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 <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
  37 static inline int queue_free(struct timestamp_event_queue *q)
  38 {
  39         return PTP_MAX_TIMESTAMPS - queue_cnt(q) - 1;
  40 }
  41
  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
  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
  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
  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
 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
 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_simple_remove(&ptp_clocks_map, ptp->index);
 178         kfree(ptp);
 179 }
 180
 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
 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
 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_simple_get(&ptp_clocks_map, 0, MINORMASK + 1, 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_simple_remove(&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
 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
 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
 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
 402 int ptp_clock_index(struct ptp_clock *ptp)
 403 {
 404         return ptp->index;
 405 }
 406 EXPORT_SYMBOL(ptp_clock_index);
 407
 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
 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
 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
 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
 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
 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");