#!/bin/bash

bye() {
  echo "$1"
  cd /
  rm -rf $orig_dir
  exit
}

orig_dir=`pwd`

# Make sure this is a NV
if ! grep -q "model:.*ReadyNAS NV" /proc/sys/dev/boot/info; then
  mesg="Unsuccessful setting minimum fan speed.  Wrong system detected."
  bye "$mesg"
fi

# Make sure this is running the right system rev
if ! grep -q "system_rev:.*0005" /proc/sys/dev/boot/info; then
  mesg="Unsuccessful setting minimum fan speed.  Wrong system rev detected."
  bye "$mesg"
fi


# Check fan speed to make sure it's in range.  This tells us if the fan
# adapter is installed
echo 255 > /proc/sys/dev/hwmon/fan0_speed_control
sleep 5
speed=`cat /proc/sys/dev/hwmon/fan_0`

if [ $speed -gt 2500 ]; then
  mesg="Unsuccessful setting minimum fan speed.  Fan adapter not installed."
  bye "$mesg"
fi


# After install fan adaptor, change VPD to version 4

# Remove USB modules if neccessary
rmmod usb-uhci ehci-hcd
if lsmod | egrep -q "usb-uhci|ehci-hcd"; then
  mesg="Unsuccessful setting minimum fan speed.  Disconnect USB devices and try again."
  bye "$mesg"
fi

# Temp working directory, use system temp if possible
mkdir vpd_change_temp_dir
cd vpd_change_temp_dir

# Min RPM 1900 / 64 = 29 = 0x1d * 64 = 1856 RPM
printf "\x1d" > min_rpm
dd if=min_rpm of=/dev/mtdblock0 bs=1 seek=33153 count=1

# Min PWM 16
printf "\x10" > min_pwm
dd if=min_pwm of=/dev/mtdblock0 bs=1 seek=33154 count=1

# CFT PWM 255
printf "\xff" > cft_pwm
dd if=cft_pwm of=/dev/mtdblock0 bs=1 seek=33155 count=1

# Change System revision number
printf "\x04" > sys_rev
dd if=sys_rev of=/dev/mtdblock0 bs=1 seek=33159

# Force fan recalibration
rm -f /etc/frontview/fan_setting_*


# Clean up
cd ..
rm -rf vpd_change_temp_dir

mesg="Successfully set minimum fan speed.  Please reboot the ReadyNAS now."
bye "$mesg"