#!/usr/bin/env python3

#
# This file is part of LiteX-Boards.
#
# Copyright (c) 2021 Ilia Sergachev <ilia@sergachev.ch>
# SPDX-License-Identifier: BSD-2-Clause

from migen import *

from litex.gen import *

from litex_boards.platforms import digilent_zedboard
from litex.build.tools import write_to_file

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.soc import SoCRegion
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:
            self.comb += ClockSignal("sys").eq(ClockSignal("ps7"))
            self.comb += ResetSignal("sys").eq(ResetSignal("ps7") | self.rst)
        else:
            # Clk.
            clk100 = platform.request("clk100")

            # PLL.
            self.pll = pll = S7PLL(speedgrade=-1)
            self.comb += pll.reset.eq(self.rst)
            pll.register_clkin(clk100, 100e6)
            pll.create_clkout(self.cd_sys, sys_clk_freq)
            # Ignore sys_clk to pll.clkin path created by SoC's rst.
            platform.add_false_path_constraints(self.cd_sys.clk, pll.clkin)

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


class BaseSoC(SoCCore):

    def __init__(self, sys_clk_freq=100e6, with_led_chaser=True, **kwargs):
        platform = digilent_zedboard.Platform()

        # CRG --------------------------------------------------------------------------------------
        use_ps7_clk = (kwargs.get("cpu_type", None) == "zynq7000")
        self.crg = _CRG(platform, sys_clk_freq, use_ps7_clk)

        # SoCCore ----------------------------------------------------------------------------------
        if kwargs.get("cpu_type", None) == "zynq7000":
            kwargs["integrated_sram_size"] = 0
        SoCCore.__init__(self, platform, sys_clk_freq, ident="LiteX SoC on Zedboard", **kwargs)

        # Zynq7000 Integration ---------------------------------------------------------------------
        if kwargs.get("cpu_type", None) == "zynq7000":
            self.cpu.set_ps7(name="Zynq",
                             preset="ZedBoard",
                             config={'PCW_FPGA0_PERIPHERAL_FREQMHZ': sys_clk_freq / 1e6})

            self.bus.add_region("sram", SoCRegion(
                origin = self.cpu.mem_map["sram"],
                size   = 512 * 1024 * 1024 - self.cpu.mem_map["sram"])
            )
            self.bus.add_region("rom", SoCRegion(
                origin = self.cpu.mem_map["rom"],
                size   = 256 * 1024 * 1024 // 8,
                linker = True)
            )
            self.constants["CONFIG_CLOCK_FREQUENCY"] = 666666687

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

    def finalize(self, *args, **kwargs):
        super(BaseSoC, self).finalize(*args, **kwargs)
        if self.cpu_type != "zynq7000":
            return

        libxil_path = os.path.join(self.builder.software_dir, 'libxil')
        os.makedirs(os.path.realpath(libxil_path), exist_ok=True)
        lib = os.path.join(libxil_path, 'embeddedsw')
        if not os.path.exists(lib):
            os.system("git clone --depth 1 https://github.com/Xilinx/embeddedsw {}".format(lib))

        os.makedirs(os.path.realpath(self.builder.include_dir), exist_ok=True)
        for header in [
            'XilinxProcessorIPLib/drivers/uartps/src/xuartps_hw.h',
            'lib/bsp/standalone/src/common/xil_types.h',
            'lib/bsp/standalone/src/common/xil_assert.h',
            'lib/bsp/standalone/src/common/xil_io.h',
            'lib/bsp/standalone/src/common/xil_printf.h',
            'lib/bsp/standalone/src/common/xstatus.h',
            'lib/bsp/standalone/src/common/xdebug.h',
            'lib/bsp/standalone/src/arm/cortexa9/xpseudo_asm.h',
            'lib/bsp/standalone/src/arm/cortexa9/xreg_cortexa9.h',
            'lib/bsp/standalone/src/arm/cortexa9/xil_cache.h',
            'lib/bsp/standalone/src/arm/cortexa9/xparameters_ps.h',
            'lib/bsp/standalone/src/arm/cortexa9/xil_errata.h',
            'lib/bsp/standalone/src/arm/cortexa9/xtime_l.h',
            'lib/bsp/standalone/src/arm/common/xil_exception.h',
            'lib/bsp/standalone/src/arm/common/gcc/xpseudo_asm_gcc.h',
        ]:
            shutil.copy(os.path.join(lib, header), self.builder.include_dir)
        write_to_file(os.path.join(self.builder.include_dir, 'bspconfig.h'),
                      '#define FPU_HARD_FLOAT_ABI_ENABLED 1')
        write_to_file(os.path.join(self.builder.include_dir, 'xparameters.h'), '''
#ifndef __XPARAMETERS_H
#define __XPARAMETERS_H

#include "xparameters_ps.h"

#define STDOUT_BASEADDRESS 0xE0001000
#define XPAR_PS7_DDR_0_S_AXI_BASEADDR 0x00100000
#define XPAR_PS7_DDR_0_S_AXI_HIGHADDR 0x3FFFFFFF

#endif
''')


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


def main():
    from litex.build.parser import LiteXArgumentParser
    parser = LiteXArgumentParser(platform=digilent_zedboard.Platform, description="LiteX SoC on Zedboard.")
    parser.add_target_argument("--sys-clk-freq", default=100e6, type=float, help="System clock frequency.")
    parser.set_defaults(cpu_type="zynq7000")
    parser.set_defaults(no_uart=True)
    args = parser.parse_args()

    soc = BaseSoC(
        sys_clk_freq = args.sys_clk_freq,
        **parser.soc_argdict
    )
    builder = Builder(soc, **parser.builder_argdict)
    if args.cpu_type == "zynq7000":
        soc.builder = builder
        builder.add_software_package('libxil')
        builder.add_software_library('libxil')
    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()