ecp5: Adding LPF parser

Signed-off-by: David Shah <dave@ds0.me>

ecp5/arch.h

@@ -917,6 +917,9 @@ struct Arch : BaseCtx
 
     GlobalInfoPOD globalInfoAtLoc(Location loc);
 
+    // Apply LPF constraints to the context
+    bool applyLPF(std::string filename, std::istream &in);
+
     IdString id_trellis_slice;
     IdString id_clk, id_lsr;
     IdString id_clkmux, id_lsrmux;

ecp5/lpf.cc

@@ -0,0 +1,103 @@
+/*
+ *  nextpnr -- Next Generation Place and Route
+ *
+ *  Copyright (C) 2018  David Shah <david@symbioticeda.com>
+ *
+ *  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 <sstream>
+#include "log.h"
+#include "log.h"
+
+NEXTPNR_NAMESPACE_BEGIN
+
+bool Arch::applyLPF(std::string filename, std::istream &in)
+{
+    auto isempty = [] (const std::string &str) {return std::all_of(str.begin(), str.end(), [](char c){return isblank(c);});};
+    auto strip_quotes = [] (const std::string &str) {if (str.at(0) == '"') {
+        NPNR_ASSERT(str.back() == '"');
+        return str.substr(1, str.size() - 2);
+    } else {
+        return str;
+    }};
+
+    try {
+        if (!in)
+            log_error("failed to open LPF file\n");
+        std::string line;
+        std::string linebuf;
+        while (std::getline(in, line)) {
+            size_t cstart = line.find('#');
+            if (cstart != std::string::npos)
+                line = line.substr(0, cstart);
+            if (isempty(line))
+                continue;
+            linebuf += line;
+            // Look for a command up to a semicolon
+            size_t scpos = linebuf.find(';');
+            while (scpos != std::string::npos) {
+                std::string command = linebuf.substr(0, scpos);
+                // Split command into words
+                std::stringstream ss(line);
+                std::vector<std::string> words;
+                std::string tmp;
+                while (ss >> tmp)
+                    words.push_back(tmp);
+                if (words.size() >= 0) {
+                    std::string verb = words.at(0);
+                    if(verb == "BLOCK" || verb == "SYSCONFIG" || verb == "FREQUENCY") {
+                        log_warning("    ignoring unsupported LPF command '%s'\n", command.c_str());
+                    } else if (verb == "LOCATE") {
+                        NPNR_ASSERT(words.at(1) == "COMP");
+                        std::string cell = strip_quotes(words.at(2));
+                        NPNR_ASSERT(words.at(1) == "SITE");
+                        auto fnd_cell = cells.find(id(cell));
+                        if (fnd_cell == cells.end()) {
+                            log_warning("unmatched LPF 'LOCATE COMP' '%s'\n", cell.c_str());
+                        } else {
+                            fnd_cell->second->attrs[id("LOC")] = strip_quotes(words.at(3));
+                        }
+                    } else if (verb == "IOBUF") {
+                        NPNR_ASSERT(words.at(1) == "PORT");
+                        std::string cell = strip_quotes(words.at(2));
+                        auto fnd_cell = cells.find(id(cell));
+                        if (fnd_cell == cells.end()) {
+                            log_warning("unmatched LPF 'IOBUF PORT' '%s'\n", cell.c_str());
+                        } else {
+                            for (size_t i = 3; i < words.size(); i++) {
+                                std::string setting = words.at(i);
+                                size_t eqpos = setting.find('=');
+                                NPNR_ASSERT(eqpos != std::string::npos);
+                                std::string key = setting.substr(0, eqpos), value = setting.substr(eqpos + 1);
+                                fnd_cell->second->attrs[id(key)] = value;
+                            }
+                        }
+                    }
+                }
+
+                linebuf = linebuf.substr(scpos+1);
+                scpos = linebuf.find(';');
+            }
+        }
+        if (!isempty(linebuf))
+            log_error("unexpected end of LPF file\n");
+        settings.emplace(id("input/lpf"), filename);
+        return true;
+    } catch (log_execution_error_exception) {
+        return false;
+    }
+}
+
+NEXTPNR_NAMESPACE_END

ecp5/main.cc

@@ -35,6 +35,7 @@ class ECP5CommandHandler : public CommandHandler
     virtual ~ECP5CommandHandler(){};
     std::unique_ptr<Context> createContext() override;
     void setupArchContext(Context *ctx) override{};
+    void customAfterLoad(Context *ctx) override;
     void validate() override;
     void customBitstream(Context *ctx) override;
 
@@ -56,9 +57,13 @@ po::options_description ECP5CommandHandler::getArchOptions()
     specific.add_options()("um5g-25k", "set device type to LFE5UM5G-25F");
     specific.add_options()("um5g-45k", "set device type to LFE5UM5G-45F");
     specific.add_options()("um5g-85k", "set device type to LFE5UM5G-85F");
+
     specific.add_options()("package", po::value<std::string>(), "select device package (defaults to CABGA381)");
     specific.add_options()("basecfg", po::value<std::string>(), "base chip configuration in Trellis text format");
     specific.add_options()("textcfg", po::value<std::string>(), "textual configuration in Trellis format to write");
+
+    specific.add_options()("lpf", po::value<std::vector<std::string>>(), "LPF pin constraint file(s)");
+
     return specific;
 }
 void ECP5CommandHandler::validate()
@@ -111,6 +116,17 @@ std::unique_ptr<Context> ECP5CommandHandler::createContext()
     return std::unique_ptr<Context>(new Context(chipArgs));
 }
 
+void ECP5CommandHandler::customAfterLoad(Context *ctx)
+{
+    if (vm.count("lpf")) {
+        std::vector<std::string> files = vm["lpf"].as<std::vector<std::string>>();
+        for (const auto &filename : files) {
+            std::ifstream in(filename);
+            ctx->applyLPF(filename, in);
+        }
+    }
+}
+
 int main(int argc, char *argv[])
 {
     ECP5CommandHandler handler(argc, argv);