#!/bin/bash
#
# find-driver - find the driver exporting a chip as reported by 'sensors'
# Copyright (C) 2018  Ondřej Lysoněk
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.

shopt -s nullglob

function usage() {
	echo "Usage: $0 <chip name>" >&2
	echo >&2
	echo 'Chip name is a string in the format <chip>-<bus>-<address>' >&2 
	echo 'as reported by the "sensors" program. For example the chip' >&2
	echo 'name can be "coretemp-isa-0000" or "acpitz-virtual-0".' >&2
}

function get_chip() {
	echo "$1" | sed -r -e 's/^(.+)-[^-]+-[^-]+$/\1/'
}

if [ "$#" -lt 1 ]; then
	usage
	exit 1
fi
ARG=$1; shift
if [ "$ARG" = "-h" ] || [ "$ARG" = "--help" ]; then
	usage
	test "$#" -eq 0
	exit
elif [ "$ARG" = "-d" ] || [ "$ARG" = "--debug" ]; then
	test "$#" -eq 1 || { usage; exit 1; }
	set -x
	CHIP=$(get_chip "$1")
else
	test "$#" -eq 0 || { usage; exit 1; }
	CHIP=$(get_chip "$ARG")
fi

DEVICE=
for i in /sys/class/hwmon/hwmon*; do
	NAME=
	if [ -f "$i/name" ]; then
		NAME=$(cat "$i/name")
	elif [ -L "$i/device" ]; then
		TARGET=$(readlink -f "$i/device")
		if [ -f "$TARGET/name" ]; then
			NAME=$(cat "$TARGET/name")
		fi
	fi
	if [ "$NAME" = "$CHIP" ]; then
		DEVICE="$i"
		break
	fi
done
test -n "$DEVICE" || { echo 'Chip not found.' >&2; exit 1; }

DRIVER=unknown
MODULE=unknown
while true; do
	if [ -L "$DEVICE/driver" ]; then
		DRIVER_DIR=$(readlink -f "$DEVICE/driver")
		DRIVER=$(basename "$DRIVER_DIR")
		if [ -L "$DRIVER_DIR/module" ]; then
			MODULE=$(basename $(readlink "$DRIVER_DIR/module"))
		fi
		break
	elif [ -L "$DEVICE/device" ]; then
		DEVICE=$(readlink -f "$DEVICE/device")
	else
		break
	fi
done

echo "Driver: $DRIVER"
echo "Module: $MODULE"