From cf2db7a4c474569d372c176e9790dd4f6ae24a03 Mon Sep 17 00:00:00 2001
From: "William D. Jones" <thor0505@comcast.net>
Date: Sat, 30 Jan 2021 22:42:16 -0500
Subject: [PATCH] machxo2: Write out pips to bitstream.

---
 machxo2/arch.cc      | 27 +++++++++++++++++++++++++++
 machxo2/arch.h       | 15 +++++++++++++++
 machxo2/bitstream.cc | 41 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 83 insertions(+)

diff --git a/machxo2/arch.cc b/machxo2/arch.cc
index 4ab3dc5b..dbe17fd9 100644
--- a/machxo2/arch.cc
+++ b/machxo2/arch.cc
@@ -124,6 +124,33 @@ std::string Arch::getChipName() const
     }
 }
 
+std::string Arch::getFullChipName() const
+{
+    std::string name = getChipName();
+    name += "-";
+    switch (args.speed) {
+    case ArchArgs::SPEED_1:
+        name += "1";
+        break;
+    case ArchArgs::SPEED_2:
+        name += "2";
+        break;
+    case ArchArgs::SPEED_3:
+        name += "3";
+    case ArchArgs::SPEED_4:
+        name += "4";
+        break;
+    case ArchArgs::SPEED_5:
+        name += "5";
+        break;
+    case ArchArgs::SPEED_6:
+        name += "6";
+        break;
+    }
+    name += args.package;
+    return name;
+}
+
 IdString Arch::archArgsToId(ArchArgs args) const
 {
     if (args.type == ArchArgs::LCMXO2_256HC) {
diff --git a/machxo2/arch.h b/machxo2/arch.h
index f06739e4..6cca9798 100644
--- a/machxo2/arch.h
+++ b/machxo2/arch.h
@@ -501,6 +501,8 @@ struct Arch : BaseCtx
     static bool isAvailable(ArchArgs::ArchArgsTypes chip);
 
     std::string getChipName() const;
+    // Extra helper
+    std::string getFullChipName() const;
 
     IdString archId() const { return id("machxo2"); }
     ArchArgs archArgs() const { return args; }
@@ -882,6 +884,19 @@ struct Arch : BaseCtx
         return range;
     }
 
+    // Extra Pip helpers.
+    int8_t getPipClass(PipId pip) const { return tileInfo(pip)->pips_data[pip.index].pip_type; }
+
+    std::string getPipTilename(PipId pip) const
+    {
+        auto &tileloc = chip_info->tile_info[pip.location.y * chip_info->width + pip.location.x];
+        for (int i = 0; i < tileloc.num_tiles; i++) {
+            if (tileloc.tile_names[i].type_idx == tileInfo(pip)->pips_data[pip.index].tile_type)
+                return tileloc.tile_names[i].name.get();
+        }
+        NPNR_ASSERT_FALSE("failed to find Pip tile");
+    }
+
     // Group
     GroupId getGroupByName(IdString name) const;
     IdString getGroupName(GroupId group) const;
diff --git a/machxo2/bitstream.cc b/machxo2/bitstream.cc
index eec07cb1..58f5f85e 100644
--- a/machxo2/bitstream.cc
+++ b/machxo2/bitstream.cc
@@ -22,6 +22,7 @@
 
 #include "bitstream.h"
 #include "config.h"
+#include "nextpnr.h"
 
 NEXTPNR_NAMESPACE_BEGIN
 
@@ -47,6 +48,35 @@ namespace BaseConfigs {
     }
 } // namespace BaseConfigs
 
+// Convert an absolute wire name to a relative Trellis one
+static std::string get_trellis_wirename(Context *ctx, Location loc, WireId wire)
+{
+    std::string basename = ctx->tileInfo(wire)->wire_data[wire.index].name.get();
+    std::string prefix2 = basename.substr(0, 2);
+    if (prefix2 == "G_" || prefix2 == "L_" || prefix2 == "R_")
+        return basename;
+    if (loc == wire.location)
+        return basename;
+    std::string rel_prefix;
+    if (wire.location.y < loc.y)
+        rel_prefix += "N" + std::to_string(loc.y - wire.location.y);
+    if (wire.location.y > loc.y)
+        rel_prefix += "S" + std::to_string(wire.location.y - loc.y);
+    if (wire.location.x > loc.x)
+        rel_prefix += "E" + std::to_string(wire.location.x - loc.x);
+    if (wire.location.x < loc.x)
+        rel_prefix += "W" + std::to_string(loc.x - wire.location.x);
+    return rel_prefix + "_" + basename;
+}
+
+static void set_pip(Context *ctx, ChipConfig &cc, PipId pip)
+{
+    std::string tile = ctx->getPipTilename(pip);
+    std::string source = get_trellis_wirename(ctx, pip.location, ctx->getPipSrcWire(pip));
+    std::string sink = get_trellis_wirename(ctx, pip.location, ctx->getPipDstWire(pip));
+    cc.tiles[tile].add_arc(sink, source);
+}
+
 void write_bitstream(Context *ctx, std::string text_config_file)
 {
     ChipConfig cc;
@@ -59,6 +89,17 @@ void write_bitstream(Context *ctx, std::string text_config_file)
         NPNR_ASSERT_FALSE("Unsupported device type");
     }
 
+    cc.metadata.push_back("Part: " + ctx->getFullChipName());
+
+    // Add all set, configurable pips to the config
+    for (auto pip : ctx->getPips()) {
+        if (ctx->getBoundPipNet(pip) != nullptr) {
+            if (ctx->getPipClass(pip) == 0) { // ignore fixed pips
+                set_pip(ctx, cc, pip);
+            }
+        }
+    }
+
     // Configure chip
     if (!text_config_file.empty()) {
         std::ofstream out_config(text_config_file);