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 #include <linux/timekeeping.h>
  26
  27 #include "ptp_private.h"
  28
  29 static int ptp_disable_pinfunc(struct ptp_clock_info *ops,
  30                                enum ptp_pin_function func, unsigned int chan)
  31 {
  32         struct ptp_clock_request rq;
  33         int err = 0;
  34
  35         memset(&rq, 0, sizeof(rq));
  36
  37         switch (func) {
  38         case PTP_PF_NONE:
  39                 break;
  40         case PTP_PF_EXTTS:
  41                 rq.type = PTP_CLK_REQ_EXTTS;
  42                 rq.extts.index = chan;
  43                 err = ops->enable(ops, &rq, 0);
  44                 break;
  45         case PTP_PF_PEROUT:
  46                 rq.type = PTP_CLK_REQ_PEROUT;
  47                 rq.perout.index = chan;
  48                 err = ops->enable(ops, &rq, 0);
  49                 break;
  50         case PTP_PF_PHYSYNC:
  51                 break;
  52         default:
  53                 return -EINVAL;
  54         }
  55
  56         return err;
  57 }
  58
  59 int ptp_set_pinfunc(struct ptp_clock *ptp, unsigned int pin,
  60                     enum ptp_pin_function func, unsigned int chan)
  61 {
  62         struct ptp_clock_info *info = ptp->info;
  63         struct ptp_pin_desc *pin1 = NULL, *pin2 = &info->pin_config[pin];
  64         unsigned int i;
  65
  66         /* Check to see if any other pin previously had this function. */
  67         for (i = 0; i < info->n_pins; i++) {
  68                 if (info->pin_config[i].func == func &&
  69                     info->pin_config[i].chan == chan) {
  70                         pin1 = &info->pin_config[i];
  71                         break;
  72                 }
  73         }
  74         if (pin1 && i == pin)
  75                 return 0;
  76
  77         /* Check the desired function and channel. */
  78         switch (func) {
  79         case PTP_PF_NONE:
  80                 break;
  81         case PTP_PF_EXTTS:
  82                 if (chan >= info->n_ext_ts)
  83                         return -EINVAL;
  84                 break;
  85         case PTP_PF_PEROUT:
  86                 if (chan >= info->n_per_out)
  87                         return -EINVAL;
  88                 break;
  89         case PTP_PF_PHYSYNC:
  90                 if (chan != 0)
  91                         return -EINVAL;
  92                 break;
  93         default:
  94                 return -EINVAL;
  95         }
  96
  97         if (info->verify(info, pin, func, chan)) {
  98                 pr_err("driver cannot use function %u on pin %u\n", func, chan);
  99                 return -EOPNOTSUPP;
 100         }
 101
 102         /* Disable whatever function was previously assigned. */
 103         if (pin1) {
 104                 ptp_disable_pinfunc(info, func, chan);
 105                 pin1->func = PTP_PF_NONE;
 106                 pin1->chan = 0;
 107         }
 108         ptp_disable_pinfunc(info, pin2->func, pin2->chan);
 109         pin2->func = func;
 110         pin2->chan = chan;
 111
 112         return 0;
 113 }
 114
 115 int ptp_open(struct posix_clock *pc, fmode_t fmode)
 116 {
 117         return 0;
 118 }
 119
 120 long ptp_ioctl(struct posix_clock *pc, unsigned int cmd, unsigned long arg)
 121 {
 122         struct ptp_clock_caps caps;
 123         struct ptp_clock_request req;
 124         struct ptp_sys_offset *sysoff = NULL;
 125         struct ptp_sys_offset_precise precise_offset;
 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         struct system_device_crosststamp xtstamp;
 132         int enable, err = 0;
 133         unsigned int i, pin_index;
 134
 135         switch (cmd) {
 136
 137         case PTP_CLOCK_GETCAPS:
 138                 memset(&caps, 0, sizeof(caps));
 139                 caps.max_adj = ptp->info->max_adj;
 140                 caps.n_alarm = ptp->info->n_alarm;
 141                 caps.n_ext_ts = ptp->info->n_ext_ts;
 142                 caps.n_per_out = ptp->info->n_per_out;
 143                 caps.pps = ptp->info->pps;
 144                 caps.n_pins = ptp->info->n_pins;
 145                 caps.cross_timestamping = ptp->info->getcrosststamp != NULL;
 146                 if (copy_to_user((void __user *)arg, &caps, sizeof(caps)))
 147                         err = -EFAULT;
 148                 break;
 149
 150         case PTP_EXTTS_REQUEST:
 151                 if (copy_from_user(&req.extts, (void __user *)arg,
 152                                    sizeof(req.extts))) {
 153                         err = -EFAULT;
 154                         break;
 155                 }
 156                 if (req.extts.index >= ops->n_ext_ts) {
 157                         err = -EINVAL;
 158                         break;
 159                 }
 160                 req.type = PTP_CLK_REQ_EXTTS;
 161                 enable = req.extts.flags & PTP_ENABLE_FEATURE ? 1 : 0;
 162                 err = ops->enable(ops, &req, enable);
 163                 break;
 164
 165         case PTP_PEROUT_REQUEST:
 166                 if (copy_from_user(&req.perout, (void __user *)arg,
 167                                    sizeof(req.perout))) {
 168                         err = -EFAULT;
 169                         break;
 170                 }
 171                 if (req.perout.index >= ops->n_per_out) {
 172                         err = -EINVAL;
 173                         break;
 174                 }
 175                 req.type = PTP_CLK_REQ_PEROUT;
 176                 enable = req.perout.period.sec || req.perout.period.nsec;
 177                 err = ops->enable(ops, &req, enable);
 178                 break;
 179
 180         case PTP_ENABLE_PPS:
 181                 if (!capable(CAP_SYS_TIME))
 182                         return -EPERM;
 183                 req.type = PTP_CLK_REQ_PPS;
 184                 enable = arg ? 1 : 0;
 185                 err = ops->enable(ops, &req, enable);
 186                 break;
 187
 188         case PTP_SYS_OFFSET_PRECISE:
 189                 if (!ptp->info->getcrosststamp) {
 190                         err = -EOPNOTSUPP;
 191                         break;
 192                 }
 193                 err = ptp->info->getcrosststamp(ptp->info, &xtstamp);
 194                 if (err)
 195                         break;
 196
 197                 memset(&precise_offset, 0, sizeof(precise_offset));
 198                 ts = ktime_to_timespec64(xtstamp.device);
 199                 precise_offset.device.sec = ts.tv_sec;
 200                 precise_offset.device.nsec = ts.tv_nsec;
 201                 ts = ktime_to_timespec64(xtstamp.sys_realtime);
 202                 precise_offset.sys_realtime.sec = ts.tv_sec;
 203                 precise_offset.sys_realtime.nsec = ts.tv_nsec;
 204                 ts = ktime_to_timespec64(xtstamp.sys_monoraw);
 205                 precise_offset.sys_monoraw.sec = ts.tv_sec;
 206                 precise_offset.sys_monoraw.nsec = ts.tv_nsec;
 207                 if (copy_to_user((void __user *)arg, &precise_offset,
 208                                  sizeof(precise_offset)))
 209                         err = -EFAULT;
 210                 break;
 211
 212         case PTP_SYS_OFFSET:
 213                 sysoff = memdup_user((void __user *)arg, sizeof(*sysoff));
 214                 if (IS_ERR(sysoff)) {
 215                         err = PTR_ERR(sysoff);
 216                         sysoff = NULL;
 217                         break;
 218                 }
 219                 if (sysoff->n_samples > PTP_MAX_SAMPLES) {
 220                         err = -EINVAL;
 221                         break;
 222                 }
 223                 pct = &sysoff->ts[0];
 224                 for (i = 0; i < sysoff->n_samples; i++) {
 225                         ktime_get_real_ts64(&ts);
 226                         pct->sec = ts.tv_sec;
 227                         pct->nsec = ts.tv_nsec;
 228                         pct++;
 229                         ptp->info->gettime64(ptp->info, &ts);
 230                         pct->sec = ts.tv_sec;
 231                         pct->nsec = ts.tv_nsec;
 232                         pct++;
 233                 }
 234                 ktime_get_real_ts64(&ts);
 235                 pct->sec = ts.tv_sec;
 236                 pct->nsec = ts.tv_nsec;
 237                 if (copy_to_user((void __user *)arg, sysoff, sizeof(*sysoff)))
 238                         err = -EFAULT;
 239                 break;
 240
 241         case PTP_PIN_GETFUNC:
 242                 if (copy_from_user(&pd, (void __user *)arg, sizeof(pd))) {
 243                         err = -EFAULT;
 244                         break;
 245                 }
 246                 pin_index = pd.index;
 247                 if (pin_index >= ops->n_pins) {
 248                         err = -EINVAL;
 249                         break;
 250                 }
 251                 if (mutex_lock_interruptible(&ptp->pincfg_mux))
 252                         return -ERESTARTSYS;
 253                 pd = ops->pin_config[pin_index];
 254                 mutex_unlock(&ptp->pincfg_mux);
 255                 if (!err && copy_to_user((void __user *)arg, &pd, sizeof(pd)))
 256                         err = -EFAULT;
 257                 break;
 258
 259         case PTP_PIN_SETFUNC:
 260                 if (copy_from_user(&pd, (void __user *)arg, sizeof(pd))) {
 261                         err = -EFAULT;
 262                         break;
 263                 }
 264                 pin_index = pd.index;
 265                 if (pin_index >= ops->n_pins) {
 266                         err = -EINVAL;
 267                         break;
 268                 }
 269                 if (mutex_lock_interruptible(&ptp->pincfg_mux))
 270                         return -ERESTARTSYS;
 271                 err = ptp_set_pinfunc(ptp, pin_index, pd.func, pd.chan);
 272                 mutex_unlock(&ptp->pincfg_mux);
 273                 break;
 274
 275         default:
 276                 err = -ENOTTY;
 277                 break;
 278         }
 279
 280         kfree(sysoff);
 281         return err;
 282 }
 283
 284 __poll_t ptp_poll(struct posix_clock *pc, struct file *fp, poll_table *wait)
 285 {
 286         struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
 287
 288         poll_wait(fp, &ptp->tsev_wq, wait);
 289
 290         return queue_cnt(&ptp->tsevq) ? EPOLLIN : 0;
 291 }
 292
 293 #define EXTTS_BUFSIZE (PTP_BUF_TIMESTAMPS * sizeof(struct ptp_extts_event))
 294
 295 ssize_t ptp_read(struct posix_clock *pc,
 296                  uint rdflags, char __user *buf, size_t cnt)
 297 {
 298         struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
 299         struct timestamp_event_queue *queue = &ptp->tsevq;
 300         struct ptp_extts_event *event;
 301         unsigned long flags;
 302         size_t qcnt, i;
 303         int result;
 304
 305         if (cnt % sizeof(struct ptp_extts_event) != 0)
 306                 return -EINVAL;
 307
 308         if (cnt > EXTTS_BUFSIZE)
 309                 cnt = EXTTS_BUFSIZE;
 310
 311         cnt = cnt / sizeof(struct ptp_extts_event);
 312
 313         if (mutex_lock_interruptible(&ptp->tsevq_mux))
 314                 return -ERESTARTSYS;
 315
 316         if (wait_event_interruptible(ptp->tsev_wq,
 317                                      ptp->defunct || queue_cnt(queue))) {
 318                 mutex_unlock(&ptp->tsevq_mux);
 319                 return -ERESTARTSYS;
 320         }
 321
 322         if (ptp->defunct) {
 323                 mutex_unlock(&ptp->tsevq_mux);
 324                 return -ENODEV;
 325         }
 326
 327         event = kmalloc(EXTTS_BUFSIZE, GFP_KERNEL);
 328         if (!event) {
 329                 mutex_unlock(&ptp->tsevq_mux);
 330                 return -ENOMEM;
 331         }
 332
 333         spin_lock_irqsave(&queue->lock, flags);
 334
 335         qcnt = queue_cnt(queue);
 336
 337         if (cnt > qcnt)
 338                 cnt = qcnt;
 339
 340         for (i = 0; i < cnt; i++) {
 341                 event[i] = queue->buf[queue->head];
 342                 queue->head = (queue->head + 1) % PTP_MAX_TIMESTAMPS;
 343         }
 344
 345         spin_unlock_irqrestore(&queue->lock, flags);
 346
 347         cnt = cnt * sizeof(struct ptp_extts_event);
 348
 349         mutex_unlock(&ptp->tsevq_mux);
 350
 351         result = cnt;
 352         if (copy_to_user(buf, event, cnt))
 353                 result = -EFAULT;
 354
 355         kfree(event);
 356         return result;
 357 }