bus.hh

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/*
 * Copyright (c) 2012 ARM Limited
 * All rights reserved
 *
 * The license below extends only to copyright in the software and shall
 * not be construed as granting a license to any other intellectual
 * property including but not limited to intellectual property relating
 * to a hardware implementation of the functionality of the software
 * licensed hereunder.  You may use the software subject to the license
 * terms below provided that you ensure that this notice is replicated
 * unmodified and in its entirety in all distributions of the software,
 * modified or unmodified, in source code or in binary form.
 *
 * 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.
 *
 * Authors: Peter Enns
 */


#ifndef __DEV_I2C_BUS_HH__
#define __DEV_I2C_BUS_HH__

#include <map>

#include "dev/io_device.hh"
#include "params/I2CBus.hh"

class I2CDevice;

class I2CBus : public BasicPioDevice
{
  protected:

    enum I2CState {
        IDLE,
        RECEIVING_ADDR,
        RECEIVING_DATA,
        SENDING_DATA,
    };

    static const int SB_CONTROLS = 0x0;
    static const int SB_CONTROLC = 0x4;

    uint8_t scl;
    uint8_t sda;

    enum I2CState state;

    int currBit;

    uint8_t i2cAddr;

    uint8_t message;

    std::map<uint8_t, I2CDevice*> devices;

    void updateSignals(PacketPtr pkt);

    bool isClockSet(PacketPtr pkt) const;

    bool isStart(PacketPtr pkt) const;

    bool isEnd(PacketPtr pkt) const;

  public:

    I2CBus(const I2CBusParams* p);

    Tick read(PacketPtr pkt) override;
    Tick write(PacketPtr pkt) override;

    void serialize(CheckpointOut &cp) const override;
    void unserialize(CheckpointIn &cp) override;
};

#endif // __DEV_I2C_BUS_HH__