generic: Add APIs for controlling cell->bel pin mapping

Signed-off-by: gatecat <gatecat@ds0.me>

4 files changed, 29 insertions, 3 deletions

diff --git a/generic/arch.cc b/generic/arch.cc
index 7cd71179..999e5033 100644
--- a/generic/arch.cc
+++ b/generic/arch.cc
@@ -249,6 +249,12 @@ void Arch::addCellTimingClockToOut(IdString cell, IdString port, IdString clock,
     cellTiming[cell].portClasses[port] = TMG_REGISTER_OUTPUT;
 }
 
+void Arch::clearCellBelPinMap(IdString cell, IdString cell_pin) { cells.at(cell)->bel_pins[cell_pin].clear(); }
+void Arch::addCellBelPinMapping(IdString cell, IdString cell_pin, IdString bel_pin)
+{
+    cells.at(cell)->bel_pins[cell_pin].push_back(bel_pin);
+}
+
 // ---------------------------------------------------------------
 
 Arch::Arch(ArchArgs args) : chipName("generic"), args(args)
@@ -342,7 +348,10 @@ std::vector<IdString> Arch::getBelPins(BelId bel) const
     return ret;
 }
 
-std::array<IdString, 1> Arch::getBelPinsForCellPin(CellInfo *cell_info, IdString pin) const { return {pin}; }
+const std::vector<IdString> &Arch::getBelPinsForCellPin(CellInfo *cell_info, IdString pin) const
+{
+    return cell_info->bel_pins.at(pin);
+}
 
 // ---------------------------------------------------------------
 
@@ -694,6 +703,10 @@ void Arch::assignArchInfo()
             ci->is_slice = false;
         }
         ci->user_group = int_or_default(ci->attrs, id("PACK_GROUP"), -1);
+        // If no manual cell->bel pin rule has been created; assign a default one
+        for (auto &p : ci->ports)
+            if (!ci->bel_pins.count(p.first))
+                ci->bel_pins.emplace(p.first, std::vector<IdString>{p.first});
     }
 }
 
diff --git a/generic/arch.h b/generic/arch.h
index 2a0c7158..007478eb 100644
--- a/generic/arch.h
+++ b/generic/arch.h
@@ -125,7 +125,7 @@ struct ArchRanges
     using TileBelsRangeT = const std::vector<BelId> &;
     using BelAttrsRangeT = const std::map<IdString, std::string> &;
     using BelPinsRangeT = std::vector<IdString>;
-    using CellBelPinRangeT = std::array<IdString, 1>;
+    using CellBelPinRangeT = const std::vector<IdString> &;
     // Wires
     using AllWiresRangeT = const std::vector<WireId> &;
     using DownhillPipRangeT = const std::vector<PipId> &;
@@ -207,6 +207,9 @@ struct Arch : ArchAPI<ArchRanges>
     void addCellTimingSetupHold(IdString cell, IdString port, IdString clock, DelayInfo setup, DelayInfo hold);
     void addCellTimingClockToOut(IdString cell, IdString port, IdString clock, DelayInfo clktoq);
 
+    void clearCellBelPinMap(IdString cell, IdString cell_pin);
+    void addCellBelPinMapping(IdString cell, IdString cell_pin, IdString bel_pin);
+
     // ---------------------------------------------------------------
     // Common Arch API. Every arch must provide the following methods.
 
@@ -244,7 +247,7 @@ struct Arch : ArchAPI<ArchRanges>
     WireId getBelPinWire(BelId bel, IdString pin) const override;
     PortType getBelPinType(BelId bel, IdString pin) const override;
     std::vector<IdString> getBelPins(BelId bel) const override;
-    std::array<IdString, 1> getBelPinsForCellPin(CellInfo *cell_info, IdString pin) const override;
+    const std::vector<IdString> &getBelPinsForCellPin(CellInfo *cell_info, IdString pin) const override;
 
     WireId getWireByName(IdStringList name) const override;
     IdStringList getWireName(WireId wire) const override;
diff --git a/generic/arch_pybindings.cc b/generic/arch_pybindings.cc
index 3dc04206..35ec3b33 100644
--- a/generic/arch_pybindings.cc
+++ b/generic/arch_pybindings.cc
@@ -226,6 +226,14 @@ void arch_wrap_python(py::module &m)
                     pass_through<DelayInfo>>::def_wrap(ctx_cls, "addCellTimingClockToOut", "cell"_a, "port"_a,
                                                        "clock"_a, "clktoq"_a);
 
+    fn_wrapper_2a_v<Context, decltype(&Context::clearCellBelPinMap), &Context::clearCellBelPinMap,
+                    conv_from_str<IdString>, conv_from_str<IdString>>::def_wrap(ctx_cls, "clearCellBelPinMap", "cell"_a,
+                                                                                "cell_pin"_a);
+    fn_wrapper_3a_v<Context, decltype(&Context::addCellBelPinMapping), &Context::addCellBelPinMapping,
+                    conv_from_str<IdString>, conv_from_str<IdString>,
+                    conv_from_str<IdString>>::def_wrap(ctx_cls, "addCellBelPinMapping", "cell"_a, "cell_pin"_a,
+                                                       "bel_pin"_a);
+
     // const\_range\<BelBucketId\> getBelBuckets() const
     fn_wrapper_0a<Context, decltype(&Context::getBelBuckets), &Context::getBelBuckets,
                   wrap_context<const std::vector<BelBucketId> &>>::def_wrap(ctx_cls, "getBelBuckets");
diff --git a/generic/archdefs.h b/generic/archdefs.h
index fad36894..30503414 100644
--- a/generic/archdefs.h
+++ b/generic/archdefs.h
@@ -68,6 +68,8 @@ struct ArchCellInfo
     bool is_slice;
     // Only packing rule for slice type primitives is a single clock per tile
     const NetInfo *slice_clk;
+    // Cell to bel pin mapping
+    std::unordered_map<IdString, std::vector<IdString>> bel_pins;
 };
 
 NEXTPNR_NAMESPACE_END