todr(9) - NetBSD Manual Pages

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TODR(9)                NetBSD Kernel Developer's Manual                TODR(9)


NAME

     todr_attach, todr_gettime, todr_settime, clock_ymdhms_to_secs,
     clock_secs_to_ymdhms -- time-of-day clock support


SYNOPSIS

     #include <dev/clock_subr.h>

     void
     todr_attach(todr_chip_handle_t);

     int
     todr_gettime(todr_chip_handle_t, struct timeval *);

     int
     todr_settime(todr_chip_handle_t, struct timeval *);

     int
     clock_secs_to_ymdhms(time_t, struct clock_ymdhms *);

     time_t
     clock_ymdhms_to_secs(struct clock_ymdhms *);


DESCRIPTION

     The todr_*() functions provide an interface to read, set and control
     `time-of-day' devices.  A driver for a `time-of-day' device registers its
     todr_chip_handle_t with machine-dependent code using the todr_attach()
     function.  Alternatively, a machine-dependent front-end to a
     `time-of-day' device driver may obtain the todr_chip_handle_t directly.

     The todr_gettime() retrieves the current data and time from the TODR
     device and returns it in the struct timeval storage provided by the
     caller.  todr_settime() sets the date and time in the TODR device repre-
     sented by todr_chip_handle_t according to the struct timeval argument.

     The utilities clock_secs_to_ymdhms() and clock_ymdhms_to_secs() are pro-
     vided to convert a time value in seconds to and from a structure repre-
     senting the date and time as a
     <year,month,day,weekday,hour,minute,seconds> tuple.  This structure is
     defined as follows:

     struct clock_ymdhms {
             uint64_t dt_year;       /* Year */
             u_char dt_mon;          /* Month (1-12) */
             u_char dt_day;          /* Day (1-31) */
             u_char dt_wday;         /* Day of week (0-6) */
             u_char dt_hour;         /* Hour (0-23) */
             u_char dt_min;          /* Minute (0-59) */
             u_char dt_sec;          /* Second (0-59) */
     };

     Note: leap years are recognised by these conversion routines.


RETURN VALUES

     The todr_*() functions return 0 if the requested operation was success-
     ful; otherwise an error code from <sys/errno.h> shall be returned.  How-
     ever, behaviour is undefined if an invalid todr_chip_handle_t is passed
     to any of these functions.

     The clock_ymdhms_to_secs() function returns -1 if the time in seconds
     would be less that zero or too large to fit in a time_t.  The
     clock_secs_to_ymdhms() function returns 0 on success or EINVAL if the
     time passed is negative.


SEE ALSO

     intersil7170(4), mk48txx(4), inittodr(9), resettodr(9), time_second(9)

NetBSD 10.1                   September 10, 2014                   NetBSD 10.1