Implement audio devices and streams HAL delegating to legacy HAL

Changes made to the .hal definition:

  - introduce Effect ID returned by the IEffectsFactory that
    needs to be passed to IStream.{add|remove}Effect; otherwise
    it's impossible to retrieve the underlying HAL effect handle;

  - change "bus address" in DeviceAddress to "string" type;

  - fix signature of some methods w.r.t. returning Result;

  - remove unused "struct AudioPatch".

Bug: 30222631
Test: make
Change-Id: Icb51729ef57bb2a5b0b78609735e7481bc04f95c
diff --git a/audio/2.0/default/DevicesFactory.cpp b/audio/2.0/default/DevicesFactory.cpp
new file mode 100644
index 0000000..1e087f2
--- /dev/null
+++ b/audio/2.0/default/DevicesFactory.cpp
@@ -0,0 +1,103 @@
+/*
+ * Copyright (C) 2016 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 "DevicesFactoryHAL"
+
+#include <string.h>
+
+#include <utils/Log.h>
+
+#include "Device.h"
+#include "DevicesFactory.h"
+#include "PrimaryDevice.h"
+
+namespace android {
+namespace hardware {
+namespace audio {
+namespace V2_0 {
+namespace implementation {
+
+// static
+const char* DevicesFactory::deviceToString(IDevicesFactory::Device device) {
+    switch (device) {
+        case IDevicesFactory::Device::PRIMARY: return AUDIO_HARDWARE_MODULE_ID_PRIMARY;
+        case IDevicesFactory::Device::A2DP: return AUDIO_HARDWARE_MODULE_ID_A2DP;
+        case IDevicesFactory::Device::USB: return AUDIO_HARDWARE_MODULE_ID_USB;
+        case IDevicesFactory::Device::R_SUBMIX: return AUDIO_HARDWARE_MODULE_ID_REMOTE_SUBMIX;
+    }
+}
+
+// static
+int DevicesFactory::loadAudioInterface(const char *if_name, audio_hw_device_t **dev)
+{
+    const hw_module_t *mod;
+    int rc;
+
+    rc = hw_get_module_by_class(AUDIO_HARDWARE_MODULE_ID, if_name, &mod);
+    if (rc) {
+        ALOGE("%s couldn't load audio hw module %s.%s (%s)", __func__,
+                AUDIO_HARDWARE_MODULE_ID, if_name, strerror(-rc));
+        goto out;
+    }
+    rc = audio_hw_device_open(mod, dev);
+    if (rc) {
+        ALOGE("%s couldn't open audio hw device in %s.%s (%s)", __func__,
+                AUDIO_HARDWARE_MODULE_ID, if_name, strerror(-rc));
+        goto out;
+    }
+    if ((*dev)->common.version < AUDIO_DEVICE_API_VERSION_MIN) {
+        ALOGE("%s wrong audio hw device version %04x", __func__, (*dev)->common.version);
+        rc = -EINVAL;
+        audio_hw_device_close(*dev);
+        goto out;
+    }
+    return OK;
+
+out:
+    *dev = NULL;
+    return rc;
+}
+
+// Methods from ::android::hardware::audio::V2_0::IDevicesFactory follow.
+Return<void> DevicesFactory::openDevice(IDevicesFactory::Device device, openDevice_cb _hidl_cb)  {
+    audio_hw_device_t *halDevice;
+    int halStatus = loadAudioInterface(deviceToString(device), &halDevice);
+    Result retval(Result::OK);
+    sp<IDevice> result;
+    if (halStatus == OK) {
+        if (device == IDevicesFactory::Device::PRIMARY) {
+            result = new PrimaryDevice(halDevice);
+        } else {
+            result = new ::android::hardware::audio::V2_0::implementation::Device(halDevice);
+        }
+    } else if (halStatus == -EINVAL) {
+        retval = Result::NOT_INITIALIZED;
+    } else {
+        retval = Result::INVALID_ARGUMENTS;
+    }
+    _hidl_cb(retval, result);
+    return Void();
+}
+
+IDevicesFactory* HIDL_FETCH_IDevicesFactory(const char* /* name */) {
+    return new DevicesFactory();
+}
+
+}  // namespace implementation
+}  // namespace V2_0
+}  // namespace audio
+}  // namespace hardware
+}  // namespace android