1 /*
2 * Copyright (C) 2023 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 #include <cmath>
18 #include <limits>
19
20 #define LOG_TAG "AHAL_StreamAlsa"
21 #include <android-base/logging.h>
22
23 #include <Utils.h>
24 #include <audio_utils/clock.h>
25 #include <error/expected_utils.h>
26
27 #include "core-impl/StreamAlsa.h"
28
29 namespace aidl::android::hardware::audio::core {
30
StreamAlsa(StreamContext * context,const Metadata & metadata,int readWriteRetries)31 StreamAlsa::StreamAlsa(StreamContext* context, const Metadata& metadata, int readWriteRetries)
32 : StreamCommonImpl(context, metadata),
33 mBufferSizeFrames(getContext().getBufferSizeInFrames()),
34 mFrameSizeBytes(getContext().getFrameSize()),
35 mSampleRate(getContext().getSampleRate()),
36 mIsInput(isInput(metadata)),
37 mConfig(alsa::getPcmConfig(getContext(), mIsInput)),
38 mReadWriteRetries(readWriteRetries) {}
39
init()40 ::android::status_t StreamAlsa::init() {
41 return mConfig.has_value() ? ::android::OK : ::android::NO_INIT;
42 }
43
drain(StreamDescriptor::DrainMode)44 ::android::status_t StreamAlsa::drain(StreamDescriptor::DrainMode) {
45 if (!mIsInput) {
46 static constexpr float kMicrosPerSecond = MICROS_PER_SECOND;
47 const size_t delayUs = static_cast<size_t>(
48 std::roundf(mBufferSizeFrames * kMicrosPerSecond / mSampleRate));
49 usleep(delayUs);
50 }
51 return ::android::OK;
52 }
53
flush()54 ::android::status_t StreamAlsa::flush() {
55 return ::android::OK;
56 }
57
pause()58 ::android::status_t StreamAlsa::pause() {
59 return ::android::OK;
60 }
61
standby()62 ::android::status_t StreamAlsa::standby() {
63 mAlsaDeviceProxies.clear();
64 return ::android::OK;
65 }
66
start()67 ::android::status_t StreamAlsa::start() {
68 if (!mAlsaDeviceProxies.empty()) {
69 // This is a resume after a pause.
70 return ::android::OK;
71 }
72 decltype(mAlsaDeviceProxies) alsaDeviceProxies;
73 for (const auto& device : getDeviceProfiles()) {
74 alsa::DeviceProxy proxy;
75 if (device.isExternal) {
76 // Always ask alsa configure as required since the configuration should be supported
77 // by the connected device. That is guaranteed by `setAudioPortConfig` and
78 // `setAudioPatch`.
79 proxy = alsa::openProxyForExternalDevice(
80 device, const_cast<struct pcm_config*>(&mConfig.value()),
81 true /*require_exact_match*/);
82 } else {
83 proxy = alsa::openProxyForAttachedDevice(
84 device, const_cast<struct pcm_config*>(&mConfig.value()), mBufferSizeFrames);
85 }
86 if (proxy.get() == nullptr) {
87 return ::android::NO_INIT;
88 }
89 alsaDeviceProxies.push_back(std::move(proxy));
90 }
91 mAlsaDeviceProxies = std::move(alsaDeviceProxies);
92 return ::android::OK;
93 }
94
transfer(void * buffer,size_t frameCount,size_t * actualFrameCount,int32_t * latencyMs)95 ::android::status_t StreamAlsa::transfer(void* buffer, size_t frameCount, size_t* actualFrameCount,
96 int32_t* latencyMs) {
97 if (mAlsaDeviceProxies.empty()) {
98 LOG(FATAL) << __func__ << ": no opened devices";
99 return ::android::NO_INIT;
100 }
101 const size_t bytesToTransfer = frameCount * mFrameSizeBytes;
102 unsigned maxLatency = 0;
103 if (mIsInput) {
104 // For input case, only support single device.
105 proxy_read_with_retries(mAlsaDeviceProxies[0].get(), buffer, bytesToTransfer,
106 mReadWriteRetries);
107 maxLatency = proxy_get_latency(mAlsaDeviceProxies[0].get());
108 } else {
109 for (auto& proxy : mAlsaDeviceProxies) {
110 proxy_write_with_retries(proxy.get(), buffer, bytesToTransfer, mReadWriteRetries);
111 maxLatency = std::max(maxLatency, proxy_get_latency(proxy.get()));
112 }
113 }
114 *actualFrameCount = frameCount;
115 maxLatency = std::min(maxLatency, static_cast<unsigned>(std::numeric_limits<int32_t>::max()));
116 *latencyMs = maxLatency;
117 return ::android::OK;
118 }
119
refinePosition(StreamDescriptor::Position * position)120 ::android::status_t StreamAlsa::refinePosition(StreamDescriptor::Position* position) {
121 if (mAlsaDeviceProxies.empty()) {
122 LOG(WARNING) << __func__ << ": no opened devices";
123 return ::android::NO_INIT;
124 }
125 // Since the proxy can only count transferred frames since its creation,
126 // we override its counter value with ours and let it to correct for buffered frames.
127 alsa::resetTransferredFrames(mAlsaDeviceProxies[0], position->frames);
128 if (mIsInput) {
129 if (int ret = proxy_get_capture_position(mAlsaDeviceProxies[0].get(), &position->frames,
130 &position->timeNs);
131 ret != 0) {
132 LOG(WARNING) << __func__ << ": failed to retrieve capture position: " << ret;
133 return ::android::INVALID_OPERATION;
134 }
135 } else {
136 uint64_t hwFrames;
137 struct timespec timestamp;
138 if (int ret = proxy_get_presentation_position(mAlsaDeviceProxies[0].get(), &hwFrames,
139 ×tamp);
140 ret == 0) {
141 if (hwFrames > std::numeric_limits<int64_t>::max()) {
142 hwFrames -= std::numeric_limits<int64_t>::max();
143 }
144 position->frames = static_cast<int64_t>(hwFrames);
145 position->timeNs = audio_utils_ns_from_timespec(×tamp);
146 } else {
147 LOG(WARNING) << __func__ << ": failed to retrieve presentation position: " << ret;
148 return ::android::INVALID_OPERATION;
149 }
150 }
151 return ::android::OK;
152 }
153
shutdown()154 void StreamAlsa::shutdown() {
155 mAlsaDeviceProxies.clear();
156 }
157
158 } // namespace aidl::android::hardware::audio::core
159