mc146818.cc revision 9730:f3b53a5a559e 
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 * Authors: Ali Saidi
29 *          Andrew Schultz
30 *          Miguel Serrano
31 */
32
33#include <sys/time.h>
34
35#include <ctime>
36#include <string>
37
38#include "base/bitfield.hh"
39#include "base/time.hh"
40#include "base/trace.hh"
41#include "debug/MC146818.hh"
42#include "dev/mc146818.hh"
43#include "dev/rtcreg.h"
44
45using namespace std;
46
47static uint8_t
48bcdize(uint8_t val)
49{
50    uint8_t result;
51    result = val % 10;
52    result += (val / 10) << 4;
53    return result;
54}
55
56static uint8_t
57unbcdize(uint8_t val)
58{
59    uint8_t result;
60    result = val & 0xf;
61    result += (val >> 4) * 10;
62    return result;
63}
64
65void
66MC146818::setTime(const struct tm time)
67{
68    curTime = time;
69    year = time.tm_year;
70    // Unix is 0-11 for month, data seet says start at 1
71    mon = time.tm_mon + 1;
72    mday = time.tm_mday;
73    hour = time.tm_hour;
74    min = time.tm_min;
75    sec = time.tm_sec;
76
77    // Datasheet says 1 is sunday
78    wday = time.tm_wday + 1;
79
80    if (!stat_regB.dm) {
81        // The datasheet says that the year field can be either BCD or
82        // years since 1900.  Linux seems to be happy with years since
83        // 1900.
84        year = bcdize(year % 100);
85        mon = bcdize(mon);
86        mday = bcdize(mday);
87        hour = bcdize(hour);
88        min = bcdize(min);
89        sec = bcdize(sec);
90    }
91}
92
93MC146818::MC146818(EventManager *em, const string &n, const struct tm time,
94                   bool bcd, Tick frequency)
95    : EventManager(em), _name(n), event(this, frequency), tickEvent(this)
96{
97    memset(clock_data, 0, sizeof(clock_data));
98
99    stat_regA = 0;
100    stat_regA.dv = RTCA_DV_32768HZ;
101    stat_regA.rs = RTCA_RS_1024HZ;
102
103    stat_regB = 0;
104    stat_regB.pie = 1;
105    stat_regB.format24h = 1;
106    stat_regB.dm = bcd ? 0 : 1;
107
108    setTime(time);
109    DPRINTFN("Real-time clock set to %s", asctime(&time));
110}
111
112MC146818::~MC146818()
113{
114    deschedule(tickEvent);
115    deschedule(event);
116}
117
118bool
119MC146818::rega_dv_disabled(const RtcRegA &reg)
120{
121    return reg.dv == RTCA_DV_DISABLED0 ||
122        reg.dv == RTCA_DV_DISABLED1;
123}
124
125void
126MC146818::writeData(const uint8_t addr, const uint8_t data)
127{
128    bool panic_unsupported(false);
129
130    if (addr < RTC_STAT_REGA) {
131        clock_data[addr] = data;
132        curTime.tm_sec = unbcdize(sec);
133        curTime.tm_min = unbcdize(min);
134        curTime.tm_hour = unbcdize(hour);
135        curTime.tm_mday = unbcdize(mday);
136        curTime.tm_mon = unbcdize(mon) - 1;
137        curTime.tm_year = ((unbcdize(year) + 50) % 100) + 1950;
138        curTime.tm_wday = unbcdize(wday) - 1;
139    } else {
140        switch (addr) {
141          case RTC_STAT_REGA: {
142              RtcRegA old_rega(stat_regA);
143              stat_regA = data;
144              // The "update in progress" bit is read only.
145              stat_regA.uip = old_rega;
146
147              if (stat_regA.dv != RTCA_DV_32768HZ) {
148                  inform("RTC: Unimplemented divider configuration: %i\n",
149                        stat_regA.dv);
150                  panic_unsupported = true;
151              }
152
153              if (stat_regA.rs != RTCA_RS_1024HZ) {
154                  inform("RTC: Unimplemented interrupt rate: %i\n",
155                        stat_regA.rs);
156                  panic_unsupported = true;
157              }
158          } break;
159          case RTC_STAT_REGB:
160            stat_regB = data;
161            if (stat_regB.set) {
162                inform("RTC: Updating stopping not implemented.\n");
163                panic_unsupported = true;
164            }
165
166            if (stat_regB.aie || stat_regB.uie) {
167                inform("RTC: Unimplemented interrupt configuration: %s %s\n",
168                      stat_regB.aie ? "alarm" : "",
169                      stat_regB.uie ? "update" : "");
170                panic_unsupported = true;
171            }
172
173            if (stat_regB.dm) {
174                inform("RTC: The binary interface is not fully implemented.\n");
175                panic_unsupported = true;
176            }
177
178            if (!stat_regB.format24h) {
179                inform("RTC: The 12h time format not supported.\n");
180                panic_unsupported = true;
181            }
182
183            if (stat_regB.dse) {
184                inform("RTC: Automatic daylight saving time not supported.\n");
185                panic_unsupported = true;
186            }
187
188            if (stat_regB.pie) {
189                if (!event.scheduled())
190                    event.scheduleIntr();
191            } else {
192                if (event.scheduled())
193                    deschedule(event);
194            }
195            break;
196          case RTC_STAT_REGC:
197          case RTC_STAT_REGD:
198            panic("RTC status registers C and D are not implemented.\n");
199            break;
200        }
201    }
202
203    if (panic_unsupported)
204        panic("Unimplemented RTC configuration!\n");
205
206}
207
208uint8_t
209MC146818::readData(uint8_t addr)
210{
211    if (addr < RTC_STAT_REGA)
212        return clock_data[addr];
213    else {
214        switch (addr) {
215          case RTC_STAT_REGA:
216            // toggle UIP bit for linux
217            stat_regA.uip = !stat_regA.uip;
218            return stat_regA;
219            break;
220          case RTC_STAT_REGB:
221            return stat_regB;
222            break;
223          case RTC_STAT_REGC:
224          case RTC_STAT_REGD:
225            return 0x00;
226            break;
227          default:
228            panic("Shouldn't be here");
229        }
230    }
231}
232
233void
234MC146818::tickClock()
235{
236    if (stat_regB.set)
237        return;
238    time_t calTime = mkutctime(&curTime);
239    calTime++;
240    setTime(*gmtime(&calTime));
241}
242
243void
244MC146818::serialize(const string &base, ostream &os)
245{
246    uint8_t regA_serial(stat_regA);
247    uint8_t regB_serial(stat_regB);
248
249    arrayParamOut(os, base + ".clock_data", clock_data, sizeof(clock_data));
250    paramOut(os, base + ".stat_regA", (uint8_t)regA_serial);
251    paramOut(os, base + ".stat_regB", (uint8_t)regB_serial);
252
253    //
254    // save the timer tick and rtc clock tick values to correctly reschedule
255    // them during unserialize
256    //
257    Tick rtcTimerInterruptTickOffset = event.when() - curTick();
258    SERIALIZE_SCALAR(rtcTimerInterruptTickOffset);
259    Tick rtcClockTickOffset = tickEvent.when() - curTick();
260    SERIALIZE_SCALAR(rtcClockTickOffset);
261}
262
263void
264MC146818::unserialize(const string &base, Checkpoint *cp,
265                      const string &section)
266{
267    uint8_t tmp8;
268
269    arrayParamIn(cp, section, base + ".clock_data", clock_data,
270                 sizeof(clock_data));
271
272    paramIn(cp, section, base + ".stat_regA", tmp8);
273    stat_regA = tmp8;
274    paramIn(cp, section, base + ".stat_regB", tmp8);
275    stat_regB = tmp8;
276
277    //
278    // properly schedule the timer and rtc clock events
279    //
280    Tick rtcTimerInterruptTickOffset;
281    UNSERIALIZE_SCALAR(rtcTimerInterruptTickOffset);
282    reschedule(event, curTick() + rtcTimerInterruptTickOffset);
283    Tick rtcClockTickOffset;
284    UNSERIALIZE_SCALAR(rtcClockTickOffset);
285    reschedule(tickEvent, curTick() + rtcClockTickOffset);
286}
287
288MC146818::RTCEvent::RTCEvent(MC146818 * _parent, Tick i)
289    : parent(_parent), interval(i)
290{
291    DPRINTF(MC146818, "RTC Event Initilizing\n");
292    parent->schedule(this, curTick() + interval);
293}
294
295void
296MC146818::RTCEvent::scheduleIntr()
297{
298    parent->schedule(this, curTick() + interval);
299}
300
301void
302MC146818::RTCEvent::process()
303{
304    DPRINTF(MC146818, "RTC Timer Interrupt\n");
305    parent->schedule(this, curTick() + interval);
306    parent->handleEvent();
307}
308
309const char *
310MC146818::RTCEvent::description() const
311{
312    return "RTC interrupt";
313}
314
315void
316MC146818::RTCTickEvent::process()
317{
318    DPRINTF(MC146818, "RTC clock tick\n");
319    parent->schedule(this, curTick() + SimClock::Int::s);
320    parent->tickClock();
321}
322
323const char *
324MC146818::RTCTickEvent::description() const
325{
326    return "RTC clock tick";
327}
328