#!/opt/lnxall_app/bin/lua

-- Created by jiaqiang.ye@lnxall.com
-- Simple GPIO FAN control implementation
-- 2024/08/28

local posix = require "posix"
local invoker = require "invoker"

local gfmt = string.format
local g_iopath = nil
local g_gpio, g_threshold = 141, 65 -- 141, FAN control GPIO for QIYANG latest board
local g_fandis, g_fanen = "1\n", "0\n"
local g_thermal = "/sys/class/thermal/thermal_zone%d/temp"

local function fan_ctrl(onoff)
	if type(g_iopath) ~= "string" then
		return nil
	end

	local out = io.open(g_iopath, "wb")
	if not out then
		io.stderr:write(gfmt("Error, failed to open '%s'\n", g_iopath))
		io.stderr:flush()
		return false
	end

	out:write(onoff and g_fanen or g_fandis)
	out:close(); out = nil
	return true
end

local function has_thermal()
	local i = 0
	while i < 8 do
		local thermal = gfmt(g_thermal, i)
		if posix.access(thermal) == 0 then
			return true
		end
		i = i + 1
	end
	return false
end

local function fan_init(arg1, arg2)
	invoker.setname("FAN_CONTROL")
	local gnum, thres = nil, nil
	if type(arg1) == "string" then gnum = tonumber(arg1) end
	if gnum and gnum >= 0 then g_gpio = math.floor(gnum) end
	if type(arg2) == "string" then thres = tonumber(arg2) end
	if thres and thres > 0 then g_threshold = math.floor(thres) end

	if not has_thermal() then
		io.stderr:write("Error, no thermal device found.\n")
		io.stderr:flush()
		return nil
	end
	io.stdout:write(gfmt("FAN GPIO: %d, temperature threshold: %d\n",
		g_gpio, g_threshold))
	io.stdout:flush()

	local gpath = gfmt("/sys/class/gpio/gpio%d", g_gpio)
	g_iopath = gpath .. "/value"

	if posix.access(gpath) ~= 0 then
		local exp = io.open("/sys/class/gpio/export", "wb")
		if exp then
			gnum = gfmt("%d\n", g_gpio)
			exp:write(gnum)
			exp:close()
			invoker.msleep(200)
		end
		if posix.access(gpath) ~= 0 then
			io.stderr:write(gfmt("Error, failed to export GPIO: %d\n", g_gpio))
			io.stderr:flush()
			return false
		end
	end

	gpath = gpath .. "/direction"
	local isout = invoker.readfile(gpath, invoker.TRIMEND)
	if isout ~= "out" then
		local dirp = io.open(gpath, "wb")
		if dirp then
			dirp:write("out\n")
			dirp:close(); dirp = nil
		end
		isout = invoker.readfile(gpath, invoker.TRIMEND)
	end

	if isout ~= "out" then
		if type(isout) ~= "string" then isout = "unknown" end
		io.stderr:write(gfmt("Error, invalid FAN GPIO direction: %s\n", isout))
		io.stderr:flush()
	end
	return fan_ctrl(false)
end

local function get_temps(hight)
	local i, temps, overtemp = 0, {}, false
	while i < 8 do
		local thermal = gfmt(g_thermal, i)
		if posix.access(thermal) == 0 then
			local t = invoker.readfile(thermal, invoker.TRIMEND)
			if not t then
				overtemp = true
				io.stderr:write(gfmt("Error, failed to read '%s'\n", thermal))
				io.stderr:flush()
				break
			end
			t = tonumber(t)
			if t then
				t = math.floor(t / 1000 + 0.5)
				if t > hight then overtemp = true end
				temps[#temps + 1] = t
			end
		end
		i = i + 1
	end
	return temps, overtemp
end

local function mainloop()
	while true do
		local t, over = get_temps(g_threshold)
		if over then
			for i, temp in ipairs(t) do
				io.stdout:write(gfmt("CPU[%d] temperature: %d\n", i, temp))
				io.stdout:flush()
			end
			fan_ctrl(true)
			invoker.waitsec(600)
		else
			fan_ctrl(false)
			invoker.waitsec(120)
		end
	end
end

if not fan_init(arg[1], arg[2]) then
	invoker.waitsec(900)
	os.exit(9)
end
mainloop()
os.exit(0)