October 1, 2006 INTERSIL7170 4

### NAME

intersil7170 - Intersil ICM7170 time-of-day clock driver

### SYNOPSIS

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 convention is to have clock's two-digit year represent the year 1968.

```sc_flag`
  This flag is used to specify machine-dependent features.

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 behaviour 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 NetBSD1.5.

### AUTHORS

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