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"); 490