gamepad_device_linux.h

// Copyright 2018 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef DEVICE_GAMEPAD_GAMEPAD_DEVICE_LINUX_
#define DEVICE_GAMEPAD_GAMEPAD_DEVICE_LINUX_

#include <memory>
#include <string>
#include <vector>

#include "base/files/scoped_file.h"
#include "base/memory/weak_ptr.h"
#include "device/gamepad/abstract_haptic_gamepad.h"
#include "device/gamepad/gamepad_id_list.h"
#include "device/gamepad/gamepad_standard_mappings.h"
#include "device/gamepad/udev_gamepad_linux.h"

extern "C" {
struct udev_device;
}

namespace device {

class Dualshock4Controller;
class HidHapticGamepad;
class XboxHidController;

// GamepadDeviceLinux represents a single gamepad device which may be accessed
// through multiple host interfaces. Gamepad button and axis state are queried
// through the joydev interface, while haptics commands are routed through the
// evdev interface. A gamepad must be enumerated through joydev to be usable,
// but the evdev interface is only required for haptic effects.
//
// For some devices, haptics are not supported through evdev and are instead
// sent through the raw HID (hidraw) interface.
class GamepadDeviceLinux final : public AbstractHapticGamepad {
 public:
  using OpenDeviceNodeCallback = base::OnceCallback<void(GamepadDeviceLinux*)>;

  GamepadDeviceLinux(const std::string& syspath_prefix,
                     scoped_refptr<base::SequencedTaskRunner> dbus_runner);
  ~GamepadDeviceLinux() override;

  // Returns true if no device nodes are associated with this device.
  bool IsEmpty() const;

  int GetJoydevIndex() const { return joydev_index_; }
  uint16_t GetVendorId() const { return vendor_id_; }
  uint16_t GetProductId() const { return product_id_; }
  uint16_t GetVersionNumber() const { return version_number_; }
  std::string GetName() const { return name_; }
  std::string GetSyspathPrefix() const { return syspath_prefix_; }
  GamepadBusType GetBusType() const { return bus_type_; }
  GamepadStandardMappingFunction GetMappingFunction() const;

  bool SupportsVibration() const;

  // Reads the current gamepad state into |pad|.
  void ReadPadState(Gamepad* pad);

  // Reads the state of gamepad buttons and axes using joydev. Returns true if
  // |pad| was updated.
  bool ReadJoydevState(Gamepad* pad);

  // Discovers and assigns button indices for key codes that are outside the
  // normal gamepad button range.
  void InitializeEvdevSpecialKeys();

  // Reads the state of keys outside the normal button range using evdev.
  // Returns true if |pad| was updated.
  bool ReadEvdevSpecialKeys(Gamepad* pad);

  // Returns true if |pad_info| describes this device.
  bool IsSameDevice(const UdevGamepadLinux& pad_info);

  // Opens the joydev device node and queries device info.
  bool OpenJoydevNode(const UdevGamepadLinux& pad_info, udev_device* device);

  // Closes the joydev device node and clears device info.
  void CloseJoydevNode();

  // Opens the evdev device node and initializes haptics.
  bool OpenEvdevNode(const UdevGamepadLinux& pad_info);

  // Closes the evdev device node and shuts down haptics.
  void CloseEvdevNode();

  // Opens the hidraw device node and initializes haptics.
  void OpenHidrawNode(const UdevGamepadLinux& pad_info,
                      OpenDeviceNodeCallback callback);

  // Closes the hidraw device node and shuts down haptics.
  void CloseHidrawNode();

  // AbstractHapticGamepad public implementation.
  void SetVibration(double strong_magnitude, double weak_magnitude) override;
  void SetZeroVibration() override;
  base::WeakPtr<AbstractHapticGamepad> GetWeakPtr() override;

 private:
  // AbstractHapticGamepad private implementation.
  void DoShutdown() override;

  void OnOpenHidrawNodeComplete(OpenDeviceNodeCallback callback,
                                base::ScopedFD fd);
  void InitializeHidraw(base::ScopedFD fd);

  // The syspath prefix is used to identify device nodes that refer to the same
  // underlying gamepad through different interfaces.
  //
  // Joydev and evdev nodes that refer to the same device will share a parent
  // node that represents the physical device. We can compare the syspaths of
  // the parent nodes to determine when two nodes refer to the same device.
  //
  // The syspath for a hidraw node will match the parent syspath of a joydev or
  // evdev node up to the subsystem. To simplify this comparison, we only store
  // the syspath prefix up to the subsystem.
  std::string syspath_prefix_;

  // The file descriptor for the device's joydev node.
  base::ScopedFD joydev_fd_;

  // The index of the device's joydev node, or -1 if unknown.
  // The joydev index is the integer at the end of the joydev node path and is
  // used to assign the gamepad to a slot. For example, a device with path
  // /dev/input/js2 has index 2 and will be assigned to the 3rd gamepad slot.
  int joydev_index_ = -1;

  // Maps from indices in the Gamepad buttons array to a boolean value
  // indicating whether the button index is already mapped.
  std::vector<bool> button_indices_used_;

  // An identifier for the gamepad device model.
  GamepadId gamepad_id_ = GamepadId::kUnknownGamepad;

  // The vendor ID of the device.
  uint16_t vendor_id_;

  // The product ID of the device.
  uint16_t product_id_;

  // The version of the HID specification that this device is compliant with.
  // The hid-sony driver patches this value to indicate that a newer mapping has
  // been applied.
  uint16_t hid_specification_version_;

  // The version number of the device.
  uint16_t version_number_;

  // A string identifying the manufacturer and model of the device.
  std::string name_;

  // The file descriptor for the device's evdev node.
  base::ScopedFD evdev_fd_;

  // The ID of the haptic effect stored on the device, or -1 if none is stored.
  int effect_id_ = -1;

  // True if the device supports rumble effects through the evdev device node.
  bool supports_force_feedback_ = false;

  // Set to true once the evdev button capabilities have been checked.
  bool evdev_special_keys_initialized_ = false;

  // Mapping from "special" index (an index within the kSpecialKeys table) to
  // button index (an index within the Gamepad buttons array), or -1 if the
  // button is not mapped. Empty if no special buttons are mapped.
  std::vector<int> special_button_map_;

  // The file descriptor for the device's hidraw node.
  base::ScopedFD hidraw_fd_;

  // The type of the bus through which the device is connected, or
  // GAMEPAD_BUS_UNKNOWN if the bus type could not be determined.
  GamepadBusType bus_type_ = GAMEPAD_BUS_UNKNOWN;

  // Dualshock4 functionality, if available.
  std::unique_ptr<Dualshock4Controller> dualshock4_;

  // Xbox Wireless Controller behaves like a HID gamepad when connected over
  // Bluetooth. In this mode, haptics functionality is provided by |xbox_hid_|.
  // When connected over USB, Xbox Wireless Controller is supported through the
  // platform driver (xpad).
  std::unique_ptr<XboxHidController> xbox_hid_;

  // A controller that uses a HID output report for vibration effects.
  std::unique_ptr<HidHapticGamepad> hid_haptics_;

  // Task runner to use for D-Bus tasks. D-Bus client classes (including
  // PermissionBrokerClient) are not thread-safe and should be used only on the
  // UI thread.
  scoped_refptr<base::SequencedTaskRunner> dbus_runner_;

  // Task runner to use for gamepad polling.
  scoped_refptr<base::SequencedTaskRunner> polling_runner_;

  // Weak pointer factory for use only on the |polling_runner_| thread.
  base::WeakPtrFactory<GamepadDeviceLinux> weak_factory_{this};
};

}  // namespace device

#endif  // DEVICE_GAMEPAD_GAMEPAD_DEVICE_LINUX_