[libcamera-devel] [PATCH v4 24/37] ipa: Add core.mojom

[Paul Elder]

Add a base mojom file to contain empty mojom definitions of libcamera
objects, as well as documentation for the IPA interfaces that need to be
defined in the mojom files.

Signed-off-by: Paul Elder <paul.elder at ideasonboard.com>

---
Changes in v4:
- move docs to IPA guide

Changes in v3:
- add doc that structs need to be defined
- add doc to recommend namespacing
- change indentation
- add requirement that base controls *must* be defined in
  libcamera::{pipeline_name}::Controls

New in v2
---
 include/libcamera/ipa/core.mojom       | 18 ++++++++++++++++++
 include/libcamera/ipa/meson.build      | 18 +++++++++++++++---
 src/libcamera/proxy/meson.build        |  2 +-
 src/libcamera/proxy/worker/meson.build |  2 +-
 4 files changed, 35 insertions(+), 5 deletions(-)
 create mode 100644 include/libcamera/ipa/core.mojom

diff --git a/include/libcamera/ipa/core.mojom b/include/libcamera/ipa/core.mojom
new file mode 100644
index 00000000..ed26aaad
--- /dev/null
+++ b/include/libcamera/ipa/core.mojom
@@ -0,0 +1,18 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+/*
+ * Any libcamera objects that are used by any interfaces must be declared
+ * here, and a de/serializer be implemented in IPADataSerializer. In addition,
+ * the corresponding header file (or forward-declarations) must be placed in
+ * {pipeline_name}.h.
+ *
+ * For libcamera types, the [hasFd] attribute is needed to notify the compiler
+ * that the struct embeds a FileDescriptor.
+ */
+struct CameraSensorInfo {};
+struct ControlInfoMap {};
+struct ControlList {};
+struct FileDescriptor {};
+[hasFd] struct IPABuffer {};
+struct IPASettings {};
+struct IPAStream {};
diff --git a/include/libcamera/ipa/meson.build b/include/libcamera/ipa/meson.build
index d7a2b6b2..b7caec95 100644
--- a/include/libcamera/ipa/meson.build
+++ b/include/libcamera/ipa/meson.build
@@ -13,6 +13,17 @@ install_headers(libcamera_ipa_headers,
 # Prepare IPA/IPC generation components
 #
 
+core_mojom_file = 'core.mojom'
+ipa_mojom_core = custom_target(core_mojom_file.split('.')[0] + '_mojom_module',
+                               input : core_mojom_file,
+                               output : core_mojom_file + '-module',
+                               command : [
+                                   mojom_parser,
+                                   '--output-root', meson.build_root(),
+                                   '--input-root', meson.source_root(),
+                                   '--mojoms', '@INPUT@'
+                               ])
+
 ipa_mojom_files = []
 
 ipa_mojoms = []
@@ -30,6 +41,7 @@ foreach file : ipa_mojom_files
     mojom = custom_target(file.split('.')[0] + '_mojom_module',
                           input : file,
                           output : file + '-module',
+                          depends : ipa_mojom_core,
                           command : [
                               mojom_parser,
                               '--output-root', meson.build_root(),
@@ -41,7 +53,7 @@ foreach file : ipa_mojom_files
     header = custom_target(name + '_ipa_interface_h',
                            input : mojom,
                            output : name + '_ipa_interface.h',
-                           depends : mojom_templates,
+                           depends : [mojom_templates, ipa_mojom_core],
                            command : [
                                mojom_generator, 'generate',
                                '-g', 'libcamera',
@@ -55,7 +67,7 @@ foreach file : ipa_mojom_files
     serializer = custom_target(name + '_ipa_serializer_h',
                                input : mojom,
                                output : name + '_ipa_serializer.h',
-                               depends : mojom_templates,
+                               depends : [mojom_templates, ipa_mojom_core],
                                command : [
                                    mojom_generator, 'generate',
                                    '-g', 'libcamera',
@@ -69,7 +81,7 @@ foreach file : ipa_mojom_files
     proxy_header = custom_target(name + '_proxy_h',
                                  input : mojom,
                                  output : 'ipa_proxy_' + name + '.h',
-                                 depends : mojom_templates,
+                                 depends : [mojom_templates, ipa_mojom_core],
                                  command : [
                                      mojom_generator, 'generate',
                                      '-g', 'libcamera',
diff --git a/src/libcamera/proxy/meson.build b/src/libcamera/proxy/meson.build
index ac68ad08..f27b453a 100644
--- a/src/libcamera/proxy/meson.build
+++ b/src/libcamera/proxy/meson.build
@@ -10,7 +10,7 @@ foreach mojom : ipa_mojoms
     proxy = custom_target(mojom['name'] + '_proxy_cpp',
                           input : mojom['mojom'],
                           output : 'ipa_proxy_' + mojom['name'] + '.cpp',
-                          depends : [mojom_templates],
+                          depends : [mojom_templates, ipa_mojom_core],
                           command : [
                               mojom_generator, 'generate',
                               '-g', 'libcamera',
diff --git a/src/libcamera/proxy/worker/meson.build b/src/libcamera/proxy/worker/meson.build
index 8e0b978a..628bb050 100644
--- a/src/libcamera/proxy/worker/meson.build
+++ b/src/libcamera/proxy/worker/meson.build
@@ -11,7 +11,7 @@ foreach mojom : ipa_mojoms
     worker = custom_target(mojom['name'] + '_proxy_worker',
                            input : mojom['mojom'],
                            output : 'ipa_proxy_' + mojom['name'] + '_worker.cpp',
-                           depends : [mojom_templates],
+                           depends : [mojom_templates, ipa_mojom_core],
                            command : [
                                mojom_generator, 'generate',
                                '-g', 'libcamera',
-- 
2.27.0