kernel/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 timespec64 *ts)
 171 {
 172         u64 ns;
 173         unsigned long flags;
 174         struct cpts *cpts = container_of(ptp, struct cpts, info);
 175
 176         spin_lock_irqsave(&cpts->lock, flags);
 177         ns = timecounter_read(&cpts->tc);
 178         spin_unlock_irqrestore(&cpts->lock, flags);
 179
 180         *ts = ns_to_timespec64(ns);
 181
 182         return 0;
 183 }
 184
 185 static int cpts_ptp_settime(struct ptp_clock_info *ptp,
 186                             const struct timespec64 *ts)
 187 {
 188         u64 ns;
 189         unsigned long flags;
 190         struct cpts *cpts = container_of(ptp, struct cpts, info);
 191
 192         ns = timespec64_to_ns(ts);
 193
 194         spin_lock_irqsave(&cpts->lock, flags);
 195         timecounter_init(&cpts->tc, &cpts->cc, ns);
 196         spin_unlock_irqrestore(&cpts->lock, flags);
 197
 198         return 0;
 199 }
 200
 201 static int cpts_ptp_enable(struct ptp_clock_info *ptp,
 202                            struct ptp_clock_request *rq, int on)
 203 {
 204         return -EOPNOTSUPP;
 205 }
 206
 207 static struct ptp_clock_info cpts_info = {
 208         .owner          = THIS_MODULE,
 209         .name           = "CTPS timer",
 210         .max_adj        = 1000000,
 211         .n_ext_ts       = 0,
 212         .n_pins         = 0,
 213         .pps            = 0,
 214         .adjfreq        = cpts_ptp_adjfreq,
 215         .adjtime        = cpts_ptp_adjtime,
 216         .gettime64      = cpts_ptp_gettime,
 217         .settime64      = cpts_ptp_settime,
 218         .enable         = cpts_ptp_enable,
 219 };
 220
 221 static void cpts_overflow_check(struct work_struct *work)
 222 {
 223         struct timespec64 ts;
 224         struct cpts *cpts = container_of(work, struct cpts, overflow_work.work);
 225
 226         cpts_write32(cpts, CPTS_EN, control);
 227         cpts_write32(cpts, TS_PEND_EN, int_enable);
 228         cpts_ptp_gettime(&cpts->info, &ts);
 229         pr_debug("cpts overflow check at %lld.%09lu\n", ts.tv_sec, ts.tv_nsec);
 230         schedule_delayed_work(&cpts->overflow_work, CPTS_OVERFLOW_PERIOD);
 231 }
 232
 233 static void cpts_clk_init(struct device *dev, struct cpts *cpts)
 234 {
 235         cpts->refclk = devm_clk_get(dev, "cpts");
 236         if (IS_ERR(cpts->refclk)) {
 237                 dev_err(dev, "Failed to get cpts refclk\n");
 238                 cpts->refclk = NULL;
 239                 return;
 240         }
 241         clk_prepare_enable(cpts->refclk);
 242 }
 243
 244 static void cpts_clk_release(struct cpts *cpts)
 245 {
 246         clk_disable(cpts->refclk);
 247 }
 248
 249 static int cpts_match(struct sk_buff *skb, unsigned int ptp_class,
 250                       u16 ts_seqid, u8 ts_msgtype)
 251 {
 252         u16 *seqid;
 253         unsigned int offset = 0;
 254         u8 *msgtype, *data = skb->data;
 255
 256         if (ptp_class & PTP_CLASS_VLAN)
 257                 offset += VLAN_HLEN;
 258
 259         switch (ptp_class & PTP_CLASS_PMASK) {
 260         case PTP_CLASS_IPV4:
 261                 offset += ETH_HLEN + IPV4_HLEN(data + offset) + UDP_HLEN;
 262                 break;
 263         case PTP_CLASS_IPV6:
 264                 offset += ETH_HLEN + IP6_HLEN + UDP_HLEN;
 265                 break;
 266         case PTP_CLASS_L2:
 267                 offset += ETH_HLEN;
 268                 break;
 269         default:
 270                 return 0;
 271         }
 272
 273         if (skb->len + ETH_HLEN < offset + OFF_PTP_SEQUENCE_ID + sizeof(*seqid))
 274                 return 0;
 275
 276         if (unlikely(ptp_class & PTP_CLASS_V1))
 277                 msgtype = data + offset + OFF_PTP_CONTROL;
 278         else
 279                 msgtype = data + offset;
 280
 281         seqid = (u16 *)(data + offset + OFF_PTP_SEQUENCE_ID);
 282
 283         return (ts_msgtype == (*msgtype & 0xf) && ts_seqid == ntohs(*seqid));
 284 }
 285
 286 static u64 cpts_find_ts(struct cpts *cpts, struct sk_buff *skb, int ev_type)
 287 {
 288         u64 ns = 0;
 289         struct cpts_event *event;
 290         struct list_head *this, *next;
 291         unsigned int class = ptp_classify_raw(skb);
 292         unsigned long flags;
 293         u16 seqid;
 294         u8 mtype;
 295
 296         if (class == PTP_CLASS_NONE)
 297                 return 0;
 298
 299         spin_lock_irqsave(&cpts->lock, flags);
 300         cpts_fifo_read(cpts, CPTS_EV_PUSH);
 301         list_for_each_safe(this, next, &cpts->events) {
 302                 event = list_entry(this, struct cpts_event, list);
 303                 if (event_expired(event)) {
 304                         list_del_init(&event->list);
 305                         list_add(&event->list, &cpts->pool);
 306                         continue;
 307                 }
 308                 mtype = (event->high >> MESSAGE_TYPE_SHIFT) & MESSAGE_TYPE_MASK;
 309                 seqid = (event->high >> SEQUENCE_ID_SHIFT) & SEQUENCE_ID_MASK;
 310                 if (ev_type == event_type(event) &&
 311                     cpts_match(skb, class, seqid, mtype)) {
 312                         ns = timecounter_cyc2time(&cpts->tc, event->low);
 313                         list_del_init(&event->list);
 314                         list_add(&event->list, &cpts->pool);
 315                         break;
 316                 }
 317         }
 318         spin_unlock_irqrestore(&cpts->lock, flags);
 319
 320         return ns;
 321 }
 322
 323 void cpts_rx_timestamp(struct cpts *cpts, struct sk_buff *skb)
 324 {
 325         u64 ns;
 326         struct skb_shared_hwtstamps *ssh;
 327
 328         if (!cpts->rx_enable)
 329                 return;
 330         ns = cpts_find_ts(cpts, skb, CPTS_EV_RX);
 331         if (!ns)
 332                 return;
 333         ssh = skb_hwtstamps(skb);
 334         memset(ssh, 0, sizeof(*ssh));
 335         ssh->hwtstamp = ns_to_ktime(ns);
 336 }
 337
 338 void cpts_tx_timestamp(struct cpts *cpts, struct sk_buff *skb)
 339 {
 340         u64 ns;
 341         struct skb_shared_hwtstamps ssh;
 342
 343         if (!(skb_shinfo(skb)->tx_flags & SKBTX_IN_PROGRESS))
 344                 return;
 345         ns = cpts_find_ts(cpts, skb, CPTS_EV_TX);
 346         if (!ns)
 347                 return;
 348         memset(&ssh, 0, sizeof(ssh));
 349         ssh.hwtstamp = ns_to_ktime(ns);
 350         skb_tstamp_tx(skb, &ssh);
 351 }
 352
 353 #endif /*CONFIG_TI_CPTS*/
 354
 355 int cpts_register(struct device *dev, struct cpts *cpts,
 356                   u32 mult, u32 shift)
 357 {
 358 #ifdef CONFIG_TI_CPTS
 359         int err, i;
 360         unsigned long flags;
 361
 362         cpts->info = cpts_info;
 363         cpts->clock = ptp_clock_register(&cpts->info, dev);
 364         if (IS_ERR(cpts->clock)) {
 365                 err = PTR_ERR(cpts->clock);
 366                 cpts->clock = NULL;
 367                 return err;
 368         }
 369         spin_lock_init(&cpts->lock);
 370
 371         cpts->cc.read = cpts_systim_read;
 372         cpts->cc.mask = CLOCKSOURCE_MASK(32);
 373         cpts->cc_mult = mult;
 374         cpts->cc.mult = mult;
 375         cpts->cc.shift = shift;
 376
 377         INIT_LIST_HEAD(&cpts->events);
 378         INIT_LIST_HEAD(&cpts->pool);
 379         for (i = 0; i < CPTS_MAX_EVENTS; i++)
 380                 list_add(&cpts->pool_data[i].list, &cpts->pool);
 381
 382         cpts_clk_init(dev, cpts);
 383         cpts_write32(cpts, CPTS_EN, control);
 384         cpts_write32(cpts, TS_PEND_EN, int_enable);
 385
 386         spin_lock_irqsave(&cpts->lock, flags);
 387         timecounter_init(&cpts->tc, &cpts->cc, ktime_to_ns(ktime_get_real()));
 388         spin_unlock_irqrestore(&cpts->lock, flags);
 389
 390         INIT_DELAYED_WORK(&cpts->overflow_work, cpts_overflow_check);
 391         schedule_delayed_work(&cpts->overflow_work, CPTS_OVERFLOW_PERIOD);
 392
 393         cpts->phc_index = ptp_clock_index(cpts->clock);
 394 #endif
 395         return 0;
 396 }
 397
 398 void cpts_unregister(struct cpts *cpts)
 399 {
 400 #ifdef CONFIG_TI_CPTS
 401         if (cpts->clock) {
 402                 ptp_clock_unregister(cpts->clock);
 403                 cancel_delayed_work_sync(&cpts->overflow_work);
 404         }
 405         if (cpts->refclk)
 406                 cpts_clk_release(cpts);
 407 #endif
 408 }