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 <stdint.h>
23
24 #include <utils/Errors.h>
25 #include <utils/LinearTransform.h>
26
27 #include "common_clock.h"
28
29 namespace android {
30
CommonClock()31 CommonClock::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
init(uint64_t local_freq)42 bool 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 %lld/%lld",
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
localToCommon(int64_t local,int64_t * common_out) const67 status_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
commonToLocal(int64_t common,int64_t * local_out) const79 status_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
localDurationToCommonDuration(int64_t localDur) const91 int64_t CommonClock::localDurationToCommonDuration(int64_t localDur) const {
92 int64_t ret;
93 duration_trans_.doForwardTransform(localDur, &ret);
94 return ret;
95 }
96
setBasis(int64_t local,int64_t common)97 void 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
resetBasis()105 void 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
setSlew(int64_t change_time,int32_t ppm)113 status_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