[PATCH] RTC Subsystem: library functions

RTC and date/time related functions. Signed-off-by: Alessandro Zummo <a.zummo@towertech.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>

[PATCH] RTC Subsystem: library functions
RTC and date/time related functions. Signed-off-by: Alessandro Zummo <a.zummo@towertech.it> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Alessandro Zummo · Linus Torvalds
1 parent d23ee8fe6e
Showing 6 changed files with 120 additions and 0 deletions Side-by-side Diff
drivers/Kconfig
drivers/Makefile
drivers/rtc/Kconfig
drivers/rtc/Makefile
drivers/rtc/rtc-lib.c
include/linux/rtc.h
@@ -70,5 +70,7 @@
  
 source "drivers/edac/Kconfig"
  
+source "drivers/rtc/Kconfig"
+
 endmenu
@@ -56,6 +56,7 @@
 obj-$(CONFIG_GAMEPORT)		+= input/gameport/
 obj-$(CONFIG_INPUT)		+= input/
 obj-$(CONFIG_I2O)		+= message/
+obj-$(CONFIG_RTC_LIB)		+= rtc/
 obj-$(CONFIG_I2C)		+= i2c/
 obj-$(CONFIG_W1)		+= w1/
 obj-$(CONFIG_HWMON)		+= hwmon/
+#
+# RTC class/drivers configuration
+#
+
+config RTC_LIB
+	tristate
+#
+# Makefile for RTC class/drivers.
+#
+
+obj-$(CONFIG_RTC_LIB)	+= rtc-lib.o
+/*
+ * rtc and date/time utility functions
+ *
+ * Copyright (C) 2005-06 Tower Technologies
+ * Author: Alessandro Zummo <a.zummo@towertech.it>
+ *
+ * based on arch/arm/common/rtctime.c and other bits
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+*/
+
+#include <linux/module.h>
+#include <linux/rtc.h>
+
+static const unsigned char rtc_days_in_month[] = {
+	31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
+};
+
+#define LEAPS_THRU_END_OF(y) ((y)/4 - (y)/100 + (y)/400)
+#define LEAP_YEAR(year) ((!(year % 4) && (year % 100)) || !(year % 400))
+
+int rtc_month_days(unsigned int month, unsigned int year)
+{
+	return rtc_days_in_month[month] + (LEAP_YEAR(year) && month == 1);
+}
+EXPORT_SYMBOL(rtc_month_days);
+
+/*
+ * Convert seconds since 01-01-1970 00:00:00 to Gregorian date.
+ */
+void rtc_time_to_tm(unsigned long time, struct rtc_time *tm)
+{
+	register int days, month, year;
+
+	days = time / 86400;
+	time -= days * 86400;
+
+	/* day of the week, 1970-01-01 was a Thursday */
+	tm->tm_wday = (days + 4) % 7;
+
+	year = 1970 + days / 365;
+	days -= (year - 1970) * 365
+		+ LEAPS_THRU_END_OF(year - 1)
+		- LEAPS_THRU_END_OF(1970 - 1);
+	if (days < 0) {
+		year -= 1;
+		days += 365 + LEAP_YEAR(year);
+	}
+	tm->tm_year = year - 1900;
+	tm->tm_yday = days + 1;
+
+	for (month = 0; month < 11; month++) {
+		int newdays;
+
+		newdays = days - rtc_month_days(month, year);
+		if (newdays < 0)
+			break;
+		days = newdays;
+	}
+	tm->tm_mon = month;
+	tm->tm_mday = days + 1;
+
+	tm->tm_hour = time / 3600;
+	time -= tm->tm_hour * 3600;
+	tm->tm_min = time / 60;
+	tm->tm_sec = time - tm->tm_min * 60;
+}
+EXPORT_SYMBOL(rtc_time_to_tm);
+
+/*
+ * Does the rtc_time represent a valid date/time?
+ */
+int rtc_valid_tm(struct rtc_time *tm)
+{
+	if (tm->tm_year < 70
+		|| tm->tm_mon >= 12
+		|| tm->tm_mday < 1
+		|| tm->tm_mday > rtc_month_days(tm->tm_mon, tm->tm_year + 1900)
+		|| tm->tm_hour >= 24
+		|| tm->tm_min >= 60
+		|| tm->tm_sec >= 60)
+		return -EINVAL;
+
+	return 0;
+}
+EXPORT_SYMBOL(rtc_valid_tm);
+
+/*
+ * Convert Gregorian date to seconds since 01-01-1970 00:00:00.
+ */
+int rtc_tm_to_time(struct rtc_time *tm, unsigned long *time)
+{
+	*time = mktime(tm->tm_year + 1900, tm->tm_mon + 1, tm->tm_mday,
+			tm->tm_hour, tm->tm_min, tm->tm_sec);
+	return 0;
+}
+EXPORT_SYMBOL(rtc_tm_to_time);
+
+MODULE_LICENSE("GPL");
@@ -95,6 +95,11 @@
  
 #include <linux/interrupt.h>
  
+extern int rtc_month_days(unsigned int month, unsigned int year);
+extern int rtc_valid_tm(struct rtc_time *tm);
+extern int rtc_tm_to_time(struct rtc_time *tm, unsigned long *time);
+extern void rtc_time_to_tm(unsigned long time, struct rtc_time *tm);
+
 typedef struct rtc_task {
 	void (*func)(void *private_data);
 	void *private_data;
...	...	@@ -70,5 +70,7 @@
70	70
71	71	source "drivers/edac/Kconfig"
72	72
	73	+source "drivers/rtc/Kconfig"
	74	+
73	75	endmenu
...	...	@@ -56,6 +56,7 @@
56	56	obj-$(CONFIG_GAMEPORT) += input/gameport/
57	57	obj-$(CONFIG_INPUT) += input/
58	58	obj-$(CONFIG_I2O) += message/
	59	+obj-$(CONFIG_RTC_LIB) += rtc/
59	60	obj-$(CONFIG_I2C) += i2c/
60	61	obj-$(CONFIG_W1) += w1/
61	62	obj-$(CONFIG_HWMON) += hwmon/
	1	+#
	2	+# RTC class/drivers configuration
	3	+#
	4	+
	5	+config RTC_LIB
	6	+ tristate
	1	+#
	2	+# Makefile for RTC class/drivers.
	3	+#
	4	+
	5	+obj-$(CONFIG_RTC_LIB) += rtc-lib.o
	1	+/*
	2	+ * rtc and date/time utility functions
	3	+ *
	4	+ * Copyright (C) 2005-06 Tower Technologies
	5	+ * Author: Alessandro Zummo <a.zummo@towertech.it>
	6	+ *
	7	+ * based on arch/arm/common/rtctime.c and other bits
	8	+ *
	9	+ * This program is free software; you can redistribute it and/or modify
	10	+ * it under the terms of the GNU General Public License version 2 as
	11	+ * published by the Free Software Foundation.
	12	+*/
	13	+
	14	+#include <linux/module.h>
	15	+#include <linux/rtc.h>
	16	+
	17	+static const unsigned char rtc_days_in_month[] = {
	18	+ 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31
	19	+};
	20	+
	21	+#define LEAPS_THRU_END_OF(y) ((y)/4 - (y)/100 + (y)/400)
	22	+#define LEAP_YEAR(year) ((!(year % 4) && (year % 100)) \|\| !(year % 400))
	23	+
	24	+int rtc_month_days(unsigned int month, unsigned int year)
	25	+{
	26	+ return rtc_days_in_month[month] + (LEAP_YEAR(year) && month == 1);
	27	+}
	28	+EXPORT_SYMBOL(rtc_month_days);
	29	+
	30	+/*
	31	+ * Convert seconds since 01-01-1970 00:00:00 to Gregorian date.
	32	+ */
	33	+void rtc_time_to_tm(unsigned long time, struct rtc_time *tm)
	34	+{
	35	+ register int days, month, year;
	36	+
	37	+ days = time / 86400;
	38	+ time -= days * 86400;
	39	+
	40	+ /* day of the week, 1970-01-01 was a Thursday */
	41	+ tm->tm_wday = (days + 4) % 7;
	42	+
	43	+ year = 1970 + days / 365;
	44	+ days -= (year - 1970) * 365
	45	+ + LEAPS_THRU_END_OF(year - 1)
	46	+ - LEAPS_THRU_END_OF(1970 - 1);
	47	+ if (days < 0) {
	48	+ year -= 1;
	49	+ days += 365 + LEAP_YEAR(year);
	50	+ }
	51	+ tm->tm_year = year - 1900;
	52	+ tm->tm_yday = days + 1;
	53	+
	54	+ for (month = 0; month < 11; month++) {
	55	+ int newdays;
	56	+
	57	+ newdays = days - rtc_month_days(month, year);
	58	+ if (newdays < 0)
	59	+ break;
	60	+ days = newdays;
	61	+ }
	62	+ tm->tm_mon = month;
	63	+ tm->tm_mday = days + 1;
	64	+
	65	+ tm->tm_hour = time / 3600;
	66	+ time -= tm->tm_hour * 3600;
	67	+ tm->tm_min = time / 60;
	68	+ tm->tm_sec = time - tm->tm_min * 60;
	69	+}
	70	+EXPORT_SYMBOL(rtc_time_to_tm);
	71	+
	72	+/*
	73	+ * Does the rtc_time represent a valid date/time?
	74	+ */
	75	+int rtc_valid_tm(struct rtc_time *tm)
	76	+{
	77	+ if (tm->tm_year < 70
	78	+ \|\| tm->tm_mon >= 12
	79	+ \|\| tm->tm_mday < 1
	80	+ \|\| tm->tm_mday > rtc_month_days(tm->tm_mon, tm->tm_year + 1900)
	81	+ \|\| tm->tm_hour >= 24
	82	+ \|\| tm->tm_min >= 60
	83	+ \|\| tm->tm_sec >= 60)
	84	+ return -EINVAL;
	85	+
	86	+ return 0;
	87	+}
	88	+EXPORT_SYMBOL(rtc_valid_tm);
	89	+
	90	+/*
	91	+ * Convert Gregorian date to seconds since 01-01-1970 00:00:00.
	92	+ */
	93	+int rtc_tm_to_time(struct rtc_time tm, unsigned long time)
	94	+{
	95	+ *time = mktime(tm->tm_year + 1900, tm->tm_mon + 1, tm->tm_mday,
	96	+ tm->tm_hour, tm->tm_min, tm->tm_sec);
	97	+ return 0;
	98	+}
	99	+EXPORT_SYMBOL(rtc_tm_to_time);
	100	+
	101	+MODULE_LICENSE("GPL");
...	...	@@ -95,6 +95,11 @@
95	95
96	96	#include <linux/interrupt.h>
97	97
	98	+extern int rtc_month_days(unsigned int month, unsigned int year);
	99	+extern int rtc_valid_tm(struct rtc_time *tm);
	100	+extern int rtc_tm_to_time(struct rtc_time tm, unsigned long time);
	101	+extern void rtc_time_to_tm(unsigned long time, struct rtc_time *tm);
	102	+
98	103	typedef struct rtc_task {
99	104	void (func)(void private_data);
100	105	void *private_data;