Loading...
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;
49static int w1_timeout_us = 0;
50int w1_max_slave_count = 64;
51int w1_max_slave_ttl = 10;
52
53module_param_named(timeout, w1_timeout, int, 0);
54MODULE_PARM_DESC(timeout, "time in seconds between automatic slave searches");
55module_param_named(timeout_us, w1_timeout_us, int, 0);
56MODULE_PARM_DESC(timeout, "time in microseconds between automatic slave"
57 " searches");
58/* A search stops when w1_max_slave_count devices have been found in that
59 * search. The next search will start over and detect the same set of devices
60 * on a static 1-wire bus. Memory is not allocated based on this number, just
61 * on the number of devices known to the kernel. Having a high number does not
62 * consume additional resources. As a special case, if there is only one
63 * device on the network and w1_max_slave_count is set to 1, the device id can
64 * be read directly skipping the normal slower search process.
65 */
66module_param_named(max_slave_count, w1_max_slave_count, int, 0);
67MODULE_PARM_DESC(max_slave_count,
68 "maximum number of slaves detected in a search");
69module_param_named(slave_ttl, w1_max_slave_ttl, int, 0);
70MODULE_PARM_DESC(slave_ttl,
71 "Number of searches not seeing a slave before it will be removed");
72
73DEFINE_MUTEX(w1_mlock);
74LIST_HEAD(w1_masters);
75
76static int w1_master_match(struct device *dev, struct device_driver *drv)
77{
78 return 1;
79}
80
81static int w1_master_probe(struct device *dev)
82{
83 return -ENODEV;
84}
85
86static void w1_master_release(struct device *dev)
87{
88 struct w1_master *md = dev_to_w1_master(dev);
89
90 dev_dbg(dev, "%s: Releasing %s.\n", __func__, md->name);
91 memset(md, 0, sizeof(struct w1_master) + sizeof(struct w1_bus_master));
92 kfree(md);
93}
94
95static void w1_slave_release(struct device *dev)
96{
97 struct w1_slave *sl = dev_to_w1_slave(dev);
98
99 dev_dbg(dev, "%s: Releasing %s [%p]\n", __func__, sl->name, sl);
100
101 w1_family_put(sl->family);
102 sl->master->slave_count--;
103}
104
105static ssize_t name_show(struct device *dev, struct device_attribute *attr, char *buf)
106{
107 struct w1_slave *sl = dev_to_w1_slave(dev);
108
109 return sprintf(buf, "%s\n", sl->name);
110}
111static DEVICE_ATTR_RO(name);
112
113static ssize_t id_show(struct device *dev,
114 struct device_attribute *attr, char *buf)
115{
116 struct w1_slave *sl = dev_to_w1_slave(dev);
117 ssize_t count = sizeof(sl->reg_num);
118
119 memcpy(buf, (u8 *)&sl->reg_num, count);
120 return count;
121}
122static DEVICE_ATTR_RO(id);
123
124static struct attribute *w1_slave_attrs[] = {
125 &dev_attr_name.attr,
126 &dev_attr_id.attr,
127 NULL,
128};
129ATTRIBUTE_GROUPS(w1_slave);
130
131/* Default family */
132
133static ssize_t rw_write(struct file *filp, struct kobject *kobj,
134 struct bin_attribute *bin_attr, char *buf, loff_t off,
135 size_t count)
136{
137 struct w1_slave *sl = kobj_to_w1_slave(kobj);
138
139 mutex_lock(&sl->master->mutex);
140 if (w1_reset_select_slave(sl)) {
141 count = 0;
142 goto out_up;
143 }
144
145 w1_write_block(sl->master, buf, count);
146
147out_up:
148 mutex_unlock(&sl->master->mutex);
149 return count;
150}
151
152static ssize_t rw_read(struct file *filp, struct kobject *kobj,
153 struct bin_attribute *bin_attr, char *buf, loff_t off,
154 size_t count)
155{
156 struct w1_slave *sl = kobj_to_w1_slave(kobj);
157
158 mutex_lock(&sl->master->mutex);
159 w1_read_block(sl->master, buf, count);
160 mutex_unlock(&sl->master->mutex);
161 return count;
162}
163
164static BIN_ATTR_RW(rw, PAGE_SIZE);
165
166static struct bin_attribute *w1_slave_bin_attrs[] = {
167 &bin_attr_rw,
168 NULL,
169};
170
171static const struct attribute_group w1_slave_default_group = {
172 .bin_attrs = w1_slave_bin_attrs,
173};
174
175static const struct attribute_group *w1_slave_default_groups[] = {
176 &w1_slave_default_group,
177 NULL,
178};
179
180static struct w1_family_ops w1_default_fops = {
181 .groups = w1_slave_default_groups,
182};
183
184static struct w1_family w1_default_family = {
185 .fops = &w1_default_fops,
186};
187
188static int w1_uevent(struct device *dev, struct kobj_uevent_env *env);
189
190static struct bus_type w1_bus_type = {
191 .name = "w1",
192 .match = w1_master_match,
193 .uevent = w1_uevent,
194};
195
196struct device_driver w1_master_driver = {
197 .name = "w1_master_driver",
198 .bus = &w1_bus_type,
199 .probe = w1_master_probe,
200};
201
202struct device w1_master_device = {
203 .parent = NULL,
204 .bus = &w1_bus_type,
205 .init_name = "w1 bus master",
206 .driver = &w1_master_driver,
207 .release = &w1_master_release
208};
209
210static struct device_driver w1_slave_driver = {
211 .name = "w1_slave_driver",
212 .bus = &w1_bus_type,
213};
214
215#if 0
216struct device w1_slave_device = {
217 .parent = NULL,
218 .bus = &w1_bus_type,
219 .init_name = "w1 bus slave",
220 .driver = &w1_slave_driver,
221 .release = &w1_slave_release
222};
223#endif /* 0 */
224
225static ssize_t w1_master_attribute_show_name(struct device *dev, struct device_attribute *attr, char *buf)
226{
227 struct w1_master *md = dev_to_w1_master(dev);
228 ssize_t count;
229
230 mutex_lock(&md->mutex);
231 count = sprintf(buf, "%s\n", md->name);
232 mutex_unlock(&md->mutex);
233
234 return count;
235}
236
237static ssize_t w1_master_attribute_store_search(struct device * dev,
238 struct device_attribute *attr,
239 const char * buf, size_t count)
240{
241 long tmp;
242 struct w1_master *md = dev_to_w1_master(dev);
243 int ret;
244
245 ret = kstrtol(buf, 0, &tmp);
246 if (ret)
247 return ret;
248
249 mutex_lock(&md->mutex);
250 md->search_count = tmp;
251 mutex_unlock(&md->mutex);
252 /* Only wake if it is going to be searching. */
253 if (tmp)
254 wake_up_process(md->thread);
255
256 return count;
257}
258
259static ssize_t w1_master_attribute_show_search(struct device *dev,
260 struct device_attribute *attr,
261 char *buf)
262{
263 struct w1_master *md = dev_to_w1_master(dev);
264 ssize_t count;
265
266 mutex_lock(&md->mutex);
267 count = sprintf(buf, "%d\n", md->search_count);
268 mutex_unlock(&md->mutex);
269
270 return count;
271}
272
273static ssize_t w1_master_attribute_store_pullup(struct device *dev,
274 struct device_attribute *attr,
275 const char *buf, size_t count)
276{
277 long tmp;
278 struct w1_master *md = dev_to_w1_master(dev);
279 int ret;
280
281 ret = kstrtol(buf, 0, &tmp);
282 if (ret)
283 return ret;
284
285 mutex_lock(&md->mutex);
286 md->enable_pullup = tmp;
287 mutex_unlock(&md->mutex);
288
289 return count;
290}
291
292static ssize_t w1_master_attribute_show_pullup(struct device *dev,
293 struct device_attribute *attr,
294 char *buf)
295{
296 struct w1_master *md = dev_to_w1_master(dev);
297 ssize_t count;
298
299 mutex_lock(&md->mutex);
300 count = sprintf(buf, "%d\n", md->enable_pullup);
301 mutex_unlock(&md->mutex);
302
303 return count;
304}
305
306static ssize_t w1_master_attribute_show_pointer(struct device *dev, struct device_attribute *attr, char *buf)
307{
308 struct w1_master *md = dev_to_w1_master(dev);
309 ssize_t count;
310
311 mutex_lock(&md->mutex);
312 count = sprintf(buf, "0x%p\n", md->bus_master);
313 mutex_unlock(&md->mutex);
314 return count;
315}
316
317static ssize_t w1_master_attribute_show_timeout(struct device *dev, struct device_attribute *attr, char *buf)
318{
319 ssize_t count;
320 count = sprintf(buf, "%d\n", w1_timeout);
321 return count;
322}
323
324static ssize_t w1_master_attribute_show_timeout_us(struct device *dev,
325 struct device_attribute *attr, char *buf)
326{
327 ssize_t count;
328 count = sprintf(buf, "%d\n", w1_timeout_us);
329 return count;
330}
331
332static ssize_t w1_master_attribute_store_max_slave_count(struct device *dev,
333 struct device_attribute *attr, const char *buf, size_t count)
334{
335 int tmp;
336 struct w1_master *md = dev_to_w1_master(dev);
337
338 if (kstrtoint(buf, 0, &tmp) == -EINVAL || tmp < 1)
339 return -EINVAL;
340
341 mutex_lock(&md->mutex);
342 md->max_slave_count = tmp;
343 /* allow each time the max_slave_count is updated */
344 clear_bit(W1_WARN_MAX_COUNT, &md->flags);
345 mutex_unlock(&md->mutex);
346
347 return count;
348}
349
350static ssize_t w1_master_attribute_show_max_slave_count(struct device *dev, struct device_attribute *attr, char *buf)
351{
352 struct w1_master *md = dev_to_w1_master(dev);
353 ssize_t count;
354
355 mutex_lock(&md->mutex);
356 count = sprintf(buf, "%d\n", md->max_slave_count);
357 mutex_unlock(&md->mutex);
358 return count;
359}
360
361static ssize_t w1_master_attribute_show_attempts(struct device *dev, struct device_attribute *attr, char *buf)
362{
363 struct w1_master *md = dev_to_w1_master(dev);
364 ssize_t count;
365
366 mutex_lock(&md->mutex);
367 count = sprintf(buf, "%lu\n", md->attempts);
368 mutex_unlock(&md->mutex);
369 return count;
370}
371
372static ssize_t w1_master_attribute_show_slave_count(struct device *dev, struct device_attribute *attr, char *buf)
373{
374 struct w1_master *md = dev_to_w1_master(dev);
375 ssize_t count;
376
377 mutex_lock(&md->mutex);
378 count = sprintf(buf, "%d\n", md->slave_count);
379 mutex_unlock(&md->mutex);
380 return count;
381}
382
383static ssize_t w1_master_attribute_show_slaves(struct device *dev,
384 struct device_attribute *attr, char *buf)
385{
386 struct w1_master *md = dev_to_w1_master(dev);
387 int c = PAGE_SIZE;
388 struct list_head *ent, *n;
389 struct w1_slave *sl = NULL;
390
391 mutex_lock(&md->list_mutex);
392
393 list_for_each_safe(ent, n, &md->slist) {
394 sl = list_entry(ent, struct w1_slave, w1_slave_entry);
395
396 c -= snprintf(buf + PAGE_SIZE - c, c, "%s\n", sl->name);
397 }
398 if (!sl)
399 c -= snprintf(buf + PAGE_SIZE - c, c, "not found.\n");
400
401 mutex_unlock(&md->list_mutex);
402
403 return PAGE_SIZE - c;
404}
405
406static ssize_t w1_master_attribute_show_add(struct device *dev,
407 struct device_attribute *attr, char *buf)
408{
409 int c = PAGE_SIZE;
410 c -= snprintf(buf+PAGE_SIZE - c, c,
411 "write device id xx-xxxxxxxxxxxx to add slave\n");
412 return PAGE_SIZE - c;
413}
414
415static int w1_atoreg_num(struct device *dev, const char *buf, size_t count,
416 struct w1_reg_num *rn)
417{
418 unsigned int family;
419 unsigned long long id;
420 int i;
421 u64 rn64_le;
422
423 /* The CRC value isn't read from the user because the sysfs directory
424 * doesn't include it and most messages from the bus search don't
425 * print it either. It would be unreasonable for the user to then
426 * provide it.
427 */
428 const char *error_msg = "bad slave string format, expecting "
429 "ff-dddddddddddd\n";
430
431 if (buf[2] != '-') {
432 dev_err(dev, "%s", error_msg);
433 return -EINVAL;
434 }
435 i = sscanf(buf, "%02x-%012llx", &family, &id);
436 if (i != 2) {
437 dev_err(dev, "%s", error_msg);
438 return -EINVAL;
439 }
440 rn->family = family;
441 rn->id = id;
442
443 rn64_le = cpu_to_le64(*(u64 *)rn);
444 rn->crc = w1_calc_crc8((u8 *)&rn64_le, 7);
445
446#if 0
447 dev_info(dev, "With CRC device is %02x.%012llx.%02x.\n",
448 rn->family, (unsigned long long)rn->id, rn->crc);
449#endif
450
451 return 0;
452}
453
454/* Searches the slaves in the w1_master and returns a pointer or NULL.
455 * Note: must not hold list_mutex
456 */
457struct w1_slave *w1_slave_search_device(struct w1_master *dev,
458 struct w1_reg_num *rn)
459{
460 struct w1_slave *sl;
461 mutex_lock(&dev->list_mutex);
462 list_for_each_entry(sl, &dev->slist, w1_slave_entry) {
463 if (sl->reg_num.family == rn->family &&
464 sl->reg_num.id == rn->id &&
465 sl->reg_num.crc == rn->crc) {
466 mutex_unlock(&dev->list_mutex);
467 return sl;
468 }
469 }
470 mutex_unlock(&dev->list_mutex);
471 return NULL;
472}
473
474static ssize_t w1_master_attribute_store_add(struct device *dev,
475 struct device_attribute *attr,
476 const char *buf, size_t count)
477{
478 struct w1_master *md = dev_to_w1_master(dev);
479 struct w1_reg_num rn;
480 struct w1_slave *sl;
481 ssize_t result = count;
482
483 if (w1_atoreg_num(dev, buf, count, &rn))
484 return -EINVAL;
485
486 mutex_lock(&md->mutex);
487 sl = w1_slave_search_device(md, &rn);
488 /* It would be nice to do a targeted search one the one-wire bus
489 * for the new device to see if it is out there or not. But the
490 * current search doesn't support that.
491 */
492 if (sl) {
493 dev_info(dev, "Device %s already exists\n", sl->name);
494 result = -EINVAL;
495 } else {
496 w1_attach_slave_device(md, &rn);
497 }
498 mutex_unlock(&md->mutex);
499
500 return result;
501}
502
503static ssize_t w1_master_attribute_show_remove(struct device *dev,
504 struct device_attribute *attr, char *buf)
505{
506 int c = PAGE_SIZE;
507 c -= snprintf(buf+PAGE_SIZE - c, c,
508 "write device id xx-xxxxxxxxxxxx to remove slave\n");
509 return PAGE_SIZE - c;
510}
511
512static ssize_t w1_master_attribute_store_remove(struct device *dev,
513 struct device_attribute *attr,
514 const char *buf, size_t count)
515{
516 struct w1_master *md = dev_to_w1_master(dev);
517 struct w1_reg_num rn;
518 struct w1_slave *sl;
519 ssize_t result = count;
520
521 if (w1_atoreg_num(dev, buf, count, &rn))
522 return -EINVAL;
523
524 mutex_lock(&md->mutex);
525 sl = w1_slave_search_device(md, &rn);
526 if (sl) {
527 result = w1_slave_detach(sl);
528 /* refcnt 0 means it was detached in the call */
529 if (result == 0)
530 result = count;
531 } else {
532 dev_info(dev, "Device %02x-%012llx doesn't exists\n", rn.family,
533 (unsigned long long)rn.id);
534 result = -EINVAL;
535 }
536 mutex_unlock(&md->mutex);
537
538 return result;
539}
540
541#define W1_MASTER_ATTR_RO(_name, _mode) \
542 struct device_attribute w1_master_attribute_##_name = \
543 __ATTR(w1_master_##_name, _mode, \
544 w1_master_attribute_show_##_name, NULL)
545
546#define W1_MASTER_ATTR_RW(_name, _mode) \
547 struct device_attribute w1_master_attribute_##_name = \
548 __ATTR(w1_master_##_name, _mode, \
549 w1_master_attribute_show_##_name, \
550 w1_master_attribute_store_##_name)
551
552static W1_MASTER_ATTR_RO(name, S_IRUGO);
553static W1_MASTER_ATTR_RO(slaves, S_IRUGO);
554static W1_MASTER_ATTR_RO(slave_count, S_IRUGO);
555static W1_MASTER_ATTR_RW(max_slave_count, S_IRUGO | S_IWUSR | S_IWGRP);
556static W1_MASTER_ATTR_RO(attempts, S_IRUGO);
557static W1_MASTER_ATTR_RO(timeout, S_IRUGO);
558static W1_MASTER_ATTR_RO(timeout_us, S_IRUGO);
559static W1_MASTER_ATTR_RO(pointer, S_IRUGO);
560static W1_MASTER_ATTR_RW(search, S_IRUGO | S_IWUSR | S_IWGRP);
561static W1_MASTER_ATTR_RW(pullup, S_IRUGO | S_IWUSR | S_IWGRP);
562static W1_MASTER_ATTR_RW(add, S_IRUGO | S_IWUSR | S_IWGRP);
563static W1_MASTER_ATTR_RW(remove, S_IRUGO | S_IWUSR | S_IWGRP);
564
565static struct attribute *w1_master_default_attrs[] = {
566 &w1_master_attribute_name.attr,
567 &w1_master_attribute_slaves.attr,
568 &w1_master_attribute_slave_count.attr,
569 &w1_master_attribute_max_slave_count.attr,
570 &w1_master_attribute_attempts.attr,
571 &w1_master_attribute_timeout.attr,
572 &w1_master_attribute_timeout_us.attr,
573 &w1_master_attribute_pointer.attr,
574 &w1_master_attribute_search.attr,
575 &w1_master_attribute_pullup.attr,
576 &w1_master_attribute_add.attr,
577 &w1_master_attribute_remove.attr,
578 NULL
579};
580
581static struct attribute_group w1_master_defattr_group = {
582 .attrs = w1_master_default_attrs,
583};
584
585int w1_create_master_attributes(struct w1_master *master)
586{
587 return sysfs_create_group(&master->dev.kobj, &w1_master_defattr_group);
588}
589
590void w1_destroy_master_attributes(struct w1_master *master)
591{
592 sysfs_remove_group(&master->dev.kobj, &w1_master_defattr_group);
593}
594
595static int w1_uevent(struct device *dev, struct kobj_uevent_env *env)
596{
597 struct w1_master *md = NULL;
598 struct w1_slave *sl = NULL;
599 char *event_owner, *name;
600 int err = 0;
601
602 if (dev->driver == &w1_master_driver) {
603 md = container_of(dev, struct w1_master, dev);
604 event_owner = "master";
605 name = md->name;
606 } else if (dev->driver == &w1_slave_driver) {
607 sl = container_of(dev, struct w1_slave, dev);
608 event_owner = "slave";
609 name = sl->name;
610 } else {
611 dev_dbg(dev, "Unknown event.\n");
612 return -EINVAL;
613 }
614
615 dev_dbg(dev, "Hotplug event for %s %s, bus_id=%s.\n",
616 event_owner, name, dev_name(dev));
617
618 if (dev->driver != &w1_slave_driver || !sl)
619 goto end;
620
621 err = add_uevent_var(env, "W1_FID=%02X", sl->reg_num.family);
622 if (err)
623 goto end;
624
625 err = add_uevent_var(env, "W1_SLAVE_ID=%024LX",
626 (unsigned long long)sl->reg_num.id);
627end:
628 return err;
629}
630
631static int w1_family_notify(unsigned long action, struct w1_slave *sl)
632{
633 struct w1_family_ops *fops;
634 int err;
635
636 fops = sl->family->fops;
637
638 if (!fops)
639 return 0;
640
641 switch (action) {
642 case BUS_NOTIFY_ADD_DEVICE:
643 /* if the family driver needs to initialize something... */
644 if (fops->add_slave) {
645 err = fops->add_slave(sl);
646 if (err < 0) {
647 dev_err(&sl->dev,
648 "add_slave() call failed. err=%d\n",
649 err);
650 return err;
651 }
652 }
653 if (fops->groups) {
654 err = sysfs_create_groups(&sl->dev.kobj, fops->groups);
655 if (err) {
656 dev_err(&sl->dev,
657 "sysfs group creation failed. err=%d\n",
658 err);
659 return err;
660 }
661 }
662
663 break;
664 case BUS_NOTIFY_DEL_DEVICE:
665 if (fops->remove_slave)
666 sl->family->fops->remove_slave(sl);
667 if (fops->groups)
668 sysfs_remove_groups(&sl->dev.kobj, fops->groups);
669 break;
670 }
671 return 0;
672}
673
674static int __w1_attach_slave_device(struct w1_slave *sl)
675{
676 int err;
677
678 sl->dev.parent = &sl->master->dev;
679 sl->dev.driver = &w1_slave_driver;
680 sl->dev.bus = &w1_bus_type;
681 sl->dev.release = &w1_slave_release;
682 sl->dev.groups = w1_slave_groups;
683
684 dev_set_name(&sl->dev, "%02x-%012llx",
685 (unsigned int) sl->reg_num.family,
686 (unsigned long long) sl->reg_num.id);
687 snprintf(&sl->name[0], sizeof(sl->name),
688 "%02x-%012llx",
689 (unsigned int) sl->reg_num.family,
690 (unsigned long long) sl->reg_num.id);
691
692 dev_dbg(&sl->dev, "%s: registering %s as %p.\n", __func__,
693 dev_name(&sl->dev), sl);
694
695 /* suppress for w1_family_notify before sending KOBJ_ADD */
696 dev_set_uevent_suppress(&sl->dev, true);
697
698 err = device_register(&sl->dev);
699 if (err < 0) {
700 dev_err(&sl->dev,
701 "Device registration [%s] failed. err=%d\n",
702 dev_name(&sl->dev), err);
703 return err;
704 }
705 w1_family_notify(BUS_NOTIFY_ADD_DEVICE, sl);
706
707 dev_set_uevent_suppress(&sl->dev, false);
708 kobject_uevent(&sl->dev.kobj, KOBJ_ADD);
709
710 mutex_lock(&sl->master->list_mutex);
711 list_add_tail(&sl->w1_slave_entry, &sl->master->slist);
712 mutex_unlock(&sl->master->list_mutex);
713
714 return 0;
715}
716
717int w1_attach_slave_device(struct w1_master *dev, struct w1_reg_num *rn)
718{
719 struct w1_slave *sl;
720 struct w1_family *f;
721 int err;
722 struct w1_netlink_msg msg;
723
724 sl = kzalloc(sizeof(struct w1_slave), GFP_KERNEL);
725 if (!sl) {
726 dev_err(&dev->dev,
727 "%s: failed to allocate new slave device.\n",
728 __func__);
729 return -ENOMEM;
730 }
731
732
733 sl->owner = THIS_MODULE;
734 sl->master = dev;
735 set_bit(W1_SLAVE_ACTIVE, &sl->flags);
736
737 memset(&msg, 0, sizeof(msg));
738 memcpy(&sl->reg_num, rn, sizeof(sl->reg_num));
739 atomic_set(&sl->refcnt, 1);
740 atomic_inc(&sl->master->refcnt);
741
742 /* slave modules need to be loaded in a context with unlocked mutex */
743 mutex_unlock(&dev->mutex);
744 request_module("w1-family-0x%02x", rn->family);
745 mutex_lock(&dev->mutex);
746
747 spin_lock(&w1_flock);
748 f = w1_family_registered(rn->family);
749 if (!f) {
750 f= &w1_default_family;
751 dev_info(&dev->dev, "Family %x for %02x.%012llx.%02x is not registered.\n",
752 rn->family, rn->family,
753 (unsigned long long)rn->id, rn->crc);
754 }
755 __w1_family_get(f);
756 spin_unlock(&w1_flock);
757
758 sl->family = f;
759
760
761 err = __w1_attach_slave_device(sl);
762 if (err < 0) {
763 dev_err(&dev->dev, "%s: Attaching %s failed.\n", __func__,
764 sl->name);
765 w1_family_put(sl->family);
766 kfree(sl);
767 return err;
768 }
769
770 sl->ttl = dev->slave_ttl;
771 dev->slave_count++;
772
773 memcpy(msg.id.id, rn, sizeof(msg.id));
774 msg.type = W1_SLAVE_ADD;
775 w1_netlink_send(dev, &msg);
776
777 return 0;
778}
779
780int w1_unref_slave(struct w1_slave *sl)
781{
782 struct w1_master *dev = sl->master;
783 int refcnt;
784 mutex_lock(&dev->list_mutex);
785 refcnt = atomic_sub_return(1, &sl->refcnt);
786 if (refcnt == 0) {
787 struct w1_netlink_msg msg;
788
789 dev_dbg(&sl->dev, "%s: detaching %s [%p].\n", __func__,
790 sl->name, sl);
791
792 list_del(&sl->w1_slave_entry);
793
794 memset(&msg, 0, sizeof(msg));
795 memcpy(msg.id.id, &sl->reg_num, sizeof(msg.id));
796 msg.type = W1_SLAVE_REMOVE;
797 w1_netlink_send(sl->master, &msg);
798
799 w1_family_notify(BUS_NOTIFY_DEL_DEVICE, sl);
800 device_unregister(&sl->dev);
801 #ifdef DEBUG
802 memset(sl, 0, sizeof(*sl));
803 #endif
804 kfree(sl);
805 }
806 atomic_dec(&dev->refcnt);
807 mutex_unlock(&dev->list_mutex);
808 return refcnt;
809}
810
811int w1_slave_detach(struct w1_slave *sl)
812{
813 /* Only detach a slave once as it decreases the refcnt each time. */
814 int destroy_now;
815 mutex_lock(&sl->master->list_mutex);
816 destroy_now = !test_bit(W1_SLAVE_DETACH, &sl->flags);
817 set_bit(W1_SLAVE_DETACH, &sl->flags);
818 mutex_unlock(&sl->master->list_mutex);
819
820 if (destroy_now)
821 destroy_now = !w1_unref_slave(sl);
822 return destroy_now ? 0 : -EBUSY;
823}
824
825struct w1_master *w1_search_master_id(u32 id)
826{
827 struct w1_master *dev;
828 int found = 0;
829
830 mutex_lock(&w1_mlock);
831 list_for_each_entry(dev, &w1_masters, w1_master_entry) {
832 if (dev->id == id) {
833 found = 1;
834 atomic_inc(&dev->refcnt);
835 break;
836 }
837 }
838 mutex_unlock(&w1_mlock);
839
840 return (found)?dev:NULL;
841}
842
843struct w1_slave *w1_search_slave(struct w1_reg_num *id)
844{
845 struct w1_master *dev;
846 struct w1_slave *sl = NULL;
847 int found = 0;
848
849 mutex_lock(&w1_mlock);
850 list_for_each_entry(dev, &w1_masters, w1_master_entry) {
851 mutex_lock(&dev->list_mutex);
852 list_for_each_entry(sl, &dev->slist, w1_slave_entry) {
853 if (sl->reg_num.family == id->family &&
854 sl->reg_num.id == id->id &&
855 sl->reg_num.crc == id->crc) {
856 found = 1;
857 atomic_inc(&dev->refcnt);
858 atomic_inc(&sl->refcnt);
859 break;
860 }
861 }
862 mutex_unlock(&dev->list_mutex);
863
864 if (found)
865 break;
866 }
867 mutex_unlock(&w1_mlock);
868
869 return (found)?sl:NULL;
870}
871
872void w1_reconnect_slaves(struct w1_family *f, int attach)
873{
874 struct w1_slave *sl, *sln;
875 struct w1_master *dev;
876
877 mutex_lock(&w1_mlock);
878 list_for_each_entry(dev, &w1_masters, w1_master_entry) {
879 dev_dbg(&dev->dev, "Reconnecting slaves in device %s "
880 "for family %02x.\n", dev->name, f->fid);
881 mutex_lock(&dev->mutex);
882 mutex_lock(&dev->list_mutex);
883 list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) {
884 /* If it is a new family, slaves with the default
885 * family driver and are that family will be
886 * connected. If the family is going away, devices
887 * matching that family are reconneced.
888 */
889 if ((attach && sl->family->fid == W1_FAMILY_DEFAULT
890 && sl->reg_num.family == f->fid) ||
891 (!attach && sl->family->fid == f->fid)) {
892 struct w1_reg_num rn;
893
894 mutex_unlock(&dev->list_mutex);
895 memcpy(&rn, &sl->reg_num, sizeof(rn));
896 /* If it was already in use let the automatic
897 * scan pick it up again later.
898 */
899 if (!w1_slave_detach(sl))
900 w1_attach_slave_device(dev, &rn);
901 mutex_lock(&dev->list_mutex);
902 }
903 }
904 dev_dbg(&dev->dev, "Reconnecting slaves in device %s "
905 "has been finished.\n", dev->name);
906 mutex_unlock(&dev->list_mutex);
907 mutex_unlock(&dev->mutex);
908 }
909 mutex_unlock(&w1_mlock);
910}
911
912void w1_slave_found(struct w1_master *dev, u64 rn)
913{
914 struct w1_slave *sl;
915 struct w1_reg_num *tmp;
916 u64 rn_le = cpu_to_le64(rn);
917
918 atomic_inc(&dev->refcnt);
919
920 tmp = (struct w1_reg_num *) &rn;
921
922 sl = w1_slave_search_device(dev, tmp);
923 if (sl) {
924 set_bit(W1_SLAVE_ACTIVE, &sl->flags);
925 } else {
926 if (rn && tmp->crc == w1_calc_crc8((u8 *)&rn_le, 7))
927 w1_attach_slave_device(dev, tmp);
928 }
929
930 atomic_dec(&dev->refcnt);
931}
932
933/**
934 * w1_search() - Performs a ROM Search & registers any devices found.
935 * @dev: The master device to search
936 * @search_type: W1_SEARCH to search all devices, or W1_ALARM_SEARCH
937 * to return only devices in the alarmed state
938 * @cb: Function to call when a device is found
939 *
940 * The 1-wire search is a simple binary tree search.
941 * For each bit of the address, we read two bits and write one bit.
942 * The bit written will put to sleep all devies that don't match that bit.
943 * When the two reads differ, the direction choice is obvious.
944 * When both bits are 0, we must choose a path to take.
945 * When we can scan all 64 bits without having to choose a path, we are done.
946 *
947 * See "Application note 187 1-wire search algorithm" at www.maxim-ic.com
948 *
949 */
950void w1_search(struct w1_master *dev, u8 search_type, w1_slave_found_callback cb)
951{
952 u64 last_rn, rn, tmp64;
953 int i, slave_count = 0;
954 int last_zero, last_device;
955 int search_bit, desc_bit;
956 u8 triplet_ret = 0;
957
958 search_bit = 0;
959 rn = dev->search_id;
960 last_rn = 0;
961 last_device = 0;
962 last_zero = -1;
963
964 desc_bit = 64;
965
966 while ( !last_device && (slave_count++ < dev->max_slave_count) ) {
967 last_rn = rn;
968 rn = 0;
969
970 /*
971 * Reset bus and all 1-wire device state machines
972 * so they can respond to our requests.
973 *
974 * Return 0 - device(s) present, 1 - no devices present.
975 */
976 mutex_lock(&dev->bus_mutex);
977 if (w1_reset_bus(dev)) {
978 mutex_unlock(&dev->bus_mutex);
979 dev_dbg(&dev->dev, "No devices present on the wire.\n");
980 break;
981 }
982
983 /* Do fast search on single slave bus */
984 if (dev->max_slave_count == 1) {
985 int rv;
986 w1_write_8(dev, W1_READ_ROM);
987 rv = w1_read_block(dev, (u8 *)&rn, 8);
988 mutex_unlock(&dev->bus_mutex);
989
990 if (rv == 8 && rn)
991 cb(dev, rn);
992
993 break;
994 }
995
996 /* Start the search */
997 w1_write_8(dev, search_type);
998 for (i = 0; i < 64; ++i) {
999 /* Determine the direction/search bit */
1000 if (i == desc_bit)
1001 search_bit = 1; /* took the 0 path last time, so take the 1 path */
1002 else if (i > desc_bit)
1003 search_bit = 0; /* take the 0 path on the next branch */
1004 else
1005 search_bit = ((last_rn >> i) & 0x1);
1006
1007 /* Read two bits and write one bit */
1008 triplet_ret = w1_triplet(dev, search_bit);
1009
1010 /* quit if no device responded */
1011 if ( (triplet_ret & 0x03) == 0x03 )
1012 break;
1013
1014 /* If both directions were valid, and we took the 0 path... */
1015 if (triplet_ret == 0)
1016 last_zero = i;
1017
1018 /* extract the direction taken & update the device number */
1019 tmp64 = (triplet_ret >> 2);
1020 rn |= (tmp64 << i);
1021
1022 if (test_bit(W1_ABORT_SEARCH, &dev->flags)) {
1023 mutex_unlock(&dev->bus_mutex);
1024 dev_dbg(&dev->dev, "Abort w1_search\n");
1025 return;
1026 }
1027 }
1028 mutex_unlock(&dev->bus_mutex);
1029
1030 if ( (triplet_ret & 0x03) != 0x03 ) {
1031 if ((desc_bit == last_zero) || (last_zero < 0)) {
1032 last_device = 1;
1033 dev->search_id = 0;
1034 } else {
1035 dev->search_id = rn;
1036 }
1037 desc_bit = last_zero;
1038 cb(dev, rn);
1039 }
1040
1041 if (!last_device && slave_count == dev->max_slave_count &&
1042 !test_bit(W1_WARN_MAX_COUNT, &dev->flags)) {
1043 /* Only max_slave_count will be scanned in a search,
1044 * but it will start where it left off next search
1045 * until all ids are identified and then it will start
1046 * over. A continued search will report the previous
1047 * last id as the first id (provided it is still on the
1048 * bus).
1049 */
1050 dev_info(&dev->dev, "%s: max_slave_count %d reached, "
1051 "will continue next search.\n", __func__,
1052 dev->max_slave_count);
1053 set_bit(W1_WARN_MAX_COUNT, &dev->flags);
1054 }
1055 }
1056}
1057
1058void w1_search_process_cb(struct w1_master *dev, u8 search_type,
1059 w1_slave_found_callback cb)
1060{
1061 struct w1_slave *sl, *sln;
1062
1063 mutex_lock(&dev->list_mutex);
1064 list_for_each_entry(sl, &dev->slist, w1_slave_entry)
1065 clear_bit(W1_SLAVE_ACTIVE, &sl->flags);
1066 mutex_unlock(&dev->list_mutex);
1067
1068 w1_search_devices(dev, search_type, cb);
1069
1070 mutex_lock(&dev->list_mutex);
1071 list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) {
1072 if (!test_bit(W1_SLAVE_ACTIVE, &sl->flags) && !--sl->ttl) {
1073 mutex_unlock(&dev->list_mutex);
1074 w1_slave_detach(sl);
1075 mutex_lock(&dev->list_mutex);
1076 }
1077 else if (test_bit(W1_SLAVE_ACTIVE, &sl->flags))
1078 sl->ttl = dev->slave_ttl;
1079 }
1080 mutex_unlock(&dev->list_mutex);
1081
1082 if (dev->search_count > 0)
1083 dev->search_count--;
1084}
1085
1086static void w1_search_process(struct w1_master *dev, u8 search_type)
1087{
1088 w1_search_process_cb(dev, search_type, w1_slave_found);
1089}
1090
1091/**
1092 * w1_process_callbacks() - execute each dev->async_list callback entry
1093 * @dev: w1_master device
1094 *
1095 * The w1 master list_mutex must be held.
1096 *
1097 * Return: 1 if there were commands to executed 0 otherwise
1098 */
1099int w1_process_callbacks(struct w1_master *dev)
1100{
1101 int ret = 0;
1102 struct w1_async_cmd *async_cmd, *async_n;
1103
1104 /* The list can be added to in another thread, loop until it is empty */
1105 while (!list_empty(&dev->async_list)) {
1106 list_for_each_entry_safe(async_cmd, async_n, &dev->async_list,
1107 async_entry) {
1108 /* drop the lock, if it is a search it can take a long
1109 * time */
1110 mutex_unlock(&dev->list_mutex);
1111 async_cmd->cb(dev, async_cmd);
1112 ret = 1;
1113 mutex_lock(&dev->list_mutex);
1114 }
1115 }
1116 return ret;
1117}
1118
1119int w1_process(void *data)
1120{
1121 struct w1_master *dev = (struct w1_master *) data;
1122 /* As long as w1_timeout is only set by a module parameter the sleep
1123 * time can be calculated in jiffies once.
1124 */
1125 const unsigned long jtime =
1126 usecs_to_jiffies(w1_timeout * 1000000 + w1_timeout_us);
1127 /* remainder if it woke up early */
1128 unsigned long jremain = 0;
1129
1130 for (;;) {
1131
1132 if (!jremain && dev->search_count) {
1133 mutex_lock(&dev->mutex);
1134 w1_search_process(dev, W1_SEARCH);
1135 mutex_unlock(&dev->mutex);
1136 }
1137
1138 mutex_lock(&dev->list_mutex);
1139 /* Note, w1_process_callback drops the lock while processing,
1140 * but locks it again before returning.
1141 */
1142 if (!w1_process_callbacks(dev) && jremain) {
1143 /* a wake up is either to stop the thread, process
1144 * callbacks, or search, it isn't process callbacks, so
1145 * schedule a search.
1146 */
1147 jremain = 1;
1148 }
1149
1150 __set_current_state(TASK_INTERRUPTIBLE);
1151
1152 /* hold list_mutex until after interruptible to prevent loosing
1153 * the wakeup signal when async_cmd is added.
1154 */
1155 mutex_unlock(&dev->list_mutex);
1156
1157 if (kthread_should_stop())
1158 break;
1159
1160 /* Only sleep when the search is active. */
1161 if (dev->search_count) {
1162 if (!jremain)
1163 jremain = jtime;
1164 jremain = schedule_timeout(jremain);
1165 }
1166 else
1167 schedule();
1168 }
1169
1170 atomic_dec(&dev->refcnt);
1171
1172 return 0;
1173}
1174
1175static int __init w1_init(void)
1176{
1177 int retval;
1178
1179 pr_info("Driver for 1-wire Dallas network protocol.\n");
1180
1181 w1_init_netlink();
1182
1183 retval = bus_register(&w1_bus_type);
1184 if (retval) {
1185 pr_err("Failed to register bus. err=%d.\n", retval);
1186 goto err_out_exit_init;
1187 }
1188
1189 retval = driver_register(&w1_master_driver);
1190 if (retval) {
1191 pr_err("Failed to register master driver. err=%d.\n",
1192 retval);
1193 goto err_out_bus_unregister;
1194 }
1195
1196 retval = driver_register(&w1_slave_driver);
1197 if (retval) {
1198 pr_err("Failed to register slave driver. err=%d.\n",
1199 retval);
1200 goto err_out_master_unregister;
1201 }
1202
1203 return 0;
1204
1205#if 0
1206/* For undoing the slave register if there was a step after it. */
1207err_out_slave_unregister:
1208 driver_unregister(&w1_slave_driver);
1209#endif
1210
1211err_out_master_unregister:
1212 driver_unregister(&w1_master_driver);
1213
1214err_out_bus_unregister:
1215 bus_unregister(&w1_bus_type);
1216
1217err_out_exit_init:
1218 return retval;
1219}
1220
1221static void __exit w1_fini(void)
1222{
1223 struct w1_master *dev;
1224
1225 /* Set netlink removal messages and some cleanup */
1226 list_for_each_entry(dev, &w1_masters, w1_master_entry)
1227 __w1_remove_master_device(dev);
1228
1229 w1_fini_netlink();
1230
1231 driver_unregister(&w1_slave_driver);
1232 driver_unregister(&w1_master_driver);
1233 bus_unregister(&w1_bus_type);
1234}
1235
1236module_init(w1_init);
1237module_exit(w1_fini);
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);