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 unsigned long flags; 161 struct cpts *cpts = container_of(ptp, struct cpts, info); 162 163 spin_lock_irqsave(&cpts->lock, flags); 164 timecounter_adjtime(&cpts->tc, delta); 165 spin_unlock_irqrestore(&cpts->lock, flags); 166 167 return 0; 168 } 169 170 static int cpts_ptp_gettime(struct ptp_clock_info *ptp, struct timespec *ts) 171 { 172 u64 ns; 173 u32 remainder; 174 unsigned long flags; 175 struct cpts *cpts = container_of(ptp, struct cpts, info); 176 177 spin_lock_irqsave(&cpts->lock, flags); 178 ns = timecounter_read(&cpts->tc); 179 spin_unlock_irqrestore(&cpts->lock, flags); 180 181 ts->tv_sec = div_u64_rem(ns, 1000000000, &remainder); 182 ts->tv_nsec = remainder; 183 184 return 0; 185 } 186 187 static int cpts_ptp_settime(struct ptp_clock_info *ptp, 188 const struct timespec *ts) 189 { 190 u64 ns; 191 unsigned long flags; 192 struct cpts *cpts = container_of(ptp, struct cpts, info); 193 194 ns = ts->tv_sec * 1000000000ULL; 195 ns += ts->tv_nsec; 196 197 spin_lock_irqsave(&cpts->lock, flags); 198 timecounter_init(&cpts->tc, &cpts->cc, ns); 199 spin_unlock_irqrestore(&cpts->lock, flags); 200 201 return 0; 202 } 203 204 static int cpts_ptp_enable(struct ptp_clock_info *ptp, 205 struct ptp_clock_request *rq, int on) 206 { 207 return -EOPNOTSUPP; 208 } 209 210 static struct ptp_clock_info cpts_info = { 211 .owner = THIS_MODULE, 212 .name = "CTPS timer", 213 .max_adj = 1000000, 214 .n_ext_ts = 0, 215 .n_pins = 0, 216 .pps = 0, 217 .adjfreq = cpts_ptp_adjfreq, 218 .adjtime = cpts_ptp_adjtime, 219 .gettime = cpts_ptp_gettime, 220 .settime = cpts_ptp_settime, 221 .enable = cpts_ptp_enable, 222 }; 223 224 static void cpts_overflow_check(struct work_struct *work) 225 { 226 struct timespec ts; 227 struct cpts *cpts = container_of(work, struct cpts, overflow_work.work); 228 229 cpts_write32(cpts, CPTS_EN, control); 230 cpts_write32(cpts, TS_PEND_EN, int_enable); 231 cpts_ptp_gettime(&cpts->info, &ts); 232 pr_debug("cpts overflow check at %ld.%09lu\n", ts.tv_sec, ts.tv_nsec); 233 schedule_delayed_work(&cpts->overflow_work, CPTS_OVERFLOW_PERIOD); 234 } 235 236 static void cpts_clk_init(struct device *dev, struct cpts *cpts) 237 { 238 cpts->refclk = devm_clk_get(dev, "cpts"); 239 if (IS_ERR(cpts->refclk)) { 240 dev_err(dev, "Failed to get cpts refclk\n"); 241 cpts->refclk = NULL; 242 return; 243 } 244 clk_prepare_enable(cpts->refclk); 245 } 246 247 static void cpts_clk_release(struct cpts *cpts) 248 { 249 clk_disable(cpts->refclk); 250 } 251 252 static int cpts_match(struct sk_buff *skb, unsigned int ptp_class, 253 u16 ts_seqid, u8 ts_msgtype) 254 { 255 u16 *seqid; 256 unsigned int offset = 0; 257 u8 *msgtype, *data = skb->data; 258 259 if (ptp_class & PTP_CLASS_VLAN) 260 offset += VLAN_HLEN; 261 262 switch (ptp_class & PTP_CLASS_PMASK) { 263 case PTP_CLASS_IPV4: 264 offset += ETH_HLEN + IPV4_HLEN(data + offset) + UDP_HLEN; 265 break; 266 case PTP_CLASS_IPV6: 267 offset += ETH_HLEN + IP6_HLEN + UDP_HLEN; 268 break; 269 case PTP_CLASS_L2: 270 offset += ETH_HLEN; 271 break; 272 default: 273 return 0; 274 } 275 276 if (skb->len + ETH_HLEN < offset + OFF_PTP_SEQUENCE_ID + sizeof(*seqid)) 277 return 0; 278 279 if (unlikely(ptp_class & PTP_CLASS_V1)) 280 msgtype = data + offset + OFF_PTP_CONTROL; 281 else 282 msgtype = data + offset; 283 284 seqid = (u16 *)(data + offset + OFF_PTP_SEQUENCE_ID); 285 286 return (ts_msgtype == (*msgtype & 0xf) && ts_seqid == ntohs(*seqid)); 287 } 288 289 static u64 cpts_find_ts(struct cpts *cpts, struct sk_buff *skb, int ev_type) 290 { 291 u64 ns = 0; 292 struct cpts_event *event; 293 struct list_head *this, *next; 294 unsigned int class = ptp_classify_raw(skb); 295 unsigned long flags; 296 u16 seqid; 297 u8 mtype; 298 299 if (class == PTP_CLASS_NONE) 300 return 0; 301 302 spin_lock_irqsave(&cpts->lock, flags); 303 cpts_fifo_read(cpts, CPTS_EV_PUSH); 304 list_for_each_safe(this, next, &cpts->events) { 305 event = list_entry(this, struct cpts_event, list); 306 if (event_expired(event)) { 307 list_del_init(&event->list); 308 list_add(&event->list, &cpts->pool); 309 continue; 310 } 311 mtype = (event->high >> MESSAGE_TYPE_SHIFT) & MESSAGE_TYPE_MASK; 312 seqid = (event->high >> SEQUENCE_ID_SHIFT) & SEQUENCE_ID_MASK; 313 if (ev_type == event_type(event) && 314 cpts_match(skb, class, seqid, mtype)) { 315 ns = timecounter_cyc2time(&cpts->tc, event->low); 316 list_del_init(&event->list); 317 list_add(&event->list, &cpts->pool); 318 break; 319 } 320 } 321 spin_unlock_irqrestore(&cpts->lock, flags); 322 323 return ns; 324 } 325 326 void cpts_rx_timestamp(struct cpts *cpts, struct sk_buff *skb) 327 { 328 u64 ns; 329 struct skb_shared_hwtstamps *ssh; 330 331 if (!cpts->rx_enable) 332 return; 333 ns = cpts_find_ts(cpts, skb, CPTS_EV_RX); 334 if (!ns) 335 return; 336 ssh = skb_hwtstamps(skb); 337 memset(ssh, 0, sizeof(*ssh)); 338 ssh->hwtstamp = ns_to_ktime(ns); 339 } 340 341 void cpts_tx_timestamp(struct cpts *cpts, struct sk_buff *skb) 342 { 343 u64 ns; 344 struct skb_shared_hwtstamps ssh; 345 346 if (!(skb_shinfo(skb)->tx_flags & SKBTX_IN_PROGRESS)) 347 return; 348 ns = cpts_find_ts(cpts, skb, CPTS_EV_TX); 349 if (!ns) 350 return; 351 memset(&ssh, 0, sizeof(ssh)); 352 ssh.hwtstamp = ns_to_ktime(ns); 353 skb_tstamp_tx(skb, &ssh); 354 } 355 356 #endif /*CONFIG_TI_CPTS*/ 357 358 int cpts_register(struct device *dev, struct cpts *cpts, 359 u32 mult, u32 shift) 360 { 361 #ifdef CONFIG_TI_CPTS 362 int err, i; 363 unsigned long flags; 364 365 cpts->info = cpts_info; 366 cpts->clock = ptp_clock_register(&cpts->info, dev); 367 if (IS_ERR(cpts->clock)) { 368 err = PTR_ERR(cpts->clock); 369 cpts->clock = NULL; 370 return err; 371 } 372 spin_lock_init(&cpts->lock); 373 374 cpts->cc.read = cpts_systim_read; 375 cpts->cc.mask = CLOCKSOURCE_MASK(32); 376 cpts->cc_mult = mult; 377 cpts->cc.mult = mult; 378 cpts->cc.shift = shift; 379 380 INIT_LIST_HEAD(&cpts->events); 381 INIT_LIST_HEAD(&cpts->pool); 382 for (i = 0; i < CPTS_MAX_EVENTS; i++) 383 list_add(&cpts->pool_data[i].list, &cpts->pool); 384 385 cpts_clk_init(dev, cpts); 386 cpts_write32(cpts, CPTS_EN, control); 387 cpts_write32(cpts, TS_PEND_EN, int_enable); 388 389 spin_lock_irqsave(&cpts->lock, flags); 390 timecounter_init(&cpts->tc, &cpts->cc, ktime_to_ns(ktime_get_real())); 391 spin_unlock_irqrestore(&cpts->lock, flags); 392 393 INIT_DELAYED_WORK(&cpts->overflow_work, cpts_overflow_check); 394 schedule_delayed_work(&cpts->overflow_work, CPTS_OVERFLOW_PERIOD); 395 396 cpts->phc_index = ptp_clock_index(cpts->clock); 397 #endif 398 return 0; 399 } 400 401 void cpts_unregister(struct cpts *cpts) 402 { 403 #ifdef CONFIG_TI_CPTS 404 if (cpts->clock) { 405 ptp_clock_unregister(cpts->clock); 406 cancel_delayed_work_sync(&cpts->overflow_work); 407 } 408 if (cpts->refclk) 409 cpts_clk_release(cpts); 410 #endif 411 } 412