unplugged-system/hardware/google/pixel/usb/include/pixelusb/MonitorFfs.h

102 lines
3.2 KiB
C++

/*
* Copyright (C) 2022 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 HARDWARE_GOOGLE_PIXEL_USB_MONITORFFS_H_
#define HARDWARE_GOOGLE_PIXEL_USB_MONITORFFS_H_
#include <android-base/unique_fd.h>
#include <pixelusb/CommonUtils.h>
#include <mutex>
#include <string>
#include <thread>
#include <vector>
namespace android {
namespace hardware {
namespace google {
namespace pixel {
namespace usb {
using ::android::base::unique_fd;
// MonitorFfs automously manages gadget pullup by monitoring
// the ep file status. Restarts the usb gadget when the ep
// owner restarts.
class MonitorFfs {
private:
// Monitors the endpoints Inotify events.
unique_fd mInotifyFd;
// Control pipe for shutting down the mMonitor thread.
// mMonitor exits when SHUTDOWN_MONITOR is written into
// mEventFd/
unique_fd mEventFd;
// Pools on mInotifyFd and mEventFd.
unique_fd mEpollFd;
std::vector<int> mWatchFd;
// Maintains the list of Endpoints.
std::vector<std::string> mEndpointList;
// protects the CV.
std::mutex mLock;
std::condition_variable mCv;
// protects mInotifyFd, mEpollFd.
std::mutex mLockFd;
// Flag to maintain the current status of gadget pullup.
bool mCurrentUsbFunctionsApplied;
// Thread object that executes the ep monitoring logic.
std::unique_ptr<std::thread> mMonitor;
// Callback to be invoked when gadget is pulled up.
void (*mCallback)(bool functionsApplied, void *payload);
void *mPayload;
// Name of the USB gadget. Used for pullup.
const char *const mGadgetName;
// Monitor State
bool mMonitorRunning;
public:
MonitorFfs(const char *const gadget);
// Inits all the UniqueFds.
void reset();
// Starts monitoring endpoints and pullup the gadget when
// the descriptors are written.
bool startMonitor();
// Waits for timeout_ms for gadget pull up to happen.
// Returns immediately if the gadget is already pulled up.
bool waitForPullUp(int timeout_ms);
// Adds the given fd to the watch list.
bool addInotifyFd(std::string fd);
// Adds the given endpoint to the watch list.
void addEndPoint(std::string ep);
// Registers the async callback from the caller to notify the caller
// when the gadget pull up happens.
void registerFunctionsAppliedCallback(void (*callback)(bool functionsApplied, void *(payload)),
void *payload);
bool isMonitorRunning();
// Ep monitoring and the gadget pull up logic.
static void *startMonitorFd(void *param);
};
} // namespace usb
} // namespace pixel
} // namespace google
} // namespace hardware
} // namespace android
#endif // HARDWARE_GOOGLE_PIXEL_USB_MONITORFFS_H_