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