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
  25 #include "ptp_private.h"
  26
  27 int ptp_open(struct posix_clock *pc, fmode_t fmode)
  28 {
  29         return 0;
  30 }
  31
  32 long ptp_ioctl(struct posix_clock *pc, unsigned int cmd, unsigned long arg)
  33 {
  34         struct ptp_clock_caps caps;
  35         struct ptp_clock_request req;
  36         struct ptp_sys_offset sysoff;
  37         struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
  38         struct ptp_clock_info *ops = ptp->info;
  39         struct ptp_clock_time *pct;
  40         struct timespec ts;
  41         int enable, err = 0;
  42         unsigned int i;
  43
  44         switch (cmd) {
  45
  46         case PTP_CLOCK_GETCAPS:
  47                 memset(&caps, 0, sizeof(caps));
  48                 caps.max_adj = ptp->info->max_adj;
  49                 caps.n_alarm = ptp->info->n_alarm;
  50                 caps.n_ext_ts = ptp->info->n_ext_ts;
  51                 caps.n_per_out = ptp->info->n_per_out;
  52                 caps.pps = ptp->info->pps;
  53                 if (copy_to_user((void __user *)arg, &caps, sizeof(caps)))
  54                         err = -EFAULT;
  55                 break;
  56
  57         case PTP_EXTTS_REQUEST:
  58                 if (copy_from_user(&req.extts, (void __user *)arg,
  59                                    sizeof(req.extts))) {
  60                         err = -EFAULT;
  61                         break;
  62                 }
  63                 if (req.extts.index >= ops->n_ext_ts) {
  64                         err = -EINVAL;
  65                         break;
  66                 }
  67                 req.type = PTP_CLK_REQ_EXTTS;
  68                 enable = req.extts.flags & PTP_ENABLE_FEATURE ? 1 : 0;
  69                 err = ops->enable(ops, &req, enable);
  70                 break;
  71
  72         case PTP_PEROUT_REQUEST:
  73                 if (copy_from_user(&req.perout, (void __user *)arg,
  74                                    sizeof(req.perout))) {
  75                         err = -EFAULT;
  76                         break;
  77                 }
  78                 if (req.perout.index >= ops->n_per_out) {
  79                         err = -EINVAL;
  80                         break;
  81                 }
  82                 req.type = PTP_CLK_REQ_PEROUT;
  83                 enable = req.perout.period.sec || req.perout.period.nsec;
  84                 err = ops->enable(ops, &req, enable);
  85                 break;
  86
  87         case PTP_ENABLE_PPS:
  88                 if (!capable(CAP_SYS_TIME))
  89                         return -EPERM;
  90                 req.type = PTP_CLK_REQ_PPS;
  91                 enable = arg ? 1 : 0;
  92                 err = ops->enable(ops, &req, enable);
  93                 break;
  94
  95         case PTP_SYS_OFFSET:
  96                 if (copy_from_user(&sysoff, (void __user *)arg,
  97                                    sizeof(sysoff))) {
  98                         err = -EFAULT;
  99                         break;
 100                 }
 101                 if (sysoff.n_samples > PTP_MAX_SAMPLES) {
 102                         err = -EINVAL;
 103                         break;
 104                 }
 105                 pct = &sysoff.ts[0];
 106                 for (i = 0; i < sysoff.n_samples; i++) {
 107                         getnstimeofday(&ts);
 108                         pct->sec = ts.tv_sec;
 109                         pct->nsec = ts.tv_nsec;
 110                         pct++;
 111                         ptp->info->gettime(ptp->info, &ts);
 112                         pct->sec = ts.tv_sec;
 113                         pct->nsec = ts.tv_nsec;
 114                         pct++;
 115                 }
 116                 getnstimeofday(&ts);
 117                 pct->sec = ts.tv_sec;
 118                 pct->nsec = ts.tv_nsec;
 119                 if (copy_to_user((void __user *)arg, &sysoff, sizeof(sysoff)))
 120                         err = -EFAULT;
 121                 break;
 122
 123         default:
 124                 err = -ENOTTY;
 125                 break;
 126         }
 127         return err;
 128 }
 129
 130 unsigned int ptp_poll(struct posix_clock *pc, struct file *fp, poll_table *wait)
 131 {
 132         struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
 133
 134         poll_wait(fp, &ptp->tsev_wq, wait);
 135
 136         return queue_cnt(&ptp->tsevq) ? POLLIN : 0;
 137 }
 138
 139 ssize_t ptp_read(struct posix_clock *pc,
 140                  uint rdflags, char __user *buf, size_t cnt)
 141 {
 142         struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
 143         struct timestamp_event_queue *queue = &ptp->tsevq;
 144         struct ptp_extts_event event[PTP_BUF_TIMESTAMPS];
 145         unsigned long flags;
 146         size_t qcnt, i;
 147
 148         if (cnt % sizeof(struct ptp_extts_event) != 0)
 149                 return -EINVAL;
 150
 151         if (cnt > sizeof(event))
 152                 cnt = sizeof(event);
 153
 154         cnt = cnt / sizeof(struct ptp_extts_event);
 155
 156         if (mutex_lock_interruptible(&ptp->tsevq_mux))
 157                 return -ERESTARTSYS;
 158
 159         if (wait_event_interruptible(ptp->tsev_wq,
 160                                      ptp->defunct || queue_cnt(queue))) {
 161                 mutex_unlock(&ptp->tsevq_mux);
 162                 return -ERESTARTSYS;
 163         }
 164
 165         if (ptp->defunct) {
 166                 mutex_unlock(&ptp->tsevq_mux);
 167                 return -ENODEV;
 168         }
 169
 170         spin_lock_irqsave(&queue->lock, flags);
 171
 172         qcnt = queue_cnt(queue);
 173
 174         if (cnt > qcnt)
 175                 cnt = qcnt;
 176
 177         for (i = 0; i < cnt; i++) {
 178                 event[i] = queue->buf[queue->head];
 179                 queue->head = (queue->head + 1) % PTP_MAX_TIMESTAMPS;
 180         }
 181
 182         spin_unlock_irqrestore(&queue->lock, flags);
 183
 184         cnt = cnt * sizeof(struct ptp_extts_event);
 185
 186         mutex_unlock(&ptp->tsevq_mux);
 187
 188         if (copy_to_user(buf, event, cnt))
 189                 return -EFAULT;
 190
 191         return cnt;
 192 }