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
  14 #include <linux/nospec.h>
  15
  16 #include "ptp_private.h"
  17
  18 static int ptp_disable_pinfunc(struct ptp_clock_info *ops,
  19                                enum ptp_pin_function func, unsigned int chan)
  20 {
  21         struct ptp_clock_request rq;
  22         int err = 0;
  23
  24         memset(&rq, 0, sizeof(rq));
  25
  26         switch (func) {
  27         case PTP_PF_NONE:
  28                 break;
  29         case PTP_PF_EXTTS:
  30                 rq.type = PTP_CLK_REQ_EXTTS;
  31                 rq.extts.index = chan;
  32                 err = ops->enable(ops, &rq, 0);
  33                 break;
  34         case PTP_PF_PEROUT:
  35                 rq.type = PTP_CLK_REQ_PEROUT;
  36                 rq.perout.index = chan;
  37                 err = ops->enable(ops, &rq, 0);
  38                 break;
  39         case PTP_PF_PHYSYNC:
  40                 break;
  41         default:
  42                 return -EINVAL;
  43         }
  44
  45         return err;
  46 }
  47
  48 int ptp_set_pinfunc(struct ptp_clock *ptp, unsigned int pin,
  49                     enum ptp_pin_function func, unsigned int chan)
  50 {
  51         struct ptp_clock_info *info = ptp->info;
  52         struct ptp_pin_desc *pin1 = NULL, *pin2 = &info->pin_config[pin];
  53         unsigned int i;
  54
  55         /* Check to see if any other pin previously had this function. */
  56         for (i = 0; i < info->n_pins; i++) {
  57                 if (info->pin_config[i].func == func &&
  58                     info->pin_config[i].chan == chan) {
  59                         pin1 = &info->pin_config[i];
  60                         break;
  61                 }
  62         }
  63         if (pin1 && i == pin)
  64                 return 0;
  65
  66         /* Check the desired function and channel. */
  67         switch (func) {
  68         case PTP_PF_NONE:
  69                 break;
  70         case PTP_PF_EXTTS:
  71                 if (chan >= info->n_ext_ts)
  72                         return -EINVAL;
  73                 break;
  74         case PTP_PF_PEROUT:
  75                 if (chan >= info->n_per_out)
  76                         return -EINVAL;
  77                 break;
  78         case PTP_PF_PHYSYNC:
  79                 if (chan != 0)
  80                         return -EINVAL;
  81                 break;
  82         default:
  83                 return -EINVAL;
  84         }
  85
  86         if (info->verify(info, pin, func, chan)) {
  87                 pr_err("driver cannot use function %u on pin %u\n", func, chan);
  88                 return -EOPNOTSUPP;
  89         }
  90
  91         /* Disable whatever function was previously assigned. */
  92         if (pin1) {
  93                 ptp_disable_pinfunc(info, func, chan);
  94                 pin1->func = PTP_PF_NONE;
  95                 pin1->chan = 0;
  96         }
  97         ptp_disable_pinfunc(info, pin2->func, pin2->chan);
  98         pin2->func = func;
  99         pin2->chan = chan;
 100
 101         return 0;
 102 }
 103
 104 int ptp_open(struct posix_clock *pc, fmode_t fmode)
 105 {
 106         return 0;
 107 }
 108
 109 long ptp_ioctl(struct posix_clock *pc, unsigned int cmd, unsigned long arg)
 110 {
 111         struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
 112         struct ptp_sys_offset_extended *extoff = NULL;
 113         struct ptp_sys_offset_precise precise_offset;
 114         struct system_device_crosststamp xtstamp;
 115         struct ptp_clock_info *ops = ptp->info;
 116         struct ptp_sys_offset *sysoff = NULL;
 117         struct ptp_system_timestamp sts;
 118         struct ptp_clock_request req;
 119         struct ptp_clock_caps caps;
 120         struct ptp_clock_time *pct;
 121         unsigned int i, pin_index;
 122         struct ptp_pin_desc pd;
 123         struct timespec64 ts;
 124         int enable, err = 0;
 125
 126         switch (cmd) {
 127
 128         case PTP_CLOCK_GETCAPS:
 129                 memset(&caps, 0, sizeof(caps));
 130                 caps.max_adj = ptp->info->max_adj;
 131                 caps.n_alarm = ptp->info->n_alarm;
 132                 caps.n_ext_ts = ptp->info->n_ext_ts;
 133                 caps.n_per_out = ptp->info->n_per_out;
 134                 caps.pps = ptp->info->pps;
 135                 caps.n_pins = ptp->info->n_pins;
 136                 caps.cross_timestamping = ptp->info->getcrosststamp != NULL;
 137                 if (copy_to_user((void __user *)arg, &caps, sizeof(caps)))
 138                         err = -EFAULT;
 139                 break;
 140
 141         case PTP_EXTTS_REQUEST:
 142                 if (copy_from_user(&req.extts, (void __user *)arg,
 143                                    sizeof(req.extts))) {
 144                         err = -EFAULT;
 145                         break;
 146                 }
 147                 if (req.extts.index >= ops->n_ext_ts) {
 148                         err = -EINVAL;
 149                         break;
 150                 }
 151                 req.type = PTP_CLK_REQ_EXTTS;
 152                 enable = req.extts.flags & PTP_ENABLE_FEATURE ? 1 : 0;
 153                 err = ops->enable(ops, &req, enable);
 154                 break;
 155
 156         case PTP_PEROUT_REQUEST:
 157                 if (copy_from_user(&req.perout, (void __user *)arg,
 158                                    sizeof(req.perout))) {
 159                         err = -EFAULT;
 160                         break;
 161                 }
 162                 if (req.perout.index >= ops->n_per_out) {
 163                         err = -EINVAL;
 164                         break;
 165                 }
 166                 req.type = PTP_CLK_REQ_PEROUT;
 167                 enable = req.perout.period.sec || req.perout.period.nsec;
 168                 err = ops->enable(ops, &req, enable);
 169                 break;
 170
 171         case PTP_ENABLE_PPS:
 172                 if (!capable(CAP_SYS_TIME))
 173                         return -EPERM;
 174                 req.type = PTP_CLK_REQ_PPS;
 175                 enable = arg ? 1 : 0;
 176                 err = ops->enable(ops, &req, enable);
 177                 break;
 178
 179         case PTP_SYS_OFFSET_PRECISE:
 180                 if (!ptp->info->getcrosststamp) {
 181                         err = -EOPNOTSUPP;
 182                         break;
 183                 }
 184                 err = ptp->info->getcrosststamp(ptp->info, &xtstamp);
 185                 if (err)
 186                         break;
 187
 188                 memset(&precise_offset, 0, sizeof(precise_offset));
 189                 ts = ktime_to_timespec64(xtstamp.device);
 190                 precise_offset.device.sec = ts.tv_sec;
 191                 precise_offset.device.nsec = ts.tv_nsec;
 192                 ts = ktime_to_timespec64(xtstamp.sys_realtime);
 193                 precise_offset.sys_realtime.sec = ts.tv_sec;
 194                 precise_offset.sys_realtime.nsec = ts.tv_nsec;
 195                 ts = ktime_to_timespec64(xtstamp.sys_monoraw);
 196                 precise_offset.sys_monoraw.sec = ts.tv_sec;
 197                 precise_offset.sys_monoraw.nsec = ts.tv_nsec;
 198                 if (copy_to_user((void __user *)arg, &precise_offset,
 199                                  sizeof(precise_offset)))
 200                         err = -EFAULT;
 201                 break;
 202
 203         case PTP_SYS_OFFSET_EXTENDED:
 204                 if (!ptp->info->gettimex64) {
 205                         err = -EOPNOTSUPP;
 206                         break;
 207                 }
 208                 extoff = memdup_user((void __user *)arg, sizeof(*extoff));
 209                 if (IS_ERR(extoff)) {
 210                         err = PTR_ERR(extoff);
 211                         extoff = NULL;
 212                         break;
 213                 }
 214                 if (extoff->n_samples > PTP_MAX_SAMPLES
 215                     || extoff->rsv[0] || extoff->rsv[1] || extoff->rsv[2]) {
 216                         err = -EINVAL;
 217                         break;
 218                 }
 219                 for (i = 0; i < extoff->n_samples; i++) {
 220                         err = ptp->info->gettimex64(ptp->info, &ts, &sts);
 221                         if (err)
 222                                 goto out;
 223                         extoff->ts[i][0].sec = sts.pre_ts.tv_sec;
 224                         extoff->ts[i][0].nsec = sts.pre_ts.tv_nsec;
 225                         extoff->ts[i][1].sec = ts.tv_sec;
 226                         extoff->ts[i][1].nsec = ts.tv_nsec;
 227                         extoff->ts[i][2].sec = sts.post_ts.tv_sec;
 228                         extoff->ts[i][2].nsec = sts.post_ts.tv_nsec;
 229                 }
 230                 if (copy_to_user((void __user *)arg, extoff, sizeof(*extoff)))
 231                         err = -EFAULT;
 232                 break;
 233
 234         case PTP_SYS_OFFSET:
 235                 sysoff = memdup_user((void __user *)arg, sizeof(*sysoff));
 236                 if (IS_ERR(sysoff)) {
 237                         err = PTR_ERR(sysoff);
 238                         sysoff = NULL;
 239                         break;
 240                 }
 241                 if (sysoff->n_samples > PTP_MAX_SAMPLES) {
 242                         err = -EINVAL;
 243                         break;
 244                 }
 245                 pct = &sysoff->ts[0];
 246                 for (i = 0; i < sysoff->n_samples; i++) {
 247                         ktime_get_real_ts64(&ts);
 248                         pct->sec = ts.tv_sec;
 249                         pct->nsec = ts.tv_nsec;
 250                         pct++;
 251                         if (ops->gettimex64)
 252                                 err = ops->gettimex64(ops, &ts, NULL);
 253                         else
 254                                 err = ops->gettime64(ops, &ts);
 255                         if (err)
 256                                 goto out;
 257                         pct->sec = ts.tv_sec;
 258                         pct->nsec = ts.tv_nsec;
 259                         pct++;
 260                 }
 261                 ktime_get_real_ts64(&ts);
 262                 pct->sec = ts.tv_sec;
 263                 pct->nsec = ts.tv_nsec;
 264                 if (copy_to_user((void __user *)arg, sysoff, sizeof(*sysoff)))
 265                         err = -EFAULT;
 266                 break;
 267
 268         case PTP_PIN_GETFUNC:
 269                 if (copy_from_user(&pd, (void __user *)arg, sizeof(pd))) {
 270                         err = -EFAULT;
 271                         break;
 272                 }
 273                 pin_index = pd.index;
 274                 if (pin_index >= ops->n_pins) {
 275                         err = -EINVAL;
 276                         break;
 277                 }
 278                 pin_index = array_index_nospec(pin_index, ops->n_pins);
 279                 if (mutex_lock_interruptible(&ptp->pincfg_mux))
 280                         return -ERESTARTSYS;
 281                 pd = ops->pin_config[pin_index];
 282                 mutex_unlock(&ptp->pincfg_mux);
 283                 if (!err && copy_to_user((void __user *)arg, &pd, sizeof(pd)))
 284                         err = -EFAULT;
 285                 break;
 286
 287         case PTP_PIN_SETFUNC:
 288                 if (copy_from_user(&pd, (void __user *)arg, sizeof(pd))) {
 289                         err = -EFAULT;
 290                         break;
 291                 }
 292                 pin_index = pd.index;
 293                 if (pin_index >= ops->n_pins) {
 294                         err = -EINVAL;
 295                         break;
 296                 }
 297                 pin_index = array_index_nospec(pin_index, ops->n_pins);
 298                 if (mutex_lock_interruptible(&ptp->pincfg_mux))
 299                         return -ERESTARTSYS;
 300                 err = ptp_set_pinfunc(ptp, pin_index, pd.func, pd.chan);
 301                 mutex_unlock(&ptp->pincfg_mux);
 302                 break;
 303
 304         default:
 305                 err = -ENOTTY;
 306                 break;
 307         }
 308
 309 out:
 310         kfree(extoff);
 311         kfree(sysoff);
 312         return err;
 313 }
 314
 315 __poll_t ptp_poll(struct posix_clock *pc, struct file *fp, poll_table *wait)
 316 {
 317         struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
 318
 319         poll_wait(fp, &ptp->tsev_wq, wait);
 320
 321         return queue_cnt(&ptp->tsevq) ? EPOLLIN : 0;
 322 }
 323
 324 #define EXTTS_BUFSIZE (PTP_BUF_TIMESTAMPS * sizeof(struct ptp_extts_event))
 325
 326 ssize_t ptp_read(struct posix_clock *pc,
 327                  uint rdflags, char __user *buf, size_t cnt)
 328 {
 329         struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
 330         struct timestamp_event_queue *queue = &ptp->tsevq;
 331         struct ptp_extts_event *event;
 332         unsigned long flags;
 333         size_t qcnt, i;
 334         int result;
 335
 336         if (cnt % sizeof(struct ptp_extts_event) != 0)
 337                 return -EINVAL;
 338
 339         if (cnt > EXTTS_BUFSIZE)
 340                 cnt = EXTTS_BUFSIZE;
 341
 342         cnt = cnt / sizeof(struct ptp_extts_event);
 343
 344         if (mutex_lock_interruptible(&ptp->tsevq_mux))
 345                 return -ERESTARTSYS;
 346
 347         if (wait_event_interruptible(ptp->tsev_wq,
 348                                      ptp->defunct || queue_cnt(queue))) {
 349                 mutex_unlock(&ptp->tsevq_mux);
 350                 return -ERESTARTSYS;
 351         }
 352
 353         if (ptp->defunct) {
 354                 mutex_unlock(&ptp->tsevq_mux);
 355                 return -ENODEV;
 356         }
 357
 358         event = kmalloc(EXTTS_BUFSIZE, GFP_KERNEL);
 359         if (!event) {
 360                 mutex_unlock(&ptp->tsevq_mux);
 361                 return -ENOMEM;
 362         }
 363
 364         spin_lock_irqsave(&queue->lock, flags);
 365
 366         qcnt = queue_cnt(queue);
 367
 368         if (cnt > qcnt)
 369                 cnt = qcnt;
 370
 371         for (i = 0; i < cnt; i++) {
 372                 event[i] = queue->buf[queue->head];
 373                 queue->head = (queue->head + 1) % PTP_MAX_TIMESTAMPS;
 374         }
 375
 376         spin_unlock_irqrestore(&queue->lock, flags);
 377
 378         cnt = cnt * sizeof(struct ptp_extts_event);
 379
 380         mutex_unlock(&ptp->tsevq_mux);
 381
 382         result = cnt;
 383         if (copy_to_user(buf, event, cnt))
 384                 result = -EFAULT;
 385
 386         kfree(event);
 387         return result;
 388 }