Further implementation of RTC

Gericom · Oct 6, 2024 · ac48f9d · ac48f9d
1 parent 4ea794f
commit ac48f9d
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Showing 6 changed files with 215 additions and 53 deletions.
diff --git a/code/core/arm7/source/IpcServices/RtcIpcService.cpp b/code/core/arm7/source/IpcServices/RtcIpcService.cpp
@@ -0,0 +1,15 @@
+#include "common.h"
+#include <libtwl/sio/sioRtc.h>
+#include "RtcIpcService.h"
+
+void RtcIpcService::Start()
+{
+    rtc_init();
+    ThreadIpcService::Start();
+}
+
+void RtcIpcService::HandleMessage(u32 data)
+{
+    rtc_readDateTime(reinterpret_cast<rtc_datetime_t*>(data << 2));
+    SendResponseMessage(1);
+}
diff --git a/code/core/arm7/source/IpcServices/RtcIpcService.h b/code/core/arm7/source/IpcServices/RtcIpcService.h
@@ -0,0 +1,15 @@
+#pragma once
+#include "ThreadIpcService.h"
+#include "ipcChannels.h"
+
+class RtcIpcService : public ThreadIpcService
+{
+    u32 _threadStack[128];
+
+public:
+    RtcIpcService()
+        : ThreadIpcService(IPC_CHANNEL_RTC, 10, _threadStack, sizeof(_threadStack)) { }
+
+    void Start() override;
+    void HandleMessage(u32 data) override;
+};
diff --git a/code/core/arm7/source/main.cpp b/code/core/arm7/source/main.cpp
@@ -16,6 +16,7 @@
 #include "IpcServices/GbaSoundIpcService.h"
 #include "IpcServices/SystemIpcService.h"
 #include "IpcServices/GbaSaveIpcService.h"
+#include "IpcServices/RtcIpcService.h"
 #include "Arm7State.h"
 #include "ExitMode.h"
 #include "FramerateAdjustment.h"
@@ -24,6 +25,7 @@ static FsIpcService sFsIpcService;
 static GbaSoundIpcService sGbaSoundIpcService;
 static SystemIpcService sSystemIpcService;
 static GbaSaveIpcService sGbaSaveIpcService;
+static RtcIpcService sRtcIpcService;
 static rtos_event_t sVBlankEvent;
 static volatile u8 sMcuIrqFlag = false;
 static Arm7State sState;
@@ -76,6 +78,7 @@ static void initializeIpcServices()
     sGbaSoundIpcService.Start();
     sSystemIpcService.Start();
     sGbaSaveIpcService.Start();
+    sRtcIpcService.Start();
 }
 
 static void initializeVBlankIrq()
@@ -192,6 +195,6 @@ int main()
         rtos_waitEvent(&sVBlankEvent, true, true);
         updateArm7();
     }
-    
+
     return 0;
 }
diff --git a/code/core/arm9/source/Peripherals/RomGpio/RomGpioRtc.cpp b/code/core/arm9/source/Peripherals/RomGpio/RomGpioRtc.cpp
@@ -1,5 +1,9 @@
 #include "common.h"
 #include <libtwl/mem/memSwap.h>
+#include <libtwl/ipc/ipcFifoSystem.h>
+#include <libtwl/ipc/ipcFifo.h>
+#include "cp15.h"
+#include "IpcChannels.h"
 #include "RomGpio.h"
 #include "RomGpioRtc.h"
 
@@ -24,13 +28,21 @@
 
 #define RIO_RTC_STATUS_WRITE_MASK   0b01101010
 
+[[gnu::section(".ewram.bss")]]
+RomGpioRtc::rio_rtc_datetime_t RomGpioRtc::sDSRtcDateTime alignas(32);
+
 void RomGpioRtc::Update(RomGpio& romGpio)
 {
     if (!romGpio.GetPinState(ROM_GPIO_PIN_CS))
     {
         _state = RtcTransferState::CommandWaitFallingEdge;
         _shiftRegister = 0;
         _bitCount = 0;
+        if (_offsetUpdateRequired)
+        {
+            _offsetUpdateRequired = false;
+            UpdateRtcOffset();
+        }
     }
     else
     {
@@ -111,7 +123,13 @@ void RomGpioRtc::CommandWaitRisingEdge(RomGpio& romGpio)
             }
             else
             {
-                _state = _shiftRegister & 1
+                bool isRead = _shiftRegister & 1;
+                if (isRead &&
+                    (_command == RIO_RTC_COMMAND_DATE_TIME || _command == RIO_RTC_COMMAND_TIME))
+                {
+                    UpdateDateTime();
+                }
+                _state = isRead
                     ? RtcTransferState::OutDataWaitFallingEdge
                     : RtcTransferState::InDataWaitFallingEdge;
                 _shiftRegister = 0;
@@ -147,6 +165,7 @@ void RomGpioRtc::HandleInDataWaitRisingEdge(RomGpio& romGpio)
             }
             case RIO_RTC_COMMAND_DATE_TIME:
             {
+                _offsetUpdateRequired = true;
                 switch (_byteIndex)
                 {
                     case 0:
@@ -179,6 +198,7 @@ void RomGpioRtc::HandleInDataWaitRisingEdge(RomGpio& romGpio)
             }
             case RIO_RTC_COMMAND_TIME:
             {
+                _offsetUpdateRequired = true;
                 switch (_byteIndex)
                 {
                     case 0:
@@ -289,6 +309,38 @@ void RomGpioRtc::RtcReset()
     mem_swapByte(0, &_dateTime.time.second);
     _statusRegister = 0;
     _intRegister = 0;
+    UpdateRtcOffset();
+}
+
+void RomGpioRtc::UpdateDSDateTime()
+{
+    dc_invalidateRange(&sDSRtcDateTime, sizeof(sDSRtcDateTime));
+    ipc_sendWordDirect(
+        ((((u32)&sDSRtcDateTime) >> 2) << IPC_FIFO_MSG_CHANNEL_BITS) |
+        IPC_CHANNEL_RTC);
+    while (ipc_isRecvFifoEmpty());
+    ipc_recvWordDirect();
+}
+
+void RomGpioRtc::UpdateDateTime()
+{
+    UpdateDSDateTime();
+    u32 dsRtcSecondsSince2000 = ToSecondsSinceJanuary2000(sDSRtcDateTime, true);
+    u32 secondsSince2000 = dsRtcSecondsSince2000 + _rtcOffset;
+    FromSecondsSinceJanuary2000(secondsSince2000, _dateTime, _statusRegister & RIO_RTC_STATUS_24H);
+    int weekDay = (_dateTime.date.weekDay + _weekDayOffset) % 7;
+    _dateTime.date.weekDay = weekDay < 0 ? weekDay + 7 : weekDay;
+}
+
+void RomGpioRtc::UpdateRtcOffset()
+{
+    UpdateDSDateTime();
+    u32 dsRtcSecondsSince2000 = ToSecondsSinceJanuary2000(sDSRtcDateTime, true);
+    u32 gbaRtcSecondsSince2000 = ToSecondsSinceJanuary2000(_dateTime, _statusRegister & RIO_RTC_STATUS_24H);
+    rio_rtc_datetime_t newDateTime;
+    FromSecondsSinceJanuary2000(gbaRtcSecondsSince2000, newDateTime, true);
+    _rtcOffset = gbaRtcSecondsSince2000 - dsRtcSecondsSince2000;
+    _weekDayOffset = (_dateTime.date.weekDay - newDateTime.date.weekDay) % 7;
 }
 
 void RomGpioRtc::SetYear(u8 value)
@@ -323,47 +375,12 @@ void RomGpioRtc::SetDayOfMonth(u8 value)
         value = 1;
     }
 
-    u32 daysInMonth = 0;
-    switch (_dateTime.date.month)
-    {
-        case 0x01:
-        case 0x03:
-        case 0x05:
-        case 0x07:
-        case 0x08:
-        case 0x10:
-        case 0x12:
-        {
-            daysInMonth = 31;
-            break;
-        }
-        case 0x04:
-        case 0x06:
-        case 0x09:
-        case 0x11:
-        {
-            daysInMonth = 30;
-            break;
-        }
-        case 0x02:
-        {
-            u32 year = 2000 + FromBcd(_dateTime.date.year);
-            // It is sufficient here to check if the year is divisible by 4
-            if ((year & 3) == 0)
-            {
-                daysInMonth = 29;
-            }
-            else
-            {
-                daysInMonth = 28;
-            }
-            break;
-        }
-    }
+    u32 year = FromBcd(_dateTime.date.year);
+    u32 month = FromBcd(_dateTime.date.month);
+    u32 daysInMonth = GetNumberOfDaysInMonth(2000 + year, month);
     if (FromBcd(value) > daysInMonth)
     {
         value = 1;
-        u32 month = FromBcd(_dateTime.date.month);
         if (++month == 13)
         {
             month = 1;
@@ -435,14 +452,117 @@ void RomGpioRtc::SetSecond(u8 value)
     mem_swapByte(value, &_dateTime.time.second);
 }
 
-u8 RomGpioRtc::FromBcd(u8 bcdValue)
+u32 RomGpioRtc::FromBcd(u32 bcdValue) const
+{
+    return bcdValue - 6 * (bcdValue >> 4);
+}
+
+u32 RomGpioRtc::ToBcd(u32 value) const
+{
+    static const u8 sToBcd[100] =
+    {
+        0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09,
+        0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19,
+        0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29,
+        0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39,
+        0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49,
+        0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59,
+        0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69,
+        0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79,
+        0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, 0x88, 0x89,
+        0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, 0x98, 0x99
+    };
+
+    return sToBcd[value];
+}
+
+u32 RomGpioRtc::ToSecondsSinceJanuary2000(const rio_rtc_datetime_t& dateTime, bool time24h) const
 {
-    return (bcdValue >> 4) * 10 + (bcdValue & 0xF);
+    u32 yearsSince2000 = FromBcd(dateTime.date.year);
+    u32 leapDays = yearsSince2000 / 4;
+    if ((yearsSince2000 & 3) != 0)
+    {
+        leapDays++;
+    }
+
+    u32 days = leapDays + yearsSince2000 * 365 + FromBcd(dateTime.date.monthDay) - 1;
+    u32 month = FromBcd(dateTime.date.month);
+    for (u32 i = 1; i < month; i++)
+    {
+        days += GetNumberOfDaysInMonth(2000 + yearsSince2000, i);
+    }
+
+    u32 hours = FromBcd(dateTime.time.hour & 0x1F);
+    if (!time24h && (dateTime.time.hour & 0x80))
+    {
+        hours += 12;
+    }
+
+    return ((days * 24u + hours) * 60u
+        + FromBcd(dateTime.time.minute & 0x3F)) * 60u
+        + FromBcd(dateTime.time.second & 0x3F);
 }
 
-u8 RomGpioRtc::ToBcd(u8 value)
+void RomGpioRtc::FromSecondsSinceJanuary2000(u32 secondsSinceJanuary2000, rio_rtc_datetime_t& dateTime, bool time24h) const
 {
-    u32 lowDigit = value % 10;
-    u32 highDigit = value / 10;
-    return (highDigit << 4) | lowDigit;
+    dateTime.time.second = ToBcd(secondsSinceJanuary2000 % 60);
+    u32 minutesSinceJanuary2000 = secondsSinceJanuary2000 / 60;
+    dateTime.time.minute = ToBcd(minutesSinceJanuary2000 % 60);
+    u32 hoursSinceJanuary2000 = minutesSinceJanuary2000 / 60;
+
+    u32 hours = hoursSinceJanuary2000 % 24;
+    u32 amPmFlag = hours >= 12 ? 0x80 : 0;
+    if (!time24h && hours >= 12)
+    {
+        hours -= 12;
+    }
+    dateTime.time.hour = ToBcd(hours) | amPmFlag;
+
+    u32 daysSinceJanuary2000 = hoursSinceJanuary2000 / 24;
+    dateTime.date.weekDay = ((daysSinceJanuary2000 + 5) % 7); // 1 January 2000 was a Saturday
+
+    u32 year = 2000 + daysSinceJanuary2000 * 4 / 1461;
+    u32 remainingDays = ((daysSinceJanuary2000 * 4) % 1461) / 4;
+
+    dateTime.date.year = ToBcd(year - 2000);
+
+    u32 month = 1;
+    u32 daysInMonth = GetNumberOfDaysInMonth(year, month);
+    if (remainingDays >= daysInMonth)
+    {
+        remainingDays -= daysInMonth;
+        month++;
+        daysInMonth = GetNumberOfDaysInMonth(year, month);
+        if (remainingDays >= daysInMonth)
+        {
+            remainingDays -= daysInMonth;
+            month++;
+            for (; month < 12; month++)
+            {
+                u32 daysInMonth = GetNumberOfDaysInMonth(year, month);
+                if (remainingDays < daysInMonth)
+                {
+                    break;
+                }
+                remainingDays -= daysInMonth;
+            }
+        }
+    }
+
+    dateTime.date.month = ToBcd(month);
+    dateTime.date.monthDay = ToBcd(remainingDays + 1);
+}
+
+u32 RomGpioRtc::GetNumberOfDaysInMonth(u32 year, u32 month) const
+{
+    static const u8 sDaysPerMonth[12] = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
+
+    u32 result = sDaysPerMonth[month - 1];
+    if (month == 2)
+    {
+        // It is sufficient here to check if the year is divisible by 4
+        result += ((year & 3) == 0);
+    }
+
+    return result;
 }
diff --git a/code/core/arm9/source/Peripherals/RomGpio/RomGpioRtc.h b/code/core/arm9/source/Peripherals/RomGpio/RomGpioRtc.h
@@ -40,15 +40,13 @@ class RomGpioRtc
 public:
     RomGpioRtc()
         : _state(RtcTransferState::CommandWaitFallingEdge), _shiftRegister(0), _bitCount(0)
-        , _statusRegister(0x40), _intRegister(0)
-    {
-        *(u32*)&_dateTime.date = 0x030A0224;
-        *(u32*)&_dateTime.time = 0x00300910;
-    }
+        , _statusRegister(0x40), _intRegister(0), _rtcOffset(0), _weekDayOffset(0), _offsetUpdateRequired(false) { }
 
     void Update(RomGpio& romGpio);
 
 private:
+    static rio_rtc_datetime_t sDSRtcDateTime;
+
     RtcTransferState _state;
     u32 _shiftRegister;
     u32 _bitCount;
@@ -58,12 +56,18 @@ class RomGpioRtc
     u16 _intRegister;
     rio_rtc_datetime_t _dateTime;
     u8 _padding;
+    s32 _rtcOffset;
+    s16 _weekDayOffset;
+    u16 _offsetUpdateRequired;
 
     void CommandWaitRisingEdge(RomGpio& romGpio);
     void HandleInDataWaitRisingEdge(RomGpio& romGpio);
     void HandleOutDataWaitFallingEdge(RomGpio& romGpio);
 
     void RtcReset();
+    void UpdateDSDateTime();
+    void UpdateDateTime();
+    void UpdateRtcOffset();
 
     void SetYear(u8 value);
     void SetMonth(u8 value);
@@ -73,6 +77,10 @@ class RomGpioRtc
     void SetMinute(u8 value);
     void SetSecond(u8 value);
 
-    u8 FromBcd(u8 bcdValue);
-    u8 ToBcd(u8 value);
+    u32 FromBcd(u32 bcdValue) const;
+    u32 ToBcd(u32 value) const;
+
+    u32 ToSecondsSinceJanuary2000(const rio_rtc_datetime_t& dateTime, bool time24h) const;
+    void FromSecondsSinceJanuary2000(u32 secondsSinceJanuary2000, rio_rtc_datetime_t& dateTime, bool time24h) const;
+    u32 GetNumberOfDaysInMonth(u32 year, u32 month) const;
 };
diff --git a/code/core/common/IpcChannels.h b/code/core/common/IpcChannels.h
@@ -4,3 +4,4 @@
 #define IPC_CHANNEL_SYSTEM      15
 #define IPC_CHANNEL_GBA_SOUND   16
 #define IPC_CHANNEL_FS          17
+#define IPC_CHANNEL_RTC         18