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