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         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_sys_offset_precise precise_offset;
 125         struct ptp_pin_desc pd;
 126         struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
 127         struct ptp_clock_info *ops = ptp->info;
 128         struct ptp_clock_time *pct;
 129         struct timespec64 ts;
 130         struct system_device_crosststamp xtstamp;
 131         int enable, err = 0;
 132         unsigned int i, pin_index;
 133
 134         switch (cmd) {
 135
 136         case PTP_CLOCK_GETCAPS:
 137                 memset(&caps, 0, sizeof(caps));
 138                 caps.max_adj = ptp->info->max_adj;
 139                 caps.n_alarm = ptp->info->n_alarm;
 140                 caps.n_ext_ts = ptp->info->n_ext_ts;
 141                 caps.n_per_out = ptp->info->n_per_out;
 142                 caps.pps = ptp->info->pps;
 143                 caps.n_pins = ptp->info->n_pins;
 144                 caps.cross_timestamping = ptp->info->getcrosststamp != NULL;
 145                 if (copy_to_user((void __user *)arg, &caps, sizeof(caps)))
 146                         err = -EFAULT;
 147                 break;
 148
 149         case PTP_EXTTS_REQUEST:
 150                 if (copy_from_user(&req.extts, (void __user *)arg,
 151                                    sizeof(req.extts))) {
 152                         err = -EFAULT;
 153                         break;
 154                 }
 155                 if (req.extts.index >= ops->n_ext_ts) {
 156                         err = -EINVAL;
 157                         break;
 158                 }
 159                 req.type = PTP_CLK_REQ_EXTTS;
 160                 enable = req.extts.flags & PTP_ENABLE_FEATURE ? 1 : 0;
 161                 err = ops->enable(ops, &req, enable);
 162                 break;
 163
 164         case PTP_PEROUT_REQUEST:
 165                 if (copy_from_user(&req.perout, (void __user *)arg,
 166                                    sizeof(req.perout))) {
 167                         err = -EFAULT;
 168                         break;
 169                 }
 170                 if (req.perout.index >= ops->n_per_out) {
 171                         err = -EINVAL;
 172                         break;
 173                 }
 174                 req.type = PTP_CLK_REQ_PEROUT;
 175                 enable = req.perout.period.sec || req.perout.period.nsec;
 176                 err = ops->enable(ops, &req, enable);
 177                 break;
 178
 179         case PTP_ENABLE_PPS:
 180                 if (!capable(CAP_SYS_TIME))
 181                         return -EPERM;
 182                 req.type = PTP_CLK_REQ_PPS;
 183                 enable = arg ? 1 : 0;
 184                 err = ops->enable(ops, &req, enable);
 185                 break;
 186
 187         case PTP_SYS_OFFSET_PRECISE:
 188                 if (!ptp->info->getcrosststamp) {
 189                         err = -EOPNOTSUPP;
 190                         break;
 191                 }
 192                 err = ptp->info->getcrosststamp(ptp->info, &xtstamp);
 193                 if (err)
 194                         break;
 195
 196                 memset(&precise_offset, 0, sizeof(precise_offset));
 197                 ts = ktime_to_timespec64(xtstamp.device);
 198                 precise_offset.device.sec = ts.tv_sec;
 199                 precise_offset.device.nsec = ts.tv_nsec;
 200                 ts = ktime_to_timespec64(xtstamp.sys_realtime);
 201                 precise_offset.sys_realtime.sec = ts.tv_sec;
 202                 precise_offset.sys_realtime.nsec = ts.tv_nsec;
 203                 ts = ktime_to_timespec64(xtstamp.sys_monoraw);
 204                 precise_offset.sys_monoraw.sec = ts.tv_sec;
 205                 precise_offset.sys_monoraw.nsec = ts.tv_nsec;
 206                 if (copy_to_user((void __user *)arg, &precise_offset,
 207                                  sizeof(precise_offset)))
 208                         err = -EFAULT;
 209                 break;
 210
 211         case PTP_SYS_OFFSET:
 212                 sysoff = memdup_user((void __user *)arg, sizeof(*sysoff));
 213                 if (IS_ERR(sysoff)) {
 214                         err = PTR_ERR(sysoff);
 215                         sysoff = NULL;
 216                         break;
 217                 }
 218                 if (sysoff->n_samples > PTP_MAX_SAMPLES) {
 219                         err = -EINVAL;
 220                         break;
 221                 }
 222                 pct = &sysoff->ts[0];
 223                 for (i = 0; i < sysoff->n_samples; i++) {
 224                         ktime_get_real_ts64(&ts);
 225                         pct->sec = ts.tv_sec;
 226                         pct->nsec = ts.tv_nsec;
 227                         pct++;
 228                         ptp->info->gettime64(ptp->info, &ts);
 229                         pct->sec = ts.tv_sec;
 230                         pct->nsec = ts.tv_nsec;
 231                         pct++;
 232                 }
 233                 ktime_get_real_ts64(&ts);
 234                 pct->sec = ts.tv_sec;
 235                 pct->nsec = ts.tv_nsec;
 236                 if (copy_to_user((void __user *)arg, sysoff, sizeof(*sysoff)))
 237                         err = -EFAULT;
 238                 break;
 239
 240         case PTP_PIN_GETFUNC:
 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                 pd = ops->pin_config[pin_index];
 253                 mutex_unlock(&ptp->pincfg_mux);
 254                 if (!err && copy_to_user((void __user *)arg, &pd, sizeof(pd)))
 255                         err = -EFAULT;
 256                 break;
 257
 258         case PTP_PIN_SETFUNC:
 259                 if (copy_from_user(&pd, (void __user *)arg, sizeof(pd))) {
 260                         err = -EFAULT;
 261                         break;
 262                 }
 263                 pin_index = pd.index;
 264                 if (pin_index >= ops->n_pins) {
 265                         err = -EINVAL;
 266                         break;
 267                 }
 268                 if (mutex_lock_interruptible(&ptp->pincfg_mux))
 269                         return -ERESTARTSYS;
 270                 err = ptp_set_pinfunc(ptp, pin_index, pd.func, pd.chan);
 271                 mutex_unlock(&ptp->pincfg_mux);
 272                 break;
 273
 274         default:
 275                 err = -ENOTTY;
 276                 break;
 277         }
 278
 279         kfree(sysoff);
 280         return err;
 281 }
 282
 283 __poll_t ptp_poll(struct posix_clock *pc, struct file *fp, poll_table *wait)
 284 {
 285         struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
 286
 287         poll_wait(fp, &ptp->tsev_wq, wait);
 288
 289         return queue_cnt(&ptp->tsevq) ? EPOLLIN : 0;
 290 }
 291
 292 #define EXTTS_BUFSIZE (PTP_BUF_TIMESTAMPS * sizeof(struct ptp_extts_event))
 293
 294 ssize_t ptp_read(struct posix_clock *pc,
 295                  uint rdflags, char __user *buf, size_t cnt)
 296 {
 297         struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
 298         struct timestamp_event_queue *queue = &ptp->tsevq;
 299         struct ptp_extts_event *event;
 300         unsigned long flags;
 301         size_t qcnt, i;
 302         int result;
 303
 304         if (cnt % sizeof(struct ptp_extts_event) != 0)
 305                 return -EINVAL;
 306
 307         if (cnt > EXTTS_BUFSIZE)
 308                 cnt = EXTTS_BUFSIZE;
 309
 310         cnt = cnt / sizeof(struct ptp_extts_event);
 311
 312         if (mutex_lock_interruptible(&ptp->tsevq_mux))
 313                 return -ERESTARTSYS;
 314
 315         if (wait_event_interruptible(ptp->tsev_wq,
 316                                      ptp->defunct || queue_cnt(queue))) {
 317                 mutex_unlock(&ptp->tsevq_mux);
 318                 return -ERESTARTSYS;
 319         }
 320
 321         if (ptp->defunct) {
 322                 mutex_unlock(&ptp->tsevq_mux);
 323                 return -ENODEV;
 324         }
 325
 326         event = kmalloc(EXTTS_BUFSIZE, GFP_KERNEL);
 327         if (!event) {
 328                 mutex_unlock(&ptp->tsevq_mux);
 329                 return -ENOMEM;
 330         }
 331
 332         spin_lock_irqsave(&queue->lock, flags);
 333
 334         qcnt = queue_cnt(queue);
 335
 336         if (cnt > qcnt)
 337                 cnt = qcnt;
 338
 339         for (i = 0; i < cnt; i++) {
 340                 event[i] = queue->buf[queue->head];
 341                 queue->head = (queue->head + 1) % PTP_MAX_TIMESTAMPS;
 342         }
 343
 344         spin_unlock_irqrestore(&queue->lock, flags);
 345
 346         cnt = cnt * sizeof(struct ptp_extts_event);
 347
 348         mutex_unlock(&ptp->tsevq_mux);
 349
 350         result = cnt;
 351         if (copy_to_user(buf, event, cnt))
 352                 result = -EFAULT;
 353
 354         kfree(event);
 355         return result;
 356 }