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_caps caps;
 125         struct ptp_clock_request req;
 126         struct ptp_sys_offset *sysoff = NULL;
 127         struct ptp_sys_offset_precise precise_offset;
 128         struct ptp_pin_desc pd;
 129         struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
 130         struct ptp_clock_info *ops = ptp->info;
 131         struct ptp_clock_time *pct;
 132         struct timespec64 ts;
 133         struct system_device_crosststamp xtstamp;
 134         int enable, err = 0;
 135         unsigned int i, pin_index;
 136
 137         switch (cmd) {
 138
 139         case PTP_CLOCK_GETCAPS:
 140                 memset(&caps, 0, sizeof(caps));
 141                 caps.max_adj = ptp->info->max_adj;
 142                 caps.n_alarm = ptp->info->n_alarm;
 143                 caps.n_ext_ts = ptp->info->n_ext_ts;
 144                 caps.n_per_out = ptp->info->n_per_out;
 145                 caps.pps = ptp->info->pps;
 146                 caps.n_pins = ptp->info->n_pins;
 147                 caps.cross_timestamping = ptp->info->getcrosststamp != NULL;
 148                 if (copy_to_user((void __user *)arg, &caps, sizeof(caps)))
 149                         err = -EFAULT;
 150                 break;
 151
 152         case PTP_EXTTS_REQUEST:
 153                 if (copy_from_user(&req.extts, (void __user *)arg,
 154                                    sizeof(req.extts))) {
 155                         err = -EFAULT;
 156                         break;
 157                 }
 158                 if (req.extts.index >= ops->n_ext_ts) {
 159                         err = -EINVAL;
 160                         break;
 161                 }
 162                 req.type = PTP_CLK_REQ_EXTTS;
 163                 enable = req.extts.flags & PTP_ENABLE_FEATURE ? 1 : 0;
 164                 err = ops->enable(ops, &req, enable);
 165                 break;
 166
 167         case PTP_PEROUT_REQUEST:
 168                 if (copy_from_user(&req.perout, (void __user *)arg,
 169                                    sizeof(req.perout))) {
 170                         err = -EFAULT;
 171                         break;
 172                 }
 173                 if (req.perout.index >= ops->n_per_out) {
 174                         err = -EINVAL;
 175                         break;
 176                 }
 177                 req.type = PTP_CLK_REQ_PEROUT;
 178                 enable = req.perout.period.sec || req.perout.period.nsec;
 179                 err = ops->enable(ops, &req, enable);
 180                 break;
 181
 182         case PTP_ENABLE_PPS:
 183                 if (!capable(CAP_SYS_TIME))
 184                         return -EPERM;
 185                 req.type = PTP_CLK_REQ_PPS;
 186                 enable = arg ? 1 : 0;
 187                 err = ops->enable(ops, &req, enable);
 188                 break;
 189
 190         case PTP_SYS_OFFSET_PRECISE:
 191                 if (!ptp->info->getcrosststamp) {
 192                         err = -EOPNOTSUPP;
 193                         break;
 194                 }
 195                 err = ptp->info->getcrosststamp(ptp->info, &xtstamp);
 196                 if (err)
 197                         break;
 198
 199                 memset(&precise_offset, 0, sizeof(precise_offset));
 200                 ts = ktime_to_timespec64(xtstamp.device);
 201                 precise_offset.device.sec = ts.tv_sec;
 202                 precise_offset.device.nsec = ts.tv_nsec;
 203                 ts = ktime_to_timespec64(xtstamp.sys_realtime);
 204                 precise_offset.sys_realtime.sec = ts.tv_sec;
 205                 precise_offset.sys_realtime.nsec = ts.tv_nsec;
 206                 ts = ktime_to_timespec64(xtstamp.sys_monoraw);
 207                 precise_offset.sys_monoraw.sec = ts.tv_sec;
 208                 precise_offset.sys_monoraw.nsec = ts.tv_nsec;
 209                 if (copy_to_user((void __user *)arg, &precise_offset,
 210                                  sizeof(precise_offset)))
 211                         err = -EFAULT;
 212                 break;
 213
 214         case PTP_SYS_OFFSET:
 215                 sysoff = memdup_user((void __user *)arg, sizeof(*sysoff));
 216                 if (IS_ERR(sysoff)) {
 217                         err = PTR_ERR(sysoff);
 218                         sysoff = NULL;
 219                         break;
 220                 }
 221                 if (sysoff->n_samples > PTP_MAX_SAMPLES) {
 222                         err = -EINVAL;
 223                         break;
 224                 }
 225                 pct = &sysoff->ts[0];
 226                 for (i = 0; i < sysoff->n_samples; i++) {
 227                         ktime_get_real_ts64(&ts);
 228                         pct->sec = ts.tv_sec;
 229                         pct->nsec = ts.tv_nsec;
 230                         pct++;
 231                         err = ptp->info->gettime64(ptp->info, &ts);
 232                         if (err)
 233                                 goto out;
 234                         pct->sec = ts.tv_sec;
 235                         pct->nsec = ts.tv_nsec;
 236                         pct++;
 237                 }
 238                 ktime_get_real_ts64(&ts);
 239                 pct->sec = ts.tv_sec;
 240                 pct->nsec = ts.tv_nsec;
 241                 if (copy_to_user((void __user *)arg, sysoff, sizeof(*sysoff)))
 242                         err = -EFAULT;
 243                 break;
 244
 245         case PTP_PIN_GETFUNC:
 246                 if (copy_from_user(&pd, (void __user *)arg, sizeof(pd))) {
 247                         err = -EFAULT;
 248                         break;
 249                 }
 250                 pin_index = pd.index;
 251                 if (pin_index >= ops->n_pins) {
 252                         err = -EINVAL;
 253                         break;
 254                 }
 255                 pin_index = array_index_nospec(pin_index, ops->n_pins);
 256                 if (mutex_lock_interruptible(&ptp->pincfg_mux))
 257                         return -ERESTARTSYS;
 258                 pd = ops->pin_config[pin_index];
 259                 mutex_unlock(&ptp->pincfg_mux);
 260                 if (!err && copy_to_user((void __user *)arg, &pd, sizeof(pd)))
 261                         err = -EFAULT;
 262                 break;
 263
 264         case PTP_PIN_SETFUNC:
 265                 if (copy_from_user(&pd, (void __user *)arg, sizeof(pd))) {
 266                         err = -EFAULT;
 267                         break;
 268                 }
 269                 pin_index = pd.index;
 270                 if (pin_index >= ops->n_pins) {
 271                         err = -EINVAL;
 272                         break;
 273                 }
 274                 pin_index = array_index_nospec(pin_index, ops->n_pins);
 275                 if (mutex_lock_interruptible(&ptp->pincfg_mux))
 276                         return -ERESTARTSYS;
 277                 err = ptp_set_pinfunc(ptp, pin_index, pd.func, pd.chan);
 278                 mutex_unlock(&ptp->pincfg_mux);
 279                 break;
 280
 281         default:
 282                 err = -ENOTTY;
 283                 break;
 284         }
 285
 286 out:
 287         kfree(sysoff);
 288         return err;
 289 }
 290
 291 __poll_t ptp_poll(struct posix_clock *pc, struct file *fp, poll_table *wait)
 292 {
 293         struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
 294
 295         poll_wait(fp, &ptp->tsev_wq, wait);
 296
 297         return queue_cnt(&ptp->tsevq) ? EPOLLIN : 0;
 298 }
 299
 300 #define EXTTS_BUFSIZE (PTP_BUF_TIMESTAMPS * sizeof(struct ptp_extts_event))
 301
 302 ssize_t ptp_read(struct posix_clock *pc,
 303                  uint rdflags, char __user *buf, size_t cnt)
 304 {
 305         struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
 306         struct timestamp_event_queue *queue = &ptp->tsevq;
 307         struct ptp_extts_event *event;
 308         unsigned long flags;
 309         size_t qcnt, i;
 310         int result;
 311
 312         if (cnt % sizeof(struct ptp_extts_event) != 0)
 313                 return -EINVAL;
 314
 315         if (cnt > EXTTS_BUFSIZE)
 316                 cnt = EXTTS_BUFSIZE;
 317
 318         cnt = cnt / sizeof(struct ptp_extts_event);
 319
 320         if (mutex_lock_interruptible(&ptp->tsevq_mux))
 321                 return -ERESTARTSYS;
 322
 323         if (wait_event_interruptible(ptp->tsev_wq,
 324                                      ptp->defunct || queue_cnt(queue))) {
 325                 mutex_unlock(&ptp->tsevq_mux);
 326                 return -ERESTARTSYS;
 327         }
 328
 329         if (ptp->defunct) {
 330                 mutex_unlock(&ptp->tsevq_mux);
 331                 return -ENODEV;
 332         }
 333
 334         event = kmalloc(EXTTS_BUFSIZE, GFP_KERNEL);
 335         if (!event) {
 336                 mutex_unlock(&ptp->tsevq_mux);
 337                 return -ENOMEM;
 338         }
 339
 340         spin_lock_irqsave(&queue->lock, flags);
 341
 342         qcnt = queue_cnt(queue);
 343
 344         if (cnt > qcnt)
 345                 cnt = qcnt;
 346
 347         for (i = 0; i < cnt; i++) {
 348                 event[i] = queue->buf[queue->head];
 349                 queue->head = (queue->head + 1) % PTP_MAX_TIMESTAMPS;
 350         }
 351
 352         spin_unlock_irqrestore(&queue->lock, flags);
 353
 354         cnt = cnt * sizeof(struct ptp_extts_event);
 355
 356         mutex_unlock(&ptp->tsevq_mux);
 357
 358         result = cnt;
 359         if (copy_to_user(buf, event, cnt))
 360                 result = -EFAULT;
 361
 362         kfree(event);
 363         return result;
 364 }