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 void cpts_purge_txq(struct cpts *cpts) 90 { 91 struct cpts_skb_cb_data *skb_cb; 92 struct sk_buff *skb, *tmp; 93 int removed = 0; 94 95 skb_queue_walk_safe(&cpts->txq, skb, tmp) { 96 skb_cb = (struct cpts_skb_cb_data *)skb->cb; 97 if (time_after(jiffies, skb_cb->tmo)) { 98 __skb_unlink(skb, &cpts->txq); 99 dev_consume_skb_any(skb); 100 ++removed; 101 } 102 } 103 104 if (removed) 105 dev_dbg(cpts->dev, "txq cleaned up %d\n", removed); 106 } 107 108 static bool cpts_match_tx_ts(struct cpts *cpts, struct cpts_event *event) 109 { 110 struct sk_buff *skb, *tmp; 111 u16 seqid; 112 u8 mtype; 113 bool found = false; 114 115 mtype = (event->high >> MESSAGE_TYPE_SHIFT) & MESSAGE_TYPE_MASK; 116 seqid = (event->high >> SEQUENCE_ID_SHIFT) & SEQUENCE_ID_MASK; 117 118 /* no need to grab txq.lock as access is always done under cpts->lock */ 119 skb_queue_walk_safe(&cpts->txq, skb, tmp) { 120 struct skb_shared_hwtstamps ssh; 121 unsigned int class = ptp_classify_raw(skb); 122 struct cpts_skb_cb_data *skb_cb = 123 (struct cpts_skb_cb_data *)skb->cb; 124 125 if (cpts_match(skb, class, seqid, mtype)) { 126 u64 ns = timecounter_cyc2time(&cpts->tc, event->low); 127 128 memset(&ssh, 0, sizeof(ssh)); 129 ssh.hwtstamp = ns_to_ktime(ns); 130 skb_tstamp_tx(skb, &ssh); 131 found = true; 132 __skb_unlink(skb, &cpts->txq); 133 dev_consume_skb_any(skb); 134 dev_dbg(cpts->dev, "match tx timestamp mtype %u seqid %04x\n", 135 mtype, seqid); 136 break; 137 } 138 139 if (time_after(jiffies, skb_cb->tmo)) { 140 /* timeout any expired skbs over 1s */ 141 dev_dbg(cpts->dev, "expiring tx timestamp from txq\n"); 142 __skb_unlink(skb, &cpts->txq); 143 dev_consume_skb_any(skb); 144 } 145 } 146 147 return found; 148 } 149 150 /* 151 * Returns zero if matching event type was found. 152 */ 153 static int cpts_fifo_read(struct cpts *cpts, int match) 154 { 155 int i, type = -1; 156 u32 hi, lo; 157 struct cpts_event *event; 158 159 for (i = 0; i < CPTS_FIFO_DEPTH; i++) { 160 if (cpts_fifo_pop(cpts, &hi, &lo)) 161 break; 162 163 if (list_empty(&cpts->pool) && cpts_purge_events(cpts)) { 164 pr_err("cpts: event pool empty\n"); 165 return -1; 166 } 167 168 event = list_first_entry(&cpts->pool, struct cpts_event, list); 169 event->tmo = jiffies + 2; 170 event->high = hi; 171 event->low = lo; 172 type = event_type(event); 173 switch (type) { 174 case CPTS_EV_TX: 175 if (cpts_match_tx_ts(cpts, event)) { 176 /* if the new event matches an existing skb, 177 * then don't queue it 178 */ 179 break; 180 } 181 /* fall through */ 182 case CPTS_EV_PUSH: 183 case CPTS_EV_RX: 184 list_del_init(&event->list); 185 list_add_tail(&event->list, &cpts->events); 186 break; 187 case CPTS_EV_ROLL: 188 case CPTS_EV_HALF: 189 case CPTS_EV_HW: 190 break; 191 default: 192 pr_err("cpts: unknown event type\n"); 193 break; 194 } 195 if (type == match) 196 break; 197 } 198 return type == match ? 0 : -1; 199 } 200 201 static u64 cpts_systim_read(const struct cyclecounter *cc) 202 { 203 u64 val = 0; 204 struct cpts_event *event; 205 struct list_head *this, *next; 206 struct cpts *cpts = container_of(cc, struct cpts, cc); 207 208 cpts_write32(cpts, TS_PUSH, ts_push); 209 if (cpts_fifo_read(cpts, CPTS_EV_PUSH)) 210 pr_err("cpts: unable to obtain a time stamp\n"); 211 212 list_for_each_safe(this, next, &cpts->events) { 213 event = list_entry(this, struct cpts_event, list); 214 if (event_type(event) == CPTS_EV_PUSH) { 215 list_del_init(&event->list); 216 list_add(&event->list, &cpts->pool); 217 val = event->low; 218 break; 219 } 220 } 221 222 return val; 223 } 224 225 /* PTP clock operations */ 226 227 static int cpts_ptp_adjfreq(struct ptp_clock_info *ptp, s32 ppb) 228 { 229 u64 adj; 230 u32 diff, mult; 231 int neg_adj = 0; 232 unsigned long flags; 233 struct cpts *cpts = container_of(ptp, struct cpts, info); 234 235 if (ppb < 0) { 236 neg_adj = 1; 237 ppb = -ppb; 238 } 239 mult = cpts->cc_mult; 240 adj = mult; 241 adj *= ppb; 242 diff = div_u64(adj, 1000000000ULL); 243 244 spin_lock_irqsave(&cpts->lock, flags); 245 246 timecounter_read(&cpts->tc); 247 248 cpts->cc.mult = neg_adj ? mult - diff : mult + diff; 249 250 spin_unlock_irqrestore(&cpts->lock, flags); 251 252 return 0; 253 } 254 255 static int cpts_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta) 256 { 257 unsigned long flags; 258 struct cpts *cpts = container_of(ptp, struct cpts, info); 259 260 spin_lock_irqsave(&cpts->lock, flags); 261 timecounter_adjtime(&cpts->tc, delta); 262 spin_unlock_irqrestore(&cpts->lock, flags); 263 264 return 0; 265 } 266 267 static int cpts_ptp_gettime(struct ptp_clock_info *ptp, struct timespec64 *ts) 268 { 269 u64 ns; 270 unsigned long flags; 271 struct cpts *cpts = container_of(ptp, struct cpts, info); 272 273 spin_lock_irqsave(&cpts->lock, flags); 274 ns = timecounter_read(&cpts->tc); 275 spin_unlock_irqrestore(&cpts->lock, flags); 276 277 *ts = ns_to_timespec64(ns); 278 279 return 0; 280 } 281 282 static int cpts_ptp_settime(struct ptp_clock_info *ptp, 283 const struct timespec64 *ts) 284 { 285 u64 ns; 286 unsigned long flags; 287 struct cpts *cpts = container_of(ptp, struct cpts, info); 288 289 ns = timespec64_to_ns(ts); 290 291 spin_lock_irqsave(&cpts->lock, flags); 292 timecounter_init(&cpts->tc, &cpts->cc, ns); 293 spin_unlock_irqrestore(&cpts->lock, flags); 294 295 return 0; 296 } 297 298 static int cpts_ptp_enable(struct ptp_clock_info *ptp, 299 struct ptp_clock_request *rq, int on) 300 { 301 return -EOPNOTSUPP; 302 } 303 304 static long cpts_overflow_check(struct ptp_clock_info *ptp) 305 { 306 struct cpts *cpts = container_of(ptp, struct cpts, info); 307 unsigned long delay = cpts->ov_check_period; 308 struct timespec64 ts; 309 unsigned long flags; 310 311 spin_lock_irqsave(&cpts->lock, flags); 312 ts = ns_to_timespec64(timecounter_read(&cpts->tc)); 313 314 if (!skb_queue_empty(&cpts->txq)) { 315 cpts_purge_txq(cpts); 316 if (!skb_queue_empty(&cpts->txq)) 317 delay = CPTS_SKB_TX_WORK_TIMEOUT; 318 } 319 spin_unlock_irqrestore(&cpts->lock, flags); 320 321 pr_debug("cpts overflow check at %lld.%09ld\n", 322 (long long)ts.tv_sec, ts.tv_nsec); 323 return (long)delay; 324 } 325 326 static const struct ptp_clock_info cpts_info = { 327 .owner = THIS_MODULE, 328 .name = "CTPS timer", 329 .max_adj = 1000000, 330 .n_ext_ts = 0, 331 .n_pins = 0, 332 .pps = 0, 333 .adjfreq = cpts_ptp_adjfreq, 334 .adjtime = cpts_ptp_adjtime, 335 .gettime64 = cpts_ptp_gettime, 336 .settime64 = cpts_ptp_settime, 337 .enable = cpts_ptp_enable, 338 .do_aux_work = cpts_overflow_check, 339 }; 340 341 static int cpts_match(struct sk_buff *skb, unsigned int ptp_class, 342 u16 ts_seqid, u8 ts_msgtype) 343 { 344 u16 *seqid; 345 unsigned int offset = 0; 346 u8 *msgtype, *data = skb->data; 347 348 if (ptp_class & PTP_CLASS_VLAN) 349 offset += VLAN_HLEN; 350 351 switch (ptp_class & PTP_CLASS_PMASK) { 352 case PTP_CLASS_IPV4: 353 offset += ETH_HLEN + IPV4_HLEN(data + offset) + UDP_HLEN; 354 break; 355 case PTP_CLASS_IPV6: 356 offset += ETH_HLEN + IP6_HLEN + UDP_HLEN; 357 break; 358 case PTP_CLASS_L2: 359 offset += ETH_HLEN; 360 break; 361 default: 362 return 0; 363 } 364 365 if (skb->len + ETH_HLEN < offset + OFF_PTP_SEQUENCE_ID + sizeof(*seqid)) 366 return 0; 367 368 if (unlikely(ptp_class & PTP_CLASS_V1)) 369 msgtype = data + offset + OFF_PTP_CONTROL; 370 else 371 msgtype = data + offset; 372 373 seqid = (u16 *)(data + offset + OFF_PTP_SEQUENCE_ID); 374 375 return (ts_msgtype == (*msgtype & 0xf) && ts_seqid == ntohs(*seqid)); 376 } 377 378 static u64 cpts_find_ts(struct cpts *cpts, struct sk_buff *skb, int ev_type) 379 { 380 u64 ns = 0; 381 struct cpts_event *event; 382 struct list_head *this, *next; 383 unsigned int class = ptp_classify_raw(skb); 384 unsigned long flags; 385 u16 seqid; 386 u8 mtype; 387 388 if (class == PTP_CLASS_NONE) 389 return 0; 390 391 spin_lock_irqsave(&cpts->lock, flags); 392 cpts_fifo_read(cpts, -1); 393 list_for_each_safe(this, next, &cpts->events) { 394 event = list_entry(this, struct cpts_event, list); 395 if (event_expired(event)) { 396 list_del_init(&event->list); 397 list_add(&event->list, &cpts->pool); 398 continue; 399 } 400 mtype = (event->high >> MESSAGE_TYPE_SHIFT) & MESSAGE_TYPE_MASK; 401 seqid = (event->high >> SEQUENCE_ID_SHIFT) & SEQUENCE_ID_MASK; 402 if (ev_type == event_type(event) && 403 cpts_match(skb, class, seqid, mtype)) { 404 ns = timecounter_cyc2time(&cpts->tc, event->low); 405 list_del_init(&event->list); 406 list_add(&event->list, &cpts->pool); 407 break; 408 } 409 } 410 411 if (ev_type == CPTS_EV_TX && !ns) { 412 struct cpts_skb_cb_data *skb_cb = 413 (struct cpts_skb_cb_data *)skb->cb; 414 /* Not found, add frame to queue for processing later. 415 * The periodic FIFO check will handle this. 416 */ 417 skb_get(skb); 418 /* get the timestamp for timeouts */ 419 skb_cb->tmo = jiffies + msecs_to_jiffies(100); 420 __skb_queue_tail(&cpts->txq, skb); 421 ptp_schedule_worker(cpts->clock, 0); 422 } 423 spin_unlock_irqrestore(&cpts->lock, flags); 424 425 return ns; 426 } 427 428 void cpts_rx_timestamp(struct cpts *cpts, struct sk_buff *skb) 429 { 430 u64 ns; 431 struct skb_shared_hwtstamps *ssh; 432 433 ns = cpts_find_ts(cpts, skb, CPTS_EV_RX); 434 if (!ns) 435 return; 436 ssh = skb_hwtstamps(skb); 437 memset(ssh, 0, sizeof(*ssh)); 438 ssh->hwtstamp = ns_to_ktime(ns); 439 } 440 EXPORT_SYMBOL_GPL(cpts_rx_timestamp); 441 442 void cpts_tx_timestamp(struct cpts *cpts, struct sk_buff *skb) 443 { 444 u64 ns; 445 struct skb_shared_hwtstamps ssh; 446 447 if (!(skb_shinfo(skb)->tx_flags & SKBTX_IN_PROGRESS)) 448 return; 449 ns = cpts_find_ts(cpts, skb, CPTS_EV_TX); 450 if (!ns) 451 return; 452 memset(&ssh, 0, sizeof(ssh)); 453 ssh.hwtstamp = ns_to_ktime(ns); 454 skb_tstamp_tx(skb, &ssh); 455 } 456 EXPORT_SYMBOL_GPL(cpts_tx_timestamp); 457 458 int cpts_register(struct cpts *cpts) 459 { 460 int err, i; 461 462 skb_queue_head_init(&cpts->txq); 463 INIT_LIST_HEAD(&cpts->events); 464 INIT_LIST_HEAD(&cpts->pool); 465 for (i = 0; i < CPTS_MAX_EVENTS; i++) 466 list_add(&cpts->pool_data[i].list, &cpts->pool); 467 468 clk_enable(cpts->refclk); 469 470 cpts_write32(cpts, CPTS_EN, control); 471 cpts_write32(cpts, TS_PEND_EN, int_enable); 472 473 timecounter_init(&cpts->tc, &cpts->cc, ktime_to_ns(ktime_get_real())); 474 475 cpts->clock = ptp_clock_register(&cpts->info, cpts->dev); 476 if (IS_ERR(cpts->clock)) { 477 err = PTR_ERR(cpts->clock); 478 cpts->clock = NULL; 479 goto err_ptp; 480 } 481 cpts->phc_index = ptp_clock_index(cpts->clock); 482 483 ptp_schedule_worker(cpts->clock, cpts->ov_check_period); 484 return 0; 485 486 err_ptp: 487 clk_disable(cpts->refclk); 488 return err; 489 } 490 EXPORT_SYMBOL_GPL(cpts_register); 491 492 void cpts_unregister(struct cpts *cpts) 493 { 494 if (WARN_ON(!cpts->clock)) 495 return; 496 497 ptp_clock_unregister(cpts->clock); 498 cpts->clock = NULL; 499 500 cpts_write32(cpts, 0, int_enable); 501 cpts_write32(cpts, 0, control); 502 503 /* Drop all packet */ 504 skb_queue_purge(&cpts->txq); 505 506 clk_disable(cpts->refclk); 507 } 508 EXPORT_SYMBOL_GPL(cpts_unregister); 509 510 static void cpts_calc_mult_shift(struct cpts *cpts) 511 { 512 u64 frac, maxsec, ns; 513 u32 freq; 514 515 freq = clk_get_rate(cpts->refclk); 516 517 /* Calc the maximum number of seconds which we can run before 518 * wrapping around. 519 */ 520 maxsec = cpts->cc.mask; 521 do_div(maxsec, freq); 522 /* limit conversation rate to 10 sec as higher values will produce 523 * too small mult factors and so reduce the conversion accuracy 524 */ 525 if (maxsec > 10) 526 maxsec = 10; 527 528 /* Calc overflow check period (maxsec / 2) */ 529 cpts->ov_check_period = (HZ * maxsec) / 2; 530 dev_info(cpts->dev, "cpts: overflow check period %lu (jiffies)\n", 531 cpts->ov_check_period); 532 533 if (cpts->cc.mult || cpts->cc.shift) 534 return; 535 536 clocks_calc_mult_shift(&cpts->cc.mult, &cpts->cc.shift, 537 freq, NSEC_PER_SEC, maxsec); 538 539 frac = 0; 540 ns = cyclecounter_cyc2ns(&cpts->cc, freq, cpts->cc.mask, &frac); 541 542 dev_info(cpts->dev, 543 "CPTS: ref_clk_freq:%u calc_mult:%u calc_shift:%u error:%lld nsec/sec\n", 544 freq, cpts->cc.mult, cpts->cc.shift, (ns - NSEC_PER_SEC)); 545 } 546 547 static int cpts_of_parse(struct cpts *cpts, struct device_node *node) 548 { 549 int ret = -EINVAL; 550 u32 prop; 551 552 if (!of_property_read_u32(node, "cpts_clock_mult", &prop)) 553 cpts->cc.mult = prop; 554 555 if (!of_property_read_u32(node, "cpts_clock_shift", &prop)) 556 cpts->cc.shift = prop; 557 558 if ((cpts->cc.mult && !cpts->cc.shift) || 559 (!cpts->cc.mult && cpts->cc.shift)) 560 goto of_error; 561 562 return 0; 563 564 of_error: 565 dev_err(cpts->dev, "CPTS: Missing property in the DT.\n"); 566 return ret; 567 } 568 569 struct cpts *cpts_create(struct device *dev, void __iomem *regs, 570 struct device_node *node) 571 { 572 struct cpts *cpts; 573 int ret; 574 575 cpts = devm_kzalloc(dev, sizeof(*cpts), GFP_KERNEL); 576 if (!cpts) 577 return ERR_PTR(-ENOMEM); 578 579 cpts->dev = dev; 580 cpts->reg = (struct cpsw_cpts __iomem *)regs; 581 spin_lock_init(&cpts->lock); 582 583 ret = cpts_of_parse(cpts, node); 584 if (ret) 585 return ERR_PTR(ret); 586 587 cpts->refclk = devm_clk_get(dev, "cpts"); 588 if (IS_ERR(cpts->refclk)) { 589 dev_err(dev, "Failed to get cpts refclk\n"); 590 return ERR_CAST(cpts->refclk); 591 } 592 593 ret = clk_prepare(cpts->refclk); 594 if (ret) 595 return ERR_PTR(ret); 596 597 cpts->cc.read = cpts_systim_read; 598 cpts->cc.mask = CLOCKSOURCE_MASK(32); 599 cpts->info = cpts_info; 600 601 cpts_calc_mult_shift(cpts); 602 /* save cc.mult original value as it can be modified 603 * by cpts_ptp_adjfreq(). 604 */ 605 cpts->cc_mult = cpts->cc.mult; 606 607 return cpts; 608 } 609 EXPORT_SYMBOL_GPL(cpts_create); 610 611 void cpts_release(struct cpts *cpts) 612 { 613 if (!cpts) 614 return; 615 616 if (WARN_ON(!cpts->refclk)) 617 return; 618 619 clk_unprepare(cpts->refclk); 620 } 621 EXPORT_SYMBOL_GPL(cpts_release); 622 623 MODULE_LICENSE("GPL v2"); 624 MODULE_DESCRIPTION("TI CPTS driver"); 625 MODULE_AUTHOR("Richard Cochran <richardcochran@gmail.com>"); 626