1 /*
2  * Copyright (C) 2012 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License"); you may not
5  * use this file except in compliance with the License. You may obtain a copy of
6  * 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, WITHOUT
12  * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
13  * License for the specific language governing permissions and limitations under
14  * the License.
15  */
16 
17 // TODO remove all the headers upto asound.h after removing pcm_drain hack
18 #include <errno.h>
19 #include <unistd.h>
20 #include <poll.h>
21 #include <sys/ioctl.h>
22 #include <sys/mman.h>
23 #include <sys/time.h>
24 #include <limits.h>
25 #include <linux/ioctl.h>
26 #define __force
27 #define __bitwise
28 #define __user
29 #include <sound/asound.h>
30 
31 #include <string.h>
32 #include <tinyalsa/asoundlib.h>
33 
34 #include "audio/AudioHardware.h"
35 #include "audio/Buffer.h"
36 #include "Log.h"
37 
38 #include "audio/AudioPlaybackLocal.h"
39 
40 
AudioPlaybackLocal(int hwId)41 AudioPlaybackLocal::AudioPlaybackLocal(int hwId)
42     : mHwId(hwId),
43       mPcmHandle(NULL)
44 {
45     LOGV("AudioPlaybackLocal %x", (unsigned long)this);
46 }
47 
~AudioPlaybackLocal()48 AudioPlaybackLocal::~AudioPlaybackLocal()
49 {
50     LOGV("~AudioPlaybackLocal %x", (unsigned long)this);
51     releaseHw();
52 }
53 
doPrepare(AudioHardware::SamplingRate samplingRate,int samplesInOneGo)54 bool AudioPlaybackLocal::doPrepare(AudioHardware::SamplingRate samplingRate, int samplesInOneGo)
55 {
56     releaseHw();
57 
58     struct pcm_config config;
59 
60     memset(&config, 0, sizeof(config));
61     config.channels = 2;
62     config.rate = samplingRate;
63     config.period_size = 1024;
64     config.period_count = 64;
65     config.format = PCM_FORMAT_S16_LE;
66     config.start_threshold = 0;
67     config.stop_threshold =  0;
68     config.silence_threshold = 0;
69 
70     mPcmHandle = pcm_open(mHwId, 0, PCM_OUT, &config);
71     if (!mPcmHandle || !pcm_is_ready(mPcmHandle)) {
72        LOGE("Unable to open PCM device(%d) (%s)\n", mHwId, pcm_get_error(mPcmHandle));
73        return false;
74     }
75 
76     mSamples = samplesInOneGo;
77     mSizes = samplesInOneGo * 4; // stereo, 16bit
78 
79     return true;
80 }
81 
doPlaybackOrRecord(android::sp<Buffer> & buffer)82 bool AudioPlaybackLocal::doPlaybackOrRecord(android::sp<Buffer>& buffer)
83 {
84     if (buffer->amountToHandle() < (size_t)mSizes) {
85         mSizes = buffer->amountToHandle();
86     }
87     if (pcm_write(mPcmHandle, buffer->getUnhanledData(), mSizes)) {
88         LOGE("AudioPlaybackLocal error %s", pcm_get_error(mPcmHandle));
89         return false;
90     }
91     buffer->increaseHandled(mSizes);
92     LOGV("AudioPlaybackLocal::doPlaybackOrRecord %d", buffer->amountHandled());
93     return true;
94 }
95 
doStop()96 void AudioPlaybackLocal::doStop()
97 {
98     // TODO: remove when pcm_stop does pcm_drain
99     // hack to have snd_pcm_drain equivalent
100     struct pcm_ {
101         int fd;
102     };
103     pcm_* pcm = (pcm_*)mPcmHandle;
104     ioctl(pcm->fd, SNDRV_PCM_IOCTL_DRAIN);
105     pcm_stop(mPcmHandle);
106 }
107 
releaseHw()108 void AudioPlaybackLocal::releaseHw()
109 {
110     if (mPcmHandle != NULL) {
111         LOGV("releaseHw %x", (unsigned long)this);
112         doStop();
113         pcm_close(mPcmHandle);
114         mPcmHandle = NULL;
115     }
116 }
117