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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * cec-api.c - HDMI Consumer Electronics Control framework - API4 *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 25static 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 34static __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 | 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;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 56static 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 adapter64 */65 if (valid_initiator || valid_follower)66 return false;67 /*68 * All others can only access the CEC adapter if there is no69 * exclusive initiator and they are in INITIATOR mode.70 */71 return adap->cec_initiator ||72 fh->mode_initiator == CEC_MODE_NO_INITIATOR;73}74 75static 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 91static 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 104static 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 121static 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 else139 __cec_s_phys_addr(adap, phys_addr, block);140 mutex_unlock(&adap->lock);141 return err;142}143 144static 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 /*151 * We use memcpy here instead of assignment since there is a152 * hole at the end of struct cec_log_addrs that an assignment153 * might ignore. So when we do copy_to_user() we could leak154 * one byte of memory.155 */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);161 162 if (copy_to_user(parg, &log_addrs, sizeof(log_addrs)))163 return -EFAULT;164 return 0;165}166 167static long cec_adap_s_log_addrs(struct cec_adapter *adap, struct cec_fh *fh,168 bool block, struct cec_log_addrs __user *parg)169{170 struct cec_log_addrs log_addrs;171 long err = -EBUSY;172 173 if (!(adap->capabilities & CEC_CAP_LOG_ADDRS))174 return -ENOTTY;175 if (copy_from_user(&log_addrs, parg, sizeof(log_addrs)))176 return -EFAULT;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_claiming_log_addrs && !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);185 if (!err)186 log_addrs = adap->log_addrs;187 }188 mutex_unlock(&adap->lock);189 if (err)190 return err;191 if (copy_to_user(parg, &log_addrs, sizeof(log_addrs)))192 return -EFAULT;193 return 0;194}195 196static long cec_adap_g_connector_info(struct cec_adapter *adap,197 struct cec_log_addrs __user *parg)198{199 int ret = 0;200 201 if (!(adap->capabilities & CEC_CAP_CONNECTOR_INFO))202 return -ENOTTY;203 204 mutex_lock(&adap->lock);205 if (copy_to_user(parg, &adap->conn_info, sizeof(adap->conn_info)))206 ret = -EFAULT;207 mutex_unlock(&adap->lock);208 return ret;209}210 211static long cec_transmit(struct cec_adapter *adap, struct cec_fh *fh,212 bool block, struct cec_msg __user *parg)213{214 struct cec_msg msg = {};215 long err = 0;216 217 if (!(adap->capabilities & CEC_CAP_TRANSMIT))218 return -ENOTTY;219 if (copy_from_user(&msg, parg, sizeof(msg)))220 return -EFAULT;221 222 mutex_lock(&adap->lock);223 if (adap->log_addrs.num_log_addrs == 0)224 err = -EPERM;225 else if (adap->is_configuring)226 err = -ENONET;227 else if (cec_is_busy(adap, fh))228 err = -EBUSY;229 else230 err = cec_transmit_msg_fh(adap, &msg, fh, block);231 mutex_unlock(&adap->lock);232 if (err)233 return err;234 if (copy_to_user(parg, &msg, sizeof(msg)))235 return -EFAULT;236 return 0;237}238 239/* Called by CEC_RECEIVE: wait for a message to arrive */240static int cec_receive_msg(struct cec_fh *fh, struct cec_msg *msg, bool block)241{242 u32 timeout = msg->timeout;243 int res;244 245 do {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);253 254 list_del(&entry->list);255 *msg = entry->msg;256 kfree(entry);257 fh->queued_msgs--;258 mutex_unlock(&fh->lock);259 /* restore original timeout value */260 msg->timeout = timeout;261 return 0;262 }263 264 /* No, return EAGAIN in non-blocking mode or wait */265 mutex_unlock(&fh->lock);266 267 /* Return when in non-blocking mode */268 if (!block)269 return -EAGAIN;270 271 if (msg->timeout) {272 /* The user specified a timeout */273 res = wait_event_interruptible_timeout(fh->wait,274 fh->queued_msgs,275 msecs_to_jiffies(msg->timeout));276 if (res == 0)277 res = -ETIMEDOUT;278 else if (res > 0)279 res = 0;280 } else {281 /* Wait indefinitely */282 res = wait_event_interruptible(fh->wait,283 fh->queued_msgs);284 }285 /* Exit on error, otherwise loop to get the new message */286 } while (!res);287 return res;288}289 290static long cec_receive(struct cec_adapter *adap, struct cec_fh *fh,291 bool block, struct cec_msg __user *parg)292{293 struct cec_msg msg = {};294 long err;295 296 if (copy_from_user(&msg, parg, sizeof(msg)))297 return -EFAULT;298 299 err = cec_receive_msg(fh, &msg, block);300 if (err)301 return err;302 msg.flags = 0;303 if (copy_to_user(parg, &msg, sizeof(msg)))304 return -EFAULT;305 return 0;306}307 308static long cec_dqevent(struct cec_adapter *adap, struct cec_fh *fh,309 bool block, struct cec_event __user *parg)310{311 struct cec_event_entry *ev = NULL;312 u64 ts = ~0ULL;313 unsigned int i;314 unsigned int ev_idx;315 long err = 0;316 317 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);322 if (err)323 return err;324 mutex_lock(&fh->lock);325 }326 327 /* 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);332 333 if (entry && entry->ev.ts <= ts) {334 ev = entry;335 ev_idx = i;336 ts = ev->ev.ts;337 }338 }339 340 if (!ev) {341 err = -EAGAIN;342 goto unlock;343 }344 list_del(&ev->list);345 346 if (copy_to_user(parg, &ev->ev, sizeof(ev->ev)))347 err = -EFAULT;348 if (ev_idx >= CEC_NUM_CORE_EVENTS)349 kfree(ev);350 fh->queued_events[ev_idx]--;351 fh->total_queued_events--;352 353unlock:354 mutex_unlock(&fh->lock);355 return err;356}357 358static long cec_g_mode(struct cec_adapter *adap, struct cec_fh *fh,359 u32 __user *parg)360{361 u32 mode = fh->mode_initiator | fh->mode_follower;362 363 if (copy_to_user(parg, &mode, sizeof(mode)))364 return -EFAULT;365 return 0;366}367 368static long cec_s_mode(struct cec_adapter *adap, struct cec_fh *fh,369 u32 __user *parg)370{371 u32 mode;372 u8 mode_initiator;373 u8 mode_follower;374 bool send_pin_event = false;375 long err = 0;376 377 if (copy_from_user(&mode, parg, sizeof(mode)))378 return -EFAULT;379 if (mode & ~(CEC_MODE_INITIATOR_MSK | CEC_MODE_FOLLOWER_MSK)) {380 dprintk(1, "%s: invalid mode bits set\n", __func__);381 return -EINVAL;382 }383 384 mode_initiator = mode & CEC_MODE_INITIATOR_MSK;385 mode_follower = mode & CEC_MODE_FOLLOWER_MSK;386 387 if (mode_initiator > CEC_MODE_EXCL_INITIATOR ||388 mode_follower > CEC_MODE_MONITOR_ALL) {389 dprintk(1, "%s: unknown mode\n", __func__);390 return -EINVAL;391 }392 393 if (mode_follower == CEC_MODE_MONITOR_ALL &&394 !(adap->capabilities & CEC_CAP_MONITOR_ALL)) {395 dprintk(1, "%s: MONITOR_ALL not supported\n", __func__);396 return -EINVAL;397 }398 399 if (mode_follower == CEC_MODE_MONITOR_PIN &&400 !(adap->capabilities & CEC_CAP_MONITOR_PIN)) {401 dprintk(1, "%s: MONITOR_PIN not supported\n", __func__);402 return -EINVAL;403 }404 405 /* 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__);411 return -EINVAL;412 }413 414 /* 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",417 __func__);418 return -EINVAL;419 }420 421 /* Monitor modes require CAP_NET_ADMIN */422 if (mode_follower >= CEC_MODE_MONITOR_PIN && !capable(CAP_NET_ADMIN))423 return -EPERM;424 425 mutex_lock(&adap->lock);426 /*427 * You can't become exclusive follower if someone else already428 * has that job.429 */430 if ((mode_follower == CEC_MODE_EXCL_FOLLOWER ||431 mode_follower == CEC_MODE_EXCL_FOLLOWER_PASSTHRU) &&432 adap->cec_follower && adap->cec_follower != fh)433 err = -EBUSY;434 /*435 * You can't become exclusive initiator if someone else already436 * has that job.437 */438 if (mode_initiator == CEC_MODE_EXCL_INITIATOR &&439 adap->cec_initiator && adap->cec_initiator != fh)440 err = -EBUSY;441 442 if (!err) {443 bool old_mon_all = fh->mode_follower == CEC_MODE_MONITOR_ALL;444 bool new_mon_all = mode_follower == CEC_MODE_MONITOR_ALL;445 446 if (old_mon_all != new_mon_all) {447 if (new_mon_all)448 err = cec_monitor_all_cnt_inc(adap);449 else450 cec_monitor_all_cnt_dec(adap);451 }452 }453 454 if (!err) {455 bool old_mon_pin = fh->mode_follower == CEC_MODE_MONITOR_PIN;456 bool new_mon_pin = mode_follower == CEC_MODE_MONITOR_PIN;457 458 if (old_mon_pin != new_mon_pin) {459 send_pin_event = new_mon_pin;460 if (new_mon_pin)461 err = cec_monitor_pin_cnt_inc(adap);462 else463 cec_monitor_pin_cnt_dec(adap);464 }465 }466 467 if (err) {468 mutex_unlock(&adap->lock);469 return err;470 }471 472 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,479 };480 481 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);484 }485 if (mode_follower == CEC_MODE_EXCL_FOLLOWER ||486 mode_follower == CEC_MODE_EXCL_FOLLOWER_PASSTHRU) {487 adap->passthrough =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;493 }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);501 return 0;502}503 504static long cec_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)505{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;510 511 if (!cec_is_registered(adap))512 return -ENODEV;513 514 switch (cmd) {515 case CEC_ADAP_G_CAPS:516 return cec_adap_g_caps(adap, parg);517 518 case CEC_ADAP_G_PHYS_ADDR:519 return cec_adap_g_phys_addr(adap, parg);520 521 case CEC_ADAP_S_PHYS_ADDR:522 return cec_adap_s_phys_addr(adap, fh, block, parg);523 524 case CEC_ADAP_G_LOG_ADDRS:525 return cec_adap_g_log_addrs(adap, parg);526 527 case CEC_ADAP_S_LOG_ADDRS:528 return cec_adap_s_log_addrs(adap, fh, block, parg);529 530 case CEC_ADAP_G_CONNECTOR_INFO:531 return cec_adap_g_connector_info(adap, parg);532 533 case CEC_TRANSMIT:534 return cec_transmit(adap, fh, block, parg);535 536 case CEC_RECEIVE:537 return cec_receive(adap, fh, block, parg);538 539 case CEC_DQEVENT:540 return cec_dqevent(adap, fh, block, parg);541 542 case CEC_G_MODE:543 return cec_g_mode(adap, fh, parg);544 545 case CEC_S_MODE:546 return cec_s_mode(adap, fh, parg);547 548 default:549 return -ENOTTY;550 }551}552 553static int cec_open(struct inode *inode, struct file *filp)554{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);559 /*560 * Initial events that are automatically sent when the cec device is561 * opened.562 */563 struct cec_event ev = {564 .event = CEC_EVENT_STATE_CHANGE,565 .flags = CEC_EVENT_FL_INITIAL_STATE,566 };567 unsigned int i;568 int err;569 570 if (!fh)571 return -ENOMEM;572 573 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);579 580 fh->mode_initiator = CEC_MODE_INITIATOR;581 fh->adap = adap;582 583 err = cec_get_device(adap);584 if (err) {585 kfree(fh);586 return err;587 }588 589 filp->private_data = fh;590 591 /* 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_PIN598 if (adap->pin && adap->pin->ops->read_hpd &&599 !adap->devnode.unregistered) {600 err = adap->pin->ops->read_hpd(adap);601 if (err >= 0) {602 ev.event = err ? CEC_EVENT_PIN_HPD_HIGH :603 CEC_EVENT_PIN_HPD_LOW;604 cec_queue_event_fh(fh, &ev, 0);605 }606 }607 if (adap->pin && adap->pin->ops->read_5v &&608 !adap->devnode.unregistered) {609 err = adap->pin->ops->read_5v(adap);610 if (err >= 0) {611 ev.event = err ? CEC_EVENT_PIN_5V_HIGH :612 CEC_EVENT_PIN_5V_LOW;613 cec_queue_event_fh(fh, &ev, 0);614 }615 }616#endif617 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);623 624 return 0;625}626 627/* Override for the release function */628static 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 mutex_lock(&devnode->lock_fhs);652 list_del(&fh->list);653 mutex_unlock(&devnode->lock_fhs);654 mutex_unlock(&devnode->lock);655 656 /* 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);661 662 data->blocking = false;663 data->fh = NULL;664 list_del_init(&data->xfer_list);665 }666 mutex_unlock(&adap->lock);667 668 mutex_lock(&fh->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 mutex_unlock(&fh->lock);687 kfree(fh);688 689 cec_put_device(adap);690 filp->private_data = NULL;691 return 0;692}693 694const struct file_operations cec_devnode_fops = {695 .owner = THIS_MODULE,696 .open = cec_open,697 .unlocked_ioctl = cec_ioctl,698 .compat_ioctl = cec_ioctl,699 .release = cec_release,700 .poll = cec_poll,701};702