pokeemerald/src/siirtc.c
2019-01-30 19:48:28 -06:00

446 lines
9.5 KiB
C

// Ruby/Sapphire/Emerald cartridges contain a Seiko Instruments Inc. (SII)
// S-3511A real-time clock (RTC). This library ("SIIRTC_V001") is for
// communicating with the RTC.
#include "gba/gba.h"
#include "siirtc.h"
#define STATUS_INTFE 0x02 // frequency interrupt enable
#define STATUS_INTME 0x08 // per-minute interrupt enable
#define STATUS_INTAE 0x20 // alarm interrupt enable
#define STATUS_24HOUR 0x40 // 0: 12-hour mode, 1: 24-hour mode
#define STATUS_POWER 0x80 // power on or power failure occurred
#define TEST_MODE 0x80 // flag in the "second" byte
#define ALARM_AM 0x00
#define ALARM_PM 0x80
#define OFFSET_YEAR offsetof(struct SiiRtcInfo, year)
#define OFFSET_MONTH offsetof(struct SiiRtcInfo, month)
#define OFFSET_DAY offsetof(struct SiiRtcInfo, day)
#define OFFSET_DAY_OF_WEEK offsetof(struct SiiRtcInfo, dayOfWeek)
#define OFFSET_HOUR offsetof(struct SiiRtcInfo, hour)
#define OFFSET_MINUTE offsetof(struct SiiRtcInfo, minute)
#define OFFSET_SECOND offsetof(struct SiiRtcInfo, second)
#define OFFSET_STATUS offsetof(struct SiiRtcInfo, status)
#define OFFSET_ALARM_HOUR offsetof(struct SiiRtcInfo, alarmHour)
#define OFFSET_ALARM_MINUTE offsetof(struct SiiRtcInfo, alarmMinute)
#define INFO_BUF(info, index) (*((u8 *)(info) + (index)))
#define DATETIME_BUF(info, index) INFO_BUF(info, OFFSET_YEAR + index)
#define DATETIME_BUF_LEN (OFFSET_SECOND - OFFSET_YEAR + 1)
#define TIME_BUF(info, index) INFO_BUF(info, OFFSET_HOUR + index)
#define TIME_BUF_LEN (OFFSET_SECOND - OFFSET_HOUR + 1)
#define WR 0 // command for writing data
#define RD 1 // command for reading data
#define CMD(n) (0x60 | (n << 1))
#define CMD_RESET CMD(0)
#define CMD_STATUS CMD(1)
#define CMD_DATETIME CMD(2)
#define CMD_TIME CMD(3)
#define CMD_ALARM CMD(4)
#define SCK_HI 1
#define SIO_HI 2
#define CS_HI 4
#define DIR_0_IN 0
#define DIR_0_OUT 1
#define DIR_1_IN 0
#define DIR_1_OUT 2
#define DIR_2_IN 0
#define DIR_2_OUT 4
#define DIR_ALL_IN (DIR_0_IN | DIR_1_IN | DIR_2_IN)
#define DIR_ALL_OUT (DIR_0_OUT | DIR_1_OUT | DIR_2_OUT)
#define GPIO_PORT_DATA (*(vu16 *)0x80000C4)
#define GPIO_PORT_DIRECTION (*(vu16 *)0x80000C6)
#define GPIO_PORT_READ_ENABLE (*(vu16 *)0x80000C8)
extern vu16 GPIOPortDirection;
static u16 sDummy; // unused variable
static bool8 sLocked;
static int WriteCommand(u8 value);
static int WriteData(u8 value);
static u8 ReadData();
static void EnableGpioPortRead();
static void DisableGpioPortRead();
static const char AgbLibRtcVersion[] = "SIIRTC_V001";
void SiiRtcUnprotect()
{
EnableGpioPortRead();
sLocked = FALSE;
}
void SiiRtcProtect()
{
DisableGpioPortRead();
sLocked = TRUE;
}
u8 SiiRtcProbe()
{
u8 errorCode;
struct SiiRtcInfo rtc;
if (!SiiRtcGetStatus(&rtc))
return 0;
errorCode = 0;
if ((rtc.status & (SIIRTCINFO_POWER | SIIRTCINFO_24HOUR)) == SIIRTCINFO_POWER
|| (rtc.status & (SIIRTCINFO_POWER | SIIRTCINFO_24HOUR)) == 0)
{
// The RTC is in 12-hour mode. Reset it and switch to 24-hour mode.
// Note that the conditions are redundant and equivalent to simply
// "(rtc.status & SIIRTCINFO_24HOUR) == 0". It's possible that this
// was also intended to handle resetting the clock after power failure
// but a mistake was made.
if (!SiiRtcReset())
return 0;
errorCode++;
}
SiiRtcGetTime(&rtc);
if (rtc.second & TEST_MODE)
{
// The RTC is in test mode. Reset it to leave test mode.
if (!SiiRtcReset())
return (errorCode << 4) & 0xF0;
errorCode++;
}
return (errorCode << 4) | 1;
}
bool8 SiiRtcReset()
{
u8 result;
struct SiiRtcInfo rtc;
if (sLocked == TRUE)
return FALSE;
sLocked = TRUE;
GPIO_PORT_DATA = SCK_HI;
GPIO_PORT_DATA = SCK_HI | CS_HI;
GPIO_PORT_DIRECTION = DIR_ALL_OUT;
WriteCommand(CMD_RESET | WR);
GPIO_PORT_DATA = SCK_HI;
GPIO_PORT_DATA = SCK_HI;
sLocked = FALSE;
rtc.status = SIIRTCINFO_24HOUR;
result = SiiRtcSetStatus(&rtc);
return result;
}
bool8 SiiRtcGetStatus(struct SiiRtcInfo *rtc)
{
u8 statusData;
if (sLocked == TRUE)
return FALSE;
sLocked = TRUE;
GPIO_PORT_DATA = SCK_HI;
GPIO_PORT_DATA = SCK_HI | CS_HI;
GPIO_PORT_DIRECTION = DIR_ALL_OUT;
WriteCommand(CMD_STATUS | RD);
GPIO_PORT_DIRECTION = DIR_0_OUT | DIR_1_IN | DIR_2_OUT;
statusData = ReadData();
rtc->status = (statusData & (STATUS_POWER | STATUS_24HOUR))
| ((statusData & STATUS_INTAE) >> 3)
| ((statusData & STATUS_INTME) >> 2)
| ((statusData & STATUS_INTFE) >> 1);
GPIO_PORT_DATA = SCK_HI;
GPIO_PORT_DATA = SCK_HI;
sLocked = FALSE;
return TRUE;
}
bool8 SiiRtcSetStatus(struct SiiRtcInfo *rtc)
{
u8 statusData;
if (sLocked == TRUE)
return FALSE;
sLocked = TRUE;
GPIO_PORT_DATA = SCK_HI;
GPIO_PORT_DATA = SCK_HI | CS_HI;
statusData = STATUS_24HOUR
| ((rtc->status & SIIRTCINFO_INTAE) << 3)
| ((rtc->status & SIIRTCINFO_INTME) << 2)
| ((rtc->status & SIIRTCINFO_INTFE) << 1);
GPIO_PORT_DIRECTION = DIR_ALL_OUT;
WriteCommand(CMD_STATUS | WR);
WriteData(statusData);
GPIO_PORT_DATA = SCK_HI;
GPIO_PORT_DATA = SCK_HI;
sLocked = FALSE;
return TRUE;
}
bool8 SiiRtcGetDateTime(struct SiiRtcInfo *rtc)
{
u8 i;
if (sLocked == TRUE)
return FALSE;
sLocked = TRUE;
GPIO_PORT_DATA = SCK_HI;
GPIO_PORT_DATA = SCK_HI | CS_HI;
GPIO_PORT_DIRECTION = DIR_ALL_OUT;
WriteCommand(CMD_DATETIME | RD);
GPIO_PORT_DIRECTION = DIR_0_OUT | DIR_1_IN | DIR_2_OUT;
for (i = 0; i < DATETIME_BUF_LEN; i++)
DATETIME_BUF(rtc, i) = ReadData();
INFO_BUF(rtc, OFFSET_HOUR) &= 0x7F;
GPIO_PORT_DATA = SCK_HI;
GPIO_PORT_DATA = SCK_HI;
sLocked = FALSE;
return TRUE;
}
bool8 SiiRtcSetDateTime(struct SiiRtcInfo *rtc)
{
u8 i;
if (sLocked == TRUE)
return FALSE;
sLocked = TRUE;
GPIO_PORT_DATA = SCK_HI;
GPIO_PORT_DATA = SCK_HI | CS_HI;
GPIO_PORT_DIRECTION = DIR_ALL_OUT;
WriteCommand(CMD_DATETIME | WR);
for (i = 0; i < DATETIME_BUF_LEN; i++)
WriteData(DATETIME_BUF(rtc, i));
GPIO_PORT_DATA = SCK_HI;
GPIO_PORT_DATA = SCK_HI;
sLocked = FALSE;
return TRUE;
}
bool8 SiiRtcGetTime(struct SiiRtcInfo *rtc)
{
u8 i;
if (sLocked == TRUE)
return FALSE;
sLocked = TRUE;
GPIO_PORT_DATA = SCK_HI;
GPIO_PORT_DATA = SCK_HI | CS_HI;
GPIO_PORT_DIRECTION = DIR_ALL_OUT;
WriteCommand(CMD_TIME | RD);
GPIO_PORT_DIRECTION = DIR_0_OUT | DIR_1_IN | DIR_2_OUT;
for (i = 0; i < TIME_BUF_LEN; i++)
TIME_BUF(rtc, i) = ReadData();
INFO_BUF(rtc, OFFSET_HOUR) &= 0x7F;
GPIO_PORT_DATA = SCK_HI;
GPIO_PORT_DATA = SCK_HI;
sLocked = FALSE;
return TRUE;
}
bool8 SiiRtcSetTime(struct SiiRtcInfo *rtc)
{
u8 i;
if (sLocked == TRUE)
return FALSE;
sLocked = TRUE;
GPIO_PORT_DATA = SCK_HI;
GPIO_PORT_DATA = SCK_HI | CS_HI;
GPIO_PORT_DIRECTION = DIR_ALL_OUT;
WriteCommand(CMD_TIME | WR);
for (i = 0; i < TIME_BUF_LEN; i++)
WriteData(TIME_BUF(rtc, i));
GPIO_PORT_DATA = SCK_HI;
GPIO_PORT_DATA = SCK_HI;
sLocked = FALSE;
return TRUE;
}
bool8 SiiRtcSetAlarm(struct SiiRtcInfo *rtc)
{
u8 i;
u8 alarmData[2];
if (sLocked == TRUE)
return FALSE;
sLocked = TRUE;
// Decode BCD.
alarmData[0] = (rtc->alarmHour & 0xF) + 10 * ((rtc->alarmHour >> 4) & 0xF);
// The AM/PM flag must be set correctly even in 24-hour mode.
if (alarmData[0] < 12)
alarmData[0] = rtc->alarmHour | ALARM_AM;
else
alarmData[0] = rtc->alarmHour | ALARM_PM;
alarmData[1] = rtc->alarmMinute;
GPIO_PORT_DATA = SCK_HI;
GPIO_PORT_DATA = SCK_HI | CS_HI;
GPIOPortDirection = DIR_ALL_OUT; // Why is this the only instance that uses a symbol?
WriteCommand(CMD_ALARM | WR);
for (i = 0; i < 2; i++)
WriteData(alarmData[i]);
GPIO_PORT_DATA = SCK_HI;
GPIO_PORT_DATA = SCK_HI;
sLocked = FALSE;
return TRUE;
}
static int WriteCommand(u8 value)
{
u8 i;
u8 temp;
for (i = 0; i < 8; i++)
{
temp = ((value >> (7 - i)) & 1);
GPIO_PORT_DATA = (temp << 1) | CS_HI;
GPIO_PORT_DATA = (temp << 1) | CS_HI;
GPIO_PORT_DATA = (temp << 1) | CS_HI;
GPIO_PORT_DATA = (temp << 1) | SCK_HI | CS_HI;
}
// control reaches end of non-void function
}
static int WriteData(u8 value)
{
u8 i;
u8 temp;
for (i = 0; i < 8; i++)
{
temp = ((value >> i) & 1);
GPIO_PORT_DATA = (temp << 1) | CS_HI;
GPIO_PORT_DATA = (temp << 1) | CS_HI;
GPIO_PORT_DATA = (temp << 1) | CS_HI;
GPIO_PORT_DATA = (temp << 1) | SCK_HI | CS_HI;
}
// control reaches end of non-void function
}
static u8 ReadData()
{
u8 i;
u8 temp;
u8 value;
for (i = 0; i < 8; i++)
{
GPIO_PORT_DATA = CS_HI;
GPIO_PORT_DATA = CS_HI;
GPIO_PORT_DATA = CS_HI;
GPIO_PORT_DATA = CS_HI;
GPIO_PORT_DATA = CS_HI;
GPIO_PORT_DATA = SCK_HI | CS_HI;
temp = ((GPIO_PORT_DATA & SIO_HI) >> 1);
value = (value >> 1) | (temp << 7); // UB: accessing uninitialized var
}
return value;
}
static void EnableGpioPortRead()
{
GPIO_PORT_READ_ENABLE = 1;
}
static void DisableGpioPortRead()
{
GPIO_PORT_READ_ENABLE = 0;
}