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         struct timespec t2;
 129         int enable, err = 0;
 130         unsigned int i, pin_index;
 131
 132         switch (cmd) {
 133
 134         case PTP_CLOCK_GETCAPS:
 135                 memset(&caps, 0, sizeof(caps));
 136                 caps.max_adj = ptp->info->max_adj;
 137                 caps.n_alarm = ptp->info->n_alarm;
 138                 caps.n_ext_ts = ptp->info->n_ext_ts;
 139                 caps.n_per_out = ptp->info->n_per_out;
 140                 caps.pps = ptp->info->pps;
 141                 caps.n_pins = ptp->info->n_pins;
 142                 if (copy_to_user((void __user *)arg, &caps, sizeof(caps)))
 143                         err = -EFAULT;
 144                 break;
 145
 146         case PTP_EXTTS_REQUEST:
 147                 if (copy_from_user(&req.extts, (void __user *)arg,
 148                                    sizeof(req.extts))) {
 149                         err = -EFAULT;
 150                         break;
 151                 }
 152                 if (req.extts.index >= ops->n_ext_ts) {
 153                         err = -EINVAL;
 154                         break;
 155                 }
 156                 req.type = PTP_CLK_REQ_EXTTS;
 157                 enable = req.extts.flags & PTP_ENABLE_FEATURE ? 1 : 0;
 158                 err = ops->enable(ops, &req, enable);
 159                 break;
 160
 161         case PTP_PEROUT_REQUEST:
 162                 if (copy_from_user(&req.perout, (void __user *)arg,
 163                                    sizeof(req.perout))) {
 164                         err = -EFAULT;
 165                         break;
 166                 }
 167                 if (req.perout.index >= ops->n_per_out) {
 168                         err = -EINVAL;
 169                         break;
 170                 }
 171                 req.type = PTP_CLK_REQ_PEROUT;
 172                 enable = req.perout.period.sec || req.perout.period.nsec;
 173                 err = ops->enable(ops, &req, enable);
 174                 break;
 175
 176         case PTP_ENABLE_PPS:
 177                 if (!capable(CAP_SYS_TIME))
 178                         return -EPERM;
 179                 req.type = PTP_CLK_REQ_PPS;
 180                 enable = arg ? 1 : 0;
 181                 err = ops->enable(ops, &req, enable);
 182                 break;
 183
 184         case PTP_SYS_OFFSET:
 185                 sysoff = kmalloc(sizeof(*sysoff), GFP_KERNEL);
 186                 if (!sysoff) {
 187                         err = -ENOMEM;
 188                         break;
 189                 }
 190                 if (copy_from_user(sysoff, (void __user *)arg,
 191                                    sizeof(*sysoff))) {
 192                         err = -EFAULT;
 193                         break;
 194                 }
 195                 if (sysoff->n_samples > PTP_MAX_SAMPLES) {
 196                         err = -EINVAL;
 197                         break;
 198                 }
 199                 pct = &sysoff->ts[0];
 200                 for (i = 0; i < sysoff->n_samples; i++) {
 201                         getnstimeofday64(&ts);
 202                         pct->sec = ts.tv_sec;
 203                         pct->nsec = ts.tv_nsec;
 204                         pct++;
 205                         if (ptp->info->gettime64) {
 206                                 ptp->info->gettime64(ptp->info, &ts);
 207                         } else {
 208                                 ptp->info->gettime(ptp->info, &t2);
 209                                 ts = timespec_to_timespec64(t2);
 210                         }
 211                         pct->sec = ts.tv_sec;
 212                         pct->nsec = ts.tv_nsec;
 213                         pct++;
 214                 }
 215                 getnstimeofday64(&ts);
 216                 pct->sec = ts.tv_sec;
 217                 pct->nsec = ts.tv_nsec;
 218                 if (copy_to_user((void __user *)arg, sysoff, sizeof(*sysoff)))
 219                         err = -EFAULT;
 220                 break;
 221
 222         case PTP_PIN_GETFUNC:
 223                 if (copy_from_user(&pd, (void __user *)arg, sizeof(pd))) {
 224                         err = -EFAULT;
 225                         break;
 226                 }
 227                 pin_index = pd.index;
 228                 if (pin_index >= ops->n_pins) {
 229                         err = -EINVAL;
 230                         break;
 231                 }
 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                 if (mutex_lock_interruptible(&ptp->pincfg_mux))
 251                         return -ERESTARTSYS;
 252                 err = ptp_set_pinfunc(ptp, pin_index, pd.func, pd.chan);
 253                 mutex_unlock(&ptp->pincfg_mux);
 254                 break;
 255
 256         default:
 257                 err = -ENOTTY;
 258                 break;
 259         }
 260
 261         kfree(sysoff);
 262         return err;
 263 }
 264
 265 unsigned int ptp_poll(struct posix_clock *pc, struct file *fp, poll_table *wait)
 266 {
 267         struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
 268
 269         poll_wait(fp, &ptp->tsev_wq, wait);
 270
 271         return queue_cnt(&ptp->tsevq) ? POLLIN : 0;
 272 }
 273
 274 #define EXTTS_BUFSIZE (PTP_BUF_TIMESTAMPS * sizeof(struct ptp_extts_event))
 275
 276 ssize_t ptp_read(struct posix_clock *pc,
 277                  uint rdflags, char __user *buf, size_t cnt)
 278 {
 279         struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
 280         struct timestamp_event_queue *queue = &ptp->tsevq;
 281         struct ptp_extts_event *event;
 282         unsigned long flags;
 283         size_t qcnt, i;
 284         int result;
 285
 286         if (cnt % sizeof(struct ptp_extts_event) != 0)
 287                 return -EINVAL;
 288
 289         if (cnt > EXTTS_BUFSIZE)
 290                 cnt = EXTTS_BUFSIZE;
 291
 292         cnt = cnt / sizeof(struct ptp_extts_event);
 293
 294         if (mutex_lock_interruptible(&ptp->tsevq_mux))
 295                 return -ERESTARTSYS;
 296
 297         if (wait_event_interruptible(ptp->tsev_wq,
 298                                      ptp->defunct || queue_cnt(queue))) {
 299                 mutex_unlock(&ptp->tsevq_mux);
 300                 return -ERESTARTSYS;
 301         }
 302
 303         if (ptp->defunct) {
 304                 mutex_unlock(&ptp->tsevq_mux);
 305                 return -ENODEV;
 306         }
 307
 308         event = kmalloc(EXTTS_BUFSIZE, GFP_KERNEL);
 309         if (!event) {
 310                 mutex_unlock(&ptp->tsevq_mux);
 311                 return -ENOMEM;
 312         }
 313
 314         spin_lock_irqsave(&queue->lock, flags);
 315
 316         qcnt = queue_cnt(queue);
 317
 318         if (cnt > qcnt)
 319                 cnt = qcnt;
 320
 321         for (i = 0; i < cnt; i++) {
 322                 event[i] = queue->buf[queue->head];
 323                 queue->head = (queue->head + 1) % PTP_MAX_TIMESTAMPS;
 324         }
 325
 326         spin_unlock_irqrestore(&queue->lock, flags);
 327
 328         cnt = cnt * sizeof(struct ptp_extts_event);
 329
 330         mutex_unlock(&ptp->tsevq_mux);
 331
 332         result = cnt;
 333         if (copy_to_user(buf, event, cnt))
 334                 result = -EFAULT;
 335
 336         kfree(event);
 337         return result;
 338 }