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      1 /*
      2  * Copyright (C) 2017 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 #define LOG_TAG "VibratorService"
     18 
     19 #include <log/log.h>
     20 
     21 #include <hardware/hardware.h>
     22 #include <hardware/vibrator.h>
     23 
     24 #include "Vibrator.h"
     25 
     26 #include <cinttypes>
     27 #include <cmath>
     28 #include <iostream>
     29 #include <fstream>
     30 
     31 
     32 namespace android {
     33 namespace hardware {
     34 namespace vibrator {
     35 namespace V1_0 {
     36 namespace implementation {
     37 
     38 static constexpr int MAX_VOLTAGE = 3596;
     39 static constexpr int MIN_VOLTAGE = 116;
     40 
     41 static constexpr uint32_t CLICK_TIMING_MS = 20;
     42 
     43 Vibrator::Vibrator(std::ofstream&& enable, std::ofstream&& amplitude) :
     44         mEnable(std::move(enable)),
     45         mAmplitude(std::move(amplitude)) {}
     46 
     47 // Methods from ::android::hardware::vibrator::V1_0::IVibrator follow.
     48 Return<Status> Vibrator::on(uint32_t timeout_ms) {
     49     mEnable << timeout_ms << std::endl;
     50     if (!mEnable) {
     51         ALOGE("Failed to turn vibrator on (%d): %s", errno, strerror(errno));
     52         return Status::UNKNOWN_ERROR;
     53     }
     54     return Status::OK;
     55 }
     56 
     57 Return<Status> Vibrator::off()  {
     58     mEnable << 0 << std::endl;
     59     if (!mEnable) {
     60         ALOGE("Failed to turn vibrator off (%d): %s", errno, strerror(errno));
     61         return Status::UNKNOWN_ERROR;
     62     }
     63     return Status::OK;
     64 }
     65 
     66 Return<bool> Vibrator::supportsAmplitudeControl()  {
     67     return true;
     68 }
     69 
     70 Return<Status> Vibrator::setAmplitude(uint8_t amplitude) {
     71     if (amplitude == 0) {
     72         return Status::BAD_VALUE;
     73     }
     74     // Scale the voltage such that an amplitude of 1 is MIN_VOLTAGE, an amplitude of 255 is
     75     // MAX_VOLTAGE, and there are equal steps for every value in between.
     76     long voltage =
     77             std::lround((amplitude - 1) / 254.0 * (MAX_VOLTAGE - MIN_VOLTAGE) + MIN_VOLTAGE);
     78     ALOGE("Setting amplitude  to: %ld", voltage);
     79     mAmplitude << voltage << std::endl;
     80     if (!mAmplitude) {
     81         ALOGE("Failed to set amplitude (%d): %s", errno, strerror(errno));
     82         return Status::UNKNOWN_ERROR;
     83     }
     84     return Status::OK;
     85 }
     86 
     87 Return<void> Vibrator::perform(Effect effect, EffectStrength strength, perform_cb _hidl_cb) {
     88     if (effect == Effect::CLICK) {
     89         uint8_t amplitude;
     90         switch (strength) {
     91         case EffectStrength::LIGHT:
     92             amplitude = 36;
     93             break;
     94         case EffectStrength::MEDIUM:
     95             amplitude = 128;
     96             break;
     97         case EffectStrength::STRONG:
     98             amplitude = 255;
     99             break;
    100         default:
    101             _hidl_cb(Status::UNSUPPORTED_OPERATION, 0);
    102             return Void();
    103         }
    104         on(CLICK_TIMING_MS);
    105         setAmplitude(amplitude);
    106         _hidl_cb(Status::OK, CLICK_TIMING_MS);
    107     } else {
    108         _hidl_cb(Status::UNSUPPORTED_OPERATION, 0);
    109     }
    110     return Void();
    111 }
    112 
    113 } // namespace implementation
    114 }  // namespace V1_0
    115 }  // namespace vibrator
    116 }  // namespace hardware
    117 }  // namespace android
    118