ODROID-C1 display tool

c1_displaytool.sh

#!/bin/bash
# 
# Copyright (c) 2015, Jan Holthuis <jan.holthuis@ruhr-uni-bochum.de>
# All rights reserved.
# 
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 
# 1. Redistributions of source code must retain the above copyright
#    notice, this list of conditions and the following disclaimer.
#
# 2. Redistributions in binary form must reproduce the above copyright
#    notice, this list of conditions and the following disclaimer in
#    the documentation and/or other materials provided with the
#    distribution.
#
# 3. Neither the name of the copyright holder nor the names of its
#    contributors may be used to endorse or promote products derived
#    from this software without specific prior written permission.
# 
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
# HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
# BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
# OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
# AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY
# WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
# POSSIBILITY OF SUCH DAMAGE.

function mode2info() {
    local result=""
    case "$1" in
        vga)            result="640x480" ;;
        480p)           result="720x480" ;;
        576p)           result="720x576" ;;
        800x480p60hz)   result="800x480" ;;
        800x600p60hz)   result="800x600" ;;
        1024x600p60hz)  result="1024x600" ;;
        1024x768p60hz)  result="1024x768" ;;
        1360x768p60hz)  result="1360x768" ;;
        1366x768p60hz)  result="1366x768" ;;
        1440x900p60hz)  result="1440x900" ;;
        1600x900p60hz)  result="1600x900" ;;
        1680x1050p60hz) result="1680x1050" ;;
        720p)           result="1280x720" ;;
        800p)           result="1280x800" ;;
        sxga)           result="1280x1024" ;;
        1080i50hz)      result="1080i@50Hz" ;;
        1080p24hz)      result="1080p@24Hz" ;;
        1080p50hz)      result="1080p@50Hz" ;;
        1080p)          result="1080p@60Hz" ;;
        1920x1200)      result="1920x1200" ;;
    esac
    if [ -z "$result" ]; then
        return 1
    else
        echo "$result"
        return 0
    fi
}

function mode2axis() {
    local result=""
    case "$1" in
        vga)            result="0 0 639 749" ;;
        480p)           result="0 0 719 479" ;;
        576p)           result="0 0 719 575" ;;
        800x480p60hz)   result="0 0 799 479" ;;
        800x600p60hz)   result="0 0 799 599" ;;
        1024x600p60hz)  result="0 0 1023 599" ;;
        1024x768p60hz)  result="0 0 1023 767" ;;
        1360x768p60hz)  result="0 0 1359 767" ;;
        1366x768p60hz)  result="0 0 1365 767" ;;
        1440x900p60hz)  result="0 0 1439 899" ;;
        1600x900p60hz)  result="0 0 1599 899" ;;
        1680x1050p60hz) result="0 0 1679 1049" ;;
        720p)           result="0 0 1279 719" ;;
        800p)           result="0 0 1279 799" ;;
        sxga)           result="0 0 1279 1023" ;;
        1080*)          result="0 0 1919 1079" ;;
        1920x1200)      result="0 0 1919 1199" ;;
        
    esac
    if [ -z "$result" ]; then
        return 1
    else
        echo "$result"
        return 0
    fi
}

function mode2geometry() {
    local result=""
    case "$1" in
        vga*)           result="640 480 640 960";;
        480*)           result="720 480 720 960";;
        576*)           result="720 576 720 1152";;
        800x480p60hz)   result="800 480 800 960";;
        800x600p60hz)   result="800 600 800 1200";;
        1024x600p60hz)  result="1024 600 1024 1200";;
        1024x768p60hz)  result="1024 768 1024 1536";;
        1360x768p60hz)  result="1360 768 1360 1536";;
        1366x768p60hz)  result="1366 768 1366 1536";;
        1440x900p60hz)  result="1440 900 1440 1800";;
        1600x900p60hz)  result="1600 900 1600 1800";;
        1680x1050p60hz) result="1680 1050 1680 2100";;
        720p)           result="1280 720 1280 1440";;
        800p)           result="1280 800 1280 1600";;
        sxga)           result="1280 1024 1280 2048";;
        1080*)          result="1920 1080 1920 2160";;
        1920x1200)      result="1920 1200 1920 2400";;
    esac
    if [ -z "$result" ]; then
        return 1
    else
        echo "$result"
        return 0
    fi
}

SCRIPTNAME="c1_displaytool"
SCRIPTVERSION="0.1"
USAGE="Usage: $(basename "$0") [-h] [-v] [-m mode] [-b bpp]"

# Parse command line options.
while getopts hvm:b: OPT; do
    case "$OPT" in
        h)
            echo $USAGE
            exit 0
            ;;
        v)
            echo "${SCRIPTNAME} v${SCRIPTVERSION}"
            echo "(c) 2015, Jan Holthuis <jan.holthuis@ruhr-uni-bochum.de>"
            echo
            echo "This program is free software: you can redistribute it and/or modify"
            echo "it under the terms of the BSD 3-Clause License."
            exit 0
            ;;
        m)
            mode=$OPTARG
            ;;
        b)
            bpp=$OPTARG
            ;;
        \?)
            # getopts issues an error message
            echo $USAGE >&2
            exit 1
            ;;
    esac
done

# Get current mode
cur_mode=$(cat "/sys/class/display/mode")
if [ "$?" -ne "0" ]; then
    echo "ERROR: unable to get current mode" >&2
    exit 1
fi

# Get current bpp
cur_bpp=$(cat "/sys/class/graphics/fb0/bits_per_pixel")
if [ "$?" -ne "0" ]; then
    echo "ERROR: unable to get current bpp" >&2
    exit 2
fi

# Check if any changes have been requested
if ( [ -z "$mode" ] || [ "$cur_mode" == "$mode" ] ) && ( [ -z "$bpp" ] || [ "$cur_bpp" == "$bpp" ] ); then
    # No change requested, printing current values
    cur_info=$(mode2info "$cur_mode")
    echo "Current setting: $cur_mode ($cur_info) at $cur_bpp bpp"
    exit 0
fi

# Check if mode setting is valid
info=$(mode2info "$mode")
if [ -n "$mode" ] && [ -z "$info" ]; then
    echo "ERROR: invalid mode '$mode'" >&2
    exit 3
fi

# Check if bpp setting is valid
if [ -n "$bpp" ] && ( [ "$bpp" != "16" ] && [ "$bpp" != "24" ] && [ "$bpp" != "32" ] ); then
    echo "ERROR: invalid bpp '$bpp' (must be 16, 24 or 32)" >&2
    exit 4
fi

# If mode/bpp is not set, keep current setting
if [ -n "$mode" ] && [ "$cur_mode" != "$mode" ]; then
    echo "Changing mode from '$cur_mode' to '$mode' ($info)"
else
    mode="$cur_mode"
fi

if [ -n "$bpp" ] && [ "$cur_bpp" != "$bpp" ]; then
    echo "Changing bpp from '$cur_bpp' to '$bpp'"
else
    bpp="$cur_bpp"
fi

# Get the needed axis/geometry values
axis=$(mode2axis "$mode")
geometry=$(mode2geometry "$mode")
if [ -z "$axis" ] || [ -z "$geometry" ]; then
    # This shouldn't happen
    echo "ERROR: Failed to get respective axis/geometry values" >&2
    exit 5
fi

# Settings look ok, let's check if we actually have the necessary write permissions
files=('/dev/fb0' '/sys/class/display/mode' '/sys/class/graphics/fb0/free_scale_axis' '/sys/class/graphics/fb0/window_axis')
for file in "${files[@]}"
do
    if ! [ -w "$file" ]; then
        echo "ERROR: You don't have permission to write to '$file'!" >&2
	exit 6
    fi
done

# OK, we can do it!
echo "Executing 'fbset -fb /dev/fb0 -g $geometry $bpp'..."
fbset -fb /dev/fb0 -g $geometry $bpp
if [ "$?" -ne "0" ]; then
    echo "ERROR: fbdev command returned with non-zero exit status $?, aborting..." >&2
    exit 7
fi

echo "Setting display mode to $mode..."
echo "$mode" > /sys/class/display/mode

echo "Setting free_scale_axis to '$axis'..."
echo "$axis" > /sys/class/graphics/fb0/free_scale_axis

echo "Setting window_axis to '$axis'..."
echo "$axis" > /sys/class/graphics/fb0/window_axis

echo "Done."
exit 0