#!/usr/bin/env python3

#
# This file is part of LiteX-Boards.
#
# Copyright (c) 2020 Fei Gao <feig@princeton.edu>
# Copyright (c) 2020 Florent Kermarrec <florent@enjoy-digital.fr>
# Copyright (c) 2022 Jiajie Chen <c@jia.je>
# SPDX-License-Identifier: BSD-2-Clause

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

from litex.gen import *

from litex_boards.platforms import xilinx_vcu128

from litex.soc.cores.clock import *
from litex.soc.cores.ram.xilinx_usp_hbm2 import USPHBM2
from litex.soc.interconnect.axi import *
from litex.soc.integration.soc_core import *
from litex.soc.integration.soc import SoCRegion
from litex.soc.integration.builder import *
from litex.soc.cores.led import LedChaser

from litedram.modules import MT40A512M16
from litedram.phy import usddrphy

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

class _CRG(LiteXModule):
    def __init__(self, platform, sys_clk_freq, with_hbm):
        self.rst       = Signal()
        self.cd_sys    = ClockDomain()
        if with_hbm:
            self.cd_hbm_ref = ClockDomain()
            self.cd_apb     = ClockDomain()
        else: # DDR4
            self.cd_sys4x  = ClockDomain()
            self.cd_pll4x  = ClockDomain()
            self.cd_idelay = ClockDomain()

        # # #

        self.pll = pll = USMMCM(speedgrade=-2)
        self.comb += pll.reset.eq(platform.request("cpu_reset") | self.rst)
        pll.register_clkin(platform.request("clk100_ddr4"), 100e6)
        if with_hbm:
            pll.create_clkout(self.cd_sys,     sys_clk_freq)
            pll.create_clkout(self.cd_hbm_ref, 100e6)
            pll.create_clkout(self.cd_apb,     100e6)
            platform.add_false_path_constraints(self.cd_sys.clk, self.cd_apb.clk)
        else:
            pll.create_clkout(self.cd_pll4x, sys_clk_freq*4, buf=None, with_reset=False)
            pll.create_clkout(self.cd_idelay, 500e6)
            platform.add_false_path_constraints(self.cd_sys.clk, pll.clkin) # Ignore sys_clk to pll.clkin path created by SoC's rst.

            self.specials += [
                Instance("BUFGCE_DIV",
                    p_BUFGCE_DIVIDE=4,
                    i_CE=1, i_I=self.cd_pll4x.clk, o_O=self.cd_sys.clk),
                Instance("BUFGCE",
                    i_CE=1, i_I=self.cd_pll4x.clk, o_O=self.cd_sys4x.clk),
            ]

            self.idelayctrl = USIDELAYCTRL(cd_ref=self.cd_idelay, cd_sys=self.cd_sys)

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

class BaseSoC(SoCCore):
    def __init__(self, sys_clk_freq=125e6, with_led_chaser=True, with_hbm=False, **kwargs):
        platform = xilinx_vcu128.Platform()

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

        # SoCCore ----------------------------------------------------------------------------------
        SoCCore.__init__(self, platform, sys_clk_freq, ident="LiteX SoC on VCU128", **kwargs)

        # HBM --------------------------------------------------------------------------------------
        if with_hbm:
            # Add HBM Core.
            self.hbm = hbm = ClockDomainsRenamer({"axi": "sys"})(USPHBM2(platform))

            # Get HBM .xci.
            os.system("wget https://github.com/litex-hub/litex-boards/files/6893157/hbm_0.xci.txt")
            os.makedirs("ip/hbm", exist_ok=True)
            os.system("mv hbm_0.xci.txt ip/hbm/hbm_0.xci")

            # Connect four of the HBM's AXI interfaces to the main bus of the SoC.
            for i in range(4):
                axi_hbm      = hbm.axi[i]
                axi_lite_hbm = AXILiteInterface(data_width=256, address_width=33)
                self.submodules += AXILite2AXI(axi_lite_hbm, axi_hbm)
                self.bus.add_slave(f"hbm{i}", axi_lite_hbm, SoCRegion(origin=0x4000_0000 + 0x1000_0000*i, size=0x1000_0000)) # 256MB.
            # Link HBM2 channel 0 as main RAM
            self.bus.add_region("main_ram", SoCRegion(origin=0x4000_0000, size=0x1000_0000, linker=True)) # 256MB.
        elif not self.integrated_main_ram_size:
            # DDR4 SDRAM -------------------------------------------------------------------------------
            self.ddrphy = usddrphy.USPDDRPHY(
                pads             = platform.request("ddram"),
                memtype          = "DDR4",
                sys_clk_freq     = sys_clk_freq,
                is_clam_shell    = True,
                iodelay_clk_freq = 500e6)
            self.add_sdram("sdram",
                phy           = self.ddrphy,
                module        = MT40A512M16(sys_clk_freq, "1:4"),
                size          = 0x40000000,
                l2_cache_size = kwargs.get("l2_size", 8192)
            )

        # 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=xilinx_vcu128.Platform, description="LiteX SoC on VCU128.")
    parser.add_target_argument("--sys-clk-freq",  default=125e6, type=float, help="System clock frequency.")
    parser.add_target_argument("--with-hbm",      action="store_true",       help="Use HBM2.")
    args = parser.parse_args()

    soc = BaseSoC(
        sys_clk_freq = args.sys_clk_freq,
        with_hbm     = args.with_hbm,
        **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()