[libcamera-devel] [PATCH v3 26/38] ipa: Add core.mojom
Paul Elder
paul.elder at ideasonboard.com
Fri Oct 2 16:31:42 CEST 2020
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 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 | 83 ++++++++++++++++++++++++++
include/libcamera/ipa/meson.build | 18 +++++-
src/libcamera/proxy/meson.build | 2 +-
src/libcamera/proxy/worker/meson.build | 2 +-
4 files changed, 100 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..81d68bae
--- /dev/null
+++ b/include/libcamera/ipa/core.mojom
@@ -0,0 +1,83 @@
+/* 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 has an fd.
+ */
+struct CameraSensorInfo {};
+struct ControlInfoMap {};
+struct ControlList {};
+struct FileDescriptor {};
+[hasFd] struct IPABuffer {};
+struct IPASettings {};
+struct IPAStream {};
+
+/*
+ * Any custom structs that the IPA interfaces use must be defined here,
+ * usin the mojo interface definition language.
+ *
+ * It is recommended to use namespacing, to avoid potential collisions with
+ * libcamera types. Use mojom's module directive for this.
+ */
+
+/*
+ * \class IPACoreInterface
+ *
+ * This mojo interface describes the main interface of the IPA. It must be
+ * defined.
+ *
+ * The main interface must be named as IPA{pipeline_name}Interface.
+ * IPACoreInterface serves as an example and documentation, where
+ * {pipeline_name} is Core.
+ *
+ * At minimum, the following three functions must be present (and implemented):
+ * init(IPASettings settings) => (int32 ret);
+ * start() => (int32 ret);
+ * stop();
+ *
+ * All input parameters will become const references, except for primitives,
+ * which will simply become const. Output parameters will become pointers,
+ * unless there is only one primitive output parameter, in which case it will
+ * become a regular return value.
+ *
+ * const is not allowed inside of arrays and maps. mojo arrays will become C++
+ * vectors.
+ *
+ * By default, all methods defined in the main interface are synchronous. This
+ * means that in the case of IPC (ie. isolated IPA), the function call will not
+ * return until the return value or output parameters are ready. To specify an
+ * asynchronous function, the [async] attribute can be used. Asynchronous
+ * methods must not have any return value or output parameters, since in the
+ * case of IPC the call needs to return immediately.
+ *
+ * In addition the following must be defined in {pipeline_name}.h in the
+ * libcamera namespace:
+ *
+ * static ControlInfoMap {pipeline_name}::Controls;
+ *
+ * It may be empty.
+ */
+
+/*
+ * \class IPACoreCallbackInterface
+ *
+ * This mojo interface describes the callback interface of the IPA. It must be
+ * defined. If there are no callback functions, then it may be empty.
+ *
+ * The callback interface must be named as IPA{pipeline_name}CallbackInterface.
+ * IPACoreCallbackInterface serves as an example and documentation, where
+ * {pipeline_name} is Core.
+ *
+ * Methods defined in the callback interface shall not return anything. This
+ * also means that these methods must be asynchronous and not synchronous.
+ * Therefore the [async] tag is not necessary.
+ *
+ * Methods defined in the callback interface will become Signals in the IPA
+ * interface. The IPA can emit signals, while the pipeline handler can connect
+ * slots to them.
+ */
diff --git a/include/libcamera/ipa/meson.build b/include/libcamera/ipa/meson.build
index 337948d2..590a1464 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 + '_generated_h',
input : mojom,
output : name + '_generated.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 + '_serializer_h',
input : mojom,
output : name + '_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 5490811b..353e5cf1 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
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