#!/usr/bin/env python3

# This file is Copyright (c) 2013-2014 Sebastien Bourdeauducq <sb@m-labs.hk>
# This file is Copyright (c) 2014-2019 Florent Kermarrec <florent@enjoy-digital.fr>
# This file is Copyright (c) 2014 Yann Sionneau <ys@m-labs.hk>
# License: BSD

import os
import argparse
from fractions import Fraction

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

from litex.build.io import DDROutput

from litex_boards.platforms import minispartan6

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 AS4C16M16
from litedram.phy import GENSDRPHY

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

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

        # # #

        self.submodules.pll = pll = S6PLL(speedgrade=-1)
        pll.register_clkin(platform.request("clk32"), 32e6)
        pll.create_clkout(self.cd_sys,    clk_freq)
        pll.create_clkout(self.cd_sys_ps, clk_freq, phase=90)

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

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

class BaseSoC(SoCCore):
    def __init__(self, sys_clk_freq=int(80e6), **kwargs):
        platform = minispartan6.Platform()

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

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

        # SDR SDRAM --------------------------------------------------------------------------------
        if not self.integrated_main_ram_size:
            self.submodules.sdrphy = GENSDRPHY(platform.request("sdram"))
            self.add_sdram("sdram",
                phy                     = self.sdrphy,
                module                  = AS4C16M16(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
            )

        # Leds -------------------------------------------------------------------------------------
        self.submodules.leds = LedChaser(
            pads         = Cat(*[platform.request("user_led", i) for i in range(8)]),
            sys_clk_freq = sys_clk_freq)
        self.add_csr("leds")

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

def main():
    parser = argparse.ArgumentParser(description="LiteX SoC on MiniSpartan6")
    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)
    args = parser.parse_args()

    soc = BaseSoC(**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()