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      1 /*
      2  * Copyright (C) 2012 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 #ifndef __COMMON_CLOCK_H__
     18 #define __COMMON_CLOCK_H__
     19 
     20 #include <stdint.h>
     21 
     22 #include <utils/Errors.h>
     23 #include <utils/threads.h>
     24 
     25 #include "LinearTransform.h"
     26 
     27 namespace android {
     28 
     29 class CommonClock {
     30   public:
     31     CommonClock();
     32 
     33     bool      init(uint64_t local_freq);
     34 
     35     status_t  localToCommon(int64_t local, int64_t *common_out) const;
     36     status_t  commonToLocal(int64_t common, int64_t *local_out) const;
     37     int64_t   localDurationToCommonDuration(int64_t localDur) const;
     38     uint64_t  getCommonFreq() const { return kCommonFreq; }
     39     bool      isValid() const { return cur_trans_valid_; }
     40     status_t  setSlew(int64_t change_time, int32_t ppm);
     41     void      setBasis(int64_t local, int64_t common);
     42     void      resetBasis();
     43   private:
     44     mutable Mutex lock_;
     45 
     46     int32_t  cur_slew_;
     47     uint32_t local_to_common_freq_numer_;
     48     uint32_t local_to_common_freq_denom_;
     49 
     50     LinearTransform duration_trans_;
     51     LinearTransform cur_trans_;
     52     bool cur_trans_valid_;
     53 
     54     static const uint64_t kCommonFreq = 1000000ull;
     55 };
     56 
     57 }  // namespace android
     58 #endif  // __COMMON_CLOCK_H__
     59