usb: make max interface count configurable at compile time.

embassy-usb/gen_config.py

@@ -0,0 +1,73 @@
+import os
+
+abspath = os.path.abspath(__file__)
+dname = os.path.dirname(abspath)
+os.chdir(dname)
+
+features = []
+
+
+def feature(name, default, min, max, pow2=None):
+    vals = set()
+    val = min
+    while val <= max:
+        vals.add(val)
+        if pow2 == True or (isinstance(pow2, int) and val >= pow2):
+            val *= 2
+        else:
+            val += 1
+    vals.add(default)
+
+    features.append(
+        {
+            "name": name,
+            "default": default,
+            "vals": sorted(list(vals)),
+        }
+    )
+
+
+feature("max_interface_count", default=4, min=1, max=8)
+
+# ========= Update Cargo.toml
+
+things = ""
+for f in features:
+    name = f["name"].replace("_", "-")
+    for val in f["vals"]:
+        things += f"{name}-{val} = []"
+        if val == f["default"]:
+            things += " # Default"
+        things += "\n"
+    things += "\n"
+
+SEPARATOR_START = "# BEGIN AUTOGENERATED CONFIG FEATURES\n"
+SEPARATOR_END = "# END AUTOGENERATED CONFIG FEATURES\n"
+HELP = "# Generated by gen_config.py. DO NOT EDIT.\n"
+with open("Cargo.toml", "r") as f:
+    data = f.read()
+before, data = data.split(SEPARATOR_START, maxsplit=1)
+_, after = data.split(SEPARATOR_END, maxsplit=1)
+data = before + SEPARATOR_START + HELP + things + SEPARATOR_END + after
+with open("Cargo.toml", "w") as f:
+    f.write(data)
+
+
+# ========= Update build.rs
+
+things = ""
+for f in features:
+    name = f["name"].upper()
+    things += f'    ("{name}", {f["default"]}),\n'
+
+SEPARATOR_START = "// BEGIN AUTOGENERATED CONFIG FEATURES\n"
+SEPARATOR_END = "// END AUTOGENERATED CONFIG FEATURES\n"
+HELP = "    // Generated by gen_config.py. DO NOT EDIT.\n"
+with open("build.rs", "r") as f:
+    data = f.read()
+before, data = data.split(SEPARATOR_START, maxsplit=1)
+_, after = data.split(SEPARATOR_END, maxsplit=1)
+data = before + SEPARATOR_START + HELP + \
+    things + "    " + SEPARATOR_END + after
+with open("build.rs", "w") as f:
+    f.write(data)