_device = {
225 .parent = NULL,
226 .bus = &w1_bus_type,
227 .bus_id = "w1 bus slave",
228 .driver = &w1_slave_driver,
3aca692d 229 .release = &w1_slave_release
7f772ed8 230};
2c5bfdac 231#endif /* 0 */
7f772ed8 232
060b8845 233static ssize_t w1_master_attribute_show_name(struct device *dev, struct device_attribute *attr, char *buf)
1da177e4 234{
db2d0008 235 struct w1_master *md = dev_to_w1_master(dev);
1da177e4 236 ssize_t count;
7785925d 237
abd52a13 238 mutex_lock(&md->mutex);
1da177e4 239 count = sprintf(buf, "%s\n", md->name);
abd52a13 240 mutex_unlock(&md->mutex);
1da177e4
LT
241
242 return count;
243}
244
2a9d0c17
EP
245static ssize_t w1_master_attribute_store_search(struct device * dev,
246 struct device_attribute *attr,
247 const char * buf, size_t count)
248{
db2d0008 249 struct w1_master *md = dev_to_w1_master(dev);
2a9d0c17 250
abd52a13 251 mutex_lock(&md->mutex);
2a9d0c17 252 md->search_count = simple_strtol(buf, NULL, 0);
abd52a13 253 mutex_unlock(&md->mutex);
2a9d0c17
EP
254
255 return count;
256}
257
258static ssize_t w1_master_attribute_show_search(struct device *dev,
259 struct device_attribute *attr,
260 char *buf)
261{
db2d0008 262 struct w1_master *md = dev_to_w1_master(dev);
2a9d0c17
EP
263 ssize_t count;
264
abd52a13 265 mutex_lock(&md->mutex);
2a9d0c17 266 count = sprintf(buf, "%d\n", md->search_count);
abd52a13 267 mutex_unlock(&md->mutex);
2a9d0c17
EP
268
269 return count;
270}
271
060b8845 272static ssize_t w1_master_attribute_show_pointer(struct device *dev, struct device_attribute *attr, char *buf)
1da177e4 273{
db2d0008 274 struct w1_master *md = dev_to_w1_master(dev);
1da177e4 275 ssize_t count;
7785925d 276
abd52a13 277 mutex_lock(&md->mutex);
1da177e4 278 count = sprintf(buf, "0x%p\n", md->bus_master);
abd52a13 279 mutex_unlock(&md->mutex);
1da177e4
LT
280 return count;
281}
282
060b8845 283static ssize_t w1_master_attribute_show_timeout(struct device *dev, struct device_attribute *attr, char *buf)
1da177e4
LT
284{
285 ssize_t count;
286 count = sprintf(buf, "%d\n", w1_timeout);
287 return count;
288}
289
060b8845 290static ssize_t w1_master_attribute_show_max_slave_count(struct device *dev, struct device_attribute *attr, char *buf)
1da177e4 291{
db2d0008 292 struct w1_master *md = dev_to_w1_master(dev);
1da177e4 293 ssize_t count;
7785925d 294
abd52a13 295 mutex_lock(&md->mutex);
1da177e4 296 count = sprintf(buf, "%d\n", md->max_slave_count);
abd52a13 297 mutex_unlock(&md->mutex);
1da177e4
LT
298 return count;
299}
300
060b8845 301static ssize_t w1_master_attribute_show_attempts(struct device *dev, struct device_attribute *attr, char *buf)
1da177e4 302{
db2d0008 303 struct w1_master *md = dev_to_w1_master(dev);
1da177e4 304 ssize_t count;
7785925d 305
abd52a13 306 mutex_lock(&md->mutex);
1da177e4 307 count = sprintf(buf, "%lu\n", md->attempts);
abd52a13 308 mutex_unlock(&md->mutex);
1da177e4
LT
309 return count;
310}
311
060b8845 312static ssize_t w1_master_attribute_show_slave_count(struct device *dev, struct device_attribute *attr, char *buf)
1da177e4 313{
db2d0008 314 struct w1_master *md = dev_to_w1_master(dev);
1da177e4 315 ssize_t count;
7785925d 316
abd52a13 317 mutex_lock(&md->mutex);
1da177e4 318 count = sprintf(buf, "%d\n", md->slave_count);
abd52a13 319 mutex_unlock(&md->mutex);
1da177e4
LT
320 return count;
321}
322
060b8845 323static ssize_t w1_master_attribute_show_slaves(struct device *dev, struct device_attribute *attr, char *buf)
1da177e4 324{
db2d0008 325 struct w1_master *md = dev_to_w1_master(dev);
1da177e4
LT
326 int c = PAGE_SIZE;
327
abd52a13 328 mutex_lock(&md->mutex);
1da177e4
LT
329
330 if (md->slave_count == 0)
331 c -= snprintf(buf + PAGE_SIZE - c, c, "not found.\n");
332 else {
333 struct list_head *ent, *n;
334 struct w1_slave *sl;
335
336 list_for_each_safe(ent, n, &md->slist) {
337 sl = list_entry(ent, struct w1_slave, w1_slave_entry);
338
7785925d 339 c -= snprintf(buf + PAGE_SIZE - c, c, "%s\n", sl->name);
1da177e4
LT
340 }
341 }
342
abd52a13 343 mutex_unlock(&md->mutex);
1da177e4
LT
344
345 return PAGE_SIZE - c;
346}
347
7785925d
EP
348#define W1_MASTER_ATTR_RO(_name, _mode) \
349 struct device_attribute w1_master_attribute_##_name = \
350 __ATTR(w1_master_##_name, _mode, \
351 w1_master_attribute_show_##_name, NULL)
352
2a9d0c17
EP
353#define W1_MASTER_ATTR_RW(_name, _mode) \
354 struct device_attribute w1_master_attribute_##_name = \
355 __ATTR(w1_master_##_name, _mode, \
356 w1_master_attribute_show_##_name, \
357 w1_master_attribute_store_##_name)
358
7785925d
EP
359static W1_MASTER_ATTR_RO(name, S_IRUGO);
360static W1_MASTER_ATTR_RO(slaves, S_IRUGO);
361static W1_MASTER_ATTR_RO(slave_count, S_IRUGO);
362static W1_MASTER_ATTR_RO(max_slave_count, S_IRUGO);
363static W1_MASTER_ATTR_RO(attempts, S_IRUGO);
364static W1_MASTER_ATTR_RO(timeout, S_IRUGO);
365static W1_MASTER_ATTR_RO(pointer, S_IRUGO);
2a9d0c17 366static W1_MASTER_ATTR_RW(search, S_IRUGO | S_IWUGO);
7785925d
EP
367
368static struct attribute *w1_master_default_attrs[] = {
369 &w1_master_attribute_name.attr,
370 &w1_master_attribute_slaves.attr,
371 &w1_master_attribute_slave_count.attr,
372 &w1_master_attribute_max_slave_count.attr,
373 &w1_master_attribute_attempts.attr,
374 &w1_master_attribute_timeout.attr,
375 &w1_master_attribute_pointer.attr,
2a9d0c17 376 &w1_master_attribute_search.attr,
7785925d 377 NULL
1da177e4
LT
378};
379
7785925d
EP
380static struct attribute_group w1_master_defattr_group = {
381 .attrs = w1_master_default_attrs,
1da177e4
LT
382};
383
7785925d
EP
384int w1_create_master_attributes(struct w1_master *master)
385{
386 return sysfs_create_group(&master->dev.kobj, &w1_master_defattr_group);
387}
388
c30c9b15 389void w1_destroy_master_attributes(struct w1_master *master)
7785925d
EP
390{
391 sysfs_remove_group(&master->dev.kobj, &w1_master_defattr_group);
392}
393
7f772ed8 394#ifdef CONFIG_HOTPLUG
7eff2e7a 395static int w1_uevent(struct device *dev, struct kobj_uevent_env *env)
7f772ed8
EP
396{
397 struct w1_master *md = NULL;
398 struct w1_slave *sl = NULL;
399 char *event_owner, *name;
7eff2e7a 400 int err;
7f772ed8
EP
401
402 if (dev->driver == &w1_master_driver) {
403 md = container_of(dev, struct w1_master, dev);
404 event_owner = "master";
405 name = md->name;
406 } else if (dev->driver == &w1_slave_driver) {
407 sl = container_of(dev, struct w1_slave, dev);
408 event_owner = "slave";
409 name = sl->name;
410 } else {
312c004d 411 dev_dbg(dev, "Unknown event.\n");
7f772ed8
EP
412 return -EINVAL;
413 }
414
c6976a4e
AM
415 dev_dbg(dev, "Hotplug event for %s %s, bus_id=%s.\n",
416 event_owner, name, dev->bus_id);
7f772ed8
EP
417
418 if (dev->driver != &w1_slave_driver || !sl)
419 return 0;
420
7eff2e7a 421 err = add_uevent_var(env, "W1_FID=%02X", sl->reg_num.family);
7f772ed8
EP
422 if (err)
423 return err;
424
7eff2e7a
KS
425 err = add_uevent_var(env, "W1_SLAVE_ID=%024LX",
426 (unsigned long long)sl->reg_num.id);
7f772ed8
EP
427 if (err)
428 return err;
429
430 return 0;
431};
432#else
7eff2e7a 433static int w1_uevent(struct device *dev, struct kobj_uevent_env *env)
7f772ed8
EP
434{
435 return 0;
436}
437#endif
438
1da177e4
LT
439static int __w1_attach_slave_device(struct w1_slave *sl)
440{
441 int err;
442
443 sl->dev.parent = &sl->master->dev;
7f772ed8 444 sl->dev.driver = &w1_slave_driver;
1da177e4
LT
445 sl->dev.bus = &w1_bus_type;
446 sl->dev.release = &w1_slave_release;
447
448 snprintf(&sl->dev.bus_id[0], sizeof(sl->dev.bus_id),
6b729861
EP
449 "%02x-%012llx",
450 (unsigned int) sl->reg_num.family,
451 (unsigned long long) sl->reg_num.id);
452 snprintf(&sl->name[0], sizeof(sl->name),
453 "%02x-%012llx",
454 (unsigned int) sl->reg_num.family,
455 (unsigned long long) sl->reg_num.id);
1da177e4 456
c6976a4e 457 dev_dbg(&sl->dev, "%s: registering %s as %p.\n", __func__,
60ed34be 458 &sl->dev.bus_id[0], sl);
1da177e4
LT
459
460 err = device_register(&sl->dev);
461 if (err < 0) {
462 dev_err(&sl->dev,
6b729861
EP
463 "Device registration [%s] failed. err=%d\n",
464 sl->dev.bus_id, err);
1da177e4
LT
465 return err;
466 }
467
d2a4ef6a
EP
468 /* Create "name" entry */
469 err = device_create_file(&sl->dev, &w1_slave_attr_name);
470 if (err < 0) {
471 dev_err(&sl->dev,
472 "sysfs file creation for [%s] failed. err=%d\n",
473 sl->dev.bus_id, err);
474 goto out_unreg;
475 }
1da177e4 476
d2a4ef6a
EP
477 /* Create "id" entry */
478 err = sysfs_create_bin_file(&sl->dev.kobj, &w1_slave_attr_bin_id);
1da177e4
LT
479 if (err < 0) {
480 dev_err(&sl->dev,
6b729861
EP
481 "sysfs file creation for [%s] failed. err=%d\n",
482 sl->dev.bus_id, err);
d2a4ef6a 483 goto out_rem1;
1da177e4
LT
484 }
485
d2a4ef6a
EP
486 /* if the family driver needs to initialize something... */
487 if (sl->family->fops && sl->family->fops->add_slave &&
488 ((err = sl->family->fops->add_slave(sl)) < 0)) {
489 dev_err(&sl->dev,
490 "sysfs file creation for [%s] failed. err=%d\n",
491 sl->dev.bus_id, err);
492 goto out_rem2;
1da177e4
LT
493 }
494
495 list_add_tail(&sl->w1_slave_entry, &sl->master->slist);
496
497 return 0;
d2a4ef6a
EP
498
499out_rem2:
500 sysfs_remove_bin_file(&sl->dev.kobj, &w1_slave_attr_bin_id);
501out_rem1:
502 device_remove_file(&sl->dev, &w1_slave_attr_name);
503out_unreg:
504 device_unregister(&sl->dev);
505 return err;
1da177e4
LT
506}
507
508static int w1_attach_slave_device(struct w1_master *dev, struct w1_reg_num *rn)
509{
510 struct w1_slave *sl;
511 struct w1_family *f;
512 int err;
513 struct w1_netlink_msg msg;
514
dd00cc48 515 sl = kzalloc(sizeof(struct w1_slave), GFP_KERNEL);
1da177e4
LT
516 if (!sl) {
517 dev_err(&dev->dev,
518 "%s: failed to allocate new slave device.\n",
519 __func__);
520 return -ENOMEM;
521 }
522
1da177e4
LT
523
524 sl->owner = THIS_MODULE;
525 sl->master = dev;
526 set_bit(W1_SLAVE_ACTIVE, (long *)&sl->flags);
527
12003375 528 memset(&msg, 0, sizeof(msg));
1da177e4
LT
529 memcpy(&sl->reg_num, rn, sizeof(sl->reg_num));
530 atomic_set(&sl->refcnt, 0);
3aca692d 531 init_completion(&sl->released);
1da177e4
LT
532
533 spin_lock(&w1_flock);
534 f = w1_family_registered(rn->family);
535 if (!f) {
99c5bfe9 536 f= &w1_default_family;
1da177e4
LT
537 dev_info(&dev->dev, "Family %x for %02x.%012llx.%02x is not registered.\n",
538 rn->family, rn->family,
539 (unsigned long long)rn->id, rn->crc);
1da177e4
LT
540 }
541 __w1_family_get(f);
542 spin_unlock(&w1_flock);
543
544 sl->family = f;
545
546
547 err = __w1_attach_slave_device(sl);
548 if (err < 0) {
549 dev_err(&dev->dev, "%s: Attaching %s failed.\n", __func__,
550 sl->name);
551 w1_family_put(sl->family);
552 kfree(sl);
553 return err;
554 }
555
556 sl->ttl = dev->slave_ttl;
557 dev->slave_count++;
558
12003375 559 memcpy(msg.id.id, rn, sizeof(msg.id));
1da177e4
LT
560 msg.type = W1_SLAVE_ADD;
561 w1_netlink_send(dev, &msg);
562
563 return 0;
564}
565
c30c9b15 566void w1_slave_detach(struct w1_slave *sl)
1da177e4
LT
567{
568 struct w1_netlink_msg msg;
7785925d 569
7c8f5703 570 dev_dbg(&sl->dev, "%s: detaching %s [%p].\n", __func__, sl->name, sl);
1da177e4 571
3aca692d 572 list_del(&sl->w1_slave_entry);
1da177e4 573
d2a4ef6a
EP
574 if (sl->family->fops && sl->family->fops->remove_slave)
575 sl->family->fops->remove_slave(sl);
576
12003375
EP
577 memset(&msg, 0, sizeof(msg));
578 memcpy(msg.id.id, &sl->reg_num, sizeof(msg.id));
3aca692d
EP
579 msg.type = W1_SLAVE_REMOVE;
580 w1_netlink_send(sl->master, &msg);
581
d2a4ef6a
EP
582 sysfs_remove_bin_file(&sl->dev.kobj, &w1_slave_attr_bin_id);
583 device_remove_file(&sl->dev, &w1_slave_attr_name);
1da177e4 584 device_unregister(&sl->dev);
1da177e4 585
3aca692d
EP
586 wait_for_completion(&sl->released);
587 kfree(sl);
1da177e4
LT
588}
589
12003375
EP
590struct w1_master *w1_search_master_id(u32 id)
591{
592 struct w1_master *dev;
593 int found = 0;
594
abd52a13 595 mutex_lock(&w1_mlock);
12003375
EP
596 list_for_each_entry(dev, &w1_masters, w1_master_entry) {
597 if (dev->id == id) {
598 found = 1;
599 atomic_inc(&dev->refcnt);
600 break;
601 }
602 }
abd52a13 603 mutex_unlock(&w1_mlock);
12003375
EP
604
605 return (found)?dev:NULL;
606}
607
608struct w1_slave *w1_search_slave(struct w1_reg_num *id)
609{
610 struct w1_master *dev;
611 struct w1_slave *sl = NULL;
612 int found = 0;
613
abd52a13 614 mutex_lock(&w1_mlock);
12003375 615 list_for_each_entry(dev, &w1_masters, w1_master_entry) {
abd52a13 616 mutex_lock(&dev->mutex);
12003375
EP
617 list_for_each_entry(sl, &dev->slist, w1_slave_entry) {
618 if (sl->reg_num.family == id->family &&
619 sl->reg_num.id == id->id &&
620 sl->reg_num.crc == id->crc) {
621 found = 1;
622 atomic_inc(&dev->refcnt);
623 atomic_inc(&sl->refcnt);
624 break;
625 }
626 }
abd52a13 627 mutex_unlock(&dev->mutex);
12003375
EP
628
629 if (found)
630 break;
631 }
abd52a13 632 mutex_unlock(&w1_mlock);
12003375
EP
633
634 return (found)?sl:NULL;
635}
636
c30c9b15 637void w1_reconnect_slaves(struct w1_family *f, int attach)
6adf87bd 638{
c30c9b15 639 struct w1_slave *sl, *sln;
6adf87bd
EP
640 struct w1_master *dev;
641
abd52a13 642 mutex_lock(&w1_mlock);
6adf87bd 643 list_for_each_entry(dev, &w1_masters, w1_master_entry) {
c30c9b15
DF
644 dev_dbg(&dev->dev, "Reconnecting slaves in device %s "
645 "for family %02x.\n", dev->name, f->fid);
646 mutex_lock(&dev->mutex);
647 list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) {
648 /* If it is a new family, slaves with the default
649 * family driver and are that family will be
650 * connected. If the family is going away, devices
651 * matching that family are reconneced.
652 */
653 if ((attach && sl->family->fid == W1_FAMILY_DEFAULT
654 && sl->reg_num.family == f->fid) ||
655 (!attach && sl->family->fid == f->fid)) {
656 struct w1_reg_num rn;
657
658 memcpy(&rn, &sl->reg_num, sizeof(rn));
659 w1_slave_detach(sl);
660
661 w1_attach_slave_device(dev, &rn);
662 }
663 }
664 dev_dbg(&dev->dev, "Reconnecting slaves in device %s "
665 "has been finished.\n", dev->name);
666 mutex_unlock(&dev->mutex);
6adf87bd 667 }
abd52a13 668 mutex_unlock(&w1_mlock);
6adf87bd
EP
669}
670
c30c9b15 671static void w1_slave_found(struct w1_master *dev, u64 rn)
1da177e4
LT
672{
673 int slave_count;
674 struct w1_slave *sl;
675 struct list_head *ent;
676 struct w1_reg_num *tmp;
0e65f828 677 u64 rn_le = cpu_to_le64(rn);
1da177e4 678
c30c9b15 679 atomic_inc(&dev->refcnt);
7785925d 680
1da177e4
LT
681 tmp = (struct w1_reg_num *) &rn;
682
683 slave_count = 0;
684 list_for_each(ent, &dev->slist) {
685
686 sl = list_entry(ent, struct w1_slave, w1_slave_entry);
687
688 if (sl->reg_num.family == tmp->family &&
689 sl->reg_num.id == tmp->id &&
690 sl->reg_num.crc == tmp->crc) {
691 set_bit(W1_SLAVE_ACTIVE, (long *)&sl->flags);
692 break;
1da177e4
LT
693 }
694
695 slave_count++;
696 }
697
8523ff45 698 if (slave_count == dev->slave_count &&
0e65f828 699 rn && ((rn >> 56) & 0xff) == w1_calc_crc8((u8 *)&rn_le, 7)) {
8523ff45 700 w1_attach_slave_device(dev, tmp);
1da177e4 701 }
7785925d 702
1da177e4
LT
703 atomic_dec(&dev->refcnt);
704}
705
6b729861
EP
706/**
707 * Performs a ROM Search & registers any devices found.
708 * The 1-wire search is a simple binary tree search.
709 * For each bit of the address, we read two bits and write one bit.
710 * The bit written will put to sleep all devies that don't match that bit.
711 * When the two reads differ, the direction choice is obvious.
712 * When both bits are 0, we must choose a path to take.
713 * When we can scan all 64 bits without having to choose a path, we are done.
714 *
715 * See "Application note 187 1-wire search algorithm" at www.maxim-ic.com
716 *
717 * @dev The master device to search
718 * @cb Function to call when a device is found
719 */
12003375 720void w1_search(struct w1_master *dev, u8 search_type, w1_slave_found_callback cb)
1da177e4 721{
6b729861
EP
722 u64 last_rn, rn, tmp64;
723 int i, slave_count = 0;
724 int last_zero, last_device;
725 int search_bit, desc_bit;
726 u8 triplet_ret = 0;
1da177e4 727
6b729861
EP
728 search_bit = 0;
729 rn = last_rn = 0;
730 last_device = 0;
731 last_zero = -1;
1da177e4
LT
732
733 desc_bit = 64;
734
6b729861
EP
735 while ( !last_device && (slave_count++ < dev->max_slave_count) ) {
736 last_rn = rn;
1da177e4
LT
737 rn = 0;
738
1da177e4
LT
739 /*
740 * Reset bus and all 1-wire device state machines
741 * so they can respond to our requests.
742 *
743 * Return 0 - device(s) present, 1 - no devices present.
744 */
745 if (w1_reset_bus(dev)) {
2da5bf80 746 dev_dbg(&dev->dev, "No devices present on the wire.\n");
1da177e4
LT
747 break;
748 }
749
6b729861 750 /* Start the search */
12003375 751 w1_write_8(dev, search_type);
1da177e4 752 for (i = 0; i < 64; ++i) {
6b729861
EP
753 /* Determine the direction/search bit */
754 if (i == desc_bit)
755 search_bit = 1; /* took the 0 path last time, so take the 1 path */
756 else if (i > desc_bit)
757 search_bit = 0; /* take the 0 path on the next branch */
1da177e4 758 else
6b729861 759 search_bit = ((last_rn >> i) & 0x1);
1da177e4 760
6b729861
EP
761 /** Read two bits and write one bit */
762 triplet_ret = w1_triplet(dev, search_bit);
763
764 /* quit if no device responded */
765 if ( (triplet_ret & 0x03) == 0x03 )
766 break;
1da177e4 767
6b729861
EP
768 /* If both directions were valid, and we took the 0 path... */
769 if (triplet_ret == 0)
770 last_zero = i;
1da177e4 771
6b729861
EP
772 /* extract the direction taken & update the device number */
773 tmp64 = (triplet_ret >> 2);
774 rn |= (tmp64 << i);
0d671b27
DF
775
776 if (test_bit(W1_MASTER_NEED_EXIT, &dev->flags)) {
777 printk(KERN_INFO "Abort w1_search (exiting)\n");
778 return;
779 }
6b729861 780 }
7785925d 781
6b729861
EP
782 if ( (triplet_ret & 0x03) != 0x03 ) {
783 if ( (desc_bit == last_zero) || (last_zero < 0))
784 last_device = 1;
785 desc_bit = last_zero;
c30c9b15 786 cb(dev, rn);
6b729861 787 }
1da177e4
LT
788 }
789}
790
12003375
EP
791void w1_search_process(struct w1_master *dev, u8 search_type)
792{
793 struct w1_slave *sl, *sln;
794
795 list_for_each_entry(sl, &dev->slist, w1_slave_entry)
796 clear_bit(W1_SLAVE_ACTIVE, (long *)&sl->flags);
797
798 w1_search_devices(dev, search_type, w1_slave_found);
799
800 list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) {
a2a6c74d 801 if (!test_bit(W1_SLAVE_ACTIVE, (unsigned long *)&sl->flags) && !--sl->ttl)
12003375 802 w1_slave_detach(sl);
a2a6c74d 803 else if (test_bit(W1_SLAVE_ACTIVE, (unsigned long *)&sl->flags))
12003375
EP
804 sl->ttl = dev->slave_ttl;
805 }
806
807 if (dev->search_count > 0)
808 dev->search_count--;
809}
810
1da177e4
LT
811int w1_process(void *data)
812{
813 struct w1_master *dev = (struct w1_master *) data;
1da177e4 814
674a396c 815 while (!kthread_should_stop() && !test_bit(W1_MASTER_NEED_EXIT, &dev->flags)) {
3e1d1d28 816 try_to_freeze();
1da177e4
LT
817 msleep_interruptible(w1_timeout * 1000);
818
674a396c 819 if (kthread_should_stop() || test_bit(W1_MASTER_NEED_EXIT, &dev->flags))
1da177e4
LT
820 break;
821
822 if (!dev->initialized)
823 continue;
824
2a9d0c17
EP
825 if (dev->search_count == 0)
826 continue;
827
abd52a13 828 mutex_lock(&dev->mutex);
12003375 829 w1_search_process(dev, W1_SEARCH);
abd52a13 830 mutex_unlock(&dev->mutex);
1da177e4
LT
831 }
832
833 atomic_dec(&dev->refcnt);
1da177e4
LT
834
835 return 0;
836}
837
7785925d 838static int w1_init(void)
1da177e4
LT
839{
840 int retval;
841
842 printk(KERN_INFO "Driver for 1-wire Dallas network protocol.\n");
843
12003375
EP
844 w1_init_netlink();
845
1da177e4
LT
846 retval = bus_register(&w1_bus_type);
847 if (retval) {
848 printk(KERN_ERR "Failed to register bus. err=%d.\n", retval);
849 goto err_out_exit_init;
850 }
851
7f772ed8 852 retval = driver_register(&w1_master_driver);
1da177e4
LT
853 if (retval) {
854 printk(KERN_ERR
855 "Failed to register master driver. err=%d.\n",
856 retval);
857 goto err_out_bus_unregister;
858 }
859
7f772ed8
EP
860 retval = driver_register(&w1_slave_driver);
861 if (retval) {
862 printk(KERN_ERR
863 "Failed to register master driver. err=%d.\n",
864 retval);
865 goto err_out_master_unregister;
866 }
867
1da177e4
LT
868 return 0;
869
c30c9b15
DF
870#if 0
871/* For undoing the slave register if there was a step after it. */
7f772ed8
EP
872err_out_slave_unregister:
873 driver_unregister(&w1_slave_driver);
c30c9b15 874#endif
7f772ed8
EP
875
876err_out_master_unregister:
877 driver_unregister(&w1_master_driver);
1da177e4
LT
878
879err_out_bus_unregister:
880 bus_unregister(&w1_bus_type);
881
882err_out_exit_init:
883 return retval;
884}
885
7785925d 886static void w1_fini(void)
1da177e4
LT
887{
888 struct w1_master *dev;
1da177e4 889
c30c9b15 890 /* Set netlink removal messages and some cleanup */
7785925d 891 list_for_each_entry(dev, &w1_masters, w1_master_entry)
1da177e4 892 __w1_remove_master_device(dev);
1da177e4 893
12003375
EP
894 w1_fini_netlink();
895
7f772ed8
EP
896 driver_unregister(&w1_slave_driver);
897 driver_unregister(&w1_master_driver);
1da177e4
LT
898 bus_unregister(&w1_bus_type);
899}
900
901module_init(w1_init);
902module_exit(w1_fini);