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                 ptp->dialed_frequency = tx->freq;
 154         } else if (tx->modes & ADJ_OFFSET) {
 155                 if (ops->adjphase) {
 156                         s32 max_phase_adj = ops->getmaxphase(ops);
 157                         s32 offset = tx->offset;
 158
 159                         if (!(tx->modes & ADJ_NANO))
 160                                 offset *= NSEC_PER_USEC;
 161
 162                         if (offset > max_phase_adj || offset < -max_phase_adj)
 163                                 return -ERANGE;
 164
 165                         err = ops->adjphase(ops, offset);
 166                 }
 167         } else if (tx->modes == 0) {
 168                 tx->freq = ptp->dialed_frequency;
 169                 err = 0;
 170         }
 171
 172         return err;
 173 }
 174
 175 static struct posix_clock_operations ptp_clock_ops = {
 176         .owner          = THIS_MODULE,
 177         .clock_adjtime  = ptp_clock_adjtime,
 178         .clock_gettime  = ptp_clock_gettime,
 179         .clock_getres   = ptp_clock_getres,
 180         .clock_settime  = ptp_clock_settime,
 181         .ioctl          = ptp_ioctl,
 182         .open           = ptp_open,
 183         .release        = ptp_release,
 184         .poll           = ptp_poll,
 185         .read           = ptp_read,
 186 };
 187
 188 static void ptp_clock_release(struct device *dev)
 189 {
 190         struct ptp_clock *ptp = container_of(dev, struct ptp_clock, dev);
 191         struct timestamp_event_queue *tsevq;
 192         unsigned long flags;
 193
 194         ptp_cleanup_pin_groups(ptp);
 195         kfree(ptp->vclock_index);
 196         mutex_destroy(&ptp->pincfg_mux);
 197         mutex_destroy(&ptp->n_vclocks_mux);
 198         /* Delete first entry */
 199         spin_lock_irqsave(&ptp->tsevqs_lock, flags);
 200         tsevq = list_first_entry(&ptp->tsevqs, struct timestamp_event_queue,
 201                                  qlist);
 202         list_del(&tsevq->qlist);
 203         spin_unlock_irqrestore(&ptp->tsevqs_lock, flags);
 204         bitmap_free(tsevq->mask);
 205         kfree(tsevq);
 206         debugfs_remove(ptp->debugfs_root);
 207         xa_erase(&ptp_clocks_map, ptp->index);
 208         kfree(ptp);
 209 }
 210
 211 static int ptp_getcycles64(struct ptp_clock_info *info, struct timespec64 *ts)
 212 {
 213         if (info->getcyclesx64)
 214                 return info->getcyclesx64(info, ts, NULL);
 215         else
 216                 return info->gettime64(info, ts);
 217 }
 218
 219 static void ptp_aux_kworker(struct kthread_work *work)
 220 {
 221         struct ptp_clock *ptp = container_of(work, struct ptp_clock,
 222                                              aux_work.work);
 223         struct ptp_clock_info *info = ptp->info;
 224         long delay;
 225
 226         delay = info->do_aux_work(info);
 227
 228         if (delay >= 0)
 229                 kthread_queue_delayed_work(ptp->kworker, &ptp->aux_work, delay);
 230 }
 231
 232 /* public interface */
 233
 234 struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
 235                                      struct device *parent)
 236 {
 237         struct ptp_clock *ptp;
 238         struct timestamp_event_queue *queue = NULL;
 239         int err, index, major = MAJOR(ptp_devt);
 240         char debugfsname[16];
 241         size_t size;
 242
 243         if (info->n_alarm > PTP_MAX_ALARMS)
 244                 return ERR_PTR(-EINVAL);
 245
 246         /* Initialize a clock structure. */
 247         ptp = kzalloc(sizeof(struct ptp_clock), GFP_KERNEL);
 248         if (!ptp) {
 249                 err = -ENOMEM;
 250                 goto no_memory;
 251         }
 252
 253         err = xa_alloc(&ptp_clocks_map, &index, ptp, xa_limit_31b,
 254                        GFP_KERNEL);
 255         if (err)
 256                 goto no_slot;
 257
 258         ptp->clock.ops = ptp_clock_ops;
 259         ptp->info = info;
 260         ptp->devid = MKDEV(major, index);
 261         ptp->index = index;
 262         INIT_LIST_HEAD(&ptp->tsevqs);
 263         queue = kzalloc(sizeof(*queue), GFP_KERNEL);
 264         if (!queue) {
 265                 err = -ENOMEM;
 266                 goto no_memory_queue;
 267         }
 268         list_add_tail(&queue->qlist, &ptp->tsevqs);
 269         spin_lock_init(&ptp->tsevqs_lock);
 270         queue->mask = bitmap_alloc(PTP_MAX_CHANNELS, GFP_KERNEL);
 271         if (!queue->mask) {
 272                 err = -ENOMEM;
 273                 goto no_memory_bitmap;
 274         }
 275         bitmap_set(queue->mask, 0, PTP_MAX_CHANNELS);
 276         spin_lock_init(&queue->lock);
 277         mutex_init(&ptp->pincfg_mux);
 278         mutex_init(&ptp->n_vclocks_mux);
 279         init_waitqueue_head(&ptp->tsev_wq);
 280
 281         if (ptp->info->getcycles64 || ptp->info->getcyclesx64) {
 282                 ptp->has_cycles = true;
 283                 if (!ptp->info->getcycles64 && ptp->info->getcyclesx64)
 284                         ptp->info->getcycles64 = ptp_getcycles64;
 285         } else {
 286                 /* Free running cycle counter not supported, use time. */
 287                 ptp->info->getcycles64 = ptp_getcycles64;
 288
 289                 if (ptp->info->gettimex64)
 290                         ptp->info->getcyclesx64 = ptp->info->gettimex64;
 291
 292                 if (ptp->info->getcrosststamp)
 293                         ptp->info->getcrosscycles = ptp->info->getcrosststamp;
 294         }
 295
 296         if (ptp->info->do_aux_work) {
 297                 kthread_init_delayed_work(&ptp->aux_work, ptp_aux_kworker);
 298                 ptp->kworker = kthread_create_worker(0, "ptp%d", ptp->index);
 299                 if (IS_ERR(ptp->kworker)) {
 300                         err = PTR_ERR(ptp->kworker);
 301                         pr_err("failed to create ptp aux_worker %d\n", err);
 302                         goto kworker_err;
 303                 }
 304         }
 305
 306         /* PTP virtual clock is being registered under physical clock */
 307         if (parent && parent->class && parent->class->name &&
 308             strcmp(parent->class->name, "ptp") == 0)
 309                 ptp->is_virtual_clock = true;
 310
 311         if (!ptp->is_virtual_clock) {
 312                 ptp->max_vclocks = PTP_DEFAULT_MAX_VCLOCKS;
 313
 314                 size = sizeof(int) * ptp->max_vclocks;
 315                 ptp->vclock_index = kzalloc(size, GFP_KERNEL);
 316                 if (!ptp->vclock_index) {
 317                         err = -ENOMEM;
 318                         goto no_mem_for_vclocks;
 319                 }
 320         }
 321
 322         err = ptp_populate_pin_groups(ptp);
 323         if (err)
 324                 goto no_pin_groups;
 325
 326         /* Register a new PPS source. */
 327         if (info->pps) {
 328                 struct pps_source_info pps;
 329                 memset(&pps, 0, sizeof(pps));
 330                 snprintf(pps.name, PPS_MAX_NAME_LEN, "ptp%d", index);
 331                 pps.mode = PTP_PPS_MODE;
 332                 pps.owner = info->owner;
 333                 ptp->pps_source = pps_register_source(&pps, PTP_PPS_DEFAULTS);
 334                 if (IS_ERR(ptp->pps_source)) {
 335                         err = PTR_ERR(ptp->pps_source);
 336                         pr_err("failed to register pps source\n");
 337                         goto no_pps;
 338                 }
 339                 ptp->pps_source->lookup_cookie = ptp;
 340         }
 341
 342         /* Initialize a new device of our class in our clock structure. */
 343         device_initialize(&ptp->dev);
 344         ptp->dev.devt = ptp->devid;
 345         ptp->dev.class = &ptp_class;
 346         ptp->dev.parent = parent;
 347         ptp->dev.groups = ptp->pin_attr_groups;
 348         ptp->dev.release = ptp_clock_release;
 349         dev_set_drvdata(&ptp->dev, ptp);
 350         dev_set_name(&ptp->dev, "ptp%d", ptp->index);
 351
 352         /* Create a posix clock and link it to the device. */
 353         err = posix_clock_register(&ptp->clock, &ptp->dev);
 354         if (err) {
 355                 if (ptp->pps_source)
 356                         pps_unregister_source(ptp->pps_source);
 357
 358                 if (ptp->kworker)
 359                         kthread_destroy_worker(ptp->kworker);
 360
 361                 put_device(&ptp->dev);
 362
 363                 pr_err("failed to create posix clock\n");
 364                 return ERR_PTR(err);
 365         }
 366
 367         /* Debugfs initialization */
 368         snprintf(debugfsname, sizeof(debugfsname), "ptp%d", ptp->index);
 369         ptp->debugfs_root = debugfs_create_dir(debugfsname, NULL);
 370
 371         return ptp;
 372
 373 no_pps:
 374         ptp_cleanup_pin_groups(ptp);
 375 no_pin_groups:
 376         kfree(ptp->vclock_index);
 377 no_mem_for_vclocks:
 378         if (ptp->kworker)
 379                 kthread_destroy_worker(ptp->kworker);
 380 kworker_err:
 381         mutex_destroy(&ptp->pincfg_mux);
 382         mutex_destroy(&ptp->n_vclocks_mux);
 383         bitmap_free(queue->mask);
 384 no_memory_bitmap:
 385         list_del(&queue->qlist);
 386         kfree(queue);
 387 no_memory_queue:
 388         xa_erase(&ptp_clocks_map, index);
 389 no_slot:
 390         kfree(ptp);
 391 no_memory:
 392         return ERR_PTR(err);
 393 }
 394 EXPORT_SYMBOL(ptp_clock_register);
 395
 396 static int unregister_vclock(struct device *dev, void *data)
 397 {
 398         struct ptp_clock *ptp = dev_get_drvdata(dev);
 399
 400         ptp_vclock_unregister(info_to_vclock(ptp->info));
 401         return 0;
 402 }
 403
 404 int ptp_clock_unregister(struct ptp_clock *ptp)
 405 {
 406         if (ptp_vclock_in_use(ptp)) {
 407                 device_for_each_child(&ptp->dev, NULL, unregister_vclock);
 408         }
 409
 410         ptp->defunct = 1;
 411         wake_up_interruptible(&ptp->tsev_wq);
 412
 413         if (ptp->kworker) {
 414                 kthread_cancel_delayed_work_sync(&ptp->aux_work);
 415                 kthread_destroy_worker(ptp->kworker);
 416         }
 417
 418         /* Release the clock's resources. */
 419         if (ptp->pps_source)
 420                 pps_unregister_source(ptp->pps_source);
 421
 422         posix_clock_unregister(&ptp->clock);
 423
 424         return 0;
 425 }
 426 EXPORT_SYMBOL(ptp_clock_unregister);
 427
 428 void ptp_clock_event(struct ptp_clock *ptp, struct ptp_clock_event *event)
 429 {
 430         struct timestamp_event_queue *tsevq;
 431         struct pps_event_time evt;
 432         unsigned long flags;
 433
 434         switch (event->type) {
 435
 436         case PTP_CLOCK_ALARM:
 437                 break;
 438
 439         case PTP_CLOCK_EXTTS:
 440         case PTP_CLOCK_EXTOFF:
 441                 /* Enqueue timestamp on selected queues */
 442                 spin_lock_irqsave(&ptp->tsevqs_lock, flags);
 443                 list_for_each_entry(tsevq, &ptp->tsevqs, qlist) {
 444                         if (test_bit((unsigned int)event->index, tsevq->mask))
 445                                 enqueue_external_timestamp(tsevq, event);
 446                 }
 447                 spin_unlock_irqrestore(&ptp->tsevqs_lock, flags);
 448                 wake_up_interruptible(&ptp->tsev_wq);
 449                 break;
 450
 451         case PTP_CLOCK_PPS:
 452                 pps_get_ts(&evt);
 453                 pps_event(ptp->pps_source, &evt, PTP_PPS_EVENT, NULL);
 454                 break;
 455
 456         case PTP_CLOCK_PPSUSR:
 457                 pps_event(ptp->pps_source, &event->pps_times,
 458                           PTP_PPS_EVENT, NULL);
 459                 break;
 460         }
 461 }
 462 EXPORT_SYMBOL(ptp_clock_event);
 463
 464 int ptp_clock_index(struct ptp_clock *ptp)
 465 {
 466         return ptp->index;
 467 }
 468 EXPORT_SYMBOL(ptp_clock_index);
 469
 470 int ptp_find_pin(struct ptp_clock *ptp,
 471                  enum ptp_pin_function func, unsigned int chan)
 472 {
 473         struct ptp_pin_desc *pin = NULL;
 474         int i;
 475
 476         for (i = 0; i < ptp->info->n_pins; i++) {
 477                 if (ptp->info->pin_config[i].func == func &&
 478                     ptp->info->pin_config[i].chan == chan) {
 479                         pin = &ptp->info->pin_config[i];
 480                         break;
 481                 }
 482         }
 483
 484         return pin ? i : -1;
 485 }
 486 EXPORT_SYMBOL(ptp_find_pin);
 487
 488 int ptp_find_pin_unlocked(struct ptp_clock *ptp,
 489                           enum ptp_pin_function func, unsigned int chan)
 490 {
 491         int result;
 492
 493         mutex_lock(&ptp->pincfg_mux);
 494
 495         result = ptp_find_pin(ptp, func, chan);
 496
 497         mutex_unlock(&ptp->pincfg_mux);
 498
 499         return result;
 500 }
 501 EXPORT_SYMBOL(ptp_find_pin_unlocked);
 502
 503 int ptp_schedule_worker(struct ptp_clock *ptp, unsigned long delay)
 504 {
 505         return kthread_mod_delayed_work(ptp->kworker, &ptp->aux_work, delay);
 506 }
 507 EXPORT_SYMBOL(ptp_schedule_worker);
 508
 509 void ptp_cancel_worker_sync(struct ptp_clock *ptp)
 510 {
 511         kthread_cancel_delayed_work_sync(&ptp->aux_work);
 512 }
 513 EXPORT_SYMBOL(ptp_cancel_worker_sync);
 514
 515 /* module operations */
 516
 517 static void __exit ptp_exit(void)
 518 {
 519         class_unregister(&ptp_class);
 520         unregister_chrdev_region(ptp_devt, MINORMASK + 1);
 521         xa_destroy(&ptp_clocks_map);
 522 }
 523
 524 static int __init ptp_init(void)
 525 {
 526         int err;
 527
 528         err = class_register(&ptp_class);
 529         if (err) {
 530                 pr_err("ptp: failed to allocate class\n");
 531                 return err;
 532         }
 533
 534         err = alloc_chrdev_region(&ptp_devt, 0, MINORMASK + 1, "ptp");
 535         if (err < 0) {
 536                 pr_err("ptp: failed to allocate device region\n");
 537                 goto no_region;
 538         }
 539
 540         pr_info("PTP clock support registered\n");
 541         return 0;
 542
 543 no_region:
 544         class_unregister(&ptp_class);
 545         return err;
 546 }
 547
 548 subsys_initcall(ptp_init);
 549 module_exit(ptp_exit);
 550
 551 MODULE_AUTHOR("Richard Cochran <[email protected]>");
 552 MODULE_DESCRIPTION("PTP clocks support");
 553 MODULE_LICENSE("GPL");