soctemp/pmutemp 0.0.5 for A20/AXP209 devices

soctemp() {
    # function to read out the thermal probes of the touch panel controller
    # that is integrated into the A20 SoC. For background information have a
    # look at http://forum.lemaker.org/thread-8137-3-1-3.html

    # SoCTempAdjustment is needed because the A20 SoC delivers somewhat
    # uncalibrated temp values. Even after calibration the values are
    # inaccurate by a few degrees
    SoCTempAdjustment=1447

    # ensure module sunxi-dbgreg.ko is loaded
    grep -q sunxi_dbgreg </proc/modules || ( modprobe sunxi-dbgreg ; sleep 0.1 )

    # prepare registers
    echo 'f1c25000:27003f' > /sys/devices/virtual/misc/sunxi-dbgreg/rw/write;
    echo 'f1c25010:40000' > /sys/devices/virtual/misc/sunxi-dbgreg/rw/write;
    echo 'f1c25018:10fff' > /sys/devices/virtual/misc/sunxi-dbgreg/rw/write;
    echo 'f1c25004:90' > /sys/devices/virtual/misc/sunxi-dbgreg/rw/write;

    # let the value be written to syslog
    echo 'f1c25020' > /sys/devices/virtual/misc/sunxi-dbgreg/rw/read;

    # wait 0.1 seconds
    sleep 0.1

    # read return value from syslog and transform it into degrees Celsius
    HexVal=$(tail /var/log/syslog | awk -F" 0x" '/ 0x/ {print $2}' | tail -n1 )
    CelsiusVal=$(echo $(( 0x${HexVal} - ${SoCTempAdjustment} )) | awk '{printf ("%0.1f",$1/10); }')
    case $1 in
        f|F)
            echo ${CelsiusVal} | awk '{print "approx. "( ( 9/5 ) * $1 ) + 32"°F"}'
            ;;
        *)
            echo "approx. ${CelsiusVal}°C"
            ;;
    esac
} # soctemp

pmutemp() {
    # function to read out the thermal probe inside the AXP209 power
    # management unit via I2C
    CelsiusVal=$(awk '{printf ("%0.1f",$1/1000); }' </sys/devices/platform/sunxi-i2c.0/i2c-0/0-0034/temp1_input)
    case $1 in
        f|F)
            echo ${CelsiusVal} | awk '{print "approx. "( ( 9/5 ) * $1 ) + 32"°F"}'
            ;;
        *)
            echo "approx. ${CelsiusVal}°C"
            ;;
    esac
} # pmutemp