efinix: add a list of values to fix in xml

Sometimes the Python API of the interface designer produce a wrong XML
file. Values can be changed in the XML file with this new list.
For example:

fix_pll = [
	#      Tag              name                    properties / values
	("comp_output_clock", "mipi_clk",             [("out_divider", "20")]),
        ("comp_output_clock", "mipi_tx_clk_fastclk",  [("out_divider", "4"), ("phase_setting", "3")]),
        ("comp_output_clock", "mipi_tx_data_fastclk", [("out_divider", "4"), ("phase_setting", "1")]),
        ("comp_output_clock", "mipi_tx_slowclk",      [("out_divider", "16")])
]

platform.toolchain.ifacewriter.fix_xml += fix_pll

litex/build/efinix/efinity.py

@@ -313,6 +313,10 @@ class EfinityToolchain:
         if self.ifacewriter.xml_blocks or platform.iobank_info:
             self.ifacewriter.generate_xml_blocks()
 
+        # Because the Python API is sometimes bugged, we need to tweak the generated xml
+        if self.ifacewriter.fix_xml:
+            self.ifacewriter.fix_xml_values()
+
         # Run
         if run:
             # Synthesis/Mapping.

litex/build/efinix/ifacewriter.py

@@ -36,6 +36,7 @@ class InterfaceWriter:
         self.efinity_path = efinity_path
         self.blocks       = []
         self.xml_blocks   = []
+        self.fix_xml      = []
         self.filename     = ""
         self.platform     = None
 
@@ -43,6 +44,25 @@ class InterfaceWriter:
         self.filename = build_name
         self.platform = platform
 
+    def fix_xml_values(self):
+        et.register_namespace("efxpt", "http://www.efinixinc.com/peri_design_db")
+        tree = et.parse(self.filename + ".peri.xml")
+        root = tree.getroot()
+        for tag, name, values in self.fix_xml:
+            for e in tree.iter():
+                if (tag in e.tag) and (name == e.get("name")):
+                    for n, v in values:
+                        e.set(n, v)
+
+        xml_string = et.tostring(root, "utf-8")
+        reparsed = expatbuilder.parseString(xml_string, False)
+        print_string = reparsed.toprettyxml(indent="    ")
+
+        # Remove lines with only whitespaces. Not sure why they are here
+        print_string = os.linesep.join([s for s in print_string.splitlines() if s.strip()])
+
+        tools.write_to_file("{}.peri.xml".format(self.filename), print_string)
+
     def generate_xml_blocks(self):
         et.register_namespace("efxpt", "http://www.efinixinc.com/peri_design_db")
         tree = et.parse(self.filename + ".peri.xml")