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_free(&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_alloc_max(&ptp_clocks_map, MINORMASK, 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_free(&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"); 493