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 = dev_to_w1_master(dev);
93 complete(&md->dev_released);
96 static void w1_slave_release(struct device *dev)
98 struct w1_slave *sl = dev_to_w1_slave(dev);
99 complete(&sl->dev_released);
102 static ssize_t w1_default_read_name(struct device *dev, struct device_attribute *attr, char *buf)
104 return sprintf(buf, "No family registered.\n");
107 static ssize_t w1_default_read_bin(struct kobject *kobj, char *buf, loff_t off,
110 return sprintf(buf, "No family registered.\n");
113 static struct device_attribute w1_slave_attribute =
114 __ATTR(name, S_IRUGO, w1_default_read_name, NULL);
116 static struct bin_attribute w1_slave_bin_attribute = {
120 .owner = THIS_MODULE,
122 .size = W1_SLAVE_DATA_SIZE,
123 .read = &w1_default_read_bin,
126 static int w1_hotplug(struct device *dev, char **envp, int num_envp, char *buffer, int buffer_size);
128 static struct bus_type w1_bus_type = {
130 .match = w1_master_match,
131 .hotplug = w1_hotplug,
134 struct device_driver w1_master_driver = {
135 .name = "w1_master_driver",
137 .probe = w1_master_probe,
138 .remove = w1_master_remove,
141 struct device w1_master_device = {
144 .bus_id = "w1 bus master",
145 .driver = &w1_master_driver,
146 .release = &w1_master_release
149 struct device_driver w1_slave_driver = {
150 .name = "w1_slave_driver",
154 struct device w1_slave_device = {
157 .bus_id = "w1 bus slave",
158 .driver = &w1_slave_driver,
161 static ssize_t w1_master_attribute_show_name(struct device *dev, struct device_attribute *attr, char *buf)
163 struct w1_master *md = dev_to_w1_master(dev);
166 if (down_interruptible (&md->mutex))
169 count = sprintf(buf, "%s\n", md->name);
176 static ssize_t w1_master_attribute_store_search(struct device * dev,
177 struct device_attribute *attr,
178 const char * buf, size_t count)
180 struct w1_master *md = dev_to_w1_master(dev);
182 if (down_interruptible (&md->mutex))
185 md->search_count = simple_strtol(buf, NULL, 0);
192 static ssize_t w1_master_attribute_show_search(struct device *dev,
193 struct device_attribute *attr,
196 struct w1_master *md = dev_to_w1_master(dev);
199 if (down_interruptible (&md->mutex))
202 count = sprintf(buf, "%d\n", md->search_count);
209 static ssize_t w1_master_attribute_show_pointer(struct device *dev, struct device_attribute *attr, char *buf)
211 struct w1_master *md = dev_to_w1_master(dev);
214 if (down_interruptible(&md->mutex))
217 count = sprintf(buf, "0x%p\n", md->bus_master);
223 static ssize_t w1_master_attribute_show_timeout(struct device *dev, struct device_attribute *attr, char *buf)
226 count = sprintf(buf, "%d\n", w1_timeout);
230 static ssize_t w1_master_attribute_show_max_slave_count(struct device *dev, struct device_attribute *attr, char *buf)
232 struct w1_master *md = dev_to_w1_master(dev);
235 if (down_interruptible(&md->mutex))
238 count = sprintf(buf, "%d\n", md->max_slave_count);
244 static ssize_t w1_master_attribute_show_attempts(struct device *dev, struct device_attribute *attr, char *buf)
246 struct w1_master *md = dev_to_w1_master(dev);
249 if (down_interruptible(&md->mutex))
252 count = sprintf(buf, "%lu\n", md->attempts);
258 static ssize_t w1_master_attribute_show_slave_count(struct device *dev, struct device_attribute *attr, char *buf)
260 struct w1_master *md = dev_to_w1_master(dev);
263 if (down_interruptible(&md->mutex))
266 count = sprintf(buf, "%d\n", md->slave_count);
272 static ssize_t w1_master_attribute_show_slaves(struct device *dev, struct device_attribute *attr, char *buf)
274 struct w1_master *md = dev_to_w1_master(dev);
277 if (down_interruptible(&md->mutex))
280 if (md->slave_count == 0)
281 c -= snprintf(buf + PAGE_SIZE - c, c, "not found.\n");
283 struct list_head *ent, *n;
286 list_for_each_safe(ent, n, &md->slist) {
287 sl = list_entry(ent, struct w1_slave, w1_slave_entry);
289 c -= snprintf(buf + PAGE_SIZE - c, c, "%s\n", sl->name);
295 return PAGE_SIZE - c;
298 #define W1_MASTER_ATTR_RO(_name, _mode) \
299 struct device_attribute w1_master_attribute_##_name = \
300 __ATTR(w1_master_##_name, _mode, \
301 w1_master_attribute_show_##_name, NULL)
303 #define W1_MASTER_ATTR_RW(_name, _mode) \
304 struct device_attribute w1_master_attribute_##_name = \
305 __ATTR(w1_master_##_name, _mode, \
306 w1_master_attribute_show_##_name, \
307 w1_master_attribute_store_##_name)
309 static W1_MASTER_ATTR_RO(name, S_IRUGO);
310 static W1_MASTER_ATTR_RO(slaves, S_IRUGO);
311 static W1_MASTER_ATTR_RO(slave_count, S_IRUGO);
312 static W1_MASTER_ATTR_RO(max_slave_count, S_IRUGO);
313 static W1_MASTER_ATTR_RO(attempts, S_IRUGO);
314 static W1_MASTER_ATTR_RO(timeout, S_IRUGO);
315 static W1_MASTER_ATTR_RO(pointer, S_IRUGO);
316 static W1_MASTER_ATTR_RW(search, S_IRUGO | S_IWUGO);
318 static struct attribute *w1_master_default_attrs[] = {
319 &w1_master_attribute_name.attr,
320 &w1_master_attribute_slaves.attr,
321 &w1_master_attribute_slave_count.attr,
322 &w1_master_attribute_max_slave_count.attr,
323 &w1_master_attribute_attempts.attr,
324 &w1_master_attribute_timeout.attr,
325 &w1_master_attribute_pointer.attr,
326 &w1_master_attribute_search.attr,
330 static struct attribute_group w1_master_defattr_group = {
331 .attrs = w1_master_default_attrs,
334 int w1_create_master_attributes(struct w1_master *master)
336 return sysfs_create_group(&master->dev.kobj, &w1_master_defattr_group);
339 void w1_destroy_master_attributes(struct w1_master *master)
341 sysfs_remove_group(&master->dev.kobj, &w1_master_defattr_group);
344 #ifdef CONFIG_HOTPLUG
345 static int w1_hotplug(struct device *dev, char **envp, int num_envp, char *buffer, int buffer_size)
347 struct w1_master *md = NULL;
348 struct w1_slave *sl = NULL;
349 char *event_owner, *name;
350 int err, cur_index=0, cur_len=0;
352 if (dev->driver == &w1_master_driver) {
353 md = container_of(dev, struct w1_master, dev);
354 event_owner = "master";
356 } else if (dev->driver == &w1_slave_driver) {
357 sl = container_of(dev, struct w1_slave, dev);
358 event_owner = "slave";
361 dev_dbg(dev, "Unknown hotplug event.\n");
365 dev_dbg(dev, "Hotplug event for %s %s, bus_id=%s.\n", event_owner, name, dev->bus_id);
367 if (dev->driver != &w1_slave_driver || !sl)
370 err = add_hotplug_env_var(envp, num_envp, &cur_index, buffer, buffer_size, &cur_len, "W1_FID=%02X", sl->reg_num.family);
374 err = add_hotplug_env_var(envp, num_envp, &cur_index, buffer, buffer_size, &cur_len, "W1_SLAVE_ID=%024LX", (u64)sl->reg_num.id);
381 static int w1_hotplug(struct device *dev, char **envp, int num_envp, char *buffer, int buffer_size)
387 static int __w1_attach_slave_device(struct w1_slave *sl)
391 sl->dev.parent = &sl->master->dev;
392 sl->dev.driver = &w1_slave_driver;
393 sl->dev.bus = &w1_bus_type;
394 sl->dev.release = &w1_slave_release;
396 snprintf(&sl->dev.bus_id[0], sizeof(sl->dev.bus_id),
398 (unsigned int) sl->reg_num.family,
399 (unsigned long long) sl->reg_num.id);
400 snprintf(&sl->name[0], sizeof(sl->name),
402 (unsigned int) sl->reg_num.family,
403 (unsigned long long) sl->reg_num.id);
405 dev_dbg(&sl->dev, "%s: registering %s.\n", __func__,
408 err = device_register(&sl->dev);
411 "Device registration [%s] failed. err=%d\n",
412 sl->dev.bus_id, err);
416 memcpy(&sl->attr_bin, &w1_slave_bin_attribute, sizeof(sl->attr_bin));
417 memcpy(&sl->attr_name, &w1_slave_attribute, sizeof(sl->attr_name));
419 sl->attr_bin.read = sl->family->fops->rbin;
420 sl->attr_name.show = sl->family->fops->rname;
422 err = device_create_file(&sl->dev, &sl->attr_name);
425 "sysfs file creation for [%s] failed. err=%d\n",
426 sl->dev.bus_id, err);
427 device_unregister(&sl->dev);
431 if ( sl->attr_bin.read ) {
432 err = sysfs_create_bin_file(&sl->dev.kobj, &sl->attr_bin);
435 "sysfs file creation for [%s] failed. err=%d\n",
436 sl->dev.bus_id, err);
437 device_remove_file(&sl->dev, &sl->attr_name);
438 device_unregister(&sl->dev);
443 list_add_tail(&sl->w1_slave_entry, &sl->master->slist);
448 static int w1_attach_slave_device(struct w1_master *dev, struct w1_reg_num *rn)
453 struct w1_netlink_msg msg;
455 sl = kmalloc(sizeof(struct w1_slave), GFP_KERNEL);
458 "%s: failed to allocate new slave device.\n",
463 memset(sl, 0, sizeof(*sl));
465 sl->owner = THIS_MODULE;
467 set_bit(W1_SLAVE_ACTIVE, (long *)&sl->flags);
469 memcpy(&sl->reg_num, rn, sizeof(sl->reg_num));
470 atomic_set(&sl->refcnt, 0);
471 init_completion(&sl->dev_released);
473 spin_lock(&w1_flock);
474 f = w1_family_registered(rn->family);
476 f= &w1_default_family;
477 dev_info(&dev->dev, "Family %x for %02x.%012llx.%02x is not registered.\n",
478 rn->family, rn->family,
479 (unsigned long long)rn->id, rn->crc);
482 spin_unlock(&w1_flock);
487 err = __w1_attach_slave_device(sl);
489 dev_err(&dev->dev, "%s: Attaching %s failed.\n", __func__,
491 w1_family_put(sl->family);
496 sl->ttl = dev->slave_ttl;
499 memcpy(&msg.id.id, rn, sizeof(msg.id.id));
500 msg.type = W1_SLAVE_ADD;
501 w1_netlink_send(dev, &msg);
506 static void w1_slave_detach(struct w1_slave *sl)
508 struct w1_netlink_msg msg;
510 dev_info(&sl->dev, "%s: detaching %s.\n", __func__, sl->name);
512 while (atomic_read(&sl->refcnt)) {
513 printk(KERN_INFO "Waiting for %s to become free: refcnt=%d.\n",
514 sl->name, atomic_read(&sl->refcnt));
516 if (msleep_interruptible(1000))
517 flush_signals(current);
520 if ( sl->attr_bin.read ) {
521 sysfs_remove_bin_file (&sl->dev.kobj, &sl->attr_bin);
523 device_remove_file(&sl->dev, &sl->attr_name);
524 device_unregister(&sl->dev);
525 w1_family_put(sl->family);
527 sl->master->slave_count--;
529 memcpy(&msg.id.id, &sl->reg_num, sizeof(msg.id.id));
530 msg.type = W1_SLAVE_REMOVE;
531 w1_netlink_send(sl->master, &msg);
534 static struct w1_master *w1_search_master(unsigned long data)
536 struct w1_master *dev;
539 spin_lock_bh(&w1_mlock);
540 list_for_each_entry(dev, &w1_masters, w1_master_entry) {
541 if (dev->bus_master->data == data) {
543 atomic_inc(&dev->refcnt);
547 spin_unlock_bh(&w1_mlock);
549 return (found)?dev:NULL;
552 void w1_reconnect_slaves(struct w1_family *f)
554 struct w1_master *dev;
556 spin_lock_bh(&w1_mlock);
557 list_for_each_entry(dev, &w1_masters, w1_master_entry) {
558 dev_info(&dev->dev, "Reconnecting slaves in %s into new family %02x.\n",
560 set_bit(W1_MASTER_NEED_RECONNECT, &dev->flags);
562 spin_unlock_bh(&w1_mlock);
565 static void w1_slave_found(unsigned long data, u64 rn)
569 struct list_head *ent;
570 struct w1_reg_num *tmp;
571 int family_found = 0;
572 struct w1_master *dev;
573 u64 rn_le = cpu_to_le64(rn);
575 dev = w1_search_master(data);
577 printk(KERN_ERR "Failed to find w1 master device for data %08lx, it is impossible.\n",
582 tmp = (struct w1_reg_num *) &rn;
585 list_for_each(ent, &dev->slist) {
587 sl = list_entry(ent, struct w1_slave, w1_slave_entry);
589 if (sl->reg_num.family == tmp->family &&
590 sl->reg_num.id == tmp->id &&
591 sl->reg_num.crc == tmp->crc) {
592 set_bit(W1_SLAVE_ACTIVE, (long *)&sl->flags);
594 } else if (sl->reg_num.family == tmp->family) {
602 if (slave_count == dev->slave_count &&
603 rn && ((rn >> 56) & 0xff) == w1_calc_crc8((u8 *)&rn_le, 7)) {
604 w1_attach_slave_device(dev, tmp);
607 atomic_dec(&dev->refcnt);
611 * Performs a ROM Search & registers any devices found.
612 * The 1-wire search is a simple binary tree search.
613 * For each bit of the address, we read two bits and write one bit.
614 * The bit written will put to sleep all devies that don't match that bit.
615 * When the two reads differ, the direction choice is obvious.
616 * When both bits are 0, we must choose a path to take.
617 * When we can scan all 64 bits without having to choose a path, we are done.
619 * See "Application note 187 1-wire search algorithm" at www.maxim-ic.com
621 * @dev The master device to search
622 * @cb Function to call when a device is found
624 void w1_search(struct w1_master *dev, w1_slave_found_callback cb)
626 u64 last_rn, rn, tmp64;
627 int i, slave_count = 0;
628 int last_zero, last_device;
629 int search_bit, desc_bit;
639 while ( !last_device && (slave_count++ < dev->max_slave_count) ) {
644 * Reset bus and all 1-wire device state machines
645 * so they can respond to our requests.
647 * Return 0 - device(s) present, 1 - no devices present.
649 if (w1_reset_bus(dev)) {
650 dev_dbg(&dev->dev, "No devices present on the wire.\n");
654 /* Start the search */
655 w1_write_8(dev, W1_SEARCH);
656 for (i = 0; i < 64; ++i) {
657 /* Determine the direction/search bit */
659 search_bit = 1; /* took the 0 path last time, so take the 1 path */
660 else if (i > desc_bit)
661 search_bit = 0; /* take the 0 path on the next branch */
663 search_bit = ((last_rn >> i) & 0x1);
665 /** Read two bits and write one bit */
666 triplet_ret = w1_triplet(dev, search_bit);
668 /* quit if no device responded */
669 if ( (triplet_ret & 0x03) == 0x03 )
672 /* If both directions were valid, and we took the 0 path... */
673 if (triplet_ret == 0)
676 /* extract the direction taken & update the device number */
677 tmp64 = (triplet_ret >> 2);
681 if ( (triplet_ret & 0x03) != 0x03 ) {
682 if ( (desc_bit == last_zero) || (last_zero < 0))
684 desc_bit = last_zero;
685 cb(dev->bus_master->data, rn);
690 static int w1_control(void *data)
692 struct w1_slave *sl, *sln;
693 struct w1_master *dev, *n;
694 int err, have_to_wait = 0;
696 daemonize("w1_control");
697 allow_signal(SIGTERM);
699 while (!control_needs_exit || have_to_wait) {
703 msleep_interruptible(w1_timeout * 1000);
705 if (signal_pending(current))
706 flush_signals(current);
708 list_for_each_entry_safe(dev, n, &w1_masters, w1_master_entry) {
709 if (!control_needs_exit && !dev->flags)
712 * Little race: we can create thread but not set the flag.
713 * Get a chance for external process to set flag up.
715 if (!dev->initialized) {
720 if (control_needs_exit) {
721 set_bit(W1_MASTER_NEED_EXIT, &dev->flags);
723 err = kill_proc(dev->kpid, SIGTERM, 1);
726 "Failed to send signal to w1 kernel thread %d.\n",
730 if (test_bit(W1_MASTER_NEED_EXIT, &dev->flags)) {
731 wait_for_completion(&dev->dev_exited);
732 spin_lock_bh(&w1_mlock);
733 list_del(&dev->w1_master_entry);
734 spin_unlock_bh(&w1_mlock);
736 list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) {
737 list_del(&sl->w1_slave_entry);
742 w1_destroy_master_attributes(dev);
743 atomic_dec(&dev->refcnt);
747 if (test_bit(W1_MASTER_NEED_RECONNECT, &dev->flags)) {
748 dev_info(&dev->dev, "Reconnecting slaves in device %s.\n", dev->name);
750 list_for_each_entry(sl, &dev->slist, w1_slave_entry) {
751 if (sl->family->fid == W1_FAMILY_DEFAULT) {
752 struct w1_reg_num rn;
753 list_del(&sl->w1_slave_entry);
756 memcpy(&rn, &sl->reg_num, sizeof(rn));
760 w1_attach_slave_device(dev, &rn);
763 clear_bit(W1_MASTER_NEED_RECONNECT, &dev->flags);
769 complete_and_exit(&w1_control_complete, 0);
772 int w1_process(void *data)
774 struct w1_master *dev = (struct w1_master *) data;
775 struct w1_slave *sl, *sln;
777 daemonize("%s", dev->name);
778 allow_signal(SIGTERM);
780 while (!test_bit(W1_MASTER_NEED_EXIT, &dev->flags)) {
782 msleep_interruptible(w1_timeout * 1000);
784 if (signal_pending(current))
785 flush_signals(current);
787 if (test_bit(W1_MASTER_NEED_EXIT, &dev->flags))
790 if (!dev->initialized)
793 if (dev->search_count == 0)
796 if (down_interruptible(&dev->mutex))
799 list_for_each_entry(sl, &dev->slist, w1_slave_entry)
800 clear_bit(W1_SLAVE_ACTIVE, (long *)&sl->flags);
802 w1_search_devices(dev, w1_slave_found);
804 list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) {
805 if (!test_bit(W1_SLAVE_ACTIVE, (unsigned long *)&sl->flags) && !--sl->ttl) {
806 list_del (&sl->w1_slave_entry);
808 w1_slave_detach (sl);
812 } else if (test_bit(W1_SLAVE_ACTIVE, (unsigned long *)&sl->flags))
813 sl->ttl = dev->slave_ttl;
816 if (dev->search_count > 0)
822 atomic_dec(&dev->refcnt);
823 complete_and_exit(&dev->dev_exited, 0);
828 static int w1_init(void)
832 printk(KERN_INFO "Driver for 1-wire Dallas network protocol.\n");
834 retval = bus_register(&w1_bus_type);
836 printk(KERN_ERR "Failed to register bus. err=%d.\n", retval);
837 goto err_out_exit_init;
840 retval = driver_register(&w1_master_driver);
843 "Failed to register master driver. err=%d.\n",
845 goto err_out_bus_unregister;
848 retval = driver_register(&w1_slave_driver);
851 "Failed to register master driver. err=%d.\n",
853 goto err_out_master_unregister;
856 control_thread = kernel_thread(&w1_control, NULL, 0);
857 if (control_thread < 0) {
858 printk(KERN_ERR "Failed to create control thread. err=%d\n",
860 retval = control_thread;
861 goto err_out_slave_unregister;
866 err_out_slave_unregister:
867 driver_unregister(&w1_slave_driver);
869 err_out_master_unregister:
870 driver_unregister(&w1_master_driver);
872 err_out_bus_unregister:
873 bus_unregister(&w1_bus_type);
879 static void w1_fini(void)
881 struct w1_master *dev;
883 list_for_each_entry(dev, &w1_masters, w1_master_entry)
884 __w1_remove_master_device(dev);
886 control_needs_exit = 1;
887 wait_for_completion(&w1_control_complete);
889 driver_unregister(&w1_slave_driver);
890 driver_unregister(&w1_master_driver);
891 bus_unregister(&w1_bus_type);
894 module_init(w1_init);
895 module_exit(w1_fini);