xref: /netbsd/share/man/man9/todr.9 (revision bf9ec67e)
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37.Dd July 22, 2000
38.Dt TODR 9
39.Os
40.Sh NAME
41.Nm todr_gettime
42.Nm todr_settime
43.Nm todr_getcal
44.Nm todr_setcal
45.Nm clock_ymdhms_to_secs
46.Nm clock_secs_to_ymdhms
47.Nd time-of-day clock support
48.Sh SYNOPSIS
49.Fd #include \*[Lt]dev/clock_subr.h\*[Gt]
50.Ft int
51.Fn todr_gettime "todr_chip_handle_t" "struct timeval *"
52.Ft int
53.Fn todr_settime "todr_chip_handle_t" "struct timeval *"
54.Ft int
55.Fn todr_getcal "todr_chip_handle_t" "int *"
56.Ft int
57.Fn todr_setcal "todr_chip_handle_t" "int"
58.Ft void
59.Fn clock_secs_to_ymdhms "int" "struct clock_ymdhms *"
60.Ft time_t
61.Fn clock_ymdhms_to_secs "struct clock_ymdhms *"
62.Sh DESCRIPTION
63The
64.Fn todr_*
65functions provide an interface to read, set and control
66.Ql time-of-day
67devices. The
68.Fa todr_chip_handle_t
69should be obtained from a driver for a particular hardware device that
70implements this interface. Examples of such drivers currently include
71.Xr mk48txx 4
72and
73.Xr intersil7170 4 .
74.Pp
75The
76.Fn todr_gettime
77retrieves the current data and time from the TODR device and returns it
78in the
79.Fa struct timeval
80storage provided by the caller.
81.Fn todr_settime
82sets the date and time in the TODR device represented by
83.Fa todr_chip_handle_t
84according to the
85.Fa struct timeval
86argument.
87.Pp
88.Fn todr_setcal
89specifies a calibration value in PPM units to be programmed in the TODR
90device. Positive values shall speed up the TODR clock, negative values
91shall slow it down. If the device in not capable of handling calibration,
92this function shall return
93.Va EOPNOTSUPP .
94The measurement and calculations necessary to utilize this method is
95expected to be provided by higher-level software modules.
96.Fn todr_getcal
97returns the current calibration (in PPM units) in effect on the TODR device.
98.Pp
99The utilities
100.Fn clock_secs_to_ymdhms
101and
102.Fn clock_ymdhms_to_secs
103are provided to convert a time value in seconds to and from a structure
104representing the date and time as a
105.Aq year,month,day,weekday,hour,minute,seconds
106tuple. This structure is defined as follows:
107.Bd -literal
108struct clock_ymdhms {
109	u_short dt_year;	/* Year */
110	u_char dt_mon;		/* Month (1-12) */
111	u_char dt_day;		/* Day (0-365) */
112	u_char dt_wday;		/* Day of week (0-6) */
113	u_char dt_hour;		/* Hour (0-23) */
114	u_char dt_min;		/* Minute (0-59) */
115	u_char dt_sec;		/* Second (0-59) */
116};
117.Ed
118.Pp
119Note: leap years are recognised by these conversion routines.
120.Sh RETURN VALUES
121The
122.Fn todr_*
123functions return 0 if the requested operation was successful;
124otherwise an error code from
125.Aq Pa sys/errno.h
126shall be returned. However, behaviour is undefined if an invalid
127.Fa todr_chip_handle_t
128is passed to any of these functions.
129The
130.Fn clock_secs_to_ymdhms
131and
132.Fn clock_ymdhms_to_secs
133functions never fail.
134.Sh SEE ALSO
135.Xr inittodr 9 ,
136.Xr resettodr 9 ,
137.Xr time 9
138