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