xref: /gem5/src/dev/alpha/tsunami_io.hh

/*
 * Copyright (c) 2004-2005 The Regents of The University of Michigan
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met: redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer;
 * redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the distribution;
 * neither the name of the copyright holders nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/** @file
 * Tsunami I/O Space mapping including RTC/timer interrupts
 */

#ifndef __DEV_TSUNAMI_IO_HH__
#define __DEV_TSUNAMI_IO_HH__

#include "dev/io_device.hh"
#include "base/range.hh"
#include "dev/tsunami.hh"
#include "sim/eventq.hh"

/**
 * Tsunami I/O device is a catch all for all the south bridge stuff we care
 * to implement.
 */
class TsunamiIO : public BasicPioDevice
{
  private:
    struct tm tm;

  protected:
    /** Real-Time Clock (MC146818) */
    class RTC
    {
      private:
        /** Event for RTC periodic interrupt */
        struct RTCEvent : public Event
        {
            /** A pointer back to tsunami to create interrupt the processor. */
            Tsunami* tsunami;
            Tick interval;

            RTCEvent(Tsunami* t, Tick i);

            /** Schedule the RTC periodic interrupt */
            void scheduleIntr();

            /** Event process to occur at interrupt*/
            virtual void process();

            /** Event description */
            virtual const char *description();
        };

      private:
        std::string _name;
        const std::string &name() const { return _name; }

        /** RTC periodic interrupt event */
        RTCEvent event;

        /** Current RTC register address/index */
        int addr;

        /** Data for real-time clock function */
        union {
            uint8_t clock_data[10];

            struct {
                uint8_t sec;
                uint8_t sec_alrm;
                uint8_t min;
                uint8_t min_alrm;
                uint8_t hour;
                uint8_t hour_alrm;
                uint8_t wday;
                uint8_t mday;
                uint8_t mon;
                uint8_t year;
            };
        };

        /** RTC status register A */
        uint8_t stat_regA;

        /** RTC status register B */
        uint8_t stat_regB;

      public:
        RTC(const std::string &name, Tsunami* t, Tick i);

        /** Set the initial RTC time/date */
        void set_time(time_t t);

        /** RTC address port: write address of RTC RAM data to access */
        void writeAddr(const uint8_t data);

        /** RTC write data */
        void writeData(const uint8_t data);

        /** RTC read data */
        void readData(uint8_t *data);

        /**
          * Serialize this object to the given output stream.
          * @param os The stream to serialize to.
          */
        void serialize(const std::string &base, std::ostream &os);

        /**
         * Reconstruct the state of this object from a checkpoint.
         * @param cp The checkpoint use.
         * @param section The section name of this object
         */
        void unserialize(const std::string &base, Checkpoint *cp,
                         const std::string &section);
    };

    /** Programmable Interval Timer (Intel 8254) */
    class PITimer
    {
        /** Counter element for PIT */
        class Counter
        {
            /** Event for counter interrupt */
            class CounterEvent : public Event
            {
              private:
                /** Pointer back to Counter */
                Counter* counter;
                Tick interval;

              public:
                CounterEvent(Counter*);

                /** Event process */
                virtual void process();

                /** Event description */
                virtual const char *description();

                friend class Counter;
            };

          private:
            std::string _name;
            const std::string &name() const { return _name; }

            CounterEvent event;

            /** Current count value */
            uint16_t count;

            /** Latched count */
            uint16_t latched_count;

            /** Interrupt period */
            uint16_t period;

            /** Current mode of operation */
            uint8_t mode;

            /** Output goes high when the counter reaches zero */
            bool output_high;

            /** State of the count latch */
            bool latch_on;

            /** Set of values for read_byte and write_byte */
            enum {LSB, MSB};

            /** Determine which byte of a 16-bit count value to read/write */
            uint8_t read_byte, write_byte;

          public:
            Counter(const std::string &name);

            /** Latch the current count (if one is not already latched) */
            void latchCount();

            /** Set the read/write mode */
            void setRW(int rw_val);

            /** Set operational mode */
            void setMode(int mode_val);

            /** Set count encoding */
            void setBCD(int bcd_val);

            /** Read a count byte */
            void read(uint8_t *data);

            /** Write a count byte */
            void write(const uint8_t data);

            /** Is the output high? */
            bool outputHigh();

            /**
             * Serialize this object to the given output stream.
             * @param os The stream to serialize to.
             */
            void serialize(const std::string &base, std::ostream &os);

            /**
             * Reconstruct the state of this object from a checkpoint.
             * @param cp The checkpoint use.
             * @param section The section name of this object
             */
            void unserialize(const std::string &base, Checkpoint *cp,
                             const std::string &section);
        };

      private:
        std::string _name;
        const std::string &name() const { return _name; }

        /** PIT has three seperate counters */
        Counter *counter[3];

      public:
        /** Public way to access individual counters (avoid array accesses) */
        Counter counter0;
        Counter counter1;
        Counter counter2;

        PITimer(const std::string &name);

        /** Write control word */
        void writeControl(const uint8_t data);

        /**
         * Serialize this object to the given output stream.
         * @param os The stream to serialize to.
         */
        void serialize(const std::string &base, std::ostream &os);

        /**
         * Reconstruct the state of this object from a checkpoint.
         * @param cp The checkpoint use.
         * @param section The section name of this object
         */
        void unserialize(const std::string &base, Checkpoint *cp,
                         const std::string &section);
    };

    /** Mask of the PIC1 */
    uint8_t mask1;

    /** Mask of the PIC2 */
    uint8_t mask2;

    /** Mode of PIC1. Not used for anything */
    uint8_t mode1;

    /** Mode of PIC2. Not used for anything */
    uint8_t mode2;

    /** Raw PIC interrupt register before masking */
    uint8_t picr; //Raw PIC interrput register

    /** Is the pic interrupting right now or not. */
    bool picInterrupting;

    /** A pointer to the Tsunami device which be belong to */
    Tsunami *tsunami;

    /** Intel 8253 Periodic Interval Timer */
    PITimer pitimer;

    RTC rtc;

    /** The interval is set via two writes to the PIT.
     * This variable contains a flag as to how many writes have happened, and
     * the time so far.
     */
    uint16_t timerData;

  public:
    /**
     * Return the freqency of the RTC
     * @return interrupt rate of the RTC
     */
    Tick frequency() const;

    struct Params : public BasicPioDevice::Params
    {
        Tick frequency;
        Tsunami *tsunami;
        time_t init_time;
    };
  protected:
    const Params *params() const { return (const Params*)_params; }

  public:
    /**
     * Initialize all the data for devices supported by Tsunami I/O.
     * @param p pointer to Params struct
     */
    TsunamiIO(Params *p);

    virtual Tick read(Packet &pkt);
    virtual Tick write(Packet &pkt);

    /**
     * Post an PIC interrupt to the CPU via the CChip
     * @param bitvector interrupt to post.
     */
    void postPIC(uint8_t bitvector);

    /**
     * Clear a posted interrupt
     * @param bitvector interrupt to clear
     */
    void clearPIC(uint8_t bitvector);

    /**
     * Serialize this object to the given output stream.
     * @param os The stream to serialize to.
     */
    virtual void serialize(std::ostream &os);

    /**
     * Reconstruct the state of this object from a checkpoint.
     * @param cp The checkpoint use.
     * @param section The section name of this object
     */
    virtual void unserialize(Checkpoint *cp, const std::string &section);

};

#endif // __DEV_TSUNAMI_IO_HH__