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