camera/provider/2.4/ICameraProvider.hal

/*
 * Copyright (C) 2016 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.provider@2.4;

import ICameraProviderCallback;
import android.hardware.camera.common@1.0::types;
import android.hardware.camera.device@1.0::ICameraDevice;
import android.hardware.camera.device@3.2::ICameraDevice;

/**
 * Camera provider HAL, which enumerates the available individual camera devices
 * known to the provider, and provides updates about changes to device status,
 * such as connection, disconnection, or torch mode enable/disable.
 *
 * The provider is responsible for generating a list of camera device service
 * names that can then be opened via the hardware service manager.
 *
 * Multiple camera provider HALs may be present in a single system.
 * For discovery, the service names, and process names, must be of the form
 * "android.hardware.camera.provider@<major>.<minor>/<type>/<instance>"
 * where
 *   - <major>/<minor> is the provider HAL HIDL version,
 *   - <type> is the type of devices this provider knows about, such as
 *     "internal", "legacy", "usb", or "remote"
 *   - <instance> is a non-negative integer starting from 0 to disambiguate
 *     between multiple HALs of the same type.
 *
 * The "legacy" type is only used for passthrough legacy HAL mode, and must
 * not be used by a standalone binderized HAL.
 *
 * The device instance names enumerated by the provider must be of the form
 * "device@<major>.<minor>/<type>/<id>" where
 * <major>/<minor> is the HIDL version of the interface. <id> is either a small
 * incrementing integer for "internal" device types, with 0 being the main
 * back-facing camera and 1 being the main front-facing camera, if they exist.
 * Or, for external devices such as type "usb", a unique serial number that can
 * be used to identify the device reliably when it is disconnected and
 * reconnected. Multiple providers may not enumerate the same device ID.
 *
 */
interface ICameraProvider {

    /**
     * setCallback:
     *
     * Provide a callback interface to the HAL provider to inform framework of
     * asynchronous camera events. The framework must call this function once
     * during camera service startup, before any other calls to the provider
     * (note that in case the camera service restarts, this method must be
     * invoked again during its startup).
     *
     * @param callback
     *     A non-null callback interface to invoke when camera events occur.
     * @return status
     *     Status code for the operation, one of:
     *     OK:
     *         On success
     *     INTERNAL_ERROR:
     *         An unexpected internal error occurred while setting the callbacks
     *     ILLEGAL_ARGUMENT:
     *         The callback argument is invalid (for example, null).
     *
     */
    setCallback(ICameraProviderCallback callback) generates (Status status);

    /**
     * getVendorTags:
     *
     * Retrieve all vendor tags supported by devices discoverable through this
     * provider. The tags are grouped into sections.
     *
     * @return status
     *     Status code for the operation, one of:
     *     OK:
     *         On success
     *     INTERNAL_ERROR:
     *         An unexpected internal error occurred while setting the callbacks
     * @return sections
     *     The supported vendor tag sections; empty if there are no supported
     *     vendor tags, or status is not OK.
     *
     */
    getVendorTags() generates (Status status, vec<VendorTagSection> sections);

    /**
     * getCameraDeviceList:
     *
     * Returns the list of internal camera device interfaces known to this
     * camera provider. These devices can then be accessed via the hardware
     * service manager.
     *
     * External camera devices (camera facing EXTERNAL) must be reported through
     * the device status change callback, not in this list. Only devices with
     * facing BACK or FRONT must be listed here.
     *
     * @return status Status code for the operation, one of:
     *     OK:
     *         On a succesful generation of camera ID list
     *     INTERNAL_ERROR:
     *         A camera ID list cannot be created. This may be due to
     *         a failure to initialize the camera subsystem, for example.
     * @return cameraDeviceServiceNames The vector of internal camera device
     *     names known to this provider.
     */
    getCameraIdList()
            generates (Status status, vec<string> cameraDeviceNames);

    /**
     * getCameraDeviceInterface_VN_x:
     *
     * Return a android.hardware.camera.device@N.x/ICameraDevice interface for
     * the requested device name. This does not power on the camera device, but
     * simply acquires the interface for querying the device static information,
     * or to additionally open the device for active use.
     *
     * A separate method is required for each major revision of the camera device
     * HAL interface, since they are not compatible with each other.
     *
     * Valid device names for this provider can be obtained via either
     * getCameraIdList(), or via availability callbacks from
     * ICameraProviderCallback::cameraDeviceStatusChange().
     *
     * The returned interface must be of the highest defined minor version for
     * the major version; it's the responsibility of the HAL client to ensure
     * they do not use methods/etc that are not valid for the actual minor
     * version of the device.
     *
     * @param cameraDeviceName the name of the device to get an interface to.
     * @return status Status code for the operation, one of:
     *     OK:
     *         On a succesful generation of camera ID list
     *     ILLEGAL_ARGUMENT:
     *         This device name is unknown, or has been disconnected
     *     OPERATION_NOT_SUPPORTED:
     *         The specified device does not support this major version of the
     *         HAL interface.
     *     INTERNAL_ERROR:
     *         A camera interface cannot be returned due to an unexpected
     *         internal error.
     * @return device The inteface to this camera device, or null in case of
     *     error.
     */
    getCameraDeviceInterface_V1_x(string cameraDeviceName) generates
            (Status status,
             android.hardware.camera.device@1.0::ICameraDevice device);
    getCameraDeviceInterface_V3_x(string cameraDeviceName) generates
            (Status status,
             android.hardware.camera.device@3.2::ICameraDevice device);

};