-- -------------------------------------------------------------------------- --
--               TRASHERNET - A Trashy Ethernet Stack for FPGAs               --
-- -------------------------------------------------------------------------- --
-- top_hwitl.vhd: Top level design for hardware-in-the-loop tests
--
--   Target: Simulation
-- -------------------------------------------------------------------------- --
-- Author       : Markus Koch <markus@notsyncing.net>
-- Contributors : None
-- License      : Mozilla Public License (MPL) Version 2
-- -------------------------------------------------------------------------- --

library ieee;
use ieee.std_logic_1164.all;
use ieee.numeric_std.all;

use ieee.math_real.all;

library trashernet;
use trashernet.trashernet_pkg.all;

entity top_hwitl is
	port(
		clk        : in  std_logic;
		rst_n      : in  std_logic;
		rx_p       : in  std_logic;
		tx_p       : out std_logic;
		tx_n       : out std_logic;
		led_n      : out std_logic_vector(7 downto 0); -- @suppress: Used in different architectures
		button_n   : in  std_logic_vector(3 downto 0); -- @suppress: Used in different architectures
		debug_data : out std_logic_vector(7 downto 0) -- @suppress: Used in different architectures
	);
end entity top_hwitl;

architecture mac of top_hwitl is
	component pll0
		port(
			CLK   : in  std_logic;
			CLKOP : out std_logic;
			LOCK  : out std_logic
		);
	end component pll0;

	constant F_CLK     : integer := 50000000;
	constant F_CLK_PHY : integer := 140000000;

	constant ETH_CONFIG : configuration_t := (
		mac_address => (x"00", x"ff", x"ff", x"11", x"22", x"33")
	);

	signal rst     : std_logic;
	signal clk_phy : std_logic;

	signal phy_out : phy_out_t;
	signal phy_in  : phy_in_t;

	signal mac_out : mac_out_t;
	signal mac_in  : mac_in_t;

	type status_t is (IDLE, TX);
	signal state          : status_t;
	constant BYTE_CNT_MAX : integer := 100;
	signal byte_cnt       : integer range 0 to BYTE_CNT_MAX;

	constant TMO_MAX : integer := integer(round((real(F_CLK) * 0.25))) - 1;
	signal tmo       : integer range 0 to TMO_MAX;
begin
	trashernet_mac_inst : entity trashernet.trashernet_mac
		port map(
			clk     => clk,
			rst     => rst,
			phy_out => phy_out,
			phy_in  => phy_in,
			mac_out => mac_out,
			mac_in  => mac_in
		);

	pll0_inst : pll0
		port map(
			CLK   => clk,
			CLKOP => clk_phy,
			LOCK  => open
		);

	trashernet_phy_cdc_inst : entity trashernet.trashernet_phy_cdc
		generic map(
			F_CLK     => F_CLK,
			F_CLK_PHY => F_CLK_PHY
		)
		port map(
			clk     => clk,
			phy_clk => clk_phy,
			rst     => rst,
			phy_out => phy_out,
			phy_in  => phy_in,
			rx_p    => rx_p,
			tx_p    => tx_p,
			tx_n    => tx_n
		);

	reset_sync : process(clk, rst_n) is
	begin
		if (rst_n = '0') then
			rst <= '1';
		elsif (rising_edge(clk)) then
			rst <= '0';
		end if;
	end process reset_sync;

	receiver : process(clk, rst) is
	begin
		if rst then
			state                 <= IDLE;
			mac_in.tx_mac_data_en <= '0';
			tmo                   <= 0;
		elsif rising_edge(clk) then
			if (tmo /= 0) then
				tmo <= tmo - 1;
			end if;
			case state is
				when IDLE =>
					if mac_out.rx_mac_crc_ok then
						if (mac_out.rx_header.mac_destination = ETH_CONFIG.mac_address) then -- Note: We won't respond to broadcasts!
							state                            <= TX;
							byte_cnt                         <= BYTE_CNT_MAX;
							mac_in.tx_header.mac_destination <= mac_out.rx_header.mac_source;
						end if;
					end if;

					if tmo = 0 then
						state                            <= TX;
						byte_cnt                         <= BYTE_CNT_MAX;
						mac_in.tx_header.mac_destination <= (others => x"FF");
					end if;
				when TX =>
					tmo                            <= TMO_MAX;
					mac_in.tx_header.mac_ethertype <= (x"00", std_logic_vector(to_unsigned(BYTE_CNT_MAX, 8)));
					mac_in.tx_mac_data_en          <= '1';
					mac_in.tx_mac_data             <= std_logic_vector(to_unsigned(byte_cnt, 8));
					if mac_out.tx_mac_data_ack then
						if byte_cnt = 1 then
							mac_in.tx_mac_data_en <= '0';
							state                 <= IDLE;
						else
							byte_cnt <= byte_cnt - 1;
						end if;
					end if;
			end case;

		end if;
	end process receiver;

	mac_in.tx_header.mac_source <= ETH_CONFIG.mac_address;

	debug_data(0) <= tx_p;
	debug_data(1) <= tx_n;

end architecture mac;

-- -------------------------------------------------------------------------- --
-- top_hwitl (eth)
-- -------------------------------------------------------------------------- --

library ieee;
use ieee.std_logic_1164.all;
use ieee.numeric_std.all;

use ieee.math_real.all;

library trashernet;
use trashernet.trashernet_pkg.all;

architecture eth of top_hwitl is
	component pll0
		port(
			CLK   : in  std_logic;
			CLKOP : out std_logic;
			LOCK  : out std_logic
		);
	end component pll0;

	constant F_CLK     : integer := 50000000;
	constant F_CLK_PHY : integer := 140000000;

	constant ETH_CONFIG : configuration_t      := (
		mac_address => (x"00", x"FF", x"FF", x"11", x"22", x"33")
	);
	constant IP_CONFIG  : ipv4_configuration_t := (
		ip_address  => (x"C0", x"A8", x"02", x"02"),
		subnet_mask => (x"FF", x"FF", x"FF", x"00"),
		gateway     => (x"C0", x"A8", x"02", x"01")
	);

	signal rst     : std_logic;
	signal clk_phy : std_logic;

	signal phy_out : phy_out_t;
	signal phy_in  : phy_in_t;

	signal mac_out : mac_out_t;
	signal mac_in  : mac_in_t;

	constant PROT_ARP              : integer                     := 0;
	constant PROT_IPV4             : integer                     := 1;
	constant ETHERNET_II_PROTOCOLS : ethernet_ii_protocol_vector := (
		PROT_ARP  => ETHERNET_II_PROTOCOL_ARP,
		PROT_IPV4 => ETHERNET_II_PROTOCOL_IPV4
	);
	signal ethernet_i_out          : ethernet_i_out_t;
	signal ethernet_i_in           : ethernet_i_in_t;
	signal ethernet_ii_out         : ethernet_ii_out_vector(ETHERNET_II_PROTOCOLS'range);
	signal ethernet_ii_in          : ethernet_ii_in_vector(ETHERNET_II_PROTOCOLS'range);

	signal arp_out : arp_out_t;
	signal arp_in  : arp_in_t;

	signal ipv4_out : ipv4_out_t;
	signal ipv4_in  : ipv4_in_t;
begin
	trashernet_ipv4_inst : entity trashernet.trashernet_ipv4
		port map(
			clk             => clk,
			rst             => rst,
			ipv4_config     => IP_CONFIG,
			arp_out         => arp_out,
			arp_in          => arp_in,
			ethernet_ii_out => ethernet_ii_out(PROT_IPV4),
			ethernet_ii_in  => ethernet_ii_in(PROT_IPV4),
			ipv4_out        => ipv4_out,
			ipv4_in         => ipv4_in
		);

	trashernet_arp_inst : entity trashernet.trashernet_arp
		generic map(
			SYSTICK_FREQ => F_CLK
		)
		port map(
			clk             => clk,
			rst             => rst,
			systick         => '1',
			mac_config      => ETH_CONFIG,
			ip_config       => IP_CONFIG,
			arp_out         => arp_out,
			arp_in          => arp_in,
			ethernet_ii_out => ethernet_ii_out(PROT_ARP),
			ethernet_ii_in  => ethernet_ii_in(PROT_ARP)
		);

	ethernet_i_in <= ethernet_i_in_t'(
		tx_mac_address => (others => (others => '-')),
		tx_data        => (others => '-'),
		tx_en          => '0',
		tx_length      => (others => '-')
	);

	trashernet_eth_inst : entity trashernet.trashernet_eth
		generic map(
			ETHERNET_II_PROTOCOLS => ETHERNET_II_PROTOCOLS
		)
		port map(
			clk             => clk,
			rst             => rst,
			mac_out         => mac_out,
			mac_in          => mac_in,
			config          => ETH_CONFIG,
			ethernet_i_out  => ethernet_i_out,
			ethernet_i_in   => ethernet_i_in,
			ethernet_ii_out => ethernet_ii_out,
			ethernet_ii_in  => ethernet_ii_in
		);

	trashernet_mac_inst : entity trashernet.trashernet_mac
		port map(
			clk     => clk,
			rst     => rst,
			phy_out => phy_out,
			phy_in  => phy_in,
			mac_out => mac_out,
			mac_in  => mac_in
		);

	pll0_inst : pll0
		port map(
			CLK   => clk,
			CLKOP => clk_phy,
			LOCK  => open
		);

	trashernet_phy_cdc_inst : entity trashernet.trashernet_phy_cdc
		generic map(
			F_CLK     => F_CLK,
			F_CLK_PHY => F_CLK_PHY
		)
		port map(
			clk     => clk,
			phy_clk => clk_phy,
			rst     => rst,
			phy_out => phy_out,
			phy_in  => phy_in,
			rx_p    => rx_p,
			tx_p    => tx_p,
			tx_n    => tx_n
		);

	reset_sync : process(clk, rst_n) is
	begin
		if (rst_n = '0') then
			rst <= '1';
		elsif (rising_edge(clk)) then
			rst <= '0';
		end if;
	end process reset_sync;

	receiver : process(clk, rst) is
	begin
		if rst then

		elsif rising_edge(clk) then
			if ethernet_i_out.rx_header_rcv then
				report "RX ETH-I: " & to_string(to_integer(ethernet_i_out.rx_length));
			end if;
			if (ethernet_ii_out(PROT_ARP).rx_header_rcv) then
				report "RX ARP";
			end if;
			if (ethernet_ii_out(PROT_IPV4).rx_header_rcv) then
				report "RX IP";
			end if;

			if ipv4_out.rx_data_valid then
				report "RX IP data: " & to_hstring(ipv4_out.rx_data);
			end if;
			if ipv4_out.rx_ok_stb then
				report "RX IP OK";
			end if;
			if ipv4_out.rx_error_stb then
				report "RX IP error";
			end if;
			if ipv4_out.rx_header_rcv then
				report "RX IP start. PROT=" & to_hstring(ipv4_out.rx_protocol) & ", FROM=" & ip_to_string(ipv4_out.rx_ip_address);
			end if;
		end if;
	end process receiver;

	arp_request_test : process(clk, rst) is
	begin
		if rst then
			arp_in.arp_ip        <= (x"C0", x"A8", x"02", x"01");
			arp_in.arp_query_stb <= '0';

		elsif rising_edge(clk) then
			arp_in.arp_query_stb <= not button_n(0);

			if arp_out.arp_ok_stb then
				report "Found MAC: " & mac_to_string(arp_out.arp_mac);
			end if;
			if arp_out.arp_fail_stb then
				report "ARP failed";
			end if;
		end if;
	end process arp_request_test;

end architecture eth;