Add SF2 IO buffer insertion

Signed-off-by: Clifford Wolf <clifford@clifford.at>

1 files changed, 130 insertions, 0 deletions

diff --git a/techlibs/sf2/sf2_iobs.cc b/techlibs/sf2/sf2_iobs.cc
new file mode 100644
index 000000000..27141430c
--- /dev/null
+++ b/techlibs/sf2/sf2_iobs.cc
@@ -0,0 +1,130 @@
+/*
+ *  yosys -- Yosys Open SYnthesis Suite
+ *
+ *  Copyright (C) 2012  Clifford Wolf <clifford@clifford.at>
+ *
+ *  Permission to use, copy, modify, and/or distribute this software for any
+ *  purpose with or without fee is hereby granted, provided that the above
+ *  copyright notice and this permission notice appear in all copies.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ *  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ *  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ *  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ *  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ *  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ *  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ */
+
+#include "kernel/yosys.h"
+#include "kernel/sigtools.h"
+
+USING_YOSYS_NAMESPACE
+PRIVATE_NAMESPACE_BEGIN
+
+struct Sf2IobsPass : public Pass {
+	Sf2IobsPass() : Pass("sf2_iobs", "SF2: insert IO buffers") { }
+	void help() YS_OVERRIDE
+	{
+		//   |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|
+		log("\n");
+		log("    sf2_iobs [options] [selection]\n");
+		log("\n");
+		log("Add SF2 I/O buffers to top module IOs as needed.\n");
+		log("\n");
+	}
+	void execute(std::vector<std::string> args, RTLIL::Design *design) YS_OVERRIDE
+	{
+		log_header(design, "Executing sf2_iobs pass (insert IO buffers).\n");
+
+		size_t argidx;
+		for (argidx = 1; argidx < args.size(); argidx++)
+		{
+			// if (args[argidx] == "-singleton") {
+			// 	singleton_mode = true;
+			// 	continue;
+			// }
+			break;
+		}
+		extra_args(args, argidx, design);
+
+		Module *module = design->top_module();
+
+		if (module == nullptr)
+			log_cmd_error("No top module found.\n");
+
+		SigMap sigmap(module);
+
+		pool<SigBit> clk_bits;
+		pool<SigBit> handled_io_bits;
+		dict<SigBit, SigBit> rewrite_bits;
+		vector<pair<Cell*, SigBit>> pad_bits;
+
+		for (auto cell : module->cells())
+		{
+			if (cell->type == "\\SLE") {
+				for (auto bit : sigmap(cell->getPort("\\CLK")))
+					clk_bits.insert(bit);
+			}
+			if (cell->type.in("\\INBUF", "\\OUTBUF", "\\CLKBUF")) {
+				for (auto bit : sigmap(cell->getPort("\\PAD")))
+					handled_io_bits.insert(bit);
+			}
+		}
+
+		for (auto wire : vector<Wire*>(module->wires()))
+		{
+			if (!wire->port_input && !wire->port_output)
+				continue;
+
+			for (int index = 0; index < GetSize(wire); index++)
+			{
+				SigBit bit(wire, index);
+				SigBit canonical_bit = sigmap(bit);
+
+				if (handled_io_bits.count(canonical_bit))
+					continue;
+
+				if (wire->port_input && wire->port_output)
+					log_error("Failed to add buffer for inout port bit %s.\n", log_signal(bit));
+
+				IdString buf_type, buf_port;
+
+				if (wire->port_output) {
+					buf_type = "\\OUTBUF";
+					buf_port = "\\D";
+				} else if (clk_bits.count(canonical_bit)) {
+					buf_type = "\\CLKBUF";
+					buf_port = "\\Y";
+				} else {
+					buf_type = "\\INBUF";
+					buf_port = "\\Y";
+				}
+
+				Cell *c = module->addCell(NEW_ID, buf_type);
+				SigBit new_bit = module->addWire(NEW_ID);
+				c->setPort(buf_port, new_bit);
+				pad_bits.push_back(make_pair(c, bit));
+				rewrite_bits[canonical_bit] = new_bit;
+
+				log("Added %s cell %s for port bit %s.\n", log_id(c->type), log_id(c), log_signal(bit));
+			}
+		}
+
+		auto rewrite_function = [&](SigSpec &s) {
+			for (auto &bit : s) {
+				SigBit canonical_bit = sigmap(bit);
+				if (rewrite_bits.count(canonical_bit))
+					bit = rewrite_bits.at(canonical_bit);
+			}
+		};
+
+		module->rewrite_sigspecs(rewrite_function);
+
+		for (auto &it : pad_bits)
+			it.first->setPort("\\PAD", it.second);
+	}
+} Sf2IobsPass;
+
+PRIVATE_NAMESPACE_END