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 /* private globals */ 28 29 static dev_t ptp_devt; 30 static struct class *ptp_class; 31 32 static DEFINE_IDA(ptp_clocks_map); 33 34 /* time stamp event queue operations */ 35 36 static inline int queue_free(struct timestamp_event_queue *q) 37 { 38 return PTP_MAX_TIMESTAMPS - queue_cnt(q) - 1; 39 } 40 41 static void enqueue_external_timestamp(struct timestamp_event_queue *queue, 42 struct ptp_clock_event *src) 43 { 44 struct ptp_extts_event *dst; 45 unsigned long flags; 46 s64 seconds; 47 u32 remainder; 48 49 seconds = div_u64_rem(src->timestamp, 1000000000, &remainder); 50 51 spin_lock_irqsave(&queue->lock, flags); 52 53 dst = &queue->buf[queue->tail]; 54 dst->index = src->index; 55 dst->t.sec = seconds; 56 dst->t.nsec = remainder; 57 58 if (!queue_free(queue)) 59 queue->head = (queue->head + 1) % PTP_MAX_TIMESTAMPS; 60 61 queue->tail = (queue->tail + 1) % PTP_MAX_TIMESTAMPS; 62 63 spin_unlock_irqrestore(&queue->lock, flags); 64 } 65 66 s32 scaled_ppm_to_ppb(long ppm) 67 { 68 /* 69 * The 'freq' field in the 'struct timex' is in parts per 70 * million, but with a 16 bit binary fractional field. 71 * 72 * We want to calculate 73 * 74 * ppb = scaled_ppm * 1000 / 2^16 75 * 76 * which simplifies to 77 * 78 * ppb = scaled_ppm * 125 / 2^13 79 */ 80 s64 ppb = 1 + ppm; 81 ppb *= 125; 82 ppb >>= 13; 83 return (s32) ppb; 84 } 85 EXPORT_SYMBOL(scaled_ppm_to_ppb); 86 87 /* posix clock implementation */ 88 89 static int ptp_clock_getres(struct posix_clock *pc, struct timespec64 *tp) 90 { 91 tp->tv_sec = 0; 92 tp->tv_nsec = 1; 93 return 0; 94 } 95 96 static int ptp_clock_settime(struct posix_clock *pc, const struct timespec64 *tp) 97 { 98 struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock); 99 100 return ptp->info->settime64(ptp->info, tp); 101 } 102 103 static int ptp_clock_gettime(struct posix_clock *pc, struct timespec64 *tp) 104 { 105 struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock); 106 int err; 107 108 if (ptp->info->gettimex64) 109 err = ptp->info->gettimex64(ptp->info, tp, NULL); 110 else 111 err = ptp->info->gettime64(ptp->info, tp); 112 return err; 113 } 114 115 static int ptp_clock_adjtime(struct posix_clock *pc, struct __kernel_timex *tx) 116 { 117 struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock); 118 struct ptp_clock_info *ops; 119 int err = -EOPNOTSUPP; 120 121 ops = ptp->info; 122 123 if (tx->modes & ADJ_SETOFFSET) { 124 struct timespec64 ts; 125 ktime_t kt; 126 s64 delta; 127 128 ts.tv_sec = tx->time.tv_sec; 129 ts.tv_nsec = tx->time.tv_usec; 130 131 if (!(tx->modes & ADJ_NANO)) 132 ts.tv_nsec *= 1000; 133 134 if ((unsigned long) ts.tv_nsec >= NSEC_PER_SEC) 135 return -EINVAL; 136 137 kt = timespec64_to_ktime(ts); 138 delta = ktime_to_ns(kt); 139 err = ops->adjtime(ops, delta); 140 } else if (tx->modes & ADJ_FREQUENCY) { 141 s32 ppb = scaled_ppm_to_ppb(tx->freq); 142 if (ppb > ops->max_adj || ppb < -ops->max_adj) 143 return -ERANGE; 144 if (ops->adjfine) 145 err = ops->adjfine(ops, tx->freq); 146 else 147 err = ops->adjfreq(ops, ppb); 148 ptp->dialed_frequency = tx->freq; 149 } else if (tx->modes & ADJ_OFFSET) { 150 if (ops->adjphase) { 151 s32 offset = tx->offset; 152 153 if (!(tx->modes & ADJ_NANO)) 154 offset *= NSEC_PER_USEC; 155 156 err = ops->adjphase(ops, offset); 157 } 158 } else if (tx->modes == 0) { 159 tx->freq = ptp->dialed_frequency; 160 err = 0; 161 } 162 163 return err; 164 } 165 166 static struct posix_clock_operations ptp_clock_ops = { 167 .owner = THIS_MODULE, 168 .clock_adjtime = ptp_clock_adjtime, 169 .clock_gettime = ptp_clock_gettime, 170 .clock_getres = ptp_clock_getres, 171 .clock_settime = ptp_clock_settime, 172 .ioctl = ptp_ioctl, 173 .open = ptp_open, 174 .poll = ptp_poll, 175 .read = ptp_read, 176 }; 177 178 static void ptp_clock_release(struct device *dev) 179 { 180 struct ptp_clock *ptp = container_of(dev, struct ptp_clock, dev); 181 182 ptp_cleanup_pin_groups(ptp); 183 mutex_destroy(&ptp->tsevq_mux); 184 mutex_destroy(&ptp->pincfg_mux); 185 ida_simple_remove(&ptp_clocks_map, ptp->index); 186 kfree(ptp); 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); 209 210 if (info->n_alarm > PTP_MAX_ALARMS) 211 return ERR_PTR(-EINVAL); 212 213 /* Initialize a clock structure. */ 214 err = -ENOMEM; 215 ptp = kzalloc(sizeof(struct ptp_clock), GFP_KERNEL); 216 if (ptp == NULL) 217 goto no_memory; 218 219 index = ida_simple_get(&ptp_clocks_map, 0, MINORMASK + 1, GFP_KERNEL); 220 if (index < 0) { 221 err = index; 222 goto no_slot; 223 } 224 225 ptp->clock.ops = ptp_clock_ops; 226 ptp->info = info; 227 ptp->devid = MKDEV(major, index); 228 ptp->index = index; 229 spin_lock_init(&ptp->tsevq.lock); 230 mutex_init(&ptp->tsevq_mux); 231 mutex_init(&ptp->pincfg_mux); 232 init_waitqueue_head(&ptp->tsev_wq); 233 234 if (ptp->info->do_aux_work) { 235 kthread_init_delayed_work(&ptp->aux_work, ptp_aux_kworker); 236 ptp->kworker = kthread_create_worker(0, "ptp%d", ptp->index); 237 if (IS_ERR(ptp->kworker)) { 238 err = PTR_ERR(ptp->kworker); 239 pr_err("failed to create ptp aux_worker %d\n", err); 240 goto kworker_err; 241 } 242 } 243 244 err = ptp_populate_pin_groups(ptp); 245 if (err) 246 goto no_pin_groups; 247 248 /* Register a new PPS source. */ 249 if (info->pps) { 250 struct pps_source_info pps; 251 memset(&pps, 0, sizeof(pps)); 252 snprintf(pps.name, PPS_MAX_NAME_LEN, "ptp%d", index); 253 pps.mode = PTP_PPS_MODE; 254 pps.owner = info->owner; 255 ptp->pps_source = pps_register_source(&pps, PTP_PPS_DEFAULTS); 256 if (IS_ERR(ptp->pps_source)) { 257 err = PTR_ERR(ptp->pps_source); 258 pr_err("failed to register pps source\n"); 259 goto no_pps; 260 } 261 } 262 263 /* Initialize a new device of our class in our clock structure. */ 264 device_initialize(&ptp->dev); 265 ptp->dev.devt = ptp->devid; 266 ptp->dev.class = ptp_class; 267 ptp->dev.parent = parent; 268 ptp->dev.groups = ptp->pin_attr_groups; 269 ptp->dev.release = ptp_clock_release; 270 dev_set_drvdata(&ptp->dev, ptp); 271 dev_set_name(&ptp->dev, "ptp%d", ptp->index); 272 273 /* Create a posix clock and link it to the device. */ 274 err = posix_clock_register(&ptp->clock, &ptp->dev); 275 if (err) { 276 pr_err("failed to create posix clock\n"); 277 goto no_clock; 278 } 279 280 return ptp; 281 282 no_clock: 283 if (ptp->pps_source) 284 pps_unregister_source(ptp->pps_source); 285 no_pps: 286 ptp_cleanup_pin_groups(ptp); 287 no_pin_groups: 288 if (ptp->kworker) 289 kthread_destroy_worker(ptp->kworker); 290 kworker_err: 291 mutex_destroy(&ptp->tsevq_mux); 292 mutex_destroy(&ptp->pincfg_mux); 293 ida_simple_remove(&ptp_clocks_map, index); 294 no_slot: 295 kfree(ptp); 296 no_memory: 297 return ERR_PTR(err); 298 } 299 EXPORT_SYMBOL(ptp_clock_register); 300 301 int ptp_clock_unregister(struct ptp_clock *ptp) 302 { 303 ptp->defunct = 1; 304 wake_up_interruptible(&ptp->tsev_wq); 305 306 if (ptp->kworker) { 307 kthread_cancel_delayed_work_sync(&ptp->aux_work); 308 kthread_destroy_worker(ptp->kworker); 309 } 310 311 /* Release the clock's resources. */ 312 if (ptp->pps_source) 313 pps_unregister_source(ptp->pps_source); 314 315 posix_clock_unregister(&ptp->clock); 316 317 return 0; 318 } 319 EXPORT_SYMBOL(ptp_clock_unregister); 320 321 void ptp_clock_event(struct ptp_clock *ptp, struct ptp_clock_event *event) 322 { 323 struct pps_event_time evt; 324 325 switch (event->type) { 326 327 case PTP_CLOCK_ALARM: 328 break; 329 330 case PTP_CLOCK_EXTTS: 331 enqueue_external_timestamp(&ptp->tsevq, event); 332 wake_up_interruptible(&ptp->tsev_wq); 333 break; 334 335 case PTP_CLOCK_PPS: 336 pps_get_ts(&evt); 337 pps_event(ptp->pps_source, &evt, PTP_PPS_EVENT, NULL); 338 break; 339 340 case PTP_CLOCK_PPSUSR: 341 pps_event(ptp->pps_source, &event->pps_times, 342 PTP_PPS_EVENT, NULL); 343 break; 344 } 345 } 346 EXPORT_SYMBOL(ptp_clock_event); 347 348 int ptp_clock_index(struct ptp_clock *ptp) 349 { 350 return ptp->index; 351 } 352 EXPORT_SYMBOL(ptp_clock_index); 353 354 int ptp_find_pin(struct ptp_clock *ptp, 355 enum ptp_pin_function func, unsigned int chan) 356 { 357 struct ptp_pin_desc *pin = NULL; 358 int i; 359 360 for (i = 0; i < ptp->info->n_pins; i++) { 361 if (ptp->info->pin_config[i].func == func && 362 ptp->info->pin_config[i].chan == chan) { 363 pin = &ptp->info->pin_config[i]; 364 break; 365 } 366 } 367 368 return pin ? i : -1; 369 } 370 EXPORT_SYMBOL(ptp_find_pin); 371 372 int ptp_find_pin_unlocked(struct ptp_clock *ptp, 373 enum ptp_pin_function func, unsigned int chan) 374 { 375 int result; 376 377 mutex_lock(&ptp->pincfg_mux); 378 379 result = ptp_find_pin(ptp, func, chan); 380 381 mutex_unlock(&ptp->pincfg_mux); 382 383 return result; 384 } 385 EXPORT_SYMBOL(ptp_find_pin_unlocked); 386 387 int ptp_schedule_worker(struct ptp_clock *ptp, unsigned long delay) 388 { 389 return kthread_mod_delayed_work(ptp->kworker, &ptp->aux_work, delay); 390 } 391 EXPORT_SYMBOL(ptp_schedule_worker); 392 393 void ptp_cancel_worker_sync(struct ptp_clock *ptp) 394 { 395 kthread_cancel_delayed_work_sync(&ptp->aux_work); 396 } 397 EXPORT_SYMBOL(ptp_cancel_worker_sync); 398 399 /* module operations */ 400 401 static void __exit ptp_exit(void) 402 { 403 class_destroy(ptp_class); 404 unregister_chrdev_region(ptp_devt, MINORMASK + 1); 405 ida_destroy(&ptp_clocks_map); 406 } 407 408 static int __init ptp_init(void) 409 { 410 int err; 411 412 ptp_class = class_create(THIS_MODULE, "ptp"); 413 if (IS_ERR(ptp_class)) { 414 pr_err("ptp: failed to allocate class\n"); 415 return PTR_ERR(ptp_class); 416 } 417 418 err = alloc_chrdev_region(&ptp_devt, 0, MINORMASK + 1, "ptp"); 419 if (err < 0) { 420 pr_err("ptp: failed to allocate device region\n"); 421 goto no_region; 422 } 423 424 ptp_class->dev_groups = ptp_groups; 425 pr_info("PTP clock support registered\n"); 426 return 0; 427 428 no_region: 429 class_destroy(ptp_class); 430 return err; 431 } 432 433 subsys_initcall(ptp_init); 434 module_exit(ptp_exit); 435 436 MODULE_AUTHOR("Richard Cochran <richardcochran@gmail.com>"); 437 MODULE_DESCRIPTION("PTP clocks support"); 438 MODULE_LICENSE("GPL"); 439