services/core/java/com/android/server/hdmi/SetArcTransmissionStateAction.java

/*
 * Copyright (C) 2014 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.android.server.hdmi;

import android.hardware.hdmi.HdmiDeviceInfo;
import android.util.Slog;

/**
 * Feature action that handles enabling/disabling of ARC transmission channel.
 * Once TV gets <Initiate ARC>, TV sends <Report ARC Initiated> to AV Receiver.
 * If it fails or it gets <Terminate ARC>, TV just disables ARC.
 */
final class SetArcTransmissionStateAction extends HdmiCecFeatureAction {
    private static final String TAG = "SetArcTransmissionStateAction";

    // State in which the action sent <Rerpot Arc Initiated> and
    // is waiting for time out. If it receives <Feature Abort> within timeout
    // ARC should be disabled.
    private static final int STATE_WAITING_TIMEOUT = 1;

    private final boolean mEnabled;
    private final int mAvrAddress;

    /**
     * @Constructor
     *
     * @param source {@link HdmiCecLocalDevice} instance
     * @param enabled whether to enable ARC Transmission channel
     */
    SetArcTransmissionStateAction(HdmiCecLocalDevice source, int avrAddress,
            boolean enabled) {
        super(source);
        HdmiUtils.verifyAddressType(getSourceAddress(), HdmiDeviceInfo.DEVICE_TV);
        HdmiUtils.verifyAddressType(avrAddress, HdmiDeviceInfo.DEVICE_AUDIO_SYSTEM);
        mAvrAddress = avrAddress;
        mEnabled = enabled;
    }

    @Override
    boolean start() {
        // Seq #37.
        if (mEnabled) {
            // Enable ARC status immediately before sending <Report Arc Initiated>.
            // If AVR responds with <Feature Abort>, disable ARC status again.
            // This is different from spec that says that turns ARC status to
            // "Enabled" if <Report ARC Initiated> is acknowledged and no
            // <Feature Abort> is received.
            // But implemented this way to save the time having to wait for
            // <Feature Abort>.
            setArcStatus(true);
            // If succeeds to send <Report ARC Initiated>, wait general timeout
            // to check whether there is no <Feature Abort> for <Report ARC Initiated>.
            mState = STATE_WAITING_TIMEOUT;
            addTimer(mState, HdmiConfig.TIMEOUT_MS);
            sendReportArcInitiated();
        } else {
            setArcStatus(false);
            finish();
        }
        return true;
    }

    private void sendReportArcInitiated() {
        HdmiCecMessage command =
                HdmiCecMessageBuilder.buildReportArcInitiated(getSourceAddress(), mAvrAddress);
        sendCommand(command, new HdmiControlService.SendMessageCallback() {
            @Override
            public void onSendCompleted(int error) {
                switch (error) {
                    case Constants.SEND_RESULT_SUCCESS:
                    case Constants.SEND_RESULT_BUSY:
                    case Constants.SEND_RESULT_FAILURE:
                        // The result of the command transmission, unless it is an obvious
                        // failure indicated by the target device (or lack thereof), should
                        // not affect the ARC status. Ignores it silently.
                        break;
                    case Constants.SEND_RESULT_NAK:
                        // If <Report ARC Initiated> is negatively ack'ed, disable ARC and
                        // send <Report ARC Terminated> directly.
                        setArcStatus(false);
                        HdmiLogger.debug("Failed to send <Report Arc Initiated>.");
                        finish();
                        break;
                }
            }
        });
    }

    private void setArcStatus(boolean enabled) {
        boolean wasEnabled = tv().setArcStatus(enabled);
        Slog.i(TAG, "Change arc status [old:" + wasEnabled + ", new:" + enabled + "]");

        // If enabled before and set to "disabled" and send <Report Arc Terminated> to
        // av reciever.
        if (!enabled && wasEnabled) {
            sendCommand(HdmiCecMessageBuilder.buildReportArcTerminated(getSourceAddress(),
                    mAvrAddress));
        }
    }

    @Override
    boolean processCommand(HdmiCecMessage cmd) {
        if (mState != STATE_WAITING_TIMEOUT) {
            return false;
        }

        int opcode = cmd.getOpcode();
        if (opcode == Constants.MESSAGE_FEATURE_ABORT) {
            int originalOpcode = cmd.getParams()[0] & 0xFF;
            if (originalOpcode == Constants.MESSAGE_REPORT_ARC_INITIATED) {
                HdmiLogger.debug("Feature aborted for <Report Arc Initiated>");
                setArcStatus(false);
                finish();
                return true;
            }
        }
        return false;
    }

    @Override
    void handleTimerEvent(int state) {
        if (mState != state || mState != STATE_WAITING_TIMEOUT) {
            return;
        }
        // Expire timeout for <Feature Abort>.
        finish();
    }
}