4 * Copyright (c) 2004 Evgeniy Polyakov <johnpol@2ka.mipt.ru>
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.
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.
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
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>
36 #include <asm/atomic.h>
41 #include "w1_family.h"
42 #include "w1_netlink.h"
44 MODULE_LICENSE("GPL");
45 MODULE_AUTHOR("Evgeniy Polyakov <johnpol@2ka.mipt.ru>");
46 MODULE_DESCRIPTION("Driver for 1-wire Dallas network protocol.");
48 static int w1_timeout
= 10;
49 int w1_max_slave_count
= 10;
50 int w1_max_slave_ttl
= 10;
52 module_param_named(timeout
, w1_timeout
, int, 0);
53 module_param_named(max_slave_count
, w1_max_slave_count
, int, 0);
54 module_param_named(slave_ttl
, w1_max_slave_ttl
, int, 0);
56 DEFINE_MUTEX(w1_mlock
);
57 LIST_HEAD(w1_masters
);
59 static int w1_attach_slave_device(struct w1_master
*dev
, struct w1_reg_num
*rn
);
61 static int w1_master_match(struct device
*dev
, struct device_driver
*drv
)
66 static int w1_master_probe(struct device
*dev
)
71 static void w1_master_release(struct device
*dev
)
73 struct w1_master
*md
= dev_to_w1_master(dev
);
75 dev_dbg(dev
, "%s: Releasing %s.\n", __func__
, md
->name
);
76 memset(md
, 0, sizeof(struct w1_master
) + sizeof(struct w1_bus_master
));
80 static void w1_slave_release(struct device
*dev
)
82 struct w1_slave
*sl
= dev_to_w1_slave(dev
);
84 dev_dbg(dev
, "%s: Releasing %s.\n", __func__
, sl
->name
);
86 while (atomic_read(&sl
->refcnt
)) {
87 dev_dbg(dev
, "Waiting for %s to become free: refcnt=%d.\n",
88 sl
->name
, atomic_read(&sl
->refcnt
));
89 if (msleep_interruptible(1000))
90 flush_signals(current
);
93 w1_family_put(sl
->family
);
94 sl
->master
->slave_count
--;
96 complete(&sl
->released
);
99 static ssize_t
w1_slave_read_name(struct device
*dev
, struct device_attribute
*attr
, char *buf
)
101 struct w1_slave
*sl
= dev_to_w1_slave(dev
);
103 return sprintf(buf
, "%s\n", sl
->name
);
106 static ssize_t
w1_slave_read_id(struct device
*dev
,
107 struct device_attribute
*attr
, char *buf
)
109 struct w1_slave
*sl
= dev_to_w1_slave(dev
);
110 ssize_t count
= sizeof(sl
->reg_num
);
112 memcpy(buf
, (u8
*)&sl
->reg_num
, count
);
116 static struct device_attribute w1_slave_attr_name
=
117 __ATTR(name
, S_IRUGO
, w1_slave_read_name
, NULL
);
118 static struct device_attribute w1_slave_attr_id
=
119 __ATTR(id
, S_IRUGO
, w1_slave_read_id
, NULL
);
123 static ssize_t
w1_default_write(struct file
*filp
, struct kobject
*kobj
,
124 struct bin_attribute
*bin_attr
,
125 char *buf
, loff_t off
, size_t count
)
127 struct w1_slave
*sl
= kobj_to_w1_slave(kobj
);
129 mutex_lock(&sl
->master
->mutex
);
130 if (w1_reset_select_slave(sl
)) {
135 w1_write_block(sl
->master
, buf
, count
);
138 mutex_unlock(&sl
->master
->mutex
);
142 static ssize_t
w1_default_read(struct file
*filp
, struct kobject
*kobj
,
143 struct bin_attribute
*bin_attr
,
144 char *buf
, loff_t off
, size_t count
)
146 struct w1_slave
*sl
= kobj_to_w1_slave(kobj
);
148 mutex_lock(&sl
->master
->mutex
);
149 w1_read_block(sl
->master
, buf
, count
);
150 mutex_unlock(&sl
->master
->mutex
);
154 static struct bin_attribute w1_default_attr
= {
157 .mode
= S_IRUGO
| S_IWUSR
,
160 .read
= w1_default_read
,
161 .write
= w1_default_write
,
164 static int w1_default_add_slave(struct w1_slave
*sl
)
166 return sysfs_create_bin_file(&sl
->dev
.kobj
, &w1_default_attr
);
169 static void w1_default_remove_slave(struct w1_slave
*sl
)
171 sysfs_remove_bin_file(&sl
->dev
.kobj
, &w1_default_attr
);
174 static struct w1_family_ops w1_default_fops
= {
175 .add_slave
= w1_default_add_slave
,
176 .remove_slave
= w1_default_remove_slave
,
179 static struct w1_family w1_default_family
= {
180 .fops
= &w1_default_fops
,
183 static int w1_uevent(struct device
*dev
, struct kobj_uevent_env
*env
);
185 static struct bus_type w1_bus_type
= {
187 .match
= w1_master_match
,
191 struct device_driver w1_master_driver
= {
192 .name
= "w1_master_driver",
194 .probe
= w1_master_probe
,
197 struct device w1_master_device
= {
200 .init_name
= "w1 bus master",
201 .driver
= &w1_master_driver
,
202 .release
= &w1_master_release
205 static struct device_driver w1_slave_driver
= {
206 .name
= "w1_slave_driver",
211 static ssize_t
w1_master_attribute_show_name(struct device
*dev
, struct device_attribute
*attr
, char *buf
)
213 struct w1_master
*md
= dev_to_w1_master(dev
);
216 mutex_lock(&md
->mutex
);
217 count
= sprintf(buf
, "%s\n", md
->name
);
218 mutex_unlock(&md
->mutex
);
223 static ssize_t
w1_master_attribute_store_search(struct device
* dev
,
224 struct device_attribute
*attr
,
225 const char * buf
, size_t count
)
228 struct w1_master
*md
= dev_to_w1_master(dev
);
230 if (strict_strtol(buf
, 0, &tmp
) == -EINVAL
)
233 mutex_lock(&md
->mutex
);
234 md
->search_count
= tmp
;
235 mutex_unlock(&md
->mutex
);
236 wake_up_process(md
->thread
);
241 static ssize_t
w1_master_attribute_show_search(struct device
*dev
,
242 struct device_attribute
*attr
,
245 struct w1_master
*md
= dev_to_w1_master(dev
);
248 mutex_lock(&md
->mutex
);
249 count
= sprintf(buf
, "%d\n", md
->search_count
);
250 mutex_unlock(&md
->mutex
);
255 static ssize_t
w1_master_attribute_store_pullup(struct device
*dev
,
256 struct device_attribute
*attr
,
257 const char *buf
, size_t count
)
260 struct w1_master
*md
= dev_to_w1_master(dev
);
262 if (strict_strtol(buf
, 0, &tmp
) == -EINVAL
)
265 mutex_lock(&md
->mutex
);
266 md
->enable_pullup
= tmp
;
267 mutex_unlock(&md
->mutex
);
268 wake_up_process(md
->thread
);
273 static ssize_t
w1_master_attribute_show_pullup(struct device
*dev
,
274 struct device_attribute
*attr
,
277 struct w1_master
*md
= dev_to_w1_master(dev
);
280 mutex_lock(&md
->mutex
);
281 count
= sprintf(buf
, "%d\n", md
->enable_pullup
);
282 mutex_unlock(&md
->mutex
);
287 static ssize_t
w1_master_attribute_show_pointer(struct device
*dev
, struct device_attribute
*attr
, char *buf
)
289 struct w1_master
*md
= dev_to_w1_master(dev
);
292 mutex_lock(&md
->mutex
);
293 count
= sprintf(buf
, "0x%p\n", md
->bus_master
);
294 mutex_unlock(&md
->mutex
);
298 static ssize_t
w1_master_attribute_show_timeout(struct device
*dev
, struct device_attribute
*attr
, char *buf
)
301 count
= sprintf(buf
, "%d\n", w1_timeout
);
305 static ssize_t
w1_master_attribute_show_max_slave_count(struct device
*dev
, struct device_attribute
*attr
, char *buf
)
307 struct w1_master
*md
= dev_to_w1_master(dev
);
310 mutex_lock(&md
->mutex
);
311 count
= sprintf(buf
, "%d\n", md
->max_slave_count
);
312 mutex_unlock(&md
->mutex
);
316 static ssize_t
w1_master_attribute_show_attempts(struct device
*dev
, struct device_attribute
*attr
, char *buf
)
318 struct w1_master
*md
= dev_to_w1_master(dev
);
321 mutex_lock(&md
->mutex
);
322 count
= sprintf(buf
, "%lu\n", md
->attempts
);
323 mutex_unlock(&md
->mutex
);
327 static ssize_t
w1_master_attribute_show_slave_count(struct device
*dev
, struct device_attribute
*attr
, char *buf
)
329 struct w1_master
*md
= dev_to_w1_master(dev
);
332 mutex_lock(&md
->mutex
);
333 count
= sprintf(buf
, "%d\n", md
->slave_count
);
334 mutex_unlock(&md
->mutex
);
338 static ssize_t
w1_master_attribute_show_slaves(struct device
*dev
,
339 struct device_attribute
*attr
, char *buf
)
341 struct w1_master
*md
= dev_to_w1_master(dev
);
344 mutex_lock(&md
->mutex
);
346 if (md
->slave_count
== 0)
347 c
-= snprintf(buf
+ PAGE_SIZE
- c
, c
, "not found.\n");
349 struct list_head
*ent
, *n
;
352 list_for_each_safe(ent
, n
, &md
->slist
) {
353 sl
= list_entry(ent
, struct w1_slave
, w1_slave_entry
);
355 c
-= snprintf(buf
+ PAGE_SIZE
- c
, c
, "%s\n", sl
->name
);
359 mutex_unlock(&md
->mutex
);
361 return PAGE_SIZE
- c
;
364 static ssize_t
w1_master_attribute_show_add(struct device
*dev
,
365 struct device_attribute
*attr
, char *buf
)
368 c
-= snprintf(buf
+PAGE_SIZE
- c
, c
,
369 "write device id xx-xxxxxxxxxxxx to add slave\n");
370 return PAGE_SIZE
- c
;
373 static int w1_atoreg_num(struct device
*dev
, const char *buf
, size_t count
,
374 struct w1_reg_num
*rn
)
377 unsigned long long id
;
381 /* The CRC value isn't read from the user because the sysfs directory
382 * doesn't include it and most messages from the bus search don't
383 * print it either. It would be unreasonable for the user to then
386 const char *error_msg
= "bad slave string format, expecting "
390 dev_err(dev
, "%s", error_msg
);
393 i
= sscanf(buf
, "%02x-%012llx", &family
, &id
);
395 dev_err(dev
, "%s", error_msg
);
401 rn64_le
= cpu_to_le64(*(u64
*)rn
);
402 rn
->crc
= w1_calc_crc8((u8
*)&rn64_le
, 7);
408 /* Searches the slaves in the w1_master and returns a pointer or NULL.
409 * Note: must hold the mutex
411 static struct w1_slave
*w1_slave_search_device(struct w1_master
*dev
,
412 struct w1_reg_num
*rn
)
415 list_for_each_entry(sl
, &dev
->slist
, w1_slave_entry
) {
416 if (sl
->reg_num
.family
== rn
->family
&&
417 sl
->reg_num
.id
== rn
->id
&&
418 sl
->reg_num
.crc
== rn
->crc
) {
425 static ssize_t
w1_master_attribute_store_add(struct device
*dev
,
426 struct device_attribute
*attr
,
427 const char *buf
, size_t count
)
429 struct w1_master
*md
= dev_to_w1_master(dev
);
430 struct w1_reg_num rn
;
432 ssize_t result
= count
;
434 if (w1_atoreg_num(dev
, buf
, count
, &rn
))
437 mutex_lock(&md
->mutex
);
438 sl
= w1_slave_search_device(md
, &rn
);
439 /* It would be nice to do a targeted search one the one-wire bus
440 * for the new device to see if it is out there or not. But the
441 * current search doesn't support that.
444 dev_info(dev
, "Device %s already exists\n", sl
->name
);
447 w1_attach_slave_device(md
, &rn
);
449 mutex_unlock(&md
->mutex
);
454 static ssize_t
w1_master_attribute_show_remove(struct device
*dev
,
455 struct device_attribute
*attr
, char *buf
)
458 c
-= snprintf(buf
+PAGE_SIZE
- c
, c
,
459 "write device id xx-xxxxxxxxxxxx to remove slave\n");
460 return PAGE_SIZE
- c
;
463 static ssize_t
w1_master_attribute_store_remove(struct device
*dev
,
464 struct device_attribute
*attr
,
465 const char *buf
, size_t count
)
467 struct w1_master
*md
= dev_to_w1_master(dev
);
468 struct w1_reg_num rn
;
470 ssize_t result
= count
;
472 if (w1_atoreg_num(dev
, buf
, count
, &rn
))
475 mutex_lock(&md
->mutex
);
476 sl
= w1_slave_search_device(md
, &rn
);
480 dev_info(dev
, "Device %02x-%012llx doesn't exists\n", rn
.family
,
481 (unsigned long long)rn
.id
);
484 mutex_unlock(&md
->mutex
);
489 #define W1_MASTER_ATTR_RO(_name, _mode) \
490 struct device_attribute w1_master_attribute_##_name = \
491 __ATTR(w1_master_##_name, _mode, \
492 w1_master_attribute_show_##_name, NULL)
494 #define W1_MASTER_ATTR_RW(_name, _mode) \
495 struct device_attribute w1_master_attribute_##_name = \
496 __ATTR(w1_master_##_name, _mode, \
497 w1_master_attribute_show_##_name, \
498 w1_master_attribute_store_##_name)
500 static W1_MASTER_ATTR_RO(name
, S_IRUGO
);
501 static W1_MASTER_ATTR_RO(slaves
, S_IRUGO
);
502 static W1_MASTER_ATTR_RO(slave_count
, S_IRUGO
);
503 static W1_MASTER_ATTR_RO(max_slave_count
, S_IRUGO
);
504 static W1_MASTER_ATTR_RO(attempts
, S_IRUGO
);
505 static W1_MASTER_ATTR_RO(timeout
, S_IRUGO
);
506 static W1_MASTER_ATTR_RO(pointer
, S_IRUGO
);
507 static W1_MASTER_ATTR_RW(search
, S_IRUGO
| S_IWUGO
);
508 static W1_MASTER_ATTR_RW(pullup
, S_IRUGO
| S_IWUGO
);
509 static W1_MASTER_ATTR_RW(add
, S_IRUGO
| S_IWUGO
);
510 static W1_MASTER_ATTR_RW(remove
, S_IRUGO
| S_IWUGO
);
512 static struct attribute
*w1_master_default_attrs
[] = {
513 &w1_master_attribute_name
.attr
,
514 &w1_master_attribute_slaves
.attr
,
515 &w1_master_attribute_slave_count
.attr
,
516 &w1_master_attribute_max_slave_count
.attr
,
517 &w1_master_attribute_attempts
.attr
,
518 &w1_master_attribute_timeout
.attr
,
519 &w1_master_attribute_pointer
.attr
,
520 &w1_master_attribute_search
.attr
,
521 &w1_master_attribute_pullup
.attr
,
522 &w1_master_attribute_add
.attr
,
523 &w1_master_attribute_remove
.attr
,
527 static struct attribute_group w1_master_defattr_group
= {
528 .attrs
= w1_master_default_attrs
,
531 int w1_create_master_attributes(struct w1_master
*master
)
533 return sysfs_create_group(&master
->dev
.kobj
, &w1_master_defattr_group
);
536 void w1_destroy_master_attributes(struct w1_master
*master
)
538 sysfs_remove_group(&master
->dev
.kobj
, &w1_master_defattr_group
);
541 #ifdef CONFIG_HOTPLUG
542 static int w1_uevent(struct device
*dev
, struct kobj_uevent_env
*env
)
544 struct w1_master
*md
= NULL
;
545 struct w1_slave
*sl
= NULL
;
546 char *event_owner
, *name
;
549 if (dev
->driver
== &w1_master_driver
) {
550 md
= container_of(dev
, struct w1_master
, dev
);
551 event_owner
= "master";
553 } else if (dev
->driver
== &w1_slave_driver
) {
554 sl
= container_of(dev
, struct w1_slave
, dev
);
555 event_owner
= "slave";
558 dev_dbg(dev
, "Unknown event.\n");
562 dev_dbg(dev
, "Hotplug event for %s %s, bus_id=%s.\n",
563 event_owner
, name
, dev_name(dev
));
565 if (dev
->driver
!= &w1_slave_driver
|| !sl
)
568 err
= add_uevent_var(env
, "W1_FID=%02X", sl
->reg_num
.family
);
572 err
= add_uevent_var(env
, "W1_SLAVE_ID=%024LX",
573 (unsigned long long)sl
->reg_num
.id
);
580 static int w1_uevent(struct device
*dev
, struct kobj_uevent_env
*env
)
586 static int __w1_attach_slave_device(struct w1_slave
*sl
)
590 sl
->dev
.parent
= &sl
->master
->dev
;
591 sl
->dev
.driver
= &w1_slave_driver
;
592 sl
->dev
.bus
= &w1_bus_type
;
593 sl
->dev
.release
= &w1_slave_release
;
595 dev_set_name(&sl
->dev
, "%02x-%012llx",
596 (unsigned int) sl
->reg_num
.family
,
597 (unsigned long long) sl
->reg_num
.id
);
598 snprintf(&sl
->name
[0], sizeof(sl
->name
),
600 (unsigned int) sl
->reg_num
.family
,
601 (unsigned long long) sl
->reg_num
.id
);
603 dev_dbg(&sl
->dev
, "%s: registering %s as %p.\n", __func__
,
604 dev_name(&sl
->dev
), sl
);
606 err
= device_register(&sl
->dev
);
609 "Device registration [%s] failed. err=%d\n",
610 dev_name(&sl
->dev
), err
);
614 /* Create "name" entry */
615 err
= device_create_file(&sl
->dev
, &w1_slave_attr_name
);
618 "sysfs file creation for [%s] failed. err=%d\n",
619 dev_name(&sl
->dev
), err
);
623 /* Create "id" entry */
624 err
= device_create_file(&sl
->dev
, &w1_slave_attr_id
);
627 "sysfs file creation for [%s] failed. err=%d\n",
628 dev_name(&sl
->dev
), err
);
632 /* if the family driver needs to initialize something... */
633 if (sl
->family
->fops
&& sl
->family
->fops
->add_slave
&&
634 ((err
= sl
->family
->fops
->add_slave(sl
)) < 0)) {
636 "sysfs file creation for [%s] failed. err=%d\n",
637 dev_name(&sl
->dev
), err
);
641 list_add_tail(&sl
->w1_slave_entry
, &sl
->master
->slist
);
646 device_remove_file(&sl
->dev
, &w1_slave_attr_id
);
648 device_remove_file(&sl
->dev
, &w1_slave_attr_name
);
650 device_unregister(&sl
->dev
);
654 static int w1_attach_slave_device(struct w1_master
*dev
, struct w1_reg_num
*rn
)
659 struct w1_netlink_msg msg
;
661 sl
= kzalloc(sizeof(struct w1_slave
), GFP_KERNEL
);
664 "%s: failed to allocate new slave device.\n",
670 sl
->owner
= THIS_MODULE
;
672 set_bit(W1_SLAVE_ACTIVE
, (long *)&sl
->flags
);
674 memset(&msg
, 0, sizeof(msg
));
675 memcpy(&sl
->reg_num
, rn
, sizeof(sl
->reg_num
));
676 atomic_set(&sl
->refcnt
, 0);
677 init_completion(&sl
->released
);
679 spin_lock(&w1_flock
);
680 f
= w1_family_registered(rn
->family
);
682 f
= &w1_default_family
;
683 dev_info(&dev
->dev
, "Family %x for %02x.%012llx.%02x is not registered.\n",
684 rn
->family
, rn
->family
,
685 (unsigned long long)rn
->id
, rn
->crc
);
688 spin_unlock(&w1_flock
);
693 err
= __w1_attach_slave_device(sl
);
695 dev_err(&dev
->dev
, "%s: Attaching %s failed.\n", __func__
,
697 w1_family_put(sl
->family
);
702 sl
->ttl
= dev
->slave_ttl
;
705 memcpy(msg
.id
.id
, rn
, sizeof(msg
.id
));
706 msg
.type
= W1_SLAVE_ADD
;
707 w1_netlink_send(dev
, &msg
);
712 void w1_slave_detach(struct w1_slave
*sl
)
714 struct w1_netlink_msg msg
;
716 dev_dbg(&sl
->dev
, "%s: detaching %s [%p].\n", __func__
, sl
->name
, sl
);
718 list_del(&sl
->w1_slave_entry
);
720 if (sl
->family
->fops
&& sl
->family
->fops
->remove_slave
)
721 sl
->family
->fops
->remove_slave(sl
);
723 memset(&msg
, 0, sizeof(msg
));
724 memcpy(msg
.id
.id
, &sl
->reg_num
, sizeof(msg
.id
));
725 msg
.type
= W1_SLAVE_REMOVE
;
726 w1_netlink_send(sl
->master
, &msg
);
728 device_remove_file(&sl
->dev
, &w1_slave_attr_id
);
729 device_remove_file(&sl
->dev
, &w1_slave_attr_name
);
730 device_unregister(&sl
->dev
);
732 wait_for_completion(&sl
->released
);
736 struct w1_master
*w1_search_master_id(u32 id
)
738 struct w1_master
*dev
;
741 mutex_lock(&w1_mlock
);
742 list_for_each_entry(dev
, &w1_masters
, w1_master_entry
) {
745 atomic_inc(&dev
->refcnt
);
749 mutex_unlock(&w1_mlock
);
751 return (found
)?dev
:NULL
;
754 struct w1_slave
*w1_search_slave(struct w1_reg_num
*id
)
756 struct w1_master
*dev
;
757 struct w1_slave
*sl
= NULL
;
760 mutex_lock(&w1_mlock
);
761 list_for_each_entry(dev
, &w1_masters
, w1_master_entry
) {
762 mutex_lock(&dev
->mutex
);
763 list_for_each_entry(sl
, &dev
->slist
, w1_slave_entry
) {
764 if (sl
->reg_num
.family
== id
->family
&&
765 sl
->reg_num
.id
== id
->id
&&
766 sl
->reg_num
.crc
== id
->crc
) {
768 atomic_inc(&dev
->refcnt
);
769 atomic_inc(&sl
->refcnt
);
773 mutex_unlock(&dev
->mutex
);
778 mutex_unlock(&w1_mlock
);
780 return (found
)?sl
:NULL
;
783 void w1_reconnect_slaves(struct w1_family
*f
, int attach
)
785 struct w1_slave
*sl
, *sln
;
786 struct w1_master
*dev
;
788 mutex_lock(&w1_mlock
);
789 list_for_each_entry(dev
, &w1_masters
, w1_master_entry
) {
790 dev_dbg(&dev
->dev
, "Reconnecting slaves in device %s "
791 "for family %02x.\n", dev
->name
, f
->fid
);
792 mutex_lock(&dev
->mutex
);
793 list_for_each_entry_safe(sl
, sln
, &dev
->slist
, w1_slave_entry
) {
794 /* If it is a new family, slaves with the default
795 * family driver and are that family will be
796 * connected. If the family is going away, devices
797 * matching that family are reconneced.
799 if ((attach
&& sl
->family
->fid
== W1_FAMILY_DEFAULT
800 && sl
->reg_num
.family
== f
->fid
) ||
801 (!attach
&& sl
->family
->fid
== f
->fid
)) {
802 struct w1_reg_num rn
;
804 memcpy(&rn
, &sl
->reg_num
, sizeof(rn
));
807 w1_attach_slave_device(dev
, &rn
);
810 dev_dbg(&dev
->dev
, "Reconnecting slaves in device %s "
811 "has been finished.\n", dev
->name
);
812 mutex_unlock(&dev
->mutex
);
814 mutex_unlock(&w1_mlock
);
817 static void w1_slave_found(struct w1_master
*dev
, u64 rn
)
820 struct w1_reg_num
*tmp
;
821 u64 rn_le
= cpu_to_le64(rn
);
823 atomic_inc(&dev
->refcnt
);
825 tmp
= (struct w1_reg_num
*) &rn
;
827 sl
= w1_slave_search_device(dev
, tmp
);
829 set_bit(W1_SLAVE_ACTIVE
, (long *)&sl
->flags
);
831 if (rn
&& tmp
->crc
== w1_calc_crc8((u8
*)&rn_le
, 7))
832 w1_attach_slave_device(dev
, tmp
);
835 atomic_dec(&dev
->refcnt
);
839 * Performs a ROM Search & registers any devices found.
840 * The 1-wire search is a simple binary tree search.
841 * For each bit of the address, we read two bits and write one bit.
842 * The bit written will put to sleep all devies that don't match that bit.
843 * When the two reads differ, the direction choice is obvious.
844 * When both bits are 0, we must choose a path to take.
845 * When we can scan all 64 bits without having to choose a path, we are done.
847 * See "Application note 187 1-wire search algorithm" at www.maxim-ic.com
849 * @dev The master device to search
850 * @cb Function to call when a device is found
852 void w1_search(struct w1_master
*dev
, u8 search_type
, w1_slave_found_callback cb
)
854 u64 last_rn
, rn
, tmp64
;
855 int i
, slave_count
= 0;
856 int last_zero
, last_device
;
857 int search_bit
, desc_bit
;
867 while ( !last_device
&& (slave_count
++ < dev
->max_slave_count
) ) {
872 * Reset bus and all 1-wire device state machines
873 * so they can respond to our requests.
875 * Return 0 - device(s) present, 1 - no devices present.
877 if (w1_reset_bus(dev
)) {
878 dev_dbg(&dev
->dev
, "No devices present on the wire.\n");
882 /* Start the search */
883 w1_write_8(dev
, search_type
);
884 for (i
= 0; i
< 64; ++i
) {
885 /* Determine the direction/search bit */
887 search_bit
= 1; /* took the 0 path last time, so take the 1 path */
888 else if (i
> desc_bit
)
889 search_bit
= 0; /* take the 0 path on the next branch */
891 search_bit
= ((last_rn
>> i
) & 0x1);
893 /** Read two bits and write one bit */
894 triplet_ret
= w1_triplet(dev
, search_bit
);
896 /* quit if no device responded */
897 if ( (triplet_ret
& 0x03) == 0x03 )
900 /* If both directions were valid, and we took the 0 path... */
901 if (triplet_ret
== 0)
904 /* extract the direction taken & update the device number */
905 tmp64
= (triplet_ret
>> 2);
908 if (kthread_should_stop()) {
909 dev_dbg(&dev
->dev
, "Abort w1_search\n");
914 if ( (triplet_ret
& 0x03) != 0x03 ) {
915 if ( (desc_bit
== last_zero
) || (last_zero
< 0))
917 desc_bit
= last_zero
;
923 void w1_search_process(struct w1_master
*dev
, u8 search_type
)
925 struct w1_slave
*sl
, *sln
;
927 list_for_each_entry(sl
, &dev
->slist
, w1_slave_entry
)
928 clear_bit(W1_SLAVE_ACTIVE
, (long *)&sl
->flags
);
930 w1_search_devices(dev
, search_type
, w1_slave_found
);
932 list_for_each_entry_safe(sl
, sln
, &dev
->slist
, w1_slave_entry
) {
933 if (!test_bit(W1_SLAVE_ACTIVE
, (unsigned long *)&sl
->flags
) && !--sl
->ttl
)
935 else if (test_bit(W1_SLAVE_ACTIVE
, (unsigned long *)&sl
->flags
))
936 sl
->ttl
= dev
->slave_ttl
;
939 if (dev
->search_count
> 0)
943 int w1_process(void *data
)
945 struct w1_master
*dev
= (struct w1_master
*) data
;
946 /* As long as w1_timeout is only set by a module parameter the sleep
947 * time can be calculated in jiffies once.
949 const unsigned long jtime
= msecs_to_jiffies(w1_timeout
* 1000);
951 while (!kthread_should_stop()) {
952 if (dev
->search_count
) {
953 mutex_lock(&dev
->mutex
);
954 w1_search_process(dev
, W1_SEARCH
);
955 mutex_unlock(&dev
->mutex
);
959 __set_current_state(TASK_INTERRUPTIBLE
);
961 if (kthread_should_stop())
964 /* Only sleep when the search is active. */
965 if (dev
->search_count
)
966 schedule_timeout(jtime
);
971 atomic_dec(&dev
->refcnt
);
976 static int __init
w1_init(void)
980 printk(KERN_INFO
"Driver for 1-wire Dallas network protocol.\n");
984 retval
= bus_register(&w1_bus_type
);
986 printk(KERN_ERR
"Failed to register bus. err=%d.\n", retval
);
987 goto err_out_exit_init
;
990 retval
= driver_register(&w1_master_driver
);
993 "Failed to register master driver. err=%d.\n",
995 goto err_out_bus_unregister
;
998 retval
= driver_register(&w1_slave_driver
);
1001 "Failed to register master driver. err=%d.\n",
1003 goto err_out_master_unregister
;
1009 err_out_master_unregister
:
1010 driver_unregister(&w1_master_driver
);
1012 err_out_bus_unregister
:
1013 bus_unregister(&w1_bus_type
);
1019 static void __exit
w1_fini(void)
1021 struct w1_master
*dev
;
1023 /* Set netlink removal messages and some cleanup */
1024 list_for_each_entry(dev
, &w1_masters
, w1_master_entry
)
1025 __w1_remove_master_device(dev
);
1029 driver_unregister(&w1_slave_driver
);
1030 driver_unregister(&w1_master_driver
);
1031 bus_unregister(&w1_bus_type
);
1034 module_init(w1_init
);
1035 module_exit(w1_fini
);