Merge branch 'master' into xc7

README.md

@@ -49,8 +49,9 @@ Getting started
 
 ### nextpnr-ice40
 
-To build the iCE40 version of nextpnr, install [icestorm](http://www.clifford.at/icestorm/) with chipdbs installed in `/usr/local/share/icebox`
+To build the iCE40 version of nextpnr, install [icestorm](http://www.clifford.at/icestorm/) with chipdbs installed in `/usr/local/share/icebox`,
-(or another location, which should be passed as -DICEBOX_ROOT=/path/to/icebox to CMake).
+or another location, which should be passed as `-DICEBOX_ROOT=/path/to/share/icebox` (ensure to point it to `share/icebox` and not where the
+icebox binaries are installed) to CMake.
 Then build and install `nextpnr-ice40` using the following commands:
 
 ```

common/chain_utils.h

@@ -51,7 +51,8 @@ std::vector<CellChain> find_chains(const Context *ctx, F1 cell_type_predicate, F
             CellChain chain;
             CellInfo *end = start;
             while (end != nullptr) {
-                chain.cells.push_back(end);
+                if (chained.insert(end->name).second)
+                    chain.cells.push_back(end);
                 end = get_next(ctx, end);
             }
             if (chain.cells.size() >= min_length) {

ecp5/cells.cc

@@ -416,7 +416,7 @@ void nxio_to_tr(Context *ctx, CellInfo *nxio, CellInfo *trio, std::vector<std::u
             ctx, donet, [](const Context *ctx, const CellInfo *cell) { return cell->type == ctx->id("$_TBUF_"); },
             ctx->id("Y"));
     if (tbuf) {
-        replace_port(tbuf, ctx->id("I"), trio, ctx->id("I"));
+        replace_port(tbuf, ctx->id("A"), trio, ctx->id("I"));
         // Need to invert E to form T
         std::unique_ptr<CellInfo> inv_lut = create_ecp5_cell(ctx, ctx->id("LUT4"), trio->name.str(ctx) + "$invert_T");
         replace_port(tbuf, ctx->id("E"), inv_lut.get(), ctx->id("A"));

ecp5/pack.cc

@@ -299,7 +299,16 @@ class Ecp5Packer
                     // iobuf
                     log_info("%s feeds TRELLIS_IO %s, removing %s %s.\n", ci->name.c_str(ctx), trio->name.c_str(ctx),
                              ci->type.c_str(ctx), ci->name.c_str(ctx));
+
                     NetInfo *net = trio->ports.at(ctx->id("B")).net;
+                    if (((ci->type == ctx->id("$nextpnr_ibuf") || ci->type == ctx->id("$nextpnr_iobuf")) &&
+                         net->users.size() > 1) ||
+                        (ci->type == ctx->id("$nextpnr_obuf") &&
+                         (net->users.size() > 2 || net->driver.cell != nullptr)) ||
+                        (ci->type == ctx->id("$nextpnr_iobuf") && ci->ports.at(ctx->id("I")).net != nullptr &&
+                         ci->ports.at(ctx->id("I")).net->driver.cell != nullptr))
+                        log_error("Pin B of %s '%s' connected to more than a single top level IO.\n",
+                                  trio->type.c_str(ctx), trio->name.c_str(ctx));
                     if (net != nullptr) {
                         ctx->nets.erase(net->name);
                         trio->ports.at(ctx->id("B")).net = nullptr;
@@ -1497,6 +1506,10 @@ class Ecp5Packer
                     iol = create_pio_iologic(pio, ci);
                 set_iologic_mode(iol, "IDDRX1_ODDRX1");
                 replace_port(ci, ctx->id("Q"), iol, id_IOLDO);
+                if (!pio->ports.count(id_IOLDO)) {
+                    pio->ports[id_IOLDO].name = id_IOLDO;
+                    pio->ports[id_IOLDO].type = PORT_IN;
+                }
                 replace_port(pio, id_I, pio, id_IOLDO);
                 pio->params[ctx->id("DATAMUX_ODDR")] = "IOLDO";
                 set_iologic_sclk(iol, ci, ctx->id("SCLK"), false);

ice40/bitstream.cc

@@ -527,10 +527,23 @@ void write_asc(const Context *ctx, std::ostream &out)
                 }
 
                 if (ctx->args.type == ArchArgs::UP5K) {
+                    std::string pullup_resistor = "100K";
+                    if (cell.second->attrs.count(ctx->id("PULLUP_RESISTOR")))
+                        pullup_resistor = cell.second->attrs.at(ctx->id("PULLUP_RESISTOR"));
+                    NPNR_ASSERT(pullup_resistor == "100K" || pullup_resistor == "10K" || pullup_resistor == "6P8K" ||
+                                pullup_resistor == "3P3K");
                     if (iez == 0) {
-                        set_config(ti, config.at(iey).at(iex), "IoCtrl.cf_bit_39", !pullup);
+                        set_config(ti, config.at(iey).at(iex), "IoCtrl.cf_bit_39",
+                                   (!pullup) || (pullup_resistor != "100K"));
+                        set_config(ti, config.at(iey).at(iex), "IoCtrl.cf_bit_36", pullup && pullup_resistor == "3P3K");
+                        set_config(ti, config.at(iey).at(iex), "IoCtrl.cf_bit_37", pullup && pullup_resistor == "6P8K");
+                        set_config(ti, config.at(iey).at(iex), "IoCtrl.cf_bit_38", pullup && pullup_resistor == "10K");
                     } else if (iez == 1) {
-                        set_config(ti, config.at(iey).at(iex), "IoCtrl.cf_bit_35", !pullup);
+                        set_config(ti, config.at(iey).at(iex), "IoCtrl.cf_bit_35",
+                                   (!pullup) || (pullup_resistor != "100K"));
+                        set_config(ti, config.at(iey).at(iex), "IoCtrl.cf_bit_32", pullup && pullup_resistor == "3P3K");
+                        set_config(ti, config.at(iey).at(iex), "IoCtrl.cf_bit_33", pullup && pullup_resistor == "6P8K");
+                        set_config(ti, config.at(iey).at(iex), "IoCtrl.cf_bit_34", pullup && pullup_resistor == "10K");
                     }
                 }
             } else {

ice40/main.cc

@@ -70,6 +70,8 @@ po::options_description Ice40CommandHandler::getArchOptions()
     specific.add_options()("no-promote-globals", "disable all global promotion");
     specific.add_options()("opt-timing", "run post-placement timing optimisation pass (experimental)");
     specific.add_options()("tmfuzz", "run path delay estimate fuzzer");
+    specific.add_options()("pcf-allow-unconstrained", "don't require PCF to constrain all IO");
+
     return specific;
 }
 void Ice40CommandHandler::validate()
@@ -87,6 +89,8 @@ void Ice40CommandHandler::customAfterLoad(Context *ctx)
         std::ifstream pcf(filename);
         if (!apply_pcf(ctx, filename, pcf))
             log_error("Loading PCF failed.\n");
+    } else {
+        log_warning("No PCF file specified; IO pins will be placed automatically\n");
     }
 }
 void Ice40CommandHandler::customBitstream(Context *ctx)
@@ -164,6 +168,9 @@ std::unique_ptr<Context> Ice40CommandHandler::createContext()
         ctx->settings[ctx->id("no_promote_globals")] = "1";
     if (vm.count("opt-timing"))
         ctx->settings[ctx->id("opt_timing")] = "1";
+    if (vm.count("pcf-allow-unconstrained"))
+        ctx->settings[ctx->id("pcf_allow_unconstrained")] = "1";
+
     return ctx;
 }
 

ice40/pack.cc

@@ -478,9 +478,6 @@ static void pack_io(Context *ctx)
             }
             packed_cells.insert(ci->name);
             std::copy(ci->attrs.begin(), ci->attrs.end(), std::inserter(sb->attrs, sb->attrs.begin()));
-            if (!sb->attrs.count(ctx->id("BEL")))
-                log_warning("IO '%s' is not constrained to a pin and will be automatically placed\n",
-                            ci->name.c_str(ctx));
         } else if (is_sb_io(ctx, ci) || is_sb_gb_io(ctx, ci)) {
             NetInfo *net = ci->ports.at(ctx->id("PACKAGE_PIN")).net;
             if ((net != nullptr) && (net->users.size() > 1))
@@ -1181,20 +1178,26 @@ static void pack_special(Context *ctx)
                 log_info("  PLL '%s' has LOCK output, need to pass all outputs via LUT\n", ci->name.c_str(ctx));
                 bool found_lut = false;
                 bool all_luts = true;
+                bool found_carry = false;
                 unsigned int lut_count = 0;
                 for (const auto &user : port.net->users) {
                     NPNR_ASSERT(user.cell != nullptr);
                     if (user.cell->type == ctx->id("ICESTORM_LC")) {
-                        found_lut = true;
+                        if (bool_or_default(user.cell->params, ctx->id("CARRY_ENABLE"), false)) {
-                        lut_count++;
+                            found_carry = true;
+                            all_luts = false;
+                        } else {
+                            found_lut = true;
+                            lut_count++;
+                        }
                     } else {
                         all_luts = false;
                     }
                 }
 
-                if (found_lut && all_luts) {
+                if (found_lut && all_luts && lut_count < 8) {
                     // Every user is a LUT, carry on now.
-                } else if (found_lut && !all_luts && lut_count < 8) {
+                } else if (found_lut && !all_luts && !found_carry && lut_count < 8) {
                     // Strategy: create a pass-through LUT, move all non-LUT users behind it.
                     log_info("  LUT strategy for %s: move non-LUT users to new LUT\n", port.name.c_str(ctx));
                     auto pt = spliceLUT(ctx, packed.get(), port.name, true);

ice40/pcf.cc

@@ -21,6 +21,7 @@
 #include "pcf.h"
 #include <sstream>
 #include "log.h"
+#include "util.h"
 
 NEXTPNR_NAMESPACE_BEGIN
 
@@ -47,17 +48,43 @@ bool apply_pcf(Context *ctx, std::string filename, std::istream &in)
             if (words.size() == 0)
                 continue;
             std::string cmd = words.at(0);
+            bool nowarn = false;
             if (cmd == "set_io") {
                 size_t args_end = 1;
-                while (args_end < words.size() && words.at(args_end).at(0) == '-')
+                std::vector<std::pair<IdString, std::string>> extra_attrs;
+                while (args_end < words.size() && words.at(args_end).at(0) == '-') {
+                    const auto &setting = words.at(args_end);
+                    if (setting == "-pullup") {
+                        const auto &value = words.at(++args_end);
+                        if (value == "yes" || value == "1")
+                            extra_attrs.emplace_back(std::make_pair(ctx->id("PULLUP"), "1"));
+                        else if (value == "no" || value == "0")
+                            extra_attrs.emplace_back(std::make_pair(ctx->id("PULLUP"), "0"));
+                        else
+                            log_error("Invalid value '%s' for -pullup (on line %d)\n", value.c_str(), lineno);
+                    } else if (setting == "-pullup_resistor") {
+                        const auto &value = words.at(++args_end);
+                        if (ctx->args.type != ArchArgs::UP5K)
+                            log_error("Pullup resistance can only be set on UP5K (on line %d)\n", lineno);
+                        if (value != "3P3K" && value != "6P8K" && value != "10K" && value != "100K")
+                            log_error("Invalid value '%s' for -pullup_resistor (on line %d)\n", value.c_str(), lineno);
+                        extra_attrs.emplace_back(std::make_pair(ctx->id("PULLUP_RESISTOR"), value));
+                    } else if (setting == "-nowarn") {
+                        nowarn = true;
+                    } else if (setting == "--warn-no-port") {
+                    } else {
+                        log_warning("Ignoring PCF setting '%s' (on line %d)\n", setting.c_str(), lineno);
+                    }
                     args_end++;
+                }
                 if (args_end >= words.size() - 1)
                     log_error("expected PCF syntax 'set_io cell pin' (on line %d)\n", lineno);
                 std::string cell = words.at(args_end);
                 std::string pin = words.at(args_end + 1);
                 auto fnd_cell = ctx->cells.find(ctx->id(cell));
                 if (fnd_cell == ctx->cells.end()) {
-                    log_warning("unmatched constraint '%s' (on line %d)\n", cell.c_str(), lineno);
+                    if (!nowarn)
+                        log_warning("unmatched constraint '%s' (on line %d)\n", cell.c_str(), lineno);
                 } else {
                     BelId pin_bel = ctx->getPackagePinBel(pin);
                     if (pin_bel == BelId())
@@ -67,11 +94,28 @@ bool apply_pcf(Context *ctx, std::string filename, std::istream &in)
                     fnd_cell->second->attrs[ctx->id("BEL")] = ctx->getBelName(pin_bel).str(ctx);
                     log_info("constrained '%s' to bel '%s'\n", cell.c_str(),
                              fnd_cell->second->attrs[ctx->id("BEL")].c_str());
+                    for (const auto &attr : extra_attrs)
+                        fnd_cell->second->attrs[attr.first] = attr.second;
                 }
             } else {
                 log_error("unsupported PCF command '%s' (on line %d)\n", cmd.c_str(), lineno);
             }
         }
+        for (auto cell : sorted(ctx->cells)) {
+            CellInfo *ci = cell.second;
+            if (ci->type == ctx->id("$nextpnr_ibuf") || ci->type == ctx->id("$nextpnr_obuf") ||
+                ci->type == ctx->id("$nextpnr_iobuf")) {
+                if (!ci->attrs.count(ctx->id("BEL"))) {
+                    if (bool_or_default(ctx->settings, ctx->id("pcf_allow_unconstrained")))
+                        log_warning("IO '%s' is unconstrained in PCF and will be automatically placed\n",
+                                    cell.first.c_str(ctx));
+                    else
+                        log_error("IO '%s' is unconstrained in PCF (override this error with "
+                                  "--pcf-allow-unconstrained)\n",
+                                  cell.first.c_str(ctx));
+                }
+            }
+        }
         ctx->settings.emplace(ctx->id("input/pcf"), filename);
         return true;
     } catch (log_execution_error_exception) {