linux/drivers/ptp/ptp_chardev.c
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   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
  28static 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
  58int 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
 113int ptp_open(struct posix_clock *pc, fmode_t fmode)
 114{
 115        return 0;
 116}
 117
 118long 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
 259unsigned 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
 270ssize_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}
 333