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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * PTP 1588 clock support
4 *
5 * Copyright (C) 2010 OMICRON electronics GmbH
6 */
7#include <linux/device.h>
8#include <linux/err.h>
9#include <linux/init.h>
10#include <linux/kernel.h>
11#include <linux/module.h>
12#include <linux/overflow.h>
13#include <linux/posix-clock.h>
14#include <linux/pps_kernel.h>
15#include <linux/property.h>
16#include <linux/slab.h>
17#include <linux/syscalls.h>
18#include <linux/uaccess.h>
19#include <linux/debugfs.h>
20#include <linux/xarray.h>
21#include <uapi/linux/sched/types.h>
22
23#include "ptp_private.h"
24
25#define PTP_MAX_ALARMS 4
26#define PTP_PPS_DEFAULTS (PPS_CAPTUREASSERT | PPS_OFFSETASSERT)
27#define PTP_PPS_EVENT PPS_CAPTUREASSERT
28#define PTP_PPS_MODE (PTP_PPS_DEFAULTS | PPS_CANWAIT | PPS_TSFMT_TSPEC)
29
30const struct class ptp_class = {
31 .name = "ptp",
32 .dev_groups = ptp_groups
33};
34
35/* private globals */
36
37static dev_t ptp_devt;
38
39static DEFINE_XARRAY_ALLOC(ptp_clocks_map);
40
41/* time stamp event queue operations */
42
43static inline int queue_free(struct timestamp_event_queue *q)
44{
45 return PTP_MAX_TIMESTAMPS - queue_cnt(q) - 1;
46}
47
48static void enqueue_external_timestamp(struct timestamp_event_queue *queue,
49 struct ptp_clock_event *src)
50{
51 struct ptp_extts_event *dst;
52 struct timespec64 offset_ts;
53 unsigned long flags;
54 s64 seconds;
55 u32 remainder;
56
57 if (src->type == PTP_CLOCK_EXTTS) {
58 seconds = div_u64_rem(src->timestamp, 1000000000, &remainder);
59 } else if (src->type == PTP_CLOCK_EXTOFF) {
60 offset_ts = ns_to_timespec64(src->offset);
61 seconds = offset_ts.tv_sec;
62 remainder = offset_ts.tv_nsec;
63 } else {
64 WARN(1, "%s: unknown type %d\n", __func__, src->type);
65 return;
66 }
67
68 spin_lock_irqsave(&queue->lock, flags);
69
70 dst = &queue->buf[queue->tail];
71 dst->index = src->index;
72 dst->flags = PTP_EXTTS_EVENT_VALID;
73 dst->t.sec = seconds;
74 dst->t.nsec = remainder;
75 if (src->type == PTP_CLOCK_EXTOFF)
76 dst->flags |= PTP_EXT_OFFSET;
77
78 /* Both WRITE_ONCE() are paired with READ_ONCE() in queue_cnt() */
79 if (!queue_free(queue))
80 WRITE_ONCE(queue->head, (queue->head + 1) % PTP_MAX_TIMESTAMPS);
81
82 WRITE_ONCE(queue->tail, (queue->tail + 1) % PTP_MAX_TIMESTAMPS);
83
84 spin_unlock_irqrestore(&queue->lock, flags);
85}
86
87/* posix clock implementation */
88
89static int ptp_clock_getres(struct posix_clock *pc, struct timespec64 *tp)
90{
91 tp->tv_sec = 0;
92 tp->tv_nsec = 1;
93 return 0;
94}
95
96static int ptp_clock_settime(struct posix_clock *pc, const struct timespec64 *tp)
97{
98 struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
99
100 if (ptp_clock_freerun(ptp)) {
101 pr_err_ratelimited("ptp: physical clock is free running\n");
102 return -EBUSY;
103 }
104
105 if (!timespec64_valid_settod(tp))
106 return -EINVAL;
107
108 return ptp->info->settime64(ptp->info, tp);
109}
110
111static int ptp_clock_gettime(struct posix_clock *pc, struct timespec64 *tp)
112{
113 struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
114 int err;
115
116 if (ptp->info->gettimex64)
117 err = ptp->info->gettimex64(ptp->info, tp, NULL);
118 else
119 err = ptp->info->gettime64(ptp->info, tp);
120 return err;
121}
122
123static int ptp_clock_adjtime(struct posix_clock *pc, struct __kernel_timex *tx)
124{
125 struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
126 struct ptp_clock_info *ops;
127 int err = -EOPNOTSUPP;
128
129 if (tx->modes & (ADJ_SETOFFSET | ADJ_FREQUENCY | ADJ_OFFSET) &&
130 ptp_clock_freerun(ptp)) {
131 pr_err("ptp: physical clock is free running\n");
132 return -EBUSY;
133 }
134
135 ops = ptp->info;
136
137 if (tx->modes & ADJ_SETOFFSET) {
138 struct timespec64 ts, ts2;
139 ktime_t kt;
140 s64 delta;
141
142 ts.tv_sec = tx->time.tv_sec;
143 ts.tv_nsec = tx->time.tv_usec;
144
145 if (!(tx->modes & ADJ_NANO))
146 ts.tv_nsec *= 1000;
147
148 if ((unsigned long) ts.tv_nsec >= NSEC_PER_SEC)
149 return -EINVAL;
150
151 /* Make sure the offset is valid */
152 err = ptp_clock_gettime(pc, &ts2);
153 if (err)
154 return err;
155 ts2 = timespec64_add(ts2, ts);
156 if (!timespec64_valid_settod(&ts2))
157 return -EINVAL;
158
159 kt = timespec64_to_ktime(ts);
160 delta = ktime_to_ns(kt);
161 err = ops->adjtime(ops, delta);
162 } else if (tx->modes & ADJ_FREQUENCY) {
163 long ppb;
164 s64 tmp;
165
166 /*
167 * scaled_ppm_to_ppb() multiplies (1 + freq) by 125 in s64;
168 * reject a ->freq large enough to overflow that, which would
169 * otherwise wrap the result back into the max_adj range.
170 */
171 if (check_add_overflow((s64)tx->freq, (s64)1, &tmp) ||
172 check_mul_overflow(tmp, (s64)125, &tmp))
173 return -ERANGE;
174 ppb = scaled_ppm_to_ppb(tx->freq);
175 if (ppb > ops->max_adj || ppb < -ops->max_adj)
176 return -ERANGE;
177 err = ops->adjfine(ops, tx->freq);
178 if (!err)
179 ptp->dialed_frequency = tx->freq;
180 } else if (tx->modes & ADJ_OFFSET) {
181 if (ops->adjphase) {
182 s32 max_phase_adj = ops->getmaxphase(ops);
183 s32 offset = tx->offset;
184
185 if (!(tx->modes & ADJ_NANO))
186 offset *= NSEC_PER_USEC;
187
188 if (offset > max_phase_adj || offset < -max_phase_adj)
189 return -ERANGE;
190
191 err = ops->adjphase(ops, offset);
192 }
193 } else if (tx->modes == 0) {
194 tx->freq = ptp->dialed_frequency;
195 err = 0;
196 }
197
198 return err;
199}
200
201static struct posix_clock_operations ptp_clock_ops = {
202 .owner = THIS_MODULE,
203 .clock_adjtime = ptp_clock_adjtime,
204 .clock_gettime = ptp_clock_gettime,
205 .clock_getres = ptp_clock_getres,
206 .clock_settime = ptp_clock_settime,
207 .ioctl = ptp_ioctl,
208 .open = ptp_open,
209 .release = ptp_release,
210 .poll = ptp_poll,
211 .read = ptp_read,
212};
213
214static void ptp_clock_release(struct device *dev)
215{
216 struct ptp_clock *ptp = container_of(dev, struct ptp_clock, dev);
217 struct timestamp_event_queue *tsevq;
218 unsigned long flags;
219
220 ptp_cleanup_pin_groups(ptp);
221 kfree(ptp->vclock_index);
222 mutex_destroy(&ptp->pincfg_mux);
223 mutex_destroy(&ptp->n_vclocks_mux);
224 /* Delete first entry */
225 spin_lock_irqsave(&ptp->tsevqs_lock, flags);
226 tsevq = list_first_entry(&ptp->tsevqs, struct timestamp_event_queue,
227 qlist);
228 list_del(&tsevq->qlist);
229 spin_unlock_irqrestore(&ptp->tsevqs_lock, flags);
230 bitmap_free(tsevq->mask);
231 kfree(tsevq);
232 debugfs_remove(ptp->debugfs_root);
233 xa_erase(&ptp_clocks_map, ptp->index);
234 kfree(ptp);
235}
236
237static int ptp_getcycles64(struct ptp_clock_info *info, struct timespec64 *ts)
238{
239 if (info->getcyclesx64)
240 return info->getcyclesx64(info, ts, NULL);
241 else
242 return info->gettime64(info, ts);
243}
244
245static int ptp_enable(struct ptp_clock_info *ptp, struct ptp_clock_request *request, int on)
246{
247 return -EOPNOTSUPP;
248}
249
250static void ptp_aux_kworker(struct kthread_work *work)
251{
252 struct ptp_clock *ptp = container_of(work, struct ptp_clock,
253 aux_work.work);
254 struct ptp_clock_info *info = ptp->info;
255 long delay;
256
257 delay = info->do_aux_work(info);
258
259 if (delay >= 0)
260 kthread_queue_delayed_work(ptp->kworker, &ptp->aux_work, delay);
261}
262
263static ssize_t ptp_n_perout_loopback_read(struct file *filep,
264 char __user *buffer,
265 size_t count, loff_t *pos)
266{
267 struct ptp_clock *ptp = filep->private_data;
268 char buf[12] = {};
269
270 snprintf(buf, sizeof(buf), "%d\n", ptp->info->n_per_lp);
271
272 return simple_read_from_buffer(buffer, count, pos, buf, strlen(buf));
273}
274
275static const struct file_operations ptp_n_perout_loopback_fops = {
276 .owner = THIS_MODULE,
277 .open = simple_open,
278 .read = ptp_n_perout_loopback_read,
279};
280
281static ssize_t ptp_perout_loopback_write(struct file *filep,
282 const char __user *buffer,
283 size_t count, loff_t *ppos)
284{
285 struct ptp_clock *ptp = filep->private_data;
286 struct ptp_clock_info *ops = ptp->info;
287 unsigned int index, enable;
288 int len, cnt, err;
289 char buf[32] = {};
290
291 if (*ppos || !count)
292 return -EINVAL;
293
294 if (count >= sizeof(buf))
295 return -ENOSPC;
296
297 len = simple_write_to_buffer(buf, sizeof(buf) - 1,
298 ppos, buffer, count);
299 if (len < 0)
300 return len;
301
302 buf[len] = '\0';
303 cnt = sscanf(buf, "%u %u", &index, &enable);
304 if (cnt != 2)
305 return -EINVAL;
306
307 if (index >= ops->n_per_lp)
308 return -EINVAL;
309
310 if (enable != 0 && enable != 1)
311 return -EINVAL;
312
313 err = ops->perout_loopback(ops, index, enable);
314 if (err)
315 return err;
316
317 return count;
318}
319
320static const struct file_operations ptp_perout_loopback_ops = {
321 .owner = THIS_MODULE,
322 .open = simple_open,
323 .write = ptp_perout_loopback_write,
324};
325
326/* public interface */
327
328struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
329 struct device *parent)
330{
331 struct ptp_clock *ptp;
332 struct timestamp_event_queue *queue = NULL;
333 int err, index, major = MAJOR(ptp_devt);
334 char debugfsname[16];
335 size_t size;
336
337 if (WARN_ON_ONCE(info->n_alarm > PTP_MAX_ALARMS ||
338 (!info->gettimex64 && !info->gettime64) ||
339 !info->settime64))
340 return ERR_PTR(-EINVAL);
341
342 /* Initialize a clock structure. */
343 ptp = kzalloc_obj(struct ptp_clock);
344 if (!ptp) {
345 err = -ENOMEM;
346 goto no_memory;
347 }
348
349 err = xa_alloc(&ptp_clocks_map, &index, ptp, xa_limit_31b,
350 GFP_KERNEL);
351 if (err)
352 goto no_slot;
353
354 ptp->clock.ops = ptp_clock_ops;
355 ptp->info = info;
356 ptp->devid = MKDEV(major, index);
357 ptp->index = index;
358 INIT_LIST_HEAD(&ptp->tsevqs);
359 queue = kzalloc_obj(*queue);
360 if (!queue) {
361 err = -ENOMEM;
362 goto no_memory_queue;
363 }
364 list_add_tail(&queue->qlist, &ptp->tsevqs);
365 spin_lock_init(&ptp->tsevqs_lock);
366 queue->mask = bitmap_alloc(PTP_MAX_CHANNELS, GFP_KERNEL);
367 if (!queue->mask) {
368 err = -ENOMEM;
369 goto no_memory_bitmap;
370 }
371 bitmap_set(queue->mask, 0, PTP_MAX_CHANNELS);
372 spin_lock_init(&queue->lock);
373 mutex_init(&ptp->pincfg_mux);
374 mutex_init(&ptp->n_vclocks_mux);
375 init_waitqueue_head(&ptp->tsev_wq);
376
377 if (ptp->info->getcycles64 || ptp->info->getcyclesx64) {
378 ptp->has_cycles = true;
379 if (!ptp->info->getcycles64 && ptp->info->getcyclesx64)
380 ptp->info->getcycles64 = ptp_getcycles64;
381 } else {
382 /* Free running cycle counter not supported, use time. */
383 ptp->info->getcycles64 = ptp_getcycles64;
384
385 if (ptp->info->gettimex64)
386 ptp->info->getcyclesx64 = ptp->info->gettimex64;
387
388 if (ptp->info->getcrosststamp)
389 ptp->info->getcrosscycles = ptp->info->getcrosststamp;
390 }
391
392 if (!ptp->info->enable)
393 ptp->info->enable = ptp_enable;
394
395 if (ptp->info->do_aux_work) {
396 kthread_init_delayed_work(&ptp->aux_work, ptp_aux_kworker);
397 ptp->kworker = kthread_run_worker(0, "ptp%d", ptp->index);
398 if (IS_ERR(ptp->kworker)) {
399 err = PTR_ERR(ptp->kworker);
400 pr_err("failed to create ptp aux_worker %d\n", err);
401 goto kworker_err;
402 }
403 }
404
405 /* PTP virtual clock is being registered under physical clock */
406 if (parent && parent->class && parent->class->name &&
407 strcmp(parent->class->name, "ptp") == 0)
408 ptp->is_virtual_clock = true;
409
410 if (!ptp->is_virtual_clock) {
411 ptp->max_vclocks = PTP_DEFAULT_MAX_VCLOCKS;
412
413 size = sizeof(int) * ptp->max_vclocks;
414 ptp->vclock_index = kzalloc(size, GFP_KERNEL);
415 if (!ptp->vclock_index) {
416 err = -ENOMEM;
417 goto no_mem_for_vclocks;
418 }
419 }
420
421 err = ptp_populate_pin_groups(ptp);
422 if (err)
423 goto no_pin_groups;
424
425 /* Register a new PPS source. */
426 if (info->pps) {
427 struct pps_source_info pps;
428 memset(&pps, 0, sizeof(pps));
429 snprintf(pps.name, PPS_MAX_NAME_LEN, "ptp%d", index);
430 pps.mode = PTP_PPS_MODE;
431 pps.owner = info->owner;
432 ptp->pps_source = pps_register_source(&pps, PTP_PPS_DEFAULTS);
433 if (IS_ERR(ptp->pps_source)) {
434 err = PTR_ERR(ptp->pps_source);
435 pr_err("failed to register pps source\n");
436 goto no_pps;
437 }
438 ptp->pps_source->lookup_cookie = ptp;
439 }
440
441 /* Initialize a new device of our class in our clock structure. */
442 device_initialize(&ptp->dev);
443 ptp->dev.devt = ptp->devid;
444 ptp->dev.class = &ptp_class;
445 ptp->dev.parent = parent;
446 ptp->dev.groups = ptp->pin_attr_groups;
447 ptp->dev.release = ptp_clock_release;
448 dev_set_drvdata(&ptp->dev, ptp);
449 dev_set_name(&ptp->dev, "ptp%d", ptp->index);
450
451 /* Create a posix clock and link it to the device. */
452 err = posix_clock_register(&ptp->clock, &ptp->dev);
453 if (err) {
454 if (ptp->pps_source)
455 pps_unregister_source(ptp->pps_source);
456
457 if (ptp->kworker)
458 kthread_destroy_worker(ptp->kworker);
459
460 put_device(&ptp->dev);
461
462 pr_err("failed to create posix clock\n");
463 return ERR_PTR(err);
464 }
465
466 /* Debugfs initialization */
467 snprintf(debugfsname, sizeof(debugfsname), "ptp%d", ptp->index);
468 ptp->debugfs_root = debugfs_create_dir(debugfsname, NULL);
469 if (info->n_per_lp > 0 && info->perout_loopback) {
470 debugfs_create_file("n_perout_loopback", 0400, ptp->debugfs_root,
471 ptp, &ptp_n_perout_loopback_fops);
472 debugfs_create_file("perout_loopback", 0200, ptp->debugfs_root,
473 ptp, &ptp_perout_loopback_ops);
474 }
475
476 return ptp;
477
478no_pps:
479 ptp_cleanup_pin_groups(ptp);
480no_pin_groups:
481 kfree(ptp->vclock_index);
482no_mem_for_vclocks:
483 if (ptp->kworker)
484 kthread_destroy_worker(ptp->kworker);
485kworker_err:
486 mutex_destroy(&ptp->pincfg_mux);
487 mutex_destroy(&ptp->n_vclocks_mux);
488 bitmap_free(queue->mask);
489no_memory_bitmap:
490 list_del(&queue->qlist);
491 kfree(queue);
492no_memory_queue:
493 xa_erase(&ptp_clocks_map, index);
494no_slot:
495 kfree(ptp);
496no_memory:
497 return ERR_PTR(err);
498}
499EXPORT_SYMBOL(ptp_clock_register);
500
501static int unregister_vclock(struct device *dev, void *data)
502{
503 struct ptp_clock *ptp = dev_get_drvdata(dev);
504
505 ptp_vclock_unregister(info_to_vclock(ptp->info));
506 return 0;
507}
508
509int ptp_clock_unregister(struct ptp_clock *ptp)
510{
511 if (ptp_vclock_in_use(ptp)) {
512 device_for_each_child(&ptp->dev, NULL, unregister_vclock);
513 }
514
515 /* Get the device to stop posix_clock_unregister() doing the last put
516 * and freeing the structure(s)
517 */
518 get_device(&ptp->dev);
519
520 /* Wake up any userspace waiting for an event. */
521 ptp->defunct = 1;
522 wake_up_interruptible(&ptp->tsev_wq);
523
524 /* Tear down the POSIX clock, which removes the user interface. */
525 posix_clock_unregister(&ptp->clock);
526
527 /* Disable all sources of event generation. */
528 ptp_disable_all_events(ptp);
529
530 if (ptp->kworker) {
531 kthread_cancel_delayed_work_sync(&ptp->aux_work);
532 kthread_destroy_worker(ptp->kworker);
533 }
534
535 /* Release the clock's resources. */
536 if (ptp->pps_source)
537 pps_unregister_source(ptp->pps_source);
538
539 /* The final put, normally here, will invoke ptp_clock_release(). */
540 put_device(&ptp->dev);
541
542 return 0;
543}
544EXPORT_SYMBOL(ptp_clock_unregister);
545
546void ptp_clock_event(struct ptp_clock *ptp, struct ptp_clock_event *event)
547{
548 struct timestamp_event_queue *tsevq;
549 struct pps_event_time evt;
550 unsigned long flags;
551
552 switch (event->type) {
553
554 case PTP_CLOCK_ALARM:
555 break;
556
557 case PTP_CLOCK_EXTTS:
558 case PTP_CLOCK_EXTOFF:
559 /* Enqueue timestamp on selected queues */
560 spin_lock_irqsave(&ptp->tsevqs_lock, flags);
561 list_for_each_entry(tsevq, &ptp->tsevqs, qlist) {
562 if (test_bit((unsigned int)event->index, tsevq->mask))
563 enqueue_external_timestamp(tsevq, event);
564 }
565 spin_unlock_irqrestore(&ptp->tsevqs_lock, flags);
566 wake_up_interruptible(&ptp->tsev_wq);
567 break;
568
569 case PTP_CLOCK_PPS:
570 pps_get_ts(&evt);
571 pps_event(ptp->pps_source, &evt, PTP_PPS_EVENT, NULL);
572 break;
573
574 case PTP_CLOCK_PPSUSR:
575 pps_event(ptp->pps_source, &event->pps_times,
576 PTP_PPS_EVENT, NULL);
577 break;
578 }
579}
580EXPORT_SYMBOL(ptp_clock_event);
581
582int ptp_clock_index(struct ptp_clock *ptp)
583{
584 return ptp->index;
585}
586EXPORT_SYMBOL(ptp_clock_index);
587
588static int ptp_clock_of_node_match(struct device *dev, const void *data)
589{
590 const struct device_node *parent_np = data;
591
592 return (dev->parent && dev_of_node(dev->parent) == parent_np);
593}
594
595int ptp_clock_index_by_of_node(struct device_node *np)
596{
597 struct ptp_clock *ptp;
598 struct device *dev;
599 int phc_index;
600
601 dev = class_find_device(&ptp_class, NULL, np,
602 ptp_clock_of_node_match);
603 if (!dev)
604 return -1;
605
606 ptp = dev_get_drvdata(dev);
607 phc_index = ptp_clock_index(ptp);
608 put_device(dev);
609
610 return phc_index;
611}
612EXPORT_SYMBOL_GPL(ptp_clock_index_by_of_node);
613
614static int ptp_clock_dev_match(struct device *dev, const void *data)
615{
616 const struct device *parent = data;
617
618 return dev->parent == parent;
619}
620
621int ptp_clock_index_by_dev(struct device *parent)
622{
623 struct ptp_clock *ptp;
624 struct device *dev;
625 int phc_index;
626
627 dev = class_find_device(&ptp_class, NULL, parent,
628 ptp_clock_dev_match);
629 if (!dev)
630 return -1;
631
632 ptp = dev_get_drvdata(dev);
633 phc_index = ptp_clock_index(ptp);
634 put_device(dev);
635
636 return phc_index;
637}
638EXPORT_SYMBOL_GPL(ptp_clock_index_by_dev);
639
640int ptp_find_pin(struct ptp_clock *ptp,
641 enum ptp_pin_function func, unsigned int chan)
642{
643 struct ptp_pin_desc *pin = NULL;
644 int i;
645
646 for (i = 0; i < ptp->info->n_pins; i++) {
647 if (ptp->info->pin_config[i].func == func &&
648 ptp->info->pin_config[i].chan == chan) {
649 pin = &ptp->info->pin_config[i];
650 break;
651 }
652 }
653
654 return pin ? i : -1;
655}
656EXPORT_SYMBOL(ptp_find_pin);
657
658int ptp_find_pin_unlocked(struct ptp_clock *ptp,
659 enum ptp_pin_function func, unsigned int chan)
660{
661 int result;
662
663 mutex_lock(&ptp->pincfg_mux);
664
665 result = ptp_find_pin(ptp, func, chan);
666
667 mutex_unlock(&ptp->pincfg_mux);
668
669 return result;
670}
671EXPORT_SYMBOL(ptp_find_pin_unlocked);
672
673int ptp_schedule_worker(struct ptp_clock *ptp, unsigned long delay)
674{
675 return kthread_mod_delayed_work(ptp->kworker, &ptp->aux_work, delay);
676}
677EXPORT_SYMBOL(ptp_schedule_worker);
678
679void ptp_cancel_worker_sync(struct ptp_clock *ptp)
680{
681 kthread_cancel_delayed_work_sync(&ptp->aux_work);
682}
683EXPORT_SYMBOL(ptp_cancel_worker_sync);
684
685/* module operations */
686
687static void __exit ptp_exit(void)
688{
689 class_unregister(&ptp_class);
690 unregister_chrdev_region(ptp_devt, MINORMASK + 1);
691 xa_destroy(&ptp_clocks_map);
692}
693
694static int __init ptp_init(void)
695{
696 int err;
697
698 err = class_register(&ptp_class);
699 if (err) {
700 pr_err("ptp: failed to allocate class\n");
701 return err;
702 }
703
704 err = alloc_chrdev_region(&ptp_devt, 0, MINORMASK + 1, "ptp");
705 if (err < 0) {
706 pr_err("ptp: failed to allocate device region\n");
707 goto no_region;
708 }
709
710 pr_info("PTP clock support registered\n");
711 return 0;
712
713no_region:
714 class_unregister(&ptp_class);
715 return err;
716}
717
718subsys_initcall(ptp_init);
719module_exit(ptp_exit);
720
721MODULE_AUTHOR("Richard Cochran <[email protected]>");
722MODULE_DESCRIPTION("PTP clocks support");
723MODULE_LICENSE("GPL");