#!/bin/bash
# #########################################################
# Script to run on witherspoon BMC to read/set vrm voltages


# #########################################################
d2v () {
# usage:   d2v <decimal volts>

echo $1 | awk '{print $1 * 256 + .5}' | cut -d '.' -f 1
}


# #########################################################
v2d () {
# usage:   v2d <hex val>

printf "	%0.3fV" `echo $1 | awk '{print $1 / 256}'`
}


# #########################################################
i2d () {
# usage:  i2d <hex val> <current divisor>

# parse current mantisa and exponent
# format: SEEE ESMM MMMM MMMM
let e=$1/0x800
let esign=e/0x10
let m=$1\&0x07FF
let msign=m/0x0400

if [ $msign -eq 1 ]
then
  # calc ones compliment
  let m=($m^0x07FF)+1
  m="-$m"
fi
if [ $esign -eq 1 ]
then
  # calc ones compliment
  let e=(e^0x1F)+1
  e="-$e"
fi
printf "	%0.3fA\n" `echo $m $e $2 | awk '{print ($1 * 2^$2)}'`
}


# #########################################################
rw_vc () {
# usage:   rw_vc <bus> <addr> <current divisor> <channel> <value>

# select channel
if [ $4 != "x" ]
then
  i2cset -y $1 $2 0 $4 b
fi

# write new voltage set point
if [ ! -e $5 ]
then
  i2cset -y $1 $2 0x21 `d2v $5` w
fi

# print voltage set point
v2d `i2cget -y $1 $2 0x21 w`

# print voltage
v2d `i2cget -y $1 $2 0x8B w`

# print current
i2d `i2cget -y $1 $2 0x8C w` $3

# default back to channel 0
if [ $4 != "x" ]
then
  i2cset -y $1 $2 0 0 b
fi
}


# #########################################################
# Main

if [ -e $1 ]
then
  $0 vdda vcsa vdna vioa vddra vppa vddb vcsb vdnb viob vddrb vppb
  exit
fi

if [ $1 == "-h" ]
then
  echo "  Usage: vrm [<rail>=[value] [<rail>=[value]] ...]"
  echo "    rail: vdda vcsa vdna vioa vddra vppa vddb vcsb vdnb viob vddrb vppb vdnd viod"
  echo "    value: volts"
  echo
  echo "    e.g., vrm vioa=1.0 viob=1.0"
  echo
  exit
fi

echo "rail	set	read	current"
echo "-------	------- ------- -------"
for param in ${@:1}
do
  rail=`echo $param | cut -d'=' -f 1`
  val=`echo ${param}= | cut -d'=' -f 2`
  echo -n "$rail"
  case "$rail" in
    vdda)
      rw_vc 4 0x70 2 0 $val
      ;;
    vddb)
      rw_vc 5 0x70 2 0 $val
      ;;
    vcsa)
      rw_vc 4 0x70 4 1 $val
      ;;
    vcsb)
      rw_vc 5 0x70 4 1 $val
      ;;
    vdna)
      rw_vc 4 0x71 2 0 $val
      ;;
    vdnb)
      rw_vc 5 0x71 2 0 $val
      ;;
    vioa)
      rw_vc 4 0x40 2 x $val
      ;;
    viob)
      rw_vc 5 0x40 2 x $val
      ;;
    vddra)
      rw_vc 4 0x71 2 1 $val
      ;;
    vddrb)
      rw_vc 5 0x71 2 1 $val
      ;;
    vppa)
      rw_vc 12 0x41 2 x $val
      ;;
    vppb)
      rw_vc 13 0x41 2 x $val
      ;;
    vdnd)
      rw_vc 2 0x70 2 0 $val
      ;;
    viod)
      rw_vc 2 0x70 2 1 $val
      ;;
    *)
      echo "	non-existant"
  esac
done