Commit | Line | Data |
---|---|---|
74ba9207 | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
eae9d2ba RG |
2 | /* |
3 | * PPS core file | |
4 | * | |
eae9d2ba | 5 | * Copyright (C) 2005-2009 Rodolfo Giometti <giometti@linux.it> |
eae9d2ba RG |
6 | */ |
7 | ||
7f7cce74 | 8 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
eae9d2ba RG |
9 | |
10 | #include <linux/kernel.h> | |
11 | #include <linux/module.h> | |
12 | #include <linux/init.h> | |
13 | #include <linux/sched.h> | |
14 | #include <linux/uaccess.h> | |
15 | #include <linux/idr.h> | |
2a5cd6e2 | 16 | #include <linux/mutex.h> |
eae9d2ba RG |
17 | #include <linux/cdev.h> |
18 | #include <linux/poll.h> | |
19 | #include <linux/pps_kernel.h> | |
083e5866 | 20 | #include <linux/slab.h> |
eae9d2ba | 21 | |
717c0336 AG |
22 | #include "kc.h" |
23 | ||
eae9d2ba RG |
24 | /* |
25 | * Local variables | |
26 | */ | |
27 | ||
28 | static dev_t pps_devt; | |
29 | static struct class *pps_class; | |
30 | ||
2a5cd6e2 | 31 | static DEFINE_MUTEX(pps_idr_lock); |
083e5866 AG |
32 | static DEFINE_IDR(pps_idr); |
33 | ||
eae9d2ba RG |
34 | /* |
35 | * Char device methods | |
36 | */ | |
37 | ||
afc9a42b | 38 | static __poll_t pps_cdev_poll(struct file *file, poll_table *wait) |
eae9d2ba RG |
39 | { |
40 | struct pps_device *pps = file->private_data; | |
41 | ||
42 | poll_wait(file, &pps->queue, wait); | |
43 | ||
a9a08845 | 44 | return EPOLLIN | EPOLLRDNORM; |
eae9d2ba RG |
45 | } |
46 | ||
47 | static int pps_cdev_fasync(int fd, struct file *file, int on) | |
48 | { | |
49 | struct pps_device *pps = file->private_data; | |
50 | return fasync_helper(fd, file, on, &pps->async_queue); | |
51 | } | |
52 | ||
c2a49fe8 MR |
53 | static int pps_cdev_pps_fetch(struct pps_device *pps, struct pps_fdata *fdata) |
54 | { | |
55 | unsigned int ev = pps->last_ev; | |
56 | int err = 0; | |
57 | ||
58 | /* Manage the timeout */ | |
59 | if (fdata->timeout.flags & PPS_TIME_INVALID) | |
60 | err = wait_event_interruptible(pps->queue, | |
61 | ev != pps->last_ev); | |
62 | else { | |
63 | unsigned long ticks; | |
64 | ||
65 | dev_dbg(pps->dev, "timeout %lld.%09d\n", | |
66 | (long long) fdata->timeout.sec, | |
67 | fdata->timeout.nsec); | |
68 | ticks = fdata->timeout.sec * HZ; | |
69 | ticks += fdata->timeout.nsec / (NSEC_PER_SEC / HZ); | |
70 | ||
71 | if (ticks != 0) { | |
72 | err = wait_event_interruptible_timeout( | |
73 | pps->queue, | |
74 | ev != pps->last_ev, | |
75 | ticks); | |
76 | if (err == 0) | |
77 | return -ETIMEDOUT; | |
78 | } | |
79 | } | |
80 | ||
81 | /* Check for pending signals */ | |
82 | if (err == -ERESTARTSYS) { | |
83 | dev_dbg(pps->dev, "pending signal caught\n"); | |
84 | return -EINTR; | |
85 | } | |
86 | ||
87 | return 0; | |
88 | } | |
89 | ||
eae9d2ba RG |
90 | static long pps_cdev_ioctl(struct file *file, |
91 | unsigned int cmd, unsigned long arg) | |
92 | { | |
93 | struct pps_device *pps = file->private_data; | |
94 | struct pps_kparams params; | |
eae9d2ba RG |
95 | void __user *uarg = (void __user *) arg; |
96 | int __user *iuarg = (int __user *) arg; | |
97 | int err; | |
98 | ||
99 | switch (cmd) { | |
100 | case PPS_GETPARAMS: | |
7f7cce74 | 101 | dev_dbg(pps->dev, "PPS_GETPARAMS\n"); |
eae9d2ba | 102 | |
cbf83cc5 RG |
103 | spin_lock_irq(&pps->lock); |
104 | ||
105 | /* Get the current parameters */ | |
106 | params = pps->params; | |
107 | ||
108 | spin_unlock_irq(&pps->lock); | |
109 | ||
110 | err = copy_to_user(uarg, ¶ms, sizeof(struct pps_kparams)); | |
eae9d2ba RG |
111 | if (err) |
112 | return -EFAULT; | |
113 | ||
114 | break; | |
115 | ||
116 | case PPS_SETPARAMS: | |
7f7cce74 | 117 | dev_dbg(pps->dev, "PPS_SETPARAMS\n"); |
eae9d2ba RG |
118 | |
119 | /* Check the capabilities */ | |
120 | if (!capable(CAP_SYS_TIME)) | |
121 | return -EPERM; | |
122 | ||
123 | err = copy_from_user(¶ms, uarg, sizeof(struct pps_kparams)); | |
124 | if (err) | |
125 | return -EFAULT; | |
126 | if (!(params.mode & (PPS_CAPTUREASSERT | PPS_CAPTURECLEAR))) { | |
7f7cce74 | 127 | dev_dbg(pps->dev, "capture mode unspecified (%x)\n", |
eae9d2ba RG |
128 | params.mode); |
129 | return -EINVAL; | |
130 | } | |
131 | ||
132 | /* Check for supported capabilities */ | |
133 | if ((params.mode & ~pps->info.mode) != 0) { | |
7f7cce74 | 134 | dev_dbg(pps->dev, "unsupported capabilities (%x)\n", |
eae9d2ba RG |
135 | params.mode); |
136 | return -EINVAL; | |
137 | } | |
138 | ||
139 | spin_lock_irq(&pps->lock); | |
140 | ||
141 | /* Save the new parameters */ | |
142 | pps->params = params; | |
143 | ||
144 | /* Restore the read only parameters */ | |
145 | if ((params.mode & (PPS_TSFMT_TSPEC | PPS_TSFMT_NTPFP)) == 0) { | |
146 | /* section 3.3 of RFC 2783 interpreted */ | |
7f7cce74 | 147 | dev_dbg(pps->dev, "time format unspecified (%x)\n", |
eae9d2ba RG |
148 | params.mode); |
149 | pps->params.mode |= PPS_TSFMT_TSPEC; | |
150 | } | |
151 | if (pps->info.mode & PPS_CANWAIT) | |
152 | pps->params.mode |= PPS_CANWAIT; | |
153 | pps->params.api_version = PPS_API_VERS; | |
154 | ||
155 | spin_unlock_irq(&pps->lock); | |
156 | ||
157 | break; | |
158 | ||
159 | case PPS_GETCAP: | |
7f7cce74 | 160 | dev_dbg(pps->dev, "PPS_GETCAP\n"); |
eae9d2ba RG |
161 | |
162 | err = put_user(pps->info.mode, iuarg); | |
163 | if (err) | |
164 | return -EFAULT; | |
165 | ||
166 | break; | |
167 | ||
86d921f9 AG |
168 | case PPS_FETCH: { |
169 | struct pps_fdata fdata; | |
170 | ||
7f7cce74 | 171 | dev_dbg(pps->dev, "PPS_FETCH\n"); |
eae9d2ba RG |
172 | |
173 | err = copy_from_user(&fdata, uarg, sizeof(struct pps_fdata)); | |
174 | if (err) | |
175 | return -EFAULT; | |
176 | ||
c2a49fe8 MR |
177 | err = pps_cdev_pps_fetch(pps, &fdata); |
178 | if (err) | |
179 | return err; | |
eae9d2ba RG |
180 | |
181 | /* Return the fetched timestamp */ | |
182 | spin_lock_irq(&pps->lock); | |
183 | ||
184 | fdata.info.assert_sequence = pps->assert_sequence; | |
185 | fdata.info.clear_sequence = pps->clear_sequence; | |
186 | fdata.info.assert_tu = pps->assert_tu; | |
187 | fdata.info.clear_tu = pps->clear_tu; | |
188 | fdata.info.current_mode = pps->current_mode; | |
189 | ||
190 | spin_unlock_irq(&pps->lock); | |
191 | ||
192 | err = copy_to_user(uarg, &fdata, sizeof(struct pps_fdata)); | |
193 | if (err) | |
194 | return -EFAULT; | |
195 | ||
196 | break; | |
86d921f9 | 197 | } |
717c0336 AG |
198 | case PPS_KC_BIND: { |
199 | struct pps_bind_args bind_args; | |
200 | ||
201 | dev_dbg(pps->dev, "PPS_KC_BIND\n"); | |
202 | ||
203 | /* Check the capabilities */ | |
204 | if (!capable(CAP_SYS_TIME)) | |
205 | return -EPERM; | |
206 | ||
207 | if (copy_from_user(&bind_args, uarg, | |
208 | sizeof(struct pps_bind_args))) | |
209 | return -EFAULT; | |
210 | ||
211 | /* Check for supported capabilities */ | |
212 | if ((bind_args.edge & ~pps->info.mode) != 0) { | |
213 | dev_err(pps->dev, "unsupported capabilities (%x)\n", | |
214 | bind_args.edge); | |
215 | return -EINVAL; | |
216 | } | |
217 | ||
218 | /* Validate parameters roughly */ | |
219 | if (bind_args.tsformat != PPS_TSFMT_TSPEC || | |
220 | (bind_args.edge & ~PPS_CAPTUREBOTH) != 0 || | |
221 | bind_args.consumer != PPS_KC_HARDPPS) { | |
222 | dev_err(pps->dev, "invalid kernel consumer bind" | |
223 | " parameters (%x)\n", bind_args.edge); | |
224 | return -EINVAL; | |
225 | } | |
226 | ||
227 | err = pps_kc_bind(pps, &bind_args); | |
228 | if (err < 0) | |
229 | return err; | |
230 | ||
231 | break; | |
232 | } | |
eae9d2ba RG |
233 | default: |
234 | return -ENOTTY; | |
eae9d2ba RG |
235 | } |
236 | ||
237 | return 0; | |
238 | } | |
239 | ||
2ac66657 MR |
240 | #ifdef CONFIG_COMPAT |
241 | static long pps_cdev_compat_ioctl(struct file *file, | |
242 | unsigned int cmd, unsigned long arg) | |
243 | { | |
c2a49fe8 MR |
244 | struct pps_device *pps = file->private_data; |
245 | void __user *uarg = (void __user *) arg; | |
246 | ||
2ac66657 MR |
247 | cmd = _IOC(_IOC_DIR(cmd), _IOC_TYPE(cmd), _IOC_NR(cmd), sizeof(void *)); |
248 | ||
c2a49fe8 MR |
249 | if (cmd == PPS_FETCH) { |
250 | struct pps_fdata_compat compat; | |
251 | struct pps_fdata fdata; | |
252 | int err; | |
253 | ||
254 | dev_dbg(pps->dev, "PPS_FETCH\n"); | |
255 | ||
256 | err = copy_from_user(&compat, uarg, sizeof(struct pps_fdata_compat)); | |
257 | if (err) | |
258 | return -EFAULT; | |
259 | ||
260 | memcpy(&fdata.timeout, &compat.timeout, | |
261 | sizeof(struct pps_ktime_compat)); | |
262 | ||
263 | err = pps_cdev_pps_fetch(pps, &fdata); | |
264 | if (err) | |
265 | return err; | |
266 | ||
267 | /* Return the fetched timestamp */ | |
268 | spin_lock_irq(&pps->lock); | |
269 | ||
270 | compat.info.assert_sequence = pps->assert_sequence; | |
271 | compat.info.clear_sequence = pps->clear_sequence; | |
272 | compat.info.current_mode = pps->current_mode; | |
273 | ||
274 | memcpy(&compat.info.assert_tu, &pps->assert_tu, | |
275 | sizeof(struct pps_ktime_compat)); | |
276 | memcpy(&compat.info.clear_tu, &pps->clear_tu, | |
277 | sizeof(struct pps_ktime_compat)); | |
278 | ||
279 | spin_unlock_irq(&pps->lock); | |
280 | ||
281 | return copy_to_user(uarg, &compat, | |
282 | sizeof(struct pps_fdata_compat)) ? -EFAULT : 0; | |
283 | } | |
284 | ||
2ac66657 MR |
285 | return pps_cdev_ioctl(file, cmd, arg); |
286 | } | |
287 | #else | |
288 | #define pps_cdev_compat_ioctl NULL | |
289 | #endif | |
290 | ||
eae9d2ba RG |
291 | static int pps_cdev_open(struct inode *inode, struct file *file) |
292 | { | |
293 | struct pps_device *pps = container_of(inode->i_cdev, | |
294 | struct pps_device, cdev); | |
eae9d2ba | 295 | file->private_data = pps; |
d953e0e8 | 296 | kobject_get(&pps->dev->kobj); |
eae9d2ba RG |
297 | return 0; |
298 | } | |
299 | ||
300 | static int pps_cdev_release(struct inode *inode, struct file *file) | |
301 | { | |
d953e0e8 GS |
302 | struct pps_device *pps = container_of(inode->i_cdev, |
303 | struct pps_device, cdev); | |
304 | kobject_put(&pps->dev->kobj); | |
eae9d2ba RG |
305 | return 0; |
306 | } | |
307 | ||
308 | /* | |
309 | * Char device stuff | |
310 | */ | |
311 | ||
312 | static const struct file_operations pps_cdev_fops = { | |
313 | .owner = THIS_MODULE, | |
314 | .llseek = no_llseek, | |
315 | .poll = pps_cdev_poll, | |
316 | .fasync = pps_cdev_fasync, | |
2ac66657 | 317 | .compat_ioctl = pps_cdev_compat_ioctl, |
eae9d2ba RG |
318 | .unlocked_ioctl = pps_cdev_ioctl, |
319 | .open = pps_cdev_open, | |
320 | .release = pps_cdev_release, | |
321 | }; | |
322 | ||
083e5866 AG |
323 | static void pps_device_destruct(struct device *dev) |
324 | { | |
325 | struct pps_device *pps = dev_get_drvdata(dev); | |
326 | ||
d953e0e8 GS |
327 | cdev_del(&pps->cdev); |
328 | ||
329 | /* Now we can release the ID for re-use */ | |
330 | pr_debug("deallocating pps%d\n", pps->id); | |
2a5cd6e2 | 331 | mutex_lock(&pps_idr_lock); |
083e5866 | 332 | idr_remove(&pps_idr, pps->id); |
2a5cd6e2 | 333 | mutex_unlock(&pps_idr_lock); |
083e5866 AG |
334 | |
335 | kfree(dev); | |
336 | kfree(pps); | |
337 | } | |
338 | ||
eae9d2ba RG |
339 | int pps_register_cdev(struct pps_device *pps) |
340 | { | |
341 | int err; | |
5e196d34 AG |
342 | dev_t devt; |
343 | ||
2a5cd6e2 | 344 | mutex_lock(&pps_idr_lock); |
19dd2da3 TH |
345 | /* |
346 | * Get new ID for the new PPS source. After idr_alloc() calling | |
347 | * the new source will be freely available into the kernel. | |
083e5866 | 348 | */ |
19dd2da3 TH |
349 | err = idr_alloc(&pps_idr, pps, 0, PPS_MAX_SOURCES, GFP_KERNEL); |
350 | if (err < 0) { | |
351 | if (err == -ENOSPC) { | |
352 | pr_err("%s: too many PPS sources in the system\n", | |
353 | pps->info.name); | |
354 | err = -EBUSY; | |
355 | } | |
356 | goto out_unlock; | |
083e5866 | 357 | } |
19dd2da3 TH |
358 | pps->id = err; |
359 | mutex_unlock(&pps_idr_lock); | |
083e5866 | 360 | |
5e196d34 | 361 | devt = MKDEV(MAJOR(pps_devt), pps->id); |
eae9d2ba | 362 | |
eae9d2ba RG |
363 | cdev_init(&pps->cdev, &pps_cdev_fops); |
364 | pps->cdev.owner = pps->info.owner; | |
365 | ||
5e196d34 | 366 | err = cdev_add(&pps->cdev, devt, 1); |
eae9d2ba | 367 | if (err) { |
7f7cce74 | 368 | pr_err("%s: failed to add char device %d:%d\n", |
eae9d2ba | 369 | pps->info.name, MAJOR(pps_devt), pps->id); |
083e5866 | 370 | goto free_idr; |
eae9d2ba | 371 | } |
5e196d34 | 372 | pps->dev = device_create(pps_class, pps->info.dev, devt, pps, |
eae9d2ba | 373 | "pps%d", pps->id); |
668f06b9 EG |
374 | if (IS_ERR(pps->dev)) { |
375 | err = PTR_ERR(pps->dev); | |
eae9d2ba | 376 | goto del_cdev; |
668f06b9 | 377 | } |
eae9d2ba | 378 | |
d953e0e8 | 379 | /* Override the release function with our own */ |
083e5866 AG |
380 | pps->dev->release = pps_device_destruct; |
381 | ||
eae9d2ba RG |
382 | pr_debug("source %s got cdev (%d:%d)\n", pps->info.name, |
383 | MAJOR(pps_devt), pps->id); | |
384 | ||
385 | return 0; | |
386 | ||
387 | del_cdev: | |
388 | cdev_del(&pps->cdev); | |
389 | ||
083e5866 | 390 | free_idr: |
2a5cd6e2 | 391 | mutex_lock(&pps_idr_lock); |
083e5866 | 392 | idr_remove(&pps_idr, pps->id); |
19dd2da3 | 393 | out_unlock: |
2a5cd6e2 | 394 | mutex_unlock(&pps_idr_lock); |
eae9d2ba RG |
395 | return err; |
396 | } | |
397 | ||
398 | void pps_unregister_cdev(struct pps_device *pps) | |
399 | { | |
d953e0e8 | 400 | pr_debug("unregistering pps%d\n", pps->id); |
513b032c | 401 | pps->lookup_cookie = NULL; |
5e196d34 | 402 | device_destroy(pps_class, pps->dev->devt); |
eae9d2ba RG |
403 | } |
404 | ||
513b032c GS |
405 | /* |
406 | * Look up a pps device by magic cookie. | |
407 | * The cookie is usually a pointer to some enclosing device, but this | |
408 | * code doesn't care; you should never be dereferencing it. | |
409 | * | |
410 | * This is a bit of a kludge that is currently used only by the PPS | |
411 | * serial line discipline. It may need to be tweaked when a second user | |
412 | * is found. | |
413 | * | |
414 | * There is no function interface for setting the lookup_cookie field. | |
415 | * It's initialized to NULL when the pps device is created, and if a | |
416 | * client wants to use it, just fill it in afterward. | |
417 | * | |
418 | * The cookie is automatically set to NULL in pps_unregister_source() | |
419 | * so that it will not be used again, even if the pps device cannot | |
420 | * be removed from the idr due to pending references holding the minor | |
421 | * number in use. | |
422 | */ | |
423 | struct pps_device *pps_lookup_dev(void const *cookie) | |
424 | { | |
425 | struct pps_device *pps; | |
426 | unsigned id; | |
427 | ||
428 | rcu_read_lock(); | |
429 | idr_for_each_entry(&pps_idr, pps, id) | |
430 | if (cookie == pps->lookup_cookie) | |
431 | break; | |
432 | rcu_read_unlock(); | |
433 | return pps; | |
434 | } | |
435 | EXPORT_SYMBOL(pps_lookup_dev); | |
436 | ||
eae9d2ba RG |
437 | /* |
438 | * Module stuff | |
439 | */ | |
440 | ||
441 | static void __exit pps_exit(void) | |
442 | { | |
443 | class_destroy(pps_class); | |
444 | unregister_chrdev_region(pps_devt, PPS_MAX_SOURCES); | |
445 | } | |
446 | ||
447 | static int __init pps_init(void) | |
448 | { | |
449 | int err; | |
450 | ||
451 | pps_class = class_create(THIS_MODULE, "pps"); | |
7ad12566 | 452 | if (IS_ERR(pps_class)) { |
7f7cce74 | 453 | pr_err("failed to allocate class\n"); |
7ad12566 | 454 | return PTR_ERR(pps_class); |
eae9d2ba | 455 | } |
bd0eae4e | 456 | pps_class->dev_groups = pps_groups; |
eae9d2ba RG |
457 | |
458 | err = alloc_chrdev_region(&pps_devt, 0, PPS_MAX_SOURCES, "pps"); | |
459 | if (err < 0) { | |
7f7cce74 | 460 | pr_err("failed to allocate char device region\n"); |
eae9d2ba RG |
461 | goto remove_class; |
462 | } | |
463 | ||
464 | pr_info("LinuxPPS API ver. %d registered\n", PPS_API_VERS); | |
465 | pr_info("Software ver. %s - Copyright 2005-2007 Rodolfo Giometti " | |
466 | "<giometti@linux.it>\n", PPS_VERSION); | |
467 | ||
468 | return 0; | |
469 | ||
470 | remove_class: | |
471 | class_destroy(pps_class); | |
472 | ||
473 | return err; | |
474 | } | |
475 | ||
476 | subsys_initcall(pps_init); | |
477 | module_exit(pps_exit); | |
478 | ||
479 | MODULE_AUTHOR("Rodolfo Giometti <giometti@linux.it>"); | |
480 | MODULE_DESCRIPTION("LinuxPPS support (RFC 2783) - ver. " PPS_VERSION); | |
481 | MODULE_LICENSE("GPL"); |