xref: /linux/drivers/media/cec/core/cec-api.c (revision e5a52fd2b8cdb700b3c07b030e050a49ef3156b9)
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 	poll_wait(filp, &fh->wait, poll);
42 	if (!cec_is_registered(adap))
43 		return EPOLLERR | EPOLLHUP;
44 	mutex_lock(&adap->lock);
45 	if (adap->is_configured &&
46 	    adap->transmit_queue_sz < CEC_MAX_MSG_TX_QUEUE_SZ)
47 		res |= EPOLLOUT | EPOLLWRNORM;
48 	if (fh->queued_msgs)
49 		res |= EPOLLIN | EPOLLRDNORM;
50 	if (fh->total_queued_events)
51 		res |= EPOLLPRI;
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 	strscpy(caps.driver, adap->devnode.dev.parent->driver->name,
81 		sizeof(caps.driver));
82 	strscpy(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 int cec_validate_phys_addr(u16 phys_addr)
105 {
106 	int i;
107 
108 	if (phys_addr == CEC_PHYS_ADDR_INVALID)
109 		return 0;
110 	for (i = 0; i < 16; i += 4)
111 		if (phys_addr & (0xf << i))
112 			break;
113 	if (i == 16)
114 		return 0;
115 	for (i += 4; i < 16; i += 4)
116 		if ((phys_addr & (0xf << i)) == 0)
117 			return -EINVAL;
118 	return 0;
119 }
120 
121 static long cec_adap_s_phys_addr(struct cec_adapter *adap, struct cec_fh *fh,
122 				 bool block, __u16 __user *parg)
123 {
124 	u16 phys_addr;
125 	long err;
126 
127 	if (!(adap->capabilities & CEC_CAP_PHYS_ADDR))
128 		return -ENOTTY;
129 	if (copy_from_user(&phys_addr, parg, sizeof(phys_addr)))
130 		return -EFAULT;
131 
132 	err = cec_validate_phys_addr(phys_addr);
133 	if (err)
134 		return err;
135 	mutex_lock(&adap->lock);
136 	if (cec_is_busy(adap, fh))
137 		err = -EBUSY;
138 	else
139 		__cec_s_phys_addr(adap, phys_addr, block);
140 	mutex_unlock(&adap->lock);
141 	return err;
142 }
143 
144 static long cec_adap_g_log_addrs(struct cec_adapter *adap,
145 				 struct cec_log_addrs __user *parg)
146 {
147 	struct cec_log_addrs log_addrs;
148 
149 	mutex_lock(&adap->lock);
150 	log_addrs = adap->log_addrs;
151 	if (!adap->is_configured)
152 		memset(log_addrs.log_addr, CEC_LOG_ADDR_INVALID,
153 		       sizeof(log_addrs.log_addr));
154 	mutex_unlock(&adap->lock);
155 
156 	if (copy_to_user(parg, &log_addrs, sizeof(log_addrs)))
157 		return -EFAULT;
158 	return 0;
159 }
160 
161 static long cec_adap_s_log_addrs(struct cec_adapter *adap, struct cec_fh *fh,
162 				 bool block, struct cec_log_addrs __user *parg)
163 {
164 	struct cec_log_addrs log_addrs;
165 	long err = -EBUSY;
166 
167 	if (!(adap->capabilities & CEC_CAP_LOG_ADDRS))
168 		return -ENOTTY;
169 	if (copy_from_user(&log_addrs, parg, sizeof(log_addrs)))
170 		return -EFAULT;
171 	log_addrs.flags &= CEC_LOG_ADDRS_FL_ALLOW_UNREG_FALLBACK |
172 			   CEC_LOG_ADDRS_FL_ALLOW_RC_PASSTHRU |
173 			   CEC_LOG_ADDRS_FL_CDC_ONLY;
174 	mutex_lock(&adap->lock);
175 	if (!adap->is_configuring &&
176 	    (!log_addrs.num_log_addrs || !adap->is_configured) &&
177 	    !cec_is_busy(adap, fh)) {
178 		err = __cec_s_log_addrs(adap, &log_addrs, block);
179 		if (!err)
180 			log_addrs = adap->log_addrs;
181 	}
182 	mutex_unlock(&adap->lock);
183 	if (err)
184 		return err;
185 	if (copy_to_user(parg, &log_addrs, sizeof(log_addrs)))
186 		return -EFAULT;
187 	return 0;
188 }
189 
190 static long cec_adap_g_connector_info(struct cec_adapter *adap,
191 				      struct cec_log_addrs __user *parg)
192 {
193 	int ret = 0;
194 
195 	if (!(adap->capabilities & CEC_CAP_CONNECTOR_INFO))
196 		return -ENOTTY;
197 
198 	mutex_lock(&adap->lock);
199 	if (copy_to_user(parg, &adap->conn_info, sizeof(adap->conn_info)))
200 		ret = -EFAULT;
201 	mutex_unlock(&adap->lock);
202 	return ret;
203 }
204 
205 static long cec_transmit(struct cec_adapter *adap, struct cec_fh *fh,
206 			 bool block, struct cec_msg __user *parg)
207 {
208 	struct cec_msg msg = {};
209 	long err = 0;
210 
211 	if (!(adap->capabilities & CEC_CAP_TRANSMIT))
212 		return -ENOTTY;
213 	if (copy_from_user(&msg, parg, sizeof(msg)))
214 		return -EFAULT;
215 
216 	mutex_lock(&adap->lock);
217 	if (adap->log_addrs.num_log_addrs == 0)
218 		err = -EPERM;
219 	else if (adap->is_configuring)
220 		err = -ENONET;
221 	else if (cec_is_busy(adap, fh))
222 		err = -EBUSY;
223 	else
224 		err = cec_transmit_msg_fh(adap, &msg, fh, block);
225 	mutex_unlock(&adap->lock);
226 	if (err)
227 		return err;
228 	if (copy_to_user(parg, &msg, sizeof(msg)))
229 		return -EFAULT;
230 	return 0;
231 }
232 
233 /* Called by CEC_RECEIVE: wait for a message to arrive */
234 static int cec_receive_msg(struct cec_fh *fh, struct cec_msg *msg, bool block)
235 {
236 	u32 timeout = msg->timeout;
237 	int res;
238 
239 	do {
240 		mutex_lock(&fh->lock);
241 		/* Are there received messages queued up? */
242 		if (fh->queued_msgs) {
243 			/* Yes, return the first one */
244 			struct cec_msg_entry *entry =
245 				list_first_entry(&fh->msgs,
246 						 struct cec_msg_entry, list);
247 
248 			list_del(&entry->list);
249 			*msg = entry->msg;
250 			kfree(entry);
251 			fh->queued_msgs--;
252 			mutex_unlock(&fh->lock);
253 			/* restore original timeout value */
254 			msg->timeout = timeout;
255 			return 0;
256 		}
257 
258 		/* No, return EAGAIN in non-blocking mode or wait */
259 		mutex_unlock(&fh->lock);
260 
261 		/* Return when in non-blocking mode */
262 		if (!block)
263 			return -EAGAIN;
264 
265 		if (msg->timeout) {
266 			/* The user specified a timeout */
267 			res = wait_event_interruptible_timeout(fh->wait,
268 							       fh->queued_msgs,
269 				msecs_to_jiffies(msg->timeout));
270 			if (res == 0)
271 				res = -ETIMEDOUT;
272 			else if (res > 0)
273 				res = 0;
274 		} else {
275 			/* Wait indefinitely */
276 			res = wait_event_interruptible(fh->wait,
277 						       fh->queued_msgs);
278 		}
279 		/* Exit on error, otherwise loop to get the new message */
280 	} while (!res);
281 	return res;
282 }
283 
284 static long cec_receive(struct cec_adapter *adap, struct cec_fh *fh,
285 			bool block, struct cec_msg __user *parg)
286 {
287 	struct cec_msg msg = {};
288 	long err;
289 
290 	if (copy_from_user(&msg, parg, sizeof(msg)))
291 		return -EFAULT;
292 
293 	err = cec_receive_msg(fh, &msg, block);
294 	if (err)
295 		return err;
296 	msg.flags = 0;
297 	if (copy_to_user(parg, &msg, sizeof(msg)))
298 		return -EFAULT;
299 	return 0;
300 }
301 
302 static long cec_dqevent(struct cec_adapter *adap, struct cec_fh *fh,
303 			bool block, struct cec_event __user *parg)
304 {
305 	struct cec_event_entry *ev = NULL;
306 	u64 ts = ~0ULL;
307 	unsigned int i;
308 	unsigned int ev_idx;
309 	long err = 0;
310 
311 	mutex_lock(&fh->lock);
312 	while (!fh->total_queued_events && block) {
313 		mutex_unlock(&fh->lock);
314 		err = wait_event_interruptible(fh->wait,
315 					       fh->total_queued_events);
316 		if (err)
317 			return err;
318 		mutex_lock(&fh->lock);
319 	}
320 
321 	/* Find the oldest event */
322 	for (i = 0; i < CEC_NUM_EVENTS; i++) {
323 		struct cec_event_entry *entry =
324 			list_first_entry_or_null(&fh->events[i],
325 						 struct cec_event_entry, list);
326 
327 		if (entry && entry->ev.ts <= ts) {
328 			ev = entry;
329 			ev_idx = i;
330 			ts = ev->ev.ts;
331 		}
332 	}
333 
334 	if (!ev) {
335 		err = -EAGAIN;
336 		goto unlock;
337 	}
338 	list_del(&ev->list);
339 
340 	if (copy_to_user(parg, &ev->ev, sizeof(ev->ev)))
341 		err = -EFAULT;
342 	if (ev_idx >= CEC_NUM_CORE_EVENTS)
343 		kfree(ev);
344 	fh->queued_events[ev_idx]--;
345 	fh->total_queued_events--;
346 
347 unlock:
348 	mutex_unlock(&fh->lock);
349 	return err;
350 }
351 
352 static long cec_g_mode(struct cec_adapter *adap, struct cec_fh *fh,
353 		       u32 __user *parg)
354 {
355 	u32 mode = fh->mode_initiator | fh->mode_follower;
356 
357 	if (copy_to_user(parg, &mode, sizeof(mode)))
358 		return -EFAULT;
359 	return 0;
360 }
361 
362 static long cec_s_mode(struct cec_adapter *adap, struct cec_fh *fh,
363 		       u32 __user *parg)
364 {
365 	u32 mode;
366 	u8 mode_initiator;
367 	u8 mode_follower;
368 	bool send_pin_event = false;
369 	long err = 0;
370 
371 	if (copy_from_user(&mode, parg, sizeof(mode)))
372 		return -EFAULT;
373 	if (mode & ~(CEC_MODE_INITIATOR_MSK | CEC_MODE_FOLLOWER_MSK)) {
374 		dprintk(1, "%s: invalid mode bits set\n", __func__);
375 		return -EINVAL;
376 	}
377 
378 	mode_initiator = mode & CEC_MODE_INITIATOR_MSK;
379 	mode_follower = mode & CEC_MODE_FOLLOWER_MSK;
380 
381 	if (mode_initiator > CEC_MODE_EXCL_INITIATOR ||
382 	    mode_follower > CEC_MODE_MONITOR_ALL) {
383 		dprintk(1, "%s: unknown mode\n", __func__);
384 		return -EINVAL;
385 	}
386 
387 	if (mode_follower == CEC_MODE_MONITOR_ALL &&
388 	    !(adap->capabilities & CEC_CAP_MONITOR_ALL)) {
389 		dprintk(1, "%s: MONITOR_ALL not supported\n", __func__);
390 		return -EINVAL;
391 	}
392 
393 	if (mode_follower == CEC_MODE_MONITOR_PIN &&
394 	    !(adap->capabilities & CEC_CAP_MONITOR_PIN)) {
395 		dprintk(1, "%s: MONITOR_PIN not supported\n", __func__);
396 		return -EINVAL;
397 	}
398 
399 	/* Follower modes should always be able to send CEC messages */
400 	if ((mode_initiator == CEC_MODE_NO_INITIATOR ||
401 	     !(adap->capabilities & CEC_CAP_TRANSMIT)) &&
402 	    mode_follower >= CEC_MODE_FOLLOWER &&
403 	    mode_follower <= CEC_MODE_EXCL_FOLLOWER_PASSTHRU) {
404 		dprintk(1, "%s: cannot transmit\n", __func__);
405 		return -EINVAL;
406 	}
407 
408 	/* Monitor modes require CEC_MODE_NO_INITIATOR */
409 	if (mode_initiator && mode_follower >= CEC_MODE_MONITOR_PIN) {
410 		dprintk(1, "%s: monitor modes require NO_INITIATOR\n",
411 			__func__);
412 		return -EINVAL;
413 	}
414 
415 	/* Monitor modes require CAP_NET_ADMIN */
416 	if (mode_follower >= CEC_MODE_MONITOR_PIN && !capable(CAP_NET_ADMIN))
417 		return -EPERM;
418 
419 	mutex_lock(&adap->lock);
420 	/*
421 	 * You can't become exclusive follower if someone else already
422 	 * has that job.
423 	 */
424 	if ((mode_follower == CEC_MODE_EXCL_FOLLOWER ||
425 	     mode_follower == CEC_MODE_EXCL_FOLLOWER_PASSTHRU) &&
426 	    adap->cec_follower && adap->cec_follower != fh)
427 		err = -EBUSY;
428 	/*
429 	 * You can't become exclusive initiator if someone else already
430 	 * has that job.
431 	 */
432 	if (mode_initiator == CEC_MODE_EXCL_INITIATOR &&
433 	    adap->cec_initiator && adap->cec_initiator != fh)
434 		err = -EBUSY;
435 
436 	if (!err) {
437 		bool old_mon_all = fh->mode_follower == CEC_MODE_MONITOR_ALL;
438 		bool new_mon_all = mode_follower == CEC_MODE_MONITOR_ALL;
439 
440 		if (old_mon_all != new_mon_all) {
441 			if (new_mon_all)
442 				err = cec_monitor_all_cnt_inc(adap);
443 			else
444 				cec_monitor_all_cnt_dec(adap);
445 		}
446 	}
447 
448 	if (!err) {
449 		bool old_mon_pin = fh->mode_follower == CEC_MODE_MONITOR_PIN;
450 		bool new_mon_pin = mode_follower == CEC_MODE_MONITOR_PIN;
451 
452 		if (old_mon_pin != new_mon_pin) {
453 			send_pin_event = new_mon_pin;
454 			if (new_mon_pin)
455 				err = cec_monitor_pin_cnt_inc(adap);
456 			else
457 				cec_monitor_pin_cnt_dec(adap);
458 		}
459 	}
460 
461 	if (err) {
462 		mutex_unlock(&adap->lock);
463 		return err;
464 	}
465 
466 	if (fh->mode_follower == CEC_MODE_FOLLOWER)
467 		adap->follower_cnt--;
468 	if (mode_follower == CEC_MODE_FOLLOWER)
469 		adap->follower_cnt++;
470 	if (send_pin_event) {
471 		struct cec_event ev = {
472 			.flags = CEC_EVENT_FL_INITIAL_STATE,
473 		};
474 
475 		ev.event = adap->cec_pin_is_high ? CEC_EVENT_PIN_CEC_HIGH :
476 						   CEC_EVENT_PIN_CEC_LOW;
477 		cec_queue_event_fh(fh, &ev, 0);
478 	}
479 	if (mode_follower == CEC_MODE_EXCL_FOLLOWER ||
480 	    mode_follower == CEC_MODE_EXCL_FOLLOWER_PASSTHRU) {
481 		adap->passthrough =
482 			mode_follower == CEC_MODE_EXCL_FOLLOWER_PASSTHRU;
483 		adap->cec_follower = fh;
484 	} else if (adap->cec_follower == fh) {
485 		adap->passthrough = false;
486 		adap->cec_follower = NULL;
487 	}
488 	if (mode_initiator == CEC_MODE_EXCL_INITIATOR)
489 		adap->cec_initiator = fh;
490 	else if (adap->cec_initiator == fh)
491 		adap->cec_initiator = NULL;
492 	fh->mode_initiator = mode_initiator;
493 	fh->mode_follower = mode_follower;
494 	mutex_unlock(&adap->lock);
495 	return 0;
496 }
497 
498 static long cec_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
499 {
500 	struct cec_fh *fh = filp->private_data;
501 	struct cec_adapter *adap = fh->adap;
502 	bool block = !(filp->f_flags & O_NONBLOCK);
503 	void __user *parg = (void __user *)arg;
504 
505 	if (!cec_is_registered(adap))
506 		return -ENODEV;
507 
508 	switch (cmd) {
509 	case CEC_ADAP_G_CAPS:
510 		return cec_adap_g_caps(adap, parg);
511 
512 	case CEC_ADAP_G_PHYS_ADDR:
513 		return cec_adap_g_phys_addr(adap, parg);
514 
515 	case CEC_ADAP_S_PHYS_ADDR:
516 		return cec_adap_s_phys_addr(adap, fh, block, parg);
517 
518 	case CEC_ADAP_G_LOG_ADDRS:
519 		return cec_adap_g_log_addrs(adap, parg);
520 
521 	case CEC_ADAP_S_LOG_ADDRS:
522 		return cec_adap_s_log_addrs(adap, fh, block, parg);
523 
524 	case CEC_ADAP_G_CONNECTOR_INFO:
525 		return cec_adap_g_connector_info(adap, parg);
526 
527 	case CEC_TRANSMIT:
528 		return cec_transmit(adap, fh, block, parg);
529 
530 	case CEC_RECEIVE:
531 		return cec_receive(adap, fh, block, parg);
532 
533 	case CEC_DQEVENT:
534 		return cec_dqevent(adap, fh, block, parg);
535 
536 	case CEC_G_MODE:
537 		return cec_g_mode(adap, fh, parg);
538 
539 	case CEC_S_MODE:
540 		return cec_s_mode(adap, fh, parg);
541 
542 	default:
543 		return -ENOTTY;
544 	}
545 }
546 
547 static int cec_open(struct inode *inode, struct file *filp)
548 {
549 	struct cec_devnode *devnode =
550 		container_of(inode->i_cdev, struct cec_devnode, cdev);
551 	struct cec_adapter *adap = to_cec_adapter(devnode);
552 	struct cec_fh *fh = kzalloc(sizeof(*fh), GFP_KERNEL);
553 	/*
554 	 * Initial events that are automatically sent when the cec device is
555 	 * opened.
556 	 */
557 	struct cec_event ev = {
558 		.event = CEC_EVENT_STATE_CHANGE,
559 		.flags = CEC_EVENT_FL_INITIAL_STATE,
560 	};
561 	unsigned int i;
562 	int err;
563 
564 	if (!fh)
565 		return -ENOMEM;
566 
567 	INIT_LIST_HEAD(&fh->msgs);
568 	INIT_LIST_HEAD(&fh->xfer_list);
569 	for (i = 0; i < CEC_NUM_EVENTS; i++)
570 		INIT_LIST_HEAD(&fh->events[i]);
571 	mutex_init(&fh->lock);
572 	init_waitqueue_head(&fh->wait);
573 
574 	fh->mode_initiator = CEC_MODE_INITIATOR;
575 	fh->adap = adap;
576 
577 	err = cec_get_device(devnode);
578 	if (err) {
579 		kfree(fh);
580 		return err;
581 	}
582 
583 	mutex_lock(&devnode->lock);
584 	if (list_empty(&devnode->fhs) &&
585 	    !adap->needs_hpd &&
586 	    adap->phys_addr == CEC_PHYS_ADDR_INVALID) {
587 		err = adap->ops->adap_enable(adap, true);
588 		if (err) {
589 			mutex_unlock(&devnode->lock);
590 			kfree(fh);
591 			return err;
592 		}
593 	}
594 	filp->private_data = fh;
595 
596 	/* Queue up initial state events */
597 	ev.state_change.phys_addr = adap->phys_addr;
598 	ev.state_change.log_addr_mask = adap->log_addrs.log_addr_mask;
599 	ev.state_change.have_conn_info =
600 		adap->conn_info.type != CEC_CONNECTOR_TYPE_NO_CONNECTOR;
601 	cec_queue_event_fh(fh, &ev, 0);
602 #ifdef CONFIG_CEC_PIN
603 	if (adap->pin && adap->pin->ops->read_hpd) {
604 		err = adap->pin->ops->read_hpd(adap);
605 		if (err >= 0) {
606 			ev.event = err ? CEC_EVENT_PIN_HPD_HIGH :
607 					 CEC_EVENT_PIN_HPD_LOW;
608 			cec_queue_event_fh(fh, &ev, 0);
609 		}
610 	}
611 	if (adap->pin && adap->pin->ops->read_5v) {
612 		err = adap->pin->ops->read_5v(adap);
613 		if (err >= 0) {
614 			ev.event = err ? CEC_EVENT_PIN_5V_HIGH :
615 					 CEC_EVENT_PIN_5V_LOW;
616 			cec_queue_event_fh(fh, &ev, 0);
617 		}
618 	}
619 #endif
620 
621 	list_add(&fh->list, &devnode->fhs);
622 	mutex_unlock(&devnode->lock);
623 
624 	return 0;
625 }
626 
627 /* Override for the release function */
628 static int cec_release(struct inode *inode, struct file *filp)
629 {
630 	struct cec_devnode *devnode = cec_devnode_data(filp);
631 	struct cec_adapter *adap = to_cec_adapter(devnode);
632 	struct cec_fh *fh = filp->private_data;
633 	unsigned int i;
634 
635 	mutex_lock(&adap->lock);
636 	if (adap->cec_initiator == fh)
637 		adap->cec_initiator = NULL;
638 	if (adap->cec_follower == fh) {
639 		adap->cec_follower = NULL;
640 		adap->passthrough = false;
641 	}
642 	if (fh->mode_follower == CEC_MODE_FOLLOWER)
643 		adap->follower_cnt--;
644 	if (fh->mode_follower == CEC_MODE_MONITOR_PIN)
645 		cec_monitor_pin_cnt_dec(adap);
646 	if (fh->mode_follower == CEC_MODE_MONITOR_ALL)
647 		cec_monitor_all_cnt_dec(adap);
648 	mutex_unlock(&adap->lock);
649 
650 	mutex_lock(&devnode->lock);
651 	list_del(&fh->list);
652 	if (cec_is_registered(adap) && list_empty(&devnode->fhs) &&
653 	    !adap->needs_hpd && adap->phys_addr == CEC_PHYS_ADDR_INVALID) {
654 		WARN_ON(adap->ops->adap_enable(adap, false));
655 	}
656 	mutex_unlock(&devnode->lock);
657 
658 	/* Unhook pending transmits from this filehandle. */
659 	mutex_lock(&adap->lock);
660 	while (!list_empty(&fh->xfer_list)) {
661 		struct cec_data *data =
662 			list_first_entry(&fh->xfer_list, struct cec_data, xfer_list);
663 
664 		data->blocking = false;
665 		data->fh = NULL;
666 		list_del(&data->xfer_list);
667 	}
668 	mutex_unlock(&adap->lock);
669 	while (!list_empty(&fh->msgs)) {
670 		struct cec_msg_entry *entry =
671 			list_first_entry(&fh->msgs, struct cec_msg_entry, list);
672 
673 		list_del(&entry->list);
674 		kfree(entry);
675 	}
676 	for (i = CEC_NUM_CORE_EVENTS; i < CEC_NUM_EVENTS; i++) {
677 		while (!list_empty(&fh->events[i])) {
678 			struct cec_event_entry *entry =
679 				list_first_entry(&fh->events[i],
680 						 struct cec_event_entry, list);
681 
682 			list_del(&entry->list);
683 			kfree(entry);
684 		}
685 	}
686 	kfree(fh);
687 
688 	cec_put_device(devnode);
689 	filp->private_data = NULL;
690 	return 0;
691 }
692 
693 const struct file_operations cec_devnode_fops = {
694 	.owner = THIS_MODULE,
695 	.open = cec_open,
696 	.unlocked_ioctl = cec_ioctl,
697 	.compat_ioctl = cec_ioctl,
698 	.release = cec_release,
699 	.poll = cec_poll,
700 	.llseek = no_llseek,
701 };
702