From e6450a179bb87bfafcd05d2937ef327703bb17ba Mon Sep 17 00:00:00 2001
From: Miodrag Milanovic <mmicko@gmail.com>
Date: Thu, 9 Jan 2025 14:27:21 +0100
Subject: [PATCH] Added MX2 and MX4 support

---
 himbaechel/uarch/gatemate/constids.inc | 10 +++++++
 himbaechel/uarch/gatemate/gatemate.cc  | 32 +++++++++++++++++++++
 himbaechel/uarch/gatemate/gatemate.h   |  6 ++++
 himbaechel/uarch/gatemate/pack.cc      | 39 ++++++++++++++++++++++++++
 4 files changed, 87 insertions(+)

diff --git a/himbaechel/uarch/gatemate/constids.inc b/himbaechel/uarch/gatemate/constids.inc
index 226fa34f..a5bc0be2 100644
--- a/himbaechel/uarch/gatemate/constids.inc
+++ b/himbaechel/uarch/gatemate/constids.inc
@@ -119,3 +119,13 @@ X(2D_IN)
 
 X(CC_BUFG)
 X(BUFG)
+
+X(CC_MX2)
+X(CC_MX4)
+X(FUNCTION)
+X(D0)
+X(D1)
+X(D2)
+X(D3)
+X(S0)
+X(S1)
diff --git a/himbaechel/uarch/gatemate/gatemate.cc b/himbaechel/uarch/gatemate/gatemate.cc
index 3ce01300..d69a864e 100644
--- a/himbaechel/uarch/gatemate/gatemate.cc
+++ b/himbaechel/uarch/gatemate/gatemate.cc
@@ -149,6 +149,38 @@ void GateMateImpl::postRoute()
     }
 }
 
+void GateMateImpl::postPlace()
+{
+    log_break();
+    log_info("Limiting routing...\n");
+    for (auto &cell : ctx->cells) {
+        CellInfo &ci = *cell.second;
+        if (ci.type == id_CPE) {
+            if (!ci.params.count(id_FUNCTION)) continue;
+            uint8_t func = int_or_default(ci.params, id_FUNCTION, 0);
+            if (func!=4) continue; // Skip all that are not MUX
+            for (int i = 1; i <= 4; i++) {
+                IdString port = ctx->idf("IN%d", i);
+                NetInfo *net = ci.getPort(port);
+                if (!net)
+                    continue;
+                WireId dwire = ctx->getBelPinWire(ci.bel, port);
+                for (PipId pip : ctx->getPipsUphill(dwire)) {
+                    const auto extra_data = *reinterpret_cast<const GateMatePipExtraDataPOD *>(
+                            chip_pip_info(ctx->chip_info, pip).extra_data.get());
+                    if (!extra_data.name)
+                        continue;
+                    if (extra_data.type == PipExtra::PIP_EXTRA_MUX && (extra_data.flags & MUX_CPE_INV)) {
+                        blocked_pips.emplace(pip);
+                    }
+                }
+            }
+        }
+    }
+    ctx->assignArchInfo();
+}
+
+
 void GateMateImpl::setupArchContext()
 {
     const ArchArgs &args = ctx->args;
diff --git a/himbaechel/uarch/gatemate/gatemate.h b/himbaechel/uarch/gatemate/gatemate.h
index ed4a8c4f..cc91598e 100644
--- a/himbaechel/uarch/gatemate/gatemate.h
+++ b/himbaechel/uarch/gatemate/gatemate.h
@@ -40,6 +40,7 @@ struct GateMateImpl : HimbaechelAPI
 
     void pack() override;
 
+    void postPlace() override;
     void postRoute() override;
 
     bool isBelLocationValid(BelId bel, bool explain_invalid = false) const override;
@@ -50,6 +51,9 @@ struct GateMateImpl : HimbaechelAPI
     void write_bitstream(const std::string &device, const std::string &filename);
     bool read_bitstream(const std::string &device, const std::string &filename);
 
+    bool checkPipAvail(PipId pip) const override { return blocked_pips.count(pip) == 0; }
+    bool checkPipAvailForNet(PipId pip, const NetInfo *net) const override { return checkPipAvail(pip); };
+
     void parse_ccf(const std::string &filename);
 
     IdString getBelBucketForCellType(IdString cell_type) const;
@@ -59,6 +63,8 @@ struct GateMateImpl : HimbaechelAPI
         const auto &extra_data = *reinterpret_cast<const GateMatePipExtraDataPOD*>(chip_pip_info(ctx->chip_info, pip).extra_data.get());
         return extra_data.type == PipExtra::PIP_EXTRA_MUX && (extra_data.flags & MUX_INVERT);
     }
+
+    pool<PipId> blocked_pips;
 };
 
 NEXTPNR_NAMESPACE_END
diff --git a/himbaechel/uarch/gatemate/pack.cc b/himbaechel/uarch/gatemate/pack.cc
index 34cc8794..8f16616c 100644
--- a/himbaechel/uarch/gatemate/pack.cc
+++ b/himbaechel/uarch/gatemate/pack.cc
@@ -316,6 +316,45 @@ void GateMatePacker::pack_cpe()
         ci.type = id_CPE;
     }
 
+    for (auto &cell : ctx->cells) {
+        CellInfo &ci = *cell.second;
+        if (!ci.type.in(id_CC_MX2, id_CC_MX4))
+            continue;
+        if (ci.type == id_CC_MX2) {
+            ci.renamePort(id_S0, id_IN6);
+            ci.renamePort(id_D0, id_IN1);
+            ci.renamePort(id_D1, id_IN2);
+            ci.renamePort(id_Y, id_OUT1);
+
+            ci.params[id_FUNCTION] = Property(0b100, 3);
+            ci.params[id_INIT_L02] = Property(0b1100, 4); // IN6
+            ci.params[id_INIT_L10] = Property(0b0011, 4);
+            ci.params[id_INIT_L11] = Property(0b0011, 4);
+            ci.params[id_INIT_L20] = Property(0b0011, 4);
+            ci.params[id_O1] = Property(0b11, 2);
+            ci.type = id_CPE;
+        } else {
+            ci.renamePort(id_D0, id_IN1);
+            ci.renamePort(id_D1, id_IN2);
+            ci.renamePort(id_D2, id_IN3);
+            ci.renamePort(id_D3, id_IN4);
+
+            ci.renamePort(id_S0, id_IN6);
+            ci.renamePort(id_S1, id_IN8);
+            ci.renamePort(id_Y, id_OUT1);
+
+            ci.params[id_FUNCTION] = Property(0b100, 3);
+            ci.params[id_INIT_L02] = Property(0b1100, 4); // IN6
+            ci.params[id_INIT_L03] = Property(0b1100, 4); // IN8
+            
+            ci.params[id_INIT_L10] = Property(0b1111, 4);
+            ci.params[id_INIT_L11] = Property(0b0011, 4);
+            ci.params[id_INIT_L20] = Property(0b1100, 4);
+            ci.params[id_O1] = Property(0b11, 2);
+            ci.type = id_CPE;
+        }
+    }
+
     for (auto &cell : ctx->cells) {
         CellInfo &ci = *cell.second;
         if (!ci.type.in(id_CC_DFF))