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 #ifdef CONFIG_TI_CPTS 35 36 #define cpts_read32(c, r) __raw_readl(&c->reg->r) 37 #define cpts_write32(c, v, r) __raw_writel(v, &c->reg->r) 38 39 static int event_expired(struct cpts_event *event) 40 { 41 return time_after(jiffies, event->tmo); 42 } 43 44 static int event_type(struct cpts_event *event) 45 { 46 return (event->high >> EVENT_TYPE_SHIFT) & EVENT_TYPE_MASK; 47 } 48 49 static int cpts_fifo_pop(struct cpts *cpts, u32 *high, u32 *low) 50 { 51 u32 r = cpts_read32(cpts, intstat_raw); 52 53 if (r & TS_PEND_RAW) { 54 *high = cpts_read32(cpts, event_high); 55 *low = cpts_read32(cpts, event_low); 56 cpts_write32(cpts, EVENT_POP, event_pop); 57 return 0; 58 } 59 return -1; 60 } 61 62 /* 63 * Returns zero if matching event type was found. 64 */ 65 static int cpts_fifo_read(struct cpts *cpts, int match) 66 { 67 int i, type = -1; 68 u32 hi, lo; 69 struct cpts_event *event; 70 71 for (i = 0; i < CPTS_FIFO_DEPTH; i++) { 72 if (cpts_fifo_pop(cpts, &hi, &lo)) 73 break; 74 if (list_empty(&cpts->pool)) { 75 pr_err("cpts: event pool is empty\n"); 76 return -1; 77 } 78 event = list_first_entry(&cpts->pool, struct cpts_event, list); 79 event->tmo = jiffies + 2; 80 event->high = hi; 81 event->low = lo; 82 type = event_type(event); 83 switch (type) { 84 case CPTS_EV_PUSH: 85 case CPTS_EV_RX: 86 case CPTS_EV_TX: 87 list_del_init(&event->list); 88 list_add_tail(&event->list, &cpts->events); 89 break; 90 case CPTS_EV_ROLL: 91 case CPTS_EV_HALF: 92 case CPTS_EV_HW: 93 break; 94 default: 95 pr_err("cpts: unknown event type\n"); 96 break; 97 } 98 if (type == match) 99 break; 100 } 101 return type == match ? 0 : -1; 102 } 103 104 static cycle_t cpts_systim_read(const struct cyclecounter *cc) 105 { 106 u64 val = 0; 107 struct cpts_event *event; 108 struct list_head *this, *next; 109 struct cpts *cpts = container_of(cc, struct cpts, cc); 110 111 cpts_write32(cpts, TS_PUSH, ts_push); 112 if (cpts_fifo_read(cpts, CPTS_EV_PUSH)) 113 pr_err("cpts: unable to obtain a time stamp\n"); 114 115 list_for_each_safe(this, next, &cpts->events) { 116 event = list_entry(this, struct cpts_event, list); 117 if (event_type(event) == CPTS_EV_PUSH) { 118 list_del_init(&event->list); 119 list_add(&event->list, &cpts->pool); 120 val = event->low; 121 break; 122 } 123 } 124 125 return val; 126 } 127 128 /* PTP clock operations */ 129 130 static int cpts_ptp_adjfreq(struct ptp_clock_info *ptp, s32 ppb) 131 { 132 u64 adj; 133 u32 diff, mult; 134 int neg_adj = 0; 135 unsigned long flags; 136 struct cpts *cpts = container_of(ptp, struct cpts, info); 137 138 if (ppb < 0) { 139 neg_adj = 1; 140 ppb = -ppb; 141 } 142 mult = cpts->cc_mult; 143 adj = mult; 144 adj *= ppb; 145 diff = div_u64(adj, 1000000000ULL); 146 147 spin_lock_irqsave(&cpts->lock, flags); 148 149 timecounter_read(&cpts->tc); 150 151 cpts->cc.mult = neg_adj ? mult - diff : mult + diff; 152 153 spin_unlock_irqrestore(&cpts->lock, flags); 154 155 return 0; 156 } 157 158 static int cpts_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta) 159 { 160 s64 now; 161 unsigned long flags; 162 struct cpts *cpts = container_of(ptp, struct cpts, info); 163 164 spin_lock_irqsave(&cpts->lock, flags); 165 now = timecounter_read(&cpts->tc); 166 now += delta; 167 timecounter_init(&cpts->tc, &cpts->cc, now); 168 spin_unlock_irqrestore(&cpts->lock, flags); 169 170 return 0; 171 } 172 173 static int cpts_ptp_gettime(struct ptp_clock_info *ptp, struct timespec *ts) 174 { 175 u64 ns; 176 u32 remainder; 177 unsigned long flags; 178 struct cpts *cpts = container_of(ptp, struct cpts, info); 179 180 spin_lock_irqsave(&cpts->lock, flags); 181 ns = timecounter_read(&cpts->tc); 182 spin_unlock_irqrestore(&cpts->lock, flags); 183 184 ts->tv_sec = div_u64_rem(ns, 1000000000, &remainder); 185 ts->tv_nsec = remainder; 186 187 return 0; 188 } 189 190 static int cpts_ptp_settime(struct ptp_clock_info *ptp, 191 const struct timespec *ts) 192 { 193 u64 ns; 194 unsigned long flags; 195 struct cpts *cpts = container_of(ptp, struct cpts, info); 196 197 ns = ts->tv_sec * 1000000000ULL; 198 ns += ts->tv_nsec; 199 200 spin_lock_irqsave(&cpts->lock, flags); 201 timecounter_init(&cpts->tc, &cpts->cc, ns); 202 spin_unlock_irqrestore(&cpts->lock, flags); 203 204 return 0; 205 } 206 207 static int cpts_ptp_enable(struct ptp_clock_info *ptp, 208 struct ptp_clock_request *rq, int on) 209 { 210 return -EOPNOTSUPP; 211 } 212 213 static struct ptp_clock_info cpts_info = { 214 .owner = THIS_MODULE, 215 .name = "CTPS timer", 216 .max_adj = 1000000, 217 .n_ext_ts = 0, 218 .n_pins = 0, 219 .pps = 0, 220 .adjfreq = cpts_ptp_adjfreq, 221 .adjtime = cpts_ptp_adjtime, 222 .gettime = cpts_ptp_gettime, 223 .settime = cpts_ptp_settime, 224 .enable = cpts_ptp_enable, 225 }; 226 227 static void cpts_overflow_check(struct work_struct *work) 228 { 229 struct timespec ts; 230 struct cpts *cpts = container_of(work, struct cpts, overflow_work.work); 231 232 cpts_write32(cpts, CPTS_EN, control); 233 cpts_write32(cpts, TS_PEND_EN, int_enable); 234 cpts_ptp_gettime(&cpts->info, &ts); 235 pr_debug("cpts overflow check at %ld.%09lu\n", ts.tv_sec, ts.tv_nsec); 236 schedule_delayed_work(&cpts->overflow_work, CPTS_OVERFLOW_PERIOD); 237 } 238 239 static void cpts_clk_init(struct device *dev, struct cpts *cpts) 240 { 241 cpts->refclk = devm_clk_get(dev, "cpts"); 242 if (IS_ERR(cpts->refclk)) { 243 dev_err(dev, "Failed to get cpts refclk\n"); 244 cpts->refclk = NULL; 245 return; 246 } 247 clk_prepare_enable(cpts->refclk); 248 } 249 250 static void cpts_clk_release(struct cpts *cpts) 251 { 252 clk_disable(cpts->refclk); 253 } 254 255 static int cpts_match(struct sk_buff *skb, unsigned int ptp_class, 256 u16 ts_seqid, u8 ts_msgtype) 257 { 258 u16 *seqid; 259 unsigned int offset = 0; 260 u8 *msgtype, *data = skb->data; 261 262 if (ptp_class & PTP_CLASS_VLAN) 263 offset += VLAN_HLEN; 264 265 switch (ptp_class & PTP_CLASS_PMASK) { 266 case PTP_CLASS_IPV4: 267 offset += ETH_HLEN + IPV4_HLEN(data) + UDP_HLEN; 268 break; 269 case PTP_CLASS_IPV6: 270 offset += ETH_HLEN + IP6_HLEN + UDP_HLEN; 271 break; 272 case PTP_CLASS_L2: 273 offset += ETH_HLEN; 274 break; 275 default: 276 return 0; 277 } 278 279 if (skb->len + ETH_HLEN < offset + OFF_PTP_SEQUENCE_ID + sizeof(*seqid)) 280 return 0; 281 282 if (unlikely(ptp_class & PTP_CLASS_V1)) 283 msgtype = data + offset + OFF_PTP_CONTROL; 284 else 285 msgtype = data + offset; 286 287 seqid = (u16 *)(data + offset + OFF_PTP_SEQUENCE_ID); 288 289 return (ts_msgtype == (*msgtype & 0xf) && ts_seqid == ntohs(*seqid)); 290 } 291 292 static u64 cpts_find_ts(struct cpts *cpts, struct sk_buff *skb, int ev_type) 293 { 294 u64 ns = 0; 295 struct cpts_event *event; 296 struct list_head *this, *next; 297 unsigned int class = ptp_classify_raw(skb); 298 unsigned long flags; 299 u16 seqid; 300 u8 mtype; 301 302 if (class == PTP_CLASS_NONE) 303 return 0; 304 305 spin_lock_irqsave(&cpts->lock, flags); 306 cpts_fifo_read(cpts, CPTS_EV_PUSH); 307 list_for_each_safe(this, next, &cpts->events) { 308 event = list_entry(this, struct cpts_event, list); 309 if (event_expired(event)) { 310 list_del_init(&event->list); 311 list_add(&event->list, &cpts->pool); 312 continue; 313 } 314 mtype = (event->high >> MESSAGE_TYPE_SHIFT) & MESSAGE_TYPE_MASK; 315 seqid = (event->high >> SEQUENCE_ID_SHIFT) & SEQUENCE_ID_MASK; 316 if (ev_type == event_type(event) && 317 cpts_match(skb, class, seqid, mtype)) { 318 ns = timecounter_cyc2time(&cpts->tc, event->low); 319 list_del_init(&event->list); 320 list_add(&event->list, &cpts->pool); 321 break; 322 } 323 } 324 spin_unlock_irqrestore(&cpts->lock, flags); 325 326 return ns; 327 } 328 329 void cpts_rx_timestamp(struct cpts *cpts, struct sk_buff *skb) 330 { 331 u64 ns; 332 struct skb_shared_hwtstamps *ssh; 333 334 if (!cpts->rx_enable) 335 return; 336 ns = cpts_find_ts(cpts, skb, CPTS_EV_RX); 337 if (!ns) 338 return; 339 ssh = skb_hwtstamps(skb); 340 memset(ssh, 0, sizeof(*ssh)); 341 ssh->hwtstamp = ns_to_ktime(ns); 342 } 343 344 void cpts_tx_timestamp(struct cpts *cpts, struct sk_buff *skb) 345 { 346 u64 ns; 347 struct skb_shared_hwtstamps ssh; 348 349 if (!(skb_shinfo(skb)->tx_flags & SKBTX_IN_PROGRESS)) 350 return; 351 ns = cpts_find_ts(cpts, skb, CPTS_EV_TX); 352 if (!ns) 353 return; 354 memset(&ssh, 0, sizeof(ssh)); 355 ssh.hwtstamp = ns_to_ktime(ns); 356 skb_tstamp_tx(skb, &ssh); 357 } 358 359 #endif /*CONFIG_TI_CPTS*/ 360 361 int cpts_register(struct device *dev, struct cpts *cpts, 362 u32 mult, u32 shift) 363 { 364 #ifdef CONFIG_TI_CPTS 365 int err, i; 366 unsigned long flags; 367 368 cpts->info = cpts_info; 369 cpts->clock = ptp_clock_register(&cpts->info, dev); 370 if (IS_ERR(cpts->clock)) { 371 err = PTR_ERR(cpts->clock); 372 cpts->clock = NULL; 373 return err; 374 } 375 spin_lock_init(&cpts->lock); 376 377 cpts->cc.read = cpts_systim_read; 378 cpts->cc.mask = CLOCKSOURCE_MASK(32); 379 cpts->cc_mult = mult; 380 cpts->cc.mult = mult; 381 cpts->cc.shift = shift; 382 383 INIT_LIST_HEAD(&cpts->events); 384 INIT_LIST_HEAD(&cpts->pool); 385 for (i = 0; i < CPTS_MAX_EVENTS; i++) 386 list_add(&cpts->pool_data[i].list, &cpts->pool); 387 388 cpts_clk_init(dev, cpts); 389 cpts_write32(cpts, CPTS_EN, control); 390 cpts_write32(cpts, TS_PEND_EN, int_enable); 391 392 spin_lock_irqsave(&cpts->lock, flags); 393 timecounter_init(&cpts->tc, &cpts->cc, ktime_to_ns(ktime_get_real())); 394 spin_unlock_irqrestore(&cpts->lock, flags); 395 396 INIT_DELAYED_WORK(&cpts->overflow_work, cpts_overflow_check); 397 schedule_delayed_work(&cpts->overflow_work, CPTS_OVERFLOW_PERIOD); 398 399 cpts->phc_index = ptp_clock_index(cpts->clock); 400 #endif 401 return 0; 402 } 403 404 void cpts_unregister(struct cpts *cpts) 405 { 406 #ifdef CONFIG_TI_CPTS 407 if (cpts->clock) { 408 ptp_clock_unregister(cpts->clock); 409 cancel_delayed_work_sync(&cpts->overflow_work); 410 } 411 if (cpts->refclk) 412 cpts_clk_release(cpts); 413 #endif 414 } 415