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)
217 struct w1_master *md = container_of(dev, struct w1_master, dev);
220 if (down_interruptible(&md->mutex))
223 if (md->slave_count == 0)
224 c -= snprintf(buf + PAGE_SIZE - c, c, "not found.\n");
226 struct list_head *ent, *n;
229 list_for_each_safe(ent, n, &md->slist) {
230 sl = list_entry(ent, struct w1_slave, w1_slave_entry);
232 c -= snprintf(buf + PAGE_SIZE - c, c, "%s\n", sl->name);
238 return PAGE_SIZE - c;
241 #define W1_MASTER_ATTR_RO(_name, _mode) \
242 struct device_attribute w1_master_attribute_##_name = \
243 __ATTR(w1_master_##_name, _mode, \
244 w1_master_attribute_show_##_name, NULL)
246 static W1_MASTER_ATTR_RO(name, S_IRUGO);
247 static W1_MASTER_ATTR_RO(slaves, S_IRUGO);
248 static W1_MASTER_ATTR_RO(slave_count, S_IRUGO);
249 static W1_MASTER_ATTR_RO(max_slave_count, S_IRUGO);
250 static W1_MASTER_ATTR_RO(attempts, S_IRUGO);
251 static W1_MASTER_ATTR_RO(timeout, S_IRUGO);
252 static W1_MASTER_ATTR_RO(pointer, S_IRUGO);
254 static struct attribute *w1_master_default_attrs[] = {
255 &w1_master_attribute_name.attr,
256 &w1_master_attribute_slaves.attr,
257 &w1_master_attribute_slave_count.attr,
258 &w1_master_attribute_max_slave_count.attr,
259 &w1_master_attribute_attempts.attr,
260 &w1_master_attribute_timeout.attr,
261 &w1_master_attribute_pointer.attr,
265 static struct attribute_group w1_master_defattr_group = {
266 .attrs = w1_master_default_attrs,
269 int w1_create_master_attributes(struct w1_master *master)
271 return sysfs_create_group(&master->dev.kobj, &w1_master_defattr_group);
274 void w1_destroy_master_attributes(struct w1_master *master)
276 sysfs_remove_group(&master->dev.kobj, &w1_master_defattr_group);
279 static int __w1_attach_slave_device(struct w1_slave *sl)
283 sl->dev.parent = &sl->master->dev;
284 sl->dev.driver = sl->master->driver;
285 sl->dev.bus = &w1_bus_type;
286 sl->dev.release = &w1_slave_release;
288 snprintf(&sl->dev.bus_id[0], sizeof(sl->dev.bus_id),
290 (unsigned int) sl->reg_num.family,
291 (unsigned long long) sl->reg_num.id);
292 snprintf (&sl->name[0], sizeof(sl->name),
294 (unsigned int) sl->reg_num.family,
295 (unsigned long long) sl->reg_num.id);
297 dev_dbg(&sl->dev, "%s: registering %s.\n", __func__,
300 err = device_register(&sl->dev);
303 "Device registration [%s] failed. err=%d\n",
304 sl->dev.bus_id, err);
308 memcpy(&sl->attr_bin, &w1_slave_bin_attribute, sizeof(sl->attr_bin));
309 memcpy(&sl->attr_name, &w1_slave_attribute, sizeof(sl->attr_name));
311 sl->attr_bin.read = sl->family->fops->rbin;
312 sl->attr_name.show = sl->family->fops->rname;
314 err = device_create_file(&sl->dev, &sl->attr_name);
317 "sysfs file creation for [%s] failed. err=%d\n",
318 sl->dev.bus_id, err);
319 device_unregister(&sl->dev);
323 err = sysfs_create_bin_file(&sl->dev.kobj, &sl->attr_bin);
326 "sysfs file creation for [%s] failed. err=%d\n",
327 sl->dev.bus_id, err);
328 device_remove_file(&sl->dev, &sl->attr_name);
329 device_unregister(&sl->dev);
333 list_add_tail(&sl->w1_slave_entry, &sl->master->slist);
338 static int w1_attach_slave_device(struct w1_master *dev, struct w1_reg_num *rn)
343 struct w1_netlink_msg msg;
345 sl = kmalloc(sizeof(struct w1_slave), GFP_KERNEL);
348 "%s: failed to allocate new slave device.\n",
353 memset(sl, 0, sizeof(*sl));
355 sl->owner = THIS_MODULE;
357 set_bit(W1_SLAVE_ACTIVE, (long *)&sl->flags);
359 memcpy(&sl->reg_num, rn, sizeof(sl->reg_num));
360 atomic_set(&sl->refcnt, 0);
361 init_completion(&sl->dev_released);
363 spin_lock(&w1_flock);
364 f = w1_family_registered(rn->family);
366 spin_unlock(&w1_flock);
367 dev_info(&dev->dev, "Family %x for %02x.%012llx.%02x is not registered.\n",
368 rn->family, rn->family,
369 (unsigned long long)rn->id, rn->crc);
374 spin_unlock(&w1_flock);
379 err = __w1_attach_slave_device(sl);
381 dev_err(&dev->dev, "%s: Attaching %s failed.\n", __func__,
383 w1_family_put(sl->family);
388 sl->ttl = dev->slave_ttl;
391 memcpy(&msg.id.id, rn, sizeof(msg.id.id));
392 msg.type = W1_SLAVE_ADD;
393 w1_netlink_send(dev, &msg);
398 static void w1_slave_detach(struct w1_slave *sl)
400 struct w1_netlink_msg msg;
402 dev_info(&sl->dev, "%s: detaching %s.\n", __func__, sl->name);
404 while (atomic_read(&sl->refcnt)) {
405 printk(KERN_INFO "Waiting for %s to become free: refcnt=%d.\n",
406 sl->name, atomic_read(&sl->refcnt));
408 if (msleep_interruptible(1000))
409 flush_signals(current);
412 sysfs_remove_bin_file (&sl->dev.kobj, &sl->attr_bin);
413 device_remove_file(&sl->dev, &sl->attr_name);
414 device_unregister(&sl->dev);
415 w1_family_put(sl->family);
417 memcpy(&msg.id.id, &sl->reg_num, sizeof(msg.id.id));
418 msg.type = W1_SLAVE_REMOVE;
419 w1_netlink_send(sl->master, &msg);
422 static struct w1_master *w1_search_master(unsigned long data)
424 struct w1_master *dev;
427 spin_lock_bh(&w1_mlock);
428 list_for_each_entry(dev, &w1_masters, w1_master_entry) {
429 if (dev->bus_master->data == data) {
431 atomic_inc(&dev->refcnt);
435 spin_unlock_bh(&w1_mlock);
437 return (found)?dev:NULL;
440 static void w1_slave_found(unsigned long data, u64 rn)
444 struct list_head *ent;
445 struct w1_reg_num *tmp;
446 int family_found = 0;
447 struct w1_master *dev;
449 dev = w1_search_master(data);
451 printk(KERN_ERR "Failed to find w1 master device for data %08lx, it is impossible.\n",
456 tmp = (struct w1_reg_num *) &rn;
459 list_for_each(ent, &dev->slist) {
461 sl = list_entry(ent, struct w1_slave, w1_slave_entry);
463 if (sl->reg_num.family == tmp->family &&
464 sl->reg_num.id == tmp->id &&
465 sl->reg_num.crc == tmp->crc) {
466 set_bit(W1_SLAVE_ACTIVE, (long *)&sl->flags);
468 } else if (sl->reg_num.family == tmp->family) {
476 rn = cpu_to_le64(rn);
478 if (slave_count == dev->slave_count &&
479 rn && ((le64_to_cpu(rn) >> 56) & 0xff) == w1_calc_crc8((u8 *)&rn, 7)) {
480 w1_attach_slave_device(dev, tmp);
483 atomic_dec(&dev->refcnt);
486 void w1_search(struct w1_master *dev)
490 int last_family_desc, last_zero, last_device;
491 int search_bit, id_bit, comp_bit, desc_bit;
493 search_bit = id_bit = comp_bit = 0;
495 last_device = last_zero = last_family_desc = 0;
499 while (!(id_bit && comp_bit) && !last_device &&
500 count++ < dev->max_slave_count) {
504 last_family_desc = 0;
507 * Reset bus and all 1-wire device state machines
508 * so they can respond to our requests.
510 * Return 0 - device(s) present, 1 - no devices present.
512 if (w1_reset_bus(dev)) {
513 dev_info(&dev->dev, "No devices present on the wire.\n");
518 w1_write_8(dev, W1_SEARCH);
519 for (i = 0; i < 64; ++i) {
521 * Read 2 bits from bus.
522 * All who don't sleep must send ID bit and COMPLEMENT ID bit.
523 * They actually are ANDed between all senders.
525 id_bit = w1_touch_bit(dev, 1);
526 comp_bit = w1_touch_bit(dev, 1);
528 if (id_bit && comp_bit)
531 if (id_bit == 0 && comp_bit == 0) {
534 else if (i > desc_bit)
537 search_bit = ((last >> i) & 0x1);
539 if (search_bit == 0) {
542 last_family_desc = last_zero;
553 * and make all who don't have "search_bit" in "i"'th position
554 * in it's registration number sleep.
556 if (dev->bus_master->touch_bit)
557 w1_touch_bit(dev, search_bit);
559 w1_write_bit(dev, search_bit);
564 if (desc_bit == last_zero)
567 desc_bit = last_zero;
569 w1_slave_found(dev->bus_master->data, rn);
573 static int w1_control(void *data)
575 struct w1_slave *sl, *sln;
576 struct w1_master *dev, *n;
577 int err, have_to_wait = 0;
579 daemonize("w1_control");
580 allow_signal(SIGTERM);
582 while (!control_needs_exit || have_to_wait) {
585 try_to_freeze(PF_FREEZE);
586 msleep_interruptible(w1_timeout * 1000);
588 if (signal_pending(current))
589 flush_signals(current);
591 list_for_each_entry_safe(dev, n, &w1_masters, w1_master_entry) {
592 if (!control_needs_exit && !dev->need_exit)
595 * Little race: we can create thread but not set the flag.
596 * Get a chance for external process to set flag up.
598 if (!dev->initialized) {
603 spin_lock_bh(&w1_mlock);
604 list_del(&dev->w1_master_entry);
605 spin_unlock_bh(&w1_mlock);
607 if (control_needs_exit) {
610 err = kill_proc(dev->kpid, SIGTERM, 1);
613 "Failed to send signal to w1 kernel thread %d.\n",
617 wait_for_completion(&dev->dev_exited);
619 list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) {
620 list_del(&sl->w1_slave_entry);
625 w1_destroy_master_attributes(dev);
626 atomic_dec(&dev->refcnt);
630 complete_and_exit(&w1_control_complete, 0);
633 int w1_process(void *data)
635 struct w1_master *dev = (struct w1_master *) data;
636 struct w1_slave *sl, *sln;
638 daemonize("%s", dev->name);
639 allow_signal(SIGTERM);
641 while (!dev->need_exit) {
642 try_to_freeze(PF_FREEZE);
643 msleep_interruptible(w1_timeout * 1000);
645 if (signal_pending(current))
646 flush_signals(current);
651 if (!dev->initialized)
654 if (down_interruptible(&dev->mutex))
657 list_for_each_entry(sl, &dev->slist, w1_slave_entry)
658 clear_bit(W1_SLAVE_ACTIVE, (long *)&sl->flags);
660 w1_search_devices(dev, w1_slave_found);
662 list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) {
663 if (!test_bit(W1_SLAVE_ACTIVE, (unsigned long *)&sl->flags) && !--sl->ttl) {
664 list_del (&sl->w1_slave_entry);
666 w1_slave_detach (sl);
670 } else if (test_bit(W1_SLAVE_ACTIVE, (unsigned long *)&sl->flags))
671 sl->ttl = dev->slave_ttl;
676 atomic_dec(&dev->refcnt);
677 complete_and_exit(&dev->dev_exited, 0);
682 static int w1_init(void)
686 printk(KERN_INFO "Driver for 1-wire Dallas network protocol.\n");
688 retval = bus_register(&w1_bus_type);
690 printk(KERN_ERR "Failed to register bus. err=%d.\n", retval);
691 goto err_out_exit_init;
694 retval = driver_register(&w1_driver);
697 "Failed to register master driver. err=%d.\n",
699 goto err_out_bus_unregister;
702 control_thread = kernel_thread(&w1_control, NULL, 0);
703 if (control_thread < 0) {
704 printk(KERN_ERR "Failed to create control thread. err=%d\n",
706 retval = control_thread;
707 goto err_out_driver_unregister;
712 err_out_driver_unregister:
713 driver_unregister(&w1_driver);
715 err_out_bus_unregister:
716 bus_unregister(&w1_bus_type);
722 static void w1_fini(void)
724 struct w1_master *dev;
726 list_for_each_entry(dev, &w1_masters, w1_master_entry)
727 __w1_remove_master_device(dev);
729 control_needs_exit = 1;
730 wait_for_completion(&w1_control_complete);
732 driver_unregister(&w1_driver);
733 bus_unregister(&w1_bus_type);
736 module_init(w1_init);
737 module_exit(w1_fini);