src/dev/serial/serial.cc

   1 /*
   2  * Copyright (c) 2014, 2017 ARM Limited
   3  * All rights reserved
   4  *
   5  * The license below extends only to copyright in the software and shall
   6  * not be construed as granting a license to any other intellectual
   7  * property including but not limited to intellectual property relating
   8  * to a hardware implementation of the functionality of the software
   9  * licensed hereunder.  You may use the software subject to the license
  10  * terms below provided that you ensure that this notice is replicated
  11  * unmodified and in its entirety in all distributions of the software,
  12  * modified or unmodified, in source code or in binary form.
  13  *
  14  * Redistribution and use in source and binary forms, with or without
  15  * modification, are permitted provided that the following conditions are
  16  * met: redistributions of source code must retain the above copyright
  17  * notice, this list of conditions and the following disclaimer;
  18  * redistributions in binary form must reproduce the above copyright
  19  * notice, this list of conditions and the following disclaimer in the
  20  * documentation and/or other materials provided with the distribution;
  21  * neither the name of the copyright holders nor the names of its
  22  * contributors may be used to endorse or promote products derived from
  23  * this software without specific prior written permission.
  24  *
  25  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  26  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  27  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  28  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  29  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  30  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  31  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  32  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  33  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  34  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  35  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  36  *
  37  * Authors: Andreas Sandberg
  38  */
  39
  40 #include "dev/serial/serial.hh"
  41
  42 #include "base/logging.hh"
  43 #include "params/SerialDevice.hh"
  44 #include "params/SerialNullDevice.hh"
  45
  46 SerialDevice::SerialDevice(const SerialDeviceParams *p)
  47     : SimObject(p), interfaceCallback(nullptr)
  48 {
  49 }
  50
  51 SerialDevice::~SerialDevice()
  52 {
  53 }
  54
  55 void
  56 SerialDevice::regInterfaceCallback(Callback *c)
  57 {
  58     // This can happen if the user has connected multiple UARTs to the
  59     // same terminal. In that case, each of them tries to register
  60     // callbacks.
  61     if (interfaceCallback)
  62         fatal("A UART has already been associated with this device.\n");
  63     interfaceCallback = c;
  64 }
  65
  66 void
  67 SerialDevice::notifyInterface()
  68 {
  69     assert(dataAvailable());
  70     // Registering a callback is optional.
  71     if (interfaceCallback)
  72         interfaceCallback->process();
  73 }
  74
  75
  76
  77
  78 SerialNullDevice::SerialNullDevice(const SerialNullDeviceParams *p)
  79     : SerialDevice(p)
  80 {
  81 }
  82
  83 uint8_t
  84 SerialNullDevice::readData()
  85 {
  86     panic("SerialNullDevice does not have pending data.\n");
  87 }
  88
  89
  90
  91 SerialNullDevice *
  92 SerialNullDeviceParams::create()
  93 {
  94     return new SerialNullDevice(this);
  95 }