2 * cec-api.c - HDMI Consumer Electronics Control framework - API
4 * Copyright 2016 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
6 * This program is free software; you may redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; version 2 of the License.
10 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
11 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
12 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
13 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
14 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
15 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
16 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
20 #include <linux/errno.h>
21 #include <linux/init.h>
22 #include <linux/module.h>
23 #include <linux/kernel.h>
24 #include <linux/kmod.h>
25 #include <linux/ktime.h>
26 #include <linux/slab.h>
28 #include <linux/string.h>
29 #include <linux/types.h>
30 #include <linux/uaccess.h>
31 #include <linux/version.h>
33 #include <media/cec-pin.h>
36 static inline struct cec_devnode *cec_devnode_data(struct file *filp)
38 struct cec_fh *fh = filp->private_data;
40 return &fh->adap->devnode;
43 /* CEC file operations */
45 static unsigned int cec_poll(struct file *filp,
46 struct poll_table_struct *poll)
48 struct cec_devnode *devnode = cec_devnode_data(filp);
49 struct cec_fh *fh = filp->private_data;
50 struct cec_adapter *adap = fh->adap;
53 if (!devnode->registered)
54 return POLLERR | POLLHUP;
55 mutex_lock(&adap->lock);
56 if (adap->is_configured &&
57 adap->transmit_queue_sz < CEC_MAX_MSG_TX_QUEUE_SZ)
58 res |= POLLOUT | POLLWRNORM;
60 res |= POLLIN | POLLRDNORM;
61 if (fh->total_queued_events)
63 poll_wait(filp, &fh->wait, poll);
64 mutex_unlock(&adap->lock);
68 static bool cec_is_busy(const struct cec_adapter *adap,
69 const struct cec_fh *fh)
71 bool valid_initiator = adap->cec_initiator && adap->cec_initiator == fh;
72 bool valid_follower = adap->cec_follower && adap->cec_follower == fh;
75 * Exclusive initiators and followers can always access the CEC adapter
77 if (valid_initiator || valid_follower)
80 * All others can only access the CEC adapter if there is no
81 * exclusive initiator and they are in INITIATOR mode.
83 return adap->cec_initiator ||
84 fh->mode_initiator == CEC_MODE_NO_INITIATOR;
87 static long cec_adap_g_caps(struct cec_adapter *adap,
88 struct cec_caps __user *parg)
90 struct cec_caps caps = {};
92 strlcpy(caps.driver, adap->devnode.dev.parent->driver->name,
94 strlcpy(caps.name, adap->name, sizeof(caps.name));
95 caps.available_log_addrs = adap->available_log_addrs;
96 caps.capabilities = adap->capabilities;
97 caps.version = LINUX_VERSION_CODE;
98 if (copy_to_user(parg, &caps, sizeof(caps)))
103 static long cec_adap_g_phys_addr(struct cec_adapter *adap,
108 mutex_lock(&adap->lock);
109 phys_addr = adap->phys_addr;
110 mutex_unlock(&adap->lock);
111 if (copy_to_user(parg, &phys_addr, sizeof(phys_addr)))
116 static int cec_validate_phys_addr(u16 phys_addr)
120 if (phys_addr == CEC_PHYS_ADDR_INVALID)
122 for (i = 0; i < 16; i += 4)
123 if (phys_addr & (0xf << i))
127 for (i += 4; i < 16; i += 4)
128 if ((phys_addr & (0xf << i)) == 0)
133 static long cec_adap_s_phys_addr(struct cec_adapter *adap, struct cec_fh *fh,
134 bool block, __u16 __user *parg)
139 if (!(adap->capabilities & CEC_CAP_PHYS_ADDR))
141 if (copy_from_user(&phys_addr, parg, sizeof(phys_addr)))
144 err = cec_validate_phys_addr(phys_addr);
147 mutex_lock(&adap->lock);
148 if (cec_is_busy(adap, fh))
151 __cec_s_phys_addr(adap, phys_addr, block);
152 mutex_unlock(&adap->lock);
156 static long cec_adap_g_log_addrs(struct cec_adapter *adap,
157 struct cec_log_addrs __user *parg)
159 struct cec_log_addrs log_addrs;
161 mutex_lock(&adap->lock);
162 log_addrs = adap->log_addrs;
163 if (!adap->is_configured)
164 memset(log_addrs.log_addr, CEC_LOG_ADDR_INVALID,
165 sizeof(log_addrs.log_addr));
166 mutex_unlock(&adap->lock);
168 if (copy_to_user(parg, &log_addrs, sizeof(log_addrs)))
173 static long cec_adap_s_log_addrs(struct cec_adapter *adap, struct cec_fh *fh,
174 bool block, struct cec_log_addrs __user *parg)
176 struct cec_log_addrs log_addrs;
179 if (!(adap->capabilities & CEC_CAP_LOG_ADDRS))
181 if (copy_from_user(&log_addrs, parg, sizeof(log_addrs)))
183 log_addrs.flags &= CEC_LOG_ADDRS_FL_ALLOW_UNREG_FALLBACK |
184 CEC_LOG_ADDRS_FL_ALLOW_RC_PASSTHRU |
185 CEC_LOG_ADDRS_FL_CDC_ONLY;
186 mutex_lock(&adap->lock);
187 if (!adap->is_configuring &&
188 (!log_addrs.num_log_addrs || !adap->is_configured) &&
189 !cec_is_busy(adap, fh)) {
190 err = __cec_s_log_addrs(adap, &log_addrs, block);
192 log_addrs = adap->log_addrs;
194 mutex_unlock(&adap->lock);
197 if (copy_to_user(parg, &log_addrs, sizeof(log_addrs)))
202 static long cec_transmit(struct cec_adapter *adap, struct cec_fh *fh,
203 bool block, struct cec_msg __user *parg)
205 struct cec_msg msg = {};
208 if (!(adap->capabilities & CEC_CAP_TRANSMIT))
210 if (copy_from_user(&msg, parg, sizeof(msg)))
213 /* A CDC-Only device can only send CDC messages */
214 if ((adap->log_addrs.flags & CEC_LOG_ADDRS_FL_CDC_ONLY) &&
215 (msg.len == 1 || msg.msg[1] != CEC_MSG_CDC_MESSAGE))
218 mutex_lock(&adap->lock);
219 if (adap->log_addrs.num_log_addrs == 0)
221 else if (adap->is_configuring)
223 else if (!adap->is_configured &&
224 (adap->needs_hpd || msg.msg[0] != 0xf0))
226 else if (cec_is_busy(adap, fh))
229 err = cec_transmit_msg_fh(adap, &msg, fh, block);
230 mutex_unlock(&adap->lock);
233 if (copy_to_user(parg, &msg, sizeof(msg)))
238 /* Called by CEC_RECEIVE: wait for a message to arrive */
239 static int cec_receive_msg(struct cec_fh *fh, struct cec_msg *msg, bool block)
241 u32 timeout = msg->timeout;
245 mutex_lock(&fh->lock);
246 /* Are there received messages queued up? */
247 if (fh->queued_msgs) {
248 /* Yes, return the first one */
249 struct cec_msg_entry *entry =
250 list_first_entry(&fh->msgs,
251 struct cec_msg_entry, list);
253 list_del(&entry->list);
257 mutex_unlock(&fh->lock);
258 /* restore original timeout value */
259 msg->timeout = timeout;
263 /* No, return EAGAIN in non-blocking mode or wait */
264 mutex_unlock(&fh->lock);
266 /* Return when in non-blocking mode */
271 /* The user specified a timeout */
272 res = wait_event_interruptible_timeout(fh->wait,
274 msecs_to_jiffies(msg->timeout));
280 /* Wait indefinitely */
281 res = wait_event_interruptible(fh->wait,
284 /* Exit on error, otherwise loop to get the new message */
289 static long cec_receive(struct cec_adapter *adap, struct cec_fh *fh,
290 bool block, struct cec_msg __user *parg)
292 struct cec_msg msg = {};
295 if (copy_from_user(&msg, parg, sizeof(msg)))
298 err = cec_receive_msg(fh, &msg, block);
302 if (copy_to_user(parg, &msg, sizeof(msg)))
307 static long cec_dqevent(struct cec_adapter *adap, struct cec_fh *fh,
308 bool block, struct cec_event __user *parg)
310 struct cec_event_entry *ev = NULL;
316 mutex_lock(&fh->lock);
317 while (!fh->total_queued_events && block) {
318 mutex_unlock(&fh->lock);
319 err = wait_event_interruptible(fh->wait,
320 fh->total_queued_events);
323 mutex_lock(&fh->lock);
326 /* Find the oldest event */
327 for (i = 0; i < CEC_NUM_EVENTS; i++) {
328 struct cec_event_entry *entry =
329 list_first_entry_or_null(&fh->events[i],
330 struct cec_event_entry, list);
332 if (entry && entry->ev.ts <= ts) {
345 if (copy_to_user(parg, &ev->ev, sizeof(ev->ev)))
347 if (ev_idx >= CEC_NUM_CORE_EVENTS)
349 fh->queued_events[ev_idx]--;
350 fh->total_queued_events--;
353 mutex_unlock(&fh->lock);
357 static long cec_g_mode(struct cec_adapter *adap, struct cec_fh *fh,
360 u32 mode = fh->mode_initiator | fh->mode_follower;
362 if (copy_to_user(parg, &mode, sizeof(mode)))
367 static long cec_s_mode(struct cec_adapter *adap, struct cec_fh *fh,
375 if (copy_from_user(&mode, parg, sizeof(mode)))
377 if (mode & ~(CEC_MODE_INITIATOR_MSK | CEC_MODE_FOLLOWER_MSK)) {
378 dprintk(1, "%s: invalid mode bits set\n", __func__);
382 mode_initiator = mode & CEC_MODE_INITIATOR_MSK;
383 mode_follower = mode & CEC_MODE_FOLLOWER_MSK;
385 if (mode_initiator > CEC_MODE_EXCL_INITIATOR ||
386 mode_follower > CEC_MODE_MONITOR_ALL) {
387 dprintk(1, "%s: unknown mode\n", __func__);
391 if (mode_follower == CEC_MODE_MONITOR_ALL &&
392 !(adap->capabilities & CEC_CAP_MONITOR_ALL)) {
393 dprintk(1, "%s: MONITOR_ALL not supported\n", __func__);
397 if (mode_follower == CEC_MODE_MONITOR_PIN &&
398 !(adap->capabilities & CEC_CAP_MONITOR_PIN)) {
399 dprintk(1, "%s: MONITOR_PIN not supported\n", __func__);
403 /* Follower modes should always be able to send CEC messages */
404 if ((mode_initiator == CEC_MODE_NO_INITIATOR ||
405 !(adap->capabilities & CEC_CAP_TRANSMIT)) &&
406 mode_follower >= CEC_MODE_FOLLOWER &&
407 mode_follower <= CEC_MODE_EXCL_FOLLOWER_PASSTHRU) {
408 dprintk(1, "%s: cannot transmit\n", __func__);
412 /* Monitor modes require CEC_MODE_NO_INITIATOR */
413 if (mode_initiator && mode_follower >= CEC_MODE_MONITOR_PIN) {
414 dprintk(1, "%s: monitor modes require NO_INITIATOR\n",
419 /* Monitor modes require CAP_NET_ADMIN */
420 if (mode_follower >= CEC_MODE_MONITOR_PIN && !capable(CAP_NET_ADMIN))
423 mutex_lock(&adap->lock);
425 * You can't become exclusive follower if someone else already
428 if ((mode_follower == CEC_MODE_EXCL_FOLLOWER ||
429 mode_follower == CEC_MODE_EXCL_FOLLOWER_PASSTHRU) &&
430 adap->cec_follower && adap->cec_follower != fh)
433 * You can't become exclusive initiator if someone else already
436 if (mode_initiator == CEC_MODE_EXCL_INITIATOR &&
437 adap->cec_initiator && adap->cec_initiator != fh)
441 bool old_mon_all = fh->mode_follower == CEC_MODE_MONITOR_ALL;
442 bool new_mon_all = mode_follower == CEC_MODE_MONITOR_ALL;
444 if (old_mon_all != new_mon_all) {
446 err = cec_monitor_all_cnt_inc(adap);
448 cec_monitor_all_cnt_dec(adap);
453 mutex_unlock(&adap->lock);
457 if (fh->mode_follower == CEC_MODE_FOLLOWER)
458 adap->follower_cnt--;
459 if (fh->mode_follower == CEC_MODE_MONITOR_PIN)
460 adap->monitor_pin_cnt--;
461 if (mode_follower == CEC_MODE_FOLLOWER)
462 adap->follower_cnt++;
463 if (mode_follower == CEC_MODE_MONITOR_PIN) {
464 struct cec_event ev = {
465 .flags = CEC_EVENT_FL_INITIAL_STATE,
468 ev.event = adap->cec_pin_is_high ? CEC_EVENT_PIN_CEC_HIGH :
469 CEC_EVENT_PIN_CEC_LOW;
470 cec_queue_event_fh(fh, &ev, 0);
471 adap->monitor_pin_cnt++;
473 if (mode_follower == CEC_MODE_EXCL_FOLLOWER ||
474 mode_follower == CEC_MODE_EXCL_FOLLOWER_PASSTHRU) {
476 mode_follower == CEC_MODE_EXCL_FOLLOWER_PASSTHRU;
477 adap->cec_follower = fh;
478 } else if (adap->cec_follower == fh) {
479 adap->passthrough = false;
480 adap->cec_follower = NULL;
482 if (mode_initiator == CEC_MODE_EXCL_INITIATOR)
483 adap->cec_initiator = fh;
484 else if (adap->cec_initiator == fh)
485 adap->cec_initiator = NULL;
486 fh->mode_initiator = mode_initiator;
487 fh->mode_follower = mode_follower;
488 mutex_unlock(&adap->lock);
492 static long cec_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
494 struct cec_devnode *devnode = cec_devnode_data(filp);
495 struct cec_fh *fh = filp->private_data;
496 struct cec_adapter *adap = fh->adap;
497 bool block = !(filp->f_flags & O_NONBLOCK);
498 void __user *parg = (void __user *)arg;
500 if (!devnode->registered)
504 case CEC_ADAP_G_CAPS:
505 return cec_adap_g_caps(adap, parg);
507 case CEC_ADAP_G_PHYS_ADDR:
508 return cec_adap_g_phys_addr(adap, parg);
510 case CEC_ADAP_S_PHYS_ADDR:
511 return cec_adap_s_phys_addr(adap, fh, block, parg);
513 case CEC_ADAP_G_LOG_ADDRS:
514 return cec_adap_g_log_addrs(adap, parg);
516 case CEC_ADAP_S_LOG_ADDRS:
517 return cec_adap_s_log_addrs(adap, fh, block, parg);
520 return cec_transmit(adap, fh, block, parg);
523 return cec_receive(adap, fh, block, parg);
526 return cec_dqevent(adap, fh, block, parg);
529 return cec_g_mode(adap, fh, parg);
532 return cec_s_mode(adap, fh, parg);
539 static int cec_open(struct inode *inode, struct file *filp)
541 struct cec_devnode *devnode =
542 container_of(inode->i_cdev, struct cec_devnode, cdev);
543 struct cec_adapter *adap = to_cec_adapter(devnode);
544 struct cec_fh *fh = kzalloc(sizeof(*fh), GFP_KERNEL);
546 * Initial events that are automatically sent when the cec device is
549 struct cec_event ev_state = {
550 .event = CEC_EVENT_STATE_CHANGE,
551 .flags = CEC_EVENT_FL_INITIAL_STATE,
559 INIT_LIST_HEAD(&fh->msgs);
560 INIT_LIST_HEAD(&fh->xfer_list);
561 for (i = 0; i < CEC_NUM_EVENTS; i++)
562 INIT_LIST_HEAD(&fh->events[i]);
563 mutex_init(&fh->lock);
564 init_waitqueue_head(&fh->wait);
566 fh->mode_initiator = CEC_MODE_INITIATOR;
569 err = cec_get_device(devnode);
575 mutex_lock(&devnode->lock);
576 if (list_empty(&devnode->fhs) &&
578 adap->phys_addr == CEC_PHYS_ADDR_INVALID) {
579 err = adap->ops->adap_enable(adap, true);
581 mutex_unlock(&devnode->lock);
586 filp->private_data = fh;
588 /* Queue up initial state events */
589 ev_state.state_change.phys_addr = adap->phys_addr;
590 ev_state.state_change.log_addr_mask = adap->log_addrs.log_addr_mask;
591 cec_queue_event_fh(fh, &ev_state, 0);
593 list_add(&fh->list, &devnode->fhs);
594 mutex_unlock(&devnode->lock);
599 /* Override for the release function */
600 static int cec_release(struct inode *inode, struct file *filp)
602 struct cec_devnode *devnode = cec_devnode_data(filp);
603 struct cec_adapter *adap = to_cec_adapter(devnode);
604 struct cec_fh *fh = filp->private_data;
607 mutex_lock(&adap->lock);
608 if (adap->cec_initiator == fh)
609 adap->cec_initiator = NULL;
610 if (adap->cec_follower == fh) {
611 adap->cec_follower = NULL;
612 adap->passthrough = false;
614 if (fh->mode_follower == CEC_MODE_FOLLOWER)
615 adap->follower_cnt--;
616 if (fh->mode_follower == CEC_MODE_MONITOR_PIN)
617 adap->monitor_pin_cnt--;
618 if (fh->mode_follower == CEC_MODE_MONITOR_ALL)
619 cec_monitor_all_cnt_dec(adap);
620 mutex_unlock(&adap->lock);
622 mutex_lock(&devnode->lock);
624 if (list_empty(&devnode->fhs) &&
626 adap->phys_addr == CEC_PHYS_ADDR_INVALID) {
627 WARN_ON(adap->ops->adap_enable(adap, false));
629 mutex_unlock(&devnode->lock);
631 /* Unhook pending transmits from this filehandle. */
632 mutex_lock(&adap->lock);
633 while (!list_empty(&fh->xfer_list)) {
634 struct cec_data *data =
635 list_first_entry(&fh->xfer_list, struct cec_data, xfer_list);
637 data->blocking = false;
639 list_del(&data->xfer_list);
641 mutex_unlock(&adap->lock);
642 while (!list_empty(&fh->msgs)) {
643 struct cec_msg_entry *entry =
644 list_first_entry(&fh->msgs, struct cec_msg_entry, list);
646 list_del(&entry->list);
649 for (i = CEC_NUM_CORE_EVENTS; i < CEC_NUM_EVENTS; i++) {
650 while (!list_empty(&fh->events[i])) {
651 struct cec_event_entry *entry =
652 list_first_entry(&fh->events[i],
653 struct cec_event_entry, list);
655 list_del(&entry->list);
661 cec_put_device(devnode);
662 filp->private_data = NULL;
666 const struct file_operations cec_devnode_fops = {
667 .owner = THIS_MODULE,
669 .unlocked_ioctl = cec_ioctl,
670 .release = cec_release,