From 68b67af1bd2a66b16e573117aba4e3c76ff8a930 Mon Sep 17 00:00:00 2001
From: Florent Kermarrec <florent@enjoy-digital.fr>
Date: Fri, 22 Oct 2021 20:02:17 +0200
Subject: [PATCH] build/efinix/common: Add initial Tristate/SDRTristate
 support.

---
 litex/build/efinix/common.py | 53 +++++++++++++++++++++++++++++++++++-
 1 file changed, 52 insertions(+), 1 deletion(-)

diff --git a/litex/build/efinix/common.py b/litex/build/efinix/common.py
index e04a08075..cd140ef91 100644
--- a/litex/build/efinix/common.py
+++ b/litex/build/efinix/common.py
@@ -10,6 +10,8 @@ from migen.genlib.resetsync import AsyncResetSynchronizer
 
 from litex.build.io import *
 
+from litex.build.efinix.efinity import EfinityToolchain
+
 # Efinix AsyncResetSynchronizer --------------------------------------------------------------------
 
 class EfinixAsyncResetSynchronizerImpl(Module):
@@ -38,8 +40,57 @@ class EfinixAsyncResetSynchronizer:
     def lower(dr):
         return EfinixAsyncResetSynchronizerImpl(dr.cd, dr.async_reset)
 
+# Efinix Tristate ----------------------------------------------------------------------------------
+
+class EfinixTristateImpl(Module):
+    def __init__(self, platform, io, o, oe, i):
+        nbits, sign = value_bits_sign(io)
+        assert nbits == 1
+        io_name = platform.get_pin_name(io)
+        print(io_name)
+        io_loc  = platform.get_pin_location(io)
+        self.comb += [
+            platform.add_iface_io(io_name + "_OUT").eq(o),
+            platform.add_iface_io(io_name + "_OE").eq(oe),
+            i.eq(platform.add_iface_io(io_name + "_IN"))
+        ]
+        block = {
+            "type"    : "GPIO",
+            "mode"    : "INOUT",
+            "name"    : io_name,
+            "location": [io_loc[0]],
+        }
+        platform.toolchain.ifacewriter.blocks.append(block)
+        #platform.delete(io) # FIXME!
+
+class EfinixTristate(Module):
+    @staticmethod
+    def lower(dr):
+        return EfinixTristateImpl(dr.platform, dr.target, dr.o, dr.oe, dr.i)
+
+# Efinix SDRTristate -------------------------------------------------------------------------------
+
+class EfinixSDRTristateImpl(Module):
+    def __init__(self, platform, io, o, oe, i, clk):
+        _o  = Signal()
+        _oe = Signal()
+        _i  = Signal()
+        self.specials += SDROutput(o, _o, clk)
+        self.specials += SDRInput(_i, i, clk)
+        self.submodules += InferedSDRIO(oe, _oe, clk)
+        tristate = Tristate(io, _o, _oe, _i)
+        tristate.platform = platform
+        self.specials += tristate
+
+class EfinixSDRTristate(Module):
+    @staticmethod
+    def lower(dr):
+        return EfinixSDRTristateImpl(dr.platform, dr.io, dr.o, dr.oe, dr.i, dr.clk)
+
 # Efinix Special Overrides -------------------------------------------------------------------------
 
 efinix_special_overrides = {
-    AsyncResetSynchronizer: EfinixAsyncResetSynchronizer
+    AsyncResetSynchronizer : EfinixAsyncResetSynchronizer,
+    Tristate               : EfinixTristate,
+    SDRTristate            : EfinixSDRTristate,
 }