/* Copyright 2016-2023 melonDS team This file is part of melonDS. melonDS is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version. melonDS is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with melonDS. If not, see http://www.gnu.org/licenses/. */ #include #include "NDS.h" #include "RTC.h" #include "Platform.h" using Platform::Log; using Platform::LogLevel; void WriteDateTime(int num, u8 val); RTC::RTC() { NDS::RegisterEventFunc(NDS::Event_RTC, 0, MemberEventFunc(RTC, ClockTimer)); ResetState(); // indicate the power was off // this will be changed if a previously saved RTC state is loaded State.StatusReg1 = 0x80; } RTC::~RTC() { NDS::UnregisterEventFunc(NDS::Event_RTC, 0); } void RTC::Reset() { Input = 0; InputBit = 0; InputPos = 0; memset(Output, 0, sizeof(Output)); OutputPos = 0; CurCmd = 0; ClockCount = 0; ScheduleTimer(true); } void RTC::DoSavestate(Savestate* file) { file->Section("RTC."); file->Var16(&IO); file->Var8(&Input); file->Var32(&InputBit); file->Var32(&InputPos); file->VarArray(Output, sizeof(Output)); file->Var32(&OutputBit); file->Var32(&OutputPos); file->Var8(&CurCmd); file->VarArray(&State, sizeof(State)); file->Var32((u32*)&TimerError); file->Var32(&ClockCount); } u8 RTC::BCD(u8 val) { return (val % 10) | ((val / 10) << 4); } u8 RTC::FromBCD(u8 val) { return (val & 0xF) + ((val >> 4) * 10); } u8 RTC::BCDIncrement(u8 val) { val++; if ((val & 0x0F) >= 0x0A) val += 0x06; if ((val & 0xF0) >= 0xA0) val += 0x60; return val; } u8 RTC::BCDSanitize(u8 val, u8 vmin, u8 vmax) { if (val < vmin || val > vmax) val = vmin; else if ((val & 0x0F) >= 0x0A) val = vmin; else if ((val & 0xF0) >= 0xA0) val = vmin; return val; } void RTC::GetState(StateData& state) { memcpy(&state, &State, sizeof(State)); } void RTC::SetState(StateData& state) { memcpy(&State, &state, sizeof(State)); // sanitize the input state for (int i = 0; i < 7; i++) WriteDateTime(i+1, State.DateTime[i]); } void RTC::GetDateTime(int& year, int& month, int& day, int& hour, int& minute, int& second) { year = FromBCD(State.DateTime[0]); year += 2000; month = FromBCD(State.DateTime[1] & 0x3F); day = FromBCD(State.DateTime[2] & 0x3F); hour = FromBCD(State.DateTime[4] & 0x3F); if (!(State.StatusReg1 & (1<<1))) { // 12-hour mode if (State.DateTime[4] & 0x40) hour += 12; } minute = FromBCD(State.DateTime[5] & 0x7F); second = FromBCD(State.DateTime[6] & 0x7F); } void RTC::SetDateTime(int year, int month, int day, int hour, int minute, int second) { int monthdays[13] = {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31}; // the year range of the DS RTC is limited to 2000-2099 year %= 100; if (year < 0) year = 0; if (!(year & 3)) monthdays[2] = 29; if (month < 1 || month > 12) month = 1; if (day < 1 || day > monthdays[month]) day = 1; if (hour < 0 || hour > 23) hour = 0; if (minute < 0 || minute > 59) minute = 0; if (second < 0 || second > 59) second = 0; // note on day-of-week value // that RTC register is a simple incrementing counter and the assignation is defined by software // DS/DSi firmware counts from 0=Sunday int numdays = (year * 365) + ((year+3) / 4); // account for leap years for (int m = 1; m < month; m++) { numdays += monthdays[m]; } numdays += (day-1); // 01/01/2000 is a Saturday, so the starting value is 6 int dayofweek = (6 + numdays) % 7; int pm = (hour >= 12) ? 0x40 : 0; if (!(State.StatusReg1 & (1<<1))) { // 12-hour mode if (pm) hour -= 12; } State.DateTime[0] = BCD(year); State.DateTime[1] = BCD(month); State.DateTime[2] = BCD(day); State.DateTime[3] = dayofweek; State.DateTime[4] = BCD(hour) | pm; State.DateTime[5] = BCD(minute); State.DateTime[6] = BCD(second); State.StatusReg1 &= ~0x80; } void RTC::ResetState() { memset(&State, 0, sizeof(State)); State.DateTime[1] = 1; State.DateTime[2] = 1; } void RTC::SetIRQ(u8 irq) { u8 oldstat = State.IRQFlag; State.IRQFlag |= irq; State.StatusReg1 |= irq; if ((!(oldstat & 0x30)) && (State.IRQFlag & 0x30)) { if ((NDS::RCnt & 0xC100) == 0x8100) { // CHECKME: is the IRQ status readable in RCNT? NDS::SetIRQ(1, NDS::IRQ_RTC); } } } void RTC::ClearIRQ(u8 irq) { State.IRQFlag &= ~irq; } void RTC::ProcessIRQ(int type) // 0=minute carry 1=periodic 2=status reg write { // INT1 switch (State.StatusReg2 & 0x0F) { case 0b0000: // none if (type == 2) { ClearIRQ(0x10); } break; case 0b0001: case 0b0101: // selected frequency steady interrupt if ((type == 1 && (!(ClockCount & 0x3FF))) || (type == 2)) { u32 mask = 0; if (State.Alarm1[2] & (1<<0)) mask |= 0x4000; if (State.Alarm1[2] & (1<<1)) mask |= 0x2000; if (State.Alarm1[2] & (1<<2)) mask |= 0x1000; if (State.Alarm1[2] & (1<<3)) mask |= 0x0800; if (State.Alarm1[2] & (1<<4)) mask |= 0x0400; if (mask && ((ClockCount & mask) != mask)) SetIRQ(0x10); else ClearIRQ(0x10); } break; case 0b0010: case 0b0110: // per-minute edge interrupt if ((type == 0) || (type == 2 && (State.IRQFlag & 0x01))) { SetIRQ(0x10); } break; case 0b0011: // per-minute steady interrupt 1 (duty 30s) if ((type == 0) || (type == 2 && (State.IRQFlag & 0x01))) { SetIRQ(0x10); } else if ((type == 1) && (State.DateTime[6] == 0x30) && ((ClockCount & 0x7FFF) == 0)) { ClearIRQ(0x10); } break; case 0b0111: // per-minute steady interrupt 2 (duty 256 cycles) if ((type == 0) || (type == 2 && (State.IRQFlag & 0x01))) { SetIRQ(0x10); } else if ((type == 1) && (State.DateTime[6] == 0x00) && ((ClockCount & 0x7FFF) == 256)) { ClearIRQ(0x10); } break; case 0b0100: // alarm interrupt if (type == 0) { bool cond = true; if (State.Alarm1[0] & (1<<7)) cond = cond && ((State.Alarm1[0] & 0x07) == State.DateTime[3]); if (State.Alarm1[1] & (1<<7)) cond = cond && ((State.Alarm1[1] & 0x7F) == State.DateTime[4]); if (State.Alarm1[2] & (1<<7)) cond = cond && ((State.Alarm1[2] & 0x7F) == State.DateTime[5]); if (NDS::ConsoleType == 1) { if (State.AlarmDate1[1] & (1<<6)) cond = cond && (State.AlarmDate1[0] == State.DateTime[0]); if (State.AlarmDate1[1] & (1<<7)) cond = cond && ((State.AlarmDate1[1] & 0x1F) == State.DateTime[1]); if (State.AlarmDate1[2] & (1<<7)) cond = cond && ((State.AlarmDate1[2] & 0x3F) == State.DateTime[2]); } if (cond) SetIRQ(0x10); else ClearIRQ(0x10); } break; default: // 32KHz output if (type == 1) { SetIRQ(0x10); ClearIRQ(0x10); } break; } // INT2 if (State.StatusReg2 & (1<<6)) { // alarm interrupt if (type == 0) { bool cond = true; if (State.Alarm2[0] & (1<<7)) cond = cond && ((State.Alarm2[0] & 0x07) == State.DateTime[3]); if (State.Alarm2[1] & (1<<7)) cond = cond && ((State.Alarm2[1] & 0x7F) == State.DateTime[4]); if (State.Alarm2[2] & (1<<7)) cond = cond && ((State.Alarm2[2] & 0x7F) == State.DateTime[5]); if (NDS::ConsoleType == 1) { if (State.AlarmDate2[1] & (1<<6)) cond = cond && (State.AlarmDate2[0] == State.DateTime[0]); if (State.AlarmDate2[1] & (1<<7)) cond = cond && ((State.AlarmDate2[1] & 0x1F) == State.DateTime[1]); if (State.AlarmDate2[2] & (1<<7)) cond = cond && ((State.AlarmDate2[2] & 0x3F) == State.DateTime[2]); } if (cond) SetIRQ(0x20); else ClearIRQ(0x20); } } else { if (type == 2) { ClearIRQ(0x20); } } } u8 RTC::DaysInMonth() { u8 numdays; switch (State.DateTime[1]) { case 0x01: // Jan case 0x03: // Mar case 0x05: // May case 0x07: // Jul case 0x08: // Aug case 0x10: // Oct case 0x12: // Dec numdays = 0x31; break; case 0x04: // Apr case 0x06: // Jun case 0x09: // Sep case 0x11: // Nov numdays = 0x30; break; case 0x02: // Feb { numdays = 0x28; // leap year: if year divisible by 4 and not divisible by 100 unless divisible by 400 // the limited year range (2000-2099) simplifies this int year = State.DateTime[0]; year = (year & 0xF) + ((year >> 4) * 10); if (!(year & 3)) numdays = 0x29; } break; default: // ??? return 0; } return numdays; } void RTC::CountYear() { State.DateTime[0] = BCDIncrement(State.DateTime[0]); } void RTC::CountMonth() { State.DateTime[1] = BCDIncrement(State.DateTime[1]); if (State.DateTime[1] > 0x12) { State.DateTime[1] = 1; CountYear(); } } void RTC::CheckEndOfMonth() { if (State.DateTime[2] > DaysInMonth()) { State.DateTime[2] = 1; CountMonth(); } } void RTC::CountDay() { // day-of-week counter State.DateTime[3]++; if (State.DateTime[3] >= 7) State.DateTime[3] = 0; // day counter State.DateTime[2] = BCDIncrement(State.DateTime[2]); CheckEndOfMonth(); } void RTC::CountHour() { u8 hour = BCDIncrement(State.DateTime[4] & 0x3F); u8 pm = State.DateTime[4] & 0x40; if (State.StatusReg1 & (1<<1)) { // 24-hour mode if (hour >= 0x24) { hour = 0; CountDay(); } pm = (hour >= 0x12) ? 0x40 : 0; } else { // 12-hour mode if (hour >= 0x12) { hour = 0; if (pm) CountDay(); pm ^= 0x40; } } State.DateTime[4] = hour | pm; } void RTC::CountMinute() { State.MinuteCount++; State.DateTime[5] = BCDIncrement(State.DateTime[5]); if (State.DateTime[5] >= 0x60) { State.DateTime[5] = 0; CountHour(); } State.IRQFlag |= 0x01; // store minute carry flag ProcessIRQ(0); } void RTC::CountSecond() { State.DateTime[6] = BCDIncrement(State.DateTime[6]); if (State.DateTime[6] >= 0x60) { State.DateTime[6] = 0; CountMinute(); } } void RTC::ScheduleTimer(bool first) { if (first) TimerError = 0; // the RTC clock runs at 32768Hz // cycles = 33513982 / 32768 s32 sysclock = 33513982 + TimerError; s32 delay = sysclock >> 15; TimerError = sysclock & 0x7FFF; NDS::ScheduleEvent(NDS::Event_RTC, !first, delay, 0, 0); } void RTC::ClockTimer(u32 param) { ClockCount++; if (!(ClockCount & 0x7FFF)) { // count up one second CountSecond(); } else if ((ClockCount & 0x7FFF) == 4) { // minute-carry flag lasts 4 cycles State.IRQFlag &= ~0x01; } ProcessIRQ(1); ScheduleTimer(false); } void RTC::WriteDateTime(int num, u8 val) { switch (num) { case 1: // year State.DateTime[0] = BCDSanitize(val, 0x00, 0x99); break; case 2: // month State.DateTime[1] = BCDSanitize(val & 0x1F, 0x01, 0x12); break; case 3: // day State.DateTime[2] = BCDSanitize(val & 0x3F, 0x01, 0x31); CheckEndOfMonth(); break; case 4: // day of week State.DateTime[3] = BCDSanitize(val & 0x07, 0x00, 0x06); break; case 5: // hour { u8 hour = val & 0x3F; u8 pm = val & 0x40; if (State.StatusReg1 & (1<<1)) { // 24-hour mode hour = BCDSanitize(hour, 0x00, 0x23); pm = (hour >= 0x12) ? 0x40 : 0; } else { // 12-hour mode hour = BCDSanitize(hour, 0x00, 0x11); } State.DateTime[4] = hour | pm; } break; case 6: // minute State.DateTime[5] = BCDSanitize(val & 0x7F, 0x00, 0x59); break; case 7: // second State.DateTime[6] = BCDSanitize(val & 0x7F, 0x00, 0x59); break; } } void RTC::SaveDateTime() { int y, m, d, h, i, s; GetDateTime(y, m, d, h, i, s); Platform::WriteDateTime(y, m, d, h, i, s); } void RTC::CmdRead() { if ((CurCmd & 0x0F) == 0x06) { switch (CurCmd & 0x70) { case 0x00: Output[0] = State.StatusReg1; State.StatusReg1 &= 0x0F; // clear auto-clearing bit4-7 break; case 0x40: Output[0] = State.StatusReg2; break; case 0x20: memcpy(Output, &State.DateTime[0], 7); break; case 0x60: memcpy(Output, &State.DateTime[4], 3); break; case 0x10: if (State.StatusReg2 & 0x04) memcpy(Output, &State.Alarm1[0], 3); else Output[0] = State.Alarm1[2]; break; case 0x50: memcpy(Output, &State.Alarm2[0], 3); break; case 0x30: Output[0] = State.ClockAdjust; break; case 0x70: Output[0] = State.FreeReg; break; } return; } else if ((CurCmd & 0x0F) == 0x0E) { if (NDS::ConsoleType != 1) { Log(LogLevel::Debug, "RTC: unknown read command %02X\n", CurCmd); return; } switch (CurCmd & 0x70) { case 0x00: Output[0] = (State.MinuteCount >> 16) & 0xFF; Output[1] = (State.MinuteCount >> 8) & 0xFF; Output[2] = State.MinuteCount & 0xFF; break; case 0x40: Output[0] = State.FOUT1; break; case 0x20: Output[0] = State.FOUT2; break; case 0x10: memcpy(Output, &State.AlarmDate1[0], 3); break; case 0x50: memcpy(Output, &State.AlarmDate2[0], 3); break; default: Log(LogLevel::Debug, "RTC: unknown read command %02X\n", CurCmd); break; } return; } Log(LogLevel::Debug, "RTC: unknown read command %02X\n", CurCmd); } void RTC::CmdWrite(u8 val) { if ((CurCmd & 0x0F) == 0x06) { switch (CurCmd & 0x70) { case 0x00: if (InputPos == 1) { u8 oldval = State.StatusReg1; if (val & (1<<0)) // reset ResetState(); State.StatusReg1 = (State.StatusReg1 & 0xF0) | (val & 0x0E); if ((State.StatusReg1 ^ oldval) & (1<<1)) { // AM/PM changed u8 hour = State.DateTime[4] & 0x3F; u8 pm = State.DateTime[4] & 0x40; if (State.StatusReg1 & (1<<1)) { // 24-hour mode if (pm) { hour += 0x12; if ((hour & 0x0F) >= 0x0A) hour += 0x06; } hour = BCDSanitize(hour, 0x00, 0x23); } else { // 12-hour mode if (hour >= 0x12) { pm = 0x40; hour -= 0x12; if ((hour & 0x0F) >= 0x0A) hour -= 0x06; } else pm = 0; hour = BCDSanitize(hour, 0x00, 0x11); } State.DateTime[4] = hour | pm; } } break; case 0x40: if (InputPos == 1) { State.StatusReg2 = val; ProcessIRQ(2); } break; case 0x20: if (InputPos <= 7) WriteDateTime(InputPos, val); if (InputPos == 7) SaveDateTime(); break; case 0x60: if (InputPos <= 3) WriteDateTime(InputPos+4, val); if (InputPos == 3) SaveDateTime(); break; case 0x10: if (State.StatusReg2 & 0x04) { if (InputPos <= 3) State.Alarm1[InputPos-1] = val; } else { if (InputPos == 1) State.Alarm1[2] = val; } break; case 0x50: if (InputPos <= 3) State.Alarm2[InputPos-1] = val; break; case 0x30: if (InputPos == 1) State.ClockAdjust = val; break; case 0x70: if (InputPos == 1) State.FreeReg = val; break; } return; } else if ((CurCmd & 0x0F) == 0x0E) { if (NDS::ConsoleType != 1) { Log(LogLevel::Debug, "RTC: unknown write command %02X\n", CurCmd); return; } switch (CurCmd & 0x70) { case 0x00: Log(LogLevel::Debug, "RTC: trying to write read-only minute counter\n"); break; case 0x40: if (InputPos == 1) State.FOUT1 = val; break; case 0x20: if (InputPos == 1) State.FOUT2 = val; break; case 0x10: if (InputPos <= 3) State.AlarmDate1[InputPos-1] = val; break; case 0x50: if (InputPos <= 3) State.AlarmDate2[InputPos-1] = val; break; default: Log(LogLevel::Debug, "RTC: unknown write command %02X\n", CurCmd); break; } return; } Log(LogLevel::Debug, "RTC: unknown write command %02X\n", CurCmd); } void RTC::ByteIn(u8 val) { if (InputPos == 0) { if ((val & 0xF0) == 0x60) { u8 rev[16] = {0x06, 0x86, 0x46, 0xC6, 0x26, 0xA6, 0x66, 0xE6, 0x16, 0x96, 0x56, 0xD6, 0x36, 0xB6, 0x76, 0xF6}; CurCmd = rev[val & 0xF]; } else CurCmd = val; if (NDS::ConsoleType == 1) { // for DSi: handle extra commands if (((CurCmd & 0xF0) == 0x70) && ((CurCmd & 0xFE) != 0x76)) { u8 rev[16] = {0x0E, 0x8E, 0x4E, 0xCE, 0x2E, 0xAE, 0x6E, 0xEE, 0x1E, 0x9E, 0x5E, 0xDE, 0x3E, 0xBE, 0x7E, 0xFE}; CurCmd = rev[CurCmd & 0xF]; } } if (CurCmd & 0x80) { CmdRead(); } return; } CmdWrite(val); } u16 RTC::Read() { //printf("RTC READ %04X\n", IO); return IO; } void RTC::Write(u16 val, bool byte) { if (byte) val |= (IO & 0xFF00); //printf("RTC WRITE %04X\n", val); if (val & 0x0004) { if (!(IO & 0x0004)) { // start transfer Input = 0; InputBit = 0; InputPos = 0; memset(Output, 0, sizeof(Output)); OutputBit = 0; OutputPos = 0; } else { if (!(val & 0x0002)) // clock low { if (val & 0x0010) { // write if (val & 0x0001) Input |= (1<= 8) { InputBit = 0; ByteIn(Input); Input = 0; InputPos++; } } else { // read if (Output[OutputPos] & (1<= 8) { OutputBit = 0; if (OutputPos < 7) OutputPos++; } } } } } if (val & 0x0010) IO = val; else IO = (IO & 0x0001) | (val & 0xFFFE); }