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 30 #include "cpts.h" 31 32 #ifdef CONFIG_TI_CPTS 33 34 static struct sock_filter ptp_filter[] = { 35 PTP_FILTER 36 }; 37 38 #define cpts_read32(c, r) __raw_readl(&c->reg->r) 39 #define cpts_write32(c, v, r) __raw_writel(v, &c->reg->r) 40 41 static int event_expired(struct cpts_event *event) 42 { 43 return time_after(jiffies, event->tmo); 44 } 45 46 static int event_type(struct cpts_event *event) 47 { 48 return (event->high >> EVENT_TYPE_SHIFT) & EVENT_TYPE_MASK; 49 } 50 51 static int cpts_fifo_pop(struct cpts *cpts, u32 *high, u32 *low) 52 { 53 u32 r = cpts_read32(cpts, intstat_raw); 54 55 if (r & TS_PEND_RAW) { 56 *high = cpts_read32(cpts, event_high); 57 *low = cpts_read32(cpts, event_low); 58 cpts_write32(cpts, EVENT_POP, event_pop); 59 return 0; 60 } 61 return -1; 62 } 63 64 /* 65 * Returns zero if matching event type was found. 66 */ 67 static int cpts_fifo_read(struct cpts *cpts, int match) 68 { 69 int i, type = -1; 70 u32 hi, lo; 71 struct cpts_event *event; 72 73 for (i = 0; i < CPTS_FIFO_DEPTH; i++) { 74 if (cpts_fifo_pop(cpts, &hi, &lo)) 75 break; 76 if (list_empty(&cpts->pool)) { 77 pr_err("cpts: event pool is empty\n"); 78 return -1; 79 } 80 event = list_first_entry(&cpts->pool, struct cpts_event, list); 81 event->tmo = jiffies + 2; 82 event->high = hi; 83 event->low = lo; 84 type = event_type(event); 85 switch (type) { 86 case CPTS_EV_PUSH: 87 case CPTS_EV_RX: 88 case CPTS_EV_TX: 89 list_del_init(&event->list); 90 list_add_tail(&event->list, &cpts->events); 91 break; 92 case CPTS_EV_ROLL: 93 case CPTS_EV_HALF: 94 case CPTS_EV_HW: 95 break; 96 default: 97 pr_err("cpts: unkown event type\n"); 98 break; 99 } 100 if (type == match) 101 break; 102 } 103 return type == match ? 0 : -1; 104 } 105 106 static cycle_t cpts_systim_read(const struct cyclecounter *cc) 107 { 108 u64 val = 0; 109 struct cpts_event *event; 110 struct list_head *this, *next; 111 struct cpts *cpts = container_of(cc, struct cpts, cc); 112 113 cpts_write32(cpts, TS_PUSH, ts_push); 114 if (cpts_fifo_read(cpts, CPTS_EV_PUSH)) 115 pr_err("cpts: unable to obtain a time stamp\n"); 116 117 list_for_each_safe(this, next, &cpts->events) { 118 event = list_entry(this, struct cpts_event, list); 119 if (event_type(event) == CPTS_EV_PUSH) { 120 list_del_init(&event->list); 121 list_add(&event->list, &cpts->pool); 122 val = event->low; 123 break; 124 } 125 } 126 127 return val; 128 } 129 130 /* PTP clock operations */ 131 132 static int cpts_ptp_adjfreq(struct ptp_clock_info *ptp, s32 ppb) 133 { 134 u64 adj; 135 u32 diff, mult; 136 int neg_adj = 0; 137 unsigned long flags; 138 struct cpts *cpts = container_of(ptp, struct cpts, info); 139 140 if (ppb < 0) { 141 neg_adj = 1; 142 ppb = -ppb; 143 } 144 mult = cpts->cc_mult; 145 adj = mult; 146 adj *= ppb; 147 diff = div_u64(adj, 1000000000ULL); 148 149 spin_lock_irqsave(&cpts->lock, flags); 150 151 timecounter_read(&cpts->tc); 152 153 cpts->cc.mult = neg_adj ? mult - diff : mult + diff; 154 155 spin_unlock_irqrestore(&cpts->lock, flags); 156 157 return 0; 158 } 159 160 static int cpts_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta) 161 { 162 s64 now; 163 unsigned long flags; 164 struct cpts *cpts = container_of(ptp, struct cpts, info); 165 166 spin_lock_irqsave(&cpts->lock, flags); 167 now = timecounter_read(&cpts->tc); 168 now += delta; 169 timecounter_init(&cpts->tc, &cpts->cc, now); 170 spin_unlock_irqrestore(&cpts->lock, flags); 171 172 return 0; 173 } 174 175 static int cpts_ptp_gettime(struct ptp_clock_info *ptp, struct timespec *ts) 176 { 177 u64 ns; 178 u32 remainder; 179 unsigned long flags; 180 struct cpts *cpts = container_of(ptp, struct cpts, info); 181 182 spin_lock_irqsave(&cpts->lock, flags); 183 ns = timecounter_read(&cpts->tc); 184 spin_unlock_irqrestore(&cpts->lock, flags); 185 186 ts->tv_sec = div_u64_rem(ns, 1000000000, &remainder); 187 ts->tv_nsec = remainder; 188 189 return 0; 190 } 191 192 static int cpts_ptp_settime(struct ptp_clock_info *ptp, 193 const struct timespec *ts) 194 { 195 u64 ns; 196 unsigned long flags; 197 struct cpts *cpts = container_of(ptp, struct cpts, info); 198 199 ns = ts->tv_sec * 1000000000ULL; 200 ns += ts->tv_nsec; 201 202 spin_lock_irqsave(&cpts->lock, flags); 203 timecounter_init(&cpts->tc, &cpts->cc, ns); 204 spin_unlock_irqrestore(&cpts->lock, flags); 205 206 return 0; 207 } 208 209 static int cpts_ptp_enable(struct ptp_clock_info *ptp, 210 struct ptp_clock_request *rq, int on) 211 { 212 return -EOPNOTSUPP; 213 } 214 215 static struct ptp_clock_info cpts_info = { 216 .owner = THIS_MODULE, 217 .name = "CTPS timer", 218 .max_adj = 1000000, 219 .n_ext_ts = 0, 220 .pps = 0, 221 .adjfreq = cpts_ptp_adjfreq, 222 .adjtime = cpts_ptp_adjtime, 223 .gettime = cpts_ptp_gettime, 224 .settime = cpts_ptp_settime, 225 .enable = cpts_ptp_enable, 226 }; 227 228 static void cpts_overflow_check(struct work_struct *work) 229 { 230 struct timespec ts; 231 struct cpts *cpts = container_of(work, struct cpts, overflow_work.work); 232 233 cpts_write32(cpts, CPTS_EN, control); 234 cpts_write32(cpts, TS_PEND_EN, int_enable); 235 cpts_ptp_gettime(&cpts->info, &ts); 236 pr_debug("cpts overflow check at %ld.%09lu\n", ts.tv_sec, ts.tv_nsec); 237 schedule_delayed_work(&cpts->overflow_work, CPTS_OVERFLOW_PERIOD); 238 } 239 240 #define CPTS_REF_CLOCK_NAME "cpsw_cpts_rft_clk" 241 242 static void cpts_clk_init(struct cpts *cpts) 243 { 244 cpts->refclk = clk_get(NULL, CPTS_REF_CLOCK_NAME); 245 if (IS_ERR(cpts->refclk)) { 246 pr_err("Failed to clk_get %s\n", CPTS_REF_CLOCK_NAME); 247 cpts->refclk = NULL; 248 return; 249 } 250 clk_prepare_enable(cpts->refclk); 251 } 252 253 static void cpts_clk_release(struct cpts *cpts) 254 { 255 clk_disable(cpts->refclk); 256 clk_put(cpts->refclk); 257 } 258 259 static int cpts_match(struct sk_buff *skb, unsigned int ptp_class, 260 u16 ts_seqid, u8 ts_msgtype) 261 { 262 u16 *seqid; 263 unsigned int offset; 264 u8 *msgtype, *data = skb->data; 265 266 switch (ptp_class) { 267 case PTP_CLASS_V1_IPV4: 268 case PTP_CLASS_V2_IPV4: 269 offset = ETH_HLEN + IPV4_HLEN(data) + UDP_HLEN; 270 break; 271 case PTP_CLASS_V1_IPV6: 272 case PTP_CLASS_V2_IPV6: 273 offset = OFF_PTP6; 274 break; 275 case PTP_CLASS_V2_L2: 276 offset = ETH_HLEN; 277 break; 278 case PTP_CLASS_V2_VLAN: 279 offset = ETH_HLEN + VLAN_HLEN; 280 break; 281 default: 282 return 0; 283 } 284 285 if (skb->len + ETH_HLEN < offset + OFF_PTP_SEQUENCE_ID + sizeof(*seqid)) 286 return 0; 287 288 if (unlikely(ptp_class & PTP_CLASS_V1)) 289 msgtype = data + offset + OFF_PTP_CONTROL; 290 else 291 msgtype = data + offset; 292 293 seqid = (u16 *)(data + offset + OFF_PTP_SEQUENCE_ID); 294 295 return (ts_msgtype == (*msgtype & 0xf) && ts_seqid == ntohs(*seqid)); 296 } 297 298 static u64 cpts_find_ts(struct cpts *cpts, struct sk_buff *skb, int ev_type) 299 { 300 u64 ns = 0; 301 struct cpts_event *event; 302 struct list_head *this, *next; 303 unsigned int class = sk_run_filter(skb, ptp_filter); 304 unsigned long flags; 305 u16 seqid; 306 u8 mtype; 307 308 if (class == PTP_CLASS_NONE) 309 return 0; 310 311 spin_lock_irqsave(&cpts->lock, flags); 312 cpts_fifo_read(cpts, CPTS_EV_PUSH); 313 list_for_each_safe(this, next, &cpts->events) { 314 event = list_entry(this, struct cpts_event, list); 315 if (event_expired(event)) { 316 list_del_init(&event->list); 317 list_add(&event->list, &cpts->pool); 318 continue; 319 } 320 mtype = (event->high >> MESSAGE_TYPE_SHIFT) & MESSAGE_TYPE_MASK; 321 seqid = (event->high >> SEQUENCE_ID_SHIFT) & SEQUENCE_ID_MASK; 322 if (ev_type == event_type(event) && 323 cpts_match(skb, class, seqid, mtype)) { 324 ns = timecounter_cyc2time(&cpts->tc, event->low); 325 list_del_init(&event->list); 326 list_add(&event->list, &cpts->pool); 327 break; 328 } 329 } 330 spin_unlock_irqrestore(&cpts->lock, flags); 331 332 return ns; 333 } 334 335 void cpts_rx_timestamp(struct cpts *cpts, struct sk_buff *skb) 336 { 337 u64 ns; 338 struct skb_shared_hwtstamps *ssh; 339 340 if (!cpts->rx_enable) 341 return; 342 ns = cpts_find_ts(cpts, skb, CPTS_EV_RX); 343 if (!ns) 344 return; 345 ssh = skb_hwtstamps(skb); 346 memset(ssh, 0, sizeof(*ssh)); 347 ssh->hwtstamp = ns_to_ktime(ns); 348 } 349 350 void cpts_tx_timestamp(struct cpts *cpts, struct sk_buff *skb) 351 { 352 u64 ns; 353 struct skb_shared_hwtstamps ssh; 354 355 if (!(skb_shinfo(skb)->tx_flags & SKBTX_IN_PROGRESS)) 356 return; 357 ns = cpts_find_ts(cpts, skb, CPTS_EV_TX); 358 if (!ns) 359 return; 360 memset(&ssh, 0, sizeof(ssh)); 361 ssh.hwtstamp = ns_to_ktime(ns); 362 skb_tstamp_tx(skb, &ssh); 363 } 364 365 #endif /*CONFIG_TI_CPTS*/ 366 367 int cpts_register(struct device *dev, struct cpts *cpts, 368 u32 mult, u32 shift) 369 { 370 #ifdef CONFIG_TI_CPTS 371 int err, i; 372 unsigned long flags; 373 374 if (ptp_filter_init(ptp_filter, ARRAY_SIZE(ptp_filter))) { 375 pr_err("cpts: bad ptp filter\n"); 376 return -EINVAL; 377 } 378 cpts->info = cpts_info; 379 cpts->clock = ptp_clock_register(&cpts->info, dev); 380 if (IS_ERR(cpts->clock)) { 381 err = PTR_ERR(cpts->clock); 382 cpts->clock = NULL; 383 return err; 384 } 385 spin_lock_init(&cpts->lock); 386 387 cpts->cc.read = cpts_systim_read; 388 cpts->cc.mask = CLOCKSOURCE_MASK(32); 389 cpts->cc_mult = mult; 390 cpts->cc.mult = mult; 391 cpts->cc.shift = shift; 392 393 INIT_LIST_HEAD(&cpts->events); 394 INIT_LIST_HEAD(&cpts->pool); 395 for (i = 0; i < CPTS_MAX_EVENTS; i++) 396 list_add(&cpts->pool_data[i].list, &cpts->pool); 397 398 cpts_clk_init(cpts); 399 cpts_write32(cpts, CPTS_EN, control); 400 cpts_write32(cpts, TS_PEND_EN, int_enable); 401 402 spin_lock_irqsave(&cpts->lock, flags); 403 timecounter_init(&cpts->tc, &cpts->cc, ktime_to_ns(ktime_get_real())); 404 spin_unlock_irqrestore(&cpts->lock, flags); 405 406 INIT_DELAYED_WORK(&cpts->overflow_work, cpts_overflow_check); 407 schedule_delayed_work(&cpts->overflow_work, CPTS_OVERFLOW_PERIOD); 408 409 cpts->phc_index = ptp_clock_index(cpts->clock); 410 #endif 411 return 0; 412 } 413 414 void cpts_unregister(struct cpts *cpts) 415 { 416 #ifdef CONFIG_TI_CPTS 417 if (cpts->clock) { 418 ptp_clock_unregister(cpts->clock); 419 cancel_delayed_work_sync(&cpts->overflow_work); 420 } 421 if (cpts->refclk) 422 cpts_clk_release(cpts); 423 #endif 424 } 425