#!/usr/bin/env python3

#
# This file is part of LiteX-Boards.
#
# Copyright (c) 2019-2020 Florent Kermarrec <florent@enjoy-digital.fr>
# SPDX-License-Identifier: BSD-2-Clause

import os
import argparse

from migen import *

from litex.build.io import DDROutput

from litex_boards.platforms import linsn_rv901t

from litex.soc.integration.soc_core import *
from litex.soc.integration.builder import *
from litex.soc.cores.clock import S6PLL
from litex.soc.cores.led import LedChaser

from litedram.modules import M12L64322A
from litedram.phy import GENSDRPHY

from liteeth.phy.s6rgmii import LiteEthPHYRGMII

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

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

        # # #

        clk25 = platform.request("clk25")

        self.submodules.pll = pll = S6PLL(speedgrade=-2)
        self.comb += pll.reset.eq(self.rst)
        pll.register_clkin(clk25, 25e6)
        pll.create_clkout(self.cd_sys,    sys_clk_freq)
        pll.create_clkout(self.cd_sys_ps, sys_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(75e6), with_ethernet=False, with_etherbone=False, eth_phy=0, with_led_chaser=True, **kwargs):
        platform     = linsn_rv901t.Platform()

        # SoCCore ----------------------------------------------------------------------------------
        SoCCore.__init__(self, platform, sys_clk_freq,
            ident          = "LiteX SoC on Linsn RV901T",
            ident_version  = True,
            **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"), sys_clk_freq)
            self.add_sdram("sdram",
                phy           = self.sdrphy,
                module        = M12L64322A(sys_clk_freq, "1:1"),
                l2_cache_size = kwargs.get("l2_size", 8192)
            )

        # Ethernet / Etherbone ---------------------------------------------------------------------
        if with_ethernet or with_etherbone:
            self.submodules.ethphy = LiteEthPHYRGMII(
                clock_pads = self.platform.request("eth_clocks", eth_phy),
                pads       = self.platform.request("eth", eth_phy),
                tx_delay   = 0e-9)
            if with_ethernet:
                self.add_ethernet(phy=self.ethphy, with_timing_constraints=False)
            if with_etherbone:
                self.add_etherbone(phy=self.ethphy, with_timing_constraints=False)
            # Timing Constraints.
            platform.add_period_constraint(platform.lookup_request("eth_clocks", eth_phy).rx, 1e9/125e6)
            platform.add_false_path_constraints(self.crg.cd_sys.clk, platform.lookup_request("eth_clocks", eth_phy).rx)

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

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

def main():
    parser = argparse.ArgumentParser(description="LiteX SoC on Linsn RV901T")
    parser.add_argument("--build",         action="store_true", help="Build bitstream.")
    parser.add_argument("--load",          action="store_true", help="Load bitstream.")
    parser.add_argument("--sys-clk-freq",  default=75e6,        help="System clock frequency.")
    ethopts = parser.add_mutually_exclusive_group()
    ethopts.add_argument("--with-ethernet",  action="store_true", help="Enable Ethernet support.")
    ethopts.add_argument("--with-etherbone", action="store_true", help="Enable Etherbone support.")
    parser.add_argument("--eth-phy",         default=0, type=int, help="Ethernet PHY (0 or 1).")
    builder_args(parser)
    soc_core_args(parser)
    args = parser.parse_args()

    soc = BaseSoC(
        sys_clk_freq   = int(float(args.sys_clk_freq)),
        with_ethernet  = args.with_ethernet,
        with_etherbone = args.with_etherbone,
        eth_phy        = int(args.eth_phy),
        **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(os.path.join(builder.gateware_dir, soc.build_name + ".bit"))

if __name__ == "__main__":
    main()