# -*- coding: utf-8 -*-
#
# AWL simulator - PiXtend hardware interface
#
# Copyright 2018 Michael Buesch <m@bues.ch>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License along
# with this program; if not, write to the Free Software Foundation, Inc.,
# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
#

from __future__ import division, absolute_import, print_function, unicode_literals
from awlsim.common.compat import *

from awlsim.common.util import *
from awlsim.common.exceptions import *

#from awlsimhw_pixtend.main cimport * #@cy

from awlsim.common.datatypehelpers import * #+cimport

from awlsim.core.hardware_params import *
from awlsim.core.hardware import * #+cimport
from awlsim.core.operators import * #+cimport
from awlsim.core.operatortypes import * #+cimport
from awlsim.core.offset import * #+cimport
from awlsim.core.cpu import * #+cimport

import time


class AbstractIO(object): #+cdef
	"""PiXtend abstract I/O handler.
	"""

	setters = ()
	getters = ()
	directionSetters = ()

	def __init__(self, pixtend, index, bitOffset):
		self.pixtend = pixtend
		self.index = index
		self.byteOffset = bitOffset // 8
		self.bitOffset = bitOffset % 8

	def setup(self, secondaryOffset): #+cpdef
		self.byteOffset += secondaryOffset
		try:
			self.setter = self.setters[self.index]
		except IndexError:
			self.setter = None
		try:
			self.getter = self.getters[self.index]
		except IndexError:
			self.getter = None
		try:
			self.directionSetter = self.directionSetters[self.index]
		except IndexError:
			self.directionSetter = None

	def set(self, dataBytes): #@nocy
#@cy	cdef set(self, bytearray dataBytes):
		raise NotImplementedError

	def get(self, dataBytes): #@nocy
#@cy	cdef get(self, bytearray dataBytes):
		raise NotImplementedError

	def setDirection(self, outDirection): #+cpdef
		if self.directionSetter:
			self.directionSetter(self, outDirection)

class AbstractBitIO(AbstractIO): #+cdef
	"""PiXtend abstract bit I/O handler.
	"""

	def setup(self, secondaryOffset): #+cpdef
		AbstractIO.setup(self, secondaryOffset)

		self.bitMask = 1 << self.bitOffset
		self.invBitMask = (~self.bitMask) & 0xFF

	def set(self, dataBytes): #@nocy
#@cy	cdef set(self, bytearray dataBytes):
		self.setter(self, (dataBytes[self.byteOffset] >> self.bitOffset) & 1)

	def get(self, dataBytes): #@nocy
#@cy	cdef get(self, bytearray dataBytes):
		if self.getter(self):
			dataBytes[self.byteOffset] |= self.bitMask
		else:
			dataBytes[self.byteOffset] &= self.invBitMask

class AbstractWordIO(AbstractIO): #+cdef
	"""PiXtend abstract word I/O handler.
	"""

	def set(self, dataBytes): #@nocy
#@cy	cdef set(self, bytearray dataBytes):
		self.setter(self,
			    (dataBytes[self.byteOffset] << 8) |\
			    (dataBytes[self.byteOffset + 1]))

	def get(self, dataBytes): #@nocy
#@cy	cdef get(self, bytearray dataBytes):
#@cy		cdef uint16_t value

		value = self.getter(self)
		dataBytes[self.byteOffset] = (value >> 8) & 0xFF
		dataBytes[self.byteOffset + 1] = value & 0xFF

class Relay(AbstractBitIO): #+cdef
	"""PiXtend relay I/O handler.
	"""

	def __setRelay0(self, state):
		self.pixtend.relay0 = state

	def __setRelay1(self, state):
		self.pixtend.relay1 = state

	def __setRelay2(self, state):
		self.pixtend.relay2 = state

	def __setRelay3(self, state):
		self.pixtend.relay3 = state

	setters = (
		__setRelay0,
		__setRelay1,
		__setRelay2,
		__setRelay3,
	)

class DigitalOut(AbstractBitIO): #+cdef
	"""PiXtend digital output I/O handler.
	"""

	def __setDO0(self, state):
		self.pixtend.digital_output0 = state

	def __setDO1(self, state):
		self.pixtend.digital_output1 = state

	def __setDO2(self, state):
		self.pixtend.digital_output2 = state

	def __setDO3(self, state):
		self.pixtend.digital_output3 = state

	def __setDO4(self, state):
		self.pixtend.digital_output4 = state

	def __setDO5(self, state):
		self.pixtend.digital_output5 = state

	setters = (
		__setDO0,
		__setDO1,
		__setDO2,
		__setDO3,
		__setDO4,
		__setDO5,
	)

class DigitalIn(AbstractBitIO): #+cdef
	"""PiXtend digital input I/O handler.
	"""

	def __getDI0(self):
		return self.pixtend.digital_input0

	def __getDI1(self):
		return self.pixtend.digital_input1

	def __getDI2(self):
		return self.pixtend.digital_input2

	def __getDI3(self):
		return self.pixtend.digital_input3

	def __getDI4(self):
		return self.pixtend.digital_input4

	def __getDI5(self):
		return self.pixtend.digital_input5

	def __getDI6(self):
		return self.pixtend.digital_input6

	def __getDI7(self):
		return self.pixtend.digital_input7

	getters = (
		__getDI0,
		__getDI1,
		__getDI2,
		__getDI3,
		__getDI4,
		__getDI5,
		__getDI6,
		__getDI7,
	)

class GPIO(AbstractBitIO): #+cdef
	"""PiXtend GPIO I/O handler.
	"""

	def __getGPIO0(self):
		return self.pixtend.gpio0

	def __getGPIO1(self):
		return self.pixtend.gpio1

	def __getGPIO2(self):
		return self.pixtend.gpio2

	def __getGPIO3(self):
		return self.pixtend.gpio3

	getters = (
		__getGPIO0,
		__getGPIO1,
		__getGPIO2,
		__getGPIO3,
	)

	def __setGPIO0(self, state):
		self.pixtend.gpio0 = state

	def __setGPIO1(self, state):
		self.pixtend.gpio1 = state

	def __setGPIO2(self, state):
		self.pixtend.gpio2 = state

	def __setGPIO3(self, state):
		self.pixtend.gpio3 = state

	setters = (
		__setGPIO0,
		__setGPIO1,
		__setGPIO2,
		__setGPIO3,
	)

	def __setDirGPIO0(self, outDirection):
		self.pixtend.gpio0_direction =\
			self.pixtend.GPIO_OUTPUT if outDirection else\
			self.pixtend.GPIO_INPUT

	def __setDirGPIO1(self, outDirection):
		self.pixtend.gpio1_direction =\
			self.pixtend.GPIO_OUTPUT if outDirection else\
			self.pixtend.GPIO_INPUT

	def __setDirGPIO2(self, outDirection):
		self.pixtend.gpio2_direction =\
			self.pixtend.GPIO_OUTPUT if outDirection else\
			self.pixtend.GPIO_INPUT

	def __setDirGPIO3(self, outDirection):
		self.pixtend.gpio3_direction =\
			self.pixtend.GPIO_OUTPUT if outDirection else\
			self.pixtend.GPIO_INPUT

	directionSetters = (
		__setDirGPIO0,
		__setDirGPIO1,
		__setDirGPIO2,
		__setDirGPIO3,
	)

class AnalogIn(AbstractWordIO): #+cdef
	"""PiXtend analog input I/O handler.
	"""

	def __init__(self, *args, **kwargs):
		AbstractWordIO.__init__(self, *args, **kwargs)

		self.jumper10V = None
		self.numberOfSamples = None

	def __convertV(self, V): #@nocy
#@cy	cdef uint16_t __convertV(self, double V):
		return max(min(int(round(V * 2764.8)), 32767), -32768)

	def __convertMA(self, mA): #@nocy
#@cy	cdef uint16_t __convertMA(self, double mA):
		return max(min(int(round((mA - 4.0) * 1728.0)), 32767), -32768)

	def __getAI0(self):
		return self.__convertV(self.pixtend.analog_input0)

	def __getAI1(self):
		return self.__convertV(self.pixtend.analog_input1)

	def __getAI2(self):
		return self.__convertMA(self.pixtend.analog_input2)

	def __getAI3(self):
		return self.__convertMA(self.pixtend.analog_input3)

	getters = (
		__getAI0,
		__getAI1,
		__getAI2,
		__getAI3,
	)

	def __setJumper10V_AI0(self, jumper10V):
		self.pixtend.analog_input0_10volts_jumper = jumper10V

	def __setJumper10V_AI1(self, jumper10V):
		self.pixtend.analog_input1_10volts_jumper = jumper10V

	settersJumper10V = (
		__setJumper10V_AI0,
		__setJumper10V_AI1,
	)

	def __setNos_AI0(self, nos):
		self.pixtend.analog_input0_nos = nos

	def __setNos_AI1(self, nos):
		self.pixtend.analog_input1_nos = nos

	def __setNos_AI2(self, nos):
		self.pixtend.analog_input2_nos = nos

	def __setNos_AI3(self, nos):
		self.pixtend.analog_input3_nos = nos

	settersNos = (
		__setNos_AI0,
		__setNos_AI1,
		__setNos_AI2,
		__setNos_AI3,
	)

	@staticmethod
	def setFreq(pixtend, freqKHz):
		kHz2MHz = {
			125	: 0.125,
			250	: 0.250,
			500	: 0.500,
			1000	: 1.0,
			2000	: 2.0,
			4000	: 4.0,
			8000	: 8.0,
		}
		try:
			freqMHz = kHz2MHz[freqKHz]
		except KeyError as e:
			raise ValueError
		pixtend.analog_input_nos_freq = freqMHz

	def setup(self, secondaryOffset): #+cpdef
		AbstractWordIO.setup(self, secondaryOffset)

		if self.jumper10V is not None:
			setJumper10V = self.settersJumper10V[self.index]
			setJumper10V(self, self.pixtend.ON if self.jumper10V
					   else self.pixtend.OFF)

		if self.numberOfSamples is not None:
			setNos = self.settersNos[self.index]
			setNos(self, self.numberOfSamples)

class AnalogOut(AbstractWordIO): #+cdef
	"""PiXtend analog output I/O handler.
	"""

	def __convert(self, s7Value): #@nocy
#@cy	cdef uint16_t __convert(self, uint16_t s7Value):
		# dac = (s7Value / 27648) * 1023
		return clamp(int(round((wordToSignedPyInt(s7Value) * 1023) / 27648)),
			     0, 1023)

	def __setAO0(self, value):
		pixtend = self.pixtend
		pixtend.dac_selection = pixtend.DAC_A
		pixtend.set_dac_output(self.__convert(value))

	def __setAO1(self, value):
		pixtend = self.pixtend
		pixtend.dac_selection = pixtend.DAC_B
		pixtend.set_dac_output(self.__convert(value))

	setters = (
		__setAO0,
		__setAO1,
	)

class PWMPeriod(AbstractWordIO): #+cdef
	"""PiXtend PWM period I/O handler.
	"""

	def setPWMPeriod(self, period):
		self.pixtend.pwm_ctrl_period = clamp(period, 0, 65000)
		self.pixtend.pwm_ctrl_configure()

	setters = (
		setPWMPeriod,
	)

class PWM(AbstractWordIO): #+cdef
	"""PiXtend PWM output I/O handler.
	"""

	def __init__(self, *args, **kwargs):
		AbstractWordIO.__init__(self, *args, **kwargs)

		self.overDrive = None

	def __setPWM0(self, value):
		self.pixtend.pwm0 = clamp(value, 0, 65000)

	def __setPWM1(self, value):
		self.pixtend.pwm1 = clamp(value, 0, 65000)

	setters = (
		__setPWM0,
		__setPWM1,
	)

	@staticmethod
	def setServoMode(pixtend, enServoMode):
		pixtend.pwm_ctrl_mode = 0 if enServoMode else 1
		pixtend.pwm_ctrl_configure()

	def __setServoOverDrive0(self, enOverDrive):
		self.pixtend.pwm_ctrl_od0 = 1 if enOverDrive else 0
		self.pixtend.pwm_ctrl_configure()

	def __setServoOverDrive1(self, enOverDrive):
		self.pixtend.pwm_ctrl_od1 = 1 if enOverDrive else 0
		self.pixtend.pwm_ctrl_configure()

	settersOverDrive = (
		__setServoOverDrive0,
		__setServoOverDrive1,
	)

	@staticmethod
	def setBaseFreq(pixtend, freqHz):
		cpuHz = 16000000
		csMap = {
			0		: (0, 0, 0), # PS=off
			cpuHz // 1	: (0, 0, 1), # PS=1
			cpuHz // 8	: (0, 1, 0), # PS=8
			cpuHz // 64	: (0, 1, 1), # PS=64
			cpuHz // 256	: (1, 0, 0), # PS=256
			cpuHz // 1024	: (1, 0, 1), # PS=1024
		}
		try:
			cs2, cs1, cs0 = csMap[freqHz]
		except KeyError as e:
			raise ValueError
		pixtend.pwm_ctrl_cs0 = cs0
		pixtend.pwm_ctrl_cs1 = cs1
		pixtend.pwm_ctrl_cs2 = cs2
		pixtend.pwm_ctrl_configure()

	def setup(self, secondaryOffset): #+cpdef
		AbstractWordIO.setup(self, secondaryOffset)

		if self.overDrive is not None:
			setOverDrive = self.settersOverDrive[self.index]
			setOverDrive(self, self.overDrive)

class HardwareInterface_PiXtend(AbstractHardwareInterface): #+cdef
	name = "PiXtend"

	#TODO DHT
	#TODO hum
	#TODO DAC
	#TODO RS232
	#TODO RS485

	NR_RELAYS	= 4
	NR_DO		= 6
	NR_DI		= 8
	NR_GPIO		= 4
	NR_DAC		= 2
	NR_ADC		= 4
	NR_PWM		= 2

	paramDescs = [
		HwParamDesc_int("pollIntMs",
				defaultValue=100,
				minValue=25,
				maxValue=10000,
				description="PiXtend auto-mode poll interval time, in milliseconds"),
		HwParamDesc_bool("testMode",
				defaultValue=False,
				description="Enable testing mode. DO NOT USE THIS OPTION!",
				hidden=True),
	]
	for i in range(NR_RELAYS):
		paramDescs.append(HwParamDesc_oper(
				"relay%d_addr" % i,
				allowedOperTypes=(AwlOperatorTypes.MEM_A,),
				allowedOperWidths=(1,),
				description="Relay output %d address" % i))
	for i in range(NR_DO):
		paramDescs.append(HwParamDesc_oper(
				"digitalOut%d_addr" % i,
				allowedOperTypes=(AwlOperatorTypes.MEM_A,),
				allowedOperWidths=(1,),
				description="Digital output %d address" % i))
	for i in range(NR_DI):
		paramDescs.append(HwParamDesc_oper(
				"digitalIn%d_addr" % i,
				allowedOperTypes=(AwlOperatorTypes.MEM_E,),
				allowedOperWidths=(1,),
				description="Digital input %d address" % i))
	for i in range(NR_GPIO):
		paramDescs.append(HwParamDesc_oper(
				"gpio%d_addr" % i,
				allowedOperTypes=(AwlOperatorTypes.MEM_E,
						  AwlOperatorTypes.MEM_A,),
				allowedOperWidths=(1,),
				description="GPIO %d address (can be input (I/E) or output (Q/A))" % i))
	for i in range(NR_DAC):
		paramDescs.append(HwParamDesc_oper(
				"analogOut%d_addr" % i,
				allowedOperTypes=(AwlOperatorTypes.MEM_A,),
				allowedOperWidths=(16,),
				description="Analog output (DAC) %d address" % i))
	for i in range(NR_ADC):
		paramDescs.append(HwParamDesc_oper(
				"analogIn%d_addr" % i,
				allowedOperTypes=(AwlOperatorTypes.MEM_E,),
				allowedOperWidths=(16,),
				description="Analog input %d word address" % i))
		if i <= 1:
			paramDescs.append(HwParamDesc_bool(
					"analogIn%d_10V" % i,
					defaultValue=True,
					description="TRUE: Use 10 volts input. FALSE: Use 5 volts input"))
		paramDescs.append(HwParamDesc_int(
				"analogIn%d_nos" % i,
				defaultValue=10,
				minValue=1,
				maxValue=50,
				description="Number of samples for analog input (1, 5, 10 or 50)"))
		#TODO optional: analogs in PEW only
	paramDescs.append(HwParamDesc_int(
			"analogIn_kHz",
			defaultValue=125,
			minValue=125,
			maxValue=8000,
			description="Analog sampling frequency in kHz. Default: 125 kHz."))
	for i in range(NR_PWM):
		paramDescs.append(HwParamDesc_oper(
				"pwm%d_addr" % i,
				allowedOperTypes=(AwlOperatorTypes.MEM_A,),
				allowedOperWidths=(16,),
				description="PWM (Pulse Width Modulation) output %d word address" % i))
		paramDescs.append(HwParamDesc_bool(
				"pwm%d_servoOverDrive" % i,
				defaultValue=False,
				description="Enable PWM %d servo mode "
					    "over drive (only if pwm_servoMode=True)." % i))
	paramDescs.append(HwParamDesc_bool(
			"pwm_servoMode",
			defaultValue=False,
			description="Enable PWM servo mode."))
	paramDescs.append(HwParamDesc_int(
			"pwm_baseFreqHz",
			defaultValue=0,
			minValue=0,
			maxValue=16000000,
			description="PWM base frequency, in Hz. "
				    "Possible values: 16000000, 2000000, 250000, 62500, 15625, 0. "
				    "Set to 0 to disable PWM."))
	paramDescs.append(HwParamDesc_oper(
			"pwm_period",
			allowedOperTypes=(AwlOperatorTypes.MEM_A,
					  AwlOperatorTypes.IMM),
			description="PWM period.\n"
				"This can either be an integer between 0 and L#65000.\n"
				"Or an output word (AW, QW) where the program "
				"writes the desired period to.\n"
				"Defaults to L#65000, if not specified."))

	def __init__(self, sim, parameters={}):
		AbstractHardwareInterface.__init__(self,
						   sim = sim,
						   parameters = parameters)
		self.__pixtendInitialized = False
		self.__pixtend = None

	def __build(self):
		def updateOffs(byteOffset, byteWidth, first, last):
			if first is None or byteOffset < first:
				first = byteOffset
			if last is None or byteOffset + byteWidth - 1 > last:
				last = byteOffset + byteWidth - 1
			return first, last

		# Build all Relay() objects
		self.__relays = []
		firstRelayByte = lastRelayByte = None
		for i in range(self.NR_RELAYS):
			oper = self.getParamValueByName("relay%d_addr" % i)
			if oper is None:
				continue
			bitOffset = oper.offset.toLongBitOffset()
			r = Relay(self.__pixtend, i, bitOffset)
			self.__relays.append(r)
			firstRelayByte, lastRelayByte = updateOffs(
					bitOffset // 8, 1,
					firstRelayByte, lastRelayByte)

		# Build all DigitalOut() objects
		self.__DOs = []
		firstDOByte = lastDOByte = None
		for i in range(self.NR_DO):
			oper = self.getParamValueByName("digitalOut%d_addr" % i)
			if oper is None:
				continue
			bitOffset = oper.offset.toLongBitOffset()
			do = DigitalOut(self.__pixtend, i, bitOffset)
			self.__DOs.append(do)
			firstDOByte, lastDOByte = updateOffs(
					bitOffset // 8, 1,
					firstDOByte, lastDOByte)

		# Build all DigitalIn() objects
		self.__DIs = []
		firstDIByte = lastDIByte = None
		for i in range(self.NR_DI):
			oper = self.getParamValueByName("digitalIn%d_addr" % i)
			if oper is None:
				continue
			bitOffset = oper.offset.toLongBitOffset()
			di = DigitalIn(self.__pixtend, i, bitOffset)
			self.__DIs.append(di)
			firstDIByte, lastDIByte = updateOffs(
					bitOffset // 8, 1,
					firstDIByte, lastDIByte)

		# Build all GPIO output objects
		self.__GPIO_out = []
		firstGPIOOutByte = lastGPIOOutByte = None
		for i in range(self.NR_GPIO):
			oper = self.getParamValueByName("gpio%d_addr" % i)
			if oper is None:
				continue
			if oper.operType != AwlOperatorTypes.MEM_A:
				continue
			bitOffset = oper.offset.toLongBitOffset()
			gpio = GPIO(self.__pixtend, i, bitOffset)
			self.__GPIO_out.append(gpio)
			firstGPIOOutByte, lastGPIOOutByte = updateOffs(
					bitOffset // 8, 1,
					firstGPIOOutByte, lastGPIOOutByte)

		# Build all GPIO input objects
		self.__GPIO_in = []
		firstGPIOInByte = lastGPIOInByte = None
		for i in range(self.NR_GPIO):
			oper = self.getParamValueByName("gpio%d_addr" % i)
			if oper is None:
				continue
			if oper.operType != AwlOperatorTypes.MEM_E:
				continue
			bitOffset = oper.offset.toLongBitOffset()
			gpio = GPIO(self.__pixtend, i, bitOffset)
			self.__GPIO_in.append(gpio)
			firstGPIOInByte, lastGPIOInByte = updateOffs(
					bitOffset // 8, 1,
					firstGPIOInByte, lastGPIOInByte)

		# Build all analog input objects
		self.__AIs = []
		firstAIByte = lastAIByte = None
		for i in range(self.NR_ADC):
			oper = self.getParamValueByName("analogIn%d_addr" % i)
			if oper is None:
				continue
			if oper.offset.bitOffset or oper.width != 16:
				pass#TODO error
			bitOffset = oper.offset.toLongBitOffset()
			ai = AnalogIn(self.__pixtend, i, bitOffset)
			self.__AIs.append(ai)
			firstAIByte, lastAIByte = updateOffs(
					bitOffset // 8, 2,
					firstAIByte, lastAIByte)
			if i <= 1:
				ai.jumper10V = self.getParamValueByName("analogIn%d_10V" % i)
			ai.numberOfSamples = self.getParamValueByName("analogIn%d_nos" % i)

		# Build all analog output objects
		self.__AOs = []
		firstAOByte = lastAOByte = None
		for i in range(self.NR_DAC):
			oper = self.getParamValueByName("analogOut%d_addr" % i)
			if oper is None:
				continue
			if oper.offset.bitOffset or oper.width != 16:
				pass#TODO error
			bitOffset = oper.offset.toLongBitOffset()
			ao = AnalogOut(self.__pixtend, i, bitOffset)
			self.__AOs.append(ao)
			firstAOByte, lastAOByte = updateOffs(
					bitOffset // 8, 2,
					firstAOByte, lastAOByte)

		# Build all PWM() objects
		self.__PWMs = []
		firstPWMByte = lastPWMByte = None
		for i in range(self.NR_PWM):
			oper = self.getParamValueByName("pwm%d_addr" % i)
			if oper is None:
				continue
			if oper.offset.bitOffset or oper.width != 16:
				pass#TODO error
			bitOffset = oper.offset.toLongBitOffset()
			pwm = PWM(self.__pixtend, i, bitOffset)
			self.__PWMs.append(pwm)
			firstPWMByte, lastPWMByte = updateOffs(
					bitOffset // 8, 2,
					firstPWMByte, lastPWMByte)
			pwm.overDrive = self.getParamValueByName("pwm%d_servoOverDrive" % i)
		# Handle pwm_period parameter.
		try:
			oper = self.getParamValueByName("pwm_period")
			if not oper:
				# Use default constant pwm_period
				PWMPeriod(self.__pixtend, 0, 0).setPWMPeriod(65000)
			else:
				if oper.operType == AwlOperatorTypes.IMM:
					# Use custom constant pwm_period
					period = oper.immediate
					if period < 0 or period > 65000:
						raise ValueError
					PWMPeriod(self.__pixtend, 0, 0).setPWMPeriod(period)
				elif oper.operType == AwlOperatorTypes.MEM_A and\
				     oper.width == 16:
					# Use custom dynamic pwm_period
					bitOffset = oper.offset.toLongBitOffset()
					pwm = PWMPeriod(self.__pixtend, 0, bitOffset)
					self.__PWMs.append(pwm)
					firstPWMByte, lastPWMByte = updateOffs(
							bitOffset // 8, 2,
							firstPWMByte, lastPWMByte)
					pwm.setPWMPeriod(0)
				else:
					raise ValueError
		except ValueError as e:
			self.raiseException("Unsupported 'pwm_period' parameter value.")

		# Find the offsets of the first and the last output byte
		firstOutByte = lastOutByte = None
		for firstByteOffset, lastByteOffset in (
				(firstRelayByte, lastRelayByte),
				(firstDOByte, lastDOByte),
				(firstGPIOOutByte, lastGPIOOutByte),
				(firstAOByte, lastAOByte),
				(firstPWMByte, lastPWMByte)):
			for byteOffset in (firstByteOffset, lastByteOffset):
				if byteOffset is not None:
					firstOutByte, lastOutByte = updateOffs(
						byteOffset, 1,
						firstOutByte, lastOutByte)

		# Find the offsets of the first and the last input byte
		firstInByte = lastInByte = None
		for firstByteOffset, lastByteOffset in (
				(firstDIByte, lastDIByte),
				(firstGPIOInByte, lastGPIOInByte),
				(firstAIByte, lastAIByte)):
			for byteOffset in (firstByteOffset, lastByteOffset):
				if byteOffset is not None:
					firstInByte, lastInByte = updateOffs(
						byteOffset, 1,
						firstInByte, lastInByte)

		# Store the output base and size
		if firstOutByte is None or lastOutByte is None:
			self.__outBase = 0
			self.__outSize = 0
		else:
			self.__outBase = self.outputAddressBase + firstOutByte
			self.__outSize = lastOutByte - firstOutByte + 1

			# Setup all outputs
			for out in itertools.chain(self.__relays,
						   self.__DOs,
						   self.__GPIO_out,
						   self.__AOs,
						   self.__PWMs):
				out.setup(-firstOutByte)
				out.setDirection(True)

		# Store the input base and size
		if firstInByte is None or lastInByte is None:
			self.__inBase = 0
			self.__inSize = 0
		else:
			self.__inBase = self.inputAddressBase + firstInByte
			self.__inSize = lastInByte - firstInByte + 1

			# Setup all inputs
			for inp in itertools.chain(self.__DIs,
						   self.__GPIO_in,
						   self.__AIs):
				inp.setup(-firstInByte)
				inp.setDirection(False)

		# Configure AnalogOut SPI communication.
		try:
			if self.__AOs:
				self.__pixtend.open_dac()
		except (IOError, ValueError) as e:
			self.raiseException("Failed to open DAC communication: %s" % str(e))

		# Configure global values of AnalogIn.
		try:
			AnalogIn.setFreq(self.__pixtend,
					 self.getParamValueByName("analogIn_kHz"))
		except ValueError as e:
			self.raiseException("Unsupported 'analogIn_kHz' parameter value. "
				"Supported values are: 125, 250, 500, 1000, 4000, 8000.")

		# Configure global values of PWM.
		try:
			PWM.setServoMode(self.__pixtend,
					 self.getParamValueByName("pwm_servoMode"))
		except ValueError as e:
			self.raiseException("Unsupported 'pwm_servoMode' parameter value.")
		try:
			freqHz = self.getParamValueByName("pwm_baseFreqHz")
			if not self.__PWMs:
				freqHz = 0
			PWM.setBaseFreq(self.__pixtend, freqHz)
		except ValueError as e:
			self.raiseException("Unsupported 'pwm_baseFreqHz' parameter value. "
				"Supported values are: 16000000, 2000000, 250000, 62500, 15625, 0.")

		# Build a list of all outputs
		self.__allOutputs = []
		self.__allOutputs.extend(self.__relays)
		self.__allOutputs.extend(self.__DOs)
		self.__allOutputs.extend(self.__GPIO_out)
		self.__allOutputs.extend(self.__PWMs)

		# Build a list of all inputs
		self.__allInputs = []
		self.__allInputs.extend(self.__DIs)
		self.__allInputs.extend(self.__GPIO_in)
		self.__allInputs.extend(self.__AIs)

	def doStartup(self):
		if not self.__pixtendInitialized:
			try:
				from pixtendlib import Pixtend
				self.__PiXtend_class = Pixtend
			except ImportError as e:
				self.raiseException("Failed to import pixtendlib.Pixtend module"
					":\n%s" % str(e))

			self.__pollInt = float(self.getParamValueByName("pollIntMs")) / 1000.0
			if self.getParamValueByName("testMode"):
				self.__pollInt = 0.0 # In test mode use poll interval = 0

			# Initialize PiXtend
			try:
				self.__pixtend = self.__PiXtend_class()
				self.__pixtend.open()
				t = 0
				while not self.__pixtendPoll(self.cpu.now):
					t += 1
					if t >= 50:
						self.raiseException("Timeout waiting "
							"for PiXtend auto-mode.")
					time.sleep(self.__pollInt)
			except Exception as e:
				self.raiseException("Failed to init PiXtend: %s" % (
					str(e)))
			self.__build()

			self.__nextPoll = self.cpu.now + self.__pollInt
			self.__pixtendInitialized = True

	def doShutdown(self):
		if self.__pixtendInitialized:
			self.__pixtend.close()
			self.__pixtend = None
			self.__pixtendInitialized = False

	def readInputs(self): #+cdef
#@cy		cdef S7CPU cpu
#@cy		cdef uint32_t size
#@cy		cdef bytearray data
#@cy		cdef AbstractIO inp

		cpu = self.cpu

		size = self.__inSize
		if size:
			data = cpu.fetchInputRange(self.__inBase, size)

			# Handle all inputs
			for inp in self.__allInputs:
				inp.get(data)

			cpu.storeInputRange(self.__inBase, data)

	def writeOutputs(self): #+cdef
#@cy		cdef S7CPU cpu
#@cy		cdef uint32_t size
#@cy		cdef double now
#@cy		cdef bytearray data
#@cy		cdef AbstractIO out

		cpu = self.cpu

		size = self.__outSize
		if size:
			data = cpu.fetchOutputRange(self.__outBase, size)

			# Handle all outputs (except DAC/AnalogOut)
			for out in self.__allOutputs:
				out.set(data)

		# Run one PiXtend poll cycle, if required.
		now = cpu.now
		if now >= self.__nextPoll:
			if not self.__pixtendPoll(now):
				self.raiseException("PiXtend auto_mode() poll failed.")

			if size:
				# Handle the DAC/AnalogOut outputs.
				for out in self.__AOs:
					out.set(data)

	def __pixtendPoll(self, now): #@nocy
#@cy	cdef ExBool_t __pixtendPoll(self, double now):
		# Poll PiXtend auto_mode
		self.__nextPoll = now + self.__pollInt
		return self.__pixtend.auto_mode() == 0 and\
		       (self.__pixtend.uc_status & 1) != 0

	def __syncPixtendPoll(self): #+cdef
#@cy		cdef S7CPU cpu
#@cy		cdef uint32_t retries
#@cy		cdef uint32_t timeout

		# Synchronously run one PiXtend poll cycle.
		cpu = self.cpu
		retries = 0
		while True:
			# Wait for the next possible poll slot.
			timeout = int(self.__pollInt * 2000.0)
			while cpu.now < self.__nextPoll:
				timeout -= 1
				if timeout <= 0:
					self.raiseException("PiXtend poll wait timeout.")
				time.sleep(0.001)
				cpu.updateTimestamp()
			# Poll PiXtend.
			if not self.__pixtendPoll(cpu.now):
				retries += 1
				if retries >= 3:
					self.raiseException("PiXtend auto_mode() poll failed (sync).")

	def directReadInput(self, accessWidth, accessOffset): #@nocy
#@cy	cdef bytearray directReadInput(self, uint32_t accessWidth, uint32_t accessOffset):
		self.__syncPixtendPoll()
		pass#TODO
		return bytearray()

	def directWriteOutput(self, accessWidth, accessOffset, data): #@nocy
#@cy	cdef ExBool_t directWriteOutput(self, uint32_t accessWidth, uint32_t accessOffset, bytearray data) except ExBool_val:
		pass#TODO
		self.__syncPixtendPoll()
		return False

# Module entry point
HardwareInterface = HardwareInterface_PiXtend