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 | ||
62 | static int w1_master_match(struct device *dev, struct device_driver *drv) | |
63 | { | |
64 | return 1; | |
65 | } | |
66 | ||
67 | static int w1_master_probe(struct device *dev) | |
68 | { | |
69 | return -ENODEV; | |
70 | } | |
71 | ||
72 | static int w1_master_remove(struct device *dev) | |
73 | { | |
74 | return 0; | |
75 | } | |
76 | ||
77 | static void w1_master_release(struct device *dev) | |
78 | { | |
79 | struct w1_master *md = container_of(dev, struct w1_master, dev); | |
80 | ||
81 | complete(&md->dev_released); | |
82 | } | |
83 | ||
84 | static void w1_slave_release(struct device *dev) | |
85 | { | |
86 | struct w1_slave *sl = container_of(dev, struct w1_slave, dev); | |
87 | ||
88 | complete(&sl->dev_released); | |
89 | } | |
90 | ||
060b8845 | 91 | static ssize_t w1_default_read_name(struct device *dev, struct device_attribute *attr, char *buf) |
1da177e4 LT |
92 | { |
93 | return sprintf(buf, "No family registered.\n"); | |
94 | } | |
95 | ||
96 | static ssize_t w1_default_read_bin(struct kobject *kobj, char *buf, loff_t off, | |
97 | size_t count) | |
98 | { | |
99 | return sprintf(buf, "No family registered.\n"); | |
100 | } | |
101 | ||
7785925d EP |
102 | static struct device_attribute w1_slave_attribute = |
103 | __ATTR(name, S_IRUGO, w1_default_read_name, NULL); | |
104 | ||
105 | static struct device_attribute w1_slave_attribute_val = | |
106 | __ATTR(value, S_IRUGO, w1_default_read_name, NULL); | |
107 | ||
108 | static struct bin_attribute w1_slave_bin_attribute = { | |
109 | .attr = { | |
110 | .name = "w1_slave", | |
111 | .mode = S_IRUGO, | |
112 | .owner = THIS_MODULE, | |
113 | }, | |
114 | .size = W1_SLAVE_DATA_SIZE, | |
115 | .read = &w1_default_read_bin, | |
116 | }; | |
117 | ||
118 | ||
1da177e4 LT |
119 | static struct bus_type w1_bus_type = { |
120 | .name = "w1", | |
121 | .match = w1_master_match, | |
122 | }; | |
123 | ||
124 | struct device_driver w1_driver = { | |
125 | .name = "w1_driver", | |
126 | .bus = &w1_bus_type, | |
127 | .probe = w1_master_probe, | |
128 | .remove = w1_master_remove, | |
129 | }; | |
130 | ||
131 | struct device w1_device = { | |
132 | .parent = NULL, | |
133 | .bus = &w1_bus_type, | |
134 | .bus_id = "w1 bus master", | |
135 | .driver = &w1_driver, | |
136 | .release = &w1_master_release | |
137 | }; | |
138 | ||
060b8845 | 139 | static ssize_t w1_master_attribute_show_name(struct device *dev, struct device_attribute *attr, char *buf) |
1da177e4 LT |
140 | { |
141 | struct w1_master *md = container_of (dev, struct w1_master, dev); | |
142 | ssize_t count; | |
7785925d | 143 | |
1da177e4 LT |
144 | if (down_interruptible (&md->mutex)) |
145 | return -EBUSY; | |
146 | ||
147 | count = sprintf(buf, "%s\n", md->name); | |
7785925d | 148 | |
1da177e4 LT |
149 | up(&md->mutex); |
150 | ||
151 | return count; | |
152 | } | |
153 | ||
060b8845 | 154 | static ssize_t w1_master_attribute_show_pointer(struct device *dev, struct device_attribute *attr, char *buf) |
1da177e4 LT |
155 | { |
156 | struct w1_master *md = container_of(dev, struct w1_master, dev); | |
157 | ssize_t count; | |
7785925d | 158 | |
1da177e4 LT |
159 | if (down_interruptible(&md->mutex)) |
160 | return -EBUSY; | |
161 | ||
162 | count = sprintf(buf, "0x%p\n", md->bus_master); | |
7785925d | 163 | |
1da177e4 LT |
164 | up(&md->mutex); |
165 | return count; | |
166 | } | |
167 | ||
060b8845 | 168 | static ssize_t w1_master_attribute_show_timeout(struct device *dev, struct device_attribute *attr, char *buf) |
1da177e4 LT |
169 | { |
170 | ssize_t count; | |
171 | count = sprintf(buf, "%d\n", w1_timeout); | |
172 | return count; | |
173 | } | |
174 | ||
060b8845 | 175 | static ssize_t w1_master_attribute_show_max_slave_count(struct device *dev, struct device_attribute *attr, char *buf) |
1da177e4 LT |
176 | { |
177 | struct w1_master *md = container_of(dev, struct w1_master, dev); | |
178 | ssize_t count; | |
7785925d | 179 | |
1da177e4 LT |
180 | if (down_interruptible(&md->mutex)) |
181 | return -EBUSY; | |
182 | ||
183 | count = sprintf(buf, "%d\n", md->max_slave_count); | |
7785925d | 184 | |
1da177e4 LT |
185 | up(&md->mutex); |
186 | return count; | |
187 | } | |
188 | ||
060b8845 | 189 | static ssize_t w1_master_attribute_show_attempts(struct device *dev, struct device_attribute *attr, char *buf) |
1da177e4 LT |
190 | { |
191 | struct w1_master *md = container_of(dev, struct w1_master, dev); | |
192 | ssize_t count; | |
7785925d | 193 | |
1da177e4 LT |
194 | if (down_interruptible(&md->mutex)) |
195 | return -EBUSY; | |
196 | ||
197 | count = sprintf(buf, "%lu\n", md->attempts); | |
7785925d | 198 | |
1da177e4 LT |
199 | up(&md->mutex); |
200 | return count; | |
201 | } | |
202 | ||
060b8845 | 203 | static ssize_t w1_master_attribute_show_slave_count(struct device *dev, struct device_attribute *attr, char *buf) |
1da177e4 LT |
204 | { |
205 | struct w1_master *md = container_of(dev, struct w1_master, dev); | |
206 | ssize_t count; | |
7785925d | 207 | |
1da177e4 LT |
208 | if (down_interruptible(&md->mutex)) |
209 | return -EBUSY; | |
210 | ||
211 | count = sprintf(buf, "%d\n", md->slave_count); | |
7785925d | 212 | |
1da177e4 LT |
213 | up(&md->mutex); |
214 | return count; | |
215 | } | |
216 | ||
060b8845 | 217 | static ssize_t w1_master_attribute_show_slaves(struct device *dev, struct device_attribute *attr, char *buf) |
1da177e4 LT |
218 | |
219 | { | |
220 | struct w1_master *md = container_of(dev, struct w1_master, dev); | |
221 | int c = PAGE_SIZE; | |
222 | ||
223 | if (down_interruptible(&md->mutex)) | |
224 | return -EBUSY; | |
225 | ||
226 | if (md->slave_count == 0) | |
227 | c -= snprintf(buf + PAGE_SIZE - c, c, "not found.\n"); | |
228 | else { | |
229 | struct list_head *ent, *n; | |
230 | struct w1_slave *sl; | |
231 | ||
232 | list_for_each_safe(ent, n, &md->slist) { | |
233 | sl = list_entry(ent, struct w1_slave, w1_slave_entry); | |
234 | ||
7785925d | 235 | c -= snprintf(buf + PAGE_SIZE - c, c, "%s\n", sl->name); |
1da177e4 LT |
236 | } |
237 | } | |
238 | ||
239 | up(&md->mutex); | |
240 | ||
241 | return PAGE_SIZE - c; | |
242 | } | |
243 | ||
7785925d EP |
244 | #define W1_MASTER_ATTR_RO(_name, _mode) \ |
245 | struct device_attribute w1_master_attribute_##_name = \ | |
246 | __ATTR(w1_master_##_name, _mode, \ | |
247 | w1_master_attribute_show_##_name, NULL) | |
248 | ||
249 | static W1_MASTER_ATTR_RO(name, S_IRUGO); | |
250 | static W1_MASTER_ATTR_RO(slaves, S_IRUGO); | |
251 | static W1_MASTER_ATTR_RO(slave_count, S_IRUGO); | |
252 | static W1_MASTER_ATTR_RO(max_slave_count, S_IRUGO); | |
253 | static W1_MASTER_ATTR_RO(attempts, S_IRUGO); | |
254 | static W1_MASTER_ATTR_RO(timeout, S_IRUGO); | |
255 | static W1_MASTER_ATTR_RO(pointer, S_IRUGO); | |
256 | ||
257 | static struct attribute *w1_master_default_attrs[] = { | |
258 | &w1_master_attribute_name.attr, | |
259 | &w1_master_attribute_slaves.attr, | |
260 | &w1_master_attribute_slave_count.attr, | |
261 | &w1_master_attribute_max_slave_count.attr, | |
262 | &w1_master_attribute_attempts.attr, | |
263 | &w1_master_attribute_timeout.attr, | |
264 | &w1_master_attribute_pointer.attr, | |
265 | NULL | |
1da177e4 LT |
266 | }; |
267 | ||
7785925d EP |
268 | static struct attribute_group w1_master_defattr_group = { |
269 | .attrs = w1_master_default_attrs, | |
1da177e4 LT |
270 | }; |
271 | ||
7785925d EP |
272 | int w1_create_master_attributes(struct w1_master *master) |
273 | { | |
274 | return sysfs_create_group(&master->dev.kobj, &w1_master_defattr_group); | |
275 | } | |
276 | ||
277 | void w1_destroy_master_attributes(struct w1_master *master) | |
278 | { | |
279 | sysfs_remove_group(&master->dev.kobj, &w1_master_defattr_group); | |
280 | } | |
281 | ||
1da177e4 LT |
282 | static int __w1_attach_slave_device(struct w1_slave *sl) |
283 | { | |
284 | int err; | |
285 | ||
286 | sl->dev.parent = &sl->master->dev; | |
287 | sl->dev.driver = sl->master->driver; | |
288 | sl->dev.bus = &w1_bus_type; | |
289 | sl->dev.release = &w1_slave_release; | |
290 | ||
291 | snprintf(&sl->dev.bus_id[0], sizeof(sl->dev.bus_id), | |
292 | "%02x-%012llx", | |
293 | (unsigned int) sl->reg_num.family, | |
294 | (unsigned long long) sl->reg_num.id); | |
295 | snprintf (&sl->name[0], sizeof(sl->name), | |
296 | "%02x-%012llx", | |
297 | (unsigned int) sl->reg_num.family, | |
298 | (unsigned long long) sl->reg_num.id); | |
299 | ||
300 | dev_dbg(&sl->dev, "%s: registering %s.\n", __func__, | |
301 | &sl->dev.bus_id[0]); | |
302 | ||
303 | err = device_register(&sl->dev); | |
304 | if (err < 0) { | |
305 | dev_err(&sl->dev, | |
306 | "Device registration [%s] failed. err=%d\n", | |
307 | sl->dev.bus_id, err); | |
308 | return err; | |
309 | } | |
310 | ||
311 | memcpy(&sl->attr_bin, &w1_slave_bin_attribute, sizeof(sl->attr_bin)); | |
312 | memcpy(&sl->attr_name, &w1_slave_attribute, sizeof(sl->attr_name)); | |
313 | memcpy(&sl->attr_val, &w1_slave_attribute_val, sizeof(sl->attr_val)); | |
7785925d | 314 | |
1da177e4 LT |
315 | sl->attr_bin.read = sl->family->fops->rbin; |
316 | sl->attr_name.show = sl->family->fops->rname; | |
317 | sl->attr_val.show = sl->family->fops->rval; | |
318 | sl->attr_val.attr.name = sl->family->fops->rvalname; | |
319 | ||
320 | err = device_create_file(&sl->dev, &sl->attr_name); | |
321 | if (err < 0) { | |
322 | dev_err(&sl->dev, | |
323 | "sysfs file creation for [%s] failed. err=%d\n", | |
324 | sl->dev.bus_id, err); | |
325 | device_unregister(&sl->dev); | |
326 | return err; | |
327 | } | |
328 | ||
329 | err = device_create_file(&sl->dev, &sl->attr_val); | |
330 | if (err < 0) { | |
331 | dev_err(&sl->dev, | |
332 | "sysfs file creation for [%s] failed. err=%d\n", | |
333 | sl->dev.bus_id, err); | |
334 | device_remove_file(&sl->dev, &sl->attr_name); | |
335 | device_unregister(&sl->dev); | |
336 | return err; | |
337 | } | |
338 | ||
339 | err = sysfs_create_bin_file(&sl->dev.kobj, &sl->attr_bin); | |
340 | if (err < 0) { | |
341 | dev_err(&sl->dev, | |
342 | "sysfs file creation for [%s] failed. err=%d\n", | |
343 | sl->dev.bus_id, err); | |
344 | device_remove_file(&sl->dev, &sl->attr_name); | |
345 | device_remove_file(&sl->dev, &sl->attr_val); | |
346 | device_unregister(&sl->dev); | |
347 | return err; | |
348 | } | |
349 | ||
350 | list_add_tail(&sl->w1_slave_entry, &sl->master->slist); | |
351 | ||
352 | return 0; | |
353 | } | |
354 | ||
355 | static int w1_attach_slave_device(struct w1_master *dev, struct w1_reg_num *rn) | |
356 | { | |
357 | struct w1_slave *sl; | |
358 | struct w1_family *f; | |
359 | int err; | |
360 | struct w1_netlink_msg msg; | |
361 | ||
362 | sl = kmalloc(sizeof(struct w1_slave), GFP_KERNEL); | |
363 | if (!sl) { | |
364 | dev_err(&dev->dev, | |
365 | "%s: failed to allocate new slave device.\n", | |
366 | __func__); | |
367 | return -ENOMEM; | |
368 | } | |
369 | ||
370 | memset(sl, 0, sizeof(*sl)); | |
371 | ||
372 | sl->owner = THIS_MODULE; | |
373 | sl->master = dev; | |
374 | set_bit(W1_SLAVE_ACTIVE, (long *)&sl->flags); | |
375 | ||
376 | memcpy(&sl->reg_num, rn, sizeof(sl->reg_num)); | |
377 | atomic_set(&sl->refcnt, 0); | |
378 | init_completion(&sl->dev_released); | |
379 | ||
380 | spin_lock(&w1_flock); | |
381 | f = w1_family_registered(rn->family); | |
382 | if (!f) { | |
383 | spin_unlock(&w1_flock); | |
384 | dev_info(&dev->dev, "Family %x for %02x.%012llx.%02x is not registered.\n", | |
385 | rn->family, rn->family, | |
386 | (unsigned long long)rn->id, rn->crc); | |
387 | kfree(sl); | |
388 | return -ENODEV; | |
389 | } | |
390 | __w1_family_get(f); | |
391 | spin_unlock(&w1_flock); | |
392 | ||
393 | sl->family = f; | |
394 | ||
395 | ||
396 | err = __w1_attach_slave_device(sl); | |
397 | if (err < 0) { | |
398 | dev_err(&dev->dev, "%s: Attaching %s failed.\n", __func__, | |
399 | sl->name); | |
400 | w1_family_put(sl->family); | |
401 | kfree(sl); | |
402 | return err; | |
403 | } | |
404 | ||
405 | sl->ttl = dev->slave_ttl; | |
406 | dev->slave_count++; | |
407 | ||
408 | memcpy(&msg.id.id, rn, sizeof(msg.id.id)); | |
409 | msg.type = W1_SLAVE_ADD; | |
410 | w1_netlink_send(dev, &msg); | |
411 | ||
412 | return 0; | |
413 | } | |
414 | ||
415 | static void w1_slave_detach(struct w1_slave *sl) | |
416 | { | |
417 | struct w1_netlink_msg msg; | |
7785925d | 418 | |
1da177e4 LT |
419 | dev_info(&sl->dev, "%s: detaching %s.\n", __func__, sl->name); |
420 | ||
421 | while (atomic_read(&sl->refcnt)) { | |
422 | printk(KERN_INFO "Waiting for %s to become free: refcnt=%d.\n", | |
423 | sl->name, atomic_read(&sl->refcnt)); | |
424 | ||
425 | if (msleep_interruptible(1000)) | |
426 | flush_signals(current); | |
427 | } | |
428 | ||
429 | sysfs_remove_bin_file (&sl->dev.kobj, &sl->attr_bin); | |
430 | device_remove_file(&sl->dev, &sl->attr_name); | |
431 | device_remove_file(&sl->dev, &sl->attr_val); | |
432 | device_unregister(&sl->dev); | |
433 | w1_family_put(sl->family); | |
434 | ||
435 | memcpy(&msg.id.id, &sl->reg_num, sizeof(msg.id.id)); | |
436 | msg.type = W1_SLAVE_REMOVE; | |
437 | w1_netlink_send(sl->master, &msg); | |
438 | } | |
439 | ||
440 | static struct w1_master *w1_search_master(unsigned long data) | |
441 | { | |
442 | struct w1_master *dev; | |
443 | int found = 0; | |
7785925d EP |
444 | |
445 | spin_lock_bh(&w1_mlock); | |
1da177e4 LT |
446 | list_for_each_entry(dev, &w1_masters, w1_master_entry) { |
447 | if (dev->bus_master->data == data) { | |
448 | found = 1; | |
449 | atomic_inc(&dev->refcnt); | |
450 | break; | |
451 | } | |
452 | } | |
7785925d | 453 | spin_unlock_bh(&w1_mlock); |
1da177e4 LT |
454 | |
455 | return (found)?dev:NULL; | |
456 | } | |
457 | ||
7785925d | 458 | static void w1_slave_found(unsigned long data, u64 rn) |
1da177e4 LT |
459 | { |
460 | int slave_count; | |
461 | struct w1_slave *sl; | |
462 | struct list_head *ent; | |
463 | struct w1_reg_num *tmp; | |
464 | int family_found = 0; | |
465 | struct w1_master *dev; | |
466 | ||
467 | dev = w1_search_master(data); | |
468 | if (!dev) { | |
469 | printk(KERN_ERR "Failed to find w1 master device for data %08lx, it is impossible.\n", | |
470 | data); | |
471 | return; | |
472 | } | |
7785925d | 473 | |
1da177e4 LT |
474 | tmp = (struct w1_reg_num *) &rn; |
475 | ||
476 | slave_count = 0; | |
477 | list_for_each(ent, &dev->slist) { | |
478 | ||
479 | sl = list_entry(ent, struct w1_slave, w1_slave_entry); | |
480 | ||
481 | if (sl->reg_num.family == tmp->family && | |
482 | sl->reg_num.id == tmp->id && | |
483 | sl->reg_num.crc == tmp->crc) { | |
484 | set_bit(W1_SLAVE_ACTIVE, (long *)&sl->flags); | |
485 | break; | |
7785925d | 486 | } else if (sl->reg_num.family == tmp->family) { |
1da177e4 LT |
487 | family_found = 1; |
488 | break; | |
489 | } | |
490 | ||
491 | slave_count++; | |
492 | } | |
493 | ||
8523ff45 | 494 | rn = cpu_to_le64(rn); |
495 | ||
496 | if (slave_count == dev->slave_count && | |
497 | rn && ((le64_to_cpu(rn) >> 56) & 0xff) == w1_calc_crc8((u8 *)&rn, 7)) { | |
498 | w1_attach_slave_device(dev, tmp); | |
1da177e4 | 499 | } |
7785925d | 500 | |
1da177e4 LT |
501 | atomic_dec(&dev->refcnt); |
502 | } | |
503 | ||
504 | void w1_search(struct w1_master *dev) | |
505 | { | |
506 | u64 last, rn, tmp; | |
507 | int i, count = 0; | |
508 | int last_family_desc, last_zero, last_device; | |
509 | int search_bit, id_bit, comp_bit, desc_bit; | |
510 | ||
511 | search_bit = id_bit = comp_bit = 0; | |
512 | rn = tmp = last = 0; | |
513 | last_device = last_zero = last_family_desc = 0; | |
514 | ||
515 | desc_bit = 64; | |
516 | ||
7785925d EP |
517 | while (!(id_bit && comp_bit) && !last_device && |
518 | count++ < dev->max_slave_count) { | |
1da177e4 LT |
519 | last = rn; |
520 | rn = 0; | |
521 | ||
522 | last_family_desc = 0; | |
523 | ||
524 | /* | |
525 | * Reset bus and all 1-wire device state machines | |
526 | * so they can respond to our requests. | |
527 | * | |
528 | * Return 0 - device(s) present, 1 - no devices present. | |
529 | */ | |
530 | if (w1_reset_bus(dev)) { | |
531 | dev_info(&dev->dev, "No devices present on the wire.\n"); | |
532 | break; | |
533 | } | |
534 | ||
535 | #if 1 | |
536 | w1_write_8(dev, W1_SEARCH); | |
537 | for (i = 0; i < 64; ++i) { | |
538 | /* | |
539 | * Read 2 bits from bus. | |
540 | * All who don't sleep must send ID bit and COMPLEMENT ID bit. | |
541 | * They actually are ANDed between all senders. | |
542 | */ | |
543 | id_bit = w1_touch_bit(dev, 1); | |
544 | comp_bit = w1_touch_bit(dev, 1); | |
545 | ||
546 | if (id_bit && comp_bit) | |
547 | break; | |
548 | ||
549 | if (id_bit == 0 && comp_bit == 0) { | |
550 | if (i == desc_bit) | |
551 | search_bit = 1; | |
552 | else if (i > desc_bit) | |
553 | search_bit = 0; | |
554 | else | |
555 | search_bit = ((last >> i) & 0x1); | |
556 | ||
557 | if (search_bit == 0) { | |
558 | last_zero = i; | |
559 | if (last_zero < 9) | |
560 | last_family_desc = last_zero; | |
561 | } | |
562 | ||
7785925d | 563 | } else |
1da177e4 LT |
564 | search_bit = id_bit; |
565 | ||
566 | tmp = search_bit; | |
567 | rn |= (tmp << i); | |
568 | ||
569 | /* | |
570 | * Write 1 bit to bus | |
571 | * and make all who don't have "search_bit" in "i"'th position | |
572 | * in it's registration number sleep. | |
573 | */ | |
574 | if (dev->bus_master->touch_bit) | |
575 | w1_touch_bit(dev, search_bit); | |
576 | else | |
577 | w1_write_bit(dev, search_bit); | |
578 | ||
579 | } | |
580 | #endif | |
581 | ||
582 | if (desc_bit == last_zero) | |
583 | last_device = 1; | |
584 | ||
585 | desc_bit = last_zero; | |
7785925d | 586 | |
1da177e4 LT |
587 | w1_slave_found(dev->bus_master->data, rn); |
588 | } | |
589 | } | |
590 | ||
7785925d | 591 | static int w1_control(void *data) |
1da177e4 | 592 | { |
7785925d EP |
593 | struct w1_slave *sl, *sln; |
594 | struct w1_master *dev, *n; | |
1da177e4 LT |
595 | int err, have_to_wait = 0; |
596 | ||
597 | daemonize("w1_control"); | |
598 | allow_signal(SIGTERM); | |
599 | ||
600 | while (!control_needs_exit || have_to_wait) { | |
601 | have_to_wait = 0; | |
602 | ||
603 | try_to_freeze(PF_FREEZE); | |
604 | msleep_interruptible(w1_timeout * 1000); | |
605 | ||
606 | if (signal_pending(current)) | |
607 | flush_signals(current); | |
608 | ||
7785925d | 609 | list_for_each_entry_safe(dev, n, &w1_masters, w1_master_entry) { |
1da177e4 LT |
610 | if (!control_needs_exit && !dev->need_exit) |
611 | continue; | |
612 | /* | |
613 | * Little race: we can create thread but not set the flag. | |
614 | * Get a chance for external process to set flag up. | |
615 | */ | |
616 | if (!dev->initialized) { | |
617 | have_to_wait = 1; | |
618 | continue; | |
619 | } | |
620 | ||
7785925d | 621 | spin_lock_bh(&w1_mlock); |
1da177e4 | 622 | list_del(&dev->w1_master_entry); |
7785925d | 623 | spin_unlock_bh(&w1_mlock); |
1da177e4 LT |
624 | |
625 | if (control_needs_exit) { | |
626 | dev->need_exit = 1; | |
627 | ||
628 | err = kill_proc(dev->kpid, SIGTERM, 1); | |
629 | if (err) | |
630 | dev_err(&dev->dev, | |
631 | "Failed to send signal to w1 kernel thread %d.\n", | |
632 | dev->kpid); | |
633 | } | |
634 | ||
635 | wait_for_completion(&dev->dev_exited); | |
636 | ||
7785925d EP |
637 | list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) { |
638 | list_del(&sl->w1_slave_entry); | |
1da177e4 | 639 | |
7785925d EP |
640 | w1_slave_detach(sl); |
641 | kfree(sl); | |
1da177e4 LT |
642 | } |
643 | w1_destroy_master_attributes(dev); | |
644 | atomic_dec(&dev->refcnt); | |
645 | } | |
646 | } | |
647 | ||
648 | complete_and_exit(&w1_control_complete, 0); | |
649 | } | |
650 | ||
651 | int w1_process(void *data) | |
652 | { | |
653 | struct w1_master *dev = (struct w1_master *) data; | |
7785925d | 654 | struct w1_slave *sl, *sln; |
1da177e4 LT |
655 | |
656 | daemonize("%s", dev->name); | |
657 | allow_signal(SIGTERM); | |
658 | ||
659 | while (!dev->need_exit) { | |
660 | try_to_freeze(PF_FREEZE); | |
661 | msleep_interruptible(w1_timeout * 1000); | |
662 | ||
663 | if (signal_pending(current)) | |
664 | flush_signals(current); | |
665 | ||
666 | if (dev->need_exit) | |
667 | break; | |
668 | ||
669 | if (!dev->initialized) | |
670 | continue; | |
671 | ||
672 | if (down_interruptible(&dev->mutex)) | |
673 | continue; | |
674 | ||
7785925d | 675 | list_for_each_entry(sl, &dev->slist, w1_slave_entry) |
1da177e4 | 676 | clear_bit(W1_SLAVE_ACTIVE, (long *)&sl->flags); |
1da177e4 | 677 | |
7785925d | 678 | w1_search_devices(dev, w1_slave_found); |
1da177e4 | 679 | |
7785925d EP |
680 | list_for_each_entry_safe(sl, sln, &dev->slist, w1_slave_entry) { |
681 | if (!test_bit(W1_SLAVE_ACTIVE, (unsigned long *)&sl->flags) && !--sl->ttl) { | |
1da177e4 LT |
682 | list_del (&sl->w1_slave_entry); |
683 | ||
684 | w1_slave_detach (sl); | |
685 | kfree (sl); | |
686 | ||
687 | dev->slave_count--; | |
7785925d | 688 | } else if (test_bit(W1_SLAVE_ACTIVE, (unsigned long *)&sl->flags)) |
1da177e4 LT |
689 | sl->ttl = dev->slave_ttl; |
690 | } | |
691 | up(&dev->mutex); | |
692 | } | |
693 | ||
694 | atomic_dec(&dev->refcnt); | |
695 | complete_and_exit(&dev->dev_exited, 0); | |
696 | ||
697 | return 0; | |
698 | } | |
699 | ||
7785925d | 700 | static int w1_init(void) |
1da177e4 LT |
701 | { |
702 | int retval; | |
703 | ||
704 | printk(KERN_INFO "Driver for 1-wire Dallas network protocol.\n"); | |
705 | ||
706 | retval = bus_register(&w1_bus_type); | |
707 | if (retval) { | |
708 | printk(KERN_ERR "Failed to register bus. err=%d.\n", retval); | |
709 | goto err_out_exit_init; | |
710 | } | |
711 | ||
712 | retval = driver_register(&w1_driver); | |
713 | if (retval) { | |
714 | printk(KERN_ERR | |
715 | "Failed to register master driver. err=%d.\n", | |
716 | retval); | |
717 | goto err_out_bus_unregister; | |
718 | } | |
719 | ||
720 | control_thread = kernel_thread(&w1_control, NULL, 0); | |
721 | if (control_thread < 0) { | |
722 | printk(KERN_ERR "Failed to create control thread. err=%d\n", | |
723 | control_thread); | |
724 | retval = control_thread; | |
725 | goto err_out_driver_unregister; | |
726 | } | |
727 | ||
728 | return 0; | |
729 | ||
730 | err_out_driver_unregister: | |
731 | driver_unregister(&w1_driver); | |
732 | ||
733 | err_out_bus_unregister: | |
734 | bus_unregister(&w1_bus_type); | |
735 | ||
736 | err_out_exit_init: | |
737 | return retval; | |
738 | } | |
739 | ||
7785925d | 740 | static void w1_fini(void) |
1da177e4 LT |
741 | { |
742 | struct w1_master *dev; | |
1da177e4 | 743 | |
7785925d | 744 | list_for_each_entry(dev, &w1_masters, w1_master_entry) |
1da177e4 | 745 | __w1_remove_master_device(dev); |
1da177e4 LT |
746 | |
747 | control_needs_exit = 1; | |
1da177e4 LT |
748 | wait_for_completion(&w1_control_complete); |
749 | ||
750 | driver_unregister(&w1_driver); | |
751 | bus_unregister(&w1_bus_type); | |
752 | } | |
753 | ||
754 | module_init(w1_init); | |
755 | module_exit(w1_fini); |