// Copyright 2017 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.

module device.mojom;

struct SerialDeviceInfo {
  string path;
  uint16 vendor_id;
  bool has_vendor_id = false;
  uint16 product_id;
  bool has_product_id = false;
  string? display_name;
};

enum SerialSendError {
  NONE,
  DISCONNECTED,
  PENDING,
  TIMEOUT,
  SYSTEM_ERROR,
};

enum SerialReceiveError {
  NONE,
  DISCONNECTED,
  TIMEOUT,
  DEVICE_LOST,
  BREAK,
  FRAME_ERROR,
  OVERRUN,
  BUFFER_OVERFLOW,
  PARITY_ERROR,
  SYSTEM_ERROR,
};

enum SerialDataBits {
  NONE,
  SEVEN,
  EIGHT,
};

enum SerialParityBit {
  NONE,
  NO_PARITY,
  ODD,
  EVEN,
};

enum SerialStopBits {
  NONE,
  ONE,
  TWO,
};

struct SerialConnectionOptions {
  uint32 bitrate = 0;
  SerialDataBits data_bits = NONE;
  SerialParityBit parity_bit = NONE;
  SerialStopBits stop_bits = NONE;
  bool cts_flow_control;
  bool has_cts_flow_control = false;
};

struct SerialConnectionInfo {
  uint32 bitrate = 0;
  SerialDataBits data_bits = NONE;
  SerialParityBit parity_bit = NONE;
  SerialStopBits stop_bits = NONE;
  bool cts_flow_control;
};

struct SerialHostControlSignals {
  bool dtr;
  bool has_dtr = false;
  bool rts;
  bool has_rts = false;
};

struct SerialDeviceControlSignals {
  bool dcd;
  bool cts;
  bool ri;
  bool dsr;
};

// Discovers and enumerates serial devices available to the host.
interface SerialDeviceEnumerator {
  GetDevices() => (array<SerialDeviceInfo> devices);
};

// Performs asynchronous I/O on serial devices.
interface SerialIoHandler {
  // Initiates an Open of the device then returns result.
  Open(string port, SerialConnectionOptions options) => (bool success);

  // Performs a Read operation then returns retrieved data and the
  // result. Note that the Read may succeed partially, means that even if
  // |error| indicates an error other than NONE, |data| may still contain
  // some retrieved data with the max size |bytes|. Behavior is undefined if
  // this is called while a Read is already pending.
  Read(uint32 bytes) => (array<uint8> data, SerialReceiveError error);

  // Performs a Write operation then returns written data and the result.
  // Note that the Write may succeed partially, means that even if |error|
  // indicates an error other than NONE, |bytes_written| bytes have already been
  // written although it may be <= size of |data|. Behavior is undefined if this
  // is called while a Write is already pending.
  Write(array<uint8> data) => (uint32 bytes_written, SerialSendError error);

  // Attempts to cancel a pending read operation.
  CancelRead(SerialReceiveError reason);

  // Attempts to cancel a pending write operation.
  CancelWrite(SerialSendError reason);

  // Flushes input and output buffers.
  Flush() => (bool success);

  // Reads current control signals (DCD, CTS, etc.).
  GetControlSignals() => (SerialDeviceControlSignals signals);

  // Sets one or more control signals (DTR and/or RTS) and returns result.
  SetControlSignals(SerialHostControlSignals signals) => (bool success);

  // Performs platform-specific port configuration and returns result.
  ConfigurePort(SerialConnectionOptions options) => (bool success);

  // Performs a platform-specific port configuration query and returns got info.
  GetPortInfo() => (SerialConnectionInfo info);

  // Initiates a BREAK signal. Places the transmission line in a break state
  // until the |ClearBreak| is called.
  SetBreak() => (bool success);

  // Terminates the BREAK signal. Places the transmission line in a nonbreak
  // state.
  ClearBreak() => (bool success);
};