#!/usr/bin/env python3

#
# This file is part of LiteX-Boards.
#
# Copyright (c) 2018-2019 Florent Kermarrec <florent@enjoy-digital.fr>
# Copyright (c) 2018 David Shah <dave@ds0.me>
# SPDX-License-Identifier: BSD-2-Clause

import os
import argparse
import sys

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

from litex.build.io import DDROutput

from litex_boards.platforms import ulx3s

from litex.build.lattice.trellis import trellis_args, trellis_argdict

from litex.soc.cores.clock import *
from litex.soc.integration.soc_core import *
from litex.soc.integration.builder import *
from litex.soc.cores.video import VideoECP5HDMIPHY
from litex.soc.cores.led import LedChaser
from litex.soc.cores.spi import SPIMaster
from litex.soc.cores.gpio import GPIOOut

from litedram import modules as litedram_modules
from litedram.phy import GENSDRPHY, HalfRateGENSDRPHY

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

class _CRG(Module):
    def __init__(self, platform, sys_clk_freq, with_usb_pll=False, with_video_pll=False, sdram_rate="1:1"):
        self.rst = Signal()
        self.clock_domains.cd_sys    = ClockDomain()
        if sdram_rate == "1:2":
            self.clock_domains.cd_sys2x    = ClockDomain()
            self.clock_domains.cd_sys2x_ps = ClockDomain(reset_less=True)
        else:
            self.clock_domains.cd_sys_ps = ClockDomain(reset_less=True)

        # # #

        # Clk / Rst
        clk25 = platform.request("clk25")
        rst   = platform.request("rst")

        # PLL
        self.submodules.pll = pll = ECP5PLL()
        self.comb += pll.reset.eq(rst | self.rst)
        pll.register_clkin(clk25, 25e6)
        pll.create_clkout(self.cd_sys,    sys_clk_freq)
        if sdram_rate == "1:2":
            pll.create_clkout(self.cd_sys2x,    2*sys_clk_freq)
            pll.create_clkout(self.cd_sys2x_ps, 2*sys_clk_freq, phase=180) # Idealy 90° but needs to be increased.
        else:
           pll.create_clkout(self.cd_sys_ps, sys_clk_freq, phase=90)

        # USB PLL
        if with_usb_pll:
            self.submodules.usb_pll = usb_pll = ECP5PLL()
            self.comb += usb_pll.reset.eq(rst | self.rst)
            usb_pll.register_clkin(clk25, 25e6)
            self.clock_domains.cd_usb_12 = ClockDomain()
            self.clock_domains.cd_usb_48 = ClockDomain()
            usb_pll.create_clkout(self.cd_usb_12, 12e6, margin=0)
            usb_pll.create_clkout(self.cd_usb_48, 48e6, margin=0)

        # Video PLL
        if with_video_pll:
            self.submodules.video_pll = video_pll = ECP5PLL()
            self.comb += video_pll.reset.eq(rst | self.rst)
            video_pll.register_clkin(clk25, 25e6)
            self.clock_domains.cd_hdmi   = ClockDomain()
            self.clock_domains.cd_hdmi5x = ClockDomain()
            video_pll.create_clkout(self.cd_hdmi,    25e6, margin=0)
            video_pll.create_clkout(self.cd_hdmi5x, 125e6, margin=0)

        # SDRAM clock
        sdram_clk = ClockSignal("sys2x_ps" if sdram_rate == "1:2" else "sys_ps")
        self.specials += DDROutput(1, 0, platform.request("sdram_clock"), sdram_clk)

        # Prevent ESP32 from resetting FPGA
        self.comb += platform.request("wifi_gpio0").eq(1)

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

class BaseSoC(SoCCore):
    def __init__(self, device="LFE5U-45F", revision="2.0", toolchain="trellis",
        sys_clk_freq=int(50e6), sdram_module_cls="MT48LC16M16", sdram_rate="1:1",
        with_video_terminal=False, with_video_framebuffer=False, spiflash=False, **kwargs):
        platform = ulx3s.Platform(device=device, revision=revision, toolchain=toolchain)
        if spiflash:
            self.mem_map = {**SoCCore.mem_map, **{"spiflash": 0x80000000}}

        # SoCCore ----------------------------------------------------------------------------------
        SoCCore.__init__(self, platform, sys_clk_freq,
            ident          = "LiteX SoC on ULX3S",
            ident_version  = True,
            **kwargs)

        # CRG --------------------------------------------------------------------------------------
        with_usb_pll   = kwargs.get("uart_name", None) == "usb_acm"
        with_video_pll = with_video_terminal or with_video_framebuffer
        self.submodules.crg = _CRG(platform, sys_clk_freq, with_usb_pll, with_video_pll, sdram_rate=sdram_rate)

        # SDR SDRAM --------------------------------------------------------------------------------
        if not self.integrated_main_ram_size:
            sdrphy_cls = HalfRateGENSDRPHY if sdram_rate == "1:2" else GENSDRPHY
            self.submodules.sdrphy = sdrphy_cls(platform.request("sdram"), sys_clk_freq)
            self.add_sdram("sdram",
                phy              = self.sdrphy,
                module           = getattr(litedram_modules, sdram_module_cls)(sys_clk_freq, sdram_rate),
                size             = 0x40000000,
                l2_cache_size    = kwargs.get("l2_size", 8192),
                l2_cache_reverse = False
            )

        # Video ------------------------------------------------------------------------------------
        if with_video_terminal or with_video_framebuffer:
            self.submodules.videophy = VideoECP5HDMIPHY(platform.request("gpdi"), clock_domain="hdmi")
            if with_video_terminal:
                self.add_video_terminal(phy=self.videophy, timings="640x480@75Hz", clock_domain="hdmi")
            if with_video_framebuffer:
                self.add_video_framebuffer(phy=self.videophy, timings="640x480@75Hz", clock_domain="hdmi")
                self.comb += platform.request("ext0p").eq(self.video_framebuffer.underflow) # FIXME: Remove, used to debug SDRAM underflows.

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

    def add_oled(self):
        pads = self.platform.request("oled_spi")
        pads.miso = Signal()
        self.submodules.oled_spi = SPIMaster(pads, 8, self.sys_clk_freq, 8e6)
        self.oled_spi.add_clk_divider()

        self.submodules.oled_ctl = GPIOOut(self.platform.request("oled_ctl"))

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

def main():
    parser = argparse.ArgumentParser(description="LiteX SoC on ULX3S")
    parser.add_argument("--build",           action="store_true",   help="Build bitstream")
    parser.add_argument("--load",            action="store_true",   help="Load bitstream")
    parser.add_argument("--toolchain",       default="trellis",     help="FPGA toolchain: trellis (default) or diamond")
    parser.add_argument("--device",          default="LFE5U-45F",   help="FPGA device: LFE5U-12F, LFE5U-25F, LFE5U-45F (default)  or LFE5U-85F")
    parser.add_argument("--revision",        default="2.0",         help="Board revision: 2.0 (default) or 1.7")
    parser.add_argument("--sys-clk-freq",    default=50e6,          help="System clock frequency  (default: 50MHz)")
    parser.add_argument("--sdram-module",    default="MT48LC16M16", help="SDRAM module: MT48LC16M16 (default), AS4C32M16 or AS4C16M16")
    parser.add_argument("--with-spiflash",   action="store_true",   help="Make the SPI Flash accessible from the SoC")
    parser.add_argument("--flash-boot-adr",  type=lambda x: int(x,0), default=None, help="Flash boot address")
    sdopts = parser.add_mutually_exclusive_group()
    sdopts.add_argument("--with-spi-sdcard", action="store_true",   help="Enable SPI-mode SDCard support")
    sdopts.add_argument("--with-sdcard",     action="store_true",   help="Enable SDCard support")
    parser.add_argument("--with-oled",       action="store_true",   help="Enable SDD1331 OLED support")
    parser.add_argument("--sdram-rate",      default="1:1",         help="SDRAM Rate: 1:1 Full Rate (default), 1:2 Half Rate")
    viopts = parser.add_mutually_exclusive_group()
    viopts.add_argument("--with-video-terminal",    action="store_true", help="Enable Video Terminal (HDMI)")
    viopts.add_argument("--with-video-framebuffer", action="store_true", help="Enable Video Framebuffer (HDMI)")
    builder_args(parser)
    soc_core_args(parser)
    trellis_args(parser)
    args = parser.parse_args()

    soc = BaseSoC(
        device                 = args.device,
        revision               = args.revision,
        toolchain              = args.toolchain,
        sys_clk_freq           = int(float(args.sys_clk_freq)),
        sdram_module_cls       = args.sdram_module,
        sdram_rate             = args.sdram_rate,
        with_video_terminal    = args.with_video_terminal,
        with_video_framebuffer = args.with_video_framebuffer,
        spiflash               = args.with_spiflash,
        **soc_core_argdict(args))
    if args.with_spi_sdcard:
        soc.add_spi_sdcard()
    if args.with_sdcard:
        soc.add_sdcard()
    if args.with_oled:
        soc.add_oled()
    if args.with_spiflash:
        soc.add_spi_flash(mode="1x", dummy_cycles=8)
        if args.flash_boot_adr:
            soc.add_constant("FLASH_BOOT_ADDRESS", args.flash_boot_adr)

    builder = Builder(soc, **builder_argdict(args))
    builder_kargs = trellis_argdict(args) if args.toolchain == "trellis" else {}
    builder.build(**builder_kargs, run=args.build)

    if args.load:
        prog = soc.platform.create_programmer()
        prog.load_bitstream(os.path.join(builder.gateware_dir, soc.build_name + ".svf"))

if __name__ == "__main__":
    main()
