drivers/media/cec/cec-api.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * cec-api.c - HDMI Consumer Electronics Control framework - API
   4  *
   5  * Copyright 2016 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
   6  */
   7
   8 #include <linux/errno.h>
   9 #include <linux/init.h>
  10 #include <linux/module.h>
  11 #include <linux/kernel.h>
  12 #include <linux/kmod.h>
  13 #include <linux/ktime.h>
  14 #include <linux/slab.h>
  15 #include <linux/mm.h>
  16 #include <linux/string.h>
  17 #include <linux/types.h>
  18 #include <linux/uaccess.h>
  19 #include <linux/version.h>
  20
  21 #include <media/cec-pin.h>
  22 #include "cec-priv.h"
  23 #include "cec-pin-priv.h"
  24
  25 static inline struct cec_devnode *cec_devnode_data(struct file *filp)
  26 {
  27         struct cec_fh *fh = filp->private_data;
  28
  29         return &fh->adap->devnode;
  30 }
  31
  32 /* CEC file operations */
  33
  34 static __poll_t cec_poll(struct file *filp,
  35                              struct poll_table_struct *poll)
  36 {
  37         struct cec_fh *fh = filp->private_data;
  38         struct cec_adapter *adap = fh->adap;
  39         __poll_t res = 0;
  40
  41         if (!cec_is_registered(adap))
  42                 return EPOLLERR | EPOLLHUP;
  43         mutex_lock(&adap->lock);
  44         if (adap->is_configured &&
  45             adap->transmit_queue_sz < CEC_MAX_MSG_TX_QUEUE_SZ)
  46                 res |= EPOLLOUT | EPOLLWRNORM;
  47         if (fh->queued_msgs)
  48                 res |= EPOLLIN | EPOLLRDNORM;
  49         if (fh->total_queued_events)
  50                 res |= EPOLLPRI;
  51         poll_wait(filp, &fh->wait, poll);
  52         mutex_unlock(&adap->lock);
  53         return res;
  54 }
  55
  56 static bool cec_is_busy(const struct cec_adapter *adap,
  57                         const struct cec_fh *fh)
  58 {
  59         bool valid_initiator = adap->cec_initiator && adap->cec_initiator == fh;
  60         bool valid_follower = adap->cec_follower && adap->cec_follower == fh;
  61
  62         /*
  63          * Exclusive initiators and followers can always access the CEC adapter
  64          */
  65         if (valid_initiator || valid_follower)
  66                 return false;
  67         /*
  68          * All others can only access the CEC adapter if there is no
  69          * exclusive initiator and they are in INITIATOR mode.
  70          */
  71         return adap->cec_initiator ||
  72                fh->mode_initiator == CEC_MODE_NO_INITIATOR;
  73 }
  74
  75 static long cec_adap_g_caps(struct cec_adapter *adap,
  76                             struct cec_caps __user *parg)
  77 {
  78         struct cec_caps caps = {};
  79
  80         strlcpy(caps.driver, adap->devnode.dev.parent->driver->name,
  81                 sizeof(caps.driver));
  82         strlcpy(caps.name, adap->name, sizeof(caps.name));
  83         caps.available_log_addrs = adap->available_log_addrs;
  84         caps.capabilities = adap->capabilities;
  85         caps.version = LINUX_VERSION_CODE;
  86         if (copy_to_user(parg, &caps, sizeof(caps)))
  87                 return -EFAULT;
  88         return 0;
  89 }
  90
  91 static long cec_adap_g_phys_addr(struct cec_adapter *adap,
  92                                  __u16 __user *parg)
  93 {
  94         u16 phys_addr;
  95
  96         mutex_lock(&adap->lock);
  97         phys_addr = adap->phys_addr;
  98         mutex_unlock(&adap->lock);
  99         if (copy_to_user(parg, &phys_addr, sizeof(phys_addr)))
 100                 return -EFAULT;
 101         return 0;
 102 }
 103
 104 static long cec_adap_s_phys_addr(struct cec_adapter *adap, struct cec_fh *fh,
 105                                  bool block, __u16 __user *parg)
 106 {
 107         u16 phys_addr;
 108         long err;
 109
 110         if (!(adap->capabilities & CEC_CAP_PHYS_ADDR))
 111                 return -ENOTTY;
 112         if (copy_from_user(&phys_addr, parg, sizeof(phys_addr)))
 113                 return -EFAULT;
 114
 115         err = cec_phys_addr_validate(phys_addr, NULL, NULL);
 116         if (err)
 117                 return err;
 118         mutex_lock(&adap->lock);
 119         if (cec_is_busy(adap, fh))
 120                 err = -EBUSY;
 121         else
 122                 __cec_s_phys_addr(adap, phys_addr, block);
 123         mutex_unlock(&adap->lock);
 124         return err;
 125 }
 126
 127 static long cec_adap_g_log_addrs(struct cec_adapter *adap,
 128                                  struct cec_log_addrs __user *parg)
 129 {
 130         struct cec_log_addrs log_addrs;
 131
 132         mutex_lock(&adap->lock);
 133         log_addrs = adap->log_addrs;
 134         if (!adap->is_configured)
 135                 memset(log_addrs.log_addr, CEC_LOG_ADDR_INVALID,
 136                        sizeof(log_addrs.log_addr));
 137         mutex_unlock(&adap->lock);
 138
 139         if (copy_to_user(parg, &log_addrs, sizeof(log_addrs)))
 140                 return -EFAULT;
 141         return 0;
 142 }
 143
 144 static long cec_adap_s_log_addrs(struct cec_adapter *adap, struct cec_fh *fh,
 145                                  bool block, struct cec_log_addrs __user *parg)
 146 {
 147         struct cec_log_addrs log_addrs;
 148         long err = -EBUSY;
 149
 150         if (!(adap->capabilities & CEC_CAP_LOG_ADDRS))
 151                 return -ENOTTY;
 152         if (copy_from_user(&log_addrs, parg, sizeof(log_addrs)))
 153                 return -EFAULT;
 154         log_addrs.flags &= CEC_LOG_ADDRS_FL_ALLOW_UNREG_FALLBACK |
 155                            CEC_LOG_ADDRS_FL_ALLOW_RC_PASSTHRU |
 156                            CEC_LOG_ADDRS_FL_CDC_ONLY;
 157         mutex_lock(&adap->lock);
 158         if (!adap->is_configuring &&
 159             (!log_addrs.num_log_addrs || !adap->is_configured) &&
 160             !cec_is_busy(adap, fh)) {
 161                 err = __cec_s_log_addrs(adap, &log_addrs, block);
 162                 if (!err)
 163                         log_addrs = adap->log_addrs;
 164         }
 165         mutex_unlock(&adap->lock);
 166         if (err)
 167                 return err;
 168         if (copy_to_user(parg, &log_addrs, sizeof(log_addrs)))
 169                 return -EFAULT;
 170         return 0;
 171 }
 172
 173 static long cec_transmit(struct cec_adapter *adap, struct cec_fh *fh,
 174                          bool block, struct cec_msg __user *parg)
 175 {
 176         struct cec_msg msg = {};
 177         long err = 0;
 178
 179         if (!(adap->capabilities & CEC_CAP_TRANSMIT))
 180                 return -ENOTTY;
 181         if (copy_from_user(&msg, parg, sizeof(msg)))
 182                 return -EFAULT;
 183
 184         /* A CDC-Only device can only send CDC messages */
 185         if ((adap->log_addrs.flags & CEC_LOG_ADDRS_FL_CDC_ONLY) &&
 186             (msg.len == 1 || msg.msg[1] != CEC_MSG_CDC_MESSAGE))
 187                 return -EINVAL;
 188
 189         mutex_lock(&adap->lock);
 190         if (adap->log_addrs.num_log_addrs == 0)
 191                 err = -EPERM;
 192         else if (adap->is_configuring)
 193                 err = -ENONET;
 194         else if (!adap->is_configured &&
 195                  (adap->needs_hpd || msg.msg[0] != 0xf0))
 196                 err = -ENONET;
 197         else if (cec_is_busy(adap, fh))
 198                 err = -EBUSY;
 199         else
 200                 err = cec_transmit_msg_fh(adap, &msg, fh, block);
 201         mutex_unlock(&adap->lock);
 202         if (err)
 203                 return err;
 204         if (copy_to_user(parg, &msg, sizeof(msg)))
 205                 return -EFAULT;
 206         return 0;
 207 }
 208
 209 /* Called by CEC_RECEIVE: wait for a message to arrive */
 210 static int cec_receive_msg(struct cec_fh *fh, struct cec_msg *msg, bool block)
 211 {
 212         u32 timeout = msg->timeout;
 213         int res;
 214
 215         do {
 216                 mutex_lock(&fh->lock);
 217                 /* Are there received messages queued up? */
 218                 if (fh->queued_msgs) {
 219                         /* Yes, return the first one */
 220                         struct cec_msg_entry *entry =
 221                                 list_first_entry(&fh->msgs,
 222                                                  struct cec_msg_entry, list);
 223
 224                         list_del(&entry->list);
 225                         *msg = entry->msg;
 226                         kfree(entry);
 227                         fh->queued_msgs--;
 228                         mutex_unlock(&fh->lock);
 229                         /* restore original timeout value */
 230                         msg->timeout = timeout;
 231                         return 0;
 232                 }
 233
 234                 /* No, return EAGAIN in non-blocking mode or wait */
 235                 mutex_unlock(&fh->lock);
 236
 237                 /* Return when in non-blocking mode */
 238                 if (!block)
 239                         return -EAGAIN;
 240
 241                 if (msg->timeout) {
 242                         /* The user specified a timeout */
 243                         res = wait_event_interruptible_timeout(fh->wait,
 244                                                                fh->queued_msgs,
 245                                 msecs_to_jiffies(msg->timeout));
 246                         if (res == 0)
 247                                 res = -ETIMEDOUT;
 248                         else if (res > 0)
 249                                 res = 0;
 250                 } else {
 251                         /* Wait indefinitely */
 252                         res = wait_event_interruptible(fh->wait,
 253                                                        fh->queued_msgs);
 254                 }
 255                 /* Exit on error, otherwise loop to get the new message */
 256         } while (!res);
 257         return res;
 258 }
 259
 260 static long cec_receive(struct cec_adapter *adap, struct cec_fh *fh,
 261                         bool block, struct cec_msg __user *parg)
 262 {
 263         struct cec_msg msg = {};
 264         long err;
 265
 266         if (copy_from_user(&msg, parg, sizeof(msg)))
 267                 return -EFAULT;
 268
 269         err = cec_receive_msg(fh, &msg, block);
 270         if (err)
 271                 return err;
 272         msg.flags = 0;
 273         if (copy_to_user(parg, &msg, sizeof(msg)))
 274                 return -EFAULT;
 275         return 0;
 276 }
 277
 278 static long cec_dqevent(struct cec_adapter *adap, struct cec_fh *fh,
 279                         bool block, struct cec_event __user *parg)
 280 {
 281         struct cec_event_entry *ev = NULL;
 282         u64 ts = ~0ULL;
 283         unsigned int i;
 284         unsigned int ev_idx;
 285         long err = 0;
 286
 287         mutex_lock(&fh->lock);
 288         while (!fh->total_queued_events && block) {
 289                 mutex_unlock(&fh->lock);
 290                 err = wait_event_interruptible(fh->wait,
 291                                                fh->total_queued_events);
 292                 if (err)
 293                         return err;
 294                 mutex_lock(&fh->lock);
 295         }
 296
 297         /* Find the oldest event */
 298         for (i = 0; i < CEC_NUM_EVENTS; i++) {
 299                 struct cec_event_entry *entry =
 300                         list_first_entry_or_null(&fh->events[i],
 301                                                  struct cec_event_entry, list);
 302
 303                 if (entry && entry->ev.ts <= ts) {
 304                         ev = entry;
 305                         ev_idx = i;
 306                         ts = ev->ev.ts;
 307                 }
 308         }
 309
 310         if (!ev) {
 311                 err = -EAGAIN;
 312                 goto unlock;
 313         }
 314         list_del(&ev->list);
 315
 316         if (copy_to_user(parg, &ev->ev, sizeof(ev->ev)))
 317                 err = -EFAULT;
 318         if (ev_idx >= CEC_NUM_CORE_EVENTS)
 319                 kfree(ev);
 320         fh->queued_events[ev_idx]--;
 321         fh->total_queued_events--;
 322
 323 unlock:
 324         mutex_unlock(&fh->lock);
 325         return err;
 326 }
 327
 328 static long cec_g_mode(struct cec_adapter *adap, struct cec_fh *fh,
 329                        u32 __user *parg)
 330 {
 331         u32 mode = fh->mode_initiator | fh->mode_follower;
 332
 333         if (copy_to_user(parg, &mode, sizeof(mode)))
 334                 return -EFAULT;
 335         return 0;
 336 }
 337
 338 static long cec_s_mode(struct cec_adapter *adap, struct cec_fh *fh,
 339                        u32 __user *parg)
 340 {
 341         u32 mode;
 342         u8 mode_initiator;
 343         u8 mode_follower;
 344         bool send_pin_event = false;
 345         long err = 0;
 346
 347         if (copy_from_user(&mode, parg, sizeof(mode)))
 348                 return -EFAULT;
 349         if (mode & ~(CEC_MODE_INITIATOR_MSK | CEC_MODE_FOLLOWER_MSK)) {
 350                 dprintk(1, "%s: invalid mode bits set\n", __func__);
 351                 return -EINVAL;
 352         }
 353
 354         mode_initiator = mode & CEC_MODE_INITIATOR_MSK;
 355         mode_follower = mode & CEC_MODE_FOLLOWER_MSK;
 356
 357         if (mode_initiator > CEC_MODE_EXCL_INITIATOR ||
 358             mode_follower > CEC_MODE_MONITOR_ALL) {
 359                 dprintk(1, "%s: unknown mode\n", __func__);
 360                 return -EINVAL;
 361         }
 362
 363         if (mode_follower == CEC_MODE_MONITOR_ALL &&
 364             !(adap->capabilities & CEC_CAP_MONITOR_ALL)) {
 365                 dprintk(1, "%s: MONITOR_ALL not supported\n", __func__);
 366                 return -EINVAL;
 367         }
 368
 369         if (mode_follower == CEC_MODE_MONITOR_PIN &&
 370             !(adap->capabilities & CEC_CAP_MONITOR_PIN)) {
 371                 dprintk(1, "%s: MONITOR_PIN not supported\n", __func__);
 372                 return -EINVAL;
 373         }
 374
 375         /* Follower modes should always be able to send CEC messages */
 376         if ((mode_initiator == CEC_MODE_NO_INITIATOR ||
 377              !(adap->capabilities & CEC_CAP_TRANSMIT)) &&
 378             mode_follower >= CEC_MODE_FOLLOWER &&
 379             mode_follower <= CEC_MODE_EXCL_FOLLOWER_PASSTHRU) {
 380                 dprintk(1, "%s: cannot transmit\n", __func__);
 381                 return -EINVAL;
 382         }
 383
 384         /* Monitor modes require CEC_MODE_NO_INITIATOR */
 385         if (mode_initiator && mode_follower >= CEC_MODE_MONITOR_PIN) {
 386                 dprintk(1, "%s: monitor modes require NO_INITIATOR\n",
 387                         __func__);
 388                 return -EINVAL;
 389         }
 390
 391         /* Monitor modes require CAP_NET_ADMIN */
 392         if (mode_follower >= CEC_MODE_MONITOR_PIN && !capable(CAP_NET_ADMIN))
 393                 return -EPERM;
 394
 395         mutex_lock(&adap->lock);
 396         /*
 397          * You can't become exclusive follower if someone else already
 398          * has that job.
 399          */
 400         if ((mode_follower == CEC_MODE_EXCL_FOLLOWER ||
 401              mode_follower == CEC_MODE_EXCL_FOLLOWER_PASSTHRU) &&
 402             adap->cec_follower && adap->cec_follower != fh)
 403                 err = -EBUSY;
 404         /*
 405          * You can't become exclusive initiator if someone else already
 406          * has that job.
 407          */
 408         if (mode_initiator == CEC_MODE_EXCL_INITIATOR &&
 409             adap->cec_initiator && adap->cec_initiator != fh)
 410                 err = -EBUSY;
 411
 412         if (!err) {
 413                 bool old_mon_all = fh->mode_follower == CEC_MODE_MONITOR_ALL;
 414                 bool new_mon_all = mode_follower == CEC_MODE_MONITOR_ALL;
 415
 416                 if (old_mon_all != new_mon_all) {
 417                         if (new_mon_all)
 418                                 err = cec_monitor_all_cnt_inc(adap);
 419                         else
 420                                 cec_monitor_all_cnt_dec(adap);
 421                 }
 422         }
 423
 424         if (!err) {
 425                 bool old_mon_pin = fh->mode_follower == CEC_MODE_MONITOR_PIN;
 426                 bool new_mon_pin = mode_follower == CEC_MODE_MONITOR_PIN;
 427
 428                 if (old_mon_pin != new_mon_pin) {
 429                         send_pin_event = new_mon_pin;
 430                         if (new_mon_pin)
 431                                 err = cec_monitor_pin_cnt_inc(adap);
 432                         else
 433                                 cec_monitor_pin_cnt_dec(adap);
 434                 }
 435         }
 436
 437         if (err) {
 438                 mutex_unlock(&adap->lock);
 439                 return err;
 440         }
 441
 442         if (fh->mode_follower == CEC_MODE_FOLLOWER)
 443                 adap->follower_cnt--;
 444         if (mode_follower == CEC_MODE_FOLLOWER)
 445                 adap->follower_cnt++;
 446         if (send_pin_event) {
 447                 struct cec_event ev = {
 448                         .flags = CEC_EVENT_FL_INITIAL_STATE,
 449                 };
 450
 451                 ev.event = adap->cec_pin_is_high ? CEC_EVENT_PIN_CEC_HIGH :
 452                                                    CEC_EVENT_PIN_CEC_LOW;
 453                 cec_queue_event_fh(fh, &ev, 0);
 454         }
 455         if (mode_follower == CEC_MODE_EXCL_FOLLOWER ||
 456             mode_follower == CEC_MODE_EXCL_FOLLOWER_PASSTHRU) {
 457                 adap->passthrough =
 458                         mode_follower == CEC_MODE_EXCL_FOLLOWER_PASSTHRU;
 459                 adap->cec_follower = fh;
 460         } else if (adap->cec_follower == fh) {
 461                 adap->passthrough = false;
 462                 adap->cec_follower = NULL;
 463         }
 464         if (mode_initiator == CEC_MODE_EXCL_INITIATOR)
 465                 adap->cec_initiator = fh;
 466         else if (adap->cec_initiator == fh)
 467                 adap->cec_initiator = NULL;
 468         fh->mode_initiator = mode_initiator;
 469         fh->mode_follower = mode_follower;
 470         mutex_unlock(&adap->lock);
 471         return 0;
 472 }
 473
 474 static long cec_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 475 {
 476         struct cec_fh *fh = filp->private_data;
 477         struct cec_adapter *adap = fh->adap;
 478         bool block = !(filp->f_flags & O_NONBLOCK);
 479         void __user *parg = (void __user *)arg;
 480
 481         if (!cec_is_registered(adap))
 482                 return -ENODEV;
 483
 484         switch (cmd) {
 485         case CEC_ADAP_G_CAPS:
 486                 return cec_adap_g_caps(adap, parg);
 487
 488         case CEC_ADAP_G_PHYS_ADDR:
 489                 return cec_adap_g_phys_addr(adap, parg);
 490
 491         case CEC_ADAP_S_PHYS_ADDR:
 492                 return cec_adap_s_phys_addr(adap, fh, block, parg);
 493
 494         case CEC_ADAP_G_LOG_ADDRS:
 495                 return cec_adap_g_log_addrs(adap, parg);
 496
 497         case CEC_ADAP_S_LOG_ADDRS:
 498                 return cec_adap_s_log_addrs(adap, fh, block, parg);
 499
 500         case CEC_TRANSMIT:
 501                 return cec_transmit(adap, fh, block, parg);
 502
 503         case CEC_RECEIVE:
 504                 return cec_receive(adap, fh, block, parg);
 505
 506         case CEC_DQEVENT:
 507                 return cec_dqevent(adap, fh, block, parg);
 508
 509         case CEC_G_MODE:
 510                 return cec_g_mode(adap, fh, parg);
 511
 512         case CEC_S_MODE:
 513                 return cec_s_mode(adap, fh, parg);
 514
 515         default:
 516                 return -ENOTTY;
 517         }
 518 }
 519
 520 static int cec_open(struct inode *inode, struct file *filp)
 521 {
 522         struct cec_devnode *devnode =
 523                 container_of(inode->i_cdev, struct cec_devnode, cdev);
 524         struct cec_adapter *adap = to_cec_adapter(devnode);
 525         struct cec_fh *fh = kzalloc(sizeof(*fh), GFP_KERNEL);
 526         /*
 527          * Initial events that are automatically sent when the cec device is
 528          * opened.
 529          */
 530         struct cec_event ev = {
 531                 .event = CEC_EVENT_STATE_CHANGE,
 532                 .flags = CEC_EVENT_FL_INITIAL_STATE,
 533         };
 534         unsigned int i;
 535         int err;
 536
 537         if (!fh)
 538                 return -ENOMEM;
 539
 540         INIT_LIST_HEAD(&fh->msgs);
 541         INIT_LIST_HEAD(&fh->xfer_list);
 542         for (i = 0; i < CEC_NUM_EVENTS; i++)
 543                 INIT_LIST_HEAD(&fh->events[i]);
 544         mutex_init(&fh->lock);
 545         init_waitqueue_head(&fh->wait);
 546
 547         fh->mode_initiator = CEC_MODE_INITIATOR;
 548         fh->adap = adap;
 549
 550         err = cec_get_device(devnode);
 551         if (err) {
 552                 kfree(fh);
 553                 return err;
 554         }
 555
 556         mutex_lock(&devnode->lock);
 557         if (list_empty(&devnode->fhs) &&
 558             !adap->needs_hpd &&
 559             adap->phys_addr == CEC_PHYS_ADDR_INVALID) {
 560                 err = adap->ops->adap_enable(adap, true);
 561                 if (err) {
 562                         mutex_unlock(&devnode->lock);
 563                         kfree(fh);
 564                         return err;
 565                 }
 566         }
 567         filp->private_data = fh;
 568
 569         /* Queue up initial state events */
 570         ev.state_change.phys_addr = adap->phys_addr;
 571         ev.state_change.log_addr_mask = adap->log_addrs.log_addr_mask;
 572         cec_queue_event_fh(fh, &ev, 0);
 573 #ifdef CONFIG_CEC_PIN
 574         if (adap->pin && adap->pin->ops->read_hpd) {
 575                 err = adap->pin->ops->read_hpd(adap);
 576                 if (err >= 0) {
 577                         ev.event = err ? CEC_EVENT_PIN_HPD_HIGH :
 578                                          CEC_EVENT_PIN_HPD_LOW;
 579                         cec_queue_event_fh(fh, &ev, 0);
 580                 }
 581         }
 582 #endif
 583
 584         list_add(&fh->list, &devnode->fhs);
 585         mutex_unlock(&devnode->lock);
 586
 587         return 0;
 588 }
 589
 590 /* Override for the release function */
 591 static int cec_release(struct inode *inode, struct file *filp)
 592 {
 593         struct cec_devnode *devnode = cec_devnode_data(filp);
 594         struct cec_adapter *adap = to_cec_adapter(devnode);
 595         struct cec_fh *fh = filp->private_data;
 596         unsigned int i;
 597
 598         mutex_lock(&adap->lock);
 599         if (adap->cec_initiator == fh)
 600                 adap->cec_initiator = NULL;
 601         if (adap->cec_follower == fh) {
 602                 adap->cec_follower = NULL;
 603                 adap->passthrough = false;
 604         }
 605         if (fh->mode_follower == CEC_MODE_FOLLOWER)
 606                 adap->follower_cnt--;
 607         if (fh->mode_follower == CEC_MODE_MONITOR_PIN)
 608                 cec_monitor_pin_cnt_dec(adap);
 609         if (fh->mode_follower == CEC_MODE_MONITOR_ALL)
 610                 cec_monitor_all_cnt_dec(adap);
 611         mutex_unlock(&adap->lock);
 612
 613         mutex_lock(&devnode->lock);
 614         list_del(&fh->list);
 615         if (cec_is_registered(adap) && list_empty(&devnode->fhs) &&
 616             !adap->needs_hpd && adap->phys_addr == CEC_PHYS_ADDR_INVALID) {
 617                 WARN_ON(adap->ops->adap_enable(adap, false));
 618         }
 619         mutex_unlock(&devnode->lock);
 620
 621         /* Unhook pending transmits from this filehandle. */
 622         mutex_lock(&adap->lock);
 623         while (!list_empty(&fh->xfer_list)) {
 624                 struct cec_data *data =
 625                         list_first_entry(&fh->xfer_list, struct cec_data, xfer_list);
 626
 627                 data->blocking = false;
 628                 data->fh = NULL;
 629                 list_del(&data->xfer_list);
 630         }
 631         mutex_unlock(&adap->lock);
 632         while (!list_empty(&fh->msgs)) {
 633                 struct cec_msg_entry *entry =
 634                         list_first_entry(&fh->msgs, struct cec_msg_entry, list);
 635
 636                 list_del(&entry->list);
 637                 kfree(entry);
 638         }
 639         for (i = CEC_NUM_CORE_EVENTS; i < CEC_NUM_EVENTS; i++) {
 640                 while (!list_empty(&fh->events[i])) {
 641                         struct cec_event_entry *entry =
 642                                 list_first_entry(&fh->events[i],
 643                                                  struct cec_event_entry, list);
 644
 645                         list_del(&entry->list);
 646                         kfree(entry);
 647                 }
 648         }
 649         kfree(fh);
 650
 651         cec_put_device(devnode);
 652         filp->private_data = NULL;
 653         return 0;
 654 }
 655
 656 const struct file_operations cec_devnode_fops = {
 657         .owner = THIS_MODULE,
 658         .open = cec_open,
 659         .unlocked_ioctl = cec_ioctl,
 660         .release = cec_release,
 661         .poll = cec_poll,
 662         .llseek = no_llseek,
 663 };