2 * Copyright (c) 2004 Evgeniy Polyakov <zbr@ioremap.net>
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
15 #include <linux/delay.h>
16 #include <linux/kernel.h>
17 #include <linux/module.h>
18 #include <linux/moduleparam.h>
19 #include <linux/list.h>
20 #include <linux/interrupt.h>
21 #include <linux/spinlock.h>
22 #include <linux/timer.h>
23 #include <linux/device.h>
24 #include <linux/slab.h>
25 #include <linux/sched.h>
26 #include <linux/kthread.h>
27 #include <linux/freezer.h>
29 #include <linux/atomic.h>
31 #include "w1_internal.h"
32 #include "w1_netlink.h"
34 #define W1_FAMILY_DEFAULT 0
36 static int w1_timeout
= 10;
37 module_param_named(timeout
, w1_timeout
, int, 0);
38 MODULE_PARM_DESC(timeout
, "time in seconds between automatic slave searches");
40 static int w1_timeout_us
= 0;
41 module_param_named(timeout_us
, w1_timeout_us
, int, 0);
42 MODULE_PARM_DESC(timeout_us
,
43 "time in microseconds between automatic slave searches");
45 /* A search stops when w1_max_slave_count devices have been found in that
46 * search. The next search will start over and detect the same set of devices
47 * on a static 1-wire bus. Memory is not allocated based on this number, just
48 * on the number of devices known to the kernel. Having a high number does not
49 * consume additional resources. As a special case, if there is only one
50 * device on the network and w1_max_slave_count is set to 1, the device id can
51 * be read directly skipping the normal slower search process.
53 int w1_max_slave_count
= 64;
54 module_param_named(max_slave_count
, w1_max_slave_count
, int, 0);
55 MODULE_PARM_DESC(max_slave_count
,
56 "maximum number of slaves detected in a search");
58 int w1_max_slave_ttl
= 10;
59 module_param_named(slave_ttl
, w1_max_slave_ttl
, int, 0);
60 MODULE_PARM_DESC(slave_ttl
,
61 "Number of searches not seeing a slave before it will be removed");
63 DEFINE_MUTEX(w1_mlock
);
64 LIST_HEAD(w1_masters
);
66 static int w1_master_match(struct device
*dev
, struct device_driver
*drv
)
71 static int w1_master_probe(struct device
*dev
)
76 static void w1_master_release(struct device
*dev
)
78 struct w1_master
*md
= dev_to_w1_master(dev
);
80 dev_dbg(dev
, "%s: Releasing %s.\n", __func__
, md
->name
);
81 memset(md
, 0, sizeof(struct w1_master
) + sizeof(struct w1_bus_master
));
85 static void w1_slave_release(struct device
*dev
)
87 struct w1_slave
*sl
= dev_to_w1_slave(dev
);
89 dev_dbg(dev
, "%s: Releasing %s [%p]\n", __func__
, sl
->name
, sl
);
91 w1_family_put(sl
->family
);
92 sl
->master
->slave_count
--;
95 static ssize_t
name_show(struct device
*dev
, struct device_attribute
*attr
, char *buf
)
97 struct w1_slave
*sl
= dev_to_w1_slave(dev
);
99 return sprintf(buf
, "%s\n", sl
->name
);
101 static DEVICE_ATTR_RO(name
);
103 static ssize_t
id_show(struct device
*dev
,
104 struct device_attribute
*attr
, char *buf
)
106 struct w1_slave
*sl
= dev_to_w1_slave(dev
);
107 ssize_t count
= sizeof(sl
->reg_num
);
109 memcpy(buf
, (u8
*)&sl
->reg_num
, count
);
112 static DEVICE_ATTR_RO(id
);
114 static struct attribute
*w1_slave_attrs
[] = {
119 ATTRIBUTE_GROUPS(w1_slave
);
123 static ssize_t
rw_write(struct file
*filp
, struct kobject
*kobj
,
124 struct bin_attribute
*bin_attr
, char *buf
, loff_t off
,
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
rw_read(struct file
*filp
, struct kobject
*kobj
,
143 struct bin_attribute
*bin_attr
, char *buf
, loff_t off
,
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 BIN_ATTR_RW(rw
, PAGE_SIZE
);
156 static struct bin_attribute
*w1_slave_bin_attrs
[] = {
161 static const struct attribute_group w1_slave_default_group
= {
162 .bin_attrs
= w1_slave_bin_attrs
,
165 static const struct attribute_group
*w1_slave_default_groups
[] = {
166 &w1_slave_default_group
,
170 static struct w1_family_ops w1_default_fops
= {
171 .groups
= w1_slave_default_groups
,
174 static struct w1_family w1_default_family
= {
175 .fops
= &w1_default_fops
,
178 static int w1_uevent(struct device
*dev
, struct kobj_uevent_env
*env
);
180 static struct bus_type w1_bus_type
= {
182 .match
= w1_master_match
,
186 struct device_driver w1_master_driver
= {
187 .name
= "w1_master_driver",
189 .probe
= w1_master_probe
,
192 struct device w1_master_device
= {
195 .init_name
= "w1 bus master",
196 .driver
= &w1_master_driver
,
197 .release
= &w1_master_release
200 static struct device_driver w1_slave_driver
= {
201 .name
= "w1_slave_driver",
206 struct device w1_slave_device
= {
209 .init_name
= "w1 bus slave",
210 .driver
= &w1_slave_driver
,
211 .release
= &w1_slave_release
215 static ssize_t
w1_master_attribute_show_name(struct device
*dev
, struct device_attribute
*attr
, char *buf
)
217 struct w1_master
*md
= dev_to_w1_master(dev
);
220 mutex_lock(&md
->mutex
);
221 count
= sprintf(buf
, "%s\n", md
->name
);
222 mutex_unlock(&md
->mutex
);
227 static ssize_t
w1_master_attribute_store_search(struct device
* dev
,
228 struct device_attribute
*attr
,
229 const char * buf
, size_t count
)
232 struct w1_master
*md
= dev_to_w1_master(dev
);
235 ret
= kstrtol(buf
, 0, &tmp
);
239 mutex_lock(&md
->mutex
);
240 md
->search_count
= tmp
;
241 mutex_unlock(&md
->mutex
);
242 /* Only wake if it is going to be searching. */
244 wake_up_process(md
->thread
);
249 static ssize_t
w1_master_attribute_show_search(struct device
*dev
,
250 struct device_attribute
*attr
,
253 struct w1_master
*md
= dev_to_w1_master(dev
);
256 mutex_lock(&md
->mutex
);
257 count
= sprintf(buf
, "%d\n", md
->search_count
);
258 mutex_unlock(&md
->mutex
);
263 static ssize_t
w1_master_attribute_store_pullup(struct device
*dev
,
264 struct device_attribute
*attr
,
265 const char *buf
, size_t count
)
268 struct w1_master
*md
= dev_to_w1_master(dev
);
271 ret
= kstrtol(buf
, 0, &tmp
);
275 mutex_lock(&md
->mutex
);
276 md
->enable_pullup
= tmp
;
277 mutex_unlock(&md
->mutex
);
282 static ssize_t
w1_master_attribute_show_pullup(struct device
*dev
,
283 struct device_attribute
*attr
,
286 struct w1_master
*md
= dev_to_w1_master(dev
);
289 mutex_lock(&md
->mutex
);
290 count
= sprintf(buf
, "%d\n", md
->enable_pullup
);
291 mutex_unlock(&md
->mutex
);
296 static ssize_t
w1_master_attribute_show_pointer(struct device
*dev
, struct device_attribute
*attr
, char *buf
)
298 struct w1_master
*md
= dev_to_w1_master(dev
);
301 mutex_lock(&md
->mutex
);
302 count
= sprintf(buf
, "0x%p\n", md
->bus_master
);
303 mutex_unlock(&md
->mutex
);
307 static ssize_t
w1_master_attribute_show_timeout(struct device
*dev
, struct device_attribute
*attr
, char *buf
)
310 count
= sprintf(buf
, "%d\n", w1_timeout
);
314 static ssize_t
w1_master_attribute_show_timeout_us(struct device
*dev
,
315 struct device_attribute
*attr
, char *buf
)
318 count
= sprintf(buf
, "%d\n", w1_timeout_us
);
322 static ssize_t
w1_master_attribute_store_max_slave_count(struct device
*dev
,
323 struct device_attribute
*attr
, const char *buf
, size_t count
)
326 struct w1_master
*md
= dev_to_w1_master(dev
);
328 if (kstrtoint(buf
, 0, &tmp
) || tmp
< 1)
331 mutex_lock(&md
->mutex
);
332 md
->max_slave_count
= tmp
;
333 /* allow each time the max_slave_count is updated */
334 clear_bit(W1_WARN_MAX_COUNT
, &md
->flags
);
335 mutex_unlock(&md
->mutex
);
340 static ssize_t
w1_master_attribute_show_max_slave_count(struct device
*dev
, struct device_attribute
*attr
, char *buf
)
342 struct w1_master
*md
= dev_to_w1_master(dev
);
345 mutex_lock(&md
->mutex
);
346 count
= sprintf(buf
, "%d\n", md
->max_slave_count
);
347 mutex_unlock(&md
->mutex
);
351 static ssize_t
w1_master_attribute_show_attempts(struct device
*dev
, struct device_attribute
*attr
, char *buf
)
353 struct w1_master
*md
= dev_to_w1_master(dev
);
356 mutex_lock(&md
->mutex
);
357 count
= sprintf(buf
, "%lu\n", md
->attempts
);
358 mutex_unlock(&md
->mutex
);
362 static ssize_t
w1_master_attribute_show_slave_count(struct device
*dev
, struct device_attribute
*attr
, char *buf
)
364 struct w1_master
*md
= dev_to_w1_master(dev
);
367 mutex_lock(&md
->mutex
);
368 count
= sprintf(buf
, "%d\n", md
->slave_count
);
369 mutex_unlock(&md
->mutex
);
373 static ssize_t
w1_master_attribute_show_slaves(struct device
*dev
,
374 struct device_attribute
*attr
, char *buf
)
376 struct w1_master
*md
= dev_to_w1_master(dev
);
378 struct list_head
*ent
, *n
;
379 struct w1_slave
*sl
= NULL
;
381 mutex_lock(&md
->list_mutex
);
383 list_for_each_safe(ent
, n
, &md
->slist
) {
384 sl
= list_entry(ent
, struct w1_slave
, w1_slave_entry
);
386 c
-= snprintf(buf
+ PAGE_SIZE
- c
, c
, "%s\n", sl
->name
);
389 c
-= snprintf(buf
+ PAGE_SIZE
- c
, c
, "not found.\n");
391 mutex_unlock(&md
->list_mutex
);
393 return PAGE_SIZE
- c
;
396 static ssize_t
w1_master_attribute_show_add(struct device
*dev
,
397 struct device_attribute
*attr
, char *buf
)
400 c
-= snprintf(buf
+PAGE_SIZE
- c
, c
,
401 "write device id xx-xxxxxxxxxxxx to add slave\n");
402 return PAGE_SIZE
- c
;
405 static int w1_atoreg_num(struct device
*dev
, const char *buf
, size_t count
,
406 struct w1_reg_num
*rn
)
409 unsigned long long id
;
413 /* The CRC value isn't read from the user because the sysfs directory
414 * doesn't include it and most messages from the bus search don't
415 * print it either. It would be unreasonable for the user to then
418 const char *error_msg
= "bad slave string format, expecting "
422 dev_err(dev
, "%s", error_msg
);
425 i
= sscanf(buf
, "%02x-%012llx", &family
, &id
);
427 dev_err(dev
, "%s", error_msg
);
433 rn64_le
= cpu_to_le64(*(u64
*)rn
);
434 rn
->crc
= w1_calc_crc8((u8
*)&rn64_le
, 7);
437 dev_info(dev
, "With CRC device is %02x.%012llx.%02x.\n",
438 rn
->family
, (unsigned long long)rn
->id
, rn
->crc
);
444 /* Searches the slaves in the w1_master and returns a pointer or NULL.
445 * Note: must not hold list_mutex
447 struct w1_slave
*w1_slave_search_device(struct w1_master
*dev
,
448 struct w1_reg_num
*rn
)
451 mutex_lock(&dev
->list_mutex
);
452 list_for_each_entry(sl
, &dev
->slist
, w1_slave_entry
) {
453 if (sl
->reg_num
.family
== rn
->family
&&
454 sl
->reg_num
.id
== rn
->id
&&
455 sl
->reg_num
.crc
== rn
->crc
) {
456 mutex_unlock(&dev
->list_mutex
);
460 mutex_unlock(&dev
->list_mutex
);
464 static ssize_t
w1_master_attribute_store_add(struct device
*dev
,
465 struct device_attribute
*attr
,
466 const char *buf
, size_t count
)
468 struct w1_master
*md
= dev_to_w1_master(dev
);
469 struct w1_reg_num rn
;
471 ssize_t result
= count
;
473 if (w1_atoreg_num(dev
, buf
, count
, &rn
))
476 mutex_lock(&md
->mutex
);
477 sl
= w1_slave_search_device(md
, &rn
);
478 /* It would be nice to do a targeted search one the one-wire bus
479 * for the new device to see if it is out there or not. But the
480 * current search doesn't support that.
483 dev_info(dev
, "Device %s already exists\n", sl
->name
);
486 w1_attach_slave_device(md
, &rn
);
488 mutex_unlock(&md
->mutex
);
493 static ssize_t
w1_master_attribute_show_remove(struct device
*dev
,
494 struct device_attribute
*attr
, char *buf
)
497 c
-= snprintf(buf
+PAGE_SIZE
- c
, c
,
498 "write device id xx-xxxxxxxxxxxx to remove slave\n");
499 return PAGE_SIZE
- c
;
502 static ssize_t
w1_master_attribute_store_remove(struct device
*dev
,
503 struct device_attribute
*attr
,
504 const char *buf
, size_t count
)
506 struct w1_master
*md
= dev_to_w1_master(dev
);
507 struct w1_reg_num rn
;
509 ssize_t result
= count
;
511 if (w1_atoreg_num(dev
, buf
, count
, &rn
))
514 mutex_lock(&md
->mutex
);
515 sl
= w1_slave_search_device(md
, &rn
);
517 result
= w1_slave_detach(sl
);
518 /* refcnt 0 means it was detached in the call */
522 dev_info(dev
, "Device %02x-%012llx doesn't exists\n", rn
.family
,
523 (unsigned long long)rn
.id
);
526 mutex_unlock(&md
->mutex
);
531 #define W1_MASTER_ATTR_RO(_name, _mode) \
532 struct device_attribute w1_master_attribute_##_name = \
533 __ATTR(w1_master_##_name, _mode, \
534 w1_master_attribute_show_##_name, NULL)
536 #define W1_MASTER_ATTR_RW(_name, _mode) \
537 struct device_attribute w1_master_attribute_##_name = \
538 __ATTR(w1_master_##_name, _mode, \
539 w1_master_attribute_show_##_name, \
540 w1_master_attribute_store_##_name)
542 static W1_MASTER_ATTR_RO(name
, S_IRUGO
);
543 static W1_MASTER_ATTR_RO(slaves
, S_IRUGO
);
544 static W1_MASTER_ATTR_RO(slave_count
, S_IRUGO
);
545 static W1_MASTER_ATTR_RW(max_slave_count
, S_IRUGO
| S_IWUSR
| S_IWGRP
);
546 static W1_MASTER_ATTR_RO(attempts
, S_IRUGO
);
547 static W1_MASTER_ATTR_RO(timeout
, S_IRUGO
);
548 static W1_MASTER_ATTR_RO(timeout_us
, S_IRUGO
);
549 static W1_MASTER_ATTR_RO(pointer
, S_IRUGO
);
550 static W1_MASTER_ATTR_RW(search
, S_IRUGO
| S_IWUSR
| S_IWGRP
);
551 static W1_MASTER_ATTR_RW(pullup
, S_IRUGO
| S_IWUSR
| S_IWGRP
);
552 static W1_MASTER_ATTR_RW(add
, S_IRUGO
| S_IWUSR
| S_IWGRP
);
553 static W1_MASTER_ATTR_RW(remove
, S_IRUGO
| S_IWUSR
| S_IWGRP
);
555 static struct attribute
*w1_master_default_attrs
[] = {
556 &w1_master_attribute_name
.attr
,
557 &w1_master_attribute_slaves
.attr
,
558 &w1_master_attribute_slave_count
.attr
,
559 &w1_master_attribute_max_slave_count
.attr
,
560 &w1_master_attribute_attempts
.attr
,
561 &w1_master_attribute_timeout
.attr
,
562 &w1_master_attribute_timeout_us
.attr
,
563 &w1_master_attribute_pointer
.attr
,
564 &w1_master_attribute_search
.attr
,
565 &w1_master_attribute_pullup
.attr
,
566 &w1_master_attribute_add
.attr
,
567 &w1_master_attribute_remove
.attr
,
571 static struct attribute_group w1_master_defattr_group
= {
572 .attrs
= w1_master_default_attrs
,
575 int w1_create_master_attributes(struct w1_master
*master
)
577 return sysfs_create_group(&master
->dev
.kobj
, &w1_master_defattr_group
);
580 void w1_destroy_master_attributes(struct w1_master
*master
)
582 sysfs_remove_group(&master
->dev
.kobj
, &w1_master_defattr_group
);
585 static int w1_uevent(struct device
*dev
, struct kobj_uevent_env
*env
)
587 struct w1_master
*md
= NULL
;
588 struct w1_slave
*sl
= NULL
;
589 char *event_owner
, *name
;
592 if (dev
->driver
== &w1_master_driver
) {
593 md
= container_of(dev
, struct w1_master
, dev
);
594 event_owner
= "master";
596 } else if (dev
->driver
== &w1_slave_driver
) {
597 sl
= container_of(dev
, struct w1_slave
, dev
);
598 event_owner
= "slave";
601 dev_dbg(dev
, "Unknown event.\n");
605 dev_dbg(dev
, "Hotplug event for %s %s, bus_id=%s.\n",
606 event_owner
, name
, dev_name(dev
));
608 if (dev
->driver
!= &w1_slave_driver
|| !sl
)
611 err
= add_uevent_var(env
, "W1_FID=%02X", sl
->reg_num
.family
);
615 err
= add_uevent_var(env
, "W1_SLAVE_ID=%024LX",
616 (unsigned long long)sl
->reg_num
.id
);
621 static int w1_family_notify(unsigned long action
, struct w1_slave
*sl
)
623 struct w1_family_ops
*fops
;
626 fops
= sl
->family
->fops
;
632 case BUS_NOTIFY_ADD_DEVICE
:
633 /* if the family driver needs to initialize something... */
634 if (fops
->add_slave
) {
635 err
= fops
->add_slave(sl
);
638 "add_slave() call failed. err=%d\n",
644 err
= sysfs_create_groups(&sl
->dev
.kobj
, fops
->groups
);
647 "sysfs group creation failed. err=%d\n",
654 case BUS_NOTIFY_DEL_DEVICE
:
655 if (fops
->remove_slave
)
656 sl
->family
->fops
->remove_slave(sl
);
658 sysfs_remove_groups(&sl
->dev
.kobj
, fops
->groups
);
664 static int __w1_attach_slave_device(struct w1_slave
*sl
)
668 sl
->dev
.parent
= &sl
->master
->dev
;
669 sl
->dev
.driver
= &w1_slave_driver
;
670 sl
->dev
.bus
= &w1_bus_type
;
671 sl
->dev
.release
= &w1_slave_release
;
672 sl
->dev
.groups
= w1_slave_groups
;
674 dev_set_name(&sl
->dev
, "%02x-%012llx",
675 (unsigned int) sl
->reg_num
.family
,
676 (unsigned long long) sl
->reg_num
.id
);
677 snprintf(&sl
->name
[0], sizeof(sl
->name
),
679 (unsigned int) sl
->reg_num
.family
,
680 (unsigned long long) sl
->reg_num
.id
);
682 dev_dbg(&sl
->dev
, "%s: registering %s as %p.\n", __func__
,
683 dev_name(&sl
->dev
), sl
);
685 /* suppress for w1_family_notify before sending KOBJ_ADD */
686 dev_set_uevent_suppress(&sl
->dev
, true);
688 err
= device_register(&sl
->dev
);
691 "Device registration [%s] failed. err=%d\n",
692 dev_name(&sl
->dev
), err
);
695 w1_family_notify(BUS_NOTIFY_ADD_DEVICE
, sl
);
697 dev_set_uevent_suppress(&sl
->dev
, false);
698 kobject_uevent(&sl
->dev
.kobj
, KOBJ_ADD
);
700 mutex_lock(&sl
->master
->list_mutex
);
701 list_add_tail(&sl
->w1_slave_entry
, &sl
->master
->slist
);
702 mutex_unlock(&sl
->master
->list_mutex
);
707 int w1_attach_slave_device(struct w1_master
*dev
, struct w1_reg_num
*rn
)
712 struct w1_netlink_msg msg
;
714 sl
= kzalloc(sizeof(struct w1_slave
), GFP_KERNEL
);
717 "%s: failed to allocate new slave device.\n",
723 sl
->owner
= THIS_MODULE
;
725 set_bit(W1_SLAVE_ACTIVE
, &sl
->flags
);
727 memset(&msg
, 0, sizeof(msg
));
728 memcpy(&sl
->reg_num
, rn
, sizeof(sl
->reg_num
));
729 atomic_set(&sl
->refcnt
, 1);
730 atomic_inc(&sl
->master
->refcnt
);
733 /* slave modules need to be loaded in a context with unlocked mutex */
734 mutex_unlock(&dev
->mutex
);
735 request_module("w1-family-0x%02x", rn
->family
);
736 mutex_lock(&dev
->mutex
);
738 spin_lock(&w1_flock
);
739 f
= w1_family_registered(rn
->family
);
741 f
= &w1_default_family
;
742 dev_info(&dev
->dev
, "Family %x for %02x.%012llx.%02x is not registered.\n",
743 rn
->family
, rn
->family
,
744 (unsigned long long)rn
->id
, rn
->crc
);
747 spin_unlock(&w1_flock
);
751 err
= __w1_attach_slave_device(sl
);
753 dev_err(&dev
->dev
, "%s: Attaching %s failed.\n", __func__
,
756 w1_family_put(sl
->family
);
757 atomic_dec(&sl
->master
->refcnt
);
762 sl
->ttl
= dev
->slave_ttl
;
764 memcpy(msg
.id
.id
, rn
, sizeof(msg
.id
));
765 msg
.type
= W1_SLAVE_ADD
;
766 w1_netlink_send(dev
, &msg
);
771 int w1_unref_slave(struct w1_slave
*sl
)
773 struct w1_master
*dev
= sl
->master
;
775 mutex_lock(&dev
->list_mutex
);
776 refcnt
= atomic_sub_return(1, &sl
->refcnt
);
778 struct w1_netlink_msg msg
;
780 dev_dbg(&sl
->dev
, "%s: detaching %s [%p].\n", __func__
,
783 list_del(&sl
->w1_slave_entry
);
785 memset(&msg
, 0, sizeof(msg
));
786 memcpy(msg
.id
.id
, &sl
->reg_num
, sizeof(msg
.id
));
787 msg
.type
= W1_SLAVE_REMOVE
;
788 w1_netlink_send(sl
->master
, &msg
);
790 w1_family_notify(BUS_NOTIFY_DEL_DEVICE
, sl
);
791 device_unregister(&sl
->dev
);
793 memset(sl
, 0, sizeof(*sl
));
797 atomic_dec(&dev
->refcnt
);
798 mutex_unlock(&dev
->list_mutex
);
802 int w1_slave_detach(struct w1_slave
*sl
)
804 /* Only detach a slave once as it decreases the refcnt each time. */
806 mutex_lock(&sl
->master
->list_mutex
);
807 destroy_now
= !test_bit(W1_SLAVE_DETACH
, &sl
->flags
);
808 set_bit(W1_SLAVE_DETACH
, &sl
->flags
);
809 mutex_unlock(&sl
->master
->list_mutex
);
812 destroy_now
= !w1_unref_slave(sl
);
813 return destroy_now
? 0 : -EBUSY
;
816 struct w1_master
*w1_search_master_id(u32 id
)
818 struct w1_master
*dev
;
821 mutex_lock(&w1_mlock
);
822 list_for_each_entry(dev
, &w1_masters
, w1_master_entry
) {
825 atomic_inc(&dev
->refcnt
);
829 mutex_unlock(&w1_mlock
);
831 return (found
)?dev
:NULL
;
834 struct w1_slave
*w1_search_slave(struct w1_reg_num
*id
)
836 struct w1_master
*dev
;
837 struct w1_slave
*sl
= NULL
;
840 mutex_lock(&w1_mlock
);
841 list_for_each_entry(dev
, &w1_masters
, w1_master_entry
) {
842 mutex_lock(&dev
->list_mutex
);
843 list_for_each_entry(sl
, &dev
->slist
, w1_slave_entry
) {
844 if (sl
->reg_num
.family
== id
->family
&&
845 sl
->reg_num
.id
== id
->id
&&
846 sl
->reg_num
.crc
== id
->crc
) {
848 atomic_inc(&dev
->refcnt
);
849 atomic_inc(&sl
->refcnt
);
853 mutex_unlock(&dev
->list_mutex
);
858 mutex_unlock(&w1_mlock
);
860 return (found
)?sl
:NULL
;
863 void w1_reconnect_slaves(struct w1_family
*f
, int attach
)
865 struct w1_slave
*sl
, *sln
;
866 struct w1_master
*dev
;
868 mutex_lock(&w1_mlock
);
869 list_for_each_entry(dev
, &w1_masters
, w1_master_entry
) {
870 dev_dbg(&dev
->dev
, "Reconnecting slaves in device %s "
871 "for family %02x.\n", dev
->name
, f
->fid
);
872 mutex_lock(&dev
->mutex
);
873 mutex_lock(&dev
->list_mutex
);
874 list_for_each_entry_safe(sl
, sln
, &dev
->slist
, w1_slave_entry
) {
875 /* If it is a new family, slaves with the default
876 * family driver and are that family will be
877 * connected. If the family is going away, devices
878 * matching that family are reconneced.
880 if ((attach
&& sl
->family
->fid
== W1_FAMILY_DEFAULT
881 && sl
->reg_num
.family
== f
->fid
) ||
882 (!attach
&& sl
->family
->fid
== f
->fid
)) {
883 struct w1_reg_num rn
;
885 mutex_unlock(&dev
->list_mutex
);
886 memcpy(&rn
, &sl
->reg_num
, sizeof(rn
));
887 /* If it was already in use let the automatic
888 * scan pick it up again later.
890 if (!w1_slave_detach(sl
))
891 w1_attach_slave_device(dev
, &rn
);
892 mutex_lock(&dev
->list_mutex
);
895 dev_dbg(&dev
->dev
, "Reconnecting slaves in device %s "
896 "has been finished.\n", dev
->name
);
897 mutex_unlock(&dev
->list_mutex
);
898 mutex_unlock(&dev
->mutex
);
900 mutex_unlock(&w1_mlock
);
903 void w1_slave_found(struct w1_master
*dev
, u64 rn
)
906 struct w1_reg_num
*tmp
;
907 u64 rn_le
= cpu_to_le64(rn
);
909 atomic_inc(&dev
->refcnt
);
911 tmp
= (struct w1_reg_num
*) &rn
;
913 sl
= w1_slave_search_device(dev
, tmp
);
915 set_bit(W1_SLAVE_ACTIVE
, &sl
->flags
);
917 if (rn
&& tmp
->crc
== w1_calc_crc8((u8
*)&rn_le
, 7))
918 w1_attach_slave_device(dev
, tmp
);
921 atomic_dec(&dev
->refcnt
);
925 * w1_search() - Performs a ROM Search & registers any devices found.
926 * @dev: The master device to search
927 * @search_type: W1_SEARCH to search all devices, or W1_ALARM_SEARCH
928 * to return only devices in the alarmed state
929 * @cb: Function to call when a device is found
931 * The 1-wire search is a simple binary tree search.
932 * For each bit of the address, we read two bits and write one bit.
933 * The bit written will put to sleep all devies that don't match that bit.
934 * When the two reads differ, the direction choice is obvious.
935 * When both bits are 0, we must choose a path to take.
936 * When we can scan all 64 bits without having to choose a path, we are done.
938 * See "Application note 187 1-wire search algorithm" at www.maxim-ic.com
941 void w1_search(struct w1_master
*dev
, u8 search_type
, w1_slave_found_callback cb
)
943 u64 last_rn
, rn
, tmp64
;
944 int i
, slave_count
= 0;
945 int last_zero
, last_device
;
946 int search_bit
, desc_bit
;
957 while ( !last_device
&& (slave_count
++ < dev
->max_slave_count
) ) {
962 * Reset bus and all 1-wire device state machines
963 * so they can respond to our requests.
965 * Return 0 - device(s) present, 1 - no devices present.
967 mutex_lock(&dev
->bus_mutex
);
968 if (w1_reset_bus(dev
)) {
969 mutex_unlock(&dev
->bus_mutex
);
970 dev_dbg(&dev
->dev
, "No devices present on the wire.\n");
974 /* Do fast search on single slave bus */
975 if (dev
->max_slave_count
== 1) {
977 w1_write_8(dev
, W1_READ_ROM
);
978 rv
= w1_read_block(dev
, (u8
*)&rn
, 8);
979 mutex_unlock(&dev
->bus_mutex
);
987 /* Start the search */
988 w1_write_8(dev
, search_type
);
989 for (i
= 0; i
< 64; ++i
) {
990 /* Determine the direction/search bit */
992 search_bit
= 1; /* took the 0 path last time, so take the 1 path */
993 else if (i
> desc_bit
)
994 search_bit
= 0; /* take the 0 path on the next branch */
996 search_bit
= ((last_rn
>> i
) & 0x1);
998 /* Read two bits and write one bit */
999 triplet_ret
= w1_triplet(dev
, search_bit
);
1001 /* quit if no device responded */
1002 if ( (triplet_ret
& 0x03) == 0x03 )
1005 /* If both directions were valid, and we took the 0 path... */
1006 if (triplet_ret
== 0)
1009 /* extract the direction taken & update the device number */
1010 tmp64
= (triplet_ret
>> 2);
1013 if (test_bit(W1_ABORT_SEARCH
, &dev
->flags
)) {
1014 mutex_unlock(&dev
->bus_mutex
);
1015 dev_dbg(&dev
->dev
, "Abort w1_search\n");
1019 mutex_unlock(&dev
->bus_mutex
);
1021 if ( (triplet_ret
& 0x03) != 0x03 ) {
1022 if ((desc_bit
== last_zero
) || (last_zero
< 0)) {
1026 dev
->search_id
= rn
;
1028 desc_bit
= last_zero
;
1032 if (!last_device
&& slave_count
== dev
->max_slave_count
&&
1033 !test_bit(W1_WARN_MAX_COUNT
, &dev
->flags
)) {
1034 /* Only max_slave_count will be scanned in a search,
1035 * but it will start where it left off next search
1036 * until all ids are identified and then it will start
1037 * over. A continued search will report the previous
1038 * last id as the first id (provided it is still on the
1041 dev_info(&dev
->dev
, "%s: max_slave_count %d reached, "
1042 "will continue next search.\n", __func__
,
1043 dev
->max_slave_count
);
1044 set_bit(W1_WARN_MAX_COUNT
, &dev
->flags
);
1049 void w1_search_process_cb(struct w1_master
*dev
, u8 search_type
,
1050 w1_slave_found_callback cb
)
1052 struct w1_slave
*sl
, *sln
;
1054 mutex_lock(&dev
->list_mutex
);
1055 list_for_each_entry(sl
, &dev
->slist
, w1_slave_entry
)
1056 clear_bit(W1_SLAVE_ACTIVE
, &sl
->flags
);
1057 mutex_unlock(&dev
->list_mutex
);
1059 w1_search_devices(dev
, search_type
, cb
);
1061 mutex_lock(&dev
->list_mutex
);
1062 list_for_each_entry_safe(sl
, sln
, &dev
->slist
, w1_slave_entry
) {
1063 if (!test_bit(W1_SLAVE_ACTIVE
, &sl
->flags
) && !--sl
->ttl
) {
1064 mutex_unlock(&dev
->list_mutex
);
1065 w1_slave_detach(sl
);
1066 mutex_lock(&dev
->list_mutex
);
1068 else if (test_bit(W1_SLAVE_ACTIVE
, &sl
->flags
))
1069 sl
->ttl
= dev
->slave_ttl
;
1071 mutex_unlock(&dev
->list_mutex
);
1073 if (dev
->search_count
> 0)
1074 dev
->search_count
--;
1077 static void w1_search_process(struct w1_master
*dev
, u8 search_type
)
1079 w1_search_process_cb(dev
, search_type
, w1_slave_found
);
1083 * w1_process_callbacks() - execute each dev->async_list callback entry
1084 * @dev: w1_master device
1086 * The w1 master list_mutex must be held.
1088 * Return: 1 if there were commands to executed 0 otherwise
1090 int w1_process_callbacks(struct w1_master
*dev
)
1093 struct w1_async_cmd
*async_cmd
, *async_n
;
1095 /* The list can be added to in another thread, loop until it is empty */
1096 while (!list_empty(&dev
->async_list
)) {
1097 list_for_each_entry_safe(async_cmd
, async_n
, &dev
->async_list
,
1099 /* drop the lock, if it is a search it can take a long
1101 mutex_unlock(&dev
->list_mutex
);
1102 async_cmd
->cb(dev
, async_cmd
);
1104 mutex_lock(&dev
->list_mutex
);
1110 int w1_process(void *data
)
1112 struct w1_master
*dev
= (struct w1_master
*) data
;
1113 /* As long as w1_timeout is only set by a module parameter the sleep
1114 * time can be calculated in jiffies once.
1116 const unsigned long jtime
=
1117 usecs_to_jiffies(w1_timeout
* 1000000 + w1_timeout_us
);
1118 /* remainder if it woke up early */
1119 unsigned long jremain
= 0;
1123 if (!jremain
&& dev
->search_count
) {
1124 mutex_lock(&dev
->mutex
);
1125 w1_search_process(dev
, W1_SEARCH
);
1126 mutex_unlock(&dev
->mutex
);
1129 mutex_lock(&dev
->list_mutex
);
1130 /* Note, w1_process_callback drops the lock while processing,
1131 * but locks it again before returning.
1133 if (!w1_process_callbacks(dev
) && jremain
) {
1134 /* a wake up is either to stop the thread, process
1135 * callbacks, or search, it isn't process callbacks, so
1136 * schedule a search.
1141 __set_current_state(TASK_INTERRUPTIBLE
);
1143 /* hold list_mutex until after interruptible to prevent loosing
1144 * the wakeup signal when async_cmd is added.
1146 mutex_unlock(&dev
->list_mutex
);
1148 if (kthread_should_stop())
1151 /* Only sleep when the search is active. */
1152 if (dev
->search_count
) {
1155 jremain
= schedule_timeout(jremain
);
1161 atomic_dec(&dev
->refcnt
);
1166 static int __init
w1_init(void)
1170 pr_info("Driver for 1-wire Dallas network protocol.\n");
1174 retval
= bus_register(&w1_bus_type
);
1176 pr_err("Failed to register bus. err=%d.\n", retval
);
1177 goto err_out_exit_init
;
1180 retval
= driver_register(&w1_master_driver
);
1182 pr_err("Failed to register master driver. err=%d.\n",
1184 goto err_out_bus_unregister
;
1187 retval
= driver_register(&w1_slave_driver
);
1189 pr_err("Failed to register slave driver. err=%d.\n",
1191 goto err_out_master_unregister
;
1197 /* For undoing the slave register if there was a step after it. */
1198 err_out_slave_unregister
:
1199 driver_unregister(&w1_slave_driver
);
1202 err_out_master_unregister
:
1203 driver_unregister(&w1_master_driver
);
1205 err_out_bus_unregister
:
1206 bus_unregister(&w1_bus_type
);
1212 static void __exit
w1_fini(void)
1214 struct w1_master
*dev
;
1216 /* Set netlink removal messages and some cleanup */
1217 list_for_each_entry(dev
, &w1_masters
, w1_master_entry
)
1218 __w1_remove_master_device(dev
);
1222 driver_unregister(&w1_slave_driver
);
1223 driver_unregister(&w1_master_driver
);
1224 bus_unregister(&w1_bus_type
);
1227 module_init(w1_init
);
1228 module_exit(w1_fini
);
1230 MODULE_AUTHOR("Evgeniy Polyakov <zbr@ioremap.net>");
1231 MODULE_DESCRIPTION("Driver for 1-wire Dallas network protocol.");
1232 MODULE_LICENSE("GPL");