#!/usr/bin/env python3

# This file is Copyright (c) 2018-2019 Florent Kermarrec <florent@enjoy-digital.fr>
# License: BSD

import argparse

from migen import *

from litex_boards.platforms import nexys4ddr

from litex.soc.cores.clock import *
from litex.soc.integration.soc_sdram import *
from litex.soc.integration.builder import *

from litedram.modules import MT47H64M16
from litedram.phy import s7ddrphy

from liteeth.phy.rmii import LiteEthPHYRMII
from liteeth.mac import LiteEthMAC

# CRG ----------------------------------------------------------------------------------------------

class _CRG(Module):
    def __init__(self, platform, sys_clk_freq):
        self.clock_domains.cd_sys       = ClockDomain()
        self.clock_domains.cd_sys2x     = ClockDomain(reset_less=True)
        self.clock_domains.cd_sys2x_dqs = ClockDomain(reset_less=True)
        self.clock_domains.cd_clk200    = ClockDomain()
        self.clock_domains.cd_eth       = ClockDomain()

        # # #

        self.submodules.pll = pll = S7MMCM(speedgrade=-1)
        self.comb += pll.reset.eq(~platform.request("cpu_reset"))
        pll.register_clkin(platform.request("clk100"), 100e6)
        pll.create_clkout(self.cd_sys,       sys_clk_freq)
        pll.create_clkout(self.cd_sys2x,     2*sys_clk_freq)
        pll.create_clkout(self.cd_sys2x_dqs, 2*sys_clk_freq, phase=90)
        pll.create_clkout(self.cd_clk200,    200e6)
        pll.create_clkout(self.cd_eth,       50e6)

        self.submodules.idelayctrl = S7IDELAYCTRL(self.cd_clk200)

# BaseSoC ------------------------------------------------------------------------------------------

class BaseSoC(SoCSDRAM):
    def __init__(self, sys_clk_freq=int(100e6), **kwargs):
        platform = nexys4ddr.Platform()

        # SoCSDRAM ---------------------------------------------------------------------------------
        SoCSDRAM.__init__(self, platform, clk_freq=sys_clk_freq, **kwargs)

        # CRG --------------------------------------------------------------------------------------
        self.submodules.crg = _CRG(platform, sys_clk_freq)

        # DDR2 SDRAM -------------------------------------------------------------------------------
        if not self.integrated_main_ram_size:
            self.submodules.ddrphy = s7ddrphy.A7DDRPHY(platform.request("ddram"),
                memtype      = "DDR2",
                nphases      = 2,
                sys_clk_freq = sys_clk_freq)
            self.add_csr("ddrphy")
            sdram_module = MT47H64M16(sys_clk_freq, "1:2")
            self.register_sdram(self.ddrphy,
                geom_settings   = sdram_module.geom_settings,
                timing_settings = sdram_module.timing_settings)

# EthernetSoC --------------------------------------------------------------------------------------

class EthernetSoC(BaseSoC):
    mem_map = {
        "ethmac": 0xb0000000,
    }
    mem_map.update(BaseSoC.mem_map)

    def __init__(self, **kwargs):
        BaseSoC.__init__(self, **kwargs)

        # Ethernet ---------------------------------------------------------------------------------
        # phy
        self.submodules.ethphy = LiteEthPHYRMII(
            clock_pads = self.platform.request("eth_clocks"),
            pads       = self.platform.request("eth"))
        self.add_csr("ethphy")
        # mac
        self.submodules.ethmac = LiteEthMAC(
            phy        = self.ethphy,
            dw         = 32,
            interface  = "wishbone",
            endianness = self.cpu.endianness)
        self.add_wb_slave(self.mem_map["ethmac"], self.ethmac.bus, 0x2000)
        self.add_memory_region("ethmac", self.mem_map["ethmac"], 0x2000, type="io")
        self.add_csr("ethmac")
        self.add_interrupt("ethmac")
        # timing constraints
        self.platform.add_period_constraint(self.ethphy.crg.cd_eth_rx.clk, 1e9/25e6)
        self.platform.add_period_constraint(self.ethphy.crg.cd_eth_tx.clk, 1e9/25e6)
        self.platform.add_false_path_constraints(
            self.crg.cd_sys.clk,
            self.ethphy.crg.cd_eth_rx.clk,
            self.ethphy.crg.cd_eth_tx.clk)

# Build --------------------------------------------------------------------------------------------

def main():
    parser = argparse.ArgumentParser(description="LiteX SoC on Nexys4DDR")
    builder_args(parser)
    soc_sdram_args(parser)
    parser.add_argument("--sys-clk-freq", default=75e6,
                        help="system clock frequency (default=75MHz)")
    parser.add_argument("--with-ethernet", action="store_true",
                        help="enable Ethernet support")
    args = parser.parse_args()

    cls = EthernetSoC if args.with_ethernet else BaseSoC
    soc = cls(sys_clk_freq=int(float(args.sys_clk_freq)), **soc_sdram_argdict(args))
    builder = Builder(soc, **builder_argdict(args))
    builder.build()


if __name__ == "__main__":
    main()