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/posix-clock.h>
13 #include <linux/pps_kernel.h>
14 #include <linux/slab.h>
15 #include <linux/syscalls.h>
16 #include <linux/uaccess.h>
17 #include <linux/debugfs.h>
18 #include <linux/xarray.h>
19 #include <uapi/linux/sched/types.h>
20
21 #include "ptp_private.h"
22
23 #define PTP_MAX_ALARMS 4
24 #define PTP_PPS_DEFAULTS (PPS_CAPTUREASSERT | PPS_OFFSETASSERT)
25 #define PTP_PPS_EVENT PPS_CAPTUREASSERT
26 #define PTP_PPS_MODE (PTP_PPS_DEFAULTS | PPS_CANWAIT | PPS_TSFMT_TSPEC)
27
28 const struct class ptp_class = {
29 .name = "ptp",
30 .dev_groups = ptp_groups
31 };
32
33 /* private globals */
34
35 static dev_t ptp_devt;
36
37 static DEFINE_XARRAY_ALLOC(ptp_clocks_map);
38
39 /* time stamp event queue operations */
40
queue_free(struct timestamp_event_queue * q)41 static inline int queue_free(struct timestamp_event_queue *q)
42 {
43 return PTP_MAX_TIMESTAMPS - queue_cnt(q) - 1;
44 }
45
enqueue_external_timestamp(struct timestamp_event_queue * queue,struct ptp_clock_event * src)46 static void enqueue_external_timestamp(struct timestamp_event_queue *queue,
47 struct ptp_clock_event *src)
48 {
49 struct ptp_extts_event *dst;
50 struct timespec64 offset_ts;
51 unsigned long flags;
52 s64 seconds;
53 u32 remainder;
54
55 if (src->type == PTP_CLOCK_EXTTS) {
56 seconds = div_u64_rem(src->timestamp, 1000000000, &remainder);
57 } else if (src->type == PTP_CLOCK_EXTOFF) {
58 offset_ts = ns_to_timespec64(src->offset);
59 seconds = offset_ts.tv_sec;
60 remainder = offset_ts.tv_nsec;
61 } else {
62 WARN(1, "%s: unknown type %d\n", __func__, src->type);
63 return;
64 }
65
66 spin_lock_irqsave(&queue->lock, flags);
67
68 dst = &queue->buf[queue->tail];
69 dst->index = src->index;
70 dst->flags = PTP_EXTTS_EVENT_VALID;
71 dst->t.sec = seconds;
72 dst->t.nsec = remainder;
73 if (src->type == PTP_CLOCK_EXTOFF)
74 dst->flags |= PTP_EXT_OFFSET;
75
76 /* Both WRITE_ONCE() are paired with READ_ONCE() in queue_cnt() */
77 if (!queue_free(queue))
78 WRITE_ONCE(queue->head, (queue->head + 1) % PTP_MAX_TIMESTAMPS);
79
80 WRITE_ONCE(queue->tail, (queue->tail + 1) % PTP_MAX_TIMESTAMPS);
81
82 spin_unlock_irqrestore(&queue->lock, flags);
83 }
84
85 /* posix clock implementation */
86
ptp_clock_getres(struct posix_clock * pc,struct timespec64 * tp)87 static int ptp_clock_getres(struct posix_clock *pc, struct timespec64 *tp)
88 {
89 tp->tv_sec = 0;
90 tp->tv_nsec = 1;
91 return 0;
92 }
93
ptp_clock_settime(struct posix_clock * pc,const struct timespec64 * tp)94 static int ptp_clock_settime(struct posix_clock *pc, const struct timespec64 *tp)
95 {
96 struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
97
98 if (ptp_clock_freerun(ptp)) {
99 pr_err("ptp: physical clock is free running\n");
100 return -EBUSY;
101 }
102
103 return ptp->info->settime64(ptp->info, tp);
104 }
105
ptp_clock_gettime(struct posix_clock * pc,struct timespec64 * tp)106 static int ptp_clock_gettime(struct posix_clock *pc, struct timespec64 *tp)
107 {
108 struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
109 int err;
110
111 if (ptp->info->gettimex64)
112 err = ptp->info->gettimex64(ptp->info, tp, NULL);
113 else
114 err = ptp->info->gettime64(ptp->info, tp);
115 return err;
116 }
117
ptp_clock_adjtime(struct posix_clock * pc,struct __kernel_timex * tx)118 static int ptp_clock_adjtime(struct posix_clock *pc, struct __kernel_timex *tx)
119 {
120 struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
121 struct ptp_clock_info *ops;
122 int err = -EOPNOTSUPP;
123
124 if (ptp_clock_freerun(ptp)) {
125 pr_err("ptp: physical clock is free running\n");
126 return -EBUSY;
127 }
128
129 ops = ptp->info;
130
131 if (tx->modes & ADJ_SETOFFSET) {
132 struct timespec64 ts;
133 ktime_t kt;
134 s64 delta;
135
136 ts.tv_sec = tx->time.tv_sec;
137 ts.tv_nsec = tx->time.tv_usec;
138
139 if (!(tx->modes & ADJ_NANO))
140 ts.tv_nsec *= 1000;
141
142 if ((unsigned long) ts.tv_nsec >= NSEC_PER_SEC)
143 return -EINVAL;
144
145 kt = timespec64_to_ktime(ts);
146 delta = ktime_to_ns(kt);
147 err = ops->adjtime(ops, delta);
148 } else if (tx->modes & ADJ_FREQUENCY) {
149 long ppb = scaled_ppm_to_ppb(tx->freq);
150 if (ppb > ops->max_adj || ppb < -ops->max_adj)
151 return -ERANGE;
152 err = ops->adjfine(ops, tx->freq);
153 if (!err)
154 ptp->dialed_frequency = tx->freq;
155 } else if (tx->modes & ADJ_OFFSET) {
156 if (ops->adjphase) {
157 s32 max_phase_adj = ops->getmaxphase(ops);
158 s32 offset = tx->offset;
159
160 if (!(tx->modes & ADJ_NANO))
161 offset *= NSEC_PER_USEC;
162
163 if (offset > max_phase_adj || offset < -max_phase_adj)
164 return -ERANGE;
165
166 err = ops->adjphase(ops, offset);
167 }
168 } else if (tx->modes == 0) {
169 tx->freq = ptp->dialed_frequency;
170 err = 0;
171 }
172
173 return err;
174 }
175
176 static struct posix_clock_operations ptp_clock_ops = {
177 .owner = THIS_MODULE,
178 .clock_adjtime = ptp_clock_adjtime,
179 .clock_gettime = ptp_clock_gettime,
180 .clock_getres = ptp_clock_getres,
181 .clock_settime = ptp_clock_settime,
182 .ioctl = ptp_ioctl,
183 .open = ptp_open,
184 .release = ptp_release,
185 .poll = ptp_poll,
186 .read = ptp_read,
187 };
188
ptp_clock_release(struct device * dev)189 static void ptp_clock_release(struct device *dev)
190 {
191 struct ptp_clock *ptp = container_of(dev, struct ptp_clock, dev);
192 struct timestamp_event_queue *tsevq;
193 unsigned long flags;
194
195 ptp_cleanup_pin_groups(ptp);
196 kfree(ptp->vclock_index);
197 mutex_destroy(&ptp->pincfg_mux);
198 mutex_destroy(&ptp->n_vclocks_mux);
199 /* Delete first entry */
200 spin_lock_irqsave(&ptp->tsevqs_lock, flags);
201 tsevq = list_first_entry(&ptp->tsevqs, struct timestamp_event_queue,
202 qlist);
203 list_del(&tsevq->qlist);
204 spin_unlock_irqrestore(&ptp->tsevqs_lock, flags);
205 bitmap_free(tsevq->mask);
206 kfree(tsevq);
207 debugfs_remove(ptp->debugfs_root);
208 xa_erase(&ptp_clocks_map, ptp->index);
209 kfree(ptp);
210 }
211
ptp_getcycles64(struct ptp_clock_info * info,struct timespec64 * ts)212 static int ptp_getcycles64(struct ptp_clock_info *info, struct timespec64 *ts)
213 {
214 if (info->getcyclesx64)
215 return info->getcyclesx64(info, ts, NULL);
216 else
217 return info->gettime64(info, ts);
218 }
219
ptp_enable(struct ptp_clock_info * ptp,struct ptp_clock_request * request,int on)220 static int ptp_enable(struct ptp_clock_info *ptp, struct ptp_clock_request *request, int on)
221 {
222 return -EOPNOTSUPP;
223 }
224
ptp_aux_kworker(struct kthread_work * work)225 static void ptp_aux_kworker(struct kthread_work *work)
226 {
227 struct ptp_clock *ptp = container_of(work, struct ptp_clock,
228 aux_work.work);
229 struct ptp_clock_info *info = ptp->info;
230 long delay;
231
232 delay = info->do_aux_work(info);
233
234 if (delay >= 0)
235 kthread_queue_delayed_work(ptp->kworker, &ptp->aux_work, delay);
236 }
237
238 /* public interface */
239
ptp_clock_register(struct ptp_clock_info * info,struct device * parent)240 struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
241 struct device *parent)
242 {
243 struct ptp_clock *ptp;
244 struct timestamp_event_queue *queue = NULL;
245 int err, index, major = MAJOR(ptp_devt);
246 char debugfsname[16];
247 size_t size;
248
249 if (info->n_alarm > PTP_MAX_ALARMS)
250 return ERR_PTR(-EINVAL);
251
252 /* Initialize a clock structure. */
253 ptp = kzalloc(sizeof(struct ptp_clock), GFP_KERNEL);
254 if (!ptp) {
255 err = -ENOMEM;
256 goto no_memory;
257 }
258
259 err = xa_alloc(&ptp_clocks_map, &index, ptp, xa_limit_31b,
260 GFP_KERNEL);
261 if (err)
262 goto no_slot;
263
264 ptp->clock.ops = ptp_clock_ops;
265 ptp->info = info;
266 ptp->devid = MKDEV(major, index);
267 ptp->index = index;
268 INIT_LIST_HEAD(&ptp->tsevqs);
269 queue = kzalloc(sizeof(*queue), GFP_KERNEL);
270 if (!queue) {
271 err = -ENOMEM;
272 goto no_memory_queue;
273 }
274 list_add_tail(&queue->qlist, &ptp->tsevqs);
275 spin_lock_init(&ptp->tsevqs_lock);
276 queue->mask = bitmap_alloc(PTP_MAX_CHANNELS, GFP_KERNEL);
277 if (!queue->mask) {
278 err = -ENOMEM;
279 goto no_memory_bitmap;
280 }
281 bitmap_set(queue->mask, 0, PTP_MAX_CHANNELS);
282 spin_lock_init(&queue->lock);
283 mutex_init(&ptp->pincfg_mux);
284 mutex_init(&ptp->n_vclocks_mux);
285 init_waitqueue_head(&ptp->tsev_wq);
286
287 if (ptp->info->getcycles64 || ptp->info->getcyclesx64) {
288 ptp->has_cycles = true;
289 if (!ptp->info->getcycles64 && ptp->info->getcyclesx64)
290 ptp->info->getcycles64 = ptp_getcycles64;
291 } else {
292 /* Free running cycle counter not supported, use time. */
293 ptp->info->getcycles64 = ptp_getcycles64;
294
295 if (ptp->info->gettimex64)
296 ptp->info->getcyclesx64 = ptp->info->gettimex64;
297
298 if (ptp->info->getcrosststamp)
299 ptp->info->getcrosscycles = ptp->info->getcrosststamp;
300 }
301
302 if (!ptp->info->enable)
303 ptp->info->enable = ptp_enable;
304
305 if (ptp->info->do_aux_work) {
306 kthread_init_delayed_work(&ptp->aux_work, ptp_aux_kworker);
307 ptp->kworker = kthread_run_worker(0, "ptp%d", ptp->index);
308 if (IS_ERR(ptp->kworker)) {
309 err = PTR_ERR(ptp->kworker);
310 pr_err("failed to create ptp aux_worker %d\n", err);
311 goto kworker_err;
312 }
313 }
314
315 /* PTP virtual clock is being registered under physical clock */
316 if (parent && parent->class && parent->class->name &&
317 strcmp(parent->class->name, "ptp") == 0)
318 ptp->is_virtual_clock = true;
319
320 if (!ptp->is_virtual_clock) {
321 ptp->max_vclocks = PTP_DEFAULT_MAX_VCLOCKS;
322
323 size = sizeof(int) * ptp->max_vclocks;
324 ptp->vclock_index = kzalloc(size, GFP_KERNEL);
325 if (!ptp->vclock_index) {
326 err = -ENOMEM;
327 goto no_mem_for_vclocks;
328 }
329 }
330
331 err = ptp_populate_pin_groups(ptp);
332 if (err)
333 goto no_pin_groups;
334
335 /* Register a new PPS source. */
336 if (info->pps) {
337 struct pps_source_info pps;
338 memset(&pps, 0, sizeof(pps));
339 snprintf(pps.name, PPS_MAX_NAME_LEN, "ptp%d", index);
340 pps.mode = PTP_PPS_MODE;
341 pps.owner = info->owner;
342 ptp->pps_source = pps_register_source(&pps, PTP_PPS_DEFAULTS);
343 if (IS_ERR(ptp->pps_source)) {
344 err = PTR_ERR(ptp->pps_source);
345 pr_err("failed to register pps source\n");
346 goto no_pps;
347 }
348 ptp->pps_source->lookup_cookie = ptp;
349 }
350
351 /* Initialize a new device of our class in our clock structure. */
352 device_initialize(&ptp->dev);
353 ptp->dev.devt = ptp->devid;
354 ptp->dev.class = &ptp_class;
355 ptp->dev.parent = parent;
356 ptp->dev.groups = ptp->pin_attr_groups;
357 ptp->dev.release = ptp_clock_release;
358 dev_set_drvdata(&ptp->dev, ptp);
359 dev_set_name(&ptp->dev, "ptp%d", ptp->index);
360
361 /* Create a posix clock and link it to the device. */
362 err = posix_clock_register(&ptp->clock, &ptp->dev);
363 if (err) {
364 if (ptp->pps_source)
365 pps_unregister_source(ptp->pps_source);
366
367 if (ptp->kworker)
368 kthread_destroy_worker(ptp->kworker);
369
370 put_device(&ptp->dev);
371
372 pr_err("failed to create posix clock\n");
373 return ERR_PTR(err);
374 }
375
376 /* Debugfs initialization */
377 snprintf(debugfsname, sizeof(debugfsname), "ptp%d", ptp->index);
378 ptp->debugfs_root = debugfs_create_dir(debugfsname, NULL);
379
380 return ptp;
381
382 no_pps:
383 ptp_cleanup_pin_groups(ptp);
384 no_pin_groups:
385 kfree(ptp->vclock_index);
386 no_mem_for_vclocks:
387 if (ptp->kworker)
388 kthread_destroy_worker(ptp->kworker);
389 kworker_err:
390 mutex_destroy(&ptp->pincfg_mux);
391 mutex_destroy(&ptp->n_vclocks_mux);
392 bitmap_free(queue->mask);
393 no_memory_bitmap:
394 list_del(&queue->qlist);
395 kfree(queue);
396 no_memory_queue:
397 xa_erase(&ptp_clocks_map, index);
398 no_slot:
399 kfree(ptp);
400 no_memory:
401 return ERR_PTR(err);
402 }
403 EXPORT_SYMBOL(ptp_clock_register);
404
unregister_vclock(struct device * dev,void * data)405 static int unregister_vclock(struct device *dev, void *data)
406 {
407 struct ptp_clock *ptp = dev_get_drvdata(dev);
408
409 ptp_vclock_unregister(info_to_vclock(ptp->info));
410 return 0;
411 }
412
ptp_clock_unregister(struct ptp_clock * ptp)413 int ptp_clock_unregister(struct ptp_clock *ptp)
414 {
415 if (ptp_vclock_in_use(ptp)) {
416 device_for_each_child(&ptp->dev, NULL, unregister_vclock);
417 }
418
419 ptp->defunct = 1;
420 wake_up_interruptible(&ptp->tsev_wq);
421
422 if (ptp->kworker) {
423 kthread_cancel_delayed_work_sync(&ptp->aux_work);
424 kthread_destroy_worker(ptp->kworker);
425 }
426
427 /* Release the clock's resources. */
428 if (ptp->pps_source)
429 pps_unregister_source(ptp->pps_source);
430
431 posix_clock_unregister(&ptp->clock);
432
433 return 0;
434 }
435 EXPORT_SYMBOL(ptp_clock_unregister);
436
ptp_clock_event(struct ptp_clock * ptp,struct ptp_clock_event * event)437 void ptp_clock_event(struct ptp_clock *ptp, struct ptp_clock_event *event)
438 {
439 struct timestamp_event_queue *tsevq;
440 struct pps_event_time evt;
441 unsigned long flags;
442
443 switch (event->type) {
444
445 case PTP_CLOCK_ALARM:
446 break;
447
448 case PTP_CLOCK_EXTTS:
449 case PTP_CLOCK_EXTOFF:
450 /* Enqueue timestamp on selected queues */
451 spin_lock_irqsave(&ptp->tsevqs_lock, flags);
452 list_for_each_entry(tsevq, &ptp->tsevqs, qlist) {
453 if (test_bit((unsigned int)event->index, tsevq->mask))
454 enqueue_external_timestamp(tsevq, event);
455 }
456 spin_unlock_irqrestore(&ptp->tsevqs_lock, flags);
457 wake_up_interruptible(&ptp->tsev_wq);
458 break;
459
460 case PTP_CLOCK_PPS:
461 pps_get_ts(&evt);
462 pps_event(ptp->pps_source, &evt, PTP_PPS_EVENT, NULL);
463 break;
464
465 case PTP_CLOCK_PPSUSR:
466 pps_event(ptp->pps_source, &event->pps_times,
467 PTP_PPS_EVENT, NULL);
468 break;
469 }
470 }
471 EXPORT_SYMBOL(ptp_clock_event);
472
ptp_clock_index(struct ptp_clock * ptp)473 int ptp_clock_index(struct ptp_clock *ptp)
474 {
475 return ptp->index;
476 }
477 EXPORT_SYMBOL(ptp_clock_index);
478
ptp_find_pin(struct ptp_clock * ptp,enum ptp_pin_function func,unsigned int chan)479 int ptp_find_pin(struct ptp_clock *ptp,
480 enum ptp_pin_function func, unsigned int chan)
481 {
482 struct ptp_pin_desc *pin = NULL;
483 int i;
484
485 for (i = 0; i < ptp->info->n_pins; i++) {
486 if (ptp->info->pin_config[i].func == func &&
487 ptp->info->pin_config[i].chan == chan) {
488 pin = &ptp->info->pin_config[i];
489 break;
490 }
491 }
492
493 return pin ? i : -1;
494 }
495 EXPORT_SYMBOL(ptp_find_pin);
496
ptp_find_pin_unlocked(struct ptp_clock * ptp,enum ptp_pin_function func,unsigned int chan)497 int ptp_find_pin_unlocked(struct ptp_clock *ptp,
498 enum ptp_pin_function func, unsigned int chan)
499 {
500 int result;
501
502 mutex_lock(&ptp->pincfg_mux);
503
504 result = ptp_find_pin(ptp, func, chan);
505
506 mutex_unlock(&ptp->pincfg_mux);
507
508 return result;
509 }
510 EXPORT_SYMBOL(ptp_find_pin_unlocked);
511
ptp_schedule_worker(struct ptp_clock * ptp,unsigned long delay)512 int ptp_schedule_worker(struct ptp_clock *ptp, unsigned long delay)
513 {
514 return kthread_mod_delayed_work(ptp->kworker, &ptp->aux_work, delay);
515 }
516 EXPORT_SYMBOL(ptp_schedule_worker);
517
ptp_cancel_worker_sync(struct ptp_clock * ptp)518 void ptp_cancel_worker_sync(struct ptp_clock *ptp)
519 {
520 kthread_cancel_delayed_work_sync(&ptp->aux_work);
521 }
522 EXPORT_SYMBOL(ptp_cancel_worker_sync);
523
524 /* module operations */
525
ptp_exit(void)526 static void __exit ptp_exit(void)
527 {
528 class_unregister(&ptp_class);
529 unregister_chrdev_region(ptp_devt, MINORMASK + 1);
530 xa_destroy(&ptp_clocks_map);
531 }
532
ptp_init(void)533 static int __init ptp_init(void)
534 {
535 int err;
536
537 err = class_register(&ptp_class);
538 if (err) {
539 pr_err("ptp: failed to allocate class\n");
540 return err;
541 }
542
543 err = alloc_chrdev_region(&ptp_devt, 0, MINORMASK + 1, "ptp");
544 if (err < 0) {
545 pr_err("ptp: failed to allocate device region\n");
546 goto no_region;
547 }
548
549 pr_info("PTP clock support registered\n");
550 return 0;
551
552 no_region:
553 class_unregister(&ptp_class);
554 return err;
555 }
556
557 subsys_initcall(ptp_init);
558 module_exit(ptp_exit);
559
560 MODULE_AUTHOR("Richard Cochran <richardcochran@gmail.com>");
561 MODULE_DESCRIPTION("PTP clocks support");
562 MODULE_LICENSE("GPL");
563