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/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
  28 struct class *ptp_class;
  29
  30 /* private globals */
  31
  32 static dev_t ptp_devt;
  33
  34 static DEFINE_IDA(ptp_clocks_map);
  35
  36 /* time stamp event queue operations */
  37
  38 static inline int queue_free(struct timestamp_event_queue *q)
  39 {
  40         return PTP_MAX_TIMESTAMPS - queue_cnt(q) - 1;
  41 }
  42
  43 static 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(src->timestamp, 1000000000, &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(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(&queue->lock, flags);
  66 }
  67
  68 /* posix clock implementation */
  69
  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
  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
  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
 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         .release        = ptp_release,
 167         .poll           = ptp_poll,
 168         .read           = ptp_read,
 169 };
 170
 171 static 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(ptp->vclock_index);
 179         mutex_destroy(&ptp->pincfg_mux);
 180         mutex_destroy(&ptp->n_vclocks_mux);
 181         /* Delete first entry */
 182         spin_lock_irqsave(&ptp->tsevqs_lock, flags);
 183         tsevq = list_first_entry(&ptp->tsevqs, struct timestamp_event_queue,
 184                                  qlist);
 185         list_del(&tsevq->qlist);
 186         spin_unlock_irqrestore(&ptp->tsevqs_lock, flags);
 187         bitmap_free(tsevq->mask);
 188         kfree(tsevq);
 189         debugfs_remove(ptp->debugfs_root);
 190         ida_free(&ptp_clocks_map, ptp->index);
 191         kfree(ptp);
 192 }
 193
 194 static 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
 202 static 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(ptp->kworker, &ptp->aux_work, delay);
 213 }
 214
 215 /* public interface */
 216
 217 struct 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(-EINVAL);
 228
 229         /* Initialize a clock structure. */
 230         err = -ENOMEM;
 231         ptp = kzalloc(sizeof(struct ptp_clock), GFP_KERNEL);
 232         if (ptp == NULL)
 233                 goto no_memory;
 234
 235         index = ida_alloc_max(&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(&ptp->tsevqs);
 246         queue = kzalloc(sizeof(*queue), GFP_KERNEL);
 247         if (!queue)
 248                 goto no_memory_queue;
 249         list_add_tail(&queue->qlist, &ptp->tsevqs);
 250         spin_lock_init(&ptp->tsevqs_lock);
 251         queue->mask = bitmap_alloc(PTP_MAX_CHANNELS, GFP_KERNEL);
 252         if (!queue->mask)
 253                 goto no_memory_bitmap;
 254         bitmap_set(queue->mask, 0, PTP_MAX_CHANNELS);
 255         spin_lock_init(&queue->lock);
 256         mutex_init(&ptp->pincfg_mux);
 257         mutex_init(&ptp->n_vclocks_mux);
 258         init_waitqueue_head(&ptp->tsev_wq);
 259
 260         if (ptp->info->getcycles64 || ptp->info->getcyclesx64) {
 261                 ptp->has_cycles = true;
 262                 if (!ptp->info->getcycles64 && ptp->info->getcyclesx64)
 263                         ptp->info->getcycles64 = ptp_getcycles64;
 264         } else {
 265                 /* Free running cycle counter not supported, use time. */
 266                 ptp->info->getcycles64 = ptp_getcycles64;
 267
 268                 if (ptp->info->gettimex64)
 269                         ptp->info->getcyclesx64 = ptp->info->gettimex64;
 270
 271                 if (ptp->info->getcrosststamp)
 272                         ptp->info->getcrosscycles = ptp->info->getcrosststamp;
 273         }
 274
 275         if (ptp->info->do_aux_work) {
 276                 kthread_init_delayed_work(&ptp->aux_work, ptp_aux_kworker);
 277                 ptp->kworker = kthread_create_worker(0, "ptp%d", ptp->index);
 278                 if (IS_ERR(ptp->kworker)) {
 279                         err = PTR_ERR(ptp->kworker);
 280                         pr_err("failed to create ptp aux_worker %d\n", err);
 281                         goto kworker_err;
 282                 }
 283         }
 284
 285         /* PTP virtual clock is being registered under physical clock */
 286         if (parent && parent->class && parent->class->name &&
 287             strcmp(parent->class->name, "ptp") == 0)
 288                 ptp->is_virtual_clock = true;
 289
 290         if (!ptp->is_virtual_clock) {
 291                 ptp->max_vclocks = PTP_DEFAULT_MAX_VCLOCKS;
 292
 293                 size = sizeof(int) * ptp->max_vclocks;
 294                 ptp->vclock_index = kzalloc(size, GFP_KERNEL);
 295                 if (!ptp->vclock_index) {
 296                         err = -ENOMEM;
 297                         goto no_mem_for_vclocks;
 298                 }
 299         }
 300
 301         err = ptp_populate_pin_groups(ptp);
 302         if (err)
 303                 goto no_pin_groups;
 304
 305         /* Register a new PPS source. */
 306         if (info->pps) {
 307                 struct pps_source_info pps;
 308                 memset(&pps, 0, sizeof(pps));
 309                 snprintf(pps.name, PPS_MAX_NAME_LEN, "ptp%d", index);
 310                 pps.mode = PTP_PPS_MODE;
 311                 pps.owner = info->owner;
 312                 ptp->pps_source = pps_register_source(&pps, PTP_PPS_DEFAULTS);
 313                 if (IS_ERR(ptp->pps_source)) {
 314                         err = PTR_ERR(ptp->pps_source);
 315                         pr_err("failed to register pps source\n");
 316                         goto no_pps;
 317                 }
 318                 ptp->pps_source->lookup_cookie = ptp;
 319         }
 320
 321         /* Initialize a new device of our class in our clock structure. */
 322         device_initialize(&ptp->dev);
 323         ptp->dev.devt = ptp->devid;
 324         ptp->dev.class = ptp_class;
 325         ptp->dev.parent = parent;
 326         ptp->dev.groups = ptp->pin_attr_groups;
 327         ptp->dev.release = ptp_clock_release;
 328         dev_set_drvdata(&ptp->dev, ptp);
 329         dev_set_name(&ptp->dev, "ptp%d", ptp->index);
 330
 331         /* Create a posix clock and link it to the device. */
 332         err = posix_clock_register(&ptp->clock, &ptp->dev);
 333         if (err) {
 334                 if (ptp->pps_source)
 335                         pps_unregister_source(ptp->pps_source);
 336
 337                 if (ptp->kworker)
 338                         kthread_destroy_worker(ptp->kworker);
 339
 340                 put_device(&ptp->dev);
 341
 342                 pr_err("failed to create posix clock\n");
 343                 return ERR_PTR(err);
 344         }
 345
 346         /* Debugfs initialization */
 347         snprintf(debugfsname, sizeof(debugfsname), "ptp%d", ptp->index);
 348         ptp->debugfs_root = debugfs_create_dir(debugfsname, NULL);
 349
 350         return ptp;
 351
 352 no_pps:
 353         ptp_cleanup_pin_groups(ptp);
 354 no_pin_groups:
 355         kfree(ptp->vclock_index);
 356 no_mem_for_vclocks:
 357         if (ptp->kworker)
 358                 kthread_destroy_worker(ptp->kworker);
 359 kworker_err:
 360         mutex_destroy(&ptp->pincfg_mux);
 361         mutex_destroy(&ptp->n_vclocks_mux);
 362         bitmap_free(queue->mask);
 363 no_memory_bitmap:
 364         list_del(&queue->qlist);
 365         kfree(queue);
 366 no_memory_queue:
 367         ida_free(&ptp_clocks_map, index);
 368 no_slot:
 369         kfree(ptp);
 370 no_memory:
 371         return ERR_PTR(err);
 372 }
 373 EXPORT_SYMBOL(ptp_clock_register);
 374
 375 static int unregister_vclock(struct device *dev, void *data)
 376 {
 377         struct ptp_clock *ptp = dev_get_drvdata(dev);
 378
 379         ptp_vclock_unregister(info_to_vclock(ptp->info));
 380         return 0;
 381 }
 382
 383 int ptp_clock_unregister(struct ptp_clock *ptp)
 384 {
 385         if (ptp_vclock_in_use(ptp)) {
 386                 device_for_each_child(&ptp->dev, NULL, unregister_vclock);
 387         }
 388
 389         ptp->defunct = 1;
 390         wake_up_interruptible(&ptp->tsev_wq);
 391
 392         if (ptp->kworker) {
 393                 kthread_cancel_delayed_work_sync(&ptp->aux_work);
 394                 kthread_destroy_worker(ptp->kworker);
 395         }
 396
 397         /* Release the clock's resources. */
 398         if (ptp->pps_source)
 399                 pps_unregister_source(ptp->pps_source);
 400
 401         posix_clock_unregister(&ptp->clock);
 402
 403         return 0;
 404 }
 405 EXPORT_SYMBOL(ptp_clock_unregister);
 406
 407 void ptp_clock_event(struct ptp_clock *ptp, struct ptp_clock_event *event)
 408 {
 409         struct timestamp_event_queue *tsevq;
 410         struct pps_event_time evt;
 411         unsigned long flags;
 412
 413         switch (event->type) {
 414
 415         case PTP_CLOCK_ALARM:
 416                 break;
 417
 418         case PTP_CLOCK_EXTTS:
 419                 /* Enqueue timestamp on selected queues */
 420                 spin_lock_irqsave(&ptp->tsevqs_lock, flags);
 421                 list_for_each_entry(tsevq, &ptp->tsevqs, qlist) {
 422                         if (test_bit((unsigned int)event->index, tsevq->mask))
 423                                 enqueue_external_timestamp(tsevq, event);
 424                 }
 425                 spin_unlock_irqrestore(&ptp->tsevqs_lock, flags);
 426                 wake_up_interruptible(&ptp->tsev_wq);
 427                 break;
 428
 429         case PTP_CLOCK_PPS:
 430                 pps_get_ts(&evt);
 431                 pps_event(ptp->pps_source, &evt, PTP_PPS_EVENT, NULL);
 432                 break;
 433
 434         case PTP_CLOCK_PPSUSR:
 435                 pps_event(ptp->pps_source, &event->pps_times,
 436                           PTP_PPS_EVENT, NULL);
 437                 break;
 438         }
 439 }
 440 EXPORT_SYMBOL(ptp_clock_event);
 441
 442 int ptp_clock_index(struct ptp_clock *ptp)
 443 {
 444         return ptp->index;
 445 }
 446 EXPORT_SYMBOL(ptp_clock_index);
 447
 448 int ptp_find_pin(struct ptp_clock *ptp,
 449                  enum ptp_pin_function func, unsigned int chan)
 450 {
 451         struct ptp_pin_desc *pin = NULL;
 452         int i;
 453
 454         for (i = 0; i < ptp->info->n_pins; i++) {
 455                 if (ptp->info->pin_config[i].func == func &&
 456                     ptp->info->pin_config[i].chan == chan) {
 457                         pin = &ptp->info->pin_config[i];
 458                         break;
 459                 }
 460         }
 461
 462         return pin ? i : -1;
 463 }
 464 EXPORT_SYMBOL(ptp_find_pin);
 465
 466 int ptp_find_pin_unlocked(struct ptp_clock *ptp,
 467                           enum ptp_pin_function func, unsigned int chan)
 468 {
 469         int result;
 470
 471         mutex_lock(&ptp->pincfg_mux);
 472
 473         result = ptp_find_pin(ptp, func, chan);
 474
 475         mutex_unlock(&ptp->pincfg_mux);
 476
 477         return result;
 478 }
 479 EXPORT_SYMBOL(ptp_find_pin_unlocked);
 480
 481 int ptp_schedule_worker(struct ptp_clock *ptp, unsigned long delay)
 482 {
 483         return kthread_mod_delayed_work(ptp->kworker, &ptp->aux_work, delay);
 484 }
 485 EXPORT_SYMBOL(ptp_schedule_worker);
 486
 487 void ptp_cancel_worker_sync(struct ptp_clock *ptp)
 488 {
 489         kthread_cancel_delayed_work_sync(&ptp->aux_work);
 490 }
 491 EXPORT_SYMBOL(ptp_cancel_worker_sync);
 492
 493 /* module operations */
 494
 495 static void __exit ptp_exit(void)
 496 {
 497         class_destroy(ptp_class);
 498         unregister_chrdev_region(ptp_devt, MINORMASK + 1);
 499         ida_destroy(&ptp_clocks_map);
 500 }
 501
 502 static int __init ptp_init(void)
 503 {
 504         int err;
 505
 506         ptp_class = class_create("ptp");
 507         if (IS_ERR(ptp_class)) {
 508                 pr_err("ptp: failed to allocate class\n");
 509                 return PTR_ERR(ptp_class);
 510         }
 511
 512         err = alloc_chrdev_region(&ptp_devt, 0, MINORMASK + 1, "ptp");
 513         if (err < 0) {
 514                 pr_err("ptp: failed to allocate device region\n");
 515                 goto no_region;
 516         }
 517
 518         ptp_class->dev_groups = ptp_groups;
 519         pr_info("PTP clock support registered\n");
 520         return 0;
 521
 522 no_region:
 523         class_destroy(ptp_class);
 524         return err;
 525 }
 526
 527 subsys_initcall(ptp_init);
 528 module_exit(ptp_exit);
 529
 530 MODULE_AUTHOR("Richard Cochran <richardcochran@gmail.com>");
 531 MODULE_DESCRIPTION("PTP clocks support");
 532 MODULE_LICENSE("GPL");