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
28struct class *ptp_class;
29
30/* private globals */
31
32static dev_t ptp_devt;
33
34static DEFINE_IDA(ptp_clocks_map);
35
36/* time stamp event queue operations */
37
38static inline int queue_free(struct timestamp_event_queue *q)
39{
40 return PTP_MAX_TIMESTAMPS - queue_cnt(q) - 1;
41}
42
43static 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
70static 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
77static 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
89static 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
101static 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
158static 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
171static 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
194static 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
202static 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
217struct 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
351no_pps:
352 ptp_cleanup_pin_groups(ptp);
353no_pin_groups:
354 kfree(objp: ptp->vclock_index);
355no_mem_for_vclocks:
356 if (ptp->kworker)
357 kthread_destroy_worker(worker: ptp->kworker);
358kworker_err:
359 mutex_destroy(lock: &ptp->pincfg_mux);
360 mutex_destroy(lock: &ptp->n_vclocks_mux);
361 bitmap_free(bitmap: queue->mask);
362no_memory_bitmap:
363 list_del(entry: &queue->qlist);
364 kfree(objp: queue);
365no_memory_queue:
366 ida_free(&ptp_clocks_map, id: index);
367no_slot:
368 kfree(objp: ptp);
369no_memory:
370 return ERR_PTR(error: err);
371}
372EXPORT_SYMBOL(ptp_clock_register);
373
374static 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
382int 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}
404EXPORT_SYMBOL(ptp_clock_unregister);
405
406void 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}
436EXPORT_SYMBOL(ptp_clock_event);
437
438int ptp_clock_index(struct ptp_clock *ptp)
439{
440 return ptp->index;
441}
442EXPORT_SYMBOL(ptp_clock_index);
443
444int 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}
460EXPORT_SYMBOL(ptp_find_pin);
461
462int 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}
475EXPORT_SYMBOL(ptp_find_pin_unlocked);
476
477int 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}
481EXPORT_SYMBOL(ptp_schedule_worker);
482
483void ptp_cancel_worker_sync(struct ptp_clock *ptp)
484{
485 kthread_cancel_delayed_work_sync(work: &ptp->aux_work);
486}
487EXPORT_SYMBOL(ptp_cancel_worker_sync);
488
489/* module operations */
490
491static 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
498static 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
518no_region:
519 class_destroy(cls: ptp_class);
520 return err;
521}
522
523subsys_initcall(ptp_init);
524module_exit(ptp_exit);
525
526MODULE_AUTHOR("Richard Cochran <richardcochran@gmail.com>");
527MODULE_DESCRIPTION("PTP clocks support");
528MODULE_LICENSE("GPL");
529

source code of linux/drivers/ptp/ptp_clock.c