libcamera: properties: Add location property

Re-use the Control generation infrastructure to generate libcamera properties
and define the first 'Location' property.

Introduce three additional files:

- include/libcamera/property_ids.h
  Defines the properties ids

- src/libcamera/property_ids.cpp
  Defines the properties Control<> instances

- src/libcamera/property_ids.yaml
  Provide the first 'Location' property definition.

Reviewed-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Jacopo Mondi <jacopo@jmondi.org>

include/libcamera/meson.build

@@ -25,15 +25,23 @@ install_headers(libcamera_api,
 
 gen_controls = files('../../src/libcamera/gen-controls.py')
 
-control_ids_h = custom_target('control_ids_h',
-                              input : files('../../src/libcamera/control_ids.yaml', 'control_ids.h.in'),
-                              output : 'control_ids.h',
-                              depend_files : gen_controls,
-                              command : [gen_controls, '-o', '@OUTPUT@', '@INPUT@'],
-                              install : true,
-                              install_dir : join_paths('include', include_dir))
+control_source_files = [
+    'control_ids',
+    'property_ids',
+]
 
-libcamera_api += control_ids_h
+control_headers = []
+
+foreach header : control_source_files
+    input_files = files('../../src/libcamera/' + header +'.yaml', header + '.h.in')
+    control_headers += custom_target(header + '_h',
+                                     input : input_files,
+                                     output : header + '.h',
+                                     depend_files : gen_controls,
+                                     command : [gen_controls, '-o', '@OUTPUT@', '@INPUT@'],
+                                     install : true,
+                                     install_dir : join_paths('include', include_dir))
+endforeach
 
 gen_header = files('gen-header.sh')
 

include/libcamera/property_ids.h.in

@@ -0,0 +1,33 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2019, Google Inc.
+ *
+ * property_ids.h : Property ID list
+ *
+ * This file is auto-generated. Do not edit.
+ */
+
+#ifndef __LIBCAMERA_PROPERTY_IDS_H__
+#define __LIBCAMERA_PROPERTY_IDS_H__
+
+#include <stdint.h>
+
+#include <libcamera/controls.h>
+
+namespace libcamera {
+
+namespace properties {
+
+enum {
+${ids}
+};
+
+${controls}
+
+extern const ControlIdMap properties;
+
+} /* namespace propertiess */
+
+} /* namespace libcamera */
+
+#endif // __LIBCAMERA_PROPERTY_IDS_H__

src/libcamera/meson.build

@@ -69,14 +69,19 @@ endif
 
 gen_controls = files('gen-controls.py')
 
-control_ids_cpp = custom_target('control_ids_cpp',
-                                input : files('control_ids.yaml', 'control_ids.cpp.in'),
-                                output : 'control_ids.cpp',
-                                depend_files : gen_controls,
-                                command : [gen_controls, '-o', '@OUTPUT@', '@INPUT@'])
+control_sources = []
 
-libcamera_sources += control_ids_cpp
-libcamera_sources += control_ids_h
+foreach source : control_source_files
+    input_files = files(source +'.yaml', source + '.cpp.in')
+    control_sources += custom_target(source + '_cpp',
+                                     input : input_files,
+                                     output : source + '.cpp',
+                                     depend_files : gen_controls,
+                                     command : [gen_controls, '-o', '@OUTPUT@', '@INPUT@'])
+endforeach
+
+libcamera_sources += control_headers
+libcamera_sources += control_sources
 
 gen_version = join_paths(meson.source_root(), 'utils', 'gen-version.sh')
 

src/libcamera/property_ids.cpp.in

@@ -0,0 +1,43 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2019, Google Inc.
+ *
+ * property_ids.cpp : Property ID list
+ *
+ * This file is auto-generated. Do not edit.
+ */
+
+#include <libcamera/property_ids.h>
+
+/**
+ * \file property_ids.h
+ * \brief Camera property identifiers
+ */
+
+namespace libcamera {
+
+/**
+ * \brief Namespace for libcamera properties
+ */
+namespace properties {
+
+${controls_doc}
+
+#ifndef __DOXYGEN__
+/*
+ * Keep the properties definitions hidden from doxygen as it incorrectly parses
+ * them as functions.
+ */
+${controls_def}
+#endif
+
+/**
+ * \brief List of all supported libcamera properties
+ */
+extern const ControlIdMap properties {
+${controls_map}
+};
+
+} /* namespace properties */
+
+} /* namespace libcamera */

src/libcamera/property_ids.yaml

@@ -0,0 +1,28 @@
+# SPDX-License-Identifier: LGPL-2.1-or-later
+#
+# Copyright (C) 2019, Google Inc.
+#
+%YAML 1.2
+---
+controls:
+  - Location:
+      type: int32_t
+      description: |
+        Camera mounting location
+      enum:
+        - name: CameraLocationFront
+          value: 0
+          description: |
+            The camera is mounted on the front side of the device, facing the
+            user
+        - name: CameraLocationBack
+          value: 1
+          description: |
+            The camera is mounted on the back side of the device, facing away
+            from the user
+        - name: CameraLocationExternal
+          value: 2
+          description: |
+            The camera is attached to the device in a way that allows it to
+            be moved freely
+...