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Diffstat (limited to 'services/common_time/clock_recovery.h')
-rw-r--r-- | services/common_time/clock_recovery.h | 159 |
1 files changed, 0 insertions, 159 deletions
diff --git a/services/common_time/clock_recovery.h b/services/common_time/clock_recovery.h deleted file mode 100644 index b6c87ff..0000000 --- a/services/common_time/clock_recovery.h +++ /dev/null @@ -1,159 +0,0 @@ -/* - * Copyright (C) 2011 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. - */ - -#ifndef __CLOCK_RECOVERY_H__ -#define __CLOCK_RECOVERY_H__ - -#include <stdint.h> -#include <common_time/ICommonClock.h> -#include <utils/LinearTransform.h> -#include <utils/threads.h> - -#ifdef TIME_SERVICE_DEBUG -#include "diag_thread.h" -#endif - -#include "utils.h" - -namespace android { - -class CommonClock; -class LocalClock; - -class ClockRecoveryLoop { - public: - ClockRecoveryLoop(LocalClock* local_clock, CommonClock* common_clock); - ~ClockRecoveryLoop(); - - void reset(bool position, bool frequency); - bool pushDisciplineEvent(int64_t local_time, - int64_t nominal_common_time, - int64_t data_point_rtt); - int32_t getLastErrorEstimate(); - - // Applies the next step in any ongoing slew change operation. Returns a - // timeout suitable for use with poll/select indicating the number of mSec - // until the next change should be applied. - int applyRateLimitedSlew(); - - private: - - // Tuned using the "Good Gain" method. - // See: - // http://techteach.no/publications/books/dynamics_and_control/tuning_pid_controller.pdf - - // Controller period (1Hz for now). - static const float dT; - - // Controller gain, positive and unitless. Larger values converge faster, - // but can cause instability. - static const float Kc; - - // Integral reset time. Smaller values cause loop to track faster, but can - // also cause instability. - static const float Ti; - - // Controller output filter time constant. Range (0-1). Smaller values make - // output smoother, but slow convergence. - static const float Tf; - - // Low-pass filter for bias tracker. - static const float bias_Fc; // HZ - static const float bias_RC; // Computed in constructor. - static const float bias_Alpha; // Computed inconstructor. - - // The maximum allowed error (as indicated by a pushDisciplineEvent) before - // we panic. - static const int64_t panic_thresh_; - - // The maximum allowed error rtt time for packets to be used for control - // feedback, unless the packet is the best in recent memory. - static const int64_t control_thresh_; - - typedef struct { - int64_t local_time; - int64_t observed_common_time; - int64_t nominal_common_time; - int64_t rtt; - bool point_used; - } DisciplineDataPoint; - - static uint32_t findMinRTTNdx(DisciplineDataPoint* data, uint32_t count); - - void reset_l(bool position, bool frequency); - void setTargetCorrection_l(int32_t tgt); - bool applySlew_l(); - - // The local clock HW abstraction we use as the basis for common time. - LocalClock* local_clock_; - bool local_clock_can_slew_; - - // The common clock we end up controlling along with the lock used to - // serialize operations. - CommonClock* common_clock_; - Mutex lock_; - - // parameters maintained while running and reset during a reset - // of the frequency correction. - bool last_error_est_valid_; - int32_t last_error_est_usec_; - float last_delta_f_; - int32_t integrated_error_; - int32_t tgt_correction_; - int32_t cur_correction_; - LinearTransform time_to_cur_slew_; - int64_t slew_change_end_time_; - Timeout next_slew_change_timeout_; - - // Contoller Output. - float CO; - - // Bias tracking for trajectory estimation. - float CObias; - float lastCObias; - - // Controller output bounds. The controller will not try to - // slew faster that +/-100ppm offset from center per interation. - static const float COmin; - static const float COmax; - - // State kept for filtering the discipline data. - static const uint32_t kFilterSize = 16; - DisciplineDataPoint filter_data_[kFilterSize]; - uint32_t filter_wr_; - bool filter_full_; - - static const uint32_t kStartupFilterSize = 4; - DisciplineDataPoint startup_filter_data_[kStartupFilterSize]; - uint32_t startup_filter_wr_; - - // Minimum number of milliseconds over which we allow a full range change - // (from rail to rail) of the VCXO control signal. This is the rate - // limiting factor which keeps us from changing the clock rate so fast that - // we get in trouble with certain HDMI sinks. - static const uint32_t kMinFullRangeSlewChange_mSec; - - // How much time (in msec) to wait - static const int kSlewChangeStepPeriod_mSec; - -#ifdef TIME_SERVICE_DEBUG - sp<DiagThread> diag_thread_; -#endif -}; - -} // namespace android - -#endif // __CLOCK_RECOVERY_H__ |