Pulled the conversion between seconds since the epoche and the split up

(year, month,...) representation out of the x86 specific code and put
respective support functions into real_time_clock.c. We'll need those
for the PPC specific part too.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@15827 a95241bf-73f2-0310-859d-f6bbb57e9c96

headers/private/kernel/real_time_clock.h

@@ -8,6 +8,10 @@
 
 #include <KernelExport.h>
 
+#include <time.h>
+
+
+#define RTC_EPOCHE_BASE_YEAR	1970
 
 #ifdef __cplusplus
 extern "C" {
@@ -26,6 +30,11 @@ typedef struct rtc_info {
 
 status_t get_rtc_info(rtc_info *info);
 
+// Both functions use the passed struct tm only partially
+// (no tm_wday, tm_yday, tm_isdst).
+uint32 rtc_tm_to_secs(const struct tm *t);
+void rtc_secs_to_tm(uint32 seconds, struct tm *t);
+
 bigtime_t _user_system_time(void);
 status_t _user_set_real_time_clock(uint32 time);
 status_t _user_set_timezone(int32 timezoneOffset, bool daylightSavingTime);

src/system/kernel/arch/x86/arch_real_time_clock.c

@@ -9,16 +9,12 @@
 #include <arch/real_time_clock.h>
 #include <arch/cpu.h>
 
+#include <real_time_clock.h>
 #include <real_time_data.h>
 
 
 #define CMOS_ADDR_PORT 0x70
 #define CMOS_DATA_PORT 0x71
-#define BASE_YEAR 1970
-#define SECONDS_31 2678400
-#define SECONDS_30 2592000
-#define SECONDS_28 2419200
-#define SECONDS_DAY 86400
 
 typedef struct	{
 	uint8 second;
@@ -30,10 +26,6 @@ typedef struct	{
 	uint8 century;
 } cmos_time;
 
-static uint32 sSecsPerMonth[12] = {SECONDS_31, SECONDS_28, SECONDS_31, SECONDS_30, 
-	SECONDS_31, SECONDS_30, SECONDS_31, SECONDS_31, SECONDS_30, SECONDS_31, SECONDS_30,
-	SECONDS_31};
-
 
 static uint32
 bcd_to_int(uint8 bcd)
@@ -64,22 +56,6 @@ int_to_bcd(uint32 number)
 }
 
 
-static bool
-leap_year(uint32 year)
-{
-	if (year % 400 == 0)
-		return true;
-
-	if (year % 100 == 0)
-		return false;
-
-	if (year % 4 == 0)
-		return true;
-
-	return false;
-}
-
-
 static int
 same_time(const cmos_time *time1, const cmos_time *time2)
 {
@@ -160,105 +136,39 @@ write_cmos_clock(cmos_time *cmos)
 }
 
 
-static inline uint32
-secs_this_year(uint32 year)
-{
-	if (leap_year(year))
-		return 31622400;
-	
-	return 31536000;
-}
-
-
 static uint32
 cmos_to_secs(const cmos_time *cmos)
 {
-	uint32 wholeYear;
+	struct tm t;
-	uint32 time = 0;
+	t.tm_year = bcd_to_int(cmos->century) * 100 + bcd_to_int(cmos->year)
-	uint32 i;
+		- RTC_EPOCHE_BASE_YEAR;
+	t.tm_mon = bcd_to_int(cmos->month) - 1;
+	t.tm_mday = bcd_to_int(cmos->day);
+	t.tm_hour = bcd_to_int(cmos->hour);
+	t.tm_min = bcd_to_int(cmos->minute);
+	t.tm_sec = bcd_to_int(cmos->second);
 
-	wholeYear = bcd_to_int(cmos->century) * 100 + bcd_to_int(cmos->year);
+	return rtc_tm_to_secs(&t);
-
-	// ToDo: get rid of these loops and compute the correct value
-	//	i.e. days = (long)(year > 0) + year*365 + --year/4 - year/100 + year/400;
-	//	let sSecsPerMonth[] have the values already added up
-
-	// Add up the seconds from all years since 1970 that have elapsed.
-	for (i = BASE_YEAR; i < wholeYear; ++i) {
-		time += secs_this_year(i);
-	}
-
-	// Add up the seconds from all months passed this year.
-	for (i = 0; i < bcd_to_int(cmos->month) - 1 && i < 12; ++i)
-		time += sSecsPerMonth[i];
-
-	// Add up the seconds from all days passed this month.
-	if (leap_year(wholeYear) && bcd_to_int(cmos->month) > 2)
-		time += SECONDS_DAY;
-
-	time += (bcd_to_int(cmos->day) - 1) * SECONDS_DAY;
-	time += bcd_to_int(cmos->hour) * 3600;
-	time += bcd_to_int(cmos->minute) * 60;
-	time += bcd_to_int(cmos->second);
-
-	return time;
 }
 
 
 static void
 secs_to_cmos(uint32 seconds, cmos_time *cmos)
 {
-	uint32 wholeYear = BASE_YEAR;
+	int wholeYear;
-	uint32 secsThisYear;
-	bool keepLooping;
-	bool isLeapYear;
-	int temp;
-	int month;
 
-	keepLooping = 1;
+	struct tm t;
+	rtc_secs_to_tm(seconds, &t);
 
-	// Determine the current year by starting at 1970 and incrementing whole_year as long as
+	wholeYear = t.tm_year + RTC_EPOCHE_BASE_YEAR;
-	// we can keep subtracting secs_this_year from seconds.
-	while (keepLooping) {
-		secsThisYear = secs_this_year(wholeYear);
-
-		if (seconds >= secsThisYear) {
-			seconds -= secsThisYear;
-			++wholeYear;
-		} else
-			keepLooping = false;
-	}
 
 	cmos->century = int_to_bcd(wholeYear / 100);
 	cmos->year = int_to_bcd(wholeYear % 100);
-
+	cmos->month = int_to_bcd(t.tm_mon + 1);
-	// Determine the current month
+	cmos->day = int_to_bcd(t.tm_mday);
-	month = 1;
+	cmos->hour = int_to_bcd(t.tm_hour);
-	isLeapYear = leap_year(wholeYear);
+	cmos->minute = int_to_bcd(t.tm_min);
-	do {
+	cmos->second = int_to_bcd(t.tm_sec);
-		temp = seconds - sSecsPerMonth[month - 1];
-
-		if (isLeapYear && month == 2)
-			temp -= SECONDS_DAY;
-
-		if (temp >= 0) {
-			seconds = temp;
-			++month;
-		}
-	} while (temp >= 0 && month < 13);
-
-	cmos->month = int_to_bcd(month);
-
-	cmos->day = int_to_bcd(seconds / SECONDS_DAY + 1);
-	seconds = seconds % SECONDS_DAY;
-
-	cmos->hour = int_to_bcd(seconds / 3600);
-	seconds = seconds % 3600;
-
-	cmos->minute = int_to_bcd(seconds / 60);
-	seconds = seconds % 60;
-
-	cmos->second = int_to_bcd(seconds);
 }
 
 

src/system/kernel/real_time_clock.c

@@ -155,6 +155,136 @@ get_rtc_info(rtc_info *info)
 }
 
 
+// #pragma mark -
+
+
+#define SECONDS_31 2678400
+#define SECONDS_30 2592000
+#define SECONDS_28 2419200
+#define SECONDS_DAY 86400
+
+static uint32 sSecsPerMonth[12] = {SECONDS_31, SECONDS_28, SECONDS_31, SECONDS_30, 
+	SECONDS_31, SECONDS_30, SECONDS_31, SECONDS_31, SECONDS_30, SECONDS_31, SECONDS_30,
+	SECONDS_31};
+
+
+static bool
+leap_year(uint32 year)
+{
+	if (year % 400 == 0)
+		return true;
+
+	if (year % 100 == 0)
+		return false;
+
+	if (year % 4 == 0)
+		return true;
+
+	return false;
+}
+
+
+static inline uint32
+secs_this_year(uint32 year)
+{
+	if (leap_year(year))
+		return 31622400;
+	
+	return 31536000;
+}
+
+
+uint32
+rtc_tm_to_secs(const struct tm *t)
+{
+	uint32 wholeYear;
+	uint32 time = 0;
+	uint32 i;
+
+	wholeYear = 1900 + t->tm_year;
+
+	// ToDo: get rid of these loops and compute the correct value
+	//	i.e. days = (long)(year > 0) + year*365 + --year/4 - year/100 + year/400;
+	//	let sSecsPerMonth[] have the values already added up
+
+	// Add up the seconds from all years since 1970 that have elapsed.
+	for (i = RTC_EPOCHE_BASE_YEAR; i < wholeYear; ++i) {
+		time += secs_this_year(i);
+	}
+
+	// Add up the seconds from all months passed this year.
+	for (i = 0; i < t->tm_mon && i < 12; ++i)
+		time += sSecsPerMonth[i];
+
+	// Add up the seconds from all days passed this month.
+	if (leap_year(wholeYear) && t->tm_mon >= 2)
+		time += SECONDS_DAY;
+
+	time += (t->tm_mday - 1) * SECONDS_DAY;
+	time += t->tm_hour * 3600;
+	time += t->tm_min * 60;
+	time += t->tm_sec;
+
+	return time;
+}
+
+
+void
+rtc_secs_to_tm(uint32 seconds, struct tm *t)
+{
+	uint32 wholeYear = RTC_EPOCHE_BASE_YEAR;
+	uint32 secsThisYear;
+	bool keepLooping;
+	bool isLeapYear;
+	int temp;
+	int month;
+
+	keepLooping = 1;
+
+	// Determine the current year by starting at 1970 and incrementing whole_year as long as
+	// we can keep subtracting secs_this_year from seconds.
+	while (keepLooping) {
+		secsThisYear = secs_this_year(wholeYear);
+
+		if (seconds >= secsThisYear) {
+			seconds -= secsThisYear;
+			++wholeYear;
+		} else
+			keepLooping = false;
+	}
+
+	t->tm_year = wholeYear - RTC_EPOCHE_BASE_YEAR;
+
+	// Determine the current month
+	month = 0;
+	isLeapYear = leap_year(wholeYear);
+	do {
+		temp = seconds - sSecsPerMonth[month];
+
+		if (isLeapYear && month == 1)
+			temp -= SECONDS_DAY;
+
+		if (temp >= 0) {
+			seconds = temp;
+			++month;
+		}
+	} while (temp >= 0 && month < 12);
+
+	t->tm_mon = month;
+
+	t->tm_mday = seconds / SECONDS_DAY + 1;
+	seconds = seconds % SECONDS_DAY;
+
+	t->tm_hour = seconds / 3600;
+	seconds = seconds % 3600;
+
+	t->tm_min = seconds / 60;
+	seconds = seconds % 60;
+
+	t->tm_sec = seconds;
+}
+
+
 //	#pragma mark -
 //	public userland API