verify_ad9361_spi

#!/bin/sh

#finds the AD9361 device
for i in $(find -L /sys/bus/iio/devices -maxdepth 2 -name name)
do
  dev_name=$(cat $i)
  if [ "$dev_name" = "ad9361-phy" ] ; then
    ad9361=$(echo $i | sed 's:/name$::')
    break
  fi
done

if [ "x$ad9361" = "x" ] ; then
  echo can not find ad9361 in /sys
  exit
fi

# does a walking ones/zeros on the SPI bus.
# register 0x28 is 'GPO0 Rx delay'
cd $ad9361
expect=0x1
up=1
reg=0x28
echo $reg $expect > ./direct_reg_access
echo $reg > ./direct_reg_access
i=0
k=0
echo "preforming walking one/zero tests on SPI register $reg"
trap 'printf "\nread %d times\n" $k; exit 0' 2
echo -n 1
while [ 1 ]
do
#   sleep .5
   i=`expr $i + 1`
   k=`expr $k + 1`
   foo=$(cat ./direct_reg_access)
   #echo $i $expect $foo
   if [ "$foo" != "$expect" ] ; then
      echo -n "$foo is not equal to '$expect' "
      date
   fi
   if [ $i -gt 999 ] ; then
      #echo 1000 reads of $expect worked
      j=`printf "%d" $expect`
      if [ $up -eq 1 ] ; then
        if [ $j -eq 0 ] ; then
           up=0;
           echo -n 0
        fi
        if [ $j -eq 255 ] ; then
          j=1
        else
          j=`expr '(' $j '*' 2 ')' % 256`
        fi
        expect=`printf "0x%X" $j`
      else
        if [ $j -eq 255 ] ; then
          up=1
          echo -n 1
        fi
	if [ $j -eq 0 ] ; then
          j=127
        else
          j=`expr '(' $j '/' 2 ')' + 128`
        fi
        expect=`printf "0x%X" $j`
      fi
      echo $reg $expect > ./direct_reg_access
      i=0
   fi
done