drivers/ptp/ptp_chardev.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * PTP 1588 clock support - character device implementation.
   4  *
   5  * Copyright (C) 2010 OMICRON electronics GmbH
   6  */
   7 #include <linux/module.h>
   8 #include <linux/posix-clock.h>
   9 #include <linux/poll.h>
  10 #include <linux/sched.h>
  11 #include <linux/slab.h>
  12 #include <linux/timekeeping.h>
  13 #include <linux/debugfs.h>
  14
  15 #include <linux/nospec.h>
  16
  17 #include "ptp_private.h"
  18
  19 static int ptp_disable_pinfunc(struct ptp_clock_info *ops,
  20                                enum ptp_pin_function func, unsigned int chan)
  21 {
  22         struct ptp_clock_request rq;
  23         int err = 0;
  24
  25         memset(&rq, 0, sizeof(rq));
  26
  27         switch (func) {
  28         case PTP_PF_NONE:
  29                 break;
  30         case PTP_PF_EXTTS:
  31                 rq.type = PTP_CLK_REQ_EXTTS;
  32                 rq.extts.index = chan;
  33                 err = ops->enable(ops, &rq, 0);
  34                 break;
  35         case PTP_PF_PEROUT:
  36                 rq.type = PTP_CLK_REQ_PEROUT;
  37                 rq.perout.index = chan;
  38                 err = ops->enable(ops, &rq, 0);
  39                 break;
  40         case PTP_PF_PHYSYNC:
  41                 break;
  42         default:
  43                 return -EINVAL;
  44         }
  45
  46         return err;
  47 }
  48
  49 int ptp_set_pinfunc(struct ptp_clock *ptp, unsigned int pin,
  50                     enum ptp_pin_function func, unsigned int chan)
  51 {
  52         struct ptp_clock_info *info = ptp->info;
  53         struct ptp_pin_desc *pin1 = NULL, *pin2 = &info->pin_config[pin];
  54         unsigned int i;
  55
  56         /* Check to see if any other pin previously had this function. */
  57         for (i = 0; i < info->n_pins; i++) {
  58                 if (info->pin_config[i].func == func &&
  59                     info->pin_config[i].chan == chan) {
  60                         pin1 = &info->pin_config[i];
  61                         break;
  62                 }
  63         }
  64         if (pin1 && i == pin)
  65                 return 0;
  66
  67         /* Check the desired function and channel. */
  68         switch (func) {
  69         case PTP_PF_NONE:
  70                 break;
  71         case PTP_PF_EXTTS:
  72                 if (chan >= info->n_ext_ts)
  73                         return -EINVAL;
  74                 break;
  75         case PTP_PF_PEROUT:
  76                 if (chan >= info->n_per_out)
  77                         return -EINVAL;
  78                 break;
  79         case PTP_PF_PHYSYNC:
  80                 if (chan != 0)
  81                         return -EINVAL;
  82                 break;
  83         default:
  84                 return -EINVAL;
  85         }
  86
  87         if (info->verify(info, pin, func, chan)) {
  88                 pr_err("driver cannot use function %u and channel %u on pin %u\n",
  89                        func, chan, pin);
  90                 return -EOPNOTSUPP;
  91         }
  92
  93         /* Disable whatever function was previously assigned. */
  94         if (pin1) {
  95                 ptp_disable_pinfunc(info, func, chan);
  96                 pin1->func = PTP_PF_NONE;
  97                 pin1->chan = 0;
  98         }
  99         ptp_disable_pinfunc(info, pin2->func, pin2->chan);
 100         pin2->func = func;
 101         pin2->chan = chan;
 102
 103         return 0;
 104 }
 105
 106 int ptp_open(struct posix_clock_context *pccontext, fmode_t fmode)
 107 {
 108         struct ptp_clock *ptp =
 109                 container_of(pccontext->clk, struct ptp_clock, clock);
 110         struct timestamp_event_queue *queue;
 111         char debugfsname[32];
 112         unsigned long flags;
 113
 114         queue = kzalloc(sizeof(*queue), GFP_KERNEL);
 115         if (!queue)
 116                 return -EINVAL;
 117         queue->mask = bitmap_alloc(PTP_MAX_CHANNELS, GFP_KERNEL);
 118         if (!queue->mask) {
 119                 kfree(queue);
 120                 return -EINVAL;
 121         }
 122         bitmap_set(queue->mask, 0, PTP_MAX_CHANNELS);
 123         spin_lock_init(&queue->lock);
 124         spin_lock_irqsave(&ptp->tsevqs_lock, flags);
 125         list_add_tail(&queue->qlist, &ptp->tsevqs);
 126         spin_unlock_irqrestore(&ptp->tsevqs_lock, flags);
 127         pccontext->private_clkdata = queue;
 128
 129         /* Debugfs contents */
 130         sprintf(debugfsname, "0x%p", queue);
 131         queue->debugfs_instance =
 132                 debugfs_create_dir(debugfsname, ptp->debugfs_root);
 133         queue->dfs_bitmap.array = (u32 *)queue->mask;
 134         queue->dfs_bitmap.n_elements =
 135                 DIV_ROUND_UP(PTP_MAX_CHANNELS, BITS_PER_BYTE * sizeof(u32));
 136         debugfs_create_u32_array("mask", 0444, queue->debugfs_instance,
 137                                  &queue->dfs_bitmap);
 138
 139         return 0;
 140 }
 141
 142 int ptp_release(struct posix_clock_context *pccontext)
 143 {
 144         struct timestamp_event_queue *queue = pccontext->private_clkdata;
 145         unsigned long flags;
 146         struct ptp_clock *ptp =
 147                 container_of(pccontext->clk, struct ptp_clock, clock);
 148
 149         debugfs_remove(queue->debugfs_instance);
 150         pccontext->private_clkdata = NULL;
 151         spin_lock_irqsave(&ptp->tsevqs_lock, flags);
 152         list_del(&queue->qlist);
 153         spin_unlock_irqrestore(&ptp->tsevqs_lock, flags);
 154         bitmap_free(queue->mask);
 155         kfree(queue);
 156         return 0;
 157 }
 158
 159 long ptp_ioctl(struct posix_clock_context *pccontext, unsigned int cmd,
 160                unsigned long arg)
 161 {
 162         struct ptp_clock *ptp =
 163                 container_of(pccontext->clk, struct ptp_clock, clock);
 164         struct ptp_sys_offset_extended *extoff = NULL;
 165         struct ptp_sys_offset_precise precise_offset;
 166         struct system_device_crosststamp xtstamp;
 167         struct ptp_clock_info *ops = ptp->info;
 168         struct ptp_sys_offset *sysoff = NULL;
 169         struct timestamp_event_queue *tsevq;
 170         struct ptp_system_timestamp sts;
 171         struct ptp_clock_request req;
 172         struct ptp_clock_caps caps;
 173         struct ptp_clock_time *pct;
 174         unsigned int i, pin_index;
 175         struct ptp_pin_desc pd;
 176         struct timespec64 ts;
 177         int enable, err = 0;
 178
 179         tsevq = pccontext->private_clkdata;
 180
 181         switch (cmd) {
 182
 183         case PTP_CLOCK_GETCAPS:
 184         case PTP_CLOCK_GETCAPS2:
 185                 memset(&caps, 0, sizeof(caps));
 186
 187                 caps.max_adj = ptp->info->max_adj;
 188                 caps.n_alarm = ptp->info->n_alarm;
 189                 caps.n_ext_ts = ptp->info->n_ext_ts;
 190                 caps.n_per_out = ptp->info->n_per_out;
 191                 caps.pps = ptp->info->pps;
 192                 caps.n_pins = ptp->info->n_pins;
 193                 caps.cross_timestamping = ptp->info->getcrosststamp != NULL;
 194                 caps.adjust_phase = ptp->info->adjphase != NULL &&
 195                                     ptp->info->getmaxphase != NULL;
 196                 if (caps.adjust_phase)
 197                         caps.max_phase_adj = ptp->info->getmaxphase(ptp->info);
 198                 if (copy_to_user((void __user *)arg, &caps, sizeof(caps)))
 199                         err = -EFAULT;
 200                 break;
 201
 202         case PTP_EXTTS_REQUEST:
 203         case PTP_EXTTS_REQUEST2:
 204                 memset(&req, 0, sizeof(req));
 205
 206                 if (copy_from_user(&req.extts, (void __user *)arg,
 207                                    sizeof(req.extts))) {
 208                         err = -EFAULT;
 209                         break;
 210                 }
 211                 if (cmd == PTP_EXTTS_REQUEST2) {
 212                         /* Tell the drivers to check the flags carefully. */
 213                         req.extts.flags |= PTP_STRICT_FLAGS;
 214                         /* Make sure no reserved bit is set. */
 215                         if ((req.extts.flags & ~PTP_EXTTS_VALID_FLAGS) ||
 216                             req.extts.rsv[0] || req.extts.rsv[1]) {
 217                                 err = -EINVAL;
 218                                 break;
 219                         }
 220                         /* Ensure one of the rising/falling edge bits is set. */
 221                         if ((req.extts.flags & PTP_ENABLE_FEATURE) &&
 222                             (req.extts.flags & PTP_EXTTS_EDGES) == 0) {
 223                                 err = -EINVAL;
 224                                 break;
 225                         }
 226                 } else if (cmd == PTP_EXTTS_REQUEST) {
 227                         req.extts.flags &= PTP_EXTTS_V1_VALID_FLAGS;
 228                         req.extts.rsv[0] = 0;
 229                         req.extts.rsv[1] = 0;
 230                 }
 231                 if (req.extts.index >= ops->n_ext_ts) {
 232                         err = -EINVAL;
 233                         break;
 234                 }
 235                 req.type = PTP_CLK_REQ_EXTTS;
 236                 enable = req.extts.flags & PTP_ENABLE_FEATURE ? 1 : 0;
 237                 if (mutex_lock_interruptible(&ptp->pincfg_mux))
 238                         return -ERESTARTSYS;
 239                 err = ops->enable(ops, &req, enable);
 240                 mutex_unlock(&ptp->pincfg_mux);
 241                 break;
 242
 243         case PTP_PEROUT_REQUEST:
 244         case PTP_PEROUT_REQUEST2:
 245                 memset(&req, 0, sizeof(req));
 246
 247                 if (copy_from_user(&req.perout, (void __user *)arg,
 248                                    sizeof(req.perout))) {
 249                         err = -EFAULT;
 250                         break;
 251                 }
 252                 if (cmd == PTP_PEROUT_REQUEST2) {
 253                         struct ptp_perout_request *perout = &req.perout;
 254
 255                         if (perout->flags & ~PTP_PEROUT_VALID_FLAGS) {
 256                                 err = -EINVAL;
 257                                 break;
 258                         }
 259                         /*
 260                          * The "on" field has undefined meaning if
 261                          * PTP_PEROUT_DUTY_CYCLE isn't set, we must still treat
 262                          * it as reserved, which must be set to zero.
 263                          */
 264                         if (!(perout->flags & PTP_PEROUT_DUTY_CYCLE) &&
 265                             (perout->rsv[0] || perout->rsv[1] ||
 266                              perout->rsv[2] || perout->rsv[3])) {
 267                                 err = -EINVAL;
 268                                 break;
 269                         }
 270                         if (perout->flags & PTP_PEROUT_DUTY_CYCLE) {
 271                                 /* The duty cycle must be subunitary. */
 272                                 if (perout->on.sec > perout->period.sec ||
 273                                     (perout->on.sec == perout->period.sec &&
 274                                      perout->on.nsec > perout->period.nsec)) {
 275                                         err = -ERANGE;
 276                                         break;
 277                                 }
 278                         }
 279                         if (perout->flags & PTP_PEROUT_PHASE) {
 280                                 /*
 281                                  * The phase should be specified modulo the
 282                                  * period, therefore anything equal or larger
 283                                  * than 1 period is invalid.
 284                                  */
 285                                 if (perout->phase.sec > perout->period.sec ||
 286                                     (perout->phase.sec == perout->period.sec &&
 287                                      perout->phase.nsec >= perout->period.nsec)) {
 288                                         err = -ERANGE;
 289                                         break;
 290                                 }
 291                         }
 292                 } else if (cmd == PTP_PEROUT_REQUEST) {
 293                         req.perout.flags &= PTP_PEROUT_V1_VALID_FLAGS;
 294                         req.perout.rsv[0] = 0;
 295                         req.perout.rsv[1] = 0;
 296                         req.perout.rsv[2] = 0;
 297                         req.perout.rsv[3] = 0;
 298                 }
 299                 if (req.perout.index >= ops->n_per_out) {
 300                         err = -EINVAL;
 301                         break;
 302                 }
 303                 req.type = PTP_CLK_REQ_PEROUT;
 304                 enable = req.perout.period.sec || req.perout.period.nsec;
 305                 if (mutex_lock_interruptible(&ptp->pincfg_mux))
 306                         return -ERESTARTSYS;
 307                 err = ops->enable(ops, &req, enable);
 308                 mutex_unlock(&ptp->pincfg_mux);
 309                 break;
 310
 311         case PTP_ENABLE_PPS:
 312         case PTP_ENABLE_PPS2:
 313                 memset(&req, 0, sizeof(req));
 314
 315                 if (!capable(CAP_SYS_TIME))
 316                         return -EPERM;
 317                 req.type = PTP_CLK_REQ_PPS;
 318                 enable = arg ? 1 : 0;
 319                 if (mutex_lock_interruptible(&ptp->pincfg_mux))
 320                         return -ERESTARTSYS;
 321                 err = ops->enable(ops, &req, enable);
 322                 mutex_unlock(&ptp->pincfg_mux);
 323                 break;
 324
 325         case PTP_SYS_OFFSET_PRECISE:
 326         case PTP_SYS_OFFSET_PRECISE2:
 327                 if (!ptp->info->getcrosststamp) {
 328                         err = -EOPNOTSUPP;
 329                         break;
 330                 }
 331                 err = ptp->info->getcrosststamp(ptp->info, &xtstamp);
 332                 if (err)
 333                         break;
 334
 335                 memset(&precise_offset, 0, sizeof(precise_offset));
 336                 ts = ktime_to_timespec64(xtstamp.device);
 337                 precise_offset.device.sec = ts.tv_sec;
 338                 precise_offset.device.nsec = ts.tv_nsec;
 339                 ts = ktime_to_timespec64(xtstamp.sys_realtime);
 340                 precise_offset.sys_realtime.sec = ts.tv_sec;
 341                 precise_offset.sys_realtime.nsec = ts.tv_nsec;
 342                 ts = ktime_to_timespec64(xtstamp.sys_monoraw);
 343                 precise_offset.sys_monoraw.sec = ts.tv_sec;
 344                 precise_offset.sys_monoraw.nsec = ts.tv_nsec;
 345                 if (copy_to_user((void __user *)arg, &precise_offset,
 346                                  sizeof(precise_offset)))
 347                         err = -EFAULT;
 348                 break;
 349
 350         case PTP_SYS_OFFSET_EXTENDED:
 351         case PTP_SYS_OFFSET_EXTENDED2:
 352                 if (!ptp->info->gettimex64) {
 353                         err = -EOPNOTSUPP;
 354                         break;
 355                 }
 356                 extoff = memdup_user((void __user *)arg, sizeof(*extoff));
 357                 if (IS_ERR(extoff)) {
 358                         err = PTR_ERR(extoff);
 359                         extoff = NULL;
 360                         break;
 361                 }
 362                 if (extoff->n_samples > PTP_MAX_SAMPLES
 363                     || extoff->rsv[0] || extoff->rsv[1] || extoff->rsv[2]) {
 364                         err = -EINVAL;
 365                         break;
 366                 }
 367                 for (i = 0; i < extoff->n_samples; i++) {
 368                         err = ptp->info->gettimex64(ptp->info, &ts, &sts);
 369                         if (err)
 370                                 goto out;
 371                         extoff->ts[i][0].sec = sts.pre_ts.tv_sec;
 372                         extoff->ts[i][0].nsec = sts.pre_ts.tv_nsec;
 373                         extoff->ts[i][1].sec = ts.tv_sec;
 374                         extoff->ts[i][1].nsec = ts.tv_nsec;
 375                         extoff->ts[i][2].sec = sts.post_ts.tv_sec;
 376                         extoff->ts[i][2].nsec = sts.post_ts.tv_nsec;
 377                 }
 378                 if (copy_to_user((void __user *)arg, extoff, sizeof(*extoff)))
 379                         err = -EFAULT;
 380                 break;
 381
 382         case PTP_SYS_OFFSET:
 383         case PTP_SYS_OFFSET2:
 384                 sysoff = memdup_user((void __user *)arg, sizeof(*sysoff));
 385                 if (IS_ERR(sysoff)) {
 386                         err = PTR_ERR(sysoff);
 387                         sysoff = NULL;
 388                         break;
 389                 }
 390                 if (sysoff->n_samples > PTP_MAX_SAMPLES) {
 391                         err = -EINVAL;
 392                         break;
 393                 }
 394                 pct = &sysoff->ts[0];
 395                 for (i = 0; i < sysoff->n_samples; i++) {
 396                         ktime_get_real_ts64(&ts);
 397                         pct->sec = ts.tv_sec;
 398                         pct->nsec = ts.tv_nsec;
 399                         pct++;
 400                         if (ops->gettimex64)
 401                                 err = ops->gettimex64(ops, &ts, NULL);
 402                         else
 403                                 err = ops->gettime64(ops, &ts);
 404                         if (err)
 405                                 goto out;
 406                         pct->sec = ts.tv_sec;
 407                         pct->nsec = ts.tv_nsec;
 408                         pct++;
 409                 }
 410                 ktime_get_real_ts64(&ts);
 411                 pct->sec = ts.tv_sec;
 412                 pct->nsec = ts.tv_nsec;
 413                 if (copy_to_user((void __user *)arg, sysoff, sizeof(*sysoff)))
 414                         err = -EFAULT;
 415                 break;
 416
 417         case PTP_PIN_GETFUNC:
 418         case PTP_PIN_GETFUNC2:
 419                 if (copy_from_user(&pd, (void __user *)arg, sizeof(pd))) {
 420                         err = -EFAULT;
 421                         break;
 422                 }
 423                 if ((pd.rsv[0] || pd.rsv[1] || pd.rsv[2]
 424                                 || pd.rsv[3] || pd.rsv[4])
 425                         && cmd == PTP_PIN_GETFUNC2) {
 426                         err = -EINVAL;
 427                         break;
 428                 } else if (cmd == PTP_PIN_GETFUNC) {
 429                         pd.rsv[0] = 0;
 430                         pd.rsv[1] = 0;
 431                         pd.rsv[2] = 0;
 432                         pd.rsv[3] = 0;
 433                         pd.rsv[4] = 0;
 434                 }
 435                 pin_index = pd.index;
 436                 if (pin_index >= ops->n_pins) {
 437                         err = -EINVAL;
 438                         break;
 439                 }
 440                 pin_index = array_index_nospec(pin_index, ops->n_pins);
 441                 if (mutex_lock_interruptible(&ptp->pincfg_mux))
 442                         return -ERESTARTSYS;
 443                 pd = ops->pin_config[pin_index];
 444                 mutex_unlock(&ptp->pincfg_mux);
 445                 if (!err && copy_to_user((void __user *)arg, &pd, sizeof(pd)))
 446                         err = -EFAULT;
 447                 break;
 448
 449         case PTP_PIN_SETFUNC:
 450         case PTP_PIN_SETFUNC2:
 451                 if (copy_from_user(&pd, (void __user *)arg, sizeof(pd))) {
 452                         err = -EFAULT;
 453                         break;
 454                 }
 455                 if ((pd.rsv[0] || pd.rsv[1] || pd.rsv[2]
 456                                 || pd.rsv[3] || pd.rsv[4])
 457                         && cmd == PTP_PIN_SETFUNC2) {
 458                         err = -EINVAL;
 459                         break;
 460                 } else if (cmd == PTP_PIN_SETFUNC) {
 461                         pd.rsv[0] = 0;
 462                         pd.rsv[1] = 0;
 463                         pd.rsv[2] = 0;
 464                         pd.rsv[3] = 0;
 465                         pd.rsv[4] = 0;
 466                 }
 467                 pin_index = pd.index;
 468                 if (pin_index >= ops->n_pins) {
 469                         err = -EINVAL;
 470                         break;
 471                 }
 472                 pin_index = array_index_nospec(pin_index, ops->n_pins);
 473                 if (mutex_lock_interruptible(&ptp->pincfg_mux))
 474                         return -ERESTARTSYS;
 475                 err = ptp_set_pinfunc(ptp, pin_index, pd.func, pd.chan);
 476                 mutex_unlock(&ptp->pincfg_mux);
 477                 break;
 478
 479         case PTP_MASK_CLEAR_ALL:
 480                 bitmap_clear(tsevq->mask, 0, PTP_MAX_CHANNELS);
 481                 break;
 482
 483         case PTP_MASK_EN_SINGLE:
 484                 if (copy_from_user(&i, (void __user *)arg, sizeof(i))) {
 485                         err = -EFAULT;
 486                         break;
 487                 }
 488                 if (i >= PTP_MAX_CHANNELS) {
 489                         err = -EFAULT;
 490                         break;
 491                 }
 492                 set_bit(i, tsevq->mask);
 493                 break;
 494
 495         default:
 496                 err = -ENOTTY;
 497                 break;
 498         }
 499
 500 out:
 501         kfree(extoff);
 502         kfree(sysoff);
 503         return err;
 504 }
 505
 506 __poll_t ptp_poll(struct posix_clock_context *pccontext, struct file *fp,
 507                   poll_table *wait)
 508 {
 509         struct ptp_clock *ptp =
 510                 container_of(pccontext->clk, struct ptp_clock, clock);
 511         struct timestamp_event_queue *queue;
 512
 513         queue = pccontext->private_clkdata;
 514         if (!queue)
 515                 return EPOLLERR;
 516
 517         poll_wait(fp, &ptp->tsev_wq, wait);
 518
 519         return queue_cnt(queue) ? EPOLLIN : 0;
 520 }
 521
 522 #define EXTTS_BUFSIZE (PTP_BUF_TIMESTAMPS * sizeof(struct ptp_extts_event))
 523
 524 ssize_t ptp_read(struct posix_clock_context *pccontext, uint rdflags,
 525                  char __user *buf, size_t cnt)
 526 {
 527         struct ptp_clock *ptp =
 528                 container_of(pccontext->clk, struct ptp_clock, clock);
 529         struct timestamp_event_queue *queue;
 530         struct ptp_extts_event *event;
 531         unsigned long flags;
 532         size_t qcnt, i;
 533         int result;
 534
 535         queue = pccontext->private_clkdata;
 536         if (!queue) {
 537                 result = -EINVAL;
 538                 goto exit;
 539         }
 540
 541         if (cnt % sizeof(struct ptp_extts_event) != 0) {
 542                 result = -EINVAL;
 543                 goto exit;
 544         }
 545
 546         if (cnt > EXTTS_BUFSIZE)
 547                 cnt = EXTTS_BUFSIZE;
 548
 549         cnt = cnt / sizeof(struct ptp_extts_event);
 550
 551         if (wait_event_interruptible(ptp->tsev_wq,
 552                                      ptp->defunct || queue_cnt(queue))) {
 553                 return -ERESTARTSYS;
 554         }
 555
 556         if (ptp->defunct) {
 557                 result = -ENODEV;
 558                 goto exit;
 559         }
 560
 561         event = kmalloc(EXTTS_BUFSIZE, GFP_KERNEL);
 562         if (!event) {
 563                 result = -ENOMEM;
 564                 goto exit;
 565         }
 566
 567         spin_lock_irqsave(&queue->lock, flags);
 568
 569         qcnt = queue_cnt(queue);
 570
 571         if (cnt > qcnt)
 572                 cnt = qcnt;
 573
 574         for (i = 0; i < cnt; i++) {
 575                 event[i] = queue->buf[queue->head];
 576                 /* Paired with READ_ONCE() in queue_cnt() */
 577                 WRITE_ONCE(queue->head, (queue->head + 1) % PTP_MAX_TIMESTAMPS);
 578         }
 579
 580         spin_unlock_irqrestore(&queue->lock, flags);
 581
 582         cnt = cnt * sizeof(struct ptp_extts_event);
 583
 584         result = cnt;
 585         if (copy_to_user(buf, event, cnt)) {
 586                 result = -EFAULT;
 587                 goto free_event;
 588         }
 589
 590 free_event:
 591         kfree(event);
 592 exit:
 593         return result;
 594 }