TODR(9) 						   BSD 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 *);

     void
     clock_secs_to_ymdhms(int, 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 represented by todr_chip_handle_t according to the struct timeval argument.

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

     struct clock_ymdhms {
	     u_short 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 successful; otherwise an error code from <sys/errno.h> shall be returned.
     However, 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 never fails.

SEE ALSO

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

BSD
								 September 6, 2006							       BSD