#!/usr/bin/env python3

#
# This file is part of LiteX-Boards.
#
# Copyright (c) 2021 Florent Kermarrec <florent@enjoy-digital.fr>
# SPDX-License-Identifier: BSD-2-Clause

import os
import argparse
import sys

from migen import *

from litex_boards.platforms import litex_m2_baseboard

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.builder import *

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

class _CRG(Module):
    def __init__(self, platform, sys_clk_freq):
        self.rst = Signal()
        self.clock_domains.cd_por     = ClockDomain(reset_less=True)
        self.clock_domains.cd_sys     = ClockDomain()
        # # #

        # Clk / Rst
        clk50 = platform.request("clk50")

        # Power on reset
        por_count = Signal(16, reset=2**16-1)
        por_done  = Signal()
        self.comb += self.cd_por.clk.eq(clk50)
        self.comb += por_done.eq(por_count == 0)
        self.sync.por += If(~por_done, por_count.eq(por_count - 1))

        # PLL
        self.submodules.pll = pll = ECP5PLL()
        self.comb += pll.reset.eq(~por_done | self.rst)
        pll.register_clkin(clk50, 50e6)
        pll.create_clkout(self.cd_sys, sys_clk_freq)

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

class BaseSoC(SoCCore):
    def __init__(self, sys_clk_freq=int(75e6), **kwargs):
        platform = litex_m2_baseboard.Platform(toolchain="trellis")

        # SoCCore ----------------------------------------------------------------------------------
        SoCCore.__init__(self, platform, sys_clk_freq,
            ident          = "LiteX SoC on LiteX M2 Baseboard",
            ident_version  = True,
            **kwargs)

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

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

def main():
    parser = argparse.ArgumentParser(description="LiteX SoC on LiteX M2 Baseboard")
    parser.add_argument("--build",        action="store_true", help="Build bitstream")
    parser.add_argument("--load",         action="store_true", help="Load bitstream")
    parser.add_argument("--flash",        action="store_true", help="Flash bitstream to SPI Flash")
    parser.add_argument("--sys-clk-freq", default=75e6,        help="System clock frequency (default: 75MHz)")
    builder_args(parser)
    soc_core_args(parser)
    trellis_args(parser)
    args = parser.parse_args()

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

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

    if args.flash:
        prog = soc.platform.create_programmer()
        prog.flash(None, os.path.join(builder.gateware_dir, soc.build_name + ".bit"))

if __name__ == "__main__":
    main()