src/dev/x86/i8254.cc

   1 /*
   2  * Copyright (c) 2008 The Regents of The University of Michigan
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions are
   7  * met: redistributions of source code must retain the above copyright
   8  * notice, this list of conditions and the following disclaimer;
   9  * redistributions in binary form must reproduce the above copyright
  10  * notice, this list of conditions and the following disclaimer in the
  11  * documentation and/or other materials provided with the distribution;
  12  * neither the name of the copyright holders nor the names of its
  13  * contributors may be used to endorse or promote products derived from
  14  * this software without specific prior written permission.
  15  *
  16  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  17  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  18  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  19  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  20  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  21  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  22  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  26  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27  *
  28  * Authors: Gabe Black
  29  */
  30
  31 #include "dev/x86/i8254.hh"
  32
  33 #include "debug/I8254.hh"
  34 #include "dev/x86/intdev.hh"
  35 #include "mem/packet.hh"
  36 #include "mem/packet_access.hh"
  37
  38 void
  39 X86ISA::I8254::counterInterrupt(unsigned int num)
  40 {
  41     DPRINTF(I8254, "Interrupt from counter %d.\n", num);
  42     if (num == 0) {
  43         for (auto *wire: intPin) {
  44             wire->raise();
  45             //XXX This is a hack.
  46             wire->lower();
  47         }
  48     }
  49 }
  50
  51 Tick
  52 X86ISA::I8254::read(PacketPtr pkt)
  53 {
  54     assert(pkt->getSize() == 1);
  55     Addr offset = pkt->getAddr() - pioAddr;
  56     if (offset < 3) {
  57         pkt->setLE(pit.readCounter(offset));
  58     } else if (offset == 3) {
  59         pkt->setLE(uint8_t(-1));
  60     } else {
  61         panic("Read from undefined i8254 register.\n");
  62     }
  63     pkt->makeAtomicResponse();
  64     return latency;
  65 }
  66
  67 Tick
  68 X86ISA::I8254::write(PacketPtr pkt)
  69 {
  70     assert(pkt->getSize() == 1);
  71     Addr offset = pkt->getAddr() - pioAddr;
  72     if (offset < 3) {
  73         pit.writeCounter(offset, pkt->getLE<uint8_t>());
  74     } else if (offset == 3) {
  75         pit.writeControl(pkt->getLE<uint8_t>());
  76     } else {
  77         panic("Write to undefined i8254 register.\n");
  78     }
  79     pkt->makeAtomicResponse();
  80     return latency;
  81 }
  82
  83 void
  84 X86ISA::I8254::serialize(CheckpointOut &cp) const
  85 {
  86     pit.serialize("pit", cp);
  87 }
  88
  89 void
  90 X86ISA::I8254::unserialize(CheckpointIn &cp)
  91 {
  92     pit.unserialize("pit", cp);
  93 }
  94
  95 void
  96 X86ISA::I8254::startup()
  97 {
  98     pit.startup();
  99 }
 100
 101 X86ISA::I8254 *
 102 I8254Params::create()
 103 {
 104     return new X86ISA::I8254(this);
 105 }