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>
34 #include <asm/atomic.h>
40 #include "w1_family.h"
41 #include "w1_netlink.h"
43 MODULE_LICENSE("GPL");
44 MODULE_AUTHOR("Evgeniy Polyakov <johnpol@2ka.mipt.ru>");
45 MODULE_DESCRIPTION("Driver for 1-wire Dallas network protocol.");
47 static int w1_timeout
= 10;
48 int w1_max_slave_count
= 10;
49 int w1_max_slave_ttl
= 10;
51 module_param_named(timeout
, w1_timeout
, int, 0);
52 module_param_named(max_slave_count
, w1_max_slave_count
, int, 0);
53 module_param_named(slave_ttl
, w1_max_slave_ttl
, int, 0);
55 DEFINE_SPINLOCK(w1_mlock
);
56 LIST_HEAD(w1_masters
);
58 static pid_t control_thread
;
59 static int control_needs_exit
;
60 static DECLARE_COMPLETION(w1_control_complete
);
62 /* stuff for the default family */
63 static ssize_t
w1_famdefault_read_name(struct device
*dev
, struct device_attribute
*attr
, char *buf
)
65 struct w1_slave
*sl
= container_of(dev
, struct w1_slave
, dev
);
66 return(sprintf(buf
, "%s\n", sl
->name
));
68 static struct w1_family_ops w1_default_fops
= {
69 .rname
= &w1_famdefault_read_name
,
71 static struct w1_family w1_default_family
= {
72 .fops
= &w1_default_fops
,
75 static int w1_master_match(struct device
*dev
, struct device_driver
*drv
)
80 static int w1_master_probe(struct device
*dev
)
85 static int w1_master_remove(struct device
*dev
)
90 static void w1_master_release(struct device
*dev
)
92 struct w1_master
*md
= container_of(dev
, struct w1_master
, dev
);
94 complete(&md
->dev_released
);
97 static void w1_slave_release(struct device
*dev
)
99 struct w1_slave
*sl
= container_of(dev
, struct w1_slave
, dev
);
101 complete(&sl
->dev_released
);
104 static ssize_t
w1_default_read_name(struct device
*dev
, struct device_attribute
*attr
, char *buf
)
106 return sprintf(buf
, "No family registered.\n");
109 static ssize_t
w1_default_read_bin(struct kobject
*kobj
, char *buf
, loff_t off
,
112 return sprintf(buf
, "No family registered.\n");
115 static struct device_attribute w1_slave_attribute
=
116 __ATTR(name
, S_IRUGO
, w1_default_read_name
, NULL
);
118 static struct bin_attribute w1_slave_bin_attribute
= {
122 .owner
= THIS_MODULE
,
124 .size
= W1_SLAVE_DATA_SIZE
,
125 .read
= &w1_default_read_bin
,
129 static struct bus_type w1_bus_type
= {
131 .match
= w1_master_match
,
134 struct device_driver w1_driver
= {
137 .probe
= w1_master_probe
,
138 .remove
= w1_master_remove
,
141 struct device w1_device
= {
144 .bus_id
= "w1 bus master",
145 .driver
= &w1_driver
,
146 .release
= &w1_master_release
149 static ssize_t
w1_master_attribute_show_name(struct device
*dev
, struct device_attribute
*attr
, char *buf
)
151 struct w1_master
*md
= container_of(dev
, struct w1_master
, dev
);
154 if (down_interruptible (&md
->mutex
))
157 count
= sprintf(buf
, "%s\n", md
->name
);
164 static ssize_t
w1_master_attribute_store_search(struct device
* dev
,
165 struct device_attribute
*attr
,
166 const char * buf
, size_t count
)
168 struct w1_master
*md
= container_of(dev
, struct w1_master
, dev
);
170 if (down_interruptible (&md
->mutex
))
173 md
->search_count
= simple_strtol(buf
, NULL
, 0);
180 static ssize_t
w1_master_attribute_show_search(struct device
*dev
,
181 struct device_attribute
*attr
,
184 struct w1_master
*md
= container_of(dev
, struct w1_master
, dev
);
187 if (down_interruptible (&md
->mutex
))
190 count
= sprintf(buf
, "%d\n", md
->search_count
);
197 static ssize_t
w1_master_attribute_show_pointer(struct device
*dev
, struct device_attribute
*attr
, char *buf
)
199 struct w1_master
*md
= container_of(dev
, struct w1_master
, dev
);
202 if (down_interruptible(&md
->mutex
))
205 count
= sprintf(buf
, "0x%p\n", md
->bus_master
);
211 static ssize_t
w1_master_attribute_show_timeout(struct device
*dev
, struct device_attribute
*attr
, char *buf
)
214 count
= sprintf(buf
, "%d\n", w1_timeout
);
218 static ssize_t
w1_master_attribute_show_max_slave_count(struct device
*dev
, struct device_attribute
*attr
, char *buf
)
220 struct w1_master
*md
= container_of(dev
, struct w1_master
, dev
);
223 if (down_interruptible(&md
->mutex
))
226 count
= sprintf(buf
, "%d\n", md
->max_slave_count
);
232 static ssize_t
w1_master_attribute_show_attempts(struct device
*dev
, struct device_attribute
*attr
, char *buf
)
234 struct w1_master
*md
= container_of(dev
, struct w1_master
, dev
);
237 if (down_interruptible(&md
->mutex
))
240 count
= sprintf(buf
, "%lu\n", md
->attempts
);
246 static ssize_t
w1_master_attribute_show_slave_count(struct device
*dev
, struct device_attribute
*attr
, char *buf
)
248 struct w1_master
*md
= container_of(dev
, struct w1_master
, dev
);
251 if (down_interruptible(&md
->mutex
))
254 count
= sprintf(buf
, "%d\n", md
->slave_count
);
260 static ssize_t
w1_master_attribute_show_slaves(struct device
*dev
, struct device_attribute
*attr
, char *buf
)
262 struct w1_master
*md
= container_of(dev
, struct w1_master
, dev
);
265 if (down_interruptible(&md
->mutex
))
268 if (md
->slave_count
== 0)
269 c
-= snprintf(buf
+ PAGE_SIZE
- c
, c
, "not found.\n");
271 struct list_head
*ent
, *n
;
274 list_for_each_safe(ent
, n
, &md
->slist
) {
275 sl
= list_entry(ent
, struct w1_slave
, w1_slave_entry
);
277 c
-= snprintf(buf
+ PAGE_SIZE
- c
, c
, "%s\n", sl
->name
);
283 return PAGE_SIZE
- c
;
286 #define W1_MASTER_ATTR_RO(_name, _mode) \
287 struct device_attribute w1_master_attribute_##_name = \
288 __ATTR(w1_master_##_name, _mode, \
289 w1_master_attribute_show_##_name, NULL)
291 #define W1_MASTER_ATTR_RW(_name, _mode) \
292 struct device_attribute w1_master_attribute_##_name = \
293 __ATTR(w1_master_##_name, _mode, \
294 w1_master_attribute_show_##_name, \
295 w1_master_attribute_store_##_name)
297 static W1_MASTER_ATTR_RO(name
, S_IRUGO
);
298 static W1_MASTER_ATTR_RO(slaves
, S_IRUGO
);
299 static W1_MASTER_ATTR_RO(slave_count
, S_IRUGO
);
300 static W1_MASTER_ATTR_RO(max_slave_count
, S_IRUGO
);
301 static W1_MASTER_ATTR_RO(attempts
, S_IRUGO
);
302 static W1_MASTER_ATTR_RO(timeout
, S_IRUGO
);
303 static W1_MASTER_ATTR_RO(pointer
, S_IRUGO
);
304 static W1_MASTER_ATTR_RW(search
, S_IRUGO
| S_IWUGO
);
306 static struct attribute
*w1_master_default_attrs
[] = {
307 &w1_master_attribute_name
.attr
,
308 &w1_master_attribute_slaves
.attr
,
309 &w1_master_attribute_slave_count
.attr
,
310 &w1_master_attribute_max_slave_count
.attr
,
311 &w1_master_attribute_attempts
.attr
,
312 &w1_master_attribute_timeout
.attr
,
313 &w1_master_attribute_pointer
.attr
,
314 &w1_master_attribute_search
.attr
,
318 static struct attribute_group w1_master_defattr_group
= {
319 .attrs
= w1_master_default_attrs
,
322 int w1_create_master_attributes(struct w1_master
*master
)
324 return sysfs_create_group(&master
->dev
.kobj
, &w1_master_defattr_group
);
327 void w1_destroy_master_attributes(struct w1_master
*master
)
329 sysfs_remove_group(&master
->dev
.kobj
, &w1_master_defattr_group
);
332 static int __w1_attach_slave_device(struct w1_slave
*sl
)
336 sl
->dev
.parent
= &sl
->master
->dev
;
337 sl
->dev
.driver
= sl
->master
->driver
;
338 sl
->dev
.bus
= &w1_bus_type
;
339 sl
->dev
.release
= &w1_slave_release
;
341 snprintf(&sl
->dev
.bus_id
[0], sizeof(sl
->dev
.bus_id
),
343 (unsigned int) sl
->reg_num
.family
,
344 (unsigned long long) sl
->reg_num
.id
);
345 snprintf(&sl
->name
[0], sizeof(sl
->name
),
347 (unsigned int) sl
->reg_num
.family
,
348 (unsigned long long) sl
->reg_num
.id
);
350 dev_dbg(&sl
->dev
, "%s: registering %s.\n", __func__
,
353 err
= device_register(&sl
->dev
);
356 "Device registration [%s] failed. err=%d\n",
357 sl
->dev
.bus_id
, err
);
361 memcpy(&sl
->attr_bin
, &w1_slave_bin_attribute
, sizeof(sl
->attr_bin
));
362 memcpy(&sl
->attr_name
, &w1_slave_attribute
, sizeof(sl
->attr_name
));
364 sl
->attr_bin
.read
= sl
->family
->fops
->rbin
;
365 sl
->attr_name
.show
= sl
->family
->fops
->rname
;
367 err
= device_create_file(&sl
->dev
, &sl
->attr_name
);
370 "sysfs file creation for [%s] failed. err=%d\n",
371 sl
->dev
.bus_id
, err
);
372 device_unregister(&sl
->dev
);
376 if ( sl
->attr_bin
.read
) {
377 err
= sysfs_create_bin_file(&sl
->dev
.kobj
, &sl
->attr_bin
);
380 "sysfs file creation for [%s] failed. err=%d\n",
381 sl
->dev
.bus_id
, err
);
382 device_remove_file(&sl
->dev
, &sl
->attr_name
);
383 device_unregister(&sl
->dev
);
388 list_add_tail(&sl
->w1_slave_entry
, &sl
->master
->slist
);
393 static int w1_attach_slave_device(struct w1_master
*dev
, struct w1_reg_num
*rn
)
398 struct w1_netlink_msg msg
;
400 sl
= kmalloc(sizeof(struct w1_slave
), GFP_KERNEL
);
403 "%s: failed to allocate new slave device.\n",
408 memset(sl
, 0, sizeof(*sl
));
410 sl
->owner
= THIS_MODULE
;
412 set_bit(W1_SLAVE_ACTIVE
, (long *)&sl
->flags
);
414 memcpy(&sl
->reg_num
, rn
, sizeof(sl
->reg_num
));
415 atomic_set(&sl
->refcnt
, 0);
416 init_completion(&sl
->dev_released
);
418 spin_lock(&w1_flock
);
419 f
= w1_family_registered(rn
->family
);
421 f
= &w1_default_family
;
422 dev_info(&dev
->dev
, "Family %x for %02x.%012llx.%02x is not registered.\n",
423 rn
->family
, rn
->family
,
424 (unsigned long long)rn
->id
, rn
->crc
);
427 spin_unlock(&w1_flock
);
432 err
= __w1_attach_slave_device(sl
);
434 dev_err(&dev
->dev
, "%s: Attaching %s failed.\n", __func__
,
436 w1_family_put(sl
->family
);
441 sl
->ttl
= dev
->slave_ttl
;
444 memcpy(&msg
.id
.id
, rn
, sizeof(msg
.id
.id
));
445 msg
.type
= W1_SLAVE_ADD
;
446 w1_netlink_send(dev
, &msg
);
451 static void w1_slave_detach(struct w1_slave
*sl
)
453 struct w1_netlink_msg msg
;
455 dev_info(&sl
->dev
, "%s: detaching %s.\n", __func__
, sl
->name
);
457 while (atomic_read(&sl
->refcnt
)) {
458 printk(KERN_INFO
"Waiting for %s to become free: refcnt=%d.\n",
459 sl
->name
, atomic_read(&sl
->refcnt
));
461 if (msleep_interruptible(1000))
462 flush_signals(current
);
465 if ( sl
->attr_bin
.read
) {
466 sysfs_remove_bin_file (&sl
->dev
.kobj
, &sl
->attr_bin
);
468 device_remove_file(&sl
->dev
, &sl
->attr_name
);
469 device_unregister(&sl
->dev
);
470 w1_family_put(sl
->family
);
472 sl
->master
->slave_count
--;
474 memcpy(&msg
.id
.id
, &sl
->reg_num
, sizeof(msg
.id
.id
));
475 msg
.type
= W1_SLAVE_REMOVE
;
476 w1_netlink_send(sl
->master
, &msg
);
479 static struct w1_master
*w1_search_master(unsigned long data
)
481 struct w1_master
*dev
;
484 spin_lock_bh(&w1_mlock
);
485 list_for_each_entry(dev
, &w1_masters
, w1_master_entry
) {
486 if (dev
->bus_master
->data
== data
) {
488 atomic_inc(&dev
->refcnt
);
492 spin_unlock_bh(&w1_mlock
);
494 return (found
)?dev
:NULL
;
497 void w1_reconnect_slaves(struct w1_family
*f
)
499 struct w1_master
*dev
;
501 spin_lock_bh(&w1_mlock
);
502 list_for_each_entry(dev
, &w1_masters
, w1_master_entry
) {
503 dev_info(&dev
->dev
, "Reconnecting slaves in %s into new family %02x.\n",
505 set_bit(W1_MASTER_NEED_RECONNECT
, &dev
->flags
);
507 spin_unlock_bh(&w1_mlock
);
511 static void w1_slave_found(unsigned long data
, u64 rn
)
515 struct list_head
*ent
;
516 struct w1_reg_num
*tmp
;
517 int family_found
= 0;
518 struct w1_master
*dev
;
520 dev
= w1_search_master(data
);
522 printk(KERN_ERR
"Failed to find w1 master device for data %08lx, it is impossible.\n",
527 tmp
= (struct w1_reg_num
*) &rn
;
530 list_for_each(ent
, &dev
->slist
) {
532 sl
= list_entry(ent
, struct w1_slave
, w1_slave_entry
);
534 if (sl
->reg_num
.family
== tmp
->family
&&
535 sl
->reg_num
.id
== tmp
->id
&&
536 sl
->reg_num
.crc
== tmp
->crc
) {
537 set_bit(W1_SLAVE_ACTIVE
, (long *)&sl
->flags
);
539 } else if (sl
->reg_num
.family
== tmp
->family
) {
547 rn
= cpu_to_le64(rn
);
549 if (slave_count
== dev
->slave_count
&&
550 rn
&& ((le64_to_cpu(rn
) >> 56) & 0xff) == w1_calc_crc8((u8
*)&rn
, 7)) {
551 w1_attach_slave_device(dev
, tmp
);
554 atomic_dec(&dev
->refcnt
);
558 * Performs a ROM Search & registers any devices found.
559 * The 1-wire search is a simple binary tree search.
560 * For each bit of the address, we read two bits and write one bit.
561 * The bit written will put to sleep all devies that don't match that bit.
562 * When the two reads differ, the direction choice is obvious.
563 * When both bits are 0, we must choose a path to take.
564 * When we can scan all 64 bits without having to choose a path, we are done.
566 * See "Application note 187 1-wire search algorithm" at www.maxim-ic.com
568 * @dev The master device to search
569 * @cb Function to call when a device is found
571 void w1_search(struct w1_master
*dev
, w1_slave_found_callback cb
)
573 u64 last_rn
, rn
, tmp64
;
574 int i
, slave_count
= 0;
575 int last_zero
, last_device
;
576 int search_bit
, desc_bit
;
586 while ( !last_device
&& (slave_count
++ < dev
->max_slave_count
) ) {
591 * Reset bus and all 1-wire device state machines
592 * so they can respond to our requests.
594 * Return 0 - device(s) present, 1 - no devices present.
596 if (w1_reset_bus(dev
)) {
597 dev_info(&dev
->dev
, "No devices present on the wire.\n");
601 /* Start the search */
602 w1_write_8(dev
, W1_SEARCH
);
603 for (i
= 0; i
< 64; ++i
) {
604 /* Determine the direction/search bit */
606 search_bit
= 1; /* took the 0 path last time, so take the 1 path */
607 else if (i
> desc_bit
)
608 search_bit
= 0; /* take the 0 path on the next branch */
610 search_bit
= ((last_rn
>> i
) & 0x1);
612 /** Read two bits and write one bit */
613 triplet_ret
= w1_triplet(dev
, search_bit
);
615 /* quit if no device responded */
616 if ( (triplet_ret
& 0x03) == 0x03 )
619 /* If both directions were valid, and we took the 0 path... */
620 if (triplet_ret
== 0)
623 /* extract the direction taken & update the device number */
624 tmp64
= (triplet_ret
>> 2);
628 if ( (triplet_ret
& 0x03) != 0x03 ) {
629 if ( (desc_bit
== last_zero
) || (last_zero
< 0))
631 desc_bit
= last_zero
;
632 cb(dev
->bus_master
->data
, rn
);
637 static int w1_control(void *data
)
639 struct w1_slave
*sl
, *sln
;
640 struct w1_master
*dev
, *n
;
641 int err
, have_to_wait
= 0;
643 daemonize("w1_control");
644 allow_signal(SIGTERM
);
646 while (!control_needs_exit
|| have_to_wait
) {
649 try_to_freeze(PF_FREEZE
);
650 msleep_interruptible(w1_timeout
* 1000);
652 if (signal_pending(current
))
653 flush_signals(current
);
655 list_for_each_entry_safe(dev
, n
, &w1_masters
, w1_master_entry
) {
656 if (!control_needs_exit
&& !dev
->flags
)
659 * Little race: we can create thread but not set the flag.
660 * Get a chance for external process to set flag up.
662 if (!dev
->initialized
) {
667 if (control_needs_exit
) {
668 set_bit(W1_MASTER_NEED_EXIT
, &dev
->flags
);
670 err
= kill_proc(dev
->kpid
, SIGTERM
, 1);
673 "Failed to send signal to w1 kernel thread %d.\n",
677 if (test_bit(W1_MASTER_NEED_EXIT
, &dev
->flags
)) {
678 wait_for_completion(&dev
->dev_exited
);
679 spin_lock_bh(&w1_mlock
);
680 list_del(&dev
->w1_master_entry
);
681 spin_unlock_bh(&w1_mlock
);
683 list_for_each_entry_safe(sl
, sln
, &dev
->slist
, w1_slave_entry
) {
684 list_del(&sl
->w1_slave_entry
);
689 w1_destroy_master_attributes(dev
);
690 atomic_dec(&dev
->refcnt
);
694 if (test_bit(W1_MASTER_NEED_RECONNECT
, &dev
->flags
)) {
695 dev_info(&dev
->dev
, "Reconnecting slaves in device %s.\n", dev
->name
);
697 list_for_each_entry(sl
, &dev
->slist
, w1_slave_entry
) {
698 if (sl
->family
->fid
== W1_FAMILY_DEFAULT
) {
699 struct w1_reg_num rn
;
700 list_del(&sl
->w1_slave_entry
);
703 memcpy(&rn
, &sl
->reg_num
, sizeof(rn
));
707 w1_attach_slave_device(dev
, &rn
);
710 clear_bit(W1_MASTER_NEED_RECONNECT
, &dev
->flags
);
716 complete_and_exit(&w1_control_complete
, 0);
719 int w1_process(void *data
)
721 struct w1_master
*dev
= (struct w1_master
*) data
;
722 struct w1_slave
*sl
, *sln
;
724 daemonize("%s", dev
->name
);
725 allow_signal(SIGTERM
);
727 while (!test_bit(W1_MASTER_NEED_EXIT
, &dev
->flags
)) {
728 try_to_freeze(PF_FREEZE
);
729 msleep_interruptible(w1_timeout
* 1000);
731 if (signal_pending(current
))
732 flush_signals(current
);
734 if (test_bit(W1_MASTER_NEED_EXIT
, &dev
->flags
))
737 if (!dev
->initialized
)
740 if (dev
->search_count
== 0)
743 if (down_interruptible(&dev
->mutex
))
746 list_for_each_entry(sl
, &dev
->slist
, w1_slave_entry
)
747 clear_bit(W1_SLAVE_ACTIVE
, (long *)&sl
->flags
);
749 w1_search_devices(dev
, w1_slave_found
);
751 list_for_each_entry_safe(sl
, sln
, &dev
->slist
, w1_slave_entry
) {
752 if (!test_bit(W1_SLAVE_ACTIVE
, (unsigned long *)&sl
->flags
) && !--sl
->ttl
) {
753 list_del (&sl
->w1_slave_entry
);
755 w1_slave_detach (sl
);
759 } else if (test_bit(W1_SLAVE_ACTIVE
, (unsigned long *)&sl
->flags
))
760 sl
->ttl
= dev
->slave_ttl
;
763 if (dev
->search_count
> 0)
769 atomic_dec(&dev
->refcnt
);
770 complete_and_exit(&dev
->dev_exited
, 0);
775 static int w1_init(void)
779 printk(KERN_INFO
"Driver for 1-wire Dallas network protocol.\n");
781 retval
= bus_register(&w1_bus_type
);
783 printk(KERN_ERR
"Failed to register bus. err=%d.\n", retval
);
784 goto err_out_exit_init
;
787 retval
= driver_register(&w1_driver
);
790 "Failed to register master driver. err=%d.\n",
792 goto err_out_bus_unregister
;
795 control_thread
= kernel_thread(&w1_control
, NULL
, 0);
796 if (control_thread
< 0) {
797 printk(KERN_ERR
"Failed to create control thread. err=%d\n",
799 retval
= control_thread
;
800 goto err_out_driver_unregister
;
805 err_out_driver_unregister
:
806 driver_unregister(&w1_driver
);
808 err_out_bus_unregister
:
809 bus_unregister(&w1_bus_type
);
815 static void w1_fini(void)
817 struct w1_master
*dev
;
819 list_for_each_entry(dev
, &w1_masters
, w1_master_entry
)
820 __w1_remove_master_device(dev
);
822 control_needs_exit
= 1;
823 wait_for_completion(&w1_control_complete
);
825 driver_unregister(&w1_driver
);
826 bus_unregister(&w1_bus_type
);
829 module_init(w1_init
);
830 module_exit(w1_fini
);