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 static int w1_timeout_us = 0;
50 int w1_max_slave_count = 64;
51 int w1_max_slave_ttl = 10;
53 module_param_named(timeout, w1_timeout, int, 0);
54 MODULE_PARM_DESC(timeout, "time in seconds between automatic slave searches");
55 module_param_named(timeout_us, w1_timeout_us, int, 0);
56 MODULE_PARM_DESC(timeout, "time in microseconds between automatic slave"
58 /* A search stops when w1_max_slave_count devices have been found in that
59 * search. The next search will start over and detect the same set of devices
60 * on a static 1-wire bus. Memory is not allocated based on this number, just
61 * on the number of devices known to the kernel. Having a high number does not
62 * consume additional resources. As a special case, if there is only one
63 * device on the network and w1_max_slave_count is set to 1, the device id can
64 * be read directly skipping the normal slower search process.
66 module_param_named(max_slave_count, w1_max_slave_count, int, 0);
67 MODULE_PARM_DESC(max_slave_count,
68 "maximum number of slaves detected in a search");
69 module_param_named(slave_ttl, w1_max_slave_ttl, int, 0);
70 MODULE_PARM_DESC(slave_ttl,
71 "Number of searches not seeing a slave before it will be removed");
73 DEFINE_MUTEX(w1_mlock);
74 LIST_HEAD(w1_masters);
76 static int w1_master_match(struct device *dev, struct device_driver *drv)
81 static int w1_master_probe(struct device *dev)
86 static void w1_master_release(struct device *dev)
88 struct w1_master *md = dev_to_w1_master(dev);
90 dev_dbg(dev, "%s: Releasing %s.\n", __func__, md->name);
91 memset(md, 0, sizeof(struct w1_master) + sizeof(struct w1_bus_master));
95 static void w1_slave_release(struct device *dev)
97 struct w1_slave *sl = dev_to_w1_slave(dev);
99 dev_dbg(dev, "%s: Releasing %s [%p]\n", __func__, sl->name, sl);
101 w1_family_put(sl->family);
102 sl->master->slave_count--;
105 static ssize_t name_show(struct device *dev, struct device_attribute *attr, char *buf)
107 struct w1_slave *sl = dev_to_w1_slave(dev);
109 return sprintf(buf, "%s\n", sl->name);
111 static DEVICE_ATTR_RO(name);
113 static ssize_t id_show(struct device *dev,
114 struct device_attribute *attr, char *buf)
116 struct w1_slave *sl = dev_to_w1_slave(dev);
117 ssize_t count = sizeof(sl->reg_num);
119 memcpy(buf, (u8 *)&sl->reg_num, count);
122 static DEVICE_ATTR_RO(id);
124 static struct attribute *w1_slave_attrs[] = {
129 ATTRIBUTE_GROUPS(w1_slave);
133 static ssize_t rw_write(struct file *filp, struct kobject *kobj,
134 struct bin_attribute *bin_attr, char *buf, loff_t off,
137 struct w1_slave *sl = kobj_to_w1_slave(kobj);
139 mutex_lock(&sl->master->mutex);
140 if (w1_reset_select_slave(sl)) {
145 w1_write_block(sl->master, buf, count);
148 mutex_unlock(&sl->master->mutex);
152 static ssize_t rw_read(struct file *filp, struct kobject *kobj,
153 struct bin_attribute *bin_attr, char *buf, loff_t off,
156 struct w1_slave *sl = kobj_to_w1_slave(kobj);
158 mutex_lock(&sl->master->mutex);
159 w1_read_block(sl->master, buf, count);
160 mutex_unlock(&sl->master->mutex);
164 static BIN_ATTR_RW(rw, PAGE_SIZE);
166 static struct bin_attribute *w1_slave_bin_attrs[] = {
171 static const struct attribute_group w1_slave_default_group = {
172 .bin_attrs = w1_slave_bin_attrs,
175 static const struct attribute_group *w1_slave_default_groups[] = {
176 &w1_slave_default_group,
180 static struct w1_family_ops w1_default_fops = {
181 .groups = w1_slave_default_groups,
184 static struct w1_family w1_default_family = {
185 .fops = &w1_default_fops,
188 static int w1_uevent(struct device *dev, struct kobj_uevent_env *env);
190 static struct bus_type w1_bus_type = {
192 .match = w1_master_match,
196 struct device_driver w1_master_driver = {
197 .name = "w1_master_driver",
199 .probe = w1_master_probe,
202 struct device w1_master_device = {
205 .init_name = "w1 bus master",
206 .driver = &w1_master_driver,
207 .release = &w1_master_release
210 static struct device_driver w1_slave_driver = {
211 .name = "w1_slave_driver",
216 struct device w1_slave_device = {
219 .init_name = "w1 bus slave",
220 .driver = &w1_slave_driver,
221 .release = &w1_slave_release
225 static ssize_t w1_master_attribute_show_name(struct device *dev, struct device_attribute *attr, char *buf)
227 struct w1_master *md = dev_to_w1_master(dev);
230 mutex_lock(&md->mutex);
231 count = sprintf(buf, "%s\n", md->name);
232 mutex_unlock(&md->mutex);
237 static ssize_t w1_master_attribute_store_search(struct device * dev,
238 struct device_attribute *attr,
239 const char * buf, size_t count)
242 struct w1_master *md = dev_to_w1_master(dev);
245 ret = kstrtol(buf, 0, &tmp);
249 mutex_lock(&md->mutex);
250 md->search_count = tmp;
251 mutex_unlock(&md->mutex);
252 /* Only wake if it is going to be searching. */
254 wake_up_process(md->thread);
259 static ssize_t w1_master_attribute_show_search(struct device *dev,
260 struct device_attribute *attr,
263 struct w1_master *md = dev_to_w1_master(dev);
266 mutex_lock(&md->mutex);
267 count = sprintf(buf, "%d\n", md->search_count);
268 mutex_unlock(&md->mutex);
273 static ssize_t w1_master_attribute_store_pullup(struct device *dev,
274 struct device_attribute *attr,
275 const char *buf, size_t count)
278 struct w1_master *md = dev_to_w1_master(dev);
281 ret = kstrtol(buf, 0, &tmp);
285 mutex_lock(&md->mutex);
286 md->enable_pullup = tmp;
287 mutex_unlock(&md->mutex);
292 static ssize_t w1_master_attribute_show_pullup(struct device *dev,
293 struct device_attribute *attr,
296 struct w1_master *md = dev_to_w1_master(dev);
299 mutex_lock(&md->mutex);
300 count = sprintf(buf, "%d\n", md->enable_pullup);
301 mutex_unlock(&md->mutex);
306 static ssize_t w1_master_attribute_show_pointer(struct device *dev, struct device_attribute *attr, char *buf)
308 struct w1_master *md = dev_to_w1_master(dev);
311 mutex_lock(&md->mutex);
312 count = sprintf(buf, "0x%p\n", md->bus_master);
313 mutex_unlock(&md->mutex);
317 static ssize_t w1_master_attribute_show_timeout(struct device *dev, struct device_attribute *attr, char *buf)
320 count = sprintf(buf, "%d\n", w1_timeout);
324 static ssize_t w1_master_attribute_show_timeout_us(struct device *dev,
325 struct device_attribute *attr, char *buf)
328 count = sprintf(buf, "%d\n", w1_timeout_us);
332 static ssize_t w1_master_attribute_store_max_slave_count(struct device *dev,
333 struct device_attribute *attr, const char *buf, size_t count)
336 struct w1_master *md = dev_to_w1_master(dev);
338 if (kstrtoint(buf, 0, &tmp) == -EINVAL || tmp < 1)
341 mutex_lock(&md->mutex);
342 md->max_slave_count = tmp;
343 /* allow each time the max_slave_count is updated */
344 clear_bit(W1_WARN_MAX_COUNT, &md->flags);
345 mutex_unlock(&md->mutex);
350 static ssize_t w1_master_attribute_show_max_slave_count(struct device *dev, struct device_attribute *attr, char *buf)
352 struct w1_master *md = dev_to_w1_master(dev);
355 mutex_lock(&md->mutex);
356 count = sprintf(buf, "%d\n", md->max_slave_count);
357 mutex_unlock(&md->mutex);
361 static ssize_t w1_master_attribute_show_attempts(struct device *dev, struct device_attribute *attr, char *buf)
363 struct w1_master *md = dev_to_w1_master(dev);
366 mutex_lock(&md->mutex);
367 count = sprintf(buf, "%lu\n", md->attempts);
368 mutex_unlock(&md->mutex);
372 static ssize_t w1_master_attribute_show_slave_count(struct device *dev, struct device_attribute *attr, char *buf)
374 struct w1_master *md = dev_to_w1_master(dev);
377 mutex_lock(&md->mutex);
378 count = sprintf(buf, "%d\n", md->slave_count);
379 mutex_unlock(&md->mutex);
383 static ssize_t w1_master_attribute_show_slaves(struct device *dev,
384 struct device_attribute *attr, char *buf)
386 struct w1_master *md = dev_to_w1_master(dev);
388 struct list_head *ent, *n;
389 struct w1_slave *sl = NULL;
391 mutex_lock(&md->list_mutex);
393 list_for_each_safe(ent, n, &md->slist) {
394 sl = list_entry(ent, struct w1_slave, w1_slave_entry);
396 c -= snprintf(buf + PAGE_SIZE - c, c, "%s\n", sl->name);
399 c -= snprintf(buf + PAGE_SIZE - c, c, "not found.\n");
401 mutex_unlock(&md->list_mutex);
403 return PAGE_SIZE - c;
406 static ssize_t w1_master_attribute_show_add(struct device *dev,
407 struct device_attribute *attr, char *buf)
410 c -= snprintf(buf+PAGE_SIZE - c, c,
411 "write device id xx-xxxxxxxxxxxx to add slave\n");
412 return PAGE_SIZE - c;
415 static int w1_atoreg_num(struct device *dev, const char *buf, size_t count,
416 struct w1_reg_num *rn)
419 unsigned long long id;
423 /* The CRC value isn't read from the user because the sysfs directory
424 * doesn't include it and most messages from the bus search don't
425 * print it either. It would be unreasonable for the user to then
428 const char *error_msg = "bad slave string format, expecting "
432 dev_err(dev, "%s", error_msg);
435 i = sscanf(buf, "%02x-%012llx", &family, &id);
437 dev_err(dev, "%s", error_msg);
443 rn64_le = cpu_to_le64(*(u64 *)rn);
444 rn->crc = w1_calc_crc8((u8 *)&rn64_le, 7);
447 dev_info(dev, "With CRC device is %02x.%012llx.%02x.\n",
448 rn->family, (unsigned long long)rn->id, rn->crc);
454 /* Searches the slaves in the w1_master and returns a pointer or NULL.
455 * Note: must not hold list_mutex
457 struct w1_slave *w1_slave_search_device(struct w1_master *dev,
458 struct w1_reg_num *rn)
461 mutex_lock(&dev->list_mutex);
462 list_for_each_entry(sl, &dev->slist, w1_slave_entry) {
463 if (sl->reg_num.family == rn->family &&
464 sl->reg_num.id == rn->id &&
465 sl->reg_num.crc == rn->crc) {
466 mutex_unlock(&dev->list_mutex);
470 mutex_unlock(&dev->list_mutex);
474 static ssize_t w1_master_attribute_store_add(struct device *dev,
475 struct device_attribute *attr,
476 const char *buf, size_t count)
478 struct w1_master *md = dev_to_w1_master(dev);
479 struct w1_reg_num rn;
481 ssize_t result = count;
483 if (w1_atoreg_num(dev, buf, count, &rn))
486 mutex_lock(&md->mutex);
487 sl = w1_slave_search_device(md, &rn);
488 /* It would be nice to do a targeted search one the one-wire bus
489 * for the new device to see if it is out there or not. But the
490 * current search doesn't support that.
493 dev_info(dev, "Device %s already exists\n", sl->name);
496 w1_attach_slave_device(md, &rn);
498 mutex_unlock(&md->mutex);
503 static ssize_t w1_master_attribute_show_remove(struct device *dev,
504 struct device_attribute *attr, char *buf)
507 c -= snprintf(buf+PAGE_SIZE - c, c,
508 "write device id xx-xxxxxxxxxxxx to remove slave\n");
509 return PAGE_SIZE - c;
512 static ssize_t w1_master_attribute_store_remove(struct device *dev,
513 struct device_attribute *attr,
514 const char *buf, size_t count)
516 struct w1_master *md = dev_to_w1_master(dev);
517 struct w1_reg_num rn;
519 ssize_t result = count;
521 if (w1_atoreg_num(dev, buf, count, &rn))
524 mutex_lock(&md->mutex);
525 sl = w1_slave_search_device(md, &rn);
527 result = w1_slave_detach(sl);
528 /* refcnt 0 means it was detached in the call */
532 dev_info(dev, "Device %02x-%012llx doesn't exists\n", rn.family,
533 (unsigned long long)rn.id);
536 mutex_unlock(&md->mutex);
541 #define W1_MASTER_ATTR_RO(_name, _mode) \
542 struct device_attribute w1_master_attribute_##_name = \
543 __ATTR(w1_master_##_name, _mode, \
544 w1_master_attribute_show_##_name, NULL)
546 #define W1_MASTER_ATTR_RW(_name, _mode) \
547 struct device_attribute w1_master_attribute_##_name = \
548 __ATTR(w1_master_##_name, _mode, \
549 w1_master_attribute_show_##_name, \
550 w1_master_attribute_store_##_name)
552 static W1_MASTER_ATTR_RO(name, S_IRUGO);
553 static W1_MASTER_ATTR_RO(slaves, S_IRUGO);
554 static W1_MASTER_ATTR_RO(slave_count, S_IRUGO);
555 static W1_MASTER_ATTR_RW(max_slave_count, S_IRUGO | S_IWUSR | S_IWGRP);
556 static W1_MASTER_ATTR_RO(attempts, S_IRUGO);
557 static W1_MASTER_ATTR_RO(timeout, S_IRUGO);
558 static W1_MASTER_ATTR_RO(timeout_us, S_IRUGO);
559 static W1_MASTER_ATTR_RO(pointer, S_IRUGO);
560 static W1_MASTER_ATTR_RW(search, S_IRUGO | S_IWUSR | S_IWGRP);
561 static W1_MASTER_ATTR_RW(pullup, S_IRUGO | S_IWUSR | S_IWGRP);
562 static W1_MASTER_ATTR_RW(add, S_IRUGO | S_IWUSR | S_IWGRP);
563 static W1_MASTER_ATTR_RW(remove, S_IRUGO | S_IWUSR | S_IWGRP);
565 static struct attribute *w1_master_default_attrs[] = {
566 &w1_master_attribute_name.attr,
567 &w1_master_attribute_slaves.attr,
568 &w1_master_attribute_slave_count.attr,
569 &w1_master_attribute_max_slave_count.attr,
570 &w1_master_attribute_attempts.attr,
571 &w1_master_attribute_timeout.attr,
572 &w1_master_attribute_timeout_us.attr,
573 &w1_master_attribute_pointer.attr,
574 &w1_master_attribute_search.attr,
575 &w1_master_attribute_pullup.attr,
576 &w1_master_attribute_add.attr,
577 &w1_master_attribute_remove.attr,
581 static struct attribute_group w1_master_defattr_group = {
582 .attrs = w1_master_default_attrs,
585 int w1_create_master_attributes(struct w1_master *master)
587 return sysfs_create_group(&master->dev.kobj, &w1_master_defattr_group);
590 void w1_destroy_master_attributes(struct w1_master *master)
592 sysfs_remove_group(&master->dev.kobj, &w1_master_defattr_group);
595 static int w1_uevent(struct device *dev, struct kobj_uevent_env *env)
597 struct w1_master *md = NULL;
598 struct w1_slave *sl = NULL;
599 char *event_owner, *name;
602 if (dev->driver == &w1_master_driver) {
603 md = container_of(dev, struct w1_master, dev);
604 event_owner = "master";
606 } else if (dev->driver == &w1_slave_driver) {
607 sl = container_of(dev, struct w1_slave, dev);
608 event_owner = "slave";
611 dev_dbg(dev, "Unknown event.\n");
615 dev_dbg(dev, "Hotplug event for %s %s, bus_id=%s.\n",
616 event_owner, name, dev_name(dev));
618 if (dev->driver != &w1_slave_driver || !sl)
621 err = add_uevent_var(env, "W1_FID=%02X", sl->reg_num.family);
625 err = add_uevent_var(env, "W1_SLAVE_ID=%024LX",
626 (unsigned long long)sl->reg_num.id);
631 static int w1_family_notify(unsigned long action, struct w1_slave *sl)
633 struct w1_family_ops *fops;
636 fops = sl->family->fops;
642 case BUS_NOTIFY_ADD_DEVICE:
643 /* if the family driver needs to initialize something... */
644 if (fops->add_slave) {
645 err = fops->add_slave(sl);
648 "add_slave() call failed. err=%d\n",
654 err = sysfs_create_groups(&sl->dev.kobj, fops->groups);
657 "sysfs group creation failed. err=%d\n",
664 case BUS_NOTIFY_DEL_DEVICE:
665 if (fops->remove_slave)
666 sl->family->fops->remove_slave(sl);
668 sysfs_remove_groups(&sl->dev.kobj, fops->groups);
674 static int __w1_attach_slave_device(struct w1_slave *sl)
678 sl->dev.parent = &sl->master->dev;
679 sl->dev.driver = &w1_slave_driver;
680 sl->dev.bus = &w1_bus_type;
681 sl->dev.release = &w1_slave_release;
682 sl->dev.groups = w1_slave_groups;
684 dev_set_name(&sl->dev, "%02x-%012llx",
685 (unsigned int) sl->reg_num.family,
686 (unsigned long long) sl->reg_num.id);
687 snprintf(&sl->name[0], sizeof(sl->name),
689 (unsigned int) sl->reg_num.family,
690 (unsigned long long) sl->reg_num.id);
692 dev_dbg(&sl->dev, "%s: registering %s as %p.\n", __func__,
693 dev_name(&sl->dev), sl);
695 /* suppress for w1_family_notify before sending KOBJ_ADD */
696 dev_set_uevent_suppress(&sl->dev, true);
698 err = device_register(&sl->dev);
701 "Device registration [%s] failed. err=%d\n",
702 dev_name(&sl->dev), err);
705 w1_family_notify(BUS_NOTIFY_ADD_DEVICE, sl);
707 dev_set_uevent_suppress(&sl->dev, false);
708 kobject_uevent(&sl->dev.kobj, KOBJ_ADD);
710 mutex_lock(&sl->master->list_mutex);
711 list_add_tail(&sl->w1_slave_entry, &sl->master->slist);
712 mutex_unlock(&sl->master->list_mutex);
717 int w1_attach_slave_device(struct w1_master *dev, struct w1_reg_num *rn)
722 struct w1_netlink_msg msg;
724 sl = kzalloc(sizeof(struct w1_slave), GFP_KERNEL);
727 "%s: failed to allocate new slave device.\n",
733 sl->owner = THIS_MODULE;
735 set_bit(W1_SLAVE_ACTIVE, &sl->flags);
737 memset(&msg, 0, sizeof(msg));
738 memcpy(&sl->reg_num, rn, sizeof(sl->reg_num));
739 atomic_set(&sl->refcnt, 1);
740 atomic_inc(&sl->master->refcnt);
742 /* slave modules need to be loaded in a context with unlocked mutex */
743 mutex_unlock(&dev->mutex);
744 request_module("w1-family-0x%02x", rn->family);
745 mutex_lock(&dev->mutex);
747 spin_lock(&w1_flock);
748 f = w1_family_registered(rn->family);
750 f= &w1_default_family;
751 dev_info(&dev->dev, "Family %x for %02x.%012llx.%02x is not registered.\n",
752 rn->family, rn->family,
753 (unsigned long long)rn->id, rn->crc);
756 spin_unlock(&w1_flock);
761 err = __w1_attach_slave_device(sl);
763 dev_err(&dev->dev, "%s: Attaching %s failed.\n", __func__,
765 w1_family_put(sl->family);
766 atomic_dec(&sl->master->refcnt);
771 sl->ttl = dev->slave_ttl;
774 memcpy(msg.id.id, rn, sizeof(msg.id));
775 msg.type = W1_SLAVE_ADD;
776 w1_netlink_send(dev, &msg);
781 int w1_unref_slave(struct w1_slave *sl)
783 struct w1_master *dev = sl->master;
785 mutex_lock(&dev->list_mutex);
786 refcnt = atomic_sub_return(1, &sl->refcnt);
788 struct w1_netlink_msg msg;
790 dev_dbg(&sl->dev, "%s: detaching %s [%p].\n", __func__,
793 list_del(&sl->w1_slave_entry);
795 memset(&msg, 0, sizeof(msg));
796 memcpy(msg.id.id, &sl->reg_num, sizeof(msg.id));
797 msg.type = W1_SLAVE_REMOVE;
798 w1_netlink_send(sl->master, &msg);
800 w1_family_notify(BUS_NOTIFY_DEL_DEVICE, sl);
801 device_unregister(&sl->dev);
803 memset(sl, 0, sizeof(*sl));
807 atomic_dec(&dev->refcnt);
808 mutex_unlock(&dev->list_mutex);
812 int w1_slave_detach(struct w1_slave *sl)
814 /* Only detach a slave once as it decreases the refcnt each time. */
816 mutex_lock(&sl->master->list_mutex);
817 destroy_now = !test_bit(W1_SLAVE_DETACH, &sl->flags);
818 set_bit(W1_SLAVE_DETACH, &sl->flags);
819 mutex_unlock(&sl->master->list_mutex);
822 destroy_now = !w1_unref_slave(sl);
823 return destroy_now ? 0 : -EBUSY;
826 struct w1_master *w1_search_master_id(u32 id)
828 struct w1_master *dev;
831 mutex_lock(&w1_mlock);
832 list_for_each_entry(dev, &w1_masters, w1_master_entry) {
835 atomic_inc(&dev->refcnt);
839 mutex_unlock(&w1_mlock);
841 return (found)?dev:NULL;
844 struct w1_slave *w1_search_slave(struct w1_reg_num *id)
846 struct w1_master *dev;
847 struct w1_slave *sl = NULL;
850 mutex_lock(&w1_mlock);
851 list_for_each_entry(dev, &w1_masters, w1_master_entry) {
852 mutex_lock(&dev->list_mutex);
853 list_for_each_entry(sl, &dev->slist, w1_slave_entry) {
854 if (sl->reg_num.family == id->family &&
855 sl->reg_num.id == id->id &&
856 sl->reg_num.crc == id->crc) {
858 atomic_inc(&dev->refcnt);
859 atomic_inc(&sl->refcnt);
863 mutex_unlock(&dev->list_mutex);
868 mutex_unlock(&w1_mlock);
870 return (found)?sl:NULL;
873 void w1_reconnect_slaves(struct w1_family *f, int attach)
875 struct w1_slave *sl, *sln;
876 struct w1_master *dev;
878 mutex_lock(&w1_mlock);
879 list_for_each_entry(dev, &w1_masters, w1_master_entry) {
880 dev_dbg(&dev->dev, "Reconnecting slaves in device %s "
881 "for family %02x.\n", dev->name, f->fid);
882 mutex_lock(&dev->mutex);
883 mutex_lock(&dev->list_mutex);
884 list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) {
885 /* If it is a new family, slaves with the default
886 * family driver and are that family will be
887 * connected. If the family is going away, devices
888 * matching that family are reconneced.
890 if ((attach && sl->family->fid == W1_FAMILY_DEFAULT
891 && sl->reg_num.family == f->fid) ||
892 (!attach && sl->family->fid == f->fid)) {
893 struct w1_reg_num rn;
895 mutex_unlock(&dev->list_mutex);
896 memcpy(&rn, &sl->reg_num, sizeof(rn));
897 /* If it was already in use let the automatic
898 * scan pick it up again later.
900 if (!w1_slave_detach(sl))
901 w1_attach_slave_device(dev, &rn);
902 mutex_lock(&dev->list_mutex);
905 dev_dbg(&dev->dev, "Reconnecting slaves in device %s "
906 "has been finished.\n", dev->name);
907 mutex_unlock(&dev->list_mutex);
908 mutex_unlock(&dev->mutex);
910 mutex_unlock(&w1_mlock);
913 void w1_slave_found(struct w1_master *dev, u64 rn)
916 struct w1_reg_num *tmp;
917 u64 rn_le = cpu_to_le64(rn);
919 atomic_inc(&dev->refcnt);
921 tmp = (struct w1_reg_num *) &rn;
923 sl = w1_slave_search_device(dev, tmp);
925 set_bit(W1_SLAVE_ACTIVE, &sl->flags);
927 if (rn && tmp->crc == w1_calc_crc8((u8 *)&rn_le, 7))
928 w1_attach_slave_device(dev, tmp);
931 atomic_dec(&dev->refcnt);
935 * w1_search() - Performs a ROM Search & registers any devices found.
936 * @dev: The master device to search
937 * @search_type: W1_SEARCH to search all devices, or W1_ALARM_SEARCH
938 * to return only devices in the alarmed state
939 * @cb: Function to call when a device is found
941 * The 1-wire search is a simple binary tree search.
942 * For each bit of the address, we read two bits and write one bit.
943 * The bit written will put to sleep all devies that don't match that bit.
944 * When the two reads differ, the direction choice is obvious.
945 * When both bits are 0, we must choose a path to take.
946 * When we can scan all 64 bits without having to choose a path, we are done.
948 * See "Application note 187 1-wire search algorithm" at www.maxim-ic.com
951 void w1_search(struct w1_master *dev, u8 search_type, w1_slave_found_callback cb)
953 u64 last_rn, rn, tmp64;
954 int i, slave_count = 0;
955 int last_zero, last_device;
956 int search_bit, desc_bit;
967 while ( !last_device && (slave_count++ < dev->max_slave_count) ) {
972 * Reset bus and all 1-wire device state machines
973 * so they can respond to our requests.
975 * Return 0 - device(s) present, 1 - no devices present.
977 mutex_lock(&dev->bus_mutex);
978 if (w1_reset_bus(dev)) {
979 mutex_unlock(&dev->bus_mutex);
980 dev_dbg(&dev->dev, "No devices present on the wire.\n");
984 /* Do fast search on single slave bus */
985 if (dev->max_slave_count == 1) {
987 w1_write_8(dev, W1_READ_ROM);
988 rv = w1_read_block(dev, (u8 *)&rn, 8);
989 mutex_unlock(&dev->bus_mutex);
997 /* Start the search */
998 w1_write_8(dev, search_type);
999 for (i = 0; i < 64; ++i) {
1000 /* Determine the direction/search bit */
1002 search_bit = 1; /* took the 0 path last time, so take the 1 path */
1003 else if (i > desc_bit)
1004 search_bit = 0; /* take the 0 path on the next branch */
1006 search_bit = ((last_rn >> i) & 0x1);
1008 /* Read two bits and write one bit */
1009 triplet_ret = w1_triplet(dev, search_bit);
1011 /* quit if no device responded */
1012 if ( (triplet_ret & 0x03) == 0x03 )
1015 /* If both directions were valid, and we took the 0 path... */
1016 if (triplet_ret == 0)
1019 /* extract the direction taken & update the device number */
1020 tmp64 = (triplet_ret >> 2);
1023 if (test_bit(W1_ABORT_SEARCH, &dev->flags)) {
1024 mutex_unlock(&dev->bus_mutex);
1025 dev_dbg(&dev->dev, "Abort w1_search\n");
1029 mutex_unlock(&dev->bus_mutex);
1031 if ( (triplet_ret & 0x03) != 0x03 ) {
1032 if ((desc_bit == last_zero) || (last_zero < 0)) {
1036 dev->search_id = rn;
1038 desc_bit = last_zero;
1042 if (!last_device && slave_count == dev->max_slave_count &&
1043 !test_bit(W1_WARN_MAX_COUNT, &dev->flags)) {
1044 /* Only max_slave_count will be scanned in a search,
1045 * but it will start where it left off next search
1046 * until all ids are identified and then it will start
1047 * over. A continued search will report the previous
1048 * last id as the first id (provided it is still on the
1051 dev_info(&dev->dev, "%s: max_slave_count %d reached, "
1052 "will continue next search.\n", __func__,
1053 dev->max_slave_count);
1054 set_bit(W1_WARN_MAX_COUNT, &dev->flags);
1059 void w1_search_process_cb(struct w1_master *dev, u8 search_type,
1060 w1_slave_found_callback cb)
1062 struct w1_slave *sl, *sln;
1064 mutex_lock(&dev->list_mutex);
1065 list_for_each_entry(sl, &dev->slist, w1_slave_entry)
1066 clear_bit(W1_SLAVE_ACTIVE, &sl->flags);
1067 mutex_unlock(&dev->list_mutex);
1069 w1_search_devices(dev, search_type, cb);
1071 mutex_lock(&dev->list_mutex);
1072 list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) {
1073 if (!test_bit(W1_SLAVE_ACTIVE, &sl->flags) && !--sl->ttl) {
1074 mutex_unlock(&dev->list_mutex);
1075 w1_slave_detach(sl);
1076 mutex_lock(&dev->list_mutex);
1078 else if (test_bit(W1_SLAVE_ACTIVE, &sl->flags))
1079 sl->ttl = dev->slave_ttl;
1081 mutex_unlock(&dev->list_mutex);
1083 if (dev->search_count > 0)
1084 dev->search_count--;
1087 static void w1_search_process(struct w1_master *dev, u8 search_type)
1089 w1_search_process_cb(dev, search_type, w1_slave_found);
1093 * w1_process_callbacks() - execute each dev->async_list callback entry
1094 * @dev: w1_master device
1096 * The w1 master list_mutex must be held.
1098 * Return: 1 if there were commands to executed 0 otherwise
1100 int w1_process_callbacks(struct w1_master *dev)
1103 struct w1_async_cmd *async_cmd, *async_n;
1105 /* The list can be added to in another thread, loop until it is empty */
1106 while (!list_empty(&dev->async_list)) {
1107 list_for_each_entry_safe(async_cmd, async_n, &dev->async_list,
1109 /* drop the lock, if it is a search it can take a long
1111 mutex_unlock(&dev->list_mutex);
1112 async_cmd->cb(dev, async_cmd);
1114 mutex_lock(&dev->list_mutex);
1120 int w1_process(void *data)
1122 struct w1_master *dev = (struct w1_master *) data;
1123 /* As long as w1_timeout is only set by a module parameter the sleep
1124 * time can be calculated in jiffies once.
1126 const unsigned long jtime =
1127 usecs_to_jiffies(w1_timeout * 1000000 + w1_timeout_us);
1128 /* remainder if it woke up early */
1129 unsigned long jremain = 0;
1133 if (!jremain && dev->search_count) {
1134 mutex_lock(&dev->mutex);
1135 w1_search_process(dev, W1_SEARCH);
1136 mutex_unlock(&dev->mutex);
1139 mutex_lock(&dev->list_mutex);
1140 /* Note, w1_process_callback drops the lock while processing,
1141 * but locks it again before returning.
1143 if (!w1_process_callbacks(dev) && jremain) {
1144 /* a wake up is either to stop the thread, process
1145 * callbacks, or search, it isn't process callbacks, so
1146 * schedule a search.
1152 __set_current_state(TASK_INTERRUPTIBLE);
1154 /* hold list_mutex until after interruptible to prevent loosing
1155 * the wakeup signal when async_cmd is added.
1157 mutex_unlock(&dev->list_mutex);
1159 if (kthread_should_stop())
1162 /* Only sleep when the search is active. */
1163 if (dev->search_count) {
1166 jremain = schedule_timeout(jremain);
1172 atomic_dec(&dev->refcnt);
1177 static int __init w1_init(void)
1181 pr_info("Driver for 1-wire Dallas network protocol.\n");
1185 retval = bus_register(&w1_bus_type);
1187 pr_err("Failed to register bus. err=%d.\n", retval);
1188 goto err_out_exit_init;
1191 retval = driver_register(&w1_master_driver);
1193 pr_err("Failed to register master driver. err=%d.\n",
1195 goto err_out_bus_unregister;
1198 retval = driver_register(&w1_slave_driver);
1200 pr_err("Failed to register slave driver. err=%d.\n",
1202 goto err_out_master_unregister;
1208 /* For undoing the slave register if there was a step after it. */
1209 err_out_slave_unregister:
1210 driver_unregister(&w1_slave_driver);
1213 err_out_master_unregister:
1214 driver_unregister(&w1_master_driver);
1216 err_out_bus_unregister:
1217 bus_unregister(&w1_bus_type);
1223 static void __exit w1_fini(void)
1225 struct w1_master *dev;
1227 /* Set netlink removal messages and some cleanup */
1228 list_for_each_entry(dev, &w1_masters, w1_master_entry)
1229 __w1_remove_master_device(dev);
1233 driver_unregister(&w1_slave_driver);
1234 driver_unregister(&w1_master_driver);
1235 bus_unregister(&w1_bus_type);
1238 module_init(w1_init);
1239 module_exit(w1_fini);