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Commit | Line | Data |
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eae9d2ba RG |
1 | /* |
2 | * PPS core file | |
3 | * | |
4 | * | |
5 | * Copyright (C) 2005-2009 Rodolfo Giometti <giometti@linux.it> | |
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., 675 Mass Ave, Cambridge, MA 02139, USA. | |
20 | */ | |
21 | ||
7f7cce74 | 22 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
eae9d2ba RG |
23 | |
24 | #include <linux/kernel.h> | |
25 | #include <linux/module.h> | |
26 | #include <linux/init.h> | |
27 | #include <linux/sched.h> | |
28 | #include <linux/uaccess.h> | |
29 | #include <linux/idr.h> | |
2a5cd6e2 | 30 | #include <linux/mutex.h> |
eae9d2ba RG |
31 | #include <linux/cdev.h> |
32 | #include <linux/poll.h> | |
33 | #include <linux/pps_kernel.h> | |
083e5866 | 34 | #include <linux/slab.h> |
eae9d2ba | 35 | |
717c0336 AG |
36 | #include "kc.h" |
37 | ||
eae9d2ba RG |
38 | /* |
39 | * Local variables | |
40 | */ | |
41 | ||
42 | static dev_t pps_devt; | |
43 | static struct class *pps_class; | |
44 | ||
2a5cd6e2 | 45 | static DEFINE_MUTEX(pps_idr_lock); |
083e5866 AG |
46 | static DEFINE_IDR(pps_idr); |
47 | ||
eae9d2ba RG |
48 | /* |
49 | * Char device methods | |
50 | */ | |
51 | ||
52 | static unsigned int pps_cdev_poll(struct file *file, poll_table *wait) | |
53 | { | |
54 | struct pps_device *pps = file->private_data; | |
55 | ||
56 | poll_wait(file, &pps->queue, wait); | |
57 | ||
58 | return POLLIN | POLLRDNORM; | |
59 | } | |
60 | ||
61 | static int pps_cdev_fasync(int fd, struct file *file, int on) | |
62 | { | |
63 | struct pps_device *pps = file->private_data; | |
64 | return fasync_helper(fd, file, on, &pps->async_queue); | |
65 | } | |
66 | ||
c2a49fe8 MR |
67 | static int pps_cdev_pps_fetch(struct pps_device *pps, struct pps_fdata *fdata) |
68 | { | |
69 | unsigned int ev = pps->last_ev; | |
70 | int err = 0; | |
71 | ||
72 | /* Manage the timeout */ | |
73 | if (fdata->timeout.flags & PPS_TIME_INVALID) | |
74 | err = wait_event_interruptible(pps->queue, | |
75 | ev != pps->last_ev); | |
76 | else { | |
77 | unsigned long ticks; | |
78 | ||
79 | dev_dbg(pps->dev, "timeout %lld.%09d\n", | |
80 | (long long) fdata->timeout.sec, | |
81 | fdata->timeout.nsec); | |
82 | ticks = fdata->timeout.sec * HZ; | |
83 | ticks += fdata->timeout.nsec / (NSEC_PER_SEC / HZ); | |
84 | ||
85 | if (ticks != 0) { | |
86 | err = wait_event_interruptible_timeout( | |
87 | pps->queue, | |
88 | ev != pps->last_ev, | |
89 | ticks); | |
90 | if (err == 0) | |
91 | return -ETIMEDOUT; | |
92 | } | |
93 | } | |
94 | ||
95 | /* Check for pending signals */ | |
96 | if (err == -ERESTARTSYS) { | |
97 | dev_dbg(pps->dev, "pending signal caught\n"); | |
98 | return -EINTR; | |
99 | } | |
100 | ||
101 | return 0; | |
102 | } | |
103 | ||
eae9d2ba RG |
104 | static long pps_cdev_ioctl(struct file *file, |
105 | unsigned int cmd, unsigned long arg) | |
106 | { | |
107 | struct pps_device *pps = file->private_data; | |
108 | struct pps_kparams params; | |
eae9d2ba RG |
109 | void __user *uarg = (void __user *) arg; |
110 | int __user *iuarg = (int __user *) arg; | |
111 | int err; | |
112 | ||
113 | switch (cmd) { | |
114 | case PPS_GETPARAMS: | |
7f7cce74 | 115 | dev_dbg(pps->dev, "PPS_GETPARAMS\n"); |
eae9d2ba | 116 | |
cbf83cc5 RG |
117 | spin_lock_irq(&pps->lock); |
118 | ||
119 | /* Get the current parameters */ | |
120 | params = pps->params; | |
121 | ||
122 | spin_unlock_irq(&pps->lock); | |
123 | ||
124 | err = copy_to_user(uarg, ¶ms, sizeof(struct pps_kparams)); | |
eae9d2ba RG |
125 | if (err) |
126 | return -EFAULT; | |
127 | ||
128 | break; | |
129 | ||
130 | case PPS_SETPARAMS: | |
7f7cce74 | 131 | dev_dbg(pps->dev, "PPS_SETPARAMS\n"); |
eae9d2ba RG |
132 | |
133 | /* Check the capabilities */ | |
134 | if (!capable(CAP_SYS_TIME)) | |
135 | return -EPERM; | |
136 | ||
137 | err = copy_from_user(¶ms, uarg, sizeof(struct pps_kparams)); | |
138 | if (err) | |
139 | return -EFAULT; | |
140 | if (!(params.mode & (PPS_CAPTUREASSERT | PPS_CAPTURECLEAR))) { | |
7f7cce74 | 141 | dev_dbg(pps->dev, "capture mode unspecified (%x)\n", |
eae9d2ba RG |
142 | params.mode); |
143 | return -EINVAL; | |
144 | } | |
145 | ||
146 | /* Check for supported capabilities */ | |
147 | if ((params.mode & ~pps->info.mode) != 0) { | |
7f7cce74 | 148 | dev_dbg(pps->dev, "unsupported capabilities (%x)\n", |
eae9d2ba RG |
149 | params.mode); |
150 | return -EINVAL; | |
151 | } | |
152 | ||
153 | spin_lock_irq(&pps->lock); | |
154 | ||
155 | /* Save the new parameters */ | |
156 | pps->params = params; | |
157 | ||
158 | /* Restore the read only parameters */ | |
159 | if ((params.mode & (PPS_TSFMT_TSPEC | PPS_TSFMT_NTPFP)) == 0) { | |
160 | /* section 3.3 of RFC 2783 interpreted */ | |
7f7cce74 | 161 | dev_dbg(pps->dev, "time format unspecified (%x)\n", |
eae9d2ba RG |
162 | params.mode); |
163 | pps->params.mode |= PPS_TSFMT_TSPEC; | |
164 | } | |
165 | if (pps->info.mode & PPS_CANWAIT) | |
166 | pps->params.mode |= PPS_CANWAIT; | |
167 | pps->params.api_version = PPS_API_VERS; | |
168 | ||
169 | spin_unlock_irq(&pps->lock); | |
170 | ||
171 | break; | |
172 | ||
173 | case PPS_GETCAP: | |
7f7cce74 | 174 | dev_dbg(pps->dev, "PPS_GETCAP\n"); |
eae9d2ba RG |
175 | |
176 | err = put_user(pps->info.mode, iuarg); | |
177 | if (err) | |
178 | return -EFAULT; | |
179 | ||
180 | break; | |
181 | ||
86d921f9 AG |
182 | case PPS_FETCH: { |
183 | struct pps_fdata fdata; | |
184 | ||
7f7cce74 | 185 | dev_dbg(pps->dev, "PPS_FETCH\n"); |
eae9d2ba RG |
186 | |
187 | err = copy_from_user(&fdata, uarg, sizeof(struct pps_fdata)); | |
188 | if (err) | |
189 | return -EFAULT; | |
190 | ||
c2a49fe8 MR |
191 | err = pps_cdev_pps_fetch(pps, &fdata); |
192 | if (err) | |
193 | return err; | |
eae9d2ba RG |
194 | |
195 | /* Return the fetched timestamp */ | |
196 | spin_lock_irq(&pps->lock); | |
197 | ||
198 | fdata.info.assert_sequence = pps->assert_sequence; | |
199 | fdata.info.clear_sequence = pps->clear_sequence; | |
200 | fdata.info.assert_tu = pps->assert_tu; | |
201 | fdata.info.clear_tu = pps->clear_tu; | |
202 | fdata.info.current_mode = pps->current_mode; | |
203 | ||
204 | spin_unlock_irq(&pps->lock); | |
205 | ||
206 | err = copy_to_user(uarg, &fdata, sizeof(struct pps_fdata)); | |
207 | if (err) | |
208 | return -EFAULT; | |
209 | ||
210 | break; | |
86d921f9 | 211 | } |
717c0336 AG |
212 | case PPS_KC_BIND: { |
213 | struct pps_bind_args bind_args; | |
214 | ||
215 | dev_dbg(pps->dev, "PPS_KC_BIND\n"); | |
216 | ||
217 | /* Check the capabilities */ | |
218 | if (!capable(CAP_SYS_TIME)) | |
219 | return -EPERM; | |
220 | ||
221 | if (copy_from_user(&bind_args, uarg, | |
222 | sizeof(struct pps_bind_args))) | |
223 | return -EFAULT; | |
224 | ||
225 | /* Check for supported capabilities */ | |
226 | if ((bind_args.edge & ~pps->info.mode) != 0) { | |
227 | dev_err(pps->dev, "unsupported capabilities (%x)\n", | |
228 | bind_args.edge); | |
229 | return -EINVAL; | |
230 | } | |
231 | ||
232 | /* Validate parameters roughly */ | |
233 | if (bind_args.tsformat != PPS_TSFMT_TSPEC || | |
234 | (bind_args.edge & ~PPS_CAPTUREBOTH) != 0 || | |
235 | bind_args.consumer != PPS_KC_HARDPPS) { | |
236 | dev_err(pps->dev, "invalid kernel consumer bind" | |
237 | " parameters (%x)\n", bind_args.edge); | |
238 | return -EINVAL; | |
239 | } | |
240 | ||
241 | err = pps_kc_bind(pps, &bind_args); | |
242 | if (err < 0) | |
243 | return err; | |
244 | ||
245 | break; | |
246 | } | |
eae9d2ba RG |
247 | default: |
248 | return -ENOTTY; | |
eae9d2ba RG |
249 | } |
250 | ||
251 | return 0; | |
252 | } | |
253 | ||
2ac66657 MR |
254 | #ifdef CONFIG_COMPAT |
255 | static long pps_cdev_compat_ioctl(struct file *file, | |
256 | unsigned int cmd, unsigned long arg) | |
257 | { | |
c2a49fe8 MR |
258 | struct pps_device *pps = file->private_data; |
259 | void __user *uarg = (void __user *) arg; | |
260 | ||
2ac66657 MR |
261 | cmd = _IOC(_IOC_DIR(cmd), _IOC_TYPE(cmd), _IOC_NR(cmd), sizeof(void *)); |
262 | ||
c2a49fe8 MR |
263 | if (cmd == PPS_FETCH) { |
264 | struct pps_fdata_compat compat; | |
265 | struct pps_fdata fdata; | |
266 | int err; | |
267 | ||
268 | dev_dbg(pps->dev, "PPS_FETCH\n"); | |
269 | ||
270 | err = copy_from_user(&compat, uarg, sizeof(struct pps_fdata_compat)); | |
271 | if (err) | |
272 | return -EFAULT; | |
273 | ||
274 | memcpy(&fdata.timeout, &compat.timeout, | |
275 | sizeof(struct pps_ktime_compat)); | |
276 | ||
277 | err = pps_cdev_pps_fetch(pps, &fdata); | |
278 | if (err) | |
279 | return err; | |
280 | ||
281 | /* Return the fetched timestamp */ | |
282 | spin_lock_irq(&pps->lock); | |
283 | ||
284 | compat.info.assert_sequence = pps->assert_sequence; | |
285 | compat.info.clear_sequence = pps->clear_sequence; | |
286 | compat.info.current_mode = pps->current_mode; | |
287 | ||
288 | memcpy(&compat.info.assert_tu, &pps->assert_tu, | |
289 | sizeof(struct pps_ktime_compat)); | |
290 | memcpy(&compat.info.clear_tu, &pps->clear_tu, | |
291 | sizeof(struct pps_ktime_compat)); | |
292 | ||
293 | spin_unlock_irq(&pps->lock); | |
294 | ||
295 | return copy_to_user(uarg, &compat, | |
296 | sizeof(struct pps_fdata_compat)) ? -EFAULT : 0; | |
297 | } | |
298 | ||
2ac66657 MR |
299 | return pps_cdev_ioctl(file, cmd, arg); |
300 | } | |
301 | #else | |
302 | #define pps_cdev_compat_ioctl NULL | |
303 | #endif | |
304 | ||
eae9d2ba RG |
305 | static int pps_cdev_open(struct inode *inode, struct file *file) |
306 | { | |
307 | struct pps_device *pps = container_of(inode->i_cdev, | |
308 | struct pps_device, cdev); | |
eae9d2ba | 309 | file->private_data = pps; |
d953e0e8 | 310 | kobject_get(&pps->dev->kobj); |
eae9d2ba RG |
311 | return 0; |
312 | } | |
313 | ||
314 | static int pps_cdev_release(struct inode *inode, struct file *file) | |
315 | { | |
d953e0e8 GS |
316 | struct pps_device *pps = container_of(inode->i_cdev, |
317 | struct pps_device, cdev); | |
318 | kobject_put(&pps->dev->kobj); | |
eae9d2ba RG |
319 | return 0; |
320 | } | |
321 | ||
322 | /* | |
323 | * Char device stuff | |
324 | */ | |
325 | ||
326 | static const struct file_operations pps_cdev_fops = { | |
327 | .owner = THIS_MODULE, | |
328 | .llseek = no_llseek, | |
329 | .poll = pps_cdev_poll, | |
330 | .fasync = pps_cdev_fasync, | |
2ac66657 | 331 | .compat_ioctl = pps_cdev_compat_ioctl, |
eae9d2ba RG |
332 | .unlocked_ioctl = pps_cdev_ioctl, |
333 | .open = pps_cdev_open, | |
334 | .release = pps_cdev_release, | |
335 | }; | |
336 | ||
083e5866 AG |
337 | static void pps_device_destruct(struct device *dev) |
338 | { | |
339 | struct pps_device *pps = dev_get_drvdata(dev); | |
340 | ||
d953e0e8 GS |
341 | cdev_del(&pps->cdev); |
342 | ||
343 | /* Now we can release the ID for re-use */ | |
344 | pr_debug("deallocating pps%d\n", pps->id); | |
2a5cd6e2 | 345 | mutex_lock(&pps_idr_lock); |
083e5866 | 346 | idr_remove(&pps_idr, pps->id); |
2a5cd6e2 | 347 | mutex_unlock(&pps_idr_lock); |
083e5866 AG |
348 | |
349 | kfree(dev); | |
350 | kfree(pps); | |
351 | } | |
352 | ||
eae9d2ba RG |
353 | int pps_register_cdev(struct pps_device *pps) |
354 | { | |
355 | int err; | |
5e196d34 AG |
356 | dev_t devt; |
357 | ||
2a5cd6e2 | 358 | mutex_lock(&pps_idr_lock); |
19dd2da3 TH |
359 | /* |
360 | * Get new ID for the new PPS source. After idr_alloc() calling | |
361 | * the new source will be freely available into the kernel. | |
083e5866 | 362 | */ |
19dd2da3 TH |
363 | err = idr_alloc(&pps_idr, pps, 0, PPS_MAX_SOURCES, GFP_KERNEL); |
364 | if (err < 0) { | |
365 | if (err == -ENOSPC) { | |
366 | pr_err("%s: too many PPS sources in the system\n", | |
367 | pps->info.name); | |
368 | err = -EBUSY; | |
369 | } | |
370 | goto out_unlock; | |
083e5866 | 371 | } |
19dd2da3 TH |
372 | pps->id = err; |
373 | mutex_unlock(&pps_idr_lock); | |
083e5866 | 374 | |
5e196d34 | 375 | devt = MKDEV(MAJOR(pps_devt), pps->id); |
eae9d2ba | 376 | |
eae9d2ba RG |
377 | cdev_init(&pps->cdev, &pps_cdev_fops); |
378 | pps->cdev.owner = pps->info.owner; | |
379 | ||
5e196d34 | 380 | err = cdev_add(&pps->cdev, devt, 1); |
eae9d2ba | 381 | if (err) { |
7f7cce74 | 382 | pr_err("%s: failed to add char device %d:%d\n", |
eae9d2ba | 383 | pps->info.name, MAJOR(pps_devt), pps->id); |
083e5866 | 384 | goto free_idr; |
eae9d2ba | 385 | } |
5e196d34 | 386 | pps->dev = device_create(pps_class, pps->info.dev, devt, pps, |
eae9d2ba | 387 | "pps%d", pps->id); |
668f06b9 EG |
388 | if (IS_ERR(pps->dev)) { |
389 | err = PTR_ERR(pps->dev); | |
eae9d2ba | 390 | goto del_cdev; |
668f06b9 | 391 | } |
eae9d2ba | 392 | |
d953e0e8 | 393 | /* Override the release function with our own */ |
083e5866 AG |
394 | pps->dev->release = pps_device_destruct; |
395 | ||
eae9d2ba RG |
396 | pr_debug("source %s got cdev (%d:%d)\n", pps->info.name, |
397 | MAJOR(pps_devt), pps->id); | |
398 | ||
399 | return 0; | |
400 | ||
401 | del_cdev: | |
402 | cdev_del(&pps->cdev); | |
403 | ||
083e5866 | 404 | free_idr: |
2a5cd6e2 | 405 | mutex_lock(&pps_idr_lock); |
083e5866 | 406 | idr_remove(&pps_idr, pps->id); |
19dd2da3 | 407 | out_unlock: |
2a5cd6e2 | 408 | mutex_unlock(&pps_idr_lock); |
eae9d2ba RG |
409 | return err; |
410 | } | |
411 | ||
412 | void pps_unregister_cdev(struct pps_device *pps) | |
413 | { | |
d953e0e8 | 414 | pr_debug("unregistering pps%d\n", pps->id); |
513b032c | 415 | pps->lookup_cookie = NULL; |
5e196d34 | 416 | device_destroy(pps_class, pps->dev->devt); |
eae9d2ba RG |
417 | } |
418 | ||
513b032c GS |
419 | /* |
420 | * Look up a pps device by magic cookie. | |
421 | * The cookie is usually a pointer to some enclosing device, but this | |
422 | * code doesn't care; you should never be dereferencing it. | |
423 | * | |
424 | * This is a bit of a kludge that is currently used only by the PPS | |
425 | * serial line discipline. It may need to be tweaked when a second user | |
426 | * is found. | |
427 | * | |
428 | * There is no function interface for setting the lookup_cookie field. | |
429 | * It's initialized to NULL when the pps device is created, and if a | |
430 | * client wants to use it, just fill it in afterward. | |
431 | * | |
432 | * The cookie is automatically set to NULL in pps_unregister_source() | |
433 | * so that it will not be used again, even if the pps device cannot | |
434 | * be removed from the idr due to pending references holding the minor | |
435 | * number in use. | |
436 | */ | |
437 | struct pps_device *pps_lookup_dev(void const *cookie) | |
438 | { | |
439 | struct pps_device *pps; | |
440 | unsigned id; | |
441 | ||
442 | rcu_read_lock(); | |
443 | idr_for_each_entry(&pps_idr, pps, id) | |
444 | if (cookie == pps->lookup_cookie) | |
445 | break; | |
446 | rcu_read_unlock(); | |
447 | return pps; | |
448 | } | |
449 | EXPORT_SYMBOL(pps_lookup_dev); | |
450 | ||
eae9d2ba RG |
451 | /* |
452 | * Module stuff | |
453 | */ | |
454 | ||
455 | static void __exit pps_exit(void) | |
456 | { | |
457 | class_destroy(pps_class); | |
458 | unregister_chrdev_region(pps_devt, PPS_MAX_SOURCES); | |
459 | } | |
460 | ||
461 | static int __init pps_init(void) | |
462 | { | |
463 | int err; | |
464 | ||
465 | pps_class = class_create(THIS_MODULE, "pps"); | |
7ad12566 | 466 | if (IS_ERR(pps_class)) { |
7f7cce74 | 467 | pr_err("failed to allocate class\n"); |
7ad12566 | 468 | return PTR_ERR(pps_class); |
eae9d2ba | 469 | } |
bd0eae4e | 470 | pps_class->dev_groups = pps_groups; |
eae9d2ba RG |
471 | |
472 | err = alloc_chrdev_region(&pps_devt, 0, PPS_MAX_SOURCES, "pps"); | |
473 | if (err < 0) { | |
7f7cce74 | 474 | pr_err("failed to allocate char device region\n"); |
eae9d2ba RG |
475 | goto remove_class; |
476 | } | |
477 | ||
478 | pr_info("LinuxPPS API ver. %d registered\n", PPS_API_VERS); | |
479 | pr_info("Software ver. %s - Copyright 2005-2007 Rodolfo Giometti " | |
480 | "<giometti@linux.it>\n", PPS_VERSION); | |
481 | ||
482 | return 0; | |
483 | ||
484 | remove_class: | |
485 | class_destroy(pps_class); | |
486 | ||
487 | return err; | |
488 | } | |
489 | ||
490 | subsys_initcall(pps_init); | |
491 | module_exit(pps_exit); | |
492 | ||
493 | MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>"); | |
494 | MODULE_DESCRIPTION("LinuxPPS support (RFC 2783) - ver. " PPS_VERSION); | |
495 | MODULE_LICENSE("GPL"); |