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