// Copyright 2018 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;

// Flags that can be passed to Serial/Config()

// Select the character width
const uint32 SERIAL_DATA_BITS_5    = 0x0;
const uint32 SERIAL_DATA_BITS_6    = 0x1;
const uint32 SERIAL_DATA_BITS_7    = 0x2;
const uint32 SERIAL_DATA_BITS_8    = 0x3;
const uint32 SERIAL_DATA_BITS_MASK = 0x3;

// Select the number of stop bits
const uint32 SERIAL_STOP_BITS_1    = 0x0;
const uint32 SERIAL_STOP_BITS_2    = 0x4;
const uint32 SERIAL_STOP_BITS_MASK = 0x4;

// Select the parity mechanism
const uint32 SERIAL_PARITY_NONE = 0x00;
const uint32 SERIAL_PARITY_EVEN = 0x08;
const uint32 SERIAL_PARITY_ODD  = 0x10;
const uint32 SERIAL_PARITY_MASK = 0x18;

// Select the flow control mechanism
const uint32 SERIAL_FLOW_CTRL_NONE    = 0x00;
const uint32 SERIAL_FLOW_CTRL_CTS_RTS = 0x20;
const uint32 SERIAL_FLOW_CTRL_MASK    = 0x20;

// Set this flag to change baud rate but leave other properties unchanged
const uint32 SERIAL_SET_BAUD_RATE_ONLY = 0x80000000;

struct SerialPortInfo {
    /// Values from the FIDL enum fuchsia.hardware.serial.Class
    uint32 serial_class;
    /// Vendor and product ID of hardware attached to this serial port,
    /// or zero if not applicable.
    uint32 serial_vid;
    uint32 serial_pid;
};

/// High level serial protocol for use by client drivers.
/// When used with the platform device protocol, "port" will be relative to
/// the list of serial ports assigned to your device rather than the global
/// list of serial ports.
[Transport = "Banjo", BanjoLayout = "ddk-protocol"]
protocol Serial {
    GetInfo() -> (zx.status s, SerialPortInfo info);
    /// Configures the given serial port.
    Config(uint32 baud_rate, uint32 flags) -> (zx.status s);
    /// Returns a socket that can be used for reading and writing data
    /// from the given serial port.
    OpenSocket() -> (zx.status s, zx.handle:SOCKET handle);
};