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
  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: unknown 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 }