From f943a395f69fa2ada941bba3ca0de60747ab1c4d Mon Sep 17 00:00:00 2001
From: Florent Kermarrec <florent@enjoy-digital.fr>
Date: Mon, 3 Jul 2023 18:07:36 +0200
Subject: [PATCH] liteeth_gen: Add DHCP support and demonstrate it on
 udp_usp_gth_sgmii.yml config.

---
 examples/udp_usp_gth_sgmii.yml |  1 +
 liteeth/gen.py                 | 29 +++++++++++++++++++++++++++++
 2 files changed, 30 insertions(+)

diff --git a/examples/udp_usp_gth_sgmii.yml b/examples/udp_usp_gth_sgmii.yml
index 4dbb403..8c02281 100644
--- a/examples/udp_usp_gth_sgmii.yml
+++ b/examples/udp_usp_gth_sgmii.yml
@@ -14,6 +14,7 @@ refclk_freq : 156.25e6
 clk_freq    : 25e6
 core        : udp
 data_width  : 32
+dhcp        : True
 
 # UDP Ports --------------------------------------------------------------------
 udp_ports:   {
diff --git a/liteeth/gen.py b/liteeth/gen.py
index 84668c8..bcd9aad 100755
--- a/liteeth/gen.py
+++ b/liteeth/gen.py
@@ -46,6 +46,7 @@ from liteeth.common import *
 from liteeth import phy as liteeth_phys
 from liteeth.mac import LiteEthMAC
 from liteeth.core import LiteEthUDPIPCore
+from liteeth.core.dhcp import LiteEthDHCP
 
 from liteeth.frontend.etherbone import LiteEthEtherbone
 
@@ -63,6 +64,14 @@ _io = [
     # Interrupt
     ("interrupt", 0, Pins(1)),
 
+    # DHCP.
+    ("dhcp", 0,
+        Subsignal("start",      Pins(1)),
+        Subsignal("done",       Pins(1)),
+        Subsignal("timeout",    Pins(1)),
+        Subsignal("ip_address", Pins(32)),
+    ),
+
     # MII PHY Pads
     ("mii_clocks", 0,
         Subsignal("tx", Pins(1)),
@@ -327,10 +336,13 @@ class UDPCore(PHYCore):
             mac_address = platform.request("mac_address")
 
         # IP Address.
+        dhcp       = core_config.get("dhcp", False)
         ip_address = core_config.get("ip_address", None)
         # Get IP Address from IOs when not specified.
         if ip_address is None:
             ip_address = platform.request("ip_address")
+        else:
+            assert not dhcp
 
         # PHY --------------------------------------------------------------------------------------
         PHYCore.__init__(self, platform, core_config)
@@ -345,6 +357,23 @@ class UDPCore(PHYCore):
             with_sys_datapath = (data_width == 32),
         )
 
+        # DHCP -------------------------------------------------------------------------------------
+
+        if dhcp:
+            dhcp_pads = platform.request("dhcp")
+            dhcp_port = self.core.udp.crossbar.get_port(68, dw=32, cd="sys")
+            if isinstance(mac_address, Signal):
+                dhcp_mac_address = mac_address
+            else:
+                dhcp_mac_address = Signal(48, reset=0x10e2d5000001)
+            self.submodules.dhcp = LiteEthDHCP(udp_port=dhcp_port, sys_clk_freq=self.sys_clk_freq)
+            self.comb += [
+                self.dhcp.start.eq(dhcp_pads.start),
+                dhcp_pads.done.eq(self.dhcp.done),
+                dhcp_pads.timeout.eq(self.dhcp.timeout),
+                dhcp_pads.ip_address.eq(self.dhcp.ip_address),
+            ]
+
         # Etherbone --------------------------------------------------------------------------------
 
         etherbone              = core_config.get("etherbone", False)