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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#define W1_FAMILY_DS28E04 0x1C /* for crc quirk */
29
30
31static int w1_timeout = 10;
32module_param_named(timeout, w1_timeout, int, 0);
33MODULE_PARM_DESC(timeout, "time in seconds between automatic slave searches");
34
35static int w1_timeout_us;
36module_param_named(timeout_us, w1_timeout_us, int, 0);
37MODULE_PARM_DESC(timeout_us,
38 "time in microseconds between automatic slave searches");
39
40/* A search stops when w1_max_slave_count devices have been found in that
41 * search. The next search will start over and detect the same set of devices
42 * on a static 1-wire bus. Memory is not allocated based on this number, just
43 * on the number of devices known to the kernel. Having a high number does not
44 * consume additional resources. As a special case, if there is only one
45 * device on the network and w1_max_slave_count is set to 1, the device id can
46 * be read directly skipping the normal slower search process.
47 */
48int w1_max_slave_count = 64;
49module_param_named(max_slave_count, w1_max_slave_count, int, 0);
50MODULE_PARM_DESC(max_slave_count,
51 "maximum number of slaves detected in a search");
52
53int w1_max_slave_ttl = 10;
54module_param_named(slave_ttl, w1_max_slave_ttl, int, 0);
55MODULE_PARM_DESC(slave_ttl,
56 "Number of searches not seeing a slave before it will be removed");
57
58DEFINE_MUTEX(w1_mlock);
59LIST_HEAD(w1_masters);
60
61static int w1_master_probe(struct device *dev)
62{
63 return -ENODEV;
64}
65
66static void w1_master_release(struct device *dev)
67{
68 struct w1_master *md = dev_to_w1_master(dev);
69
70 dev_dbg(dev, "%s: Releasing %s.\n", __func__, md->name);
71 memset(md, 0, sizeof(struct w1_master) + sizeof(struct w1_bus_master));
72 kfree(md);
73}
74
75static void w1_slave_release(struct device *dev)
76{
77 struct w1_slave *sl = dev_to_w1_slave(dev);
78
79 dev_dbg(dev, "%s: Releasing %s [%p]\n", __func__, sl->name, sl);
80
81 w1_family_put(sl->family);
82 sl->master->slave_count--;
83}
84
85static ssize_t name_show(struct device *dev, struct device_attribute *attr, char *buf)
86{
87 struct w1_slave *sl = dev_to_w1_slave(dev);
88
89 return sprintf(buf, "%s\n", sl->name);
90}
91static DEVICE_ATTR_RO(name);
92
93static ssize_t id_show(struct device *dev,
94 struct device_attribute *attr, char *buf)
95{
96 struct w1_slave *sl = dev_to_w1_slave(dev);
97 ssize_t count = sizeof(sl->reg_num);
98
99 memcpy(buf, (u8 *)&sl->reg_num, count);
100 return count;
101}
102static DEVICE_ATTR_RO(id);
103
104static struct attribute *w1_slave_attrs[] = {
105 &dev_attr_name.attr,
106 &dev_attr_id.attr,
107 NULL,
108};
109ATTRIBUTE_GROUPS(w1_slave);
110
111/* Default family */
112
113static ssize_t rw_write(struct file *filp, struct kobject *kobj,
114 struct bin_attribute *bin_attr, char *buf, loff_t off,
115 size_t count)
116{
117 struct w1_slave *sl = kobj_to_w1_slave(kobj);
118
119 mutex_lock(&sl->master->mutex);
120 if (w1_reset_select_slave(sl)) {
121 count = 0;
122 goto out_up;
123 }
124
125 w1_write_block(sl->master, buf, count);
126
127out_up:
128 mutex_unlock(&sl->master->mutex);
129 return count;
130}
131
132static ssize_t rw_read(struct file *filp, struct kobject *kobj,
133 struct bin_attribute *bin_attr, char *buf, loff_t off,
134 size_t count)
135{
136 struct w1_slave *sl = kobj_to_w1_slave(kobj);
137
138 mutex_lock(&sl->master->mutex);
139 w1_read_block(sl->master, buf, count);
140 mutex_unlock(&sl->master->mutex);
141 return count;
142}
143
144static BIN_ATTR_RW(rw, PAGE_SIZE);
145
146static struct bin_attribute *w1_slave_bin_attrs[] = {
147 &bin_attr_rw,
148 NULL,
149};
150
151static const struct attribute_group w1_slave_default_group = {
152 .bin_attrs = w1_slave_bin_attrs,
153};
154
155static const struct attribute_group *w1_slave_default_groups[] = {
156 &w1_slave_default_group,
157 NULL,
158};
159
160static const struct w1_family_ops w1_default_fops = {
161 .groups = w1_slave_default_groups,
162};
163
164static struct w1_family w1_default_family = {
165 .fops = &w1_default_fops,
166};
167
168static int w1_uevent(const struct device *dev, struct kobj_uevent_env *env);
169
170static struct bus_type w1_bus_type = {
171 .name = "w1",
172 .uevent = w1_uevent,
173};
174
175struct device_driver w1_master_driver = {
176 .name = "w1_master_driver",
177 .bus = &w1_bus_type,
178 .probe = w1_master_probe,
179};
180
181struct device w1_master_device = {
182 .parent = NULL,
183 .bus = &w1_bus_type,
184 .init_name = "w1 bus master",
185 .driver = &w1_master_driver,
186 .release = &w1_master_release
187};
188
189static struct device_driver w1_slave_driver = {
190 .name = "w1_slave_driver",
191 .bus = &w1_bus_type,
192};
193
194#if 0
195struct device w1_slave_device = {
196 .parent = NULL,
197 .bus = &w1_bus_type,
198 .init_name = "w1 bus slave",
199 .driver = &w1_slave_driver,
200 .release = &w1_slave_release
201};
202#endif /* 0 */
203
204static ssize_t w1_master_attribute_show_name(struct device *dev, struct device_attribute *attr, char *buf)
205{
206 struct w1_master *md = dev_to_w1_master(dev);
207 ssize_t count;
208
209 mutex_lock(&md->mutex);
210 count = sprintf(buf, "%s\n", md->name);
211 mutex_unlock(&md->mutex);
212
213 return count;
214}
215
216static ssize_t w1_master_attribute_store_search(struct device * dev,
217 struct device_attribute *attr,
218 const char * buf, size_t count)
219{
220 long tmp;
221 struct w1_master *md = dev_to_w1_master(dev);
222 int ret;
223
224 ret = kstrtol(buf, 0, &tmp);
225 if (ret)
226 return ret;
227
228 mutex_lock(&md->mutex);
229 md->search_count = tmp;
230 mutex_unlock(&md->mutex);
231 /* Only wake if it is going to be searching. */
232 if (tmp)
233 wake_up_process(md->thread);
234
235 return count;
236}
237
238static ssize_t w1_master_attribute_show_search(struct device *dev,
239 struct device_attribute *attr,
240 char *buf)
241{
242 struct w1_master *md = dev_to_w1_master(dev);
243 ssize_t count;
244
245 mutex_lock(&md->mutex);
246 count = sprintf(buf, "%d\n", md->search_count);
247 mutex_unlock(&md->mutex);
248
249 return count;
250}
251
252static ssize_t w1_master_attribute_store_pullup(struct device *dev,
253 struct device_attribute *attr,
254 const char *buf, size_t count)
255{
256 long tmp;
257 struct w1_master *md = dev_to_w1_master(dev);
258 int ret;
259
260 ret = kstrtol(buf, 0, &tmp);
261 if (ret)
262 return ret;
263
264 mutex_lock(&md->mutex);
265 md->enable_pullup = tmp;
266 mutex_unlock(&md->mutex);
267
268 return count;
269}
270
271static ssize_t w1_master_attribute_show_pullup(struct device *dev,
272 struct device_attribute *attr,
273 char *buf)
274{
275 struct w1_master *md = dev_to_w1_master(dev);
276 ssize_t count;
277
278 mutex_lock(&md->mutex);
279 count = sprintf(buf, "%d\n", md->enable_pullup);
280 mutex_unlock(&md->mutex);
281
282 return count;
283}
284
285static ssize_t w1_master_attribute_show_pointer(struct device *dev, struct device_attribute *attr, char *buf)
286{
287 struct w1_master *md = dev_to_w1_master(dev);
288 ssize_t count;
289
290 mutex_lock(&md->mutex);
291 count = sprintf(buf, "0x%p\n", md->bus_master);
292 mutex_unlock(&md->mutex);
293 return count;
294}
295
296static ssize_t w1_master_attribute_show_timeout(struct device *dev, struct device_attribute *attr, char *buf)
297{
298 return sprintf(buf, "%d\n", w1_timeout);
299}
300
301static ssize_t w1_master_attribute_show_timeout_us(struct device *dev,
302 struct device_attribute *attr, char *buf)
303{
304 return sprintf(buf, "%d\n", w1_timeout_us);
305}
306
307static ssize_t w1_master_attribute_store_max_slave_count(struct device *dev,
308 struct device_attribute *attr, const char *buf, size_t count)
309{
310 int tmp;
311 struct w1_master *md = dev_to_w1_master(dev);
312
313 if (kstrtoint(buf, 0, &tmp) || tmp < 1)
314 return -EINVAL;
315
316 mutex_lock(&md->mutex);
317 md->max_slave_count = tmp;
318 /* allow each time the max_slave_count is updated */
319 clear_bit(W1_WARN_MAX_COUNT, &md->flags);
320 mutex_unlock(&md->mutex);
321
322 return count;
323}
324
325static ssize_t w1_master_attribute_show_max_slave_count(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, "%d\n", md->max_slave_count);
332 mutex_unlock(&md->mutex);
333 return count;
334}
335
336static ssize_t w1_master_attribute_show_attempts(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, "%lu\n", md->attempts);
343 mutex_unlock(&md->mutex);
344 return count;
345}
346
347static ssize_t w1_master_attribute_show_slave_count(struct device *dev, struct device_attribute *attr, char *buf)
348{
349 struct w1_master *md = dev_to_w1_master(dev);
350 ssize_t count;
351
352 mutex_lock(&md->mutex);
353 count = sprintf(buf, "%d\n", md->slave_count);
354 mutex_unlock(&md->mutex);
355 return count;
356}
357
358static ssize_t w1_master_attribute_show_slaves(struct device *dev,
359 struct device_attribute *attr, char *buf)
360{
361 struct w1_master *md = dev_to_w1_master(dev);
362 int c = PAGE_SIZE;
363 struct list_head *ent, *n;
364 struct w1_slave *sl = NULL;
365
366 mutex_lock(&md->list_mutex);
367
368 list_for_each_safe(ent, n, &md->slist) {
369 sl = list_entry(ent, struct w1_slave, w1_slave_entry);
370
371 c -= snprintf(buf + PAGE_SIZE - c, c, "%s\n", sl->name);
372 }
373 if (!sl)
374 c -= snprintf(buf + PAGE_SIZE - c, c, "not found.\n");
375
376 mutex_unlock(&md->list_mutex);
377
378 return PAGE_SIZE - c;
379}
380
381static ssize_t w1_master_attribute_show_add(struct device *dev,
382 struct device_attribute *attr, char *buf)
383{
384 int c = PAGE_SIZE;
385 c -= snprintf(buf+PAGE_SIZE - c, c,
386 "write device id xx-xxxxxxxxxxxx to add slave\n");
387 return PAGE_SIZE - c;
388}
389
390static int w1_atoreg_num(struct device *dev, const char *buf, size_t count,
391 struct w1_reg_num *rn)
392{
393 unsigned int family;
394 unsigned long long id;
395 int i;
396 u64 rn64_le;
397
398 /* The CRC value isn't read from the user because the sysfs directory
399 * doesn't include it and most messages from the bus search don't
400 * print it either. It would be unreasonable for the user to then
401 * provide it.
402 */
403 const char *error_msg = "bad slave string format, expecting "
404 "ff-dddddddddddd\n";
405
406 if (buf[2] != '-') {
407 dev_err(dev, "%s", error_msg);
408 return -EINVAL;
409 }
410 i = sscanf(buf, "%02x-%012llx", &family, &id);
411 if (i != 2) {
412 dev_err(dev, "%s", error_msg);
413 return -EINVAL;
414 }
415 rn->family = family;
416 rn->id = id;
417
418 rn64_le = cpu_to_le64(*(u64 *)rn);
419 rn->crc = w1_calc_crc8((u8 *)&rn64_le, 7);
420
421#if 0
422 dev_info(dev, "With CRC device is %02x.%012llx.%02x.\n",
423 rn->family, (unsigned long long)rn->id, rn->crc);
424#endif
425
426 return 0;
427}
428
429/* Searches the slaves in the w1_master and returns a pointer or NULL.
430 * Note: must not hold list_mutex
431 */
432struct w1_slave *w1_slave_search_device(struct w1_master *dev,
433 struct w1_reg_num *rn)
434{
435 struct w1_slave *sl;
436 mutex_lock(&dev->list_mutex);
437 list_for_each_entry(sl, &dev->slist, w1_slave_entry) {
438 if (sl->reg_num.family == rn->family &&
439 sl->reg_num.id == rn->id &&
440 sl->reg_num.crc == rn->crc) {
441 mutex_unlock(&dev->list_mutex);
442 return sl;
443 }
444 }
445 mutex_unlock(&dev->list_mutex);
446 return NULL;
447}
448
449static ssize_t w1_master_attribute_store_add(struct device *dev,
450 struct device_attribute *attr,
451 const char *buf, size_t count)
452{
453 struct w1_master *md = dev_to_w1_master(dev);
454 struct w1_reg_num rn;
455 struct w1_slave *sl;
456 ssize_t result = count;
457
458 if (w1_atoreg_num(dev, buf, count, &rn))
459 return -EINVAL;
460
461 mutex_lock(&md->mutex);
462 sl = w1_slave_search_device(md, &rn);
463 /* It would be nice to do a targeted search one the one-wire bus
464 * for the new device to see if it is out there or not. But the
465 * current search doesn't support that.
466 */
467 if (sl) {
468 dev_info(dev, "Device %s already exists\n", sl->name);
469 result = -EINVAL;
470 } else {
471 w1_attach_slave_device(md, &rn);
472 }
473 mutex_unlock(&md->mutex);
474
475 return result;
476}
477
478static ssize_t w1_master_attribute_show_remove(struct device *dev,
479 struct device_attribute *attr, char *buf)
480{
481 int c = PAGE_SIZE;
482 c -= snprintf(buf+PAGE_SIZE - c, c,
483 "write device id xx-xxxxxxxxxxxx to remove slave\n");
484 return PAGE_SIZE - c;
485}
486
487static ssize_t w1_master_attribute_store_remove(struct device *dev,
488 struct device_attribute *attr,
489 const char *buf, size_t count)
490{
491 struct w1_master *md = dev_to_w1_master(dev);
492 struct w1_reg_num rn;
493 struct w1_slave *sl;
494 ssize_t result;
495
496 if (w1_atoreg_num(dev, buf, count, &rn))
497 return -EINVAL;
498
499 mutex_lock(&md->mutex);
500 sl = w1_slave_search_device(md, &rn);
501 if (sl) {
502 result = w1_slave_detach(sl);
503 /* refcnt 0 means it was detached in the call */
504 if (result == 0)
505 result = count;
506 } else {
507 dev_info(dev, "Device %02x-%012llx doesn't exists\n", rn.family,
508 (unsigned long long)rn.id);
509 result = -EINVAL;
510 }
511 mutex_unlock(&md->mutex);
512
513 return result;
514}
515
516#define W1_MASTER_ATTR_RO(_name, _mode) \
517 struct device_attribute w1_master_attribute_##_name = \
518 __ATTR(w1_master_##_name, _mode, \
519 w1_master_attribute_show_##_name, NULL)
520
521#define W1_MASTER_ATTR_RW(_name, _mode) \
522 struct device_attribute w1_master_attribute_##_name = \
523 __ATTR(w1_master_##_name, _mode, \
524 w1_master_attribute_show_##_name, \
525 w1_master_attribute_store_##_name)
526
527static W1_MASTER_ATTR_RO(name, S_IRUGO);
528static W1_MASTER_ATTR_RO(slaves, S_IRUGO);
529static W1_MASTER_ATTR_RO(slave_count, S_IRUGO);
530static W1_MASTER_ATTR_RW(max_slave_count, S_IRUGO | S_IWUSR | S_IWGRP);
531static W1_MASTER_ATTR_RO(attempts, S_IRUGO);
532static W1_MASTER_ATTR_RO(timeout, S_IRUGO);
533static W1_MASTER_ATTR_RO(timeout_us, S_IRUGO);
534static W1_MASTER_ATTR_RO(pointer, S_IRUGO);
535static W1_MASTER_ATTR_RW(search, S_IRUGO | S_IWUSR | S_IWGRP);
536static W1_MASTER_ATTR_RW(pullup, S_IRUGO | S_IWUSR | S_IWGRP);
537static W1_MASTER_ATTR_RW(add, S_IRUGO | S_IWUSR | S_IWGRP);
538static W1_MASTER_ATTR_RW(remove, S_IRUGO | S_IWUSR | S_IWGRP);
539
540static struct attribute *w1_master_default_attrs[] = {
541 &w1_master_attribute_name.attr,
542 &w1_master_attribute_slaves.attr,
543 &w1_master_attribute_slave_count.attr,
544 &w1_master_attribute_max_slave_count.attr,
545 &w1_master_attribute_attempts.attr,
546 &w1_master_attribute_timeout.attr,
547 &w1_master_attribute_timeout_us.attr,
548 &w1_master_attribute_pointer.attr,
549 &w1_master_attribute_search.attr,
550 &w1_master_attribute_pullup.attr,
551 &w1_master_attribute_add.attr,
552 &w1_master_attribute_remove.attr,
553 NULL
554};
555
556static const struct attribute_group w1_master_defattr_group = {
557 .attrs = w1_master_default_attrs,
558};
559
560int w1_create_master_attributes(struct w1_master *master)
561{
562 return sysfs_create_group(&master->dev.kobj, &w1_master_defattr_group);
563}
564
565void w1_destroy_master_attributes(struct w1_master *master)
566{
567 sysfs_remove_group(&master->dev.kobj, &w1_master_defattr_group);
568}
569
570static int w1_uevent(const struct device *dev, struct kobj_uevent_env *env)
571{
572 const struct w1_master *md = NULL;
573 const struct w1_slave *sl = NULL;
574 const char *event_owner, *name;
575 int err = 0;
576
577 if (dev->driver == &w1_master_driver) {
578 md = container_of(dev, struct w1_master, dev);
579 event_owner = "master";
580 name = md->name;
581 } else if (dev->driver == &w1_slave_driver) {
582 sl = container_of(dev, struct w1_slave, dev);
583 event_owner = "slave";
584 name = sl->name;
585 } else {
586 dev_dbg(dev, "Unknown event.\n");
587 return -EINVAL;
588 }
589
590 dev_dbg(dev, "Hotplug event for %s %s, bus_id=%s.\n",
591 event_owner, name, dev_name(dev));
592
593 if (dev->driver != &w1_slave_driver || !sl)
594 goto end;
595
596 err = add_uevent_var(env, "W1_FID=%02X", sl->reg_num.family);
597 if (err)
598 goto end;
599
600 err = add_uevent_var(env, "W1_SLAVE_ID=%024LX",
601 (unsigned long long)sl->reg_num.id);
602end:
603 return err;
604}
605
606static int w1_family_notify(unsigned long action, struct w1_slave *sl)
607{
608 const struct w1_family_ops *fops;
609 int err;
610
611 fops = sl->family->fops;
612
613 if (!fops)
614 return 0;
615
616 switch (action) {
617 case BUS_NOTIFY_ADD_DEVICE:
618 /* if the family driver needs to initialize something... */
619 if (fops->add_slave) {
620 err = fops->add_slave(sl);
621 if (err < 0) {
622 dev_err(&sl->dev,
623 "add_slave() call failed. err=%d\n",
624 err);
625 return err;
626 }
627 }
628 if (fops->groups) {
629 err = sysfs_create_groups(&sl->dev.kobj, fops->groups);
630 if (err) {
631 dev_err(&sl->dev,
632 "sysfs group creation failed. err=%d\n",
633 err);
634 return err;
635 }
636 }
637 if (IS_REACHABLE(CONFIG_HWMON) && fops->chip_info) {
638 struct device *hwmon
639 = hwmon_device_register_with_info(&sl->dev,
640 "w1_slave_temp", sl,
641 fops->chip_info,
642 NULL);
643 if (IS_ERR(hwmon)) {
644 dev_warn(&sl->dev,
645 "could not create hwmon device\n");
646 } else {
647 sl->hwmon = hwmon;
648 }
649 }
650 break;
651 case BUS_NOTIFY_DEL_DEVICE:
652 if (IS_REACHABLE(CONFIG_HWMON) && fops->chip_info &&
653 sl->hwmon)
654 hwmon_device_unregister(sl->hwmon);
655 if (fops->remove_slave)
656 sl->family->fops->remove_slave(sl);
657 if (fops->groups)
658 sysfs_remove_groups(&sl->dev.kobj, fops->groups);
659 break;
660 }
661 return 0;
662}
663
664static int __w1_attach_slave_device(struct w1_slave *sl)
665{
666 int err;
667
668 sl->dev.parent = &sl->master->dev;
669 sl->dev.driver = &w1_slave_driver;
670 sl->dev.bus = &w1_bus_type;
671 sl->dev.release = &w1_slave_release;
672 sl->dev.groups = w1_slave_groups;
673 sl->dev.of_node = of_find_matching_node(sl->master->dev.of_node,
674 sl->family->of_match_table);
675
676 dev_set_name(&sl->dev, "%02x-%012llx",
677 (unsigned int) sl->reg_num.family,
678 (unsigned long long) sl->reg_num.id);
679 snprintf(&sl->name[0], sizeof(sl->name),
680 "%02x-%012llx",
681 (unsigned int) sl->reg_num.family,
682 (unsigned long long) sl->reg_num.id);
683
684 dev_dbg(&sl->dev, "%s: registering %s as %p.\n", __func__,
685 dev_name(&sl->dev), sl);
686
687 /* suppress for w1_family_notify before sending KOBJ_ADD */
688 dev_set_uevent_suppress(&sl->dev, true);
689
690 err = device_register(&sl->dev);
691 if (err < 0) {
692 dev_err(&sl->dev,
693 "Device registration [%s] failed. err=%d\n",
694 dev_name(&sl->dev), err);
695 of_node_put(sl->dev.of_node);
696 put_device(&sl->dev);
697 return err;
698 }
699 w1_family_notify(BUS_NOTIFY_ADD_DEVICE, sl);
700
701 dev_set_uevent_suppress(&sl->dev, false);
702 kobject_uevent(&sl->dev.kobj, KOBJ_ADD);
703
704 mutex_lock(&sl->master->list_mutex);
705 list_add_tail(&sl->w1_slave_entry, &sl->master->slist);
706 mutex_unlock(&sl->master->list_mutex);
707
708 return 0;
709}
710
711int w1_attach_slave_device(struct w1_master *dev, struct w1_reg_num *rn)
712{
713 struct w1_slave *sl;
714 struct w1_family *f;
715 int err;
716 struct w1_netlink_msg msg;
717
718 sl = kzalloc(sizeof(struct w1_slave), GFP_KERNEL);
719 if (!sl) {
720 dev_err(&dev->dev,
721 "%s: failed to allocate new slave device.\n",
722 __func__);
723 return -ENOMEM;
724 }
725
726
727 sl->owner = THIS_MODULE;
728 sl->master = dev;
729 set_bit(W1_SLAVE_ACTIVE, &sl->flags);
730
731 memset(&msg, 0, sizeof(msg));
732 memcpy(&sl->reg_num, rn, sizeof(sl->reg_num));
733 atomic_set(&sl->refcnt, 1);
734 atomic_inc(&sl->master->refcnt);
735 dev->slave_count++;
736 dev_info(&dev->dev, "Attaching one wire slave %02x.%012llx crc %02x\n",
737 rn->family, (unsigned long long)rn->id, rn->crc);
738
739 /* slave modules need to be loaded in a context with unlocked mutex */
740 mutex_unlock(&dev->mutex);
741 request_module("w1-family-0x%02X", rn->family);
742 mutex_lock(&dev->mutex);
743
744 spin_lock(&w1_flock);
745 f = w1_family_registered(rn->family);
746 if (!f) {
747 f= &w1_default_family;
748 dev_info(&dev->dev, "Family %x for %02x.%012llx.%02x is not registered.\n",
749 rn->family, rn->family,
750 (unsigned long long)rn->id, rn->crc);
751 }
752 __w1_family_get(f);
753 spin_unlock(&w1_flock);
754
755 sl->family = f;
756
757 err = __w1_attach_slave_device(sl);
758 if (err < 0) {
759 dev_err(&dev->dev, "%s: Attaching %s failed.\n", __func__,
760 sl->name);
761 dev->slave_count--;
762 w1_family_put(sl->family);
763 atomic_dec(&sl->master->refcnt);
764 kfree(sl);
765 return err;
766 }
767
768 sl->ttl = dev->slave_ttl;
769
770 memcpy(msg.id.id, rn, sizeof(msg.id));
771 msg.type = W1_SLAVE_ADD;
772 w1_netlink_send(dev, &msg);
773
774 return 0;
775}
776
777int w1_unref_slave(struct w1_slave *sl)
778{
779 struct w1_master *dev = sl->master;
780 int refcnt;
781 mutex_lock(&dev->list_mutex);
782 refcnt = atomic_sub_return(1, &sl->refcnt);
783 if (refcnt == 0) {
784 struct w1_netlink_msg msg;
785
786 dev_dbg(&sl->dev, "%s: detaching %s [%p].\n", __func__,
787 sl->name, sl);
788
789 list_del(&sl->w1_slave_entry);
790
791 memset(&msg, 0, sizeof(msg));
792 memcpy(msg.id.id, &sl->reg_num, sizeof(msg.id));
793 msg.type = W1_SLAVE_REMOVE;
794 w1_netlink_send(sl->master, &msg);
795
796 w1_family_notify(BUS_NOTIFY_DEL_DEVICE, sl);
797 device_unregister(&sl->dev);
798 #ifdef DEBUG
799 memset(sl, 0, sizeof(*sl));
800 #endif
801 kfree(sl);
802 }
803 atomic_dec(&dev->refcnt);
804 mutex_unlock(&dev->list_mutex);
805 return refcnt;
806}
807
808int w1_slave_detach(struct w1_slave *sl)
809{
810 /* Only detach a slave once as it decreases the refcnt each time. */
811 int destroy_now;
812 mutex_lock(&sl->master->list_mutex);
813 destroy_now = !test_bit(W1_SLAVE_DETACH, &sl->flags);
814 set_bit(W1_SLAVE_DETACH, &sl->flags);
815 mutex_unlock(&sl->master->list_mutex);
816
817 if (destroy_now)
818 destroy_now = !w1_unref_slave(sl);
819 return destroy_now ? 0 : -EBUSY;
820}
821
822struct w1_master *w1_search_master_id(u32 id)
823{
824 struct w1_master *dev = NULL, *iter;
825
826 mutex_lock(&w1_mlock);
827 list_for_each_entry(iter, &w1_masters, w1_master_entry) {
828 if (iter->id == id) {
829 dev = iter;
830 atomic_inc(&iter->refcnt);
831 break;
832 }
833 }
834 mutex_unlock(&w1_mlock);
835
836 return dev;
837}
838
839struct w1_slave *w1_search_slave(struct w1_reg_num *id)
840{
841 struct w1_master *dev;
842 struct w1_slave *sl = NULL, *iter;
843
844 mutex_lock(&w1_mlock);
845 list_for_each_entry(dev, &w1_masters, w1_master_entry) {
846 mutex_lock(&dev->list_mutex);
847 list_for_each_entry(iter, &dev->slist, w1_slave_entry) {
848 if (iter->reg_num.family == id->family &&
849 iter->reg_num.id == id->id &&
850 iter->reg_num.crc == id->crc) {
851 sl = iter;
852 atomic_inc(&dev->refcnt);
853 atomic_inc(&iter->refcnt);
854 break;
855 }
856 }
857 mutex_unlock(&dev->list_mutex);
858
859 if (sl)
860 break;
861 }
862 mutex_unlock(&w1_mlock);
863
864 return sl;
865}
866
867void w1_reconnect_slaves(struct w1_family *f, int attach)
868{
869 struct w1_slave *sl, *sln;
870 struct w1_master *dev;
871
872 mutex_lock(&w1_mlock);
873 list_for_each_entry(dev, &w1_masters, w1_master_entry) {
874 dev_dbg(&dev->dev, "Reconnecting slaves in device %s "
875 "for family %02x.\n", dev->name, f->fid);
876 mutex_lock(&dev->mutex);
877 mutex_lock(&dev->list_mutex);
878 list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) {
879 /* If it is a new family, slaves with the default
880 * family driver and are that family will be
881 * connected. If the family is going away, devices
882 * matching that family are reconneced.
883 */
884 if ((attach && sl->family->fid == W1_FAMILY_DEFAULT
885 && sl->reg_num.family == f->fid) ||
886 (!attach && sl->family->fid == f->fid)) {
887 struct w1_reg_num rn;
888
889 mutex_unlock(&dev->list_mutex);
890 memcpy(&rn, &sl->reg_num, sizeof(rn));
891 /* If it was already in use let the automatic
892 * scan pick it up again later.
893 */
894 if (!w1_slave_detach(sl))
895 w1_attach_slave_device(dev, &rn);
896 mutex_lock(&dev->list_mutex);
897 }
898 }
899 dev_dbg(&dev->dev, "Reconnecting slaves in device %s "
900 "has been finished.\n", dev->name);
901 mutex_unlock(&dev->list_mutex);
902 mutex_unlock(&dev->mutex);
903 }
904 mutex_unlock(&w1_mlock);
905}
906
907static int w1_addr_crc_is_valid(struct w1_master *dev, u64 rn)
908{
909 u64 rn_le = cpu_to_le64(rn);
910 struct w1_reg_num *tmp = (struct w1_reg_num *)&rn;
911 u8 crc;
912
913 crc = w1_calc_crc8((u8 *)&rn_le, 7);
914
915 /* quirk:
916 * DS28E04 (1w eeprom) has strapping pins to change
917 * address, but will not update the crc. So normal rules
918 * for consistent w1 addresses are violated. We test
919 * with the 7 LSBs of the address forced high.
920 *
921 * (char*)&rn_le = { family, addr_lsb, ..., addr_msb, crc }.
922 */
923 if (crc != tmp->crc && tmp->family == W1_FAMILY_DS28E04) {
924 u64 corr_le = rn_le;
925
926 ((u8 *)&corr_le)[1] |= 0x7f;
927 crc = w1_calc_crc8((u8 *)&corr_le, 7);
928
929 dev_info(&dev->dev, "DS28E04 crc workaround on %02x.%012llx.%02x\n",
930 tmp->family, (unsigned long long)tmp->id, tmp->crc);
931 }
932
933 if (crc != tmp->crc) {
934 dev_dbg(&dev->dev, "w1 addr crc mismatch: %02x.%012llx.%02x != 0x%02x.\n",
935 tmp->family, (unsigned long long)tmp->id, tmp->crc, crc);
936 return 0;
937 }
938 return 1;
939}
940
941void w1_slave_found(struct w1_master *dev, u64 rn)
942{
943 struct w1_slave *sl;
944 struct w1_reg_num *tmp;
945
946 atomic_inc(&dev->refcnt);
947
948 tmp = (struct w1_reg_num *) &rn;
949
950 sl = w1_slave_search_device(dev, tmp);
951 if (sl) {
952 set_bit(W1_SLAVE_ACTIVE, &sl->flags);
953 } else {
954 if (rn && w1_addr_crc_is_valid(dev, rn))
955 w1_attach_slave_device(dev, tmp);
956 }
957
958 atomic_dec(&dev->refcnt);
959}
960
961/**
962 * w1_search() - Performs a ROM Search & registers any devices found.
963 * @dev: The master device to search
964 * @search_type: W1_SEARCH to search all devices, or W1_ALARM_SEARCH
965 * to return only devices in the alarmed state
966 * @cb: Function to call when a device is found
967 *
968 * The 1-wire search is a simple binary tree search.
969 * For each bit of the address, we read two bits and write one bit.
970 * The bit written will put to sleep all devies that don't match that bit.
971 * When the two reads differ, the direction choice is obvious.
972 * When both bits are 0, we must choose a path to take.
973 * When we can scan all 64 bits without having to choose a path, we are done.
974 *
975 * See "Application note 187 1-wire search algorithm" at www.maxim-ic.com
976 *
977 */
978void w1_search(struct w1_master *dev, u8 search_type, w1_slave_found_callback cb)
979{
980 u64 last_rn, rn, tmp64;
981 int i, slave_count = 0;
982 int last_zero, last_device;
983 int search_bit, desc_bit;
984 u8 triplet_ret = 0;
985
986 search_bit = 0;
987 rn = dev->search_id;
988 last_rn = 0;
989 last_device = 0;
990 last_zero = -1;
991
992 desc_bit = 64;
993
994 while ( !last_device && (slave_count++ < dev->max_slave_count) ) {
995 last_rn = rn;
996 rn = 0;
997
998 /*
999 * Reset bus and all 1-wire device state machines
1000 * so they can respond to our requests.
1001 *
1002 * Return 0 - device(s) present, 1 - no devices present.
1003 */
1004 mutex_lock(&dev->bus_mutex);
1005 if (w1_reset_bus(dev)) {
1006 mutex_unlock(&dev->bus_mutex);
1007 dev_dbg(&dev->dev, "No devices present on the wire.\n");
1008 break;
1009 }
1010
1011 /* Do fast search on single slave bus */
1012 if (dev->max_slave_count == 1) {
1013 int rv;
1014 w1_write_8(dev, W1_READ_ROM);
1015 rv = w1_read_block(dev, (u8 *)&rn, 8);
1016 mutex_unlock(&dev->bus_mutex);
1017
1018 if (rv == 8 && rn)
1019 cb(dev, rn);
1020
1021 break;
1022 }
1023
1024 /* Start the search */
1025 w1_write_8(dev, search_type);
1026 for (i = 0; i < 64; ++i) {
1027 /* Determine the direction/search bit */
1028 if (i == desc_bit)
1029 search_bit = 1; /* took the 0 path last time, so take the 1 path */
1030 else if (i > desc_bit)
1031 search_bit = 0; /* take the 0 path on the next branch */
1032 else
1033 search_bit = ((last_rn >> i) & 0x1);
1034
1035 /* Read two bits and write one bit */
1036 triplet_ret = w1_triplet(dev, search_bit);
1037
1038 /* quit if no device responded */
1039 if ( (triplet_ret & 0x03) == 0x03 )
1040 break;
1041
1042 /* If both directions were valid, and we took the 0 path... */
1043 if (triplet_ret == 0)
1044 last_zero = i;
1045
1046 /* extract the direction taken & update the device number */
1047 tmp64 = (triplet_ret >> 2);
1048 rn |= (tmp64 << i);
1049
1050 if (test_bit(W1_ABORT_SEARCH, &dev->flags)) {
1051 mutex_unlock(&dev->bus_mutex);
1052 dev_dbg(&dev->dev, "Abort w1_search\n");
1053 return;
1054 }
1055 }
1056 mutex_unlock(&dev->bus_mutex);
1057
1058 if ( (triplet_ret & 0x03) != 0x03 ) {
1059 if ((desc_bit == last_zero) || (last_zero < 0)) {
1060 last_device = 1;
1061 dev->search_id = 0;
1062 } else {
1063 dev->search_id = rn;
1064 }
1065 desc_bit = last_zero;
1066 cb(dev, rn);
1067 }
1068
1069 if (!last_device && slave_count == dev->max_slave_count &&
1070 !test_bit(W1_WARN_MAX_COUNT, &dev->flags)) {
1071 /* Only max_slave_count will be scanned in a search,
1072 * but it will start where it left off next search
1073 * until all ids are identified and then it will start
1074 * over. A continued search will report the previous
1075 * last id as the first id (provided it is still on the
1076 * bus).
1077 */
1078 dev_info(&dev->dev, "%s: max_slave_count %d reached, "
1079 "will continue next search.\n", __func__,
1080 dev->max_slave_count);
1081 set_bit(W1_WARN_MAX_COUNT, &dev->flags);
1082 }
1083 }
1084}
1085
1086void w1_search_process_cb(struct w1_master *dev, u8 search_type,
1087 w1_slave_found_callback cb)
1088{
1089 struct w1_slave *sl, *sln;
1090
1091 mutex_lock(&dev->list_mutex);
1092 list_for_each_entry(sl, &dev->slist, w1_slave_entry)
1093 clear_bit(W1_SLAVE_ACTIVE, &sl->flags);
1094 mutex_unlock(&dev->list_mutex);
1095
1096 w1_search_devices(dev, search_type, cb);
1097
1098 mutex_lock(&dev->list_mutex);
1099 list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) {
1100 if (!test_bit(W1_SLAVE_ACTIVE, &sl->flags) && !--sl->ttl) {
1101 mutex_unlock(&dev->list_mutex);
1102 w1_slave_detach(sl);
1103 mutex_lock(&dev->list_mutex);
1104 }
1105 else if (test_bit(W1_SLAVE_ACTIVE, &sl->flags))
1106 sl->ttl = dev->slave_ttl;
1107 }
1108 mutex_unlock(&dev->list_mutex);
1109
1110 if (dev->search_count > 0)
1111 dev->search_count--;
1112}
1113
1114static void w1_search_process(struct w1_master *dev, u8 search_type)
1115{
1116 w1_search_process_cb(dev, search_type, w1_slave_found);
1117}
1118
1119/**
1120 * w1_process_callbacks() - execute each dev->async_list callback entry
1121 * @dev: w1_master device
1122 *
1123 * The w1 master list_mutex must be held.
1124 *
1125 * Return: 1 if there were commands to executed 0 otherwise
1126 */
1127int w1_process_callbacks(struct w1_master *dev)
1128{
1129 int ret = 0;
1130 struct w1_async_cmd *async_cmd, *async_n;
1131
1132 /* The list can be added to in another thread, loop until it is empty */
1133 while (!list_empty(&dev->async_list)) {
1134 list_for_each_entry_safe(async_cmd, async_n, &dev->async_list,
1135 async_entry) {
1136 /* drop the lock, if it is a search it can take a long
1137 * time */
1138 mutex_unlock(&dev->list_mutex);
1139 async_cmd->cb(dev, async_cmd);
1140 ret = 1;
1141 mutex_lock(&dev->list_mutex);
1142 }
1143 }
1144 return ret;
1145}
1146
1147int w1_process(void *data)
1148{
1149 struct w1_master *dev = (struct w1_master *) data;
1150 /* As long as w1_timeout is only set by a module parameter the sleep
1151 * time can be calculated in jiffies once.
1152 */
1153 const unsigned long jtime =
1154 usecs_to_jiffies(w1_timeout * 1000000 + w1_timeout_us);
1155 /* remainder if it woke up early */
1156 unsigned long jremain = 0;
1157
1158 atomic_inc(&dev->refcnt);
1159
1160 for (;;) {
1161
1162 if (!jremain && dev->search_count) {
1163 mutex_lock(&dev->mutex);
1164 w1_search_process(dev, W1_SEARCH);
1165 mutex_unlock(&dev->mutex);
1166 }
1167
1168 mutex_lock(&dev->list_mutex);
1169 /* Note, w1_process_callback drops the lock while processing,
1170 * but locks it again before returning.
1171 */
1172 if (!w1_process_callbacks(dev) && jremain) {
1173 /* a wake up is either to stop the thread, process
1174 * callbacks, or search, it isn't process callbacks, so
1175 * schedule a search.
1176 */
1177 jremain = 1;
1178 }
1179
1180 __set_current_state(TASK_INTERRUPTIBLE);
1181
1182 /* hold list_mutex until after interruptible to prevent loosing
1183 * the wakeup signal when async_cmd is added.
1184 */
1185 mutex_unlock(&dev->list_mutex);
1186
1187 if (kthread_should_stop()) {
1188 __set_current_state(TASK_RUNNING);
1189 break;
1190 }
1191
1192 /* Only sleep when the search is active. */
1193 if (dev->search_count) {
1194 if (!jremain)
1195 jremain = jtime;
1196 jremain = schedule_timeout(jremain);
1197 }
1198 else
1199 schedule();
1200 }
1201
1202 atomic_dec(&dev->refcnt);
1203
1204 return 0;
1205}
1206
1207static int __init w1_init(void)
1208{
1209 int retval;
1210
1211 pr_info("Driver for 1-wire Dallas network protocol.\n");
1212
1213 w1_init_netlink();
1214
1215 retval = bus_register(&w1_bus_type);
1216 if (retval) {
1217 pr_err("Failed to register bus. err=%d.\n", retval);
1218 goto err_out_exit_init;
1219 }
1220
1221 retval = driver_register(&w1_master_driver);
1222 if (retval) {
1223 pr_err("Failed to register master driver. err=%d.\n",
1224 retval);
1225 goto err_out_bus_unregister;
1226 }
1227
1228 retval = driver_register(&w1_slave_driver);
1229 if (retval) {
1230 pr_err("Failed to register slave driver. err=%d.\n",
1231 retval);
1232 goto err_out_master_unregister;
1233 }
1234
1235 return 0;
1236
1237#if 0
1238/* For undoing the slave register if there was a step after it. */
1239err_out_slave_unregister:
1240 driver_unregister(&w1_slave_driver);
1241#endif
1242
1243err_out_master_unregister:
1244 driver_unregister(&w1_master_driver);
1245
1246err_out_bus_unregister:
1247 bus_unregister(&w1_bus_type);
1248
1249err_out_exit_init:
1250 return retval;
1251}
1252
1253static void __exit w1_fini(void)
1254{
1255 struct w1_master *dev, *n;
1256
1257 /* Set netlink removal messages and some cleanup */
1258 list_for_each_entry_safe(dev, n, &w1_masters, w1_master_entry)
1259 __w1_remove_master_device(dev);
1260
1261 w1_fini_netlink();
1262
1263 driver_unregister(&w1_slave_driver);
1264 driver_unregister(&w1_master_driver);
1265 bus_unregister(&w1_bus_type);
1266}
1267
1268module_init(w1_init);
1269module_exit(w1_fini);
1270
1271MODULE_AUTHOR("Evgeniy Polyakov <zbr@ioremap.net>");
1272MODULE_DESCRIPTION("Driver for 1-wire Dallas network protocol.");
1273MODULE_LICENSE("GPL");
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");