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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Copyright (c) 2004 Evgeniy Polyakov <zbr@ioremap.net>
4 */
5
6#include <linux/delay.h>
7#include <linux/kernel.h>
8#include <linux/module.h>
9#include <linux/moduleparam.h>
10#include <linux/list.h>
11#include <linux/interrupt.h>
12#include <linux/spinlock.h>
13#include <linux/timer.h>
14#include <linux/device.h>
15#include <linux/slab.h>
16#include <linux/sched.h>
17#include <linux/kthread.h>
18#include <linux/freezer.h>
19#include <linux/hwmon.h>
20#include <linux/of.h>
21
22#include <linux/atomic.h>
23
24#include "w1_internal.h"
25#include "w1_netlink.h"
26
27#define W1_FAMILY_DEFAULT 0
28
29static int w1_timeout = 10;
30module_param_named(timeout, w1_timeout, int, 0);
31MODULE_PARM_DESC(timeout, "time in seconds between automatic slave searches");
32
33static int w1_timeout_us = 0;
34module_param_named(timeout_us, w1_timeout_us, int, 0);
35MODULE_PARM_DESC(timeout_us,
36 "time in microseconds between automatic slave searches");
37
38/* A search stops when w1_max_slave_count devices have been found in that
39 * search. The next search will start over and detect the same set of devices
40 * on a static 1-wire bus. Memory is not allocated based on this number, just
41 * on the number of devices known to the kernel. Having a high number does not
42 * consume additional resources. As a special case, if there is only one
43 * device on the network and w1_max_slave_count is set to 1, the device id can
44 * be read directly skipping the normal slower search process.
45 */
46int w1_max_slave_count = 64;
47module_param_named(max_slave_count, w1_max_slave_count, int, 0);
48MODULE_PARM_DESC(max_slave_count,
49 "maximum number of slaves detected in a search");
50
51int w1_max_slave_ttl = 10;
52module_param_named(slave_ttl, w1_max_slave_ttl, int, 0);
53MODULE_PARM_DESC(slave_ttl,
54 "Number of searches not seeing a slave before it will be removed");
55
56DEFINE_MUTEX(w1_mlock);
57LIST_HEAD(w1_masters);
58
59static int w1_master_match(struct device *dev, struct device_driver *drv)
60{
61 return 1;
62}
63
64static int w1_master_probe(struct device *dev)
65{
66 return -ENODEV;
67}
68
69static void w1_master_release(struct device *dev)
70{
71 struct w1_master *md = dev_to_w1_master(dev);
72
73 dev_dbg(dev, "%s: Releasing %s.\n", __func__, md->name);
74 memset(md, 0, sizeof(struct w1_master) + sizeof(struct w1_bus_master));
75 kfree(md);
76}
77
78static void w1_slave_release(struct device *dev)
79{
80 struct w1_slave *sl = dev_to_w1_slave(dev);
81
82 dev_dbg(dev, "%s: Releasing %s [%p]\n", __func__, sl->name, sl);
83
84 w1_family_put(sl->family);
85 sl->master->slave_count--;
86}
87
88static ssize_t name_show(struct device *dev, struct device_attribute *attr, char *buf)
89{
90 struct w1_slave *sl = dev_to_w1_slave(dev);
91
92 return sprintf(buf, "%s\n", sl->name);
93}
94static DEVICE_ATTR_RO(name);
95
96static ssize_t id_show(struct device *dev,
97 struct device_attribute *attr, char *buf)
98{
99 struct w1_slave *sl = dev_to_w1_slave(dev);
100 ssize_t count = sizeof(sl->reg_num);
101
102 memcpy(buf, (u8 *)&sl->reg_num, count);
103 return count;
104}
105static DEVICE_ATTR_RO(id);
106
107static struct attribute *w1_slave_attrs[] = {
108 &dev_attr_name.attr,
109 &dev_attr_id.attr,
110 NULL,
111};
112ATTRIBUTE_GROUPS(w1_slave);
113
114/* Default family */
115
116static ssize_t rw_write(struct file *filp, struct kobject *kobj,
117 struct bin_attribute *bin_attr, char *buf, loff_t off,
118 size_t count)
119{
120 struct w1_slave *sl = kobj_to_w1_slave(kobj);
121
122 mutex_lock(&sl->master->mutex);
123 if (w1_reset_select_slave(sl)) {
124 count = 0;
125 goto out_up;
126 }
127
128 w1_write_block(sl->master, buf, count);
129
130out_up:
131 mutex_unlock(&sl->master->mutex);
132 return count;
133}
134
135static ssize_t rw_read(struct file *filp, struct kobject *kobj,
136 struct bin_attribute *bin_attr, char *buf, loff_t off,
137 size_t count)
138{
139 struct w1_slave *sl = kobj_to_w1_slave(kobj);
140
141 mutex_lock(&sl->master->mutex);
142 w1_read_block(sl->master, buf, count);
143 mutex_unlock(&sl->master->mutex);
144 return count;
145}
146
147static BIN_ATTR_RW(rw, PAGE_SIZE);
148
149static struct bin_attribute *w1_slave_bin_attrs[] = {
150 &bin_attr_rw,
151 NULL,
152};
153
154static const struct attribute_group w1_slave_default_group = {
155 .bin_attrs = w1_slave_bin_attrs,
156};
157
158static const struct attribute_group *w1_slave_default_groups[] = {
159 &w1_slave_default_group,
160 NULL,
161};
162
163static struct w1_family_ops w1_default_fops = {
164 .groups = w1_slave_default_groups,
165};
166
167static struct w1_family w1_default_family = {
168 .fops = &w1_default_fops,
169};
170
171static int w1_uevent(struct device *dev, struct kobj_uevent_env *env);
172
173static struct bus_type w1_bus_type = {
174 .name = "w1",
175 .match = w1_master_match,
176 .uevent = w1_uevent,
177};
178
179struct device_driver w1_master_driver = {
180 .name = "w1_master_driver",
181 .bus = &w1_bus_type,
182 .probe = w1_master_probe,
183};
184
185struct device w1_master_device = {
186 .parent = NULL,
187 .bus = &w1_bus_type,
188 .init_name = "w1 bus master",
189 .driver = &w1_master_driver,
190 .release = &w1_master_release
191};
192
193static struct device_driver w1_slave_driver = {
194 .name = "w1_slave_driver",
195 .bus = &w1_bus_type,
196};
197
198#if 0
199struct device w1_slave_device = {
200 .parent = NULL,
201 .bus = &w1_bus_type,
202 .init_name = "w1 bus slave",
203 .driver = &w1_slave_driver,
204 .release = &w1_slave_release
205};
206#endif /* 0 */
207
208static ssize_t w1_master_attribute_show_name(struct device *dev, struct device_attribute *attr, char *buf)
209{
210 struct w1_master *md = dev_to_w1_master(dev);
211 ssize_t count;
212
213 mutex_lock(&md->mutex);
214 count = sprintf(buf, "%s\n", md->name);
215 mutex_unlock(&md->mutex);
216
217 return count;
218}
219
220static ssize_t w1_master_attribute_store_search(struct device * dev,
221 struct device_attribute *attr,
222 const char * buf, size_t count)
223{
224 long tmp;
225 struct w1_master *md = dev_to_w1_master(dev);
226 int ret;
227
228 ret = kstrtol(buf, 0, &tmp);
229 if (ret)
230 return ret;
231
232 mutex_lock(&md->mutex);
233 md->search_count = tmp;
234 mutex_unlock(&md->mutex);
235 /* Only wake if it is going to be searching. */
236 if (tmp)
237 wake_up_process(md->thread);
238
239 return count;
240}
241
242static ssize_t w1_master_attribute_show_search(struct device *dev,
243 struct device_attribute *attr,
244 char *buf)
245{
246 struct w1_master *md = dev_to_w1_master(dev);
247 ssize_t count;
248
249 mutex_lock(&md->mutex);
250 count = sprintf(buf, "%d\n", md->search_count);
251 mutex_unlock(&md->mutex);
252
253 return count;
254}
255
256static ssize_t w1_master_attribute_store_pullup(struct device *dev,
257 struct device_attribute *attr,
258 const char *buf, size_t count)
259{
260 long tmp;
261 struct w1_master *md = dev_to_w1_master(dev);
262 int ret;
263
264 ret = kstrtol(buf, 0, &tmp);
265 if (ret)
266 return ret;
267
268 mutex_lock(&md->mutex);
269 md->enable_pullup = tmp;
270 mutex_unlock(&md->mutex);
271
272 return count;
273}
274
275static ssize_t w1_master_attribute_show_pullup(struct device *dev,
276 struct device_attribute *attr,
277 char *buf)
278{
279 struct w1_master *md = dev_to_w1_master(dev);
280 ssize_t count;
281
282 mutex_lock(&md->mutex);
283 count = sprintf(buf, "%d\n", md->enable_pullup);
284 mutex_unlock(&md->mutex);
285
286 return count;
287}
288
289static ssize_t w1_master_attribute_show_pointer(struct device *dev, struct device_attribute *attr, char *buf)
290{
291 struct w1_master *md = dev_to_w1_master(dev);
292 ssize_t count;
293
294 mutex_lock(&md->mutex);
295 count = sprintf(buf, "0x%p\n", md->bus_master);
296 mutex_unlock(&md->mutex);
297 return count;
298}
299
300static ssize_t w1_master_attribute_show_timeout(struct device *dev, struct device_attribute *attr, char *buf)
301{
302 ssize_t count;
303 count = sprintf(buf, "%d\n", w1_timeout);
304 return count;
305}
306
307static ssize_t w1_master_attribute_show_timeout_us(struct device *dev,
308 struct device_attribute *attr, char *buf)
309{
310 ssize_t count;
311 count = sprintf(buf, "%d\n", w1_timeout_us);
312 return count;
313}
314
315static ssize_t w1_master_attribute_store_max_slave_count(struct device *dev,
316 struct device_attribute *attr, const char *buf, size_t count)
317{
318 int tmp;
319 struct w1_master *md = dev_to_w1_master(dev);
320
321 if (kstrtoint(buf, 0, &tmp) || tmp < 1)
322 return -EINVAL;
323
324 mutex_lock(&md->mutex);
325 md->max_slave_count = tmp;
326 /* allow each time the max_slave_count is updated */
327 clear_bit(W1_WARN_MAX_COUNT, &md->flags);
328 mutex_unlock(&md->mutex);
329
330 return count;
331}
332
333static ssize_t w1_master_attribute_show_max_slave_count(struct device *dev, struct device_attribute *attr, char *buf)
334{
335 struct w1_master *md = dev_to_w1_master(dev);
336 ssize_t count;
337
338 mutex_lock(&md->mutex);
339 count = sprintf(buf, "%d\n", md->max_slave_count);
340 mutex_unlock(&md->mutex);
341 return count;
342}
343
344static ssize_t w1_master_attribute_show_attempts(struct device *dev, struct device_attribute *attr, char *buf)
345{
346 struct w1_master *md = dev_to_w1_master(dev);
347 ssize_t count;
348
349 mutex_lock(&md->mutex);
350 count = sprintf(buf, "%lu\n", md->attempts);
351 mutex_unlock(&md->mutex);
352 return count;
353}
354
355static ssize_t w1_master_attribute_show_slave_count(struct device *dev, struct device_attribute *attr, char *buf)
356{
357 struct w1_master *md = dev_to_w1_master(dev);
358 ssize_t count;
359
360 mutex_lock(&md->mutex);
361 count = sprintf(buf, "%d\n", md->slave_count);
362 mutex_unlock(&md->mutex);
363 return count;
364}
365
366static ssize_t w1_master_attribute_show_slaves(struct device *dev,
367 struct device_attribute *attr, char *buf)
368{
369 struct w1_master *md = dev_to_w1_master(dev);
370 int c = PAGE_SIZE;
371 struct list_head *ent, *n;
372 struct w1_slave *sl = NULL;
373
374 mutex_lock(&md->list_mutex);
375
376 list_for_each_safe(ent, n, &md->slist) {
377 sl = list_entry(ent, struct w1_slave, w1_slave_entry);
378
379 c -= snprintf(buf + PAGE_SIZE - c, c, "%s\n", sl->name);
380 }
381 if (!sl)
382 c -= snprintf(buf + PAGE_SIZE - c, c, "not found.\n");
383
384 mutex_unlock(&md->list_mutex);
385
386 return PAGE_SIZE - c;
387}
388
389static ssize_t w1_master_attribute_show_add(struct device *dev,
390 struct device_attribute *attr, char *buf)
391{
392 int c = PAGE_SIZE;
393 c -= snprintf(buf+PAGE_SIZE - c, c,
394 "write device id xx-xxxxxxxxxxxx to add slave\n");
395 return PAGE_SIZE - c;
396}
397
398static int w1_atoreg_num(struct device *dev, const char *buf, size_t count,
399 struct w1_reg_num *rn)
400{
401 unsigned int family;
402 unsigned long long id;
403 int i;
404 u64 rn64_le;
405
406 /* The CRC value isn't read from the user because the sysfs directory
407 * doesn't include it and most messages from the bus search don't
408 * print it either. It would be unreasonable for the user to then
409 * provide it.
410 */
411 const char *error_msg = "bad slave string format, expecting "
412 "ff-dddddddddddd\n";
413
414 if (buf[2] != '-') {
415 dev_err(dev, "%s", error_msg);
416 return -EINVAL;
417 }
418 i = sscanf(buf, "%02x-%012llx", &family, &id);
419 if (i != 2) {
420 dev_err(dev, "%s", error_msg);
421 return -EINVAL;
422 }
423 rn->family = family;
424 rn->id = id;
425
426 rn64_le = cpu_to_le64(*(u64 *)rn);
427 rn->crc = w1_calc_crc8((u8 *)&rn64_le, 7);
428
429#if 0
430 dev_info(dev, "With CRC device is %02x.%012llx.%02x.\n",
431 rn->family, (unsigned long long)rn->id, rn->crc);
432#endif
433
434 return 0;
435}
436
437/* Searches the slaves in the w1_master and returns a pointer or NULL.
438 * Note: must not hold list_mutex
439 */
440struct w1_slave *w1_slave_search_device(struct w1_master *dev,
441 struct w1_reg_num *rn)
442{
443 struct w1_slave *sl;
444 mutex_lock(&dev->list_mutex);
445 list_for_each_entry(sl, &dev->slist, w1_slave_entry) {
446 if (sl->reg_num.family == rn->family &&
447 sl->reg_num.id == rn->id &&
448 sl->reg_num.crc == rn->crc) {
449 mutex_unlock(&dev->list_mutex);
450 return sl;
451 }
452 }
453 mutex_unlock(&dev->list_mutex);
454 return NULL;
455}
456
457static ssize_t w1_master_attribute_store_add(struct device *dev,
458 struct device_attribute *attr,
459 const char *buf, size_t count)
460{
461 struct w1_master *md = dev_to_w1_master(dev);
462 struct w1_reg_num rn;
463 struct w1_slave *sl;
464 ssize_t result = count;
465
466 if (w1_atoreg_num(dev, buf, count, &rn))
467 return -EINVAL;
468
469 mutex_lock(&md->mutex);
470 sl = w1_slave_search_device(md, &rn);
471 /* It would be nice to do a targeted search one the one-wire bus
472 * for the new device to see if it is out there or not. But the
473 * current search doesn't support that.
474 */
475 if (sl) {
476 dev_info(dev, "Device %s already exists\n", sl->name);
477 result = -EINVAL;
478 } else {
479 w1_attach_slave_device(md, &rn);
480 }
481 mutex_unlock(&md->mutex);
482
483 return result;
484}
485
486static ssize_t w1_master_attribute_show_remove(struct device *dev,
487 struct device_attribute *attr, char *buf)
488{
489 int c = PAGE_SIZE;
490 c -= snprintf(buf+PAGE_SIZE - c, c,
491 "write device id xx-xxxxxxxxxxxx to remove slave\n");
492 return PAGE_SIZE - c;
493}
494
495static ssize_t w1_master_attribute_store_remove(struct device *dev,
496 struct device_attribute *attr,
497 const char *buf, size_t count)
498{
499 struct w1_master *md = dev_to_w1_master(dev);
500 struct w1_reg_num rn;
501 struct w1_slave *sl;
502 ssize_t result = count;
503
504 if (w1_atoreg_num(dev, buf, count, &rn))
505 return -EINVAL;
506
507 mutex_lock(&md->mutex);
508 sl = w1_slave_search_device(md, &rn);
509 if (sl) {
510 result = w1_slave_detach(sl);
511 /* refcnt 0 means it was detached in the call */
512 if (result == 0)
513 result = count;
514 } else {
515 dev_info(dev, "Device %02x-%012llx doesn't exists\n", rn.family,
516 (unsigned long long)rn.id);
517 result = -EINVAL;
518 }
519 mutex_unlock(&md->mutex);
520
521 return result;
522}
523
524#define W1_MASTER_ATTR_RO(_name, _mode) \
525 struct device_attribute w1_master_attribute_##_name = \
526 __ATTR(w1_master_##_name, _mode, \
527 w1_master_attribute_show_##_name, NULL)
528
529#define W1_MASTER_ATTR_RW(_name, _mode) \
530 struct device_attribute w1_master_attribute_##_name = \
531 __ATTR(w1_master_##_name, _mode, \
532 w1_master_attribute_show_##_name, \
533 w1_master_attribute_store_##_name)
534
535static W1_MASTER_ATTR_RO(name, S_IRUGO);
536static W1_MASTER_ATTR_RO(slaves, S_IRUGO);
537static W1_MASTER_ATTR_RO(slave_count, S_IRUGO);
538static W1_MASTER_ATTR_RW(max_slave_count, S_IRUGO | S_IWUSR | S_IWGRP);
539static W1_MASTER_ATTR_RO(attempts, S_IRUGO);
540static W1_MASTER_ATTR_RO(timeout, S_IRUGO);
541static W1_MASTER_ATTR_RO(timeout_us, S_IRUGO);
542static W1_MASTER_ATTR_RO(pointer, S_IRUGO);
543static W1_MASTER_ATTR_RW(search, S_IRUGO | S_IWUSR | S_IWGRP);
544static W1_MASTER_ATTR_RW(pullup, S_IRUGO | S_IWUSR | S_IWGRP);
545static W1_MASTER_ATTR_RW(add, S_IRUGO | S_IWUSR | S_IWGRP);
546static W1_MASTER_ATTR_RW(remove, S_IRUGO | S_IWUSR | S_IWGRP);
547
548static struct attribute *w1_master_default_attrs[] = {
549 &w1_master_attribute_name.attr,
550 &w1_master_attribute_slaves.attr,
551 &w1_master_attribute_slave_count.attr,
552 &w1_master_attribute_max_slave_count.attr,
553 &w1_master_attribute_attempts.attr,
554 &w1_master_attribute_timeout.attr,
555 &w1_master_attribute_timeout_us.attr,
556 &w1_master_attribute_pointer.attr,
557 &w1_master_attribute_search.attr,
558 &w1_master_attribute_pullup.attr,
559 &w1_master_attribute_add.attr,
560 &w1_master_attribute_remove.attr,
561 NULL
562};
563
564static const struct attribute_group w1_master_defattr_group = {
565 .attrs = w1_master_default_attrs,
566};
567
568int w1_create_master_attributes(struct w1_master *master)
569{
570 return sysfs_create_group(&master->dev.kobj, &w1_master_defattr_group);
571}
572
573void w1_destroy_master_attributes(struct w1_master *master)
574{
575 sysfs_remove_group(&master->dev.kobj, &w1_master_defattr_group);
576}
577
578static int w1_uevent(struct device *dev, struct kobj_uevent_env *env)
579{
580 struct w1_master *md = NULL;
581 struct w1_slave *sl = NULL;
582 char *event_owner, *name;
583 int err = 0;
584
585 if (dev->driver == &w1_master_driver) {
586 md = container_of(dev, struct w1_master, dev);
587 event_owner = "master";
588 name = md->name;
589 } else if (dev->driver == &w1_slave_driver) {
590 sl = container_of(dev, struct w1_slave, dev);
591 event_owner = "slave";
592 name = sl->name;
593 } else {
594 dev_dbg(dev, "Unknown event.\n");
595 return -EINVAL;
596 }
597
598 dev_dbg(dev, "Hotplug event for %s %s, bus_id=%s.\n",
599 event_owner, name, dev_name(dev));
600
601 if (dev->driver != &w1_slave_driver || !sl)
602 goto end;
603
604 err = add_uevent_var(env, "W1_FID=%02X", sl->reg_num.family);
605 if (err)
606 goto end;
607
608 err = add_uevent_var(env, "W1_SLAVE_ID=%024LX",
609 (unsigned long long)sl->reg_num.id);
610end:
611 return err;
612}
613
614static int w1_family_notify(unsigned long action, struct w1_slave *sl)
615{
616 struct w1_family_ops *fops;
617 int err;
618
619 fops = sl->family->fops;
620
621 if (!fops)
622 return 0;
623
624 switch (action) {
625 case BUS_NOTIFY_ADD_DEVICE:
626 /* if the family driver needs to initialize something... */
627 if (fops->add_slave) {
628 err = fops->add_slave(sl);
629 if (err < 0) {
630 dev_err(&sl->dev,
631 "add_slave() call failed. err=%d\n",
632 err);
633 return err;
634 }
635 }
636 if (fops->groups) {
637 err = sysfs_create_groups(&sl->dev.kobj, fops->groups);
638 if (err) {
639 dev_err(&sl->dev,
640 "sysfs group creation failed. err=%d\n",
641 err);
642 return err;
643 }
644 }
645 if (IS_REACHABLE(CONFIG_HWMON) && fops->chip_info) {
646 struct device *hwmon
647 = hwmon_device_register_with_info(&sl->dev,
648 "w1_slave_temp", sl,
649 fops->chip_info,
650 NULL);
651 if (IS_ERR(hwmon)) {
652 dev_warn(&sl->dev,
653 "could not create hwmon device\n");
654 } else {
655 sl->hwmon = hwmon;
656 }
657 }
658 break;
659 case BUS_NOTIFY_DEL_DEVICE:
660 if (IS_REACHABLE(CONFIG_HWMON) && fops->chip_info &&
661 sl->hwmon)
662 hwmon_device_unregister(sl->hwmon);
663 if (fops->remove_slave)
664 sl->family->fops->remove_slave(sl);
665 if (fops->groups)
666 sysfs_remove_groups(&sl->dev.kobj, fops->groups);
667 break;
668 }
669 return 0;
670}
671
672static int __w1_attach_slave_device(struct w1_slave *sl)
673{
674 int err;
675
676 sl->dev.parent = &sl->master->dev;
677 sl->dev.driver = &w1_slave_driver;
678 sl->dev.bus = &w1_bus_type;
679 sl->dev.release = &w1_slave_release;
680 sl->dev.groups = w1_slave_groups;
681 sl->dev.of_node = of_find_matching_node(sl->master->dev.of_node,
682 sl->family->of_match_table);
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 put_device(&sl->dev);
704 return err;
705 }
706 w1_family_notify(BUS_NOTIFY_ADD_DEVICE, sl);
707
708 dev_set_uevent_suppress(&sl->dev, false);
709 kobject_uevent(&sl->dev.kobj, KOBJ_ADD);
710
711 mutex_lock(&sl->master->list_mutex);
712 list_add_tail(&sl->w1_slave_entry, &sl->master->slist);
713 mutex_unlock(&sl->master->list_mutex);
714
715 return 0;
716}
717
718int w1_attach_slave_device(struct w1_master *dev, struct w1_reg_num *rn)
719{
720 struct w1_slave *sl;
721 struct w1_family *f;
722 int err;
723 struct w1_netlink_msg msg;
724
725 sl = kzalloc(sizeof(struct w1_slave), GFP_KERNEL);
726 if (!sl) {
727 dev_err(&dev->dev,
728 "%s: failed to allocate new slave device.\n",
729 __func__);
730 return -ENOMEM;
731 }
732
733
734 sl->owner = THIS_MODULE;
735 sl->master = dev;
736 set_bit(W1_SLAVE_ACTIVE, &sl->flags);
737
738 memset(&msg, 0, sizeof(msg));
739 memcpy(&sl->reg_num, rn, sizeof(sl->reg_num));
740 atomic_set(&sl->refcnt, 1);
741 atomic_inc(&sl->master->refcnt);
742 dev->slave_count++;
743 dev_info(&dev->dev, "Attaching one wire slave %02x.%012llx crc %02x\n",
744 rn->family, (unsigned long long)rn->id, rn->crc);
745
746 /* slave modules need to be loaded in a context with unlocked mutex */
747 mutex_unlock(&dev->mutex);
748 request_module("w1-family-0x%02X", rn->family);
749 mutex_lock(&dev->mutex);
750
751 spin_lock(&w1_flock);
752 f = w1_family_registered(rn->family);
753 if (!f) {
754 f= &w1_default_family;
755 dev_info(&dev->dev, "Family %x for %02x.%012llx.%02x is not registered.\n",
756 rn->family, rn->family,
757 (unsigned long long)rn->id, rn->crc);
758 }
759 __w1_family_get(f);
760 spin_unlock(&w1_flock);
761
762 sl->family = f;
763
764 err = __w1_attach_slave_device(sl);
765 if (err < 0) {
766 dev_err(&dev->dev, "%s: Attaching %s failed.\n", __func__,
767 sl->name);
768 dev->slave_count--;
769 w1_family_put(sl->family);
770 atomic_dec(&sl->master->refcnt);
771 kfree(sl);
772 return err;
773 }
774
775 sl->ttl = dev->slave_ttl;
776
777 memcpy(msg.id.id, rn, sizeof(msg.id));
778 msg.type = W1_SLAVE_ADD;
779 w1_netlink_send(dev, &msg);
780
781 return 0;
782}
783
784int w1_unref_slave(struct w1_slave *sl)
785{
786 struct w1_master *dev = sl->master;
787 int refcnt;
788 mutex_lock(&dev->list_mutex);
789 refcnt = atomic_sub_return(1, &sl->refcnt);
790 if (refcnt == 0) {
791 struct w1_netlink_msg msg;
792
793 dev_dbg(&sl->dev, "%s: detaching %s [%p].\n", __func__,
794 sl->name, sl);
795
796 list_del(&sl->w1_slave_entry);
797
798 memset(&msg, 0, sizeof(msg));
799 memcpy(msg.id.id, &sl->reg_num, sizeof(msg.id));
800 msg.type = W1_SLAVE_REMOVE;
801 w1_netlink_send(sl->master, &msg);
802
803 w1_family_notify(BUS_NOTIFY_DEL_DEVICE, sl);
804 device_unregister(&sl->dev);
805 #ifdef DEBUG
806 memset(sl, 0, sizeof(*sl));
807 #endif
808 kfree(sl);
809 }
810 atomic_dec(&dev->refcnt);
811 mutex_unlock(&dev->list_mutex);
812 return refcnt;
813}
814
815int w1_slave_detach(struct w1_slave *sl)
816{
817 /* Only detach a slave once as it decreases the refcnt each time. */
818 int destroy_now;
819 mutex_lock(&sl->master->list_mutex);
820 destroy_now = !test_bit(W1_SLAVE_DETACH, &sl->flags);
821 set_bit(W1_SLAVE_DETACH, &sl->flags);
822 mutex_unlock(&sl->master->list_mutex);
823
824 if (destroy_now)
825 destroy_now = !w1_unref_slave(sl);
826 return destroy_now ? 0 : -EBUSY;
827}
828
829struct w1_master *w1_search_master_id(u32 id)
830{
831 struct w1_master *dev;
832 int found = 0;
833
834 mutex_lock(&w1_mlock);
835 list_for_each_entry(dev, &w1_masters, w1_master_entry) {
836 if (dev->id == id) {
837 found = 1;
838 atomic_inc(&dev->refcnt);
839 break;
840 }
841 }
842 mutex_unlock(&w1_mlock);
843
844 return (found)?dev:NULL;
845}
846
847struct w1_slave *w1_search_slave(struct w1_reg_num *id)
848{
849 struct w1_master *dev;
850 struct w1_slave *sl = NULL;
851 int found = 0;
852
853 mutex_lock(&w1_mlock);
854 list_for_each_entry(dev, &w1_masters, w1_master_entry) {
855 mutex_lock(&dev->list_mutex);
856 list_for_each_entry(sl, &dev->slist, w1_slave_entry) {
857 if (sl->reg_num.family == id->family &&
858 sl->reg_num.id == id->id &&
859 sl->reg_num.crc == id->crc) {
860 found = 1;
861 atomic_inc(&dev->refcnt);
862 atomic_inc(&sl->refcnt);
863 break;
864 }
865 }
866 mutex_unlock(&dev->list_mutex);
867
868 if (found)
869 break;
870 }
871 mutex_unlock(&w1_mlock);
872
873 return (found)?sl:NULL;
874}
875
876void w1_reconnect_slaves(struct w1_family *f, int attach)
877{
878 struct w1_slave *sl, *sln;
879 struct w1_master *dev;
880
881 mutex_lock(&w1_mlock);
882 list_for_each_entry(dev, &w1_masters, w1_master_entry) {
883 dev_dbg(&dev->dev, "Reconnecting slaves in device %s "
884 "for family %02x.\n", dev->name, f->fid);
885 mutex_lock(&dev->mutex);
886 mutex_lock(&dev->list_mutex);
887 list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) {
888 /* If it is a new family, slaves with the default
889 * family driver and are that family will be
890 * connected. If the family is going away, devices
891 * matching that family are reconneced.
892 */
893 if ((attach && sl->family->fid == W1_FAMILY_DEFAULT
894 && sl->reg_num.family == f->fid) ||
895 (!attach && sl->family->fid == f->fid)) {
896 struct w1_reg_num rn;
897
898 mutex_unlock(&dev->list_mutex);
899 memcpy(&rn, &sl->reg_num, sizeof(rn));
900 /* If it was already in use let the automatic
901 * scan pick it up again later.
902 */
903 if (!w1_slave_detach(sl))
904 w1_attach_slave_device(dev, &rn);
905 mutex_lock(&dev->list_mutex);
906 }
907 }
908 dev_dbg(&dev->dev, "Reconnecting slaves in device %s "
909 "has been finished.\n", dev->name);
910 mutex_unlock(&dev->list_mutex);
911 mutex_unlock(&dev->mutex);
912 }
913 mutex_unlock(&w1_mlock);
914}
915
916void w1_slave_found(struct w1_master *dev, u64 rn)
917{
918 struct w1_slave *sl;
919 struct w1_reg_num *tmp;
920 u64 rn_le = cpu_to_le64(rn);
921
922 atomic_inc(&dev->refcnt);
923
924 tmp = (struct w1_reg_num *) &rn;
925
926 sl = w1_slave_search_device(dev, tmp);
927 if (sl) {
928 set_bit(W1_SLAVE_ACTIVE, &sl->flags);
929 } else {
930 if (rn && tmp->crc == w1_calc_crc8((u8 *)&rn_le, 7))
931 w1_attach_slave_device(dev, tmp);
932 }
933
934 atomic_dec(&dev->refcnt);
935}
936
937/**
938 * w1_search() - Performs a ROM Search & registers any devices found.
939 * @dev: The master device to search
940 * @search_type: W1_SEARCH to search all devices, or W1_ALARM_SEARCH
941 * to return only devices in the alarmed state
942 * @cb: Function to call when a device is found
943 *
944 * The 1-wire search is a simple binary tree search.
945 * For each bit of the address, we read two bits and write one bit.
946 * The bit written will put to sleep all devies that don't match that bit.
947 * When the two reads differ, the direction choice is obvious.
948 * When both bits are 0, we must choose a path to take.
949 * When we can scan all 64 bits without having to choose a path, we are done.
950 *
951 * See "Application note 187 1-wire search algorithm" at www.maxim-ic.com
952 *
953 */
954void w1_search(struct w1_master *dev, u8 search_type, w1_slave_found_callback cb)
955{
956 u64 last_rn, rn, tmp64;
957 int i, slave_count = 0;
958 int last_zero, last_device;
959 int search_bit, desc_bit;
960 u8 triplet_ret = 0;
961
962 search_bit = 0;
963 rn = dev->search_id;
964 last_rn = 0;
965 last_device = 0;
966 last_zero = -1;
967
968 desc_bit = 64;
969
970 while ( !last_device && (slave_count++ < dev->max_slave_count) ) {
971 last_rn = rn;
972 rn = 0;
973
974 /*
975 * Reset bus and all 1-wire device state machines
976 * so they can respond to our requests.
977 *
978 * Return 0 - device(s) present, 1 - no devices present.
979 */
980 mutex_lock(&dev->bus_mutex);
981 if (w1_reset_bus(dev)) {
982 mutex_unlock(&dev->bus_mutex);
983 dev_dbg(&dev->dev, "No devices present on the wire.\n");
984 break;
985 }
986
987 /* Do fast search on single slave bus */
988 if (dev->max_slave_count == 1) {
989 int rv;
990 w1_write_8(dev, W1_READ_ROM);
991 rv = w1_read_block(dev, (u8 *)&rn, 8);
992 mutex_unlock(&dev->bus_mutex);
993
994 if (rv == 8 && rn)
995 cb(dev, rn);
996
997 break;
998 }
999
1000 /* Start the search */
1001 w1_write_8(dev, search_type);
1002 for (i = 0; i < 64; ++i) {
1003 /* Determine the direction/search bit */
1004 if (i == desc_bit)
1005 search_bit = 1; /* took the 0 path last time, so take the 1 path */
1006 else if (i > desc_bit)
1007 search_bit = 0; /* take the 0 path on the next branch */
1008 else
1009 search_bit = ((last_rn >> i) & 0x1);
1010
1011 /* Read two bits and write one bit */
1012 triplet_ret = w1_triplet(dev, search_bit);
1013
1014 /* quit if no device responded */
1015 if ( (triplet_ret & 0x03) == 0x03 )
1016 break;
1017
1018 /* If both directions were valid, and we took the 0 path... */
1019 if (triplet_ret == 0)
1020 last_zero = i;
1021
1022 /* extract the direction taken & update the device number */
1023 tmp64 = (triplet_ret >> 2);
1024 rn |= (tmp64 << i);
1025
1026 if (test_bit(W1_ABORT_SEARCH, &dev->flags)) {
1027 mutex_unlock(&dev->bus_mutex);
1028 dev_dbg(&dev->dev, "Abort w1_search\n");
1029 return;
1030 }
1031 }
1032 mutex_unlock(&dev->bus_mutex);
1033
1034 if ( (triplet_ret & 0x03) != 0x03 ) {
1035 if ((desc_bit == last_zero) || (last_zero < 0)) {
1036 last_device = 1;
1037 dev->search_id = 0;
1038 } else {
1039 dev->search_id = rn;
1040 }
1041 desc_bit = last_zero;
1042 cb(dev, rn);
1043 }
1044
1045 if (!last_device && slave_count == dev->max_slave_count &&
1046 !test_bit(W1_WARN_MAX_COUNT, &dev->flags)) {
1047 /* Only max_slave_count will be scanned in a search,
1048 * but it will start where it left off next search
1049 * until all ids are identified and then it will start
1050 * over. A continued search will report the previous
1051 * last id as the first id (provided it is still on the
1052 * bus).
1053 */
1054 dev_info(&dev->dev, "%s: max_slave_count %d reached, "
1055 "will continue next search.\n", __func__,
1056 dev->max_slave_count);
1057 set_bit(W1_WARN_MAX_COUNT, &dev->flags);
1058 }
1059 }
1060}
1061
1062void w1_search_process_cb(struct w1_master *dev, u8 search_type,
1063 w1_slave_found_callback cb)
1064{
1065 struct w1_slave *sl, *sln;
1066
1067 mutex_lock(&dev->list_mutex);
1068 list_for_each_entry(sl, &dev->slist, w1_slave_entry)
1069 clear_bit(W1_SLAVE_ACTIVE, &sl->flags);
1070 mutex_unlock(&dev->list_mutex);
1071
1072 w1_search_devices(dev, search_type, cb);
1073
1074 mutex_lock(&dev->list_mutex);
1075 list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) {
1076 if (!test_bit(W1_SLAVE_ACTIVE, &sl->flags) && !--sl->ttl) {
1077 mutex_unlock(&dev->list_mutex);
1078 w1_slave_detach(sl);
1079 mutex_lock(&dev->list_mutex);
1080 }
1081 else if (test_bit(W1_SLAVE_ACTIVE, &sl->flags))
1082 sl->ttl = dev->slave_ttl;
1083 }
1084 mutex_unlock(&dev->list_mutex);
1085
1086 if (dev->search_count > 0)
1087 dev->search_count--;
1088}
1089
1090static void w1_search_process(struct w1_master *dev, u8 search_type)
1091{
1092 w1_search_process_cb(dev, search_type, w1_slave_found);
1093}
1094
1095/**
1096 * w1_process_callbacks() - execute each dev->async_list callback entry
1097 * @dev: w1_master device
1098 *
1099 * The w1 master list_mutex must be held.
1100 *
1101 * Return: 1 if there were commands to executed 0 otherwise
1102 */
1103int w1_process_callbacks(struct w1_master *dev)
1104{
1105 int ret = 0;
1106 struct w1_async_cmd *async_cmd, *async_n;
1107
1108 /* The list can be added to in another thread, loop until it is empty */
1109 while (!list_empty(&dev->async_list)) {
1110 list_for_each_entry_safe(async_cmd, async_n, &dev->async_list,
1111 async_entry) {
1112 /* drop the lock, if it is a search it can take a long
1113 * time */
1114 mutex_unlock(&dev->list_mutex);
1115 async_cmd->cb(dev, async_cmd);
1116 ret = 1;
1117 mutex_lock(&dev->list_mutex);
1118 }
1119 }
1120 return ret;
1121}
1122
1123int w1_process(void *data)
1124{
1125 struct w1_master *dev = (struct w1_master *) data;
1126 /* As long as w1_timeout is only set by a module parameter the sleep
1127 * time can be calculated in jiffies once.
1128 */
1129 const unsigned long jtime =
1130 usecs_to_jiffies(w1_timeout * 1000000 + w1_timeout_us);
1131 /* remainder if it woke up early */
1132 unsigned long jremain = 0;
1133
1134 for (;;) {
1135
1136 if (!jremain && dev->search_count) {
1137 mutex_lock(&dev->mutex);
1138 w1_search_process(dev, W1_SEARCH);
1139 mutex_unlock(&dev->mutex);
1140 }
1141
1142 mutex_lock(&dev->list_mutex);
1143 /* Note, w1_process_callback drops the lock while processing,
1144 * but locks it again before returning.
1145 */
1146 if (!w1_process_callbacks(dev) && jremain) {
1147 /* a wake up is either to stop the thread, process
1148 * callbacks, or search, it isn't process callbacks, so
1149 * schedule a search.
1150 */
1151 jremain = 1;
1152 }
1153
1154 __set_current_state(TASK_INTERRUPTIBLE);
1155
1156 /* hold list_mutex until after interruptible to prevent loosing
1157 * the wakeup signal when async_cmd is added.
1158 */
1159 mutex_unlock(&dev->list_mutex);
1160
1161 if (kthread_should_stop())
1162 break;
1163
1164 /* Only sleep when the search is active. */
1165 if (dev->search_count) {
1166 if (!jremain)
1167 jremain = jtime;
1168 jremain = schedule_timeout(jremain);
1169 }
1170 else
1171 schedule();
1172 }
1173
1174 atomic_dec(&dev->refcnt);
1175
1176 return 0;
1177}
1178
1179static int __init w1_init(void)
1180{
1181 int retval;
1182
1183 pr_info("Driver for 1-wire Dallas network protocol.\n");
1184
1185 w1_init_netlink();
1186
1187 retval = bus_register(&w1_bus_type);
1188 if (retval) {
1189 pr_err("Failed to register bus. err=%d.\n", retval);
1190 goto err_out_exit_init;
1191 }
1192
1193 retval = driver_register(&w1_master_driver);
1194 if (retval) {
1195 pr_err("Failed to register master driver. err=%d.\n",
1196 retval);
1197 goto err_out_bus_unregister;
1198 }
1199
1200 retval = driver_register(&w1_slave_driver);
1201 if (retval) {
1202 pr_err("Failed to register slave driver. err=%d.\n",
1203 retval);
1204 goto err_out_master_unregister;
1205 }
1206
1207 return 0;
1208
1209#if 0
1210/* For undoing the slave register if there was a step after it. */
1211err_out_slave_unregister:
1212 driver_unregister(&w1_slave_driver);
1213#endif
1214
1215err_out_master_unregister:
1216 driver_unregister(&w1_master_driver);
1217
1218err_out_bus_unregister:
1219 bus_unregister(&w1_bus_type);
1220
1221err_out_exit_init:
1222 return retval;
1223}
1224
1225static void __exit w1_fini(void)
1226{
1227 struct w1_master *dev;
1228
1229 /* Set netlink removal messages and some cleanup */
1230 list_for_each_entry(dev, &w1_masters, w1_master_entry)
1231 __w1_remove_master_device(dev);
1232
1233 w1_fini_netlink();
1234
1235 driver_unregister(&w1_slave_driver);
1236 driver_unregister(&w1_master_driver);
1237 bus_unregister(&w1_bus_type);
1238}
1239
1240module_init(w1_init);
1241module_exit(w1_fini);
1242
1243MODULE_AUTHOR("Evgeniy Polyakov <zbr@ioremap.net>");
1244MODULE_DESCRIPTION("Driver for 1-wire Dallas network protocol.");
1245MODULE_LICENSE("GPL");
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);