Reference Camera v2 HAL Implementation
This is meant to be an example and a reference for device manufacturers
on how to build a new Camera v2 HAL. This first patch has basic
configuration and entry/exit.
Change-Id: Ib4166e2eadb813228af38ec31a1215940c070bbf
diff --git a/modules/camera/Camera.h b/modules/camera/Camera.h
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+++ b/modules/camera/Camera.h
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+/*
+ * Copyright (C) 2012 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef CAMERA_H_
+#define CAMERA_H_
+
+#include <pthread.h>
+#include <hardware/camera2.h>
+
+namespace default_camera_hal {
+// Camera represents a physical camera on a device.
+// This is constructed when the HAL module is loaded, one per physical camera.
+// It is opened by the framework, and must be closed before it can be opened
+// again.
+// Also, the framework can query for camera metadata with getCameraInfo.
+// For the first query, the metadata must first be allocated and initialized,
+// but once done it is used for all future calls.
+// It is protected by @mMutex, and functions that modify the Camera object hold
+// this lock when performing modifications. Currently these functions are:
+// @open, @close, and @init.
+class Camera {
+ public:
+ // id is used to distinguish cameras. 0 <= id < NUM_CAMERAS.
+ // module is a handle to the HAL module, used when the device is opened.
+ Camera(int id, const hw_module_t* module);
+ ~Camera();
+ // Open this camera, preparing it for use. Returns nonzero on failure.
+ int open();
+ // Close this camera. Returns nonzero on failure.
+ int close();
+ // Query for camera metadata, filling info struct. Returns nonzero if
+ // allocation or initialization failed.
+ int getCameraInfo(struct camera_info* info);
+ // Handle to this device passed to framework in response to open().
+ camera2_device_t mDevice;
+ private:
+ // One-time initialization of camera metadata.
+ void init();
+ // Identifier used by framework to distinguish cameras
+ int mId;
+ // True indicates camera is already open.
+ bool mBusy;
+ // Camera characteristics. NULL means it has not been allocated yet.
+ camera_metadata_t* mMetadata;
+ // Lock protecting the Camera object for modifications
+ pthread_mutex_t mMutex;
+};
+} // namespace default_camera_hal
+
+#endif // CAMERA_H_