camera/device/3.5/ICameraDeviceCallback.hal

/*
 * Copyright (C) 2018 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 android.hardware.camera.device@3.5;

import @3.2::StreamBuffer;
import @3.4::ICameraDeviceCallback;

/**
 * Callback methods for the HAL to call into the framework.
 */
interface ICameraDeviceCallback extends @3.4::ICameraDeviceCallback {

    /**
     * requestStreamBuffers:
     *
     * Synchronous callback for HAL to ask for output buffers from camera service.
     *
     * This call may be serialized in camera service so it is strongly
     * recommended to only call this method from one thread.
     *
     * When camera device advertises
     * (CameraMetadataEnumAndroidInfoSupportedBufferManagementVersion ==
     * ANDROID_INFO_SUPPORTED_BUFFER_MANAGEMENT_VERSION_HIDL_DEVICE_3_5), HAL
     * can use this method to request buffers from camera service.
     *
     * @return status Status code for the operation, one of:
     *     OK: all requested buffers are returned
     *     FAILED_PARTIAL: some streams failed while some succeeds. Check
     *             individual StreamBufferRet for details.
     *     FAILED_CONFIGURING: the request failed because camera servicve is
     *             performing configureStreams and no buffers are returned.
     *     FAILED_UNKNOWN: the request failed for unknown reason and no buffers
     *             are returned.
     *
     * Performance requirements:
     * This is a blocking call that takes more time with more buffers requested.
     * HAL must not request large amount of buffers on a latency critical code
     * path. It is highly recommended to use a dedicated thread to perform
     * all requestStreamBuffers calls, and adjust the thread priority and/or
     * timing of making the call in order for buffers to arrive before HAL is
     * ready to fill the buffer.
     */
    requestStreamBuffers(vec<BufferRequest> bufReqs)
            generates (BufferRequestStatus st, vec<StreamBufferRet> buffers);

    /**
     * returnStreamBuffers:
     *
     * Synchronous callback for HAL to return output buffers to camera service.
     *
     * If this method is called during a configureStreams call, it must be blocked
     * until camera service finishes the ongoing configureStreams call.
     */
    returnStreamBuffers(vec<StreamBuffer> buffers);

};