1/*
2 * Copyright (c) 2017-2018 ARM Limited
3 * All rights reserved
4 *
5 * The license below extends only to copyright in the software and shall
6 * not be construed as granting a license to any other intellectual
7 * property including but not limited to intellectual property relating
8 * to a hardware implementation of the functionality of the software
9 * licensed hereunder.  You may use the software subject to the license
10 * terms below provided that you ensure that this notice is replicated
11 * unmodified and in its entirety in all distributions of the software,
12 * modified or unmodified, in source code or in binary form.
13 *
14 * Copyright (c) 2008 The Regents of The University of Michigan
15 * All rights reserved.
16 *
17 * Redistribution and use in source and binary forms, with or without
18 * modification, are permitted provided that the following conditions are
19 * met: redistributions of source code must retain the above copyright
20 * notice, this list of conditions and the following disclaimer;
21 * redistributions in binary form must reproduce the above copyright
22 * notice, this list of conditions and the following disclaimer in the
23 * documentation and/or other materials provided with the distribution;
24 * neither the name of the copyright holders nor the names of its
25 * contributors may be used to endorse or promote products derived from
26 * this software without specific prior written permission.
27 *
28 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
29 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
30 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
31 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
32 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
33 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
34 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
35 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
36 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
37 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
38 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
39 *
40 * Authors: Gabe Black
41 *          Andreas Sandberg
42 */
43
44#ifndef __DEV_PS2_DEVICE_HH__
45#define __DEV_PS2_DEVICE_HH__
46
47#include <deque>
48#include <vector>
49
50#include "sim/sim_object.hh"
51
52struct PS2DeviceParams;
53
54class PS2Device : public SimObject
55{
56  public:
57    PS2Device(const PS2DeviceParams *p);
58
59    void serialize(CheckpointOut &cp) const override;
60    void unserialize(CheckpointIn &cp) override;
61
62  public: /* Host interface */
63    /**
64     * Register a data available callback into the PS/2 interface
65     *
66     * @param c Callback instance from host interface
67     */
68    void hostRegDataAvailable(const std::function<void()> &c);
69
70    /**
71     * Check if there is pending data from the PS/2 device.
72     *
73     * @return true if there is data pending that can be read using
74     * the readData() method.
75     */
76    bool hostDataAvailable() const  { return !outBuffer.empty(); }
77
78    /**
79     * Read a character from the device.
80     *
81     * @return Character from the device's output buffer, undefined if
82     * no data is pending.
83     */
84    uint8_t hostRead();
85
86    /**
87     * Transmit a character from the host interface to the device.
88     *
89     * @param c Received data.
90     */
91    void hostWrite(uint8_t c);
92
93  protected: /* Device interface */
94    /**
95     * Data received from host.
96     *
97     * Data sent to the device is buffered one byte at a time. Each
98     * time a byte is added, this function is called and passed the
99     * current buffer. It should return true if it has consumed the
100     * data and the buffer can be cleared, or false if more data is
101     * needed to process the current command.
102     *
103     * @param data Pending input data (at least one byte)
104     * @return false if more data is needed to process the current
105     * command, true otherwise.
106     */
107    virtual bool recv(const std::vector<uint8_t> &data) = 0;
108
109    /**
110     * Send data from a PS/2 device to a host
111     *
112     * @param data Pointer to data array
113     * @param size Size of the data array
114     */
115    void send(const uint8_t *data, size_t size);
116    void send(const std::vector<uint8_t> &data) {
117        send(data.data(), data.size());
118    }
119
120    /**
121     * Send a byte of data from a PS/2 device to a host
122     *
123     * @param data Byte to send
124     */
125    void send(uint8_t data) { send(&data, 1); }
126
127    /** Send an ACK byte to the host */
128    void sendAck();
129
130    /**
131     * Output buffer size
132     *
133     * Device models may use this method to query the size of the
134     * output buffer to do rate limiting.
135     */
136    size_t sendPending() const { return outBuffer.size(); }
137
138  private:
139    /** Device -> host FIFO */
140    std::deque<uint8_t> outBuffer;
141
142    /** Host -> device buffer */
143    std::vector<uint8_t> inBuffer;
144
145    std::function<void()> dataAvailableCallback;
146};
147
148#endif // __DEV_PS2_HOUSE_HH__
149