#!/bin/bash
# This script must be run after mts-io
# to read the hw-version,
# but before anything else needs the
# device tree.
sysdir=/sys/devices/platform/mts-io

I2CDIR="/sys/bus/i2c/devices"
eepromPath="${I2CDIR}/0-0056/eeprom"

DEVTREE="/sys/kernel/config/device-tree/overlays/"
SYSFS="/usr/sbin/mts-io-sysfs"
AP1_EEPROM=${I2CDIR}"/i2c-2/2-0050/eeprom"
AP2_EEPROM=${I2CDIR}"/i2c-2/2-0052/eeprom"

install_all_dtbo() {
    for f in *.dtbo ; do
        if ! [[ -f $f ]] ; then
            continue
        fi
        # f2 is the extracted device name
        base=$(basename $f .dtbo)
        /bin/mkdir ${DEVTREE}/$base || true
        /bin/cat $f >${DEVTREE}/$base/dtbo
    done
}

install_dtbo_dir() {
    if ! [[ -d ${DEVTREE} ]] ; then
        mount configfs
    fi
    install_all_dtbo
    gpiob1=0
    gpiob2=0
    if [[ -f $AP1_EEPROM ]] ; then
	eeprom1=$(mts-id-eeprom --accessory-card --in-file "$AP1_EEPROM" 2>/dev/null)
	if [[ $eeprom1 =~ [[:space:]]hw-version:[[:space:]]*\"MTAC-GPIOB- ]] ; then
	   gpiob1=1
	fi
    fi
    if [[ -f $AP2_EEPROM ]] ; then
	eeprom2=$(mts-id-eeprom --accessory-card --in-file "$AP2_EEPROM" 2>/dev/null)
	if [[ $eeprom2 =~ [[:space:]]hw-version:[[:space:]]*\"MTAC-GPIOB- ]] ; then
	   gpiob2=1
	fi
    fi

    if ((gpiob1 == 1)) || ((gpiob2 == 1)) ; then
        /usr/bin/logger -t "mts-io" -p daemon.info -s 'Loading MTAC-GPIOB Device Tree'
        cd gpiob
    else
        /usr/bin/logger -t "mts-io" -p daemon.info -s 'Loading standard SPI Device Tree'
        cd lora
    fi
    install_all_dtbo
}

# Device tree format:
# [mach]
#     [rev]
#          [file1] [file2] [file3] capability
#              [flag]
#                  [file1] [file2] [file3]
setdevtree() {
    eeprom=$(mts-id-eeprom --in-file "$eepromPath" 2>/dev/null)
    [[ $eeprom =~ [[:space:]]hw-version:[[:space:]]*\"([^\"]+) ]]
    hw=${BASH_REMATCH[1]}
    mach=${hw/%-*}
    rev=${hw/#*-/}
    echo mach is $mach
    echo rev is $rev

    regx='capa-(.*):[[:space:]]*true'
    capflags=$(echo "$eeprom" | egrep "$regx" | sed -e 's/capa-//g' -e 's/: true//')
    capflags=" ${capflags} "

    # add device tree overlays, if they exist.
    [[ -d /lib/dtoverlays ]] || return 1
    (
    cd /lib/dtoverlays
    
    cd ${mach}
    
    best="-1"
    for d in * ; do
        if awk "BEGIN{if ($d <= $rev)exit 1}" ; then
            continue
        fi
        if awk "BEGIN{if ($d < $best)exit 1}" ; then
            best="$d"
        fi
    done
    if [[ $best == -1 ]] ; then
        # No overlay found
    exit 0
    fi
    cd $best
    install_dtbo_dir
    if [[ -d capability ]] ; then
        cd capability
        for d in * ; do
            echo "We have found overlay capability directory $d"
            if [[ ${capflags} =~ [[:space:]]${d}[[:space:]] ]] ; then
                echo "This device has capabilithy $d so install the overlay"
                (
                    cd $d
                    install_dtbo_dir
                )
            fi # Does a given capability flag exist in the EEPROM
        done # Loop over all capabilities for this machine and version overlays
    fi # Is there a capability directory to be installed?
    )
}

case $1 in
  start)
    /usr/bin/logger -t "mts-io" -p daemon.info -s "Loading device tree overlay"
    setdevtree
    ;;

  stop)
    echo "Not implemented"
    ;;

  *)
    echo "Usage: $0 {start|stop}"
    exit 2
    ;;
esac