pow(4) - NetBSD Manual Pages

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POW(4)               NetBSD/x68k Kernel Interfaces Manual               POW(4)


NAME

     pow -- X68k power switch device


DESCRIPTION

     Files /dev/pow and /dev/pow1 are devices used to access the x68k power
     switch / bootstrap information and the RTC alarm timer. The following
     operations are allowed using ioctl(2) system call:

           POWIOGPOWERINFO   Getting power switch status
           POWIOGALARMINFO   Getting RTC alarm timer status
           POWIOSALARMINFO   Setting RTC alarm timer
           POWIOSSIGNAL      Setting signal number which is sent at changing
                             the power status


GETTING POWER SWITCH STATUS

     <sys/ioctl.h>
     <machine/powioctl.h>

     ioctl (fd, POWIOCGPOWERINFO, &powerinfo);
     struct x68k_powerinfo powerinfo;

     Returns the power switch status etc. in the following structure.

           struct x68k_powerinfo {
                   int pow_switch_boottime;
                   int pow_switch_current;
                   time_t pow_boottime;
                   unsigned int pow_bootcount;
                   time_t pow_usedtotal;
           };

     Each member means:

     pow_switch_boottime: The power switch status at the system start time.
             The status is known by applying logical and (&) with:

             POW_ALARMSW     True if the system started by the RTC alarm timer
             POW_EXTERNALSW  True if the EXPWON signal of the I/O slot is on
             POW_FRONTSW     True if the front power switch is on

             EXPWON-related information is not tested.

     pow_switch_current: Current power switch status. See above.

     pow_boottime: The time when NetBSD started.

     pow_bootcount, pow_usedtotal: Host's boot information from the system
             memory switch.  Total usage in count (pow_bootcount) and second
             (pow_usedtotal).


ACCESSING RTC ALARM TIMER

     <sys/ioctl.h>
     <machine/powioctl.h>

     ioctl (fd, POWIOCGALARMINFO, &alarminfo);
     struct x68k_alarminfo alarminfo;

     Returns x68k's alarm timer information in the following structure.

           struct x68k_alarminfo {
                   int al_enable;
                   unsigned int al_ontime;
                   int al_dowhat;
                   time_t al_offtime;
           };

     Each of the members means:

     al_enable: True if the alarm timer is enable.

     al_ontime: Internal expression of the alarm timer. See `C Compiler
             PRO-68K Programmers' Manual' Chapter 3 Section ALARMSET.

     al_dowhat: What to do when started by the alarm timer.  See `Programmers'
             manual'.

     al_offtime: Display the time in seconds since the alarm is activated
             until the power is turned off (though the resolution is resolved
             to minutes). Be cautious when using IOCS and the like as these
             require minute time units. 0 indicates an infinity.

     ioctl (fd, POWIOCSALARMINFO, &alarminfo);
     struct x68k_alarminfo alarminfo;

     Sets the alarm timer according to the argument alarminfo (see above).


SIGNAL

     <sys/ioctl.h>
     <machine/powioctl.h>

     ioctl (fd, POWIOCSSIGNAL, &signum);
     int signum;

     Signal signum is sent when the state of the power switch (front or exter-
     nal) changes. It becomes invalid when close(2) is called.  Note that this
     function is not provided with /dev/pow1.


SEE ALSO

     ioctl(2), poffd(8), rtcalarm(8)

     `C Compiler PRO-68K Programmers' Manual', Chapter 3 IOCS Calls, Section
     ALARMSET, Sharp


AUTHORS

     Minoura Makoto <minoura@flab.fujitsu.co.jp>.


SPECIAL THANKS

     Liam Hahne Minn <hahne@sail.t.u-tokyo.ac.jp>.


BUGS

     The file /dev/pow can only be opened by one process at a time.

NetBSD 4.0                       July 2, 1995                       NetBSD 4.0