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 static int w1_master_match(struct device
*dev
, struct device_driver
*drv
)
67 static int w1_master_probe(struct device
*dev
)
72 static int w1_master_remove(struct device
*dev
)
77 static void w1_master_release(struct device
*dev
)
79 struct w1_master
*md
= container_of(dev
, struct w1_master
, dev
);
81 complete(&md
->dev_released
);
84 static void w1_slave_release(struct device
*dev
)
86 struct w1_slave
*sl
= container_of(dev
, struct w1_slave
, dev
);
88 complete(&sl
->dev_released
);
91 static ssize_t
w1_default_read_name(struct device
*dev
, struct device_attribute
*attr
, char *buf
)
93 return sprintf(buf
, "No family registered.\n");
96 static ssize_t
w1_default_read_bin(struct kobject
*kobj
, char *buf
, loff_t off
,
99 return sprintf(buf
, "No family registered.\n");
102 static struct device_attribute w1_slave_attribute
=
103 __ATTR(name
, S_IRUGO
, w1_default_read_name
, NULL
);
105 static struct device_attribute w1_slave_attribute_val
=
106 __ATTR(value
, S_IRUGO
, w1_default_read_name
, NULL
);
108 static struct bin_attribute w1_slave_bin_attribute
= {
112 .owner
= THIS_MODULE
,
114 .size
= W1_SLAVE_DATA_SIZE
,
115 .read
= &w1_default_read_bin
,
119 static struct bus_type w1_bus_type
= {
121 .match
= w1_master_match
,
124 struct device_driver w1_driver
= {
127 .probe
= w1_master_probe
,
128 .remove
= w1_master_remove
,
131 struct device w1_device
= {
134 .bus_id
= "w1 bus master",
135 .driver
= &w1_driver
,
136 .release
= &w1_master_release
139 static ssize_t
w1_master_attribute_show_name(struct device
*dev
, struct device_attribute
*attr
, char *buf
)
141 struct w1_master
*md
= container_of (dev
, struct w1_master
, dev
);
144 if (down_interruptible (&md
->mutex
))
147 count
= sprintf(buf
, "%s\n", md
->name
);
154 static ssize_t
w1_master_attribute_show_pointer(struct device
*dev
, struct device_attribute
*attr
, char *buf
)
156 struct w1_master
*md
= container_of(dev
, struct w1_master
, dev
);
159 if (down_interruptible(&md
->mutex
))
162 count
= sprintf(buf
, "0x%p\n", md
->bus_master
);
168 static ssize_t
w1_master_attribute_show_timeout(struct device
*dev
, struct device_attribute
*attr
, char *buf
)
171 count
= sprintf(buf
, "%d\n", w1_timeout
);
175 static ssize_t
w1_master_attribute_show_max_slave_count(struct device
*dev
, struct device_attribute
*attr
, char *buf
)
177 struct w1_master
*md
= container_of(dev
, struct w1_master
, dev
);
180 if (down_interruptible(&md
->mutex
))
183 count
= sprintf(buf
, "%d\n", md
->max_slave_count
);
189 static ssize_t
w1_master_attribute_show_attempts(struct device
*dev
, struct device_attribute
*attr
, char *buf
)
191 struct w1_master
*md
= container_of(dev
, struct w1_master
, dev
);
194 if (down_interruptible(&md
->mutex
))
197 count
= sprintf(buf
, "%lu\n", md
->attempts
);
203 static ssize_t
w1_master_attribute_show_slave_count(struct device
*dev
, struct device_attribute
*attr
, char *buf
)
205 struct w1_master
*md
= container_of(dev
, struct w1_master
, dev
);
208 if (down_interruptible(&md
->mutex
))
211 count
= sprintf(buf
, "%d\n", md
->slave_count
);
217 static ssize_t
w1_master_attribute_show_slaves(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 if (md
->slave_count
== 0)
227 c
-= snprintf(buf
+ PAGE_SIZE
- c
, c
, "not found.\n");
229 struct list_head
*ent
, *n
;
232 list_for_each_safe(ent
, n
, &md
->slist
) {
233 sl
= list_entry(ent
, struct w1_slave
, w1_slave_entry
);
235 c
-= snprintf(buf
+ PAGE_SIZE
- c
, c
, "%s\n", sl
->name
);
241 return PAGE_SIZE
- c
;
244 #define W1_MASTER_ATTR_RO(_name, _mode) \
245 struct device_attribute w1_master_attribute_##_name = \
246 __ATTR(w1_master_##_name, _mode, \
247 w1_master_attribute_show_##_name, NULL)
249 static W1_MASTER_ATTR_RO(name
, S_IRUGO
);
250 static W1_MASTER_ATTR_RO(slaves
, S_IRUGO
);
251 static W1_MASTER_ATTR_RO(slave_count
, S_IRUGO
);
252 static W1_MASTER_ATTR_RO(max_slave_count
, S_IRUGO
);
253 static W1_MASTER_ATTR_RO(attempts
, S_IRUGO
);
254 static W1_MASTER_ATTR_RO(timeout
, S_IRUGO
);
255 static W1_MASTER_ATTR_RO(pointer
, S_IRUGO
);
257 static struct attribute
*w1_master_default_attrs
[] = {
258 &w1_master_attribute_name
.attr
,
259 &w1_master_attribute_slaves
.attr
,
260 &w1_master_attribute_slave_count
.attr
,
261 &w1_master_attribute_max_slave_count
.attr
,
262 &w1_master_attribute_attempts
.attr
,
263 &w1_master_attribute_timeout
.attr
,
264 &w1_master_attribute_pointer
.attr
,
268 static struct attribute_group w1_master_defattr_group
= {
269 .attrs
= w1_master_default_attrs
,
272 int w1_create_master_attributes(struct w1_master
*master
)
274 return sysfs_create_group(&master
->dev
.kobj
, &w1_master_defattr_group
);
277 void w1_destroy_master_attributes(struct w1_master
*master
)
279 sysfs_remove_group(&master
->dev
.kobj
, &w1_master_defattr_group
);
282 static int __w1_attach_slave_device(struct w1_slave
*sl
)
286 sl
->dev
.parent
= &sl
->master
->dev
;
287 sl
->dev
.driver
= sl
->master
->driver
;
288 sl
->dev
.bus
= &w1_bus_type
;
289 sl
->dev
.release
= &w1_slave_release
;
291 snprintf(&sl
->dev
.bus_id
[0], sizeof(sl
->dev
.bus_id
),
293 (unsigned int) sl
->reg_num
.family
,
294 (unsigned long long) sl
->reg_num
.id
);
295 snprintf (&sl
->name
[0], sizeof(sl
->name
),
297 (unsigned int) sl
->reg_num
.family
,
298 (unsigned long long) sl
->reg_num
.id
);
300 dev_dbg(&sl
->dev
, "%s: registering %s.\n", __func__
,
303 err
= device_register(&sl
->dev
);
306 "Device registration [%s] failed. err=%d\n",
307 sl
->dev
.bus_id
, err
);
311 memcpy(&sl
->attr_bin
, &w1_slave_bin_attribute
, sizeof(sl
->attr_bin
));
312 memcpy(&sl
->attr_name
, &w1_slave_attribute
, sizeof(sl
->attr_name
));
313 memcpy(&sl
->attr_val
, &w1_slave_attribute_val
, sizeof(sl
->attr_val
));
315 sl
->attr_bin
.read
= sl
->family
->fops
->rbin
;
316 sl
->attr_name
.show
= sl
->family
->fops
->rname
;
317 sl
->attr_val
.show
= sl
->family
->fops
->rval
;
318 sl
->attr_val
.attr
.name
= sl
->family
->fops
->rvalname
;
320 err
= device_create_file(&sl
->dev
, &sl
->attr_name
);
323 "sysfs file creation for [%s] failed. err=%d\n",
324 sl
->dev
.bus_id
, err
);
325 device_unregister(&sl
->dev
);
329 err
= device_create_file(&sl
->dev
, &sl
->attr_val
);
332 "sysfs file creation for [%s] failed. err=%d\n",
333 sl
->dev
.bus_id
, err
);
334 device_remove_file(&sl
->dev
, &sl
->attr_name
);
335 device_unregister(&sl
->dev
);
339 err
= sysfs_create_bin_file(&sl
->dev
.kobj
, &sl
->attr_bin
);
342 "sysfs file creation for [%s] failed. err=%d\n",
343 sl
->dev
.bus_id
, err
);
344 device_remove_file(&sl
->dev
, &sl
->attr_name
);
345 device_remove_file(&sl
->dev
, &sl
->attr_val
);
346 device_unregister(&sl
->dev
);
350 list_add_tail(&sl
->w1_slave_entry
, &sl
->master
->slist
);
355 static int w1_attach_slave_device(struct w1_master
*dev
, struct w1_reg_num
*rn
)
360 struct w1_netlink_msg msg
;
362 sl
= kmalloc(sizeof(struct w1_slave
), GFP_KERNEL
);
365 "%s: failed to allocate new slave device.\n",
370 memset(sl
, 0, sizeof(*sl
));
372 sl
->owner
= THIS_MODULE
;
374 set_bit(W1_SLAVE_ACTIVE
, (long *)&sl
->flags
);
376 memcpy(&sl
->reg_num
, rn
, sizeof(sl
->reg_num
));
377 atomic_set(&sl
->refcnt
, 0);
378 init_completion(&sl
->dev_released
);
380 spin_lock(&w1_flock
);
381 f
= w1_family_registered(rn
->family
);
383 spin_unlock(&w1_flock
);
384 dev_info(&dev
->dev
, "Family %x for %02x.%012llx.%02x is not registered.\n",
385 rn
->family
, rn
->family
,
386 (unsigned long long)rn
->id
, rn
->crc
);
391 spin_unlock(&w1_flock
);
396 err
= __w1_attach_slave_device(sl
);
398 dev_err(&dev
->dev
, "%s: Attaching %s failed.\n", __func__
,
400 w1_family_put(sl
->family
);
405 sl
->ttl
= dev
->slave_ttl
;
408 memcpy(&msg
.id
.id
, rn
, sizeof(msg
.id
.id
));
409 msg
.type
= W1_SLAVE_ADD
;
410 w1_netlink_send(dev
, &msg
);
415 static void w1_slave_detach(struct w1_slave
*sl
)
417 struct w1_netlink_msg msg
;
419 dev_info(&sl
->dev
, "%s: detaching %s.\n", __func__
, sl
->name
);
421 while (atomic_read(&sl
->refcnt
)) {
422 printk(KERN_INFO
"Waiting for %s to become free: refcnt=%d.\n",
423 sl
->name
, atomic_read(&sl
->refcnt
));
425 if (msleep_interruptible(1000))
426 flush_signals(current
);
429 sysfs_remove_bin_file (&sl
->dev
.kobj
, &sl
->attr_bin
);
430 device_remove_file(&sl
->dev
, &sl
->attr_name
);
431 device_remove_file(&sl
->dev
, &sl
->attr_val
);
432 device_unregister(&sl
->dev
);
433 w1_family_put(sl
->family
);
435 memcpy(&msg
.id
.id
, &sl
->reg_num
, sizeof(msg
.id
.id
));
436 msg
.type
= W1_SLAVE_REMOVE
;
437 w1_netlink_send(sl
->master
, &msg
);
440 static struct w1_master
*w1_search_master(unsigned long data
)
442 struct w1_master
*dev
;
445 spin_lock_bh(&w1_mlock
);
446 list_for_each_entry(dev
, &w1_masters
, w1_master_entry
) {
447 if (dev
->bus_master
->data
== data
) {
449 atomic_inc(&dev
->refcnt
);
453 spin_unlock_bh(&w1_mlock
);
455 return (found
)?dev
:NULL
;
458 static void w1_slave_found(unsigned long data
, u64 rn
)
462 struct list_head
*ent
;
463 struct w1_reg_num
*tmp
;
464 int family_found
= 0;
465 struct w1_master
*dev
;
467 dev
= w1_search_master(data
);
469 printk(KERN_ERR
"Failed to find w1 master device for data %08lx, it is impossible.\n",
474 tmp
= (struct w1_reg_num
*) &rn
;
477 list_for_each(ent
, &dev
->slist
) {
479 sl
= list_entry(ent
, struct w1_slave
, w1_slave_entry
);
481 if (sl
->reg_num
.family
== tmp
->family
&&
482 sl
->reg_num
.id
== tmp
->id
&&
483 sl
->reg_num
.crc
== tmp
->crc
) {
484 set_bit(W1_SLAVE_ACTIVE
, (long *)&sl
->flags
);
486 } else if (sl
->reg_num
.family
== tmp
->family
) {
494 rn
= cpu_to_le64(rn
);
496 if (slave_count
== dev
->slave_count
&&
497 rn
&& ((le64_to_cpu(rn
) >> 56) & 0xff) == w1_calc_crc8((u8
*)&rn
, 7)) {
498 w1_attach_slave_device(dev
, tmp
);
501 atomic_dec(&dev
->refcnt
);
504 void w1_search(struct w1_master
*dev
)
508 int last_family_desc
, last_zero
, last_device
;
509 int search_bit
, id_bit
, comp_bit
, desc_bit
;
511 search_bit
= id_bit
= comp_bit
= 0;
513 last_device
= last_zero
= last_family_desc
= 0;
517 while (!(id_bit
&& comp_bit
) && !last_device
&&
518 count
++ < dev
->max_slave_count
) {
522 last_family_desc
= 0;
525 * Reset bus and all 1-wire device state machines
526 * so they can respond to our requests.
528 * Return 0 - device(s) present, 1 - no devices present.
530 if (w1_reset_bus(dev
)) {
531 dev_info(&dev
->dev
, "No devices present on the wire.\n");
536 w1_write_8(dev
, W1_SEARCH
);
537 for (i
= 0; i
< 64; ++i
) {
539 * Read 2 bits from bus.
540 * All who don't sleep must send ID bit and COMPLEMENT ID bit.
541 * They actually are ANDed between all senders.
543 id_bit
= w1_touch_bit(dev
, 1);
544 comp_bit
= w1_touch_bit(dev
, 1);
546 if (id_bit
&& comp_bit
)
549 if (id_bit
== 0 && comp_bit
== 0) {
552 else if (i
> desc_bit
)
555 search_bit
= ((last
>> i
) & 0x1);
557 if (search_bit
== 0) {
560 last_family_desc
= last_zero
;
571 * and make all who don't have "search_bit" in "i"'th position
572 * in it's registration number sleep.
574 if (dev
->bus_master
->touch_bit
)
575 w1_touch_bit(dev
, search_bit
);
577 w1_write_bit(dev
, search_bit
);
582 if (desc_bit
== last_zero
)
585 desc_bit
= last_zero
;
587 w1_slave_found(dev
->bus_master
->data
, rn
);
591 static int w1_control(void *data
)
593 struct w1_slave
*sl
, *sln
;
594 struct w1_master
*dev
, *n
;
595 int err
, have_to_wait
= 0;
597 daemonize("w1_control");
598 allow_signal(SIGTERM
);
600 while (!control_needs_exit
|| have_to_wait
) {
603 try_to_freeze(PF_FREEZE
);
604 msleep_interruptible(w1_timeout
* 1000);
606 if (signal_pending(current
))
607 flush_signals(current
);
609 list_for_each_entry_safe(dev
, n
, &w1_masters
, w1_master_entry
) {
610 if (!control_needs_exit
&& !dev
->need_exit
)
613 * Little race: we can create thread but not set the flag.
614 * Get a chance for external process to set flag up.
616 if (!dev
->initialized
) {
621 spin_lock_bh(&w1_mlock
);
622 list_del(&dev
->w1_master_entry
);
623 spin_unlock_bh(&w1_mlock
);
625 if (control_needs_exit
) {
628 err
= kill_proc(dev
->kpid
, SIGTERM
, 1);
631 "Failed to send signal to w1 kernel thread %d.\n",
635 wait_for_completion(&dev
->dev_exited
);
637 list_for_each_entry_safe(sl
, sln
, &dev
->slist
, w1_slave_entry
) {
638 list_del(&sl
->w1_slave_entry
);
643 w1_destroy_master_attributes(dev
);
644 atomic_dec(&dev
->refcnt
);
648 complete_and_exit(&w1_control_complete
, 0);
651 int w1_process(void *data
)
653 struct w1_master
*dev
= (struct w1_master
*) data
;
654 struct w1_slave
*sl
, *sln
;
656 daemonize("%s", dev
->name
);
657 allow_signal(SIGTERM
);
659 while (!dev
->need_exit
) {
660 try_to_freeze(PF_FREEZE
);
661 msleep_interruptible(w1_timeout
* 1000);
663 if (signal_pending(current
))
664 flush_signals(current
);
669 if (!dev
->initialized
)
672 if (down_interruptible(&dev
->mutex
))
675 list_for_each_entry(sl
, &dev
->slist
, w1_slave_entry
)
676 clear_bit(W1_SLAVE_ACTIVE
, (long *)&sl
->flags
);
678 w1_search_devices(dev
, w1_slave_found
);
680 list_for_each_entry_safe(sl
, sln
, &dev
->slist
, w1_slave_entry
) {
681 if (!test_bit(W1_SLAVE_ACTIVE
, (unsigned long *)&sl
->flags
) && !--sl
->ttl
) {
682 list_del (&sl
->w1_slave_entry
);
684 w1_slave_detach (sl
);
688 } else if (test_bit(W1_SLAVE_ACTIVE
, (unsigned long *)&sl
->flags
))
689 sl
->ttl
= dev
->slave_ttl
;
694 atomic_dec(&dev
->refcnt
);
695 complete_and_exit(&dev
->dev_exited
, 0);
700 static int w1_init(void)
704 printk(KERN_INFO
"Driver for 1-wire Dallas network protocol.\n");
706 retval
= bus_register(&w1_bus_type
);
708 printk(KERN_ERR
"Failed to register bus. err=%d.\n", retval
);
709 goto err_out_exit_init
;
712 retval
= driver_register(&w1_driver
);
715 "Failed to register master driver. err=%d.\n",
717 goto err_out_bus_unregister
;
720 control_thread
= kernel_thread(&w1_control
, NULL
, 0);
721 if (control_thread
< 0) {
722 printk(KERN_ERR
"Failed to create control thread. err=%d\n",
724 retval
= control_thread
;
725 goto err_out_driver_unregister
;
730 err_out_driver_unregister
:
731 driver_unregister(&w1_driver
);
733 err_out_bus_unregister
:
734 bus_unregister(&w1_bus_type
);
740 static void w1_fini(void)
742 struct w1_master
*dev
;
744 list_for_each_entry(dev
, &w1_masters
, w1_master_entry
)
745 __w1_remove_master_device(dev
);
747 control_needs_exit
= 1;
748 wait_for_completion(&w1_control_complete
);
750 driver_unregister(&w1_driver
);
751 bus_unregister(&w1_bus_type
);
754 module_init(w1_init
);
755 module_exit(w1_fini
);