sdk/fidl/fuchsia.hardware.serial/serial.fidl

// Copyright 2019 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
library fuchsia.hardware.serial;

using zx;

/// Description of what type of serial device this is
type Class = strict enum : uint8 {
    GENERIC = 1;
    /// A Bluetooth host controller
    BLUETOOTH_HCI = 2;
    /// An interactive console
    CONSOLE = 3;
    /// Kernel debug serial
    KERNEL_DEBUG = 4;
};

/// Number of bits per character
type CharacterWidth = strict enum : uint8 {
    BITS_5 = 1;
    BITS_6 = 2;
    BITS_7 = 3;
    BITS_8 = 4;
};

/// Number of stop bits
type StopWidth = strict enum : uint8 {
    BITS_1 = 1;
    BITS_2 = 2;
};

/// Which parity computation to use, if any.
type Parity = strict enum : uint8 {
    NONE = 1;
    EVEN = 2;
    ODD = 3;
};

/// What flow control mechanism to use
type FlowControl = strict enum : uint8 {
    NONE = 1;
    /// Clear To Send/Request To Send
    CTS_RTS = 2;
};

type Config = struct {
    character_width CharacterWidth;
    stop_width StopWidth;
    parity Parity;
    control_flow FlowControl;
    baud_rate uint32;
};

/// Legacy synchronous device interface.
/// New drivers should implement NewDevice instead.
protocol Device {
    /// Lookup what type of serial device this is.
    GetClass() -> (struct {
        device_class Class;
    });

    /// Set the configuration of this serial device.
    SetConfig(struct {
        config Config;
    }) -> (struct {
        s zx.status;
    });
};

/// FIDL device utilizing the new asynchronous serial driver
/// instead of the synchronous FDIO-backed read/write interface.
/// New drivers should implement this instead of the Device interface above.
protocol NewDevice {
    compose Device;

    /// Reads data from the serial port
    Read() -> (struct {
        data vector<uint8>:MAX;
    }) error zx.status;

    /// Writes data to the serial port
    Write(struct {
        data vector<uint8>:MAX;
    }) -> (struct {}) error zx.status;
};

@discoverable
protocol NewDeviceProxy {
    GetChannel(resource struct {
        req server_end:NewDevice;
    });
};