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