From c0fa4fd1f442d14d8dbad2854157bb36f17d86e1 Mon Sep 17 00:00:00 2001
From: Pepijn de Vos <pepijndevos@gmail.com>
Date: Mon, 28 Sep 2020 13:12:07 +0200
Subject: [PATCH] initial build support for Gowin

---
 litex/build/gowin/__init__.py |   0
 litex/build/gowin/common.py   |   8 +++
 litex/build/gowin/gowin.py    | 113 ++++++++++++++++++++++++++++++++++
 litex/build/gowin/platform.py |  34 ++++++++++
 4 files changed, 155 insertions(+)
 create mode 100644 litex/build/gowin/__init__.py
 create mode 100644 litex/build/gowin/common.py
 create mode 100644 litex/build/gowin/gowin.py
 create mode 100644 litex/build/gowin/platform.py

diff --git a/litex/build/gowin/__init__.py b/litex/build/gowin/__init__.py
new file mode 100644
index 000000000..e69de29bb
diff --git a/litex/build/gowin/common.py b/litex/build/gowin/common.py
new file mode 100644
index 000000000..3d428dea3
--- /dev/null
+++ b/litex/build/gowin/common.py
@@ -0,0 +1,8 @@
+#
+# This file is part of LiteX.
+#
+# Copyright (c) 2020 Pepijn de Vos <pepijndevos@gmail.com>
+# Copyright (c) 2015-2018 Florent Kermarrec <florent@enjoy-digital.fr>
+# SPDX-License-Identifier: BSD-2-Clause
+
+gowin_special_overrides = {}
diff --git a/litex/build/gowin/gowin.py b/litex/build/gowin/gowin.py
new file mode 100644
index 000000000..26234a15c
--- /dev/null
+++ b/litex/build/gowin/gowin.py
@@ -0,0 +1,113 @@
+#
+# This file is part of LiteX.
+#
+# Copyright (c) 2020 Pepijn de Vos <pepijndevos@gmail.com>
+# Copyright (c) 2015-2018 Florent Kermarrec <florent@enjoy-digital.fr>
+# SPDX-License-Identifier: BSD-2-Clause
+
+import os
+import subprocess
+
+from migen.fhdl.structure import _Fragment
+
+from litex.build.generic_platform import Pins, IOStandard, Misc
+from litex.build import tools
+
+def _build_cst(named_sc, named_pc):
+    lines = []
+
+    flat_sc = []
+    for name, pins, other, resource in named_sc:
+        if len(pins) > 1:
+            for i, p in enumerate(pins):
+                flat_sc.append((f"{name}[{i}]", p, other))
+        else:
+            flat_sc.append((name, pins[0], other))
+
+    for name, pin, other in flat_sc:
+        lines.append(f"IO_LOC \"{name}\" {pin};")
+    
+        for c in other:
+            if isinstance(c, IOStandard):
+                lines.append(f"IO_PORT \"{name}\" IO_TYPE={c.name};")
+            elif isinstance(c, Misc):
+                lines.append(f"IO_PORT \"{name}\" {c.misc};")
+
+    if named_pc:
+        lines.extend(named_pc)
+
+    cst = "\n".join(lines)
+    with open("top.cst", "w") as f:
+        f.write(cst)
+
+def _build_script(name, partnumber, files, options):
+    lines = [
+        f"set_device -name {name} {partnumber}",
+        "add_file top.cst",
+    ]
+
+    for f, typ, lib in files:
+        lines.append(f"add_file {f}")
+
+    for opt, val in options.items():
+        lines.append(f"set_option -{opt} {val}")
+
+    lines.append("run all")
+
+    tcl = "\n".join(lines)
+    with open("run.tcl", "w") as f:
+        f.write(tcl)
+
+class GowinToolchain():
+    def __init__(self):
+        self.options = {}
+
+    def attr_translate(*args):
+        print(args)
+        pass
+
+    def build(self, platform, fragment,
+        build_dir      = "build",
+        build_name     = "top",
+        run            = True,
+        **kwargs):
+
+        # Create build directory
+        cwd = os.getcwd()
+        os.makedirs(build_dir, exist_ok=True)
+        os.chdir(build_dir)
+
+        # Finalize design
+        if not isinstance(fragment, _Fragment):
+            fragment = fragment.get_fragment()
+        platform.finalize(fragment)
+
+        # Generate verilog
+        v_output = platform.get_verilog(fragment, name=build_name, **kwargs)
+        named_sc, named_pc = platform.resolve_signals(v_output.ns)
+        v_file = build_name + ".v"
+        v_output.write(v_file)
+        platform.add_source(v_file)
+        
+        if platform.verilog_include_paths:
+            self.options['includ_path'] = '{' + ';'.join(platform.verilog_include_paths) + '}'
+
+        # Generate constraints file (.cst)
+        _build_cst(
+            named_sc                = named_sc,
+            named_pc                = named_pc)
+
+        # Generate TCL build script
+        script = _build_script(
+            name                    = platform.name,
+            partnumber              = platform.device,
+            files                   = platform.sources,
+            options                 = self.options)
+
+        # Run
+        if run:
+            subprocess.run(["gw_sh", "run.tcl"])
+
+        os.chdir(cwd)
+
+        return v_output.ns
diff --git a/litex/build/gowin/platform.py b/litex/build/gowin/platform.py
new file mode 100644
index 000000000..82aabc5de
--- /dev/null
+++ b/litex/build/gowin/platform.py
@@ -0,0 +1,34 @@
+#
+# This file is part of LiteX.
+#
+# Copyright (c) 2020 Pepijn de Vos <pepijndevos@gmail.com>
+# Copyright (c) 2015-2018 Florent Kermarrec <florent@enjoy-digital.fr>
+# SPDX-License-Identifier: BSD-2-Clause
+
+import os
+
+from litex.build.generic_platform import GenericPlatform
+from litex.build.gowin import common, gowin
+
+# GowinPlatform -----------------------------------------------------------------------------------
+
+class GowinPlatform(GenericPlatform):
+    bitstream_ext = ".fs"
+
+    def __init__(self, *args, toolchain="gowin", **kwargs):
+        GenericPlatform.__init__(self, *args, **kwargs)
+        if toolchain == "gowin":
+            self.toolchain = gowin.GowinToolchain()
+        elif toolchain == "apicula":
+            raise ValueError("Apicula toolchain needs more work")
+        else:
+            raise ValueError("Unknown toolchain")
+
+    def get_verilog(self, *args, special_overrides=dict(), **kwargs):
+        so = dict(common.gowin_special_overrides)
+        so.update(special_overrides)
+        return GenericPlatform.get_verilog(self, *args, special_overrides=so,
+            attr_translate=self.toolchain.attr_translate, **kwargs)
+
+    def build(self, *args, **kwargs):
+        return self.toolchain.build(self, *args, **kwargs)