drivers/net/ethernet/ti/cpts.c

   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 }