src/dev/mc146818.hh

   1 /*
   2  * Copyright (c) 2004-2005 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: Ali Saidi
  29  *          Andrew Schultz
  30  *          Miguel Serrano
  31  */
  32
  33 #ifndef __DEV_MC146818_HH__
  34 #define __DEV_MC146818_HH__
  35
  36 #include "base/bitunion.hh"
  37 #include "base/logging.hh"
  38 #include "sim/eventq_impl.hh"
  39
  40 /** Real-Time Clock (MC146818) */
  41 class MC146818 : public EventManager
  42 {
  43   protected:
  44     virtual void handleEvent()
  45     {
  46         warn("No RTC event handler defined.\n");
  47     }
  48
  49   private:
  50     /** Event for RTC periodic interrupt */
  51     struct RTCEvent : public Event
  52     {
  53         MC146818 * parent;
  54         Tick interval;
  55         Tick offset;
  56
  57         RTCEvent(MC146818 * _parent, Tick i);
  58
  59         /** Schedule the RTC periodic interrupt */
  60         void scheduleIntr();
  61
  62         /** Event process to occur at interrupt*/
  63         virtual void process();
  64
  65         /** Event description */
  66         virtual const char *description() const;
  67     };
  68
  69     /** Event for RTC periodic interrupt */
  70     struct RTCTickEvent : public Event
  71     {
  72         MC146818 * parent;
  73         Tick offset;
  74
  75         RTCTickEvent(MC146818 * _parent) :
  76             parent(_parent), offset(SimClock::Int::s)
  77         {}
  78
  79         /** Event process to occur at interrupt*/
  80         void process();
  81
  82         /** Event description */
  83         const char *description() const;
  84     };
  85
  86   private:
  87     std::string _name;
  88     const std::string &name() const { return _name; }
  89
  90     /** RTC periodic interrupt event */
  91     RTCEvent event;
  92
  93     /** RTC tick event */
  94     RTCTickEvent tickEvent;
  95
  96     /** Data for real-time clock function */
  97     union {
  98         uint8_t clock_data[10];
  99
 100         struct {
 101             uint8_t sec;
 102             uint8_t sec_alrm;
 103             uint8_t min;
 104             uint8_t min_alrm;
 105             uint8_t hour;
 106             uint8_t hour_alrm;
 107             uint8_t wday;
 108             uint8_t mday;
 109             uint8_t mon;
 110             uint8_t year;
 111         };
 112     };
 113
 114     struct tm curTime;
 115
 116     void setTime(const struct tm time);
 117
 118     BitUnion8(RtcRegA)
 119         Bitfield<7> uip;    /// 1 = date and time update in progress
 120         Bitfield<6, 4> dv;  /// Divider configuration
 121         /** Rate selection
 122             0 = Disabled
 123             For 32768 Hz time bases:
 124               Freq = 32768Hz / 2**(n-1) for n >= 3
 125               Freq = 256Hz if n = 1
 126               Freq = 128Hz if n = 2
 127             Othwerise:
 128               Freq = 32768Hz / 2**(n-1)
 129         */
 130         Bitfield<3, 0> rs;
 131     EndBitUnion(RtcRegA)
 132
 133     /// Is the DV field in regA set to disabled?
 134     static inline bool rega_dv_disabled(const RtcRegA &reg);
 135
 136     BitUnion8(RtcRegB)
 137         Bitfield<7> set;       /// stop clock updates
 138         Bitfield<6> pie;       /// 1 = enable periodic clock interrupt
 139         Bitfield<5> aie;       /// 1 = enable alarm interrupt
 140         Bitfield<4> uie;       /// 1 = enable update-ended interrupt
 141         Bitfield<3> sqwe;      /// 1 = output sqare wave at SQW pin
 142         Bitfield<2> dm;        /// 0 = BCD, 1 = Binary coded time
 143         Bitfield<1> format24h; /// 0 = 12 hours, 1 = 24 hours
 144         Bitfield<0> dse;       /// USA Daylight Savings Time enable
 145     EndBitUnion(RtcRegB)
 146
 147     /** RTC status register A */
 148     RtcRegA stat_regA;
 149
 150     /** RTC status register B */
 151     RtcRegB stat_regB;
 152
 153   public:
 154     MC146818(EventManager *em, const std::string &name, const struct tm time,
 155             bool bcd, Tick frequency);
 156     virtual ~MC146818();
 157
 158     /** Start ticking */
 159     virtual void startup();
 160
 161     /** RTC write data */
 162     void writeData(const uint8_t addr, const uint8_t data);
 163
 164     /** RTC read data */
 165     uint8_t readData(const uint8_t addr);
 166
 167     void tickClock();
 168
 169     /**
 170       * Serialize this object to the given output stream.
 171       * @param base The base name of the counter object.
 172       * @param os The stream to serialize to.
 173       */
 174     void serialize(const std::string &base, CheckpointOut &cp) const;
 175
 176     /**
 177      * Reconstruct the state of this object from a checkpoint.
 178      * @param base The base name of the counter object.
 179      * @param cp The checkpoint use.
 180      * @param section The section name of this object
 181      */
 182     void unserialize(const std::string &base, CheckpointIn &cp);
 183 };
 184
 185 #endif // __DEV_MC146818_HH__