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 <uapi/linux/sched/types.h>
19
20 #include "ptp_private.h"
21
22 #define PTP_MAX_ALARMS 4
23 #define PTP_PPS_DEFAULTS (PPS_CAPTUREASSERT | PPS_OFFSETASSERT)
24 #define PTP_PPS_EVENT PPS_CAPTUREASSERT
25 #define PTP_PPS_MODE (PTP_PPS_DEFAULTS | PPS_CANWAIT | PPS_TSFMT_TSPEC)
26
27 struct class *ptp_class;
28
29 /* private globals */
30
31 static dev_t ptp_devt;
32
33 static DEFINE_IDA(ptp_clocks_map);
34
35 /* time stamp event queue operations */
36
queue_free(struct timestamp_event_queue * q)37 static inline int queue_free(struct timestamp_event_queue *q)
38 {
39 return PTP_MAX_TIMESTAMPS - queue_cnt(q) - 1;
40 }
41
enqueue_external_timestamp(struct timestamp_event_queue * queue,struct ptp_clock_event * src)42 static void enqueue_external_timestamp(struct timestamp_event_queue *queue,
43 struct ptp_clock_event *src)
44 {
45 struct ptp_extts_event *dst;
46 unsigned long flags;
47 s64 seconds;
48 u32 remainder;
49
50 seconds = div_u64_rem(src->timestamp, 1000000000, &remainder);
51
52 spin_lock_irqsave(&queue->lock, flags);
53
54 dst = &queue->buf[queue->tail];
55 dst->index = src->index;
56 dst->t.sec = seconds;
57 dst->t.nsec = remainder;
58
59 /* Both WRITE_ONCE() are paired with READ_ONCE() in queue_cnt() */
60 if (!queue_free(queue))
61 WRITE_ONCE(queue->head, (queue->head + 1) % PTP_MAX_TIMESTAMPS);
62
63 WRITE_ONCE(queue->tail, (queue->tail + 1) % PTP_MAX_TIMESTAMPS);
64
65 spin_unlock_irqrestore(&queue->lock, flags);
66 }
67
68 /* posix clock implementation */
69
ptp_clock_getres(struct posix_clock * pc,struct timespec64 * tp)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
ptp_clock_settime(struct posix_clock * pc,const struct timespec64 * tp)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
ptp_clock_gettime(struct posix_clock * pc,struct timespec64 * tp)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
ptp_clock_adjtime(struct posix_clock * pc,struct __kernel_timex * tx)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(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 .poll = ptp_poll,
167 .read = ptp_read,
168 };
169
ptp_clock_release(struct device * dev)170 static void ptp_clock_release(struct device *dev)
171 {
172 struct ptp_clock *ptp = container_of(dev, struct ptp_clock, dev);
173
174 ptp_cleanup_pin_groups(ptp);
175 kfree(ptp->vclock_index);
176 mutex_destroy(&ptp->tsevq_mux);
177 mutex_destroy(&ptp->pincfg_mux);
178 mutex_destroy(&ptp->n_vclocks_mux);
179 ida_free(&ptp_clocks_map, ptp->index);
180 kfree(ptp);
181 }
182
ptp_getcycles64(struct ptp_clock_info * info,struct timespec64 * ts)183 static int ptp_getcycles64(struct ptp_clock_info *info, struct timespec64 *ts)
184 {
185 if (info->getcyclesx64)
186 return info->getcyclesx64(info, ts, NULL);
187 else
188 return info->gettime64(info, ts);
189 }
190
ptp_aux_kworker(struct kthread_work * work)191 static void ptp_aux_kworker(struct kthread_work *work)
192 {
193 struct ptp_clock *ptp = container_of(work, struct ptp_clock,
194 aux_work.work);
195 struct ptp_clock_info *info = ptp->info;
196 long delay;
197
198 delay = info->do_aux_work(info);
199
200 if (delay >= 0)
201 kthread_queue_delayed_work(ptp->kworker, &ptp->aux_work, delay);
202 }
203
204 /* public interface */
205
ptp_clock_register(struct ptp_clock_info * info,struct device * parent)206 struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
207 struct device *parent)
208 {
209 struct ptp_clock *ptp;
210 int err = 0, index, major = MAJOR(ptp_devt);
211 size_t size;
212
213 if (info->n_alarm > PTP_MAX_ALARMS)
214 return ERR_PTR(-EINVAL);
215
216 /* Initialize a clock structure. */
217 err = -ENOMEM;
218 ptp = kzalloc(sizeof(struct ptp_clock), GFP_KERNEL);
219 if (ptp == NULL)
220 goto no_memory;
221
222 index = ida_alloc_max(&ptp_clocks_map, MINORMASK, GFP_KERNEL);
223 if (index < 0) {
224 err = index;
225 goto no_slot;
226 }
227
228 ptp->clock.ops = ptp_clock_ops;
229 ptp->info = info;
230 ptp->devid = MKDEV(major, index);
231 ptp->index = index;
232 spin_lock_init(&ptp->tsevq.lock);
233 mutex_init(&ptp->tsevq_mux);
234 mutex_init(&ptp->pincfg_mux);
235 mutex_init(&ptp->n_vclocks_mux);
236 init_waitqueue_head(&ptp->tsev_wq);
237
238 if (ptp->info->getcycles64 || ptp->info->getcyclesx64) {
239 ptp->has_cycles = true;
240 if (!ptp->info->getcycles64 && ptp->info->getcyclesx64)
241 ptp->info->getcycles64 = ptp_getcycles64;
242 } else {
243 /* Free running cycle counter not supported, use time. */
244 ptp->info->getcycles64 = ptp_getcycles64;
245
246 if (ptp->info->gettimex64)
247 ptp->info->getcyclesx64 = ptp->info->gettimex64;
248
249 if (ptp->info->getcrosststamp)
250 ptp->info->getcrosscycles = ptp->info->getcrosststamp;
251 }
252
253 if (ptp->info->do_aux_work) {
254 kthread_init_delayed_work(&ptp->aux_work, ptp_aux_kworker);
255 ptp->kworker = kthread_create_worker(0, "ptp%d", ptp->index);
256 if (IS_ERR(ptp->kworker)) {
257 err = PTR_ERR(ptp->kworker);
258 pr_err("failed to create ptp aux_worker %d\n", err);
259 goto kworker_err;
260 }
261 }
262
263 /* PTP virtual clock is being registered under physical clock */
264 if (parent && parent->class && parent->class->name &&
265 strcmp(parent->class->name, "ptp") == 0)
266 ptp->is_virtual_clock = true;
267
268 if (!ptp->is_virtual_clock) {
269 ptp->max_vclocks = PTP_DEFAULT_MAX_VCLOCKS;
270
271 size = sizeof(int) * ptp->max_vclocks;
272 ptp->vclock_index = kzalloc(size, GFP_KERNEL);
273 if (!ptp->vclock_index) {
274 err = -ENOMEM;
275 goto no_mem_for_vclocks;
276 }
277 }
278
279 err = ptp_populate_pin_groups(ptp);
280 if (err)
281 goto no_pin_groups;
282
283 /* Register a new PPS source. */
284 if (info->pps) {
285 struct pps_source_info pps;
286 memset(&pps, 0, sizeof(pps));
287 snprintf(pps.name, PPS_MAX_NAME_LEN, "ptp%d", index);
288 pps.mode = PTP_PPS_MODE;
289 pps.owner = info->owner;
290 ptp->pps_source = pps_register_source(&pps, PTP_PPS_DEFAULTS);
291 if (IS_ERR(ptp->pps_source)) {
292 err = PTR_ERR(ptp->pps_source);
293 pr_err("failed to register pps source\n");
294 goto no_pps;
295 }
296 ptp->pps_source->lookup_cookie = ptp;
297 }
298
299 /* Initialize a new device of our class in our clock structure. */
300 device_initialize(&ptp->dev);
301 ptp->dev.devt = ptp->devid;
302 ptp->dev.class = ptp_class;
303 ptp->dev.parent = parent;
304 ptp->dev.groups = ptp->pin_attr_groups;
305 ptp->dev.release = ptp_clock_release;
306 dev_set_drvdata(&ptp->dev, ptp);
307 dev_set_name(&ptp->dev, "ptp%d", ptp->index);
308
309 /* Create a posix clock and link it to the device. */
310 err = posix_clock_register(&ptp->clock, &ptp->dev);
311 if (err) {
312 if (ptp->pps_source)
313 pps_unregister_source(ptp->pps_source);
314
315 if (ptp->kworker)
316 kthread_destroy_worker(ptp->kworker);
317
318 put_device(&ptp->dev);
319
320 pr_err("failed to create posix clock\n");
321 return ERR_PTR(err);
322 }
323
324 return ptp;
325
326 no_pps:
327 ptp_cleanup_pin_groups(ptp);
328 no_pin_groups:
329 kfree(ptp->vclock_index);
330 no_mem_for_vclocks:
331 if (ptp->kworker)
332 kthread_destroy_worker(ptp->kworker);
333 kworker_err:
334 mutex_destroy(&ptp->tsevq_mux);
335 mutex_destroy(&ptp->pincfg_mux);
336 mutex_destroy(&ptp->n_vclocks_mux);
337 ida_free(&ptp_clocks_map, index);
338 no_slot:
339 kfree(ptp);
340 no_memory:
341 return ERR_PTR(err);
342 }
343 EXPORT_SYMBOL(ptp_clock_register);
344
unregister_vclock(struct device * dev,void * data)345 static int unregister_vclock(struct device *dev, void *data)
346 {
347 struct ptp_clock *ptp = dev_get_drvdata(dev);
348
349 ptp_vclock_unregister(info_to_vclock(ptp->info));
350 return 0;
351 }
352
ptp_clock_unregister(struct ptp_clock * ptp)353 int ptp_clock_unregister(struct ptp_clock *ptp)
354 {
355 if (ptp_vclock_in_use(ptp)) {
356 device_for_each_child(&ptp->dev, NULL, unregister_vclock);
357 }
358
359 ptp->defunct = 1;
360 wake_up_interruptible(&ptp->tsev_wq);
361
362 if (ptp->kworker) {
363 kthread_cancel_delayed_work_sync(&ptp->aux_work);
364 kthread_destroy_worker(ptp->kworker);
365 }
366
367 /* Release the clock's resources. */
368 if (ptp->pps_source)
369 pps_unregister_source(ptp->pps_source);
370
371 posix_clock_unregister(&ptp->clock);
372
373 return 0;
374 }
375 EXPORT_SYMBOL(ptp_clock_unregister);
376
ptp_clock_event(struct ptp_clock * ptp,struct ptp_clock_event * event)377 void ptp_clock_event(struct ptp_clock *ptp, struct ptp_clock_event *event)
378 {
379 struct pps_event_time evt;
380
381 switch (event->type) {
382
383 case PTP_CLOCK_ALARM:
384 break;
385
386 case PTP_CLOCK_EXTTS:
387 enqueue_external_timestamp(&ptp->tsevq, event);
388 wake_up_interruptible(&ptp->tsev_wq);
389 break;
390
391 case PTP_CLOCK_PPS:
392 pps_get_ts(&evt);
393 pps_event(ptp->pps_source, &evt, PTP_PPS_EVENT, NULL);
394 break;
395
396 case PTP_CLOCK_PPSUSR:
397 pps_event(ptp->pps_source, &event->pps_times,
398 PTP_PPS_EVENT, NULL);
399 break;
400 }
401 }
402 EXPORT_SYMBOL(ptp_clock_event);
403
ptp_clock_index(struct ptp_clock * ptp)404 int ptp_clock_index(struct ptp_clock *ptp)
405 {
406 return ptp->index;
407 }
408 EXPORT_SYMBOL(ptp_clock_index);
409
ptp_find_pin(struct ptp_clock * ptp,enum ptp_pin_function func,unsigned int chan)410 int ptp_find_pin(struct ptp_clock *ptp,
411 enum ptp_pin_function func, unsigned int chan)
412 {
413 struct ptp_pin_desc *pin = NULL;
414 int i;
415
416 for (i = 0; i < ptp->info->n_pins; i++) {
417 if (ptp->info->pin_config[i].func == func &&
418 ptp->info->pin_config[i].chan == chan) {
419 pin = &ptp->info->pin_config[i];
420 break;
421 }
422 }
423
424 return pin ? i : -1;
425 }
426 EXPORT_SYMBOL(ptp_find_pin);
427
ptp_find_pin_unlocked(struct ptp_clock * ptp,enum ptp_pin_function func,unsigned int chan)428 int ptp_find_pin_unlocked(struct ptp_clock *ptp,
429 enum ptp_pin_function func, unsigned int chan)
430 {
431 int result;
432
433 mutex_lock(&ptp->pincfg_mux);
434
435 result = ptp_find_pin(ptp, func, chan);
436
437 mutex_unlock(&ptp->pincfg_mux);
438
439 return result;
440 }
441 EXPORT_SYMBOL(ptp_find_pin_unlocked);
442
ptp_schedule_worker(struct ptp_clock * ptp,unsigned long delay)443 int ptp_schedule_worker(struct ptp_clock *ptp, unsigned long delay)
444 {
445 return kthread_mod_delayed_work(ptp->kworker, &ptp->aux_work, delay);
446 }
447 EXPORT_SYMBOL(ptp_schedule_worker);
448
ptp_cancel_worker_sync(struct ptp_clock * ptp)449 void ptp_cancel_worker_sync(struct ptp_clock *ptp)
450 {
451 kthread_cancel_delayed_work_sync(&ptp->aux_work);
452 }
453 EXPORT_SYMBOL(ptp_cancel_worker_sync);
454
455 /* module operations */
456
ptp_exit(void)457 static void __exit ptp_exit(void)
458 {
459 class_destroy(ptp_class);
460 unregister_chrdev_region(ptp_devt, MINORMASK + 1);
461 ida_destroy(&ptp_clocks_map);
462 }
463
ptp_init(void)464 static int __init ptp_init(void)
465 {
466 int err;
467
468 ptp_class = class_create("ptp");
469 if (IS_ERR(ptp_class)) {
470 pr_err("ptp: failed to allocate class\n");
471 return PTR_ERR(ptp_class);
472 }
473
474 err = alloc_chrdev_region(&ptp_devt, 0, MINORMASK + 1, "ptp");
475 if (err < 0) {
476 pr_err("ptp: failed to allocate device region\n");
477 goto no_region;
478 }
479
480 ptp_class->dev_groups = ptp_groups;
481 pr_info("PTP clock support registered\n");
482 return 0;
483
484 no_region:
485 class_destroy(ptp_class);
486 return err;
487 }
488
489 subsys_initcall(ptp_init);
490 module_exit(ptp_exit);
491
492 MODULE_AUTHOR("Richard Cochran <richardcochran@gmail.com>");
493 MODULE_DESCRIPTION("PTP clocks support");
494 MODULE_LICENSE("GPL");
495