#!/usr/bin/env python3

# This file is Copyright (c) 2018-2019 Florent Kermarrec <florent@enjoy-digital.fr>
# This file is Copyright (c) 2018 David Shah <dave@ds0.me>
# License: BSD

import argparse
import sys

from migen import *
from migen.genlib.resetsync import AsyncResetSynchronizer

from litex.build.io import DDROutput

from litex_boards.platforms import ulx3s

from litex.build.lattice.trellis import trellis_args, trellis_argdict

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 litedram import modules as litedram_modules
from litedram.phy import GENSDRPHY

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

class _CRG(Module):
    def __init__(self, platform, sys_clk_freq, with_usb_pll=False):
        self.clock_domains.cd_sys    = ClockDomain()
        self.clock_domains.cd_sys_ps = ClockDomain(reset_less=True)

        # # #

        # Clk / Rst
        clk25 = platform.request("clk25")
        rst   = platform.request("rst")
        platform.add_period_constraint(clk25, 1e9/25e6)

        # PLL
        self.submodules.pll = pll = ECP5PLL()
        self.comb += pll.reset.eq(rst)
        pll.register_clkin(clk25, 25e6)
        pll.create_clkout(self.cd_sys,    sys_clk_freq, margin=0)
        pll.create_clkout(self.cd_sys_ps, sys_clk_freq, phase=90)
        self.specials += AsyncResetSynchronizer(self.cd_sys, ~pll.locked | rst)

        # USB PLL
        if with_usb_pll:
            self.clock_domains.cd_usb_12 = ClockDomain()
            self.clock_domains.cd_usb_48 = ClockDomain()
            pll.create_clkout(self.cd_usb_12, 12e6, margin=0)
            self.comb += self.cd_usb_48.clk.eq(self.cd_sys.clk)

        # SDRAM clock
        self.specials += DDROutput(1, 0, platform.request("sdram_clock"), ClockSignal("sys_ps"))

        # Prevent ESP32 from resetting FPGA
        self.comb += platform.request("wifi_gpio0").eq(1)

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

class BaseSoC(SoCCore):
    def __init__(self, device="LFE5U-45F", toolchain="trellis",
        sys_clk_freq=int(50e6), sdram_module_cls="MT48LC16M16", **kwargs):

        platform = ulx3s.Platform(device=device, toolchain=toolchain)

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

        # CRG --------------------------------------------------------------------------------------
        with_usb_pll = kwargs.get("uart_name", None) == "usb_cdc"
        self.submodules.crg = _CRG(platform, sys_clk_freq, with_usb_pll)

        # SDR SDRAM --------------------------------------------------------------------------------
        if not self.integrated_main_ram_size:
            self.submodules.sdrphy = GENSDRPHY(platform.request("sdram"))
            self.add_sdram("sdram",
                phy                     = self.sdrphy,
                module                  = getattr(litedram_modules, sdram_module_cls)(sys_clk_freq, "1:1"),
                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
            )

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

def main():
    parser = argparse.ArgumentParser(description="LiteX SoC on ULX3S")
    parser.add_argument("--gateware-toolchain", dest="toolchain", default="trellis",
        help="gateware toolchain to use, trellis (default) or diamond")
    parser.add_argument("--device", dest="device", default="LFE5U-45F",
        help="FPGA device, ULX3S can be populated with LFE5U-45F (default) or LFE5U-85F")
    parser.add_argument("--sys-clk-freq", default=48e6,
                        help="system clock frequency (default=48MHz)")
    parser.add_argument("--sdram-module", default="MT48LC16M16",
                        help="SDRAM module: MT48LC16M16, AS4C32M16 or AS4C16M16 (default=MT48LC16M16)")
    builder_args(parser)
    soc_sdram_args(parser)
    trellis_args(parser)
    args = parser.parse_args()

    soc = BaseSoC(device=args.device, toolchain=args.toolchain,
        sys_clk_freq=int(float(args.sys_clk_freq)),
        sdram_module_cls=args.sdram_module,
        **soc_sdram_argdict(args))
    builder = Builder(soc, **builder_argdict(args))
    builder_kargs = trellis_argdict(args) if args.toolchain == "trellis" else {}
    builder.build(**builder_kargs)

if __name__ == "__main__":
    main()