sm6250-common: Import Pixel thermal HAL

* From hardware/google/pixel at 728fb99bbb910be05711421310efa6827aaaa4fa.

Change-Id: I763b4dbef65084cfee337065b2c5ab465f69bca8

thermal/utils/thermal_watcher.h

@@ -0,0 +1,105 @@
+/*
+ * Copyright (C) 2018 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.
+ */
+#ifndef THERMAL_UTILS_THERMAL_WATCHER_H_
+#define THERMAL_UTILS_THERMAL_WATCHER_H_
+
+#include <chrono>
+#include <condition_variable>
+#include <future>
+#include <list>
+#include <mutex>
+#include <set>
+#include <string>
+#include <thread>
+#include <unordered_map>
+#include <vector>
+
+#include <android-base/chrono_utils.h>
+#include <android-base/unique_fd.h>
+#include <utils/Looper.h>
+#include <utils/Thread.h>
+
+namespace android {
+namespace hardware {
+namespace thermal {
+namespace V2_0 {
+namespace implementation {
+
+using android::base::boot_clock;
+using android::base::unique_fd;
+using WatcherCallback = std::function<bool(const std::set<std::string> &name)>;
+
+// A helper class for monitoring thermal files changes.
+class ThermalWatcher : public ::android::Thread {
+  public:
+    ThermalWatcher(const WatcherCallback &cb)
+        : Thread(false), cb_(cb), looper_(new Looper(true)) {}
+    ~ThermalWatcher() = default;
+
+    // Disallow copy and assign.
+    ThermalWatcher(const ThermalWatcher &) = delete;
+    void operator=(const ThermalWatcher &) = delete;
+
+    // Start the thread and return true if it succeeds.
+    bool startWatchingDeviceFiles();
+    // Give the file watcher a list of files to start watching. This helper
+    // class will by default wait for modifications to the file with a looper.
+    // This should be called before starting watcher thread.
+    void registerFilesToWatch(const std::set<std::string> &sensors_to_watch, bool uevent_monitor);
+    // Wake up the looper thus the worker thread, immediately. This can be called
+    // in any thread.
+    void wake();
+
+  private:
+    // The work done by the watcher thread. This will use inotify to check for
+    // modifications to the files to watch. If any modification is seen this
+    // will callback the registered function with the new data read from the
+    // modified file.
+    bool threadLoop() override;
+
+    // Parse uevent message
+    void parseUevent(std::set<std::string> *sensor_name);
+
+    // Maps watcher filer descriptor to watched file path.
+    std::unordered_map<int, std::string> watch_to_file_path_map_;
+
+    // The callback function. Called whenever thermal uevent is seen.
+    // The function passed in should expect a string in the form (type).
+    // Where type is the name of the thermal zone that trigger a uevent notification.
+    // Callback will return thermal trigger status for next polling decision.
+    const WatcherCallback cb_;
+
+    sp<Looper> looper_;
+
+    // For uevent socket registration.
+    android::base::unique_fd uevent_fd_;
+    // Sensor list which monitor flag is enabled.
+    std::set<std::string> monitored_sensors_;
+    // Flag to point out if any sensor across the first threshold.
+    bool thermal_triggered_;
+    // Flag to point out if device can support uevent notify.
+    bool is_polling_;
+    // Timestamp for last thermal update
+    boot_clock::time_point last_update_time_;
+};
+
+}  // namespace implementation
+}  // namespace V2_0
+}  // namespace thermal
+}  // namespace hardware
+}  // namespace android
+
+#endif  // THERMAL_UTILS_THERMAL_WATCHER_H_