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 = 10;
50 int w1_max_slave_ttl = 10;
52 module_param_named(timeout, w1_timeout, int, 0);
53 module_param_named(max_slave_count, w1_max_slave_count, int, 0);
54 module_param_named(slave_ttl, w1_max_slave_ttl, int, 0);
56 DEFINE_MUTEX(w1_mlock);
57 LIST_HEAD(w1_masters);
59 static int w1_attach_slave_device(struct w1_master *dev, struct w1_reg_num *rn);
61 static int w1_master_match(struct device *dev, struct device_driver *drv)
66 static int w1_master_probe(struct device *dev)
71 static void w1_master_release(struct device *dev)
73 struct w1_master *md = dev_to_w1_master(dev);
75 dev_dbg(dev, "%s: Releasing %s.\n", __func__, md->name);
76 memset(md, 0, sizeof(struct w1_master) + sizeof(struct w1_bus_master));
80 static void w1_slave_release(struct device *dev)
82 struct w1_slave *sl = dev_to_w1_slave(dev);
84 dev_dbg(dev, "%s: Releasing %s.\n", __func__, sl->name);
86 while (atomic_read(&sl->refcnt)) {
87 dev_dbg(dev, "Waiting for %s to become free: refcnt=%d.\n",
88 sl->name, atomic_read(&sl->refcnt));
89 if (msleep_interruptible(1000))
90 flush_signals(current);
93 w1_family_put(sl->family);
94 sl->master->slave_count--;
96 complete(&sl->released);
99 static ssize_t name_show(struct device *dev, struct device_attribute *attr, char *buf)
101 struct w1_slave *sl = dev_to_w1_slave(dev);
103 return sprintf(buf, "%s\n", sl->name);
105 static DEVICE_ATTR_RO(name);
107 static ssize_t id_show(struct device *dev,
108 struct device_attribute *attr, char *buf)
110 struct w1_slave *sl = dev_to_w1_slave(dev);
111 ssize_t count = sizeof(sl->reg_num);
113 memcpy(buf, (u8 *)&sl->reg_num, count);
116 static DEVICE_ATTR_RO(id);
118 static struct attribute *w1_slave_attrs[] = {
123 ATTRIBUTE_GROUPS(w1_slave);
127 static ssize_t rw_write(struct file *filp, struct kobject *kobj,
128 struct bin_attribute *bin_attr, char *buf, loff_t off,
131 struct w1_slave *sl = kobj_to_w1_slave(kobj);
133 mutex_lock(&sl->master->mutex);
134 if (w1_reset_select_slave(sl)) {
139 w1_write_block(sl->master, buf, count);
142 mutex_unlock(&sl->master->mutex);
146 static ssize_t rw_read(struct file *filp, struct kobject *kobj,
147 struct bin_attribute *bin_attr, char *buf, loff_t off,
150 struct w1_slave *sl = kobj_to_w1_slave(kobj);
152 mutex_lock(&sl->master->mutex);
153 w1_read_block(sl->master, buf, count);
154 mutex_unlock(&sl->master->mutex);
158 static BIN_ATTR_RW(rw, PAGE_SIZE);
160 static struct bin_attribute *w1_slave_bin_attrs[] = {
165 static const struct attribute_group w1_slave_default_group = {
166 .bin_attrs = w1_slave_bin_attrs,
169 static const struct attribute_group *w1_slave_default_groups[] = {
170 &w1_slave_default_group,
174 static struct w1_family_ops w1_default_fops = {
175 .groups = w1_slave_default_groups,
178 static struct w1_family w1_default_family = {
179 .fops = &w1_default_fops,
182 static int w1_uevent(struct device *dev, struct kobj_uevent_env *env);
184 static struct bus_type w1_bus_type = {
186 .match = w1_master_match,
190 struct device_driver w1_master_driver = {
191 .name = "w1_master_driver",
193 .probe = w1_master_probe,
196 struct device w1_master_device = {
199 .init_name = "w1 bus master",
200 .driver = &w1_master_driver,
201 .release = &w1_master_release
204 static struct device_driver w1_slave_driver = {
205 .name = "w1_slave_driver",
210 struct device w1_slave_device = {
213 .init_name = "w1 bus slave",
214 .driver = &w1_slave_driver,
215 .release = &w1_slave_release
219 static ssize_t w1_master_attribute_show_name(struct device *dev, struct device_attribute *attr, char *buf)
221 struct w1_master *md = dev_to_w1_master(dev);
224 mutex_lock(&md->mutex);
225 count = sprintf(buf, "%s\n", md->name);
226 mutex_unlock(&md->mutex);
231 static ssize_t w1_master_attribute_store_search(struct device * dev,
232 struct device_attribute *attr,
233 const char * buf, size_t count)
236 struct w1_master *md = dev_to_w1_master(dev);
238 if (strict_strtol(buf, 0, &tmp) == -EINVAL)
241 mutex_lock(&md->mutex);
242 md->search_count = tmp;
243 mutex_unlock(&md->mutex);
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);
270 if (strict_strtol(buf, 0, &tmp) == -EINVAL)
273 mutex_lock(&md->mutex);
274 md->enable_pullup = tmp;
275 mutex_unlock(&md->mutex);
276 wake_up_process(md->thread);
281 static ssize_t w1_master_attribute_show_pullup(struct device *dev,
282 struct device_attribute *attr,
285 struct w1_master *md = dev_to_w1_master(dev);
288 mutex_lock(&md->mutex);
289 count = sprintf(buf, "%d\n", md->enable_pullup);
290 mutex_unlock(&md->mutex);
295 static ssize_t w1_master_attribute_show_pointer(struct device *dev, struct device_attribute *attr, char *buf)
297 struct w1_master *md = dev_to_w1_master(dev);
300 mutex_lock(&md->mutex);
301 count = sprintf(buf, "0x%p\n", md->bus_master);
302 mutex_unlock(&md->mutex);
306 static ssize_t w1_master_attribute_show_timeout(struct device *dev, struct device_attribute *attr, char *buf)
309 count = sprintf(buf, "%d\n", w1_timeout);
313 static ssize_t w1_master_attribute_show_max_slave_count(struct device *dev, struct device_attribute *attr, char *buf)
315 struct w1_master *md = dev_to_w1_master(dev);
318 mutex_lock(&md->mutex);
319 count = sprintf(buf, "%d\n", md->max_slave_count);
320 mutex_unlock(&md->mutex);
324 static ssize_t w1_master_attribute_show_attempts(struct device *dev, struct device_attribute *attr, char *buf)
326 struct w1_master *md = dev_to_w1_master(dev);
329 mutex_lock(&md->mutex);
330 count = sprintf(buf, "%lu\n", md->attempts);
331 mutex_unlock(&md->mutex);
335 static ssize_t w1_master_attribute_show_slave_count(struct device *dev, struct device_attribute *attr, char *buf)
337 struct w1_master *md = dev_to_w1_master(dev);
340 mutex_lock(&md->mutex);
341 count = sprintf(buf, "%d\n", md->slave_count);
342 mutex_unlock(&md->mutex);
346 static ssize_t w1_master_attribute_show_slaves(struct device *dev,
347 struct device_attribute *attr, char *buf)
349 struct w1_master *md = dev_to_w1_master(dev);
352 mutex_lock(&md->mutex);
354 if (md->slave_count == 0)
355 c -= snprintf(buf + PAGE_SIZE - c, c, "not found.\n");
357 struct list_head *ent, *n;
360 list_for_each_safe(ent, n, &md->slist) {
361 sl = list_entry(ent, struct w1_slave, w1_slave_entry);
363 c -= snprintf(buf + PAGE_SIZE - c, c, "%s\n", sl->name);
367 mutex_unlock(&md->mutex);
369 return PAGE_SIZE - c;
372 static ssize_t w1_master_attribute_show_add(struct device *dev,
373 struct device_attribute *attr, char *buf)
376 c -= snprintf(buf+PAGE_SIZE - c, c,
377 "write device id xx-xxxxxxxxxxxx to add slave\n");
378 return PAGE_SIZE - c;
381 static int w1_atoreg_num(struct device *dev, const char *buf, size_t count,
382 struct w1_reg_num *rn)
385 unsigned long long id;
389 /* The CRC value isn't read from the user because the sysfs directory
390 * doesn't include it and most messages from the bus search don't
391 * print it either. It would be unreasonable for the user to then
394 const char *error_msg = "bad slave string format, expecting "
398 dev_err(dev, "%s", error_msg);
401 i = sscanf(buf, "%02x-%012llx", &family, &id);
403 dev_err(dev, "%s", error_msg);
409 rn64_le = cpu_to_le64(*(u64 *)rn);
410 rn->crc = w1_calc_crc8((u8 *)&rn64_le, 7);
413 dev_info(dev, "With CRC device is %02x.%012llx.%02x.\n",
414 rn->family, (unsigned long long)rn->id, rn->crc);
420 /* Searches the slaves in the w1_master and returns a pointer or NULL.
421 * Note: must hold the mutex
423 static struct w1_slave *w1_slave_search_device(struct w1_master *dev,
424 struct w1_reg_num *rn)
427 list_for_each_entry(sl, &dev->slist, w1_slave_entry) {
428 if (sl->reg_num.family == rn->family &&
429 sl->reg_num.id == rn->id &&
430 sl->reg_num.crc == rn->crc) {
437 static ssize_t w1_master_attribute_store_add(struct device *dev,
438 struct device_attribute *attr,
439 const char *buf, size_t count)
441 struct w1_master *md = dev_to_w1_master(dev);
442 struct w1_reg_num rn;
444 ssize_t result = count;
446 if (w1_atoreg_num(dev, buf, count, &rn))
449 mutex_lock(&md->mutex);
450 sl = w1_slave_search_device(md, &rn);
451 /* It would be nice to do a targeted search one the one-wire bus
452 * for the new device to see if it is out there or not. But the
453 * current search doesn't support that.
456 dev_info(dev, "Device %s already exists\n", sl->name);
459 w1_attach_slave_device(md, &rn);
461 mutex_unlock(&md->mutex);
466 static ssize_t w1_master_attribute_show_remove(struct device *dev,
467 struct device_attribute *attr, char *buf)
470 c -= snprintf(buf+PAGE_SIZE - c, c,
471 "write device id xx-xxxxxxxxxxxx to remove slave\n");
472 return PAGE_SIZE - c;
475 static ssize_t w1_master_attribute_store_remove(struct device *dev,
476 struct device_attribute *attr,
477 const char *buf, size_t count)
479 struct w1_master *md = dev_to_w1_master(dev);
480 struct w1_reg_num rn;
482 ssize_t result = count;
484 if (w1_atoreg_num(dev, buf, count, &rn))
487 mutex_lock(&md->mutex);
488 sl = w1_slave_search_device(md, &rn);
492 dev_info(dev, "Device %02x-%012llx doesn't exists\n", rn.family,
493 (unsigned long long)rn.id);
496 mutex_unlock(&md->mutex);
501 #define W1_MASTER_ATTR_RO(_name, _mode) \
502 struct device_attribute w1_master_attribute_##_name = \
503 __ATTR(w1_master_##_name, _mode, \
504 w1_master_attribute_show_##_name, NULL)
506 #define W1_MASTER_ATTR_RW(_name, _mode) \
507 struct device_attribute w1_master_attribute_##_name = \
508 __ATTR(w1_master_##_name, _mode, \
509 w1_master_attribute_show_##_name, \
510 w1_master_attribute_store_##_name)
512 static W1_MASTER_ATTR_RO(name, S_IRUGO);
513 static W1_MASTER_ATTR_RO(slaves, S_IRUGO);
514 static W1_MASTER_ATTR_RO(slave_count, S_IRUGO);
515 static W1_MASTER_ATTR_RO(max_slave_count, S_IRUGO);
516 static W1_MASTER_ATTR_RO(attempts, S_IRUGO);
517 static W1_MASTER_ATTR_RO(timeout, S_IRUGO);
518 static W1_MASTER_ATTR_RO(pointer, S_IRUGO);
519 static W1_MASTER_ATTR_RW(search, S_IRUGO | S_IWUSR | S_IWGRP);
520 static W1_MASTER_ATTR_RW(pullup, S_IRUGO | S_IWUSR | S_IWGRP);
521 static W1_MASTER_ATTR_RW(add, S_IRUGO | S_IWUSR | S_IWGRP);
522 static W1_MASTER_ATTR_RW(remove, S_IRUGO | S_IWUSR | S_IWGRP);
524 static struct attribute *w1_master_default_attrs[] = {
525 &w1_master_attribute_name.attr,
526 &w1_master_attribute_slaves.attr,
527 &w1_master_attribute_slave_count.attr,
528 &w1_master_attribute_max_slave_count.attr,
529 &w1_master_attribute_attempts.attr,
530 &w1_master_attribute_timeout.attr,
531 &w1_master_attribute_pointer.attr,
532 &w1_master_attribute_search.attr,
533 &w1_master_attribute_pullup.attr,
534 &w1_master_attribute_add.attr,
535 &w1_master_attribute_remove.attr,
539 static struct attribute_group w1_master_defattr_group = {
540 .attrs = w1_master_default_attrs,
543 int w1_create_master_attributes(struct w1_master *master)
545 return sysfs_create_group(&master->dev.kobj, &w1_master_defattr_group);
548 void w1_destroy_master_attributes(struct w1_master *master)
550 sysfs_remove_group(&master->dev.kobj, &w1_master_defattr_group);
553 static int w1_uevent(struct device *dev, struct kobj_uevent_env *env)
555 struct w1_master *md = NULL;
556 struct w1_slave *sl = NULL;
557 char *event_owner, *name;
560 if (dev->driver == &w1_master_driver) {
561 md = container_of(dev, struct w1_master, dev);
562 event_owner = "master";
564 } else if (dev->driver == &w1_slave_driver) {
565 sl = container_of(dev, struct w1_slave, dev);
566 event_owner = "slave";
569 dev_dbg(dev, "Unknown event.\n");
573 dev_dbg(dev, "Hotplug event for %s %s, bus_id=%s.\n",
574 event_owner, name, dev_name(dev));
576 if (dev->driver != &w1_slave_driver || !sl)
579 err = add_uevent_var(env, "W1_FID=%02X", sl->reg_num.family);
583 err = add_uevent_var(env, "W1_SLAVE_ID=%024LX",
584 (unsigned long long)sl->reg_num.id);
590 * Handle sysfs file creation and removal here, before userspace is told that
591 * the device is added / removed from the system
593 static int w1_bus_notify(struct notifier_block *nb, unsigned long action,
596 struct device *dev = data;
598 struct w1_family_ops *fops;
602 * Only care about slave devices at the moment. Yes, we should use a
603 * separate "type" for this, but for now, look at the release function
604 * to know which type it is...
606 if (dev->release != w1_slave_release)
609 sl = dev_to_w1_slave(dev);
610 fops = sl->family->fops;
613 case BUS_NOTIFY_ADD_DEVICE:
614 /* if the family driver needs to initialize something... */
615 if (fops->add_slave) {
616 err = fops->add_slave(sl);
619 "add_slave() call failed. err=%d\n",
625 err = sysfs_create_groups(&sl->dev.kobj, fops->groups);
628 "sysfs group creation failed. err=%d\n",
635 case BUS_NOTIFY_DEL_DEVICE:
636 if (fops->remove_slave)
637 sl->family->fops->remove_slave(sl);
639 sysfs_remove_groups(&sl->dev.kobj, fops->groups);
645 static struct notifier_block w1_bus_nb = {
646 .notifier_call = w1_bus_notify,
649 static int __w1_attach_slave_device(struct w1_slave *sl)
653 sl->dev.parent = &sl->master->dev;
654 sl->dev.driver = &w1_slave_driver;
655 sl->dev.bus = &w1_bus_type;
656 sl->dev.release = &w1_slave_release;
657 sl->dev.groups = w1_slave_groups;
659 dev_set_name(&sl->dev, "%02x-%012llx",
660 (unsigned int) sl->reg_num.family,
661 (unsigned long long) sl->reg_num.id);
662 snprintf(&sl->name[0], sizeof(sl->name),
664 (unsigned int) sl->reg_num.family,
665 (unsigned long long) sl->reg_num.id);
667 dev_dbg(&sl->dev, "%s: registering %s as %p.\n", __func__,
668 dev_name(&sl->dev), sl);
670 err = device_register(&sl->dev);
673 "Device registration [%s] failed. err=%d\n",
674 dev_name(&sl->dev), err);
679 dev_set_uevent_suppress(&sl->dev, false);
680 kobject_uevent(&sl->dev.kobj, KOBJ_ADD);
682 list_add_tail(&sl->w1_slave_entry, &sl->master->slist);
687 static int w1_attach_slave_device(struct w1_master *dev, struct w1_reg_num *rn)
692 struct w1_netlink_msg msg;
694 sl = kzalloc(sizeof(struct w1_slave), GFP_KERNEL);
697 "%s: failed to allocate new slave device.\n",
703 sl->owner = THIS_MODULE;
705 set_bit(W1_SLAVE_ACTIVE, (long *)&sl->flags);
707 memset(&msg, 0, sizeof(msg));
708 memcpy(&sl->reg_num, rn, sizeof(sl->reg_num));
709 atomic_set(&sl->refcnt, 0);
710 init_completion(&sl->released);
712 request_module("w1-family-0x%0x", rn->family);
714 spin_lock(&w1_flock);
715 f = w1_family_registered(rn->family);
717 f= &w1_default_family;
718 dev_info(&dev->dev, "Family %x for %02x.%012llx.%02x is not registered.\n",
719 rn->family, rn->family,
720 (unsigned long long)rn->id, rn->crc);
723 spin_unlock(&w1_flock);
728 err = __w1_attach_slave_device(sl);
730 dev_err(&dev->dev, "%s: Attaching %s failed.\n", __func__,
732 w1_family_put(sl->family);
737 sl->ttl = dev->slave_ttl;
740 memcpy(msg.id.id, rn, sizeof(msg.id));
741 msg.type = W1_SLAVE_ADD;
742 w1_netlink_send(dev, &msg);
747 void w1_slave_detach(struct w1_slave *sl)
749 struct w1_netlink_msg msg;
751 dev_dbg(&sl->dev, "%s: detaching %s [%p].\n", __func__, sl->name, sl);
753 list_del(&sl->w1_slave_entry);
755 memset(&msg, 0, sizeof(msg));
756 memcpy(msg.id.id, &sl->reg_num, sizeof(msg.id));
757 msg.type = W1_SLAVE_REMOVE;
758 w1_netlink_send(sl->master, &msg);
760 device_unregister(&sl->dev);
762 wait_for_completion(&sl->released);
766 struct w1_master *w1_search_master_id(u32 id)
768 struct w1_master *dev;
771 mutex_lock(&w1_mlock);
772 list_for_each_entry(dev, &w1_masters, w1_master_entry) {
775 atomic_inc(&dev->refcnt);
779 mutex_unlock(&w1_mlock);
781 return (found)?dev:NULL;
784 struct w1_slave *w1_search_slave(struct w1_reg_num *id)
786 struct w1_master *dev;
787 struct w1_slave *sl = NULL;
790 mutex_lock(&w1_mlock);
791 list_for_each_entry(dev, &w1_masters, w1_master_entry) {
792 mutex_lock(&dev->mutex);
793 list_for_each_entry(sl, &dev->slist, w1_slave_entry) {
794 if (sl->reg_num.family == id->family &&
795 sl->reg_num.id == id->id &&
796 sl->reg_num.crc == id->crc) {
798 atomic_inc(&dev->refcnt);
799 atomic_inc(&sl->refcnt);
803 mutex_unlock(&dev->mutex);
808 mutex_unlock(&w1_mlock);
810 return (found)?sl:NULL;
813 void w1_reconnect_slaves(struct w1_family *f, int attach)
815 struct w1_slave *sl, *sln;
816 struct w1_master *dev;
818 mutex_lock(&w1_mlock);
819 list_for_each_entry(dev, &w1_masters, w1_master_entry) {
820 dev_dbg(&dev->dev, "Reconnecting slaves in device %s "
821 "for family %02x.\n", dev->name, f->fid);
822 mutex_lock(&dev->mutex);
823 list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) {
824 /* If it is a new family, slaves with the default
825 * family driver and are that family will be
826 * connected. If the family is going away, devices
827 * matching that family are reconneced.
829 if ((attach && sl->family->fid == W1_FAMILY_DEFAULT
830 && sl->reg_num.family == f->fid) ||
831 (!attach && sl->family->fid == f->fid)) {
832 struct w1_reg_num rn;
834 memcpy(&rn, &sl->reg_num, sizeof(rn));
837 w1_attach_slave_device(dev, &rn);
840 dev_dbg(&dev->dev, "Reconnecting slaves in device %s "
841 "has been finished.\n", dev->name);
842 mutex_unlock(&dev->mutex);
844 mutex_unlock(&w1_mlock);
847 void w1_slave_found(struct w1_master *dev, u64 rn)
850 struct w1_reg_num *tmp;
851 u64 rn_le = cpu_to_le64(rn);
853 atomic_inc(&dev->refcnt);
855 tmp = (struct w1_reg_num *) &rn;
857 sl = w1_slave_search_device(dev, tmp);
859 set_bit(W1_SLAVE_ACTIVE, (long *)&sl->flags);
861 if (rn && tmp->crc == w1_calc_crc8((u8 *)&rn_le, 7))
862 w1_attach_slave_device(dev, tmp);
865 atomic_dec(&dev->refcnt);
869 * Performs a ROM Search & registers any devices found.
870 * The 1-wire search is a simple binary tree search.
871 * For each bit of the address, we read two bits and write one bit.
872 * The bit written will put to sleep all devies that don't match that bit.
873 * When the two reads differ, the direction choice is obvious.
874 * When both bits are 0, we must choose a path to take.
875 * When we can scan all 64 bits without having to choose a path, we are done.
877 * See "Application note 187 1-wire search algorithm" at www.maxim-ic.com
879 * @dev The master device to search
880 * @cb Function to call when a device is found
882 void w1_search(struct w1_master *dev, u8 search_type, w1_slave_found_callback cb)
884 u64 last_rn, rn, tmp64;
885 int i, slave_count = 0;
886 int last_zero, last_device;
887 int search_bit, desc_bit;
897 while ( !last_device && (slave_count++ < dev->max_slave_count) ) {
902 * Reset bus and all 1-wire device state machines
903 * so they can respond to our requests.
905 * Return 0 - device(s) present, 1 - no devices present.
907 mutex_lock(&dev->bus_mutex);
908 if (w1_reset_bus(dev)) {
909 mutex_unlock(&dev->bus_mutex);
910 dev_dbg(&dev->dev, "No devices present on the wire.\n");
914 /* Do fast search on single slave bus */
915 if (dev->max_slave_count == 1) {
917 w1_write_8(dev, W1_READ_ROM);
918 rv = w1_read_block(dev, (u8 *)&rn, 8);
919 mutex_unlock(&dev->bus_mutex);
927 /* Start the search */
928 w1_write_8(dev, search_type);
929 for (i = 0; i < 64; ++i) {
930 /* Determine the direction/search bit */
932 search_bit = 1; /* took the 0 path last time, so take the 1 path */
933 else if (i > desc_bit)
934 search_bit = 0; /* take the 0 path on the next branch */
936 search_bit = ((last_rn >> i) & 0x1);
938 /** Read two bits and write one bit */
939 triplet_ret = w1_triplet(dev, search_bit);
941 /* quit if no device responded */
942 if ( (triplet_ret & 0x03) == 0x03 )
945 /* If both directions were valid, and we took the 0 path... */
946 if (triplet_ret == 0)
949 /* extract the direction taken & update the device number */
950 tmp64 = (triplet_ret >> 2);
953 /* ensure we're called from kthread and not by netlink callback */
954 if (!dev->priv && kthread_should_stop()) {
955 mutex_unlock(&dev->bus_mutex);
956 dev_dbg(&dev->dev, "Abort w1_search\n");
960 mutex_unlock(&dev->bus_mutex);
962 if ( (triplet_ret & 0x03) != 0x03 ) {
963 if ( (desc_bit == last_zero) || (last_zero < 0))
965 desc_bit = last_zero;
971 void w1_search_process_cb(struct w1_master *dev, u8 search_type,
972 w1_slave_found_callback cb)
974 struct w1_slave *sl, *sln;
976 list_for_each_entry(sl, &dev->slist, w1_slave_entry)
977 clear_bit(W1_SLAVE_ACTIVE, (long *)&sl->flags);
979 w1_search_devices(dev, search_type, cb);
981 list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) {
982 if (!test_bit(W1_SLAVE_ACTIVE, (unsigned long *)&sl->flags) && !--sl->ttl)
984 else if (test_bit(W1_SLAVE_ACTIVE, (unsigned long *)&sl->flags))
985 sl->ttl = dev->slave_ttl;
988 if (dev->search_count > 0)
992 static void w1_search_process(struct w1_master *dev, u8 search_type)
994 w1_search_process_cb(dev, search_type, w1_slave_found);
997 int w1_process(void *data)
999 struct w1_master *dev = (struct w1_master *) data;
1000 /* As long as w1_timeout is only set by a module parameter the sleep
1001 * time can be calculated in jiffies once.
1003 const unsigned long jtime = msecs_to_jiffies(w1_timeout * 1000);
1005 while (!kthread_should_stop()) {
1006 if (dev->search_count) {
1007 mutex_lock(&dev->mutex);
1008 w1_search_process(dev, W1_SEARCH);
1009 mutex_unlock(&dev->mutex);
1013 __set_current_state(TASK_INTERRUPTIBLE);
1015 if (kthread_should_stop())
1018 /* Only sleep when the search is active. */
1019 if (dev->search_count)
1020 schedule_timeout(jtime);
1025 atomic_dec(&dev->refcnt);
1030 static int __init w1_init(void)
1034 printk(KERN_INFO "Driver for 1-wire Dallas network protocol.\n");
1038 retval = bus_register(&w1_bus_type);
1040 printk(KERN_ERR "Failed to register bus. err=%d.\n", retval);
1041 goto err_out_exit_init;
1044 retval = bus_register_notifier(&w1_bus_type, &w1_bus_nb);
1046 goto err_out_bus_unregister;
1048 retval = driver_register(&w1_master_driver);
1051 "Failed to register master driver. err=%d.\n",
1053 goto err_out_bus_unregister;
1056 retval = driver_register(&w1_slave_driver);
1059 "Failed to register slave driver. err=%d.\n",
1061 goto err_out_master_unregister;
1067 /* For undoing the slave register if there was a step after it. */
1068 err_out_slave_unregister:
1069 driver_unregister(&w1_slave_driver);
1072 err_out_master_unregister:
1073 driver_unregister(&w1_master_driver);
1075 err_out_bus_unregister:
1076 bus_unregister(&w1_bus_type);
1082 static void __exit w1_fini(void)
1084 struct w1_master *dev;
1086 /* Set netlink removal messages and some cleanup */
1087 list_for_each_entry(dev, &w1_masters, w1_master_entry)
1088 __w1_remove_master_device(dev);
1092 driver_unregister(&w1_slave_driver);
1093 driver_unregister(&w1_master_driver);
1094 bus_unregister(&w1_bus_type);
1097 module_init(w1_init);
1098 module_exit(w1_fini);