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_read32(c, r) readl_relaxed(&c->reg->r) 35 #define cpts_write32(c, v, r) writel_relaxed(v, &c->reg->r) 36 37 static int event_expired(struct cpts_event *event) 38 { 39 return time_after(jiffies, event->tmo); 40 } 41 42 static int event_type(struct cpts_event *event) 43 { 44 return (event->high >> EVENT_TYPE_SHIFT) & EVENT_TYPE_MASK; 45 } 46 47 static int cpts_fifo_pop(struct cpts *cpts, u32 *high, u32 *low) 48 { 49 u32 r = cpts_read32(cpts, intstat_raw); 50 51 if (r & TS_PEND_RAW) { 52 *high = cpts_read32(cpts, event_high); 53 *low = cpts_read32(cpts, event_low); 54 cpts_write32(cpts, EVENT_POP, event_pop); 55 return 0; 56 } 57 return -1; 58 } 59 60 /* 61 * Returns zero if matching event type was found. 62 */ 63 static int cpts_fifo_read(struct cpts *cpts, int match) 64 { 65 int i, type = -1; 66 u32 hi, lo; 67 struct cpts_event *event; 68 69 for (i = 0; i < CPTS_FIFO_DEPTH; i++) { 70 if (cpts_fifo_pop(cpts, &hi, &lo)) 71 break; 72 if (list_empty(&cpts->pool)) { 73 pr_err("cpts: event pool is empty\n"); 74 return -1; 75 } 76 event = list_first_entry(&cpts->pool, struct cpts_event, list); 77 event->tmo = jiffies + 2; 78 event->high = hi; 79 event->low = lo; 80 type = event_type(event); 81 switch (type) { 82 case CPTS_EV_PUSH: 83 case CPTS_EV_RX: 84 case CPTS_EV_TX: 85 list_del_init(&event->list); 86 list_add_tail(&event->list, &cpts->events); 87 break; 88 case CPTS_EV_ROLL: 89 case CPTS_EV_HALF: 90 case CPTS_EV_HW: 91 break; 92 default: 93 pr_err("cpts: unknown event type\n"); 94 break; 95 } 96 if (type == match) 97 break; 98 } 99 return type == match ? 0 : -1; 100 } 101 102 static cycle_t cpts_systim_read(const struct cyclecounter *cc) 103 { 104 u64 val = 0; 105 struct cpts_event *event; 106 struct list_head *this, *next; 107 struct cpts *cpts = container_of(cc, struct cpts, cc); 108 109 cpts_write32(cpts, TS_PUSH, ts_push); 110 if (cpts_fifo_read(cpts, CPTS_EV_PUSH)) 111 pr_err("cpts: unable to obtain a time stamp\n"); 112 113 list_for_each_safe(this, next, &cpts->events) { 114 event = list_entry(this, struct cpts_event, list); 115 if (event_type(event) == CPTS_EV_PUSH) { 116 list_del_init(&event->list); 117 list_add(&event->list, &cpts->pool); 118 val = event->low; 119 break; 120 } 121 } 122 123 return val; 124 } 125 126 /* PTP clock operations */ 127 128 static int cpts_ptp_adjfreq(struct ptp_clock_info *ptp, s32 ppb) 129 { 130 u64 adj; 131 u32 diff, mult; 132 int neg_adj = 0; 133 unsigned long flags; 134 struct cpts *cpts = container_of(ptp, struct cpts, info); 135 136 if (ppb < 0) { 137 neg_adj = 1; 138 ppb = -ppb; 139 } 140 mult = cpts->cc_mult; 141 adj = mult; 142 adj *= ppb; 143 diff = div_u64(adj, 1000000000ULL); 144 145 spin_lock_irqsave(&cpts->lock, flags); 146 147 timecounter_read(&cpts->tc); 148 149 cpts->cc.mult = neg_adj ? mult - diff : mult + diff; 150 151 spin_unlock_irqrestore(&cpts->lock, flags); 152 153 return 0; 154 } 155 156 static int cpts_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta) 157 { 158 unsigned long flags; 159 struct cpts *cpts = container_of(ptp, struct cpts, info); 160 161 spin_lock_irqsave(&cpts->lock, flags); 162 timecounter_adjtime(&cpts->tc, delta); 163 spin_unlock_irqrestore(&cpts->lock, flags); 164 165 return 0; 166 } 167 168 static int cpts_ptp_gettime(struct ptp_clock_info *ptp, struct timespec64 *ts) 169 { 170 u64 ns; 171 unsigned long flags; 172 struct cpts *cpts = container_of(ptp, struct cpts, info); 173 174 spin_lock_irqsave(&cpts->lock, flags); 175 ns = timecounter_read(&cpts->tc); 176 spin_unlock_irqrestore(&cpts->lock, flags); 177 178 *ts = ns_to_timespec64(ns); 179 180 return 0; 181 } 182 183 static int cpts_ptp_settime(struct ptp_clock_info *ptp, 184 const struct timespec64 *ts) 185 { 186 u64 ns; 187 unsigned long flags; 188 struct cpts *cpts = container_of(ptp, struct cpts, info); 189 190 ns = timespec64_to_ns(ts); 191 192 spin_lock_irqsave(&cpts->lock, flags); 193 timecounter_init(&cpts->tc, &cpts->cc, ns); 194 spin_unlock_irqrestore(&cpts->lock, flags); 195 196 return 0; 197 } 198 199 static int cpts_ptp_enable(struct ptp_clock_info *ptp, 200 struct ptp_clock_request *rq, int on) 201 { 202 return -EOPNOTSUPP; 203 } 204 205 static struct ptp_clock_info cpts_info = { 206 .owner = THIS_MODULE, 207 .name = "CTPS timer", 208 .max_adj = 1000000, 209 .n_ext_ts = 0, 210 .n_pins = 0, 211 .pps = 0, 212 .adjfreq = cpts_ptp_adjfreq, 213 .adjtime = cpts_ptp_adjtime, 214 .gettime64 = cpts_ptp_gettime, 215 .settime64 = cpts_ptp_settime, 216 .enable = cpts_ptp_enable, 217 }; 218 219 static void cpts_overflow_check(struct work_struct *work) 220 { 221 struct timespec64 ts; 222 struct cpts *cpts = container_of(work, struct cpts, overflow_work.work); 223 224 cpts_write32(cpts, CPTS_EN, control); 225 cpts_write32(cpts, TS_PEND_EN, int_enable); 226 cpts_ptp_gettime(&cpts->info, &ts); 227 pr_debug("cpts overflow check at %lld.%09lu\n", ts.tv_sec, ts.tv_nsec); 228 schedule_delayed_work(&cpts->overflow_work, CPTS_OVERFLOW_PERIOD); 229 } 230 231 static void cpts_clk_init(struct device *dev, struct cpts *cpts) 232 { 233 cpts->refclk = devm_clk_get(dev, "cpts"); 234 if (IS_ERR(cpts->refclk)) { 235 dev_err(dev, "Failed to get cpts refclk\n"); 236 cpts->refclk = NULL; 237 return; 238 } 239 clk_prepare_enable(cpts->refclk); 240 } 241 242 static void cpts_clk_release(struct cpts *cpts) 243 { 244 clk_disable(cpts->refclk); 245 } 246 247 static int cpts_match(struct sk_buff *skb, unsigned int ptp_class, 248 u16 ts_seqid, u8 ts_msgtype) 249 { 250 u16 *seqid; 251 unsigned int offset = 0; 252 u8 *msgtype, *data = skb->data; 253 254 if (ptp_class & PTP_CLASS_VLAN) 255 offset += VLAN_HLEN; 256 257 switch (ptp_class & PTP_CLASS_PMASK) { 258 case PTP_CLASS_IPV4: 259 offset += ETH_HLEN + IPV4_HLEN(data + offset) + UDP_HLEN; 260 break; 261 case PTP_CLASS_IPV6: 262 offset += ETH_HLEN + IP6_HLEN + UDP_HLEN; 263 break; 264 case PTP_CLASS_L2: 265 offset += ETH_HLEN; 266 break; 267 default: 268 return 0; 269 } 270 271 if (skb->len + ETH_HLEN < offset + OFF_PTP_SEQUENCE_ID + sizeof(*seqid)) 272 return 0; 273 274 if (unlikely(ptp_class & PTP_CLASS_V1)) 275 msgtype = data + offset + OFF_PTP_CONTROL; 276 else 277 msgtype = data + offset; 278 279 seqid = (u16 *)(data + offset + OFF_PTP_SEQUENCE_ID); 280 281 return (ts_msgtype == (*msgtype & 0xf) && ts_seqid == ntohs(*seqid)); 282 } 283 284 static u64 cpts_find_ts(struct cpts *cpts, struct sk_buff *skb, int ev_type) 285 { 286 u64 ns = 0; 287 struct cpts_event *event; 288 struct list_head *this, *next; 289 unsigned int class = ptp_classify_raw(skb); 290 unsigned long flags; 291 u16 seqid; 292 u8 mtype; 293 294 if (class == PTP_CLASS_NONE) 295 return 0; 296 297 spin_lock_irqsave(&cpts->lock, flags); 298 cpts_fifo_read(cpts, CPTS_EV_PUSH); 299 list_for_each_safe(this, next, &cpts->events) { 300 event = list_entry(this, struct cpts_event, list); 301 if (event_expired(event)) { 302 list_del_init(&event->list); 303 list_add(&event->list, &cpts->pool); 304 continue; 305 } 306 mtype = (event->high >> MESSAGE_TYPE_SHIFT) & MESSAGE_TYPE_MASK; 307 seqid = (event->high >> SEQUENCE_ID_SHIFT) & SEQUENCE_ID_MASK; 308 if (ev_type == event_type(event) && 309 cpts_match(skb, class, seqid, mtype)) { 310 ns = timecounter_cyc2time(&cpts->tc, event->low); 311 list_del_init(&event->list); 312 list_add(&event->list, &cpts->pool); 313 break; 314 } 315 } 316 spin_unlock_irqrestore(&cpts->lock, flags); 317 318 return ns; 319 } 320 321 void cpts_rx_timestamp(struct cpts *cpts, struct sk_buff *skb) 322 { 323 u64 ns; 324 struct skb_shared_hwtstamps *ssh; 325 326 if (!cpts->rx_enable) 327 return; 328 ns = cpts_find_ts(cpts, skb, CPTS_EV_RX); 329 if (!ns) 330 return; 331 ssh = skb_hwtstamps(skb); 332 memset(ssh, 0, sizeof(*ssh)); 333 ssh->hwtstamp = ns_to_ktime(ns); 334 } 335 EXPORT_SYMBOL_GPL(cpts_rx_timestamp); 336 337 void cpts_tx_timestamp(struct cpts *cpts, struct sk_buff *skb) 338 { 339 u64 ns; 340 struct skb_shared_hwtstamps ssh; 341 342 if (!(skb_shinfo(skb)->tx_flags & SKBTX_IN_PROGRESS)) 343 return; 344 ns = cpts_find_ts(cpts, skb, CPTS_EV_TX); 345 if (!ns) 346 return; 347 memset(&ssh, 0, sizeof(ssh)); 348 ssh.hwtstamp = ns_to_ktime(ns); 349 skb_tstamp_tx(skb, &ssh); 350 } 351 EXPORT_SYMBOL_GPL(cpts_tx_timestamp); 352 353 int cpts_register(struct device *dev, struct cpts *cpts, 354 u32 mult, u32 shift) 355 { 356 int err, i; 357 unsigned long flags; 358 359 cpts->info = cpts_info; 360 cpts->clock = ptp_clock_register(&cpts->info, dev); 361 if (IS_ERR(cpts->clock)) { 362 err = PTR_ERR(cpts->clock); 363 cpts->clock = NULL; 364 return err; 365 } 366 spin_lock_init(&cpts->lock); 367 368 cpts->cc.read = cpts_systim_read; 369 cpts->cc.mask = CLOCKSOURCE_MASK(32); 370 cpts->cc_mult = mult; 371 cpts->cc.mult = mult; 372 cpts->cc.shift = shift; 373 374 INIT_LIST_HEAD(&cpts->events); 375 INIT_LIST_HEAD(&cpts->pool); 376 for (i = 0; i < CPTS_MAX_EVENTS; i++) 377 list_add(&cpts->pool_data[i].list, &cpts->pool); 378 379 cpts_clk_init(dev, cpts); 380 cpts_write32(cpts, CPTS_EN, control); 381 cpts_write32(cpts, TS_PEND_EN, int_enable); 382 383 spin_lock_irqsave(&cpts->lock, flags); 384 timecounter_init(&cpts->tc, &cpts->cc, ktime_to_ns(ktime_get_real())); 385 spin_unlock_irqrestore(&cpts->lock, flags); 386 387 INIT_DELAYED_WORK(&cpts->overflow_work, cpts_overflow_check); 388 schedule_delayed_work(&cpts->overflow_work, CPTS_OVERFLOW_PERIOD); 389 390 cpts->phc_index = ptp_clock_index(cpts->clock); 391 return 0; 392 } 393 EXPORT_SYMBOL_GPL(cpts_register); 394 395 void cpts_unregister(struct cpts *cpts) 396 { 397 if (cpts->clock) { 398 ptp_clock_unregister(cpts->clock); 399 cancel_delayed_work_sync(&cpts->overflow_work); 400 } 401 if (cpts->refclk) 402 cpts_clk_release(cpts); 403 } 404 EXPORT_SYMBOL_GPL(cpts_unregister); 405 406 MODULE_LICENSE("GPL v2"); 407 MODULE_DESCRIPTION("TI CPTS driver"); 408 MODULE_AUTHOR("Richard Cochran <richardcochran@gmail.com>"); 409