Ghetto-fabulous script that sets up a 2560x1440 mode for a laptop's HDMI output, even if it doesn't allow it, and allows toggling usage.

twentyfivesixty-over-hdmi

#!/bin/bash
#
# twentyfivesixty-over-hdmi -- force an HDMI output to drive 2560x1440
#
# Ghetto-fabulous script that sets up a 2560x1440 mode for an HDMI output
# and allows toggling usage.
#
# I've been using a Dell U2713HM as an external monitor at work with my
# Lenovo Yoga 13, but unfortunately the HDMI port doesn't detect the native
# resolution of the monitor (2560x1440) as a valid output. In fact, all
# external displays I've connected have capped out at 1920x1080 regardless
# of what they actually support. Since the HDMI 1.3+ spec supports 4kx4k,
# I can't think of a reason why this wouldn't work. So, sure enough,
# setting this mode manually and forcing it to run works just fine at half
# the hz.
#
# Usage:
#
#  twentyfivesixty-over-hdmi <setup|enable|disable>
#
# @author emiller
# @date   2013-11-22
#

ACTION=${1:-}
OUTPUT_MAIN="LVDS1"
OUTPUT_HDMI="HDMI1"
MODE_NAME="2560x1440_43.00"
MODE_PRESENT=`xrandr -q | grep $MODE_NAME | grep -v grep`

function usage() {
  echo "usage: `basename $0` <setup|enable|disable>"
  exit 1
}

case $ACTION in
  setup)
    if test -z "$MODE_PRESENT"; then
      echo "creating mode $MODE_NAME for output $OUTPUT_HDMI"
      xrandr --newmode "$MODE_NAME" 162.00 2560 2608 2640 2720 1440 1443 1448 1468 +hsync +vsync
      xrandr --addmode "$OUTPUT_HDMI" "$MODE_NAME"
    else
      echo "mode $MODE_NAME for output $OUTPUT_HDMI already exists"
    fi

    ;;
  enable)
    echo "enabling $OUTPUT_HDMI @ $MODE_NAME (and disabling $OUTPUT_MAIN)"
    xrandr --output "$OUTPUT_HDMI" --primary --mode "$MODE_NAME" --output "$OUTPUT_MAIN" --off
    ;;

  disable)
    echo "enabling $OUTPUT_MAIN @ auto (and disabling $OUTPUT_HDMI)"
    xrandr --output "$OUTPUT_MAIN" --primary --auto --output "$OUTPUT_HDMI" --off
    ;;

  *)
    usage
    ;;
esac