android_device_peter_gsi/bluetooth/audio/hw/audio_bluetooth_hw.cc
Peter Cai c71693def3 gsi: Initial implementation of sysbta, a system-side bluetooth audio HAL
On platform release T, the legacy `audio.a2dp.default` HAL no longer
exists, and cannot be trivially restored for generic system-side A2DP
audio support. Rather than trying to cling on to its existence (which
does not even work anymore even if one did so), it is time to come up
with a new solution.

This commit introduces a system-side implementation of the generic
bluetooth audio HAL. The HAL itself is modelled after the default
bluetooth audio HAL, while substantial components of the default audio
HAL are also included as it has to also implement the audio HAL
interfaces.

The audio HAL implementation is delegated to `audio.sysbta.default`,
forked from `audio.bluetooth.default` from the Bluetooth apex package.
It then communicates with the bluetooth audio HAL interfaces, which need
to live in the same process (in this case, the process of the sysbta
HAL). This is why we cannot just load `audio.sysbta.default` into the
default audio HAL or the audioserver process directly, but rather have
to include our own simplistic audio HAL implementation.

For now, the audio HAL implementation only includes one for the 6.0
version, but technically, an interface for *every* audio HAL version
needs to exist. This, along with other messiness in the sysbta
implementation, will be addressed in a future commit.

Note that to actually make use of the sysbta audio hal, patches in
frameworks/av and packages/modules/Bluetooth are required to introduce
support for the property `persist.bluetooth.system_audio_hal.enabled`.
2022-08-24 15:47:06 -04:00

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/*
* Copyright 2019 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.
*/
#define LOG_TAG "BTAudioHw"
#include <android-base/logging.h>
#include <errno.h>
#include <hardware/hardware.h>
#include <log/log.h>
#include <malloc.h>
#include <string.h>
#include <system/audio.h>
#include "stream_apis.h"
#include "utils.h"
using ::android::bluetooth::audio::utils::GetAudioParamString;
using ::android::bluetooth::audio::utils::ParseAudioParams;
static int adev_set_parameters(struct audio_hw_device* dev,
const char* kvpairs) {
LOG(VERBOSE) << __func__ << ": kevpairs=[" << kvpairs << "]";
std::unordered_map<std::string, std::string> params =
ParseAudioParams(kvpairs);
if (params.empty()) return 0;
LOG(VERBOSE) << __func__ << ": ParamsMap=[" << GetAudioParamString(params)
<< "]";
if (params.find("A2dpSuspended") == params.end()) {
return -ENOSYS;
}
auto* bluetooth_device = reinterpret_cast<BluetoothAudioDevice*>(dev);
std::lock_guard<std::mutex> guard(bluetooth_device->mutex_);
for (auto sout : bluetooth_device->opened_stream_outs_) {
if (sout->stream_out_.common.set_parameters != nullptr) {
sout->stream_out_.common.set_parameters(&sout->stream_out_.common,
kvpairs);
}
}
return 0;
}
static char* adev_get_parameters(const struct audio_hw_device* dev,
const char* keys) {
LOG(VERBOSE) << __func__ << ": keys=[" << keys << "]";
return strdup("");
}
static int adev_init_check(const struct audio_hw_device* dev) { return 0; }
static int adev_set_voice_volume(struct audio_hw_device* dev, float volume) {
LOG(VERBOSE) << __func__ << ": volume=" << volume;
return -ENOSYS;
}
static int adev_set_master_volume(struct audio_hw_device* dev, float volume) {
LOG(VERBOSE) << __func__ << ": volume=" << volume;
return -ENOSYS;
}
static int adev_get_master_volume(struct audio_hw_device* dev, float* volume) {
return -ENOSYS;
}
static int adev_set_master_mute(struct audio_hw_device* dev, bool muted) {
LOG(VERBOSE) << __func__ << ": mute=" << muted;
return -ENOSYS;
}
static int adev_get_master_mute(struct audio_hw_device* dev, bool* muted) {
return -ENOSYS;
}
static int adev_set_mode(struct audio_hw_device* dev, audio_mode_t mode) {
LOG(VERBOSE) << __func__ << ": mode=" << mode;
return 0;
}
static int adev_set_mic_mute(struct audio_hw_device* dev, bool state) {
LOG(VERBOSE) << __func__ << ": state=" << state;
return -ENOSYS;
}
static int adev_get_mic_mute(const struct audio_hw_device* dev, bool* state) {
return -ENOSYS;
}
static int adev_dump(const audio_hw_device_t* device, int fd) { return 0; }
static int adev_close(hw_device_t* device) {
auto* bluetooth_device = reinterpret_cast<BluetoothAudioDevice*>(device);
delete bluetooth_device;
return 0;
}
static int adev_open(const hw_module_t* module, const char* name,
hw_device_t** device) {
LOG(VERBOSE) << __func__ << ": name=[" << name << "]";
if (strcmp(name, AUDIO_HARDWARE_INTERFACE) != 0) return -EINVAL;
auto bluetooth_audio_device = new BluetoothAudioDevice{};
struct audio_hw_device* adev = &bluetooth_audio_device->audio_device_;
if (!adev) return -ENOMEM;
adev->common.tag = HARDWARE_DEVICE_TAG;
adev->common.version = AUDIO_DEVICE_API_VERSION_2_0;
adev->common.module = (struct hw_module_t*)module;
adev->common.close = adev_close;
adev->init_check = adev_init_check;
adev->set_voice_volume = adev_set_voice_volume;
adev->set_master_volume = adev_set_master_volume;
adev->get_master_volume = adev_get_master_volume;
adev->set_mode = adev_set_mode;
adev->set_mic_mute = adev_set_mic_mute;
adev->get_mic_mute = adev_get_mic_mute;
adev->set_parameters = adev_set_parameters;
adev->get_parameters = adev_get_parameters;
adev->get_input_buffer_size = adev_get_input_buffer_size;
adev->open_output_stream = adev_open_output_stream;
adev->close_output_stream = adev_close_output_stream;
adev->open_input_stream = adev_open_input_stream;
adev->close_input_stream = adev_close_input_stream;
adev->dump = adev_dump;
adev->set_master_mute = adev_set_master_mute;
adev->get_master_mute = adev_get_master_mute;
*device = &adev->common;
return 0;
}
static struct hw_module_methods_t hal_module_methods = {
.open = adev_open,
};
struct audio_module HAL_MODULE_INFO_SYM = {
.common =
{
.tag = HARDWARE_MODULE_TAG,
.module_api_version = AUDIO_MODULE_API_VERSION_0_1,
.hal_api_version = HARDWARE_HAL_API_VERSION,
.id = AUDIO_HARDWARE_MODULE_ID,
.name = "Bluetooth Audio HW HAL",
.author = "The Android Open Source Project",
.methods = &hal_module_methods,
},
};