Merge remote-tracking branches 'asoc/topic/sgtl5000', 'asoc/topic/simple', 'asoc...

[mirror_ubuntu-bionic-kernel.git] / drivers / staging / media / cec / cec-adap.c

/*
 * cec-adap.c - HDMI Consumer Electronics Control framework - CEC adapter
 *
 * Copyright 2016 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
 *
 * This program is free software; you may redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2 of the License.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#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 "cec-priv.h"

static int cec_report_features(struct cec_adapter *adap, unsigned int la_idx);
static int cec_report_phys_addr(struct cec_adapter *adap, unsigned int la_idx);

/*
 * 400 ms is the time it takes for one 16 byte message to be
 * transferred and 5 is the maximum number of retries. Add
 * another 100 ms as a margin. So if the transmit doesn't
 * finish before that time something is really wrong and we
 * have to time out.
 *
 * This is a sign that something it really wrong and a warning
 * will be issued.
 */
#define CEC_XFER_TIMEOUT_MS (5 * 400 + 100)

#define call_op(adap, op, arg...) \
        (adap->ops->op ? adap->ops->op(adap, ## arg) : 0)

#define call_void_op(adap, op, arg...)                  \
        do {                                            \
                if (adap->ops->op)                      \
                        adap->ops->op(adap, ## arg);    \
        } while (0)

static int cec_log_addr2idx(const struct cec_adapter *adap, u8 log_addr)
{
        int i;

        for (i = 0; i < adap->log_addrs.num_log_addrs; i++)
                if (adap->log_addrs.log_addr[i] == log_addr)
                        return i;
        return -1;
}

static unsigned int cec_log_addr2dev(const struct cec_adapter *adap, u8 log_addr)
{
        int i = cec_log_addr2idx(adap, log_addr);

        return adap->log_addrs.primary_device_type[i < 0 ? 0 : i];
}

/*
 * Queue a new event for this filehandle. If ts == 0, then set it
 * to the current time.
 *
 * The two events that are currently defined do not need to keep track
 * of intermediate events, so no actual queue of events is needed,
 * instead just store the latest state and the total number of lost
 * messages.
 *
 * Should new events be added in the future that require intermediate
 * results to be queued as well, then a proper queue data structure is
 * required. But until then, just keep it simple.
 */
void cec_queue_event_fh(struct cec_fh *fh,
                        const struct cec_event *new_ev, u64 ts)
{
        struct cec_event *ev = &fh->events[new_ev->event - 1];

        if (ts == 0)
                ts = ktime_get_ns();

        mutex_lock(&fh->lock);
        if (new_ev->event == CEC_EVENT_LOST_MSGS &&
            fh->pending_events & (1 << new_ev->event)) {
                /*
                 * If there is already a lost_msgs event, then just
                 * update the lost_msgs count. This effectively
                 * merges the old and new events into one.
                 */
                ev->lost_msgs.lost_msgs += new_ev->lost_msgs.lost_msgs;
                goto unlock;
        }

        /*
         * Intermediate states are not interesting, so just
         * overwrite any older event.
         */
        *ev = *new_ev;
        ev->ts = ts;
        fh->pending_events |= 1 << new_ev->event;

unlock:
        mutex_unlock(&fh->lock);
        wake_up_interruptible(&fh->wait);
}

/* Queue a new event for all open filehandles. */
static void cec_queue_event(struct cec_adapter *adap,
                            const struct cec_event *ev)
{
        u64 ts = ktime_get_ns();
        struct cec_fh *fh;

        mutex_lock(&adap->devnode.lock);
        list_for_each_entry(fh, &adap->devnode.fhs, list)
                cec_queue_event_fh(fh, ev, ts);
        mutex_unlock(&adap->devnode.lock);
}

/*
 * Queue a new message for this filehandle. If there is no more room
 * in the queue, then send the LOST_MSGS event instead.
 */
static void cec_queue_msg_fh(struct cec_fh *fh, const struct cec_msg *msg)
{
        static const struct cec_event ev_lost_msg = {
                .ts = 0,
                .event = CEC_EVENT_LOST_MSGS,
                .flags = 0,
                {
                        .lost_msgs.lost_msgs = 1,
                },
        };
        struct cec_msg_entry *entry;

        mutex_lock(&fh->lock);
        entry = kmalloc(sizeof(*entry), GFP_KERNEL);
        if (!entry)
                goto lost_msgs;

        entry->msg = *msg;
        /* Add new msg at the end of the queue */
        list_add_tail(&entry->list, &fh->msgs);

        /*
         * if the queue now has more than CEC_MAX_MSG_RX_QUEUE_SZ
         * messages, drop the oldest one and send a lost message event.
         */
        if (fh->queued_msgs == CEC_MAX_MSG_RX_QUEUE_SZ) {
                list_del(&entry->list);
                goto lost_msgs;
        }
        fh->queued_msgs++;
        mutex_unlock(&fh->lock);
        wake_up_interruptible(&fh->wait);
        return;

lost_msgs:
        mutex_unlock(&fh->lock);
        cec_queue_event_fh(fh, &ev_lost_msg, 0);
}

/*
 * Queue the message for those filehandles that are in monitor mode.
 * If valid_la is true (this message is for us or was sent by us),
 * then pass it on to any monitoring filehandle. If this message
 * isn't for us or from us, then only give it to filehandles that
 * are in MONITOR_ALL mode.
 *
 * This can only happen if the CEC_CAP_MONITOR_ALL capability is
 * set and the CEC adapter was placed in 'monitor all' mode.
 */
static void cec_queue_msg_monitor(struct cec_adapter *adap,
                                  const struct cec_msg *msg,
                                  bool valid_la)
{
        struct cec_fh *fh;
        u32 monitor_mode = valid_la ? CEC_MODE_MONITOR :
                                      CEC_MODE_MONITOR_ALL;

        mutex_lock(&adap->devnode.lock);
        list_for_each_entry(fh, &adap->devnode.fhs, list) {
                if (fh->mode_follower >= monitor_mode)
                        cec_queue_msg_fh(fh, msg);
        }
        mutex_unlock(&adap->devnode.lock);
}

/*
 * Queue the message for follower filehandles.
 */
static void cec_queue_msg_followers(struct cec_adapter *adap,
                                    const struct cec_msg *msg)
{
        struct cec_fh *fh;

        mutex_lock(&adap->devnode.lock);
        list_for_each_entry(fh, &adap->devnode.fhs, list) {
                if (fh->mode_follower == CEC_MODE_FOLLOWER)
                        cec_queue_msg_fh(fh, msg);
        }
        mutex_unlock(&adap->devnode.lock);
}

/* Notify userspace of an adapter state change. */
static void cec_post_state_event(struct cec_adapter *adap)
{
        struct cec_event ev = {
                .event = CEC_EVENT_STATE_CHANGE,
        };

        ev.state_change.phys_addr = adap->phys_addr;
        ev.state_change.log_addr_mask = adap->log_addrs.log_addr_mask;
        cec_queue_event(adap, &ev);
}

/*
 * A CEC transmit (and a possible wait for reply) completed.
 * If this was in blocking mode, then complete it, otherwise
 * queue the message for userspace to dequeue later.
 *
 * This function is called with adap->lock held.
 */
static void cec_data_completed(struct cec_data *data)
{
        /*
         * Delete this transmit from the filehandle's xfer_list since
         * we're done with it.
         *
         * Note that if the filehandle is closed before this transmit
         * finished, then the release() function will set data->fh to NULL.
         * Without that we would be referring to a closed filehandle.
         */
        if (data->fh)
                list_del(&data->xfer_list);

        if (data->blocking) {
                /*
                 * Someone is blocking so mark the message as completed
                 * and call complete.
                 */
                data->completed = true;
                complete(&data->c);
        } else {
                /*
                 * No blocking, so just queue the message if needed and
                 * free the memory.
                 */
                if (data->fh)
                        cec_queue_msg_fh(data->fh, &data->msg);
                kfree(data);
        }
}

/*
 * A pending CEC transmit needs to be cancelled, either because the CEC
 * adapter is disabled or the transmit takes an impossibly long time to
 * finish.
 *
 * This function is called with adap->lock held.
 */
static void cec_data_cancel(struct cec_data *data)
{
        /*
         * It's either the current transmit, or it is a pending
         * transmit. Take the appropriate action to clear it.
         */
        if (data->adap->transmitting == data) {
                data->adap->transmitting = NULL;
        } else {
                list_del_init(&data->list);
                if (!(data->msg.tx_status & CEC_TX_STATUS_OK))
                        data->adap->transmit_queue_sz--;
        }

        /* Mark it as an error */
        data->msg.tx_ts = ktime_get_ns();
        data->msg.tx_status = CEC_TX_STATUS_ERROR |
                              CEC_TX_STATUS_MAX_RETRIES;
        data->attempts = 0;
        data->msg.tx_error_cnt = 1;
        /* Queue transmitted message for monitoring purposes */
        cec_queue_msg_monitor(data->adap, &data->msg, 1);

        cec_data_completed(data);
}

/*
 * Main CEC state machine
 *
 * Wait until the thread should be stopped, or we are not transmitting and
 * a new transmit message is queued up, in which case we start transmitting
 * that message. When the adapter finished transmitting the message it will
 * call cec_transmit_done().
 *
 * If the adapter is disabled, then remove all queued messages instead.
 *
 * If the current transmit times out, then cancel that transmit.
 */
int cec_thread_func(void *_adap)
{
        struct cec_adapter *adap = _adap;

        for (;;) {
                unsigned int signal_free_time;
                struct cec_data *data;
                bool timeout = false;
                u8 attempts;

                if (adap->transmitting) {
                        int err;

                        /*
                         * We are transmitting a message, so add a timeout
                         * to prevent the state machine to get stuck waiting
                         * for this message to finalize and add a check to
                         * see if the adapter is disabled in which case the
                         * transmit should be canceled.
                         */
                        err = wait_event_interruptible_timeout(adap->kthread_waitq,
                                kthread_should_stop() ||
                                (!adap->is_configured && !adap->is_configuring) ||
                                (!adap->transmitting &&
                                 !list_empty(&adap->transmit_queue)),
                                msecs_to_jiffies(CEC_XFER_TIMEOUT_MS));
                        timeout = err == 0;
                } else {
                        /* Otherwise we just wait for something to happen. */
                        wait_event_interruptible(adap->kthread_waitq,
                                kthread_should_stop() ||
                                (!adap->transmitting &&
                                 !list_empty(&adap->transmit_queue)));
                }

                mutex_lock(&adap->lock);

                if ((!adap->is_configured && !adap->is_configuring) ||
                    kthread_should_stop()) {
                        /*
                         * If the adapter is disabled, or we're asked to stop,
                         * then cancel any pending transmits.
                         */
                        while (!list_empty(&adap->transmit_queue)) {
                                data = list_first_entry(&adap->transmit_queue,
                                                        struct cec_data, list);
                                cec_data_cancel(data);
                        }
                        if (adap->transmitting)
                                cec_data_cancel(adap->transmitting);

                        /*
                         * Cancel the pending timeout work. We have to unlock
                         * the mutex when flushing the work since
                         * cec_wait_timeout() will take it. This is OK since
                         * no new entries can be added to wait_queue as long
                         * as adap->transmitting is NULL, which it is due to
                         * the cec_data_cancel() above.
                         */
                        while (!list_empty(&adap->wait_queue)) {
                                data = list_first_entry(&adap->wait_queue,
                                                        struct cec_data, list);

                                if (!cancel_delayed_work(&data->work)) {
                                        mutex_unlock(&adap->lock);
                                        flush_scheduled_work();
                                        mutex_lock(&adap->lock);
                                }
                                cec_data_cancel(data);
                        }
                        goto unlock;
                }

                if (adap->transmitting && timeout) {
                        /*
                         * If we timeout, then log that. This really shouldn't
                         * happen and is an indication of a faulty CEC adapter
                         * driver, or the CEC bus is in some weird state.
                         */
                        dprintk(0, "message %*ph timed out!\n",
                                adap->transmitting->msg.len,
                                adap->transmitting->msg.msg);
                        /* Just give up on this. */
                        cec_data_cancel(adap->transmitting);
                        goto unlock;
                }

                /*
                 * If we are still transmitting, or there is nothing new to
                 * transmit, then just continue waiting.
                 */
                if (adap->transmitting || list_empty(&adap->transmit_queue))
                        goto unlock;

                /* Get a new message to transmit */
                data = list_first_entry(&adap->transmit_queue,
                                        struct cec_data, list);
                list_del_init(&data->list);
                adap->transmit_queue_sz--;
                /* Make this the current transmitting message */
                adap->transmitting = data;

                /*
                 * Suggested number of attempts as per the CEC 2.0 spec:
                 * 4 attempts is the default, except for 'secondary poll
                 * messages', i.e. poll messages not sent during the adapter
                 * configuration phase when it allocates logical addresses.
                 */
                if (data->msg.len == 1 && adap->is_configured)
                        attempts = 2;
                else
                        attempts = 4;

                /* Set the suggested signal free time */
                if (data->attempts) {
                        /* should be >= 3 data bit periods for a retry */
                        signal_free_time = CEC_SIGNAL_FREE_TIME_RETRY;
                } else if (data->new_initiator) {
                        /* should be >= 5 data bit periods for new initiator */
                        signal_free_time = CEC_SIGNAL_FREE_TIME_NEW_INITIATOR;
                } else {
                        /*
                         * should be >= 7 data bit periods for sending another
                         * frame immediately after another.
                         */
                        signal_free_time = CEC_SIGNAL_FREE_TIME_NEXT_XFER;
                }
                if (data->attempts == 0)
                        data->attempts = attempts;

                /* Tell the adapter to transmit, cancel on error */
                if (adap->ops->adap_transmit(adap, data->attempts,
                                             signal_free_time, &data->msg))
                        cec_data_cancel(data);

unlock:
                mutex_unlock(&adap->lock);

                if (kthread_should_stop())
                        break;
        }
        return 0;
}

/*
 * Called by the CEC adapter if a transmit finished.
 */
void cec_transmit_done(struct cec_adapter *adap, u8 status, u8 arb_lost_cnt,
                       u8 nack_cnt, u8 low_drive_cnt, u8 error_cnt)
{
        struct cec_data *data;
        struct cec_msg *msg;
        u64 ts = ktime_get_ns();

        dprintk(2, "cec_transmit_done %02x\n", status);
        mutex_lock(&adap->lock);
        data = adap->transmitting;
        if (!data) {
                /*
                 * This can happen if a transmit was issued and the cable is
                 * unplugged while the transmit is ongoing. Ignore this
                 * transmit in that case.
                 */
                dprintk(1, "cec_transmit_done without an ongoing transmit!\n");
                goto unlock;
        }

        msg = &data->msg;

        /* Drivers must fill in the status! */
        WARN_ON(status == 0);
        msg->tx_ts = ts;
        msg->tx_status |= status;
        msg->tx_arb_lost_cnt += arb_lost_cnt;
        msg->tx_nack_cnt += nack_cnt;
        msg->tx_low_drive_cnt += low_drive_cnt;
        msg->tx_error_cnt += error_cnt;

        /* Mark that we're done with this transmit */
        adap->transmitting = NULL;

        /*
         * If there are still retry attempts left and there was an error and
         * the hardware didn't signal that it retried itself (by setting
         * CEC_TX_STATUS_MAX_RETRIES), then we will retry ourselves.
         */
        if (data->attempts > 1 &&
            !(status & (CEC_TX_STATUS_MAX_RETRIES | CEC_TX_STATUS_OK))) {
                /* Retry this message */
                data->attempts--;
                /* Add the message in front of the transmit queue */
                list_add(&data->list, &adap->transmit_queue);
                adap->transmit_queue_sz++;
                goto wake_thread;
        }

        data->attempts = 0;

        /* Always set CEC_TX_STATUS_MAX_RETRIES on error */
        if (!(status & CEC_TX_STATUS_OK))
                msg->tx_status |= CEC_TX_STATUS_MAX_RETRIES;

        /* Queue transmitted message for monitoring purposes */
        cec_queue_msg_monitor(adap, msg, 1);

        if ((status & CEC_TX_STATUS_OK) && adap->is_configured &&
            msg->timeout) {
                /*
                 * Queue the message into the wait queue if we want to wait
                 * for a reply.
                 */
                list_add_tail(&data->list, &adap->wait_queue);
                schedule_delayed_work(&data->work,
                                      msecs_to_jiffies(msg->timeout));
        } else {
                /* Otherwise we're done */
                cec_data_completed(data);
        }

wake_thread:
        /*
         * Wake up the main thread to see if another message is ready
         * for transmitting or to retry the current message.
         */
        wake_up_interruptible(&adap->kthread_waitq);
unlock:
        mutex_unlock(&adap->lock);
}
EXPORT_SYMBOL_GPL(cec_transmit_done);

/*
 * Called when waiting for a reply times out.
 */
static void cec_wait_timeout(struct work_struct *work)
{
        struct cec_data *data = container_of(work, struct cec_data, work.work);
        struct cec_adapter *adap = data->adap;

        mutex_lock(&adap->lock);
        /*
         * Sanity check in case the timeout and the arrival of the message
         * happened at the same time.
         */
        if (list_empty(&data->list))
                goto unlock;

        /* Mark the message as timed out */
        list_del_init(&data->list);
        data->msg.rx_ts = ktime_get_ns();
        data->msg.rx_status = CEC_RX_STATUS_TIMEOUT;
        cec_data_completed(data);
unlock:
        mutex_unlock(&adap->lock);
}

/*
 * Transmit a message. The fh argument may be NULL if the transmit is not
 * associated with a specific filehandle.
 *
 * This function is called with adap->lock held.
 */
int cec_transmit_msg_fh(struct cec_adapter *adap, struct cec_msg *msg,
                        struct cec_fh *fh, bool block)
{
        struct cec_data *data;
        u8 last_initiator = 0xff;
        unsigned int timeout;
        int res = 0;

        msg->rx_ts = 0;
        msg->tx_ts = 0;
        msg->rx_status = 0;
        msg->tx_status = 0;
        msg->tx_arb_lost_cnt = 0;
        msg->tx_nack_cnt = 0;
        msg->tx_low_drive_cnt = 0;
        msg->tx_error_cnt = 0;
        msg->flags = 0;
        msg->sequence = ++adap->sequence;
        if (!msg->sequence)
                msg->sequence = ++adap->sequence;

        if (msg->reply && msg->timeout == 0) {
                /* Make sure the timeout isn't 0. */
                msg->timeout = 1000;
        }

        /* Sanity checks */
        if (msg->len == 0 || msg->len > CEC_MAX_MSG_SIZE) {
                dprintk(1, "cec_transmit_msg: invalid length %d\n", msg->len);
                return -EINVAL;
        }
        if (msg->timeout && msg->len == 1) {
                dprintk(1, "cec_transmit_msg: can't reply for poll msg\n");
                return -EINVAL;
        }
        memset(msg->msg + msg->len, 0, sizeof(msg->msg) - msg->len);
        if (msg->len == 1) {
                if (cec_msg_initiator(msg) != 0xf ||
                    cec_msg_destination(msg) == 0xf) {
                        dprintk(1, "cec_transmit_msg: invalid poll message\n");
                        return -EINVAL;
                }
                if (cec_has_log_addr(adap, cec_msg_destination(msg))) {
                        /*
                         * If the destination is a logical address our adapter
                         * has already claimed, then just NACK this.
                         * It depends on the hardware what it will do with a
                         * POLL to itself (some OK this), so it is just as
                         * easy to handle it here so the behavior will be
                         * consistent.
                         */
                        msg->tx_ts = ktime_get_ns();
                        msg->tx_status = CEC_TX_STATUS_NACK |
                                         CEC_TX_STATUS_MAX_RETRIES;
                        msg->tx_nack_cnt = 1;
                        return 0;
                }
        }
        if (msg->len > 1 && !cec_msg_is_broadcast(msg) &&
            cec_has_log_addr(adap, cec_msg_destination(msg))) {
                dprintk(1, "cec_transmit_msg: destination is the adapter itself\n");
                return -EINVAL;
        }
        if (cec_msg_initiator(msg) != 0xf &&
            !cec_has_log_addr(adap, cec_msg_initiator(msg))) {
                dprintk(1, "cec_transmit_msg: initiator has unknown logical address %d\n",
                        cec_msg_initiator(msg));
                return -EINVAL;
        }
        if (!adap->is_configured && !adap->is_configuring)
                return -ENONET;

        if (adap->transmit_queue_sz >= CEC_MAX_MSG_TX_QUEUE_SZ)
                return -EBUSY;

        data = kzalloc(sizeof(*data), GFP_KERNEL);
        if (!data)
                return -ENOMEM;

        if (msg->len > 1 && msg->msg[1] == CEC_MSG_CDC_MESSAGE) {
                msg->msg[2] = adap->phys_addr >> 8;
                msg->msg[3] = adap->phys_addr & 0xff;
        }

        if (msg->timeout)
                dprintk(2, "cec_transmit_msg: %*ph (wait for 0x%02x%s)\n",
                        msg->len, msg->msg, msg->reply, !block ? ", nb" : "");
        else
                dprintk(2, "cec_transmit_msg: %*ph%s\n",
                        msg->len, msg->msg, !block ? " (nb)" : "");

        data->msg = *msg;
        data->fh = fh;
        data->adap = adap;
        data->blocking = block;

        /*
         * Determine if this message follows a message from the same
         * initiator. Needed to determine the free signal time later on.
         */
        if (msg->len > 1) {
                if (!(list_empty(&adap->transmit_queue))) {
                        const struct cec_data *last;

                        last = list_last_entry(&adap->transmit_queue,
                                               const struct cec_data, list);
                        last_initiator = cec_msg_initiator(&last->msg);
                } else if (adap->transmitting) {
                        last_initiator =
                                cec_msg_initiator(&adap->transmitting->msg);
                }
        }
        data->new_initiator = last_initiator != cec_msg_initiator(msg);
        init_completion(&data->c);
        INIT_DELAYED_WORK(&data->work, cec_wait_timeout);

        if (fh)
                list_add_tail(&data->xfer_list, &fh->xfer_list);
        list_add_tail(&data->list, &adap->transmit_queue);
        adap->transmit_queue_sz++;
        if (!adap->transmitting)
                wake_up_interruptible(&adap->kthread_waitq);

        /* All done if we don't need to block waiting for completion */
        if (!block)
                return 0;

        /*
         * If we don't get a completion before this time something is really
         * wrong and we time out.
         */
        timeout = CEC_XFER_TIMEOUT_MS;
        /* Add the requested timeout if we have to wait for a reply as well */
        if (msg->timeout)
                timeout += msg->timeout;

        /*
         * Release the lock and wait, retake the lock afterwards.
         */
        mutex_unlock(&adap->lock);
        res = wait_for_completion_killable_timeout(&data->c,
                                                   msecs_to_jiffies(timeout));
        mutex_lock(&adap->lock);

        if (data->completed) {
                /* The transmit completed (possibly with an error) */
                *msg = data->msg;
                kfree(data);
                return 0;
        }
        /*
         * The wait for completion timed out or was interrupted, so mark this
         * as non-blocking and disconnect from the filehandle since it is
         * still 'in flight'. When it finally completes it will just drop the
         * result silently.
         */
        data->blocking = false;
        if (data->fh)
                list_del(&data->xfer_list);
        data->fh = NULL;

        if (res == 0) { /* timed out */
                /* Check if the reply or the transmit failed */
                if (msg->timeout && (msg->tx_status & CEC_TX_STATUS_OK))
                        msg->rx_status = CEC_RX_STATUS_TIMEOUT;
                else
                        msg->tx_status = CEC_TX_STATUS_MAX_RETRIES;
        }
        return res > 0 ? 0 : res;
}

/* Helper function to be used by drivers and this framework. */
int cec_transmit_msg(struct cec_adapter *adap, struct cec_msg *msg,
                     bool block)
{
        int ret;

        mutex_lock(&adap->lock);
        ret = cec_transmit_msg_fh(adap, msg, NULL, block);
        mutex_unlock(&adap->lock);
        return ret;
}
EXPORT_SYMBOL_GPL(cec_transmit_msg);

/*
 * I don't like forward references but without this the low-level
 * cec_received_msg() function would come after a bunch of high-level
 * CEC protocol handling functions. That was very confusing.
 */
static int cec_receive_notify(struct cec_adapter *adap, struct cec_msg *msg,
                              bool is_reply);

/* Called by the CEC adapter if a message is received */
void cec_received_msg(struct cec_adapter *adap, struct cec_msg *msg)
{
        struct cec_data *data;
        u8 msg_init = cec_msg_initiator(msg);
        u8 msg_dest = cec_msg_destination(msg);
        bool is_reply = false;
        bool valid_la = true;

        if (WARN_ON(!msg->len || msg->len > CEC_MAX_MSG_SIZE))
                return;

        msg->rx_ts = ktime_get_ns();
        msg->rx_status = CEC_RX_STATUS_OK;
        msg->sequence = msg->reply = msg->timeout = 0;
        msg->tx_status = 0;
        msg->tx_ts = 0;
        msg->flags = 0;
        memset(msg->msg + msg->len, 0, sizeof(msg->msg) - msg->len);

        mutex_lock(&adap->lock);
        dprintk(2, "cec_received_msg: %*ph\n", msg->len, msg->msg);

        /* Check if this message was for us (directed or broadcast). */
        if (!cec_msg_is_broadcast(msg))
                valid_la = cec_has_log_addr(adap, msg_dest);

        /* It's a valid message and not a poll or CDC message */
        if (valid_la && msg->len > 1 && msg->msg[1] != CEC_MSG_CDC_MESSAGE) {
                u8 cmd = msg->msg[1];
                bool abort = cmd == CEC_MSG_FEATURE_ABORT;

                /* The aborted command is in msg[2] */
                if (abort)
                        cmd = msg->msg[2];

                /*
                 * Walk over all transmitted messages that are waiting for a
                 * reply.
                 */
                list_for_each_entry(data, &adap->wait_queue, list) {
                        struct cec_msg *dst = &data->msg;

                        /* Does the command match? */
                        if ((abort && cmd != dst->msg[1]) ||
                            (!abort && cmd != dst->reply))
                                continue;

                        /* Does the addressing match? */
                        if (msg_init != cec_msg_destination(dst) &&
                            !cec_msg_is_broadcast(dst))
                                continue;

                        /* We got a reply */
                        memcpy(dst->msg, msg->msg, msg->len);
                        dst->len = msg->len;
                        dst->rx_ts = msg->rx_ts;
                        dst->rx_status = msg->rx_status;
                        if (abort)
                                dst->rx_status |= CEC_RX_STATUS_FEATURE_ABORT;
                        /* Remove it from the wait_queue */
                        list_del_init(&data->list);

                        /* Cancel the pending timeout work */
                        if (!cancel_delayed_work(&data->work)) {
                                mutex_unlock(&adap->lock);
                                flush_scheduled_work();
                                mutex_lock(&adap->lock);
                        }
                        /*
                         * Mark this as a reply, provided someone is still
                         * waiting for the answer.
                         */
                        if (data->fh)
                                is_reply = true;
                        cec_data_completed(data);
                        break;
                }
        }
        mutex_unlock(&adap->lock);

        /* Pass the message on to any monitoring filehandles */
        cec_queue_msg_monitor(adap, msg, valid_la);

        /* We're done if it is not for us or a poll message */
        if (!valid_la || msg->len <= 1)
                return;

        if (adap->log_addrs.log_addr_mask == 0)
                return;

        /*
         * Process the message on the protocol level. If is_reply is true,
         * then cec_receive_notify() won't pass on the reply to the listener(s)
         * since that was already done by cec_data_completed() above.
         */
        cec_receive_notify(adap, msg, is_reply);
}
EXPORT_SYMBOL_GPL(cec_received_msg);

/* Logical Address Handling */

/*
 * Attempt to claim a specific logical address.
 *
 * This function is called with adap->lock held.
 */
static int cec_config_log_addr(struct cec_adapter *adap,
                               unsigned int idx,
                               unsigned int log_addr)
{
        struct cec_log_addrs *las = &adap->log_addrs;
        struct cec_msg msg = { };
        int err;

        if (cec_has_log_addr(adap, log_addr))
                return 0;

        /* Send poll message */
        msg.len = 1;
        msg.msg[0] = 0xf0 | log_addr;
        err = cec_transmit_msg_fh(adap, &msg, NULL, true);

        /*
         * While trying to poll the physical address was reset
         * and the adapter was unconfigured, so bail out.
         */
        if (!adap->is_configuring)
                return -EINTR;

        if (err)
                return err;

        if (msg.tx_status & CEC_TX_STATUS_OK)
                return 0;

        /*
         * Message not acknowledged, so this logical
         * address is free to use.
         */
        err = adap->ops->adap_log_addr(adap, log_addr);
        if (err)
                return err;

        las->log_addr[idx] = log_addr;
        las->log_addr_mask |= 1 << log_addr;
        adap->phys_addrs[log_addr] = adap->phys_addr;

        dprintk(2, "claimed addr %d (%d)\n", log_addr,
                las->primary_device_type[idx]);
        return 1;
}

/*
 * Unconfigure the adapter: clear all logical addresses and send
 * the state changed event.
 *
 * This function is called with adap->lock held.
 */
static void cec_adap_unconfigure(struct cec_adapter *adap)
{
        WARN_ON(adap->ops->adap_log_addr(adap, CEC_LOG_ADDR_INVALID));
        adap->log_addrs.log_addr_mask = 0;
        adap->is_configuring = false;
        adap->is_configured = false;
        memset(adap->phys_addrs, 0xff, sizeof(adap->phys_addrs));
        wake_up_interruptible(&adap->kthread_waitq);
        cec_post_state_event(adap);
}

/*
 * Attempt to claim the required logical addresses.
 */
static int cec_config_thread_func(void *arg)
{
        /* The various LAs for each type of device */
        static const u8 tv_log_addrs[] = {
                CEC_LOG_ADDR_TV, CEC_LOG_ADDR_SPECIFIC,
                CEC_LOG_ADDR_INVALID
        };
        static const u8 record_log_addrs[] = {
                CEC_LOG_ADDR_RECORD_1, CEC_LOG_ADDR_RECORD_2,
                CEC_LOG_ADDR_RECORD_3,
                CEC_LOG_ADDR_BACKUP_1, CEC_LOG_ADDR_BACKUP_2,
                CEC_LOG_ADDR_INVALID
        };
        static const u8 tuner_log_addrs[] = {
                CEC_LOG_ADDR_TUNER_1, CEC_LOG_ADDR_TUNER_2,
                CEC_LOG_ADDR_TUNER_3, CEC_LOG_ADDR_TUNER_4,
                CEC_LOG_ADDR_BACKUP_1, CEC_LOG_ADDR_BACKUP_2,
                CEC_LOG_ADDR_INVALID
        };
        static const u8 playback_log_addrs[] = {
                CEC_LOG_ADDR_PLAYBACK_1, CEC_LOG_ADDR_PLAYBACK_2,
                CEC_LOG_ADDR_PLAYBACK_3,
                CEC_LOG_ADDR_BACKUP_1, CEC_LOG_ADDR_BACKUP_2,
                CEC_LOG_ADDR_INVALID
        };
        static const u8 audiosystem_log_addrs[] = {
                CEC_LOG_ADDR_AUDIOSYSTEM,
                CEC_LOG_ADDR_INVALID
        };
        static const u8 specific_use_log_addrs[] = {
                CEC_LOG_ADDR_SPECIFIC,
                CEC_LOG_ADDR_BACKUP_1, CEC_LOG_ADDR_BACKUP_2,
                CEC_LOG_ADDR_INVALID
        };
        static const u8 *type2addrs[6] = {
                [CEC_LOG_ADDR_TYPE_TV] = tv_log_addrs,
                [CEC_LOG_ADDR_TYPE_RECORD] = record_log_addrs,
                [CEC_LOG_ADDR_TYPE_TUNER] = tuner_log_addrs,
                [CEC_LOG_ADDR_TYPE_PLAYBACK] = playback_log_addrs,
                [CEC_LOG_ADDR_TYPE_AUDIOSYSTEM] = audiosystem_log_addrs,
                [CEC_LOG_ADDR_TYPE_SPECIFIC] = specific_use_log_addrs,
        };
        static const u16 type2mask[] = {
                [CEC_LOG_ADDR_TYPE_TV] = CEC_LOG_ADDR_MASK_TV,
                [CEC_LOG_ADDR_TYPE_RECORD] = CEC_LOG_ADDR_MASK_RECORD,
                [CEC_LOG_ADDR_TYPE_TUNER] = CEC_LOG_ADDR_MASK_TUNER,
                [CEC_LOG_ADDR_TYPE_PLAYBACK] = CEC_LOG_ADDR_MASK_PLAYBACK,
                [CEC_LOG_ADDR_TYPE_AUDIOSYSTEM] = CEC_LOG_ADDR_MASK_AUDIOSYSTEM,
                [CEC_LOG_ADDR_TYPE_SPECIFIC] = CEC_LOG_ADDR_MASK_SPECIFIC,
        };
        struct cec_adapter *adap = arg;
        struct cec_log_addrs *las = &adap->log_addrs;
        int err;
        int i, j;

        mutex_lock(&adap->lock);
        dprintk(1, "physical address: %x.%x.%x.%x, claim %d logical addresses\n",
                cec_phys_addr_exp(adap->phys_addr), las->num_log_addrs);
        las->log_addr_mask = 0;

        if (las->log_addr_type[0] == CEC_LOG_ADDR_TYPE_UNREGISTERED)
                goto configured;

        for (i = 0; i < las->num_log_addrs; i++) {
                unsigned int type = las->log_addr_type[i];
                const u8 *la_list;
                u8 last_la;

                /*
                 * The TV functionality can only map to physical address 0.
                 * For any other address, try the Specific functionality
                 * instead as per the spec.
                 */
                if (adap->phys_addr && type == CEC_LOG_ADDR_TYPE_TV)
                        type = CEC_LOG_ADDR_TYPE_SPECIFIC;

                la_list = type2addrs[type];
                last_la = las->log_addr[i];
                las->log_addr[i] = CEC_LOG_ADDR_INVALID;
                if (last_la == CEC_LOG_ADDR_INVALID ||
                    last_la == CEC_LOG_ADDR_UNREGISTERED ||
                    !(last_la & type2mask[type]))
                        last_la = la_list[0];

                err = cec_config_log_addr(adap, i, last_la);
                if (err > 0) /* Reused last LA */
                        continue;

                if (err < 0)
                        goto unconfigure;

                for (j = 0; la_list[j] != CEC_LOG_ADDR_INVALID; j++) {
                        /* Tried this one already, skip it */
                        if (la_list[j] == last_la)
                                continue;
                        /* The backup addresses are CEC 2.0 specific */
                        if ((la_list[j] == CEC_LOG_ADDR_BACKUP_1 ||
                             la_list[j] == CEC_LOG_ADDR_BACKUP_2) &&
                            las->cec_version < CEC_OP_CEC_VERSION_2_0)
                                continue;

                        err = cec_config_log_addr(adap, i, la_list[j]);
                        if (err == 0) /* LA is in use */
                                continue;
                        if (err < 0)
                                goto unconfigure;
                        /* Done, claimed an LA */
                        break;
                }

                if (la_list[j] == CEC_LOG_ADDR_INVALID)
                        dprintk(1, "could not claim LA %d\n", i);
        }

        if (adap->log_addrs.log_addr_mask == 0 &&
            !(las->flags & CEC_LOG_ADDRS_FL_ALLOW_UNREG_FALLBACK))
                goto unconfigure;

configured:
        if (adap->log_addrs.log_addr_mask == 0) {
                /* Fall back to unregistered */
                las->log_addr[0] = CEC_LOG_ADDR_UNREGISTERED;
                las->log_addr_mask = 1 << las->log_addr[0];
                for (i = 1; i < las->num_log_addrs; i++)
                        las->log_addr[i] = CEC_LOG_ADDR_INVALID;
        }
        adap->is_configured = true;
        adap->is_configuring = false;
        cec_post_state_event(adap);
        mutex_unlock(&adap->lock);

        for (i = 0; i < las->num_log_addrs; i++) {
                if (las->log_addr[i] == CEC_LOG_ADDR_INVALID)
                        continue;

                /*
                 * Report Features must come first according
                 * to CEC 2.0
                 */
                if (las->log_addr[i] != CEC_LOG_ADDR_UNREGISTERED)
                        cec_report_features(adap, i);
                cec_report_phys_addr(adap, i);
        }
        for (i = las->num_log_addrs; i < CEC_MAX_LOG_ADDRS; i++)
                las->log_addr[i] = CEC_LOG_ADDR_INVALID;
        mutex_lock(&adap->lock);
        adap->kthread_config = NULL;
        mutex_unlock(&adap->lock);
        complete(&adap->config_completion);
        return 0;

unconfigure:
        for (i = 0; i < las->num_log_addrs; i++)
                las->log_addr[i] = CEC_LOG_ADDR_INVALID;
        cec_adap_unconfigure(adap);
        adap->kthread_config = NULL;
        mutex_unlock(&adap->lock);
        complete(&adap->config_completion);
        return 0;
}

/*
 * Called from either __cec_s_phys_addr or __cec_s_log_addrs to claim the
 * logical addresses.
 *
 * This function is called with adap->lock held.
 */
static void cec_claim_log_addrs(struct cec_adapter *adap, bool block)
{
        if (WARN_ON(adap->is_configuring || adap->is_configured))
                return;

        init_completion(&adap->config_completion);

        /* Ready to kick off the thread */
        adap->is_configuring = true;
        adap->kthread_config = kthread_run(cec_config_thread_func, adap,
                                           "ceccfg-%s", adap->name);
        if (IS_ERR(adap->kthread_config)) {
                adap->kthread_config = NULL;
        } else if (block) {
                mutex_unlock(&adap->lock);
                wait_for_completion(&adap->config_completion);
                mutex_lock(&adap->lock);
        }
}

/* Set a new physical address and send an event notifying userspace of this.
 *
 * This function is called with adap->lock held.
 */
void __cec_s_phys_addr(struct cec_adapter *adap, u16 phys_addr, bool block)
{
        if (phys_addr == adap->phys_addr || adap->devnode.unregistered)
                return;

        if (phys_addr == CEC_PHYS_ADDR_INVALID ||
            adap->phys_addr != CEC_PHYS_ADDR_INVALID) {
                adap->phys_addr = CEC_PHYS_ADDR_INVALID;
                cec_post_state_event(adap);
                cec_adap_unconfigure(adap);
                /* Disabling monitor all mode should always succeed */
                if (adap->monitor_all_cnt)
                        WARN_ON(call_op(adap, adap_monitor_all_enable, false));
                WARN_ON(adap->ops->adap_enable(adap, false));
                if (phys_addr == CEC_PHYS_ADDR_INVALID)
                        return;
        }

        if (adap->ops->adap_enable(adap, true))
                return;

        if (adap->monitor_all_cnt &&
            call_op(adap, adap_monitor_all_enable, true)) {
                WARN_ON(adap->ops->adap_enable(adap, false));
                return;
        }
        adap->phys_addr = phys_addr;
        cec_post_state_event(adap);
        if (adap->log_addrs.num_log_addrs)
                cec_claim_log_addrs(adap, block);
}

void cec_s_phys_addr(struct cec_adapter *adap, u16 phys_addr, bool block)
{
        if (IS_ERR_OR_NULL(adap))
                return;

        if (WARN_ON(adap->capabilities & CEC_CAP_PHYS_ADDR))
                return;
        mutex_lock(&adap->lock);
        __cec_s_phys_addr(adap, phys_addr, block);
        mutex_unlock(&adap->lock);
}
EXPORT_SYMBOL_GPL(cec_s_phys_addr);

/*
 * Called from either the ioctl or a driver to set the logical addresses.
 *
 * This function is called with adap->lock held.
 */
int __cec_s_log_addrs(struct cec_adapter *adap,
                      struct cec_log_addrs *log_addrs, bool block)
{
        u16 type_mask = 0;
        int i;

        if (adap->devnode.unregistered)
                return -ENODEV;

        if (!log_addrs || log_addrs->num_log_addrs == 0) {
                adap->log_addrs.num_log_addrs = 0;
                cec_adap_unconfigure(adap);
                return 0;
        }

        /* Ensure the osd name is 0-terminated */
        log_addrs->osd_name[sizeof(log_addrs->osd_name) - 1] = '\0';

        /* Sanity checks */
        if (log_addrs->num_log_addrs > adap->available_log_addrs) {
                dprintk(1, "num_log_addrs > %d\n", adap->available_log_addrs);
                return -EINVAL;
        }

        /*
         * Vendor ID is a 24 bit number, so check if the value is
         * within the correct range.
         */
        if (log_addrs->vendor_id != CEC_VENDOR_ID_NONE &&
            (log_addrs->vendor_id & 0xff000000) != 0)
                return -EINVAL;

        if (log_addrs->cec_version != CEC_OP_CEC_VERSION_1_4 &&
            log_addrs->cec_version != CEC_OP_CEC_VERSION_2_0)
                return -EINVAL;

        if (log_addrs->num_log_addrs > 1)
                for (i = 0; i < log_addrs->num_log_addrs; i++)
                        if (log_addrs->log_addr_type[i] ==
                                        CEC_LOG_ADDR_TYPE_UNREGISTERED) {
                                dprintk(1, "num_log_addrs > 1 can't be combined with unregistered LA\n");
                                return -EINVAL;
                        }

        for (i = 0; i < log_addrs->num_log_addrs; i++) {
                const u8 feature_sz = ARRAY_SIZE(log_addrs->features[0]);
                u8 *features = log_addrs->features[i];
                bool op_is_dev_features = false;

                log_addrs->log_addr[i] = CEC_LOG_ADDR_INVALID;
                if (type_mask & (1 << log_addrs->log_addr_type[i])) {
                        dprintk(1, "duplicate logical address type\n");
                        return -EINVAL;
                }
                type_mask |= 1 << log_addrs->log_addr_type[i];
                if ((type_mask & (1 << CEC_LOG_ADDR_TYPE_RECORD)) &&
                    (type_mask & (1 << CEC_LOG_ADDR_TYPE_PLAYBACK))) {
                        /* Record already contains the playback functionality */
                        dprintk(1, "invalid record + playback combination\n");
                        return -EINVAL;
                }
                if (log_addrs->primary_device_type[i] >
                                        CEC_OP_PRIM_DEVTYPE_PROCESSOR) {
                        dprintk(1, "unknown primary device type\n");
                        return -EINVAL;
                }
                if (log_addrs->primary_device_type[i] == 2) {
                        dprintk(1, "invalid primary device type\n");
                        return -EINVAL;
                }
                if (log_addrs->log_addr_type[i] > CEC_LOG_ADDR_TYPE_UNREGISTERED) {
                        dprintk(1, "unknown logical address type\n");
                        return -EINVAL;
                }
                for (i = 0; i < feature_sz; i++) {
                        if ((features[i] & 0x80) == 0) {
                                if (op_is_dev_features)
                                        break;
                                op_is_dev_features = true;
                        }
                }
                if (!op_is_dev_features || i == feature_sz) {
                        dprintk(1, "malformed features\n");
                        return -EINVAL;
                }
                /* Zero unused part of the feature array */
                memset(features + i + 1, 0, feature_sz - i - 1);
        }

        if (log_addrs->cec_version >= CEC_OP_CEC_VERSION_2_0) {
                if (log_addrs->num_log_addrs > 2) {
                        dprintk(1, "CEC 2.0 allows no more than 2 logical addresses\n");
                        return -EINVAL;
                }
                if (log_addrs->num_log_addrs == 2) {
                        if (!(type_mask & ((1 << CEC_LOG_ADDR_TYPE_AUDIOSYSTEM) |
                                           (1 << CEC_LOG_ADDR_TYPE_TV)))) {
                                dprintk(1, "Two LAs is only allowed for audiosystem and TV\n");
                                return -EINVAL;
                        }
                        if (!(type_mask & ((1 << CEC_LOG_ADDR_TYPE_PLAYBACK) |
                                           (1 << CEC_LOG_ADDR_TYPE_RECORD)))) {
                                dprintk(1, "An audiosystem/TV can only be combined with record or playback\n");
                                return -EINVAL;
                        }
                }
        }

        /* Zero unused LAs */
        for (i = log_addrs->num_log_addrs; i < CEC_MAX_LOG_ADDRS; i++) {
                log_addrs->primary_device_type[i] = 0;
                log_addrs->log_addr_type[i] = 0;
                log_addrs->all_device_types[i] = 0;
                memset(log_addrs->features[i], 0,
                       sizeof(log_addrs->features[i]));
        }

        log_addrs->log_addr_mask = adap->log_addrs.log_addr_mask;
        adap->log_addrs = *log_addrs;
        if (adap->phys_addr != CEC_PHYS_ADDR_INVALID)
                cec_claim_log_addrs(adap, block);
        return 0;
}

int cec_s_log_addrs(struct cec_adapter *adap,
                    struct cec_log_addrs *log_addrs, bool block)
{
        int err;

        if (WARN_ON(adap->capabilities & CEC_CAP_LOG_ADDRS))
                return -EINVAL;
        mutex_lock(&adap->lock);
        err = __cec_s_log_addrs(adap, log_addrs, block);
        mutex_unlock(&adap->lock);
        return err;
}
EXPORT_SYMBOL_GPL(cec_s_log_addrs);

/* High-level core CEC message handling */

/* Transmit the Report Features message */
static int cec_report_features(struct cec_adapter *adap, unsigned int la_idx)
{
        struct cec_msg msg = { };
        const struct cec_log_addrs *las = &adap->log_addrs;
        const u8 *features = las->features[la_idx];
        bool op_is_dev_features = false;
        unsigned int idx;

        /* This is 2.0 and up only */
        if (adap->log_addrs.cec_version < CEC_OP_CEC_VERSION_2_0)
                return 0;

        /* Report Features */
        msg.msg[0] = (las->log_addr[la_idx] << 4) | 0x0f;
        msg.len = 4;
        msg.msg[1] = CEC_MSG_REPORT_FEATURES;
        msg.msg[2] = adap->log_addrs.cec_version;
        msg.msg[3] = las->all_device_types[la_idx];

        /* Write RC Profiles first, then Device Features */
        for (idx = 0; idx < ARRAY_SIZE(las->features[0]); idx++) {
                msg.msg[msg.len++] = features[idx];
                if ((features[idx] & CEC_OP_FEAT_EXT) == 0) {
                        if (op_is_dev_features)
                                break;
                        op_is_dev_features = true;
                }
        }
        return cec_transmit_msg(adap, &msg, false);
}

/* Transmit the Report Physical Address message */
static int cec_report_phys_addr(struct cec_adapter *adap, unsigned int la_idx)
{
        const struct cec_log_addrs *las = &adap->log_addrs;
        struct cec_msg msg = { };

        /* Report Physical Address */
        msg.msg[0] = (las->log_addr[la_idx] << 4) | 0x0f;
        cec_msg_report_physical_addr(&msg, adap->phys_addr,
                                     las->primary_device_type[la_idx]);
        dprintk(2, "config: la %d pa %x.%x.%x.%x\n",
                las->log_addr[la_idx],
                        cec_phys_addr_exp(adap->phys_addr));
        return cec_transmit_msg(adap, &msg, false);
}

/* Transmit the Feature Abort message */
static int cec_feature_abort_reason(struct cec_adapter *adap,
                                    struct cec_msg *msg, u8 reason)
{
        struct cec_msg tx_msg = { };

        /*
         * Don't reply with CEC_MSG_FEATURE_ABORT to a CEC_MSG_FEATURE_ABORT
         * message!
         */
        if (msg->msg[1] == CEC_MSG_FEATURE_ABORT)
                return 0;
        cec_msg_set_reply_to(&tx_msg, msg);
        cec_msg_feature_abort(&tx_msg, msg->msg[1], reason);
        return cec_transmit_msg(adap, &tx_msg, false);
}

static int cec_feature_abort(struct cec_adapter *adap, struct cec_msg *msg)
{
        return cec_feature_abort_reason(adap, msg,
                                        CEC_OP_ABORT_UNRECOGNIZED_OP);
}

static int cec_feature_refused(struct cec_adapter *adap, struct cec_msg *msg)
{
        return cec_feature_abort_reason(adap, msg,
                                        CEC_OP_ABORT_REFUSED);
}

/*
 * Called when a CEC message is received. This function will do any
 * necessary core processing. The is_reply bool is true if this message
 * is a reply to an earlier transmit.
 *
 * The message is either a broadcast message or a valid directed message.
 */
static int cec_receive_notify(struct cec_adapter *adap, struct cec_msg *msg,
                              bool is_reply)
{
        bool is_broadcast = cec_msg_is_broadcast(msg);
        u8 dest_laddr = cec_msg_destination(msg);
        u8 init_laddr = cec_msg_initiator(msg);
        u8 devtype = cec_log_addr2dev(adap, dest_laddr);
        int la_idx = cec_log_addr2idx(adap, dest_laddr);
        bool from_unregistered = init_laddr == 0xf;
        struct cec_msg tx_cec_msg = { };

        dprintk(1, "cec_receive_notify: %*ph\n", msg->len, msg->msg);

        if (adap->ops->received) {
                /* Allow drivers to process the message first */
                if (adap->ops->received(adap, msg) != -ENOMSG)
                        return 0;
        }

        /*
         * REPORT_PHYSICAL_ADDR, CEC_MSG_USER_CONTROL_PRESSED and
         * CEC_MSG_USER_CONTROL_RELEASED messages always have to be
         * handled by the CEC core, even if the passthrough mode is on.
         * The others are just ignored if passthrough mode is on.
         */
        switch (msg->msg[1]) {
        case CEC_MSG_GET_CEC_VERSION:
        case CEC_MSG_GIVE_DEVICE_VENDOR_ID:
        case CEC_MSG_ABORT:
        case CEC_MSG_GIVE_DEVICE_POWER_STATUS:
        case CEC_MSG_GIVE_PHYSICAL_ADDR:
        case CEC_MSG_GIVE_OSD_NAME:
        case CEC_MSG_GIVE_FEATURES:
                /*
                 * Skip processing these messages if the passthrough mode
                 * is on.
                 */
                if (adap->passthrough)
                        goto skip_processing;
                /* Ignore if addressing is wrong */
                if (is_broadcast || from_unregistered)
                        return 0;
                break;

        case CEC_MSG_USER_CONTROL_PRESSED:
        case CEC_MSG_USER_CONTROL_RELEASED:
                /* Wrong addressing mode: don't process */
                if (is_broadcast || from_unregistered)
                        goto skip_processing;
                break;

        case CEC_MSG_REPORT_PHYSICAL_ADDR:
                /*
                 * This message is always processed, regardless of the
                 * passthrough setting.
                 *
                 * Exception: don't process if wrong addressing mode.
                 */
                if (!is_broadcast)
                        goto skip_processing;
                break;

        default:
                break;
        }

        cec_msg_set_reply_to(&tx_cec_msg, msg);

        switch (msg->msg[1]) {
        /* The following messages are processed but still passed through */
        case CEC_MSG_REPORT_PHYSICAL_ADDR: {
                u16 pa = (msg->msg[2] << 8) | msg->msg[3];

                if (!from_unregistered)
                        adap->phys_addrs[init_laddr] = pa;
                dprintk(1, "Reported physical address %x.%x.%x.%x for logical address %d\n",
                        cec_phys_addr_exp(pa), init_laddr);
                break;
        }

        case CEC_MSG_USER_CONTROL_PRESSED:
                if (!(adap->capabilities & CEC_CAP_RC))
                        break;

#if IS_REACHABLE(CONFIG_RC_CORE)
                switch (msg->msg[2]) {
                /*
                 * Play function, this message can have variable length
                 * depending on the specific play function that is used.
                 */
                case 0x60:
                        if (msg->len == 2)
                                rc_keydown(adap->rc, RC_TYPE_CEC,
                                           msg->msg[2], 0);
                        else
                                rc_keydown(adap->rc, RC_TYPE_CEC,
                                           msg->msg[2] << 8 | msg->msg[3], 0);
                        break;
                /*
                 * Other function messages that are not handled.
                 * Currently the RC framework does not allow to supply an
                 * additional parameter to a keypress. These "keys" contain
                 * other information such as channel number, an input number
                 * etc.
                 * For the time being these messages are not processed by the
                 * framework and are simply forwarded to the user space.
                 */
                case 0x56: case 0x57:
                case 0x67: case 0x68: case 0x69: case 0x6a:
                        break;
                default:
                        rc_keydown(adap->rc, RC_TYPE_CEC, msg->msg[2], 0);
                        break;
                }
#endif
                break;

        case CEC_MSG_USER_CONTROL_RELEASED:
                if (!(adap->capabilities & CEC_CAP_RC))
                        break;
#if IS_REACHABLE(CONFIG_RC_CORE)
                rc_keyup(adap->rc);
#endif
                break;

        /*
         * The remaining messages are only processed if the passthrough mode
         * is off.
         */
        case CEC_MSG_GET_CEC_VERSION:
                cec_msg_cec_version(&tx_cec_msg, adap->log_addrs.cec_version);
                return cec_transmit_msg(adap, &tx_cec_msg, false);

        case CEC_MSG_GIVE_PHYSICAL_ADDR:
                /* Do nothing for CEC switches using addr 15 */
                if (devtype == CEC_OP_PRIM_DEVTYPE_SWITCH && dest_laddr == 15)
                        return 0;
                cec_msg_report_physical_addr(&tx_cec_msg, adap->phys_addr, devtype);
                return cec_transmit_msg(adap, &tx_cec_msg, false);

        case CEC_MSG_GIVE_DEVICE_VENDOR_ID:
                if (adap->log_addrs.vendor_id == CEC_VENDOR_ID_NONE)
                        return cec_feature_abort(adap, msg);
                cec_msg_device_vendor_id(&tx_cec_msg, adap->log_addrs.vendor_id);
                return cec_transmit_msg(adap, &tx_cec_msg, false);

        case CEC_MSG_ABORT:
                /* Do nothing for CEC switches */
                if (devtype == CEC_OP_PRIM_DEVTYPE_SWITCH)
                        return 0;
                return cec_feature_refused(adap, msg);

        case CEC_MSG_GIVE_OSD_NAME: {
                if (adap->log_addrs.osd_name[0] == 0)
                        return cec_feature_abort(adap, msg);
                cec_msg_set_osd_name(&tx_cec_msg, adap->log_addrs.osd_name);
                return cec_transmit_msg(adap, &tx_cec_msg, false);
        }

        case CEC_MSG_GIVE_FEATURES:
                if (adap->log_addrs.cec_version >= CEC_OP_CEC_VERSION_2_0)
                        return cec_report_features(adap, la_idx);
                return 0;

        default:
                /*
                 * Unprocessed messages are aborted if userspace isn't doing
                 * any processing either.
                 */
                if (!is_broadcast && !is_reply && !adap->follower_cnt &&
                    !adap->cec_follower && msg->msg[1] != CEC_MSG_FEATURE_ABORT)
                        return cec_feature_abort(adap, msg);
                break;
        }

skip_processing:
        /* If this was a reply, then we're done */
        if (is_reply)
                return 0;

        /*
         * Send to the exclusive follower if there is one, otherwise send
         * to all followers.
         */
        if (adap->cec_follower)
                cec_queue_msg_fh(adap->cec_follower, msg);
        else
                cec_queue_msg_followers(adap, msg);
        return 0;
}

/*
 * Helper functions to keep track of the 'monitor all' use count.
 *
 * These functions are called with adap->lock held.
 */
int cec_monitor_all_cnt_inc(struct cec_adapter *adap)
{
        int ret = 0;

        if (adap->monitor_all_cnt == 0)
                ret = call_op(adap, adap_monitor_all_enable, 1);
        if (ret == 0)
                adap->monitor_all_cnt++;
        return ret;
}

void cec_monitor_all_cnt_dec(struct cec_adapter *adap)
{
        adap->monitor_all_cnt--;
        if (adap->monitor_all_cnt == 0)
                WARN_ON(call_op(adap, adap_monitor_all_enable, 0));
}

#ifdef CONFIG_MEDIA_CEC_DEBUG
/*
 * Log the current state of the CEC adapter.
 * Very useful for debugging.
 */
int cec_adap_status(struct seq_file *file, void *priv)
{
        struct cec_adapter *adap = dev_get_drvdata(file->private);
        struct cec_data *data;

        mutex_lock(&adap->lock);
        seq_printf(file, "configured: %d\n", adap->is_configured);
        seq_printf(file, "configuring: %d\n", adap->is_configuring);
        seq_printf(file, "phys_addr: %x.%x.%x.%x\n",
                   cec_phys_addr_exp(adap->phys_addr));
        seq_printf(file, "number of LAs: %d\n", adap->log_addrs.num_log_addrs);
        seq_printf(file, "LA mask: 0x%04x\n", adap->log_addrs.log_addr_mask);
        if (adap->cec_follower)
                seq_printf(file, "has CEC follower%s\n",
                           adap->passthrough ? " (in passthrough mode)" : "");
        if (adap->cec_initiator)
                seq_puts(file, "has CEC initiator\n");
        if (adap->monitor_all_cnt)
                seq_printf(file, "file handles in Monitor All mode: %u\n",
                           adap->monitor_all_cnt);
        data = adap->transmitting;
        if (data)
                seq_printf(file, "transmitting message: %*ph (reply: %02x, timeout: %ums)\n",
                           data->msg.len, data->msg.msg, data->msg.reply,
                           data->msg.timeout);
        seq_printf(file, "pending transmits: %u\n", adap->transmit_queue_sz);
        list_for_each_entry(data, &adap->transmit_queue, list) {
                seq_printf(file, "queued tx message: %*ph (reply: %02x, timeout: %ums)\n",
                           data->msg.len, data->msg.msg, data->msg.reply,
                           data->msg.timeout);
        }
        list_for_each_entry(data, &adap->wait_queue, list) {
                seq_printf(file, "message waiting for reply: %*ph (reply: %02x, timeout: %ums)\n",
                           data->msg.len, data->msg.msg, data->msg.reply,
                           data->msg.timeout);
        }

        call_void_op(adap, adap_status, file);
        mutex_unlock(&adap->lock);
        return 0;
}
#endif