hidl: Implement vendor.lineage.powershare@1.0 HAL for Xiaomi

* This feature is present in Xiaomi Mi 10/Pro/Ultra and for the Xiaomi
   family of SM8350, LAHAINA devices.

Change-Id: Icabcee87980611d97a837f86a52d94033de337ef

hidl/powershare/Android.bp

@@ -0,0 +1,26 @@
+//
+// Copyright (C) 2020 The LineageOS Project
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+
+cc_binary {
+    name: "vendor.lineage.powershare@1.0-service.xiaomi",
+    defaults: ["hidl_defaults"],
+    relative_install_path: "hw",
+    init_rc: ["vendor.lineage.powershare@1.0-service.xiaomi.rc"],
+    vintf_fragments: ["vendor.lineage.powershare@1.0-service.xiaomi.xml"],
+    srcs: [
+        "service.cpp",
+        "PowerShare.cpp",
+    ],
+    shared_libs: [
+        "libbase",
+        "libhardware",
+        "libhidlbase",
+        "liblog",
+        "libutils",
+        "vendor.lineage.powershare@1.0",
+    ],
+    proprietary: true,
+}

hidl/powershare/PowerShare.cpp

@@ -0,0 +1,61 @@
+/*
+ * Copyright (C) 2020 The LineageOS Project
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#define LOG_TAG "PowerShareService"
+
+#include "PowerShare.h"
+#include <hidl/HidlTransportSupport.h>
+#include <fstream>
+
+namespace vendor {
+namespace lineage {
+namespace powershare {
+namespace V1_0 {
+namespace implementation {
+
+#define WIRELESS_TX_ENABLE_PATH "/proc/wireless/enable_tx"
+
+/*
+ * Write value to path and close file.
+ */
+template <typename T>
+static void set(const std::string& path, const T& value) {
+    std::ofstream file(path);
+    file << value;
+}
+
+template <typename T>
+static T get(const std::string& path, const T& def) {
+    std::ifstream file(path);
+    T result;
+
+    file >> result;
+    return file.fail() ? def : result;
+}
+
+Return<bool> PowerShare::isEnabled() {
+    return get<std::string>(WIRELESS_TX_ENABLE_PATH, "disable") != "disable";
+}
+
+Return<bool> PowerShare::setEnabled(bool enable) {
+    set(WIRELESS_TX_ENABLE_PATH, enable ? 1 : 0);
+
+    return isEnabled();
+}
+
+Return<uint32_t> PowerShare::getMinBattery() {
+    return 0;
+}
+
+Return<uint32_t> PowerShare::setMinBattery(uint32_t) {
+    return getMinBattery();
+}
+
+}  // namespace implementation
+}  // namespace V1_0
+}  // namespace powershare
+}  // namespace lineage
+}  // namespace vendor

hidl/powershare/PowerShare.h

@@ -0,0 +1,36 @@
+/*
+ * Copyright (C) 2020 The LineageOS Project
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#ifndef VENDOR_LINEAGE_POWERSHARE_V1_0_POWERSHARE_H
+#define VENDOR_LINEAGE_POWERSHARE_V1_0_POWERSHARE_H
+
+#include <vendor/lineage/powershare/1.0/IPowerShare.h>
+
+namespace vendor {
+namespace lineage {
+namespace powershare {
+namespace V1_0 {
+namespace implementation {
+
+using ::android::sp;
+using ::android::hardware::Return;
+using ::android::hardware::Void;
+
+class PowerShare : public IPowerShare {
+  public:
+    Return<bool> isEnabled() override;
+    Return<bool> setEnabled(bool enable) override;
+    Return<uint32_t> getMinBattery() override;
+    Return<uint32_t> setMinBattery(uint32_t minBattery) override;
+};
+
+}  // namespace implementation
+}  // namespace V1_0
+}  // namespace powershare
+}  // namespace lineage
+}  // namespace vendor
+
+#endif  // VENDOR_LINEAGE_POWERSHARE_V1_0_POWERSHARE_H

hidl/powershare/service.cpp

@@ -0,0 +1,40 @@
+/*
+ * Copyright (C) 2020 The LineageOS Project
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#define LOG_TAG "vendor.lineage.powershare@1.0-service.xiaomi"
+
+#include <android-base/logging.h>
+#include <hidl/HidlTransportSupport.h>
+
+#include "PowerShare.h"
+
+using android::hardware::configureRpcThreadpool;
+using android::hardware::joinRpcThreadpool;
+
+using vendor::lineage::powershare::V1_0::IPowerShare;
+using vendor::lineage::powershare::V1_0::implementation::PowerShare;
+
+using android::OK;
+using android::status_t;
+
+int main() {
+    android::sp<IPowerShare> service = new PowerShare();
+
+    configureRpcThreadpool(1, true);
+
+    status_t status = service->registerAsService();
+    if (status != OK) {
+        LOG(ERROR) << "Cannot register PowerShare HAL service.";
+        return 1;
+    }
+
+    LOG(INFO) << "PowerShare HAL service ready.";
+
+    joinRpcThreadpool();
+
+    LOG(ERROR) << "PowerShare HAL service failed to join thread pool.";
+    return 1;
+}

hidl/powershare/vendor.lineage.powershare@1.0-service.xiaomi.rc

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

hidl/powershare/vendor.lineage.powershare@1.0-service.xiaomi.xml

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