// Copyright 2022 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.mailbox;

using zx;

const MBOX_FIFO_SIZE uint32 = 128; // bytes
type MboxTx = struct {
    cmd uint32;
    tx_buffer vector<uint8>:MBOX_FIFO_SIZE;
};

type MboxRx = struct {
    rx_buffer vector<uint8>:MBOX_FIFO_SIZE;
};

@discoverable
closed protocol Device {
    // |channel| : vendor specific identifier used to communicate with different hardware blocks.
    strict SendCommand(struct {
        channel uint8;
        mdata MboxTx;
    }) -> () error zx.Status;

    // |channel| : vendor specific identifier used to communicate with different hardware blocks.
    // |rx_len | : rx_len is equal to the number of bytes of the transmitted data MboxTx.tx_buffer.
    strict ReceiveData(struct {
        channel uint8;
        rx_len uint8;
    }) -> (struct {
        mdata MboxRx;
    }) error zx.Status;
};

service Service {
    device client_end:Device;
};