#!/usr/bin/env python3

#
# This file is part of LiteX-Boards.
#
# Copyright (c) 2021 Nathaniel Lewis <github@nrlewis.dev>
# SPDX-License-Identifier: BSD-2-Clause

from migen import *

from litex.gen import LiteXModule

from litex_boards.platforms import alchitry_au

from litex.soc.interconnect.csr import *
from litex.soc.integration.soc_core import *
from litex.soc.integration.builder import *

from litex.soc.cores.clock import *
from litex.soc.cores.led import LedChaser

from litedram.modules import AS4C128M16
from litedram.phy import s7ddrphy

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

class CRG(LiteXModule):
    def __init__(self, platform, sys_clk_freq):
        self.rst          = Signal()
        self.cd_sys       = ClockDomain()
        self.cd_sys4x     = ClockDomain()
        self.cd_sys4x_dqs = ClockDomain()
        self.cd_idelay    = ClockDomain()

        # Clk/Rst
        clk100 = platform.request("clk100")

        # PLL
        self.pll = pll = S7PLL()
        self.comb += pll.reset.eq(~platform.request("cpu_reset") | self.rst)
        pll.register_clkin(clk100, 100e6)
        pll.create_clkout(self.cd_sys,       sys_clk_freq)
        pll.create_clkout(self.cd_sys4x,     4*sys_clk_freq)
        pll.create_clkout(self.cd_sys4x_dqs, 4*sys_clk_freq, phase=90)
        pll.create_clkout(self.cd_idelay,    200e6)
        platform.add_false_path_constraints(self.cd_sys.clk, pll.clkin) # Ignore sys_clk to pll.clkin path created by SoC's rst.

        self.idelayctrl = S7IDELAYCTRL(self.cd_idelay)

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

class BaseSoC(SoCCore):
    def __init__(self, variant="au", sys_clk_freq=int(83333333), with_spi_flash=False, with_led_chaser=True, **kwargs):
        platform = alchitry_au.Platform(variant=variant)

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

        # SoCCore ----------------------------------------------------------------------------------
        SoCCore.__init__(self, platform, sys_clk_freq, ident="LiteX SoC on Alchitry Au(+)", **kwargs)

        # DDR3 SDRAM -------------------------------------------------------------------------------
        if not self.integrated_main_ram_size:
            self.ddrphy = s7ddrphy.A7DDRPHY(platform.request("ddram"),
                memtype          = "DDR3",
                nphases          = 4,
                sys_clk_freq     = sys_clk_freq,
                iodelay_clk_freq = 200e6)
            self.add_sdram("sdram",
                phy           = self.ddrphy,
                module        = AS4C128M16(sys_clk_freq, "1:4"),
                l2_cache_size = kwargs.get("l2_size", 8192)
            )

        # SPI Flash --------------------------------------------------------------------------------
        if with_spi_flash:
            from litespi.modules import SST26VF032B
            from litespi.opcodes import SpiNorFlashOpCodes as Codes
            self.add_spi_flash(mode="4x", module=SST26VF032B(Codes.READ_1_1_1), with_master=True)

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

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

def main():
    from litex.build.parser import LiteXArgumentParser
    parser = LiteXArgumentParser(platform=alchitry_au.Platform, description="LiteX SoC on Alchitry Au(+)")
    parser.add_target_argument("--flash",           action="store_true", help="Flash bitstream.")
    parser.add_target_argument("--variant",         default="au",        help="Board variant (au or au+).")
    parser.add_target_argument("--sys-clk-freq",    default=83333333,    help="System clock frequency.")
    parser.add_target_argument("--with-spi-flash",  action="store_true", help="Enable SPI Flash (MMAPed).")
    args = parser.parse_args()

    soc = BaseSoC(
        variant        = args.variant,
        sys_clk_freq   = int(float(args.sys_clk_freq)),
        with_spi_flash = args.with_spi_flash,
        **parser.soc_core_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 args.flash:
        prog = soc.platform.create_programmer()
        prog.flash(0, builder.get_bitstream_filename(mode="flash"))

if __name__ == "__main__":
    main()