drivers/ptp/ptp_clock.c

   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
  41 static inline int queue_free(struct timestamp_event_queue *q)
  42 {
  43         return PTP_MAX_TIMESTAMPS - queue_cnt(q) - 1;
  44 }
  45
  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
  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
  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
 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
 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
 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
 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
 220 static void ptp_aux_kworker(struct kthread_work *work)
 221 {
 222         struct ptp_clock *ptp = container_of(work, struct ptp_clock,
 223                                              aux_work.work);
 224         struct ptp_clock_info *info = ptp->info;
 225         long delay;
 226
 227         delay = info->do_aux_work(info);
 228
 229         if (delay >= 0)
 230                 kthread_queue_delayed_work(ptp->kworker, &ptp->aux_work, delay);
 231 }
 232
 233 /* public interface */
 234
 235 struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
 236                                      struct device *parent)
 237 {
 238         struct ptp_clock *ptp;
 239         struct timestamp_event_queue *queue = NULL;
 240         int err, index, major = MAJOR(ptp_devt);
 241         char debugfsname[16];
 242         size_t size;
 243
 244         if (info->n_alarm > PTP_MAX_ALARMS)
 245                 return ERR_PTR(-EINVAL);
 246
 247         /* Initialize a clock structure. */
 248         ptp = kzalloc(sizeof(struct ptp_clock), GFP_KERNEL);
 249         if (!ptp) {
 250                 err = -ENOMEM;
 251                 goto no_memory;
 252         }
 253
 254         err = xa_alloc(&ptp_clocks_map, &index, ptp, xa_limit_31b,
 255                        GFP_KERNEL);
 256         if (err)
 257                 goto no_slot;
 258
 259         ptp->clock.ops = ptp_clock_ops;
 260         ptp->info = info;
 261         ptp->devid = MKDEV(major, index);
 262         ptp->index = index;
 263         INIT_LIST_HEAD(&ptp->tsevqs);
 264         queue = kzalloc(sizeof(*queue), GFP_KERNEL);
 265         if (!queue) {
 266                 err = -ENOMEM;
 267                 goto no_memory_queue;
 268         }
 269         list_add_tail(&queue->qlist, &ptp->tsevqs);
 270         spin_lock_init(&ptp->tsevqs_lock);
 271         queue->mask = bitmap_alloc(PTP_MAX_CHANNELS, GFP_KERNEL);
 272         if (!queue->mask) {
 273                 err = -ENOMEM;
 274                 goto no_memory_bitmap;
 275         }
 276         bitmap_set(queue->mask, 0, PTP_MAX_CHANNELS);
 277         spin_lock_init(&queue->lock);
 278         mutex_init(&ptp->pincfg_mux);
 279         mutex_init(&ptp->n_vclocks_mux);
 280         init_waitqueue_head(&ptp->tsev_wq);
 281
 282         if (ptp->info->getcycles64 || ptp->info->getcyclesx64) {
 283                 ptp->has_cycles = true;
 284                 if (!ptp->info->getcycles64 && ptp->info->getcyclesx64)
 285                         ptp->info->getcycles64 = ptp_getcycles64;
 286         } else {
 287                 /* Free running cycle counter not supported, use time. */
 288                 ptp->info->getcycles64 = ptp_getcycles64;
 289
 290                 if (ptp->info->gettimex64)
 291                         ptp->info->getcyclesx64 = ptp->info->gettimex64;
 292
 293                 if (ptp->info->getcrosststamp)
 294                         ptp->info->getcrosscycles = ptp->info->getcrosststamp;
 295         }
 296
 297         if (ptp->info->do_aux_work) {
 298                 kthread_init_delayed_work(&ptp->aux_work, ptp_aux_kworker);
 299                 ptp->kworker = kthread_create_worker(0, "ptp%d", ptp->index);
 300                 if (IS_ERR(ptp->kworker)) {
 301                         err = PTR_ERR(ptp->kworker);
 302                         pr_err("failed to create ptp aux_worker %d\n", err);
 303                         goto kworker_err;
 304                 }
 305         }
 306
 307         /* PTP virtual clock is being registered under physical clock */
 308         if (parent && parent->class && parent->class->name &&
 309             strcmp(parent->class->name, "ptp") == 0)
 310                 ptp->is_virtual_clock = true;
 311
 312         if (!ptp->is_virtual_clock) {
 313                 ptp->max_vclocks = PTP_DEFAULT_MAX_VCLOCKS;
 314
 315                 size = sizeof(int) * ptp->max_vclocks;
 316                 ptp->vclock_index = kzalloc(size, GFP_KERNEL);
 317                 if (!ptp->vclock_index) {
 318                         err = -ENOMEM;
 319                         goto no_mem_for_vclocks;
 320                 }
 321         }
 322
 323         err = ptp_populate_pin_groups(ptp);
 324         if (err)
 325                 goto no_pin_groups;
 326
 327         /* Register a new PPS source. */
 328         if (info->pps) {
 329                 struct pps_source_info pps;
 330                 memset(&pps, 0, sizeof(pps));
 331                 snprintf(pps.name, PPS_MAX_NAME_LEN, "ptp%d", index);
 332                 pps.mode = PTP_PPS_MODE;
 333                 pps.owner = info->owner;
 334                 ptp->pps_source = pps_register_source(&pps, PTP_PPS_DEFAULTS);
 335                 if (IS_ERR(ptp->pps_source)) {
 336                         err = PTR_ERR(ptp->pps_source);
 337                         pr_err("failed to register pps source\n");
 338                         goto no_pps;
 339                 }
 340                 ptp->pps_source->lookup_cookie = ptp;
 341         }
 342
 343         /* Initialize a new device of our class in our clock structure. */
 344         device_initialize(&ptp->dev);
 345         ptp->dev.devt = ptp->devid;
 346         ptp->dev.class = &ptp_class;
 347         ptp->dev.parent = parent;
 348         ptp->dev.groups = ptp->pin_attr_groups;
 349         ptp->dev.release = ptp_clock_release;
 350         dev_set_drvdata(&ptp->dev, ptp);
 351         dev_set_name(&ptp->dev, "ptp%d", ptp->index);
 352
 353         /* Create a posix clock and link it to the device. */
 354         err = posix_clock_register(&ptp->clock, &ptp->dev);
 355         if (err) {
 356                 if (ptp->pps_source)
 357                         pps_unregister_source(ptp->pps_source);
 358
 359                 if (ptp->kworker)
 360                         kthread_destroy_worker(ptp->kworker);
 361
 362                 put_device(&ptp->dev);
 363
 364                 pr_err("failed to create posix clock\n");
 365                 return ERR_PTR(err);
 366         }
 367
 368         /* Debugfs initialization */
 369         snprintf(debugfsname, sizeof(debugfsname), "ptp%d", ptp->index);
 370         ptp->debugfs_root = debugfs_create_dir(debugfsname, NULL);
 371
 372         return ptp;
 373
 374 no_pps:
 375         ptp_cleanup_pin_groups(ptp);
 376 no_pin_groups:
 377         kfree(ptp->vclock_index);
 378 no_mem_for_vclocks:
 379         if (ptp->kworker)
 380                 kthread_destroy_worker(ptp->kworker);
 381 kworker_err:
 382         mutex_destroy(&ptp->pincfg_mux);
 383         mutex_destroy(&ptp->n_vclocks_mux);
 384         bitmap_free(queue->mask);
 385 no_memory_bitmap:
 386         list_del(&queue->qlist);
 387         kfree(queue);
 388 no_memory_queue:
 389         xa_erase(&ptp_clocks_map, index);
 390 no_slot:
 391         kfree(ptp);
 392 no_memory:
 393         return ERR_PTR(err);
 394 }
 395 EXPORT_SYMBOL(ptp_clock_register);
 396
 397 static int unregister_vclock(struct device *dev, void *data)
 398 {
 399         struct ptp_clock *ptp = dev_get_drvdata(dev);
 400
 401         ptp_vclock_unregister(info_to_vclock(ptp->info));
 402         return 0;
 403 }
 404
 405 int ptp_clock_unregister(struct ptp_clock *ptp)
 406 {
 407         if (ptp_vclock_in_use(ptp)) {
 408                 device_for_each_child(&ptp->dev, NULL, unregister_vclock);
 409         }
 410
 411         ptp->defunct = 1;
 412         wake_up_interruptible(&ptp->tsev_wq);
 413
 414         if (ptp->kworker) {
 415                 kthread_cancel_delayed_work_sync(&ptp->aux_work);
 416                 kthread_destroy_worker(ptp->kworker);
 417         }
 418
 419         /* Release the clock's resources. */
 420         if (ptp->pps_source)
 421                 pps_unregister_source(ptp->pps_source);
 422
 423         posix_clock_unregister(&ptp->clock);
 424
 425         return 0;
 426 }
 427 EXPORT_SYMBOL(ptp_clock_unregister);
 428
 429 void ptp_clock_event(struct ptp_clock *ptp, struct ptp_clock_event *event)
 430 {
 431         struct timestamp_event_queue *tsevq;
 432         struct pps_event_time evt;
 433         unsigned long flags;
 434
 435         switch (event->type) {
 436
 437         case PTP_CLOCK_ALARM:
 438                 break;
 439
 440         case PTP_CLOCK_EXTTS:
 441         case PTP_CLOCK_EXTOFF:
 442                 /* Enqueue timestamp on selected queues */
 443                 spin_lock_irqsave(&ptp->tsevqs_lock, flags);
 444                 list_for_each_entry(tsevq, &ptp->tsevqs, qlist) {
 445                         if (test_bit((unsigned int)event->index, tsevq->mask))
 446                                 enqueue_external_timestamp(tsevq, event);
 447                 }
 448                 spin_unlock_irqrestore(&ptp->tsevqs_lock, flags);
 449                 wake_up_interruptible(&ptp->tsev_wq);
 450                 break;
 451
 452         case PTP_CLOCK_PPS:
 453                 pps_get_ts(&evt);
 454                 pps_event(ptp->pps_source, &evt, PTP_PPS_EVENT, NULL);
 455                 break;
 456
 457         case PTP_CLOCK_PPSUSR:
 458                 pps_event(ptp->pps_source, &event->pps_times,
 459                           PTP_PPS_EVENT, NULL);
 460                 break;
 461         }
 462 }
 463 EXPORT_SYMBOL(ptp_clock_event);
 464
 465 int ptp_clock_index(struct ptp_clock *ptp)
 466 {
 467         return ptp->index;
 468 }
 469 EXPORT_SYMBOL(ptp_clock_index);
 470
 471 int ptp_find_pin(struct ptp_clock *ptp,
 472                  enum ptp_pin_function func, unsigned int chan)
 473 {
 474         struct ptp_pin_desc *pin = NULL;
 475         int i;
 476
 477         for (i = 0; i < ptp->info->n_pins; i++) {
 478                 if (ptp->info->pin_config[i].func == func &&
 479                     ptp->info->pin_config[i].chan == chan) {
 480                         pin = &ptp->info->pin_config[i];
 481                         break;
 482                 }
 483         }
 484
 485         return pin ? i : -1;
 486 }
 487 EXPORT_SYMBOL(ptp_find_pin);
 488
 489 int ptp_find_pin_unlocked(struct ptp_clock *ptp,
 490                           enum ptp_pin_function func, unsigned int chan)
 491 {
 492         int result;
 493
 494         mutex_lock(&ptp->pincfg_mux);
 495
 496         result = ptp_find_pin(ptp, func, chan);
 497
 498         mutex_unlock(&ptp->pincfg_mux);
 499
 500         return result;
 501 }
 502 EXPORT_SYMBOL(ptp_find_pin_unlocked);
 503
 504 int ptp_schedule_worker(struct ptp_clock *ptp, unsigned long delay)
 505 {
 506         return kthread_mod_delayed_work(ptp->kworker, &ptp->aux_work, delay);
 507 }
 508 EXPORT_SYMBOL(ptp_schedule_worker);
 509
 510 void ptp_cancel_worker_sync(struct ptp_clock *ptp)
 511 {
 512         kthread_cancel_delayed_work_sync(&ptp->aux_work);
 513 }
 514 EXPORT_SYMBOL(ptp_cancel_worker_sync);
 515
 516 /* module operations */
 517
 518 static void __exit ptp_exit(void)
 519 {
 520         class_unregister(&ptp_class);
 521         unregister_chrdev_region(ptp_devt, MINORMASK + 1);
 522         xa_destroy(&ptp_clocks_map);
 523 }
 524
 525 static int __init ptp_init(void)
 526 {
 527         int err;
 528
 529         err = class_register(&ptp_class);
 530         if (err) {
 531                 pr_err("ptp: failed to allocate class\n");
 532                 return err;
 533         }
 534
 535         err = alloc_chrdev_region(&ptp_devt, 0, MINORMASK + 1, "ptp");
 536         if (err < 0) {
 537                 pr_err("ptp: failed to allocate device region\n");
 538                 goto no_region;
 539         }
 540
 541         pr_info("PTP clock support registered\n");
 542         return 0;
 543
 544 no_region:
 545         class_unregister(&ptp_class);
 546         return err;
 547 }
 548
 549 subsys_initcall(ptp_init);
 550 module_exit(ptp_exit);
 551
 552 MODULE_AUTHOR("Richard Cochran <richardcochran@gmail.com>");
 553 MODULE_DESCRIPTION("PTP clocks support");
 554 MODULE_LICENSE("GPL");