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
  26 #include <linux/nospec.h>
  27
  28 #include "ptp_private.h"
  29
  30 static int ptp_disable_pinfunc(struct ptp_clock_info *ops,
  31                                enum ptp_pin_function func, unsigned int chan)
  32 {
  33         struct ptp_clock_request rq;
  34         int err = 0;
  35
  36         memset(&rq, 0, sizeof(rq));
  37
  38         switch (func) {
  39         case PTP_PF_NONE:
  40                 break;
  41         case PTP_PF_EXTTS:
  42                 rq.type = PTP_CLK_REQ_EXTTS;
  43                 rq.extts.index = chan;
  44                 err = ops->enable(ops, &rq, 0);
  45                 break;
  46         case PTP_PF_PEROUT:
  47                 rq.type = PTP_CLK_REQ_PEROUT;
  48                 rq.perout.index = chan;
  49                 err = ops->enable(ops, &rq, 0);
  50                 break;
  51         case PTP_PF_PHYSYNC:
  52                 break;
  53         default:
  54                 return -EINVAL;
  55         }
  56
  57         return err;
  58 }
  59
  60 int ptp_set_pinfunc(struct ptp_clock *ptp, unsigned int pin,
  61                     enum ptp_pin_function func, unsigned int chan)
  62 {
  63         struct ptp_clock_info *info = ptp->info;
  64         struct ptp_pin_desc *pin1 = NULL, *pin2 = &info->pin_config[pin];
  65         unsigned int i;
  66
  67         /* Check to see if any other pin previously had this function. */
  68         for (i = 0; i < info->n_pins; i++) {
  69                 if (info->pin_config[i].func == func &&
  70                     info->pin_config[i].chan == chan) {
  71                         pin1 = &info->pin_config[i];
  72                         break;
  73                 }
  74         }
  75         if (pin1 && i == pin)
  76                 return 0;
  77
  78         /* Check the desired function and channel. */
  79         switch (func) {
  80         case PTP_PF_NONE:
  81                 break;
  82         case PTP_PF_EXTTS:
  83                 if (chan >= info->n_ext_ts)
  84                         return -EINVAL;
  85                 break;
  86         case PTP_PF_PEROUT:
  87                 if (chan >= info->n_per_out)
  88                         return -EINVAL;
  89                 break;
  90         case PTP_PF_PHYSYNC:
  91                 if (chan != 0)
  92                         return -EINVAL;
  93                 break;
  94         default:
  95                 return -EINVAL;
  96         }
  97
  98         if (info->verify(info, pin, func, chan)) {
  99                 pr_err("driver cannot use function %u on pin %u\n", func, chan);
 100                 return -EOPNOTSUPP;
 101         }
 102
 103         /* Disable whatever function was previously assigned. */
 104         if (pin1) {
 105                 ptp_disable_pinfunc(info, func, chan);
 106                 pin1->func = PTP_PF_NONE;
 107                 pin1->chan = 0;
 108         }
 109         ptp_disable_pinfunc(info, pin2->func, pin2->chan);
 110         pin2->func = func;
 111         pin2->chan = chan;
 112
 113         return 0;
 114 }
 115
 116 int ptp_open(struct posix_clock *pc, fmode_t fmode)
 117 {
 118         return 0;
 119 }
 120
 121 long ptp_ioctl(struct posix_clock *pc, unsigned int cmd, unsigned long arg)
 122 {
 123         struct ptp_clock_caps caps;
 124         struct ptp_clock_request req;
 125         struct ptp_sys_offset *sysoff = NULL;
 126         struct ptp_pin_desc pd;
 127         struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
 128         struct ptp_clock_info *ops = ptp->info;
 129         struct ptp_clock_time *pct;
 130         struct timespec64 ts;
 131         int enable, err = 0;
 132         unsigned int i, pin_index;
 133
 134         switch (cmd) {
 135
 136         case PTP_CLOCK_GETCAPS:
 137                 memset(&caps, 0, sizeof(caps));
 138                 caps.max_adj = ptp->info->max_adj;
 139                 caps.n_alarm = ptp->info->n_alarm;
 140                 caps.n_ext_ts = ptp->info->n_ext_ts;
 141                 caps.n_per_out = ptp->info->n_per_out;
 142                 caps.pps = ptp->info->pps;
 143                 caps.n_pins = ptp->info->n_pins;
 144                 if (copy_to_user((void __user *)arg, &caps, sizeof(caps)))
 145                         err = -EFAULT;
 146                 break;
 147
 148         case PTP_EXTTS_REQUEST:
 149                 if (copy_from_user(&req.extts, (void __user *)arg,
 150                                    sizeof(req.extts))) {
 151                         err = -EFAULT;
 152                         break;
 153                 }
 154                 if (req.extts.index >= ops->n_ext_ts) {
 155                         err = -EINVAL;
 156                         break;
 157                 }
 158                 req.type = PTP_CLK_REQ_EXTTS;
 159                 enable = req.extts.flags & PTP_ENABLE_FEATURE ? 1 : 0;
 160                 err = ops->enable(ops, &req, enable);
 161                 break;
 162
 163         case PTP_PEROUT_REQUEST:
 164                 if (copy_from_user(&req.perout, (void __user *)arg,
 165                                    sizeof(req.perout))) {
 166                         err = -EFAULT;
 167                         break;
 168                 }
 169                 if (req.perout.index >= ops->n_per_out) {
 170                         err = -EINVAL;
 171                         break;
 172                 }
 173                 req.type = PTP_CLK_REQ_PEROUT;
 174                 enable = req.perout.period.sec || req.perout.period.nsec;
 175                 err = ops->enable(ops, &req, enable);
 176                 break;
 177
 178         case PTP_ENABLE_PPS:
 179                 if (!capable(CAP_SYS_TIME))
 180                         return -EPERM;
 181                 req.type = PTP_CLK_REQ_PPS;
 182                 enable = arg ? 1 : 0;
 183                 err = ops->enable(ops, &req, enable);
 184                 break;
 185
 186         case PTP_SYS_OFFSET:
 187                 sysoff = kmalloc(sizeof(*sysoff), GFP_KERNEL);
 188                 if (!sysoff) {
 189                         err = -ENOMEM;
 190                         break;
 191                 }
 192                 if (copy_from_user(sysoff, (void __user *)arg,
 193                                    sizeof(*sysoff))) {
 194                         err = -EFAULT;
 195                         break;
 196                 }
 197                 if (sysoff->n_samples > PTP_MAX_SAMPLES) {
 198                         err = -EINVAL;
 199                         break;
 200                 }
 201                 pct = &sysoff->ts[0];
 202                 for (i = 0; i < sysoff->n_samples; i++) {
 203                         getnstimeofday64(&ts);
 204                         pct->sec = ts.tv_sec;
 205                         pct->nsec = ts.tv_nsec;
 206                         pct++;
 207                         err = ptp->info->gettime64(ptp->info, &ts);
 208                         if (err)
 209                                 goto out;
 210                         pct->sec = ts.tv_sec;
 211                         pct->nsec = ts.tv_nsec;
 212                         pct++;
 213                 }
 214                 getnstimeofday64(&ts);
 215                 pct->sec = ts.tv_sec;
 216                 pct->nsec = ts.tv_nsec;
 217                 if (copy_to_user((void __user *)arg, sysoff, sizeof(*sysoff)))
 218                         err = -EFAULT;
 219                 break;
 220
 221         case PTP_PIN_GETFUNC:
 222                 if (copy_from_user(&pd, (void __user *)arg, sizeof(pd))) {
 223                         err = -EFAULT;
 224                         break;
 225                 }
 226                 pin_index = pd.index;
 227                 if (pin_index >= ops->n_pins) {
 228                         err = -EINVAL;
 229                         break;
 230                 }
 231                 pin_index = array_index_nospec(pin_index, ops->n_pins);
 232                 if (mutex_lock_interruptible(&ptp->pincfg_mux))
 233                         return -ERESTARTSYS;
 234                 pd = ops->pin_config[pin_index];
 235                 mutex_unlock(&ptp->pincfg_mux);
 236                 if (!err && copy_to_user((void __user *)arg, &pd, sizeof(pd)))
 237                         err = -EFAULT;
 238                 break;
 239
 240         case PTP_PIN_SETFUNC:
 241                 if (copy_from_user(&pd, (void __user *)arg, sizeof(pd))) {
 242                         err = -EFAULT;
 243                         break;
 244                 }
 245                 pin_index = pd.index;
 246                 if (pin_index >= ops->n_pins) {
 247                         err = -EINVAL;
 248                         break;
 249                 }
 250                 pin_index = array_index_nospec(pin_index, ops->n_pins);
 251                 if (mutex_lock_interruptible(&ptp->pincfg_mux))
 252                         return -ERESTARTSYS;
 253                 err = ptp_set_pinfunc(ptp, pin_index, pd.func, pd.chan);
 254                 mutex_unlock(&ptp->pincfg_mux);
 255                 break;
 256
 257         default:
 258                 err = -ENOTTY;
 259                 break;
 260         }
 261
 262 out:
 263         kfree(sysoff);
 264         return err;
 265 }
 266
 267 unsigned int ptp_poll(struct posix_clock *pc, struct file *fp, poll_table *wait)
 268 {
 269         struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
 270
 271         poll_wait(fp, &ptp->tsev_wq, wait);
 272
 273         return queue_cnt(&ptp->tsevq) ? POLLIN : 0;
 274 }
 275
 276 #define EXTTS_BUFSIZE (PTP_BUF_TIMESTAMPS * sizeof(struct ptp_extts_event))
 277
 278 ssize_t ptp_read(struct posix_clock *pc,
 279                  uint rdflags, char __user *buf, size_t cnt)
 280 {
 281         struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
 282         struct timestamp_event_queue *queue = &ptp->tsevq;
 283         struct ptp_extts_event *event;
 284         unsigned long flags;
 285         size_t qcnt, i;
 286         int result;
 287
 288         if (cnt % sizeof(struct ptp_extts_event) != 0)
 289                 return -EINVAL;
 290
 291         if (cnt > EXTTS_BUFSIZE)
 292                 cnt = EXTTS_BUFSIZE;
 293
 294         cnt = cnt / sizeof(struct ptp_extts_event);
 295
 296         if (mutex_lock_interruptible(&ptp->tsevq_mux))
 297                 return -ERESTARTSYS;
 298
 299         if (wait_event_interruptible(ptp->tsev_wq,
 300                                      ptp->defunct || queue_cnt(queue))) {
 301                 mutex_unlock(&ptp->tsevq_mux);
 302                 return -ERESTARTSYS;
 303         }
 304
 305         if (ptp->defunct) {
 306                 mutex_unlock(&ptp->tsevq_mux);
 307                 return -ENODEV;
 308         }
 309
 310         event = kmalloc(EXTTS_BUFSIZE, GFP_KERNEL);
 311         if (!event) {
 312                 mutex_unlock(&ptp->tsevq_mux);
 313                 return -ENOMEM;
 314         }
 315
 316         spin_lock_irqsave(&queue->lock, flags);
 317
 318         qcnt = queue_cnt(queue);
 319
 320         if (cnt > qcnt)
 321                 cnt = qcnt;
 322
 323         for (i = 0; i < cnt; i++) {
 324                 event[i] = queue->buf[queue->head];
 325                 queue->head = (queue->head + 1) % PTP_MAX_TIMESTAMPS;
 326         }
 327
 328         spin_unlock_irqrestore(&queue->lock, flags);
 329
 330         cnt = cnt * sizeof(struct ptp_extts_event);
 331
 332         mutex_unlock(&ptp->tsevq_mux);
 333
 334         result = cnt;
 335         if (copy_to_user(buf, event, cnt))
 336                 result = -EFAULT;
 337
 338         kfree(event);
 339         return result;
 340 }