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