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 /* Both WRITE_ONCE() are paired with READ_ONCE() in queue_cnt() */ 60 if (!queue_free(queue)) 61 WRITE_ONCE(queue->head, (queue->head + 1) % PTP_MAX_TIMESTAMPS); 62 63 WRITE_ONCE(queue->tail, (queue->tail + 1) % PTP_MAX_TIMESTAMPS); 64 65 spin_unlock_irqrestore(&queue->lock, flags); 66 } 67 68 /* posix clock implementation */ 69 70 static int ptp_clock_getres(struct posix_clock *pc, struct timespec64 *tp) 71 { 72 tp->tv_sec = 0; 73 tp->tv_nsec = 1; 74 return 0; 75 } 76 77 static int ptp_clock_settime(struct posix_clock *pc, const struct timespec64 *tp) 78 { 79 struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock); 80 81 if (ptp_clock_freerun(ptp)) { 82 pr_err("ptp: physical clock is free running\n"); 83 return -EBUSY; 84 } 85 86 return ptp->info->settime64(ptp->info, tp); 87 } 88 89 static int ptp_clock_gettime(struct posix_clock *pc, struct timespec64 *tp) 90 { 91 struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock); 92 int err; 93 94 if (ptp->info->gettimex64) 95 err = ptp->info->gettimex64(ptp->info, tp, NULL); 96 else 97 err = ptp->info->gettime64(ptp->info, tp); 98 return err; 99 } 100 101 static int ptp_clock_adjtime(struct posix_clock *pc, struct __kernel_timex *tx) 102 { 103 struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock); 104 struct ptp_clock_info *ops; 105 int err = -EOPNOTSUPP; 106 107 if (ptp_clock_freerun(ptp)) { 108 pr_err("ptp: physical clock is free running\n"); 109 return -EBUSY; 110 } 111 112 ops = ptp->info; 113 114 if (tx->modes & ADJ_SETOFFSET) { 115 struct timespec64 ts; 116 ktime_t kt; 117 s64 delta; 118 119 ts.tv_sec = tx->time.tv_sec; 120 ts.tv_nsec = tx->time.tv_usec; 121 122 if (!(tx->modes & ADJ_NANO)) 123 ts.tv_nsec *= 1000; 124 125 if ((unsigned long) ts.tv_nsec >= NSEC_PER_SEC) 126 return -EINVAL; 127 128 kt = timespec64_to_ktime(ts); 129 delta = ktime_to_ns(kt); 130 err = ops->adjtime(ops, delta); 131 } else if (tx->modes & ADJ_FREQUENCY) { 132 long ppb = scaled_ppm_to_ppb(tx->freq); 133 if (ppb > ops->max_adj || ppb < -ops->max_adj) 134 return -ERANGE; 135 err = ops->adjfine(ops, tx->freq); 136 ptp->dialed_frequency = tx->freq; 137 } else if (tx->modes & ADJ_OFFSET) { 138 if (ops->adjphase) { 139 s32 max_phase_adj = ops->getmaxphase(ops); 140 s32 offset = tx->offset; 141 142 if (!(tx->modes & ADJ_NANO)) 143 offset *= NSEC_PER_USEC; 144 145 if (offset > max_phase_adj || offset < -max_phase_adj) 146 return -ERANGE; 147 148 err = ops->adjphase(ops, offset); 149 } 150 } else if (tx->modes == 0) { 151 tx->freq = ptp->dialed_frequency; 152 err = 0; 153 } 154 155 return err; 156 } 157 158 static struct posix_clock_operations ptp_clock_ops = { 159 .owner = THIS_MODULE, 160 .clock_adjtime = ptp_clock_adjtime, 161 .clock_gettime = ptp_clock_gettime, 162 .clock_getres = ptp_clock_getres, 163 .clock_settime = ptp_clock_settime, 164 .ioctl = ptp_ioctl, 165 .open = ptp_open, 166 .poll = ptp_poll, 167 .read = ptp_read, 168 }; 169 170 static void ptp_clock_release(struct device *dev) 171 { 172 struct ptp_clock *ptp = container_of(dev, struct ptp_clock, dev); 173 174 ptp_cleanup_pin_groups(ptp); 175 kfree(ptp->vclock_index); 176 mutex_destroy(&ptp->tsevq_mux); 177 mutex_destroy(&ptp->pincfg_mux); 178 mutex_destroy(&ptp->n_vclocks_mux); 179 ida_free(&ptp_clocks_map, ptp->index); 180 kfree(ptp); 181 } 182 183 static int ptp_getcycles64(struct ptp_clock_info *info, struct timespec64 *ts) 184 { 185 if (info->getcyclesx64) 186 return info->getcyclesx64(info, ts, NULL); 187 else 188 return info->gettime64(info, ts); 189 } 190 191 static void ptp_aux_kworker(struct kthread_work *work) 192 { 193 struct ptp_clock *ptp = container_of(work, struct ptp_clock, 194 aux_work.work); 195 struct ptp_clock_info *info = ptp->info; 196 long delay; 197 198 delay = info->do_aux_work(info); 199 200 if (delay >= 0) 201 kthread_queue_delayed_work(ptp->kworker, &ptp->aux_work, delay); 202 } 203 204 /* public interface */ 205 206 struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info, 207 struct device *parent) 208 { 209 struct ptp_clock *ptp; 210 int err = 0, index, major = MAJOR(ptp_devt); 211 size_t size; 212 213 if (info->n_alarm > PTP_MAX_ALARMS) 214 return ERR_PTR(-EINVAL); 215 216 /* Initialize a clock structure. */ 217 err = -ENOMEM; 218 ptp = kzalloc(sizeof(struct ptp_clock), GFP_KERNEL); 219 if (ptp == NULL) 220 goto no_memory; 221 222 index = ida_alloc_max(&ptp_clocks_map, MINORMASK, GFP_KERNEL); 223 if (index < 0) { 224 err = index; 225 goto no_slot; 226 } 227 228 ptp->clock.ops = ptp_clock_ops; 229 ptp->info = info; 230 ptp->devid = MKDEV(major, index); 231 ptp->index = index; 232 spin_lock_init(&ptp->tsevq.lock); 233 mutex_init(&ptp->tsevq_mux); 234 mutex_init(&ptp->pincfg_mux); 235 mutex_init(&ptp->n_vclocks_mux); 236 init_waitqueue_head(&ptp->tsev_wq); 237 238 if (ptp->info->getcycles64 || ptp->info->getcyclesx64) { 239 ptp->has_cycles = true; 240 if (!ptp->info->getcycles64 && ptp->info->getcyclesx64) 241 ptp->info->getcycles64 = ptp_getcycles64; 242 } else { 243 /* Free running cycle counter not supported, use time. */ 244 ptp->info->getcycles64 = ptp_getcycles64; 245 246 if (ptp->info->gettimex64) 247 ptp->info->getcyclesx64 = ptp->info->gettimex64; 248 249 if (ptp->info->getcrosststamp) 250 ptp->info->getcrosscycles = ptp->info->getcrosststamp; 251 } 252 253 if (ptp->info->do_aux_work) { 254 kthread_init_delayed_work(&ptp->aux_work, ptp_aux_kworker); 255 ptp->kworker = kthread_create_worker(0, "ptp%d", ptp->index); 256 if (IS_ERR(ptp->kworker)) { 257 err = PTR_ERR(ptp->kworker); 258 pr_err("failed to create ptp aux_worker %d\n", err); 259 goto kworker_err; 260 } 261 } 262 263 /* PTP virtual clock is being registered under physical clock */ 264 if (parent && parent->class && parent->class->name && 265 strcmp(parent->class->name, "ptp") == 0) 266 ptp->is_virtual_clock = true; 267 268 if (!ptp->is_virtual_clock) { 269 ptp->max_vclocks = PTP_DEFAULT_MAX_VCLOCKS; 270 271 size = sizeof(int) * ptp->max_vclocks; 272 ptp->vclock_index = kzalloc(size, GFP_KERNEL); 273 if (!ptp->vclock_index) { 274 err = -ENOMEM; 275 goto no_mem_for_vclocks; 276 } 277 } 278 279 err = ptp_populate_pin_groups(ptp); 280 if (err) 281 goto no_pin_groups; 282 283 /* Register a new PPS source. */ 284 if (info->pps) { 285 struct pps_source_info pps; 286 memset(&pps, 0, sizeof(pps)); 287 snprintf(pps.name, PPS_MAX_NAME_LEN, "ptp%d", index); 288 pps.mode = PTP_PPS_MODE; 289 pps.owner = info->owner; 290 ptp->pps_source = pps_register_source(&pps, PTP_PPS_DEFAULTS); 291 if (IS_ERR(ptp->pps_source)) { 292 err = PTR_ERR(ptp->pps_source); 293 pr_err("failed to register pps source\n"); 294 goto no_pps; 295 } 296 ptp->pps_source->lookup_cookie = ptp; 297 } 298 299 /* Initialize a new device of our class in our clock structure. */ 300 device_initialize(&ptp->dev); 301 ptp->dev.devt = ptp->devid; 302 ptp->dev.class = ptp_class; 303 ptp->dev.parent = parent; 304 ptp->dev.groups = ptp->pin_attr_groups; 305 ptp->dev.release = ptp_clock_release; 306 dev_set_drvdata(&ptp->dev, ptp); 307 dev_set_name(&ptp->dev, "ptp%d", ptp->index); 308 309 /* Create a posix clock and link it to the device. */ 310 err = posix_clock_register(&ptp->clock, &ptp->dev); 311 if (err) { 312 if (ptp->pps_source) 313 pps_unregister_source(ptp->pps_source); 314 315 if (ptp->kworker) 316 kthread_destroy_worker(ptp->kworker); 317 318 put_device(&ptp->dev); 319 320 pr_err("failed to create posix clock\n"); 321 return ERR_PTR(err); 322 } 323 324 return ptp; 325 326 no_pps: 327 ptp_cleanup_pin_groups(ptp); 328 no_pin_groups: 329 kfree(ptp->vclock_index); 330 no_mem_for_vclocks: 331 if (ptp->kworker) 332 kthread_destroy_worker(ptp->kworker); 333 kworker_err: 334 mutex_destroy(&ptp->tsevq_mux); 335 mutex_destroy(&ptp->pincfg_mux); 336 mutex_destroy(&ptp->n_vclocks_mux); 337 ida_free(&ptp_clocks_map, index); 338 no_slot: 339 kfree(ptp); 340 no_memory: 341 return ERR_PTR(err); 342 } 343 EXPORT_SYMBOL(ptp_clock_register); 344 345 static int unregister_vclock(struct device *dev, void *data) 346 { 347 struct ptp_clock *ptp = dev_get_drvdata(dev); 348 349 ptp_vclock_unregister(info_to_vclock(ptp->info)); 350 return 0; 351 } 352 353 int ptp_clock_unregister(struct ptp_clock *ptp) 354 { 355 if (ptp_vclock_in_use(ptp)) { 356 device_for_each_child(&ptp->dev, NULL, unregister_vclock); 357 } 358 359 ptp->defunct = 1; 360 wake_up_interruptible(&ptp->tsev_wq); 361 362 if (ptp->kworker) { 363 kthread_cancel_delayed_work_sync(&ptp->aux_work); 364 kthread_destroy_worker(ptp->kworker); 365 } 366 367 /* Release the clock's resources. */ 368 if (ptp->pps_source) 369 pps_unregister_source(ptp->pps_source); 370 371 posix_clock_unregister(&ptp->clock); 372 373 return 0; 374 } 375 EXPORT_SYMBOL(ptp_clock_unregister); 376 377 void ptp_clock_event(struct ptp_clock *ptp, struct ptp_clock_event *event) 378 { 379 struct pps_event_time evt; 380 381 switch (event->type) { 382 383 case PTP_CLOCK_ALARM: 384 break; 385 386 case PTP_CLOCK_EXTTS: 387 enqueue_external_timestamp(&ptp->tsevq, event); 388 wake_up_interruptible(&ptp->tsev_wq); 389 break; 390 391 case PTP_CLOCK_PPS: 392 pps_get_ts(&evt); 393 pps_event(ptp->pps_source, &evt, PTP_PPS_EVENT, NULL); 394 break; 395 396 case PTP_CLOCK_PPSUSR: 397 pps_event(ptp->pps_source, &event->pps_times, 398 PTP_PPS_EVENT, NULL); 399 break; 400 } 401 } 402 EXPORT_SYMBOL(ptp_clock_event); 403 404 int ptp_clock_index(struct ptp_clock *ptp) 405 { 406 return ptp->index; 407 } 408 EXPORT_SYMBOL(ptp_clock_index); 409 410 int ptp_find_pin(struct ptp_clock *ptp, 411 enum ptp_pin_function func, unsigned int chan) 412 { 413 struct ptp_pin_desc *pin = NULL; 414 int i; 415 416 for (i = 0; i < ptp->info->n_pins; i++) { 417 if (ptp->info->pin_config[i].func == func && 418 ptp->info->pin_config[i].chan == chan) { 419 pin = &ptp->info->pin_config[i]; 420 break; 421 } 422 } 423 424 return pin ? i : -1; 425 } 426 EXPORT_SYMBOL(ptp_find_pin); 427 428 int ptp_find_pin_unlocked(struct ptp_clock *ptp, 429 enum ptp_pin_function func, unsigned int chan) 430 { 431 int result; 432 433 mutex_lock(&ptp->pincfg_mux); 434 435 result = ptp_find_pin(ptp, func, chan); 436 437 mutex_unlock(&ptp->pincfg_mux); 438 439 return result; 440 } 441 EXPORT_SYMBOL(ptp_find_pin_unlocked); 442 443 int ptp_schedule_worker(struct ptp_clock *ptp, unsigned long delay) 444 { 445 return kthread_mod_delayed_work(ptp->kworker, &ptp->aux_work, delay); 446 } 447 EXPORT_SYMBOL(ptp_schedule_worker); 448 449 void ptp_cancel_worker_sync(struct ptp_clock *ptp) 450 { 451 kthread_cancel_delayed_work_sync(&ptp->aux_work); 452 } 453 EXPORT_SYMBOL(ptp_cancel_worker_sync); 454 455 /* module operations */ 456 457 static void __exit ptp_exit(void) 458 { 459 class_destroy(ptp_class); 460 unregister_chrdev_region(ptp_devt, MINORMASK + 1); 461 ida_destroy(&ptp_clocks_map); 462 } 463 464 static int __init ptp_init(void) 465 { 466 int err; 467 468 ptp_class = class_create("ptp"); 469 if (IS_ERR(ptp_class)) { 470 pr_err("ptp: failed to allocate class\n"); 471 return PTR_ERR(ptp_class); 472 } 473 474 err = alloc_chrdev_region(&ptp_devt, 0, MINORMASK + 1, "ptp"); 475 if (err < 0) { 476 pr_err("ptp: failed to allocate device region\n"); 477 goto no_region; 478 } 479 480 ptp_class->dev_groups = ptp_groups; 481 pr_info("PTP clock support registered\n"); 482 return 0; 483 484 no_region: 485 class_destroy(ptp_class); 486 return err; 487 } 488 489 subsys_initcall(ptp_init); 490 module_exit(ptp_exit); 491 492 MODULE_AUTHOR("Richard Cochran <richardcochran@gmail.com>"); 493 MODULE_DESCRIPTION("PTP clocks support"); 494 MODULE_LICENSE("GPL"); 495