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