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                 break;
  92         default:
  93                 return -EINVAL;
  94         }
  95
  96         if (info->verify(info, pin, func, chan)) {
  97                 pr_err("driver cannot use function %u on pin %u\n", func, chan);
  98                 return -EOPNOTSUPP;
  99         }
 100
 101         /* Disable whatever function was previously assigned. */
 102         if (pin1) {
 103                 ptp_disable_pinfunc(info, func, chan);
 104                 pin1->func = PTP_PF_NONE;
 105                 pin1->chan = 0;
 106         }
 107         ptp_disable_pinfunc(info, pin2->func, pin2->chan);
 108         pin2->func = func;
 109         pin2->chan = chan;
 110
 111         return 0;
 112 }
 113
 114 int ptp_open(struct posix_clock *pc, fmode_t fmode)
 115 {
 116         return 0;
 117 }
 118
 119 long ptp_ioctl(struct posix_clock *pc, unsigned int cmd, unsigned long arg)
 120 {
 121         struct ptp_clock_caps caps;
 122         struct ptp_clock_request req;
 123         struct ptp_sys_offset *sysoff = NULL;
 124         struct ptp_pin_desc pd;
 125         struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
 126         struct ptp_clock_info *ops = ptp->info;
 127         struct ptp_clock_time *pct;
 128         struct timespec64 ts;
 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                         ptp->info->gettime64(ptp->info, &ts);
 206                         pct->sec = ts.tv_sec;
 207                         pct->nsec = ts.tv_nsec;
 208                         pct++;
 209                 }
 210                 getnstimeofday64(&ts);
 211                 pct->sec = ts.tv_sec;
 212                 pct->nsec = ts.tv_nsec;
 213                 if (copy_to_user((void __user *)arg, sysoff, sizeof(*sysoff)))
 214                         err = -EFAULT;
 215                 break;
 216
 217         case PTP_PIN_GETFUNC:
 218                 if (copy_from_user(&pd, (void __user *)arg, sizeof(pd))) {
 219                         err = -EFAULT;
 220                         break;
 221                 }
 222                 pin_index = pd.index;
 223                 if (pin_index >= ops->n_pins) {
 224                         err = -EINVAL;
 225                         break;
 226                 }
 227                 if (mutex_lock_interruptible(&ptp->pincfg_mux))
 228                         return -ERESTARTSYS;
 229                 pd = ops->pin_config[pin_index];
 230                 mutex_unlock(&ptp->pincfg_mux);
 231                 if (!err && copy_to_user((void __user *)arg, &pd, sizeof(pd)))
 232                         err = -EFAULT;
 233                 break;
 234
 235         case PTP_PIN_SETFUNC:
 236                 if (copy_from_user(&pd, (void __user *)arg, sizeof(pd))) {
 237                         err = -EFAULT;
 238                         break;
 239                 }
 240                 pin_index = pd.index;
 241                 if (pin_index >= ops->n_pins) {
 242                         err = -EINVAL;
 243                         break;
 244                 }
 245                 if (mutex_lock_interruptible(&ptp->pincfg_mux))
 246                         return -ERESTARTSYS;
 247                 err = ptp_set_pinfunc(ptp, pin_index, pd.func, pd.chan);
 248                 mutex_unlock(&ptp->pincfg_mux);
 249                 break;
 250
 251         default:
 252                 err = -ENOTTY;
 253                 break;
 254         }
 255
 256         kfree(sysoff);
 257         return err;
 258 }
 259
 260 unsigned int ptp_poll(struct posix_clock *pc, struct file *fp, poll_table *wait)
 261 {
 262         struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
 263
 264         poll_wait(fp, &ptp->tsev_wq, wait);
 265
 266         return queue_cnt(&ptp->tsevq) ? POLLIN : 0;
 267 }
 268
 269 #define EXTTS_BUFSIZE (PTP_BUF_TIMESTAMPS * sizeof(struct ptp_extts_event))
 270
 271 ssize_t ptp_read(struct posix_clock *pc,
 272                  uint rdflags, char __user *buf, size_t cnt)
 273 {
 274         struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
 275         struct timestamp_event_queue *queue = &ptp->tsevq;
 276         struct ptp_extts_event *event;
 277         unsigned long flags;
 278         size_t qcnt, i;
 279         int result;
 280
 281         if (cnt % sizeof(struct ptp_extts_event) != 0)
 282                 return -EINVAL;
 283
 284         if (cnt > EXTTS_BUFSIZE)
 285                 cnt = EXTTS_BUFSIZE;
 286
 287         cnt = cnt / sizeof(struct ptp_extts_event);
 288
 289         if (mutex_lock_interruptible(&ptp->tsevq_mux))
 290                 return -ERESTARTSYS;
 291
 292         if (wait_event_interruptible(ptp->tsev_wq,
 293                                      ptp->defunct || queue_cnt(queue))) {
 294                 mutex_unlock(&ptp->tsevq_mux);
 295                 return -ERESTARTSYS;
 296         }
 297
 298         if (ptp->defunct) {
 299                 mutex_unlock(&ptp->tsevq_mux);
 300                 return -ENODEV;
 301         }
 302
 303         event = kmalloc(EXTTS_BUFSIZE, GFP_KERNEL);
 304         if (!event) {
 305                 mutex_unlock(&ptp->tsevq_mux);
 306                 return -ENOMEM;
 307         }
 308
 309         spin_lock_irqsave(&queue->lock, flags);
 310
 311         qcnt = queue_cnt(queue);
 312
 313         if (cnt > qcnt)
 314                 cnt = qcnt;
 315
 316         for (i = 0; i < cnt; i++) {
 317                 event[i] = queue->buf[queue->head];
 318                 queue->head = (queue->head + 1) % PTP_MAX_TIMESTAMPS;
 319         }
 320
 321         spin_unlock_irqrestore(&queue->lock, flags);
 322
 323         cnt = cnt * sizeof(struct ptp_extts_event);
 324
 325         mutex_unlock(&ptp->tsevq_mux);
 326
 327         result = cnt;
 328         if (copy_to_user(buf, event, cnt))
 329                 result = -EFAULT;
 330
 331         kfree(event);
 332         return result;
 333 }