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 bin_attribute w1_slave_bin_attribute = {
109 .owner = THIS_MODULE,
111 .size = W1_SLAVE_DATA_SIZE,
112 .read = &w1_default_read_bin,
116 static struct bus_type w1_bus_type = {
118 .match = w1_master_match,
121 struct device_driver w1_driver = {
124 .probe = w1_master_probe,
125 .remove = w1_master_remove,
128 struct device w1_device = {
131 .bus_id = "w1 bus master",
132 .driver = &w1_driver,
133 .release = &w1_master_release
136 static ssize_t w1_master_attribute_show_name(struct device *dev, struct device_attribute *attr, char *buf)
138 struct w1_master *md = container_of(dev, struct w1_master, dev);
141 if (down_interruptible (&md->mutex))
144 count = sprintf(buf, "%s\n", md->name);
151 static ssize_t w1_master_attribute_show_pointer(struct device *dev, struct device_attribute *attr, char *buf)
153 struct w1_master *md = container_of(dev, struct w1_master, dev);
156 if (down_interruptible(&md->mutex))
159 count = sprintf(buf, "0x%p\n", md->bus_master);
165 static ssize_t w1_master_attribute_show_timeout(struct device *dev, struct device_attribute *attr, char *buf)
168 count = sprintf(buf, "%d\n", w1_timeout);
172 static ssize_t w1_master_attribute_show_max_slave_count(struct device *dev, struct device_attribute *attr, char *buf)
174 struct w1_master *md = container_of(dev, struct w1_master, dev);
177 if (down_interruptible(&md->mutex))
180 count = sprintf(buf, "%d\n", md->max_slave_count);
186 static ssize_t w1_master_attribute_show_attempts(struct device *dev, struct device_attribute *attr, char *buf)
188 struct w1_master *md = container_of(dev, struct w1_master, dev);
191 if (down_interruptible(&md->mutex))
194 count = sprintf(buf, "%lu\n", md->attempts);
200 static ssize_t w1_master_attribute_show_slave_count(struct device *dev, struct device_attribute *attr, char *buf)
202 struct w1_master *md = container_of(dev, struct w1_master, dev);
205 if (down_interruptible(&md->mutex))
208 count = sprintf(buf, "%d\n", md->slave_count);
214 static ssize_t w1_master_attribute_show_slaves(struct device *dev, struct device_attribute *attr, char *buf)
216 struct w1_master *md = container_of(dev, struct w1_master, dev);
219 if (down_interruptible(&md->mutex))
222 if (md->slave_count == 0)
223 c -= snprintf(buf + PAGE_SIZE - c, c, "not found.\n");
225 struct list_head *ent, *n;
228 list_for_each_safe(ent, n, &md->slist) {
229 sl = list_entry(ent, struct w1_slave, w1_slave_entry);
231 c -= snprintf(buf + PAGE_SIZE - c, c, "%s\n", sl->name);
237 return PAGE_SIZE - c;
240 #define W1_MASTER_ATTR_RO(_name, _mode) \
241 struct device_attribute w1_master_attribute_##_name = \
242 __ATTR(w1_master_##_name, _mode, \
243 w1_master_attribute_show_##_name, NULL)
245 static W1_MASTER_ATTR_RO(name, S_IRUGO);
246 static W1_MASTER_ATTR_RO(slaves, S_IRUGO);
247 static W1_MASTER_ATTR_RO(slave_count, S_IRUGO);
248 static W1_MASTER_ATTR_RO(max_slave_count, S_IRUGO);
249 static W1_MASTER_ATTR_RO(attempts, S_IRUGO);
250 static W1_MASTER_ATTR_RO(timeout, S_IRUGO);
251 static W1_MASTER_ATTR_RO(pointer, S_IRUGO);
253 static struct attribute *w1_master_default_attrs[] = {
254 &w1_master_attribute_name.attr,
255 &w1_master_attribute_slaves.attr,
256 &w1_master_attribute_slave_count.attr,
257 &w1_master_attribute_max_slave_count.attr,
258 &w1_master_attribute_attempts.attr,
259 &w1_master_attribute_timeout.attr,
260 &w1_master_attribute_pointer.attr,
264 static struct attribute_group w1_master_defattr_group = {
265 .attrs = w1_master_default_attrs,
268 int w1_create_master_attributes(struct w1_master *master)
270 return sysfs_create_group(&master->dev.kobj, &w1_master_defattr_group);
273 void w1_destroy_master_attributes(struct w1_master *master)
275 sysfs_remove_group(&master->dev.kobj, &w1_master_defattr_group);
278 static int __w1_attach_slave_device(struct w1_slave *sl)
282 sl->dev.parent = &sl->master->dev;
283 sl->dev.driver = sl->master->driver;
284 sl->dev.bus = &w1_bus_type;
285 sl->dev.release = &w1_slave_release;
287 snprintf(&sl->dev.bus_id[0], sizeof(sl->dev.bus_id),
289 (unsigned int) sl->reg_num.family,
290 (unsigned long long) sl->reg_num.id);
291 snprintf(&sl->name[0], sizeof(sl->name),
293 (unsigned int) sl->reg_num.family,
294 (unsigned long long) sl->reg_num.id);
296 dev_dbg(&sl->dev, "%s: registering %s.\n", __func__,
299 err = device_register(&sl->dev);
302 "Device registration [%s] failed. err=%d\n",
303 sl->dev.bus_id, err);
307 memcpy(&sl->attr_bin, &w1_slave_bin_attribute, sizeof(sl->attr_bin));
308 memcpy(&sl->attr_name, &w1_slave_attribute, sizeof(sl->attr_name));
310 sl->attr_bin.read = sl->family->fops->rbin;
311 sl->attr_name.show = sl->family->fops->rname;
313 err = device_create_file(&sl->dev, &sl->attr_name);
316 "sysfs file creation for [%s] failed. err=%d\n",
317 sl->dev.bus_id, err);
318 device_unregister(&sl->dev);
322 err = sysfs_create_bin_file(&sl->dev.kobj, &sl->attr_bin);
325 "sysfs file creation for [%s] failed. err=%d\n",
326 sl->dev.bus_id, err);
327 device_remove_file(&sl->dev, &sl->attr_name);
328 device_unregister(&sl->dev);
332 list_add_tail(&sl->w1_slave_entry, &sl->master->slist);
337 static int w1_attach_slave_device(struct w1_master *dev, struct w1_reg_num *rn)
342 struct w1_netlink_msg msg;
344 sl = kmalloc(sizeof(struct w1_slave), GFP_KERNEL);
347 "%s: failed to allocate new slave device.\n",
352 memset(sl, 0, sizeof(*sl));
354 sl->owner = THIS_MODULE;
356 set_bit(W1_SLAVE_ACTIVE, (long *)&sl->flags);
358 memcpy(&sl->reg_num, rn, sizeof(sl->reg_num));
359 atomic_set(&sl->refcnt, 0);
360 init_completion(&sl->dev_released);
362 spin_lock(&w1_flock);
363 f = w1_family_registered(rn->family);
365 spin_unlock(&w1_flock);
366 dev_info(&dev->dev, "Family %x for %02x.%012llx.%02x is not registered.\n",
367 rn->family, rn->family,
368 (unsigned long long)rn->id, rn->crc);
373 spin_unlock(&w1_flock);
378 err = __w1_attach_slave_device(sl);
380 dev_err(&dev->dev, "%s: Attaching %s failed.\n", __func__,
382 w1_family_put(sl->family);
387 sl->ttl = dev->slave_ttl;
390 memcpy(&msg.id.id, rn, sizeof(msg.id.id));
391 msg.type = W1_SLAVE_ADD;
392 w1_netlink_send(dev, &msg);
397 static void w1_slave_detach(struct w1_slave *sl)
399 struct w1_netlink_msg msg;
401 dev_info(&sl->dev, "%s: detaching %s.\n", __func__, sl->name);
403 while (atomic_read(&sl->refcnt)) {
404 printk(KERN_INFO "Waiting for %s to become free: refcnt=%d.\n",
405 sl->name, atomic_read(&sl->refcnt));
407 if (msleep_interruptible(1000))
408 flush_signals(current);
411 sysfs_remove_bin_file (&sl->dev.kobj, &sl->attr_bin);
412 device_remove_file(&sl->dev, &sl->attr_name);
413 device_unregister(&sl->dev);
414 w1_family_put(sl->family);
416 memcpy(&msg.id.id, &sl->reg_num, sizeof(msg.id.id));
417 msg.type = W1_SLAVE_REMOVE;
418 w1_netlink_send(sl->master, &msg);
421 static struct w1_master *w1_search_master(unsigned long data)
423 struct w1_master *dev;
426 spin_lock_bh(&w1_mlock);
427 list_for_each_entry(dev, &w1_masters, w1_master_entry) {
428 if (dev->bus_master->data == data) {
430 atomic_inc(&dev->refcnt);
434 spin_unlock_bh(&w1_mlock);
436 return (found)?dev:NULL;
439 static void w1_slave_found(unsigned long data, u64 rn)
443 struct list_head *ent;
444 struct w1_reg_num *tmp;
445 int family_found = 0;
446 struct w1_master *dev;
448 dev = w1_search_master(data);
450 printk(KERN_ERR "Failed to find w1 master device for data %08lx, it is impossible.\n",
455 tmp = (struct w1_reg_num *) &rn;
458 list_for_each(ent, &dev->slist) {
460 sl = list_entry(ent, struct w1_slave, w1_slave_entry);
462 if (sl->reg_num.family == tmp->family &&
463 sl->reg_num.id == tmp->id &&
464 sl->reg_num.crc == tmp->crc) {
465 set_bit(W1_SLAVE_ACTIVE, (long *)&sl->flags);
467 } else if (sl->reg_num.family == tmp->family) {
475 rn = cpu_to_le64(rn);
477 if (slave_count == dev->slave_count &&
478 rn && ((le64_to_cpu(rn) >> 56) & 0xff) == w1_calc_crc8((u8 *)&rn, 7)) {
479 w1_attach_slave_device(dev, tmp);
482 atomic_dec(&dev->refcnt);
486 * Performs a ROM Search & registers any devices found.
487 * The 1-wire search is a simple binary tree search.
488 * For each bit of the address, we read two bits and write one bit.
489 * The bit written will put to sleep all devies that don't match that bit.
490 * When the two reads differ, the direction choice is obvious.
491 * When both bits are 0, we must choose a path to take.
492 * When we can scan all 64 bits without having to choose a path, we are done.
494 * See "Application note 187 1-wire search algorithm" at www.maxim-ic.com
496 * @dev The master device to search
497 * @cb Function to call when a device is found
499 void w1_search(struct w1_master *dev, w1_slave_found_callback cb)
501 u64 last_rn, rn, tmp64;
502 int i, slave_count = 0;
503 int last_zero, last_device;
504 int search_bit, desc_bit;
514 while ( !last_device && (slave_count++ < dev->max_slave_count) ) {
519 * Reset bus and all 1-wire device state machines
520 * so they can respond to our requests.
522 * Return 0 - device(s) present, 1 - no devices present.
524 if (w1_reset_bus(dev)) {
525 dev_info(&dev->dev, "No devices present on the wire.\n");
529 /* Start the search */
530 w1_write_8(dev, W1_SEARCH);
531 for (i = 0; i < 64; ++i) {
532 /* Determine the direction/search bit */
534 search_bit = 1; /* took the 0 path last time, so take the 1 path */
535 else if (i > desc_bit)
536 search_bit = 0; /* take the 0 path on the next branch */
538 search_bit = ((last_rn >> i) & 0x1);
540 /** Read two bits and write one bit */
541 triplet_ret = w1_triplet(dev, search_bit);
543 /* quit if no device responded */
544 if ( (triplet_ret & 0x03) == 0x03 )
547 /* If both directions were valid, and we took the 0 path... */
548 if (triplet_ret == 0)
551 /* extract the direction taken & update the device number */
552 tmp64 = (triplet_ret >> 2);
556 if ( (triplet_ret & 0x03) != 0x03 ) {
557 if ( (desc_bit == last_zero) || (last_zero < 0))
559 desc_bit = last_zero;
560 cb(dev->bus_master->data, rn);
565 static int w1_control(void *data)
567 struct w1_slave *sl, *sln;
568 struct w1_master *dev, *n;
569 int err, have_to_wait = 0;
571 daemonize("w1_control");
572 allow_signal(SIGTERM);
574 while (!control_needs_exit || have_to_wait) {
577 try_to_freeze(PF_FREEZE);
578 msleep_interruptible(w1_timeout * 1000);
580 if (signal_pending(current))
581 flush_signals(current);
583 list_for_each_entry_safe(dev, n, &w1_masters, w1_master_entry) {
584 if (!control_needs_exit && !dev->need_exit)
587 * Little race: we can create thread but not set the flag.
588 * Get a chance for external process to set flag up.
590 if (!dev->initialized) {
595 spin_lock_bh(&w1_mlock);
596 list_del(&dev->w1_master_entry);
597 spin_unlock_bh(&w1_mlock);
599 if (control_needs_exit) {
602 err = kill_proc(dev->kpid, SIGTERM, 1);
605 "Failed to send signal to w1 kernel thread %d.\n",
609 wait_for_completion(&dev->dev_exited);
611 list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) {
612 list_del(&sl->w1_slave_entry);
617 w1_destroy_master_attributes(dev);
618 atomic_dec(&dev->refcnt);
622 complete_and_exit(&w1_control_complete, 0);
625 int w1_process(void *data)
627 struct w1_master *dev = (struct w1_master *) data;
628 struct w1_slave *sl, *sln;
630 daemonize("%s", dev->name);
631 allow_signal(SIGTERM);
633 while (!dev->need_exit) {
634 try_to_freeze(PF_FREEZE);
635 msleep_interruptible(w1_timeout * 1000);
637 if (signal_pending(current))
638 flush_signals(current);
643 if (!dev->initialized)
646 if (down_interruptible(&dev->mutex))
649 list_for_each_entry(sl, &dev->slist, w1_slave_entry)
650 clear_bit(W1_SLAVE_ACTIVE, (long *)&sl->flags);
652 w1_search_devices(dev, w1_slave_found);
654 list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) {
655 if (!test_bit(W1_SLAVE_ACTIVE, (unsigned long *)&sl->flags) && !--sl->ttl) {
656 list_del (&sl->w1_slave_entry);
658 w1_slave_detach (sl);
662 } else if (test_bit(W1_SLAVE_ACTIVE, (unsigned long *)&sl->flags))
663 sl->ttl = dev->slave_ttl;
668 atomic_dec(&dev->refcnt);
669 complete_and_exit(&dev->dev_exited, 0);
674 static int w1_init(void)
678 printk(KERN_INFO "Driver for 1-wire Dallas network protocol.\n");
680 retval = bus_register(&w1_bus_type);
682 printk(KERN_ERR "Failed to register bus. err=%d.\n", retval);
683 goto err_out_exit_init;
686 retval = driver_register(&w1_driver);
689 "Failed to register master driver. err=%d.\n",
691 goto err_out_bus_unregister;
694 control_thread = kernel_thread(&w1_control, NULL, 0);
695 if (control_thread < 0) {
696 printk(KERN_ERR "Failed to create control thread. err=%d\n",
698 retval = control_thread;
699 goto err_out_driver_unregister;
704 err_out_driver_unregister:
705 driver_unregister(&w1_driver);
707 err_out_bus_unregister:
708 bus_unregister(&w1_bus_type);
714 static void w1_fini(void)
716 struct w1_master *dev;
718 list_for_each_entry(dev, &w1_masters, w1_master_entry)
719 __w1_remove_master_device(dev);
721 control_needs_exit = 1;
722 wait_for_completion(&w1_control_complete);
724 driver_unregister(&w1_driver);
725 bus_unregister(&w1_bus_type);
728 module_init(w1_init);
729 module_exit(w1_fini);