1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
|
// SPDX-License-Identifier: GPL-2.0-only
/*
* cec-api.c - HDMI Consumer Electronics Control framework - API
*
* Copyright 2016 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
*/
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/kmod.h>
#include <linux/ktime.h>
#include <linux/slab.h>
#include <linux/mm.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/uaccess.h>
#include <linux/version.h>
#include <media/cec-pin.h>
#include "cec-priv.h"
#include "cec-pin-priv.h"
static inline struct cec_devnode *cec_devnode_data(struct file *filp)
{
struct cec_fh *fh = filp->private_data;
return &fh->adap->devnode;
}
/* CEC file operations */
static __poll_t cec_poll(struct file *filp,
struct poll_table_struct *poll)
{
struct cec_fh *fh = filp->private_data;
struct cec_adapter *adap = fh->adap;
__poll_t res = 0;
if (!cec_is_registered(adap))
return EPOLLERR | EPOLLHUP;
mutex_lock(&adap->lock);
if (adap->is_configured &&
adap->transmit_queue_sz < CEC_MAX_MSG_TX_QUEUE_SZ)
res |= EPOLLOUT | EPOLLWRNORM;
if (fh->queued_msgs)
res |= EPOLLIN | EPOLLRDNORM;
if (fh->total_queued_events)
res |= EPOLLPRI;
poll_wait(filp, &fh->wait, poll);
mutex_unlock(&adap->lock);
return res;
}
static bool cec_is_busy(const struct cec_adapter *adap,
const struct cec_fh *fh)
{
bool valid_initiator = adap->cec_initiator && adap->cec_initiator == fh;
bool valid_follower = adap->cec_follower && adap->cec_follower == fh;
/*
* Exclusive initiators and followers can always access the CEC adapter
*/
if (valid_initiator || valid_follower)
return false;
/*
* All others can only access the CEC adapter if there is no
* exclusive initiator and they are in INITIATOR mode.
*/
return adap->cec_initiator ||
fh->mode_initiator == CEC_MODE_NO_INITIATOR;
}
static long cec_adap_g_caps(struct cec_adapter *adap,
struct cec_caps __user *parg)
{
struct cec_caps caps = {};
strscpy(caps.driver, adap->devnode.dev.parent->driver->name,
sizeof(caps.driver));
strscpy(caps.name, adap->name, sizeof(caps.name));
caps.available_log_addrs = adap->available_log_addrs;
caps.capabilities = adap->capabilities;
caps.version = LINUX_VERSION_CODE;
if (copy_to_user(parg, &caps, sizeof(caps)))
return -EFAULT;
return 0;
}
static long cec_adap_g_phys_addr(struct cec_adapter *adap,
__u16 __user *parg)
{
u16 phys_addr;
mutex_lock(&adap->lock);
phys_addr = adap->phys_addr;
mutex_unlock(&adap->lock);
if (copy_to_user(parg, &phys_addr, sizeof(phys_addr)))
return -EFAULT;
return 0;
}
static long cec_adap_s_phys_addr(struct cec_adapter *adap, struct cec_fh *fh,
bool block, __u16 __user *parg)
{
u16 phys_addr;
long err;
if (!(adap->capabilities & CEC_CAP_PHYS_ADDR))
return -ENOTTY;
if (copy_from_user(&phys_addr, parg, sizeof(phys_addr)))
return -EFAULT;
err = cec_phys_addr_validate(phys_addr, NULL, NULL);
if (err)
return err;
mutex_lock(&adap->lock);
if (cec_is_busy(adap, fh))
err = -EBUSY;
else
__cec_s_phys_addr(adap, phys_addr, block);
mutex_unlock(&adap->lock);
return err;
}
static long cec_adap_g_log_addrs(struct cec_adapter *adap,
struct cec_log_addrs __user *parg)
{
struct cec_log_addrs log_addrs;
mutex_lock(&adap->lock);
log_addrs = adap->log_addrs;
if (!adap->is_configured)
memset(log_addrs.log_addr, CEC_LOG_ADDR_INVALID,
sizeof(log_addrs.log_addr));
mutex_unlock(&adap->lock);
if (copy_to_user(parg, &log_addrs, sizeof(log_addrs)))
return -EFAULT;
return 0;
}
static long cec_adap_s_log_addrs(struct cec_adapter *adap, struct cec_fh *fh,
bool block, struct cec_log_addrs __user *parg)
{
struct cec_log_addrs log_addrs;
long err = -EBUSY;
if (!(adap->capabilities & CEC_CAP_LOG_ADDRS))
return -ENOTTY;
if (copy_from_user(&log_addrs, parg, sizeof(log_addrs)))
return -EFAULT;
log_addrs.flags &= CEC_LOG_ADDRS_FL_ALLOW_UNREG_FALLBACK |
CEC_LOG_ADDRS_FL_ALLOW_RC_PASSTHRU |
CEC_LOG_ADDRS_FL_CDC_ONLY;
mutex_lock(&adap->lock);
if (!adap->is_configuring &&
(!log_addrs.num_log_addrs || !adap->is_configured) &&
!cec_is_busy(adap, fh)) {
err = __cec_s_log_addrs(adap, &log_addrs, block);
if (!err)
log_addrs = adap->log_addrs;
}
mutex_unlock(&adap->lock);
if (err)
return err;
if (copy_to_user(parg, &log_addrs, sizeof(log_addrs)))
return -EFAULT;
return 0;
}
static long cec_transmit(struct cec_adapter *adap, struct cec_fh *fh,
bool block, struct cec_msg __user *parg)
{
struct cec_msg msg = {};
long err = 0;
if (!(adap->capabilities & CEC_CAP_TRANSMIT))
return -ENOTTY;
if (copy_from_user(&msg, parg, sizeof(msg)))
return -EFAULT;
/* A CDC-Only device can only send CDC messages */
if ((adap->log_addrs.flags & CEC_LOG_ADDRS_FL_CDC_ONLY) &&
(msg.len == 1 || msg.msg[1] != CEC_MSG_CDC_MESSAGE))
return -EINVAL;
mutex_lock(&adap->lock);
if (adap->log_addrs.num_log_addrs == 0)
err = -EPERM;
else if (adap->is_configuring)
err = -ENONET;
else if (!adap->is_configured &&
(adap->needs_hpd || msg.msg[0] != 0xf0))
err = -ENONET;
else if (cec_is_busy(adap, fh))
err = -EBUSY;
else
err = cec_transmit_msg_fh(adap, &msg, fh, block);
mutex_unlock(&adap->lock);
if (err)
return err;
if (copy_to_user(parg, &msg, sizeof(msg)))
return -EFAULT;
return 0;
}
/* Called by CEC_RECEIVE: wait for a message to arrive */
static int cec_receive_msg(struct cec_fh *fh, struct cec_msg *msg, bool block)
{
u32 timeout = msg->timeout;
int res;
do {
mutex_lock(&fh->lock);
/* Are there received messages queued up? */
if (fh->queued_msgs) {
/* Yes, return the first one */
struct cec_msg_entry *entry =
list_first_entry(&fh->msgs,
struct cec_msg_entry, list);
list_del(&entry->list);
*msg = entry->msg;
kfree(entry);
fh->queued_msgs--;
mutex_unlock(&fh->lock);
/* restore original timeout value */
msg->timeout = timeout;
return 0;
}
/* No, return EAGAIN in non-blocking mode or wait */
mutex_unlock(&fh->lock);
/* Return when in non-blocking mode */
if (!block)
return -EAGAIN;
if (msg->timeout) {
/* The user specified a timeout */
res = wait_event_interruptible_timeout(fh->wait,
fh->queued_msgs,
msecs_to_jiffies(msg->timeout));
if (res == 0)
res = -ETIMEDOUT;
else if (res > 0)
res = 0;
} else {
/* Wait indefinitely */
res = wait_event_interruptible(fh->wait,
fh->queued_msgs);
}
/* Exit on error, otherwise loop to get the new message */
} while (!res);
return res;
}
static long cec_receive(struct cec_adapter *adap, struct cec_fh *fh,
bool block, struct cec_msg __user *parg)
{
struct cec_msg msg = {};
long err;
if (copy_from_user(&msg, parg, sizeof(msg)))
return -EFAULT;
err = cec_receive_msg(fh, &msg, block);
if (err)
return err;
msg.flags = 0;
if (copy_to_user(parg, &msg, sizeof(msg)))
return -EFAULT;
return 0;
}
static long cec_dqevent(struct cec_adapter *adap, struct cec_fh *fh,
bool block, struct cec_event __user *parg)
{
struct cec_event_entry *ev = NULL;
u64 ts = ~0ULL;
unsigned int i;
unsigned int ev_idx;
long err = 0;
mutex_lock(&fh->lock);
while (!fh->total_queued_events && block) {
mutex_unlock(&fh->lock);
err = wait_event_interruptible(fh->wait,
fh->total_queued_events);
if (err)
return err;
mutex_lock(&fh->lock);
}
/* Find the oldest event */
for (i = 0; i < CEC_NUM_EVENTS; i++) {
struct cec_event_entry *entry =
list_first_entry_or_null(&fh->events[i],
struct cec_event_entry, list);
if (entry && entry->ev.ts <= ts) {
ev = entry;
ev_idx = i;
ts = ev->ev.ts;
}
}
if (!ev) {
err = -EAGAIN;
goto unlock;
}
list_del(&ev->list);
if (copy_to_user(parg, &ev->ev, sizeof(ev->ev)))
err = -EFAULT;
if (ev_idx >= CEC_NUM_CORE_EVENTS)
kfree(ev);
fh->queued_events[ev_idx]--;
fh->total_queued_events--;
unlock:
mutex_unlock(&fh->lock);
return err;
}
static long cec_g_mode(struct cec_adapter *adap, struct cec_fh *fh,
u32 __user *parg)
{
u32 mode = fh->mode_initiator | fh->mode_follower;
if (copy_to_user(parg, &mode, sizeof(mode)))
return -EFAULT;
return 0;
}
static long cec_s_mode(struct cec_adapter *adap, struct cec_fh *fh,
u32 __user *parg)
{
u32 mode;
u8 mode_initiator;
u8 mode_follower;
bool send_pin_event = false;
long err = 0;
if (copy_from_user(&mode, parg, sizeof(mode)))
return -EFAULT;
if (mode & ~(CEC_MODE_INITIATOR_MSK | CEC_MODE_FOLLOWER_MSK)) {
dprintk(1, "%s: invalid mode bits set\n", __func__);
return -EINVAL;
}
mode_initiator = mode & CEC_MODE_INITIATOR_MSK;
mode_follower = mode & CEC_MODE_FOLLOWER_MSK;
if (mode_initiator > CEC_MODE_EXCL_INITIATOR ||
mode_follower > CEC_MODE_MONITOR_ALL) {
dprintk(1, "%s: unknown mode\n", __func__);
return -EINVAL;
}
if (mode_follower == CEC_MODE_MONITOR_ALL &&
!(adap->capabilities & CEC_CAP_MONITOR_ALL)) {
dprintk(1, "%s: MONITOR_ALL not supported\n", __func__);
return -EINVAL;
}
if (mode_follower == CEC_MODE_MONITOR_PIN &&
!(adap->capabilities & CEC_CAP_MONITOR_PIN)) {
dprintk(1, "%s: MONITOR_PIN not supported\n", __func__);
return -EINVAL;
}
/* Follower modes should always be able to send CEC messages */
if ((mode_initiator == CEC_MODE_NO_INITIATOR ||
!(adap->capabilities & CEC_CAP_TRANSMIT)) &&
mode_follower >= CEC_MODE_FOLLOWER &&
mode_follower <= CEC_MODE_EXCL_FOLLOWER_PASSTHRU) {
dprintk(1, "%s: cannot transmit\n", __func__);
return -EINVAL;
}
/* Monitor modes require CEC_MODE_NO_INITIATOR */
if (mode_initiator && mode_follower >= CEC_MODE_MONITOR_PIN) {
dprintk(1, "%s: monitor modes require NO_INITIATOR\n",
__func__);
return -EINVAL;
}
/* Monitor modes require CAP_NET_ADMIN */
if (mode_follower >= CEC_MODE_MONITOR_PIN && !capable(CAP_NET_ADMIN))
return -EPERM;
mutex_lock(&adap->lock);
/*
* You can't become exclusive follower if someone else already
* has that job.
*/
if ((mode_follower == CEC_MODE_EXCL_FOLLOWER ||
mode_follower == CEC_MODE_EXCL_FOLLOWER_PASSTHRU) &&
adap->cec_follower && adap->cec_follower != fh)
err = -EBUSY;
/*
* You can't become exclusive initiator if someone else already
* has that job.
*/
if (mode_initiator == CEC_MODE_EXCL_INITIATOR &&
adap->cec_initiator && adap->cec_initiator != fh)
err = -EBUSY;
if (!err) {
bool old_mon_all = fh->mode_follower == CEC_MODE_MONITOR_ALL;
bool new_mon_all = mode_follower == CEC_MODE_MONITOR_ALL;
if (old_mon_all != new_mon_all) {
if (new_mon_all)
err = cec_monitor_all_cnt_inc(adap);
else
cec_monitor_all_cnt_dec(adap);
}
}
if (!err) {
bool old_mon_pin = fh->mode_follower == CEC_MODE_MONITOR_PIN;
bool new_mon_pin = mode_follower == CEC_MODE_MONITOR_PIN;
if (old_mon_pin != new_mon_pin) {
send_pin_event = new_mon_pin;
if (new_mon_pin)
err = cec_monitor_pin_cnt_inc(adap);
else
cec_monitor_pin_cnt_dec(adap);
}
}
if (err) {
mutex_unlock(&adap->lock);
return err;
}
if (fh->mode_follower == CEC_MODE_FOLLOWER)
adap->follower_cnt--;
if (mode_follower == CEC_MODE_FOLLOWER)
adap->follower_cnt++;
if (send_pin_event) {
struct cec_event ev = {
.flags = CEC_EVENT_FL_INITIAL_STATE,
};
ev.event = adap->cec_pin_is_high ? CEC_EVENT_PIN_CEC_HIGH :
CEC_EVENT_PIN_CEC_LOW;
cec_queue_event_fh(fh, &ev, 0);
}
if (mode_follower == CEC_MODE_EXCL_FOLLOWER ||
mode_follower == CEC_MODE_EXCL_FOLLOWER_PASSTHRU) {
adap->passthrough =
mode_follower == CEC_MODE_EXCL_FOLLOWER_PASSTHRU;
adap->cec_follower = fh;
} else if (adap->cec_follower == fh) {
adap->passthrough = false;
adap->cec_follower = NULL;
}
if (mode_initiator == CEC_MODE_EXCL_INITIATOR)
adap->cec_initiator = fh;
else if (adap->cec_initiator == fh)
adap->cec_initiator = NULL;
fh->mode_initiator = mode_initiator;
fh->mode_follower = mode_follower;
mutex_unlock(&adap->lock);
return 0;
}
static long cec_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{
struct cec_fh *fh = filp->private_data;
struct cec_adapter *adap = fh->adap;
bool block = !(filp->f_flags & O_NONBLOCK);
void __user *parg = (void __user *)arg;
if (!cec_is_registered(adap))
return -ENODEV;
switch (cmd) {
case CEC_ADAP_G_CAPS:
return cec_adap_g_caps(adap, parg);
case CEC_ADAP_G_PHYS_ADDR:
return cec_adap_g_phys_addr(adap, parg);
case CEC_ADAP_S_PHYS_ADDR:
return cec_adap_s_phys_addr(adap, fh, block, parg);
case CEC_ADAP_G_LOG_ADDRS:
return cec_adap_g_log_addrs(adap, parg);
case CEC_ADAP_S_LOG_ADDRS:
return cec_adap_s_log_addrs(adap, fh, block, parg);
case CEC_TRANSMIT:
return cec_transmit(adap, fh, block, parg);
case CEC_RECEIVE:
return cec_receive(adap, fh, block, parg);
case CEC_DQEVENT:
return cec_dqevent(adap, fh, block, parg);
case CEC_G_MODE:
return cec_g_mode(adap, fh, parg);
case CEC_S_MODE:
return cec_s_mode(adap, fh, parg);
default:
return -ENOTTY;
}
}
static int cec_open(struct inode *inode, struct file *filp)
{
struct cec_devnode *devnode =
container_of(inode->i_cdev, struct cec_devnode, cdev);
struct cec_adapter *adap = to_cec_adapter(devnode);
struct cec_fh *fh = kzalloc(sizeof(*fh), GFP_KERNEL);
/*
* Initial events that are automatically sent when the cec device is
* opened.
*/
struct cec_event ev = {
.event = CEC_EVENT_STATE_CHANGE,
.flags = CEC_EVENT_FL_INITIAL_STATE,
};
unsigned int i;
int err;
if (!fh)
return -ENOMEM;
INIT_LIST_HEAD(&fh->msgs);
INIT_LIST_HEAD(&fh->xfer_list);
for (i = 0; i < CEC_NUM_EVENTS; i++)
INIT_LIST_HEAD(&fh->events[i]);
mutex_init(&fh->lock);
init_waitqueue_head(&fh->wait);
fh->mode_initiator = CEC_MODE_INITIATOR;
fh->adap = adap;
err = cec_get_device(devnode);
if (err) {
kfree(fh);
return err;
}
mutex_lock(&devnode->lock);
if (list_empty(&devnode->fhs) &&
!adap->needs_hpd &&
adap->phys_addr == CEC_PHYS_ADDR_INVALID) {
err = adap->ops->adap_enable(adap, true);
if (err) {
mutex_unlock(&devnode->lock);
kfree(fh);
return err;
}
}
filp->private_data = fh;
/* Queue up initial state events */
ev.state_change.phys_addr = adap->phys_addr;
ev.state_change.log_addr_mask = adap->log_addrs.log_addr_mask;
cec_queue_event_fh(fh, &ev, 0);
#ifdef CONFIG_CEC_PIN
if (adap->pin && adap->pin->ops->read_hpd) {
err = adap->pin->ops->read_hpd(adap);
if (err >= 0) {
ev.event = err ? CEC_EVENT_PIN_HPD_HIGH :
CEC_EVENT_PIN_HPD_LOW;
cec_queue_event_fh(fh, &ev, 0);
}
}
if (adap->pin && adap->pin->ops->read_5v) {
err = adap->pin->ops->read_5v(adap);
if (err >= 0) {
ev.event = err ? CEC_EVENT_PIN_5V_HIGH :
CEC_EVENT_PIN_5V_LOW;
cec_queue_event_fh(fh, &ev, 0);
}
}
#endif
list_add(&fh->list, &devnode->fhs);
mutex_unlock(&devnode->lock);
return 0;
}
/* Override for the release function */
static int cec_release(struct inode *inode, struct file *filp)
{
struct cec_devnode *devnode = cec_devnode_data(filp);
struct cec_adapter *adap = to_cec_adapter(devnode);
struct cec_fh *fh = filp->private_data;
unsigned int i;
mutex_lock(&adap->lock);
if (adap->cec_initiator == fh)
adap->cec_initiator = NULL;
if (adap->cec_follower == fh) {
adap->cec_follower = NULL;
adap->passthrough = false;
}
if (fh->mode_follower == CEC_MODE_FOLLOWER)
adap->follower_cnt--;
if (fh->mode_follower == CEC_MODE_MONITOR_PIN)
cec_monitor_pin_cnt_dec(adap);
if (fh->mode_follower == CEC_MODE_MONITOR_ALL)
cec_monitor_all_cnt_dec(adap);
mutex_unlock(&adap->lock);
mutex_lock(&devnode->lock);
list_del(&fh->list);
if (cec_is_registered(adap) && list_empty(&devnode->fhs) &&
!adap->needs_hpd && adap->phys_addr == CEC_PHYS_ADDR_INVALID) {
WARN_ON(adap->ops->adap_enable(adap, false));
}
mutex_unlock(&devnode->lock);
/* Unhook pending transmits from this filehandle. */
mutex_lock(&adap->lock);
while (!list_empty(&fh->xfer_list)) {
struct cec_data *data =
list_first_entry(&fh->xfer_list, struct cec_data, xfer_list);
data->blocking = false;
data->fh = NULL;
list_del(&data->xfer_list);
}
mutex_unlock(&adap->lock);
while (!list_empty(&fh->msgs)) {
struct cec_msg_entry *entry =
list_first_entry(&fh->msgs, struct cec_msg_entry, list);
list_del(&entry->list);
kfree(entry);
}
for (i = CEC_NUM_CORE_EVENTS; i < CEC_NUM_EVENTS; i++) {
while (!list_empty(&fh->events[i])) {
struct cec_event_entry *entry =
list_first_entry(&fh->events[i],
struct cec_event_entry, list);
list_del(&entry->list);
kfree(entry);
}
}
kfree(fh);
cec_put_device(devnode);
filp->private_data = NULL;
return 0;
}
const struct file_operations cec_devnode_fops = {
.owner = THIS_MODULE,
.open = cec_open,
.unlocked_ioctl = cec_ioctl,
.release = cec_release,
.poll = cec_poll,
.llseek = no_llseek,
};
|