ecp5: Negative clock support, general slice improvements

Signed-off-by: David Shah <davey1576@gmail.com>

3 files changed, 41 insertions, 4 deletions

diff --git a/ecp5/bitstream.cc b/ecp5/bitstream.cc
index 0c2d511d..296ea753 100644
--- a/ecp5/bitstream.cc
+++ b/ecp5/bitstream.cc
@@ -260,6 +260,17 @@ void write_bitstream(Context *ctx, std::string base_config_file, std::string tex
                                              str_or_default(ci->params, ctx->id("SRMODE"), "LSR_OVER_CE"));
                     cc.tiles[tname].add_enum("LSR1.LSRMUX", str_or_default(ci->params, ctx->id("LSRMUX"), "LSR"));
                 }
+
+                NetInfo *clknet = nullptr;
+                if (ci->ports.find(ctx->id("CLK")) != ci->ports.end() && ci->ports.at(ctx->id("CLK")).net != nullptr)
+                    clknet = ci->ports.at(ctx->id("CLK")).net;
+                if (ctx->getBoundWireNet(ctx->getWireByName(
+                            ctx->id(fmt_str("X" << bel.location.x << "/Y" << bel.location.y << "/CLK0")))) == clknet) {
+                    cc.tiles[tname].add_enum("CLK0.CLKMUX", str_or_default(ci->params, ctx->id("CLKMUX"), "CLK"));
+                } else if (ctx->getBoundWireNet(ctx->getWireByName(ctx->id(
+                                   fmt_str("X" << bel.location.x << "/Y" << bel.location.y << "/CLK1")))) == clknet) {
+                    cc.tiles[tname].add_enum("CLK1.CLKMUX", str_or_default(ci->params, ctx->id("CLKMUX"), "CLK"));
+                }
             }
 
             if (str_or_default(ci->params, ctx->id("MODE"), "LOGIC") == "CCU2") {
@@ -267,13 +278,23 @@ void write_bitstream(Context *ctx, std::string base_config_file, std::string tex
                                          str_or_default(ci->params, ctx->id("INJECT1_0"), "YES"));
                 cc.tiles[tname].add_enum(slice + ".CCU2.INJECT1_1",
                                          str_or_default(ci->params, ctx->id("INJECT1_1"), "YES"));
+            } else {
+                // Don't interfere with cascade mux wiring
+                cc.tiles[tname].add_enum(slice + ".CCU2.INJECT1_0",
+                                         str_or_default(ci->params, ctx->id("INJECT1_0"), "_NONE_"));
+                cc.tiles[tname].add_enum(slice + ".CCU2.INJECT1_1",
+                                         str_or_default(ci->params, ctx->id("INJECT1_1"), "_NONE_"));
             }
 
             if (str_or_default(ci->params, ctx->id("MODE"), "LOGIC") == "DPRAM" && slice == "SLICEA") {
                 cc.tiles[tname].add_enum(slice + ".WREMUX", str_or_default(ci->params, ctx->id("WREMUX"), "WRE"));
 
-                // FIXME: WCKMUX
-                NPNR_ASSERT(str_or_default(ci->params, ctx->id("WCKMUX"), "WCK") == "WCK");
+                NetInfo *wcknet = nullptr;
+                std::string wckmux = str_or_default(ci->params, ctx->id("WCKMUX"), "WCK");
+                wckmux = (wckmux == "WCK") ? "CLK" : wckmux;
+                if (ci->ports.find(ctx->id("WCK")) != ci->ports.end() && ci->ports.at(ctx->id("WCK")).net != nullptr)
+                    wcknet = ci->ports.at(ctx->id("WCK")).net;
+                cc.tiles[tname].add_enum("CLK1.CLKMUX", wckmux);
             }
 
             // Tie unused inputs high
diff --git a/ecp5/cells.cc b/ecp5/cells.cc
index 815ae228..a728104d 100644
--- a/ecp5/cells.cc
+++ b/ecp5/cells.cc
@@ -185,6 +185,8 @@ void ff_to_slice(Context *ctx, CellInfo *ff, CellInfo *lc, int index, bool drive
     set_param_safe(has_ff, lc, ctx->id("GSR"), str_or_default(ff->params, ctx->id("GSR"), "DISABLED"));
     set_param_safe(has_ff, lc, ctx->id("CEMUX"), str_or_default(ff->params, ctx->id("CEMUX"), "1"));
     set_param_safe(has_ff, lc, ctx->id("LSRMUX"), str_or_default(ff->params, ctx->id("LSRMUX"), "LSR"));
+    set_param_safe(has_ff, lc, ctx->id("CLKMUX"), str_or_default(ff->params, ctx->id("CLKMUX"), "CLK"));
+
     lc->params[ctx->id(reg + "_SD")] = driven_by_lut ? "1" : "0";
     lc->params[ctx->id(reg + "_REGSET")] = str_or_default(ff->params, ctx->id("REGSET"), "RESET");
     replace_port_safe(has_ff, ff, ctx->id("CLK"), lc, ctx->id("CLK"));
diff --git a/ecp5/pack.cc b/ecp5/pack.cc
index 60ac55f6..0045617b 100644
--- a/ecp5/pack.cc
+++ b/ecp5/pack.cc
@@ -128,6 +128,20 @@ class Ecp5Packer
         return true;
     }
 
+    // Return true if a FF can be added to a DPRAM slice
+    bool can_pack_ff_dram(CellInfo *dpram, CellInfo *ff)
+    {
+        std::string wckmux = str_or_default(dpram->params, ctx->id("WCKMUX"), "WCK");
+        std::string clkmux = str_or_default(ff->params, ctx->id("CLKMUX"), "CLK");
+        if (wckmux != clkmux && !(wckmux == "WCK" && clkmux == "CLK"))
+            return false;
+        std::string wremux = str_or_default(dpram->params, ctx->id("WREMUX"), "WRE");
+        std::string lsrmux = str_or_default(ff->params, ctx->id("LSRMUX"), "LSR");
+        if (wremux != lsrmux && !(wremux == "WRE" && lsrmux == "LSR"))
+            return false;
+        return true;
+    }
+
     // Return true if two LUTs can be paired considering FF compatibility
     bool can_pack_lutff(IdString lut0, IdString lut1)
     {
@@ -598,7 +612,7 @@ class Ecp5Packer
                     if (f0net != nullptr) {
                         ff0 = net_only_drives(ctx, f0net, is_ff, ctx->id("DI"), false);
                         if (ff0 != nullptr && can_add_ff_to_tile(tile_ffs, ff0)) {
-                            if (net_or_nullptr(ff0, ctx->id("CLK")) == net_or_nullptr(slice, ctx->id("WCK"))) {
+                            if (can_pack_ff_dram(slice, ff0)) {
                                 ff_packing.push_back(std::make_tuple(ff0, slice, 0));
                                 tile_ffs.push_back(ff0);
                                 packed_cells.insert(ff0->name);
@@ -612,7 +626,7 @@ class Ecp5Packer
                         ff1 = net_only_drives(ctx, f1net, is_ff, ctx->id("DI"), false);
                         if (ff1 != nullptr && (ff0 == nullptr || can_pack_ffs(ff0, ff1)) &&
                             can_add_ff_to_tile(tile_ffs, ff1)) {
-                            if (net_or_nullptr(ff1, ctx->id("CLK")) == net_or_nullptr(slice, ctx->id("WCK"))) {
+                            if (can_pack_ff_dram(slice, ff1)) {
                                 ff_packing.push_back(std::make_tuple(ff1, slice, 1));
                                 tile_ffs.push_back(ff1);
                                 packed_cells.insert(ff1->name);