Simple IO buffer insertion, enable packer by default

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

4 files changed, 65 insertions, 33 deletions

diff --git a/ice40/cells.cc b/ice40/cells.cc
index ad728d2c..b038db68 100644
--- a/ice40/cells.cc
+++ b/ice40/cells.cc
@@ -60,6 +60,26 @@ CellInfo *create_ice_cell(Design *design, IdString type, IdString name)
         add_port(new_cell, "LO", PORT_OUT);
         add_port(new_cell, "O", PORT_OUT);
         add_port(new_cell, "OUT", PORT_OUT);
+    } else if (type == "SB_IO") {
+        new_cell->params["PIN_TYPE"] = "0";
+        new_cell->params["PULLUP"] = "0";
+        new_cell->params["NEG_TRIGGER"] = "0";
+        new_cell->params["IOSTANDARD"] = "SB_LVCMOS";
+
+        add_port(new_cell, "PACKAGE_PIN", PORT_INOUT);
+
+        add_port(new_cell, "LATCH_INPUT_VALUE", PORT_IN);
+        add_port(new_cell, "CLOCK_ENABLE", PORT_IN);
+        add_port(new_cell, "INPUT_CLK", PORT_IN);
+        add_port(new_cell, "OUTPUT_CLK", PORT_IN);
+
+        add_port(new_cell, "OUTPUT_ENABLE", PORT_IN);
+        add_port(new_cell, "D_OUT_0", PORT_IN);
+        add_port(new_cell, "D_OUT_1", PORT_IN);
+
+        add_port(new_cell, "D_IN_0", PORT_OUT);
+        add_port(new_cell, "D_IN_1", PORT_OUT);
+
     } else {
         log_error("unable to create iCE40 cell of type %s", type.c_str());
     }
@@ -128,4 +148,20 @@ void dff_to_lc(CellInfo *dff, CellInfo *lc, bool pass_thru_lut)
     replace_port(dff, "Q", lc, "O");
 }
 
+void nxio_to_sb(CellInfo *nxio, CellInfo *sbio)
+{
+    if (nxio->type == "$nextpnr_ibuf") {
+        sbio->params["PIN_TYPE"] = "1";
+        auto pu_attr = nxio->attrs.find("PULLUP");
+        if (pu_attr != nxio->attrs.end())
+            sbio->params["PULLUP"] = pu_attr->second;
+        replace_port(nxio, "O", sbio, "D_IN_0");
+    } else if (nxio->type == "$nextpnr_obuf") {
+        sbio->params["PIN_TYPE"] = "25";
+        replace_port(nxio, "I", sbio, "D_OUT_0");
+    } else {
+        assert(false);
+    }
+}
+
 NEXTPNR_NAMESPACE_END
diff --git a/ice40/cells.h b/ice40/cells.h
index da4e2bd8..3cf0b718 100644
--- a/ice40/cells.h
+++ b/ice40/cells.h
@@ -61,6 +61,9 @@ void lut_to_lc(CellInfo *lut, CellInfo *lc, bool no_dff = true);
 // ignored
 void dff_to_lc(CellInfo *dff, CellInfo *lc, bool pass_thru_lut = false);
 
+// Convert a nextpnr IO buffer to a SB_IO
+void nxio_to_sb(CellInfo *nxio, CellInfo *sbio);
+
 NEXTPNR_NAMESPACE_END
 
 #endif
diff --git a/ice40/main.cc b/ice40/main.cc
index 6bda4d78..8c418cae 100644
--- a/ice40/main.cc
+++ b/ice40/main.cc
@@ -67,7 +67,6 @@ int main(int argc, char *argv[])
     options.add_options()("help,h", "show help");
     options.add_options()("gui", "start gui");
     options.add_options()("svg", "dump SVG file");
-    options.add_options()("pack", "pack design prior to place and route");
     options.add_options()("pack-only",
                           "pack design only without placement or routing");
 
@@ -195,9 +194,7 @@ int main(int argc, char *argv[])
         std::istream *f = new std::ifstream(filename);
 
         parse_json_file(f, filename, &design);
-        if (vm.count("pack") || vm.count("pack-only")) {
-            pack_design(&design);
-        }
+        pack_design(&design);
         if (!vm.count("pack-only")) {
             place_design(&design);
             route_design(&design);
diff --git a/ice40/pack.cc b/ice40/pack.cc
index 73ba0e3d..72dcadea 100644
--- a/ice40/pack.cc
+++ b/ice40/pack.cc
@@ -149,39 +149,35 @@ static void pack_io(Design *design)
     for (auto cell : design->cells) {
         CellInfo *ci = cell.second;
         if (is_nextpnr_iob(ci)) {
+            CellInfo *sb = nullptr;
             if (ci->type == "$nextpnr_ibuf" || ci->type == "$nextpnr_iobuf") {
-                CellInfo *sb = net_only_drives(ci->ports.at("O").net, is_sb_io,
-                                               "PACKAGE_PIN", true, ci);
-                if (sb != nullptr) {
-                    // Trivial case, SB_IO used. Just destroy the net and the
-                    // iobuf
-                    packed_cells.insert(ci->name);
-                    log_info("%s feeds SB_IO %s, removing %s %s.\n",
-                             ci->name.c_str(), sb->name.c_str(),
-                             ci->type.c_str(), ci->name.c_str());
-                    NetInfo *net = sb->ports.at("PACKAGE_PIN").net;
-                    if (net != nullptr) {
-                        design->nets.erase(net->name);
-                        sb->ports.at("PACKAGE_PIN").net = nullptr;
-                    }
-                }
+                sb = net_only_drives(ci->ports.at("O").net, is_sb_io,
+                                     "PACKAGE_PIN", true, ci);
+
             } else if (ci->type == "$nextpnr_obuf") {
-                CellInfo *sb = net_only_drives(ci->ports.at("I").net, is_sb_io,
-                                               "PACKAGE_PIN", true, ci);
-                if (sb != nullptr) {
-                    // Trivial case, SB_IO used. Just destroy the net and the
-                    // iobuf
-                    packed_cells.insert(ci->name);
-                    log_info("%s feeds SB_IO %s, removing %s %s.\n",
-                             ci->name.c_str(), sb->name.c_str(),
-                             ci->type.c_str(), ci->name.c_str());
-                    NetInfo *net = sb->ports.at("PACKAGE_PIN").net;
-                    if (net != nullptr) {
-                        design->nets.erase(net->name);
-                        sb->ports.at("PACKAGE_PIN").net = nullptr;
-                    }
+                sb = net_only_drives(ci->ports.at("I").net, is_sb_io,
+                                     "PACKAGE_PIN", true, ci);
+            }
+            if (sb != nullptr) {
+                // Trivial case, SB_IO used. Just destroy the net and the
+                // iobuf
+                log_info("%s feeds SB_IO %s, removing %s %s.\n",
+                         ci->name.c_str(), sb->name.c_str(), ci->type.c_str(),
+                         ci->name.c_str());
+                NetInfo *net = sb->ports.at("PACKAGE_PIN").net;
+                if (net != nullptr) {
+                    design->nets.erase(net->name);
+                    sb->ports.at("PACKAGE_PIN").net = nullptr;
                 }
+            } else {
+                // Create a SB_IO buffer
+                sb = create_ice_cell(design, "SB_IO");
+                nxio_to_sb(ci, sb);
+                new_cells.push_back(sb);
             }
+            packed_cells.insert(ci->name);
+            std::copy(ci->attrs.begin(), ci->attrs.end(),
+                      std::inserter(sb->attrs, sb->attrs.begin()));
         }
     }
     for (auto pcell : packed_cells) {