drivers/ptp/ptp_chardev.c

   1 /*
   2  * PTP 1588 clock support - character device implementation.
   3  *
   4  * Copyright (C) 2010 OMICRON electronics GmbH
   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., 675 Mass Ave, Cambridge, MA 02139, USA.
  19  */
  20 #include <linux/module.h>
  21 #include <linux/posix-clock.h>
  22 #include <linux/poll.h>
  23 #include <linux/sched.h>
  24 #include <linux/slab.h>
  25 #include <linux/timekeeping.h>
  26
  27 #include <linux/nospec.h>
  28
  29 #include "ptp_private.h"
  30
  31 static int ptp_disable_pinfunc(struct ptp_clock_info *ops,
  32                                enum ptp_pin_function func, unsigned int chan)
  33 {
  34         struct ptp_clock_request rq;
  35         int err = 0;
  36
  37         memset(&rq, 0, sizeof(rq));
  38
  39         switch (func) {
  40         case PTP_PF_NONE:
  41                 break;
  42         case PTP_PF_EXTTS:
  43                 rq.type = PTP_CLK_REQ_EXTTS;
  44                 rq.extts.index = chan;
  45                 err = ops->enable(ops, &rq, 0);
  46                 break;
  47         case PTP_PF_PEROUT:
  48                 rq.type = PTP_CLK_REQ_PEROUT;
  49                 rq.perout.index = chan;
  50                 err = ops->enable(ops, &rq, 0);
  51                 break;
  52         case PTP_PF_PHYSYNC:
  53                 break;
  54         default:
  55                 return -EINVAL;
  56         }
  57
  58         return err;
  59 }
  60
  61 int ptp_set_pinfunc(struct ptp_clock *ptp, unsigned int pin,
  62                     enum ptp_pin_function func, unsigned int chan)
  63 {
  64         struct ptp_clock_info *info = ptp->info;
  65         struct ptp_pin_desc *pin1 = NULL, *pin2 = &info->pin_config[pin];
  66         unsigned int i;
  67
  68         /* Check to see if any other pin previously had this function. */
  69         for (i = 0; i < info->n_pins; i++) {
  70                 if (info->pin_config[i].func == func &&
  71                     info->pin_config[i].chan == chan) {
  72                         pin1 = &info->pin_config[i];
  73                         break;
  74                 }
  75         }
  76         if (pin1 && i == pin)
  77                 return 0;
  78
  79         /* Check the desired function and channel. */
  80         switch (func) {
  81         case PTP_PF_NONE:
  82                 break;
  83         case PTP_PF_EXTTS:
  84                 if (chan >= info->n_ext_ts)
  85                         return -EINVAL;
  86                 break;
  87         case PTP_PF_PEROUT:
  88                 if (chan >= info->n_per_out)
  89                         return -EINVAL;
  90                 break;
  91         case PTP_PF_PHYSYNC:
  92                 if (chan != 0)
  93                         return -EINVAL;
  94                 break;
  95         default:
  96                 return -EINVAL;
  97         }
  98
  99         if (info->verify(info, pin, func, chan)) {
 100                 pr_err("driver cannot use function %u on pin %u\n", func, chan);
 101                 return -EOPNOTSUPP;
 102         }
 103
 104         /* Disable whatever function was previously assigned. */
 105         if (pin1) {
 106                 ptp_disable_pinfunc(info, func, chan);
 107                 pin1->func = PTP_PF_NONE;
 108                 pin1->chan = 0;
 109         }
 110         ptp_disable_pinfunc(info, pin2->func, pin2->chan);
 111         pin2->func = func;
 112         pin2->chan = chan;
 113
 114         return 0;
 115 }
 116
 117 int ptp_open(struct posix_clock *pc, fmode_t fmode)
 118 {
 119         return 0;
 120 }
 121
 122 long ptp_ioctl(struct posix_clock *pc, unsigned int cmd, unsigned long arg)
 123 {
 124         struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
 125         struct ptp_sys_offset_extended *extoff = NULL;
 126         struct ptp_sys_offset_precise precise_offset;
 127         struct system_device_crosststamp xtstamp;
 128         struct ptp_clock_info *ops = ptp->info;
 129         struct ptp_sys_offset *sysoff = NULL;
 130         struct ptp_system_timestamp sts;
 131         struct ptp_clock_request req;
 132         struct ptp_clock_caps caps;
 133         struct ptp_clock_time *pct;
 134         unsigned int i, pin_index;
 135         struct ptp_pin_desc pd;
 136         struct timespec64 ts;
 137         int enable, err = 0;
 138
 139         switch (cmd) {
 140
 141         case PTP_CLOCK_GETCAPS:
 142                 memset(&caps, 0, sizeof(caps));
 143                 caps.max_adj = ptp->info->max_adj;
 144                 caps.n_alarm = ptp->info->n_alarm;
 145                 caps.n_ext_ts = ptp->info->n_ext_ts;
 146                 caps.n_per_out = ptp->info->n_per_out;
 147                 caps.pps = ptp->info->pps;
 148                 caps.n_pins = ptp->info->n_pins;
 149                 caps.cross_timestamping = ptp->info->getcrosststamp != NULL;
 150                 if (copy_to_user((void __user *)arg, &caps, sizeof(caps)))
 151                         err = -EFAULT;
 152                 break;
 153
 154         case PTP_EXTTS_REQUEST:
 155                 if (copy_from_user(&req.extts, (void __user *)arg,
 156                                    sizeof(req.extts))) {
 157                         err = -EFAULT;
 158                         break;
 159                 }
 160                 if (req.extts.index >= ops->n_ext_ts) {
 161                         err = -EINVAL;
 162                         break;
 163                 }
 164                 req.type = PTP_CLK_REQ_EXTTS;
 165                 enable = req.extts.flags & PTP_ENABLE_FEATURE ? 1 : 0;
 166                 err = ops->enable(ops, &req, enable);
 167                 break;
 168
 169         case PTP_PEROUT_REQUEST:
 170                 if (copy_from_user(&req.perout, (void __user *)arg,
 171                                    sizeof(req.perout))) {
 172                         err = -EFAULT;
 173                         break;
 174                 }
 175                 if (req.perout.index >= ops->n_per_out) {
 176                         err = -EINVAL;
 177                         break;
 178                 }
 179                 req.type = PTP_CLK_REQ_PEROUT;
 180                 enable = req.perout.period.sec || req.perout.period.nsec;
 181                 err = ops->enable(ops, &req, enable);
 182                 break;
 183
 184         case PTP_ENABLE_PPS:
 185                 if (!capable(CAP_SYS_TIME))
 186                         return -EPERM;
 187                 req.type = PTP_CLK_REQ_PPS;
 188                 enable = arg ? 1 : 0;
 189                 err = ops->enable(ops, &req, enable);
 190                 break;
 191
 192         case PTP_SYS_OFFSET_PRECISE:
 193                 if (!ptp->info->getcrosststamp) {
 194                         err = -EOPNOTSUPP;
 195                         break;
 196                 }
 197                 err = ptp->info->getcrosststamp(ptp->info, &xtstamp);
 198                 if (err)
 199                         break;
 200
 201                 memset(&precise_offset, 0, sizeof(precise_offset));
 202                 ts = ktime_to_timespec64(xtstamp.device);
 203                 precise_offset.device.sec = ts.tv_sec;
 204                 precise_offset.device.nsec = ts.tv_nsec;
 205                 ts = ktime_to_timespec64(xtstamp.sys_realtime);
 206                 precise_offset.sys_realtime.sec = ts.tv_sec;
 207                 precise_offset.sys_realtime.nsec = ts.tv_nsec;
 208                 ts = ktime_to_timespec64(xtstamp.sys_monoraw);
 209                 precise_offset.sys_monoraw.sec = ts.tv_sec;
 210                 precise_offset.sys_monoraw.nsec = ts.tv_nsec;
 211                 if (copy_to_user((void __user *)arg, &precise_offset,
 212                                  sizeof(precise_offset)))
 213                         err = -EFAULT;
 214                 break;
 215
 216         case PTP_SYS_OFFSET_EXTENDED:
 217                 if (!ptp->info->gettimex64) {
 218                         err = -EOPNOTSUPP;
 219                         break;
 220                 }
 221                 extoff = memdup_user((void __user *)arg, sizeof(*extoff));
 222                 if (IS_ERR(extoff)) {
 223                         err = PTR_ERR(extoff);
 224                         extoff = NULL;
 225                         break;
 226                 }
 227                 if (extoff->n_samples > PTP_MAX_SAMPLES) {
 228                         err = -EINVAL;
 229                         break;
 230                 }
 231                 for (i = 0; i < extoff->n_samples; i++) {
 232                         err = ptp->info->gettimex64(ptp->info, &ts, &sts);
 233                         if (err)
 234                                 goto out;
 235                         extoff->ts[i][0].sec = sts.pre_ts.tv_sec;
 236                         extoff->ts[i][0].nsec = sts.pre_ts.tv_nsec;
 237                         extoff->ts[i][1].sec = ts.tv_sec;
 238                         extoff->ts[i][1].nsec = ts.tv_nsec;
 239                         extoff->ts[i][2].sec = sts.post_ts.tv_sec;
 240                         extoff->ts[i][2].nsec = sts.post_ts.tv_nsec;
 241                 }
 242                 if (copy_to_user((void __user *)arg, extoff, sizeof(*extoff)))
 243                         err = -EFAULT;
 244                 break;
 245
 246         case PTP_SYS_OFFSET:
 247                 sysoff = memdup_user((void __user *)arg, sizeof(*sysoff));
 248                 if (IS_ERR(sysoff)) {
 249                         err = PTR_ERR(sysoff);
 250                         sysoff = NULL;
 251                         break;
 252                 }
 253                 if (sysoff->n_samples > PTP_MAX_SAMPLES) {
 254                         err = -EINVAL;
 255                         break;
 256                 }
 257                 pct = &sysoff->ts[0];
 258                 for (i = 0; i < sysoff->n_samples; i++) {
 259                         ktime_get_real_ts64(&ts);
 260                         pct->sec = ts.tv_sec;
 261                         pct->nsec = ts.tv_nsec;
 262                         pct++;
 263                         if (ops->gettimex64)
 264                                 err = ops->gettimex64(ops, &ts, NULL);
 265                         else
 266                                 err = ops->gettime64(ops, &ts);
 267                         if (err)
 268                                 goto out;
 269                         pct->sec = ts.tv_sec;
 270                         pct->nsec = ts.tv_nsec;
 271                         pct++;
 272                 }
 273                 ktime_get_real_ts64(&ts);
 274                 pct->sec = ts.tv_sec;
 275                 pct->nsec = ts.tv_nsec;
 276                 if (copy_to_user((void __user *)arg, sysoff, sizeof(*sysoff)))
 277                         err = -EFAULT;
 278                 break;
 279
 280         case PTP_PIN_GETFUNC:
 281                 if (copy_from_user(&pd, (void __user *)arg, sizeof(pd))) {
 282                         err = -EFAULT;
 283                         break;
 284                 }
 285                 pin_index = pd.index;
 286                 if (pin_index >= ops->n_pins) {
 287                         err = -EINVAL;
 288                         break;
 289                 }
 290                 pin_index = array_index_nospec(pin_index, ops->n_pins);
 291                 if (mutex_lock_interruptible(&ptp->pincfg_mux))
 292                         return -ERESTARTSYS;
 293                 pd = ops->pin_config[pin_index];
 294                 mutex_unlock(&ptp->pincfg_mux);
 295                 if (!err && copy_to_user((void __user *)arg, &pd, sizeof(pd)))
 296                         err = -EFAULT;
 297                 break;
 298
 299         case PTP_PIN_SETFUNC:
 300                 if (copy_from_user(&pd, (void __user *)arg, sizeof(pd))) {
 301                         err = -EFAULT;
 302                         break;
 303                 }
 304                 pin_index = pd.index;
 305                 if (pin_index >= ops->n_pins) {
 306                         err = -EINVAL;
 307                         break;
 308                 }
 309                 pin_index = array_index_nospec(pin_index, ops->n_pins);
 310                 if (mutex_lock_interruptible(&ptp->pincfg_mux))
 311                         return -ERESTARTSYS;
 312                 err = ptp_set_pinfunc(ptp, pin_index, pd.func, pd.chan);
 313                 mutex_unlock(&ptp->pincfg_mux);
 314                 break;
 315
 316         default:
 317                 err = -ENOTTY;
 318                 break;
 319         }
 320
 321 out:
 322         kfree(extoff);
 323         kfree(sysoff);
 324         return err;
 325 }
 326
 327 __poll_t ptp_poll(struct posix_clock *pc, struct file *fp, poll_table *wait)
 328 {
 329         struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
 330
 331         poll_wait(fp, &ptp->tsev_wq, wait);
 332
 333         return queue_cnt(&ptp->tsevq) ? EPOLLIN : 0;
 334 }
 335
 336 #define EXTTS_BUFSIZE (PTP_BUF_TIMESTAMPS * sizeof(struct ptp_extts_event))
 337
 338 ssize_t ptp_read(struct posix_clock *pc,
 339                  uint rdflags, char __user *buf, size_t cnt)
 340 {
 341         struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
 342         struct timestamp_event_queue *queue = &ptp->tsevq;
 343         struct ptp_extts_event *event;
 344         unsigned long flags;
 345         size_t qcnt, i;
 346         int result;
 347
 348         if (cnt % sizeof(struct ptp_extts_event) != 0)
 349                 return -EINVAL;
 350
 351         if (cnt > EXTTS_BUFSIZE)
 352                 cnt = EXTTS_BUFSIZE;
 353
 354         cnt = cnt / sizeof(struct ptp_extts_event);
 355
 356         if (mutex_lock_interruptible(&ptp->tsevq_mux))
 357                 return -ERESTARTSYS;
 358
 359         if (wait_event_interruptible(ptp->tsev_wq,
 360                                      ptp->defunct || queue_cnt(queue))) {
 361                 mutex_unlock(&ptp->tsevq_mux);
 362                 return -ERESTARTSYS;
 363         }
 364
 365         if (ptp->defunct) {
 366                 mutex_unlock(&ptp->tsevq_mux);
 367                 return -ENODEV;
 368         }
 369
 370         event = kmalloc(EXTTS_BUFSIZE, GFP_KERNEL);
 371         if (!event) {
 372                 mutex_unlock(&ptp->tsevq_mux);
 373                 return -ENOMEM;
 374         }
 375
 376         spin_lock_irqsave(&queue->lock, flags);
 377
 378         qcnt = queue_cnt(queue);
 379
 380         if (cnt > qcnt)
 381                 cnt = qcnt;
 382
 383         for (i = 0; i < cnt; i++) {
 384                 event[i] = queue->buf[queue->head];
 385                 queue->head = (queue->head + 1) % PTP_MAX_TIMESTAMPS;
 386         }
 387
 388         spin_unlock_irqrestore(&queue->lock, flags);
 389
 390         cnt = cnt * sizeof(struct ptp_extts_event);
 391
 392         mutex_unlock(&ptp->tsevq_mux);
 393
 394         result = cnt;
 395         if (copy_to_user(buf, event, cnt))
 396                 result = -EFAULT;
 397
 398         kfree(event);
 399         return result;
 400 }