sonic-buildimage/platform/broadcom/sonic-platform-modules-dell/s6000/scripts/set-fan-speed

#!/bin/bash

# Usage:
#   Set all fans speed to $1

usage() {
  echo "This script must be run with super-user privilege."
  echo "Warning! Wrongly set fan speed may result in physical damage to the device."
  echo ""
  echo "usage:   set-fan-speed speed_in_rpm"
  echo "example: set-fan-speed 15000"
}

if [ $# -ne 1 ]; then
  usage
  exit 1
fi

PSU_FAN1=/sys/class/i2c-adapter/i2c-1/1-0058/fan1_target
PSU_FAN2=/sys/class/i2c-adapter/i2c-1/1-0059/fan1_target

# Three fan trays with each contains two separate fans
# fan1-fan4 fan2-fan5 fan3-fan6
FAN1=/sys/class/i2c-adapter/i2c-11/11-0029/hwmon/hwmon*/fan1_target
FAN2=/sys/class/i2c-adapter/i2c-11/11-0029/hwmon/hwmon*/fan2_target
FAN3=/sys/class/i2c-adapter/i2c-11/11-0029/hwmon/hwmon*/fan3_target
FAN4=/sys/class/i2c-adapter/i2c-11/11-0029/hwmon/hwmon*/fan4_target
FAN5=/sys/class/i2c-adapter/i2c-11/11-002a/hwmon/hwmon*/fan1_target
FAN6=/sys/class/i2c-adapter/i2c-11/11-002a/hwmon/hwmon*/fan2_target

speed=$1
logger -t platform-modules "Trying to set fan speed to $speed"

# Retry three times
for i in `seq 1 3`
do
  if [ -w $FAN1 -o -w $FAN2 -o -w $FAN3 ]; then
    # set default psu fan speed
    echo $speed > $PSU_FAN1
    echo $speed > $PSU_FAN2
    # set default fan speed
    echo $speed > $FAN1
    echo $speed > $FAN2
    echo $speed > $FAN3
    echo $speed > $FAN4
    echo $speed > $FAN5
    echo $speed > $FAN6

    logger -t platform-modules "Fan speed is set to $speed"

    exit 0
  fi
  # Sleep for 3 seconds to wait for device tree to be ready
  sleep 3
done

logger -p user.error -t platform-modules "Failed to set fan speed!"
exit 1