cpupowerutils: use kernel version-derived version string

As cpupowerutils is intended to be included into the kernel sources,
use the kernel versioning instead of a custom version.

The script utils/version-gen.sh is largely based on the script already
found in tools/perf/util/PERF-VERSION-GEN .

Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
diff --git a/tools/power/cpupower/utils/version-gen.sh b/tools/power/cpupower/utils/version-gen.sh
new file mode 100755
index 0000000..5ec41c5
--- /dev/null
+++ b/tools/power/cpupower/utils/version-gen.sh
@@ -0,0 +1,35 @@
+#!/bin/sh
+#
+# Script which prints out the version to use for building cpupowerutils.
+# Must be called from tools/power/cpupower/
+# 
+# Heavily based on tools/perf/util/PERF-VERSION-GEN .
+
+LF='
+'
+
+# First check if there is a .git to get the version from git describe
+# otherwise try to get the version from the kernel makefile
+if test -d ../../../.git -o -f ../../../.git &&
+	VN=$(git describe --abbrev=4 HEAD 2>/dev/null) &&
+	case "$VN" in
+	*$LF*) (exit 1) ;;
+	v[0-9]*)
+		git update-index -q --refresh
+		test -z "$(git diff-index --name-only HEAD --)" ||
+		VN="$VN-dirty" ;;
+	esac
+then
+	VN=$(echo "$VN" | sed -e 's/-/./g');
+else
+	eval $(grep '^VERSION[[:space:]]*=' ../../../Makefile|tr -d ' ')
+	eval $(grep '^PATCHLEVEL[[:space:]]*=' ../../../Makefile|tr -d ' ')
+	eval $(grep '^SUBLEVEL[[:space:]]*=' ../../../Makefile|tr -d ' ')
+	eval $(grep '^EXTRAVERSION[[:space:]]*=' ../../../Makefile|tr -d ' ')
+
+	VN="${VERSION}.${PATCHLEVEL}.${SUBLEVEL}${EXTRAVERSION}"
+fi
+
+VN=$(expr "$VN" : v*'\(.*\)')
+
+echo $VN