[platform/kernel/linux-rpi.git] / drivers / media / cec / core / cec-adap.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * cec-adap.c - HDMI Consumer Electronics Control framework - CEC adapter
 *
 * Copyright 2016 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
 */

#include <linux/errno.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/kmod.h>
#include <linux/ktime.h>
#include <linux/slab.h>
#include <linux/mm.h>
#include <linux/string.h>
#include <linux/types.h>

#include <drm/drm_connector.h>
#include <drm/drm_device.h>
#include <drm/drm_edid.h>
#include <drm/drm_file.h>

#include "cec-priv.h"

static void cec_fill_msg_report_features(struct cec_adapter *adap,
                                         struct cec_msg *msg,
                                         unsigned int la_idx);

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];
}

u16 cec_get_edid_phys_addr(const u8 *edid, unsigned int size,
                           unsigned int *offset)
{
        unsigned int loc = cec_get_edid_spa_location(edid, size);

        if (offset)
                *offset = loc;
        if (loc == 0)
                return CEC_PHYS_ADDR_INVALID;
        return (edid[loc] << 8) | edid[loc + 1];
}
EXPORT_SYMBOL_GPL(cec_get_edid_phys_addr);

void cec_fill_conn_info_from_drm(struct cec_connector_info *conn_info,
                                 const struct drm_connector *connector)
{
        memset(conn_info, 0, sizeof(*conn_info));
        conn_info->type = CEC_CONNECTOR_TYPE_DRM;
        conn_info->drm.card_no = connector->dev->primary->index;
        conn_info->drm.connector_id = connector->base.id;
}
EXPORT_SYMBOL_GPL(cec_fill_conn_info_from_drm);

/*
 * Queue a new event for this filehandle. If ts == 0, then set it
 * to the current time.
 *
 * We keep a queue of at most max_event events where max_event differs
 * per event. If the queue becomes full, then drop the oldest event and
 * keep track of how many events we've dropped.
 */
void cec_queue_event_fh(struct cec_fh *fh,
                        const struct cec_event *new_ev, u64 ts)
{
        static const u16 max_events[CEC_NUM_EVENTS] = {
                1, 1, 800, 800, 8, 8, 8, 8
        };
        struct cec_event_entry *entry;
        unsigned int ev_idx = new_ev->event - 1;

        if (WARN_ON(ev_idx >= ARRAY_SIZE(fh->events)))
                return;

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

        mutex_lock(&fh->lock);
        if (ev_idx < CEC_NUM_CORE_EVENTS)
                entry = &fh->core_events[ev_idx];
        else
                entry = kmalloc(sizeof(*entry), GFP_KERNEL);
        if (entry) {
                if (new_ev->event == CEC_EVENT_LOST_MSGS &&
                    fh->queued_events[ev_idx]) {
                        entry->ev.lost_msgs.lost_msgs +=
                                new_ev->lost_msgs.lost_msgs;
                        goto unlock;
                }
                entry->ev = *new_ev;
                entry->ev.ts = ts;

                if (fh->queued_events[ev_idx] < max_events[ev_idx]) {
                        /* Add new msg at the end of the queue */
                        list_add_tail(&entry->list, &fh->events[ev_idx]);
                        fh->queued_events[ev_idx]++;
                        fh->total_queued_events++;
                        goto unlock;
                }

                if (ev_idx >= CEC_NUM_CORE_EVENTS) {
                        list_add_tail(&entry->list, &fh->events[ev_idx]);
                        /* drop the oldest event */
                        entry = list_first_entry(&fh->events[ev_idx],
                                                 struct cec_event_entry, list);
                        list_del(&entry->list);
                        kfree(entry);
                }
        }
        /* Mark that events were lost */
        entry = list_first_entry_or_null(&fh->events[ev_idx],
                                         struct cec_event_entry, list);
        if (entry)
                entry->ev.flags |= CEC_EVENT_FL_DROPPED_EVENTS;

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

/* Notify userspace that the CEC pin changed state at the given time. */
void cec_queue_pin_cec_event(struct cec_adapter *adap, bool is_high,
                             bool dropped_events, ktime_t ts)
{
        struct cec_event ev = {
                .event = is_high ? CEC_EVENT_PIN_CEC_HIGH :
                                   CEC_EVENT_PIN_CEC_LOW,
                .flags = dropped_events ? CEC_EVENT_FL_DROPPED_EVENTS : 0,
        };
        struct cec_fh *fh;

        mutex_lock(&adap->devnode.lock_fhs);
        list_for_each_entry(fh, &adap->devnode.fhs, list) {
                if (fh->mode_follower == CEC_MODE_MONITOR_PIN)
                        cec_queue_event_fh(fh, &ev, ktime_to_ns(ts));
        }
        mutex_unlock(&adap->devnode.lock_fhs);
}
EXPORT_SYMBOL_GPL(cec_queue_pin_cec_event);

/* Notify userspace that the HPD pin changed state at the given time. */
void cec_queue_pin_hpd_event(struct cec_adapter *adap, bool is_high, ktime_t ts)
{
        struct cec_event ev = {
                .event = is_high ? CEC_EVENT_PIN_HPD_HIGH :
                                   CEC_EVENT_PIN_HPD_LOW,
        };
        struct cec_fh *fh;

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

/* Notify userspace that the 5V pin changed state at the given time. */
void cec_queue_pin_5v_event(struct cec_adapter *adap, bool is_high, ktime_t ts)
{
        struct cec_event ev = {
                .event = is_high ? CEC_EVENT_PIN_5V_HIGH :
                                   CEC_EVENT_PIN_5V_LOW,
        };
        struct cec_fh *fh;

        mutex_lock(&adap->devnode.lock_fhs);
        list_for_each_entry(fh, &adap->devnode.fhs, list)
                cec_queue_event_fh(fh, &ev, ktime_to_ns(ts));
        mutex_unlock(&adap->devnode.lock_fhs);
}
EXPORT_SYMBOL_GPL(cec_queue_pin_5v_event);

/*
 * Queue a new message for this filehandle.
 *
 * We keep a queue of at most CEC_MAX_MSG_RX_QUEUE_SZ messages. If the
 * queue becomes full, then drop the oldest message and keep track
 * of how many messages we've dropped.
 */
static void cec_queue_msg_fh(struct cec_fh *fh, const struct cec_msg *msg)
{
        static const struct cec_event ev_lost_msgs = {
                .event = CEC_EVENT_LOST_MSGS,
                .flags = 0,
                {
                        .lost_msgs = { 1 },
                },
        };
        struct cec_msg_entry *entry;

        mutex_lock(&fh->lock);
        entry = kmalloc(sizeof(*entry), GFP_KERNEL);
        if (entry) {
                entry->msg = *msg;
                /* Add new msg at the end of the queue */
                list_add_tail(&entry->list, &fh->msgs);

                if (fh->queued_msgs < CEC_MAX_MSG_RX_QUEUE_SZ) {
                        /* All is fine if there is enough room */
                        fh->queued_msgs++;
                        mutex_unlock(&fh->lock);
                        wake_up_interruptible(&fh->wait);
                        return;
                }

                /*
                 * if the message queue is full, then drop the oldest one and
                 * send a lost message event.
                 */
                entry = list_first_entry(&fh->msgs, struct cec_msg_entry, list);
                list_del(&entry->list);
                kfree(entry);
        }
        mutex_unlock(&fh->lock);

        /*
         * We lost a message, either because kmalloc failed or the queue
         * was full.
         */
        cec_queue_event_fh(fh, &ev_lost_msgs, ktime_get_ns());
}

/*
 * 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_fhs);
        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_fhs);
}

/*
 * 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_fhs);
        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_fhs);
}

/* 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;
        ev.state_change.have_conn_info =
                adap->conn_info.type != CEC_CONNECTOR_TYPE_NO_CONNECTOR;
        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_init(&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, or the reply timed out.
 *
 * This function is called with adap->lock held.
 */
static void cec_data_cancel(struct cec_data *data, u8 tx_status, u8 rx_status)
{
        struct cec_adapter *adap = data->adap;

        /*
         * It's either the current transmit, or it is a pending
         * transmit. Take the appropriate action to clear it.
         */
        if (adap->transmitting == data) {
                adap->transmitting = NULL;
        } else {
                list_del_init(&data->list);
                if (!(data->msg.tx_status & CEC_TX_STATUS_OK))
                        if (!WARN_ON(!adap->transmit_queue_sz))
                                adap->transmit_queue_sz--;
        }

        if (data->msg.tx_status & CEC_TX_STATUS_OK) {
                data->msg.rx_ts = ktime_get_ns();
                data->msg.rx_status = rx_status;
                if (!data->blocking)
                        data->msg.tx_status = 0;
        } else {
                data->msg.tx_ts = ktime_get_ns();
                data->msg.tx_status |= tx_status |
                                       CEC_TX_STATUS_MAX_RETRIES;
                data->msg.tx_error_cnt++;
                data->attempts = 0;
                if (!data->blocking)
                        data->msg.rx_status = 0;
        }

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

        if (!data->blocking && data->msg.sequence)
                /* Allow drivers to process the message first */
                call_op(adap, received, &data->msg);

        cec_data_completed(data);
}

/*
 * Flush all pending transmits and cancel any pending timeout work.
 *
 * This function is called with adap->lock held.
 */
static void cec_flush(struct cec_adapter *adap)
{
        struct cec_data *data, *n;

        /*
         * 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, CEC_TX_STATUS_ABORTED, 0);
        }
        if (adap->transmitting)
                adap->transmit_in_progress_aborted = true;

        /* Cancel the pending timeout work. */
        list_for_each_entry_safe(data, n, &adap->wait_queue, list) {
                if (cancel_delayed_work(&data->work))
                        cec_data_cancel(data, CEC_TX_STATUS_OK, CEC_RX_STATUS_ABORTED);
                /*
                 * If cancel_delayed_work returned false, then
                 * the cec_wait_timeout function is running,
                 * which will call cec_data_completed. So no
                 * need to do anything special in that case.
                 */
        }
        /*
         * If something went wrong and this counter isn't what it should
         * be, then this will reset it back to 0. Warn if it is not 0,
         * since it indicates a bug, either in this framework or in a
         * CEC driver.
         */
        if (WARN_ON(adap->transmit_queue_sz))
                adap->transmit_queue_sz = 0;
}

/*
 * 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->transmit_in_progress) {
                        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,
                                (adap->needs_hpd &&
                                 (!adap->is_configured && !adap->is_configuring)) ||
                                kthread_should_stop() ||
                                (!adap->transmit_in_progress &&
                                 !list_empty(&adap->transmit_queue)),
                                msecs_to_jiffies(adap->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->transmit_in_progress &&
                                 !list_empty(&adap->transmit_queue)));
                }

                mutex_lock(&adap->lock);

                if ((adap->needs_hpd &&
                     (!adap->is_configured && !adap->is_configuring)) ||
                    kthread_should_stop()) {
                        cec_flush(adap);
                        goto unlock;
                }

                if (adap->transmit_in_progress && timeout) {
                        /*
                         * If we timeout, then log that. Normally this does
                         * not happen and it is an indication of a faulty CEC
                         * adapter driver, or the CEC bus is in some weird
                         * state. On rare occasions it can happen if there is
                         * so much traffic on the bus that the adapter was
                         * unable to transmit for xfer_timeout_ms (2.1s by
                         * default).
                         */
                        if (adap->transmitting) {
                                pr_warn("cec-%s: message %*ph timed out\n", adap->name,
                                        adap->transmitting->msg.len,
                                        adap->transmitting->msg.msg);
                                /* Just give up on this. */
                                cec_data_cancel(adap->transmitting,
                                                CEC_TX_STATUS_TIMEOUT, 0);
                        } else {
                                pr_warn("cec-%s: transmit timed out\n", adap->name);
                        }
                        adap->transmit_in_progress = false;
                        adap->tx_timeouts++;
                        goto unlock;
                }

                /*
                 * If we are still transmitting, or there is nothing new to
                 * transmit, then just continue waiting.
                 */
                if (adap->transmit_in_progress || 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);
                if (!WARN_ON(!data->adap->transmit_queue_sz))
                        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 (adap->last_initiator !=
                           cec_msg_initiator(&data->msg)) {
                        /* should be >= 5 data bit periods for new initiator */
                        signal_free_time = CEC_SIGNAL_FREE_TIME_NEW_INITIATOR;
                        adap->last_initiator = cec_msg_initiator(&data->msg);
                } 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;

                adap->transmit_in_progress_aborted = false;
                /* Tell the adapter to transmit, cancel on error */
                if (call_op(adap, adap_transmit, data->attempts,
                            signal_free_time, &data->msg))
                        cec_data_cancel(data, CEC_TX_STATUS_ABORTED, 0);
                else
                        adap->transmit_in_progress = true;

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_ts(struct cec_adapter *adap, u8 status,
                          u8 arb_lost_cnt, u8 nack_cnt, u8 low_drive_cnt,
                          u8 error_cnt, ktime_t ts)
{
        struct cec_data *data;
        struct cec_msg *msg;
        unsigned int attempts_made = arb_lost_cnt + nack_cnt +
                                     low_drive_cnt + error_cnt;
        bool done = status & (CEC_TX_STATUS_MAX_RETRIES | CEC_TX_STATUS_OK);
        bool aborted = adap->transmit_in_progress_aborted;

        dprintk(2, "%s: status 0x%02x\n", __func__, status);
        if (attempts_made < 1)
                attempts_made = 1;

        mutex_lock(&adap->lock);
        data = adap->transmitting;
        if (!data) {
                /*
                 * This might happen if a transmit was issued and the cable is
                 * unplugged while the transmit is ongoing. Ignore this
                 * transmit in that case.
                 */
                if (!adap->transmit_in_progress)
                        dprintk(1, "%s was called without an ongoing transmit!\n",
                                __func__);
                adap->transmit_in_progress = false;
                goto wake_thread;
        }
        adap->transmit_in_progress = false;
        adap->transmit_in_progress_aborted = false;

        msg = &data->msg;

        /* Drivers must fill in the status! */
        WARN_ON(status == 0);
        msg->tx_ts = ktime_to_ns(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 (!aborted && data->attempts > attempts_made && !done) {
                /* Retry this message */
                data->attempts -= attempts_made;
                if (msg->timeout)
                        dprintk(2, "retransmit: %*ph (attempts: %d, wait for 0x%02x)\n",
                                msg->len, msg->msg, data->attempts, msg->reply);
                else
                        dprintk(2, "retransmit: %*ph (attempts: %d)\n",
                                msg->len, msg->msg, 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;
        }

        if (aborted && !done)
                status |= CEC_TX_STATUS_ABORTED;
        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);
        mutex_unlock(&adap->lock);
}
EXPORT_SYMBOL_GPL(cec_transmit_done_ts);

void cec_transmit_attempt_done_ts(struct cec_adapter *adap,
                                  u8 status, ktime_t ts)
{
        switch (status & ~CEC_TX_STATUS_MAX_RETRIES) {
        case CEC_TX_STATUS_OK:
                cec_transmit_done_ts(adap, status, 0, 0, 0, 0, ts);
                return;
        case CEC_TX_STATUS_ARB_LOST:
                cec_transmit_done_ts(adap, status, 1, 0, 0, 0, ts);
                return;
        case CEC_TX_STATUS_NACK:
                cec_transmit_done_ts(adap, status, 0, 1, 0, 0, ts);
                return;
        case CEC_TX_STATUS_LOW_DRIVE:
                cec_transmit_done_ts(adap, status, 0, 0, 1, 0, ts);
                return;
        case CEC_TX_STATUS_ERROR:
                cec_transmit_done_ts(adap, status, 0, 0, 0, 1, ts);
                return;
        default:
                /* Should never happen */
                WARN(1, "cec-%s: invalid status 0x%02x\n", adap->name, status);
                return;
        }
}
EXPORT_SYMBOL_GPL(cec_transmit_attempt_done_ts);

/*
 * 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);
        cec_data_cancel(data, CEC_TX_STATUS_OK, CEC_RX_STATUS_TIMEOUT);
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;
        bool is_raw = msg_is_raw(msg);

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

        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->sequence = 0;

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

        if (!msg->timeout)
                msg->flags &= ~CEC_MSG_FL_REPLY_TO_FOLLOWERS;

        /* Sanity checks */
        if (msg->len == 0 || msg->len > CEC_MAX_MSG_SIZE) {
                dprintk(1, "%s: invalid length %d\n", __func__, msg->len);
                return -EINVAL;
        }

        memset(msg->msg + msg->len, 0, sizeof(msg->msg) - msg->len);

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

        if (msg->timeout && msg->len == 1) {
                dprintk(1, "%s: can't reply to poll msg\n", __func__);
                return -EINVAL;
        }

        if (is_raw) {
                if (!capable(CAP_SYS_RAWIO))
                        return -EPERM;
        } else {
                /* A CDC-Only device can only send CDC messages */
                if ((adap->log_addrs.flags & CEC_LOG_ADDRS_FL_CDC_ONLY) &&
                    (msg->len == 1 || msg->msg[1] != CEC_MSG_CDC_MESSAGE)) {
                        dprintk(1, "%s: not a CDC message\n", __func__);
                        return -EINVAL;
                }

                if (msg->len >= 4 && msg->msg[1] == CEC_MSG_CDC_MESSAGE) {
                        msg->msg[2] = adap->phys_addr >> 8;
                        msg->msg[3] = adap->phys_addr & 0xff;
                }

                if (msg->len == 1) {
                        if (cec_msg_destination(msg) == 0xf) {
                                dprintk(1, "%s: invalid poll message\n",
                                        __func__);
                                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;
                                msg->sequence = ++adap->sequence;
                                if (!msg->sequence)
                                        msg->sequence = ++adap->sequence;
                                return 0;
                        }
                }
                if (msg->len > 1 && !cec_msg_is_broadcast(msg) &&
                    cec_has_log_addr(adap, cec_msg_destination(msg))) {
                        dprintk(1, "%s: destination is the adapter itself\n",
                                __func__);
                        return -EINVAL;
                }
                if (msg->len > 1 && adap->is_configured &&
                    !cec_has_log_addr(adap, cec_msg_initiator(msg))) {
                        dprintk(1, "%s: initiator has unknown logical address %d\n",
                                __func__, cec_msg_initiator(msg));
                        return -EINVAL;
                }
                /*
                 * Special case: allow Ping and IMAGE/TEXT_VIEW_ON to be
                 * transmitted to a TV, even if the adapter is unconfigured.
                 * This makes it possible to detect or wake up displays that
                 * pull down the HPD when in standby.
                 */
                if (!adap->is_configured && !adap->is_configuring &&
                    (msg->len > 2 ||
                     cec_msg_destination(msg) != CEC_LOG_ADDR_TV ||
                     (msg->len == 2 && msg->msg[1] != CEC_MSG_IMAGE_VIEW_ON &&
                      msg->msg[1] != CEC_MSG_TEXT_VIEW_ON))) {
                        dprintk(1, "%s: adapter is unconfigured\n", __func__);
                        return -ENONET;
                }
        }

        if (!adap->is_configured && !adap->is_configuring) {
                if (adap->needs_hpd) {
                        dprintk(1, "%s: adapter is unconfigured and needs HPD\n",
                                __func__);
                        return -ENONET;
                }
                if (msg->reply) {
                        dprintk(1, "%s: invalid msg->reply\n", __func__);
                        return -EINVAL;
                }
        }

        if (adap->transmit_queue_sz >= CEC_MAX_MSG_TX_QUEUE_SZ) {
                dprintk(2, "%s: transmit queue full\n", __func__);
                return -EBUSY;
        }

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

        msg->sequence = ++adap->sequence;
        if (!msg->sequence)
                msg->sequence = ++adap->sequence;

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

        init_completion(&data->c);
        INIT_DELAYED_WORK(&data->work, cec_wait_timeout);

        if (fh)
                list_add_tail(&data->xfer_list, &fh->xfer_list);
        else
                INIT_LIST_HEAD(&data->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;

        /*
         * Release the lock and wait, retake the lock afterwards.
         */
        mutex_unlock(&adap->lock);
        wait_for_completion_killable(&data->c);
        if (!data->completed)
                cancel_delayed_work_sync(&data->work);
        mutex_lock(&adap->lock);

        /* Cancel the transmit if it was interrupted */
        if (!data->completed) {
                if (data->msg.tx_status & CEC_TX_STATUS_OK)
                        cec_data_cancel(data, CEC_TX_STATUS_OK, CEC_RX_STATUS_ABORTED);
                else
                        cec_data_cancel(data, CEC_TX_STATUS_ABORTED, 0);
        }

        /* The transmit completed (possibly with an error) */
        *msg = data->msg;
        if (WARN_ON(!list_empty(&data->list)))
                list_del(&data->list);
        if (WARN_ON(!list_empty(&data->xfer_list)))
                list_del(&data->xfer_list);
        kfree(data);
        return 0;
}

/* 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);

#define DIRECTED        0x80
#define BCAST1_4        0x40
#define BCAST2_0        0x20    /* broadcast only allowed for >= 2.0 */
#define BCAST           (BCAST1_4 | BCAST2_0)
#define BOTH            (BCAST | DIRECTED)

/*
 * Specify minimum length and whether the message is directed, broadcast
 * or both. Messages that do not match the criteria are ignored as per
 * the CEC specification.
 */
static const u8 cec_msg_size[256] = {
        [CEC_MSG_ACTIVE_SOURCE] = 4 | BCAST,
        [CEC_MSG_IMAGE_VIEW_ON] = 2 | DIRECTED,
        [CEC_MSG_TEXT_VIEW_ON] = 2 | DIRECTED,
        [CEC_MSG_INACTIVE_SOURCE] = 4 | DIRECTED,
        [CEC_MSG_REQUEST_ACTIVE_SOURCE] = 2 | BCAST,
        [CEC_MSG_ROUTING_CHANGE] = 6 | BCAST,
        [CEC_MSG_ROUTING_INFORMATION] = 4 | BCAST,
        [CEC_MSG_SET_STREAM_PATH] = 4 | BCAST,
        [CEC_MSG_STANDBY] = 2 | BOTH,
        [CEC_MSG_RECORD_OFF] = 2 | DIRECTED,
        [CEC_MSG_RECORD_ON] = 3 | DIRECTED,
        [CEC_MSG_RECORD_STATUS] = 3 | DIRECTED,
        [CEC_MSG_RECORD_TV_SCREEN] = 2 | DIRECTED,
        [CEC_MSG_CLEAR_ANALOGUE_TIMER] = 13 | DIRECTED,
        [CEC_MSG_CLEAR_DIGITAL_TIMER] = 16 | DIRECTED,
        [CEC_MSG_CLEAR_EXT_TIMER] = 13 | DIRECTED,
        [CEC_MSG_SET_ANALOGUE_TIMER] = 13 | DIRECTED,
        [CEC_MSG_SET_DIGITAL_TIMER] = 16 | DIRECTED,
        [CEC_MSG_SET_EXT_TIMER] = 13 | DIRECTED,
        [CEC_MSG_SET_TIMER_PROGRAM_TITLE] = 2 | DIRECTED,
        [CEC_MSG_TIMER_CLEARED_STATUS] = 3 | DIRECTED,
        [CEC_MSG_TIMER_STATUS] = 3 | DIRECTED,
        [CEC_MSG_CEC_VERSION] = 3 | DIRECTED,
        [CEC_MSG_GET_CEC_VERSION] = 2 | DIRECTED,
        [CEC_MSG_GIVE_PHYSICAL_ADDR] = 2 | DIRECTED,
        [CEC_MSG_GET_MENU_LANGUAGE] = 2 | DIRECTED,
        [CEC_MSG_REPORT_PHYSICAL_ADDR] = 5 | BCAST,
        [CEC_MSG_SET_MENU_LANGUAGE] = 5 | BCAST,
        [CEC_MSG_REPORT_FEATURES] = 6 | BCAST,
        [CEC_MSG_GIVE_FEATURES] = 2 | DIRECTED,
        [CEC_MSG_DECK_CONTROL] = 3 | DIRECTED,
        [CEC_MSG_DECK_STATUS] = 3 | DIRECTED,
        [CEC_MSG_GIVE_DECK_STATUS] = 3 | DIRECTED,
        [CEC_MSG_PLAY] = 3 | DIRECTED,
        [CEC_MSG_GIVE_TUNER_DEVICE_STATUS] = 3 | DIRECTED,
        [CEC_MSG_SELECT_ANALOGUE_SERVICE] = 6 | DIRECTED,
        [CEC_MSG_SELECT_DIGITAL_SERVICE] = 9 | DIRECTED,
        [CEC_MSG_TUNER_DEVICE_STATUS] = 7 | DIRECTED,
        [CEC_MSG_TUNER_STEP_DECREMENT] = 2 | DIRECTED,
        [CEC_MSG_TUNER_STEP_INCREMENT] = 2 | DIRECTED,
        [CEC_MSG_DEVICE_VENDOR_ID] = 5 | BCAST,
        [CEC_MSG_GIVE_DEVICE_VENDOR_ID] = 2 | DIRECTED,
        [CEC_MSG_VENDOR_COMMAND] = 2 | DIRECTED,
        [CEC_MSG_VENDOR_COMMAND_WITH_ID] = 5 | BOTH,
        [CEC_MSG_VENDOR_REMOTE_BUTTON_DOWN] = 2 | BOTH,
        [CEC_MSG_VENDOR_REMOTE_BUTTON_UP] = 2 | BOTH,
        [CEC_MSG_SET_OSD_STRING] = 3 | DIRECTED,
        [CEC_MSG_GIVE_OSD_NAME] = 2 | DIRECTED,
        [CEC_MSG_SET_OSD_NAME] = 2 | DIRECTED,
        [CEC_MSG_MENU_REQUEST] = 3 | DIRECTED,
        [CEC_MSG_MENU_STATUS] = 3 | DIRECTED,
        [CEC_MSG_USER_CONTROL_PRESSED] = 3 | DIRECTED,
        [CEC_MSG_USER_CONTROL_RELEASED] = 2 | DIRECTED,
        [CEC_MSG_GIVE_DEVICE_POWER_STATUS] = 2 | DIRECTED,
        [CEC_MSG_REPORT_POWER_STATUS] = 3 | DIRECTED | BCAST2_0,
        [CEC_MSG_FEATURE_ABORT] = 4 | DIRECTED,
        [CEC_MSG_ABORT] = 2 | DIRECTED,
        [CEC_MSG_GIVE_AUDIO_STATUS] = 2 | DIRECTED,
        [CEC_MSG_GIVE_SYSTEM_AUDIO_MODE_STATUS] = 2 | DIRECTED,
        [CEC_MSG_REPORT_AUDIO_STATUS] = 3 | DIRECTED,
        [CEC_MSG_REPORT_SHORT_AUDIO_DESCRIPTOR] = 2 | DIRECTED,
        [CEC_MSG_REQUEST_SHORT_AUDIO_DESCRIPTOR] = 2 | DIRECTED,
        [CEC_MSG_SET_SYSTEM_AUDIO_MODE] = 3 | BOTH,
        [CEC_MSG_SET_AUDIO_VOLUME_LEVEL] = 3 | DIRECTED,
        [CEC_MSG_SYSTEM_AUDIO_MODE_REQUEST] = 2 | DIRECTED,
        [CEC_MSG_SYSTEM_AUDIO_MODE_STATUS] = 3 | DIRECTED,
        [CEC_MSG_SET_AUDIO_RATE] = 3 | DIRECTED,
        [CEC_MSG_INITIATE_ARC] = 2 | DIRECTED,
        [CEC_MSG_REPORT_ARC_INITIATED] = 2 | DIRECTED,
        [CEC_MSG_REPORT_ARC_TERMINATED] = 2 | DIRECTED,
        [CEC_MSG_REQUEST_ARC_INITIATION] = 2 | DIRECTED,
        [CEC_MSG_REQUEST_ARC_TERMINATION] = 2 | DIRECTED,
        [CEC_MSG_TERMINATE_ARC] = 2 | DIRECTED,
        [CEC_MSG_REQUEST_CURRENT_LATENCY] = 4 | BCAST,
        [CEC_MSG_REPORT_CURRENT_LATENCY] = 6 | BCAST,
        [CEC_MSG_CDC_MESSAGE] = 2 | BCAST,
};

/* Called by the CEC adapter if a message is received */
void cec_received_msg_ts(struct cec_adapter *adap,
                         struct cec_msg *msg, ktime_t ts)
{
        struct cec_data *data;
        u8 msg_init = cec_msg_initiator(msg);
        u8 msg_dest = cec_msg_destination(msg);
        u8 cmd = msg->msg[1];
        bool is_reply = false;
        bool valid_la = true;
        bool monitor_valid_la = true;
        u8 min_len = 0;

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

        if (adap->devnode.unregistered)
                return;

        /*
         * Some CEC adapters will receive the messages that they transmitted.
         * This test filters out those messages by checking if we are the
         * initiator, and just returning in that case.
         *
         * Note that this won't work if this is an Unregistered device.
         *
         * It is bad practice if the hardware receives the message that it
         * transmitted and luckily most CEC adapters behave correctly in this
         * respect.
         */
        if (msg_init != CEC_LOG_ADDR_UNREGISTERED &&
            cec_has_log_addr(adap, msg_init))
                return;

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

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

        if (!adap->transmit_in_progress)
                adap->last_initiator = 0xff;

        /* 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);
                monitor_valid_la = valid_la;
        }

        /*
         * Check if the length is not too short or if the message is a
         * broadcast message where a directed message was expected or
         * vice versa. If so, then the message has to be ignored (according
         * to section CEC 7.3 and CEC 12.2).
         */
        if (valid_la && msg->len > 1 && cec_msg_size[cmd]) {
                u8 dir_fl = cec_msg_size[cmd] & BOTH;

                min_len = cec_msg_size[cmd] & 0x1f;
                if (msg->len < min_len)
                        valid_la = false;
                else if (!cec_msg_is_broadcast(msg) && !(dir_fl & DIRECTED))
                        valid_la = false;
                else if (cec_msg_is_broadcast(msg) && !(dir_fl & BCAST))
                        valid_la = false;
                else if (cec_msg_is_broadcast(msg) &&
                         adap->log_addrs.cec_version < CEC_OP_CEC_VERSION_2_0 &&
                         !(dir_fl & BCAST1_4))
                        valid_la = false;
        }
        if (valid_la && min_len) {
                /* These messages have special length requirements */
                switch (cmd) {
                case CEC_MSG_TIMER_STATUS:
                        if (msg->msg[2] & 0x10) {
                                switch (msg->msg[2] & 0xf) {
                                case CEC_OP_PROG_INFO_NOT_ENOUGH_SPACE:
                                case CEC_OP_PROG_INFO_MIGHT_NOT_BE_ENOUGH_SPACE:
                                        if (msg->len < 5)
                                                valid_la = false;
                                        break;
                                }
                        } else if ((msg->msg[2] & 0xf) == CEC_OP_PROG_ERROR_DUPLICATE) {
                                if (msg->len < 5)
                                        valid_la = false;
                        }
                        break;
                case CEC_MSG_RECORD_ON:
                        switch (msg->msg[2]) {
                        case CEC_OP_RECORD_SRC_OWN:
                                break;
                        case CEC_OP_RECORD_SRC_DIGITAL:
                                if (msg->len < 10)
                                        valid_la = false;
                                break;
                        case CEC_OP_RECORD_SRC_ANALOG:
                                if (msg->len < 7)
                                        valid_la = false;
                                break;
                        case CEC_OP_RECORD_SRC_EXT_PLUG:
                                if (msg->len < 4)
                                        valid_la = false;
                                break;
                        case CEC_OP_RECORD_SRC_EXT_PHYS_ADDR:
                                if (msg->len < 5)
                                        valid_la = false;
                                break;
                        }
                        break;
                }
        }

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

                        /*
                         * The *only* CEC message that has two possible replies
                         * is CEC_MSG_INITIATE_ARC.
                         * In this case allow either of the two replies.
                         */
                        if (!abort && dst->msg[1] == CEC_MSG_INITIATE_ARC &&
                            (cmd == CEC_MSG_REPORT_ARC_INITIATED ||
                             cmd == CEC_MSG_REPORT_ARC_TERMINATED) &&
                            (dst->reply == CEC_MSG_REPORT_ARC_INITIATED ||
                             dst->reply == CEC_MSG_REPORT_ARC_TERMINATED))
                                dst->reply = cmd;

                        /* 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;
                        msg->flags = dst->flags;
                        msg->sequence = dst->sequence;
                        /* 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);
                                cancel_delayed_work_sync(&data->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, monitor_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_ts);

/* 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 = { };
        const unsigned int max_retries = 2;
        unsigned int i;
        int err;

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

        /* Send poll message */
        msg.len = 1;
        msg.msg[0] = (log_addr << 4) | log_addr;

        for (i = 0; i < max_retries; i++) {
                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->phys_addr == CEC_PHYS_ADDR_INVALID)
                        return -EINTR;

                /* Also bail out if the PA changed while configuring. */
                if (adap->must_reconfigure)
                        return -EINTR;

                if (err)
                        return err;

                /*
                 * The message was aborted or timed out due to a disconnect or
                 * unconfigure, just bail out.
                 */
                if (msg.tx_status &
                    (CEC_TX_STATUS_ABORTED | CEC_TX_STATUS_TIMEOUT))
                        return -EINTR;
                if (msg.tx_status & CEC_TX_STATUS_OK)
                        return 0;
                if (msg.tx_status & CEC_TX_STATUS_NACK)
                        break;
                /*
                 * Retry up to max_retries times if the message was neither
                 * OKed or NACKed. This can happen due to e.g. a Lost
                 * Arbitration condition.
                 */
        }

        /*
         * If we are unable to get an OK or a NACK after max_retries attempts
         * (and note that each attempt already consists of four polls), then
         * we assume that something is really weird and that it is not a
         * good idea to try and claim this logical address.
         */
        if (i == max_retries) {
                dprintk(0, "polling for LA %u failed with tx_status=0x%04x\n",
                        log_addr, msg.tx_status);
                return 0;
        }

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

        las->log_addr[idx] = log_addr;
        las->log_addr_mask |= 1 << log_addr;
        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)
{
        if (!adap->needs_hpd || adap->phys_addr != CEC_PHYS_ADDR_INVALID)
                WARN_ON(call_op(adap, adap_log_addr, CEC_LOG_ADDR_INVALID));
        adap->log_addrs.log_addr_mask = 0;
        adap->is_configured = false;
        cec_flush(adap);
        wake_up_interruptible(&adap->kthread_waitq);
        cec_post_state_event(adap);
        call_void_op(adap, adap_configured, false);
}

/*
 * 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;

reconfigure:
        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 ||
                    !((1 << last_la) & type2mask[type]))
                        last_la = la_list[0];

                err = cec_config_log_addr(adap, i, last_la);

                if (adap->must_reconfigure) {
                        adap->must_reconfigure = false;
                        las->log_addr_mask = 0;
                        goto reconfigure;
                }

                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;
        }
        for (i = las->num_log_addrs; i < CEC_MAX_LOG_ADDRS; i++)
                las->log_addr[i] = CEC_LOG_ADDR_INVALID;
        adap->is_configured = true;
        adap->is_configuring = false;
        adap->must_reconfigure = false;
        cec_post_state_event(adap);

        /*
         * Now post the Report Features and Report Physical Address broadcast
         * messages. Note that these are non-blocking transmits, meaning that
         * they are just queued up and once adap->lock is unlocked the main
         * thread will kick in and start transmitting these.
         *
         * If after this function is done (but before one or more of these
         * messages are actually transmitted) the CEC adapter is unconfigured,
         * then any remaining messages will be dropped by the main thread.
         */
        for (i = 0; i < las->num_log_addrs; i++) {
                struct cec_msg msg = {};

                if (las->log_addr[i] == CEC_LOG_ADDR_INVALID ||
                    (las->flags & CEC_LOG_ADDRS_FL_CDC_ONLY))
                        continue;

                msg.msg[0] = (las->log_addr[i] << 4) | 0x0f;

                /* Report Features must come first according to CEC 2.0 */
                if (las->log_addr[i] != CEC_LOG_ADDR_UNREGISTERED &&
                    adap->log_addrs.cec_version >= CEC_OP_CEC_VERSION_2_0) {
                        cec_fill_msg_report_features(adap, &msg, i);
                        cec_transmit_msg_fh(adap, &msg, NULL, false);
                }

                /* Report Physical Address */
                cec_msg_report_physical_addr(&msg, adap->phys_addr,
                                             las->primary_device_type[i]);
                dprintk(1, "config: la %d pa %x.%x.%x.%x\n",
                        las->log_addr[i],
                        cec_phys_addr_exp(adap->phys_addr));
                cec_transmit_msg_fh(adap, &msg, NULL, false);

                /* Report Vendor ID */
                if (adap->log_addrs.vendor_id != CEC_VENDOR_ID_NONE) {
                        cec_msg_device_vendor_id(&msg,
                                                 adap->log_addrs.vendor_id);
                        cec_transmit_msg_fh(adap, &msg, NULL, false);
                }
        }
        adap->kthread_config = NULL;
        complete(&adap->config_completion);
        mutex_unlock(&adap->lock);
        call_void_op(adap, adap_configured, true);
        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->is_configuring = false;
        adap->must_reconfigure = false;
        adap->kthread_config = NULL;
        complete(&adap->config_completion);
        mutex_unlock(&adap->lock);
        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;
                adap->is_configuring = false;
        } else if (block) {
                mutex_unlock(&adap->lock);
                wait_for_completion(&adap->config_completion);
                mutex_lock(&adap->lock);
        }
}

/*
 * Helper function to enable/disable the CEC adapter.
 *
 * This function is called with adap->lock held.
 */
int cec_adap_enable(struct cec_adapter *adap)
{
        bool enable;
        int ret = 0;

        enable = adap->monitor_all_cnt || adap->monitor_pin_cnt ||
                 adap->log_addrs.num_log_addrs;
        if (adap->needs_hpd)
                enable = enable && adap->phys_addr != CEC_PHYS_ADDR_INVALID;

        if (adap->devnode.unregistered)
                enable = false;

        if (enable == adap->is_enabled)
                return 0;

        /* serialize adap_enable */
        mutex_lock(&adap->devnode.lock);
        if (enable) {
                adap->last_initiator = 0xff;
                adap->transmit_in_progress = false;
                ret = adap->ops->adap_enable(adap, true);
                if (!ret) {
                        /*
                         * Enable monitor-all/pin modes if needed. We warn, but
                         * continue if this fails as this is not a critical error.
                         */
                        if (adap->monitor_all_cnt)
                                WARN_ON(call_op(adap, adap_monitor_all_enable, true));
                        if (adap->monitor_pin_cnt)
                                WARN_ON(call_op(adap, adap_monitor_pin_enable, true));
                }
        } else {
                /* Disable monitor-all/pin modes if needed (needs_hpd == 1) */
                if (adap->monitor_all_cnt)
                        WARN_ON(call_op(adap, adap_monitor_all_enable, false));
                if (adap->monitor_pin_cnt)
                        WARN_ON(call_op(adap, adap_monitor_pin_enable, false));
                WARN_ON(adap->ops->adap_enable(adap, false));
                adap->last_initiator = 0xff;
                adap->transmit_in_progress = false;
                adap->transmit_in_progress_aborted = false;
                if (adap->transmitting)
                        cec_data_cancel(adap->transmitting, CEC_TX_STATUS_ABORTED, 0);
        }
        if (!ret)
                adap->is_enabled = enable;
        wake_up_interruptible(&adap->kthread_waitq);
        mutex_unlock(&adap->devnode.lock);
        return ret;
}

/* 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)
{
        bool becomes_invalid = phys_addr == CEC_PHYS_ADDR_INVALID;
        bool is_invalid = adap->phys_addr == CEC_PHYS_ADDR_INVALID;

        if (phys_addr == adap->phys_addr)
                return;
        if (!becomes_invalid && adap->devnode.unregistered)
                return;

        dprintk(1, "new physical address %x.%x.%x.%x\n",
                cec_phys_addr_exp(phys_addr));
        if (becomes_invalid || !is_invalid) {
                adap->phys_addr = CEC_PHYS_ADDR_INVALID;
                cec_post_state_event(adap);
                cec_adap_unconfigure(adap);
                if (becomes_invalid) {
                        cec_adap_enable(adap);
                        return;
                }
        }

        adap->phys_addr = phys_addr;
        if (is_invalid)
                cec_adap_enable(adap);

        cec_post_state_event(adap);
        if (!adap->log_addrs.num_log_addrs)
                return;
        if (adap->is_configuring)
                adap->must_reconfigure = true;
        else
                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;

        mutex_lock(&adap->lock);
        __cec_s_phys_addr(adap, phys_addr, block);
        mutex_unlock(&adap->lock);
}
EXPORT_SYMBOL_GPL(cec_s_phys_addr);

void cec_s_phys_addr_from_edid(struct cec_adapter *adap,
                               const struct edid *edid)
{
        u16 pa = CEC_PHYS_ADDR_INVALID;

        if (edid && edid->extensions)
                pa = cec_get_edid_phys_addr((const u8 *)edid,
                                EDID_LENGTH * (edid->extensions + 1), NULL);
        cec_s_phys_addr(adap, pa, false);
}
EXPORT_SYMBOL_GPL(cec_s_phys_addr_from_edid);

void cec_s_conn_info(struct cec_adapter *adap,
                     const struct cec_connector_info *conn_info)
{
        if (IS_ERR_OR_NULL(adap))
                return;

        if (!(adap->capabilities & CEC_CAP_CONNECTOR_INFO))
                return;

        mutex_lock(&adap->lock);
        if (conn_info)
                adap->conn_info = *conn_info;
        else
                memset(&adap->conn_info, 0, sizeof(adap->conn_info));
        cec_post_state_event(adap);
        mutex_unlock(&adap->lock);
}
EXPORT_SYMBOL_GPL(cec_s_conn_info);

/*
 * 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 err;
        int i;

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

        if (!log_addrs || log_addrs->num_log_addrs == 0) {
                if (!adap->log_addrs.num_log_addrs)
                        return 0;
                if (adap->is_configuring || adap->is_configured)
                        cec_adap_unconfigure(adap);
                adap->log_addrs.num_log_addrs = 0;
                for (i = 0; i < CEC_MAX_LOG_ADDRS; i++)
                        adap->log_addrs.log_addr[i] = CEC_LOG_ADDR_INVALID;
                adap->log_addrs.osd_name[0] = '\0';
                adap->log_addrs.vendor_id = CEC_VENDOR_ID_NONE;
                adap->log_addrs.cec_version = CEC_OP_CEC_VERSION_2_0;
                cec_adap_enable(adap);
                return 0;
        }

        if (log_addrs->flags & CEC_LOG_ADDRS_FL_CDC_ONLY) {
                /*
                 * Sanitize log_addrs fields if a CDC-Only device is
                 * requested.
                 */
                log_addrs->num_log_addrs = 1;
                log_addrs->osd_name[0] = '\0';
                log_addrs->vendor_id = CEC_VENDOR_ID_NONE;
                log_addrs->log_addr_type[0] = CEC_LOG_ADDR_TYPE_UNREGISTERED;
                /*
                 * This is just an internal convention since a CDC-Only device
                 * doesn't have to be a switch. But switches already use
                 * unregistered, so it makes some kind of sense to pick this
                 * as the primary device. Since a CDC-Only device never sends
                 * any 'normal' CEC messages this primary device type is never
                 * sent over the CEC bus.
                 */
                log_addrs->primary_device_type[0] = CEC_OP_PRIM_DEVTYPE_SWITCH;
                log_addrs->all_device_types[0] = 0;
                log_addrs->features[0][0] = 0;
                log_addrs->features[0][1] = 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) {
                dprintk(1, "invalid vendor ID\n");
                return -EINVAL;
        }

        if (log_addrs->cec_version != CEC_OP_CEC_VERSION_1_4 &&
            log_addrs->cec_version != CEC_OP_CEC_VERSION_2_0) {
                dprintk(1, "invalid CEC version\n");
                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;
                unsigned int j;

                log_addrs->log_addr[i] = CEC_LOG_ADDR_INVALID;
                if (log_addrs->log_addr_type[i] > CEC_LOG_ADDR_TYPE_UNREGISTERED) {
                        dprintk(1, "unknown logical address type\n");
                        return -EINVAL;
                }
                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;
                }
                for (j = 0; j < feature_sz; j++) {
                        if ((features[j] & 0x80) == 0) {
                                if (op_is_dev_features)
                                        break;
                                op_is_dev_features = true;
                        }
                }
                if (!op_is_dev_features || j == feature_sz) {
                        dprintk(1, "malformed features\n");
                        return -EINVAL;
                }
                /* Zero unused part of the feature array */
                memset(features + j + 1, 0, feature_sz - j - 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;
        err = cec_adap_enable(adap);
        if (!err && adap->phys_addr != CEC_PHYS_ADDR_INVALID)
                cec_claim_log_addrs(adap, block);
        return err;
}

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

        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 */

/* Fill in the Report Features message */
static void cec_fill_msg_report_features(struct cec_adapter *adap,
                                         struct cec_msg *msg,
                                         unsigned int la_idx)
{
        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;

        /* 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;
                }
        }
}

/* 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;
        /* Don't Feature Abort messages from 'Unregistered' */
        if (cec_msg_initiator(msg) == CEC_LOG_ADDR_UNREGISTERED)
                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(2, "%s: %*ph\n", __func__, msg->len, msg->msg);

        /* If this is a CDC-Only device, then ignore any non-CDC messages */
        if (cec_is_cdc_only(&adap->log_addrs) &&
            msg->msg[1] != CEC_MSG_CDC_MESSAGE)
                return 0;

        /* Allow drivers to process the message first */
        if (adap->ops->received && !adap->devnode.unregistered &&
            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_ABORT:
        case CEC_MSG_GIVE_DEVICE_POWER_STATUS:
        case CEC_MSG_GIVE_OSD_NAME:
                /*
                 * These messages reply with a directed message, so ignore if
                 * the initiator is Unregistered.
                 */
                if (!adap->passthrough && from_unregistered)
                        return 0;
                fallthrough;
        case CEC_MSG_GIVE_DEVICE_VENDOR_ID:
        case CEC_MSG_GIVE_FEATURES:
        case CEC_MSG_GIVE_PHYSICAL_ADDR:
                /*
                 * Skip processing these messages if the passthrough mode
                 * is on.
                 */
                if (adap->passthrough)
                        goto skip_processing;
                /* Ignore if addressing is wrong */
                if (is_broadcast)
                        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];

                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) ||
                    !(adap->log_addrs.flags & CEC_LOG_ADDRS_FL_ALLOW_RC_PASSTHRU))
                        break;

#ifdef CONFIG_MEDIA_CEC_RC
                switch (msg->msg[2]) {
                /*
                 * Play function, this message can have variable length
                 * depending on the specific play function that is used.
                 */
                case CEC_OP_UI_CMD_PLAY_FUNCTION:
                        if (msg->len == 2)
                                rc_keydown(adap->rc, RC_PROTO_CEC,
                                           msg->msg[2], 0);
                        else
                                rc_keydown(adap->rc, RC_PROTO_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 CEC_OP_UI_CMD_SELECT_BROADCAST_TYPE:
                case CEC_OP_UI_CMD_SELECT_SOUND_PRESENTATION:
                case CEC_OP_UI_CMD_TUNE_FUNCTION:
                case CEC_OP_UI_CMD_SELECT_MEDIA_FUNCTION:
                case CEC_OP_UI_CMD_SELECT_AV_INPUT_FUNCTION:
                case CEC_OP_UI_CMD_SELECT_AUDIO_INPUT_FUNCTION:
                        break;
                default:
                        rc_keydown(adap->rc, RC_PROTO_CEC, msg->msg[2], 0);
                        break;
                }
#endif
                break;

        case CEC_MSG_USER_CONTROL_RELEASED:
                if (!(adap->capabilities & CEC_CAP_RC) ||
                    !(adap->log_addrs.flags & CEC_LOG_ADDRS_FL_ALLOW_RC_PASSTHRU))
                        break;
#ifdef CONFIG_MEDIA_CEC_RC
                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_feature_abort(adap, msg);
                cec_fill_msg_report_features(adap, &tx_cec_msg, la_idx);
                return cec_transmit_msg(adap, &tx_cec_msg, false);

        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, unless otherwise specified */
        if (is_reply && !(msg->flags & CEC_MSG_FL_REPLY_TO_FOLLOWERS))
                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;

        if (adap->monitor_all_cnt++)
                return 0;

        ret = cec_adap_enable(adap);
        if (ret)
                adap->monitor_all_cnt--;
        return ret;
}

void cec_monitor_all_cnt_dec(struct cec_adapter *adap)
{
        if (WARN_ON(!adap->monitor_all_cnt))
                return;
        if (--adap->monitor_all_cnt)
                return;
        WARN_ON(call_op(adap, adap_monitor_all_enable, false));
        cec_adap_enable(adap);
}

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

        if (adap->monitor_pin_cnt++)
                return 0;

        ret = cec_adap_enable(adap);
        if (ret)
                adap->monitor_pin_cnt--;
        return ret;
}

void cec_monitor_pin_cnt_dec(struct cec_adapter *adap)
{
        if (WARN_ON(!adap->monitor_pin_cnt))
                return;
        if (--adap->monitor_pin_cnt)
                return;
        WARN_ON(call_op(adap, adap_monitor_pin_enable, false));
        cec_adap_enable(adap);
}

#ifdef CONFIG_DEBUG_FS
/*
 * 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, "enabled: %d\n", adap->is_enabled);
        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);
        if (adap->monitor_pin_cnt)
                seq_printf(file, "file handles in Monitor Pin mode: %u\n",
                           adap->monitor_pin_cnt);
        if (adap->tx_timeouts) {
                seq_printf(file, "transmit timeouts: %u\n",
                           adap->tx_timeouts);
                adap->tx_timeouts = 0;
        }
        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