Commit | Line | Data |
---|---|---|
1da177e4 | 1 | /* |
7785925d | 2 | * w1.c |
1da177e4 LT |
3 | * |
4 | * Copyright (c) 2004 Evgeniy Polyakov <johnpol@2ka.mipt.ru> | |
7785925d | 5 | * |
1da177e4 LT |
6 | * |
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. | |
11 | * | |
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. | |
16 | * | |
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 | |
20 | */ | |
21 | ||
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 | ||
34 | #include <asm/atomic.h> | |
35 | ||
36 | #include "w1.h" | |
37 | #include "w1_io.h" | |
38 | #include "w1_log.h" | |
39 | #include "w1_int.h" | |
40 | #include "w1_family.h" | |
41 | #include "w1_netlink.h" | |
42 | ||
43 | MODULE_LICENSE("GPL"); | |
44 | MODULE_AUTHOR("Evgeniy Polyakov <johnpol@2ka.mipt.ru>"); | |
45 | MODULE_DESCRIPTION("Driver for 1-wire Dallas network protocol."); | |
46 | ||
47 | static int w1_timeout = 10; | |
48 | int w1_max_slave_count = 10; | |
49 | int w1_max_slave_ttl = 10; | |
50 | ||
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); | |
54 | ||
55 | DEFINE_SPINLOCK(w1_mlock); | |
56 | LIST_HEAD(w1_masters); | |
57 | ||
58 | static pid_t control_thread; | |
59 | static int control_needs_exit; | |
60 | static DECLARE_COMPLETION(w1_control_complete); | |
61 | ||
99c5bfe9 EP |
62 | /* stuff for the default family */ |
63 | static ssize_t w1_famdefault_read_name(struct device *dev, struct device_attribute *attr, char *buf) | |
64 | { | |
65 | struct w1_slave *sl = container_of(dev, struct w1_slave, dev); | |
66 | return(sprintf(buf, "%s\n", sl->name)); | |
67 | } | |
68 | static struct w1_family_ops w1_default_fops = { | |
69 | .rname = &w1_famdefault_read_name, | |
70 | }; | |
71 | static struct w1_family w1_default_family = { | |
72 | .fops = &w1_default_fops, | |
73 | }; | |
74 | ||
1da177e4 LT |
75 | static int w1_master_match(struct device *dev, struct device_driver *drv) |
76 | { | |
77 | return 1; | |
78 | } | |
79 | ||
80 | static int w1_master_probe(struct device *dev) | |
81 | { | |
82 | return -ENODEV; | |
83 | } | |
84 | ||
85 | static int w1_master_remove(struct device *dev) | |
86 | { | |
87 | return 0; | |
88 | } | |
89 | ||
90 | static void w1_master_release(struct device *dev) | |
91 | { | |
92 | struct w1_master *md = container_of(dev, struct w1_master, dev); | |
93 | ||
94 | complete(&md->dev_released); | |
95 | } | |
96 | ||
97 | static void w1_slave_release(struct device *dev) | |
98 | { | |
99 | struct w1_slave *sl = container_of(dev, struct w1_slave, dev); | |
100 | ||
101 | complete(&sl->dev_released); | |
102 | } | |
103 | ||
060b8845 | 104 | static ssize_t w1_default_read_name(struct device *dev, struct device_attribute *attr, char *buf) |
1da177e4 LT |
105 | { |
106 | return sprintf(buf, "No family registered.\n"); | |
107 | } | |
108 | ||
109 | static ssize_t w1_default_read_bin(struct kobject *kobj, char *buf, loff_t off, | |
110 | size_t count) | |
111 | { | |
112 | return sprintf(buf, "No family registered.\n"); | |
113 | } | |
114 | ||
7785925d EP |
115 | static struct device_attribute w1_slave_attribute = |
116 | __ATTR(name, S_IRUGO, w1_default_read_name, NULL); | |
117 | ||
7785925d EP |
118 | static struct bin_attribute w1_slave_bin_attribute = { |
119 | .attr = { | |
120 | .name = "w1_slave", | |
121 | .mode = S_IRUGO, | |
122 | .owner = THIS_MODULE, | |
123 | }, | |
124 | .size = W1_SLAVE_DATA_SIZE, | |
125 | .read = &w1_default_read_bin, | |
126 | }; | |
127 | ||
128 | ||
1da177e4 LT |
129 | static struct bus_type w1_bus_type = { |
130 | .name = "w1", | |
131 | .match = w1_master_match, | |
132 | }; | |
133 | ||
134 | struct device_driver w1_driver = { | |
135 | .name = "w1_driver", | |
136 | .bus = &w1_bus_type, | |
137 | .probe = w1_master_probe, | |
138 | .remove = w1_master_remove, | |
139 | }; | |
140 | ||
141 | struct device w1_device = { | |
142 | .parent = NULL, | |
143 | .bus = &w1_bus_type, | |
144 | .bus_id = "w1 bus master", | |
145 | .driver = &w1_driver, | |
146 | .release = &w1_master_release | |
147 | }; | |
148 | ||
060b8845 | 149 | static ssize_t w1_master_attribute_show_name(struct device *dev, struct device_attribute *attr, char *buf) |
1da177e4 | 150 | { |
6b729861 | 151 | struct w1_master *md = container_of(dev, struct w1_master, dev); |
1da177e4 | 152 | ssize_t count; |
7785925d | 153 | |
1da177e4 LT |
154 | if (down_interruptible (&md->mutex)) |
155 | return -EBUSY; | |
156 | ||
157 | count = sprintf(buf, "%s\n", md->name); | |
7785925d | 158 | |
1da177e4 LT |
159 | up(&md->mutex); |
160 | ||
161 | return count; | |
162 | } | |
163 | ||
2a9d0c17 EP |
164 | static ssize_t w1_master_attribute_store_search(struct device * dev, |
165 | struct device_attribute *attr, | |
166 | const char * buf, size_t count) | |
167 | { | |
168 | struct w1_master *md = container_of(dev, struct w1_master, dev); | |
169 | ||
170 | if (down_interruptible (&md->mutex)) | |
171 | return -EBUSY; | |
172 | ||
173 | md->search_count = simple_strtol(buf, NULL, 0); | |
174 | ||
175 | up(&md->mutex); | |
176 | ||
177 | return count; | |
178 | } | |
179 | ||
180 | static ssize_t w1_master_attribute_show_search(struct device *dev, | |
181 | struct device_attribute *attr, | |
182 | char *buf) | |
183 | { | |
184 | struct w1_master *md = container_of(dev, struct w1_master, dev); | |
185 | ssize_t count; | |
186 | ||
187 | if (down_interruptible (&md->mutex)) | |
188 | return -EBUSY; | |
189 | ||
190 | count = sprintf(buf, "%d\n", md->search_count); | |
191 | ||
192 | up(&md->mutex); | |
193 | ||
194 | return count; | |
195 | } | |
196 | ||
060b8845 | 197 | static ssize_t w1_master_attribute_show_pointer(struct device *dev, struct device_attribute *attr, char *buf) |
1da177e4 LT |
198 | { |
199 | struct w1_master *md = container_of(dev, struct w1_master, dev); | |
200 | ssize_t count; | |
7785925d | 201 | |
1da177e4 LT |
202 | if (down_interruptible(&md->mutex)) |
203 | return -EBUSY; | |
204 | ||
205 | count = sprintf(buf, "0x%p\n", md->bus_master); | |
7785925d | 206 | |
1da177e4 LT |
207 | up(&md->mutex); |
208 | return count; | |
209 | } | |
210 | ||
060b8845 | 211 | static ssize_t w1_master_attribute_show_timeout(struct device *dev, struct device_attribute *attr, char *buf) |
1da177e4 LT |
212 | { |
213 | ssize_t count; | |
214 | count = sprintf(buf, "%d\n", w1_timeout); | |
215 | return count; | |
216 | } | |
217 | ||
060b8845 | 218 | static ssize_t w1_master_attribute_show_max_slave_count(struct device *dev, struct device_attribute *attr, char *buf) |
1da177e4 LT |
219 | { |
220 | struct w1_master *md = container_of(dev, struct w1_master, dev); | |
221 | ssize_t count; | |
7785925d | 222 | |
1da177e4 LT |
223 | if (down_interruptible(&md->mutex)) |
224 | return -EBUSY; | |
225 | ||
226 | count = sprintf(buf, "%d\n", md->max_slave_count); | |
7785925d | 227 | |
1da177e4 LT |
228 | up(&md->mutex); |
229 | return count; | |
230 | } | |
231 | ||
060b8845 | 232 | static ssize_t w1_master_attribute_show_attempts(struct device *dev, struct device_attribute *attr, char *buf) |
1da177e4 LT |
233 | { |
234 | struct w1_master *md = container_of(dev, struct w1_master, dev); | |
235 | ssize_t count; | |
7785925d | 236 | |
1da177e4 LT |
237 | if (down_interruptible(&md->mutex)) |
238 | return -EBUSY; | |
239 | ||
240 | count = sprintf(buf, "%lu\n", md->attempts); | |
7785925d | 241 | |
1da177e4 LT |
242 | up(&md->mutex); |
243 | return count; | |
244 | } | |
245 | ||
060b8845 | 246 | static ssize_t w1_master_attribute_show_slave_count(struct device *dev, struct device_attribute *attr, char *buf) |
1da177e4 LT |
247 | { |
248 | struct w1_master *md = container_of(dev, struct w1_master, dev); | |
249 | ssize_t count; | |
7785925d | 250 | |
1da177e4 LT |
251 | if (down_interruptible(&md->mutex)) |
252 | return -EBUSY; | |
253 | ||
254 | count = sprintf(buf, "%d\n", md->slave_count); | |
7785925d | 255 | |
1da177e4 LT |
256 | up(&md->mutex); |
257 | return count; | |
258 | } | |
259 | ||
060b8845 | 260 | static ssize_t w1_master_attribute_show_slaves(struct device *dev, struct device_attribute *attr, char *buf) |
1da177e4 LT |
261 | { |
262 | struct w1_master *md = container_of(dev, struct w1_master, dev); | |
263 | int c = PAGE_SIZE; | |
264 | ||
265 | if (down_interruptible(&md->mutex)) | |
266 | return -EBUSY; | |
267 | ||
268 | if (md->slave_count == 0) | |
269 | c -= snprintf(buf + PAGE_SIZE - c, c, "not found.\n"); | |
270 | else { | |
271 | struct list_head *ent, *n; | |
272 | struct w1_slave *sl; | |
273 | ||
274 | list_for_each_safe(ent, n, &md->slist) { | |
275 | sl = list_entry(ent, struct w1_slave, w1_slave_entry); | |
276 | ||
7785925d | 277 | c -= snprintf(buf + PAGE_SIZE - c, c, "%s\n", sl->name); |
1da177e4 LT |
278 | } |
279 | } | |
280 | ||
281 | up(&md->mutex); | |
282 | ||
283 | return PAGE_SIZE - c; | |
284 | } | |
285 | ||
7785925d EP |
286 | #define W1_MASTER_ATTR_RO(_name, _mode) \ |
287 | struct device_attribute w1_master_attribute_##_name = \ | |
288 | __ATTR(w1_master_##_name, _mode, \ | |
289 | w1_master_attribute_show_##_name, NULL) | |
290 | ||
2a9d0c17 EP |
291 | #define W1_MASTER_ATTR_RW(_name, _mode) \ |
292 | struct device_attribute w1_master_attribute_##_name = \ | |
293 | __ATTR(w1_master_##_name, _mode, \ | |
294 | w1_master_attribute_show_##_name, \ | |
295 | w1_master_attribute_store_##_name) | |
296 | ||
7785925d EP |
297 | static W1_MASTER_ATTR_RO(name, S_IRUGO); |
298 | static W1_MASTER_ATTR_RO(slaves, S_IRUGO); | |
299 | static W1_MASTER_ATTR_RO(slave_count, S_IRUGO); | |
300 | static W1_MASTER_ATTR_RO(max_slave_count, S_IRUGO); | |
301 | static W1_MASTER_ATTR_RO(attempts, S_IRUGO); | |
302 | static W1_MASTER_ATTR_RO(timeout, S_IRUGO); | |
303 | static W1_MASTER_ATTR_RO(pointer, S_IRUGO); | |
2a9d0c17 | 304 | static W1_MASTER_ATTR_RW(search, S_IRUGO | S_IWUGO); |
7785925d EP |
305 | |
306 | static struct attribute *w1_master_default_attrs[] = { | |
307 | &w1_master_attribute_name.attr, | |
308 | &w1_master_attribute_slaves.attr, | |
309 | &w1_master_attribute_slave_count.attr, | |
310 | &w1_master_attribute_max_slave_count.attr, | |
311 | &w1_master_attribute_attempts.attr, | |
312 | &w1_master_attribute_timeout.attr, | |
313 | &w1_master_attribute_pointer.attr, | |
2a9d0c17 | 314 | &w1_master_attribute_search.attr, |
7785925d | 315 | NULL |
1da177e4 LT |
316 | }; |
317 | ||
7785925d EP |
318 | static struct attribute_group w1_master_defattr_group = { |
319 | .attrs = w1_master_default_attrs, | |
1da177e4 LT |
320 | }; |
321 | ||
7785925d EP |
322 | int w1_create_master_attributes(struct w1_master *master) |
323 | { | |
324 | return sysfs_create_group(&master->dev.kobj, &w1_master_defattr_group); | |
325 | } | |
326 | ||
327 | void w1_destroy_master_attributes(struct w1_master *master) | |
328 | { | |
329 | sysfs_remove_group(&master->dev.kobj, &w1_master_defattr_group); | |
330 | } | |
331 | ||
1da177e4 LT |
332 | static int __w1_attach_slave_device(struct w1_slave *sl) |
333 | { | |
334 | int err; | |
335 | ||
336 | sl->dev.parent = &sl->master->dev; | |
337 | sl->dev.driver = sl->master->driver; | |
338 | sl->dev.bus = &w1_bus_type; | |
339 | sl->dev.release = &w1_slave_release; | |
340 | ||
341 | snprintf(&sl->dev.bus_id[0], sizeof(sl->dev.bus_id), | |
6b729861 EP |
342 | "%02x-%012llx", |
343 | (unsigned int) sl->reg_num.family, | |
344 | (unsigned long long) sl->reg_num.id); | |
345 | snprintf(&sl->name[0], sizeof(sl->name), | |
346 | "%02x-%012llx", | |
347 | (unsigned int) sl->reg_num.family, | |
348 | (unsigned long long) sl->reg_num.id); | |
1da177e4 LT |
349 | |
350 | dev_dbg(&sl->dev, "%s: registering %s.\n", __func__, | |
351 | &sl->dev.bus_id[0]); | |
352 | ||
353 | err = device_register(&sl->dev); | |
354 | if (err < 0) { | |
355 | dev_err(&sl->dev, | |
6b729861 EP |
356 | "Device registration [%s] failed. err=%d\n", |
357 | sl->dev.bus_id, err); | |
1da177e4 LT |
358 | return err; |
359 | } | |
360 | ||
361 | memcpy(&sl->attr_bin, &w1_slave_bin_attribute, sizeof(sl->attr_bin)); | |
362 | memcpy(&sl->attr_name, &w1_slave_attribute, sizeof(sl->attr_name)); | |
7785925d | 363 | |
1da177e4 LT |
364 | sl->attr_bin.read = sl->family->fops->rbin; |
365 | sl->attr_name.show = sl->family->fops->rname; | |
1da177e4 LT |
366 | |
367 | err = device_create_file(&sl->dev, &sl->attr_name); | |
368 | if (err < 0) { | |
369 | dev_err(&sl->dev, | |
6b729861 EP |
370 | "sysfs file creation for [%s] failed. err=%d\n", |
371 | sl->dev.bus_id, err); | |
1da177e4 LT |
372 | device_unregister(&sl->dev); |
373 | return err; | |
374 | } | |
375 | ||
99c5bfe9 EP |
376 | if ( sl->attr_bin.read ) { |
377 | err = sysfs_create_bin_file(&sl->dev.kobj, &sl->attr_bin); | |
378 | if (err < 0) { | |
379 | dev_err(&sl->dev, | |
380 | "sysfs file creation for [%s] failed. err=%d\n", | |
381 | sl->dev.bus_id, err); | |
382 | device_remove_file(&sl->dev, &sl->attr_name); | |
383 | device_unregister(&sl->dev); | |
384 | return err; | |
385 | } | |
1da177e4 LT |
386 | } |
387 | ||
388 | list_add_tail(&sl->w1_slave_entry, &sl->master->slist); | |
389 | ||
390 | return 0; | |
391 | } | |
392 | ||
393 | static int w1_attach_slave_device(struct w1_master *dev, struct w1_reg_num *rn) | |
394 | { | |
395 | struct w1_slave *sl; | |
396 | struct w1_family *f; | |
397 | int err; | |
398 | struct w1_netlink_msg msg; | |
399 | ||
400 | sl = kmalloc(sizeof(struct w1_slave), GFP_KERNEL); | |
401 | if (!sl) { | |
402 | dev_err(&dev->dev, | |
403 | "%s: failed to allocate new slave device.\n", | |
404 | __func__); | |
405 | return -ENOMEM; | |
406 | } | |
407 | ||
408 | memset(sl, 0, sizeof(*sl)); | |
409 | ||
410 | sl->owner = THIS_MODULE; | |
411 | sl->master = dev; | |
412 | set_bit(W1_SLAVE_ACTIVE, (long *)&sl->flags); | |
413 | ||
414 | memcpy(&sl->reg_num, rn, sizeof(sl->reg_num)); | |
415 | atomic_set(&sl->refcnt, 0); | |
416 | init_completion(&sl->dev_released); | |
417 | ||
418 | spin_lock(&w1_flock); | |
419 | f = w1_family_registered(rn->family); | |
420 | if (!f) { | |
99c5bfe9 | 421 | f= &w1_default_family; |
1da177e4 LT |
422 | dev_info(&dev->dev, "Family %x for %02x.%012llx.%02x is not registered.\n", |
423 | rn->family, rn->family, | |
424 | (unsigned long long)rn->id, rn->crc); | |
1da177e4 LT |
425 | } |
426 | __w1_family_get(f); | |
427 | spin_unlock(&w1_flock); | |
428 | ||
429 | sl->family = f; | |
430 | ||
431 | ||
432 | err = __w1_attach_slave_device(sl); | |
433 | if (err < 0) { | |
434 | dev_err(&dev->dev, "%s: Attaching %s failed.\n", __func__, | |
435 | sl->name); | |
436 | w1_family_put(sl->family); | |
437 | kfree(sl); | |
438 | return err; | |
439 | } | |
440 | ||
441 | sl->ttl = dev->slave_ttl; | |
442 | dev->slave_count++; | |
443 | ||
444 | memcpy(&msg.id.id, rn, sizeof(msg.id.id)); | |
445 | msg.type = W1_SLAVE_ADD; | |
446 | w1_netlink_send(dev, &msg); | |
447 | ||
448 | return 0; | |
449 | } | |
450 | ||
451 | static void w1_slave_detach(struct w1_slave *sl) | |
452 | { | |
453 | struct w1_netlink_msg msg; | |
7785925d | 454 | |
1da177e4 LT |
455 | dev_info(&sl->dev, "%s: detaching %s.\n", __func__, sl->name); |
456 | ||
457 | while (atomic_read(&sl->refcnt)) { | |
458 | printk(KERN_INFO "Waiting for %s to become free: refcnt=%d.\n", | |
459 | sl->name, atomic_read(&sl->refcnt)); | |
460 | ||
461 | if (msleep_interruptible(1000)) | |
462 | flush_signals(current); | |
463 | } | |
464 | ||
99c5bfe9 EP |
465 | if ( sl->attr_bin.read ) { |
466 | sysfs_remove_bin_file (&sl->dev.kobj, &sl->attr_bin); | |
467 | } | |
1da177e4 | 468 | device_remove_file(&sl->dev, &sl->attr_name); |
1da177e4 LT |
469 | device_unregister(&sl->dev); |
470 | w1_family_put(sl->family); | |
471 | ||
6adf87bd EP |
472 | sl->master->slave_count--; |
473 | ||
1da177e4 LT |
474 | memcpy(&msg.id.id, &sl->reg_num, sizeof(msg.id.id)); |
475 | msg.type = W1_SLAVE_REMOVE; | |
476 | w1_netlink_send(sl->master, &msg); | |
477 | } | |
478 | ||
479 | static struct w1_master *w1_search_master(unsigned long data) | |
480 | { | |
481 | struct w1_master *dev; | |
482 | int found = 0; | |
7785925d EP |
483 | |
484 | spin_lock_bh(&w1_mlock); | |
1da177e4 LT |
485 | list_for_each_entry(dev, &w1_masters, w1_master_entry) { |
486 | if (dev->bus_master->data == data) { | |
487 | found = 1; | |
488 | atomic_inc(&dev->refcnt); | |
489 | break; | |
490 | } | |
491 | } | |
7785925d | 492 | spin_unlock_bh(&w1_mlock); |
1da177e4 LT |
493 | |
494 | return (found)?dev:NULL; | |
495 | } | |
496 | ||
6adf87bd EP |
497 | void w1_reconnect_slaves(struct w1_family *f) |
498 | { | |
499 | struct w1_master *dev; | |
500 | ||
501 | spin_lock_bh(&w1_mlock); | |
502 | list_for_each_entry(dev, &w1_masters, w1_master_entry) { | |
503 | dev_info(&dev->dev, "Reconnecting slaves in %s into new family %02x.\n", | |
504 | dev->name, f->fid); | |
505 | set_bit(W1_MASTER_NEED_RECONNECT, &dev->flags); | |
506 | } | |
507 | spin_unlock_bh(&w1_mlock); | |
508 | } | |
509 | ||
510 | ||
7785925d | 511 | static void w1_slave_found(unsigned long data, u64 rn) |
1da177e4 LT |
512 | { |
513 | int slave_count; | |
514 | struct w1_slave *sl; | |
515 | struct list_head *ent; | |
516 | struct w1_reg_num *tmp; | |
517 | int family_found = 0; | |
518 | struct w1_master *dev; | |
519 | ||
520 | dev = w1_search_master(data); | |
521 | if (!dev) { | |
522 | printk(KERN_ERR "Failed to find w1 master device for data %08lx, it is impossible.\n", | |
523 | data); | |
524 | return; | |
525 | } | |
7785925d | 526 | |
1da177e4 LT |
527 | tmp = (struct w1_reg_num *) &rn; |
528 | ||
529 | slave_count = 0; | |
530 | list_for_each(ent, &dev->slist) { | |
531 | ||
532 | sl = list_entry(ent, struct w1_slave, w1_slave_entry); | |
533 | ||
534 | if (sl->reg_num.family == tmp->family && | |
535 | sl->reg_num.id == tmp->id && | |
536 | sl->reg_num.crc == tmp->crc) { | |
537 | set_bit(W1_SLAVE_ACTIVE, (long *)&sl->flags); | |
538 | break; | |
7785925d | 539 | } else if (sl->reg_num.family == tmp->family) { |
1da177e4 LT |
540 | family_found = 1; |
541 | break; | |
542 | } | |
543 | ||
544 | slave_count++; | |
545 | } | |
546 | ||
8523ff45 | 547 | rn = cpu_to_le64(rn); |
548 | ||
549 | if (slave_count == dev->slave_count && | |
550 | rn && ((le64_to_cpu(rn) >> 56) & 0xff) == w1_calc_crc8((u8 *)&rn, 7)) { | |
551 | w1_attach_slave_device(dev, tmp); | |
1da177e4 | 552 | } |
7785925d | 553 | |
1da177e4 LT |
554 | atomic_dec(&dev->refcnt); |
555 | } | |
556 | ||
6b729861 EP |
557 | /** |
558 | * Performs a ROM Search & registers any devices found. | |
559 | * The 1-wire search is a simple binary tree search. | |
560 | * For each bit of the address, we read two bits and write one bit. | |
561 | * The bit written will put to sleep all devies that don't match that bit. | |
562 | * When the two reads differ, the direction choice is obvious. | |
563 | * When both bits are 0, we must choose a path to take. | |
564 | * When we can scan all 64 bits without having to choose a path, we are done. | |
565 | * | |
566 | * See "Application note 187 1-wire search algorithm" at www.maxim-ic.com | |
567 | * | |
568 | * @dev The master device to search | |
569 | * @cb Function to call when a device is found | |
570 | */ | |
571 | void w1_search(struct w1_master *dev, w1_slave_found_callback cb) | |
1da177e4 | 572 | { |
6b729861 EP |
573 | u64 last_rn, rn, tmp64; |
574 | int i, slave_count = 0; | |
575 | int last_zero, last_device; | |
576 | int search_bit, desc_bit; | |
577 | u8 triplet_ret = 0; | |
1da177e4 | 578 | |
6b729861 EP |
579 | search_bit = 0; |
580 | rn = last_rn = 0; | |
581 | last_device = 0; | |
582 | last_zero = -1; | |
1da177e4 LT |
583 | |
584 | desc_bit = 64; | |
585 | ||
6b729861 EP |
586 | while ( !last_device && (slave_count++ < dev->max_slave_count) ) { |
587 | last_rn = rn; | |
1da177e4 LT |
588 | rn = 0; |
589 | ||
1da177e4 LT |
590 | /* |
591 | * Reset bus and all 1-wire device state machines | |
592 | * so they can respond to our requests. | |
593 | * | |
594 | * Return 0 - device(s) present, 1 - no devices present. | |
595 | */ | |
596 | if (w1_reset_bus(dev)) { | |
597 | dev_info(&dev->dev, "No devices present on the wire.\n"); | |
598 | break; | |
599 | } | |
600 | ||
6b729861 | 601 | /* Start the search */ |
1da177e4 LT |
602 | w1_write_8(dev, W1_SEARCH); |
603 | for (i = 0; i < 64; ++i) { | |
6b729861 EP |
604 | /* Determine the direction/search bit */ |
605 | if (i == desc_bit) | |
606 | search_bit = 1; /* took the 0 path last time, so take the 1 path */ | |
607 | else if (i > desc_bit) | |
608 | search_bit = 0; /* take the 0 path on the next branch */ | |
1da177e4 | 609 | else |
6b729861 | 610 | search_bit = ((last_rn >> i) & 0x1); |
1da177e4 | 611 | |
6b729861 EP |
612 | /** Read two bits and write one bit */ |
613 | triplet_ret = w1_triplet(dev, search_bit); | |
614 | ||
615 | /* quit if no device responded */ | |
616 | if ( (triplet_ret & 0x03) == 0x03 ) | |
617 | break; | |
1da177e4 | 618 | |
6b729861 EP |
619 | /* If both directions were valid, and we took the 0 path... */ |
620 | if (triplet_ret == 0) | |
621 | last_zero = i; | |
1da177e4 | 622 | |
6b729861 EP |
623 | /* extract the direction taken & update the device number */ |
624 | tmp64 = (triplet_ret >> 2); | |
625 | rn |= (tmp64 << i); | |
626 | } | |
7785925d | 627 | |
6b729861 EP |
628 | if ( (triplet_ret & 0x03) != 0x03 ) { |
629 | if ( (desc_bit == last_zero) || (last_zero < 0)) | |
630 | last_device = 1; | |
631 | desc_bit = last_zero; | |
632 | cb(dev->bus_master->data, rn); | |
633 | } | |
1da177e4 LT |
634 | } |
635 | } | |
636 | ||
7785925d | 637 | static int w1_control(void *data) |
1da177e4 | 638 | { |
7785925d EP |
639 | struct w1_slave *sl, *sln; |
640 | struct w1_master *dev, *n; | |
1da177e4 LT |
641 | int err, have_to_wait = 0; |
642 | ||
643 | daemonize("w1_control"); | |
644 | allow_signal(SIGTERM); | |
645 | ||
646 | while (!control_needs_exit || have_to_wait) { | |
647 | have_to_wait = 0; | |
648 | ||
3e1d1d28 | 649 | try_to_freeze(); |
1da177e4 LT |
650 | msleep_interruptible(w1_timeout * 1000); |
651 | ||
652 | if (signal_pending(current)) | |
653 | flush_signals(current); | |
654 | ||
7785925d | 655 | list_for_each_entry_safe(dev, n, &w1_masters, w1_master_entry) { |
6adf87bd | 656 | if (!control_needs_exit && !dev->flags) |
1da177e4 LT |
657 | continue; |
658 | /* | |
659 | * Little race: we can create thread but not set the flag. | |
660 | * Get a chance for external process to set flag up. | |
661 | */ | |
662 | if (!dev->initialized) { | |
663 | have_to_wait = 1; | |
664 | continue; | |
665 | } | |
666 | ||
1da177e4 | 667 | if (control_needs_exit) { |
6adf87bd | 668 | set_bit(W1_MASTER_NEED_EXIT, &dev->flags); |
1da177e4 LT |
669 | |
670 | err = kill_proc(dev->kpid, SIGTERM, 1); | |
671 | if (err) | |
672 | dev_err(&dev->dev, | |
673 | "Failed to send signal to w1 kernel thread %d.\n", | |
674 | dev->kpid); | |
675 | } | |
676 | ||
6adf87bd EP |
677 | if (test_bit(W1_MASTER_NEED_EXIT, &dev->flags)) { |
678 | wait_for_completion(&dev->dev_exited); | |
679 | spin_lock_bh(&w1_mlock); | |
680 | list_del(&dev->w1_master_entry); | |
681 | spin_unlock_bh(&w1_mlock); | |
682 | ||
683 | list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) { | |
684 | list_del(&sl->w1_slave_entry); | |
685 | ||
686 | w1_slave_detach(sl); | |
687 | kfree(sl); | |
688 | } | |
689 | w1_destroy_master_attributes(dev); | |
690 | atomic_dec(&dev->refcnt); | |
691 | continue; | |
692 | } | |
693 | ||
694 | if (test_bit(W1_MASTER_NEED_RECONNECT, &dev->flags)) { | |
695 | dev_info(&dev->dev, "Reconnecting slaves in device %s.\n", dev->name); | |
696 | down(&dev->mutex); | |
697 | list_for_each_entry(sl, &dev->slist, w1_slave_entry) { | |
698 | if (sl->family->fid == W1_FAMILY_DEFAULT) { | |
699 | struct w1_reg_num rn; | |
700 | list_del(&sl->w1_slave_entry); | |
701 | w1_slave_detach(sl); | |
702 | ||
703 | memcpy(&rn, &sl->reg_num, sizeof(rn)); | |
1da177e4 | 704 | |
6adf87bd | 705 | kfree(sl); |
1da177e4 | 706 | |
6adf87bd EP |
707 | w1_attach_slave_device(dev, &rn); |
708 | } | |
709 | } | |
710 | clear_bit(W1_MASTER_NEED_RECONNECT, &dev->flags); | |
711 | up(&dev->mutex); | |
1da177e4 | 712 | } |
1da177e4 LT |
713 | } |
714 | } | |
715 | ||
716 | complete_and_exit(&w1_control_complete, 0); | |
717 | } | |
718 | ||
719 | int w1_process(void *data) | |
720 | { | |
721 | struct w1_master *dev = (struct w1_master *) data; | |
7785925d | 722 | struct w1_slave *sl, *sln; |
1da177e4 LT |
723 | |
724 | daemonize("%s", dev->name); | |
725 | allow_signal(SIGTERM); | |
726 | ||
6adf87bd | 727 | while (!test_bit(W1_MASTER_NEED_EXIT, &dev->flags)) { |
3e1d1d28 | 728 | try_to_freeze(); |
1da177e4 LT |
729 | msleep_interruptible(w1_timeout * 1000); |
730 | ||
731 | if (signal_pending(current)) | |
732 | flush_signals(current); | |
733 | ||
6adf87bd | 734 | if (test_bit(W1_MASTER_NEED_EXIT, &dev->flags)) |
1da177e4 LT |
735 | break; |
736 | ||
737 | if (!dev->initialized) | |
738 | continue; | |
739 | ||
2a9d0c17 EP |
740 | if (dev->search_count == 0) |
741 | continue; | |
742 | ||
1da177e4 LT |
743 | if (down_interruptible(&dev->mutex)) |
744 | continue; | |
745 | ||
7785925d | 746 | list_for_each_entry(sl, &dev->slist, w1_slave_entry) |
2a9d0c17 | 747 | clear_bit(W1_SLAVE_ACTIVE, (long *)&sl->flags); |
1da177e4 | 748 | |
7785925d | 749 | w1_search_devices(dev, w1_slave_found); |
1da177e4 | 750 | |
7785925d EP |
751 | list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) { |
752 | if (!test_bit(W1_SLAVE_ACTIVE, (unsigned long *)&sl->flags) && !--sl->ttl) { | |
1da177e4 LT |
753 | list_del (&sl->w1_slave_entry); |
754 | ||
755 | w1_slave_detach (sl); | |
756 | kfree (sl); | |
757 | ||
758 | dev->slave_count--; | |
7785925d | 759 | } else if (test_bit(W1_SLAVE_ACTIVE, (unsigned long *)&sl->flags)) |
1da177e4 LT |
760 | sl->ttl = dev->slave_ttl; |
761 | } | |
2a9d0c17 EP |
762 | |
763 | if (dev->search_count > 0) | |
764 | dev->search_count--; | |
765 | ||
1da177e4 LT |
766 | up(&dev->mutex); |
767 | } | |
768 | ||
769 | atomic_dec(&dev->refcnt); | |
770 | complete_and_exit(&dev->dev_exited, 0); | |
771 | ||
772 | return 0; | |
773 | } | |
774 | ||
7785925d | 775 | static int w1_init(void) |
1da177e4 LT |
776 | { |
777 | int retval; | |
778 | ||
779 | printk(KERN_INFO "Driver for 1-wire Dallas network protocol.\n"); | |
780 | ||
781 | retval = bus_register(&w1_bus_type); | |
782 | if (retval) { | |
783 | printk(KERN_ERR "Failed to register bus. err=%d.\n", retval); | |
784 | goto err_out_exit_init; | |
785 | } | |
786 | ||
787 | retval = driver_register(&w1_driver); | |
788 | if (retval) { | |
789 | printk(KERN_ERR | |
790 | "Failed to register master driver. err=%d.\n", | |
791 | retval); | |
792 | goto err_out_bus_unregister; | |
793 | } | |
794 | ||
795 | control_thread = kernel_thread(&w1_control, NULL, 0); | |
796 | if (control_thread < 0) { | |
797 | printk(KERN_ERR "Failed to create control thread. err=%d\n", | |
798 | control_thread); | |
799 | retval = control_thread; | |
800 | goto err_out_driver_unregister; | |
801 | } | |
802 | ||
803 | return 0; | |
804 | ||
805 | err_out_driver_unregister: | |
806 | driver_unregister(&w1_driver); | |
807 | ||
808 | err_out_bus_unregister: | |
809 | bus_unregister(&w1_bus_type); | |
810 | ||
811 | err_out_exit_init: | |
812 | return retval; | |
813 | } | |
814 | ||
7785925d | 815 | static void w1_fini(void) |
1da177e4 LT |
816 | { |
817 | struct w1_master *dev; | |
1da177e4 | 818 | |
7785925d | 819 | list_for_each_entry(dev, &w1_masters, w1_master_entry) |
1da177e4 | 820 | __w1_remove_master_device(dev); |
1da177e4 LT |
821 | |
822 | control_needs_exit = 1; | |
1da177e4 LT |
823 | wait_for_completion(&w1_control_complete); |
824 | ||
825 | driver_unregister(&w1_driver); | |
826 | bus_unregister(&w1_bus_type); | |
827 | } | |
828 | ||
829 | module_init(w1_init); | |
830 | module_exit(w1_fini); |