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 <plat/clock.h>
  31
  32 #include "cpts.h"
  33
  34 #ifdef CONFIG_TI_CPTS
  35
  36 static struct sock_filter ptp_filter[] = {
  37         PTP_FILTER
  38 };
  39
  40 #define cpts_read32(c, r)       __raw_readl(&c->reg->r)
  41 #define cpts_write32(c, v, r)   __raw_writel(v, &c->reg->r)
  42
  43 static int event_expired(struct cpts_event *event)
  44 {
  45         return time_after(jiffies, event->tmo);
  46 }
  47
  48 static int event_type(struct cpts_event *event)
  49 {
  50         return (event->high >> EVENT_TYPE_SHIFT) & EVENT_TYPE_MASK;
  51 }
  52
  53 static int cpts_fifo_pop(struct cpts *cpts, u32 *high, u32 *low)
  54 {
  55         u32 r = cpts_read32(cpts, intstat_raw);
  56
  57         if (r & TS_PEND_RAW) {
  58                 *high = cpts_read32(cpts, event_high);
  59                 *low  = cpts_read32(cpts, event_low);
  60                 cpts_write32(cpts, EVENT_POP, event_pop);
  61                 return 0;
  62         }
  63         return -1;
  64 }
  65
  66 /*
  67  * Returns zero if matching event type was found.
  68  */
  69 static int cpts_fifo_read(struct cpts *cpts, int match)
  70 {
  71         int i, type = -1;
  72         u32 hi, lo;
  73         struct cpts_event *event;
  74
  75         for (i = 0; i < CPTS_FIFO_DEPTH; i++) {
  76                 if (cpts_fifo_pop(cpts, &hi, &lo))
  77                         break;
  78                 if (list_empty(&cpts->pool)) {
  79                         pr_err("cpts: event pool is empty\n");
  80                         return -1;
  81                 }
  82                 event = list_first_entry(&cpts->pool, struct cpts_event, list);
  83                 event->tmo = jiffies + 2;
  84                 event->high = hi;
  85                 event->low = lo;
  86                 type = event_type(event);
  87                 switch (type) {
  88                 case CPTS_EV_PUSH:
  89                 case CPTS_EV_RX:
  90                 case CPTS_EV_TX:
  91                         list_del_init(&event->list);
  92                         list_add_tail(&event->list, &cpts->events);
  93                         break;
  94                 case CPTS_EV_ROLL:
  95                 case CPTS_EV_HALF:
  96                 case CPTS_EV_HW:
  97                         break;
  98                 default:
  99                         pr_err("cpts: unkown event type\n");
 100                         break;
 101                 }
 102                 if (type == match)
 103                         break;
 104         }
 105         return type == match ? 0 : -1;
 106 }
 107
 108 static cycle_t cpts_systim_read(const struct cyclecounter *cc)
 109 {
 110         u64 val = 0;
 111         struct cpts_event *event;
 112         struct list_head *this, *next;
 113         struct cpts *cpts = container_of(cc, struct cpts, cc);
 114
 115         cpts_write32(cpts, TS_PUSH, ts_push);
 116         if (cpts_fifo_read(cpts, CPTS_EV_PUSH))
 117                 pr_err("cpts: unable to obtain a time stamp\n");
 118
 119         list_for_each_safe(this, next, &cpts->events) {
 120                 event = list_entry(this, struct cpts_event, list);
 121                 if (event_type(event) == CPTS_EV_PUSH) {
 122                         list_del_init(&event->list);
 123                         list_add(&event->list, &cpts->pool);
 124                         val = event->low;
 125                         break;
 126                 }
 127         }
 128
 129         return val;
 130 }
 131
 132 /* PTP clock operations */
 133
 134 static int cpts_ptp_adjfreq(struct ptp_clock_info *ptp, s32 ppb)
 135 {
 136         u64 adj;
 137         u32 diff, mult;
 138         int neg_adj = 0;
 139         unsigned long flags;
 140         struct cpts *cpts = container_of(ptp, struct cpts, info);
 141
 142         if (ppb < 0) {
 143                 neg_adj = 1;
 144                 ppb = -ppb;
 145         }
 146         mult = cpts->cc_mult;
 147         adj = mult;
 148         adj *= ppb;
 149         diff = div_u64(adj, 1000000000ULL);
 150
 151         spin_lock_irqsave(&cpts->lock, flags);
 152
 153         timecounter_read(&cpts->tc);
 154
 155         cpts->cc.mult = neg_adj ? mult - diff : mult + diff;
 156
 157         spin_unlock_irqrestore(&cpts->lock, flags);
 158
 159         return 0;
 160 }
 161
 162 static int cpts_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
 163 {
 164         s64 now;
 165         unsigned long flags;
 166         struct cpts *cpts = container_of(ptp, struct cpts, info);
 167
 168         spin_lock_irqsave(&cpts->lock, flags);
 169         now = timecounter_read(&cpts->tc);
 170         now += delta;
 171         timecounter_init(&cpts->tc, &cpts->cc, now);
 172         spin_unlock_irqrestore(&cpts->lock, flags);
 173
 174         return 0;
 175 }
 176
 177 static int cpts_ptp_gettime(struct ptp_clock_info *ptp, struct timespec *ts)
 178 {
 179         u64 ns;
 180         u32 remainder;
 181         unsigned long flags;
 182         struct cpts *cpts = container_of(ptp, struct cpts, info);
 183
 184         spin_lock_irqsave(&cpts->lock, flags);
 185         ns = timecounter_read(&cpts->tc);
 186         spin_unlock_irqrestore(&cpts->lock, flags);
 187
 188         ts->tv_sec = div_u64_rem(ns, 1000000000, &remainder);
 189         ts->tv_nsec = remainder;
 190
 191         return 0;
 192 }
 193
 194 static int cpts_ptp_settime(struct ptp_clock_info *ptp,
 195                             const struct timespec *ts)
 196 {
 197         u64 ns;
 198         unsigned long flags;
 199         struct cpts *cpts = container_of(ptp, struct cpts, info);
 200
 201         ns = ts->tv_sec * 1000000000ULL;
 202         ns += ts->tv_nsec;
 203
 204         spin_lock_irqsave(&cpts->lock, flags);
 205         timecounter_init(&cpts->tc, &cpts->cc, ns);
 206         spin_unlock_irqrestore(&cpts->lock, flags);
 207
 208         return 0;
 209 }
 210
 211 static int cpts_ptp_enable(struct ptp_clock_info *ptp,
 212                            struct ptp_clock_request *rq, int on)
 213 {
 214         return -EOPNOTSUPP;
 215 }
 216
 217 static struct ptp_clock_info cpts_info = {
 218         .owner          = THIS_MODULE,
 219         .name           = "CTPS timer",
 220         .max_adj        = 1000000,
 221         .n_ext_ts       = 0,
 222         .pps            = 0,
 223         .adjfreq        = cpts_ptp_adjfreq,
 224         .adjtime        = cpts_ptp_adjtime,
 225         .gettime        = cpts_ptp_gettime,
 226         .settime        = cpts_ptp_settime,
 227         .enable         = cpts_ptp_enable,
 228 };
 229
 230 static void cpts_overflow_check(struct work_struct *work)
 231 {
 232         struct timespec ts;
 233         struct cpts *cpts = container_of(work, struct cpts, overflow_work.work);
 234
 235         cpts_write32(cpts, CPTS_EN, control);
 236         cpts_write32(cpts, TS_PEND_EN, int_enable);
 237         cpts_ptp_gettime(&cpts->info, &ts);
 238         pr_debug("cpts overflow check at %ld.%09lu\n", ts.tv_sec, ts.tv_nsec);
 239         schedule_delayed_work(&cpts->overflow_work, CPTS_OVERFLOW_PERIOD);
 240 }
 241
 242 #define CPTS_REF_CLOCK_NAME "cpsw_cpts_rft_clk"
 243
 244 static void cpts_clk_init(struct cpts *cpts)
 245 {
 246         cpts->refclk = clk_get(NULL, CPTS_REF_CLOCK_NAME);
 247         if (IS_ERR(cpts->refclk)) {
 248                 pr_err("Failed to clk_get %s\n", CPTS_REF_CLOCK_NAME);
 249                 cpts->refclk = NULL;
 250                 return;
 251         }
 252         clk_enable(cpts->refclk);
 253         cpts->freq = cpts->refclk->recalc(cpts->refclk);
 254 }
 255
 256 static void cpts_clk_release(struct cpts *cpts)
 257 {
 258         clk_disable(cpts->refclk);
 259         clk_put(cpts->refclk);
 260 }
 261
 262 static int cpts_match(struct sk_buff *skb, unsigned int ptp_class,
 263                       u16 ts_seqid, u8 ts_msgtype)
 264 {
 265         u16 *seqid;
 266         unsigned int offset;
 267         u8 *msgtype, *data = skb->data;
 268
 269         switch (ptp_class) {
 270         case PTP_CLASS_V1_IPV4:
 271         case PTP_CLASS_V2_IPV4:
 272                 offset = ETH_HLEN + IPV4_HLEN(data) + UDP_HLEN;
 273                 break;
 274         case PTP_CLASS_V1_IPV6:
 275         case PTP_CLASS_V2_IPV6:
 276                 offset = OFF_PTP6;
 277                 break;
 278         case PTP_CLASS_V2_L2:
 279                 offset = ETH_HLEN;
 280                 break;
 281         case PTP_CLASS_V2_VLAN:
 282                 offset = ETH_HLEN + VLAN_HLEN;
 283                 break;
 284         default:
 285                 return 0;
 286         }
 287
 288         if (skb->len + ETH_HLEN < offset + OFF_PTP_SEQUENCE_ID + sizeof(*seqid))
 289                 return 0;
 290
 291         if (unlikely(ptp_class & PTP_CLASS_V1))
 292                 msgtype = data + offset + OFF_PTP_CONTROL;
 293         else
 294                 msgtype = data + offset;
 295
 296         seqid = (u16 *)(data + offset + OFF_PTP_SEQUENCE_ID);
 297
 298         return (ts_msgtype == (*msgtype & 0xf) && ts_seqid == ntohs(*seqid));
 299 }
 300
 301 static u64 cpts_find_ts(struct cpts *cpts, struct sk_buff *skb, int ev_type)
 302 {
 303         u64 ns = 0;
 304         struct cpts_event *event;
 305         struct list_head *this, *next;
 306         unsigned int class = sk_run_filter(skb, ptp_filter);
 307         unsigned long flags;
 308         u16 seqid;
 309         u8 mtype;
 310
 311         if (class == PTP_CLASS_NONE)
 312                 return 0;
 313
 314         spin_lock_irqsave(&cpts->lock, flags);
 315         cpts_fifo_read(cpts, CPTS_EV_PUSH);
 316         list_for_each_safe(this, next, &cpts->events) {
 317                 event = list_entry(this, struct cpts_event, list);
 318                 if (event_expired(event)) {
 319                         list_del_init(&event->list);
 320                         list_add(&event->list, &cpts->pool);
 321                         continue;
 322                 }
 323                 mtype = (event->high >> MESSAGE_TYPE_SHIFT) & MESSAGE_TYPE_MASK;
 324                 seqid = (event->high >> SEQUENCE_ID_SHIFT) & SEQUENCE_ID_MASK;
 325                 if (ev_type == event_type(event) &&
 326                     cpts_match(skb, class, seqid, mtype)) {
 327                         ns = timecounter_cyc2time(&cpts->tc, event->low);
 328                         list_del_init(&event->list);
 329                         list_add(&event->list, &cpts->pool);
 330                         break;
 331                 }
 332         }
 333         spin_unlock_irqrestore(&cpts->lock, flags);
 334
 335         return ns;
 336 }
 337
 338 void cpts_rx_timestamp(struct cpts *cpts, struct sk_buff *skb)
 339 {
 340         u64 ns;
 341         struct skb_shared_hwtstamps *ssh;
 342
 343         if (!cpts->rx_enable)
 344                 return;
 345         ns = cpts_find_ts(cpts, skb, CPTS_EV_RX);
 346         if (!ns)
 347                 return;
 348         ssh = skb_hwtstamps(skb);
 349         memset(ssh, 0, sizeof(*ssh));
 350         ssh->hwtstamp = ns_to_ktime(ns);
 351 }
 352
 353 void cpts_tx_timestamp(struct cpts *cpts, struct sk_buff *skb)
 354 {
 355         u64 ns;
 356         struct skb_shared_hwtstamps ssh;
 357
 358         if (!(skb_shinfo(skb)->tx_flags & SKBTX_IN_PROGRESS))
 359                 return;
 360         ns = cpts_find_ts(cpts, skb, CPTS_EV_TX);
 361         if (!ns)
 362                 return;
 363         memset(&ssh, 0, sizeof(ssh));
 364         ssh.hwtstamp = ns_to_ktime(ns);
 365         skb_tstamp_tx(skb, &ssh);
 366 }
 367
 368 #endif /*CONFIG_TI_CPTS*/
 369
 370 int cpts_register(struct device *dev, struct cpts *cpts,
 371                   u32 mult, u32 shift)
 372 {
 373 #ifdef CONFIG_TI_CPTS
 374         int err, i;
 375         unsigned long flags;
 376
 377         if (ptp_filter_init(ptp_filter, ARRAY_SIZE(ptp_filter))) {
 378                 pr_err("cpts: bad ptp filter\n");
 379                 return -EINVAL;
 380         }
 381         cpts->info = cpts_info;
 382         cpts->clock = ptp_clock_register(&cpts->info, dev);
 383         if (IS_ERR(cpts->clock)) {
 384                 err = PTR_ERR(cpts->clock);
 385                 cpts->clock = NULL;
 386                 return err;
 387         }
 388         spin_lock_init(&cpts->lock);
 389
 390         cpts->cc.read = cpts_systim_read;
 391         cpts->cc.mask = CLOCKSOURCE_MASK(32);
 392         cpts->cc_mult = mult;
 393         cpts->cc.mult = mult;
 394         cpts->cc.shift = shift;
 395
 396         INIT_LIST_HEAD(&cpts->events);
 397         INIT_LIST_HEAD(&cpts->pool);
 398         for (i = 0; i < CPTS_MAX_EVENTS; i++)
 399                 list_add(&cpts->pool_data[i].list, &cpts->pool);
 400
 401         cpts_clk_init(cpts);
 402         cpts_write32(cpts, CPTS_EN, control);
 403         cpts_write32(cpts, TS_PEND_EN, int_enable);
 404
 405         spin_lock_irqsave(&cpts->lock, flags);
 406         timecounter_init(&cpts->tc, &cpts->cc, ktime_to_ns(ktime_get_real()));
 407         spin_unlock_irqrestore(&cpts->lock, flags);
 408
 409         INIT_DELAYED_WORK(&cpts->overflow_work, cpts_overflow_check);
 410         schedule_delayed_work(&cpts->overflow_work, CPTS_OVERFLOW_PERIOD);
 411
 412         cpts->phc_index = ptp_clock_index(cpts->clock);
 413 #endif
 414         return 0;
 415 }
 416
 417 void cpts_unregister(struct cpts *cpts)
 418 {
 419 #ifdef CONFIG_TI_CPTS
 420         if (cpts->clock) {
 421                 ptp_clock_unregister(cpts->clock);
 422                 cancel_delayed_work_sync(&cpts->overflow_work);
 423         }
 424         if (cpts->refclk)
 425                 cpts_clk_release(cpts);
 426 #endif
 427 }