fanmonitor

#!/bin/sh

set -e

if [ $(id -u) -ne 0 ]; then
	exec sudo -- "$0" "$@"
	exit 1
fi

if [ $# -gt 0 -a "$1" = -d ]; then
	shift
	nohup "$0" "$@" > /dev/null 2>&1 &
	exit
fi

stop=0

if [ $# -gt 0 -a \( "$1" = -s -o "$1" = -k \) ]; then
	stop=1
fi

interval=0.5
file='/sys/class/hwmon/hwmon0/pwm1'
file_temp='/sys/class/hwmon/hwmon0/temp1_input'
file0='/sys/class/hwmon/hwmon1/pwm3'
file1='/sys/class/hwmon/hwmon1/pwm4'
file2='/sys/class/hwmon/hwmon1/pwm5'
drm0='/sys/class/drm/card0/device/power_dpm_force_performance_level'
drm1='/sys/class/drm/card0/device/pp_dpm_sclk'

lock=/tmp/.fanmonitor

atexit() {
	flock -u 9 2> /dev/null || :
	exec 9>&-
	if [ -f "$lock" ]; then
		unlink "$lock"
	fi
	if [ -f "$lock.pid" ]; then
		unlink "$lock.pid"
	fi
	printf '2\n' > "${file}_enable"
	printf '5\n' > "${file0}_enable"
	printf '5\n' > "${file1}_enable"
	printf '5\n' > "${file2}_enable"
	printf 'auto\n' > "$drm0"
	exit
}

read pid _ < /proc/self/stat

if [ ! -f "$lock" ]; then
	touch "$lock"
fi
exec 9> "$lock"
if ! flock -nx 9; then
	if [ -f "$lock.pid" ]; then
		read old_pid < "$lock.pid"
		if [ -d "/proc/$old_pid" ]; then
			kill "$old_pid"
			sleep 2
			if [ -d "/proc/$old_pid" ]; then
				kill -9 "$old_pid"
				sleep 2
				if [ -d "/proc/$old_pid" ]; then
					printf 'Error to stop old monitor.\n' >&2
					exit 1
				fi
			fi
		fi
	fi
	if ! flock -nx 9; then
		printf 'Error to obtain lock.\n' >&2
		exit 1
	fi
fi

printf '%s\n' "$pid" > "$lock.pid"

trap atexit EXIT
trap atexit INT TERM

if [ $stop -ne 0 ]; then
	exit
fi

read min < "${file}_min"
read max < "${file}_max"
read speed < "$file"
speed_30=$(((max - min) / 3 + min))
speed_50=$(((max - min) / 2 + min))
speed_60=$(((max - min) * 2 / 3 + min))
speed_75=$(((max - min) * 3 / 4 + min))
speed_90=$(((max - min) * 9 / 10 + min))

downclock=0
clock=7
clock_to() {
	clock=$1
	if [ "$clock" -ge 7 ]; then
		if [ $downclock -ne 0 ]; then
			downclock=0
			printf 'auto\n' > "$drm0"
		fi
	else
		if [ $downclock -eq 0 ]; then
			downclock=1
			printf 'manual\n' > "$drm0"
		fi
		printf '%s\n' "$clock" > "$drm1"
	fi
}

first=1
change_to() {
	speed=$1
	if [ $first -ne 0 ]; then
		first=0
		printf '1\n' > "${file}_enable"
		printf '1\n' > "${file0}_enable"
		printf '1\n' > "${file1}_enable"
		printf '1\n' > "${file2}_enable"
	fi
	printf '%s\n' "$1" > "$file"
	printf '%s\n' "$1" > "$file0"
	printf '%s\n' "$1" > "$file1"
	printf '%s\n' "$1" > "$file2"
}

while :; do
	read temp < "$file_temp"
	if [ $temp -lt 40000 ]; then
		if [ $speed -gt $speed_30 ]; then
			change_to $speed_30
		fi
		if [ $downclock -ne 0 ]; then
			clock_to 7
		fi
	elif [ $temp -lt 42000 ]; then
		if [ $speed -lt $speed_30 ]; then
			change_to $speed_30
		elif [ $speed -gt $speed_50 ]; then
			change_to $speed_50
		fi
		if [ $downclock -ne 0 ]; then
			clock_to 7
		fi
	elif [ $temp -lt 44000 ]; then
		if [ $speed -lt $speed_50 ]; then
			change_to $speed_50
		elif [ $speed -gt $speed_60 ]; then
			change_to $speed_60
		fi
		if [ $downclock -ne 0 -a $clock -lt 5 ]; then
			clock_to 5
		fi
	elif [ $temp -lt 46000 ]; then
		if [ $speed -lt $speed_60 ]; then
			change_to $speed_60
		elif [ $speed -gt $speed_75 ]; then
			change_to $speed_75
		fi
		if [ $downclock -ne 0 ]; then
			if [ $clock -lt 3 ]; then
				clock_to 3
			elif [ $clock -gt 5 ]; then
				clock_to 5
			fi
		fi
	elif [ $temp -lt 47000 ]; then
		if [ $speed -lt $speed_75 ]; then
			change_to $speed_75
		elif [ $speed -gt $speed_90 ]; then
			change_to $speed_90
		fi
		if [ $clock -lt 2 ]; then
			clock_to 2
		elif [ $clock -gt 3 ]; then
			clock_to 3
		fi
	elif [ $temp -lt 48000 ]; then
		if [ $speed -lt $speed_90 ]; then
			change_to $speed_90
		fi
		if [ $clock -gt 2 ]; then
			clock_to 2
		fi
	else
		if [ $speed -ne $max ]; then
			change_to $max
		fi
		if [ $clock -gt 1 ]; then
			clock_to 1
		fi
	fi
	sleep $interval
done