intersil7170(4) - NetBSD Manual Pages

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INTERSIL7170(4)         NetBSD Kernel Interfaces Manual        INTERSIL7170(4)


NAME

     intersil7170 -- Intersil ICM7170 time-of-day clock driver


SYNOPSIS

     #include <dev/ic/intersil7170reg.h>
     #include <dev/ic/intersil7170var.h>
     define intersil7170
     file   dev/ic/intersil7170.c    intersil7170


DESCRIPTION

     The intersil7170 driver provides access to the Intersil ICM7170 time-of-
     day clock chip.  Access methods to retrieve and set date and time are
     provided through the TODR interface defined in todr(9).

     To tie an instance of this device to the system, use the
     intersil7170_attach() function and the intersil7170_softc structure
     defined as follows:

     void intersil7170_attach(struct intersil7170_softc *)

     struct intersil7170_softc {
             struct device   sc_dev;
             bus_space_tag_t sc_bst;
             bus_space_handle_t sc_bsh;
             struct todr_chip_handle sc_handle;
             u_int           sc_year0;
             u_int           sc_flag;
     };

           bus_tag

           bus_handle    Specify bus space access to the chip's non-volatile
                         memory (including the clock registers).

           sc_handle     TODR handle passed to the todr_attach() function to
                         register todr(9) interface.

           sc_year0      The actual year represented by the clock's `year'
                         counter.  This is generally dependent on the system
                         configuration in which the clock device is mounted.
                         For instance, on Sun Microsystems machines the con-
                         vention is to have clock's two-digit year represent
                         the year 1968.

           sc_flag       This flag is used to specify machine-dependent fea-
                         tures.

     Note that if the resulting date retrieved with the todr_gettime() method
     is earlier that January 1, 1970, the driver will assume that the chip's
     year counter actually represents a year in the 21st century.  This behav-
     iour can be overridden by setting the INTERSIL7170_NO_CENT_ADJUST flag in
     sc_flag.


SEE ALSO

     intro(4), todr(9)


HISTORY

     The intersil7170 driver first appeared in NetBSD 1.5.


AUTHORS

     The intersil7170 driver was written by Paul Kranenburg <pk@NetBSD.org>.

NetBSD 6.0                      October 1, 2006                     NetBSD 6.0