#!/bin/sh
#
# reset_lgw.sh (libgpiod version)
# Replaces legacy /sys/class/gpio export/direction/value usage.
#
# Usage:
#   ./reset_lgw.sh start
#   ./reset_lgw.sh stop
#
# Environment override:
#   GPIOCHIP=gpiochip0 ./reset_lgw.sh start
#

set -eu

# --- GPIO mapping (BCM numbers) ---
SX1302_RESET_PIN=23     # SX1302 reset
SX1302_POWER_EN_PIN=18  # SX1302 power enable
SX1261_RESET_PIN=22     # SX1261 reset (LBT / Spectral Scan)
AD5338R_RESET_PIN=13    # AD5338R reset (reference design; may be unused on your HAT)

CHIP="${GPIOCHIP:-gpiochip0}"

# Small sleeps to let rails settle
WAIT() { sleep 0.10; }

# gpioset helper:
# libgpiod v1.x: gpioset defaults to holding the line until the process exits.
# Using "-m time -s <sec>" makes it deterministic for pulses.
#SET_FOR() {
#  # $1=line $2=value $3=seconds
#  /usr/sbin/gpioset -m time -s "$3" "$CHIP" "$1=$2" >/dev/null 2>&1 || {
#    echo "ERROR: gpioset failed on $CHIP line $1=$2 (check chip name/permissions)" >&2
#    exit 1
#  }
#}
#
#SET_HOLD() {
#  # Hold briefly but long enough for power enable
#  # Using time mode too, so we don't leave lines requested forever.
#  /usr/sbin/gpioset -m time -s 1.0 "$CHIP" "$1=$2" >/dev/null 2>&1 || {
#    echo "ERROR: gpioset failed on $CHIP line $1=$2" >&2
#    exit 1
#  }
#}

SET_FOR_USEC() {
  # $1=line $2=value $3=usec
  /usr/sbin/gpioset --mode=time --usec "$3" "$CHIP" "$1=$2" >/dev/null 2>&1 || {
    echo "ERROR: gpioset failed on $CHIP line $1=$2" >&2
    exit 1
  }
}

SET_FOR_SEC() {
  # $1=line $2=value $3=sec (integer)
  /usr/sbin/gpioset --mode=time --sec "$3" "$CHIP" "$1=$2" >/dev/null 2>&1 || {
    echo "ERROR: gpioset failed on $CHIP line $1=$2" >&2
    exit 1
  }
}
reset() {
  echo "CoreCell power enable through ${CHIP} line ${SX1302_POWER_EN_PIN}..."
  echo "CoreCell reset through ${CHIP} line ${SX1302_RESET_PIN}..."
  echo "SX1261 reset through ${CHIP} line ${SX1261_RESET_PIN}..."
  echo "ADC reset through ${CHIP} line ${AD5338R_RESET_PIN}..."

#  # Power enable ON (hold long enough to cover the reset sequence)
#  SET_HOLD "$SX1302_POWER_EN_PIN" 1
#  WAIT
#
#  # SX1302 reset pulse (many designs are active-low; this matches Semtech script)
#  SET_FOR "$SX1302_RESET_PIN" 1 0.10
#  SET_FOR "$SX1302_RESET_PIN" 0 0.10
#  WAIT
#
#  # SX1261 reset pulse
#  SET_FOR "$SX1261_RESET_PIN" 0 0.10
#  SET_FOR "$SX1261_RESET_PIN" 1 0.10
#  WAIT
#
#  # Optional ADC reset pulse (harmless if line is unused, but may error if not present)
#  # If this line causes failure on your HAT, set AD5338R_RESET_PIN to an unused line
#  # or comment these two lines out.
#  SET_FOR "$AD5338R_RESET_PIN" 0 0.10
#  SET_FOR "$AD5338R_RESET_PIN" 1 0.10
#  WAIT

#
# 2/18/26 8:17 AM below replaces above
#
# Power enable ON for 1 second (enough to cover reset sequencing)
SET_FOR_SEC "$SX1302_POWER_EN_PIN" 1 1
WAIT

# SX1302 reset pulse (100ms high then 100ms low)
SET_FOR_USEC "$SX1302_RESET_PIN" 1 100000
SET_FOR_USEC "$SX1302_RESET_PIN" 0 100000
WAIT

# SX1261 reset pulse (100ms low then 100ms high)
SET_FOR_USEC "$SX1261_RESET_PIN" 0 100000
SET_FOR_USEC "$SX1261_RESET_PIN" 1 100000
WAIT

# ADC reset pulse (often unused on HATs; safe to try, but you can comment out if needed)
SET_FOR_USEC "$AD5338R_RESET_PIN" 0 100000
SET_FOR_USEC "$AD5338R_RESET_PIN" 1 100000
WAIT

}

case "${1:-}" in
  start) reset ;;
  stop)  reset ;;
  *)
    echo "Usage: $0 {start|stop}" >&2
    exit 1
    ;;
esac

exit 0