1/*
2 * Copyright 2018 Google, Inc.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions are
6 * met: redistributions of source code must retain the above copyright
7 * notice, this list of conditions and the following disclaimer;
8 * redistributions in binary form must reproduce the above copyright
9 * notice, this list of conditions and the following disclaimer in the
10 * documentation and/or other materials provided with the distribution;
11 * neither the name of the copyright holders nor the names of its
12 * contributors may be used to endorse or promote products derived from
13 * this software without specific prior written permission.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
16 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
17 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
18 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
19 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
20 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
21 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
25 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 *
27 * Authors: Gabe Black
28 */
29
30#include "base/logging.hh"
31#include "base/types.hh"
32#include "sim/core.hh"
33#include "sim/eventq.hh"
34#include "systemc/core/kernel.hh"
35#include "systemc/core/process_types.hh"
36#include "systemc/core/sched_event.hh"
37#include "systemc/core/scheduler.hh"
38#include "systemc/ext/channel/messages.hh"
39#include "systemc/ext/channel/sc_clock.hh"
40#include "systemc/ext/core/sc_main.hh"
41#include "systemc/ext/core/sc_module.hh" // for sc_gen_unique_name
42#include "systemc/ext/utils/sc_report_handler.hh"
43
44namespace sc_gem5
45{
46
47class ClockTick : public ScEvent
48{
49  private:
50    ::sc_core::sc_time _period;
51    std::string name;
52    Process *p;
53    ProcessMemberFuncWrapper<::sc_core::sc_clock> funcWrapper;
54
55  public:
56    ClockTick(::sc_core::sc_clock *clock, bool to,
57            ::sc_core::sc_time _period) :
58        ScEvent([this]() { tick(); }),
59        _period(_period), name(clock->basename()), p(nullptr),
60        funcWrapper(clock, to ? &::sc_core::sc_clock::tickUp :
61                                &::sc_core::sc_clock::tickDown)
62    {
63        name += std::string(to ? "_posedge_action" : "_negedge_action");
64        name = ::sc_core::sc_gen_unique_name(name.c_str());
65    }
66
67    void
68    createProcess()
69    {
70        p = new Method(name.c_str(), &funcWrapper, true);
71        p->dontInitialize(true);
72        scheduler.reg(p);
73    }
74
75    ~ClockTick()
76    {
77        if (scheduled())
78            scheduler.deschedule(this);
79        if (p)
80            p->popListNode();
81    }
82
83    void
84    tick()
85    {
86        scheduler.schedule(this, _period);
87        p->ready();
88    }
89};
90
91};
92
93namespace sc_core
94{
95
96sc_clock::sc_clock() :
97    sc_clock(sc_gen_unique_name("clock"), sc_time(1.0, SC_NS),
98            0.5, SC_ZERO_TIME, true)
99{}
100
101sc_clock::sc_clock(const char *name) :
102    sc_clock(name, sc_time(1.0, SC_NS), 0.5, SC_ZERO_TIME, true)
103{}
104
105sc_clock::sc_clock(const char *name, const sc_time &period,
106                   double duty_cycle, const sc_time &start_time,
107                   bool posedge_first) :
108    sc_interface(), sc_signal<bool>(name, posedge_first ? false : true),
109    _period(period), _dutyCycle(duty_cycle), _startTime(start_time),
110    _posedgeFirst(posedge_first)
111{
112    if (period == SC_ZERO_TIME) {
113        std::string msg =
114            "increase the period: clock '" +
115            std::string(name) + "'";
116        SC_REPORT_ERROR(SC_ID_CLOCK_PERIOD_ZERO_, msg.c_str());
117    }
118
119    if (duty_cycle * period == SC_ZERO_TIME) {
120        std::string msg =
121            "increase the period or increase the duty cycle: clock '" +
122            std::string(name) + "'";
123        SC_REPORT_ERROR(SC_ID_CLOCK_HIGH_TIME_ZERO_, msg.c_str());
124    }
125
126    if (duty_cycle * period == period) {
127        std::string msg =
128            "increase the period or decrease the duty cycle: clock '" +
129            std::string(name) + "'";
130        SC_REPORT_ERROR(SC_ID_CLOCK_LOW_TIME_ZERO_, msg.c_str());
131    }
132
133    _gem5UpEdge = new ::sc_gem5::ClockTick(this, true, period);
134    _gem5DownEdge = new ::sc_gem5::ClockTick(this, false, period);
135}
136
137sc_clock::sc_clock(const char *name, double period_v, sc_time_unit period_tu,
138                   double duty_cycle) :
139    sc_clock(name, sc_time(period_v, period_tu), duty_cycle, SC_ZERO_TIME,
140            true)
141{}
142
143sc_clock::sc_clock(const char *name, double period_v, sc_time_unit period_tu,
144                   double duty_cycle, double start_time_v,
145                   sc_time_unit start_time_tu, bool posedge_first) :
146    sc_clock(name, sc_time(period_v, period_tu), duty_cycle,
147            sc_time(start_time_v, start_time_tu), posedge_first)
148{}
149
150sc_clock::sc_clock(const char *name, double period, double duty_cycle,
151                   double start_time, bool posedge_first) :
152    sc_clock(name, sc_time(period, true), duty_cycle,
153            sc_time(start_time, true), posedge_first)
154{}
155
156sc_clock::~sc_clock()
157{
158    if (_gem5UpEdge->scheduled())
159        ::sc_gem5::scheduler.deschedule(_gem5UpEdge);
160    if (_gem5DownEdge->scheduled())
161        ::sc_gem5::scheduler.deschedule(_gem5DownEdge);
162    delete _gem5UpEdge;
163    delete _gem5DownEdge;
164}
165
166void
167sc_clock::write(const bool &)
168{
169    panic("write() called on sc_clock.");
170}
171
172const sc_time &sc_clock::period() const { return _period; }
173double sc_clock::duty_cycle() const { return _dutyCycle; }
174const sc_time &sc_clock::start_time() const { return _startTime; }
175bool sc_clock::posedge_first() const { return _posedgeFirst; }
176
177const sc_time &
178sc_clock::time_stamp()
179{
180    return sc_time_stamp();
181}
182
183void
184sc_clock::before_end_of_elaboration()
185{
186    _gem5UpEdge->createProcess();
187    _gem5DownEdge->createProcess();
188    if (_posedgeFirst) {
189        ::sc_gem5::scheduler.schedule(_gem5UpEdge, _startTime);
190        ::sc_gem5::scheduler.schedule(_gem5DownEdge,
191                _startTime + _period * _dutyCycle);
192    } else {
193        ::sc_gem5::scheduler.schedule(_gem5DownEdge, _startTime);
194        ::sc_gem5::scheduler.schedule(_gem5UpEdge,
195                _startTime + _period * (1.0 - _dutyCycle));
196    }
197}
198
199} // namespace sc_core
200