[libcamera-devel] [PATCH v1 3/5] libcamera: control: Add vendor control id range reservation

[Naushir Patuck]

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 seprate range from core libcamera controls,
breaking the existing numbering behaviour.

Signed-off-by: Naushir Patuck <naush at raspberrypi.com>
---
 include/libcamera/meson.build     |  3 ++-
 src/libcamera/control_ranges.yaml | 17 +++++++++++++++++
 utils/gen-controls.py             | 15 ++++++++++++---
 3 files changed, 31 insertions(+), 4 deletions(-)
 create mode 100644 src/libcamera/control_ranges.yaml

diff --git a/include/libcamera/meson.build b/include/libcamera/meson.build
index f8af51174f08..98339b93777c 100644
--- a/include/libcamera/meson.build
+++ b/include/libcamera/meson.build
@@ -82,11 +82,12 @@ foreach header, mode : control_source_files
     endforeach
 
     template_file = files(header + '.h.in')
+    ranges_file = files('../../src/libcamera/control_ranges.yaml')
     control_headers += custom_target(header + '_h',
                                      input : input_files,
                                      output : header + '.h',
                                      command : [gen_controls, '-o', '@OUTPUT@', '-i', '@INPUT@',
-                                                '--mode', mode, '-t', template_file],
+                                                '--mode', mode, '-t', template_file, '-r', ranges_file],
                                      install : true,
                                      install_dir : libcamera_headers_install_dir)
 endforeach
diff --git a/src/libcamera/control_ranges.yaml b/src/libcamera/control_ranges.yaml
new file mode 100644
index 000000000000..e908a8a3a110
--- /dev/null
+++ b/src/libcamera/control_ranges.yaml
@@ -0,0 +1,17 @@
+# 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 libcamera and vendor specific
+# controls.
+ranges:
+  # Core libcamera controls
+  libcamera: 0
+  # Draft designated libcamera controls
+  draft: 1000
+  # Raspberry Pi vendor controls
+  rpi: 2000
+
+...
diff --git a/utils/gen-controls.py b/utils/gen-controls.py
index 3c490a562676..a10b9fdc19ee 100755
--- a/utils/gen-controls.py
+++ b/utils/gen-controls.py
@@ -259,7 +259,7 @@ ${vendor_controls_map}
     }
 
 
-def generate_h(controls, mode):
+def generate_h(controls, mode, ranges):
     enum_template_start = string.Template('''enum ${name}Enum {''')
     enum_value_template = string.Template('''\t${name} = ${value},''')
     enum_values_template = string.Template('''extern const std::array<const ControlValue, ${size}> ${name}Values;''')
@@ -277,8 +277,10 @@ def generate_h(controls, mode):
             vendor = 'draft' if ctrl.is_draft else 'libcamera'
 
         if vendor not in ctrls:
+            if vendor not in ranges.keys():
+                raise RuntimeError('Vendor range is not defined')
+            id_value[vendor] = ranges[vendor] + 1
             ids[vendor] = []
-            id_value[vendor] = 1
             ctrls[vendor] = []
 
         # Core and draft controls use the same ID value
@@ -370,8 +372,15 @@ def main(argv):
                         help='Template file name.')
     parser.add_argument('--mode', type=str, required=True, choices=['controls', 'properties'],
                         help='Mode of operation')
+    parser.add_argument('-r', dest='ranges', type=str,
+                        help='Control id range reservation file.')
     args = parser.parse_args(argv[1:])
 
+    ranges = []
+    if args.ranges:
+        data = open(args.ranges, 'rb').read()
+        ranges = yaml.safe_load(data)['ranges']
+
     controls = []
     for input in args.inputs:
         data = open(input, 'rb').read()
@@ -382,7 +391,7 @@ def main(argv):
     if args.template.endswith('.cpp.in'):
         data = generate_cpp(controls)
     elif args.template.endswith('.h.in'):
-        data = generate_h(controls, args.mode)
+        data = generate_h(controls, args.mode, ranges)
     else:
         raise RuntimeError('Unknown template type')
 
-- 
2.34.1