xref: /gem5/src/dev/serial/serial.cc

/*
 * Copyright (c) 2014, 2017 ARM Limited
 * All rights reserved
 *
 * The license below extends only to copyright in the software and shall
 * not be construed as granting a license to any other intellectual
 * property including but not limited to intellectual property relating
 * to a hardware implementation of the functionality of the software
 * licensed hereunder.  You may use the software subject to the license
 * terms below provided that you ensure that this notice is replicated
 * unmodified and in its entirety in all distributions of the software,
 * modified or unmodified, in source code or in binary form.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met: redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer;
 * redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the distribution;
 * neither the name of the copyright holders nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * Authors: Andreas Sandberg
 */

#include "dev/serial/serial.hh"

#include "base/logging.hh"
#include "params/SerialDevice.hh"
#include "params/SerialNullDevice.hh"

SerialDevice::SerialDevice(const SerialDeviceParams *p)
    : SimObject(p), interfaceCallback(nullptr)
{
}

SerialDevice::~SerialDevice()
{
}

void
SerialDevice::regInterfaceCallback(Callback *c)
{
    // This can happen if the user has connected multiple UARTs to the
    // same terminal. In that case, each of them tries to register
    // callbacks.
    if (interfaceCallback)
        fatal("A UART has already been associated with this device.\n");
    interfaceCallback = c;
}

void
SerialDevice::notifyInterface()
{
    assert(dataAvailable());
    // Registering a callback is optional.
    if (interfaceCallback)
        interfaceCallback->process();
}




SerialNullDevice::SerialNullDevice(const SerialNullDeviceParams *p)
    : SerialDevice(p)
{
}

uint8_t
SerialNullDevice::readData()
{
    panic("SerialNullDevice does not have pending data.\n");
}



SerialNullDevice *
SerialNullDeviceParams::create()
{
    return new SerialNullDevice(this);
}