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 /* posix clock implementation */ 67 68 static int ptp_clock_getres(struct posix_clock *pc, struct timespec64 *tp) 69 { 70 tp->tv_sec = 0; 71 tp->tv_nsec = 1; 72 return 0; 73 } 74 75 static int ptp_clock_settime(struct posix_clock *pc, const struct timespec64 *tp) 76 { 77 struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock); 78 79 return ptp->info->settime64(ptp->info, tp); 80 } 81 82 static int ptp_clock_gettime(struct posix_clock *pc, struct timespec64 *tp) 83 { 84 struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock); 85 int err; 86 87 if (ptp->info->gettimex64) 88 err = ptp->info->gettimex64(ptp->info, tp, NULL); 89 else 90 err = ptp->info->gettime64(ptp->info, tp); 91 return err; 92 } 93 94 static int ptp_clock_adjtime(struct posix_clock *pc, struct __kernel_timex *tx) 95 { 96 struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock); 97 struct ptp_clock_info *ops; 98 int err = -EOPNOTSUPP; 99 100 ops = ptp->info; 101 102 if (tx->modes & ADJ_SETOFFSET) { 103 struct timespec64 ts; 104 ktime_t kt; 105 s64 delta; 106 107 ts.tv_sec = tx->time.tv_sec; 108 ts.tv_nsec = tx->time.tv_usec; 109 110 if (!(tx->modes & ADJ_NANO)) 111 ts.tv_nsec *= 1000; 112 113 if ((unsigned long) ts.tv_nsec >= NSEC_PER_SEC) 114 return -EINVAL; 115 116 kt = timespec64_to_ktime(ts); 117 delta = ktime_to_ns(kt); 118 err = ops->adjtime(ops, delta); 119 } else if (tx->modes & ADJ_FREQUENCY) { 120 long ppb = scaled_ppm_to_ppb(tx->freq); 121 if (ppb > ops->max_adj || ppb < -ops->max_adj) 122 return -ERANGE; 123 if (ops->adjfine) 124 err = ops->adjfine(ops, tx->freq); 125 else 126 err = ops->adjfreq(ops, ppb); 127 ptp->dialed_frequency = tx->freq; 128 } else if (tx->modes & ADJ_OFFSET) { 129 if (ops->adjphase) { 130 s32 offset = tx->offset; 131 132 if (!(tx->modes & ADJ_NANO)) 133 offset *= NSEC_PER_USEC; 134 135 err = ops->adjphase(ops, offset); 136 } 137 } else if (tx->modes == 0) { 138 tx->freq = ptp->dialed_frequency; 139 err = 0; 140 } 141 142 return err; 143 } 144 145 static struct posix_clock_operations ptp_clock_ops = { 146 .owner = THIS_MODULE, 147 .clock_adjtime = ptp_clock_adjtime, 148 .clock_gettime = ptp_clock_gettime, 149 .clock_getres = ptp_clock_getres, 150 .clock_settime = ptp_clock_settime, 151 .ioctl = ptp_ioctl, 152 .open = ptp_open, 153 .poll = ptp_poll, 154 .read = ptp_read, 155 }; 156 157 static void ptp_clock_release(struct device *dev) 158 { 159 struct ptp_clock *ptp = container_of(dev, struct ptp_clock, dev); 160 161 ptp_cleanup_pin_groups(ptp); 162 mutex_destroy(&ptp->tsevq_mux); 163 mutex_destroy(&ptp->pincfg_mux); 164 ida_simple_remove(&ptp_clocks_map, ptp->index); 165 kfree(ptp); 166 } 167 168 static void ptp_aux_kworker(struct kthread_work *work) 169 { 170 struct ptp_clock *ptp = container_of(work, struct ptp_clock, 171 aux_work.work); 172 struct ptp_clock_info *info = ptp->info; 173 long delay; 174 175 delay = info->do_aux_work(info); 176 177 if (delay >= 0) 178 kthread_queue_delayed_work(ptp->kworker, &ptp->aux_work, delay); 179 } 180 181 /* public interface */ 182 183 struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info, 184 struct device *parent) 185 { 186 struct ptp_clock *ptp; 187 int err = 0, index, major = MAJOR(ptp_devt); 188 189 if (info->n_alarm > PTP_MAX_ALARMS) 190 return ERR_PTR(-EINVAL); 191 192 /* Initialize a clock structure. */ 193 err = -ENOMEM; 194 ptp = kzalloc(sizeof(struct ptp_clock), GFP_KERNEL); 195 if (ptp == NULL) 196 goto no_memory; 197 198 index = ida_simple_get(&ptp_clocks_map, 0, MINORMASK + 1, GFP_KERNEL); 199 if (index < 0) { 200 err = index; 201 goto no_slot; 202 } 203 204 ptp->clock.ops = ptp_clock_ops; 205 ptp->info = info; 206 ptp->devid = MKDEV(major, index); 207 ptp->index = index; 208 spin_lock_init(&ptp->tsevq.lock); 209 mutex_init(&ptp->tsevq_mux); 210 mutex_init(&ptp->pincfg_mux); 211 init_waitqueue_head(&ptp->tsev_wq); 212 213 if (ptp->info->do_aux_work) { 214 kthread_init_delayed_work(&ptp->aux_work, ptp_aux_kworker); 215 ptp->kworker = kthread_create_worker(0, "ptp%d", ptp->index); 216 if (IS_ERR(ptp->kworker)) { 217 err = PTR_ERR(ptp->kworker); 218 pr_err("failed to create ptp aux_worker %d\n", err); 219 goto kworker_err; 220 } 221 ptp->pps_source->lookup_cookie = ptp; 222 } 223 224 err = ptp_populate_pin_groups(ptp); 225 if (err) 226 goto no_pin_groups; 227 228 /* Register a new PPS source. */ 229 if (info->pps) { 230 struct pps_source_info pps; 231 memset(&pps, 0, sizeof(pps)); 232 snprintf(pps.name, PPS_MAX_NAME_LEN, "ptp%d", index); 233 pps.mode = PTP_PPS_MODE; 234 pps.owner = info->owner; 235 ptp->pps_source = pps_register_source(&pps, PTP_PPS_DEFAULTS); 236 if (IS_ERR(ptp->pps_source)) { 237 err = PTR_ERR(ptp->pps_source); 238 pr_err("failed to register pps source\n"); 239 goto no_pps; 240 } 241 } 242 243 /* Initialize a new device of our class in our clock structure. */ 244 device_initialize(&ptp->dev); 245 ptp->dev.devt = ptp->devid; 246 ptp->dev.class = ptp_class; 247 ptp->dev.parent = parent; 248 ptp->dev.groups = ptp->pin_attr_groups; 249 ptp->dev.release = ptp_clock_release; 250 dev_set_drvdata(&ptp->dev, ptp); 251 dev_set_name(&ptp->dev, "ptp%d", ptp->index); 252 253 /* Create a posix clock and link it to the device. */ 254 err = posix_clock_register(&ptp->clock, &ptp->dev); 255 if (err) { 256 pr_err("failed to create posix clock\n"); 257 goto no_clock; 258 } 259 260 return ptp; 261 262 no_clock: 263 if (ptp->pps_source) 264 pps_unregister_source(ptp->pps_source); 265 no_pps: 266 ptp_cleanup_pin_groups(ptp); 267 no_pin_groups: 268 if (ptp->kworker) 269 kthread_destroy_worker(ptp->kworker); 270 kworker_err: 271 mutex_destroy(&ptp->tsevq_mux); 272 mutex_destroy(&ptp->pincfg_mux); 273 ida_simple_remove(&ptp_clocks_map, index); 274 no_slot: 275 kfree(ptp); 276 no_memory: 277 return ERR_PTR(err); 278 } 279 EXPORT_SYMBOL(ptp_clock_register); 280 281 int ptp_clock_unregister(struct ptp_clock *ptp) 282 { 283 ptp->defunct = 1; 284 wake_up_interruptible(&ptp->tsev_wq); 285 286 if (ptp->kworker) { 287 kthread_cancel_delayed_work_sync(&ptp->aux_work); 288 kthread_destroy_worker(ptp->kworker); 289 } 290 291 /* Release the clock's resources. */ 292 if (ptp->pps_source) 293 pps_unregister_source(ptp->pps_source); 294 295 posix_clock_unregister(&ptp->clock); 296 297 return 0; 298 } 299 EXPORT_SYMBOL(ptp_clock_unregister); 300 301 void ptp_clock_event(struct ptp_clock *ptp, struct ptp_clock_event *event) 302 { 303 struct pps_event_time evt; 304 305 switch (event->type) { 306 307 case PTP_CLOCK_ALARM: 308 break; 309 310 case PTP_CLOCK_EXTTS: 311 enqueue_external_timestamp(&ptp->tsevq, event); 312 wake_up_interruptible(&ptp->tsev_wq); 313 break; 314 315 case PTP_CLOCK_PPS: 316 pps_get_ts(&evt); 317 pps_event(ptp->pps_source, &evt, PTP_PPS_EVENT, NULL); 318 break; 319 320 case PTP_CLOCK_PPSUSR: 321 pps_event(ptp->pps_source, &event->pps_times, 322 PTP_PPS_EVENT, NULL); 323 break; 324 } 325 } 326 EXPORT_SYMBOL(ptp_clock_event); 327 328 int ptp_clock_index(struct ptp_clock *ptp) 329 { 330 return ptp->index; 331 } 332 EXPORT_SYMBOL(ptp_clock_index); 333 334 int ptp_find_pin(struct ptp_clock *ptp, 335 enum ptp_pin_function func, unsigned int chan) 336 { 337 struct ptp_pin_desc *pin = NULL; 338 int i; 339 340 for (i = 0; i < ptp->info->n_pins; i++) { 341 if (ptp->info->pin_config[i].func == func && 342 ptp->info->pin_config[i].chan == chan) { 343 pin = &ptp->info->pin_config[i]; 344 break; 345 } 346 } 347 348 return pin ? i : -1; 349 } 350 EXPORT_SYMBOL(ptp_find_pin); 351 352 int ptp_find_pin_unlocked(struct ptp_clock *ptp, 353 enum ptp_pin_function func, unsigned int chan) 354 { 355 int result; 356 357 mutex_lock(&ptp->pincfg_mux); 358 359 result = ptp_find_pin(ptp, func, chan); 360 361 mutex_unlock(&ptp->pincfg_mux); 362 363 return result; 364 } 365 EXPORT_SYMBOL(ptp_find_pin_unlocked); 366 367 int ptp_schedule_worker(struct ptp_clock *ptp, unsigned long delay) 368 { 369 return kthread_mod_delayed_work(ptp->kworker, &ptp->aux_work, delay); 370 } 371 EXPORT_SYMBOL(ptp_schedule_worker); 372 373 void ptp_cancel_worker_sync(struct ptp_clock *ptp) 374 { 375 kthread_cancel_delayed_work_sync(&ptp->aux_work); 376 } 377 EXPORT_SYMBOL(ptp_cancel_worker_sync); 378 379 /* module operations */ 380 381 static void __exit ptp_exit(void) 382 { 383 class_destroy(ptp_class); 384 unregister_chrdev_region(ptp_devt, MINORMASK + 1); 385 ida_destroy(&ptp_clocks_map); 386 } 387 388 static int __init ptp_init(void) 389 { 390 int err; 391 392 ptp_class = class_create(THIS_MODULE, "ptp"); 393 if (IS_ERR(ptp_class)) { 394 pr_err("ptp: failed to allocate class\n"); 395 return PTR_ERR(ptp_class); 396 } 397 398 err = alloc_chrdev_region(&ptp_devt, 0, MINORMASK + 1, "ptp"); 399 if (err < 0) { 400 pr_err("ptp: failed to allocate device region\n"); 401 goto no_region; 402 } 403 404 ptp_class->dev_groups = ptp_groups; 405 pr_info("PTP clock support registered\n"); 406 return 0; 407 408 no_region: 409 class_destroy(ptp_class); 410 return err; 411 } 412 413 subsys_initcall(ptp_init); 414 module_exit(ptp_exit); 415 416 MODULE_AUTHOR("Richard Cochran <richardcochran@gmail.com>"); 417 MODULE_DESCRIPTION("PTP clocks support"); 418 MODULE_LICENSE("GPL"); 419