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