1 // SPDX-License-Identifier: GPL-2.0-only
3 * cec-api.c - HDMI Consumer Electronics Control framework - API
5 * Copyright 2016 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
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>
16 #include <linux/string.h>
17 #include <linux/types.h>
18 #include <linux/uaccess.h>
19 #include <linux/version.h>
21 #include <media/cec-pin.h>
23 #include "cec-pin-priv.h"
25 static inline struct cec_devnode *cec_devnode_data(struct file *filp)
27 struct cec_fh *fh = filp->private_data;
29 return &fh->adap->devnode;
32 /* CEC file operations */
34 static __poll_t cec_poll(struct file *filp,
35 struct poll_table_struct *poll)
37 struct cec_fh *fh = filp->private_data;
38 struct cec_adapter *adap = fh->adap;
41 poll_wait(filp, &fh->wait, poll);
42 if (!cec_is_registered(adap))
43 return EPOLLERR | EPOLLHUP | EPOLLPRI;
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;
49 res |= EPOLLIN | EPOLLRDNORM;
50 if (fh->total_queued_events)
52 mutex_unlock(&adap->lock);
56 static bool cec_is_busy(const struct cec_adapter *adap,
57 const struct cec_fh *fh)
59 bool valid_initiator = adap->cec_initiator && adap->cec_initiator == fh;
60 bool valid_follower = adap->cec_follower && adap->cec_follower == fh;
63 * Exclusive initiators and followers can always access the CEC adapter
65 if (valid_initiator || valid_follower)
68 * All others can only access the CEC adapter if there is no
69 * exclusive initiator and they are in INITIATOR mode.
71 return adap->cec_initiator ||
72 fh->mode_initiator == CEC_MODE_NO_INITIATOR;
75 static long cec_adap_g_caps(struct cec_adapter *adap,
76 struct cec_caps __user *parg)
78 struct cec_caps caps = {};
80 strscpy(caps.driver, adap->devnode.dev.parent->driver->name,
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)))
91 static long cec_adap_g_phys_addr(struct cec_adapter *adap,
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)))
104 static int cec_validate_phys_addr(u16 phys_addr)
108 if (phys_addr == CEC_PHYS_ADDR_INVALID)
110 for (i = 0; i < 16; i += 4)
111 if (phys_addr & (0xf << i))
115 for (i += 4; i < 16; i += 4)
116 if ((phys_addr & (0xf << i)) == 0)
121 static long cec_adap_s_phys_addr(struct cec_adapter *adap, struct cec_fh *fh,
122 bool block, __u16 __user *parg)
127 if (!(adap->capabilities & CEC_CAP_PHYS_ADDR))
129 if (copy_from_user(&phys_addr, parg, sizeof(phys_addr)))
132 err = cec_validate_phys_addr(phys_addr);
135 mutex_lock(&adap->lock);
136 if (cec_is_busy(adap, fh))
139 __cec_s_phys_addr(adap, phys_addr, block);
140 mutex_unlock(&adap->lock);
144 static long cec_adap_g_log_addrs(struct cec_adapter *adap,
145 struct cec_log_addrs __user *parg)
147 struct cec_log_addrs log_addrs;
149 mutex_lock(&adap->lock);
151 * We use memcpy here instead of assignment since there is a
152 * hole at the end of struct cec_log_addrs that an assignment
153 * might ignore. So when we do copy_to_user() we could leak
154 * one byte of memory.
156 memcpy(&log_addrs, &adap->log_addrs, sizeof(log_addrs));
157 if (!adap->is_configured)
158 memset(log_addrs.log_addr, CEC_LOG_ADDR_INVALID,
159 sizeof(log_addrs.log_addr));
160 mutex_unlock(&adap->lock);
162 if (copy_to_user(parg, &log_addrs, sizeof(log_addrs)))
167 static long cec_adap_s_log_addrs(struct cec_adapter *adap, struct cec_fh *fh,
168 bool block, struct cec_log_addrs __user *parg)
170 struct cec_log_addrs log_addrs;
173 if (!(adap->capabilities & CEC_CAP_LOG_ADDRS))
175 if (copy_from_user(&log_addrs, parg, sizeof(log_addrs)))
177 log_addrs.flags &= CEC_LOG_ADDRS_FL_ALLOW_UNREG_FALLBACK |
178 CEC_LOG_ADDRS_FL_ALLOW_RC_PASSTHRU |
179 CEC_LOG_ADDRS_FL_CDC_ONLY;
180 mutex_lock(&adap->lock);
181 if (!adap->is_configuring &&
182 (!log_addrs.num_log_addrs || !adap->is_configured) &&
183 !cec_is_busy(adap, fh)) {
184 err = __cec_s_log_addrs(adap, &log_addrs, block);
186 log_addrs = adap->log_addrs;
188 mutex_unlock(&adap->lock);
191 if (copy_to_user(parg, &log_addrs, sizeof(log_addrs)))
196 static long cec_adap_g_connector_info(struct cec_adapter *adap,
197 struct cec_log_addrs __user *parg)
201 if (!(adap->capabilities & CEC_CAP_CONNECTOR_INFO))
204 mutex_lock(&adap->lock);
205 if (copy_to_user(parg, &adap->conn_info, sizeof(adap->conn_info)))
207 mutex_unlock(&adap->lock);
211 static long cec_transmit(struct cec_adapter *adap, struct cec_fh *fh,
212 bool block, struct cec_msg __user *parg)
214 struct cec_msg msg = {};
217 if (!(adap->capabilities & CEC_CAP_TRANSMIT))
219 if (copy_from_user(&msg, parg, sizeof(msg)))
222 mutex_lock(&adap->lock);
223 if (adap->log_addrs.num_log_addrs == 0)
225 else if (adap->is_configuring)
227 else if (cec_is_busy(adap, fh))
230 err = cec_transmit_msg_fh(adap, &msg, fh, block);
231 mutex_unlock(&adap->lock);
234 if (copy_to_user(parg, &msg, sizeof(msg)))
239 /* Called by CEC_RECEIVE: wait for a message to arrive */
240 static int cec_receive_msg(struct cec_fh *fh, struct cec_msg *msg, bool block)
242 u32 timeout = msg->timeout;
246 mutex_lock(&fh->lock);
247 /* Are there received messages queued up? */
248 if (fh->queued_msgs) {
249 /* Yes, return the first one */
250 struct cec_msg_entry *entry =
251 list_first_entry(&fh->msgs,
252 struct cec_msg_entry, list);
254 list_del(&entry->list);
258 mutex_unlock(&fh->lock);
259 /* restore original timeout value */
260 msg->timeout = timeout;
264 /* No, return EAGAIN in non-blocking mode or wait */
265 mutex_unlock(&fh->lock);
267 /* Return when in non-blocking mode */
272 /* The user specified a timeout */
273 res = wait_event_interruptible_timeout(fh->wait,
275 msecs_to_jiffies(msg->timeout));
281 /* Wait indefinitely */
282 res = wait_event_interruptible(fh->wait,
285 /* Exit on error, otherwise loop to get the new message */
290 static long cec_receive(struct cec_adapter *adap, struct cec_fh *fh,
291 bool block, struct cec_msg __user *parg)
293 struct cec_msg msg = {};
296 if (copy_from_user(&msg, parg, sizeof(msg)))
299 err = cec_receive_msg(fh, &msg, block);
303 if (copy_to_user(parg, &msg, sizeof(msg)))
308 static long cec_dqevent(struct cec_adapter *adap, struct cec_fh *fh,
309 bool block, struct cec_event __user *parg)
311 struct cec_event_entry *ev = NULL;
317 mutex_lock(&fh->lock);
318 while (!fh->total_queued_events && block) {
319 mutex_unlock(&fh->lock);
320 err = wait_event_interruptible(fh->wait,
321 fh->total_queued_events);
324 mutex_lock(&fh->lock);
327 /* Find the oldest event */
328 for (i = 0; i < CEC_NUM_EVENTS; i++) {
329 struct cec_event_entry *entry =
330 list_first_entry_or_null(&fh->events[i],
331 struct cec_event_entry, list);
333 if (entry && entry->ev.ts <= ts) {
346 if (copy_to_user(parg, &ev->ev, sizeof(ev->ev)))
348 if (ev_idx >= CEC_NUM_CORE_EVENTS)
350 fh->queued_events[ev_idx]--;
351 fh->total_queued_events--;
354 mutex_unlock(&fh->lock);
358 static long cec_g_mode(struct cec_adapter *adap, struct cec_fh *fh,
361 u32 mode = fh->mode_initiator | fh->mode_follower;
363 if (copy_to_user(parg, &mode, sizeof(mode)))
368 static long cec_s_mode(struct cec_adapter *adap, struct cec_fh *fh,
374 bool send_pin_event = false;
377 if (copy_from_user(&mode, parg, sizeof(mode)))
379 if (mode & ~(CEC_MODE_INITIATOR_MSK | CEC_MODE_FOLLOWER_MSK)) {
380 dprintk(1, "%s: invalid mode bits set\n", __func__);
384 mode_initiator = mode & CEC_MODE_INITIATOR_MSK;
385 mode_follower = mode & CEC_MODE_FOLLOWER_MSK;
387 if (mode_initiator > CEC_MODE_EXCL_INITIATOR ||
388 mode_follower > CEC_MODE_MONITOR_ALL) {
389 dprintk(1, "%s: unknown mode\n", __func__);
393 if (mode_follower == CEC_MODE_MONITOR_ALL &&
394 !(adap->capabilities & CEC_CAP_MONITOR_ALL)) {
395 dprintk(1, "%s: MONITOR_ALL not supported\n", __func__);
399 if (mode_follower == CEC_MODE_MONITOR_PIN &&
400 !(adap->capabilities & CEC_CAP_MONITOR_PIN)) {
401 dprintk(1, "%s: MONITOR_PIN not supported\n", __func__);
405 /* Follower modes should always be able to send CEC messages */
406 if ((mode_initiator == CEC_MODE_NO_INITIATOR ||
407 !(adap->capabilities & CEC_CAP_TRANSMIT)) &&
408 mode_follower >= CEC_MODE_FOLLOWER &&
409 mode_follower <= CEC_MODE_EXCL_FOLLOWER_PASSTHRU) {
410 dprintk(1, "%s: cannot transmit\n", __func__);
414 /* Monitor modes require CEC_MODE_NO_INITIATOR */
415 if (mode_initiator && mode_follower >= CEC_MODE_MONITOR_PIN) {
416 dprintk(1, "%s: monitor modes require NO_INITIATOR\n",
421 /* Monitor modes require CAP_NET_ADMIN */
422 if (mode_follower >= CEC_MODE_MONITOR_PIN && !capable(CAP_NET_ADMIN))
425 mutex_lock(&adap->lock);
427 * You can't become exclusive follower if someone else already
430 if ((mode_follower == CEC_MODE_EXCL_FOLLOWER ||
431 mode_follower == CEC_MODE_EXCL_FOLLOWER_PASSTHRU) &&
432 adap->cec_follower && adap->cec_follower != fh)
435 * You can't become exclusive initiator if someone else already
438 if (mode_initiator == CEC_MODE_EXCL_INITIATOR &&
439 adap->cec_initiator && adap->cec_initiator != fh)
443 bool old_mon_all = fh->mode_follower == CEC_MODE_MONITOR_ALL;
444 bool new_mon_all = mode_follower == CEC_MODE_MONITOR_ALL;
446 if (old_mon_all != new_mon_all) {
448 err = cec_monitor_all_cnt_inc(adap);
450 cec_monitor_all_cnt_dec(adap);
455 bool old_mon_pin = fh->mode_follower == CEC_MODE_MONITOR_PIN;
456 bool new_mon_pin = mode_follower == CEC_MODE_MONITOR_PIN;
458 if (old_mon_pin != new_mon_pin) {
459 send_pin_event = new_mon_pin;
461 err = cec_monitor_pin_cnt_inc(adap);
463 cec_monitor_pin_cnt_dec(adap);
468 mutex_unlock(&adap->lock);
472 if (fh->mode_follower == CEC_MODE_FOLLOWER)
473 adap->follower_cnt--;
474 if (mode_follower == CEC_MODE_FOLLOWER)
475 adap->follower_cnt++;
476 if (send_pin_event) {
477 struct cec_event ev = {
478 .flags = CEC_EVENT_FL_INITIAL_STATE,
481 ev.event = adap->cec_pin_is_high ? CEC_EVENT_PIN_CEC_HIGH :
482 CEC_EVENT_PIN_CEC_LOW;
483 cec_queue_event_fh(fh, &ev, 0);
485 if (mode_follower == CEC_MODE_EXCL_FOLLOWER ||
486 mode_follower == CEC_MODE_EXCL_FOLLOWER_PASSTHRU) {
488 mode_follower == CEC_MODE_EXCL_FOLLOWER_PASSTHRU;
489 adap->cec_follower = fh;
490 } else if (adap->cec_follower == fh) {
491 adap->passthrough = false;
492 adap->cec_follower = NULL;
494 if (mode_initiator == CEC_MODE_EXCL_INITIATOR)
495 adap->cec_initiator = fh;
496 else if (adap->cec_initiator == fh)
497 adap->cec_initiator = NULL;
498 fh->mode_initiator = mode_initiator;
499 fh->mode_follower = mode_follower;
500 mutex_unlock(&adap->lock);
504 static long cec_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
506 struct cec_fh *fh = filp->private_data;
507 struct cec_adapter *adap = fh->adap;
508 bool block = !(filp->f_flags & O_NONBLOCK);
509 void __user *parg = (void __user *)arg;
511 if (!cec_is_registered(adap))
515 case CEC_ADAP_G_CAPS:
516 return cec_adap_g_caps(adap, parg);
518 case CEC_ADAP_G_PHYS_ADDR:
519 return cec_adap_g_phys_addr(adap, parg);
521 case CEC_ADAP_S_PHYS_ADDR:
522 return cec_adap_s_phys_addr(adap, fh, block, parg);
524 case CEC_ADAP_G_LOG_ADDRS:
525 return cec_adap_g_log_addrs(adap, parg);
527 case CEC_ADAP_S_LOG_ADDRS:
528 return cec_adap_s_log_addrs(adap, fh, block, parg);
530 case CEC_ADAP_G_CONNECTOR_INFO:
531 return cec_adap_g_connector_info(adap, parg);
534 return cec_transmit(adap, fh, block, parg);
537 return cec_receive(adap, fh, block, parg);
540 return cec_dqevent(adap, fh, block, parg);
543 return cec_g_mode(adap, fh, parg);
546 return cec_s_mode(adap, fh, parg);
553 static int cec_open(struct inode *inode, struct file *filp)
555 struct cec_devnode *devnode =
556 container_of(inode->i_cdev, struct cec_devnode, cdev);
557 struct cec_adapter *adap = to_cec_adapter(devnode);
558 struct cec_fh *fh = kzalloc(sizeof(*fh), GFP_KERNEL);
560 * Initial events that are automatically sent when the cec device is
563 struct cec_event ev = {
564 .event = CEC_EVENT_STATE_CHANGE,
565 .flags = CEC_EVENT_FL_INITIAL_STATE,
573 INIT_LIST_HEAD(&fh->msgs);
574 INIT_LIST_HEAD(&fh->xfer_list);
575 for (i = 0; i < CEC_NUM_EVENTS; i++)
576 INIT_LIST_HEAD(&fh->events[i]);
577 mutex_init(&fh->lock);
578 init_waitqueue_head(&fh->wait);
580 fh->mode_initiator = CEC_MODE_INITIATOR;
583 err = cec_get_device(devnode);
589 filp->private_data = fh;
591 /* Queue up initial state events */
592 ev.state_change.phys_addr = adap->phys_addr;
593 ev.state_change.log_addr_mask = adap->log_addrs.log_addr_mask;
594 ev.state_change.have_conn_info =
595 adap->conn_info.type != CEC_CONNECTOR_TYPE_NO_CONNECTOR;
596 cec_queue_event_fh(fh, &ev, 0);
597 #ifdef CONFIG_CEC_PIN
598 if (adap->pin && adap->pin->ops->read_hpd &&
599 !adap->devnode.unregistered) {
600 err = adap->pin->ops->read_hpd(adap);
602 ev.event = err ? CEC_EVENT_PIN_HPD_HIGH :
603 CEC_EVENT_PIN_HPD_LOW;
604 cec_queue_event_fh(fh, &ev, 0);
607 if (adap->pin && adap->pin->ops->read_5v &&
608 !adap->devnode.unregistered) {
609 err = adap->pin->ops->read_5v(adap);
611 ev.event = err ? CEC_EVENT_PIN_5V_HIGH :
612 CEC_EVENT_PIN_5V_LOW;
613 cec_queue_event_fh(fh, &ev, 0);
618 mutex_lock(&devnode->lock);
619 mutex_lock(&devnode->lock_fhs);
620 list_add(&fh->list, &devnode->fhs);
621 mutex_unlock(&devnode->lock_fhs);
622 mutex_unlock(&devnode->lock);
627 /* Override for the release function */
628 static int cec_release(struct inode *inode, struct file *filp)
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;
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;
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);
650 mutex_lock(&devnode->lock);
651 mutex_lock(&devnode->lock_fhs);
653 mutex_unlock(&devnode->lock_fhs);
654 mutex_unlock(&devnode->lock);
656 /* Unhook pending transmits from this filehandle. */
657 mutex_lock(&adap->lock);
658 while (!list_empty(&fh->xfer_list)) {
659 struct cec_data *data =
660 list_first_entry(&fh->xfer_list, struct cec_data, xfer_list);
662 data->blocking = false;
664 list_del_init(&data->xfer_list);
666 mutex_unlock(&adap->lock);
667 while (!list_empty(&fh->msgs)) {
668 struct cec_msg_entry *entry =
669 list_first_entry(&fh->msgs, struct cec_msg_entry, list);
671 list_del(&entry->list);
674 for (i = CEC_NUM_CORE_EVENTS; i < CEC_NUM_EVENTS; i++) {
675 while (!list_empty(&fh->events[i])) {
676 struct cec_event_entry *entry =
677 list_first_entry(&fh->events[i],
678 struct cec_event_entry, list);
680 list_del(&entry->list);
686 cec_put_device(devnode);
687 filp->private_data = NULL;
691 const struct file_operations cec_devnode_fops = {
692 .owner = THIS_MODULE,
694 .unlocked_ioctl = cec_ioctl,
695 .compat_ioctl = cec_ioctl,
696 .release = cec_release,