1 /* 2 * TI Common Platform Time Sync 3 * 4 * Copyright (C) 2012 Richard Cochran <richardcochran@gmail.com> 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License as published by 8 * the Free Software Foundation; either version 2 of the License, or 9 * (at your option) any later version. 10 * 11 * This program is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for more details. 15 * 16 * You should have received a copy of the GNU General Public License 17 * along with this program; if not, write to the Free Software 18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA 19 */ 20 #include <linux/err.h> 21 #include <linux/if.h> 22 #include <linux/hrtimer.h> 23 #include <linux/module.h> 24 #include <linux/net_tstamp.h> 25 #include <linux/ptp_classify.h> 26 #include <linux/time.h> 27 #include <linux/uaccess.h> 28 #include <linux/workqueue.h> 29 #include <linux/if_ether.h> 30 #include <linux/if_vlan.h> 31 32 #include "cpts.h" 33 34 #define CPTS_SKB_TX_WORK_TIMEOUT 1 /* jiffies */ 35 36 struct cpts_skb_cb_data { 37 unsigned long tmo; 38 }; 39 40 #define cpts_read32(c, r) readl_relaxed(&c->reg->r) 41 #define cpts_write32(c, v, r) writel_relaxed(v, &c->reg->r) 42 43 static int cpts_match(struct sk_buff *skb, unsigned int ptp_class, 44 u16 ts_seqid, u8 ts_msgtype); 45 46 static int event_expired(struct cpts_event *event) 47 { 48 return time_after(jiffies, event->tmo); 49 } 50 51 static int event_type(struct cpts_event *event) 52 { 53 return (event->high >> EVENT_TYPE_SHIFT) & EVENT_TYPE_MASK; 54 } 55 56 static int cpts_fifo_pop(struct cpts *cpts, u32 *high, u32 *low) 57 { 58 u32 r = cpts_read32(cpts, intstat_raw); 59 60 if (r & TS_PEND_RAW) { 61 *high = cpts_read32(cpts, event_high); 62 *low = cpts_read32(cpts, event_low); 63 cpts_write32(cpts, EVENT_POP, event_pop); 64 return 0; 65 } 66 return -1; 67 } 68 69 static int cpts_purge_events(struct cpts *cpts) 70 { 71 struct list_head *this, *next; 72 struct cpts_event *event; 73 int removed = 0; 74 75 list_for_each_safe(this, next, &cpts->events) { 76 event = list_entry(this, struct cpts_event, list); 77 if (event_expired(event)) { 78 list_del_init(&event->list); 79 list_add(&event->list, &cpts->pool); 80 ++removed; 81 } 82 } 83 84 if (removed) 85 pr_debug("cpts: event pool cleaned up %d\n", removed); 86 return removed ? 0 : -1; 87 } 88 89 static bool cpts_match_tx_ts(struct cpts *cpts, struct cpts_event *event) 90 { 91 struct sk_buff *skb, *tmp; 92 u16 seqid; 93 u8 mtype; 94 bool found = false; 95 96 mtype = (event->high >> MESSAGE_TYPE_SHIFT) & MESSAGE_TYPE_MASK; 97 seqid = (event->high >> SEQUENCE_ID_SHIFT) & SEQUENCE_ID_MASK; 98 99 /* no need to grab txq.lock as access is always done under cpts->lock */ 100 skb_queue_walk_safe(&cpts->txq, skb, tmp) { 101 struct skb_shared_hwtstamps ssh; 102 unsigned int class = ptp_classify_raw(skb); 103 struct cpts_skb_cb_data *skb_cb = 104 (struct cpts_skb_cb_data *)skb->cb; 105 106 if (cpts_match(skb, class, seqid, mtype)) { 107 u64 ns = timecounter_cyc2time(&cpts->tc, event->low); 108 109 memset(&ssh, 0, sizeof(ssh)); 110 ssh.hwtstamp = ns_to_ktime(ns); 111 skb_tstamp_tx(skb, &ssh); 112 found = true; 113 __skb_unlink(skb, &cpts->txq); 114 dev_consume_skb_any(skb); 115 dev_dbg(cpts->dev, "match tx timestamp mtype %u seqid %04x\n", 116 mtype, seqid); 117 break; 118 } 119 120 if (time_after(jiffies, skb_cb->tmo)) { 121 /* timeout any expired skbs over 1s */ 122 dev_dbg(cpts->dev, 123 "expiring tx timestamp mtype %u seqid %04x\n", 124 mtype, seqid); 125 __skb_unlink(skb, &cpts->txq); 126 dev_consume_skb_any(skb); 127 } 128 } 129 130 return found; 131 } 132 133 /* 134 * Returns zero if matching event type was found. 135 */ 136 static int cpts_fifo_read(struct cpts *cpts, int match) 137 { 138 int i, type = -1; 139 u32 hi, lo; 140 struct cpts_event *event; 141 142 for (i = 0; i < CPTS_FIFO_DEPTH; i++) { 143 if (cpts_fifo_pop(cpts, &hi, &lo)) 144 break; 145 146 if (list_empty(&cpts->pool) && cpts_purge_events(cpts)) { 147 pr_err("cpts: event pool empty\n"); 148 return -1; 149 } 150 151 event = list_first_entry(&cpts->pool, struct cpts_event, list); 152 event->tmo = jiffies + 2; 153 event->high = hi; 154 event->low = lo; 155 type = event_type(event); 156 switch (type) { 157 case CPTS_EV_TX: 158 if (cpts_match_tx_ts(cpts, event)) { 159 /* if the new event matches an existing skb, 160 * then don't queue it 161 */ 162 break; 163 } 164 case CPTS_EV_PUSH: 165 case CPTS_EV_RX: 166 list_del_init(&event->list); 167 list_add_tail(&event->list, &cpts->events); 168 break; 169 case CPTS_EV_ROLL: 170 case CPTS_EV_HALF: 171 case CPTS_EV_HW: 172 break; 173 default: 174 pr_err("cpts: unknown event type\n"); 175 break; 176 } 177 if (type == match) 178 break; 179 } 180 return type == match ? 0 : -1; 181 } 182 183 static u64 cpts_systim_read(const struct cyclecounter *cc) 184 { 185 u64 val = 0; 186 struct cpts_event *event; 187 struct list_head *this, *next; 188 struct cpts *cpts = container_of(cc, struct cpts, cc); 189 190 cpts_write32(cpts, TS_PUSH, ts_push); 191 if (cpts_fifo_read(cpts, CPTS_EV_PUSH)) 192 pr_err("cpts: unable to obtain a time stamp\n"); 193 194 list_for_each_safe(this, next, &cpts->events) { 195 event = list_entry(this, struct cpts_event, list); 196 if (event_type(event) == CPTS_EV_PUSH) { 197 list_del_init(&event->list); 198 list_add(&event->list, &cpts->pool); 199 val = event->low; 200 break; 201 } 202 } 203 204 return val; 205 } 206 207 /* PTP clock operations */ 208 209 static int cpts_ptp_adjfreq(struct ptp_clock_info *ptp, s32 ppb) 210 { 211 u64 adj; 212 u32 diff, mult; 213 int neg_adj = 0; 214 unsigned long flags; 215 struct cpts *cpts = container_of(ptp, struct cpts, info); 216 217 if (ppb < 0) { 218 neg_adj = 1; 219 ppb = -ppb; 220 } 221 mult = cpts->cc_mult; 222 adj = mult; 223 adj *= ppb; 224 diff = div_u64(adj, 1000000000ULL); 225 226 spin_lock_irqsave(&cpts->lock, flags); 227 228 timecounter_read(&cpts->tc); 229 230 cpts->cc.mult = neg_adj ? mult - diff : mult + diff; 231 232 spin_unlock_irqrestore(&cpts->lock, flags); 233 234 return 0; 235 } 236 237 static int cpts_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta) 238 { 239 unsigned long flags; 240 struct cpts *cpts = container_of(ptp, struct cpts, info); 241 242 spin_lock_irqsave(&cpts->lock, flags); 243 timecounter_adjtime(&cpts->tc, delta); 244 spin_unlock_irqrestore(&cpts->lock, flags); 245 246 return 0; 247 } 248 249 static int cpts_ptp_gettime(struct ptp_clock_info *ptp, struct timespec64 *ts) 250 { 251 u64 ns; 252 unsigned long flags; 253 struct cpts *cpts = container_of(ptp, struct cpts, info); 254 255 spin_lock_irqsave(&cpts->lock, flags); 256 ns = timecounter_read(&cpts->tc); 257 spin_unlock_irqrestore(&cpts->lock, flags); 258 259 *ts = ns_to_timespec64(ns); 260 261 return 0; 262 } 263 264 static int cpts_ptp_settime(struct ptp_clock_info *ptp, 265 const struct timespec64 *ts) 266 { 267 u64 ns; 268 unsigned long flags; 269 struct cpts *cpts = container_of(ptp, struct cpts, info); 270 271 ns = timespec64_to_ns(ts); 272 273 spin_lock_irqsave(&cpts->lock, flags); 274 timecounter_init(&cpts->tc, &cpts->cc, ns); 275 spin_unlock_irqrestore(&cpts->lock, flags); 276 277 return 0; 278 } 279 280 static int cpts_ptp_enable(struct ptp_clock_info *ptp, 281 struct ptp_clock_request *rq, int on) 282 { 283 return -EOPNOTSUPP; 284 } 285 286 static long cpts_overflow_check(struct ptp_clock_info *ptp) 287 { 288 struct cpts *cpts = container_of(ptp, struct cpts, info); 289 unsigned long delay = cpts->ov_check_period; 290 struct timespec64 ts; 291 unsigned long flags; 292 293 spin_lock_irqsave(&cpts->lock, flags); 294 ts = ns_to_timespec64(timecounter_read(&cpts->tc)); 295 296 if (!skb_queue_empty(&cpts->txq)) 297 delay = CPTS_SKB_TX_WORK_TIMEOUT; 298 spin_unlock_irqrestore(&cpts->lock, flags); 299 300 pr_debug("cpts overflow check at %lld.%09ld\n", 301 (long long)ts.tv_sec, ts.tv_nsec); 302 return (long)delay; 303 } 304 305 static const struct ptp_clock_info cpts_info = { 306 .owner = THIS_MODULE, 307 .name = "CTPS timer", 308 .max_adj = 1000000, 309 .n_ext_ts = 0, 310 .n_pins = 0, 311 .pps = 0, 312 .adjfreq = cpts_ptp_adjfreq, 313 .adjtime = cpts_ptp_adjtime, 314 .gettime64 = cpts_ptp_gettime, 315 .settime64 = cpts_ptp_settime, 316 .enable = cpts_ptp_enable, 317 .do_aux_work = cpts_overflow_check, 318 }; 319 320 static int cpts_match(struct sk_buff *skb, unsigned int ptp_class, 321 u16 ts_seqid, u8 ts_msgtype) 322 { 323 u16 *seqid; 324 unsigned int offset = 0; 325 u8 *msgtype, *data = skb->data; 326 327 if (ptp_class & PTP_CLASS_VLAN) 328 offset += VLAN_HLEN; 329 330 switch (ptp_class & PTP_CLASS_PMASK) { 331 case PTP_CLASS_IPV4: 332 offset += ETH_HLEN + IPV4_HLEN(data + offset) + UDP_HLEN; 333 break; 334 case PTP_CLASS_IPV6: 335 offset += ETH_HLEN + IP6_HLEN + UDP_HLEN; 336 break; 337 case PTP_CLASS_L2: 338 offset += ETH_HLEN; 339 break; 340 default: 341 return 0; 342 } 343 344 if (skb->len + ETH_HLEN < offset + OFF_PTP_SEQUENCE_ID + sizeof(*seqid)) 345 return 0; 346 347 if (unlikely(ptp_class & PTP_CLASS_V1)) 348 msgtype = data + offset + OFF_PTP_CONTROL; 349 else 350 msgtype = data + offset; 351 352 seqid = (u16 *)(data + offset + OFF_PTP_SEQUENCE_ID); 353 354 return (ts_msgtype == (*msgtype & 0xf) && ts_seqid == ntohs(*seqid)); 355 } 356 357 static u64 cpts_find_ts(struct cpts *cpts, struct sk_buff *skb, int ev_type) 358 { 359 u64 ns = 0; 360 struct cpts_event *event; 361 struct list_head *this, *next; 362 unsigned int class = ptp_classify_raw(skb); 363 unsigned long flags; 364 u16 seqid; 365 u8 mtype; 366 367 if (class == PTP_CLASS_NONE) 368 return 0; 369 370 spin_lock_irqsave(&cpts->lock, flags); 371 cpts_fifo_read(cpts, -1); 372 list_for_each_safe(this, next, &cpts->events) { 373 event = list_entry(this, struct cpts_event, list); 374 if (event_expired(event)) { 375 list_del_init(&event->list); 376 list_add(&event->list, &cpts->pool); 377 continue; 378 } 379 mtype = (event->high >> MESSAGE_TYPE_SHIFT) & MESSAGE_TYPE_MASK; 380 seqid = (event->high >> SEQUENCE_ID_SHIFT) & SEQUENCE_ID_MASK; 381 if (ev_type == event_type(event) && 382 cpts_match(skb, class, seqid, mtype)) { 383 ns = timecounter_cyc2time(&cpts->tc, event->low); 384 list_del_init(&event->list); 385 list_add(&event->list, &cpts->pool); 386 break; 387 } 388 } 389 390 if (ev_type == CPTS_EV_TX && !ns) { 391 struct cpts_skb_cb_data *skb_cb = 392 (struct cpts_skb_cb_data *)skb->cb; 393 /* Not found, add frame to queue for processing later. 394 * The periodic FIFO check will handle this. 395 */ 396 skb_get(skb); 397 /* get the timestamp for timeouts */ 398 skb_cb->tmo = jiffies + msecs_to_jiffies(100); 399 __skb_queue_tail(&cpts->txq, skb); 400 ptp_schedule_worker(cpts->clock, 0); 401 } 402 spin_unlock_irqrestore(&cpts->lock, flags); 403 404 return ns; 405 } 406 407 void cpts_rx_timestamp(struct cpts *cpts, struct sk_buff *skb) 408 { 409 u64 ns; 410 struct skb_shared_hwtstamps *ssh; 411 412 if (!cpts->rx_enable) 413 return; 414 ns = cpts_find_ts(cpts, skb, CPTS_EV_RX); 415 if (!ns) 416 return; 417 ssh = skb_hwtstamps(skb); 418 memset(ssh, 0, sizeof(*ssh)); 419 ssh->hwtstamp = ns_to_ktime(ns); 420 } 421 EXPORT_SYMBOL_GPL(cpts_rx_timestamp); 422 423 void cpts_tx_timestamp(struct cpts *cpts, struct sk_buff *skb) 424 { 425 u64 ns; 426 struct skb_shared_hwtstamps ssh; 427 428 if (!(skb_shinfo(skb)->tx_flags & SKBTX_IN_PROGRESS)) 429 return; 430 ns = cpts_find_ts(cpts, skb, CPTS_EV_TX); 431 if (!ns) 432 return; 433 memset(&ssh, 0, sizeof(ssh)); 434 ssh.hwtstamp = ns_to_ktime(ns); 435 skb_tstamp_tx(skb, &ssh); 436 } 437 EXPORT_SYMBOL_GPL(cpts_tx_timestamp); 438 439 int cpts_register(struct cpts *cpts) 440 { 441 int err, i; 442 443 skb_queue_head_init(&cpts->txq); 444 INIT_LIST_HEAD(&cpts->events); 445 INIT_LIST_HEAD(&cpts->pool); 446 for (i = 0; i < CPTS_MAX_EVENTS; i++) 447 list_add(&cpts->pool_data[i].list, &cpts->pool); 448 449 clk_enable(cpts->refclk); 450 451 cpts_write32(cpts, CPTS_EN, control); 452 cpts_write32(cpts, TS_PEND_EN, int_enable); 453 454 timecounter_init(&cpts->tc, &cpts->cc, ktime_to_ns(ktime_get_real())); 455 456 cpts->clock = ptp_clock_register(&cpts->info, cpts->dev); 457 if (IS_ERR(cpts->clock)) { 458 err = PTR_ERR(cpts->clock); 459 cpts->clock = NULL; 460 goto err_ptp; 461 } 462 cpts->phc_index = ptp_clock_index(cpts->clock); 463 464 ptp_schedule_worker(cpts->clock, cpts->ov_check_period); 465 return 0; 466 467 err_ptp: 468 clk_disable(cpts->refclk); 469 return err; 470 } 471 EXPORT_SYMBOL_GPL(cpts_register); 472 473 void cpts_unregister(struct cpts *cpts) 474 { 475 if (WARN_ON(!cpts->clock)) 476 return; 477 478 ptp_clock_unregister(cpts->clock); 479 cpts->clock = NULL; 480 481 cpts_write32(cpts, 0, int_enable); 482 cpts_write32(cpts, 0, control); 483 484 /* Drop all packet */ 485 skb_queue_purge(&cpts->txq); 486 487 clk_disable(cpts->refclk); 488 } 489 EXPORT_SYMBOL_GPL(cpts_unregister); 490 491 static void cpts_calc_mult_shift(struct cpts *cpts) 492 { 493 u64 frac, maxsec, ns; 494 u32 freq; 495 496 freq = clk_get_rate(cpts->refclk); 497 498 /* Calc the maximum number of seconds which we can run before 499 * wrapping around. 500 */ 501 maxsec = cpts->cc.mask; 502 do_div(maxsec, freq); 503 /* limit conversation rate to 10 sec as higher values will produce 504 * too small mult factors and so reduce the conversion accuracy 505 */ 506 if (maxsec > 10) 507 maxsec = 10; 508 509 /* Calc overflow check period (maxsec / 2) */ 510 cpts->ov_check_period = (HZ * maxsec) / 2; 511 dev_info(cpts->dev, "cpts: overflow check period %lu (jiffies)\n", 512 cpts->ov_check_period); 513 514 if (cpts->cc.mult || cpts->cc.shift) 515 return; 516 517 clocks_calc_mult_shift(&cpts->cc.mult, &cpts->cc.shift, 518 freq, NSEC_PER_SEC, maxsec); 519 520 frac = 0; 521 ns = cyclecounter_cyc2ns(&cpts->cc, freq, cpts->cc.mask, &frac); 522 523 dev_info(cpts->dev, 524 "CPTS: ref_clk_freq:%u calc_mult:%u calc_shift:%u error:%lld nsec/sec\n", 525 freq, cpts->cc.mult, cpts->cc.shift, (ns - NSEC_PER_SEC)); 526 } 527 528 static int cpts_of_parse(struct cpts *cpts, struct device_node *node) 529 { 530 int ret = -EINVAL; 531 u32 prop; 532 533 if (!of_property_read_u32(node, "cpts_clock_mult", &prop)) 534 cpts->cc.mult = prop; 535 536 if (!of_property_read_u32(node, "cpts_clock_shift", &prop)) 537 cpts->cc.shift = prop; 538 539 if ((cpts->cc.mult && !cpts->cc.shift) || 540 (!cpts->cc.mult && cpts->cc.shift)) 541 goto of_error; 542 543 return 0; 544 545 of_error: 546 dev_err(cpts->dev, "CPTS: Missing property in the DT.\n"); 547 return ret; 548 } 549 550 struct cpts *cpts_create(struct device *dev, void __iomem *regs, 551 struct device_node *node) 552 { 553 struct cpts *cpts; 554 int ret; 555 556 cpts = devm_kzalloc(dev, sizeof(*cpts), GFP_KERNEL); 557 if (!cpts) 558 return ERR_PTR(-ENOMEM); 559 560 cpts->dev = dev; 561 cpts->reg = (struct cpsw_cpts __iomem *)regs; 562 spin_lock_init(&cpts->lock); 563 564 ret = cpts_of_parse(cpts, node); 565 if (ret) 566 return ERR_PTR(ret); 567 568 cpts->refclk = devm_clk_get(dev, "cpts"); 569 if (IS_ERR(cpts->refclk)) { 570 dev_err(dev, "Failed to get cpts refclk\n"); 571 return ERR_CAST(cpts->refclk); 572 } 573 574 clk_prepare(cpts->refclk); 575 576 cpts->cc.read = cpts_systim_read; 577 cpts->cc.mask = CLOCKSOURCE_MASK(32); 578 cpts->info = cpts_info; 579 580 cpts_calc_mult_shift(cpts); 581 /* save cc.mult original value as it can be modified 582 * by cpts_ptp_adjfreq(). 583 */ 584 cpts->cc_mult = cpts->cc.mult; 585 586 return cpts; 587 } 588 EXPORT_SYMBOL_GPL(cpts_create); 589 590 void cpts_release(struct cpts *cpts) 591 { 592 if (!cpts) 593 return; 594 595 if (WARN_ON(!cpts->refclk)) 596 return; 597 598 clk_unprepare(cpts->refclk); 599 } 600 EXPORT_SYMBOL_GPL(cpts_release); 601 602 MODULE_LICENSE("GPL v2"); 603 MODULE_DESCRIPTION("TI CPTS driver"); 604 MODULE_AUTHOR("Richard Cochran <richardcochran@gmail.com>"); 605