#!/usr/bin/env python3

#
# This file is part of LiteX-Boards.
#
# Copyright (c) 2023 Fabien Caura <fabien@acathla.tk>
# SPDX-License-Identifier: BSD-2-Clause

import argparse

from migen import *

from litex.gen import LiteXModule

from litex.build.io import DDROutput

from litex_boards.platforms import gadgetfactory_papilio_pro

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

from litedram.modules import MT48LC4M16
from litedram.phy import s6ddrphy, GENSDRPHY, HalfRateGENSDRPHY

class _CRG(LiteXModule):
    def __init__(self, platform, sys_clk_freq, sdram_rate="1:1"):
        self.rst              = Signal()
        self.cd_sys           = ClockDomain()
        if sdram_rate == "1:2":
            self.cd_sys2x     = ClockDomain()
            self.cd_sys2x_ps  = ClockDomain()
        else:
            self.cd_sys_ps    = ClockDomain()
        self.cd_vga           = ClockDomain()

        # # #

        # Clk / Rst
        clk32 = platform.request("clk32")

        # PLL
        self.pll = pll = S6PLL(speedgrade=-1)
        self.comb += pll.reset.eq(self.rst)
        pll.register_clkin(clk32, 32e6)
        pll.create_clkout(self.cd_sys, sys_clk_freq)
        if sdram_rate == "1:2":
            pll.create_clkout(self.cd_sys2x,    2*sys_clk_freq)
            pll.create_clkout(self.cd_sys2x_ps, 2*sys_clk_freq, phase=90)
        else:
            pll.create_clkout(self.cd_sys_ps, sys_clk_freq, phase=90)

        pll.create_clkout(self.cd_vga, 40e6)

        # SDRAM clock
        sdram_clk = ClockSignal("sys2x_ps" if sdram_rate == "1:2" else "sys_ps")
        self.specials += DDROutput(1, 0, platform.request("sdram_clock"), sdram_clk)

### BaseSoC

class BaseSoC(SoCCore):
    def __init__(self, sys_clk_freq=80e6,
        with_led_chaser=True,
        with_video_terminal = False,
        **kwargs):
        platform = gadgetfactory_papilio_pro.Platform()

        # CRG --------------------------------------------------------------------------------------
        self.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 Papilio Pro", **kwargs)

        # SDR SDRAM --------------------------------------------------------------------------------
        if not self.integrated_main_ram_size:
            sdrphy_cls = GENSDRPHY
            self.sdrphy = sdrphy_cls(platform.request("sdram"), sys_clk_freq)
            self.add_sdram("sdram",
                phy           = self.sdrphy,
                module        = MT48LC4M16(sys_clk_freq, "1:2"),
                l2_cache_size = 0
            )

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

        # Video Terminal
        if with_video_terminal:
            self.platform.add_extension(gadgetfactory_papilio_pro._arcade_megawing)
            self.videophy = VideoVGAPHY(platform.request("vga"), clock_domain="vga")
            self.add_video_terminal(phy=self.videophy, timings="800x600@60Hz", clock_domain="vga")

def main():
    from litex.build.parser import LiteXArgumentParser
    parser = LiteXArgumentParser(platform=gadgetfactory_papilio_pro.Platform(),
      description="LiteX SoC on Papilio Pro")
    parser.add_argument("--sys-clk-freq", default=80e6, type=float, help="System clock frequency.")
    parser.add_target_argument("--with-video-terminal", action="store_true", help="Enable Video Terminal (VGA).")
    args = parser.parse_args()

    soc = BaseSoC(
        sys_clk_freq = args.sys_clk_freq,
        with_video_terminal = args.with_video_terminal,
        **parser.soc_argdict
    )
    builder = Builder(soc, **parser.builder_argdict)
    if args.build:
        builder.build(**parser.toolchain_argdict)

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

if __name__ == "__main__":
    main()