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