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1/*
2 * w1.c
3 *
4 * Copyright (c) 2004 Evgeniy Polyakov <zbr@ioremap.net>
5 *
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20 */
21
22#include <linux/delay.h>
23#include <linux/kernel.h>
24#include <linux/module.h>
25#include <linux/moduleparam.h>
26#include <linux/list.h>
27#include <linux/interrupt.h>
28#include <linux/spinlock.h>
29#include <linux/timer.h>
30#include <linux/device.h>
31#include <linux/slab.h>
32#include <linux/sched.h>
33#include <linux/kthread.h>
34#include <linux/freezer.h>
35
36#include <linux/atomic.h>
37
38#include "w1.h"
39#include "w1_log.h"
40#include "w1_int.h"
41#include "w1_family.h"
42#include "w1_netlink.h"
43
44MODULE_LICENSE("GPL");
45MODULE_AUTHOR("Evgeniy Polyakov <zbr@ioremap.net>");
46MODULE_DESCRIPTION("Driver for 1-wire Dallas network protocol.");
47
48static int w1_timeout = 10;
49static int w1_timeout_us = 0;
50int w1_max_slave_count = 64;
51int w1_max_slave_ttl = 10;
52
53module_param_named(timeout, w1_timeout, int, 0);
54MODULE_PARM_DESC(timeout, "time in seconds between automatic slave searches");
55module_param_named(timeout_us, w1_timeout_us, int, 0);
56MODULE_PARM_DESC(timeout, "time in microseconds between automatic slave"
57 " searches");
58/* A search stops when w1_max_slave_count devices have been found in that
59 * search. The next search will start over and detect the same set of devices
60 * on a static 1-wire bus. Memory is not allocated based on this number, just
61 * on the number of devices known to the kernel. Having a high number does not
62 * consume additional resources. As a special case, if there is only one
63 * device on the network and w1_max_slave_count is set to 1, the device id can
64 * be read directly skipping the normal slower search process.
65 */
66module_param_named(max_slave_count, w1_max_slave_count, int, 0);
67MODULE_PARM_DESC(max_slave_count,
68 "maximum number of slaves detected in a search");
69module_param_named(slave_ttl, w1_max_slave_ttl, int, 0);
70MODULE_PARM_DESC(slave_ttl,
71 "Number of searches not seeing a slave before it will be removed");
72
73DEFINE_MUTEX(w1_mlock);
74LIST_HEAD(w1_masters);
75
76static int w1_master_match(struct device *dev, struct device_driver *drv)
77{
78 return 1;
79}
80
81static int w1_master_probe(struct device *dev)
82{
83 return -ENODEV;
84}
85
86static void w1_master_release(struct device *dev)
87{
88 struct w1_master *md = dev_to_w1_master(dev);
89
90 dev_dbg(dev, "%s: Releasing %s.\n", __func__, md->name);
91 memset(md, 0, sizeof(struct w1_master) + sizeof(struct w1_bus_master));
92 kfree(md);
93}
94
95static void w1_slave_release(struct device *dev)
96{
97 struct w1_slave *sl = dev_to_w1_slave(dev);
98
99 dev_dbg(dev, "%s: Releasing %s [%p]\n", __func__, sl->name, sl);
100
101 w1_family_put(sl->family);
102 sl->master->slave_count--;
103}
104
105static ssize_t name_show(struct device *dev, struct device_attribute *attr, char *buf)
106{
107 struct w1_slave *sl = dev_to_w1_slave(dev);
108
109 return sprintf(buf, "%s\n", sl->name);
110}
111static DEVICE_ATTR_RO(name);
112
113static ssize_t id_show(struct device *dev,
114 struct device_attribute *attr, char *buf)
115{
116 struct w1_slave *sl = dev_to_w1_slave(dev);
117 ssize_t count = sizeof(sl->reg_num);
118
119 memcpy(buf, (u8 *)&sl->reg_num, count);
120 return count;
121}
122static DEVICE_ATTR_RO(id);
123
124static struct attribute *w1_slave_attrs[] = {
125 &dev_attr_name.attr,
126 &dev_attr_id.attr,
127 NULL,
128};
129ATTRIBUTE_GROUPS(w1_slave);
130
131/* Default family */
132
133static ssize_t rw_write(struct file *filp, struct kobject *kobj,
134 struct bin_attribute *bin_attr, char *buf, loff_t off,
135 size_t count)
136{
137 struct w1_slave *sl = kobj_to_w1_slave(kobj);
138
139 mutex_lock(&sl->master->mutex);
140 if (w1_reset_select_slave(sl)) {
141 count = 0;
142 goto out_up;
143 }
144
145 w1_write_block(sl->master, buf, count);
146
147out_up:
148 mutex_unlock(&sl->master->mutex);
149 return count;
150}
151
152static ssize_t rw_read(struct file *filp, struct kobject *kobj,
153 struct bin_attribute *bin_attr, char *buf, loff_t off,
154 size_t count)
155{
156 struct w1_slave *sl = kobj_to_w1_slave(kobj);
157
158 mutex_lock(&sl->master->mutex);
159 w1_read_block(sl->master, buf, count);
160 mutex_unlock(&sl->master->mutex);
161 return count;
162}
163
164static BIN_ATTR_RW(rw, PAGE_SIZE);
165
166static struct bin_attribute *w1_slave_bin_attrs[] = {
167 &bin_attr_rw,
168 NULL,
169};
170
171static const struct attribute_group w1_slave_default_group = {
172 .bin_attrs = w1_slave_bin_attrs,
173};
174
175static const struct attribute_group *w1_slave_default_groups[] = {
176 &w1_slave_default_group,
177 NULL,
178};
179
180static struct w1_family_ops w1_default_fops = {
181 .groups = w1_slave_default_groups,
182};
183
184static struct w1_family w1_default_family = {
185 .fops = &w1_default_fops,
186};
187
188static int w1_uevent(struct device *dev, struct kobj_uevent_env *env);
189
190static struct bus_type w1_bus_type = {
191 .name = "w1",
192 .match = w1_master_match,
193 .uevent = w1_uevent,
194};
195
196struct device_driver w1_master_driver = {
197 .name = "w1_master_driver",
198 .bus = &w1_bus_type,
199 .probe = w1_master_probe,
200};
201
202struct device w1_master_device = {
203 .parent = NULL,
204 .bus = &w1_bus_type,
205 .init_name = "w1 bus master",
206 .driver = &w1_master_driver,
207 .release = &w1_master_release
208};
209
210static struct device_driver w1_slave_driver = {
211 .name = "w1_slave_driver",
212 .bus = &w1_bus_type,
213};
214
215#if 0
216struct device w1_slave_device = {
217 .parent = NULL,
218 .bus = &w1_bus_type,
219 .init_name = "w1 bus slave",
220 .driver = &w1_slave_driver,
221 .release = &w1_slave_release
222};
223#endif /* 0 */
224
225static ssize_t w1_master_attribute_show_name(struct device *dev, struct device_attribute *attr, char *buf)
226{
227 struct w1_master *md = dev_to_w1_master(dev);
228 ssize_t count;
229
230 mutex_lock(&md->mutex);
231 count = sprintf(buf, "%s\n", md->name);
232 mutex_unlock(&md->mutex);
233
234 return count;
235}
236
237static ssize_t w1_master_attribute_store_search(struct device * dev,
238 struct device_attribute *attr,
239 const char * buf, size_t count)
240{
241 long tmp;
242 struct w1_master *md = dev_to_w1_master(dev);
243 int ret;
244
245 ret = kstrtol(buf, 0, &tmp);
246 if (ret)
247 return ret;
248
249 mutex_lock(&md->mutex);
250 md->search_count = tmp;
251 mutex_unlock(&md->mutex);
252 /* Only wake if it is going to be searching. */
253 if (tmp)
254 wake_up_process(md->thread);
255
256 return count;
257}
258
259static ssize_t w1_master_attribute_show_search(struct device *dev,
260 struct device_attribute *attr,
261 char *buf)
262{
263 struct w1_master *md = dev_to_w1_master(dev);
264 ssize_t count;
265
266 mutex_lock(&md->mutex);
267 count = sprintf(buf, "%d\n", md->search_count);
268 mutex_unlock(&md->mutex);
269
270 return count;
271}
272
273static ssize_t w1_master_attribute_store_pullup(struct device *dev,
274 struct device_attribute *attr,
275 const char *buf, size_t count)
276{
277 long tmp;
278 struct w1_master *md = dev_to_w1_master(dev);
279 int ret;
280
281 ret = kstrtol(buf, 0, &tmp);
282 if (ret)
283 return ret;
284
285 mutex_lock(&md->mutex);
286 md->enable_pullup = tmp;
287 mutex_unlock(&md->mutex);
288
289 return count;
290}
291
292static ssize_t w1_master_attribute_show_pullup(struct device *dev,
293 struct device_attribute *attr,
294 char *buf)
295{
296 struct w1_master *md = dev_to_w1_master(dev);
297 ssize_t count;
298
299 mutex_lock(&md->mutex);
300 count = sprintf(buf, "%d\n", md->enable_pullup);
301 mutex_unlock(&md->mutex);
302
303 return count;
304}
305
306static ssize_t w1_master_attribute_show_pointer(struct device *dev, struct device_attribute *attr, char *buf)
307{
308 struct w1_master *md = dev_to_w1_master(dev);
309 ssize_t count;
310
311 mutex_lock(&md->mutex);
312 count = sprintf(buf, "0x%p\n", md->bus_master);
313 mutex_unlock(&md->mutex);
314 return count;
315}
316
317static ssize_t w1_master_attribute_show_timeout(struct device *dev, struct device_attribute *attr, char *buf)
318{
319 ssize_t count;
320 count = sprintf(buf, "%d\n", w1_timeout);
321 return count;
322}
323
324static ssize_t w1_master_attribute_show_timeout_us(struct device *dev,
325 struct device_attribute *attr, char *buf)
326{
327 ssize_t count;
328 count = sprintf(buf, "%d\n", w1_timeout_us);
329 return count;
330}
331
332static ssize_t w1_master_attribute_store_max_slave_count(struct device *dev,
333 struct device_attribute *attr, const char *buf, size_t count)
334{
335 int tmp;
336 struct w1_master *md = dev_to_w1_master(dev);
337
338 if (kstrtoint(buf, 0, &tmp) == -EINVAL || tmp < 1)
339 return -EINVAL;
340
341 mutex_lock(&md->mutex);
342 md->max_slave_count = tmp;
343 /* allow each time the max_slave_count is updated */
344 clear_bit(W1_WARN_MAX_COUNT, &md->flags);
345 mutex_unlock(&md->mutex);
346
347 return count;
348}
349
350static ssize_t w1_master_attribute_show_max_slave_count(struct device *dev, struct device_attribute *attr, char *buf)
351{
352 struct w1_master *md = dev_to_w1_master(dev);
353 ssize_t count;
354
355 mutex_lock(&md->mutex);
356 count = sprintf(buf, "%d\n", md->max_slave_count);
357 mutex_unlock(&md->mutex);
358 return count;
359}
360
361static ssize_t w1_master_attribute_show_attempts(struct device *dev, struct device_attribute *attr, char *buf)
362{
363 struct w1_master *md = dev_to_w1_master(dev);
364 ssize_t count;
365
366 mutex_lock(&md->mutex);
367 count = sprintf(buf, "%lu\n", md->attempts);
368 mutex_unlock(&md->mutex);
369 return count;
370}
371
372static ssize_t w1_master_attribute_show_slave_count(struct device *dev, struct device_attribute *attr, char *buf)
373{
374 struct w1_master *md = dev_to_w1_master(dev);
375 ssize_t count;
376
377 mutex_lock(&md->mutex);
378 count = sprintf(buf, "%d\n", md->slave_count);
379 mutex_unlock(&md->mutex);
380 return count;
381}
382
383static ssize_t w1_master_attribute_show_slaves(struct device *dev,
384 struct device_attribute *attr, char *buf)
385{
386 struct w1_master *md = dev_to_w1_master(dev);
387 int c = PAGE_SIZE;
388 struct list_head *ent, *n;
389 struct w1_slave *sl = NULL;
390
391 mutex_lock(&md->list_mutex);
392
393 list_for_each_safe(ent, n, &md->slist) {
394 sl = list_entry(ent, struct w1_slave, w1_slave_entry);
395
396 c -= snprintf(buf + PAGE_SIZE - c, c, "%s\n", sl->name);
397 }
398 if (!sl)
399 c -= snprintf(buf + PAGE_SIZE - c, c, "not found.\n");
400
401 mutex_unlock(&md->list_mutex);
402
403 return PAGE_SIZE - c;
404}
405
406static ssize_t w1_master_attribute_show_add(struct device *dev,
407 struct device_attribute *attr, char *buf)
408{
409 int c = PAGE_SIZE;
410 c -= snprintf(buf+PAGE_SIZE - c, c,
411 "write device id xx-xxxxxxxxxxxx to add slave\n");
412 return PAGE_SIZE - c;
413}
414
415static int w1_atoreg_num(struct device *dev, const char *buf, size_t count,
416 struct w1_reg_num *rn)
417{
418 unsigned int family;
419 unsigned long long id;
420 int i;
421 u64 rn64_le;
422
423 /* The CRC value isn't read from the user because the sysfs directory
424 * doesn't include it and most messages from the bus search don't
425 * print it either. It would be unreasonable for the user to then
426 * provide it.
427 */
428 const char *error_msg = "bad slave string format, expecting "
429 "ff-dddddddddddd\n";
430
431 if (buf[2] != '-') {
432 dev_err(dev, "%s", error_msg);
433 return -EINVAL;
434 }
435 i = sscanf(buf, "%02x-%012llx", &family, &id);
436 if (i != 2) {
437 dev_err(dev, "%s", error_msg);
438 return -EINVAL;
439 }
440 rn->family = family;
441 rn->id = id;
442
443 rn64_le = cpu_to_le64(*(u64 *)rn);
444 rn->crc = w1_calc_crc8((u8 *)&rn64_le, 7);
445
446#if 0
447 dev_info(dev, "With CRC device is %02x.%012llx.%02x.\n",
448 rn->family, (unsigned long long)rn->id, rn->crc);
449#endif
450
451 return 0;
452}
453
454/* Searches the slaves in the w1_master and returns a pointer or NULL.
455 * Note: must not hold list_mutex
456 */
457struct w1_slave *w1_slave_search_device(struct w1_master *dev,
458 struct w1_reg_num *rn)
459{
460 struct w1_slave *sl;
461 mutex_lock(&dev->list_mutex);
462 list_for_each_entry(sl, &dev->slist, w1_slave_entry) {
463 if (sl->reg_num.family == rn->family &&
464 sl->reg_num.id == rn->id &&
465 sl->reg_num.crc == rn->crc) {
466 mutex_unlock(&dev->list_mutex);
467 return sl;
468 }
469 }
470 mutex_unlock(&dev->list_mutex);
471 return NULL;
472}
473
474static ssize_t w1_master_attribute_store_add(struct device *dev,
475 struct device_attribute *attr,
476 const char *buf, size_t count)
477{
478 struct w1_master *md = dev_to_w1_master(dev);
479 struct w1_reg_num rn;
480 struct w1_slave *sl;
481 ssize_t result = count;
482
483 if (w1_atoreg_num(dev, buf, count, &rn))
484 return -EINVAL;
485
486 mutex_lock(&md->mutex);
487 sl = w1_slave_search_device(md, &rn);
488 /* It would be nice to do a targeted search one the one-wire bus
489 * for the new device to see if it is out there or not. But the
490 * current search doesn't support that.
491 */
492 if (sl) {
493 dev_info(dev, "Device %s already exists\n", sl->name);
494 result = -EINVAL;
495 } else {
496 w1_attach_slave_device(md, &rn);
497 }
498 mutex_unlock(&md->mutex);
499
500 return result;
501}
502
503static ssize_t w1_master_attribute_show_remove(struct device *dev,
504 struct device_attribute *attr, char *buf)
505{
506 int c = PAGE_SIZE;
507 c -= snprintf(buf+PAGE_SIZE - c, c,
508 "write device id xx-xxxxxxxxxxxx to remove slave\n");
509 return PAGE_SIZE - c;
510}
511
512static ssize_t w1_master_attribute_store_remove(struct device *dev,
513 struct device_attribute *attr,
514 const char *buf, size_t count)
515{
516 struct w1_master *md = dev_to_w1_master(dev);
517 struct w1_reg_num rn;
518 struct w1_slave *sl;
519 ssize_t result = count;
520
521 if (w1_atoreg_num(dev, buf, count, &rn))
522 return -EINVAL;
523
524 mutex_lock(&md->mutex);
525 sl = w1_slave_search_device(md, &rn);
526 if (sl) {
527 result = w1_slave_detach(sl);
528 /* refcnt 0 means it was detached in the call */
529 if (result == 0)
530 result = count;
531 } else {
532 dev_info(dev, "Device %02x-%012llx doesn't exists\n", rn.family,
533 (unsigned long long)rn.id);
534 result = -EINVAL;
535 }
536 mutex_unlock(&md->mutex);
537
538 return result;
539}
540
541#define W1_MASTER_ATTR_RO(_name, _mode) \
542 struct device_attribute w1_master_attribute_##_name = \
543 __ATTR(w1_master_##_name, _mode, \
544 w1_master_attribute_show_##_name, NULL)
545
546#define W1_MASTER_ATTR_RW(_name, _mode) \
547 struct device_attribute w1_master_attribute_##_name = \
548 __ATTR(w1_master_##_name, _mode, \
549 w1_master_attribute_show_##_name, \
550 w1_master_attribute_store_##_name)
551
552static W1_MASTER_ATTR_RO(name, S_IRUGO);
553static W1_MASTER_ATTR_RO(slaves, S_IRUGO);
554static W1_MASTER_ATTR_RO(slave_count, S_IRUGO);
555static W1_MASTER_ATTR_RW(max_slave_count, S_IRUGO | S_IWUSR | S_IWGRP);
556static W1_MASTER_ATTR_RO(attempts, S_IRUGO);
557static W1_MASTER_ATTR_RO(timeout, S_IRUGO);
558static W1_MASTER_ATTR_RO(timeout_us, S_IRUGO);
559static W1_MASTER_ATTR_RO(pointer, S_IRUGO);
560static W1_MASTER_ATTR_RW(search, S_IRUGO | S_IWUSR | S_IWGRP);
561static W1_MASTER_ATTR_RW(pullup, S_IRUGO | S_IWUSR | S_IWGRP);
562static W1_MASTER_ATTR_RW(add, S_IRUGO | S_IWUSR | S_IWGRP);
563static W1_MASTER_ATTR_RW(remove, S_IRUGO | S_IWUSR | S_IWGRP);
564
565static struct attribute *w1_master_default_attrs[] = {
566 &w1_master_attribute_name.attr,
567 &w1_master_attribute_slaves.attr,
568 &w1_master_attribute_slave_count.attr,
569 &w1_master_attribute_max_slave_count.attr,
570 &w1_master_attribute_attempts.attr,
571 &w1_master_attribute_timeout.attr,
572 &w1_master_attribute_timeout_us.attr,
573 &w1_master_attribute_pointer.attr,
574 &w1_master_attribute_search.attr,
575 &w1_master_attribute_pullup.attr,
576 &w1_master_attribute_add.attr,
577 &w1_master_attribute_remove.attr,
578 NULL
579};
580
581static struct attribute_group w1_master_defattr_group = {
582 .attrs = w1_master_default_attrs,
583};
584
585int w1_create_master_attributes(struct w1_master *master)
586{
587 return sysfs_create_group(&master->dev.kobj, &w1_master_defattr_group);
588}
589
590void w1_destroy_master_attributes(struct w1_master *master)
591{
592 sysfs_remove_group(&master->dev.kobj, &w1_master_defattr_group);
593}
594
595static int w1_uevent(struct device *dev, struct kobj_uevent_env *env)
596{
597 struct w1_master *md = NULL;
598 struct w1_slave *sl = NULL;
599 char *event_owner, *name;
600 int err = 0;
601
602 if (dev->driver == &w1_master_driver) {
603 md = container_of(dev, struct w1_master, dev);
604 event_owner = "master";
605 name = md->name;
606 } else if (dev->driver == &w1_slave_driver) {
607 sl = container_of(dev, struct w1_slave, dev);
608 event_owner = "slave";
609 name = sl->name;
610 } else {
611 dev_dbg(dev, "Unknown event.\n");
612 return -EINVAL;
613 }
614
615 dev_dbg(dev, "Hotplug event for %s %s, bus_id=%s.\n",
616 event_owner, name, dev_name(dev));
617
618 if (dev->driver != &w1_slave_driver || !sl)
619 goto end;
620
621 err = add_uevent_var(env, "W1_FID=%02X", sl->reg_num.family);
622 if (err)
623 goto end;
624
625 err = add_uevent_var(env, "W1_SLAVE_ID=%024LX",
626 (unsigned long long)sl->reg_num.id);
627end:
628 return err;
629}
630
631static int w1_family_notify(unsigned long action, struct w1_slave *sl)
632{
633 struct w1_family_ops *fops;
634 int err;
635
636 fops = sl->family->fops;
637
638 if (!fops)
639 return 0;
640
641 switch (action) {
642 case BUS_NOTIFY_ADD_DEVICE:
643 /* if the family driver needs to initialize something... */
644 if (fops->add_slave) {
645 err = fops->add_slave(sl);
646 if (err < 0) {
647 dev_err(&sl->dev,
648 "add_slave() call failed. err=%d\n",
649 err);
650 return err;
651 }
652 }
653 if (fops->groups) {
654 err = sysfs_create_groups(&sl->dev.kobj, fops->groups);
655 if (err) {
656 dev_err(&sl->dev,
657 "sysfs group creation failed. err=%d\n",
658 err);
659 return err;
660 }
661 }
662
663 break;
664 case BUS_NOTIFY_DEL_DEVICE:
665 if (fops->remove_slave)
666 sl->family->fops->remove_slave(sl);
667 if (fops->groups)
668 sysfs_remove_groups(&sl->dev.kobj, fops->groups);
669 break;
670 }
671 return 0;
672}
673
674static int __w1_attach_slave_device(struct w1_slave *sl)
675{
676 int err;
677
678 sl->dev.parent = &sl->master->dev;
679 sl->dev.driver = &w1_slave_driver;
680 sl->dev.bus = &w1_bus_type;
681 sl->dev.release = &w1_slave_release;
682 sl->dev.groups = w1_slave_groups;
683
684 dev_set_name(&sl->dev, "%02x-%012llx",
685 (unsigned int) sl->reg_num.family,
686 (unsigned long long) sl->reg_num.id);
687 snprintf(&sl->name[0], sizeof(sl->name),
688 "%02x-%012llx",
689 (unsigned int) sl->reg_num.family,
690 (unsigned long long) sl->reg_num.id);
691
692 dev_dbg(&sl->dev, "%s: registering %s as %p.\n", __func__,
693 dev_name(&sl->dev), sl);
694
695 /* suppress for w1_family_notify before sending KOBJ_ADD */
696 dev_set_uevent_suppress(&sl->dev, true);
697
698 err = device_register(&sl->dev);
699 if (err < 0) {
700 dev_err(&sl->dev,
701 "Device registration [%s] failed. err=%d\n",
702 dev_name(&sl->dev), err);
703 return err;
704 }
705 w1_family_notify(BUS_NOTIFY_ADD_DEVICE, sl);
706
707 dev_set_uevent_suppress(&sl->dev, false);
708 kobject_uevent(&sl->dev.kobj, KOBJ_ADD);
709
710 mutex_lock(&sl->master->list_mutex);
711 list_add_tail(&sl->w1_slave_entry, &sl->master->slist);
712 mutex_unlock(&sl->master->list_mutex);
713
714 return 0;
715}
716
717int w1_attach_slave_device(struct w1_master *dev, struct w1_reg_num *rn)
718{
719 struct w1_slave *sl;
720 struct w1_family *f;
721 int err;
722 struct w1_netlink_msg msg;
723
724 sl = kzalloc(sizeof(struct w1_slave), GFP_KERNEL);
725 if (!sl) {
726 dev_err(&dev->dev,
727 "%s: failed to allocate new slave device.\n",
728 __func__);
729 return -ENOMEM;
730 }
731
732
733 sl->owner = THIS_MODULE;
734 sl->master = dev;
735 set_bit(W1_SLAVE_ACTIVE, &sl->flags);
736
737 memset(&msg, 0, sizeof(msg));
738 memcpy(&sl->reg_num, rn, sizeof(sl->reg_num));
739 atomic_set(&sl->refcnt, 1);
740 atomic_inc(&sl->master->refcnt);
741
742 /* slave modules need to be loaded in a context with unlocked mutex */
743 mutex_unlock(&dev->mutex);
744 request_module("w1-family-0x%02x", rn->family);
745 mutex_lock(&dev->mutex);
746
747 spin_lock(&w1_flock);
748 f = w1_family_registered(rn->family);
749 if (!f) {
750 f= &w1_default_family;
751 dev_info(&dev->dev, "Family %x for %02x.%012llx.%02x is not registered.\n",
752 rn->family, rn->family,
753 (unsigned long long)rn->id, rn->crc);
754 }
755 __w1_family_get(f);
756 spin_unlock(&w1_flock);
757
758 sl->family = f;
759
760
761 err = __w1_attach_slave_device(sl);
762 if (err < 0) {
763 dev_err(&dev->dev, "%s: Attaching %s failed.\n", __func__,
764 sl->name);
765 w1_family_put(sl->family);
766 kfree(sl);
767 return err;
768 }
769
770 sl->ttl = dev->slave_ttl;
771 dev->slave_count++;
772
773 memcpy(msg.id.id, rn, sizeof(msg.id));
774 msg.type = W1_SLAVE_ADD;
775 w1_netlink_send(dev, &msg);
776
777 return 0;
778}
779
780int w1_unref_slave(struct w1_slave *sl)
781{
782 struct w1_master *dev = sl->master;
783 int refcnt;
784 mutex_lock(&dev->list_mutex);
785 refcnt = atomic_sub_return(1, &sl->refcnt);
786 if (refcnt == 0) {
787 struct w1_netlink_msg msg;
788
789 dev_dbg(&sl->dev, "%s: detaching %s [%p].\n", __func__,
790 sl->name, sl);
791
792 list_del(&sl->w1_slave_entry);
793
794 memset(&msg, 0, sizeof(msg));
795 memcpy(msg.id.id, &sl->reg_num, sizeof(msg.id));
796 msg.type = W1_SLAVE_REMOVE;
797 w1_netlink_send(sl->master, &msg);
798
799 w1_family_notify(BUS_NOTIFY_DEL_DEVICE, sl);
800 device_unregister(&sl->dev);
801 #ifdef DEBUG
802 memset(sl, 0, sizeof(*sl));
803 #endif
804 kfree(sl);
805 }
806 atomic_dec(&dev->refcnt);
807 mutex_unlock(&dev->list_mutex);
808 return refcnt;
809}
810
811int w1_slave_detach(struct w1_slave *sl)
812{
813 /* Only detach a slave once as it decreases the refcnt each time. */
814 int destroy_now;
815 mutex_lock(&sl->master->list_mutex);
816 destroy_now = !test_bit(W1_SLAVE_DETACH, &sl->flags);
817 set_bit(W1_SLAVE_DETACH, &sl->flags);
818 mutex_unlock(&sl->master->list_mutex);
819
820 if (destroy_now)
821 destroy_now = !w1_unref_slave(sl);
822 return destroy_now ? 0 : -EBUSY;
823}
824
825struct w1_master *w1_search_master_id(u32 id)
826{
827 struct w1_master *dev;
828 int found = 0;
829
830 mutex_lock(&w1_mlock);
831 list_for_each_entry(dev, &w1_masters, w1_master_entry) {
832 if (dev->id == id) {
833 found = 1;
834 atomic_inc(&dev->refcnt);
835 break;
836 }
837 }
838 mutex_unlock(&w1_mlock);
839
840 return (found)?dev:NULL;
841}
842
843struct w1_slave *w1_search_slave(struct w1_reg_num *id)
844{
845 struct w1_master *dev;
846 struct w1_slave *sl = NULL;
847 int found = 0;
848
849 mutex_lock(&w1_mlock);
850 list_for_each_entry(dev, &w1_masters, w1_master_entry) {
851 mutex_lock(&dev->list_mutex);
852 list_for_each_entry(sl, &dev->slist, w1_slave_entry) {
853 if (sl->reg_num.family == id->family &&
854 sl->reg_num.id == id->id &&
855 sl->reg_num.crc == id->crc) {
856 found = 1;
857 atomic_inc(&dev->refcnt);
858 atomic_inc(&sl->refcnt);
859 break;
860 }
861 }
862 mutex_unlock(&dev->list_mutex);
863
864 if (found)
865 break;
866 }
867 mutex_unlock(&w1_mlock);
868
869 return (found)?sl:NULL;
870}
871
872void w1_reconnect_slaves(struct w1_family *f, int attach)
873{
874 struct w1_slave *sl, *sln;
875 struct w1_master *dev;
876
877 mutex_lock(&w1_mlock);
878 list_for_each_entry(dev, &w1_masters, w1_master_entry) {
879 dev_dbg(&dev->dev, "Reconnecting slaves in device %s "
880 "for family %02x.\n", dev->name, f->fid);
881 mutex_lock(&dev->mutex);
882 mutex_lock(&dev->list_mutex);
883 list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) {
884 /* If it is a new family, slaves with the default
885 * family driver and are that family will be
886 * connected. If the family is going away, devices
887 * matching that family are reconneced.
888 */
889 if ((attach && sl->family->fid == W1_FAMILY_DEFAULT
890 && sl->reg_num.family == f->fid) ||
891 (!attach && sl->family->fid == f->fid)) {
892 struct w1_reg_num rn;
893
894 mutex_unlock(&dev->list_mutex);
895 memcpy(&rn, &sl->reg_num, sizeof(rn));
896 /* If it was already in use let the automatic
897 * scan pick it up again later.
898 */
899 if (!w1_slave_detach(sl))
900 w1_attach_slave_device(dev, &rn);
901 mutex_lock(&dev->list_mutex);
902 }
903 }
904 dev_dbg(&dev->dev, "Reconnecting slaves in device %s "
905 "has been finished.\n", dev->name);
906 mutex_unlock(&dev->list_mutex);
907 mutex_unlock(&dev->mutex);
908 }
909 mutex_unlock(&w1_mlock);
910}
911
912void w1_slave_found(struct w1_master *dev, u64 rn)
913{
914 struct w1_slave *sl;
915 struct w1_reg_num *tmp;
916 u64 rn_le = cpu_to_le64(rn);
917
918 atomic_inc(&dev->refcnt);
919
920 tmp = (struct w1_reg_num *) &rn;
921
922 sl = w1_slave_search_device(dev, tmp);
923 if (sl) {
924 set_bit(W1_SLAVE_ACTIVE, &sl->flags);
925 } else {
926 if (rn && tmp->crc == w1_calc_crc8((u8 *)&rn_le, 7))
927 w1_attach_slave_device(dev, tmp);
928 }
929
930 atomic_dec(&dev->refcnt);
931}
932
933/**
934 * w1_search() - Performs a ROM Search & registers any devices found.
935 * @dev: The master device to search
936 * @search_type: W1_SEARCH to search all devices, or W1_ALARM_SEARCH
937 * to return only devices in the alarmed state
938 * @cb: Function to call when a device is found
939 *
940 * The 1-wire search is a simple binary tree search.
941 * For each bit of the address, we read two bits and write one bit.
942 * The bit written will put to sleep all devies that don't match that bit.
943 * When the two reads differ, the direction choice is obvious.
944 * When both bits are 0, we must choose a path to take.
945 * When we can scan all 64 bits without having to choose a path, we are done.
946 *
947 * See "Application note 187 1-wire search algorithm" at www.maxim-ic.com
948 *
949 */
950void w1_search(struct w1_master *dev, u8 search_type, w1_slave_found_callback cb)
951{
952 u64 last_rn, rn, tmp64;
953 int i, slave_count = 0;
954 int last_zero, last_device;
955 int search_bit, desc_bit;
956 u8 triplet_ret = 0;
957
958 search_bit = 0;
959 rn = dev->search_id;
960 last_rn = 0;
961 last_device = 0;
962 last_zero = -1;
963
964 desc_bit = 64;
965
966 while ( !last_device && (slave_count++ < dev->max_slave_count) ) {
967 last_rn = rn;
968 rn = 0;
969
970 /*
971 * Reset bus and all 1-wire device state machines
972 * so they can respond to our requests.
973 *
974 * Return 0 - device(s) present, 1 - no devices present.
975 */
976 mutex_lock(&dev->bus_mutex);
977 if (w1_reset_bus(dev)) {
978 mutex_unlock(&dev->bus_mutex);
979 dev_dbg(&dev->dev, "No devices present on the wire.\n");
980 break;
981 }
982
983 /* Do fast search on single slave bus */
984 if (dev->max_slave_count == 1) {
985 int rv;
986 w1_write_8(dev, W1_READ_ROM);
987 rv = w1_read_block(dev, (u8 *)&rn, 8);
988 mutex_unlock(&dev->bus_mutex);
989
990 if (rv == 8 && rn)
991 cb(dev, rn);
992
993 break;
994 }
995
996 /* Start the search */
997 w1_write_8(dev, search_type);
998 for (i = 0; i < 64; ++i) {
999 /* Determine the direction/search bit */
1000 if (i == desc_bit)
1001 search_bit = 1; /* took the 0 path last time, so take the 1 path */
1002 else if (i > desc_bit)
1003 search_bit = 0; /* take the 0 path on the next branch */
1004 else
1005 search_bit = ((last_rn >> i) & 0x1);
1006
1007 /* Read two bits and write one bit */
1008 triplet_ret = w1_triplet(dev, search_bit);
1009
1010 /* quit if no device responded */
1011 if ( (triplet_ret & 0x03) == 0x03 )
1012 break;
1013
1014 /* If both directions were valid, and we took the 0 path... */
1015 if (triplet_ret == 0)
1016 last_zero = i;
1017
1018 /* extract the direction taken & update the device number */
1019 tmp64 = (triplet_ret >> 2);
1020 rn |= (tmp64 << i);
1021
1022 if (test_bit(W1_ABORT_SEARCH, &dev->flags)) {
1023 mutex_unlock(&dev->bus_mutex);
1024 dev_dbg(&dev->dev, "Abort w1_search\n");
1025 return;
1026 }
1027 }
1028 mutex_unlock(&dev->bus_mutex);
1029
1030 if ( (triplet_ret & 0x03) != 0x03 ) {
1031 if ((desc_bit == last_zero) || (last_zero < 0)) {
1032 last_device = 1;
1033 dev->search_id = 0;
1034 } else {
1035 dev->search_id = rn;
1036 }
1037 desc_bit = last_zero;
1038 cb(dev, rn);
1039 }
1040
1041 if (!last_device && slave_count == dev->max_slave_count &&
1042 !test_bit(W1_WARN_MAX_COUNT, &dev->flags)) {
1043 /* Only max_slave_count will be scanned in a search,
1044 * but it will start where it left off next search
1045 * until all ids are identified and then it will start
1046 * over. A continued search will report the previous
1047 * last id as the first id (provided it is still on the
1048 * bus).
1049 */
1050 dev_info(&dev->dev, "%s: max_slave_count %d reached, "
1051 "will continue next search.\n", __func__,
1052 dev->max_slave_count);
1053 set_bit(W1_WARN_MAX_COUNT, &dev->flags);
1054 }
1055 }
1056}
1057
1058void w1_search_process_cb(struct w1_master *dev, u8 search_type,
1059 w1_slave_found_callback cb)
1060{
1061 struct w1_slave *sl, *sln;
1062
1063 mutex_lock(&dev->list_mutex);
1064 list_for_each_entry(sl, &dev->slist, w1_slave_entry)
1065 clear_bit(W1_SLAVE_ACTIVE, &sl->flags);
1066 mutex_unlock(&dev->list_mutex);
1067
1068 w1_search_devices(dev, search_type, cb);
1069
1070 mutex_lock(&dev->list_mutex);
1071 list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) {
1072 if (!test_bit(W1_SLAVE_ACTIVE, &sl->flags) && !--sl->ttl) {
1073 mutex_unlock(&dev->list_mutex);
1074 w1_slave_detach(sl);
1075 mutex_lock(&dev->list_mutex);
1076 }
1077 else if (test_bit(W1_SLAVE_ACTIVE, &sl->flags))
1078 sl->ttl = dev->slave_ttl;
1079 }
1080 mutex_unlock(&dev->list_mutex);
1081
1082 if (dev->search_count > 0)
1083 dev->search_count--;
1084}
1085
1086static void w1_search_process(struct w1_master *dev, u8 search_type)
1087{
1088 w1_search_process_cb(dev, search_type, w1_slave_found);
1089}
1090
1091/**
1092 * w1_process_callbacks() - execute each dev->async_list callback entry
1093 * @dev: w1_master device
1094 *
1095 * The w1 master list_mutex must be held.
1096 *
1097 * Return: 1 if there were commands to executed 0 otherwise
1098 */
1099int w1_process_callbacks(struct w1_master *dev)
1100{
1101 int ret = 0;
1102 struct w1_async_cmd *async_cmd, *async_n;
1103
1104 /* The list can be added to in another thread, loop until it is empty */
1105 while (!list_empty(&dev->async_list)) {
1106 list_for_each_entry_safe(async_cmd, async_n, &dev->async_list,
1107 async_entry) {
1108 /* drop the lock, if it is a search it can take a long
1109 * time */
1110 mutex_unlock(&dev->list_mutex);
1111 async_cmd->cb(dev, async_cmd);
1112 ret = 1;
1113 mutex_lock(&dev->list_mutex);
1114 }
1115 }
1116 return ret;
1117}
1118
1119int w1_process(void *data)
1120{
1121 struct w1_master *dev = (struct w1_master *) data;
1122 /* As long as w1_timeout is only set by a module parameter the sleep
1123 * time can be calculated in jiffies once.
1124 */
1125 const unsigned long jtime =
1126 usecs_to_jiffies(w1_timeout * 1000000 + w1_timeout_us);
1127 /* remainder if it woke up early */
1128 unsigned long jremain = 0;
1129
1130 for (;;) {
1131
1132 if (!jremain && dev->search_count) {
1133 mutex_lock(&dev->mutex);
1134 w1_search_process(dev, W1_SEARCH);
1135 mutex_unlock(&dev->mutex);
1136 }
1137
1138 mutex_lock(&dev->list_mutex);
1139 /* Note, w1_process_callback drops the lock while processing,
1140 * but locks it again before returning.
1141 */
1142 if (!w1_process_callbacks(dev) && jremain) {
1143 /* a wake up is either to stop the thread, process
1144 * callbacks, or search, it isn't process callbacks, so
1145 * schedule a search.
1146 */
1147 jremain = 1;
1148 }
1149
1150 __set_current_state(TASK_INTERRUPTIBLE);
1151
1152 /* hold list_mutex until after interruptible to prevent loosing
1153 * the wakeup signal when async_cmd is added.
1154 */
1155 mutex_unlock(&dev->list_mutex);
1156
1157 if (kthread_should_stop())
1158 break;
1159
1160 /* Only sleep when the search is active. */
1161 if (dev->search_count) {
1162 if (!jremain)
1163 jremain = jtime;
1164 jremain = schedule_timeout(jremain);
1165 }
1166 else
1167 schedule();
1168 }
1169
1170 atomic_dec(&dev->refcnt);
1171
1172 return 0;
1173}
1174
1175static int __init w1_init(void)
1176{
1177 int retval;
1178
1179 pr_info("Driver for 1-wire Dallas network protocol.\n");
1180
1181 w1_init_netlink();
1182
1183 retval = bus_register(&w1_bus_type);
1184 if (retval) {
1185 pr_err("Failed to register bus. err=%d.\n", retval);
1186 goto err_out_exit_init;
1187 }
1188
1189 retval = driver_register(&w1_master_driver);
1190 if (retval) {
1191 pr_err("Failed to register master driver. err=%d.\n",
1192 retval);
1193 goto err_out_bus_unregister;
1194 }
1195
1196 retval = driver_register(&w1_slave_driver);
1197 if (retval) {
1198 pr_err("Failed to register slave driver. err=%d.\n",
1199 retval);
1200 goto err_out_master_unregister;
1201 }
1202
1203 return 0;
1204
1205#if 0
1206/* For undoing the slave register if there was a step after it. */
1207err_out_slave_unregister:
1208 driver_unregister(&w1_slave_driver);
1209#endif
1210
1211err_out_master_unregister:
1212 driver_unregister(&w1_master_driver);
1213
1214err_out_bus_unregister:
1215 bus_unregister(&w1_bus_type);
1216
1217err_out_exit_init:
1218 return retval;
1219}
1220
1221static void __exit w1_fini(void)
1222{
1223 struct w1_master *dev;
1224
1225 /* Set netlink removal messages and some cleanup */
1226 list_for_each_entry(dev, &w1_masters, w1_master_entry)
1227 __w1_remove_master_device(dev);
1228
1229 w1_fini_netlink();
1230
1231 driver_unregister(&w1_slave_driver);
1232 driver_unregister(&w1_master_driver);
1233 bus_unregister(&w1_bus_type);
1234}
1235
1236module_init(w1_init);
1237module_exit(w1_fini);
1// 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 = 0;
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_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 [%p]\n", __func__, sl->name, sl);
85
86 w1_family_put(sl->family);
87 sl->master->slave_count--;
88}
89
90static ssize_t name_show(struct device *dev, struct device_attribute *attr, char *buf)
91{
92 struct w1_slave *sl = dev_to_w1_slave(dev);
93
94 return sprintf(buf, "%s\n", sl->name);
95}
96static DEVICE_ATTR_RO(name);
97
98static ssize_t id_show(struct device *dev,
99 struct device_attribute *attr, char *buf)
100{
101 struct w1_slave *sl = dev_to_w1_slave(dev);
102 ssize_t count = sizeof(sl->reg_num);
103
104 memcpy(buf, (u8 *)&sl->reg_num, count);
105 return count;
106}
107static DEVICE_ATTR_RO(id);
108
109static struct attribute *w1_slave_attrs[] = {
110 &dev_attr_name.attr,
111 &dev_attr_id.attr,
112 NULL,
113};
114ATTRIBUTE_GROUPS(w1_slave);
115
116/* Default family */
117
118static ssize_t rw_write(struct file *filp, struct kobject *kobj,
119 struct bin_attribute *bin_attr, char *buf, loff_t off,
120 size_t count)
121{
122 struct w1_slave *sl = kobj_to_w1_slave(kobj);
123
124 mutex_lock(&sl->master->mutex);
125 if (w1_reset_select_slave(sl)) {
126 count = 0;
127 goto out_up;
128 }
129
130 w1_write_block(sl->master, buf, count);
131
132out_up:
133 mutex_unlock(&sl->master->mutex);
134 return count;
135}
136
137static ssize_t rw_read(struct file *filp, struct kobject *kobj,
138 struct bin_attribute *bin_attr, char *buf, loff_t off,
139 size_t count)
140{
141 struct w1_slave *sl = kobj_to_w1_slave(kobj);
142
143 mutex_lock(&sl->master->mutex);
144 w1_read_block(sl->master, buf, count);
145 mutex_unlock(&sl->master->mutex);
146 return count;
147}
148
149static BIN_ATTR_RW(rw, PAGE_SIZE);
150
151static struct bin_attribute *w1_slave_bin_attrs[] = {
152 &bin_attr_rw,
153 NULL,
154};
155
156static const struct attribute_group w1_slave_default_group = {
157 .bin_attrs = w1_slave_bin_attrs,
158};
159
160static const struct attribute_group *w1_slave_default_groups[] = {
161 &w1_slave_default_group,
162 NULL,
163};
164
165static const struct w1_family_ops w1_default_fops = {
166 .groups = w1_slave_default_groups,
167};
168
169static struct w1_family w1_default_family = {
170 .fops = &w1_default_fops,
171};
172
173static int w1_uevent(struct device *dev, struct kobj_uevent_env *env);
174
175static struct bus_type w1_bus_type = {
176 .name = "w1",
177 .match = w1_master_match,
178 .uevent = w1_uevent,
179};
180
181struct device_driver w1_master_driver = {
182 .name = "w1_master_driver",
183 .bus = &w1_bus_type,
184 .probe = w1_master_probe,
185};
186
187struct device w1_master_device = {
188 .parent = NULL,
189 .bus = &w1_bus_type,
190 .init_name = "w1 bus master",
191 .driver = &w1_master_driver,
192 .release = &w1_master_release
193};
194
195static struct device_driver w1_slave_driver = {
196 .name = "w1_slave_driver",
197 .bus = &w1_bus_type,
198};
199
200#if 0
201struct device w1_slave_device = {
202 .parent = NULL,
203 .bus = &w1_bus_type,
204 .init_name = "w1 bus slave",
205 .driver = &w1_slave_driver,
206 .release = &w1_slave_release
207};
208#endif /* 0 */
209
210static ssize_t w1_master_attribute_show_name(struct device *dev, struct device_attribute *attr, char *buf)
211{
212 struct w1_master *md = dev_to_w1_master(dev);
213 ssize_t count;
214
215 mutex_lock(&md->mutex);
216 count = sprintf(buf, "%s\n", md->name);
217 mutex_unlock(&md->mutex);
218
219 return count;
220}
221
222static ssize_t w1_master_attribute_store_search(struct device * dev,
223 struct device_attribute *attr,
224 const char * buf, size_t count)
225{
226 long tmp;
227 struct w1_master *md = dev_to_w1_master(dev);
228 int ret;
229
230 ret = kstrtol(buf, 0, &tmp);
231 if (ret)
232 return ret;
233
234 mutex_lock(&md->mutex);
235 md->search_count = tmp;
236 mutex_unlock(&md->mutex);
237 /* Only wake if it is going to be searching. */
238 if (tmp)
239 wake_up_process(md->thread);
240
241 return count;
242}
243
244static ssize_t w1_master_attribute_show_search(struct device *dev,
245 struct device_attribute *attr,
246 char *buf)
247{
248 struct w1_master *md = dev_to_w1_master(dev);
249 ssize_t count;
250
251 mutex_lock(&md->mutex);
252 count = sprintf(buf, "%d\n", md->search_count);
253 mutex_unlock(&md->mutex);
254
255 return count;
256}
257
258static ssize_t w1_master_attribute_store_pullup(struct device *dev,
259 struct device_attribute *attr,
260 const char *buf, size_t count)
261{
262 long tmp;
263 struct w1_master *md = dev_to_w1_master(dev);
264 int ret;
265
266 ret = kstrtol(buf, 0, &tmp);
267 if (ret)
268 return ret;
269
270 mutex_lock(&md->mutex);
271 md->enable_pullup = tmp;
272 mutex_unlock(&md->mutex);
273
274 return count;
275}
276
277static ssize_t w1_master_attribute_show_pullup(struct device *dev,
278 struct device_attribute *attr,
279 char *buf)
280{
281 struct w1_master *md = dev_to_w1_master(dev);
282 ssize_t count;
283
284 mutex_lock(&md->mutex);
285 count = sprintf(buf, "%d\n", md->enable_pullup);
286 mutex_unlock(&md->mutex);
287
288 return count;
289}
290
291static ssize_t w1_master_attribute_show_pointer(struct device *dev, struct device_attribute *attr, char *buf)
292{
293 struct w1_master *md = dev_to_w1_master(dev);
294 ssize_t count;
295
296 mutex_lock(&md->mutex);
297 count = sprintf(buf, "0x%p\n", md->bus_master);
298 mutex_unlock(&md->mutex);
299 return count;
300}
301
302static ssize_t w1_master_attribute_show_timeout(struct device *dev, struct device_attribute *attr, char *buf)
303{
304 ssize_t count;
305 count = sprintf(buf, "%d\n", w1_timeout);
306 return count;
307}
308
309static ssize_t w1_master_attribute_show_timeout_us(struct device *dev,
310 struct device_attribute *attr, char *buf)
311{
312 ssize_t count;
313 count = sprintf(buf, "%d\n", w1_timeout_us);
314 return count;
315}
316
317static ssize_t w1_master_attribute_store_max_slave_count(struct device *dev,
318 struct device_attribute *attr, const char *buf, size_t count)
319{
320 int tmp;
321 struct w1_master *md = dev_to_w1_master(dev);
322
323 if (kstrtoint(buf, 0, &tmp) || tmp < 1)
324 return -EINVAL;
325
326 mutex_lock(&md->mutex);
327 md->max_slave_count = tmp;
328 /* allow each time the max_slave_count is updated */
329 clear_bit(W1_WARN_MAX_COUNT, &md->flags);
330 mutex_unlock(&md->mutex);
331
332 return count;
333}
334
335static ssize_t w1_master_attribute_show_max_slave_count(struct device *dev, struct device_attribute *attr, char *buf)
336{
337 struct w1_master *md = dev_to_w1_master(dev);
338 ssize_t count;
339
340 mutex_lock(&md->mutex);
341 count = sprintf(buf, "%d\n", md->max_slave_count);
342 mutex_unlock(&md->mutex);
343 return count;
344}
345
346static ssize_t w1_master_attribute_show_attempts(struct device *dev, struct device_attribute *attr, char *buf)
347{
348 struct w1_master *md = dev_to_w1_master(dev);
349 ssize_t count;
350
351 mutex_lock(&md->mutex);
352 count = sprintf(buf, "%lu\n", md->attempts);
353 mutex_unlock(&md->mutex);
354 return count;
355}
356
357static ssize_t w1_master_attribute_show_slave_count(struct device *dev, struct device_attribute *attr, char *buf)
358{
359 struct w1_master *md = dev_to_w1_master(dev);
360 ssize_t count;
361
362 mutex_lock(&md->mutex);
363 count = sprintf(buf, "%d\n", md->slave_count);
364 mutex_unlock(&md->mutex);
365 return count;
366}
367
368static ssize_t w1_master_attribute_show_slaves(struct device *dev,
369 struct device_attribute *attr, char *buf)
370{
371 struct w1_master *md = dev_to_w1_master(dev);
372 int c = PAGE_SIZE;
373 struct list_head *ent, *n;
374 struct w1_slave *sl = NULL;
375
376 mutex_lock(&md->list_mutex);
377
378 list_for_each_safe(ent, n, &md->slist) {
379 sl = list_entry(ent, struct w1_slave, w1_slave_entry);
380
381 c -= snprintf(buf + PAGE_SIZE - c, c, "%s\n", sl->name);
382 }
383 if (!sl)
384 c -= snprintf(buf + PAGE_SIZE - c, c, "not found.\n");
385
386 mutex_unlock(&md->list_mutex);
387
388 return PAGE_SIZE - c;
389}
390
391static ssize_t w1_master_attribute_show_add(struct device *dev,
392 struct device_attribute *attr, char *buf)
393{
394 int c = PAGE_SIZE;
395 c -= snprintf(buf+PAGE_SIZE - c, c,
396 "write device id xx-xxxxxxxxxxxx to add slave\n");
397 return PAGE_SIZE - c;
398}
399
400static int w1_atoreg_num(struct device *dev, const char *buf, size_t count,
401 struct w1_reg_num *rn)
402{
403 unsigned int family;
404 unsigned long long id;
405 int i;
406 u64 rn64_le;
407
408 /* The CRC value isn't read from the user because the sysfs directory
409 * doesn't include it and most messages from the bus search don't
410 * print it either. It would be unreasonable for the user to then
411 * provide it.
412 */
413 const char *error_msg = "bad slave string format, expecting "
414 "ff-dddddddddddd\n";
415
416 if (buf[2] != '-') {
417 dev_err(dev, "%s", error_msg);
418 return -EINVAL;
419 }
420 i = sscanf(buf, "%02x-%012llx", &family, &id);
421 if (i != 2) {
422 dev_err(dev, "%s", error_msg);
423 return -EINVAL;
424 }
425 rn->family = family;
426 rn->id = id;
427
428 rn64_le = cpu_to_le64(*(u64 *)rn);
429 rn->crc = w1_calc_crc8((u8 *)&rn64_le, 7);
430
431#if 0
432 dev_info(dev, "With CRC device is %02x.%012llx.%02x.\n",
433 rn->family, (unsigned long long)rn->id, rn->crc);
434#endif
435
436 return 0;
437}
438
439/* Searches the slaves in the w1_master and returns a pointer or NULL.
440 * Note: must not hold list_mutex
441 */
442struct w1_slave *w1_slave_search_device(struct w1_master *dev,
443 struct w1_reg_num *rn)
444{
445 struct w1_slave *sl;
446 mutex_lock(&dev->list_mutex);
447 list_for_each_entry(sl, &dev->slist, w1_slave_entry) {
448 if (sl->reg_num.family == rn->family &&
449 sl->reg_num.id == rn->id &&
450 sl->reg_num.crc == rn->crc) {
451 mutex_unlock(&dev->list_mutex);
452 return sl;
453 }
454 }
455 mutex_unlock(&dev->list_mutex);
456 return NULL;
457}
458
459static ssize_t w1_master_attribute_store_add(struct device *dev,
460 struct device_attribute *attr,
461 const char *buf, size_t count)
462{
463 struct w1_master *md = dev_to_w1_master(dev);
464 struct w1_reg_num rn;
465 struct w1_slave *sl;
466 ssize_t result = count;
467
468 if (w1_atoreg_num(dev, buf, count, &rn))
469 return -EINVAL;
470
471 mutex_lock(&md->mutex);
472 sl = w1_slave_search_device(md, &rn);
473 /* It would be nice to do a targeted search one the one-wire bus
474 * for the new device to see if it is out there or not. But the
475 * current search doesn't support that.
476 */
477 if (sl) {
478 dev_info(dev, "Device %s already exists\n", sl->name);
479 result = -EINVAL;
480 } else {
481 w1_attach_slave_device(md, &rn);
482 }
483 mutex_unlock(&md->mutex);
484
485 return result;
486}
487
488static ssize_t w1_master_attribute_show_remove(struct device *dev,
489 struct device_attribute *attr, char *buf)
490{
491 int c = PAGE_SIZE;
492 c -= snprintf(buf+PAGE_SIZE - c, c,
493 "write device id xx-xxxxxxxxxxxx to remove slave\n");
494 return PAGE_SIZE - c;
495}
496
497static ssize_t w1_master_attribute_store_remove(struct device *dev,
498 struct device_attribute *attr,
499 const char *buf, size_t count)
500{
501 struct w1_master *md = dev_to_w1_master(dev);
502 struct w1_reg_num rn;
503 struct w1_slave *sl;
504 ssize_t result = count;
505
506 if (w1_atoreg_num(dev, buf, count, &rn))
507 return -EINVAL;
508
509 mutex_lock(&md->mutex);
510 sl = w1_slave_search_device(md, &rn);
511 if (sl) {
512 result = w1_slave_detach(sl);
513 /* refcnt 0 means it was detached in the call */
514 if (result == 0)
515 result = count;
516 } else {
517 dev_info(dev, "Device %02x-%012llx doesn't exists\n", rn.family,
518 (unsigned long long)rn.id);
519 result = -EINVAL;
520 }
521 mutex_unlock(&md->mutex);
522
523 return result;
524}
525
526#define W1_MASTER_ATTR_RO(_name, _mode) \
527 struct device_attribute w1_master_attribute_##_name = \
528 __ATTR(w1_master_##_name, _mode, \
529 w1_master_attribute_show_##_name, NULL)
530
531#define W1_MASTER_ATTR_RW(_name, _mode) \
532 struct device_attribute w1_master_attribute_##_name = \
533 __ATTR(w1_master_##_name, _mode, \
534 w1_master_attribute_show_##_name, \
535 w1_master_attribute_store_##_name)
536
537static W1_MASTER_ATTR_RO(name, S_IRUGO);
538static W1_MASTER_ATTR_RO(slaves, S_IRUGO);
539static W1_MASTER_ATTR_RO(slave_count, S_IRUGO);
540static W1_MASTER_ATTR_RW(max_slave_count, S_IRUGO | S_IWUSR | S_IWGRP);
541static W1_MASTER_ATTR_RO(attempts, S_IRUGO);
542static W1_MASTER_ATTR_RO(timeout, S_IRUGO);
543static W1_MASTER_ATTR_RO(timeout_us, S_IRUGO);
544static W1_MASTER_ATTR_RO(pointer, S_IRUGO);
545static W1_MASTER_ATTR_RW(search, S_IRUGO | S_IWUSR | S_IWGRP);
546static W1_MASTER_ATTR_RW(pullup, S_IRUGO | S_IWUSR | S_IWGRP);
547static W1_MASTER_ATTR_RW(add, S_IRUGO | S_IWUSR | S_IWGRP);
548static W1_MASTER_ATTR_RW(remove, S_IRUGO | S_IWUSR | S_IWGRP);
549
550static struct attribute *w1_master_default_attrs[] = {
551 &w1_master_attribute_name.attr,
552 &w1_master_attribute_slaves.attr,
553 &w1_master_attribute_slave_count.attr,
554 &w1_master_attribute_max_slave_count.attr,
555 &w1_master_attribute_attempts.attr,
556 &w1_master_attribute_timeout.attr,
557 &w1_master_attribute_timeout_us.attr,
558 &w1_master_attribute_pointer.attr,
559 &w1_master_attribute_search.attr,
560 &w1_master_attribute_pullup.attr,
561 &w1_master_attribute_add.attr,
562 &w1_master_attribute_remove.attr,
563 NULL
564};
565
566static const struct attribute_group w1_master_defattr_group = {
567 .attrs = w1_master_default_attrs,
568};
569
570int w1_create_master_attributes(struct w1_master *master)
571{
572 return sysfs_create_group(&master->dev.kobj, &w1_master_defattr_group);
573}
574
575void w1_destroy_master_attributes(struct w1_master *master)
576{
577 sysfs_remove_group(&master->dev.kobj, &w1_master_defattr_group);
578}
579
580static int w1_uevent(struct device *dev, struct kobj_uevent_env *env)
581{
582 struct w1_master *md = NULL;
583 struct w1_slave *sl = NULL;
584 char *event_owner, *name;
585 int err = 0;
586
587 if (dev->driver == &w1_master_driver) {
588 md = container_of(dev, struct w1_master, dev);
589 event_owner = "master";
590 name = md->name;
591 } else if (dev->driver == &w1_slave_driver) {
592 sl = container_of(dev, struct w1_slave, dev);
593 event_owner = "slave";
594 name = sl->name;
595 } else {
596 dev_dbg(dev, "Unknown event.\n");
597 return -EINVAL;
598 }
599
600 dev_dbg(dev, "Hotplug event for %s %s, bus_id=%s.\n",
601 event_owner, name, dev_name(dev));
602
603 if (dev->driver != &w1_slave_driver || !sl)
604 goto end;
605
606 err = add_uevent_var(env, "W1_FID=%02X", sl->reg_num.family);
607 if (err)
608 goto end;
609
610 err = add_uevent_var(env, "W1_SLAVE_ID=%024LX",
611 (unsigned long long)sl->reg_num.id);
612end:
613 return err;
614}
615
616static int w1_family_notify(unsigned long action, struct w1_slave *sl)
617{
618 const struct w1_family_ops *fops;
619 int err;
620
621 fops = sl->family->fops;
622
623 if (!fops)
624 return 0;
625
626 switch (action) {
627 case BUS_NOTIFY_ADD_DEVICE:
628 /* if the family driver needs to initialize something... */
629 if (fops->add_slave) {
630 err = fops->add_slave(sl);
631 if (err < 0) {
632 dev_err(&sl->dev,
633 "add_slave() call failed. err=%d\n",
634 err);
635 return err;
636 }
637 }
638 if (fops->groups) {
639 err = sysfs_create_groups(&sl->dev.kobj, fops->groups);
640 if (err) {
641 dev_err(&sl->dev,
642 "sysfs group creation failed. err=%d\n",
643 err);
644 return err;
645 }
646 }
647 if (IS_REACHABLE(CONFIG_HWMON) && fops->chip_info) {
648 struct device *hwmon
649 = hwmon_device_register_with_info(&sl->dev,
650 "w1_slave_temp", sl,
651 fops->chip_info,
652 NULL);
653 if (IS_ERR(hwmon)) {
654 dev_warn(&sl->dev,
655 "could not create hwmon device\n");
656 } else {
657 sl->hwmon = hwmon;
658 }
659 }
660 break;
661 case BUS_NOTIFY_DEL_DEVICE:
662 if (IS_REACHABLE(CONFIG_HWMON) && fops->chip_info &&
663 sl->hwmon)
664 hwmon_device_unregister(sl->hwmon);
665 if (fops->remove_slave)
666 sl->family->fops->remove_slave(sl);
667 if (fops->groups)
668 sysfs_remove_groups(&sl->dev.kobj, fops->groups);
669 break;
670 }
671 return 0;
672}
673
674static int __w1_attach_slave_device(struct w1_slave *sl)
675{
676 int err;
677
678 sl->dev.parent = &sl->master->dev;
679 sl->dev.driver = &w1_slave_driver;
680 sl->dev.bus = &w1_bus_type;
681 sl->dev.release = &w1_slave_release;
682 sl->dev.groups = w1_slave_groups;
683 sl->dev.of_node = of_find_matching_node(sl->master->dev.of_node,
684 sl->family->of_match_table);
685
686 dev_set_name(&sl->dev, "%02x-%012llx",
687 (unsigned int) sl->reg_num.family,
688 (unsigned long long) sl->reg_num.id);
689 snprintf(&sl->name[0], sizeof(sl->name),
690 "%02x-%012llx",
691 (unsigned int) sl->reg_num.family,
692 (unsigned long long) sl->reg_num.id);
693
694 dev_dbg(&sl->dev, "%s: registering %s as %p.\n", __func__,
695 dev_name(&sl->dev), sl);
696
697 /* suppress for w1_family_notify before sending KOBJ_ADD */
698 dev_set_uevent_suppress(&sl->dev, true);
699
700 err = device_register(&sl->dev);
701 if (err < 0) {
702 dev_err(&sl->dev,
703 "Device registration [%s] failed. err=%d\n",
704 dev_name(&sl->dev), err);
705 put_device(&sl->dev);
706 return err;
707 }
708 w1_family_notify(BUS_NOTIFY_ADD_DEVICE, sl);
709
710 dev_set_uevent_suppress(&sl->dev, false);
711 kobject_uevent(&sl->dev.kobj, KOBJ_ADD);
712
713 mutex_lock(&sl->master->list_mutex);
714 list_add_tail(&sl->w1_slave_entry, &sl->master->slist);
715 mutex_unlock(&sl->master->list_mutex);
716
717 return 0;
718}
719
720int w1_attach_slave_device(struct w1_master *dev, struct w1_reg_num *rn)
721{
722 struct w1_slave *sl;
723 struct w1_family *f;
724 int err;
725 struct w1_netlink_msg msg;
726
727 sl = kzalloc(sizeof(struct w1_slave), GFP_KERNEL);
728 if (!sl) {
729 dev_err(&dev->dev,
730 "%s: failed to allocate new slave device.\n",
731 __func__);
732 return -ENOMEM;
733 }
734
735
736 sl->owner = THIS_MODULE;
737 sl->master = dev;
738 set_bit(W1_SLAVE_ACTIVE, &sl->flags);
739
740 memset(&msg, 0, sizeof(msg));
741 memcpy(&sl->reg_num, rn, sizeof(sl->reg_num));
742 atomic_set(&sl->refcnt, 1);
743 atomic_inc(&sl->master->refcnt);
744 dev->slave_count++;
745 dev_info(&dev->dev, "Attaching one wire slave %02x.%012llx crc %02x\n",
746 rn->family, (unsigned long long)rn->id, rn->crc);
747
748 /* slave modules need to be loaded in a context with unlocked mutex */
749 mutex_unlock(&dev->mutex);
750 request_module("w1-family-0x%02X", rn->family);
751 mutex_lock(&dev->mutex);
752
753 spin_lock(&w1_flock);
754 f = w1_family_registered(rn->family);
755 if (!f) {
756 f= &w1_default_family;
757 dev_info(&dev->dev, "Family %x for %02x.%012llx.%02x is not registered.\n",
758 rn->family, rn->family,
759 (unsigned long long)rn->id, rn->crc);
760 }
761 __w1_family_get(f);
762 spin_unlock(&w1_flock);
763
764 sl->family = f;
765
766 err = __w1_attach_slave_device(sl);
767 if (err < 0) {
768 dev_err(&dev->dev, "%s: Attaching %s failed.\n", __func__,
769 sl->name);
770 dev->slave_count--;
771 w1_family_put(sl->family);
772 atomic_dec(&sl->master->refcnt);
773 kfree(sl);
774 return err;
775 }
776
777 sl->ttl = dev->slave_ttl;
778
779 memcpy(msg.id.id, rn, sizeof(msg.id));
780 msg.type = W1_SLAVE_ADD;
781 w1_netlink_send(dev, &msg);
782
783 return 0;
784}
785
786int w1_unref_slave(struct w1_slave *sl)
787{
788 struct w1_master *dev = sl->master;
789 int refcnt;
790 mutex_lock(&dev->list_mutex);
791 refcnt = atomic_sub_return(1, &sl->refcnt);
792 if (refcnt == 0) {
793 struct w1_netlink_msg msg;
794
795 dev_dbg(&sl->dev, "%s: detaching %s [%p].\n", __func__,
796 sl->name, sl);
797
798 list_del(&sl->w1_slave_entry);
799
800 memset(&msg, 0, sizeof(msg));
801 memcpy(msg.id.id, &sl->reg_num, sizeof(msg.id));
802 msg.type = W1_SLAVE_REMOVE;
803 w1_netlink_send(sl->master, &msg);
804
805 w1_family_notify(BUS_NOTIFY_DEL_DEVICE, sl);
806 device_unregister(&sl->dev);
807 #ifdef DEBUG
808 memset(sl, 0, sizeof(*sl));
809 #endif
810 kfree(sl);
811 }
812 atomic_dec(&dev->refcnt);
813 mutex_unlock(&dev->list_mutex);
814 return refcnt;
815}
816
817int w1_slave_detach(struct w1_slave *sl)
818{
819 /* Only detach a slave once as it decreases the refcnt each time. */
820 int destroy_now;
821 mutex_lock(&sl->master->list_mutex);
822 destroy_now = !test_bit(W1_SLAVE_DETACH, &sl->flags);
823 set_bit(W1_SLAVE_DETACH, &sl->flags);
824 mutex_unlock(&sl->master->list_mutex);
825
826 if (destroy_now)
827 destroy_now = !w1_unref_slave(sl);
828 return destroy_now ? 0 : -EBUSY;
829}
830
831struct w1_master *w1_search_master_id(u32 id)
832{
833 struct w1_master *dev;
834 int found = 0;
835
836 mutex_lock(&w1_mlock);
837 list_for_each_entry(dev, &w1_masters, w1_master_entry) {
838 if (dev->id == id) {
839 found = 1;
840 atomic_inc(&dev->refcnt);
841 break;
842 }
843 }
844 mutex_unlock(&w1_mlock);
845
846 return (found)?dev:NULL;
847}
848
849struct w1_slave *w1_search_slave(struct w1_reg_num *id)
850{
851 struct w1_master *dev;
852 struct w1_slave *sl = NULL;
853 int found = 0;
854
855 mutex_lock(&w1_mlock);
856 list_for_each_entry(dev, &w1_masters, w1_master_entry) {
857 mutex_lock(&dev->list_mutex);
858 list_for_each_entry(sl, &dev->slist, w1_slave_entry) {
859 if (sl->reg_num.family == id->family &&
860 sl->reg_num.id == id->id &&
861 sl->reg_num.crc == id->crc) {
862 found = 1;
863 atomic_inc(&dev->refcnt);
864 atomic_inc(&sl->refcnt);
865 break;
866 }
867 }
868 mutex_unlock(&dev->list_mutex);
869
870 if (found)
871 break;
872 }
873 mutex_unlock(&w1_mlock);
874
875 return (found)?sl:NULL;
876}
877
878void w1_reconnect_slaves(struct w1_family *f, int attach)
879{
880 struct w1_slave *sl, *sln;
881 struct w1_master *dev;
882
883 mutex_lock(&w1_mlock);
884 list_for_each_entry(dev, &w1_masters, w1_master_entry) {
885 dev_dbg(&dev->dev, "Reconnecting slaves in device %s "
886 "for family %02x.\n", dev->name, f->fid);
887 mutex_lock(&dev->mutex);
888 mutex_lock(&dev->list_mutex);
889 list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) {
890 /* If it is a new family, slaves with the default
891 * family driver and are that family will be
892 * connected. If the family is going away, devices
893 * matching that family are reconneced.
894 */
895 if ((attach && sl->family->fid == W1_FAMILY_DEFAULT
896 && sl->reg_num.family == f->fid) ||
897 (!attach && sl->family->fid == f->fid)) {
898 struct w1_reg_num rn;
899
900 mutex_unlock(&dev->list_mutex);
901 memcpy(&rn, &sl->reg_num, sizeof(rn));
902 /* If it was already in use let the automatic
903 * scan pick it up again later.
904 */
905 if (!w1_slave_detach(sl))
906 w1_attach_slave_device(dev, &rn);
907 mutex_lock(&dev->list_mutex);
908 }
909 }
910 dev_dbg(&dev->dev, "Reconnecting slaves in device %s "
911 "has been finished.\n", dev->name);
912 mutex_unlock(&dev->list_mutex);
913 mutex_unlock(&dev->mutex);
914 }
915 mutex_unlock(&w1_mlock);
916}
917
918static int w1_addr_crc_is_valid(struct w1_master *dev, u64 rn)
919{
920 u64 rn_le = cpu_to_le64(rn);
921 struct w1_reg_num *tmp = (struct w1_reg_num *)&rn;
922 u8 crc;
923
924 crc = w1_calc_crc8((u8 *)&rn_le, 7);
925
926 /* quirk:
927 * DS28E04 (1w eeprom) has strapping pins to change
928 * address, but will not update the crc. So normal rules
929 * for consistent w1 addresses are violated. We test
930 * with the 7 LSBs of the address forced high.
931 *
932 * (char*)&rn_le = { family, addr_lsb, ..., addr_msb, crc }.
933 */
934 if (crc != tmp->crc && tmp->family == W1_FAMILY_DS28E04) {
935 u64 corr_le = rn_le;
936
937 ((u8 *)&corr_le)[1] |= 0x7f;
938 crc = w1_calc_crc8((u8 *)&corr_le, 7);
939
940 dev_info(&dev->dev, "DS28E04 crc workaround on %02x.%012llx.%02x\n",
941 tmp->family, (unsigned long long)tmp->id, tmp->crc);
942 }
943
944 if (crc != tmp->crc) {
945 dev_dbg(&dev->dev, "w1 addr crc mismatch: %02x.%012llx.%02x != 0x%02x.\n",
946 tmp->family, (unsigned long long)tmp->id, tmp->crc, crc);
947 return 0;
948 }
949 return 1;
950}
951
952void w1_slave_found(struct w1_master *dev, u64 rn)
953{
954 struct w1_slave *sl;
955 struct w1_reg_num *tmp;
956
957 atomic_inc(&dev->refcnt);
958
959 tmp = (struct w1_reg_num *) &rn;
960
961 sl = w1_slave_search_device(dev, tmp);
962 if (sl) {
963 set_bit(W1_SLAVE_ACTIVE, &sl->flags);
964 } else {
965 if (rn && w1_addr_crc_is_valid(dev, rn))
966 w1_attach_slave_device(dev, tmp);
967 }
968
969 atomic_dec(&dev->refcnt);
970}
971
972/**
973 * w1_search() - Performs a ROM Search & registers any devices found.
974 * @dev: The master device to search
975 * @search_type: W1_SEARCH to search all devices, or W1_ALARM_SEARCH
976 * to return only devices in the alarmed state
977 * @cb: Function to call when a device is found
978 *
979 * The 1-wire search is a simple binary tree search.
980 * For each bit of the address, we read two bits and write one bit.
981 * The bit written will put to sleep all devies that don't match that bit.
982 * When the two reads differ, the direction choice is obvious.
983 * When both bits are 0, we must choose a path to take.
984 * When we can scan all 64 bits without having to choose a path, we are done.
985 *
986 * See "Application note 187 1-wire search algorithm" at www.maxim-ic.com
987 *
988 */
989void w1_search(struct w1_master *dev, u8 search_type, w1_slave_found_callback cb)
990{
991 u64 last_rn, rn, tmp64;
992 int i, slave_count = 0;
993 int last_zero, last_device;
994 int search_bit, desc_bit;
995 u8 triplet_ret = 0;
996
997 search_bit = 0;
998 rn = dev->search_id;
999 last_rn = 0;
1000 last_device = 0;
1001 last_zero = -1;
1002
1003 desc_bit = 64;
1004
1005 while ( !last_device && (slave_count++ < dev->max_slave_count) ) {
1006 last_rn = rn;
1007 rn = 0;
1008
1009 /*
1010 * Reset bus and all 1-wire device state machines
1011 * so they can respond to our requests.
1012 *
1013 * Return 0 - device(s) present, 1 - no devices present.
1014 */
1015 mutex_lock(&dev->bus_mutex);
1016 if (w1_reset_bus(dev)) {
1017 mutex_unlock(&dev->bus_mutex);
1018 dev_dbg(&dev->dev, "No devices present on the wire.\n");
1019 break;
1020 }
1021
1022 /* Do fast search on single slave bus */
1023 if (dev->max_slave_count == 1) {
1024 int rv;
1025 w1_write_8(dev, W1_READ_ROM);
1026 rv = w1_read_block(dev, (u8 *)&rn, 8);
1027 mutex_unlock(&dev->bus_mutex);
1028
1029 if (rv == 8 && rn)
1030 cb(dev, rn);
1031
1032 break;
1033 }
1034
1035 /* Start the search */
1036 w1_write_8(dev, search_type);
1037 for (i = 0; i < 64; ++i) {
1038 /* Determine the direction/search bit */
1039 if (i == desc_bit)
1040 search_bit = 1; /* took the 0 path last time, so take the 1 path */
1041 else if (i > desc_bit)
1042 search_bit = 0; /* take the 0 path on the next branch */
1043 else
1044 search_bit = ((last_rn >> i) & 0x1);
1045
1046 /* Read two bits and write one bit */
1047 triplet_ret = w1_triplet(dev, search_bit);
1048
1049 /* quit if no device responded */
1050 if ( (triplet_ret & 0x03) == 0x03 )
1051 break;
1052
1053 /* If both directions were valid, and we took the 0 path... */
1054 if (triplet_ret == 0)
1055 last_zero = i;
1056
1057 /* extract the direction taken & update the device number */
1058 tmp64 = (triplet_ret >> 2);
1059 rn |= (tmp64 << i);
1060
1061 if (test_bit(W1_ABORT_SEARCH, &dev->flags)) {
1062 mutex_unlock(&dev->bus_mutex);
1063 dev_dbg(&dev->dev, "Abort w1_search\n");
1064 return;
1065 }
1066 }
1067 mutex_unlock(&dev->bus_mutex);
1068
1069 if ( (triplet_ret & 0x03) != 0x03 ) {
1070 if ((desc_bit == last_zero) || (last_zero < 0)) {
1071 last_device = 1;
1072 dev->search_id = 0;
1073 } else {
1074 dev->search_id = rn;
1075 }
1076 desc_bit = last_zero;
1077 cb(dev, rn);
1078 }
1079
1080 if (!last_device && slave_count == dev->max_slave_count &&
1081 !test_bit(W1_WARN_MAX_COUNT, &dev->flags)) {
1082 /* Only max_slave_count will be scanned in a search,
1083 * but it will start where it left off next search
1084 * until all ids are identified and then it will start
1085 * over. A continued search will report the previous
1086 * last id as the first id (provided it is still on the
1087 * bus).
1088 */
1089 dev_info(&dev->dev, "%s: max_slave_count %d reached, "
1090 "will continue next search.\n", __func__,
1091 dev->max_slave_count);
1092 set_bit(W1_WARN_MAX_COUNT, &dev->flags);
1093 }
1094 }
1095}
1096
1097void w1_search_process_cb(struct w1_master *dev, u8 search_type,
1098 w1_slave_found_callback cb)
1099{
1100 struct w1_slave *sl, *sln;
1101
1102 mutex_lock(&dev->list_mutex);
1103 list_for_each_entry(sl, &dev->slist, w1_slave_entry)
1104 clear_bit(W1_SLAVE_ACTIVE, &sl->flags);
1105 mutex_unlock(&dev->list_mutex);
1106
1107 w1_search_devices(dev, search_type, cb);
1108
1109 mutex_lock(&dev->list_mutex);
1110 list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) {
1111 if (!test_bit(W1_SLAVE_ACTIVE, &sl->flags) && !--sl->ttl) {
1112 mutex_unlock(&dev->list_mutex);
1113 w1_slave_detach(sl);
1114 mutex_lock(&dev->list_mutex);
1115 }
1116 else if (test_bit(W1_SLAVE_ACTIVE, &sl->flags))
1117 sl->ttl = dev->slave_ttl;
1118 }
1119 mutex_unlock(&dev->list_mutex);
1120
1121 if (dev->search_count > 0)
1122 dev->search_count--;
1123}
1124
1125static void w1_search_process(struct w1_master *dev, u8 search_type)
1126{
1127 w1_search_process_cb(dev, search_type, w1_slave_found);
1128}
1129
1130/**
1131 * w1_process_callbacks() - execute each dev->async_list callback entry
1132 * @dev: w1_master device
1133 *
1134 * The w1 master list_mutex must be held.
1135 *
1136 * Return: 1 if there were commands to executed 0 otherwise
1137 */
1138int w1_process_callbacks(struct w1_master *dev)
1139{
1140 int ret = 0;
1141 struct w1_async_cmd *async_cmd, *async_n;
1142
1143 /* The list can be added to in another thread, loop until it is empty */
1144 while (!list_empty(&dev->async_list)) {
1145 list_for_each_entry_safe(async_cmd, async_n, &dev->async_list,
1146 async_entry) {
1147 /* drop the lock, if it is a search it can take a long
1148 * time */
1149 mutex_unlock(&dev->list_mutex);
1150 async_cmd->cb(dev, async_cmd);
1151 ret = 1;
1152 mutex_lock(&dev->list_mutex);
1153 }
1154 }
1155 return ret;
1156}
1157
1158int w1_process(void *data)
1159{
1160 struct w1_master *dev = (struct w1_master *) data;
1161 /* As long as w1_timeout is only set by a module parameter the sleep
1162 * time can be calculated in jiffies once.
1163 */
1164 const unsigned long jtime =
1165 usecs_to_jiffies(w1_timeout * 1000000 + w1_timeout_us);
1166 /* remainder if it woke up early */
1167 unsigned long jremain = 0;
1168
1169 for (;;) {
1170
1171 if (!jremain && dev->search_count) {
1172 mutex_lock(&dev->mutex);
1173 w1_search_process(dev, W1_SEARCH);
1174 mutex_unlock(&dev->mutex);
1175 }
1176
1177 mutex_lock(&dev->list_mutex);
1178 /* Note, w1_process_callback drops the lock while processing,
1179 * but locks it again before returning.
1180 */
1181 if (!w1_process_callbacks(dev) && jremain) {
1182 /* a wake up is either to stop the thread, process
1183 * callbacks, or search, it isn't process callbacks, so
1184 * schedule a search.
1185 */
1186 jremain = 1;
1187 }
1188
1189 __set_current_state(TASK_INTERRUPTIBLE);
1190
1191 /* hold list_mutex until after interruptible to prevent loosing
1192 * the wakeup signal when async_cmd is added.
1193 */
1194 mutex_unlock(&dev->list_mutex);
1195
1196 if (kthread_should_stop())
1197 break;
1198
1199 /* Only sleep when the search is active. */
1200 if (dev->search_count) {
1201 if (!jremain)
1202 jremain = jtime;
1203 jremain = schedule_timeout(jremain);
1204 }
1205 else
1206 schedule();
1207 }
1208
1209 atomic_dec(&dev->refcnt);
1210
1211 return 0;
1212}
1213
1214static int __init w1_init(void)
1215{
1216 int retval;
1217
1218 pr_info("Driver for 1-wire Dallas network protocol.\n");
1219
1220 w1_init_netlink();
1221
1222 retval = bus_register(&w1_bus_type);
1223 if (retval) {
1224 pr_err("Failed to register bus. err=%d.\n", retval);
1225 goto err_out_exit_init;
1226 }
1227
1228 retval = driver_register(&w1_master_driver);
1229 if (retval) {
1230 pr_err("Failed to register master driver. err=%d.\n",
1231 retval);
1232 goto err_out_bus_unregister;
1233 }
1234
1235 retval = driver_register(&w1_slave_driver);
1236 if (retval) {
1237 pr_err("Failed to register slave driver. err=%d.\n",
1238 retval);
1239 goto err_out_master_unregister;
1240 }
1241
1242 return 0;
1243
1244#if 0
1245/* For undoing the slave register if there was a step after it. */
1246err_out_slave_unregister:
1247 driver_unregister(&w1_slave_driver);
1248#endif
1249
1250err_out_master_unregister:
1251 driver_unregister(&w1_master_driver);
1252
1253err_out_bus_unregister:
1254 bus_unregister(&w1_bus_type);
1255
1256err_out_exit_init:
1257 return retval;
1258}
1259
1260static void __exit w1_fini(void)
1261{
1262 struct w1_master *dev;
1263
1264 /* Set netlink removal messages and some cleanup */
1265 list_for_each_entry(dev, &w1_masters, w1_master_entry)
1266 __w1_remove_master_device(dev);
1267
1268 w1_fini_netlink();
1269
1270 driver_unregister(&w1_slave_driver);
1271 driver_unregister(&w1_master_driver);
1272 bus_unregister(&w1_bus_type);
1273}
1274
1275module_init(w1_init);
1276module_exit(w1_fini);
1277
1278MODULE_AUTHOR("Evgeniy Polyakov <zbr@ioremap.net>");
1279MODULE_DESCRIPTION("Driver for 1-wire Dallas network protocol.");
1280MODULE_LICENSE("GPL");