// Copyright 2021 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.

/// FIDL definitions used for communicating to the Embedded Controller (EC) used
/// on ChromeOS devices.
library fuchsia.hardware.google.ec;

using zx;

const MAX_COMMAND_SIZE uint16 = 65535;

/// Status codes returned by the EC.
/// The canonical source for this list is in this file:
/// https://chromium.googlesource.com/chromiumos/platform/ec/+/HEAD/include/ec_commands.h
type EcStatus = flexible enum {
    SUCCESS = 0;
    INVALID_COMMAND = 1;
    ERROR = 2;
    INVALID_PARAM = 3;
    ACCESS_DENIED = 4;
    INVALID_RESPONSE = 5;
    INVALID_VERSION = 6;
    INVALID_CHECKSUM = 7;
    /// Accepted, command in progress
    IN_PROGRESS = 8;
    /// No response available
    UNAVAILABLE = 9;
    /// We got a timeout
    TIMEOUT = 10;
    /// Table / data overflow
    OVERFLOW = 11;
    /// Header contains invalid data
    INVALID_HEADER = 12;
    /// Didn't get the entire request
    REQUEST_TRUNCATED = 13;
    /// Response was too big to handle
    RESPONSE_TOO_BIG = 14;
    /// Communications bus error
    BUS_ERROR = 15;
    /// Up but too busy.  Should retry
    BUSY = 16;
    /// Header version invalid
    INVALID_HEADER_VERSION = 17;
    /// Header CRC invalid
    INVALID_HEADER_CRC = 18;
    /// Data CRC invalid
    INVALID_DATA_CRC = 19;
    /// Can't resend response
    DUP_UNAVAILABLE = 20;
};

@discoverable
closed protocol Device {
    /// Run the given command on the EC.
    strict RunCommand(struct {
        /// Command code.
        command uint16;
        /// Command version.
        command_version uint8;
        /// Request bytes, which are command-code and -version specific.
        request vector<uint8>:MAX_COMMAND_SIZE;
    }) -> (struct {
        /// Result returned by the EC command.
        result EcStatus;
        /// Response bytes, which are command-code and -version specific.
        data vector<uint8>:MAX_COMMAND_SIZE;
    }) error zx.Status;
};

service Service {
    device client_end:Device;
};