#!/usr/bin/env python3

#
# This file is part of LiteX-Boards.
#
# Copyright (c) 2021 Martin Troiber <martin.troiber@gmail.com>
# Copyright (c) 2019-2020 Florent Kermarrec <florent@enjoy-digital.fr>
# SPDX-License-Identifier: BSD-2-Clause

from migen import *

from litex.gen import LiteXModule

from litex_boards.platforms import tul_pynq_z2

from litex.soc.interconnect import axi
from litex.soc.interconnect import wishbone

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

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

class _CRG(LiteXModule):
    def __init__(self, platform, sys_clk_freq, use_ps7_clk=False):
        self.rst    = Signal()
        self.cd_sys = ClockDomain()

        # # #

        if use_ps7_clk:
            assert sys_clk_freq == 100e6
            self.comb += ClockSignal("sys").eq(ClockSignal("ps7"))
            self.comb += ResetSignal("sys").eq(ResetSignal("ps7") | self.rst)
        else:
            self.pll = pll = S7PLL(speedgrade=-1)
            self.comb += pll.reset.eq(self.rst) # ensure that ethernet is connected otherwise the CPU will reset every 2-3 seconds
            pll.register_clkin(platform.request("clk125"), 125e6)
            pll.create_clkout(self.cd_sys, sys_clk_freq)
            platform.add_false_path_constraints(self.cd_sys.clk, pll.clkin) # Ignore sys_clk to pll.clkin path created by SoC's rst.

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

class BaseSoC(SoCCore):
    def __init__(self, sys_clk_freq=100e6, **kwargs):
        platform = tul_pynq_z2.Platform()

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

        # SoCCore ----------------------------------------------------------------------------------
        if kwargs["uart_name"] == "serial":
            kwargs["uart_name"] = "usb_uart" # Use USB-UART Pmod on JB.
        SoCCore.__init__(self, platform, sys_clk_freq, ident="LiteX SoC on Pynq Z2", **kwargs)

        # Zynq7000 Integration ---------------------------------------------------------------------
        if kwargs.get("cpu_type", None) == "zynq7000":
            raise NotImplementedError

        # Leds -------------------------------------------------------------------------------------
        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=tul_pynq_z2.Platform, description="LiteX SoC on Pynq Z2.")
    parser.add_target_argument("--sys-clk-freq", default=100e6, type=float, help="System clock frequency.")
    args = parser.parse_args()

    soc = BaseSoC(
        sys_clk_freq = args.sys_clk_freq,
        **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"), device=1)

if __name__ == "__main__":
    main()