initial

README

@@ -0,0 +1,23 @@
+x200-ec-mute
+
+
+ABOUT
+-----
+
+This is a bash script to control mute button behavior on
+ThinkPad GM45 (Montevina) series such as X200, T400 etc.
+
+If your mute button doens't work or works in unexpected ways,
+you might want to try it.
+
+
+DEPENDENCIES
+------------
+
+util/ectool from coreboot
+
+
+LICENSE
+-------
+
+MIT

x200-ec-mute.sh

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+#!/bin/bash
+
+SCRIPTNAME="$0"
+VERBOSE=
+MODE=
+REGISTER=0x03
+DEPS="ectool grep awk"
+
+set -e
+
+die() {
+	>&2 echo "$@"
+	exit 1
+}
+
+usage() {
+	local exitcode="$1"
+	[ -z "$exitcode" ] && exitcode=0
+	echo "Usage: $SCRIPTNAME [-v] on|off|status"
+	exit $exitcode
+}
+
+verbose() {
+	if [ -n "$VERBOSE" ]; then
+		>&2 echo "$@"
+	fi
+}
+
+installed() {
+	command -v "$1" >/dev/null
+}
+
+read_reg() {
+	echo "0x$(ectool -d | grep '^00:' | awk '{ print $5 }')"
+}
+
+write_reg() {
+	local val="$1"
+
+	# convert decimal to hex
+	val="0x$(printf "%x" "$val")"
+
+	verbose "new reg value: $val"
+
+	ectool -w $REGISTER -z $val >/dev/null || die "Error: failed to write to the EC"
+
+	verbose "new value $val has been written to register $REGISTER";
+}
+
+[[ $EUID == 0 ]] || die "This tool must be run as root."
+[[ $# < 1 ]] && usage
+
+for prog in $DEPS; do
+	if ! installed $prog; then
+		die "Error: $prog not found"
+	fi
+done
+
+while [[ $# > 0 ]]; do
+	case $1 in
+		-v)
+			VERBOSE=1
+			;;
+
+		on | off | status)
+			MODE=$1
+			;;
+
+		*)
+			die "Error: $1: unrecognized argument"
+			;;
+	esac
+	shift
+done
+
+[ -z "$MODE" ] && usage 1
+
+# read the register
+reg=$(read_reg)
+verbose "current reg value: $reg"
+
+case $MODE in 
+	status)
+		if (( reg & 0x40 )); then
+			echo "Enabled"
+		else
+			echo "Disabled"
+		fi
+		;;
+
+	on)
+		# set bit 6
+		reg=$(( reg | 0x40 ))
+		write_reg "$reg"
+		;;
+
+	off)
+		# clear bit 6
+		reg=$(( reg & 0xbf ))
+		write_reg "$reg"
+		;;
+esac