[libcamera-devel] [PATCH v4 02/11] android: Introduce CameraBuffer interface

[Jacopo Mondi]

In order to provide support for different memory backends,
move the MappedCamera3Buffer class definition outside of the
CameraDevice class to its own file and rename it in CameraBuffer.

The interface defined in camera_buffer.h will be implemented by
different backends that will be placed in the src/android/mm
subdirectory.

Provide a first implementation for the 'generic android' backend
which matches the existing one.

Reviewed-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
Signed-off-by: Jacopo Mondi <jacopo at jmondi.org>
---
 src/android/camera_buffer.h              | 21 +++++++++++
 src/android/camera_device.cpp            | 34 +----------------
 src/android/camera_device.h              |  7 +---
 src/android/meson.build                  |  2 +
 src/android/mm/generic_camera_buffer.cpp | 47 ++++++++++++++++++++++++
 src/android/mm/meson.build               |  6 +++
 6 files changed, 79 insertions(+), 38 deletions(-)
 create mode 100644 src/android/camera_buffer.h
 create mode 100644 src/android/mm/generic_camera_buffer.cpp
 create mode 100644 src/android/mm/meson.build

diff --git a/src/android/camera_buffer.h b/src/android/camera_buffer.h
new file mode 100644
index 000000000000..00b061502d6e
--- /dev/null
+++ b/src/android/camera_buffer.h
@@ -0,0 +1,21 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2021, Google Inc.
+ *
+ * camera_buffer.h - Frame buffer handling interface definition
+ */
+#ifndef __ANDROID_CAMERA_BUFFER_H__
+#define __ANDROID_CAMERA_BUFFER_H__
+
+#include <hardware/camera3.h>
+
+#include <libcamera/internal/buffer.h>
+
+class CameraBuffer : public libcamera::MappedBuffer
+{
+public:
+	CameraBuffer(const buffer_handle_t camera3buffer, int flags);
+	~CameraBuffer();
+};
+
+#endif /* __ANDROID_CAMERA_BUFFER_H__ */
diff --git a/src/android/camera_device.cpp b/src/android/camera_device.cpp
index 16cb8c6d2b84..f47f28b8c7ee 100644
--- a/src/android/camera_device.cpp
+++ b/src/android/camera_device.cpp
@@ -257,36 +257,6 @@ void sortCamera3StreamConfigs(std::vector<Camera3StreamConfig> &unsortedConfigs,
 
 } /* namespace */
 
-MappedCamera3Buffer::MappedCamera3Buffer(const buffer_handle_t camera3buffer,
-					 int flags)
-{
-	maps_.reserve(camera3buffer->numFds);
-	error_ = 0;
-
-	for (int i = 0; i < camera3buffer->numFds; i++) {
-		if (camera3buffer->data[i] == -1)
-			continue;
-
-		off_t length = lseek(camera3buffer->data[i], 0, SEEK_END);
-		if (length < 0) {
-			error_ = -errno;
-			LOG(HAL, Error) << "Failed to query plane length";
-			break;
-		}
-
-		void *address = mmap(nullptr, length, flags, MAP_SHARED,
-				     camera3buffer->data[i], 0);
-		if (address == MAP_FAILED) {
-			error_ = -errno;
-			LOG(HAL, Error) << "Failed to mmap plane";
-			break;
-		}
-
-		maps_.emplace_back(static_cast<uint8_t *>(address),
-				   static_cast<size_t>(length));
-	}
-}
-
 /*
  * \struct Camera3RequestDescriptor
  *
@@ -1892,8 +1862,8 @@ void CameraDevice::requestComplete(Request *request)
 		 * separate thread.
 		 */
 
-		MappedCamera3Buffer mapped(*descriptor->buffers_[i].buffer,
-					   PROT_READ | PROT_WRITE);
+		CameraBuffer mapped(*descriptor->buffers_[i].buffer,
+				    PROT_READ | PROT_WRITE);
 		if (!mapped.isValid()) {
 			LOG(HAL, Error) << "Failed to mmap android blob buffer";
 			continue;
diff --git a/src/android/camera_device.h b/src/android/camera_device.h
index 9cbfcad38433..e6c192c2100b 100644
--- a/src/android/camera_device.h
+++ b/src/android/camera_device.h
@@ -24,17 +24,12 @@
 #include "libcamera/internal/log.h"
 #include "libcamera/internal/message.h"
 
+#include "camera_buffer.h"
 #include "camera_metadata.h"
 #include "camera_stream.h"
 #include "camera_worker.h"
 #include "jpeg/encoder.h"
 
-class MappedCamera3Buffer : public libcamera::MappedBuffer
-{
-public:
-	MappedCamera3Buffer(const buffer_handle_t camera3buffer, int flags);
-};
-
 class CameraDevice : protected libcamera::Loggable
 {
 public:
diff --git a/src/android/meson.build b/src/android/meson.build
index 9719c42b65c6..7004d32d4b23 100644
--- a/src/android/meson.build
+++ b/src/android/meson.build
@@ -52,6 +52,8 @@ android_hal_sources = files([
     'yuv/post_processor_yuv.cpp'
 ])
 
+subdir('mm')
+
 android_camera_metadata_sources = files([
     'metadata/camera_metadata.c',
 ])
diff --git a/src/android/mm/generic_camera_buffer.cpp b/src/android/mm/generic_camera_buffer.cpp
new file mode 100644
index 000000000000..bd9152cf9a16
--- /dev/null
+++ b/src/android/mm/generic_camera_buffer.cpp
@@ -0,0 +1,47 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2021, Google Inc.
+ *
+ * generic_camera_buffer.cpp - Generic Android frame buffer backend
+ */
+
+#include "../camera_buffer.h"
+
+#include "libcamera/internal/log.h"
+
+using namespace libcamera;
+
+LOG_DECLARE_CATEGORY(HAL)
+
+CameraBuffer::CameraBuffer(const buffer_handle_t camera3buffer, int flags)
+{
+	maps_.reserve(camera3buffer->numFds);
+	error_ = 0;
+
+	for (int i = 0; i < camera3buffer->numFds; i++) {
+		if (camera3buffer->data[i] == -1)
+			continue;
+
+		off_t length = lseek(camera3buffer->data[i], 0, SEEK_END);
+		if (length < 0) {
+			error_ = -errno;
+			LOG(HAL, Error) << "Failed to query plane length";
+			break;
+		}
+
+		void *address = mmap(nullptr, length, flags, MAP_SHARED,
+				     camera3buffer->data[i], 0);
+		if (address == MAP_FAILED) {
+			error_ = -errno;
+			LOG(HAL, Error) << "Failed to mmap plane";
+			break;
+		}
+
+		maps_.emplace_back(static_cast<uint8_t *>(address),
+				   static_cast<size_t>(length));
+	}
+}
+
+CameraBuffer::~CameraBuffer()
+{
+}
diff --git a/src/android/mm/meson.build b/src/android/mm/meson.build
new file mode 100644
index 000000000000..97f83f2a7380
--- /dev/null
+++ b/src/android/mm/meson.build
@@ -0,0 +1,6 @@
+# SPDX-License-Identifier: CC0-1.0
+
+platform = get_option('android_platform')
+if platform == 'generic'
+    android_hal_sources += files(['generic_camera_buffer.cpp'])
+endif
-- 
2.30.0