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