#!/usr/bin/env python3

#
# This file is part of LiteX-Boards.
#
# Copyright (c) 2021 Miodrag Milanovic <mmicko@gmail.com>
# SPDX-License-Identifier: BSD-2-Clause

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

from litex_boards.platforms import sipeed_tang_primer

from litex.build.generic_platform import *

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


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

class _CRG(Module):
    def __init__(self, platform, sys_clk_freq):
        self.clock_domains.cd_sys   = ClockDomain()

        # # #

        # Clk / Rst.
        clk24 = platform.request("clk24")
        rst_n = platform.request("user_btn", 0)

        self.comb += self.cd_sys.clk.eq(clk24)
        self.specials += AsyncResetSynchronizer(self.cd_sys, ~rst_n)

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

class BaseSoC(SoCCore):
    def __init__(self, sys_clk_freq=int(24e6), with_led_chaser=True, **kwargs):
        platform = sipeed_tang_primer.Platform()

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

        # SoCCore ----------------------------------------------------------------------------------
        if kwargs.get("cpu_type", "vexriscv") == "vexriscv":
            kwargs["cpu_variant"] = "minimal"
        SoCCore.__init__(self, platform, sys_clk_freq, ident="LiteX SoC on Tang Primer", **kwargs)

        # Leds -------------------------------------------------------------------------------------
        if with_led_chaser:
            self.submodules.leds = LedChaser(
                pads         = platform.request_all("user_led"),
                sys_clk_freq = sys_clk_freq)

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

def main():
    from litex.soc.integration.soc import LiteXSoCArgumentParser
    parser = LiteXSoCArgumentParser(description="LiteX SoC on Tang Primer")
    target_group = parser.add_argument_group(title="Target options")
    target_group.add_argument("--build",       action="store_true", help="Build bitstream.")
    target_group.add_argument("--load",        action="store_true", help="Load bitstream.")
    target_group.add_argument("--flash",       action="store_true", help="Flash Bitstream.")
    target_group.add_argument("--sys-clk-freq",default=24e6,        help="System clock frequency.")
    builder_args(parser)
    soc_core_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(run=args.build)

    if args.load:
        prog = soc.platform.create_programmer()
        prog.load_bitstream(builder.get_bitstream_filename(mode="sram"))

    if args.flash:
        prog = soc.platform.create_programmer()
        prog.load_bitstream(builder.get_bitstream_filename(mode="flash", ext=".bin")) # FIXME


if __name__ == "__main__":
    main()