import os
from operator import itemgetter
from collections import defaultdict
from math import ceil

from migen.fhdl.std import *
from migen.bank import csrgen
from migen.bus import wishbone, csr, lasmibus, dfi
from migen.bus import wishbone2lasmi, wishbone2csr

from misoclib import lm32, uart, dfii, lasmicon, identifier, timer, memtest

class GenSoC(Module):
	csr_base = 0xe0000000
	csr_map = {
		"crg":					0, # user
		"uart":					1, # provided
		"identifier":			2, # provided
		"timer0":				3, # provided
		"buttons":				4, # user
		"leds":					5, # user
	}
	interrupt_map = {
		"uart":			0,
		"timer0":		1,
	}
	known_platform_id = defaultdict(lambda: 0x554E, {
		"mixxeo":	0x4D58,
		"m1":		0x4D31
	})

	def __init__(self, platform, clk_freq, sram_size, l2_size=0):
		self.clk_freq = clk_freq
		self.sram_size = sram_size
		self.l2_size = l2_size

		# Wishbone
		self.submodules.cpu = lm32.LM32()
		self.submodules.sram = wishbone.SRAM(sram_size)
		self.submodules.wishbone2csr = wishbone2csr.WB2CSR()

		# rom          0x00000000 (shadow @0x80000000) user
		# SRAM/debug   0x10000000 (shadow @0x90000000) provided
		# CSR bridge   0x60000000 (shadow @0xe0000000) provided
		self._wb_masters = [self.cpu.ibus, self.cpu.dbus]
		self._wb_slaves = [
			(lambda a: a[26:29] == 1, self.sram.bus),
			(lambda a: a[27:29] == 3, self.wishbone2csr.wishbone)
		]

		# CSR
		self.submodules.uart = uart.UART(platform.request("serial"), clk_freq, baud=115200)
		self.submodules.identifier = identifier.Identifier(self.known_platform_id[platform.name], int(clk_freq),
			log2_int(l2_size) if l2_size else 0)
		self.submodules.timer0 = timer.Timer()

		# add LM32 verilog sources
		platform.add_sources(os.path.join("verilog", "lm32", "submodule", "rtl"), 
			"lm32_cpu.v", "lm32_instruction_unit.v", "lm32_decoder.v",
			"lm32_load_store_unit.v", "lm32_adder.v", "lm32_addsub.v", "lm32_logic_op.v",
			"lm32_shifter.v", "lm32_multiplier.v", "lm32_mc_arithmetic.v",
			"lm32_interrupt.v", "lm32_ram.v", "lm32_dp_ram.v", "lm32_icache.v",
			"lm32_dcache.v", "lm32_top.v", "lm32_debug.v", "lm32_jtag.v", "jtag_cores.v",
			"jtag_tap_spartan6.v", "lm32_itlb.v", "lm32_dtlb.v")
		platform.add_sources(os.path.join("verilog", "lm32"), "lm32_config.v")

	def add_wb_master(self, wbm):
		if self.finalized:
			raise FinalizeError
		self._wb_masters.append(wbm)

	def add_wb_slave(self, address_decoder, interface):
		if self.finalized:
			raise FinalizeError
		self._wb_slaves.append((address_decoder, interface))

	def do_finalize(self):
		# Wishbone
		self.submodules.wishbonecon = wishbone.InterconnectShared(self._wb_masters,
			self._wb_slaves, register=True)

		# CSR
		self.submodules.csrbankarray = csrgen.BankArray(self,
			lambda name, memory: self.csr_map[name if memory is None else name + "_" + memory.name_override])
		self.submodules.csrcon = csr.Interconnect(self.wishbone2csr.csr, self.csrbankarray.get_buses())

		# Interrupts
		for k, v in sorted(self.interrupt_map.items(), key=itemgetter(1)):
			if hasattr(self, k):
				self.comb += self.cpu.interrupt[v].eq(getattr(self, k).ev.irq)

	def ns(self, t, margin=True):
		clk_period_ns = 1000000000/self.clk_freq
		if margin:
			t += clk_period_ns/2
		return ceil(t/clk_period_ns)

class SDRAMSoC(GenSoC):
	csr_map = {
		"dfii":					6,
		"lasmicon":				7,
		"memtest_w":			8,
		"memtest_r":			9
	}
	csr_map.update(GenSoC.csr_map)

	def __init__(self, platform, clk_freq, sram_size, l2_size, with_memtest):
		GenSoC.__init__(self, platform, clk_freq, sram_size, l2_size)
		self.with_memtest = with_memtest
		self._sdram_modules_created = False

	def create_sdram_modules(self, phy_dfi, phy_settings, sdram_geom, sdram_timing):
		if self._sdram_modules_created:
			raise FinalizeError
		self._sdram_modules_created = True

		# DFI
		self.submodules.dfii = dfii.DFIInjector(sdram_geom.mux_a, sdram_geom.bank_a,
			phy_settings.dfi_d, phy_settings.nphases)
		self.submodules.dficon0 = dfi.Interconnect(self.dfii.master, phy_dfi)

		# LASMI
		self.submodules.lasmicon = lasmicon.LASMIcon(phy_settings, sdram_geom, sdram_timing)
		self.submodules.dficon1 = dfi.Interconnect(self.lasmicon.dfi, self.dfii.slave)

		self.submodules.lasmixbar = lasmibus.Crossbar([self.lasmicon.lasmic], self.lasmicon.nrowbits)

		if self.with_memtest:
			self.submodules.memtest_w = memtest.MemtestWriter(self.lasmixbar.get_master())
			self.submodules.memtest_r = memtest.MemtestReader(self.lasmixbar.get_master())

		# Wishbone bridge: map SDRAM at 0x40000000 (shadow @0xc0000000)
		self.submodules.wishbone2lasmi = wishbone2lasmi.WB2LASMI(self.l2_size//4, self.lasmixbar.get_master())
		self.add_wb_slave(lambda a: a[27:29] == 2, self.wishbone2lasmi.wishbone)

	def do_finalize(self):
		if not self._sdram_modules_created:
			raise FinalizeError("Need to call SDRAMSoC.create_sdram_modules()")
		GenSoC.do_finalize(self)