sensors/2.0/multihal/include/HalProxy.h

/*
 * Copyright (C) 2019 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.
 */

#pragma once

#include "SubHal.h"

#include <android/hardware/sensors/2.0/ISensors.h>
#include <fmq/MessageQueue.h>
#include <hardware_legacy/power.h>
#include <hidl/MQDescriptor.h>
#include <hidl/Status.h>

namespace android {
namespace hardware {
namespace sensors {
namespace V2_0 {
namespace implementation {

using ::android::sp;
using ::android::hardware::EventFlag;
using ::android::hardware::hidl_string;
using ::android::hardware::hidl_vec;
using ::android::hardware::MessageQueue;
using ::android::hardware::MQDescriptor;
using ::android::hardware::Return;
using ::android::hardware::Void;

class HalProxy : public ISensors {
  public:
    using Event = ::android::hardware::sensors::V1_0::Event;
    using OperationMode = ::android::hardware::sensors::V1_0::OperationMode;
    using RateLevel = ::android::hardware::sensors::V1_0::RateLevel;
    using Result = ::android::hardware::sensors::V1_0::Result;
    using SharedMemInfo = ::android::hardware::sensors::V1_0::SharedMemInfo;

    explicit HalProxy();
    // Test only constructor.
    explicit HalProxy(std::vector<ISensorsSubHal*>& subHalList);
    ~HalProxy();

    // Methods from ::android::hardware::sensors::V2_0::ISensors follow.
    Return<void> getSensorsList(getSensorsList_cb _hidl_cb) override;

    Return<Result> setOperationMode(OperationMode mode) override;

    Return<Result> activate(int32_t sensorHandle, bool enabled) override;

    Return<Result> initialize(
            const ::android::hardware::MQDescriptorSync<Event>& eventQueueDescriptor,
            const ::android::hardware::MQDescriptorSync<uint32_t>& wakeLockDescriptor,
            const sp<ISensorsCallback>& sensorsCallback) override;

    Return<Result> batch(int32_t sensorHandle, int64_t samplingPeriodNs,
                         int64_t maxReportLatencyNs) override;

    Return<Result> flush(int32_t sensorHandle) override;

    Return<Result> injectSensorData(const Event& event) override;

    Return<void> registerDirectChannel(const SharedMemInfo& mem,
                                       registerDirectChannel_cb _hidl_cb) override;

    Return<Result> unregisterDirectChannel(int32_t channelHandle) override;

    Return<void> configDirectReport(int32_t sensorHandle, int32_t channelHandle, RateLevel rate,
                                    configDirectReport_cb _hidl_cb) override;

    Return<void> debug(const hidl_handle& fd, const hidl_vec<hidl_string>& args) override;

    // Below methods from ::android::hardware::sensors::V2_0::ISensorsCallback with a minor change
    // to pass in the sub-HAL index. While the above methods are invoked from the sensors framework
    // via the binder, these methods are invoked from a callback provided to sub-HALs inside the
    // same process as the HalProxy, but potentially running on different threads.
    Return<void> onDynamicSensorsConnected(const hidl_vec<SensorInfo>& dynamicSensorsAdded,
                                           int32_t subHalIndex);

    Return<void> onDynamicSensorsDisconnected(const hidl_vec<int32_t>& dynamicSensorHandlesRemoved,
                                              int32_t subHalIndex);

  private:
    using EventMessageQueue = MessageQueue<Event, kSynchronizedReadWrite>;
    using WakeLockMessageQueue = MessageQueue<uint32_t, kSynchronizedReadWrite>;

    /**
     * The Event FMQ where sensor events are written
     */
    std::unique_ptr<EventMessageQueue> mEventQueue;

    /**
     * The Wake Lock FMQ that is read to determine when the framework has handled WAKE_UP events
     */
    std::unique_ptr<WakeLockMessageQueue> mWakeLockQueue;

    /**
     * Event Flag to signal to the framework when sensor events are available to be read
     */
    EventFlag* mEventQueueFlag;

    /**
     * Callback to the sensors framework to inform it that new sensors have been added or removed.
     */
    sp<ISensorsCallback> mDynamicSensorsCallback;

    /**
     * SubHal object pointers that have been saved from vendor dynamic libraries.
     */
    std::vector<ISensorsSubHal*> mSubHalList;

    /**
     * List of SensorInfo objects that contains the sensor info from subhals as
     * well as the modified sensor handle for the framework.
     *
     * The subhal index is encoded in the first byte of the sensor handle and
     * the remaining bytes are generated by the subhal to identify the sensor.
     */
    std::vector<SensorInfo> mSensorList;

    //! The current operation mode for all subhals.
    OperationMode mCurrentOperationMode = OperationMode::NORMAL;

    //! The single subHal that supports directChannel reporting.
    ISensorsSubHal* mDirectChannelSubHal = nullptr;

    /**
     * Initialize the list of SubHal objects in mSubHalList by reading from dynamic libraries
     * listed in a config file.
     */
    void initializeSubHalListFromConfigFile(const char* configFileName);

    /**
     * Initialize the list of SensorInfo objects in mSensorList by getting sensors from each
     * subhal.
     */
    void initializeSensorList();

    /**
     * Clear direct channel flags if the HalProxy has already chosen a subhal as its direct channel
     * subhal. Set the directChannelSubHal pointer to the subHal passed in if this is the first
     * direct channel enabled sensor seen.
     *
     * @param sensorInfo The SensorInfo object that may be altered to have direct channel support
     *    disabled.
     * @param subHal The subhal pointer that the current sensorInfo object came from.
     */
    void setDirectChannelFlags(SensorInfo* sensorInfo, ISensorsSubHal* subHal);

    /*
     * Get the subhal pointer which can be found by indexing into the mSubHalList vector
     * using the index from the first byte of sensorHandle.
     *
     * @param sensorHandle The handle used to identify a sensor in one of the subhals.
     */
    ISensorsSubHal* getSubHalForSensorHandle(uint32_t sensorHandle);

    /*
     * Zero out the first (most significant) byte in a number. Used in modifying the sensor handles
     * before passing them to subhals.
     *
     * @param num The uint32_t number to work with.
     *
     * @return The modified version of num param.
     */
    static uint32_t zeroOutFirstByte(uint32_t num);
};

}  // namespace implementation
}  // namespace V2_0
}  // namespace sensors
}  // namespace hardware
}  // namespace android