libcamera: control: Add vendor control id range reservation

Add a new control_ranges.yaml file that is used to reserve control id
ranges/offsets for libcamera and vendor specific controls. This file is
used by the gen-controls.py script to generate control id values for
each control.

Draft controls now have a separate range from core libcamera controls,
breaking the existing numbering behaviour.

Signed-off-by: Naushir Patuck <naush@raspberrypi.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>

src/libcamera/control_ranges.yaml

@@ -0,0 +1,18 @@
+# SPDX-License-Identifier: LGPL-2.1-or-later
+#
+# Copyright (C) 2023, Raspberry Pi Ltd
+#
+%YAML 1.1
+---
+# Specifies the control id ranges/offsets for core/draft libcamera and vendor
+# controls and properties.
+ranges:
+  # Core libcamera controls
+  libcamera: 0
+  # Draft designated libcamera controls
+  draft: 10000
+  # Raspberry Pi vendor controls
+  rpi: 20000
+  # Next range starts at 30000
+
+...

src/libcamera/meson.build

@@ -141,11 +141,13 @@ foreach mode, input_files : controls_mode_files
         template_file = files('property_ids.cpp.in')
     endif
 
+    ranges_file = files('control_ranges.yaml')
     control_sources += custom_target(mode + '_cpp',
                                      input : input_files,
                                      output : mode + '_ids.cpp',
                                      command : [gen_controls, '-o', '@OUTPUT@',
-                                                '--mode', mode, '-t', template_file, '@INPUT@'])
+                                                '--mode', mode, '-t', template_file,
+                                                '-r', ranges_file, '@INPUT@'])
 endforeach
 
 libcamera_sources += control_sources