scripts/dts: Simplify extract/interrupts.py and add some helpers

 - Have get_parent_path() return None for the root ('/'). This is handy
   when looping over path components.

 - Move _find_parent_irq_node() out of the class, call it
   parent_irq_node(), and use get_parent_path() in it.

 - Add a global err() function for reporting errors. Use it if a node
   unexpectedly has no interrupt-parent.

   Previously, this would give a Python error instead.

Signed-off-by: Ulf Magnusson <[email protected]>

Author: ulfalizer

scripts/dts/extract/globals.py

@@ -5,6 +5,8 @@
 # SPDX-License-Identifier: Apache-2.0
 #
 
+import sys
+
 from collections import defaultdict
 
 # globals
@@ -187,7 +189,10 @@ def node_label(node_path):
 
 
 def get_parent_path(node_path):
-    # Turns /foo/bar into /foo
+    # Turns /foo/bar into /foo. Returns None for /.
+
+    if node_path == '/':
+        return None
 
     return '/'.join(node_path.split('/')[:-1]) or '/'
 
@@ -467,3 +472,10 @@ def extract_cells(node_path, prop, prop_values, names, index,
                     prop_alias)
 
             insert_defs(node_path, prop_def, prop_alias)
+
+
+def err(msg):
+    # General error reporting helper. Prints a message to stderr and exits with
+    # status 1.
+
+    sys.exit("error: " + msg)

scripts/dts/extract/interrupts.py

@@ -11,17 +11,6 @@
 # @brief Manage interrupts directives.
 #
 class DTInterrupts(DTDirective):
-    def _find_parent_irq_node(self, node_path):
-        address = ''
-
-        for comp in node_path.split('/')[1:]:
-            address += '/' + comp
-            if 'interrupt-parent' in reduced[address]['props']:
-                interrupt_parent = reduced[address]['props'][
-                    'interrupt-parent']
-
-        return phandles[interrupt_parent]
-
     ##
     # @brief Extract interrupts
     #
@@ -40,7 +29,9 @@ def extract(self, node_path, prop, names, def_label):
         except:
             props = [node['props'].get(prop)]
 
-        irq_parent = self._find_parent_irq_node(node_path)
+        irq_parent = parent_irq_node(node_path)
+        if not irq_parent:
+            err(node_path + " has no interrupt-parent")
 
         l_base = def_label.split('/')
         index = 0
@@ -88,6 +79,17 @@ def extract(self, node_path, prop, names, def_label):
             index += 1
             insert_defs(node_path, prop_def, prop_alias)
 
+
+def parent_irq_node(node_path):
+    while node_path:
+        if 'interrupt-parent' in reduced[node_path]['props']:
+            return phandles[reduced[node_path]['props']['interrupt-parent']]
+
+        node_path = get_parent_path(node_path)
+
+    return None
+
+
 ##
 # @brief Management information for interrupts.
 interrupts = DTInterrupts()