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#define __STDC_LIMIT_MACROS
18
19#define LOG_TAG "common_time"
20#include <utils/Log.h>
21
22#include <inttypes.h>
23#include <stdint.h>
24
25#include <utils/Errors.h>
26
27#include "common_clock.h"
28
29namespace android {
30
31CommonClock::CommonClock() {
32    cur_slew_        = 0;
33    cur_trans_valid_ = false;
34
35    cur_trans_.a_zero = 0;
36    cur_trans_.b_zero = 0;
37    cur_trans_.a_to_b_numer = local_to_common_freq_numer_ = 1;
38    cur_trans_.a_to_b_denom = local_to_common_freq_denom_ = 1;
39    duration_trans_ = cur_trans_;
40}
41
42bool CommonClock::init(uint64_t local_freq) {
43    Mutex::Autolock lock(&lock_);
44
45    if (!local_freq)
46        return false;
47
48    uint64_t numer = kCommonFreq;
49    uint64_t denom = local_freq;
50
51    LinearTransform::reduce(&numer, &denom);
52    if ((numer > UINT32_MAX) || (denom > UINT32_MAX)) {
53        ALOGE("Overflow in CommonClock::init while trying to reduce %" PRIu64 "/%" PRIu64,
54             kCommonFreq, local_freq);
55        return false;
56    }
57
58    cur_trans_.a_to_b_numer = local_to_common_freq_numer_ =
59        static_cast<uint32_t>(numer);
60    cur_trans_.a_to_b_denom = local_to_common_freq_denom_ =
61        static_cast<uint32_t>(denom);
62    duration_trans_ = cur_trans_;
63
64    return true;
65}
66
67status_t CommonClock::localToCommon(int64_t local, int64_t *common_out) const {
68    Mutex::Autolock lock(&lock_);
69
70    if (!cur_trans_valid_)
71        return INVALID_OPERATION;
72
73    if (!cur_trans_.doForwardTransform(local, common_out))
74        return INVALID_OPERATION;
75
76    return OK;
77}
78
79status_t CommonClock::commonToLocal(int64_t common, int64_t *local_out) const {
80    Mutex::Autolock lock(&lock_);
81
82    if (!cur_trans_valid_)
83        return INVALID_OPERATION;
84
85    if (!cur_trans_.doReverseTransform(common, local_out))
86        return INVALID_OPERATION;
87
88    return OK;
89}
90
91int64_t CommonClock::localDurationToCommonDuration(int64_t localDur) const {
92    int64_t ret;
93    duration_trans_.doForwardTransform(localDur, &ret);
94    return ret;
95}
96
97void CommonClock::setBasis(int64_t local, int64_t common) {
98    Mutex::Autolock lock(&lock_);
99
100    cur_trans_.a_zero = local;
101    cur_trans_.b_zero = common;
102    cur_trans_valid_ = true;
103}
104
105void CommonClock::resetBasis() {
106    Mutex::Autolock lock(&lock_);
107
108    cur_trans_.a_zero = 0;
109    cur_trans_.b_zero = 0;
110    cur_trans_valid_ = false;
111}
112
113status_t CommonClock::setSlew(int64_t change_time, int32_t ppm) {
114    Mutex::Autolock lock(&lock_);
115
116    int64_t new_local_basis;
117    int64_t new_common_basis;
118
119    if (cur_trans_valid_) {
120        new_local_basis = change_time;
121        if (!cur_trans_.doForwardTransform(change_time, &new_common_basis)) {
122            ALOGE("Overflow when attempting to set slew rate to %d", ppm);
123            return INVALID_OPERATION;
124        }
125    } else {
126        new_local_basis = 0;
127        new_common_basis = 0;
128    }
129
130    cur_slew_ = ppm;
131    uint32_t n1 = local_to_common_freq_numer_;
132    uint32_t n2 = 1000000 + cur_slew_;
133
134    uint32_t d1 = local_to_common_freq_denom_;
135    uint32_t d2 = 1000000;
136
137    // n1/d1 has already been reduced, no need to do so here.
138    LinearTransform::reduce(&n1, &d2);
139    LinearTransform::reduce(&n2, &d1);
140    LinearTransform::reduce(&n2, &d2);
141
142    cur_trans_.a_zero = new_local_basis;
143    cur_trans_.b_zero = new_common_basis;
144    cur_trans_.a_to_b_numer = n1 * n2;
145    cur_trans_.a_to_b_denom = d1 * d2;
146
147    return OK;
148}
149
150}  // namespace android
151