#!/bin/sh
#===============================================================================
#
#  Copyright (C) 2018 by 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 hardware
#
#===============================================================================

# Bluetooth power GPIO
BT_EN_QCA_GPIO_NR="394"

# set_gpio_value <gpio_nr> <value>
set_gpio_value() {
	local SG_GPIONR="${1}"
	local SG_GPIOVAL="${2}"
	local SG_GPIOPATH="/sys/class/gpio/gpio${SG_GPIONR}"

	[ -d "${SG_GPIOPATH}" ] || printf "%s" "${SG_GPIONR}" > /sys/class/gpio/export
	printf out > "${SG_GPIOPATH}/direction" && sleep .2
	printf "${SG_GPIOVAL}" > "${SG_GPIOPATH}/value" && sleep .2
	[ -d "${SG_GPIOPATH}" ] && printf "%s" "${SG_GPIONR}" > /sys/class/gpio/unexport
}

# powercycle_gpio <gpio_nr>
powercycle_gpio() {
	set_gpio_value "${1}" 0
	set_gpio_value "${1}" 1
}

error() {
	echo ${1}
	exit 1
}

bluetooth_init() {
	# Get MAC address from the device tree. Use a default value if it has not been set.
	BT_MACADDR="$(hexdump -ve '1/1 "%02X" ":"' /proc/device-tree/bluetooth/mac-address 2>/dev/null | sed 's/:$//g')"
	if [ -z "${BT_MACADDR}" ] || [ "${BT_MACADDR}" = "00:00:00:00:00:00" ]; then
		BT_MACADDR="00:04:F3:FF:FF:BB"
	fi

	# Module version older than revision 2 has swapped CTS and RTS lines
	MOD_VERSION="$(($(cat /proc/device-tree/digi,hwid,hv 2>/dev/null | tr -d '\0' || true)))"
	if [ "${MOD_VERSION}" -lt "2" ]; then
		# Reduce the rate to avoid the need for HW flow control
		BT_RATE="115200"
		BT_RATE_CODE="00" # 115200 bps
		BT_FLOW="noflow"

		# Modify the baudrate in the firmware file
		BT_FW_FILE="/lib/firmware/qca/nvm_tlv_3.2.bin"
		if [ "$(hexdump -s 56 -n 1 -ve '1/1 "%.2x"' ${BT_FW_FILE})" != "${BT_RATE_CODE}" ]; then
			printf "\x${BT_RATE_CODE}" | dd of="${BT_FW_FILE}" bs=1 seek=56 count=1 conv=notrunc,fsync 2>/dev/null
		fi
	fi

	# Start the Bluetooth driver and bring up the interface
	HCIATTACH_LOG="/var/log/hciattach.log"

	for RETRY in $(seq 1 5)
	do
		killproc hciattach
		powercycle_gpio "${BT_EN_QCA_GPIO_NR}"
		if hciattach ttyBt qca ${BT_RATE:-3000000} -t30 ${BT_FLOW:-flow} unused ${BT_MACADDR} >${HCIATTACH_LOG} 2>&1; then
			return
		fi
		sleep 1
	done
	BT_ERROR="FAIL (hciattach)"
}

# Source function library
. /etc/init.d/functions

case "$1" in
	start)
		if [ -d "/proc/device-tree/bluetooth" ]; then
			echo -n "Starting bluetooth hardware: "
			bluetooth_init
			echo "${BT_ERROR:-done.}"
		fi
		;;
	stop)
		if [ -d "/sys/class/bluetooth/hci0" ]; then
			echo -n "Stopping bluetooth hardware: "
			killproc hciattach
			# Power down bluetooth
			set_gpio_value "${BT_EN_QCA_GPIO_NR}" 0
			echo "done."
		fi
		;;
	restart)
		$0 stop
		sleep 1
		$0 start
		;;
	*)
		echo "Usage: $0 {start|stop|restart}"
		exit 1
		;;
esac