#!/bin/sh
#===============================================================================
#
#  Copyright (C) 2025,2026, Digi International Inc.
#  All rights reserved.
#
#  This program is free software; you can redistribute it and/or modify it
#  under the terms of the GNU General Public License version 2 as published by
#  the Free Software Foundation.
#
#
#  !Description: Initialize Bluetooth interface
#
#===============================================================================

SCRIPTNAME="$(basename ${0})"
RETRIES=3
HCI_IFACE="hci0"
MODULE_NAME="hci_uart"

if grep -qs '\<digi,ccmp13\>' /proc/device-tree/compatible; then
	# CCMP13 - BT_REG_EN - GPIO PD13
	GPIO_CHIP="GPIOD"
	GPIO_NUMBER="13"
elif grep -qs '\<digi,ccmp15\>' /proc/device-tree/compatible; then
	# CCMP15 - BT_REG_EN - GPIO PZ6
	GPIO_CHIP="GPIOZ"
	GPIO_NUMBER="6"
elif grep -qs '\<digi,ccimx95\>' /proc/device-tree/compatible; then
	# CCIMX95
	GPIO_CHIP="1"
	GPIO_NUMBER="18"
fi

log() {
	if type "systemd-cat" >/dev/null 2>/dev/null; then
		systemd-cat -p "${1}" -t "${SCRIPTNAME}" printf "%s" "${2}"
	else
		logger -p "${1}" -t "${SCRIPTNAME}" "${2}"
	fi
}

bt_power() {
	gpioset "${GPIO_CHIP}" "${GPIO_NUMBER}"="${1}"
}

set_btaddr() {
	hciconfig hci0 up
	sleep 0.2
	bt_addr=$(hexdump -v -e '1/1 "%02X "' /proc/device-tree/bluetooth/mac-address \
			| awk '{ for(i=NF; i>0; i--) printf "0x%s ", $i }' \
			| sed 's/ $//')
	hcitool -i hci0 cmd 0x3f 0x0001 ${bt_addr}
	hciconfig hci0 down
	sleep 0.2
	hciconfig hci0 up
}

is_kernel_module_loaded() {
	lsmod | grep -qs -w "^${MODULE_NAME}"
}

bt_init() {
	# If module is already loaded, skip
	is_kernel_module_loaded && log info "kernel module already present, skipping" && return 1

	for i in $(seq ${RETRIES}); do
		# Perform a power cycle
		bt_power 0
		sleep 0.5
		bt_power 1

		# Load manually the kernel module
		modprobe "${MODULE_NAME}"
		sleep 1
		# Reconfigure the HCI interface with the expected MAC address
		is_kernel_module_loaded && set_btaddr && log info "Bluetooth activated" && return 0

		log err "Cannot initialize Bluetooth, retrying..."
	done

	log err "Failed to initialize Bluetooth interface"
	return 1
}

bt_stop() {
	hciconfig ${HCI_IFACE} down
	# Unload HCI driver instance
	rmmod hci_uart
	rmmod btbcm
	# Disable Bluetooth chip
	bt_power 0 && log info "Bluetooth disabled" && return 0
}

case "$1" in
	start)
		bt_init
		;;
	stop)
		bt_stop
		;;
	restart)
		$0 stop
		$0 start
		;;
	*)
		echo "Usage: $0 {start|stop|restart}"
		exit 1
		;;
esac