SCHSIO(4)                 OpenBSD Programmer's Manual                SCHSIO(4)

NAME
     schsio - SMSC SCH311x LPC Super I/O

SYNOPSIS
     schsio* at isa? port 0x2e   flags 0x0000
     schsio* at isa? port 0x4e   flags 0x0000
     schsio* at isa? port 0x162e flags 0x0000
     schsio* at isa? port 0x164e flags 0x0000

DESCRIPTION
     The schsio driver provides support for the SMSC SCH3112, SCH3114, and
     SCH3116 ICs.  Among other things, the devices contain environment sen-
     sors, a watchdog timer, and fan control.  The schsio driver supports the
     environment sensors and the watchdog timer.

     The hardware provides the following sensors:

           Sensor            Units    Typical use
           Internal diode    uK       IC internal thermal diode
           Remote diode 1    uK       External thermal diode
           Remove diode 2    uK       External thermal diode
           FAN1              RPM      Fan tachometer
           FAN2              RPM      Fan tachometer
           FAN3              RPM      Fan tachometer
           +2.5V             uV       Voltage
           +1.5V (Vccp)      uV       Voltage
           +3.3V (VCC)       uV       Voltage
           +5V               uV       Voltage
           +12V              uV       Voltage
           +3.3V (VTR)       uV       Voltage
           +3V (Vbat)        uV       Voltage

     schsio provides the standard watchdog(4) interface and may be used with
     watchdogd(8).  The watchdog timer may be configured to a value from 1
     second to 255 minutes.  The watchdog timer has a resolution of 1 second
     in the timeout interval 1 to 255 seconds.  Outside this interval, the
     resolution is 1 minute.

     Note that the pin used for signalling the timer expiration is config-
     urable and may on some boards be intended for other uses than this.  Be-
     cause of this, the chip may not by default be configured to use the pin
     for watchdog operation.  To force the schsio device to use the pin for
     watchdog operation, the driver may be configured with an autoconf(9)
     flags setting of 0x0001.

SEE ALSO
     intro(4), isa(4), watchdog(4), sensorsd(8), sysctl(8), watchdogd(8),
     autoconf(9)

HISTORY
     The schsio driver first appeared in OpenBSD 4.5.

AUTHORS
     The schsio driver was written by Michael Knudsen <mk@openbsd.org>.

OpenBSD 4.7                     March 25, 2009                               1
