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         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 + offset) + 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 }