#!/usr/bin/env python3

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

import os
import argparse

from migen import *

from litex_boards.platforms import nexys4ddr

from litex.soc.cores.clock import *
from litex.soc.integration.soc_core import *
from litex.soc.integration.soc_sdram import *
from litex.soc.integration.builder import *
from litex.soc.cores.led import LedChaser

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

from liteeth.phy.rmii import LiteEthPHYRMII

# 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(SoCCore):
    def __init__(self, sys_clk_freq=int(75e6), with_ethernet=False, **kwargs):
        platform = nexys4ddr.Platform()

        # SoCCore ----------------------------------_-----------------------------------------------
        SoCCore.__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")
            self.add_sdram("sdram",
                phy                     = self.ddrphy,
                module                  = MT47H64M16(sys_clk_freq, "1:2"),
                origin                  = self.mem_map["main_ram"],
                size                    = kwargs.get("max_sdram_size", 0x40000000),
                l2_cache_size           = kwargs.get("l2_size", 8192),
                l2_cache_min_data_width = kwargs.get("min_l2_data_width", 128),
                l2_cache_reverse        = True
            )

        # Ethernet ---------------------------------------------------------------------------------
        if with_ethernet:
            self.submodules.ethphy = LiteEthPHYRMII(
                clock_pads = self.platform.request("eth_clocks"),
                pads       = self.platform.request("eth"))
            self.add_csr("ethphy")
            self.add_ethernet(phy=self.ethphy)

        # Leds -------------------------------------------------------------------------------------
        self.submodules.leds = LedChaser(
            pads         = Cat(*[platform.request("user_led", i) for i in range(16)]),
            sys_clk_freq = sys_clk_freq)
        self.add_csr("leds")

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

def main():
    parser = argparse.ArgumentParser(description="LiteX SoC on Nexys4DDR")
    parser.add_argument("--build", action="store_true", help="Build bitstream")
    parser.add_argument("--load",  action="store_true", help="Load bitstream")
    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()

    soc = BaseSoC(sys_clk_freq=int(float(args.sys_clk_freq)),
        with_ethernet=args.with_ethernet,
        **soc_sdram_argdict(args))
    builder = Builder(soc, **builder_argdict(args))
    builder.build(run=args.build)

    if args.load:
        prog = soc.platform.create_programmer()
        prog.load_bitstream(os.path.join(builder.gateware_dir, "top.bit"))

if __name__ == "__main__":
    main()