samsung: hidl: add fastcharge implementation

* On samsung, kernel exposes a sysfs node to disable fastcharge at
   will, depending on what the user sets in battery settings UI.

 * Disabling fast charge may be useful for reducing the heat produced by
   the device while charging, or for extending the lifespan of the battery

 * This commit introduces the fastcharge HIDL, which writes in the node

              /sys/class/sec/switch/afc_disable

   0 or 1 depeding on user selection.
   0 means that fastcharge is enabled, while 1 means that fastcharge is
     disabled

Change-Id: I369ba9c437b3a83a88c2ce74d603b7d7ddd9cfbb

hidl/fastcharge/Android.mk

@@ -0,0 +1,44 @@
+#
+# Copyright (C) 2020 The LineageOS 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.
+#
+
+LOCAL_PATH := $(call my-dir)
+
+include $(CLEAR_VARS)
+
+LOCAL_SRC_FILES := \
+    FastCharge.cpp \
+    service.cpp
+
+LOCAL_C_INCLUDES := \
+    $(LOCAL_PATH)/include \
+
+LOCAL_SHARED_LIBRARIES := \
+    libbase \
+    libbinder \
+    libhidlbase \
+    libhidltransport \
+    libutils \
+    vendor.lineage.fastcharge@1.0
+
+LOCAL_MODULE := vendor.lineage.fastcharge@1.0-service.samsung
+LOCAL_INIT_RC := vendor.lineage.fastcharge@1.0-service.samsung.rc
+LOCAL_MODULE_RELATIVE_PATH := hw
+LOCAL_MODULE_TAGS := optional
+LOCAL_MODULE_OWNER := samsung
+LOCAL_VINTF_FRAGMENTS := vendor.lineage.fastcharge@1.0-service.samsung.xml
+LOCAL_VENDOR_MODULE := true
+
+include $(BUILD_EXECUTABLE)

hidl/fastcharge/FastCharge.cpp

@@ -0,0 +1,88 @@
+/*
+ * Copyright (C) 2020 The LineageOS 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 "fastcharge@1.0-service.samsung"
+
+#include "FastCharge.h"
+#include <android-base/logging.h>
+#include <fstream>
+#include <iostream>
+#include "samsung_fastcharge.h"
+
+namespace vendor {
+namespace lineage {
+namespace fastcharge {
+namespace V1_0 {
+namespace implementation {
+
+/*
+ * Write value to path and close file.
+ */
+template <typename T>
+static void set(const std::string& path, const T& value) {
+    std::ofstream file(path);
+
+    if (!file) {
+        PLOG(ERROR) << "Failed to open: " << path;
+        return;
+    }
+
+    LOG(DEBUG) << "write: " << path << " value: " << value;
+
+    file << value << std::endl;
+
+    if (!file) {
+        PLOG(ERROR) << "Failed to write: " << path << " value: " << value;
+    }
+}
+
+template <typename T>
+static T get(const std::string& path, const T& def) {
+    std::ifstream file(path);
+
+    if (!file) {
+        PLOG(ERROR) << "Failed to open: " << path;
+        return def;
+    }
+
+    T result;
+
+    file >> result;
+
+    if (file.fail()) {
+        PLOG(ERROR) << "Failed to read: " << path;
+        return def;
+    } else {
+        LOG(DEBUG) << "read: " << path << " value: " << result;
+        return result;
+    }
+}
+
+Return<bool> FastCharge::isEnabled() {
+    return get(FASTCHARGE_PATH, 0) < 1;
+}
+
+Return<bool> FastCharge::setEnabled(bool enable) {
+    set(FASTCHARGE_PATH, enable ? 0 : 1);
+
+    return isEnabled();
+}
+
+}  // namespace implementation
+}  // namespace V1_0
+}  // namespace fastcharge
+}  // namespace lineage
+}  // namespace vendor

hidl/fastcharge/FastCharge.h

@@ -0,0 +1,52 @@
+/*
+ * Copyright (C) 2020 The LineageOS 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.
+ */
+
+#ifndef VENDOR_LINEAGE_FASTCHARGE_V1_0_FASTCHARGE_H
+#define VENDOR_LINEAGE_FASTCHARGE_V1_0_FASTCHARGE_H
+
+#include <hidl/MQDescriptor.h>
+#include <hidl/Status.h>
+#include <vendor/lineage/fastcharge/1.0/IFastCharge.h>
+
+namespace vendor {
+namespace lineage {
+namespace fastcharge {
+namespace V1_0 {
+namespace implementation {
+
+using ::android::sp;
+using ::android::hardware::hidl_array;
+using ::android::hardware::hidl_memory;
+using ::android::hardware::hidl_string;
+using ::android::hardware::hidl_vec;
+using ::android::hardware::Return;
+using ::android::hardware::Void;
+
+using ::vendor::lineage::fastcharge::V1_0::IFastCharge;
+
+
+struct FastCharge : public IFastCharge {
+    Return<bool> isEnabled() override;
+    Return<bool> setEnabled(bool enable) override;
+};
+
+}  // namespace implementation
+}  // namespace V1_0
+}  // namespace fastcharge
+}  // namespace lineage
+}  // namespace vendor
+
+#endif  // VENDOR_LINEAGE_FASTCHARGE_V1_0_FASTCHARGE_H

hidl/fastcharge/include/samsung_fastcharge.h

@@ -0,0 +1,22 @@
+/*
+ * Copyright (C) 2020 The LineageOS 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.
+ */
+
+#ifndef SAMSUNG_FASTCHARGE_H
+#define SAMSUNG_FASTCHARGE_H
+
+#define FASTCHARGE_PATH "/sys/class/sec/switch/afc_disable"
+
+#endif // SAMSUNG_FASTCHARGE_H

hidl/fastcharge/service.cpp

@@ -0,0 +1,50 @@
+/*
+ * Copyright (C) 2020 The LineageOS 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 "fastcharge@1.0-service.samsung"
+
+#include <android-base/logging.h>
+#include <hidl/HidlTransportSupport.h>
+
+#include "FastCharge.h"
+
+using android::hardware::configureRpcThreadpool;
+using android::hardware::joinRpcThreadpool;
+
+using vendor::lineage::fastcharge::V1_0::IFastCharge;
+using vendor::lineage::fastcharge::V1_0::implementation::FastCharge;
+
+using android::OK;
+using android::status_t;
+
+int main() {
+    android::sp<FastCharge> service = new FastCharge();
+
+    configureRpcThreadpool(1, true);
+
+    status_t status = service->registerAsService();
+    if (status != OK) {
+        LOG(ERROR) << "Cannot register FastCharge HAL service.";
+        return 1;
+    }
+
+    LOG(INFO) << "FastCharge HAL service ready.";
+
+    joinRpcThreadpool();
+
+    LOG(ERROR) << "FastCharge HAL service failed to join thread pool.";
+    return 1;
+}

hidl/fastcharge/vendor.lineage.fastcharge@1.0-service.samsung.rc

@@ -0,0 +1,4 @@
+service vendor.fastcharge-hal-1-0 /vendor/bin/hw/vendor.lineage.fastcharge@1.0-service.samsung
+    class hal
+    user system
+    group system

hidl/fastcharge/vendor.lineage.fastcharge@1.0-service.samsung.xml

@@ -0,0 +1,11 @@
+<manifest version="1.0" type="device">
+    <hal format="hidl">
+        <name>vendor.lineage.fastcharge</name>
+        <transport>hwbinder</transport>
+        <version>1.0</version>
+        <interface>
+            <name>IFastCharge</name>
+            <instance>default</instance>
+        </interface>
+    </hal>
+</manifest>