#!/usr/bin/perl -w
use strict;

sub ctl_state {
    open FAN, "/proc/eee/fan_manual" or die "Cannot get fan state: $!";
    my $state = <FAN>;
    chomp $state;
    close FAN;
    if ($state == 0) {
        return "Automatic";
    } else {
        return "Manual";
    }
}

sub fan_stats {
    my $mode = ctl_state();
    open FAN, "/proc/eee/fan_speed" or die "Cannot get fan speed: $!";
    chomp(my $speed = <FAN>);
    close FAN;
    open FAN, "/proc/eee/fan_rpm" or die "Cannot get fan rpm: $!";
    chomp(my $rpm = <FAN>);
    close FAN;
    open TEMP, "/proc/eee/temperature" or die "Can't get temp: $!";
    chomp(my $temp = <TEMP>);
    close TEMP;
    print "$mode: $speed%, $rpm rpms, $temp C.\n"
}

sub set_fan {
    open FAN, "> /proc/eee/fan_manual" or die "Cannon set fan state: $!";
    print "Setting fan control mode...\n";
    print FAN $_[0];
    close FAN;
    sleep 1;
    if ($_[1]) {
        open SPEED, "> /proc/eee/fan_speed" or die "Can't set fan speed: $!";
        print "Setting fan speed...\n";
        print SPEED $_[1];
        close SPEED;
    }
    # give hardware a chance to catch up.
    sleep 3;
}

sub module_ck {
    if ( -e '/proc/eee' ) {
        return 1;
    } else {
        return 0;
    }
}
#================================================================
my($fan_ctrl, $fan_spd);

if ( ! module_ck() ) {
    if ( system "modprobe eee &>/dev/null" ) {
        print "Unable to load module. No root access, maybe?\n";
        exit 1;
    }
    sleep 1;
}

if ( ! @ARGV ) {
    fan_stats();
    exit 0;
} else {
    foreach ( @ARGV ) {
        if ( m/^-a/ ) {
            $fan_ctrl = 0;
            $fan_spd = 0;
            if (ctl_state() eq "Automatic") {
                print "Already in auto-mode.\n";
                exit 0;
            }
            set_fan( $fan_ctrl, $fan_spd );
            fan_stats();
            exit 0;
        }
        if ( m/^-m/ ) {
            $fan_ctrl = 1;
            m/^-m(\d{1,3})/;
            $fan_spd = $1;
            set_fan( $fan_ctrl, $fan_spd );
            fan_stats();
            exit 0;
        }
        if ( m/^-h/ ) {
            print "Fanspeed utility for eee.ko module.\n";
            print "Usage: fanspeed [-a] [-m##[#]] [-h]\n";
            print " -a      Set fan mode to automatic\n";
            print " -m##[#] Set fan mode to manual, with specified speed:\n";
            print "         -m30  sets fan to 30%\n";
            print "         -m100 sets fan to 100%\n";
            print " -h      This message\n";
            print " no options prints fan status.\n";
            exit 0;
        }
    }
}