hdmi: connection: add rpi specific aidl hal

* Needed for AIDL HDMI-CEC HAL to work. Some functions that were in the
  HIDL HDMI-CEC HAL have been moved to separate HDMI connection HAL in the
  AIDL versions. Only returns connection status of HDMI ports on Pi.
  onHotplugEvent is not implemented.
* Use hardware/interfaces/tv/hdmi/connection/aidl/ as reference.

hdmi/connection/Android.bp

@@ -0,0 +1,22 @@
+// Copyright (C) 2022 The Android Open Source Project
+// Copyright (C) 2025 KonstaKANG
+//
+// SPDX-License-Identifier: Apache-2.0
+
+cc_binary {
+    name: "android.hardware.tv.hdmi.connection-service.rpi",
+    relative_install_path: "hw",
+    init_rc: ["android.hardware.tv.hdmi.connection-service.rpi.rc"],
+    vintf_fragments: ["android.hardware.tv.hdmi.connection-service.rpi.xml"],
+    vendor: true,
+    srcs: [
+        "HdmiConnection.cpp",
+        "main.cpp",
+    ],
+    shared_libs: [
+        "android.hardware.tv.hdmi.connection-V1-ndk",
+        "libbase",
+        "libbinder_ndk",
+        "liblog",
+    ],
+}

hdmi/connection/HdmiConnection.cpp

@@ -0,0 +1,119 @@
+/*
+ * Copyright (C) 2022 The Android Open Source Project
+ * Copyright (C) 2025 KonstaKANG
+ *
+ * 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 "android.hardware.tv.hdmi.connection-service.rpi"
+
+#include "HdmiConnection.h"
+
+#include <android-base/file.h>
+#include <android-base/logging.h>
+
+using android::base::ReadFileToString;
+using ndk::ScopedAStatus;
+using std::string;
+
+namespace android {
+namespace hardware {
+namespace tv {
+namespace hdmi {
+namespace connection {
+namespace implementation {
+
+static const string drmCard = "card0";
+
+HdmiConnection::HdmiConnection() {
+    mCallback = nullptr;
+
+    for (int i = 0; i < 2; i++) {
+        mPortInfos.push_back(
+                {.type = HdmiPortType::OUTPUT,
+                 .portId = i,
+                 .cecSupported = true,
+                 .arcSupported = false,
+                 .eArcSupported = false,
+                 .physicalAddress = 0xFFFF});
+        mHpdSignal.push_back(HpdSignal::HDMI_HPD_PHYSICAL);
+    }
+}
+
+HdmiConnection::~HdmiConnection() {
+    if (mCallback != nullptr) {
+        mCallback = nullptr;
+    }
+}
+
+ScopedAStatus HdmiConnection::getPortInfo(std::vector<HdmiPortInfo>* _aidl_return) {
+    *_aidl_return = mPortInfos;
+    return ScopedAStatus::ok();
+}
+
+ScopedAStatus HdmiConnection::isConnected(int32_t portId, bool* _aidl_return) {
+    if (portId != 0 && portId != 1) {
+        *_aidl_return = false;
+        return ScopedAStatus::ok();
+    }
+
+    bool connected = false;
+    string hdmiStatusPath = "/sys/class/drm/" + drmCard + "-HDMI-A-" + to_string(portId + 1) + "/status";
+    if (!access(hdmiStatusPath.c_str(), R_OK)) {
+        string connectedValue;
+        if (ReadFileToString(hdmiStatusPath, &connectedValue)) {
+            connected = !connectedValue.compare("connected\n");
+        }
+    }
+    LOG(INFO) << "portId: " << portId << ", connected: " << connected;
+
+    *_aidl_return = connected;
+    return ScopedAStatus::ok();
+}
+
+ScopedAStatus HdmiConnection::setCallback(const std::shared_ptr<IHdmiConnectionCallback>& callback) {
+    if (mCallback != nullptr) {
+        mCallback = nullptr;
+    }
+
+    if (callback != nullptr) {
+        mCallback = callback;
+    }
+
+    return ScopedAStatus::ok();
+}
+
+ScopedAStatus HdmiConnection::setHpdSignal(HpdSignal signal, int32_t portId) {
+    if (portId != 0 && portId != 1) {
+        return ScopedAStatus::fromExceptionCode(EX_ILLEGAL_ARGUMENT);
+    }
+
+    mHpdSignal.at(portId) = signal;
+    return ScopedAStatus::ok();
+}
+
+ScopedAStatus HdmiConnection::getHpdSignal(int32_t portId, HpdSignal* _aidl_return) {
+    if (portId != 0 && portId != 1) {
+        return ScopedAStatus::fromExceptionCode(EX_ILLEGAL_ARGUMENT);
+    }
+
+    *_aidl_return = mHpdSignal.at(portId);
+    return ScopedAStatus::ok();
+}
+
+}  // namespace implementation
+}  // namespace connection
+}  // namespace hdmi
+}  // namespace tv
+}  // namespace hardware
+}  // namespace android

hdmi/connection/HdmiConnection.h

@@ -0,0 +1,62 @@
+/*
+ * Copyright (C) 2022 The Android Open Source Project
+ * Copyright (C) 2025 KonstaKANG
+ *
+ * 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.
+ */
+
+#include <aidl/android/hardware/tv/hdmi/connection/BnHdmiConnection.h>
+#include <aidl/android/hardware/tv/hdmi/connection/Result.h>
+#include <algorithm>
+#include <vector>
+
+using namespace std;
+
+namespace android {
+namespace hardware {
+namespace tv {
+namespace hdmi {
+namespace connection {
+namespace implementation {
+
+using ::aidl::android::hardware::tv::hdmi::connection::BnHdmiConnection;
+using ::aidl::android::hardware::tv::hdmi::connection::HdmiPortInfo;
+using ::aidl::android::hardware::tv::hdmi::connection::HdmiPortType;
+using ::aidl::android::hardware::tv::hdmi::connection::HpdSignal;
+using ::aidl::android::hardware::tv::hdmi::connection::IHdmiConnection;
+using ::aidl::android::hardware::tv::hdmi::connection::IHdmiConnectionCallback;
+using ::aidl::android::hardware::tv::hdmi::connection::Result;
+
+struct HdmiConnection : public BnHdmiConnection {
+    HdmiConnection();
+    ~HdmiConnection();
+    ::ndk::ScopedAStatus getPortInfo(std::vector<HdmiPortInfo>* _aidl_return) override;
+    ::ndk::ScopedAStatus isConnected(int32_t portId, bool* _aidl_return) override;
+    ::ndk::ScopedAStatus setCallback(
+            const std::shared_ptr<IHdmiConnectionCallback>& callback) override;
+    ::ndk::ScopedAStatus setHpdSignal(HpdSignal signal, int32_t portId) override;
+    ::ndk::ScopedAStatus getHpdSignal(int32_t portId, HpdSignal* _aidl_return) override;
+
+  private:
+    std::vector<HdmiPortInfo> mPortInfos;
+    std::vector<HpdSignal> mHpdSignal;
+
+    std::shared_ptr<IHdmiConnectionCallback> mCallback;
+};
+
+}  // namespace implementation
+}  // namespace connection
+}  // namespace hdmi
+}  // Namespace tv
+}  // namespace hardware
+}  // namespace android

hdmi/connection/android.hardware.tv.hdmi.connection-service.rpi.rc

@@ -0,0 +1,5 @@
+service vendor.hdmi-default /vendor/bin/hw/android.hardware.tv.hdmi.connection-service.rpi
+    interface aidl android.hardware.tv.hdmi.connection.IHdmiConnection/default
+    class hal
+    user system
+    group system

hdmi/connection/android.hardware.tv.hdmi.connection-service.rpi.xml

@@ -0,0 +1,10 @@
+<manifest version="1.0" type="device">
+    <hal format="aidl">
+        <name>android.hardware.tv.hdmi.connection</name>
+        <version>1</version>
+        <interface>
+            <name>IHdmiConnection</name>
+            <instance>default</instance>
+        </interface>
+    </hal>
+</manifest>

hdmi/connection/main.cpp

@@ -0,0 +1,37 @@
+/*
+ * Copyright (C) 2022 The Android Open Source Project
+ * Copyright (C) 2025 KonstaKANG
+ *
+ * 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.
+ */
+
+#include "HdmiConnection.h"
+
+#include <android-base/logging.h>
+#include <android/binder_manager.h>
+#include <android/binder_process.h>
+
+using android::hardware::tv::hdmi::connection::implementation::HdmiConnection;
+
+int main() {
+    ABinderProcess_setThreadPoolMaxThreadCount(1);
+    ABinderProcess_startThreadPool();
+
+    std::shared_ptr<HdmiConnection> hdmiAidl = ndk::SharedRefBase::make<HdmiConnection>();
+    const std::string instance = std::string() + HdmiConnection::descriptor + "/default";
+    binder_status_t status = AServiceManager_addService(hdmiAidl->asBinder().get(), instance.c_str());
+    CHECK_EQ(status, STATUS_OK);
+
+    ABinderProcess_joinThreadPool();
+    return EXIT_FAILURE;  // should not reach
+}