include/rtc.h

   1 /*
   2  * (C) Copyright 2001
   3  * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
   4  *
   5  * SPDX-License-Identifier:     GPL-2.0+
   6  */
   7
   8 /*
   9  * Generic RTC interface.
  10  */
  11 #ifndef _RTC_H_
  12 #define _RTC_H_
  13
  14 /* bcd<->bin functions are needed by almost all the RTC drivers, let's include
  15  * it there instead of in evey single driver */
  16
  17 #include <bcd.h>
  18
  19 /*
  20  * The struct used to pass data from the generic interface code to
  21  * the hardware dependend low-level code ande vice versa. Identical
  22  * to struct rtc_time used by the Linux kernel.
  23  *
  24  * Note that there are small but significant differences to the
  25  * common "struct time":
  26  *
  27  *              struct time:            struct rtc_time:
  28  * tm_mon       0 ... 11                1 ... 12
  29  * tm_year      years since 1900        years since 0
  30  */
  31
  32 struct rtc_time {
  33         int tm_sec;
  34         int tm_min;
  35         int tm_hour;
  36         int tm_mday;
  37         int tm_mon;
  38         int tm_year;
  39         int tm_wday;
  40         int tm_yday;
  41         int tm_isdst;
  42 };
  43
  44 int rtc_get (struct rtc_time *);
  45 int rtc_set (struct rtc_time *);
  46 void rtc_reset (void);
  47
  48 /**
  49  * rtc_read8() - Read an 8-bit register
  50  *
  51  * @reg:        Register to read
  52  * @return value read
  53  */
  54 int rtc_read8(int reg);
  55
  56 /**
  57  * rtc_write8() - Write an 8-bit register
  58  *
  59  * @reg:        Register to write
  60  * @value:      Value to write
  61  */
  62 void rtc_write8(int reg, uchar val);
  63
  64 /**
  65  * rtc_read32() - Read a 32-bit value from the RTC
  66  *
  67  * @reg:        Offset to start reading from
  68  * @return value read
  69  */
  70 u32 rtc_read32(int reg);
  71
  72 /**
  73  * rtc_write32() - Write a 32-bit value to the RTC
  74  *
  75  * @reg:        Register to start writing to
  76  * @value:      Value to write
  77  */
  78 void rtc_write32(int reg, u32 value);
  79
  80 /**
  81  * rtc_init() - Set up the real time clock ready for use
  82  */
  83 void rtc_init(void);
  84
  85 /**
  86  * rtc_calc_weekday() - Work out the weekday from a time
  87  *
  88  * This only works for the Gregorian calendar - i.e. after 1752 (in the UK).
  89  * It sets time->tm_wdaay to the correct day of the week.
  90  *
  91  * @time:       Time to inspect. tm_wday is updated
  92  * @return 0 if OK, -EINVAL if the weekday could not be determined
  93  */
  94 int rtc_calc_weekday(struct rtc_time *time);
  95
  96 /**
  97  * rtc_to_tm() - Convert a time_t value into a broken-out time
  98  *
  99  * The following fields are set up by this function:
 100  *      tm_sec, tm_min, tm_hour, tm_mday, tm_mon, tm_year, tm_wday
 101  *
 102  * Note that tm_yday and tm_isdst are set to 0.
 103  *
 104  * @time_t:     Number of seconds since 1970-01-01 00:00:00
 105  * @time:       Place to put the broken-out time
 106  * @return 0 if OK, -EINVAL if the weekday could not be determined
 107  */
 108 int rtc_to_tm(int time_t, struct rtc_time *time);
 109
 110 /**
 111  * rtc_mktime() - Convert a broken-out time into a time_t value
 112  *
 113  * The following fields need to be valid for this function to work:
 114  *      tm_sec, tm_min, tm_hour, tm_mday, tm_mon, tm_year
 115  *
 116  * Note that tm_wday and tm_yday are ignored.
 117  *
 118  * @time:       Broken-out time to convert
 119  * @return corresponding time_t value, seconds since 1970-01-01 00:00:00
 120  */
 121 unsigned long rtc_mktime(const struct rtc_time *time);
 122
 123 #endif  /* _RTC_H_ */