treewide: Use argparse.FileType in more places

Convert some scripts to use `argparse.FileType` where the change is relatively
easily doable. This allows better error messages as e.g. missing input files
will be detected during argument parsing. And it also makes writing to stdout
in absence of an explicit argument simpler.

Signed-off-by: Barnabás Pőcze <barnabas.pocze@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

utils/codegen/gen-controls.py

@@ -44,25 +44,25 @@ def main(argv):
     parser = argparse.ArgumentParser()
     parser.add_argument('--mode', '-m', type=str, required=True, choices=['controls', 'properties'],
                         help='Mode of operation')
-    parser.add_argument('--output', '-o', metavar='file', type=str,
+    parser.add_argument('--output', '-o', metavar='file', default=sys.stdout,
+                        type=argparse.FileType('w', encoding='utf-8'),
                         help='Output file name. Defaults to standard output if not specified.')
-    parser.add_argument('--ranges', '-r', type=str, required=True,
+    parser.add_argument('--ranges', '-r', required=True, type=argparse.FileType('rb'),
                         help='Control id range reservation file.')
-    parser.add_argument('--template', '-t', dest='template', type=str, required=True,
+    parser.add_argument('--template', '-t', dest='template', required=True,
+                        type=argparse.FileType('r', encoding='utf-8'),
                         help='Template file name.')
-    parser.add_argument('input', type=str, nargs='+',
+    parser.add_argument('input', nargs='+',
+                        type=argparse.FileType('rb'),
                         help='Input file name.')
 
     args = parser.parse_args(argv[1:])
 
-    ranges = {}
-    with open(args.ranges, 'rb') as f:
-        data = open(args.ranges, 'rb').read()
-        ranges = yaml.safe_load(data)['ranges']
+    ranges = yaml.safe_load(args.ranges)['ranges']
 
     controls = {}
     for input in args.input:
-        data = yaml.safe_load(open(input, 'rb').read())
+        data = yaml.safe_load(input)
 
         vendor = data['vendor']
         if vendor not in ranges.keys():
@@ -92,15 +92,10 @@ def main(argv):
     env = jinja2.Environment()
     env.filters['format_description'] = format_description
     env.filters['snake_case'] = snake_case
-    template = env.from_string(open(args.template, 'r', encoding='utf-8').read())
+    template = env.from_string(args.template.read())
     string = template.render(data)
 
-    if args.output:
-        output = open(args.output, 'w', encoding='utf-8')
-        output.write(string)
-        output.close()
-    else:
-        sys.stdout.write(string)
+    args.output.write(string)
 
     return 0