4 * Copyright (c) 2004 Evgeniy Polyakov <zbr@ioremap.net>
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 <linux/atomic.h>
41 #include "w1_family.h"
42 #include "w1_netlink.h"
44 MODULE_LICENSE("GPL");
45 MODULE_AUTHOR("Evgeniy Polyakov <zbr@ioremap.net>");
46 MODULE_DESCRIPTION("Driver for 1-wire Dallas network protocol.");
48 static int w1_timeout
= 10;
49 int w1_max_slave_count
= 64;
50 int w1_max_slave_ttl
= 10;
52 module_param_named(timeout
, w1_timeout
, int, 0);
53 MODULE_PARM_DESC(timeout
, "time in seconds between automatic slave searches");
54 /* A search stops when w1_max_slave_count devices have been found in that
55 * search. The next search will start over and detect the same set of devices
56 * on a static 1-wire bus. Memory is not allocated based on this number, just
57 * on the number of devices known to the kernel. Having a high number does not
58 * consume additional resources. As a special case, if there is only one
59 * device on the network and w1_max_slave_count is set to 1, the device id can
60 * be read directly skipping the normal slower search process.
62 module_param_named(max_slave_count
, w1_max_slave_count
, int, 0);
63 MODULE_PARM_DESC(max_slave_count
,
64 "maximum number of slaves detected in a search");
65 module_param_named(slave_ttl
, w1_max_slave_ttl
, int, 0);
66 MODULE_PARM_DESC(slave_ttl
,
67 "Number of searches not seeing a slave before it will be removed");
69 DEFINE_MUTEX(w1_mlock
);
70 LIST_HEAD(w1_masters
);
72 static int w1_master_match(struct device
*dev
, struct device_driver
*drv
)
77 static int w1_master_probe(struct device
*dev
)
82 static void w1_master_release(struct device
*dev
)
84 struct w1_master
*md
= dev_to_w1_master(dev
);
86 dev_dbg(dev
, "%s: Releasing %s.\n", __func__
, md
->name
);
87 memset(md
, 0, sizeof(struct w1_master
) + sizeof(struct w1_bus_master
));
91 static void w1_slave_release(struct device
*dev
)
93 struct w1_slave
*sl
= dev_to_w1_slave(dev
);
95 dev_dbg(dev
, "%s: Releasing %s [%p]\n", __func__
, sl
->name
, sl
);
97 w1_family_put(sl
->family
);
98 sl
->master
->slave_count
--;
101 static ssize_t
name_show(struct device
*dev
, struct device_attribute
*attr
, char *buf
)
103 struct w1_slave
*sl
= dev_to_w1_slave(dev
);
105 return sprintf(buf
, "%s\n", sl
->name
);
107 static DEVICE_ATTR_RO(name
);
109 static ssize_t
id_show(struct device
*dev
,
110 struct device_attribute
*attr
, char *buf
)
112 struct w1_slave
*sl
= dev_to_w1_slave(dev
);
113 ssize_t count
= sizeof(sl
->reg_num
);
115 memcpy(buf
, (u8
*)&sl
->reg_num
, count
);
118 static DEVICE_ATTR_RO(id
);
120 static struct attribute
*w1_slave_attrs
[] = {
125 ATTRIBUTE_GROUPS(w1_slave
);
129 static ssize_t
rw_write(struct file
*filp
, struct kobject
*kobj
,
130 struct bin_attribute
*bin_attr
, char *buf
, loff_t off
,
133 struct w1_slave
*sl
= kobj_to_w1_slave(kobj
);
135 mutex_lock(&sl
->master
->mutex
);
136 if (w1_reset_select_slave(sl
)) {
141 w1_write_block(sl
->master
, buf
, count
);
144 mutex_unlock(&sl
->master
->mutex
);
148 static ssize_t
rw_read(struct file
*filp
, struct kobject
*kobj
,
149 struct bin_attribute
*bin_attr
, char *buf
, loff_t off
,
152 struct w1_slave
*sl
= kobj_to_w1_slave(kobj
);
154 mutex_lock(&sl
->master
->mutex
);
155 w1_read_block(sl
->master
, buf
, count
);
156 mutex_unlock(&sl
->master
->mutex
);
160 static BIN_ATTR_RW(rw
, PAGE_SIZE
);
162 static struct bin_attribute
*w1_slave_bin_attrs
[] = {
167 static const struct attribute_group w1_slave_default_group
= {
168 .bin_attrs
= w1_slave_bin_attrs
,
171 static const struct attribute_group
*w1_slave_default_groups
[] = {
172 &w1_slave_default_group
,
176 static struct w1_family_ops w1_default_fops
= {
177 .groups
= w1_slave_default_groups
,
180 static struct w1_family w1_default_family
= {
181 .fops
= &w1_default_fops
,
184 static int w1_uevent(struct device
*dev
, struct kobj_uevent_env
*env
);
186 static struct bus_type w1_bus_type
= {
188 .match
= w1_master_match
,
192 struct device_driver w1_master_driver
= {
193 .name
= "w1_master_driver",
195 .probe
= w1_master_probe
,
198 struct device w1_master_device
= {
201 .init_name
= "w1 bus master",
202 .driver
= &w1_master_driver
,
203 .release
= &w1_master_release
206 static struct device_driver w1_slave_driver
= {
207 .name
= "w1_slave_driver",
212 struct device w1_slave_device
= {
215 .init_name
= "w1 bus slave",
216 .driver
= &w1_slave_driver
,
217 .release
= &w1_slave_release
221 static ssize_t
w1_master_attribute_show_name(struct device
*dev
, struct device_attribute
*attr
, char *buf
)
223 struct w1_master
*md
= dev_to_w1_master(dev
);
226 mutex_lock(&md
->mutex
);
227 count
= sprintf(buf
, "%s\n", md
->name
);
228 mutex_unlock(&md
->mutex
);
233 static ssize_t
w1_master_attribute_store_search(struct device
* dev
,
234 struct device_attribute
*attr
,
235 const char * buf
, size_t count
)
238 struct w1_master
*md
= dev_to_w1_master(dev
);
241 ret
= kstrtol(buf
, 0, &tmp
);
245 mutex_lock(&md
->mutex
);
246 md
->search_count
= tmp
;
247 mutex_unlock(&md
->mutex
);
248 /* Only wake if it is going to be searching. */
250 wake_up_process(md
->thread
);
255 static ssize_t
w1_master_attribute_show_search(struct device
*dev
,
256 struct device_attribute
*attr
,
259 struct w1_master
*md
= dev_to_w1_master(dev
);
262 mutex_lock(&md
->mutex
);
263 count
= sprintf(buf
, "%d\n", md
->search_count
);
264 mutex_unlock(&md
->mutex
);
269 static ssize_t
w1_master_attribute_store_pullup(struct device
*dev
,
270 struct device_attribute
*attr
,
271 const char *buf
, size_t count
)
274 struct w1_master
*md
= dev_to_w1_master(dev
);
277 ret
= kstrtol(buf
, 0, &tmp
);
281 mutex_lock(&md
->mutex
);
282 md
->enable_pullup
= tmp
;
283 mutex_unlock(&md
->mutex
);
288 static ssize_t
w1_master_attribute_show_pullup(struct device
*dev
,
289 struct device_attribute
*attr
,
292 struct w1_master
*md
= dev_to_w1_master(dev
);
295 mutex_lock(&md
->mutex
);
296 count
= sprintf(buf
, "%d\n", md
->enable_pullup
);
297 mutex_unlock(&md
->mutex
);
302 static ssize_t
w1_master_attribute_show_pointer(struct device
*dev
, struct device_attribute
*attr
, char *buf
)
304 struct w1_master
*md
= dev_to_w1_master(dev
);
307 mutex_lock(&md
->mutex
);
308 count
= sprintf(buf
, "0x%p\n", md
->bus_master
);
309 mutex_unlock(&md
->mutex
);
313 static ssize_t
w1_master_attribute_show_timeout(struct device
*dev
, struct device_attribute
*attr
, char *buf
)
316 count
= sprintf(buf
, "%d\n", w1_timeout
);
320 static ssize_t
w1_master_attribute_store_max_slave_count(struct device
*dev
,
321 struct device_attribute
*attr
, const char *buf
, size_t count
)
324 struct w1_master
*md
= dev_to_w1_master(dev
);
326 if (kstrtoint(buf
, 0, &tmp
) == -EINVAL
|| tmp
< 1)
329 mutex_lock(&md
->mutex
);
330 md
->max_slave_count
= tmp
;
331 /* allow each time the max_slave_count is updated */
332 clear_bit(W1_WARN_MAX_COUNT
, &md
->flags
);
333 mutex_unlock(&md
->mutex
);
338 static ssize_t
w1_master_attribute_show_max_slave_count(struct device
*dev
, struct device_attribute
*attr
, char *buf
)
340 struct w1_master
*md
= dev_to_w1_master(dev
);
343 mutex_lock(&md
->mutex
);
344 count
= sprintf(buf
, "%d\n", md
->max_slave_count
);
345 mutex_unlock(&md
->mutex
);
349 static ssize_t
w1_master_attribute_show_attempts(struct device
*dev
, struct device_attribute
*attr
, char *buf
)
351 struct w1_master
*md
= dev_to_w1_master(dev
);
354 mutex_lock(&md
->mutex
);
355 count
= sprintf(buf
, "%lu\n", md
->attempts
);
356 mutex_unlock(&md
->mutex
);
360 static ssize_t
w1_master_attribute_show_slave_count(struct device
*dev
, struct device_attribute
*attr
, char *buf
)
362 struct w1_master
*md
= dev_to_w1_master(dev
);
365 mutex_lock(&md
->mutex
);
366 count
= sprintf(buf
, "%d\n", md
->slave_count
);
367 mutex_unlock(&md
->mutex
);
371 static ssize_t
w1_master_attribute_show_slaves(struct device
*dev
,
372 struct device_attribute
*attr
, char *buf
)
374 struct w1_master
*md
= dev_to_w1_master(dev
);
376 struct list_head
*ent
, *n
;
377 struct w1_slave
*sl
= NULL
;
379 mutex_lock(&md
->list_mutex
);
381 list_for_each_safe(ent
, n
, &md
->slist
) {
382 sl
= list_entry(ent
, struct w1_slave
, w1_slave_entry
);
384 c
-= snprintf(buf
+ PAGE_SIZE
- c
, c
, "%s\n", sl
->name
);
387 c
-= snprintf(buf
+ PAGE_SIZE
- c
, c
, "not found.\n");
389 mutex_unlock(&md
->list_mutex
);
391 return PAGE_SIZE
- c
;
394 static ssize_t
w1_master_attribute_show_add(struct device
*dev
,
395 struct device_attribute
*attr
, char *buf
)
398 c
-= snprintf(buf
+PAGE_SIZE
- c
, c
,
399 "write device id xx-xxxxxxxxxxxx to add slave\n");
400 return PAGE_SIZE
- c
;
403 static int w1_atoreg_num(struct device
*dev
, const char *buf
, size_t count
,
404 struct w1_reg_num
*rn
)
407 unsigned long long id
;
411 /* The CRC value isn't read from the user because the sysfs directory
412 * doesn't include it and most messages from the bus search don't
413 * print it either. It would be unreasonable for the user to then
416 const char *error_msg
= "bad slave string format, expecting "
420 dev_err(dev
, "%s", error_msg
);
423 i
= sscanf(buf
, "%02x-%012llx", &family
, &id
);
425 dev_err(dev
, "%s", error_msg
);
431 rn64_le
= cpu_to_le64(*(u64
*)rn
);
432 rn
->crc
= w1_calc_crc8((u8
*)&rn64_le
, 7);
435 dev_info(dev
, "With CRC device is %02x.%012llx.%02x.\n",
436 rn
->family
, (unsigned long long)rn
->id
, rn
->crc
);
442 /* Searches the slaves in the w1_master and returns a pointer or NULL.
443 * Note: must not hold list_mutex
445 struct w1_slave
*w1_slave_search_device(struct w1_master
*dev
,
446 struct w1_reg_num
*rn
)
449 mutex_lock(&dev
->list_mutex
);
450 list_for_each_entry(sl
, &dev
->slist
, w1_slave_entry
) {
451 if (sl
->reg_num
.family
== rn
->family
&&
452 sl
->reg_num
.id
== rn
->id
&&
453 sl
->reg_num
.crc
== rn
->crc
) {
454 mutex_unlock(&dev
->list_mutex
);
458 mutex_unlock(&dev
->list_mutex
);
462 static ssize_t
w1_master_attribute_store_add(struct device
*dev
,
463 struct device_attribute
*attr
,
464 const char *buf
, size_t count
)
466 struct w1_master
*md
= dev_to_w1_master(dev
);
467 struct w1_reg_num rn
;
469 ssize_t result
= count
;
471 if (w1_atoreg_num(dev
, buf
, count
, &rn
))
474 mutex_lock(&md
->mutex
);
475 sl
= w1_slave_search_device(md
, &rn
);
476 /* It would be nice to do a targeted search one the one-wire bus
477 * for the new device to see if it is out there or not. But the
478 * current search doesn't support that.
481 dev_info(dev
, "Device %s already exists\n", sl
->name
);
484 w1_attach_slave_device(md
, &rn
);
486 mutex_unlock(&md
->mutex
);
491 static ssize_t
w1_master_attribute_show_remove(struct device
*dev
,
492 struct device_attribute
*attr
, char *buf
)
495 c
-= snprintf(buf
+PAGE_SIZE
- c
, c
,
496 "write device id xx-xxxxxxxxxxxx to remove slave\n");
497 return PAGE_SIZE
- c
;
500 static ssize_t
w1_master_attribute_store_remove(struct device
*dev
,
501 struct device_attribute
*attr
,
502 const char *buf
, size_t count
)
504 struct w1_master
*md
= dev_to_w1_master(dev
);
505 struct w1_reg_num rn
;
507 ssize_t result
= count
;
509 if (w1_atoreg_num(dev
, buf
, count
, &rn
))
512 mutex_lock(&md
->mutex
);
513 sl
= w1_slave_search_device(md
, &rn
);
515 result
= w1_slave_detach(sl
);
516 /* refcnt 0 means it was detached in the call */
520 dev_info(dev
, "Device %02x-%012llx doesn't exists\n", rn
.family
,
521 (unsigned long long)rn
.id
);
524 mutex_unlock(&md
->mutex
);
529 #define W1_MASTER_ATTR_RO(_name, _mode) \
530 struct device_attribute w1_master_attribute_##_name = \
531 __ATTR(w1_master_##_name, _mode, \
532 w1_master_attribute_show_##_name, NULL)
534 #define W1_MASTER_ATTR_RW(_name, _mode) \
535 struct device_attribute w1_master_attribute_##_name = \
536 __ATTR(w1_master_##_name, _mode, \
537 w1_master_attribute_show_##_name, \
538 w1_master_attribute_store_##_name)
540 static W1_MASTER_ATTR_RO(name
, S_IRUGO
);
541 static W1_MASTER_ATTR_RO(slaves
, S_IRUGO
);
542 static W1_MASTER_ATTR_RO(slave_count
, S_IRUGO
);
543 static W1_MASTER_ATTR_RW(max_slave_count
, S_IRUGO
| S_IWUSR
| S_IWGRP
);
544 static W1_MASTER_ATTR_RO(attempts
, S_IRUGO
);
545 static W1_MASTER_ATTR_RO(timeout
, S_IRUGO
);
546 static W1_MASTER_ATTR_RO(pointer
, S_IRUGO
);
547 static W1_MASTER_ATTR_RW(search
, S_IRUGO
| S_IWUSR
| S_IWGRP
);
548 static W1_MASTER_ATTR_RW(pullup
, S_IRUGO
| S_IWUSR
| S_IWGRP
);
549 static W1_MASTER_ATTR_RW(add
, S_IRUGO
| S_IWUSR
| S_IWGRP
);
550 static W1_MASTER_ATTR_RW(remove
, S_IRUGO
| S_IWUSR
| S_IWGRP
);
552 static struct attribute
*w1_master_default_attrs
[] = {
553 &w1_master_attribute_name
.attr
,
554 &w1_master_attribute_slaves
.attr
,
555 &w1_master_attribute_slave_count
.attr
,
556 &w1_master_attribute_max_slave_count
.attr
,
557 &w1_master_attribute_attempts
.attr
,
558 &w1_master_attribute_timeout
.attr
,
559 &w1_master_attribute_pointer
.attr
,
560 &w1_master_attribute_search
.attr
,
561 &w1_master_attribute_pullup
.attr
,
562 &w1_master_attribute_add
.attr
,
563 &w1_master_attribute_remove
.attr
,
567 static struct attribute_group w1_master_defattr_group
= {
568 .attrs
= w1_master_default_attrs
,
571 int w1_create_master_attributes(struct w1_master
*master
)
573 return sysfs_create_group(&master
->dev
.kobj
, &w1_master_defattr_group
);
576 void w1_destroy_master_attributes(struct w1_master
*master
)
578 sysfs_remove_group(&master
->dev
.kobj
, &w1_master_defattr_group
);
581 static int w1_uevent(struct device
*dev
, struct kobj_uevent_env
*env
)
583 struct w1_master
*md
= NULL
;
584 struct w1_slave
*sl
= NULL
;
585 char *event_owner
, *name
;
588 if (dev
->driver
== &w1_master_driver
) {
589 md
= container_of(dev
, struct w1_master
, dev
);
590 event_owner
= "master";
592 } else if (dev
->driver
== &w1_slave_driver
) {
593 sl
= container_of(dev
, struct w1_slave
, dev
);
594 event_owner
= "slave";
597 dev_dbg(dev
, "Unknown event.\n");
601 dev_dbg(dev
, "Hotplug event for %s %s, bus_id=%s.\n",
602 event_owner
, name
, dev_name(dev
));
604 if (dev
->driver
!= &w1_slave_driver
|| !sl
)
607 err
= add_uevent_var(env
, "W1_FID=%02X", sl
->reg_num
.family
);
611 err
= add_uevent_var(env
, "W1_SLAVE_ID=%024LX",
612 (unsigned long long)sl
->reg_num
.id
);
618 * Handle sysfs file creation and removal here, before userspace is told that
619 * the device is added / removed from the system
621 static int w1_bus_notify(struct notifier_block
*nb
, unsigned long action
,
624 struct device
*dev
= data
;
626 struct w1_family_ops
*fops
;
630 * Only care about slave devices at the moment. Yes, we should use a
631 * separate "type" for this, but for now, look at the release function
632 * to know which type it is...
634 if (dev
->release
!= w1_slave_release
)
637 sl
= dev_to_w1_slave(dev
);
638 fops
= sl
->family
->fops
;
644 case BUS_NOTIFY_ADD_DEVICE
:
645 /* if the family driver needs to initialize something... */
646 if (fops
->add_slave
) {
647 err
= fops
->add_slave(sl
);
650 "add_slave() call failed. err=%d\n",
656 err
= sysfs_create_groups(&sl
->dev
.kobj
, fops
->groups
);
659 "sysfs group creation failed. err=%d\n",
666 case BUS_NOTIFY_DEL_DEVICE
:
667 if (fops
->remove_slave
)
668 sl
->family
->fops
->remove_slave(sl
);
670 sysfs_remove_groups(&sl
->dev
.kobj
, fops
->groups
);
676 static struct notifier_block w1_bus_nb
= {
677 .notifier_call
= w1_bus_notify
,
680 static int __w1_attach_slave_device(struct w1_slave
*sl
)
684 sl
->dev
.parent
= &sl
->master
->dev
;
685 sl
->dev
.driver
= &w1_slave_driver
;
686 sl
->dev
.bus
= &w1_bus_type
;
687 sl
->dev
.release
= &w1_slave_release
;
688 sl
->dev
.groups
= w1_slave_groups
;
690 dev_set_name(&sl
->dev
, "%02x-%012llx",
691 (unsigned int) sl
->reg_num
.family
,
692 (unsigned long long) sl
->reg_num
.id
);
693 snprintf(&sl
->name
[0], sizeof(sl
->name
),
695 (unsigned int) sl
->reg_num
.family
,
696 (unsigned long long) sl
->reg_num
.id
);
698 dev_dbg(&sl
->dev
, "%s: registering %s as %p.\n", __func__
,
699 dev_name(&sl
->dev
), sl
);
701 err
= device_register(&sl
->dev
);
704 "Device registration [%s] failed. err=%d\n",
705 dev_name(&sl
->dev
), err
);
710 dev_set_uevent_suppress(&sl
->dev
, false);
711 kobject_uevent(&sl
->dev
.kobj
, KOBJ_ADD
);
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
);
720 int w1_attach_slave_device(struct w1_master
*dev
, struct w1_reg_num
*rn
)
725 struct w1_netlink_msg msg
;
727 sl
= kzalloc(sizeof(struct w1_slave
), GFP_KERNEL
);
730 "%s: failed to allocate new slave device.\n",
736 sl
->owner
= THIS_MODULE
;
738 set_bit(W1_SLAVE_ACTIVE
, &sl
->flags
);
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
);
745 /* slave modules need to be loaded in a context with unlocked mutex */
746 mutex_unlock(&dev
->mutex
);
747 request_module("w1-family-0x%0x", rn
->family
);
748 mutex_lock(&dev
->mutex
);
750 spin_lock(&w1_flock
);
751 f
= w1_family_registered(rn
->family
);
753 f
= &w1_default_family
;
754 dev_info(&dev
->dev
, "Family %x for %02x.%012llx.%02x is not registered.\n",
755 rn
->family
, rn
->family
,
756 (unsigned long long)rn
->id
, rn
->crc
);
759 spin_unlock(&w1_flock
);
764 err
= __w1_attach_slave_device(sl
);
766 dev_err(&dev
->dev
, "%s: Attaching %s failed.\n", __func__
,
768 w1_family_put(sl
->family
);
773 sl
->ttl
= dev
->slave_ttl
;
776 memcpy(msg
.id
.id
, rn
, sizeof(msg
.id
));
777 msg
.type
= W1_SLAVE_ADD
;
778 w1_netlink_send(dev
, &msg
);
783 int w1_unref_slave(struct w1_slave
*sl
)
785 struct w1_master
*dev
= sl
->master
;
787 mutex_lock(&dev
->list_mutex
);
788 refcnt
= atomic_sub_return(1, &sl
->refcnt
);
790 struct w1_netlink_msg msg
;
792 dev_dbg(&sl
->dev
, "%s: detaching %s [%p].\n", __func__
,
795 list_del(&sl
->w1_slave_entry
);
797 memset(&msg
, 0, sizeof(msg
));
798 memcpy(msg
.id
.id
, &sl
->reg_num
, sizeof(msg
.id
));
799 msg
.type
= W1_SLAVE_REMOVE
;
800 w1_netlink_send(sl
->master
, &msg
);
802 device_unregister(&sl
->dev
);
804 memset(sl
, 0, sizeof(*sl
));
808 atomic_dec(&dev
->refcnt
);
809 mutex_unlock(&dev
->list_mutex
);
813 int w1_slave_detach(struct w1_slave
*sl
)
815 /* Only detach a slave once as it decreases the refcnt each time. */
817 mutex_lock(&sl
->master
->list_mutex
);
818 destroy_now
= !test_bit(W1_SLAVE_DETACH
, &sl
->flags
);
819 set_bit(W1_SLAVE_DETACH
, &sl
->flags
);
820 mutex_unlock(&sl
->master
->list_mutex
);
823 destroy_now
= !w1_unref_slave(sl
);
824 return destroy_now
? 0 : -EBUSY
;
827 struct w1_master
*w1_search_master_id(u32 id
)
829 struct w1_master
*dev
;
832 mutex_lock(&w1_mlock
);
833 list_for_each_entry(dev
, &w1_masters
, w1_master_entry
) {
836 atomic_inc(&dev
->refcnt
);
840 mutex_unlock(&w1_mlock
);
842 return (found
)?dev
:NULL
;
845 struct w1_slave
*w1_search_slave(struct w1_reg_num
*id
)
847 struct w1_master
*dev
;
848 struct w1_slave
*sl
= NULL
;
851 mutex_lock(&w1_mlock
);
852 list_for_each_entry(dev
, &w1_masters
, w1_master_entry
) {
853 mutex_lock(&dev
->list_mutex
);
854 list_for_each_entry(sl
, &dev
->slist
, w1_slave_entry
) {
855 if (sl
->reg_num
.family
== id
->family
&&
856 sl
->reg_num
.id
== id
->id
&&
857 sl
->reg_num
.crc
== id
->crc
) {
859 atomic_inc(&dev
->refcnt
);
860 atomic_inc(&sl
->refcnt
);
864 mutex_unlock(&dev
->list_mutex
);
869 mutex_unlock(&w1_mlock
);
871 return (found
)?sl
:NULL
;
874 void w1_reconnect_slaves(struct w1_family
*f
, int attach
)
876 struct w1_slave
*sl
, *sln
;
877 struct w1_master
*dev
;
879 mutex_lock(&w1_mlock
);
880 list_for_each_entry(dev
, &w1_masters
, w1_master_entry
) {
881 dev_dbg(&dev
->dev
, "Reconnecting slaves in device %s "
882 "for family %02x.\n", dev
->name
, f
->fid
);
883 mutex_lock(&dev
->mutex
);
884 mutex_lock(&dev
->list_mutex
);
885 list_for_each_entry_safe(sl
, sln
, &dev
->slist
, w1_slave_entry
) {
886 /* If it is a new family, slaves with the default
887 * family driver and are that family will be
888 * connected. If the family is going away, devices
889 * matching that family are reconneced.
891 if ((attach
&& sl
->family
->fid
== W1_FAMILY_DEFAULT
892 && sl
->reg_num
.family
== f
->fid
) ||
893 (!attach
&& sl
->family
->fid
== f
->fid
)) {
894 struct w1_reg_num rn
;
896 mutex_unlock(&dev
->list_mutex
);
897 memcpy(&rn
, &sl
->reg_num
, sizeof(rn
));
898 /* If it was already in use let the automatic
899 * scan pick it up again later.
901 if (!w1_slave_detach(sl
))
902 w1_attach_slave_device(dev
, &rn
);
903 mutex_lock(&dev
->list_mutex
);
906 dev_dbg(&dev
->dev
, "Reconnecting slaves in device %s "
907 "has been finished.\n", dev
->name
);
908 mutex_unlock(&dev
->list_mutex
);
909 mutex_unlock(&dev
->mutex
);
911 mutex_unlock(&w1_mlock
);
914 void w1_slave_found(struct w1_master
*dev
, u64 rn
)
917 struct w1_reg_num
*tmp
;
918 u64 rn_le
= cpu_to_le64(rn
);
920 atomic_inc(&dev
->refcnt
);
922 tmp
= (struct w1_reg_num
*) &rn
;
924 sl
= w1_slave_search_device(dev
, tmp
);
926 set_bit(W1_SLAVE_ACTIVE
, &sl
->flags
);
928 if (rn
&& tmp
->crc
== w1_calc_crc8((u8
*)&rn_le
, 7))
929 w1_attach_slave_device(dev
, tmp
);
932 atomic_dec(&dev
->refcnt
);
936 * w1_search() - Performs a ROM Search & registers any devices found.
937 * @dev: The master device to search
938 * @search_type: W1_SEARCH to search all devices, or W1_ALARM_SEARCH
939 * to return only devices in the alarmed state
940 * @cb: Function to call when a device is found
942 * The 1-wire search is a simple binary tree search.
943 * For each bit of the address, we read two bits and write one bit.
944 * The bit written will put to sleep all devies that don't match that bit.
945 * When the two reads differ, the direction choice is obvious.
946 * When both bits are 0, we must choose a path to take.
947 * When we can scan all 64 bits without having to choose a path, we are done.
949 * See "Application note 187 1-wire search algorithm" at www.maxim-ic.com
952 void w1_search(struct w1_master
*dev
, u8 search_type
, w1_slave_found_callback cb
)
954 u64 last_rn
, rn
, tmp64
;
955 int i
, slave_count
= 0;
956 int last_zero
, last_device
;
957 int search_bit
, desc_bit
;
968 while ( !last_device
&& (slave_count
++ < dev
->max_slave_count
) ) {
973 * Reset bus and all 1-wire device state machines
974 * so they can respond to our requests.
976 * Return 0 - device(s) present, 1 - no devices present.
978 mutex_lock(&dev
->bus_mutex
);
979 if (w1_reset_bus(dev
)) {
980 mutex_unlock(&dev
->bus_mutex
);
981 dev_dbg(&dev
->dev
, "No devices present on the wire.\n");
985 /* Do fast search on single slave bus */
986 if (dev
->max_slave_count
== 1) {
988 w1_write_8(dev
, W1_READ_ROM
);
989 rv
= w1_read_block(dev
, (u8
*)&rn
, 8);
990 mutex_unlock(&dev
->bus_mutex
);
998 /* Start the search */
999 w1_write_8(dev
, search_type
);
1000 for (i
= 0; i
< 64; ++i
) {
1001 /* Determine the direction/search bit */
1003 search_bit
= 1; /* took the 0 path last time, so take the 1 path */
1004 else if (i
> desc_bit
)
1005 search_bit
= 0; /* take the 0 path on the next branch */
1007 search_bit
= ((last_rn
>> i
) & 0x1);
1009 /* Read two bits and write one bit */
1010 triplet_ret
= w1_triplet(dev
, search_bit
);
1012 /* quit if no device responded */
1013 if ( (triplet_ret
& 0x03) == 0x03 )
1016 /* If both directions were valid, and we took the 0 path... */
1017 if (triplet_ret
== 0)
1020 /* extract the direction taken & update the device number */
1021 tmp64
= (triplet_ret
>> 2);
1024 if (test_bit(W1_ABORT_SEARCH
, &dev
->flags
)) {
1025 mutex_unlock(&dev
->bus_mutex
);
1026 dev_dbg(&dev
->dev
, "Abort w1_search\n");
1030 mutex_unlock(&dev
->bus_mutex
);
1032 if ( (triplet_ret
& 0x03) != 0x03 ) {
1033 if ((desc_bit
== last_zero
) || (last_zero
< 0)) {
1037 dev
->search_id
= rn
;
1039 desc_bit
= last_zero
;
1043 if (!last_device
&& slave_count
== dev
->max_slave_count
&&
1044 !test_bit(W1_WARN_MAX_COUNT
, &dev
->flags
)) {
1045 /* Only max_slave_count will be scanned in a search,
1046 * but it will start where it left off next search
1047 * until all ids are identified and then it will start
1048 * over. A continued search will report the previous
1049 * last id as the first id (provided it is still on the
1052 dev_info(&dev
->dev
, "%s: max_slave_count %d reached, "
1053 "will continue next search.\n", __func__
,
1054 dev
->max_slave_count
);
1055 set_bit(W1_WARN_MAX_COUNT
, &dev
->flags
);
1060 void w1_search_process_cb(struct w1_master
*dev
, u8 search_type
,
1061 w1_slave_found_callback cb
)
1063 struct w1_slave
*sl
, *sln
;
1065 mutex_lock(&dev
->list_mutex
);
1066 list_for_each_entry(sl
, &dev
->slist
, w1_slave_entry
)
1067 clear_bit(W1_SLAVE_ACTIVE
, &sl
->flags
);
1068 mutex_unlock(&dev
->list_mutex
);
1070 w1_search_devices(dev
, search_type
, cb
);
1072 mutex_lock(&dev
->list_mutex
);
1073 list_for_each_entry_safe(sl
, sln
, &dev
->slist
, w1_slave_entry
) {
1074 if (!test_bit(W1_SLAVE_ACTIVE
, &sl
->flags
) && !--sl
->ttl
) {
1075 mutex_unlock(&dev
->list_mutex
);
1076 w1_slave_detach(sl
);
1077 mutex_lock(&dev
->list_mutex
);
1079 else if (test_bit(W1_SLAVE_ACTIVE
, &sl
->flags
))
1080 sl
->ttl
= dev
->slave_ttl
;
1082 mutex_unlock(&dev
->list_mutex
);
1084 if (dev
->search_count
> 0)
1085 dev
->search_count
--;
1088 static void w1_search_process(struct w1_master
*dev
, u8 search_type
)
1090 w1_search_process_cb(dev
, search_type
, w1_slave_found
);
1094 * w1_process_callbacks() - execute each dev->async_list callback entry
1095 * @dev: w1_master device
1097 * Return: 1 if there were commands to executed 0 otherwise
1099 int w1_process_callbacks(struct w1_master
*dev
)
1102 struct w1_async_cmd
*async_cmd
, *async_n
;
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
,
1108 /* drop the lock, if it is a search it can take a long
1110 mutex_unlock(&dev
->list_mutex
);
1111 async_cmd
->cb(dev
, async_cmd
);
1113 mutex_lock(&dev
->list_mutex
);
1119 int w1_process(void *data
)
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.
1125 const unsigned long jtime
= msecs_to_jiffies(w1_timeout
* 1000);
1126 /* remainder if it woke up early */
1127 unsigned long jremain
= 0;
1131 if (!jremain
&& dev
->search_count
) {
1132 mutex_lock(&dev
->mutex
);
1133 w1_search_process(dev
, W1_SEARCH
);
1134 mutex_unlock(&dev
->mutex
);
1137 mutex_lock(&dev
->list_mutex
);
1138 /* Note, w1_process_callback drops the lock while processing,
1139 * but locks it again before returning.
1141 if (!w1_process_callbacks(dev
) && jremain
) {
1142 /* a wake up is either to stop the thread, process
1143 * callbacks, or search, it isn't process callbacks, so
1144 * schedule a search.
1150 __set_current_state(TASK_INTERRUPTIBLE
);
1152 /* hold list_mutex until after interruptible to prevent loosing
1153 * the wakeup signal when async_cmd is added.
1155 mutex_unlock(&dev
->list_mutex
);
1157 if (kthread_should_stop())
1160 /* Only sleep when the search is active. */
1161 if (dev
->search_count
) {
1164 jremain
= schedule_timeout(jremain
);
1170 atomic_dec(&dev
->refcnt
);
1175 static int __init
w1_init(void)
1179 printk(KERN_INFO
"Driver for 1-wire Dallas network protocol.\n");
1183 retval
= bus_register(&w1_bus_type
);
1185 printk(KERN_ERR
"Failed to register bus. err=%d.\n", retval
);
1186 goto err_out_exit_init
;
1189 retval
= bus_register_notifier(&w1_bus_type
, &w1_bus_nb
);
1191 goto err_out_bus_unregister
;
1193 retval
= driver_register(&w1_master_driver
);
1196 "Failed to register master driver. err=%d.\n",
1198 goto err_out_bus_unregister
;
1201 retval
= driver_register(&w1_slave_driver
);
1204 "Failed to register slave driver. err=%d.\n",
1206 goto err_out_master_unregister
;
1212 /* For undoing the slave register if there was a step after it. */
1213 err_out_slave_unregister
:
1214 driver_unregister(&w1_slave_driver
);
1217 err_out_master_unregister
:
1218 driver_unregister(&w1_master_driver
);
1220 err_out_bus_unregister
:
1221 bus_unregister(&w1_bus_type
);
1227 static void __exit
w1_fini(void)
1229 struct w1_master
*dev
;
1231 /* Set netlink removal messages and some cleanup */
1232 list_for_each_entry(dev
, &w1_masters
, w1_master_entry
)
1233 __w1_remove_master_device(dev
);
1237 driver_unregister(&w1_slave_driver
);
1238 driver_unregister(&w1_master_driver
);
1239 bus_unregister(&w1_bus_type
);
1242 module_init(w1_init
);
1243 module_exit(w1_fini
);