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1/*
2 * w1.c
3 *
4 * Copyright (c) 2004 Evgeniy Polyakov <zbr@ioremap.net>
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 <linux/atomic.h>
37
38#include "w1.h"
39#include "w1_log.h"
40#include "w1_int.h"
41#include "w1_family.h"
42#include "w1_netlink.h"
43
44MODULE_LICENSE("GPL");
45MODULE_AUTHOR("Evgeniy Polyakov <zbr@ioremap.net>");
46MODULE_DESCRIPTION("Driver for 1-wire Dallas network protocol.");
47
48static int w1_timeout = 10;
49int w1_max_slave_count = 10;
50int w1_max_slave_ttl = 10;
51
52module_param_named(timeout, w1_timeout, int, 0);
53module_param_named(max_slave_count, w1_max_slave_count, int, 0);
54module_param_named(slave_ttl, w1_max_slave_ttl, int, 0);
55
56DEFINE_MUTEX(w1_mlock);
57LIST_HEAD(w1_masters);
58
59static int w1_attach_slave_device(struct w1_master *dev, struct w1_reg_num *rn);
60
61static int w1_master_match(struct device *dev, struct device_driver *drv)
62{
63 return 1;
64}
65
66static int w1_master_probe(struct device *dev)
67{
68 return -ENODEV;
69}
70
71static void w1_master_release(struct device *dev)
72{
73 struct w1_master *md = dev_to_w1_master(dev);
74
75 dev_dbg(dev, "%s: Releasing %s.\n", __func__, md->name);
76 memset(md, 0, sizeof(struct w1_master) + sizeof(struct w1_bus_master));
77 kfree(md);
78}
79
80static void w1_slave_release(struct device *dev)
81{
82 struct w1_slave *sl = dev_to_w1_slave(dev);
83
84 dev_dbg(dev, "%s: Releasing %s.\n", __func__, sl->name);
85
86 while (atomic_read(&sl->refcnt)) {
87 dev_dbg(dev, "Waiting for %s to become free: refcnt=%d.\n",
88 sl->name, atomic_read(&sl->refcnt));
89 if (msleep_interruptible(1000))
90 flush_signals(current);
91 }
92
93 w1_family_put(sl->family);
94 sl->master->slave_count--;
95
96 complete(&sl->released);
97}
98
99static ssize_t w1_slave_read_name(struct device *dev, struct device_attribute *attr, char *buf)
100{
101 struct w1_slave *sl = dev_to_w1_slave(dev);
102
103 return sprintf(buf, "%s\n", sl->name);
104}
105
106static ssize_t w1_slave_read_id(struct device *dev,
107 struct device_attribute *attr, char *buf)
108{
109 struct w1_slave *sl = dev_to_w1_slave(dev);
110 ssize_t count = sizeof(sl->reg_num);
111
112 memcpy(buf, (u8 *)&sl->reg_num, count);
113 return count;
114}
115
116static struct device_attribute w1_slave_attr_name =
117 __ATTR(name, S_IRUGO, w1_slave_read_name, NULL);
118static struct device_attribute w1_slave_attr_id =
119 __ATTR(id, S_IRUGO, w1_slave_read_id, NULL);
120
121/* Default family */
122
123static ssize_t w1_default_write(struct file *filp, struct kobject *kobj,
124 struct bin_attribute *bin_attr,
125 char *buf, loff_t off, size_t count)
126{
127 struct w1_slave *sl = kobj_to_w1_slave(kobj);
128
129 mutex_lock(&sl->master->mutex);
130 if (w1_reset_select_slave(sl)) {
131 count = 0;
132 goto out_up;
133 }
134
135 w1_write_block(sl->master, buf, count);
136
137out_up:
138 mutex_unlock(&sl->master->mutex);
139 return count;
140}
141
142static ssize_t w1_default_read(struct file *filp, struct kobject *kobj,
143 struct bin_attribute *bin_attr,
144 char *buf, loff_t off, size_t count)
145{
146 struct w1_slave *sl = kobj_to_w1_slave(kobj);
147
148 mutex_lock(&sl->master->mutex);
149 w1_read_block(sl->master, buf, count);
150 mutex_unlock(&sl->master->mutex);
151 return count;
152}
153
154static struct bin_attribute w1_default_attr = {
155 .attr = {
156 .name = "rw",
157 .mode = S_IRUGO | S_IWUSR,
158 },
159 .size = PAGE_SIZE,
160 .read = w1_default_read,
161 .write = w1_default_write,
162};
163
164static int w1_default_add_slave(struct w1_slave *sl)
165{
166 return sysfs_create_bin_file(&sl->dev.kobj, &w1_default_attr);
167}
168
169static void w1_default_remove_slave(struct w1_slave *sl)
170{
171 sysfs_remove_bin_file(&sl->dev.kobj, &w1_default_attr);
172}
173
174static struct w1_family_ops w1_default_fops = {
175 .add_slave = w1_default_add_slave,
176 .remove_slave = w1_default_remove_slave,
177};
178
179static struct w1_family w1_default_family = {
180 .fops = &w1_default_fops,
181};
182
183static int w1_uevent(struct device *dev, struct kobj_uevent_env *env);
184
185static struct bus_type w1_bus_type = {
186 .name = "w1",
187 .match = w1_master_match,
188 .uevent = w1_uevent,
189};
190
191struct device_driver w1_master_driver = {
192 .name = "w1_master_driver",
193 .bus = &w1_bus_type,
194 .probe = w1_master_probe,
195};
196
197struct device w1_master_device = {
198 .parent = NULL,
199 .bus = &w1_bus_type,
200 .init_name = "w1 bus master",
201 .driver = &w1_master_driver,
202 .release = &w1_master_release
203};
204
205static struct device_driver w1_slave_driver = {
206 .name = "w1_slave_driver",
207 .bus = &w1_bus_type,
208};
209
210#if 0
211struct 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
220static 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
232static 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
250static 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
264static 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
282static 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
296static 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
307static 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
314static 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
325static 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
336static 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
347static 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
373static 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
382static 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 */
424static 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
438static 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
467static 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
476static 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
513static W1_MASTER_ATTR_RO(name, S_IRUGO);
514static W1_MASTER_ATTR_RO(slaves, S_IRUGO);
515static W1_MASTER_ATTR_RO(slave_count, S_IRUGO);
516static W1_MASTER_ATTR_RO(max_slave_count, S_IRUGO);
517static W1_MASTER_ATTR_RO(attempts, S_IRUGO);
518static W1_MASTER_ATTR_RO(timeout, S_IRUGO);
519static W1_MASTER_ATTR_RO(pointer, S_IRUGO);
520static W1_MASTER_ATTR_RW(search, S_IRUGO | S_IWUSR | S_IWGRP);
521static W1_MASTER_ATTR_RW(pullup, S_IRUGO | S_IWUSR | S_IWGRP);
522static W1_MASTER_ATTR_RW(add, S_IRUGO | S_IWUSR | S_IWGRP);
523static W1_MASTER_ATTR_RW(remove, S_IRUGO | S_IWUSR | S_IWGRP);
524
525static 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
540static struct attribute_group w1_master_defattr_group = {
541 .attrs = w1_master_default_attrs,
542};
543
544int w1_create_master_attributes(struct w1_master *master)
545{
546 return sysfs_create_group(&master->dev.kobj, &w1_master_defattr_group);
547}
548
549void 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
555static 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
593static int w1_uevent(struct device *dev, struct kobj_uevent_env *env)
594{
595 return 0;
596}
597#endif
598
599static 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
658out_rem2:
659 device_remove_file(&sl->dev, &w1_slave_attr_id);
660out_rem1:
661 device_remove_file(&sl->dev, &w1_slave_attr_name);
662out_unreg:
663 device_unregister(&sl->dev);
664 return err;
665}
666
667static 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
725void 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
749struct 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
767struct 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
796void 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
830void 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 */
865void 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
936void w1_search_process_cb(struct w1_master *dev, u8 search_type,
937 w1_slave_found_callback cb)
938{
939 struct w1_slave *sl, *sln;
940
941 list_for_each_entry(sl, &dev->slist, w1_slave_entry)
942 clear_bit(W1_SLAVE_ACTIVE, (long *)&sl->flags);
943
944 w1_search_devices(dev, search_type, cb);
945
946 list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) {
947 if (!test_bit(W1_SLAVE_ACTIVE, (unsigned long *)&sl->flags) && !--sl->ttl)
948 w1_slave_detach(sl);
949 else if (test_bit(W1_SLAVE_ACTIVE, (unsigned long *)&sl->flags))
950 sl->ttl = dev->slave_ttl;
951 }
952
953 if (dev->search_count > 0)
954 dev->search_count--;
955}
956
957static void w1_search_process(struct w1_master *dev, u8 search_type)
958{
959 w1_search_process_cb(dev, search_type, w1_slave_found);
960}
961
962int w1_process(void *data)
963{
964 struct w1_master *dev = (struct w1_master *) data;
965 /* As long as w1_timeout is only set by a module parameter the sleep
966 * time can be calculated in jiffies once.
967 */
968 const unsigned long jtime = msecs_to_jiffies(w1_timeout * 1000);
969
970 while (!kthread_should_stop()) {
971 if (dev->search_count) {
972 mutex_lock(&dev->mutex);
973 w1_search_process(dev, W1_SEARCH);
974 mutex_unlock(&dev->mutex);
975 }
976
977 try_to_freeze();
978 __set_current_state(TASK_INTERRUPTIBLE);
979
980 if (kthread_should_stop())
981 break;
982
983 /* Only sleep when the search is active. */
984 if (dev->search_count)
985 schedule_timeout(jtime);
986 else
987 schedule();
988 }
989
990 atomic_dec(&dev->refcnt);
991
992 return 0;
993}
994
995static int __init w1_init(void)
996{
997 int retval;
998
999 printk(KERN_INFO "Driver for 1-wire Dallas network protocol.\n");
1000
1001 w1_init_netlink();
1002
1003 retval = bus_register(&w1_bus_type);
1004 if (retval) {
1005 printk(KERN_ERR "Failed to register bus. err=%d.\n", retval);
1006 goto err_out_exit_init;
1007 }
1008
1009 retval = driver_register(&w1_master_driver);
1010 if (retval) {
1011 printk(KERN_ERR
1012 "Failed to register master driver. err=%d.\n",
1013 retval);
1014 goto err_out_bus_unregister;
1015 }
1016
1017 retval = driver_register(&w1_slave_driver);
1018 if (retval) {
1019 printk(KERN_ERR
1020 "Failed to register master driver. err=%d.\n",
1021 retval);
1022 goto err_out_master_unregister;
1023 }
1024
1025 return 0;
1026
1027#if 0
1028/* For undoing the slave register if there was a step after it. */
1029err_out_slave_unregister:
1030 driver_unregister(&w1_slave_driver);
1031#endif
1032
1033err_out_master_unregister:
1034 driver_unregister(&w1_master_driver);
1035
1036err_out_bus_unregister:
1037 bus_unregister(&w1_bus_type);
1038
1039err_out_exit_init:
1040 return retval;
1041}
1042
1043static void __exit w1_fini(void)
1044{
1045 struct w1_master *dev;
1046
1047 /* Set netlink removal messages and some cleanup */
1048 list_for_each_entry(dev, &w1_masters, w1_master_entry)
1049 __w1_remove_master_device(dev);
1050
1051 w1_fini_netlink();
1052
1053 driver_unregister(&w1_slave_driver);
1054 driver_unregister(&w1_master_driver);
1055 bus_unregister(&w1_bus_type);
1056}
1057
1058module_init(w1_init);
1059module_exit(w1_fini);
1/*
2 * Copyright (c) 2004 Evgeniy Polyakov <zbr@ioremap.net>
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 */
14
15#include <linux/delay.h>
16#include <linux/kernel.h>
17#include <linux/module.h>
18#include <linux/moduleparam.h>
19#include <linux/list.h>
20#include <linux/interrupt.h>
21#include <linux/spinlock.h>
22#include <linux/timer.h>
23#include <linux/device.h>
24#include <linux/slab.h>
25#include <linux/sched.h>
26#include <linux/kthread.h>
27#include <linux/freezer.h>
28#include <linux/hwmon.h>
29
30#include <linux/atomic.h>
31
32#include "w1_internal.h"
33#include "w1_netlink.h"
34
35#define W1_FAMILY_DEFAULT 0
36
37static int w1_timeout = 10;
38module_param_named(timeout, w1_timeout, int, 0);
39MODULE_PARM_DESC(timeout, "time in seconds between automatic slave searches");
40
41static int w1_timeout_us = 0;
42module_param_named(timeout_us, w1_timeout_us, int, 0);
43MODULE_PARM_DESC(timeout_us,
44 "time in microseconds between automatic slave searches");
45
46/* A search stops when w1_max_slave_count devices have been found in that
47 * search. The next search will start over and detect the same set of devices
48 * on a static 1-wire bus. Memory is not allocated based on this number, just
49 * on the number of devices known to the kernel. Having a high number does not
50 * consume additional resources. As a special case, if there is only one
51 * device on the network and w1_max_slave_count is set to 1, the device id can
52 * be read directly skipping the normal slower search process.
53 */
54int w1_max_slave_count = 64;
55module_param_named(max_slave_count, w1_max_slave_count, int, 0);
56MODULE_PARM_DESC(max_slave_count,
57 "maximum number of slaves detected in a search");
58
59int w1_max_slave_ttl = 10;
60module_param_named(slave_ttl, w1_max_slave_ttl, int, 0);
61MODULE_PARM_DESC(slave_ttl,
62 "Number of searches not seeing a slave before it will be removed");
63
64DEFINE_MUTEX(w1_mlock);
65LIST_HEAD(w1_masters);
66
67static int w1_master_match(struct device *dev, struct device_driver *drv)
68{
69 return 1;
70}
71
72static int w1_master_probe(struct device *dev)
73{
74 return -ENODEV;
75}
76
77static void w1_master_release(struct device *dev)
78{
79 struct w1_master *md = dev_to_w1_master(dev);
80
81 dev_dbg(dev, "%s: Releasing %s.\n", __func__, md->name);
82 memset(md, 0, sizeof(struct w1_master) + sizeof(struct w1_bus_master));
83 kfree(md);
84}
85
86static void w1_slave_release(struct device *dev)
87{
88 struct w1_slave *sl = dev_to_w1_slave(dev);
89
90 dev_dbg(dev, "%s: Releasing %s [%p]\n", __func__, sl->name, sl);
91
92 w1_family_put(sl->family);
93 sl->master->slave_count--;
94}
95
96static ssize_t name_show(struct device *dev, struct device_attribute *attr, char *buf)
97{
98 struct w1_slave *sl = dev_to_w1_slave(dev);
99
100 return sprintf(buf, "%s\n", sl->name);
101}
102static DEVICE_ATTR_RO(name);
103
104static ssize_t id_show(struct device *dev,
105 struct device_attribute *attr, char *buf)
106{
107 struct w1_slave *sl = dev_to_w1_slave(dev);
108 ssize_t count = sizeof(sl->reg_num);
109
110 memcpy(buf, (u8 *)&sl->reg_num, count);
111 return count;
112}
113static DEVICE_ATTR_RO(id);
114
115static struct attribute *w1_slave_attrs[] = {
116 &dev_attr_name.attr,
117 &dev_attr_id.attr,
118 NULL,
119};
120ATTRIBUTE_GROUPS(w1_slave);
121
122/* Default family */
123
124static ssize_t rw_write(struct file *filp, struct kobject *kobj,
125 struct bin_attribute *bin_attr, char *buf, loff_t off,
126 size_t count)
127{
128 struct w1_slave *sl = kobj_to_w1_slave(kobj);
129
130 mutex_lock(&sl->master->mutex);
131 if (w1_reset_select_slave(sl)) {
132 count = 0;
133 goto out_up;
134 }
135
136 w1_write_block(sl->master, buf, count);
137
138out_up:
139 mutex_unlock(&sl->master->mutex);
140 return count;
141}
142
143static ssize_t rw_read(struct file *filp, struct kobject *kobj,
144 struct bin_attribute *bin_attr, char *buf, loff_t off,
145 size_t count)
146{
147 struct w1_slave *sl = kobj_to_w1_slave(kobj);
148
149 mutex_lock(&sl->master->mutex);
150 w1_read_block(sl->master, buf, count);
151 mutex_unlock(&sl->master->mutex);
152 return count;
153}
154
155static BIN_ATTR_RW(rw, PAGE_SIZE);
156
157static struct bin_attribute *w1_slave_bin_attrs[] = {
158 &bin_attr_rw,
159 NULL,
160};
161
162static const struct attribute_group w1_slave_default_group = {
163 .bin_attrs = w1_slave_bin_attrs,
164};
165
166static const struct attribute_group *w1_slave_default_groups[] = {
167 &w1_slave_default_group,
168 NULL,
169};
170
171static struct w1_family_ops w1_default_fops = {
172 .groups = w1_slave_default_groups,
173};
174
175static struct w1_family w1_default_family = {
176 .fops = &w1_default_fops,
177};
178
179static int w1_uevent(struct device *dev, struct kobj_uevent_env *env);
180
181static struct bus_type w1_bus_type = {
182 .name = "w1",
183 .match = w1_master_match,
184 .uevent = w1_uevent,
185};
186
187struct device_driver w1_master_driver = {
188 .name = "w1_master_driver",
189 .bus = &w1_bus_type,
190 .probe = w1_master_probe,
191};
192
193struct device w1_master_device = {
194 .parent = NULL,
195 .bus = &w1_bus_type,
196 .init_name = "w1 bus master",
197 .driver = &w1_master_driver,
198 .release = &w1_master_release
199};
200
201static struct device_driver w1_slave_driver = {
202 .name = "w1_slave_driver",
203 .bus = &w1_bus_type,
204};
205
206#if 0
207struct device w1_slave_device = {
208 .parent = NULL,
209 .bus = &w1_bus_type,
210 .init_name = "w1 bus slave",
211 .driver = &w1_slave_driver,
212 .release = &w1_slave_release
213};
214#endif /* 0 */
215
216static ssize_t w1_master_attribute_show_name(struct device *dev, struct device_attribute *attr, char *buf)
217{
218 struct w1_master *md = dev_to_w1_master(dev);
219 ssize_t count;
220
221 mutex_lock(&md->mutex);
222 count = sprintf(buf, "%s\n", md->name);
223 mutex_unlock(&md->mutex);
224
225 return count;
226}
227
228static ssize_t w1_master_attribute_store_search(struct device * dev,
229 struct device_attribute *attr,
230 const char * buf, size_t count)
231{
232 long tmp;
233 struct w1_master *md = dev_to_w1_master(dev);
234 int ret;
235
236 ret = kstrtol(buf, 0, &tmp);
237 if (ret)
238 return ret;
239
240 mutex_lock(&md->mutex);
241 md->search_count = tmp;
242 mutex_unlock(&md->mutex);
243 /* Only wake if it is going to be searching. */
244 if (tmp)
245 wake_up_process(md->thread);
246
247 return count;
248}
249
250static 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
264static 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 int ret;
271
272 ret = kstrtol(buf, 0, &tmp);
273 if (ret)
274 return ret;
275
276 mutex_lock(&md->mutex);
277 md->enable_pullup = tmp;
278 mutex_unlock(&md->mutex);
279
280 return count;
281}
282
283static ssize_t w1_master_attribute_show_pullup(struct device *dev,
284 struct device_attribute *attr,
285 char *buf)
286{
287 struct w1_master *md = dev_to_w1_master(dev);
288 ssize_t count;
289
290 mutex_lock(&md->mutex);
291 count = sprintf(buf, "%d\n", md->enable_pullup);
292 mutex_unlock(&md->mutex);
293
294 return count;
295}
296
297static ssize_t w1_master_attribute_show_pointer(struct device *dev, struct device_attribute *attr, char *buf)
298{
299 struct w1_master *md = dev_to_w1_master(dev);
300 ssize_t count;
301
302 mutex_lock(&md->mutex);
303 count = sprintf(buf, "0x%p\n", md->bus_master);
304 mutex_unlock(&md->mutex);
305 return count;
306}
307
308static ssize_t w1_master_attribute_show_timeout(struct device *dev, struct device_attribute *attr, char *buf)
309{
310 ssize_t count;
311 count = sprintf(buf, "%d\n", w1_timeout);
312 return count;
313}
314
315static ssize_t w1_master_attribute_show_timeout_us(struct device *dev,
316 struct device_attribute *attr, char *buf)
317{
318 ssize_t count;
319 count = sprintf(buf, "%d\n", w1_timeout_us);
320 return count;
321}
322
323static ssize_t w1_master_attribute_store_max_slave_count(struct device *dev,
324 struct device_attribute *attr, const char *buf, size_t count)
325{
326 int tmp;
327 struct w1_master *md = dev_to_w1_master(dev);
328
329 if (kstrtoint(buf, 0, &tmp) || tmp < 1)
330 return -EINVAL;
331
332 mutex_lock(&md->mutex);
333 md->max_slave_count = tmp;
334 /* allow each time the max_slave_count is updated */
335 clear_bit(W1_WARN_MAX_COUNT, &md->flags);
336 mutex_unlock(&md->mutex);
337
338 return count;
339}
340
341static ssize_t w1_master_attribute_show_max_slave_count(struct device *dev, struct device_attribute *attr, char *buf)
342{
343 struct w1_master *md = dev_to_w1_master(dev);
344 ssize_t count;
345
346 mutex_lock(&md->mutex);
347 count = sprintf(buf, "%d\n", md->max_slave_count);
348 mutex_unlock(&md->mutex);
349 return count;
350}
351
352static ssize_t w1_master_attribute_show_attempts(struct device *dev, struct device_attribute *attr, char *buf)
353{
354 struct w1_master *md = dev_to_w1_master(dev);
355 ssize_t count;
356
357 mutex_lock(&md->mutex);
358 count = sprintf(buf, "%lu\n", md->attempts);
359 mutex_unlock(&md->mutex);
360 return count;
361}
362
363static ssize_t w1_master_attribute_show_slave_count(struct device *dev, struct device_attribute *attr, char *buf)
364{
365 struct w1_master *md = dev_to_w1_master(dev);
366 ssize_t count;
367
368 mutex_lock(&md->mutex);
369 count = sprintf(buf, "%d\n", md->slave_count);
370 mutex_unlock(&md->mutex);
371 return count;
372}
373
374static ssize_t w1_master_attribute_show_slaves(struct device *dev,
375 struct device_attribute *attr, char *buf)
376{
377 struct w1_master *md = dev_to_w1_master(dev);
378 int c = PAGE_SIZE;
379 struct list_head *ent, *n;
380 struct w1_slave *sl = NULL;
381
382 mutex_lock(&md->list_mutex);
383
384 list_for_each_safe(ent, n, &md->slist) {
385 sl = list_entry(ent, struct w1_slave, w1_slave_entry);
386
387 c -= snprintf(buf + PAGE_SIZE - c, c, "%s\n", sl->name);
388 }
389 if (!sl)
390 c -= snprintf(buf + PAGE_SIZE - c, c, "not found.\n");
391
392 mutex_unlock(&md->list_mutex);
393
394 return PAGE_SIZE - c;
395}
396
397static ssize_t w1_master_attribute_show_add(struct device *dev,
398 struct device_attribute *attr, char *buf)
399{
400 int c = PAGE_SIZE;
401 c -= snprintf(buf+PAGE_SIZE - c, c,
402 "write device id xx-xxxxxxxxxxxx to add slave\n");
403 return PAGE_SIZE - c;
404}
405
406static int w1_atoreg_num(struct device *dev, const char *buf, size_t count,
407 struct w1_reg_num *rn)
408{
409 unsigned int family;
410 unsigned long long id;
411 int i;
412 u64 rn64_le;
413
414 /* The CRC value isn't read from the user because the sysfs directory
415 * doesn't include it and most messages from the bus search don't
416 * print it either. It would be unreasonable for the user to then
417 * provide it.
418 */
419 const char *error_msg = "bad slave string format, expecting "
420 "ff-dddddddddddd\n";
421
422 if (buf[2] != '-') {
423 dev_err(dev, "%s", error_msg);
424 return -EINVAL;
425 }
426 i = sscanf(buf, "%02x-%012llx", &family, &id);
427 if (i != 2) {
428 dev_err(dev, "%s", error_msg);
429 return -EINVAL;
430 }
431 rn->family = family;
432 rn->id = id;
433
434 rn64_le = cpu_to_le64(*(u64 *)rn);
435 rn->crc = w1_calc_crc8((u8 *)&rn64_le, 7);
436
437#if 0
438 dev_info(dev, "With CRC device is %02x.%012llx.%02x.\n",
439 rn->family, (unsigned long long)rn->id, rn->crc);
440#endif
441
442 return 0;
443}
444
445/* Searches the slaves in the w1_master and returns a pointer or NULL.
446 * Note: must not hold list_mutex
447 */
448struct w1_slave *w1_slave_search_device(struct w1_master *dev,
449 struct w1_reg_num *rn)
450{
451 struct w1_slave *sl;
452 mutex_lock(&dev->list_mutex);
453 list_for_each_entry(sl, &dev->slist, w1_slave_entry) {
454 if (sl->reg_num.family == rn->family &&
455 sl->reg_num.id == rn->id &&
456 sl->reg_num.crc == rn->crc) {
457 mutex_unlock(&dev->list_mutex);
458 return sl;
459 }
460 }
461 mutex_unlock(&dev->list_mutex);
462 return NULL;
463}
464
465static ssize_t w1_master_attribute_store_add(struct device *dev,
466 struct device_attribute *attr,
467 const char *buf, size_t count)
468{
469 struct w1_master *md = dev_to_w1_master(dev);
470 struct w1_reg_num rn;
471 struct w1_slave *sl;
472 ssize_t result = count;
473
474 if (w1_atoreg_num(dev, buf, count, &rn))
475 return -EINVAL;
476
477 mutex_lock(&md->mutex);
478 sl = w1_slave_search_device(md, &rn);
479 /* It would be nice to do a targeted search one the one-wire bus
480 * for the new device to see if it is out there or not. But the
481 * current search doesn't support that.
482 */
483 if (sl) {
484 dev_info(dev, "Device %s already exists\n", sl->name);
485 result = -EINVAL;
486 } else {
487 w1_attach_slave_device(md, &rn);
488 }
489 mutex_unlock(&md->mutex);
490
491 return result;
492}
493
494static ssize_t w1_master_attribute_show_remove(struct device *dev,
495 struct device_attribute *attr, char *buf)
496{
497 int c = PAGE_SIZE;
498 c -= snprintf(buf+PAGE_SIZE - c, c,
499 "write device id xx-xxxxxxxxxxxx to remove slave\n");
500 return PAGE_SIZE - c;
501}
502
503static ssize_t w1_master_attribute_store_remove(struct device *dev,
504 struct device_attribute *attr,
505 const char *buf, size_t count)
506{
507 struct w1_master *md = dev_to_w1_master(dev);
508 struct w1_reg_num rn;
509 struct w1_slave *sl;
510 ssize_t result = count;
511
512 if (w1_atoreg_num(dev, buf, count, &rn))
513 return -EINVAL;
514
515 mutex_lock(&md->mutex);
516 sl = w1_slave_search_device(md, &rn);
517 if (sl) {
518 result = w1_slave_detach(sl);
519 /* refcnt 0 means it was detached in the call */
520 if (result == 0)
521 result = count;
522 } else {
523 dev_info(dev, "Device %02x-%012llx doesn't exists\n", rn.family,
524 (unsigned long long)rn.id);
525 result = -EINVAL;
526 }
527 mutex_unlock(&md->mutex);
528
529 return result;
530}
531
532#define W1_MASTER_ATTR_RO(_name, _mode) \
533 struct device_attribute w1_master_attribute_##_name = \
534 __ATTR(w1_master_##_name, _mode, \
535 w1_master_attribute_show_##_name, NULL)
536
537#define W1_MASTER_ATTR_RW(_name, _mode) \
538 struct device_attribute w1_master_attribute_##_name = \
539 __ATTR(w1_master_##_name, _mode, \
540 w1_master_attribute_show_##_name, \
541 w1_master_attribute_store_##_name)
542
543static W1_MASTER_ATTR_RO(name, S_IRUGO);
544static W1_MASTER_ATTR_RO(slaves, S_IRUGO);
545static W1_MASTER_ATTR_RO(slave_count, S_IRUGO);
546static W1_MASTER_ATTR_RW(max_slave_count, S_IRUGO | S_IWUSR | S_IWGRP);
547static W1_MASTER_ATTR_RO(attempts, S_IRUGO);
548static W1_MASTER_ATTR_RO(timeout, S_IRUGO);
549static W1_MASTER_ATTR_RO(timeout_us, S_IRUGO);
550static W1_MASTER_ATTR_RO(pointer, S_IRUGO);
551static W1_MASTER_ATTR_RW(search, S_IRUGO | S_IWUSR | S_IWGRP);
552static W1_MASTER_ATTR_RW(pullup, S_IRUGO | S_IWUSR | S_IWGRP);
553static W1_MASTER_ATTR_RW(add, S_IRUGO | S_IWUSR | S_IWGRP);
554static W1_MASTER_ATTR_RW(remove, S_IRUGO | S_IWUSR | S_IWGRP);
555
556static struct attribute *w1_master_default_attrs[] = {
557 &w1_master_attribute_name.attr,
558 &w1_master_attribute_slaves.attr,
559 &w1_master_attribute_slave_count.attr,
560 &w1_master_attribute_max_slave_count.attr,
561 &w1_master_attribute_attempts.attr,
562 &w1_master_attribute_timeout.attr,
563 &w1_master_attribute_timeout_us.attr,
564 &w1_master_attribute_pointer.attr,
565 &w1_master_attribute_search.attr,
566 &w1_master_attribute_pullup.attr,
567 &w1_master_attribute_add.attr,
568 &w1_master_attribute_remove.attr,
569 NULL
570};
571
572static const struct attribute_group w1_master_defattr_group = {
573 .attrs = w1_master_default_attrs,
574};
575
576int w1_create_master_attributes(struct w1_master *master)
577{
578 return sysfs_create_group(&master->dev.kobj, &w1_master_defattr_group);
579}
580
581void w1_destroy_master_attributes(struct w1_master *master)
582{
583 sysfs_remove_group(&master->dev.kobj, &w1_master_defattr_group);
584}
585
586static int w1_uevent(struct device *dev, struct kobj_uevent_env *env)
587{
588 struct w1_master *md = NULL;
589 struct w1_slave *sl = NULL;
590 char *event_owner, *name;
591 int err = 0;
592
593 if (dev->driver == &w1_master_driver) {
594 md = container_of(dev, struct w1_master, dev);
595 event_owner = "master";
596 name = md->name;
597 } else if (dev->driver == &w1_slave_driver) {
598 sl = container_of(dev, struct w1_slave, dev);
599 event_owner = "slave";
600 name = sl->name;
601 } else {
602 dev_dbg(dev, "Unknown event.\n");
603 return -EINVAL;
604 }
605
606 dev_dbg(dev, "Hotplug event for %s %s, bus_id=%s.\n",
607 event_owner, name, dev_name(dev));
608
609 if (dev->driver != &w1_slave_driver || !sl)
610 goto end;
611
612 err = add_uevent_var(env, "W1_FID=%02X", sl->reg_num.family);
613 if (err)
614 goto end;
615
616 err = add_uevent_var(env, "W1_SLAVE_ID=%024LX",
617 (unsigned long long)sl->reg_num.id);
618end:
619 return err;
620}
621
622static int w1_family_notify(unsigned long action, struct w1_slave *sl)
623{
624 struct w1_family_ops *fops;
625 int err;
626
627 fops = sl->family->fops;
628
629 if (!fops)
630 return 0;
631
632 switch (action) {
633 case BUS_NOTIFY_ADD_DEVICE:
634 /* if the family driver needs to initialize something... */
635 if (fops->add_slave) {
636 err = fops->add_slave(sl);
637 if (err < 0) {
638 dev_err(&sl->dev,
639 "add_slave() call failed. err=%d\n",
640 err);
641 return err;
642 }
643 }
644 if (fops->groups) {
645 err = sysfs_create_groups(&sl->dev.kobj, fops->groups);
646 if (err) {
647 dev_err(&sl->dev,
648 "sysfs group creation failed. err=%d\n",
649 err);
650 return err;
651 }
652 }
653 if (IS_REACHABLE(CONFIG_HWMON) && fops->chip_info) {
654 struct device *hwmon
655 = hwmon_device_register_with_info(&sl->dev,
656 "w1_slave_temp", sl,
657 fops->chip_info,
658 NULL);
659 if (IS_ERR(hwmon)) {
660 dev_warn(&sl->dev,
661 "could not create hwmon device\n");
662 } else {
663 sl->hwmon = hwmon;
664 }
665 }
666 break;
667 case BUS_NOTIFY_DEL_DEVICE:
668 if (IS_REACHABLE(CONFIG_HWMON) && fops->chip_info &&
669 sl->hwmon)
670 hwmon_device_unregister(sl->hwmon);
671 if (fops->remove_slave)
672 sl->family->fops->remove_slave(sl);
673 if (fops->groups)
674 sysfs_remove_groups(&sl->dev.kobj, fops->groups);
675 break;
676 }
677 return 0;
678}
679
680static int __w1_attach_slave_device(struct w1_slave *sl)
681{
682 int err;
683
684 sl->dev.parent = &sl->master->dev;
685 sl->dev.driver = &w1_slave_driver;
686 sl->dev.bus = &w1_bus_type;
687 sl->dev.release = &w1_slave_release;
688 sl->dev.groups = w1_slave_groups;
689
690 dev_set_name(&sl->dev, "%02x-%012llx",
691 (unsigned int) sl->reg_num.family,
692 (unsigned long long) sl->reg_num.id);
693 snprintf(&sl->name[0], sizeof(sl->name),
694 "%02x-%012llx",
695 (unsigned int) sl->reg_num.family,
696 (unsigned long long) sl->reg_num.id);
697
698 dev_dbg(&sl->dev, "%s: registering %s as %p.\n", __func__,
699 dev_name(&sl->dev), sl);
700
701 /* suppress for w1_family_notify before sending KOBJ_ADD */
702 dev_set_uevent_suppress(&sl->dev, true);
703
704 err = device_register(&sl->dev);
705 if (err < 0) {
706 dev_err(&sl->dev,
707 "Device registration [%s] failed. err=%d\n",
708 dev_name(&sl->dev), err);
709 put_device(&sl->dev);
710 return err;
711 }
712 w1_family_notify(BUS_NOTIFY_ADD_DEVICE, sl);
713
714 dev_set_uevent_suppress(&sl->dev, false);
715 kobject_uevent(&sl->dev.kobj, KOBJ_ADD);
716
717 mutex_lock(&sl->master->list_mutex);
718 list_add_tail(&sl->w1_slave_entry, &sl->master->slist);
719 mutex_unlock(&sl->master->list_mutex);
720
721 return 0;
722}
723
724int w1_attach_slave_device(struct w1_master *dev, struct w1_reg_num *rn)
725{
726 struct w1_slave *sl;
727 struct w1_family *f;
728 int err;
729 struct w1_netlink_msg msg;
730
731 sl = kzalloc(sizeof(struct w1_slave), GFP_KERNEL);
732 if (!sl) {
733 dev_err(&dev->dev,
734 "%s: failed to allocate new slave device.\n",
735 __func__);
736 return -ENOMEM;
737 }
738
739
740 sl->owner = THIS_MODULE;
741 sl->master = dev;
742 set_bit(W1_SLAVE_ACTIVE, &sl->flags);
743
744 memset(&msg, 0, sizeof(msg));
745 memcpy(&sl->reg_num, rn, sizeof(sl->reg_num));
746 atomic_set(&sl->refcnt, 1);
747 atomic_inc(&sl->master->refcnt);
748 dev->slave_count++;
749 dev_info(&dev->dev, "Attaching one wire slave %02x.%012llx crc %02x\n",
750 rn->family, (unsigned long long)rn->id, rn->crc);
751
752 /* slave modules need to be loaded in a context with unlocked mutex */
753 mutex_unlock(&dev->mutex);
754 request_module("w1-family-0x%02x", rn->family);
755 mutex_lock(&dev->mutex);
756
757 spin_lock(&w1_flock);
758 f = w1_family_registered(rn->family);
759 if (!f) {
760 f= &w1_default_family;
761 dev_info(&dev->dev, "Family %x for %02x.%012llx.%02x is not registered.\n",
762 rn->family, rn->family,
763 (unsigned long long)rn->id, rn->crc);
764 }
765 __w1_family_get(f);
766 spin_unlock(&w1_flock);
767
768 sl->family = f;
769
770 err = __w1_attach_slave_device(sl);
771 if (err < 0) {
772 dev_err(&dev->dev, "%s: Attaching %s failed.\n", __func__,
773 sl->name);
774 dev->slave_count--;
775 w1_family_put(sl->family);
776 atomic_dec(&sl->master->refcnt);
777 kfree(sl);
778 return err;
779 }
780
781 sl->ttl = dev->slave_ttl;
782
783 memcpy(msg.id.id, rn, sizeof(msg.id));
784 msg.type = W1_SLAVE_ADD;
785 w1_netlink_send(dev, &msg);
786
787 return 0;
788}
789
790int w1_unref_slave(struct w1_slave *sl)
791{
792 struct w1_master *dev = sl->master;
793 int refcnt;
794 mutex_lock(&dev->list_mutex);
795 refcnt = atomic_sub_return(1, &sl->refcnt);
796 if (refcnt == 0) {
797 struct w1_netlink_msg msg;
798
799 dev_dbg(&sl->dev, "%s: detaching %s [%p].\n", __func__,
800 sl->name, sl);
801
802 list_del(&sl->w1_slave_entry);
803
804 memset(&msg, 0, sizeof(msg));
805 memcpy(msg.id.id, &sl->reg_num, sizeof(msg.id));
806 msg.type = W1_SLAVE_REMOVE;
807 w1_netlink_send(sl->master, &msg);
808
809 w1_family_notify(BUS_NOTIFY_DEL_DEVICE, sl);
810 device_unregister(&sl->dev);
811 #ifdef DEBUG
812 memset(sl, 0, sizeof(*sl));
813 #endif
814 kfree(sl);
815 }
816 atomic_dec(&dev->refcnt);
817 mutex_unlock(&dev->list_mutex);
818 return refcnt;
819}
820
821int w1_slave_detach(struct w1_slave *sl)
822{
823 /* Only detach a slave once as it decreases the refcnt each time. */
824 int destroy_now;
825 mutex_lock(&sl->master->list_mutex);
826 destroy_now = !test_bit(W1_SLAVE_DETACH, &sl->flags);
827 set_bit(W1_SLAVE_DETACH, &sl->flags);
828 mutex_unlock(&sl->master->list_mutex);
829
830 if (destroy_now)
831 destroy_now = !w1_unref_slave(sl);
832 return destroy_now ? 0 : -EBUSY;
833}
834
835struct w1_master *w1_search_master_id(u32 id)
836{
837 struct w1_master *dev;
838 int found = 0;
839
840 mutex_lock(&w1_mlock);
841 list_for_each_entry(dev, &w1_masters, w1_master_entry) {
842 if (dev->id == id) {
843 found = 1;
844 atomic_inc(&dev->refcnt);
845 break;
846 }
847 }
848 mutex_unlock(&w1_mlock);
849
850 return (found)?dev:NULL;
851}
852
853struct w1_slave *w1_search_slave(struct w1_reg_num *id)
854{
855 struct w1_master *dev;
856 struct w1_slave *sl = NULL;
857 int found = 0;
858
859 mutex_lock(&w1_mlock);
860 list_for_each_entry(dev, &w1_masters, w1_master_entry) {
861 mutex_lock(&dev->list_mutex);
862 list_for_each_entry(sl, &dev->slist, w1_slave_entry) {
863 if (sl->reg_num.family == id->family &&
864 sl->reg_num.id == id->id &&
865 sl->reg_num.crc == id->crc) {
866 found = 1;
867 atomic_inc(&dev->refcnt);
868 atomic_inc(&sl->refcnt);
869 break;
870 }
871 }
872 mutex_unlock(&dev->list_mutex);
873
874 if (found)
875 break;
876 }
877 mutex_unlock(&w1_mlock);
878
879 return (found)?sl:NULL;
880}
881
882void w1_reconnect_slaves(struct w1_family *f, int attach)
883{
884 struct w1_slave *sl, *sln;
885 struct w1_master *dev;
886
887 mutex_lock(&w1_mlock);
888 list_for_each_entry(dev, &w1_masters, w1_master_entry) {
889 dev_dbg(&dev->dev, "Reconnecting slaves in device %s "
890 "for family %02x.\n", dev->name, f->fid);
891 mutex_lock(&dev->mutex);
892 mutex_lock(&dev->list_mutex);
893 list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) {
894 /* If it is a new family, slaves with the default
895 * family driver and are that family will be
896 * connected. If the family is going away, devices
897 * matching that family are reconneced.
898 */
899 if ((attach && sl->family->fid == W1_FAMILY_DEFAULT
900 && sl->reg_num.family == f->fid) ||
901 (!attach && sl->family->fid == f->fid)) {
902 struct w1_reg_num rn;
903
904 mutex_unlock(&dev->list_mutex);
905 memcpy(&rn, &sl->reg_num, sizeof(rn));
906 /* If it was already in use let the automatic
907 * scan pick it up again later.
908 */
909 if (!w1_slave_detach(sl))
910 w1_attach_slave_device(dev, &rn);
911 mutex_lock(&dev->list_mutex);
912 }
913 }
914 dev_dbg(&dev->dev, "Reconnecting slaves in device %s "
915 "has been finished.\n", dev->name);
916 mutex_unlock(&dev->list_mutex);
917 mutex_unlock(&dev->mutex);
918 }
919 mutex_unlock(&w1_mlock);
920}
921
922void w1_slave_found(struct w1_master *dev, u64 rn)
923{
924 struct w1_slave *sl;
925 struct w1_reg_num *tmp;
926 u64 rn_le = cpu_to_le64(rn);
927
928 atomic_inc(&dev->refcnt);
929
930 tmp = (struct w1_reg_num *) &rn;
931
932 sl = w1_slave_search_device(dev, tmp);
933 if (sl) {
934 set_bit(W1_SLAVE_ACTIVE, &sl->flags);
935 } else {
936 if (rn && tmp->crc == w1_calc_crc8((u8 *)&rn_le, 7))
937 w1_attach_slave_device(dev, tmp);
938 }
939
940 atomic_dec(&dev->refcnt);
941}
942
943/**
944 * w1_search() - Performs a ROM Search & registers any devices found.
945 * @dev: The master device to search
946 * @search_type: W1_SEARCH to search all devices, or W1_ALARM_SEARCH
947 * to return only devices in the alarmed state
948 * @cb: Function to call when a device is found
949 *
950 * The 1-wire search is a simple binary tree search.
951 * For each bit of the address, we read two bits and write one bit.
952 * The bit written will put to sleep all devies that don't match that bit.
953 * When the two reads differ, the direction choice is obvious.
954 * When both bits are 0, we must choose a path to take.
955 * When we can scan all 64 bits without having to choose a path, we are done.
956 *
957 * See "Application note 187 1-wire search algorithm" at www.maxim-ic.com
958 *
959 */
960void w1_search(struct w1_master *dev, u8 search_type, w1_slave_found_callback cb)
961{
962 u64 last_rn, rn, tmp64;
963 int i, slave_count = 0;
964 int last_zero, last_device;
965 int search_bit, desc_bit;
966 u8 triplet_ret = 0;
967
968 search_bit = 0;
969 rn = dev->search_id;
970 last_rn = 0;
971 last_device = 0;
972 last_zero = -1;
973
974 desc_bit = 64;
975
976 while ( !last_device && (slave_count++ < dev->max_slave_count) ) {
977 last_rn = rn;
978 rn = 0;
979
980 /*
981 * Reset bus and all 1-wire device state machines
982 * so they can respond to our requests.
983 *
984 * Return 0 - device(s) present, 1 - no devices present.
985 */
986 mutex_lock(&dev->bus_mutex);
987 if (w1_reset_bus(dev)) {
988 mutex_unlock(&dev->bus_mutex);
989 dev_dbg(&dev->dev, "No devices present on the wire.\n");
990 break;
991 }
992
993 /* Do fast search on single slave bus */
994 if (dev->max_slave_count == 1) {
995 int rv;
996 w1_write_8(dev, W1_READ_ROM);
997 rv = w1_read_block(dev, (u8 *)&rn, 8);
998 mutex_unlock(&dev->bus_mutex);
999
1000 if (rv == 8 && rn)
1001 cb(dev, rn);
1002
1003 break;
1004 }
1005
1006 /* Start the search */
1007 w1_write_8(dev, search_type);
1008 for (i = 0; i < 64; ++i) {
1009 /* Determine the direction/search bit */
1010 if (i == desc_bit)
1011 search_bit = 1; /* took the 0 path last time, so take the 1 path */
1012 else if (i > desc_bit)
1013 search_bit = 0; /* take the 0 path on the next branch */
1014 else
1015 search_bit = ((last_rn >> i) & 0x1);
1016
1017 /* Read two bits and write one bit */
1018 triplet_ret = w1_triplet(dev, search_bit);
1019
1020 /* quit if no device responded */
1021 if ( (triplet_ret & 0x03) == 0x03 )
1022 break;
1023
1024 /* If both directions were valid, and we took the 0 path... */
1025 if (triplet_ret == 0)
1026 last_zero = i;
1027
1028 /* extract the direction taken & update the device number */
1029 tmp64 = (triplet_ret >> 2);
1030 rn |= (tmp64 << i);
1031
1032 if (test_bit(W1_ABORT_SEARCH, &dev->flags)) {
1033 mutex_unlock(&dev->bus_mutex);
1034 dev_dbg(&dev->dev, "Abort w1_search\n");
1035 return;
1036 }
1037 }
1038 mutex_unlock(&dev->bus_mutex);
1039
1040 if ( (triplet_ret & 0x03) != 0x03 ) {
1041 if ((desc_bit == last_zero) || (last_zero < 0)) {
1042 last_device = 1;
1043 dev->search_id = 0;
1044 } else {
1045 dev->search_id = rn;
1046 }
1047 desc_bit = last_zero;
1048 cb(dev, rn);
1049 }
1050
1051 if (!last_device && slave_count == dev->max_slave_count &&
1052 !test_bit(W1_WARN_MAX_COUNT, &dev->flags)) {
1053 /* Only max_slave_count will be scanned in a search,
1054 * but it will start where it left off next search
1055 * until all ids are identified and then it will start
1056 * over. A continued search will report the previous
1057 * last id as the first id (provided it is still on the
1058 * bus).
1059 */
1060 dev_info(&dev->dev, "%s: max_slave_count %d reached, "
1061 "will continue next search.\n", __func__,
1062 dev->max_slave_count);
1063 set_bit(W1_WARN_MAX_COUNT, &dev->flags);
1064 }
1065 }
1066}
1067
1068void w1_search_process_cb(struct w1_master *dev, u8 search_type,
1069 w1_slave_found_callback cb)
1070{
1071 struct w1_slave *sl, *sln;
1072
1073 mutex_lock(&dev->list_mutex);
1074 list_for_each_entry(sl, &dev->slist, w1_slave_entry)
1075 clear_bit(W1_SLAVE_ACTIVE, &sl->flags);
1076 mutex_unlock(&dev->list_mutex);
1077
1078 w1_search_devices(dev, search_type, cb);
1079
1080 mutex_lock(&dev->list_mutex);
1081 list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) {
1082 if (!test_bit(W1_SLAVE_ACTIVE, &sl->flags) && !--sl->ttl) {
1083 mutex_unlock(&dev->list_mutex);
1084 w1_slave_detach(sl);
1085 mutex_lock(&dev->list_mutex);
1086 }
1087 else if (test_bit(W1_SLAVE_ACTIVE, &sl->flags))
1088 sl->ttl = dev->slave_ttl;
1089 }
1090 mutex_unlock(&dev->list_mutex);
1091
1092 if (dev->search_count > 0)
1093 dev->search_count--;
1094}
1095
1096static void w1_search_process(struct w1_master *dev, u8 search_type)
1097{
1098 w1_search_process_cb(dev, search_type, w1_slave_found);
1099}
1100
1101/**
1102 * w1_process_callbacks() - execute each dev->async_list callback entry
1103 * @dev: w1_master device
1104 *
1105 * The w1 master list_mutex must be held.
1106 *
1107 * Return: 1 if there were commands to executed 0 otherwise
1108 */
1109int w1_process_callbacks(struct w1_master *dev)
1110{
1111 int ret = 0;
1112 struct w1_async_cmd *async_cmd, *async_n;
1113
1114 /* The list can be added to in another thread, loop until it is empty */
1115 while (!list_empty(&dev->async_list)) {
1116 list_for_each_entry_safe(async_cmd, async_n, &dev->async_list,
1117 async_entry) {
1118 /* drop the lock, if it is a search it can take a long
1119 * time */
1120 mutex_unlock(&dev->list_mutex);
1121 async_cmd->cb(dev, async_cmd);
1122 ret = 1;
1123 mutex_lock(&dev->list_mutex);
1124 }
1125 }
1126 return ret;
1127}
1128
1129int w1_process(void *data)
1130{
1131 struct w1_master *dev = (struct w1_master *) data;
1132 /* As long as w1_timeout is only set by a module parameter the sleep
1133 * time can be calculated in jiffies once.
1134 */
1135 const unsigned long jtime =
1136 usecs_to_jiffies(w1_timeout * 1000000 + w1_timeout_us);
1137 /* remainder if it woke up early */
1138 unsigned long jremain = 0;
1139
1140 for (;;) {
1141
1142 if (!jremain && dev->search_count) {
1143 mutex_lock(&dev->mutex);
1144 w1_search_process(dev, W1_SEARCH);
1145 mutex_unlock(&dev->mutex);
1146 }
1147
1148 mutex_lock(&dev->list_mutex);
1149 /* Note, w1_process_callback drops the lock while processing,
1150 * but locks it again before returning.
1151 */
1152 if (!w1_process_callbacks(dev) && jremain) {
1153 /* a wake up is either to stop the thread, process
1154 * callbacks, or search, it isn't process callbacks, so
1155 * schedule a search.
1156 */
1157 jremain = 1;
1158 }
1159
1160 __set_current_state(TASK_INTERRUPTIBLE);
1161
1162 /* hold list_mutex until after interruptible to prevent loosing
1163 * the wakeup signal when async_cmd is added.
1164 */
1165 mutex_unlock(&dev->list_mutex);
1166
1167 if (kthread_should_stop())
1168 break;
1169
1170 /* Only sleep when the search is active. */
1171 if (dev->search_count) {
1172 if (!jremain)
1173 jremain = jtime;
1174 jremain = schedule_timeout(jremain);
1175 }
1176 else
1177 schedule();
1178 }
1179
1180 atomic_dec(&dev->refcnt);
1181
1182 return 0;
1183}
1184
1185static int __init w1_init(void)
1186{
1187 int retval;
1188
1189 pr_info("Driver for 1-wire Dallas network protocol.\n");
1190
1191 w1_init_netlink();
1192
1193 retval = bus_register(&w1_bus_type);
1194 if (retval) {
1195 pr_err("Failed to register bus. err=%d.\n", retval);
1196 goto err_out_exit_init;
1197 }
1198
1199 retval = driver_register(&w1_master_driver);
1200 if (retval) {
1201 pr_err("Failed to register master driver. err=%d.\n",
1202 retval);
1203 goto err_out_bus_unregister;
1204 }
1205
1206 retval = driver_register(&w1_slave_driver);
1207 if (retval) {
1208 pr_err("Failed to register slave driver. err=%d.\n",
1209 retval);
1210 goto err_out_master_unregister;
1211 }
1212
1213 return 0;
1214
1215#if 0
1216/* For undoing the slave register if there was a step after it. */
1217err_out_slave_unregister:
1218 driver_unregister(&w1_slave_driver);
1219#endif
1220
1221err_out_master_unregister:
1222 driver_unregister(&w1_master_driver);
1223
1224err_out_bus_unregister:
1225 bus_unregister(&w1_bus_type);
1226
1227err_out_exit_init:
1228 return retval;
1229}
1230
1231static void __exit w1_fini(void)
1232{
1233 struct w1_master *dev;
1234
1235 /* Set netlink removal messages and some cleanup */
1236 list_for_each_entry(dev, &w1_masters, w1_master_entry)
1237 __w1_remove_master_device(dev);
1238
1239 w1_fini_netlink();
1240
1241 driver_unregister(&w1_slave_driver);
1242 driver_unregister(&w1_master_driver);
1243 bus_unregister(&w1_bus_type);
1244}
1245
1246module_init(w1_init);
1247module_exit(w1_fini);
1248
1249MODULE_AUTHOR("Evgeniy Polyakov <zbr@ioremap.net>");
1250MODULE_DESCRIPTION("Driver for 1-wire Dallas network protocol.");
1251MODULE_LICENSE("GPL");