1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * TI Common Platform Time Sync 4 * 5 * Copyright (C) 2012 Richard Cochran <richardcochran@gmail.com> 6 * 7 */ 8 #include <linux/clk-provider.h> 9 #include <linux/err.h> 10 #include <linux/if.h> 11 #include <linux/hrtimer.h> 12 #include <linux/module.h> 13 #include <linux/net_tstamp.h> 14 #include <linux/ptp_classify.h> 15 #include <linux/time.h> 16 #include <linux/uaccess.h> 17 #include <linux/workqueue.h> 18 #include <linux/if_ether.h> 19 #include <linux/if_vlan.h> 20 21 #include "cpts.h" 22 23 #define CPTS_SKB_TX_WORK_TIMEOUT 1 /* jiffies */ 24 25 struct cpts_skb_cb_data { 26 unsigned long tmo; 27 }; 28 29 #define cpts_read32(c, r) readl_relaxed(&c->reg->r) 30 #define cpts_write32(c, v, r) writel_relaxed(v, &c->reg->r) 31 32 static int cpts_match(struct sk_buff *skb, unsigned int ptp_class, 33 u16 ts_seqid, u8 ts_msgtype); 34 35 static int event_expired(struct cpts_event *event) 36 { 37 return time_after(jiffies, event->tmo); 38 } 39 40 static int event_type(struct cpts_event *event) 41 { 42 return (event->high >> EVENT_TYPE_SHIFT) & EVENT_TYPE_MASK; 43 } 44 45 static int cpts_fifo_pop(struct cpts *cpts, u32 *high, u32 *low) 46 { 47 u32 r = cpts_read32(cpts, intstat_raw); 48 49 if (r & TS_PEND_RAW) { 50 *high = cpts_read32(cpts, event_high); 51 *low = cpts_read32(cpts, event_low); 52 cpts_write32(cpts, EVENT_POP, event_pop); 53 return 0; 54 } 55 return -1; 56 } 57 58 static int cpts_purge_events(struct cpts *cpts) 59 { 60 struct list_head *this, *next; 61 struct cpts_event *event; 62 int removed = 0; 63 64 list_for_each_safe(this, next, &cpts->events) { 65 event = list_entry(this, struct cpts_event, list); 66 if (event_expired(event)) { 67 list_del_init(&event->list); 68 list_add(&event->list, &cpts->pool); 69 ++removed; 70 } 71 } 72 73 if (removed) 74 pr_debug("cpts: event pool cleaned up %d\n", removed); 75 return removed ? 0 : -1; 76 } 77 78 static void cpts_purge_txq(struct cpts *cpts) 79 { 80 struct cpts_skb_cb_data *skb_cb; 81 struct sk_buff *skb, *tmp; 82 int removed = 0; 83 84 skb_queue_walk_safe(&cpts->txq, skb, tmp) { 85 skb_cb = (struct cpts_skb_cb_data *)skb->cb; 86 if (time_after(jiffies, skb_cb->tmo)) { 87 __skb_unlink(skb, &cpts->txq); 88 dev_consume_skb_any(skb); 89 ++removed; 90 } 91 } 92 93 if (removed) 94 dev_dbg(cpts->dev, "txq cleaned up %d\n", removed); 95 } 96 97 static bool cpts_match_tx_ts(struct cpts *cpts, struct cpts_event *event) 98 { 99 struct sk_buff *skb, *tmp; 100 u16 seqid; 101 u8 mtype; 102 bool found = false; 103 104 mtype = (event->high >> MESSAGE_TYPE_SHIFT) & MESSAGE_TYPE_MASK; 105 seqid = (event->high >> SEQUENCE_ID_SHIFT) & SEQUENCE_ID_MASK; 106 107 /* no need to grab txq.lock as access is always done under cpts->lock */ 108 skb_queue_walk_safe(&cpts->txq, skb, tmp) { 109 struct skb_shared_hwtstamps ssh; 110 unsigned int class = ptp_classify_raw(skb); 111 struct cpts_skb_cb_data *skb_cb = 112 (struct cpts_skb_cb_data *)skb->cb; 113 114 if (cpts_match(skb, class, seqid, mtype)) { 115 u64 ns = timecounter_cyc2time(&cpts->tc, event->low); 116 117 memset(&ssh, 0, sizeof(ssh)); 118 ssh.hwtstamp = ns_to_ktime(ns); 119 skb_tstamp_tx(skb, &ssh); 120 found = true; 121 __skb_unlink(skb, &cpts->txq); 122 dev_consume_skb_any(skb); 123 dev_dbg(cpts->dev, "match tx timestamp mtype %u seqid %04x\n", 124 mtype, seqid); 125 break; 126 } 127 128 if (time_after(jiffies, skb_cb->tmo)) { 129 /* timeout any expired skbs over 1s */ 130 dev_dbg(cpts->dev, "expiring tx timestamp from txq\n"); 131 __skb_unlink(skb, &cpts->txq); 132 dev_consume_skb_any(skb); 133 } 134 } 135 136 return found; 137 } 138 139 /* 140 * Returns zero if matching event type was found. 141 */ 142 static int cpts_fifo_read(struct cpts *cpts, int match) 143 { 144 int i, type = -1; 145 u32 hi, lo; 146 struct cpts_event *event; 147 148 for (i = 0; i < CPTS_FIFO_DEPTH; i++) { 149 if (cpts_fifo_pop(cpts, &hi, &lo)) 150 break; 151 152 if (list_empty(&cpts->pool) && cpts_purge_events(cpts)) { 153 pr_err("cpts: event pool empty\n"); 154 return -1; 155 } 156 157 event = list_first_entry(&cpts->pool, struct cpts_event, list); 158 event->tmo = jiffies + 2; 159 event->high = hi; 160 event->low = lo; 161 type = event_type(event); 162 switch (type) { 163 case CPTS_EV_TX: 164 if (cpts_match_tx_ts(cpts, event)) { 165 /* if the new event matches an existing skb, 166 * then don't queue it 167 */ 168 break; 169 } 170 /* fall through */ 171 case CPTS_EV_PUSH: 172 case CPTS_EV_RX: 173 list_del_init(&event->list); 174 list_add_tail(&event->list, &cpts->events); 175 break; 176 case CPTS_EV_ROLL: 177 case CPTS_EV_HALF: 178 case CPTS_EV_HW: 179 break; 180 default: 181 pr_err("cpts: unknown event type\n"); 182 break; 183 } 184 if (type == match) 185 break; 186 } 187 return type == match ? 0 : -1; 188 } 189 190 static u64 cpts_systim_read(const struct cyclecounter *cc) 191 { 192 u64 val = 0; 193 struct cpts_event *event; 194 struct list_head *this, *next; 195 struct cpts *cpts = container_of(cc, struct cpts, cc); 196 197 cpts_write32(cpts, TS_PUSH, ts_push); 198 if (cpts_fifo_read(cpts, CPTS_EV_PUSH)) 199 pr_err("cpts: unable to obtain a time stamp\n"); 200 201 list_for_each_safe(this, next, &cpts->events) { 202 event = list_entry(this, struct cpts_event, list); 203 if (event_type(event) == CPTS_EV_PUSH) { 204 list_del_init(&event->list); 205 list_add(&event->list, &cpts->pool); 206 val = event->low; 207 break; 208 } 209 } 210 211 return val; 212 } 213 214 /* PTP clock operations */ 215 216 static int cpts_ptp_adjfreq(struct ptp_clock_info *ptp, s32 ppb) 217 { 218 u64 adj; 219 u32 diff, mult; 220 int neg_adj = 0; 221 unsigned long flags; 222 struct cpts *cpts = container_of(ptp, struct cpts, info); 223 224 if (ppb < 0) { 225 neg_adj = 1; 226 ppb = -ppb; 227 } 228 mult = cpts->cc_mult; 229 adj = mult; 230 adj *= ppb; 231 diff = div_u64(adj, 1000000000ULL); 232 233 spin_lock_irqsave(&cpts->lock, flags); 234 235 timecounter_read(&cpts->tc); 236 237 cpts->cc.mult = neg_adj ? mult - diff : mult + diff; 238 239 spin_unlock_irqrestore(&cpts->lock, flags); 240 241 return 0; 242 } 243 244 static int cpts_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta) 245 { 246 unsigned long flags; 247 struct cpts *cpts = container_of(ptp, struct cpts, info); 248 249 spin_lock_irqsave(&cpts->lock, flags); 250 timecounter_adjtime(&cpts->tc, delta); 251 spin_unlock_irqrestore(&cpts->lock, flags); 252 253 return 0; 254 } 255 256 static int cpts_ptp_gettime(struct ptp_clock_info *ptp, struct timespec64 *ts) 257 { 258 u64 ns; 259 unsigned long flags; 260 struct cpts *cpts = container_of(ptp, struct cpts, info); 261 262 spin_lock_irqsave(&cpts->lock, flags); 263 ns = timecounter_read(&cpts->tc); 264 spin_unlock_irqrestore(&cpts->lock, flags); 265 266 *ts = ns_to_timespec64(ns); 267 268 return 0; 269 } 270 271 static int cpts_ptp_settime(struct ptp_clock_info *ptp, 272 const struct timespec64 *ts) 273 { 274 u64 ns; 275 unsigned long flags; 276 struct cpts *cpts = container_of(ptp, struct cpts, info); 277 278 ns = timespec64_to_ns(ts); 279 280 spin_lock_irqsave(&cpts->lock, flags); 281 timecounter_init(&cpts->tc, &cpts->cc, ns); 282 spin_unlock_irqrestore(&cpts->lock, flags); 283 284 return 0; 285 } 286 287 static int cpts_ptp_enable(struct ptp_clock_info *ptp, 288 struct ptp_clock_request *rq, int on) 289 { 290 return -EOPNOTSUPP; 291 } 292 293 static long cpts_overflow_check(struct ptp_clock_info *ptp) 294 { 295 struct cpts *cpts = container_of(ptp, struct cpts, info); 296 unsigned long delay = cpts->ov_check_period; 297 struct timespec64 ts; 298 unsigned long flags; 299 300 spin_lock_irqsave(&cpts->lock, flags); 301 ts = ns_to_timespec64(timecounter_read(&cpts->tc)); 302 303 if (!skb_queue_empty(&cpts->txq)) { 304 cpts_purge_txq(cpts); 305 if (!skb_queue_empty(&cpts->txq)) 306 delay = CPTS_SKB_TX_WORK_TIMEOUT; 307 } 308 spin_unlock_irqrestore(&cpts->lock, flags); 309 310 pr_debug("cpts overflow check at %lld.%09ld\n", 311 (long long)ts.tv_sec, ts.tv_nsec); 312 return (long)delay; 313 } 314 315 static const struct ptp_clock_info cpts_info = { 316 .owner = THIS_MODULE, 317 .name = "CTPS timer", 318 .max_adj = 1000000, 319 .n_ext_ts = 0, 320 .n_pins = 0, 321 .pps = 0, 322 .adjfreq = cpts_ptp_adjfreq, 323 .adjtime = cpts_ptp_adjtime, 324 .gettime64 = cpts_ptp_gettime, 325 .settime64 = cpts_ptp_settime, 326 .enable = cpts_ptp_enable, 327 .do_aux_work = cpts_overflow_check, 328 }; 329 330 static int cpts_match(struct sk_buff *skb, unsigned int ptp_class, 331 u16 ts_seqid, u8 ts_msgtype) 332 { 333 u16 *seqid; 334 unsigned int offset = 0; 335 u8 *msgtype, *data = skb->data; 336 337 if (ptp_class & PTP_CLASS_VLAN) 338 offset += VLAN_HLEN; 339 340 switch (ptp_class & PTP_CLASS_PMASK) { 341 case PTP_CLASS_IPV4: 342 offset += ETH_HLEN + IPV4_HLEN(data + offset) + UDP_HLEN; 343 break; 344 case PTP_CLASS_IPV6: 345 offset += ETH_HLEN + IP6_HLEN + UDP_HLEN; 346 break; 347 case PTP_CLASS_L2: 348 offset += ETH_HLEN; 349 break; 350 default: 351 return 0; 352 } 353 354 if (skb->len + ETH_HLEN < offset + OFF_PTP_SEQUENCE_ID + sizeof(*seqid)) 355 return 0; 356 357 if (unlikely(ptp_class & PTP_CLASS_V1)) 358 msgtype = data + offset + OFF_PTP_CONTROL; 359 else 360 msgtype = data + offset; 361 362 seqid = (u16 *)(data + offset + OFF_PTP_SEQUENCE_ID); 363 364 return (ts_msgtype == (*msgtype & 0xf) && ts_seqid == ntohs(*seqid)); 365 } 366 367 static u64 cpts_find_ts(struct cpts *cpts, struct sk_buff *skb, int ev_type) 368 { 369 u64 ns = 0; 370 struct cpts_event *event; 371 struct list_head *this, *next; 372 unsigned int class = ptp_classify_raw(skb); 373 unsigned long flags; 374 u16 seqid; 375 u8 mtype; 376 377 if (class == PTP_CLASS_NONE) 378 return 0; 379 380 spin_lock_irqsave(&cpts->lock, flags); 381 cpts_fifo_read(cpts, -1); 382 list_for_each_safe(this, next, &cpts->events) { 383 event = list_entry(this, struct cpts_event, list); 384 if (event_expired(event)) { 385 list_del_init(&event->list); 386 list_add(&event->list, &cpts->pool); 387 continue; 388 } 389 mtype = (event->high >> MESSAGE_TYPE_SHIFT) & MESSAGE_TYPE_MASK; 390 seqid = (event->high >> SEQUENCE_ID_SHIFT) & SEQUENCE_ID_MASK; 391 if (ev_type == event_type(event) && 392 cpts_match(skb, class, seqid, mtype)) { 393 ns = timecounter_cyc2time(&cpts->tc, event->low); 394 list_del_init(&event->list); 395 list_add(&event->list, &cpts->pool); 396 break; 397 } 398 } 399 400 if (ev_type == CPTS_EV_TX && !ns) { 401 struct cpts_skb_cb_data *skb_cb = 402 (struct cpts_skb_cb_data *)skb->cb; 403 /* Not found, add frame to queue for processing later. 404 * The periodic FIFO check will handle this. 405 */ 406 skb_get(skb); 407 /* get the timestamp for timeouts */ 408 skb_cb->tmo = jiffies + msecs_to_jiffies(100); 409 __skb_queue_tail(&cpts->txq, skb); 410 ptp_schedule_worker(cpts->clock, 0); 411 } 412 spin_unlock_irqrestore(&cpts->lock, flags); 413 414 return ns; 415 } 416 417 void cpts_rx_timestamp(struct cpts *cpts, struct sk_buff *skb) 418 { 419 u64 ns; 420 struct skb_shared_hwtstamps *ssh; 421 422 ns = cpts_find_ts(cpts, skb, CPTS_EV_RX); 423 if (!ns) 424 return; 425 ssh = skb_hwtstamps(skb); 426 memset(ssh, 0, sizeof(*ssh)); 427 ssh->hwtstamp = ns_to_ktime(ns); 428 } 429 EXPORT_SYMBOL_GPL(cpts_rx_timestamp); 430 431 void cpts_tx_timestamp(struct cpts *cpts, struct sk_buff *skb) 432 { 433 u64 ns; 434 struct skb_shared_hwtstamps ssh; 435 436 if (!(skb_shinfo(skb)->tx_flags & SKBTX_IN_PROGRESS)) 437 return; 438 ns = cpts_find_ts(cpts, skb, CPTS_EV_TX); 439 if (!ns) 440 return; 441 memset(&ssh, 0, sizeof(ssh)); 442 ssh.hwtstamp = ns_to_ktime(ns); 443 skb_tstamp_tx(skb, &ssh); 444 } 445 EXPORT_SYMBOL_GPL(cpts_tx_timestamp); 446 447 int cpts_register(struct cpts *cpts) 448 { 449 int err, i; 450 451 skb_queue_head_init(&cpts->txq); 452 INIT_LIST_HEAD(&cpts->events); 453 INIT_LIST_HEAD(&cpts->pool); 454 for (i = 0; i < CPTS_MAX_EVENTS; i++) 455 list_add(&cpts->pool_data[i].list, &cpts->pool); 456 457 clk_enable(cpts->refclk); 458 459 cpts_write32(cpts, CPTS_EN, control); 460 cpts_write32(cpts, TS_PEND_EN, int_enable); 461 462 timecounter_init(&cpts->tc, &cpts->cc, ktime_get_real_ns()); 463 464 cpts->clock = ptp_clock_register(&cpts->info, cpts->dev); 465 if (IS_ERR(cpts->clock)) { 466 err = PTR_ERR(cpts->clock); 467 cpts->clock = NULL; 468 goto err_ptp; 469 } 470 cpts->phc_index = ptp_clock_index(cpts->clock); 471 472 ptp_schedule_worker(cpts->clock, cpts->ov_check_period); 473 return 0; 474 475 err_ptp: 476 clk_disable(cpts->refclk); 477 return err; 478 } 479 EXPORT_SYMBOL_GPL(cpts_register); 480 481 void cpts_unregister(struct cpts *cpts) 482 { 483 if (WARN_ON(!cpts->clock)) 484 return; 485 486 ptp_clock_unregister(cpts->clock); 487 cpts->clock = NULL; 488 489 cpts_write32(cpts, 0, int_enable); 490 cpts_write32(cpts, 0, control); 491 492 /* Drop all packet */ 493 skb_queue_purge(&cpts->txq); 494 495 clk_disable(cpts->refclk); 496 } 497 EXPORT_SYMBOL_GPL(cpts_unregister); 498 499 static void cpts_calc_mult_shift(struct cpts *cpts) 500 { 501 u64 frac, maxsec, ns; 502 u32 freq; 503 504 freq = clk_get_rate(cpts->refclk); 505 506 /* Calc the maximum number of seconds which we can run before 507 * wrapping around. 508 */ 509 maxsec = cpts->cc.mask; 510 do_div(maxsec, freq); 511 /* limit conversation rate to 10 sec as higher values will produce 512 * too small mult factors and so reduce the conversion accuracy 513 */ 514 if (maxsec > 10) 515 maxsec = 10; 516 517 /* Calc overflow check period (maxsec / 2) */ 518 cpts->ov_check_period = (HZ * maxsec) / 2; 519 dev_info(cpts->dev, "cpts: overflow check period %lu (jiffies)\n", 520 cpts->ov_check_period); 521 522 if (cpts->cc.mult || cpts->cc.shift) 523 return; 524 525 clocks_calc_mult_shift(&cpts->cc.mult, &cpts->cc.shift, 526 freq, NSEC_PER_SEC, maxsec); 527 528 frac = 0; 529 ns = cyclecounter_cyc2ns(&cpts->cc, freq, cpts->cc.mask, &frac); 530 531 dev_info(cpts->dev, 532 "CPTS: ref_clk_freq:%u calc_mult:%u calc_shift:%u error:%lld nsec/sec\n", 533 freq, cpts->cc.mult, cpts->cc.shift, (ns - NSEC_PER_SEC)); 534 } 535 536 static int cpts_of_mux_clk_setup(struct cpts *cpts, struct device_node *node) 537 { 538 struct device_node *refclk_np; 539 const char **parent_names; 540 unsigned int num_parents; 541 struct clk_hw *clk_hw; 542 int ret = -EINVAL; 543 u32 *mux_table; 544 545 refclk_np = of_get_child_by_name(node, "cpts-refclk-mux"); 546 if (!refclk_np) 547 /* refclk selection supported not for all SoCs */ 548 return 0; 549 550 num_parents = of_clk_get_parent_count(refclk_np); 551 if (num_parents < 1) { 552 dev_err(cpts->dev, "mux-clock %s must have parents\n", 553 refclk_np->name); 554 goto mux_fail; 555 } 556 557 parent_names = devm_kzalloc(cpts->dev, (sizeof(char *) * num_parents), 558 GFP_KERNEL); 559 560 mux_table = devm_kzalloc(cpts->dev, sizeof(*mux_table) * num_parents, 561 GFP_KERNEL); 562 if (!mux_table || !parent_names) { 563 ret = -ENOMEM; 564 goto mux_fail; 565 } 566 567 of_clk_parent_fill(refclk_np, parent_names, num_parents); 568 569 ret = of_property_read_variable_u32_array(refclk_np, "ti,mux-tbl", 570 mux_table, 571 num_parents, num_parents); 572 if (ret < 0) 573 goto mux_fail; 574 575 clk_hw = clk_hw_register_mux_table(cpts->dev, refclk_np->name, 576 parent_names, num_parents, 577 0, 578 &cpts->reg->rftclk_sel, 0, 0x1F, 579 0, mux_table, NULL); 580 if (IS_ERR(clk_hw)) { 581 ret = PTR_ERR(clk_hw); 582 goto mux_fail; 583 } 584 585 ret = devm_add_action_or_reset(cpts->dev, 586 (void(*)(void *))clk_hw_unregister_mux, 587 clk_hw); 588 if (ret) { 589 dev_err(cpts->dev, "add clkmux unreg action %d", ret); 590 goto mux_fail; 591 } 592 593 ret = of_clk_add_hw_provider(refclk_np, of_clk_hw_simple_get, clk_hw); 594 if (ret) 595 goto mux_fail; 596 597 ret = devm_add_action_or_reset(cpts->dev, 598 (void(*)(void *))of_clk_del_provider, 599 refclk_np); 600 if (ret) { 601 dev_err(cpts->dev, "add clkmux provider unreg action %d", ret); 602 goto mux_fail; 603 } 604 605 return ret; 606 607 mux_fail: 608 of_node_put(refclk_np); 609 return ret; 610 } 611 612 static int cpts_of_parse(struct cpts *cpts, struct device_node *node) 613 { 614 int ret = -EINVAL; 615 u32 prop; 616 617 if (!of_property_read_u32(node, "cpts_clock_mult", &prop)) 618 cpts->cc.mult = prop; 619 620 if (!of_property_read_u32(node, "cpts_clock_shift", &prop)) 621 cpts->cc.shift = prop; 622 623 if ((cpts->cc.mult && !cpts->cc.shift) || 624 (!cpts->cc.mult && cpts->cc.shift)) 625 goto of_error; 626 627 return cpts_of_mux_clk_setup(cpts, node); 628 629 of_error: 630 dev_err(cpts->dev, "CPTS: Missing property in the DT.\n"); 631 return ret; 632 } 633 634 struct cpts *cpts_create(struct device *dev, void __iomem *regs, 635 struct device_node *node) 636 { 637 struct cpts *cpts; 638 int ret; 639 640 cpts = devm_kzalloc(dev, sizeof(*cpts), GFP_KERNEL); 641 if (!cpts) 642 return ERR_PTR(-ENOMEM); 643 644 cpts->dev = dev; 645 cpts->reg = (struct cpsw_cpts __iomem *)regs; 646 spin_lock_init(&cpts->lock); 647 648 ret = cpts_of_parse(cpts, node); 649 if (ret) 650 return ERR_PTR(ret); 651 652 cpts->refclk = devm_get_clk_from_child(dev, node, "cpts"); 653 if (IS_ERR(cpts->refclk)) 654 /* try get clk from dev node for compatibility */ 655 cpts->refclk = devm_clk_get(dev, "cpts"); 656 657 if (IS_ERR(cpts->refclk)) { 658 dev_err(dev, "Failed to get cpts refclk %ld\n", 659 PTR_ERR(cpts->refclk)); 660 return ERR_CAST(cpts->refclk); 661 } 662 663 ret = clk_prepare(cpts->refclk); 664 if (ret) 665 return ERR_PTR(ret); 666 667 cpts->cc.read = cpts_systim_read; 668 cpts->cc.mask = CLOCKSOURCE_MASK(32); 669 cpts->info = cpts_info; 670 671 cpts_calc_mult_shift(cpts); 672 /* save cc.mult original value as it can be modified 673 * by cpts_ptp_adjfreq(). 674 */ 675 cpts->cc_mult = cpts->cc.mult; 676 677 return cpts; 678 } 679 EXPORT_SYMBOL_GPL(cpts_create); 680 681 void cpts_release(struct cpts *cpts) 682 { 683 if (!cpts) 684 return; 685 686 if (WARN_ON(!cpts->refclk)) 687 return; 688 689 clk_unprepare(cpts->refclk); 690 } 691 EXPORT_SYMBOL_GPL(cpts_release); 692 693 MODULE_LICENSE("GPL v2"); 694 MODULE_DESCRIPTION("TI CPTS driver"); 695 MODULE_AUTHOR("Richard Cochran <richardcochran@gmail.com>"); 696